WorldWideScience

Sample records for flows treatment efficiencies

  1. Modeling Vertical Flow Treatment Wetland Hydraulics to Optimize Treatment Efficiency

    Science.gov (United States)

    2011-03-24

    be forced to flow in a 90 serpentine manner back and forth as it moves upward through the wetland (think waiting in line at Disneyland ). This...Flow Treatment Wetland Hydraulics to Optimize Treatment Efficiency 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  2. Improvement of quantum efficiency in green light-emitting diodes with pre-TMIn flow treatment

    International Nuclear Information System (INIS)

    Lee, Ya-Ju; Chen, Yi-Ching; Lu, Tien-Chang

    2011-01-01

    The effects of pre-trimethlyindium (TMIn) flow on the improved electrical characteristics and highly stable temperature properties of InGaN green light-emitting diodes (LEDs) are discussed. For the LED sample with a pre-TMIn flow treatment, the tunnelling of injected carriers associated with threading defects is significantly reduced, which promotes the diffusion-recombination of injected carriers, as well as the overall emission efficiency of the LED. In addition, the pre-TMIn flow treatment evidently reduces the dependence of external quantum efficiency on temperature and efficiency droop of green LEDs. As a result, we conclude that the pre-TMIn flow treatment is a promising scheme for the improvement of output performance of InGaN-based green LEDs.

  3. Efficiency of a Horizontal Sub-Surface Flow Constructed Wetland Treatment System in an Arid Area

    Directory of Open Access Journals (Sweden)

    Abeer Albalawneh

    2016-02-01

    Full Text Available The main objective of this study was to evaluate the performance and treatment efficiency of the Horizontal Sub-Surface Flow Constructed Wetland treatment system (HSF-CW in an arid climate. Seventeen sub-surface, horizontal-flow HSF-CW units have been operated for approximately three years to improve the quality of partially-treated municipal wastewater. The studied design parameters included two sizes of volcanic tuff media (i.e., fine or coarse, two different bed dimensions (i.e., long and short, and three plantation types (i.e., reed, kenaf, or no vegetation as a control. The effluent Biological Oxygen Demand (BOD5, Chemical Oxygen Demand (COD, Total Suspended Solid (TSS, and phosphorus from all of the treatments were significantly lower as compared to the influent and demonstrated a removal efficiency of 55%, 51%, 67%, and 55%, respectively. There were significant increases in Electrical Conductivity (EC, sulfate, and calcium in the effluent of most HSF-CWs due to evaporative concentration and mineral dissolution from the media. The study suggests that unplanted beds with either fine or coarse media are the most suitable combinations among all of the studied designs based on their treatment efficiency and less water loss in arid conditions.

  4. Effects of Change in Tongue Pressure and Salivary Flow Rate on Swallow Efficiency Following Chemoradiation Treatment for Head and Neck Cancer

    Science.gov (United States)

    Rogus-Pulia, Nicole M.; Larson, Charles; Mittal, Bharat B; Pierce, Marge; Zecker, Steven; Kennelty, Korey; Kind, Amy; Connor, Nadine P.

    2016-01-01

    Purpose Patients treated with chemoradiation for head and neck cancer frequently develop dysphagia. Tissue damage to the oral tongue causing weakness and decreases in saliva production may contribute to dysphagia. Yet, effects of these variables on swallowing-related measures are unclear. The purpose of this study was (1) to determine effects of chemoradiation on tongue pressures, as a surrogate for strength, and salivary flow rates and (2) to elucidate relationships among tongue pressures, saliva production, and swallowing efficiency by bolus type. Methods and Materials 21 patients with head and neck cancer treated with chemoradiation were assessed before and after treatment and matched with 21 healthy control participants who did not receive chemoradiation. Each participant was given a questionnaire to rate dysphagia symptoms. Videofluoroscopic evaluation of swallowing was used to determine swallowing efficiency; the Saxon test measured salivary flow rate; and the Iowa Oral Performance Instrument (IOPI) was used for oral tongue maximum and endurance measures. Results Results revealed significantly lower tongue endurance measures for patients post-treatment as compared to controls (p=.012). Salivary flow rates also were lower compared to pre-treatment (p=.000) and controls (p=.000). Simple linear regression analyses showed that change in salivary flow rate was predictive of change in swallow efficiency measures from pre- to post-treatment for 1mL thin liquid (p=.017), 3mL nectar-thick liquid (p=.026), and 3mL standard barium pudding (p=.011) boluses. Conclusions Based on these findings, it appears that chemoradiation treatment affects tongue endurance and salivary flow rate and these changes may impact swallow efficiency. These factors should be considered when planning treatment for dysphagia. PMID:27492408

  5. Effects of Change in Tongue Pressure and Salivary Flow Rate on Swallow Efficiency Following Chemoradiation Treatment for Head and Neck Cancer.

    Science.gov (United States)

    Rogus-Pulia, Nicole M; Larson, Charles; Mittal, Bharat B; Pierce, Marge; Zecker, Steven; Kennelty, Korey; Kind, Amy; Connor, Nadine P

    2016-10-01

    Patients treated with chemoradiation for head and neck cancer frequently develop dysphagia. Tissue damage to the oral tongue causing weakness along with decreases in saliva production may contribute to dysphagia. Yet, effects of these variables on swallowing-related measures are unclear. The purpose of this study was (1) to determine effects of chemoradiation on tongue pressures, as a surrogate for strength, and salivary flow rates and (2) to elucidate relationships among tongue pressures, saliva production, and swallowing efficiency by bolus type. Twenty-one patients with head and neck cancer treated with chemoradiation were assessed before and after treatment and matched with 21 healthy control participants who did not receive chemoradiation. Each participant was given a questionnaire to rate dysphagia symptoms. Videofluoroscopic Evaluation of Swallowing (VFES) was used to determine swallowing efficiency; the Saxon test measured salivary flow rate; and the Iowa Oral Performance Instrument (IOPI) was used for oral tongue maximum and endurance measures. Results revealed significantly lower tongue endurance measures for patients post-treatment as compared to controls (p = .012). Salivary flow rates also were lower compared to pre-treatment (p = .000) and controls (p = .000). Simple linear regression analyses showed that change in salivary flow rate was predictive of change in swallow efficiency measures from pre- to post-treatment for 1 mL thin liquid (p = .017), 3 mL nectar-thick liquid (p = .026), and 3 mL standard barium pudding (p = .011) boluses. Based on these findings, it appears that chemoradiation treatment affects tongue endurance and salivary flow rate, and these changes may impact swallow efficiency. These factors should be considered when planning treatment for dysphagia.

  6. Current-flow efficiency of networks

    Science.gov (United States)

    Liu, Kai; Yan, Xiaoyong

    2018-02-01

    Many real-world networks, from infrastructure networks to social and communication networks, can be formulated as flow networks. How to realistically measure the transport efficiency of these networks is of fundamental importance. The shortest-path-based efficiency measurement has limitations, as it assumes that flow travels only along those shortest paths. Here, we propose a new metric named current-flow efficiency, in which we calculate the average reciprocal effective resistance between all pairs of nodes in the network. This metric takes the multipath effect into consideration and is more suitable for measuring the efficiency of many real-world flow equilibrium networks. Moreover, this metric can handle a disconnected graph and can thus be used to identify critical nodes and edges from the efficiency-loss perspective. We further analyze how the topological structure affects the current-flow efficiency of networks based on some model and real-world networks. Our results enable a better understanding of flow networks and shed light on the design and improvement of such networks with higher transport efficiency.

  7. Performance of the Subsurface Flow Wetland in Batch Flow for Municipal Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Abolfazle Rahmani sani

    2009-06-01

    Full Text Available Subsurface flow wetlands are one of the natural treatment methods used for municipal and industrial wastewater treatment that are economical in terms of energy consumption and cost-effectiveness. Much research has been conducted on wetland operation with continuous flow but not enough information is available on batch flow. This study investigates wetland efficiency in batch flow. For the purposes of this research, two pretreatment units of the anaerobic pond type with digestion pits and two subsurface flow wetlands with a 2-day detention time were built on the pilot scale. The cells were charged with sand of 5 mm effective size, uniformity coefficient of 1.5, and a porosity of 35%. One wetland cell and one pretreatment unit were used as control. The municipal wastewater selected to be monitored for the one-year study period had a flow rate of 26 m3/day and average BOD5 of 250mg/l, TSS of 320mg/l, TKN of 35mg/l, TP of 12mg/l and TC of 2×108 MPN/100ml from Sabzevar Wastewater Treatment Plant. The average removal efficiencies of BOD5,TSS,TKN,TP, and TC in the continuous flow for the combined control pretreatment and wetland cell were 77.2%, 92%, 91%, 89%, 96.5% while the same values for the batch flow for the combined experimental pretreatment and wetland cell were 92%, 97%, 97.5%, 97%, and 99.75%, respectively. The removal efficiency in the subsurface flow wetlands in the batch flow was higher than that of the continuous flow. Thus, for wastewaters with a high pollution level, the batch flow can be used in cell operation in cases where there is not enough land for spreading the wetland cell.

  8. Thermodynamic efficiency of information and heat flow

    International Nuclear Information System (INIS)

    Allahverdyan, Armen E; Janzing, Dominik; Mahler, Guenter

    2009-01-01

    A basic task of information processing is information transfer (flow). Here we study a pair of Brownian particles each coupled to a thermal bath at temperatures T 1 and T 2 . The information flow in such a system is defined via the time-shifted mutual information. The information flow nullifies at equilibrium, and its efficiency is defined as the ratio of the flow to the total entropy production in the system. For a stationary state the information flows from higher to lower temperatures, and its efficiency is bounded from above by (max[T 1 ,T 2 ])/(|T 1 −T 2 |). This upper bound is imposed by the second law and it quantifies the thermodynamic cost for information flow in the present class of systems. It can be reached in the adiabatic situation, where the particles have widely different characteristic times. The efficiency of heat flow—defined as the heat flow over the total amount of dissipated heat—is limited from above by the same factor. There is a complementarity between heat and information flow: the set-up which is most efficient for the former is the least efficient for the latter and vice versa. The above bound for the efficiency can be (transiently) overcome in certain non-stationary situations, but the efficiency is still limited from above. We study yet another measure of information processing (transfer entropy) proposed in the literature. Though this measure does not require any thermodynamic cost, the information flow and transfer entropy are shown to be intimately related for stationary states

  9. Influence of Pre-trimethylindium flow treatment on blue light emitting diode

    International Nuclear Information System (INIS)

    Xu, Bing; Zhao, Jun Liang; Dai, Hai Tao; Wang, Shu Guo; Lin, Ray-Ming; Chu, Fu-Chuan; Huang, Chou-Hsiung; Yu, Sheng-Fu; Sun, Xiao Wei

    2014-01-01

    The effects of Pre-trimethylindium (TMIn) flow treatment prior to quantum well growth on blue light emitting diode properties were investigated. High-resolution X-ray diffraction indicated that Pre-TMIn flow treatment did not change the composition of indium in quantum wells, but influenced electrical and optical properties of blue light emitting diode. Electroluminescence exhibited redshift with increasing TMIn treatment time. Though, the forward voltage became a little larger with longer Pre-TMIn treatment time due to the slight phase separation and indium aggregation, the efficiency droop of the device was improved effectively. - Highlights: • Pre-trimethylindium treatment can lead to longer wavelength. • External quantum efficiency can be improved effectively. • Electrical properties are not decreased using Pre-trimethylindium treatment

  10. Influence of Pre-trimethylindium flow treatment on blue light emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bing; Zhao, Jun Liang [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Dai, Hai Tao, E-mail: htdai@tju.edu.cn [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Wang, Shu Guo [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Lin, Ray-Ming, E-mail: rmlin@mail.cgu.edu.tw [Graduate Institute of Electronic Engineering and Green Technology Research Center, Chang Gung University, Taoyuan 333, Taiwan (China); Chu, Fu-Chuan; Huang, Chou-Hsiung [Graduate Institute of Electronic Engineering and Green Technology Research Center, Chang Gung University, Taoyuan 333, Taiwan (China); Yu, Sheng-Fu [Institute of Microelectronics and Department of Electrical Engineering, Center for Micro/Nano Science and Technology, Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Sun, Xiao Wei, E-mail: xwsun@sustc.edu.cn [South University of Science and Technology of China, Shenzhen, Guangdong (China)

    2014-01-31

    The effects of Pre-trimethylindium (TMIn) flow treatment prior to quantum well growth on blue light emitting diode properties were investigated. High-resolution X-ray diffraction indicated that Pre-TMIn flow treatment did not change the composition of indium in quantum wells, but influenced electrical and optical properties of blue light emitting diode. Electroluminescence exhibited redshift with increasing TMIn treatment time. Though, the forward voltage became a little larger with longer Pre-TMIn treatment time due to the slight phase separation and indium aggregation, the efficiency droop of the device was improved effectively. - Highlights: • Pre-trimethylindium treatment can lead to longer wavelength. • External quantum efficiency can be improved effectively. • Electrical properties are not decreased using Pre-trimethylindium treatment.

  11. Study of wastewater treatment plants efficiency using radiotracers

    International Nuclear Information System (INIS)

    Dawi, W. D. A.

    2010-11-01

    This study was performed to investigate and diagnose hydrodynamic behavior of the Military Hospital wastewater treatment plant. The plant comprises two units of treatment, each of them has a separate system. The investigation was carried out using ''1''3''1I as a radiotracer. The concept of residence time distribution (RTD) was used to investigate the efficiency of the aeration tanks, secondary clarifiers and chlorine tanks. Preliminary treatment and modeling of the trace data was performed using two software package applied by the International Atomic Energy Agency (IAEA) namely 4621 counter version 1.0.0 and RTD software. Plug flow pattern (parallel flow) was detected in the aeration tank and secondary clarifier of system 1 in one unit, while no homogeneous mixing was observed in the chlorine tank. Short - circuiting (by - passing) was evident in the aeration tank of system 2 in the other unit, which significantly reduced the operating efficiency. The percentage of dead volumes clearly suggests that the aeration tank and secondary clarifier were well utilized in the whole plant. (Author)

  12. Efficiency improvements of electromagnetic flow control

    International Nuclear Information System (INIS)

    Spong, E.; Reizes, J.A.; Leonardi, E.

    2005-01-01

    In turbulent flow, frictional resistance and heat transfer are controlled to a large degree by the intensity of the turbulence fluctuations in the near vicinity of a surface. In the case of a weak electrically conducting fluid, such as seawater, turbulence intensity can be controlled by subjecting the fluid to electromagnetic fields. This technique, known as Electro-magneto-hydro-dynamic (EMHD) flow control, has been shown to have promise as a means of reducing the turbulence intensity, and hence heat transfer or frictional drag of turbulent boundary layers. Unfortunately EMHD flow control currently suffers from poor efficiency due to the high energy requirements of the electromagnetic field. A numerical study has been conducted in which a new electromagnetic actuator design has been developed to provide a more efficient spatial distribution of the electromagnetic forces. The new actuator design has then been coupled to an ideal flow sensor. A flow control subroutine, embedded in the numerical model, uses the velocity information from the ideal sensor to determine the appropriate actuating force to apply to the flow at each time step. The new actuator design has been shown to be capable of successfully attenuating a sequence of artificial low speed streaks in a simplified model of a low Reynolds number turbulent boundary layer. Thus, a potential solution to the poor efficiency of EMHD flow control has been offered by providing the means whereby the expensive electromagnetic forces can be strategically and sparingly applied to the flow

  13. Efficiency of osmotic pipe flows

    DEFF Research Database (Denmark)

    Haaning, Louise Sejling; Jensen, Kaare Hartvig; Helix Nielsen, Claus

    2013-01-01

    efficiency of these flows is limited by the presence of “unstirred” concentration boundary layers near the tube walls, and our primary aim is to understand and quantify these layers and their effect on the flow. We measure the outlet flow rate Qout while varying the inlet flow rate Q*, concentration c......We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping...

  14. TensorFlow Agents: Efficient Batched Reinforcement Learning in TensorFlow

    OpenAIRE

    Hafner, Danijar; Davidson, James; Vanhoucke, Vincent

    2017-01-01

    We introduce TensorFlow Agents, an efficient infrastructure paradigm for building parallel reinforcement learning algorithms in TensorFlow. We simulate multiple environments in parallel, and group them to perform the neural network computation on a batch rather than individual observations. This allows the TensorFlow execution engine to parallelize computation, without the need for manual synchronization. Environments are stepped in separate Python processes to progress them in parallel witho...

  15. Developing measures for the evaluation of information flow efficiency in supply chains

    Directory of Open Access Journals (Sweden)

    Johanna A. Badenhorst

    2013-05-01

    Full Text Available Member organisations in a supply chain are dependent on each other to provide material, services and information to perform optimally in the supply chain. Efficient, unrestricted information flow is needed in supply chains to function properly. Information flow is thus an element of supply chain management that needs to be managed. Yet, no indication could be found in supply chain management literature of the measurement of information flow efficiency. Hence, the aim of this article is to explore the measurement of information flow efficiency in supply chain management (SCM and exploratively develop possible measures (indicators and associated metrics to measure the efficiency of information flow.In this research the theory of information and related concepts, the basic notions of information systems and the models of business performance measurement were explored. Based on information flow theory and information flow characteristics a research instrument was developed. It was used in a survey to seek inputs from supply chain managers as to the usefulness of characteristics as indicators and metrics for the measurement of information flow efficiency in a supply chain. The main contribution of the study is the development of a conceptual framework of indicators and metrics that may be used to evaluate the efficiency of information flows in supply chains. The results of this study can be used as a basis for further studies to validate the instrument for measuring information flow efficiency and to develop scales to actually measure information flow efficiency.

  16. A matrix-free implicit treatment for all speed flows on unstructured grids

    International Nuclear Information System (INIS)

    Kloczko, Th.

    2006-03-01

    The aim of this research work is the development of an efficient implicit scheme for computing compressible and low-speed flows on unstructured meshes. The first part is devoted to the review and analysis of some standard block-implicit treatments for the two-dimensional Euler and Navier-Stokes equations with a view to identify the best candidate for a fair comparison with the matrix-free treatment. The second part forms the main original contribution of this research work. It describes and analyses a matrix-free treatment that can be applied to any type of flow (inviscid/viscous, low Mach/highly compressible, steady/unsteady). The third part deals with the implementation of this treatment within the CAST3M code, and the demonstration of its advantages over existing techniques for computing applications of interest for the CEA: low-Mach number steady and unsteady flows in a Tee junction for example

  17. Multi-point optimization of recirculation flow type casing treatment in centrifugal compressors

    Science.gov (United States)

    Tun, Min Thaw; Sakaguchi, Daisaku

    2016-06-01

    High-pressure ratio and wide operating range are highly required for a turbocharger in diesel engines. A recirculation flow type casing treatment is effective for flow range enhancement of centrifugal compressors. Two ring grooves on a suction pipe and a shroud casing wall are connected by means of an annular passage and stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular bypass. The shape of baseline recirculation flow type casing is modified and optimized by using a multi-point optimization code with a metamodel assisted evolutionary algorithm embedding a commercial CFD code CFX from ANSYS. The numerical optimization results give the optimized design of casing with improving adiabatic efficiency in wide operating flow rate range. Sensitivity analysis of design parameters as a function of efficiency has been performed. It is found that the optimized casing design provides optimized recirculation flow rate, in which an increment of entropy rise is minimized at grooves and passages of the rotating impeller.

  18. Stability management of high speed axial flow compressor stage through axial extensions of bend skewed casing treatment

    Directory of Open Access Journals (Sweden)

    DilipkumarBhanudasji Alone

    2016-09-01

    Full Text Available This paper presents the experimental results to understand the performance of moderately loaded high speed single stage transonic axial flow compressor subjected to various configurations of axial extensions of bend skewed casing treatment with moderate porosity. The bend skewed casing treatment of 33% porosity was coupled with rectangular plenum chamber of depth equal to the slots depth. The five axial extensions of 20%, 40%, 60%, 80% and 100% were used for the experimental evaluations of compressor performance. The main objective was to identify the optimum extension of the casing treatment with reference to rotor leading edge which results in maximum stall margin improvements with minimum loss in the stage efficiency. At each axial extension the compressor performance is distinctive. The improvement in the stall margin was very significant at some axial extensions with 4%–5% penalty in the stage efficiency. The compressors stage shows recovery in terms of efficiency at lower axial extensions of 20% and 40% with increase in the peak stage efficiency. Measurements of flow parameters showed the typical behaviors at near stall flow conditions. Hot wire sensor was placed at the rotor upstream in the tip region to capture the oscillations in the inlet axial and tangential velocities at stall conditions. In the absence of casing treatment the compressor exhibit abrupt stall with very high oscillations in the inlet axial and tangential velocity of the flow. The extents of oscillations reduce with bend skewed casing treatment. Few measurements were also performed in the plenum chamber and salient results are presented in this paper.

  19. Financial Reporting Quality, Free Cash Flow, and Investment Efficiency

    Directory of Open Access Journals (Sweden)

    Wang Fusheng

    2015-01-01

    Full Text Available This paper based on the perspective of firm’s agency conflicts to examine the relationship between financial reporting quality and investment efficiency and to analyze the interaction effect between financial reporting and free cash flow on investment efficiency. We use 3,726 samples of Chinese listed firms during the period 2008–2012 to test the empirical models and find that financial reporting quality is negatively associated with both underinvestment and overinvestment. Further, we find that financial reporting quality is more strongly associated with overinvestment for firms with large free cash flow, which suggests that financial reporting quality can reduce information asymmetry arising from agency conflicts between the managers and investors. This paper extends the field of application of financial reporting quality and investment efficiency in the emerging capital markets in the world. Moreover, this is the first study that analyzes the interaction effect between financial reporting quality and free cash flow on investment efficiency.

  20. Assessment of cleaning efficiency of the polydisperse gas flow in double-flow dedusting system

    Directory of Open Access Journals (Sweden)

    O.G. Butenko

    2016-05-01

    Full Text Available One of priority problems of nature protection activity at the industrial enterprises is upgrading the gas emissions cleaning of polydispersed dust. To solve the problem of catching of small fraction dust the double-flow dedusting system has been offered. Aim: The aim of the work is to determine the dependency type of the cleaning efficiency of polydisperse gas flow on gas separation factor double-flow dedusting system. Materials and methods: The analysis of influence of gas separation factor in the dividing device of double-flow dedusting system on its efficiency is carried out. By drawing up the mass balance of system on gas and on the mass of dust the general dependence for breakthrough of the main catcher, characterizing overall effectiveness of system, is received. Results: It is shown that value of breakthrough factor of the main catcher depends on dimensionless efficiency factors of the equipment. The received general dependence of breakthrough factor on separation factor allows to define the optimum value of separation factor for any combined dedusting system.

  1. Flow Control by Slot Position and Noise Baffle in a Self-Recirculation Casing Treatment on an Axial Fan-Rotor

    Directory of Open Access Journals (Sweden)

    Xiangjun Li

    2017-01-01

    Full Text Available To address the situations where the casing treatment needs to be used to stabilize axial compressors through strong recirculation, this paper initiated a CFD study to investigate how the flow could be suitably controlled in the casing treatment to minimize the efficiency penalty and increase the flow range. A counter-swirl self-recirculation casing treatment was first designed on a low speed axial fan rotor as a baseline case. Then three different slot positions and the influence of including the noise baffle were numerically studied. Based on the understanding of their coeffects, the shorter noise baffle was considered and it was found that the highest efficiency was achieved in the case of the upstream slot when the length of baffle was suitably adjusted to balance the incoming flow and recirculation. The largest flow range was achieved by locating the slot at the most downstream position and using a 50% length baffle since it suitably controlled the recirculating flow and relieved the separation at the low-span region. An optimization study showed that the optimum length of the baffle for efficiency was always larger than for the flow range. Both of the two optimum values reduce as the slot moves downstream.

  2. Flow dynamics and energy efficiency of flow in the left ventricle during myocardial infarction.

    Science.gov (United States)

    Vasudevan, Vivek; Low, Adriel Jia Jun; Annamalai, Sarayu Parimal; Sampath, Smita; Poh, Kian Keong; Totman, Teresa; Mazlan, Muhammad; Croft, Grace; Richards, A Mark; de Kleijn, Dominique P V; Chin, Chih-Liang; Yap, Choon Hwai

    2017-10-01

    Cardiovascular disease is a leading cause of death worldwide, where myocardial infarction (MI) is a major category. After infarction, the heart has difficulty providing sufficient energy for circulation, and thus, understanding the heart's energy efficiency is important. We induced MI in a porcine animal model via circumflex ligation and acquired multiple-slice cine magnetic resonance (MR) images in a longitudinal manner-before infarction, and 1 week (acute) and 4 weeks (chronic) after infarction. Computational fluid dynamic simulations were performed based on MR images to obtain detailed fluid dynamics and energy dynamics of the left ventricles. Results showed that energy efficiency flow through the heart decreased at the acute time point. Since the heart was observed to experience changes in heart rate, stroke volume and chamber size over the two post-infarction time points, simulations were performed to test the effect of each of the three parameters. Increasing heart rate and stroke volume were found to significantly decrease flow energy efficiency, but the effect of chamber size was inconsistent. Strong complex interplay was observed between the three parameters, necessitating the use of non-dimensional parameterization to characterize flow energy efficiency. The ratio of Reynolds to Strouhal number, which is a form of Womersley number, was found to be the most effective non-dimensional parameter to represent energy efficiency of flow in the heart. We believe that this non-dimensional number can be computed for clinical cases via ultrasound and hypothesize that it can serve as a biomarker for clinical evaluations.

  3. Efficiencies of flat plate solar collectors at different flow rates

    DEFF Research Database (Denmark)

    Chen, Ziqian; Furbo, Simon; Perers, Bengt

    2012-01-01

    Two flat plate solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rate are obtained. The calculated efficiencies are in good agreement...

  4. Efficiency evaluation for nanomaterials applied in well bottom zone treatment after completion of well construction

    Directory of Open Access Journals (Sweden)

    GREZINA Olga Anatolyevna,

    2017-11-01

    Full Text Available Efficient development of low production wells is not possible without the bottom zone treatment, both during the well development phase when its construction is completed and in the process of flow rate reduction during the operation phase. The efficiency evaluation for the new technology, including one in which nanomaterials are used, implies comparison of the actual level achieved after the new technology has been applied with the projected baseline level that might be achieved by the previously applied technique. The paper presents geological and statistical modeling of the bottom zone acid-implosion treatment performed with the hydrochloric acid solution in combination with the shock-wave effect characterized by cyclic recurrence and dynamic mode. The analyzed results have been achieved in the low permeable carbonate reservoir of a very complex geological structure in oil operating facility. The nature and the extent of geological-technological parameters influence on the acidimplosion treatment results were determined by the multiple regression method, and the most influential parameters were selected; recommendations for boreholes selection and technological parameters of treatment were made. Models to forecast flow rate and oil production growth, reduction of fractional oil content in the well production, the acid-implosion impact duration were elaborated. The models can be used to evaluate efficiency of bottom zone treatment technologies after completion of well construction with nanomaterials application.

  5. Highway-runoff quality, and treatment efficiencies of a hydrodynamic-settling device and a stormwater-filtration device in Milwaukee, Wisconsin

    Science.gov (United States)

    Horwatich, Judy A.; Bannerman, Roger T.; Pearson, Robert

    2011-01-01

    The treatment efficiencies of two prefabricated stormwater-treatment devices were tested at a freeway site in a high-density urban part of Milwaukee, Wisconsin. One treatment device is categorized as a hydrodynamic-settling device (HSD), which removes pollutants by sedimentation and flotation. The other treatment device is categorized as a stormwater-filtration device (SFD), which removes pollutants by filtration and sedimentation. During runoff events, flow measurements were recorded and water-quality samples were collected at the inlet and outlet of each device. Efficiency-ratio and summation-of-load (SOL) calculations were used to estimate the treatment efficiency of each device. Event-mean concentrations and loads that were decreased by passing through the HSD include total suspended solids (TSS), suspended sediment (SS), total phosphorus (TP), total copper (TCu), and total zinc (TZn). The efficiency ratios for these constituents were 42, 57, 17, 33, and 23 percent, respectively. The SOL removal rates for these constituents were 25, 49, 10, 27, and 16 percent, respectively. Event-mean concentrations and loads that increased by passing through the HSD include chloride (Cl), total dissolved solids (TDS), and dissolved zinc (DZn). The efficiency ratios for these constituents were -347, -177, and 20 percent, respectively. Four constituents—dissolved phosphorus (DP), chemical oxygen demand (COD), total polycyclic aromatic hydrocarbon (PAH), and dissolved copper (DCu)—are not included in the list of computed efficiency ratio and SOL because the variability between sampled inlet and outlet pairs were not significantly different. Event-mean concentrations and loads that decreased by passing through the SFD include TSS, SS, TP, DCu, TCu, DZn, TZn, and COD. The efficiency ratios for these constituents were 59, 90, 40, 21, 66, 23, 66, and 18, respectively. The SOLs for these constituents were 50, 89, 37, 19, 60, 20, 65, and 21, respectively. Two constituents—DP and

  6. Potential exposure and treatment efficiency of nanoparticles in water supplies based on wastewater reclamation

    DEFF Research Database (Denmark)

    Kirkegaard, Peter; Hansen, Steffen Foss; Rygaard, Martin

    2015-01-01

    Water scarcity brings an increased focus on wastewater reclamation for drinking water supply. Meanwhile, the production volume of nanoparticles (NPs) is rapidly increasing, but to date there has been little attention given to the fate of NPs in water systems based on wastewater reclamation. We have...... investigated the possible concentrations of silver (Ag), titanium dioxide (TiO2), and zinc oxide (ZnO) nanoparticles in tap water for water supplies based on reclaimed wastewater. Tap water concentrations of the NPs were assessed by mass flow analyses of two typical wastewater reclamation concepts: 1) advanced...... studies are available on the removal efficiencies of NPs by advanced water treatment processes with a majority of the identified studies focusing on removal efficiencies in wastewater treatment plants and fate in surface waters. The NP removal efficiency of several treatment processes is unknown...

  7. Analysis of Wastewater Treatment Efficiency in a Soft Drinks Industry

    Science.gov (United States)

    Boguniewicz-Zabłocka, Joanna; Capodaglio, Andrea G.; Vogel, Daniel

    2017-10-01

    During manufacturing processes, most industrial plants generate wastewater which could become harmful to the environment. Discharge of untreated or improperly treated industrial wastewaters into surface water could, in fact, lead to deterioration of the receiving water body's quality. This paper concerns wastewater treatment solutions used in the soft drink production industry: wastewater treatment plant effectiveness analysis was determined in terms of basic pollution indicators, such as BOD, COD, TSS and variable pH. Initially, the performance of mechanic-biological systems for the treatment of wastewater from a specific beverages production process was studied in different periods, due to wastewater flow fluctuation. The study then showed the positive effects on treatment of wastewater augmentation by methanol, nitrogen and phosphorus salts dosed into it during the treatment process. Results confirm that after implemented modification (methanol, nitrogen and phosphorus additions) pollution removal occurs mostly with higher efficiency.

  8. Holography as a highly efficient renormalization group flow. I. Rephrasing gravity

    Science.gov (United States)

    Behr, Nicolas; Kuperstein, Stanislav; Mukhopadhyay, Ayan

    2016-07-01

    We investigate how the holographic correspondence can be reformulated as a generalization of Wilsonian renormalization group (RG) flow in a strongly interacting large-N quantum field theory. We first define a highly efficient RG flow as one in which the Ward identities related to local conservation of energy, momentum and charges preserve the same form at each scale. To achieve this, it is necessary to redefine the background metric and external sources at each scale as functionals of the effective single-trace operators. These redefinitions also absorb the contributions of the multitrace operators to these effective Ward identities. Thus, the background metric and external sources become effectively dynamical, reproducing the dual classical gravity equations in one higher dimension. Here, we focus on reconstructing the pure gravity sector as a highly efficient RG flow of the energy-momentum tensor operator, leaving the explicit constructive field theory approach for generating such RG flows to the second part of the work. We show that special symmetries of the highly efficient RG flows carry information through which we can decode the gauge fixing of bulk diffeomorphisms in the corresponding gravity equations. We also show that the highly efficient RG flow which reproduces a given classical gravity theory in a given gauge is unique provided the endpoint can be transformed to a nonrelativistic fixed point with a finite number of parameters under a universal rescaling. The results obtained here are used in the second part of this work, where we do an explicit field-theoretic construction of the RG flow and obtain the dual classical gravity theory.

  9. Fluidic oscillator-mediated microbubble generation to provide cost effective mass transfer and mixing efficiency to the wastewater treatment plants.

    Science.gov (United States)

    Rehman, Fahad; Medley, Gareth J D; Bandulasena, Hemaka; Zimmerman, William B J

    2015-02-01

    Aeration is one of the most energy intensive processes in the waste water treatment plants and any improvement in it is likely to enhance the overall efficiency of the overall process. In the current study, a fluidic oscillator has been used to produce microbubbles in the order of 100 μm in diameter by oscillating the inlet gas stream to a pair of membrane diffusers. Volumetric mass transfer coefficient was measured for steady state flow and oscillatory flow in the range of 40-100l/min. The highest improvement of 55% was observed at the flow rates of 60, 90 and 100l/min respectively. Standard oxygen transfer rate and efficiency were also calculated. Both standard oxygen transfer rate and efficiency were found to be considerably higher under oscillatory air flow conditions compared to steady state airflow. The bubble size distributions and bubble densities were measured using an acoustic bubble spectrometer and confirmed production of monodisperse bubbles with approximately 100 μm diameters with fluidic oscillation. The higher number density of microbubbles under oscillatory flow indicated the effect of the fluidic oscillation in microbubble production. Visual observations and dissolved oxygen measurements suggested that the bubble cloud generated by the fluidic oscillator was sufficient enough to provide good mixing and to maintain uniform aerobic conditions. Overall, improved mass transfer coefficients, mixing efficiency and energy efficiency of the novel microbubble generation method could offer significant savings to the water treatment plants as well as reduction in the carbon footprint. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Effect of design and operational conditions on the performance of subsurface flow treatment wetlands: Emerging organic contaminants as indicators.

    Science.gov (United States)

    Kahl, Stefanie; Nivala, Jaime; van Afferden, Manfred; Müller, Roland A; Reemtsma, Thorsten

    2017-11-15

    Six pilot-scale subsurface flow treatment wetlands loaded with primary treated municipal wastewater were monitored over one year for classical wastewater parameters and a set of emerging organic compounds (EOCs) serving as process indicators for biodegradation: caffeine, ibuprofen, naproxen, benzotriazole, diclofenac, acesulfame, and carbamazepine. The wetland technologies investigated included conventional horizontal flow, unsaturated vertical flow (single and two-stage), horizontal flow with aeration, vertical flow with aeration, and reciprocating. Treatment efficiency for classical wastewater parameters and EOCs generally increased with increasing design complexity and dissolved oxygen concentrations. The two aerated wetlands and the two-stage vertical flow system showed the highest EOC removal, and the best performance in warm season and most robust performance in the cold season. These three systems performed better than the adjacent conventional WWTP with respect to EOC removal. Acesulfame was observed to be removed (>90%) by intensified wetland systems and with use of a tertiary treatment sand filter during the warm season. Elevated temperature and high oxygen content (aerobic conditions) proved beneficial for EOC removal. For EOCs of moderate to low biodegradability, the co-occurrence of aerobic conditions and low content of readily available carbon appears essential for efficient removal. Such conditions occurred in the aerated systems and with use of a tertiary treatment sand filter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Real world efficiency of retrofit partial-flow diesel particulate filters for trucks

    International Nuclear Information System (INIS)

    Van Asch, R.; Verbeek, R.; Ligterink, N.; Kadijk, G.

    2009-11-01

    In 2006 the Dutch Ministry of Housing, Spatial Planning and the Environment (VROM) introduced an incentive scheme for retrofitting diesel particulate filters on Euro II and Euro III trucks. This scheme involves both partial flow and full flow diesel particulate filters (also called semi-open or open respectively wall-flow or closed filters). In the period 2007 till January 2009 about 15,000 partial flow filters and 8,000 full flow diesel particulate filters were installed. The minimum filtration efficiency requirement for the partial flow diesel particulate filters is 50% during the type approval test. In 2008 an engine dynamometer test programme was conducted to measure the filtration efficiency of retrofit open particulates filters of heavy trucks. This led to somewhat disappointing results with average filtration efficiencies in the range of 5-20% during city and national motorway driving conditions up to 20-40% during long distance motorway driving. This result leads to two main questions: (1) Is this result also representative for medium heavy trucks used for delivery, and (2) do similar efficiencies show up also in tests on entire vehicles, tested under conditions as close as possible to their real world usage profile. To this end, an additional measurement programme was defined, which is reported here. The objective of the study reported here is to determine the real world filtration efficiency of retrofit partial flow particulate filters for a number of trucks under different driving conditions such as city and motorway driving. The emphasis should be on medium heavy trucks typically used for national delivery.

  12. Effect of flow rate and disc area increment on the efficiency of rotating biological contactor for treating greywater

    International Nuclear Information System (INIS)

    Pathan, A.A.

    2015-01-01

    The performance of greywater treatment through RBC (Rotating Biological Contactor) is related to many factors including rotational speed of disc, surface area of the media, thickness of biological film; quality and flow rate of influent. The plastic media provides surface for biological slime. The slime is rotated alternatively into the settled wastewater and then into atmosphere to provide aerobic conditions for the microorganisms. In this study the performance of RBC is investigated at different flow rates and disk areas of media by introducing additional discs on the shaft of RBC. Initially efficiency of the RBC was observed on six flow rates at the disc area of 9.78m/sup 2/. Furthermore optimized three flow rates were used to augment the disk area. The efficiency of RBC system was improved significantly at disk area of 11.76m/sup 2/ and flow rate of 20 L/h. Under these conditions the removal of BOD5 (Biochemical Oxygen Demand) COD (Chemical Oxygen Demand) and TSS (Total Suspended Solid) was observed 83, 57 and 90% respectively. (author)

  13. Effect of air flow on tubular solar still efficiency.

    Science.gov (United States)

    Thirugnanasambantham, Arunkumar; Rajan, Jayaprakash; Ahsan, Amimul; Kandasamy, Vinothkumar

    2013-01-01

    An experimental work was reported to estimate the increase in distillate yield for a compound parabolic concentrator-concentric tubular solar still (CPC-CTSS). The CPC dramatically increases the heating of the saline water. A novel idea was proposed to study the characteristic features of CPC for desalination to produce a large quantity of distillate yield. A rectangular basin of dimension 2 m × 0.025 m × 0.02 m was fabricated of copper and was placed at the focus of the CPC. This basin is covered by two cylindrical glass tubes of length 2 m with two different diameters of 0.02 m and 0.03 m. The experimental study was operated with two modes: without and with air flow between inner and outer tubes. The rate of air flow was fixed throughout the experiment at 4.5 m/s. On the basis of performance results, the water collection rate was 1445 ml/day without air flow and 2020 ml/day with air flow and the efficiencies were 16.2% and 18.9%, respectively. THE EXPERIMENTAL STUDY WAS OPERATED WITH TWO MODES: without and with air flow between inner and outer tubes. The rate of air flow was fixed throughout the experiment at 4.5 m/s. On the basis of performance results, the water collection rate was 1445 ml/day without air flow and 2020 ml/day with air flow and the efficiencies were 16.2% and 18.9%, respectively.

  14. Developing measures for the evaluation of information flow efficiency in supply chains

    OpenAIRE

    Johanna A. Badenhorst; Claus Maurer; Tersia Brevis-Landsberg

    2013-01-01

    Member organisations in a supply chain are dependent on each other to provide material, services and information to perform optimally in the supply chain. Efficient, unrestricted information flow is needed in supply chains to function properly. Information flow is thus an element of supply chain management that needs to be managed. Yet, no indication could be found in supply chain management literature of the measurement of information flow efficiency. Hence, the aim of this article is to exp...

  15. The Efficiency of Quartz Particles Evaporation in the Argon Plasma Flow of the RF Inductively Coupled Plasma Torch

    Directory of Open Access Journals (Sweden)

    Yu. M. Grishin

    2017-01-01

    Full Text Available Owing to high-power density and high-purity plasma, a RF inductively coupled plasma torch (ICPT is widely used both in research laboratory and in industry. The potential RF ICPT application areas are powders spheroidisation, waste treatment, thermal spraying, etc.In the last decade the investigation was focused on the treatment processes of quartz into polycrystalline silicon. An analysis of these results has shown that the increasing productivity and producing high-purity silicon can be achieved only when using the electrodeless radio-frequency induction plasma torches and in case the optimum conditions for evaporation of SiO2solid particles are realized.Optimization of the RF ICPT design and power parameters calls for a wide range of computational studies. In spite of the fact that to date a large number of efforts to calculate the evaporation efficiency of powder materials have been made, a number of issues, as applied to the problem of obtaining silicon, require further research.In this paper, we present the results of a two-dimensional numerical simulation of the heating and evaporation of quartz particles in the RF ICPT channel with axial flow of gases. The main aim is to determine how the axial position of the central tube (through which the particles are injected into the discharge zone, the dispersion of the quartz powder, the amplitude of the discharge current (and, respectively, flow regimes impact on the evaporation efficiency of quartz particles.The paper presented the numerical modeling results of heating and evaporation processes of quartz particles supplied by transporting gas to the RF ICPT channel with axial gas flow (argon. Defined the impact of the axial position of the central tube, the plasma flow regime, the discharge current, the flow rate of transporting gas, and other parameters on the evaporation efficiency of quartz particles.It is shown that the evaporation efficiency of particles reaches its maximum when their

  16. Flow analysis for efficient design of wavy structured microchannel mixing devices

    Science.gov (United States)

    Kanchan, Mithun; Maniyeri, Ranjith

    2018-04-01

    Microfluidics is a rapidly growing field of applied research which is strongly driven by demands of bio-technology and medical innovation. Lab-on-chip (LOC) is one such application which deals with integrating bio-laboratory on micro-channel based single fluidic chip. Since fluid flow in such devices is restricted to laminar regime, designing an efficient passive modulator to induce chaotic mixing for such diffusion based flow is a major challenge. In the present work two-dimensional numerical simulation of viscous incompressible flow is carried out using immersed boundary method (IBM) to obtain an efficient design for wavy structured micro-channel mixing devices. The continuity and Navier-Stokes equations governing the flow are solved by fractional step based finite volume method on a staggered Cartesian grid system. IBM uses Eulerian co-ordinates to describe fluid flow and Lagrangian co-ordinates to describe solid boundary. Dirac delta function is used to couple both these co-ordinate variables. A tether forcing term is used to impose the no-slip boundary condition on the wavy structure and fluid interface. Fluid flow analysis by varying Reynolds number is carried out for four wavy structure models and one straight line model. By analyzing fluid accumulation zones and flow velocities, it can be concluded that straight line structure performs better mixing for low Reynolds number and Model 2 for higher Reynolds number. Thus wavy structures can be incorporated in micro-channels to improve mixing efficiency.

  17. Development of a new solvent-free flow efficiency coating for natural gas pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Fogg, Graham A.; Morse, Jennifer [Bredero Shaw, Houston, TX (United States)

    2005-07-01

    Pipeline design engineers have traditionally considered external anti-corrosion coatings for the protection of gas transmission pipelines, with less consideration given to the benefits of internal flow efficiency coatings. This paper reviews the benefits of using a traditional solvent-based flow efficiency coating, and the relationship between the internal surface roughness of a pipe, the pressure drop across the pipeline, and the maximum flow rate of gas through the pipeline. To improve upon existing solvent-based flow efficiency coatings, a research program was undertaken to develop a solvent-free coating. The stages in the development of this coating are discussed, resulting in the plant application of the coating and final qualification to API RP 5L2. (author)

  18. A Preliminary Investigation of Wastewater Treatment Efficiency and Economic Cost of Subsurface Flow Oyster-Shell-Bedded Constructed Wetland Systems

    Directory of Open Access Journals (Sweden)

    Chia-Chuan Hsu

    2013-06-01

    Full Text Available We conducted a preliminary investigation of wastewater treatment efficiency and economic cost of the oyster-shell-bedded constructed wetlands (CWs compared to the conventional gravel-bedded CW based on field monitoring data of water quality and numerical modeling. Four study subsurface (SSF CWs were built to receive wastewater from Taipei, Taiwan. Among these sites, two are vertical wetlands, filled with bagged- (VA and scattered- (VB oyster shells, and the other two horizontal wetlands were filled with scattered-oyster shells (HA and gravels (HB. The BOD, NO3−, DO and SS treatment efficiency of VA and VB were higher than HA and HB. However, VA was determined as the best option of CW design due to its highest cost-effectiveness in term of BOD removal (only 6.56 US$/kg as compared to VB, HA and HB (10.88–25.01 US$/kg. The results confirmed that oyster shells were an effective adsorption medium in CWs. Hydraulic design and arrangement of oyster shells could be important in determining their treatment efficiency and cost-effectiveness. A dynamic model was developed to simulate substance transmissions in different treatment processes in the CWS using AQUASIM 2.1 based on the water quality data. Feasible ranges of biomedical parameters involved were determined for characterizing the importance of different biochemical treatment processes in SSF CWs. Future work will involve extending the experimental period to confirm the treatment efficiency of the oyster-shell-bedded CW systems in long-term operation and provide more field data for the simulated model instead of the literature values.

  19. An Efficient Computational Technique for Fractal Vehicular Traffic Flow

    Directory of Open Access Journals (Sweden)

    Devendra Kumar

    2018-04-01

    Full Text Available In this work, we examine a fractal vehicular traffic flow problem. The partial differential equations describing a fractal vehicular traffic flow are solved with the aid of the local fractional homotopy perturbation Sumudu transform scheme and the local fractional reduced differential transform method. Some illustrative examples are taken to describe the success of the suggested techniques. The results derived with the aid of the suggested schemes reveal that the present schemes are very efficient for obtaining the non-differentiable solution to fractal vehicular traffic flow problem.

  20. Robust boundary treatment for open-channel flows in divergence-free incompressible SPH

    Science.gov (United States)

    Pahar, Gourabananda; Dhar, Anirban

    2017-03-01

    A robust Incompressible Smoothed Particle Hydrodynamics (ISPH) framework is developed to simulate specified inflow and outflow boundary conditions for open-channel flow. Being purely divergence-free, the framework offers smoothed and structured pressure distribution. An implicit treatment of Pressure Poison Equation and Dirichlet boundary condition is applied on free-surface to minimize error in velocity-divergence. Beyond inflow and outflow threshold, multiple layers of dummy particles are created according to specified boundary condition. Inflow boundary acts as a soluble wave-maker. Fluid particles beyond outflow threshold are removed and replaced with dummy particles with specified boundary velocity. The framework is validated against different cases of open channel flow with different boundary conditions. The model can efficiently capture flow evolution and vortex generation for random geometry and variable boundary conditions.

  1. Artificial intelligence based model for optimization of COD removal efficiency of an up-flow anaerobic sludge blanket reactor in the saline wastewater treatment.

    Science.gov (United States)

    Picos-Benítez, Alain R; López-Hincapié, Juan D; Chávez-Ramírez, Abraham U; Rodríguez-García, Adrián

    2017-03-01

    The complex non-linear behavior presented in the biological treatment of wastewater requires an accurate model to predict the system performance. This study evaluates the effectiveness of an artificial intelligence (AI) model, based on the combination of artificial neural networks (ANNs) and genetic algorithms (GAs), to find the optimum performance of an up-flow anaerobic sludge blanket reactor (UASB) for saline wastewater treatment. Chemical oxygen demand (COD) removal was predicted using conductivity, organic loading rate (OLR) and temperature as input variables. The ANN model was built from experimental data and performance was assessed through the maximum mean absolute percentage error (= 9.226%) computed from the measured and model predicted values of the COD. Accordingly, the ANN model was used as a fitness function in a GA to find the best operational condition. In the worst case scenario (low energy requirements, high OLR usage and high salinity) this model guaranteed COD removal efficiency values above 70%. This result is consistent and was validated experimentally, confirming that this ANN-GA model can be used as a tool to achieve the best performance of a UASB reactor with the minimum requirement of energy for saline wastewater treatment.

  2. Application of subsurface vertical flow constructed wetlands to reject water treatment in dairy wastewater treatment plant.

    Science.gov (United States)

    Dąbrowski, Wojciech; Karolinczak, Beata; Gajewska, Magdalena; Wojciechowska, Ewa

    2017-01-01

    The paper presents the effects of applying subsurface vertical flow constructed wetlands (SS VF) for the treatment of reject water generated in the process of aerobic sewage sludge stabilization in the biggest dairy wastewater treatment plant (WWTP) in Poland. Two SS VF beds were built: bed (A) with 0.65 m depth and bed (B) with 1.0 m depth, planted with reeds. Beds were fed with reject water with hydraulic load of 0.1 m d -1 in order to establish the differences in treatment efficiency. During an eight-months research period, a high removal efficiency of predominant pollutants was shown: BOD 5 88.1% (A) and 90.5% (B); COD 84.5% (A) and 87.5% (B); TSS 87.6% (A) and 91.9% (B); TKN 82.4% (A) and 76.5% (B); N-NH 4 + 89.2% (A) and 85.7% (B); TP 30.2% (A) and 40.6% (B). There were not statistically significant differences in the removal efficiencies between bed (B) with 1.0 m depth and bed (A) with 0.65 m depth. The research indicated that SS VF beds could be successfully applied to reject water treatment in dairy WWTPs. The study proved that the use of SS VF beds in full scale in dairy WWTPs would result in a significant decrease in pollutants' load in reject water. In the analyzed case, decreasing the load of ammonia nitrogen was of greatest importance, as it constituted 58% of the total load treated in dairy WWTP and posed a hazard to the stability of the treatment process.

  3. Dewatering and Treatment of Septage Using Vertical Flow Constructed Wetlands

    Directory of Open Access Journals (Sweden)

    Yee Yong Tan

    2017-10-01

    Full Text Available The vertical flow constructed wetland (VFCW has become an attractive decentralised technology for septage treatment. One of the main purposes of the septage treatment is to reduce the volume of raw septage through dewatering, where the solids content is retained in the wetland bed and the water content is released. The retention of solids forms a layer of sludge deposit at the wetland surface, and the drained water, the so-called leachate, typically contains a lower solids content. This article reports the performance of dewatering and filtration of a pilot-scale VFCW designed for septage treatment. A comparison between two feeding strategies, hydraulic loading rate (HLR and solids loading rate (SLR, is presented. The dewatering efficiency through drainage was found to be dependent on the solids load. The removal of total solids (TS and chemical oxygen demand (COD were excellent as the quality of leachate showed that more than 90% of TS and COD were retained in the system. This study reveals that the feeding based on SLR delivered a more sustainable performance for dewatering and solids removal. The build-up of sludge deposit significantly deteriorated the dewatering efficiency through drainage, but it tended to improve the filtration capacity.

  4. Industrial-scale application of the plunger flow electro-oxidation reactor in wastewater depth treatment.

    Science.gov (United States)

    Huang, Guolong; Yao, Jiachao; Pan, Weilong; Wang, Jiade

    2016-09-01

    Effluents after biochemical treatment contain pollutants that are mostly non-degradable. Based upon previous pilot-scale test results, an industrial-scale electro-oxidation device was built to decompose these refractory materials in the effluent from a park wastewater treatment plant. The electro-oxidation device comprised a ditch-shaped plunger flow electrolysis cell, with mesh-plate Ti/PbO2 electrodes as the anode and the same size mesh-plate Ti as the cathode. Wastewater flowed vertically through electrodes; the effective volume of the cell was 2.8 m(3), and the surface-to-volume ratio was 17.14 m(2) m(-3). The optimal current density was 100 A m(-2), and a suitable flow velocity was 14.0 m h(-1). The removal efficiencies for chemical oxygen demand and color in the effluent were over 60.0 and 84.0 %, respectively. In addition, the electro-oxidation system offered a good disinfection capability. The specific energy consumption for this industrial-scale device was 43.5 kWh kg COD(-1), with a current efficiency of 32.8 %, which was superior to the pilot-scale one. To meet the requirements for emission or reuse, the operation cost was $0.44 per ton of effluent at an average price for electricity of $0.11 kWh(-1).

  5. Efficiency of the pre-heater against flow rate on primary the beta test loop

    International Nuclear Information System (INIS)

    Edy Sumarno; Kiswanta; Bambang Heru; Ainur R; Joko P

    2013-01-01

    Calculation of efficiency of the pre-heater has been carried out against the flow rate on primary the BETA Test Loop. BETA test loop (UUB) is a facilities of experiments to study the thermal hydraulic phenomenon, especially for thermal hydraulic post-LOCA (Lost of Coolant Accident). Sequences removal on the BETA Test Loop contained a pre-heater that serves as a getter heat from the primary side to the secondary side, determination of efficiency is to compare the incoming heat energy with the energy taken out by a secondary fluid. Characterization is intended to determine the performance of a pre-heater, then used as tool for analysis, and as a reference design experiments. Calculation of efficiency methods performed by operating the pre-heater with fluid flow rate variation on the primary side. Calculation of efficiency on the results obtained that the efficiency change with every change of flow rate, the flow rate is 71.26% on 163.50 ml/s and 60.65% on 850.90 ml/s. Efficiency value can be even greater if the pre-heater tank is wrapped with thermal insulation so there is no heat leakage. (author)

  6. Treatment efficiency in wastewater treatment plant of Hat Yai Municipality by quantitative removal of microbial indicators

    Directory of Open Access Journals (Sweden)

    Duangporn Kantachote

    2009-11-01

    Full Text Available The efficiency of treatment in a wastewater treatment plant of Hat Yai Municipality through stabilization ponds and constructed wetlands was monitored by using the bacterial indicators, total coliforms (TC, fecal coliforms (FC, Escherichia coli and fecal streptococci (FS, and photosynthetic microbes. The sequence of water flow in the wastewater treatment plant is as follows: primary or anaerobic pond (P, facultative pond (F, maturation pond (M, constructed wetlands (W1, W2 and W3, and an effluent storage pond (S for the treated wastewater. The wastewater treatment plant has an approximate area of 3,264,000 m2 (2,040 rai and its dry weather flow was running at only 40,000 m3/ day. There were 10 sampling times used for all the 7 ponds during July-October, 2006.Statistical analysis using a Two-Factorial Design model, indicated that pond types significantly affected temperature, dissolved oxygen (DO, and pH (p<0.05, whereas the time of sampling during the day had a significant effect (p<0.05 only on the temperature and light intensity available to the ponds. There were also significant different removal efficiencies of the different bacterial indicator groups tested (p<0.05. The overall performance of the wastewater treatment plant effectively removed TC, FC, E. coli, and FS as follows, 99.8%, 99.8%, 75.8% and 98.8%, respectively. The amounts of bacterial indicators, except for E. coli, showed a negative correlation with levels of light intensity and DO, whereas there was no correlation between the pH and the different indicator bacteria. There was a positive middle level correlation between pHand chlorophyll a.There were five different divisions of photosynthetic organisms detected throughout the plant as follows, Cyanophyta, Chlorophyta, Bacillariophyta, Euglenophyta, and Pyrrhophyta. The least diversity was found in the anaerobic pond (P as there were only 15 genera. Euglena, an indicator of dirty water, was detected only in this pond. The

  7. Effects of different sources of protein on digestive characteristics, microbial efficiency, and nutrient flow in dairy goats

    Directory of Open Access Journals (Sweden)

    Nivea Regina de Oliveira Felisberto

    2011-10-01

    Full Text Available Diets formulated with protein sources presenting different resistance to ruminal degradation were compared by evaluating ruminal parameters, production and microbial efficiency and nutrients flow to the omasum in goats. Eight rumen cannulated non-lactating, non-pregnant goats were distributed in a 4 × 4 Latin square design with two replicates. Treatments consisted of four diets where different sources of plant protein accounted for the major protein source named soybean meal, source of higher ruminal degradability, and three other sources of higher resistance of degradation: roasted soybean, corn gluten meal, and cottonseed cake. Amounts of rumen protein were similar among rations; however, flows of dry matter, protein and non-fiber carbohydrate to omasum were higher for diets with protein source with reduced rumen degradation rate. Higher values of rumen ammonia were obtained by using ration with soybean meal as major source of protein. Higher values of pH were obtained for rations with roasted soybean e cottonseed cake. Regarding kinetic of transit, similar values were found among rations. Diets with protein sources presenting reduced ruminal degradation increase nutrients flow to the omasum in goats and alter digestive parameters such as pH and ammonia without compromising bacteria growth and efficiency, which grants their use for dairy goats with similar efficiency to rations using more degradable sources of protein.

  8. Wastewater treatment facilities: Energy efficient improvements and cogeneration

    International Nuclear Information System (INIS)

    Kunkle, R.; Gray, R.; Delzel, D.

    1992-10-01

    The Washington State Energy Office (WSEO) has worked with both the Bonneville Power Administration (BPA) and the US Department of Energy to provide technical and financial assistance to local governments. Based on a recent study conducted by Ecotope for WSEO, local governments spend an estimated $45 million on utility bills statewide. Water and wastewater facilities account for almost a third of this cost. As a result, WSEO decided to focus its efforts on the energy intensive water and wastewater sector. The ultimate goal of this project was to develop mechanisms to incorporate energy efficiency improvements into wastewater treatment facilities in retrofits and during upgrades, remodels, and new construction. Project activities included the following: The review of the existing regulatory environment for treatment system construction, A summary of financing options for efficiency improvements in treatment facilities, A literature review of energy efficiency opportunities in treatment plants, Survey and site visits to characterize existing facilities in Washington State, Estimates of the energy efficiency and cogeneration potential in the sector, and A case study to illustrate the implementation of an efficiency improvement in a treatment facility

  9. Efficient solutions to the Euler equations for supersonic flow with embedded subsonic regions

    Science.gov (United States)

    Walters, Robert W.; Dwoyer, Douglas L.

    1987-01-01

    A line Gauss-Seidel (LGS) relaxation algorithm in conjunction with a one-parameter family of upwind discretizations of the Euler equations in two dimensions is described. Convergence of the basic algorithm to the steady state is quadratic for fully supersonic flows and is linear for other flows. This is in contrast to the block alternating direction implicit methods (either central or upwind differenced) and the upwind biased relaxation schemes, all of which converge linearly, independent of the flow regime. Moreover, the algorithm presented herein is easily coupled with methods to detect regions of subsonic flow embedded in supersonic flow. This allows marching by lines in the supersonic regions, converging each line quadratically, and iterating in the subsonic regions, and yields a very efficient iteration strategy. Numerical results are presented for two-dimensional supersonic and transonic flows containing oblique and normal shock waves which confirm the efficiency of the iteration strategy.

  10. Treatment and utilization of septic tank effluent using vertical-flow constructed wetlands and vegetable hydroponics.

    Science.gov (United States)

    Cui, Li-Hua; Luo, Shi-Ming; Zhu, Xi-Zhen; Liu, Ying-Hu

    2003-01-01

    Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment. The removal rates for COD, BOD5, SS, TN, and TP were 60%, 80%, 74%, 49% and 79%, respectively, when septic tank effluent was treated by vertical flow filter. So the concentration of COD and BOD5 in the treated effluent could meet the quality standard for irrigation water. After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce, the removal efficiencies of the whole system for COD, BOD5, SS, TN and TP were 71.4%, 97.5%, 96.9%, 86.3%, and 87.4%, respectively. And it could meet the integrated wastewater discharge standard for secondary biological treatment plant. It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables. The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%-90% and 85%-96%, respectively.

  11. Studies of micromorphology and current efficiency of zinc electrodeposited from flowing chloride electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Mc Vay, Laura [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

    1986-05-01

    Results of a study of the micromorphology and current efficiency of zinc electrodeposited from flowing, acidic chloride solutions are reported. The effects of six variables were examined: flow rate, current density, zinc and hydrogen ion concentration, concentrations of nickel, iron and cadmium impurity ions, and the nature of the substrate. The development of micromorphology was studied in-situ by means of videomicrography and ex-situ by means of scanning electron microscopy. This investigation focused on the formation of grooved deposits, which are found under a wide range of deposition conditions. The major conclusions of this study are: the most important variable determining whether grooved deposits form is the interfacial concentration; large protrusions orient themselves parallel to the flow direction with the orientation starting upstream and progressing downstream; large protrusions become ridges due to growth of the highest current density portions of the electrode under mass transport control. The current efficiency was measured using EDTA titration and weight measurements. The fraction of the current taken by zinc deposition increased with zinc concentration, ranging up to 100%, and decreased with pH. The efficiency of zinc deposition was affected by the flow rate and the substrate employed. Impurities lowered the current efficiency.

  12. Efficient network-matrix architecture for general flow transport inspired by natural pinnate leaves.

    Science.gov (United States)

    Hu, Liguo; Zhou, Han; Zhu, Hanxing; Fan, Tongxiang; Zhang, Di

    2014-11-14

    Networks embedded in three dimensional matrices are beneficial to deliver physical flows to the matrices. Leaf architectures, pervasive natural network-matrix architectures, endow leaves with high transpiration rates and low water pressure drops, providing inspiration for efficient network-matrix architectures. In this study, the network-matrix model for general flow transport inspired by natural pinnate leaves is investigated analytically. The results indicate that the optimal network structure inspired by natural pinnate leaves can greatly reduce the maximum potential drop and the total potential drop caused by the flow through the network while maximizing the total flow rate through the matrix. These results can be used to design efficient networks in network-matrix architectures for a variety of practical applications, such as tissue engineering, cell culture, photovoltaic devices and heat transfer.

  13. An efficient implicit direct forcing immersed boundary method for incompressible flows

    International Nuclear Information System (INIS)

    Cai, S-G; Ouahsine, A; Smaoui, H; Favier, J; Hoarau, Y

    2015-01-01

    A novel efficient implicit direct forcing immersed boundary method for incompressible flows with complex boundaries is presented. In the previous work [1], the calculation is performed on the Cartesian grid regardless of the immersed object, with a fictitious force evaluated on the Lagrangian points to mimic the presence of the physical boundaries. However the explicit direct forcing method [1] fails to accurately impose the non-slip boundary condition on the immersed interface. In the present work, the calculation is based on the implicit treatment of the artificial force while in an effective way of system iteration. The accuracy is also improved by solving the Navier-Stokes equation with the rotational incremental pressure- correction projection method of Guermond and Shen [2]. Numerical simulations performed with the proposed method are in good agreement with those in the literature

  14. Improving domestic wastewater treatment efficiency with constructed wetland microbial fuel cells: Influence of anode material and external resistance.

    Science.gov (United States)

    Corbella, Clara; Puigagut, Jaume

    2018-08-01

    For the past few years, there has been an increasing interest in the operation of constructed wetlands as microbial fuel cells (CW-MFCs) for both the improvement of wastewater treatment efficiency and the production of energy. However, there is still scarce information on design and operation aspects to maximize CW-MFCs efficiency, especially for the treatment of real domestic wastewater. The aim of this study was to quantify the extent of treatment efficiency improvement carried out by membrane-less MFCs simulating a core of a shallow un-planted horizontal subsurface flow constructed wetland. The influence of the external resistance (50, 220, 402, 604 and 1000Ω) and the anode material (graphite and gravel) on treatment efficiency improvement were addressed. To this purpose, 6 lab-scale membrane-less MFCs were set-up and loaded in batch mode with domestic wastewater for 13weeks. Results showed that 220Ω was the best operation condition for maximising MFCs treatment efficiency, regardless the anode material employed. Gravel-based anode MFCs operated at closed circuit showed ca. 18%, 15%, 31% and 25% lower effluent concentration than unconnected MFCs to the COD, TOC, PO 4 -3 and NH 4 + -N, respectively. Main conclusion of the present work is that constructed wetlands operated as MFCs is a promising strategy to improve domestic wastewater treatment efficiency. However, further studies at pilot scale under more realistic conditions (such as planted systems operated under continuous mode) shall be performed to confirm the findings here reported. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Hydraulic Darrieus turbines efficiency for free fluid flow conditions versus power farms conditions

    Energy Technology Data Exchange (ETDEWEB)

    Antheaume, Sylvain [Electricite de France, Recherche et Developpement, Laboratoire National d' Hydraulique et Environnement, 6 Quai Watier, 78400 Chatou (France); Maitre, Thierry; Achard, Jean-Luc [Laboratoire des Ecoulements Geophysiques et Industriels, BP 53, 38041 Grenoble (France)

    2008-10-15

    The present study deals with the efficiency of cross flow water current turbine for free stream conditions versus power farm conditions. In the first part, a single turbine for free fluid flow conditions is considered. The simulations are carried out with a new in house code which couples a Navier-Stokes computation of the outer flow field with a description of the inner flow field around the turbine. The latter is based on experimental results of a Darrieus wind turbine in an unbounded domain. This code is applied for the description of a hydraulic turbine. In the second part, the interest of piling up several turbines on the same axis of rotation to make a tower is investigated. Not only is it profitable because only one alternator is needed but the simulations demonstrate the advantage of the tower configuration for the efficiency. The tower is then inserted into a cluster of several lined up towers which makes a barge. Simulations show that the average barge efficiency rises as the distance between towers is decreased and as the number of towers is increased within the row. Thereby, the efficiency of a single isolated turbine is greatly increased when set both into a tower and into a cluster of several towers corresponding to possible power farm arrangements. (author)

  16. Holography as a highly efficient RG flow I: Rephrasing gravity

    OpenAIRE

    Behr, Nicolas; Kuperstein, Stanislav; Mukhopadhyay, Ayan

    2015-01-01

    We investigate how the holographic correspondence can be reformulated as a generalisation of Wilsonian RG flow in a strongly interacting large $N$ quantum field theory. We firstly define a \\textit{highly efficient RG flow} as one in which the Ward identities related to local conservation of energy, momentum and charges preserve the same form at each scale -- to achieve this it is necessary to redefine the background metric and external sources at each scale as functionals of the effective sin...

  17. An efficient particle Fokker–Planck algorithm for rarefied gas flows

    Energy Technology Data Exchange (ETDEWEB)

    Gorji, M. Hossein; Jenny, Patrick

    2014-04-01

    This paper is devoted to the algorithmic improvement and careful analysis of the Fokker–Planck kinetic model derived by Jenny et al. [1] and Gorji et al. [2]. The motivation behind the Fokker–Planck based particle methods is to gain efficiency in low Knudsen rarefied gas flow simulations, where conventional direct simulation Monte Carlo (DSMC) becomes expensive. This can be achieved due to the fact that the resulting model equations are continuous stochastic differential equations in velocity space. Accordingly, the computational particles evolve along independent stochastic paths and thus no collision needs to be calculated. Therefore the computational cost of the solution algorithm becomes independent of the Knudsen number. In the present study, different computational improvements were persuaded in order to augment the method, including an accurate time integration scheme, local time stepping and noise reduction. For assessment of the performance, gas flow around a cylinder and lid driven cavity flow were studied. Convergence rates, accuracy and computational costs were compared with respect to DSMC for a range of Knudsen numbers (from hydrodynamic regime up to above one). In all the considered cases, the model together with the proposed scheme give rise to very efficient yet accurate solution algorithms.

  18. Efficient relaxations for joint chance constrained AC optimal power flow

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Kyri; Toomey, Bridget

    2017-07-01

    Evolving power systems with increasing levels of stochasticity call for a need to solve optimal power flow problems with large quantities of random variables. Weather forecasts, electricity prices, and shifting load patterns introduce higher levels of uncertainty and can yield optimization problems that are difficult to solve in an efficient manner. Solution methods for single chance constraints in optimal power flow problems have been considered in the literature, ensuring single constraints are satisfied with a prescribed probability; however, joint chance constraints, ensuring multiple constraints are simultaneously satisfied, have predominantly been solved via scenario-based approaches or by utilizing Boole's inequality as an upper bound. In this paper, joint chance constraints are used to solve an AC optimal power flow problem while preventing overvoltages in distribution grids under high penetrations of photovoltaic systems. A tighter version of Boole's inequality is derived and used to provide a new upper bound on the joint chance constraint, and simulation results are shown demonstrating the benefit of the proposed upper bound. The new framework allows for a less conservative and more computationally efficient solution to considering joint chance constraints, specifically regarding preventing overvoltages.

  19. A highly energy-efficient flow-through electro-Fenton process for organic pollutants degradation

    International Nuclear Information System (INIS)

    Ma, Liang; Zhou, Minghua; Ren, Gengbo; Yang, Weilu; Liang, Liang

    2016-01-01

    Highlights: • A highly energy-efficient flow-through electro-Fenton reactor was designed. • It had high H 2 O 2 yield and low energy consumption for organic pollutants degradation. • The effect of operational parameters was optimized and possible process mechanism was studied. • The novel system performed wide practicability and potential for organic pollutants degradation. - Abstract: A highly energy-efficient flow-through Electro-Fenton (E-Fenton) reactor for oxidation of methylene blue (MB) from aqueous solution was designed using a perforated DSA as anode and the graphite felt modified by carbon black and polytetrafluoroethylene (PTFE) as cathode for the in situ generation of H 2 O 2 . The modified cathode had a high H 2 O 2 production with low energy consumption, which was characterized by scanning electron microscopy (SEM), nitrogen adsorption-desorption study and contact angle. The flow-through E-Fenton system was compared to the flow-by and regular one, and confirmed to be best on MB removal and TOC degradation. The operational parameters such as current density, pH, Fe 2+ concentration and flow rate were optimized. The MB and TOC removal efficiency of the effluents could keep above 90% and 50%, respectively, and the energy consumption was 23.0 kWh/kgTOC at the current density of 50 mA, pH 3, 0.3 mM Fe 2+ , and the flow rate of 7 mL/min. ·OH was proved to be the main oxidizing species in this system. After 5 times operation, the system, especially cathode, still showed good stability. Five more organic pollutants including orange II (OG), tartrazine, acetylsalicylic acid (ASA), tetracycline (TC) and 2,4-dichlorophen (2,4-DCP) were investigated and the electric energy consumption (EEC) was compared with literatures. All results demonstrated that this flow-through E-Fenton system was energy-efficient and potential for degradation of organic pollutants.

  20. Sugarcane molasses-based bio-ethanol wastewater treatment by two-phase multi-staged up-flow anaerobic sludge blanket (UASB) combination with up-flow UASB and down-flow hanging sponge.

    Science.gov (United States)

    Choeisai, P; Jitkam, N; Silapanoraset, K; Yubolsai, C; Yoochatchaval, W; Yamaguchi, T; Onodera, T; Syutsubo, K

    2014-01-01

    This study was designed to evaluate a treatment system for high strength wastewater (vinasse) from a sugarcane molasses-based bio-ethanol plant in Thailand. A laboratory-scale two-phase treatment system composed of a sulfate reducing (SR) tank and multi-staged up-flow anaerobic sludge blanket (MS-UASB) reactor was used as the pre-treatment unit. Conventional UASB and down-flow hanging sponge (DHS) reactors were used as the post-treatment unit. The treatment system was operated for 300 days under ambient temperature conditions (24.6-29.6 °C). The hydraulic retention time (HRT) in each unit was kept at 25 h for the two-phase system and 23 h for the UASB&DHS. The influent concentration was allowed to reach up to 15,000 mg chemical oxygen demand (COD)/L. COD removal efficiency (based on influent COD) of the two-phase MS-UASB and the UASB&DHS was 54.9 and 18.7%, respectively. Due to the effective removal of sulfide in the SR tank, the MS-UASB achieved a high methane conversion ratio of up to 97%. In DHS, nitrification occurred at the outside portion of the sponge media while denitrification occurred at the inside. Consequently, 27% of the total nitrogen (TN) was removed. An amount of 32% of residual nitrogen (28 mgN/L) was in the form of nitrate, a better nitrogen state for fertilizer.

  1. Enhancing Cold Atmospheric Plasma Treatment Efficiency for Cancer Therapy

    Science.gov (United States)

    Cheng, Xiaoqian

    To improve efficiency and safety of anti-cancer therapies the researchers and clinicians alike are prompted to develop targeted combined therapies that especially minimize damage to healthy tissues while eradicating the body of cancerous tissues. Previous research in cold atmospheric plasma (CAP) and cancer cell interaction has repeatedly proven that cold plasma induced cell death. In this study, we seek to integrate the medical application of CAP. We proposed and implemented 3 novel ideas to enhance efficacy and selectivity of cancer therapy. It is postulated that the reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a major role in the CAP cancer therapy. We determined a mechanism of CAP therapy on glioblastoma cells (U87) through an understanding of the composition of CAP, including output voltage, treatment time, and gas flow-rate. We varied the characteristics of the cold plasma in order to obtain different major species (such as O, OH, N2+, and N2 lines). "plasma dosage" D ~ Q * V * t. is defined, where D is the entire "plasma dosage"; Q is the flow rate of feeding gas; V is output voltage; t is treatment time. The proper CAP dosage caused 3-fold cell death in the U87 cells compared to the normal human astrocytes E6/E7 cells. We demonstrated there is a synergy between AuNPS and CAP in cancer therapy. Specifically, the concentration of AuNPs plays an important role on plasma therapy. At an optimal concentration, gold nanoparticles can significantly induce U87 cell death up to a 30% overall increase compared to the control group with the same plasma dosage but no AuNPs applied. The ROS intensity of the corresponding conditions has a reversed trend compared to cell viability. This matches with the theory that intracellular ROS accumulation results in oxidative stress, which further changes the intracellular pathways, causing damage to the proteins, lipids and DNA. Our results show that this synergy has great potential in improving the

  2. Resource efficiency of urban sanitation systems. A comparative assessment using material and energy flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meinzinger, Franziska

    2010-07-01

    fertiliser could be substituted by nutrients recovered from wastewater; for the case study of Arba Minch this substitution amounts to a maximum of 16%. Factors such as the transport of source separated flows or complex nutrient recovery processes can result in an increasing energy demand. However, source separation and recovery processes can also lead to energy reduction, for example, by urine diversion (minus 12% for the case of Hamburg) or by the use of biogas from anaerobic treatment plants (minus 38% for the case of Arba Minch). The energy efficiency depends on determinant parameters, e.g. the amount of co-digested organic waste. The impact of these parameters can be simulated in the model. Source-separating wastewater systems can reduce the use of natural water resources, for example, by reduced flush water consumption or greywater recycling. The integration of cost estimates with material and energy flow analyses, allows a cost-effectiveness appraisal of the system developments. Assumptions such as whether the costs refer to a new development or the modification of existing infrastructure have a major impact on the cost comparison. Where the sanitation system is improved, there is invariably an increase in costs when compared to the current situation. But in addition, financial benefits can be generated. For each case study, a discussion of the driving forces, preconditions and starting points for implementation, complements the comparative assessment. In addition, potential obstacles for transformation are discussed. The study shows that the method of using combined cost, energy and material flow analysis yields purposeful insights into the resource efficiency of alternative sanitation systems. This can contribute comprehensively to system analysis and decision support. (orig.)

  3. Inlet Diameter and Flow Volume Effects on Separation and Energy Efficiency of Hydrocyclones

    Science.gov (United States)

    Erikli, Ş.; Olcay, A. B.

    2015-08-01

    This study investigates hydrocyclone performance of an oil injected screw compressor. Especially, the oil separation efficiency of a screw compressor plays a significant role for air quality and non-stop working hour of compressors has become an important issue when the efficiency in energy is considered. In this study, two separation efficiency parameters were selected to be hydrocyclone inlet diameter and flow volume height between oil reservoir surface and top of the hydrocyclone. Nine different cases were studied in which cyclone inlet diameter and flow volume height between oil reservoir surface and top were investigated in regards to separation and energy performance aspects and the effect of the parameters on the general performance appears to be causing powerful influence. Flow inside the hydrocyclone geometry was modelled by Reynolds Stress Model (RSM) and hydro particles were tracked by Discrete Phase Model (DPM). Besides, particle break up was modelled by the Taylor Analogy Breakup (TAB) model. The reversed vortex generation was observed at different planes. The upper limit of the inlet diameter of the cyclone yields the centrifugal force on particles to decrease while the flow becomes slower; and the larger diameter implies slower flow. On the contrary, the lower limit is increment in speed causes breakup problems that the particle diameters become smaller; consequently, it is harder to separate them from gas.

  4. The removal efficiency of constructed wetlands filled with the zeolite-slag hybrid substrate for the rural landfill leachate treatment.

    Science.gov (United States)

    He, Hailing; Duan, Zhiwei; Wang, Zhenqing; Yue, Bo

    2017-07-01

    The removal efficiencies of two horizontal subsurface flow constructed wetlands (HSSF CWs, down-flow (F1) and up-flow (F2)) filled with the zeolite-slag hybrid substrate for the rural landfill leachate treatment were investigated. The adsorption experiment was conducted to evaluate the potential of zeolite and slag as the wetland substrate. The effects of distance variations along the longitudinal profile of wetland bed on pollutant removal were assessed by sampling at four locations (inlet, outlet, 0.55 m, and 1.10 m from the inlet). During the operation time, the influent and effluent concentrations of chemical oxygen demand (COD), ammonia nitrogen (NH 3 -N), total nitrogen (TN), heavy metals, and polycyclic aromatic hydrocarbon (PAH) were measured. The results showed that the constructed wetlands were capable of removing COD, 20.5-48.2% (F1) and 18.6-61.2% (F2); NH 3 -N, 84.0-99.9% (F1) and 93.5-99.2% (F2); TN, 80.3-92.1% (F1) and 80.3-91.2% (F2); and heavy metals, about 90% (F1 and F2). The zeolite-slag hybrid substrate performed excellent removal efficiency for the nitrogen and heavy metals. The inlet area was the most active region of leachate removal. The up-flow constructed wetland (F2) has a higher removal efficiency for the PAH compounds. The significant removal efficiency illustrated that the rural landfill leachate can be treated using the horizontal subsurface flow constructed wetland filled with the zeolite-slag hybrid substrate.

  5. Towards More Efficient, Greener Syntheses through Flow Chemistry.

    Science.gov (United States)

    Lummiss, Justin A M; Morse, Peter D; Beingessner, Rachel L; Jamison, Timothy F

    2017-07-01

    Technological advances have an important role in the design of greener synthetic processes. In this Personal Account, we describe a wide range of thermal, photochemical, catalytic, and biphasic chemical transformations examined by our group. Each of these demonstrate how the merits of a continuous flow synthesis platform can align with some of the goals put forth by the Twelve Principles of Green Chemistry. In particular, we illustrate the potential for improved reaction efficiency in terms of atom economy, product yield and reaction rates, the ability to design synthetic process with chemical and solvent waste reduction in mind as well as highlight the benefits of the real-time monitoring capabilities in flow for highly controlled synthetic output. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Radioactive gas standby treatment apparatus with high efficiency rechargeable charcoal filter

    International Nuclear Information System (INIS)

    Hickey, T.N.; Spulgis, I.S.

    1975-01-01

    Described is a standby gas treatment system for removal of radioactive release from a nuclear containment structure not only during normal purge operations but also in the event of a design basis accident. Ventiduct trains arranged in parallel so that one is redundant are each operative to extract dust in excess of 0.3 microns and adsorb radioactive iodine and compounds thereof at 99.9 percent plus efficiency. A rechargeable gasketless charcoal filter in each train can be filled or emptied without removing the filter enclosures per se. Laminar flow filter beds entirely encapsulate the gas stream to provide low gas velocity and even distribution across the charcoal cage without channeling, thereby securing long residence time

  7. Energy Efficient Thermal Management for Natural Gas Engine Aftertreatment via Active Flow Control

    Energy Technology Data Exchange (ETDEWEB)

    David K. Irick; Ke Nguyen; Vitacheslav Naoumov; Doug Ferguson

    2006-04-01

    The project is focused on the development of an energy efficient aftertreatment system capable of reducing NOx and methane by 90% from lean-burn natural gas engines by applying active exhaust flow control. Compared to conventional passive flow-through reactors, the proposed scheme cuts supplemental energy by 50%-70%. The system consists of a Lean NOx Trap (LNT) system and an oxidation catalyst. Through alternating flow control, a major amount of engine exhaust flows through a large portion of the LNT system in the absorption mode, while a small amount of exhaust goes through a small portion of the LNT system in the regeneration or desulfurization mode. By periodically reversing the exhaust gas flow through the oxidation catalyst, a higher temperature profile is maintained in the catalyst bed resulting in greater efficiency of the oxidation catalyst at lower exhaust temperatures. The project involves conceptual design, theoretical analysis, computer simulation, prototype fabrication, and empirical studies. This report details the progress during the first twelve months of the project. The primary activities have been to develop the bench flow reactor system, develop the computer simulation and modeling of the reverse-flow oxidation catalyst, install the engine into the test cell, and begin design of the LNT system.

  8. High efficiency of CO2-activated graphite felt as electrode for vanadium redox flow battery application

    Science.gov (United States)

    Chang, Yu-Chung; Chen, Jian-Yu; Kabtamu, Daniel Manaye; Lin, Guan-Yi; Hsu, Ning-Yih; Chou, Yi-Sin; Wei, Hwa-Jou; Wang, Chen-Hao

    2017-10-01

    A simple method for preparing CO2-activated graphite felt as an electrode in a vanadium redox flow battery (VRFB) was employed by the direct treatment in a CO2 atmosphere at a high temperature for a short period. The CO2-activated graphite felt demonstrates excellent electrochemical activity and reversibility. The VRFB using the CO2-activated graphite felts in the electrodes has coulombic, voltage, and energy efficiencies of 94.52%, 88.97%, and 84.15%, respectively, which is much higher than VRFBs using the electrodes of untreated graphite felt and N2-activated graphite felt. The efficiency enhancement was attributed to the higher number of oxygen-containing functional groups on the graphite felt that are formed during the CO2-activation, leading to improving the electrochemical behaviour of the resultant VRFB.

  9. Efficient flow and human centred assembly by an interactive approach

    NARCIS (Netherlands)

    Eikhout, S.M.; Helmes, R.B.M.; Rhijn, J.W. van

    2004-01-01

    Due to fluctuations on the market, manufacturing of many product variations, and wish for fine-tuning between production and assembly a fan and motor manufacturing company wanted to improve their assembly line. The aims were efficient flow and human centered assembly in the new product line.

  10. Efficient Unsteady Flow Visualization with High-Order Access Dependencies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru

    2016-04-19

    We present a novel high-order access dependencies based model for efficient pathline computation in unsteady flow visualization. By taking longer access sequences into account to model more sophisticated data access patterns in particle tracing, our method greatly improves the accuracy and reliability in data access prediction. In our work, high-order access dependencies are calculated by tracing uniformly-seeded pathlines in both forward and backward directions in a preprocessing stage. The effectiveness of our proposed approach is demonstrated through a parallel particle tracing framework with high-order data prefetching. Results show that our method achieves higher data locality and hence improves the efficiency of pathline computation.

  11. Swine wastewater treatment using vertical subsurface flow constructed wetland planted with Napier grass

    Directory of Open Access Journals (Sweden)

    Pantip Klomjek

    2016-09-01

    Full Text Available This research aims to investigate the pollutant removal efficiencies in swine wastewater using a vertical subsurface flow constructed wetland (VSF CW planted with two species of Napier grass. The grass productivities were also cultivated and compared in order to provide information for species selection. Twelve treatment units were set up with the VSF CWs planted with Giant Napier grass (Pennisetum purpureum cv. King grass and Dwarf Napier grass (Pennisetum purpureum cv. Mott. with 2 and 5 cm d−1 of hydraulic loading rates (HLR. Comparisons of removal efficiency and grass productivity were analyzed using Duncan's Multiple Range Test and t-test at the significant level 0.05. Both species of Napier grass performed more than 70% of removal efficiency of BOD and TKN. The VSF CW planted with Giant Napier grass at 5 cm d−1 HLR performed the highest BOD removal efficiency of 94 ± 1%, while the 2 cm d−1 HLR removed COD with efficiency of 64 ± 6%. The results also showed the effluent from all treatment units contained averages of BOD, COD, TSS, TKN and pH that followed Thailand's swine wastewater quality standard. Average fresh yields and dry yields were between 4.6 ± 0.4 to 15.2 ± 1.2 and 0.5 ± 0.1 to 2.2 ± 0.1 kg m−2, respectively. The dry yields obtained from four cutting cycles in five months of CW system operation were higher than the ones planted with a traditional method, but declined continuously after each cutting cycle. Both species of Napier grass indicated their suitability to be used in the VSF CW for swine wastewater treatment.

  12. The Effect of the Volume Flow rate on the Efficiency of a Solar Collector

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    rates. Theoretically, a simplified model of the solar collector panel is built by means of the CFD (Computational Fluid Dynamics) code Fluent, where the geometry of the collector panel except the casing is fully modeled. Both lateral and longitudinal heat conduction in the absorber fins, the heat...... transfer from the absorber to the solar collector fluid and the heat loss from the absorber are considered. Flow and temperature distribution in the collector panel are investigated with buoyancy effect. Measurements are carried out with the solar collector panel. Collector efficiencies are measured......The flow distribution inside a collector panel with an area of 12.5 m² and with 16 parallel connected horizontal fins and the effect of the flow nonuniformity on the risk of boiling and on the collector efficiency have been theoretically and experimentally investigated for different volume flow...

  13. Radioactive gas standby treatment apparatus with high efficiency rechargeable charcoal filter

    International Nuclear Information System (INIS)

    Hickey, T.N.; Spulgis, I.S.

    1976-01-01

    A description is given of a standby gas treatment system for removal of radioactive release from a nuclear containment structure not only during normal purge operations but also in the event of a design basis accident. Ventiduct trains arranged in parallel so that one is redundant are each operative to extract dust in excess of 0.3 microns and adsorb radioactive iodine and compounds thereof at 99.9 percent plus efficiency. A rechargeable gasketless charcoal filter in each train can be filled or emptied without removing the filter enclosures per se. Laminar flow filter beds entirely encapsulate the gas stream to provide low gas velocity and even distribution across the charcoal cage without channeling, thereby securing long residence time. 2 claims, 9 drawing figures

  14. Cost efficiency of the non-associative flow rule simulation of an industrial component

    Science.gov (United States)

    Galdos, Lander; de Argandoña, Eneko Saenz; Mendiguren, Joseba

    2017-10-01

    In the last decade, metal forming industry is becoming more and more competitive. In this context, the FEM modeling has become a primary tool of information for the component and process design. Numerous researchers have been focused on improving the accuracy of the material models implemented on the FEM in order to improve the efficiency of the simulations. Aimed at increasing the efficiency of the anisotropic behavior modelling, in the last years the use of non-associative flow rule models (NAFR) has been presented as an alternative to the classic associative flow rule models (AFR). In this work, the cost efficiency of the used flow rule model has been numerically analyzed by simulating an industrial drawing operation with two different models of the same degree of flexibility: one AFR model and one NAFR model. From the present study, it has been concluded that the flow rule has a negligible influence on the final drawing prediction; this is mainly driven by the model parameter identification procedure. Even though the NAFR formulation is complex when compared to the AFR, the present study shows that the total simulation time while using explicit FE solvers has been reduced without loss of accuracy. Furthermore, NAFR formulations have an advantage over AFR formulations in parameter identification because the formulation decouples the yield stress and the Lankford coefficients.

  15. Efficiency of sewage treatment with septic tanks followed by constructed wetlands with different support materials

    Directory of Open Access Journals (Sweden)

    Delvio Sandri

    2013-04-01

    Full Text Available This study seeks to assess the efficiency of a sewage treatment plant comprised of three compartmentalized septic tanks installed in series followed by three parallel wetlands and seeded with species Typha sp. with subsurface flow, filled with support material of natural gravel, gravel # 2 and washed gravel, respectively. The station treats sewage generated at Unity University for Science and Technology, State University of Goiás – UnUCET/UEG. A total of 20 sewage samples were collected in order to evaluate treatment efficiency from November to December 2010 and March to April 2011. The points of analysis were at the input of the first tank (raw sewage, the output of the third septic tank and the outputs of each of the three wetlands. The total removal efficiencies were: 65.40% for chemical oxygen demand; 79.01% for biochemical oxygen demand; 59.79% for total solids; 87.12% for the total suspended solids; 92.00% for total coliforms; 95.71% for E. coli and 82.54% for turbidity. The system was effective for the treatment of sewage, within the current legislative parameters for pH, turbidity, total solids and biochemical oxygen demand. No significant difference was observed between the three different means of support, suggesting that gravel, natural gravel and washed gravel may potentially be used to fill wetlands.

  16. ECONOMIC EFFICIENCY OF DIFFERENT PROTECTION TREATMENTS IN APPLE PRODUCTION

    Directory of Open Access Journals (Sweden)

    Vesna Tomaš

    2015-06-01

    Full Text Available Apple is the most represented fruit species in Croatia. Codling moth, Cydia pomonella L, is one of the most important apple pests whose population is growing from year to year. The aim of this study was to determine the economic effectiveness of four treatments against codling moth (1 - based on baculovirus; 2 - based on the group of synthetic pyrethroid; 3 - based on kaolin, 4 - control treatment, on the three apple varieties. The experiment was performed at the Agricultural Institute Osijek, Croatia, during three years (2012-2014. In order to analyze the results of apple production it was necessary to calculate production efficiency, labor productivity, and profitability of production. The results of the research of economic efficiency according to market prices treatment 1 and treatment 2 had economic coefficient above 1 with tendency of significant growth, while treatment 3 and 4 were uneconomical. The treatment 1showed advantage over the treatment 2 because of its positive effects on human health and biodiversity, as well as satisfactory economic efficiency.

  17. Enhancing dye-sensitized solar cell efficiency by anode surface treatments

    International Nuclear Information System (INIS)

    Chang, Chao-Hsuan; Lin, Hsin-Han; Chen, Chin-Cheng; Hong, Franklin C.-N.

    2014-01-01

    In this study, titanium substrates treated with HF solution and KOH solution sequentially forming micro- and nano-structures were used for the fabrication of flexible dye-sensitized solar cells (DSSCs). After wet etching treatments, the titanium substrates were then exposed to the O 2 plasma treatment and further immersed in titanium tetrachloride (TiCl 4 ) solution. The process conditions for producing a very thin TiO 2 blocking layer were studied, in order to avoid solar cell current leakage for increasing the solar cell efficiency. Subsequently, TiO 2 nanoparticles were spin-coated on Ti substrates with varied thickness. The dye-sensitized solar cells on the titanium substrates were subjected to simulate AM 1.5 G irradiation of 100 mW/cm 2 using backside illumination mode. Surface treatments of Ti substrate and TiO 2 anode were found to play a significant role in improving the efficiency of DSSC. The efficiencies of the backside illumination solar cells were raised from 4.6% to 7.8% by integrating these surface treatments. - Highlights: • The flexible dye-sensitized solar cell (DSSC) device can be fabricated. • Many effective surface treatment methods to improve DSSC efficiency are elucidated. • The efficiency is dramatically enhanced by integrating surface treatment methods. • The back-illuminated DSSC efficiency was raised from 4.6% to 7.8%

  18. Unifying principles of irreversibility minimization for efficiency maximization in steady-flow chemically-reactive engines

    International Nuclear Information System (INIS)

    Ramakrishnan, Sankaran; Edwards, Christopher F.

    2014-01-01

    Systems research has led to the conception and development of various steady-flow, chemically-reactive, engine cycles for stationary power generation and propulsion. However, the question that remains unanswered is: What is the maximum-efficiency steady-flow chemically-reactive engine architecture permitted by physics? On the one hand the search for higher-efficiency cycles continues, often involving newer processes and devices (fuel cells, carbon separation, etc.); on the other hand the design parameters for existing cycles are continually optimized in response to improvements in device engineering. In this paper we establish that any variation in engine architecture—parametric change or process-sequence change—contributes to an efficiency increase via one of only two possible ways to minimize total irreversibility. These two principles help us unify our understanding from a large number of parametric analyses and cycle-optimization studies for any steady-flow chemically-reactive engine, and set a framework to systematically identify maximum-efficiency engine architectures. - Highlights: • A unified thermodynamic model to study chemically-reactive engine architectures is developed. • All parametric analyses of efficiency are unified by two irreversibility-minimization principles. • Variations in internal energy transfers yield a net work increase that is greater than engine irreversibility reduced. • Variations in external energy transfers yield a net work increase that is lesser than engine irreversibility reduced

  19. An Efficient Hybrid DSMC/MD Algorithm for Accurate Modeling of Micro Gas Flows

    KAUST Repository

    Liang, Tengfei

    2013-01-01

    Aiming at simulating micro gas flows with accurate boundary conditions, an efficient hybrid algorithmis developed by combining themolecular dynamics (MD) method with the direct simulationMonte Carlo (DSMC)method. The efficiency comes from the fact that theMD method is applied only within the gas-wall interaction layer, characterized by the cut-off distance of the gas-solid interaction potential, to resolve accurately the gas-wall interaction process, while the DSMC method is employed in the remaining portion of the flow field to efficiently simulate rarefied gas transport outside the gas-wall interaction layer. A unique feature about the present scheme is that the coupling between the two methods is realized by matching the molecular velocity distribution function at the DSMC/MD interface, hence there is no need for one-toone mapping between a MD gas molecule and a DSMC simulation particle. Further improvement in efficiency is achieved by taking advantage of gas rarefaction inside the gas-wall interaction layer and by employing the "smart-wall model" proposed by Barisik et al. The developed hybrid algorithm is validated on two classical benchmarks namely 1-D Fourier thermal problem and Couette shear flow problem. Both the accuracy and efficiency of the hybrid algorithm are discussed. As an application, the hybrid algorithm is employed to simulate thermal transpiration coefficient in the free-molecule regime for a system with atomically smooth surface. Result is utilized to validate the coefficients calculated from the pure DSMC simulation with Maxwell and Cercignani-Lampis gas-wall interaction models. ©c 2014 Global-Science Press.

  20. Density effect on the mixing efficiency and flow modes in T-shaped micromixers

    Directory of Open Access Journals (Sweden)

    Lobasov Alexander

    2017-01-01

    Full Text Available Flow patterns and mixing of liquids with different densities in T-shaped micromixers are numerically investigated at Reynolds number range from 1 to 250. The density ratio of the mixing media varies from 1 to 2; its effect on the flow structure and the mixing is studied. The dependences of the mixing efficiency and the pressure difference in this mixer on the density ratio and the Reynolds number are obtained. It is shown that the density ratio has a considerable effect on the flow structure, especially before the transition from the symmetric to the asymmetric flow pattern.

  1. An efficient unstructured WENO method for supersonic reactive flows

    Science.gov (United States)

    Zhao, Wen-Geng; Zheng, Hong-Wei; Liu, Feng-Jun; Shi, Xiao-Tian; Gao, Jun; Hu, Ning; Lv, Meng; Chen, Si-Cong; Zhao, Hong-Da

    2018-03-01

    An efficient high-order numerical method for supersonic reactive flows is proposed in this article. The reactive source term and convection term are solved separately by splitting scheme. In the reaction step, an adaptive time-step method is presented, which can improve the efficiency greatly. In the convection step, a third-order accurate weighted essentially non-oscillatory (WENO) method is adopted to reconstruct the solution in the unstructured grids. Numerical results show that our new method can capture the correct propagation speed of the detonation wave exactly even in coarse grids, while high order accuracy can be achieved in the smooth region. In addition, the proposed adaptive splitting method can reduce the computational cost greatly compared with the traditional splitting method.

  2. Investigations on efficiencies of HT solar collectors for different flow rates and collector tilts

    DEFF Research Database (Denmark)

    Chen, Ziqian; Perers, Bengt; Furbo, Simon

    2013-01-01

    Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between the abso......Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates and tilt. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rates are obtained. The calculated efficiencies are in good...

  3. Influence of hummocks and emergent vegetation on hydraulic performance in a surface flow wastewater treatment wetland

    Science.gov (United States)

    Keefe, Steffanie H.; Daniels, Joan S.; Runkel, Robert L.; Wass, Roland D.; Stiles, Eric A.; Barber, Larry B.

    2010-01-01

    A series of tracer experiments were conducted biannually at the start and end of the vegetation growing season in a surface flow wastewater treatment wetland located near Phoenix, AZ. Tracer experiments were conducted prior to and following reconfiguration and replanting of a 1.2 ha treatment wetland from its original design of alternating shallow and deep zones to incorporate hummocks (shallow planting beds situated perpendicular to flow). Tracer test data were analyzed using analysis of moments and the one‐dimensional transport with inflow and storage numerical model to evaluate the effects of the seasonal vegetation growth cycle and hummocks on solute transport. Following reconfiguration, vegetation coverage was relatively small, and minor changes in spatial distribution influenced wetland hydraulics. During start‐up conditions, the wetland underwent an acclimation period characterized by small vegetation coverage and large transport cross‐sectional areas. At the start of the growing season, new growth of emergent vegetation enhanced hydraulic performance. At the end of the growing season, senescing vegetation created short‐circuiting. Wetland hydrodynamics were associated with high volumetric efficiencies and velocity heterogeneities. The hummock design resulted in breakthrough curves characterized by multiple secondary tracer peaks indicative of varied flow paths created by bottom topography.

  4. Process efficiency. Redesigning social networks to improve surgery patient flow.

    Science.gov (United States)

    Samarth, Chandrika N; Gloor, Peter A

    2009-01-01

    We propose a novel approach to improve throughput of the surgery patient flow process of a Boston area teaching hospital. A social network analysis was conducted in an effort to demonstrate that process efficiency gains could be achieved through redesign of social network patterns at the workplace; in conjunction with redesign of organization structure and the implementation of workflow over an integrated information technology system. Key knowledge experts and coordinators in times of crisis were identified and a new communication structure more conducive to trust and knowledge sharing was suggested. The new communication structure is scalable without compromising on coordination required among key roles in the network for achieving efficiency gains.

  5. Effective information flow through efficient supply chain management - Value stream mapping approach Case Outokumpu Tornio Works

    OpenAIRE

    Juvonen, Piia

    2012-01-01

    ABSTRACT Juvonen, Piia Suvi Päivikki 2012. Effective information flow through efficient supply chain management -Value stream mapping approach - Case Outokumpu Tornio Works. Master`s Thesis. Kemi-Tornio University of Applied Sciences. Business and Culture. Pages 63. Appendices 2. The general aim of this thesis is to explore effective information flow through efficient supply chain management by following one of the lean management principles, value stream mapping. The specific research...

  6. Treatment of ferrous-NTA-based NO x scrubber solution by an up-flow anaerobic packed bed bioreactor.

    Science.gov (United States)

    Chandrashekhar, B; Sahu, Nidhi; Tabassum, Heena; Pai, Padmaraj; Morone, Amruta; Pandey, R A

    2015-06-01

    A bench scale system consisting of an up-flow packed bed bioreactor (UAPBR) made of polyurethane foam was used for the treatment and regeneration of aqueous solution of ferrous-NTA scrubbed with nitric oxide (NO). The biomass in the UAPBR was sequentially acclimatized under denitrifying and iron reducing conditions using ethanol as electron donor, after which nitric oxide (NO) gas was loaded continuously to the system by absorption. The system was investigated for different parameters viz. pH, removal efficiency of nitric oxide, biological reduction efficiency of Fe(II)NTA-NO and COD utilization. The Fe(II)NTA-NO reduction efficiency reached 87.8 % at a loading rate of 0.24 mmol L(-1) h(-1), while the scrubber efficiency reached more than 75 % with 250 ppm NO. Stover-Kincannon and a Plug-flow kinetic model based on Michaelis-Menten equation were used to describe the UAPBR performance with respect to Fe(II)NTA-NO and COD removal. The Stover-Kincannon model was found capable of describing the Fe(II)NTA-NO reduction (R m = 8.92 mM h(-1) and K NO = 11.46 mM h(-1)) while plug-flow model provided better fit to the COD utilization (U m = 66.62 mg L(-1) h(-1), K COD = 7.28 mg L(-1)). Analyses for pH, Fe(III)NTA, ammonium, nitrite concentration, and FTIR analysis of the medium samples indicated degradation of NTA, which leads to ammonium and nitrite accumulation in the medium, and affect the regeneration process.

  7. Separation efficiency of two waste polymer fibers for oily water treatment

    Directory of Open Access Journals (Sweden)

    Sokolović Dunja S.

    2016-01-01

    Full Text Available This work is concerned with the efficiency of two different waste polymeric materials as the filter media in a laboratory-scale bed coalescer in the horizontal fluid flow mode, operating in a steady-state regime. The applied materials are: waste polyethylene terephthalate from textile industry, BA1 and waste polypropylene from carpet industry, PP. Using these compressible fiber polymeric materials, high bed porosity (up to 98% could be obtained. The investigation was carried out over a wide range of working conditions. Bed permeability was varied in the range from 0.18•10-9 to 5.389•10-9 m2. Operating fluid velocity was varied from 19 to 80 m/h, until the critical velocity was reached. Different oily wastewaters were used in the experiments. Oily wastewater is defined as the oil-inwater emulsion model prepared using mineral oils of different physico-chemical characteristics: crude oil (A from Vojvodina region, two vacuum distillation fractions (A1, A4, and blended petroleum product with a high paraffinic content (P1. Both applied polymeric materials, BA1 and PP, showed high separation efficiency for treatment of all investigated oily wastewater. However, the BA1 material showed higher efficiency in a wider range of bed permeability and physico-chemical characteristics of oil. [Projekat Ministarstva nauke Republike Srbije, br. 172022

  8. Efficiency of a constructed wetland for wastewaters treatment

    Directory of Open Access Journals (Sweden)

    Fernanda Travaini-Lima

    Full Text Available AIM: The limnological characteristics of three different inlets water of the constructed wetland were compared in terms of concentration data and loading rate data and evaluated the removal efficiencies of nutrients, solids, BOD5, chlorophyll-a and thermotolerant coliforms (TC by the treatment system; METHODS: The constructed wetland, measuring 82.8 m² and with detention time of 1 hour and 58 minutes in the rainy season and 2 hours and 42 minutes in the dry one, was provided with four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart. Solms. The sampling sites evaluated in the dry (D and rainy (R seasons were: inlet water from aquaculture farm = IA; inlet channel of rainwater runoff = IR; inlet from UASB wastewater = IB; outlet wetland = OUT. The conductivity, pH, temperature, dissolved oxygen, alkalinity, BOD5, total soluble and dissolved solids, nitrogen, phosphorus, chlorophyll-a and TC were analyzed. Multivariate analyses, such as Cluster and Principal Components Analysis (PCA, were carried out to group sampling sites with similar limnological characteristics; RESULTS: In the PCA with the concentration data was retained 90.52% variability of data, correlating the inlet IB with high concentrations of conductivity, alkalinity, pH, TC, nutrients and solids. Regarding loading rate data, the PCA was retained 80.9% of the data's total variability and correlated the sampling sites IA D, IA R and OUT R with higher BOD5, chlorophyll-a, TDS, nitrate, nitrite, total-P, temperature, oxygen and water flow. The highest removal efficiencies rates occurred in the dry season, mainly in concentration, with 78% of ammonia, 95.5% of SRP, 94.9% of TSS and 99.9% of TC; CONCLUSIONS: The wetland was highly efficacious in the removal of nutrients, solids, BOD5, chlorophyll-a and TC, mainly during the dry season. The system restructuring to increase the detention time during the rainy season and a pre-treatment

  9. Numerical flow simulation and efficiency prediction for axial turbines by advanced turbulence models

    International Nuclear Information System (INIS)

    Jošt, D; Škerlavaj, A; Lipej, A

    2012-01-01

    Numerical prediction of an efficiency of a 6-blade Kaplan turbine is presented. At first, the results of steady state analysis performed by different turbulence models for different operating regimes are compared to the measurements. For small and optimal angles of runner blades the efficiency was quite accurately predicted, but for maximal blade angle the discrepancy between calculated and measured values was quite large. By transient analysis, especially when the Scale Adaptive Simulation Shear Stress Transport (SAS SST) model with zonal Large Eddy Simulation (ZLES) in the draft tube was used, the efficiency was significantly improved. The improvement was at all operating points, but it was the largest for maximal discharge. The reason was better flow simulation in the draft tube. Details about turbulent structure in the draft tube obtained by SST, SAS SST and SAS SST with ZLES are illustrated in order to explain the reasons for differences in flow energy losses obtained by different turbulence models.

  10. Numerical flow simulation and efficiency prediction for axial turbines by advanced turbulence models

    Science.gov (United States)

    Jošt, D.; Škerlavaj, A.; Lipej, A.

    2012-11-01

    Numerical prediction of an efficiency of a 6-blade Kaplan turbine is presented. At first, the results of steady state analysis performed by different turbulence models for different operating regimes are compared to the measurements. For small and optimal angles of runner blades the efficiency was quite accurately predicted, but for maximal blade angle the discrepancy between calculated and measured values was quite large. By transient analysis, especially when the Scale Adaptive Simulation Shear Stress Transport (SAS SST) model with zonal Large Eddy Simulation (ZLES) in the draft tube was used, the efficiency was significantly improved. The improvement was at all operating points, but it was the largest for maximal discharge. The reason was better flow simulation in the draft tube. Details about turbulent structure in the draft tube obtained by SST, SAS SST and SAS SST with ZLES are illustrated in order to explain the reasons for differences in flow energy losses obtained by different turbulence models.

  11. Propulsion efficiency and imposed flow fields of a copepod jump.

    Science.gov (United States)

    Jiang, Houshuo; Kiørboe, Thomas

    2011-02-01

    Pelagic copepods jump to relocate, to attack prey and to escape predators. However, there is a price to be paid for these jumps in terms of their energy costs and the hydrodynamic signals they generate to rheotactic predators. Using observed kinematics of various types of jumps, we computed the imposed flow fields and associated energetics of jumps by means of computational fluid dynamics simulations by modeling the copepod as a self-propelled body. The computational fluid dynamics simulation was validated by particle image velocimetry data. The flow field generated by a repositioning jump quickly evolves into two counter-rotating viscous vortex rings that are near mirror image of one another, one in the wake and one around the body of the copepod; this near symmetrical flow may provide hydrodynamic camouflage because it contains no information about the position of the copepod prey within the flow structure. The flow field associated with an escape jump sequence also includes two dominant vortex structures: one leading wake vortex generated as a result of the first jump and one around the body, but between these two vortex structures is an elongated, long-lasting flow trail with flow velocity vectors pointing towards the copepod; such a flow field may inform the predator of the whereabouts of the escaping copepod prey. High Froude propulsion efficiency (0.94-0.98) was obtained for individual power stroke durations of all simulated jumps. This is unusual for small aquatic organisms but is caused by the rapidity and impulsiveness of the jump that allows only a low-cost viscous wake vortex to travel backwards.

  12. Treatment of variable and intermittently flowing wastewaters.

    Science.gov (United States)

    Kocasoy, Günay

    1993-11-01

    The biological treatment of wastewaters originating from hotels and residential areas of seasonal use, flowing intermittently, is difficult due to the fact that bacteria cannot survive during periods of no-flow. An investigation has been conducted in order to develop a system which will be able to overcome the difficulties encountered. After a long investigation the following system has given satisfactory results. The wastewater was taken initially into an aeration tank operating as a sequential batch reactor. Waste was taken after the sedimentation phase of the reactor into a coagulation-flocculation tank where it was treated by chemical means, and then settled in order to separate the floes. When the population of bacteria in the aeration tank reached the required level, the physico-chemical treatment was terminated and the tank used for chemical treatment has been started to be used as an equalization tank while the aeration and sedimentation tanks have been used as an activated sludge unit. This system has been proved to be a satisfactory method for the above mentioned wastes.

  13. Highly efficient reversible addition-fragmentation chain-transfer polymerization in ethanol/water via flow chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Piaoran [Case Western Reserve Univ., Cleveland, OH (United States); Cao, Peng -Fei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Su, Zhe [Case Western Reserve Univ., Cleveland, OH (United States); Advincula, Rigoberto [Case Western Reserve Univ., Cleveland, OH (United States)

    2017-03-23

    Here, utilization of a flow reactor under high pressure allows highly efficient polymer synthesis via reversible addition–fragmentation chain-transfer (RAFT) polymerization in an aqueous system. Compared with the batch reaction, the flow reactor allows the RAFT polymerization to be performed in a high-efficiency manner at the same temperature. The adjustable pressure of the system allows further elevation of the reaction temperature and hence faster polymerization. Other reaction parameters, such as flow rate and initiator concentration, were also well studied to tune the monomer conversion and the molar mass dispersity (Ð) of the obtained polymers. Gel permeation chromatography, nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopies (FTIR) were utilized to monitor the polymerization process. With the initiator concentration of 0.15 mmol L–1, polymerization of poly(ethylene glycol) methyl ethermethacrylate with monomer conversion of 52% at 100 °C under 73 bar can be achieved within 40 min with narrow molar mass dispersity (D) Ð (<1.25). The strategy developed here provides a method to produce well-defined polymers via RAFT polymerization with high efficiency in a continuous manner.

  14. The treatment of pseudoaneurysms with flow diverters after malignant otitis externa.

    Science.gov (United States)

    Németh, Tamás; Szakács, László; Bella, Zsolt; Majoros, Valéria; Barzó, Pál; Vörös, Erika

    2017-12-01

    Background We report a case of bilateral malignant otitis externa complicated with bilateral petrous internal carotid artery pseudoaneurysms and their successful treatment with a flow diverter. Case report A 68-year-old woman with serious complications of type II diabetes mellitus had malignant otitis externa on the right side. She was treated with combined antibiotic therapy and underwent mastoidectomy for mastoiditis. She presented at our hospital with acute hemorrhage from the right external auditory canal. The emergency computed tomography (CT) angiography revealed a multiobulated pseudoaneurysm at the petrous segment of the right internal carotid artery. The pseudoaneurysm was treated with a 5 × 40-mm Surpass flow diverter. Three months later, she developed a malignant external otitis on the left side. As the infection progressed, a left-sided mastoiditis, a brain abscess, and a pseudoaneurysm at the petrous segment of the left internal carotid artery developed. The pseudoaneurysm caused bleeding from the left ear, and was treated with a 5 × 50-mm Surpass flow diverter. No recurrent bleeding was observed. Four months later, a follow-up angiography showed complete occlusion of the pseudoaneurysm on the left side, but a residual aneurysm could be detected on the right side. One year after the first intervention, the follow-up CT and magnetic resonance angiography revealed the complete occlusion of the aneurysms bilaterally. Conclusion The use of a flow diverter appears to be an efficient and safe method to occlude carotid pseudoaneurysms even in an inflammatory milieu.

  15. Study of High Efficiency Flow Regulation of VIGV in Centrifugal Compressor

    Directory of Open Access Journals (Sweden)

    Chunjun Ji

    2016-01-01

    Full Text Available Variable inlet guide vane (VIGV is used to control the mass flow and generate prewhirl in centrifugal compressors. Due to the tip clearance of the guide vanes and the defect of the traditional guide vane profiles, the mass flow regulation of VIGV is limited, resulting in a large waste of compressed gas. Two kinds of inlet flow channels were proposed to eliminate the influence of tip clearance. These structures were numerically investigated at different setting angles. The results show that the improved channels not only expand the range of mass flow regulation, but also reduce the power and increase the efficiency of the compressor. Ten kinds of guide vane profiles, including different thickness distribution, camber line profile, were selected to compare with the original one and with each other. In the premise of ensuring the performance of compressor, the best guide vane profile was selected. The results show that reducing the guide vane thickness, increasing the guide vane camber angle, and increasing the distance between the maximum camber position and the leading edge of guide vane can help expand the range of mass flow regulation. The achievement of this research can effectively improve the flow regulation ability of VIGV and the performance of compressor.

  16. Aeration tank settling and real time control as a tool to improve the hydraulic capacity and treatment efficiency during wet weather: Results from 7 years' full-scale operational data

    DEFF Research Database (Denmark)

    Sharma, Anitha Kumari; Guildal, T.; Thomsen, H.A.R.

    2013-01-01

    This paper investigates the aeration tank settling (ATS) operation in combination with real time control (RTC) as a tool for increasing the hydraulic capacity and improving the treatment efficiency of a wastewater treatment plant (WWTP) during wet weather flows. Results from 7 years' full...

  17. Speciation and fate of copper in sewage treatment works with and without tertiary treatment: the effect of return flows.

    Science.gov (United States)

    Innaa, D; Lester, J N; Scrimshawb, M D; Cartmell, E

    2014-01-01

    The removal of metals from wastewaters is becoming an important issue, with new environmental quality standards putting increased regulatory pressure on operators of sewage treatment works. The use of additional processes (tertiary treatment) following two-stage biological treatment is frequently seen as a way of improving effluent quality for nutrients and suspended solids, and this study investigates the impact of how back washes from these tertiary processes may impact the removal of copper during primary sedimentation. Seven sites were studied, three conventional two-stage biological treatment, and four with tertiary processes. It was apparent that fluxes of copper in traditional return flows made a significant contribution to the load to the primary treatment tanks, and that tanks. These return flows had an impact on copper removal in the primary tanks, probably due to their aerobic nature. Returning such aerobic back wash flows to the main process stream after primary treatment may therefore be worth consideration. The opportunity to treat consolidated liquor and sludge.flows in side-stream processes to remove toxic elements, as they are relatively concentrated, low volume flow streams, should also be evaluated.

  18. Removal of pharmaceuticals from wastewater by electrochemical oxidation using cylindrical flow reactor and optimization of treatment conditions.

    Science.gov (United States)

    Babu, B Ramesh; Venkatesan, P; Kanimozhi, R; Basha, C Ahmed

    2009-08-01

    This paper examines the use of electrooxidation for treatment of wastewater obtained from a pharmaceutical industry. The wastewater primarily contained Gentamicin and Dexamethasone. With NaCl as supporting electrolyte, the effluent was treated in a cylindrical flow reactor in continuous (single pass) mode under various current densities (2-5 A/dm2) and flow rates (10-40 L/h). By cyclic voltammetric (CV) analysis, the optimum condition for maximum redox reaction was determined. The efficiency of chemical oxygen demand (COD) reduction and power consumption were studied for different operating conditions. From the results it was observed that maximum COD reduction of about 85.56% was obtained at a flow rate of 10 L/h with an applied current density of 4 A/dm2. FT-IR spectra studies showed that during electrooxidation, the intensities of characteristic functional groups such as N-H, O-H were reduced and some new peaks also started to appear. Probable theory, reaction mechanism and modeling were proposed for the oxidation of pharmaceutical effluent. The experimental results demonstrated that electrooxidation treatment was very effective and capable of elevating the quality of treated wastewater to the reuse standard prescribed for pharmaceutical industries.

  19. Raise of efficiency of flocculation-precipitation treatment of exuding water from reclaimed land by irradiation

    International Nuclear Information System (INIS)

    Sawai, Teruko; Yamazaki, Masao; Sawai, Takeshi

    1984-01-01

    When rain falls on the coastal reclaimed land filled with home garbage in Tokyo, a large quantity of water containing much organic contaminant flows out. It is difficult to treat this water exuding from reclaimed land by conventional method. Because the water with low BOD which is difficult to treat by biological process flows out for long period after the stabilization of reclaimed land. When the water is treated by flocculation and precipitation, the substances with high molecular weight are easily removed, but the rate of removal of fulvic acid with low molecular weight, which accounts for more than 60% of the composition of the water, is very poor. Therefore, it was examined to change the fulvic acid to high molecular weight by irradiation, and to improve the efficiency of the flocculation-precipitation treatment of exuding water. Exuding water was sampled in Tokyo Bay No.15 reclaimed land, and it was separated into humic acid and fulvic acid. The Co-60 gamma ray of 5 kCi was irradiated to the samples. The experimental method and the results are reported. The change of fulvic acid to high molecular weight by irradiation was most efficient at pH 2.2. More than 90% of organic contaminants was able to be removed. (Kako, I.)

  20. Energy efficiency analyses of active flow aftertreatment systems for lean burn internal combustion engines

    International Nuclear Information System (INIS)

    Zheng Ming; Reader, Graham T.

    2004-01-01

    The use of three way catalytic converters in stoichiometric burn reciprocating internal combustion engine systems has proved to be an effective and efficient method for reducing the level of criteria pollutants. However, such passive systems have not been as successful in emission amelioration when combined with lean burn engines. This is because of the thermochemical nature of the exhaust gases generated by such engines. The high content of exhaust oxygen largely negates the effectiveness of three way catalytic converters, and the comparatively low temperature of the combusted gases means that supplemental energy has to be added to these gases to enable the converter to function correctly. This requirement severely reduces the energy efficiency of conventional passive aftertreatment systems. However, initial empirical studies have indicated that a possible means of improving the performance of aftertreatment devices when used with lean burn engine systems is to use active flow control of the exhaust gases. These results are reported in this paper. This concept has been further investigated by developing an energy efficiency analysis that enables the effects on aftertreatment performance of different gas flow rates, flow reversal frequencies and monolith solid properties to be investigated. Simulation results indicate that through active thermal management, the supplemental energy consumption can be drastically reduced

  1. Improving the efficiency of plasma heat treatment of metals

    International Nuclear Information System (INIS)

    Gabdrakhmanov, Az T; Israphilov, I H; Galiakbarov, A T; Samigullin, A D; Gabdrakhmanov, Al T

    2016-01-01

    This paper proposes an effective way of the plasma hardening the surface layer at the expense combined influence of the plasma jet and a cold air flow. After that influence occurs a distinctive by plasma treatment microstructure with increased microhardness (an increase of 35%) and depth. There is proposed an improved design of the vortex tube for receiving the air flow with a temperature of 20 C to - 120C. (paper)

  2. Comparison of cutting efficiency with different diamond burs and water flow rates in cutting lithium disilicate glass ceramic.

    Science.gov (United States)

    Siegel, Sharon C; Patel, Tejas

    2016-10-01

    This study compared different diamond burs and different water flow rates on the cutting efficiency of sectioning through lithium disilicate glass ceramic. The authors used a standardized cutting regimen with 4 brands of diamond burs to section through lithium disilicate glass ceramic blocks. Twelve diamonds of each brand cut through the blocks in randomized order. In the first part of the study, the authors recorded sectioning rates in millimeters per minute for each diamond bur as a measure of cutting efficiency. In the second part of the study, the authors compared sectioning rates using only 1 brand of diamond bur, with 3 different water flow rates. The authors averaged and compared cutting rates of each brand of diamond bur and the cutting rates for each flow rate using an analysis of variance and determined the differences with a Tukey honest significant difference test. One diamond bur cut significantly slower than the other 3, and one diamond bur cut significantly faster than 2 of the others. The diamond bur cutting efficiency through lithium disilicate glass ceramic with a 20 mL/min water flow rate was significantly higher than 15 mL/min. There are differences in cutting efficiency between diamond burs when sectioning lithium disilicate glass ceramic. Use a minimum of 20 mL/min of water coolant flow when sectioning lithium disilicate glass ceramic with dental diamond burs to maximize cutting efficiency. Recommendations for specific diamond burs with a coarse grit and water flow rate of 20 mL/min can be made when removing or adjusting restorations made from lithium disilicate glass ceramic. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  3. Technology’s present situation and the development prospects of energy efficiency monitoring as well as performance testing & analysis for process flow compressors

    Science.gov (United States)

    Li, L.; Zhao, Y.; Wang, L.; Yang, Q.; Liu, G.; Tang, B.; Xiao, J.

    2017-08-01

    In this paper, the background of performance testing of in-service process flow compressors set in user field are introduced, the main technique barriers faced in the field test are summarized, and the factors that result in real efficiencies of most process flow compressors being lower than the guaranteed by manufacturer are analysed. The authors investigated the present operational situation of process flow compressors in China and found that low efficiency operation of flow compressors is because the compressed gas is generally forced to flow back into the inlet pipe for adapting to the process parameters variety. For example, the anti-surge valve is always opened for centrifugal compressor. To improve the operation efficiency of process compressors the energy efficiency monitoring technology was overviewed and some suggestions are proposed in the paper, which is the basis of research on energy efficiency evaluation and/or labelling of process compressors.

  4. Geostatistical Sampling Methods for Efficient Uncertainty Analysis in Flow and Transport Problems

    Science.gov (United States)

    Liodakis, Stylianos; Kyriakidis, Phaedon; Gaganis, Petros

    2015-04-01

    In hydrogeological applications involving flow and transport of in heterogeneous porous media the spatial distribution of hydraulic conductivity is often parameterized in terms of a lognormal random field based on a histogram and variogram model inferred from data and/or synthesized from relevant knowledge. Realizations of simulated conductivity fields are then generated using geostatistical simulation involving simple random (SR) sampling and are subsequently used as inputs to physically-based simulators of flow and transport in a Monte Carlo framework for evaluating the uncertainty in the spatial distribution of solute concentration due to the uncertainty in the spatial distribution of hydraulic con- ductivity [1]. Realistic uncertainty analysis, however, calls for a large number of simulated concentration fields; hence, can become expensive in terms of both time and computer re- sources. A more efficient alternative to SR sampling is Latin hypercube (LH) sampling, a special case of stratified random sampling, which yields a more representative distribution of simulated attribute values with fewer realizations [2]. Here, term representative implies realizations spanning efficiently the range of possible conductivity values corresponding to the lognormal random field. In this work we investigate the efficiency of alternative methods to classical LH sampling within the context of simulation of flow and transport in a heterogeneous porous medium. More precisely, we consider the stratified likelihood (SL) sampling method of [3], in which attribute realizations are generated using the polar simulation method by exploring the geometrical properties of the multivariate Gaussian distribution function. In addition, we propose a more efficient version of the above method, here termed minimum energy (ME) sampling, whereby a set of N representative conductivity realizations at M locations is constructed by: (i) generating a representative set of N points distributed on the

  5. Bedrock refractive-flow cells: A passive treatment analog to funnel-and-gate

    International Nuclear Information System (INIS)

    Dick, V.; Edwards, D.

    1997-01-01

    Funnel-and-gate technology provides a mechanism to passively treat groundwater contaminant plumes, but depends on placement of a sufficient barrier (open-quotes funnelclose quotes) in the plume flow path to channel the plume to a pass-through treatment zone (open-quotes gateclose quotes). Conventional barrier technologies limit funnel-and-gate deployment to unconsolidated overburden applications. A method has been developed which allows similar passive treatment to be applied to bedrock plumes. Rather than use barriers as the funnel, the method uses engineered bedrock zones, installed via precision blasting or other means, to refract groundwater flow along a preferred path to treatment (gate). The method requires orienting the refractive cell based on the Tangent Law and extending refractive cell limbs down gradient of the gate to disperse head and control flow. A typical Refractive-Flow cell may be open-quotes Yclose quotesshaped, with each limb 3-10 ft [1-3 m] wide and several tens to a few hundred feet [10 - 100 m] in length. Treatment takes place at the center of the X. MODFLOW modeling has been used to successfully simulate desired flow. Engineered blasting has been used at full scale application to create bedrock rubble zones for active collection/flow control for several years. The method provides a previously unavailable method to passively treat contaminated groundwater in bedrock at low cost

  6. RETROFITTING CONTROL FACILITIES FOR WET-WEATHER FLOW TREATMENT

    Science.gov (United States)

    Available technologies were evaluated to demonstrate the technical feasibility and cost effectiveness of retrofitting existing facilities to handle wet-weather flow. Cost/benefit relationships were also compared to construction of new conventional control and treatment facilities...

  7. Balancing efficiency, equity and feasibility of HIV treatment in South Africa

    DEFF Research Database (Denmark)

    Baltussen, Rob; Mikkelsen, Evelinn; Tromp, Noor

    2013-01-01

    , and multi-criteria decision analysis (MCDA) to construct an evidence-base on the feasibility, efficiency, and equity of programme options including trade-offs. The approach provides programmatic guidance on the choice of treatment strategies at various decisions levels based on a sound conceptual framework......, it is now facing major concerns regarding (i) efficiency: alternative treatment policies may save more lives for the same budget; (ii) equity: there are large inequalities in who receives treatment; (iii) feasibility: still only 52% of the eligible population receives treatment.Hence, decisions...

  8. DETERMINATION OF ACTIVATED SLUDGE MODEL ASDM PARAMETERS FOR WASTE WATER TREATMENT PLANT OPERATING IN THE SEQUENTIAL–FLOW TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik

    2015-01-01

    Full Text Available This paper presents a method for calibration of activated sludge model with the use of computer program BioWin. Computer scheme has been developed on the basis of waste water treatment plant operating in the sequential – flow technology. For calibration of the activated sludge model data of influent and treated effluent from the existing object were used. As a result of conducted analysis was a change in biokinetic model and kinetic parameters parameters of wastewater treatment facilities. The presented method of study of the selected parameters impact on the activated sludge biokinetic model (including autotrophs maximum growth rate, the share of organic slurry in suspension general operational, efficiency secondary settling tanks can be used for conducting simulation studies of other treatment plants.

  9. An efficient multi-dimensional implementation of VSIAM3 and its applications to free surface flows

    Science.gov (United States)

    Yokoi, Kensuke; Furuichi, Mikito; Sakai, Mikio

    2017-12-01

    We propose an efficient multidimensional implementation of VSIAM3 (volume/surface integrated average-based multi-moment method). Although VSIAM3 is a highly capable fluid solver based on a multi-moment concept and has been used for a wide variety of fluid problems, VSIAM3 could not simulate some simple benchmark problems well (for instance, lid-driven cavity flows) due to relatively high numerical viscosity. In this paper, we resolve the issue by using the efficient multidimensional approach. The proposed VSIAM3 is shown to capture lid-driven cavity flows of the Reynolds number up to Re = 7500 with a Cartesian grid of 128 × 128, which was not capable for the original VSIAM3. We also tested the proposed framework in free surface flow problems (droplet collision and separation of We = 40 and droplet splashing on a superhydrophobic substrate). The numerical results by the proposed VSIAM3 showed reasonable agreements with these experiments. The proposed VSIAM3 could capture droplet collision and separation of We = 40 with a low numerical resolution (8 meshes for the initial diameter of droplets). We also simulated free surface flows including particles toward non-Newtonian flow applications. These numerical results have showed that the proposed VSIAM3 can robustly simulate interactions among air, particles (solid), and liquid.

  10. Towards multi-phase flow simulations in the PDE framework Peano

    KAUST Repository

    Bungartz, Hans-Joachim; Gatzhammer, Bernhard; Lieb, Michael; Mehl, Miriam; Neckel, Tobias

    2011-01-01

    for the efficient treatment of complex and changing geometries, an essential ingredient for most application scenarios. The new application functionality concerns a coupled heat-flow problem and two-phase flows. We present numerical examples, performance

  11. Interstitial fluid flow in cancer: implications for disease progression and treatment

    International Nuclear Information System (INIS)

    Munson, Jennifer M; Shieh, Adrian C

    2014-01-01

    As cancer progresses, a dynamic microenvironment develops that creates and responds to cellular and biophysical cues. Increased intratumoral pressure and corresponding increases in interstitial flow from the tumor bulk to the healthy stroma is an observational hallmark of progressing cancers. Until recently, the role of interstitial flow was thought to be mostly passive in the transport and dissemination of cancer cells to metastatic sites. With research spanning the past decade, we have seen that interstitial flow has a promigratory effect on cancer cell invasion in multiple cancer types. This invasion is one mechanism by which cancers can resist therapeutics and recur, but the role of interstitial flow in cancer therapy is limited to the understanding of transport of therapeutics. Here we outline the current understanding of the role of interstitial flow in cancer and the tumor microenvironment through cancer progression and therapy. We also discuss the current role of fluid flow in the treatment of cancer, including drug transport and therapeutic strategies. By stating the current understanding of interstitial flow in cancer progression, we can begin exploring its role in therapeutic failure and treatment resistance

  12. Numerically Simulated Impact of Gas Prandtl Number and Flow Model on Efficiency of the Machine-less Energetic Separation Device

    Directory of Open Access Journals (Sweden)

    K. S. Egorov

    2015-01-01

    Full Text Available The presented paper regards the influence of one of similarity criteria – the Prandtl number of gas (Pr - on the efficiency of the machine-less energetic separation device (Leontiev pipe, using numerical modeling in ANSYS software. This device, equally as Rank-Hilsch and Hartman-Schprenger pipes, is designed to separate one gas flow into two flows with different temperatures. One flow (supersonic streams out of the pipe with a temperature higher than initial and the other (subsonic flows out with a temperature lower than initial. This direction of energetic separation is true if the Prandtl number is less than 1 that corresponds to gases.The Prandtl number affects the efficiency of running Leontiev pipe indirectly both through a temperature difference on which a temperature recovery factor has an impact and through a thermal conductivity coefficient that shows the impact of heat transfer intensity between gas and solid wall.The Prandtl number range in the course of research was from 0.1 to 0.7. The Prandtl number value equal to 0.7 corresponds to the air or pure gases (for example, inert argon gas. The Prandtl number equal to 0.2 corresponds to the mixtures of inert gases such as helium-xenon.The numerical modeling completed for the supersonic flow with Mach number 2.0 shows that efficiency of the machine-less energetic separation device has been increased approximately 2 times with the Prandtl number decreasing from 0.7 to 0.2. Moreover, for the counter-flow scheme this effect is a little higher due to its larger heat efficiency in comparison with the straight-flow one.Also, the research shows that the main problem for the further increase of the Leontiev pipe efficiency is a small value of thermal conductivity coefficient, which requires an intensification of the heat exchange, especially in the supersonic flow. It can be obtained, for example, by using a system of oblique shock waves in the supersonic channel.

  13. Development of an Efficient Meso- scale Multi-phase Flow Solver in Nuclear Applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taehun [City Univ. (CUNY), NY (United States)

    2015-10-20

    The proposed research aims at formulating a predictive high-order Lattice Boltzmann Equation for multi-phase flows relevant to nuclear energy related application - namely, saturated and sub-cooled boiling in reactors, and liquid- liquid mixing and extraction for fuel cycle separation. An efficient flow solver will be developed based on the Finite Element based Lattice Boltzmann Method (FE- LBM), accounting for phase-change heat transfer and capable of treating multiple phases over length scales from the submicron to the meter. A thermal LBM will be developed in order to handle adjustable Prandtl number, arbitrary specific heat ratio, a wide range of temperature variations, better numerical stability during liquid-vapor phase change, and full thermo-hydrodynamic consistency. Two-phase FE-LBM will be extended to liquid–liquid–gas multi-phase flows for application to high-fidelity simulations building up from the meso-scale up to the equipment sub-component scale. While several relevant applications exist, the initial applications for demonstration of the efficient methods to be developed as part of this project include numerical investigations of Critical Heat Flux (CHF) phenomena in nuclear reactor fuel bundles, and liquid-liquid mixing and interfacial area generation for liquid-liquid separations. In addition, targeted experiments will be conducted for validation of this advanced multi-phase model.

  14. Treatment of fishpond water by recirculating horizontal and vertical flow constructed wetlands in the tropics

    DEFF Research Database (Denmark)

    Konnerup, Dennis; Trang, Ngo Thuy Diem; Brix, Hans

    2011-01-01

    quantities of phytoplankton algae were removed in the CWs but abundance of toxic algae such as Microcystis was low. It is concluded that particularly vertical flow CWs have great potential for treatment of fishpond water in recirculating aquaculture systems in the tropics as the discharge of polluted water......Common practice of aquaculture in Vietnam and other countries in South East Asia involves frequent discharge of polluted water into rivers which results in eutrophication and degradation of receiving water bodies. There is therefore a need to develop improved aquaculture systems which have a more...... efficient use of water and less environmental impact. The aim of this study was to assess the suitability of using constructed wetlands (CWs) for the treatment of fishpond water in a recirculating aquaculture system in the Mekong Delta of Vietnam. Water from a fishpond stocked with Nile tilapia (Oreochromis...

  15. METHODOLOGICAL APPROACHES TO THE ANALYSIS OF EFFICIENCY OF CASH FLOW MANAGEMENT IN INVESTMENT ACTIVITY OF THE ENTERPRISES

    OpenAIRE

    I. Magdych

    2015-01-01

    The article explores the methodological approaches to the analysis of cash flows in investment activity of the enterprise; the system of motion net cash flows, reflecting the impact of cash management efficiency on the amount and source of investment cash flows of the enterprise; analytical model of definition of effectiveness of cash management of the enterprise is proposed, based on the selected principals of modeling, comprehensive analysis of cash flows in investing activities and their o...

  16. Is treatment with liraglutide efficient?

    Science.gov (United States)

    Mezquita Raya, Pedro; Reyes García, Rebeca

    2014-04-01

    In the current context of limited economic and health resources, efficiency of drug treatments is of paramount importance, and their clinical effects and related direct costs should therefore be analyzed. Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist approved for the treatment of type 2 diabetes mellitus (T2DM) which, in addition to its normoglycemic effects, induces a significant improvement in body weight and several cardiovascular risk factors. The aim of this narrative review is to summarize the available evidence about the effects of liraglutide upon cardiovascular risk factors and how these improve its cost-effectiveness profile. Despite the relatively higher cost of liraglutide as compared to other alternative therapies, liraglutide has been shown to be cost-effective when clinical indicators and total costs associated to T2DM management are analyzed. Copyright © 2013 SEEN. Published by Elsevier Espana. All rights reserved.

  17. Efficient Hardware Implementation of the Horn-Schunck Algorithm for High-Resolution Real-Time Dense Optical Flow Sensor

    Science.gov (United States)

    Komorkiewicz, Mateusz; Kryjak, Tomasz; Gorgon, Marek

    2014-01-01

    This article presents an efficient hardware implementation of the Horn-Schunck algorithm that can be used in an embedded optical flow sensor. An architecture is proposed, that realises the iterative Horn-Schunck algorithm in a pipelined manner. This modification allows to achieve data throughput of 175 MPixels/s and makes processing of Full HD video stream (1, 920 × 1, 080 @ 60 fps) possible. The structure of the optical flow module as well as pre- and post-filtering blocks and a flow reliability computation unit is described in details. Three versions of optical flow modules, with different numerical precision, working frequency and obtained results accuracy are proposed. The errors caused by switching from floating- to fixed-point computations are also evaluated. The described architecture was tested on popular sequences from an optical flow dataset of the Middlebury University. It achieves state-of-the-art results among hardware implementations of single scale methods. The designed fixed-point architecture achieves performance of 418 GOPS with power efficiency of 34 GOPS/W. The proposed floating-point module achieves 103 GFLOPS, with power efficiency of 24 GFLOPS/W. Moreover, a 100 times speedup compared to a modern CPU with SIMD support is reported. A complete, working vision system realized on Xilinx VC707 evaluation board is also presented. It is able to compute optical flow for Full HD video stream received from an HDMI camera in real-time. The obtained results prove that FPGA devices are an ideal platform for embedded vision systems. PMID:24526303

  18. Flow Structures and Efficiency of Swimming Fish school: Numerical Study

    Science.gov (United States)

    Yatagai, Yuzuru; Hattori, Yuji

    2013-11-01

    The flow structure and energy-saving mechanism in fish school is numerically investigated by using the volume penalization method. We calculate the various patterns of configuration of fishes and investigate the relation between spatial arrangement and the performance of fish. It is found that the down-stream fish gains a hydrodynamic advantage from the upstream wake shed by the upstream fish. The most efficient configuration is that the downstream fish is placed in the wake. It reduces the drag force of the downstream fish in comparison with that in solo swimming.

  19. A highly efficient sharp-interface immersed boundary method with adaptive mesh refinement for bio-inspired flow simulations

    Science.gov (United States)

    Deng, Xiaolong; Dong, Haibo

    2017-11-01

    Developing a high-fidelity, high-efficiency numerical method for bio-inspired flow problems with flow-structure interaction is important for understanding related physics and developing many bio-inspired technologies. To simulate a fast-swimming big fish with multiple finlets or fish schooling, we need fine grids and/or a big computational domain, which are big challenges for 3-D simulations. In current work, based on the 3-D finite-difference sharp-interface immersed boundary method for incompressible flows (Mittal et al., JCP 2008), we developed an octree-like Adaptive Mesh Refinement (AMR) technique to enhance the computational ability and increase the computational efficiency. The AMR is coupled with a multigrid acceleration technique and a MPI +OpenMP hybrid parallelization. In this work, different AMR layers are treated separately and the synchronization is performed in the buffer regions and iterations are performed for the convergence of solution. Each big region is calculated by a MPI process which then uses multiple OpenMP threads for further acceleration, so that the communication cost is reduced. With these acceleration techniques, various canonical and bio-inspired flow problems with complex boundaries can be simulated accurately and efficiently. This work is supported by the MURI Grant Number N00014-14-1-0533 and NSF Grant CBET-1605434.

  20. Sulfur flows and biosolids processing: Using Material Flux Analysis (MFA) principles at wastewater treatment plants.

    Science.gov (United States)

    Fisher, R M; Alvarez-Gaitan, J P; Stuetz, R M; Moore, S J

    2017-08-01

    High flows of sulfur through wastewater treatment plants (WWTPs) may cause noxious gaseous emissions, corrosion of infrastructure, inhibit wastewater microbial communities, or contribute to acid rain if the biosolids or biogas is combusted. Yet, sulfur is an important agricultural nutrient and the direct application of biosolids to soils enables its beneficial re-use. Flows of sulfur throughout the biosolids processing of six WWTPs were investigated to identify how they were affected by biosolids processing configurations. The process of tracking sulfur flows through the sites also identified limitations in data availability and quality, highlighting future requirements for tracking substance flows. One site was investigated in more detail showing sulfur speciation throughout the plant and tracking sulfur flows in odour control systems in order to quantify outflows to air, land and ocean sinks. While the majority of sulfur from WWTPs is removed as sulfate in the secondary effluent, the sulfur content of biosolids is valuable as it can be directly returned to soils to combat the potential sulfur deficiencies. Biosolids processing configurations, which focus on maximising solids recovery, through high efficiency separation techniques in primary sedimentation tanks, thickeners and dewatering centrifuges retain more sulfur in the biosolids. However, variations in sulfur loads and concentrations entering the WWTPs affect sulfur recovery in the biosolids, suggesting industrial emitters, and chemical dosing of iron salts are responsible for differences in recovery between sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Performance of a vanadium redox flow battery with and without flow fields

    International Nuclear Information System (INIS)

    Xu, Q.; Zhao, T.S.; Zhang, C.

    2014-01-01

    Highlights: • The performances of a VRFB with/without flow fields are compared. • The respective maximum power efficiency occurs at different flow rates. • The battery with flow fields Exhibits 5% higher energy efficiency. - Abstract: A flow field is an indispensable component for fuel cells to macroscopically distribute reactants onto electrodes. However, it is still unknown whether flow fields are also required in all-vanadium redox flow batteries (VRFBs). In this work, the performance of a VRFB with flow fields is analyzed and compared with the performance of a VRFB without flow fields. It is demonstrated that the battery with flow fields has a higher discharge voltage at higher flow rates, but exhibits a larger pressure drop. The maximum power-based efficiency occurs at different flow rates for the both batteries with and without flow fields. It is found that the battery with flow fields Exhibits 5% higher energy efficiency than the battery without flow fields, when operating at the flow rates corresponding to each battery's maximum power-based efficiency. Therefore, the inclusion of flow fields in VRFBs can be an effective approach for improving system efficiency

  2. Antibody-modified iron oxide nanoparticles for efficient magnetic isolation and flow cytometric determination of L. pneumophila

    International Nuclear Information System (INIS)

    Bloemen, Maarten; Verbiest, Thierry; Denis, Carla; Meester, Luc De; Peeters, Miet; Gils, Ann; Geukens, Nick

    2015-01-01

    We report on the design of superparamagnetic nanoparticles capable of selectively isolating targeted bacteria (Legionella pneumophila, serogroup 1) from aqueous solutions. The surface of magnetite nanoparticles (NP) was functionalized with a heterobifunctional poly(ethylene glycol) ligand containing reactive groups for covalent coupling of polyclonal antibodies against L. pneumophila. These bioconjugates were used to label and magnetically isolate L. pneumophila. Flow cytometry revealed high separation and efficiency in this regard. The strain specificity and efficiency of the magnetic NP was tested with recombinant strains of E. coli (expressing the red fluorescent protein) and L. pneumophila (expressing the green fluorescent protein). The detection limit of the method (by flow cytometry) is 10 4 cells∙mL -1 . The results indicate that the new multifunctional NPs are capable of selectively attracting pathogens from a complex mixture and with high efficiency. This, conceivably, paves the way to pre-concentration protocols for numerous other pathogens. (author)

  3. Comparison of simple, small, full-scale sewage treatment systems in Brazil: UASB-maturation ponds-coarse filter; UASB-horizontal subsurface-flow wetland; vertical-flow wetland (first stage of French system).

    Science.gov (United States)

    von Sperling, M

    2015-01-01

    This paper presents a comparison between three simple sewage treatment lines involving natural processes: (a) upflow anaerobic sludge blanket (UASB) reactor-three maturation ponds in series-coarse rock filter; (b) UASB reactor-horizontal subsurface-flow constructed wetland; and (c) vertical-flow constructed wetlands treating raw sewage (first stage of the French system). The evaluation was based on several years of practical experience with three small full-scale plants receiving the same influent wastewater (population equivalents of 220, 60 and 100 inhabitants) in the city of Belo Horizonte, Brazil. The comparison included interpretation of concentrations and removal efficiencies based on monitoring data (organic matter, solids, nitrogen, phosphorus, coliforms and helminth eggs), together with an evaluation of practical aspects, such as land and volume requirements, sludge production and handling, plant management, clogging and others. Based on an integrated evaluation of all aspects involved, it is worth emphasizing that each system has its own specificities, and no generalization can be made on the best option. The overall conclusion is that the three lines are suitable for sewage treatment in small communities in warm-climate regions.

  4. Energy Efficiency Strategies for Municipal Wastewater Treatment Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Daw, J.; Hallett, K.; DeWolfe, J.; Venner, I.

    2012-01-01

    Water and wastewater systems are significant energy consumers with an estimated 3%-4% of total U.S. electricity consumption used for the movement and treatment of water and wastewater. Water-energy issues are of growing importance in the context of water shortages, higher energy and material costs, and a changing climate. In this economic environment, it is in the best interest for utilities to find efficiencies, both in water and energy use. Performing energy audits at water and wastewater treatment facilities is one way community energy managers can identify opportunities to save money, energy, and water. In this paper the importance of energy use in wastewater facilities is illustrated by a case study of a process energy audit performed for Crested Butte, Colorado's wastewater treatment plant. The energy audit identified opportunities for significant energy savings by looking at power intensive unit processes such as influent pumping, aeration, ultraviolet disinfection, and solids handling. This case study presents best practices that can be readily adopted by facility managers in their pursuit of energy and financial savings in water and wastewater treatment. This paper is intended to improve community energy managers understanding of the role that the water and wastewater sector plays in a community's total energy consumption. The energy efficiency strategies described provide information on energy savings opportunities, which can be used as a basis for discussing energy management goals with water and wastewater treatment facility managers.

  5. An efficient direct solver for rarefied gas flows with arbitrary statistics

    International Nuclear Information System (INIS)

    Diaz, Manuel A.; Yang, Jaw-Yen

    2016-01-01

    A new numerical methodology associated with a unified treatment is presented to solve the Boltzmann–BGK equation of gas dynamics for the classical and quantum gases described by the Bose–Einstein and Fermi–Dirac statistics. Utilizing a class of globally-stiffly-accurate implicit–explicit Runge–Kutta scheme for the temporal evolution, associated with the discrete ordinate method for the quadratures in the momentum space and the weighted essentially non-oscillatory method for the spatial discretization, the proposed scheme is asymptotic-preserving and imposes no non-linear solver or requires the knowledge of fugacity and temperature to capture the flow structures in the hydrodynamic (Euler) limit. The proposed treatment overcomes the limitations found in the work by Yang and Muljadi (2011) [33] due to the non-linear nature of quantum relations, and can be applied in studying the dynamics of a gas with internal degrees of freedom with correct values of the ratio of specific heat for the flow regimes for all Knudsen numbers and energy wave lengths. The present methodology is numerically validated with the unified treatment by the one-dimensional shock tube problem and the two-dimensional Riemann problems for gases of arbitrary statistics. Descriptions of ideal quantum gases including rotational degrees of freedom have been successfully achieved under the proposed methodology.

  6. Performance Improvement Of Cross-Flow Filtration For High Level Waste Treatment

    International Nuclear Information System (INIS)

    Duignan, M.; Nash, C.; Poirier, M.

    2011-01-01

    In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

  7. PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M.; Nash, C.; Poirier, M.

    2011-01-12

    In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

  8. A new treatment of capillarity to improve the stability of IMPES two-phase flow formulation

    KAUST Repository

    Kou, Jisheng

    2010-12-01

    In this paper, we present an efficient numerical method for two-phase immiscible flow in porous media with different capillarity pressures. In highly heterogeneous permeable media, the saturation is discontinuous due to different capillary pressure functions. One popular scheme is to split the system into a pressure and a saturation equation, and to apply IMplicit Pressure Explicit Saturation (IMPES) approach for time stepping. One disadvantage of IMPES is instability resulting from the explicit treatment for capillary pressure. To improve stability, the capillary pressure is usually incorporated in the saturation equation which gradients of saturation appear. This approach, however, does not apply to the case of different capillary pressure functions for multiple rock-types, because of the discontinuity of saturation across rock interfaces. In this paper, we present a new treatment of capillary pressure, which appears implicitly in the pressure equation. Using an approximation of capillary function, we substitute the implicit saturation equation into the pressure equation. The coupled pressure equation will be solved implicitly and followed by the explicit saturation equation. Five numerical examples are provided to demonstrate the advantages of our approach. Comparison shows that our proposed method is more efficient and stable than the classical IMPES approach. © 2010 Elsevier Ltd.

  9. Treatment of landfill leachate using an aerated, horizontal subsurface-flow constructed wetland.

    Science.gov (United States)

    Nivala, J; Hoos, M B; Cross, C; Wallace, S; Parkin, G

    2007-07-15

    A pilot-scale subsurface-flow constructed wetland was installed at the Jones County Municipal Landfill, near Anamosa, Iowa, in August 1999 to demonstrate the use of constructed wetlands as a viable low-cost treatment option for leachate generated at small landfills. The system was equipped with a patented wetland aeration process to aid in removal of organic matter and ammonia nitrogen. The high iron content of the leachate caused the aeration system to cease 2 years into operation. Upon the installation of a pretreatment chamber for iron removal and a new aeration system, treatment efficiencies dramatically improved. Seasonal performance with and without aeration is reported for 5-day biochemical oxygen demand (BOD(5)), chemical oxygen demand (COD), ammonia nitrogen (NH(4)-N), and nitrate nitrogen (NO(3)-N). Since winter air temperatures in Iowa can be very cold, a layer of mulch insulation was installed on top of the wetland bed to keep the system from freezing. When the insulation layer was properly maintained (either through sufficient litterfall or replenishing the mulch layer), the wetland sustained air temperatures of as low as -26 degrees C without freezing problems.

  10. Effect of physico-chemical pretreatment on the removal efficiency of horizontal subsurface-flow constructed wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Caselles-Osorio, Aracelly [Environmental Engineering Division, Hydraulics, Coastal and Environmental Engineering Department, Technical University of Catalonia, c/Jordi Girona 1-3, Modul D-1, 08034 Barcelona (Spain); Department of Biology, Atlantic University, Km 7 Higway Old Colombia Port, Barranquilla (Colombia); Garcia, Joan [Environmental Engineering Division, Hydraulics, Coastal and Environmental Engineering Department, Technical University of Catalonia, c/Jordi Girona 1-3, Modul D-1, 08034 Barcelona (Spain)]. E-mail: joan.garcia@upc.edu

    2007-03-15

    In this study, we tested the effect of a physico-chemical pretreatment on contaminant removal efficiency in two experimental horizontal subsurface-flow constructed wetlands (SSF CWs). One SSF CW was fed with settled urban wastewater, whereas the other with the same wastewater after it had undergone a physico-chemical pretreatment. The SSF CWs were operated with three different hydraulic retention times. During the experiments the effluent concentrations of COD, ammonia N and sulfate were very similar, and, therefore, the physico-chemical pretreatment did not improve the quality of the effluents. COD removal efficiency (as percentage or mass surface removal rate) was slightly greater in the SSF CW fed with pretreated wastewater. Ammonia N removal efficiency was, in general, similar in both SSF CWs and very high (80-90%). At the end of the experiments it was observed that in the SSF CW fed with settled wastewater the hydraulic conductivity decreased by a 20%. - A physico-chemical pretreatment may help to reduce the risk of clogging of subsurface-flow constructed wetlands.

  11. Effect of physico-chemical pretreatment on the removal efficiency of horizontal subsurface-flow constructed wetlands

    International Nuclear Information System (INIS)

    Caselles-Osorio, Aracelly; Garcia, Joan

    2007-01-01

    In this study, we tested the effect of a physico-chemical pretreatment on contaminant removal efficiency in two experimental horizontal subsurface-flow constructed wetlands (SSF CWs). One SSF CW was fed with settled urban wastewater, whereas the other with the same wastewater after it had undergone a physico-chemical pretreatment. The SSF CWs were operated with three different hydraulic retention times. During the experiments the effluent concentrations of COD, ammonia N and sulfate were very similar, and, therefore, the physico-chemical pretreatment did not improve the quality of the effluents. COD removal efficiency (as percentage or mass surface removal rate) was slightly greater in the SSF CW fed with pretreated wastewater. Ammonia N removal efficiency was, in general, similar in both SSF CWs and very high (80-90%). At the end of the experiments it was observed that in the SSF CW fed with settled wastewater the hydraulic conductivity decreased by a 20%. - A physico-chemical pretreatment may help to reduce the risk of clogging of subsurface-flow constructed wetlands

  12. Comparison of extracapillary and endocapillary blood flow oxygenators for open heart surgery in dogs: efficiency of gas exchange and platelet conservation.

    Science.gov (United States)

    Hoshi, Katsuichiro; Tanaka, Ryou; Shibazaki, Akira; Nagashima, Yukiko; Hirao, Hidehiro; Namiki, Ryosuke; Takashima, Kazuaki; Noishiki, Yasuharu; Yamane, Yoshihisa

    2003-03-01

    The goal of the current study was to compare the efficiency of gas exchange and platelet conservation of a new extracapillary blood flow oxygenator versus an endocapillary blood flow oxygenator during open heart surgery with extracorporeal circulation in dogs. Dilation and remodeling of the right ventricular outflow tract of dogs was performed using a patch graft technique to simulate pulmonary stenosis. Sequential pre- and post-operative blood analysis revealed that gas exchange efficiency and platelet conservation was significantly greater with the extracapillary blood flow oxygenator than with the endocapillary blood flow oxygenator. However, the priming volume of the extracapillary blood flow oxygenator was significantly greater, leading to hemodilution. We conclude that while the extracapillary blood flow oxygenator provided benefits in terms of gas exchange and platelet conservation, development of a smaller extracapillary blood flow type oxygenator to reduce hemodilution effects would be beneficial.

  13. Efficient Parallel Algorithm For Direct Numerical Simulation of Turbulent Flows

    Science.gov (United States)

    Moitra, Stuti; Gatski, Thomas B.

    1997-01-01

    A distributed algorithm for a high-order-accurate finite-difference approach to the direct numerical simulation (DNS) of transition and turbulence in compressible flows is described. This work has two major objectives. The first objective is to demonstrate that parallel and distributed-memory machines can be successfully and efficiently used to solve computationally intensive and input/output intensive algorithms of the DNS class. The second objective is to show that the computational complexity involved in solving the tridiagonal systems inherent in the DNS algorithm can be reduced by algorithm innovations that obviate the need to use a parallelized tridiagonal solver.

  14. Analysis and distributed control of power flow in DC microgrids to improve system efficiency

    DEFF Research Database (Denmark)

    Chen, Fang; Burgos, Rolando; Boroyevich, Dushan

    2016-01-01

    DC Microgrid attains popularity in integrating renewable energy sources and batteries. It also has the potential to achieve higher efficiency than ac power grid under the condition of optimized power flow. In this paper, a general dc microgrid is modeled based on a cluster of general dc nodes......, which includes constant power renewables generation, droop-controlled voltage source and different kinds of load. Then the dc power flow is solved for optimization. A voltage restoration method based on consensus communication is used to restore the voltage deviation from droop characteristic...

  15. Sterols indicate water quality and wastewater treatment efficiency.

    Science.gov (United States)

    Reichwaldt, Elke S; Ho, Wei Y; Zhou, Wenxu; Ghadouani, Anas

    2017-01-01

    As the world's population continues to grow, water pollution is presenting one of the biggest challenges worldwide. More wastewater is being generated and the demand for clean water is increasing. To ensure the safety and health of humans and the environment, highly efficient wastewater treatment systems, and a reliable assessment of water quality and pollutants are required. The advance of holistic approaches to water quality management and the increasing use of ecological water treatment technologies, such as constructed wetlands and waste stabilisation ponds (WSPs), challenge the appropriateness of commonly used water quality indicators. Instead, additional indicators, which are direct measures of the processes involved in the stabilisation of human waste, have to be established to provide an in-depth understanding of system performance. In this study we identified the sterol composition of wastewater treated in WSPs and assessed the suitability of human sterol levels as a bioindicator of treatment efficiency of wastewater in WSPs. As treatment progressed in WSPs, the relative abundance of human faecal sterols, such as coprostanol, epicoprostanol, 24-ethylcoprostanol, and sitostanol decreased significantly and the sterol composition in wastewater changed significantly. Furthermore, sterol levels were found to be correlated with commonly used wastewater quality indicators, such as BOD, TSS and E. coli. Three of the seven sterol ratios that have previously been used to track sewage pollution in the environment, detected a faecal signal in the effluent of WSPs, however, the others were influenced by high prevalence of sterols originating from algal and fungal activities. This finding poses a concern for environmental assessment studies, because environmental pollution from waste stabilisation ponds can go unnoticed. In conclusion, faecal sterols and their ratios can be used as reliable indicators of treatment efficiency and water quality during wastewater

  16. Safety and efficiency of flow diverters for treating small intracranial aneurysms: A systematic review and meta-analysis.

    Science.gov (United States)

    Yao, Xiyang; Ma, Junwei; Li, Haiying; Shen, Haitao; Lu, Xiaojun; Chen, Gang

    2017-02-01

    Background We evaluated the safety and efficiency of flow diverters (FDs) in treating small intracranial aneurysms (IAs). Materials and Methods We reviewed the literature published in PubMed and EMBASE. R for Project software was used to calculate the complete aneurysm occlusion rates, procedure-related neurologic mortality, procedure-related neurologic morbidity and procedure-related permanent morbidity. Results Ten observational studies were included in this analysis. The complete aneurysm occlusion rate was 84.23% (80.34%-87.76%), the procedure-related neurologic mortality was 0.87% (0.29%-1.74%), the procedure-related neurologic morbidity rate was 5.22% (3.62%-7.1%), the intracerebral haemorrhage rate was 1.42% (0.64%-2.49%), the ischemic rate was 2.35% (1.31%-3.68%), the subarachnoid haemorrhage rate was 0.03% (0%-0.32%) and the procedure-related permanent morbidity was 2.41% (0.81%-4.83%). Conclusions Treatment of small IAs with FDs may be correlated with high complete occlusion rates and low complication rates. Future long-term follow-up randomized trials will determine the optimal treatment for small IAs.

  17. Estimation of Resource Productivity and Efficiency: An Extended Evaluation of Sustainability Related to Material Flow

    Directory of Open Access Journals (Sweden)

    Pin-Chih Wang

    2014-09-01

    Full Text Available This study is intended to conduct an extended evaluation of sustainability based on the material flow analysis of resource productivity. We first present updated information on the material flow analysis (MFA database in Taiwan. Essential indicators are selected to quantify resource productivity associated with the economy-wide MFA of Taiwan. The study also applies the IPAT (impact-population-affluence-technology master equation to measure trends of material use efficiency in Taiwan and to compare them with those of other Asia-Pacific countries. An extended evaluation of efficiency, in comparison with selected economies by applying data envelopment analysis (DEA, is conducted accordingly. The Malmquist Productivity Index (MPI is thereby adopted to quantify the patterns and the associated changes of efficiency. Observations and summaries can be described as follows. Based on the MFA of the Taiwanese economy, the average growth rates of domestic material input (DMI; 2.83% and domestic material consumption (DMC; 2.13% in the past two decades were both less than that of gross domestic product (GDP; 4.95%. The decoupling of environmental pressures from economic growth can be observed. In terms of the decomposition analysis of the IPAT equation and in comparison with 38 other economies, the material use efficiency of Taiwan did not perform as well as its economic growth. The DEA comparisons of resource productivity show that Denmark, Germany, Luxembourg, Malta, Netherlands, United Kingdom and Japan performed the best in 2008. Since the MPI consists of technological change (frontier-shift or innovation and efficiency change (catch-up, the change in efficiency (catch-up of Taiwan has not been accomplished as expected in spite of the increase in its technological efficiency.

  18. Human Factors of Automated Driving : Predicting the Effects of Authority Transitions on Traffic Flow Efficiency

    NARCIS (Netherlands)

    Varotto, S.F.; Hoogendoorn, R.G.; Van Arem, B.; Hoogendoorn, S.P.

    2014-01-01

    Automated driving potentially has a significant impact on traffic flow efficiency. Automated vehicles, which possess cooperative capabilities, are expected to reduce congestion levels for instance by increasing road capacity, by anticipating traffic conditions further downstream and also by

  19. Efficiency of physicochemical and biological treatments of vinasse and their influence on indigenous microbiota for disposal into the environment.

    Science.gov (United States)

    Campos, Cassia Roberta; Mesquita, Vanessa Alvarenga; Silva, Cristina Ferreira; Schwan, Rosane Freitas

    2014-11-01

    Molasses-based distilleries are one of the most polluting industries generating large volumes of high strength wastewater called vinasse. Different processes covering anaerobic, aerobic as well as physicochemical methods have been employed to treat this effluent. This study evaluated the microbial communities present in the vinasse during different stages of its treatment by traditional and molecular methods. The analysis of the efficiency of each treatment was performed by physicochemical parameters and toxicity analysis. The treatment of vinasse was performed in the following steps: high flow fermentation; filtration; chemical flakes; low-flow fermentation; filtration; and neutralization. The physicochemical analysis in different stages of the vinasse treatment demonstrated that phases of treatment influenced the performance of the evaluated parameters. Among the 37 parameters, 9 were within the limits established by the Commission for Environmental Policy of Minas Gerais, Brazil (COPAM), especially BOD (96.7% of pollution reduction), suspended solids (99.9%), pH, copper (88%), iron (92.9%), and manganese (88%). Some parameters, even after treatment, did not fit the maximum allowed by legislation. The microbial population decreased reaching 3 log CFU/ml present in the steps of the flakes chemical and disinfection treatment of vinasse. Lactobacillus brevis and Pichia kudriavzevii were present in all stages of the treatments, showing that these microorganisms were resistant and demonstrated that they might be important in the treatment of vinasse. The vinasse showed a significant reduction of pollution load after the disinfection treatment however still should not be discarded into water bodies because the high values of tannins and sediment solids, but suggest the use of the effluent in the cooling coil during the distillation process of the beverage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. An efficient algorithm for incompressible N-phase flows

    International Nuclear Information System (INIS)

    Dong, S.

    2014-01-01

    We present an efficient algorithm within the phase field framework for simulating the motion of a mixture of N (N⩾2) immiscible incompressible fluids, with possibly very different physical properties such as densities, viscosities, and pairwise surface tensions. The algorithm employs a physical formulation for the N-phase system that honors the conservations of mass and momentum and the second law of thermodynamics. We present a method for uniquely determining the mixing energy density coefficients involved in the N-phase model based on the pairwise surface tensions among the N fluids. Our numerical algorithm has several attractive properties that make it computationally very efficient: (i) it has completely de-coupled the computations for different flow variables, and has also completely de-coupled the computations for the (N−1) phase field functions; (ii) the algorithm only requires the solution of linear algebraic systems after discretization, and no nonlinear algebraic solve is needed; (iii) for each flow variable the linear algebraic system involves only constant and time-independent coefficient matrices, which can be pre-computed during pre-processing, despite the variable density and variable viscosity of the N-phase mixture; (iv) within a time step the semi-discretized system involves only individual de-coupled Helmholtz-type (including Poisson) equations, despite the strongly-coupled phase–field system of fourth spatial order at the continuum level; (v) the algorithm is suitable for large density contrasts and large viscosity contrasts among the N fluids. Extensive numerical experiments have been presented for several problems involving multiple fluid phases, large density contrasts and large viscosity contrasts. In particular, we compare our simulations with the de Gennes theory, and demonstrate that our method produces physically accurate results for multiple fluid phases. We also demonstrate the significant and sometimes dramatic effects of the

  1. Treatment of graphite felt by modified Hummers method for the positive electrode of vanadium redox flow battery

    International Nuclear Information System (INIS)

    Wu, Xiaoxin; Xu, Hongfeng; Shen, Yang; Xu, Pengcheng; Lu, Lu; Fu, Jie; Zhao, Hong

    2014-01-01

    A novel and highly effective treatment based on modified Hummers method was firstly used to improve the electrochemical activity of graphite felt as the positive electrode in all-vanadium redox flow battery (VRFB). The graphite felt was treated by the modified Hummers method and characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The electrochemical performance of the prepared electrode was evaluated through cyclic voltammetry and electrochemical impedance spectroscopy. Results show that graphite felt treated by modified Hummers method exhibits excellent electrocatalytic activity and reaction rate to vanadium redox couples. In our research, the hydrogen electrode and H 2 replaced the graphite felt and V 2+ /V 3+ couple in the negative side in the VRFB performance test. The coulombic, voltage, and energy efficiencies of the VRFB with the as-prepared electrodes at 50 mA cm −2 are 95.0%, 81.3%, and 77.2%, respectively. These values are much higher than those of the cell-assembled graphite felt electrodes that were conventionally and thermally treated. The graphite felt treated by the modified Hummers method carries more hydrophilic groups, such as–OH, on its defects, which is advantageous in facilitating the redox reaction of vanadium ions, thereby improving the operation efficiency of the vanadium redox flow battery

  2. Modeling the effect of shunt current on the charge transfer efficiency of an all-vanadium redox flow battery

    Science.gov (United States)

    Chen, Yong-Song; Ho, Sze-Yuan; Chou, Han-Wen; Wei, Hwa-Jou

    2018-06-01

    In an all-vanadium redox flow battery (VRFB), a shunt current is inevitable owing to the electrically conductive electrolyte that fills the flow channels and manifolds connecting cells. The shunt current decreases the performance of a VRFB stack as well as the energy conversion efficiency of a VRFB system. To understand the shunt-current loss in a VRFB stack with various designs and operating conditions, a mathematical model is developed to investigate the effects of the shunt current on battery performance. The model is calibrated with experimental data under the same operating conditions. The effects of the battery design, including the number of cells, state of charge (SOC), operating current, and equivalent resistance of the electrolytes in the flow channels and manifolds, on the shunt current are analyzed and discussed. The charge-transfer efficiency is calculated to investigate the effects of the battery design parameters on the shunt current. When the cell number is increased from 5 to 40, the charge transfer efficiency is decreased from 0.99 to a range between 0.76 and 0.88, depending on operating current density. The charge transfer efficiency can be maintained at higher than 0.9 by limiting the cell number to less than 20.

  3. CONCEPTUAL BASES OF THE ENERGY EFFICIENT SYSTEM OF MANAGEMENT OF COMBINED UNITS OF WASTEWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    V. N. Shtepa

    2016-01-01

    Full Text Available A critical analysis of the shortcomings of the existing water purification systems is conducted. In order to ensure environmental safety and energy savings it is proposed to use the combined units, including physical, chemical, physical-and-chemical and biological methods. The attention is driven to the fact that the most effective way to maintain current water purification is an adaptive control system. The shortcomings of the management of water treatment units were revealed and it was proposed to produce their synthesis based on the mathematical apparatus of artificial intelligence systems. Taking into account the requirements of the environmental safety and the need in the energy savings, the energy efficiency criteria of combined system functioning has been developed. At an industrial plant (slaughterhouse wastewater treatment the compliance of the production conditions of the criterion has been undertaken that confirmed the criterion relevance and usefulness as applied to the synthesis of energy-efficient control systems. A synthetic control system combined the water treatment plants. Having based on the preliminary research and analysis of the current work in the subject area the architecture of a control system of combined water treatment units that use intelligent technology was developed. The key functional of the unit – information-analytical subsystem of the formation control actions including: multilayer perceptrons self-organization Kohonen network, fuzzy cognitive map. The basic difference between the developed design and its analogues is the ability to adjust the settings of equipment adaptively on the basis of processing sensor data, information on the price of consumables, volley discharges of pollutants, a sudden change in the flow and other force majeure. Adjustment of the parameters of the control system is carried out with the use of experimental and analytical data stored in the knowledge base of technological

  4. Vertical Subsurface Flow (VSSF) constructed wetland for domestic wastewater treatment

    Science.gov (United States)

    Perdana, M. C.; Sutanto, H. B.; Prihatmo, G.

    2018-04-01

    Vertical Subsurface Flow Constructed Wetland (VSSF) is appraised to become an alternative solution for treating domestic wastewater effectively and efficiently. The system which imitates the natural wetland concept is able to reduce organic material and nutrients in wastewater; therefore, it will be more feasible to be discharged to the environment. This study aimed to compare which species is more recommended to be applied for reducing organic material and nutrients in domestic wastewater. This experimental study applied four treatments, i.e 1) control (unplanted), 2) single species Iris pseudacorus, 3) single species Echinodorus palaefolius, and 4) combination (Iris pseudacorus and Echinodorus palaefolius) with three days of retention time. The application of those plants aims for holding the role in increasing wastewater quality and adding aesthetic impression at once. The plants were planted on VSSF media, in relatively same of weight and size to compare their effectiveness in decreasing organic and inorganic load. The parameters measured pervade TDS, pH, BOD5, COD, Nitrate, and Phosphate. The plants’ condition was also observed during and after the system worked. The result showed that the best average value of effectiveness for each of parameters: COD by combination treatment (50.76%), BOD5 by single I. pseudacorus (30.15%), Nitrate by single E. palaefolius (58.06%), Phosphate by single E. palaefolius (99.5%), and TDS by E.palaefolius (3.25%). The result showed that there was a significant difference of Nitrate and Phosphate reduction between control and three other treatments, while pH parameter showed non-significant change among them. In term of performance, I.pseudacorus seemed showed a preferable achievement.

  5. Energy efficiency improvements utilising mass flow control and a ring topology in a district heating network

    International Nuclear Information System (INIS)

    Laajalehto, Tatu; Kuosa, Maunu; Mäkilä, Tapio; Lampinen, Markku; Lahdelma, Risto

    2014-01-01

    Heating and cooling have a major role in the energy sector, covering 46% of total final energy use worldwide. District heating (DH) is a significant technology for improving the energy efficiency of heating systems in communities, because it enables waste heat sources to be utilised economically and therefore significantly reduces the environmental impacts of power generation. As a result of new and more stringent construction regulations for buildings, the heat demands of individual buildings are decreasing and more energy-efficient heating systems have to be developed. In this study, the energy efficiency of a new DH system which includes both a new control system called mass flow control and a new network design called a ring network is examined. A topology in the Helsinki region is studied by using a commercial DH network modelling tool, Grades Heating. The district heating network is attached to a wood-burning heat station which has a heat recovery system in use. Examination is performed by means of both technical and economic analysis. The new non-linear temperature programme that is required is adopted for supply and return temperatures, which allows greater temperature cooling and smaller flow rates. Lower district heating water temperatures are essential when reducing the heat losses in the network and heat production. Mass flow control allows smaller pressure drops in the network and thus reduces the pumping power. The aim of this study was to determine the most energy-efficient DH water supply temperatures in the case network. If the ring network design is utilised, the district heating system is easier to control. As a result the total heat consumption within the heating season is reduced compared to traditional DH systems. On the basis of the results, the new DH system is significantly more energy-efficient in the case network that was examined than the traditional design. For example, average energy losses within the constraints (which consist of heat

  6. Flow intake control using dry-weather forecast

    Science.gov (United States)

    Icke, Otto; van Schagen, Kim; Huising, Christian; Wuister, Jasper; van Dijk, Edward; Budding, Arjan

    2017-08-01

    Level-based control of the influent flow causes peak discharges at a waste water treatment plant (WWTP) after rainfall events. Furthermore, the capacity of the post-treatment is in general smaller than the maximum hydraulic capacity of the WWTP. This results in a significant bypass of the post-treatment during peak discharge. The optimisation of influent flow reduces peak discharge, and increases the treatment efficiency of the whole water cycle, which benefits the surface water quality. In this paper, it is shown that half of the bypasses of the post-treatment can be prevented by predictive control. A predictive controller for influent flow is implemented using the Aquasuitetext">® Advanced Monitoring and Control platform. Based on real-time measured water levels in the sewerage and both rainfall and dry-weather flow (DWF) predictions, a discharge limitation is determined by a volume optimisation technique. For the analysed period (February-September 2016) results at WWTP Bennekom show that about 50 % of bypass volume can be prevented. Analysis of single rainfall events shows that the used approach is still conservative and that the bypass can be even further decreased by allowing discharge limitation during precipitation.

  7. Efficient self-consistent viscous-inviscid solutions for unsteady transonic flow

    Science.gov (United States)

    Howlett, J. T.

    1985-01-01

    An improved method is presented for coupling a boundary layer code with an unsteady inviscid transonic computer code in a quasi-steady fashion. At each fixed time step, the boundary layer and inviscid equations are successively solved until the process converges. An explicit coupling of the equations is described which greatly accelerates the convergence process. Computer times for converged viscous-inviscid solutions are about 1.8 times the comparable inviscid values. Comparison of the results obtained with experimental data on three airfoils are presented. These comparisons demonstrate that the explicitly coupled viscous-inviscid solutions can provide efficient predictions of pressure distributions and lift for unsteady two-dimensional transonic flows.

  8. Numerical analysis of flow in a centrifugal compressor with circumferential grooves: influence of groove location and number on flow instability

    Science.gov (United States)

    Chen, X.; Qin, G.; Ai, Z.; Ji, Y.

    2017-08-01

    As an effective and economic method for flow range enhancement, circumferential groove casing treatment (CGCT) is widely used to increase the stall margin of compressors. Different from traditional grooved casing treatments, in which the grooves are always located over the rotor in both axial and radial compressors, one or several circumferential grooves are located along the shroud side of the diffuser passage in this paper. Numerical investigations were conducted to predict the performance of a low flow rate centrifugal compressor with CGCT in diffuser. Computational fluid dynamics (CFD) analysis is performed under stage environment in order to find the optimum location of the circumferential casing groove in consideration of stall margin enhancement and efficiency gain at design point, and the impact of groove number to the effect of this grooved casing treatment configuration in enhancing the stall margin of the compressor stage is studied. The results indicate that the centrifugal compressor with circumferential groove in vaned diffuser can obtain obvious improvement in the stall margin with sacrificing design efficiency a little. Efforts were made to study blade level flow mechanisms to determine how the CGCT impacts the compressor’s stall margin (SM) and performance. The flow structures in the passage, the tip gap, and the grooves as well as their mutual interactions were plotted and analysed.

  9. Energy efficient thermal management of data centers

    CERN Document Server

    Kumar, Pramod

    2012-01-01

    Energy Efficient Thermal Management of Data Centers examines energy flow in today's data centers. Particular focus is given to the state-of-the-art thermal management and thermal design approaches now being implemented across the multiple length scales involved. The impact of future trends in information technology hardware, and emerging software paradigms such as cloud computing and virtualization, on thermal management are also addressed. The book explores computational and experimental characterization approaches for determining temperature and air flow patterns within data centers. Thermodynamic analyses using the second law to improve energy efficiency are introduced and used in proposing improvements in cooling methodologies. Reduced-order modeling and robust multi-objective design of next generation data centers are discussed. This book also: Provides in-depth treatment of energy efficiency ideas based on  fundamental heat transfer, fluid mechanics, thermodynamics, controls, and computer science Focus...

  10. Efficient implicit LES method for the simulation of turbulent cavitating flows

    International Nuclear Information System (INIS)

    Egerer, Christian P.; Schmidt, Steffen J.; Hickel, Stefan; Adams, Nikolaus A.

    2016-01-01

    We present a numerical method for efficient large-eddy simulation of compressible liquid flows with cavitation based on an implicit subgrid-scale model. Phase change and subgrid-scale interface structures are modeled by a homogeneous mixture model that assumes local thermodynamic equilibrium. Unlike previous approaches, emphasis is placed on operating on a small stencil (at most four cells). The truncation error of the discretization is designed to function as a physically consistent subgrid-scale model for turbulence. We formulate a sensor functional that detects shock waves or pseudo-phase boundaries within the homogeneous mixture model for localizing numerical dissipation. In smooth regions of the flow field, a formally non-dissipative central discretization scheme is used in combination with a regularization term to model the effect of unresolved subgrid scales. The new method is validated by computing standard single- and two-phase test-cases. Comparison of results for a turbulent cavitating mixing layer obtained with the new method demonstrates its suitability for the target applications.

  11. High flux MWCNTs-interlinked GO hybrid membranes survived in cross-flow filtration for the treatment of strontium-containing wastewater

    International Nuclear Information System (INIS)

    Zhang, Lin; Lu, Ying; Liu, Ying-Ling; Li, Ming; Zhao, Hai-Yang; Hou, Li-An

    2016-01-01

    Graphene oxide (GO)-based membranes provide an encouraging opportunity to support high separation efficiency for wastewater treatment. However, due to the relatively weak interaction between GO nanosheets, it is difficult for bare GO-based membranes to survive in cross-flow filtration. In addition, the permeation flux of the bare GO membrane is not high sufficiently due to its narrow interlayer spacing. In this study, GO membranes interlinked with multi-walled carbon nanotubes (MWCNTs) via covalent bonds were fabricated on modified polyacrylonitrile (PAN) supports by vacuum filtration. Due to the strong bonds between GO, MWCNTs and the PAN membrane, the membranes could be used for the treatment of simulated nuclear wastewater containing strontium via a cross-flow process. The result showed a high flux of 210.7 L/(m"2 h) at 0.4 MPa, which was approximately 4 times higher than that of commercial nanofiltration membranes. The improved water permeation was attributed to the nanochannels created by the interlinked MWCNTs in the GO layers. In addition, the hybrid membrane exhibited a high rejection of 93.4% for EDTA-chelated Sr"2"+ in an alkaline solution, and could also be used to separate Na"+/Sr"2"+ mixtures. These results indicate that the MWCNTs-interlinked GO membrane has promising prospects for application in radioactive waste treatment.

  12. Treatment of High-Flow Vascular Malformations by Venous Embolization Aided by Flow Occlusion Techniques

    International Nuclear Information System (INIS)

    Jackson, James E.; Mansfield, Averil O.; Allison, David J.

    1996-01-01

    Purpose: Transvenous embolization techniques may be helpful as alternatives to the arterial route when treating high-flow vascular malformations. We present our experience using these techniques in four patients. Methods: In one patient the venous portion of the arteriovenous malformation (AVM) was punctured directly; in the other three patients it was catheterized via a retrograde venous approach. Flow occlusion techniques were utilized in all patients during embolization, which was performed with absolute alcohol or N-butyl-2-cyanoacrylate.Results: Excellent clinical and angiographic results were obtained, with obliteration of arteriovenous shunting in all patients. There were no complications.Conclusion: The embolization of certain AVMs using a venous approach is a safe and effective treatment

  13. Efficiency of hospital cholera treatment in Ecuador

    Directory of Open Access Journals (Sweden)

    Creamer Germán

    1999-01-01

    Full Text Available This study analyzed the efficiency of cholera treatment in three hospitals representative of the Ecuadorian public health system in order to provide hospital directors and administrators and health service policy-makers with information to plan responses to future epidemics and to reduce the costs of cholera treatment in general. For the study, total and excess cholera treatment costs were calculated using hospital files and statistics and an in-hospital surveillance system of the cholera cases. The type and quantity of each input used for each treatment were analyzed, as well as the number of days hospitalized, according to the severity of the illness. With this process, excess costs were determined in relation to a "treatment norm" that would have been appropriate for each patient. The researchers found that 45% of the cholera treatment costs were excessive. The most important contributor was excess recurrent costs (90%, including extended hospital stays, disproportionate use of intravenous rehydration solutions, and unnecessary laboratory tests. Excess capital costs, from land, buildings, and hospital equipment, represented 10% of the total excess treatment costs. No significant relationship was found between treatment costs and the severity of the illness, nor between costs and a patient's age. A patient's sex appeared to be an important variable, with the cost of treating women being notably higher than for men. An inverse relationship was found between treatment costs and the complexity of the hospital. The researchers concluded there was an inefficient use of resources in the treatment of cholera in the three hospitals where the research was performed.

  14. SHEAR ACCELERATION IN EXPANDING FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, F. M. [ZAH, Institut für Theoretische Astrophysik, Universität Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Duffy, P., E-mail: frank.rieger@mpi-hd.mpg.de, E-mail: peter.duffy@ucd.ie [University College Dublin, Belfield, Dublin 4 (Ireland)

    2016-12-10

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets from active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi–Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplify that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge line, and limb-brightening).

  15. Efficiency of domestic wastewater treatment plant for agricultural reuse

    Directory of Open Access Journals (Sweden)

    Claudinei Fonseca Souza

    2015-07-01

    Full Text Available The increasing demand for water has made the treatment and reuse of wastewater a topic of global importance. This work aims to monitor and evaluate the efficiency of a wastewater treatment plant’s (WWTP physical and biological treatment of wastewater by measuring the reduction of organic matter content of the effluent during the treatment and the disposal of nutrients in the treated residue. The WWTP has been designed to treat 2500 liters of wastewater per day in four compartments: a septic tank, a microalgae tank, an upflow anaerobic filter and wetlands with cultivation of Zantedeschia aethiopica L. A plant efficiency of 90% of organic matter removal was obtained, resulting in a suitable effluent for fertigation, including Na and Ca elements that showed high levels due to the accumulation of organic matter in the upflow anaerobic filter and wetlands. The WWTP removes nitrogen and phosphorus by the action of microalgae and macrophytes used in the process. The final effluent includes important agricultural elements such as nitrogen, phosphorus, calcium and potassium and, together with the load of organic matter and salts, meets the determination of NBR 13,969/1997 (Standard of the Brazilian Technical Standards Association for reuse in agriculture, but periodic monitoring of soil salinity is necessary.

  16. Long-term performance of a 20-L continuous flow microbial fuel cell for treatment of brewery wastewater

    Science.gov (United States)

    Lu, Mengqian; Chen, Shing; Babanova, Sofia; Phadke, Sujal; Salvacion, Michael; Mirhosseini, Auvid; Chan, Shirley; Carpenter, Kayla; Cortese, Rachel; Bretschger, Orianna

    2017-07-01

    Microbial fuel cells (MFCs) have been shown as a promising technology for wastewater treatment. Integration of MFCs into current wastewater treatment plant have potential to reduce the operational cost and improve the treatment performance, and scaling up MFCs will be essential. However, only a few studies have reported successful scale up attempts. Fabrication cost, treatment performance and operational lifetime are critical factors to optimize before commercialization of MFCs. To test these factors, we constructed a 20 L MFC system containing two 10 L MFC reactors and operated the system with brewery wastewater for nearly one year. Several operational conditions were tested, including different flowrates, applied external resistors, and poised anodic potentials. The condition resulting in the highest chemical oxygen demand (COD) removal efficiency (94.6 ± 1.0%) was a flow rate of 1 mL min-1 (HRT = 313 h) and an applied resistor of 10 Ω across each MFC circuit. Results from each of the eight stages of operation (325 days total) indicate that MFCs can sustain treatment rates over a long-term period and are robust enough to sustain performance even after system perturbations. possible ways to improve MFC performance were discussed for future studies.

  17. Efficiency improvement of an all-vanadium redox flow battery by harvesting low-grade heat

    Science.gov (United States)

    Reynard, Danick; Dennison, C. R.; Battistel, Alberto; Girault, Hubert H.

    2018-06-01

    Redox flow batteries (RFBs) are rugged systems, which can withstand several thousand cycles and last many years. However, they suffer from low energy density, low power density, and low efficiency. Integrating a Thermally Regenerative Electrochemical Cycle (TREC) into the RFB, it is possible to mitigate some of these drawbacks. The TREC takes advantage of the temperature dependence of the cell voltage to convert heat directly into electrical energy. Here, the performance increase of a TREC-RFB is investigated using two kinds of all-vanadium electrolyte chemistries: one containing a typical concentration of sulfuric acid and one containing a large excess of hydrochloric acid. The results show that the energy density of the system was increased by 1.3Wh L-1 and 0.8Wh L-1, respectively and the overall energy efficiency also increased by 9 and 5 percentage points, respectively. The integration of the heat exchangers necessary to change the battery temperature is readily facilitated by the design of the redox flow battery, which already utilizes fluid circulation loops.

  18. Accurate, stable and efficient Navier-Stokes solvers based on explicit treatment of the pressure term

    International Nuclear Information System (INIS)

    Johnston, Hans; Liu Jianguo

    2004-01-01

    We present numerical schemes for the incompressible Navier-Stokes equations based on a primitive variable formulation in which the incompressibility constraint has been replaced by a pressure Poisson equation. The pressure is treated explicitly in time, completely decoupling the computation of the momentum and kinematic equations. The result is a class of extremely efficient Navier-Stokes solvers. Full time accuracy is achieved for all flow variables. The key to the schemes is a Neumann boundary condition for the pressure Poisson equation which enforces the incompressibility condition for the velocity field. Irrespective of explicit or implicit time discretization of the viscous term in the momentum equation the explicit time discretization of the pressure term does not affect the time step constraint. Indeed, we prove unconditional stability of the new formulation for the Stokes equation with explicit treatment of the pressure term and first or second order implicit treatment of the viscous term. Systematic numerical experiments for the full Navier-Stokes equations indicate that a second order implicit time discretization of the viscous term, with the pressure and convective terms treated explicitly, is stable under the standard CFL condition. Additionally, various numerical examples are presented, including both implicit and explicit time discretizations, using spectral and finite difference spatial discretizations, demonstrating the accuracy, flexibility and efficiency of this class of schemes. In particular, a Galerkin formulation is presented requiring only C 0 elements to implement

  19. An efficient permeability scaling-up technique applied to the discretized flow equations

    Energy Technology Data Exchange (ETDEWEB)

    Urgelli, D.; Ding, Yu [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    Grid-block permeability scaling-up for numerical reservoir simulations has been discussed for a long time in the literature. It is now recognized that a full permeability tensor is needed to get an accurate reservoir description at large scale. However, two major difficulties are encountered: (1) grid-block permeability cannot be properly defined because it depends on boundary conditions; (2) discretization of flow equations with a full permeability tensor is not straightforward and little work has been done on this subject. In this paper, we propose a new method, which allows us to get around both difficulties. As the two major problems are closely related, a global approach will preserve the accuracy. So, in the proposed method, the permeability up-scaling technique is integrated in the discretized numerical scheme for flow simulation. The permeability is scaled-up via the transmissibility term, in accordance with the fluid flow calculation in the numerical scheme. A finite-volume scheme is particularly studied, and the transmissibility scaling-up technique for this scheme is presented. Some numerical examples are tested for flow simulation. This new method is compared with some published numerical schemes for full permeability tensor discretization where the full permeability tensor is scaled-up through various techniques. Comparing the results with fine grid simulations shows that the new method is more accurate and more efficient.

  20. On-site wastewater treatment using subsurface flow constructed wetlands in Ireland.

    Science.gov (United States)

    Gill, Laurence W; O'Luanaigh, Niall; Johnston, Paul M

    2011-01-01

    The results from an Irish EPA-funded project on the effectiveness of using constructed wetlands for treating wastewater from single households is presented, which has contributed to the design guidelines included in the new EPA Code of Practice. Three subsurface flow gravel-filled wetlands were constructed on separate sites--one to provide secondary treatment and the other two to provide tertiary treatment stages for the domestic effluent. A comprehensive analysis over three years was then conducted to provide a robust characterization of the internal dynamics of the systems, particularly with respect to N and P removal as well as evaluating the temporal water balance across the different seasons. The removal of Total N was only 29% and 30% in the secondary and tertiary treatment wetlands, respectively; particularly disappointing for the tertiary treatment process, which was receiving nitrified effluent. Studies on the (15)N stable isotope confirmed that 35% of the ammonium from the septic tank was passing straight through the process without taking part in any biogeochemical processes. However, influent N in the wetlands was shown to be biologically assimilated into organic nitrogen and then released again as soluble ammonium--so-called nitrogen "spiraling." Removal of Total P in the wetlands averaged from 28% to 45% with higher P removals measured during summer periods, although the effluent concentrations were still found to be high (> 5 mg/l on average). The phosphorus in the plant material was also analysed revealing that the annual above-ground stem matter only accounted for 1.3% to 8.4% of the annual total P-load in the wetlands. Finally, the water balance analyses showed that the mean flow discharging from both the secondary and tertiary treatment wetlands was slightly greater than the mean flow to the reed bed over the trial period, with rainfall acting to increase flows by 13% and 5%, respectively, on average in winter while just about balancing

  1. Toxic metals in WEEE: Characterization and substance flow analysis in waste treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Masahiro, E-mail: oguchi.masahiro@nies.go.jp; Sakanakura, Hirofumi; Terazono, Atsushi

    2013-10-01

    Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously. - Highlights: ► Appropriate management of toxic metals contained in WEEE is important during recycling and treatment of WEEE. ► CRT TVs contain large amount of toxic metals with high concentration and thus appropriate management is highly important. ► Mid-sized equipment is a future target for

  2. METHODOLOGICAL APPROACHES TO THE ANALYSIS OF EFFICIENCY OF CASH FLOW MANAGEMENT IN INVESTMENT ACTIVITY OF THE ENTERPRISES

    Directory of Open Access Journals (Sweden)

    I. Magdych

    2015-06-01

    Full Text Available The article explores the methodological approaches to the analysis of cash flows in investment activity of the enterprise; the system of motion net cash flows, reflecting the impact of cash management efficiency on the amount and source of investment cash flows of the enterprise; analytical model of definition of effectiveness of cash management of the enterprise is proposed, based on the selected principals of modeling, comprehensive analysis of cash flows in investing activities and their optimization for the purpose of maximization of social and economic benefit. The research performed here allowed generalization and definition of stages of analysis for investing cash flow of the enterprise with the appropriate reasoning. It is necessary that research is going concern in this direction of effectiveness valuation of cash flow management in investing activity of the enterprise.

  3. Functional efficiency comparison between split- and parallel-hybrid using advanced energy flow analysis methods

    Energy Technology Data Exchange (ETDEWEB)

    Guttenberg, Philipp; Lin, Mengyan [Romax Technology, Nottingham (United Kingdom)

    2009-07-01

    The following paper presents a comparative efficiency analysis of the Toyota Prius versus the Honda Insight using advanced Energy Flow Analysis methods. The sample study shows that even very different hybrid concepts like a split- and a parallel-hybrid can be compared in a high level of detail and demonstrates the benefit showing exemplary results. (orig.)

  4. How effective is aeration with vortex flow regulators? Pilot scale experiments

    Science.gov (United States)

    Wójtowicz, Patryk; Szlachta, Małgorzata

    2017-11-01

    Vortex flow regulators (VFR) are used in urban drainage systems as a replacement for traditional flow throttling devices. Vortex regulators are not only very efficient energy dissipators but also atomizers which are beneficial for sewer aeration. A deficit of dissolved oxygen can be a problem in both natural waters and sewerage. Hydrodynamic flow regulators can boost oxygen concentration preventing putrefaction and improving treatment of stormwater and wastewater. We were first to investigate the aeration efficiency of semi-commercial scale cylindrical vortex flow regulators to determine the potential of their application in environmental engineering and to propose modification to enhance the aeration capacity of basic designs. Different device geometries and arrangements of active outlets for both single and double discharge vortex regulators were tested in a recirculating system. In this study, we present a concise review of the current state of our extensive research on the aeration efficiency of vortex flow regulators and their application in sewerage systems.

  5. Application of double-layered skin phantoms for optical flow imaging during laser tattoo treatments

    Science.gov (United States)

    Lee, Byeong-il; Song, Woosub; Kim, Hyejin; Kang, Hyun Wook

    2016-05-01

    The feasible application of double-layered skin phantoms was evaluated to identify artificial blood flow with a Doppler optical coherence tomography (DOCT) system for laser tattoo treatments. Polydimethylsiloxane (PDMS) was used to fabricate the artificial phantoms with flow channels embedded. A double-integrating sphere system with an inverse adding-doubling method quantified both the absorption and the reduced scattering coefficients for epidermis and dermis phantoms. Both OCT and caliper measurements confirmed the double-layered phantom structure (epidermis = 136 ± 17 µm vs. dermis = 3.0 ± 0.1 mm). The DOCT method demonstrated that high flow rates were associated with high image contrast, visualizing the position and the shape of the flow channel. Application of the channel-embedded skin phantoms in conjunction with DOCT can be a reliable technique to assess dynamic variations in the blood flow during and after laser tattoo treatments.

  6. Enhanced energy efficiency in waste water treatment plants; Steigerung der Energieeffizienz auf kommunalen Klaeranlagen

    Energy Technology Data Exchange (ETDEWEB)

    Haberkern, Bernd; Maier, Werner; Schneider, Ursula [iat - Ingenieurberatung fuer Abwassertechnik, Darmstadt und Stuttgart, Darmstadt (Germany)

    2008-03-15

    In order to implement the requests of EU-IPCC-directive in a new decree for waste water treatment in Germany, best available techniques have to be defined to optimize energy efficiency in waste water treatment plants (WWTP). Therefore energy efficiency was investigated for common treatment processes and new technologies like membrane filtration, co-digestion or phosphorus recycling. In addition, the occurrence of different technologies for waste water and sludge treatment was evaluated for different size ranges of treatment plants (in population equivalents, PE) nationwide in Germany. The definition of actual and aimed values for specific energy consumption (in kWh/(PE.a)) allowed to calculate the potential energy savings in WWTP and the additional consumption due to new processes on a national level. Under consideration of the reciprocations between optimized energy consumption in WWTP and operation practice, toe-holds to increase energy efficiency according to their relevancy for the national balance could be listed. Case studies prove the feasibility of the investigated techniques and allow proposals for minimum requirements in legal regulation concerning energy efficiency in WWTP. (orig.)

  7. Improve photocurrent quantum efficiency of carbon nanotube by chemical treatment

    International Nuclear Information System (INIS)

    Wang Hongguang; Wei Jinquan; Jia Yi; Li Zhen; Zhu Hongwei; Wang Kunlin; Wu Dehai

    2012-01-01

    Highlights: ► The QE of photocurrent for the H 2 O 2 -treated CNTs reaches to 5.28% at U bias = 0.1 V. ► Moderate chemical treatment can enhance the QE of photocurrent of CNTs. ► Excessive chemical treatment decreases the photocurrent quantum efficiency of CNTs. - Abstract: High photocurrent quantum efficiency (QE) of carbon nanotubes (CNTs) is important to their photovoltaic applications. The ability of photocurrent generation of CNTs depends on their band structure and surface state. For given CNTs, it is possible to improve the QE of photocurrent by chemical modification. Here, we study the effects of simple chemical treatment on the QE of CNTs by measuring the photocurrent of macroscopic CNT bundles. The QE of the H 2 O 2 -treated CNT bundle reaches 5.28% at 0.1 V bias voltage at a laser (λ = 473 nm) illumination, which is 85% higher than that of the pristine sample. But the QE of the CNTs treated in concentrated HNO 3 is lower than that of the pristine sample. It shows that moderate chemical treatment can enhance the photocurrent QE and excessive chemical treatment will decrease the QE because of introducing lots of structural defects.

  8. Hypogonadotropic hypogonadism: new identification of testicular blood flow and varicocele after treatment with gonadotropins.

    Science.gov (United States)

    ur Rehman, Khaleeq; Shahid, Khubaib; Humayun, Hina

    2014-09-01

    To investigate testicular changes in patients with hypogonadotropic hypogonadism (HH) after treatment with gonadotropins. Patients with HH were investigated and followed before and after treatment. Urology and andrology clinic of a teaching hospital. Consecutive male patients with diagnosed HH. All patients were treated with gonadotropins during the study period and later. The hormonal status and scrotal color Doppler ultrasound (CDUS) of patients was recorded before and after treatment. Twenty-six patients with HH (ages 18-43 years) were followed for 8-29 months. After treatment, serum T and secondary sex characters improved in all and spermatogenesis developed in 61.5% of patients. Before treatment, testicular (intraparenchymal blood flow) was undetectable in all and barely detectable in three patients. This improved significantly to 4.53±5.44 and 4.27±4.97 cm/second, respectively, after treatment. Subcapsular arterial flow and testicular size also improved significantly. Similarly, after treatment, transverse epididymal diameter (TED) increased significantly. At baseline, no patient had detectable varicocele on CDUS. After treatment, varicocele was demonstrable in 23% of patients. This finding was further evaluated retrospectively from our 76 HH patient files. None of them had varicocele before treatment, but after treatment 19.73% were found to have varicocele. Patients with HH responded to gonadotropins by improvement in testicular blood flow and increase in TED. In some patients, varicocele was found to develop after treatment. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  9. An Efficient Upscaling Process Based on a Unified Fine-scale Multi-Physics Model for Flow Simulation in Naturally Fracture Carbonate Karst Reservoirs

    KAUST Repository

    Bi, Linfeng

    2009-01-01

    The main challenges in modeling fluid flow through naturally-fractured carbonate karst reservoirs are how to address various flow physics in complex geological architectures due to the presence of vugs and caves which are connected via fracture networks at multiple scales. In this paper, we present a unified multi-physics model that adapts to the complex flow regime through naturally-fractured carbonate karst reservoirs. This approach generalizes Stokes-Brinkman model (Popov et al. 2007). The fracture networks provide the essential connection between the caves in carbonate karst reservoirs. It is thus very important to resolve the flow in fracture network and the interaction between fractures and caves to better understand the complex flow behavior. The idea is to use Stokes-Brinkman model to represent flow through rock matrix, void caves as well as intermediate flows in very high permeability regions and to use an idea similar to discrete fracture network model to represent flow in fracture network. Consequently, various numerical solution strategies can be efficiently applied to greatly improve the computational efficiency in flow simulations. We have applied this unified multi-physics model as a fine-scale flow solver in scale-up computations. Both local and global scale-up are considered. It is found that global scale-up has much more accurate than local scale-up. Global scale-up requires the solution of global flow problems on fine grid, which generally is computationally expensive. The proposed model has the ability to deal with large number of fractures and caves, which facilitate the application of Stokes-Brinkman model in global scale-up computation. The proposed model flexibly adapts to the different flow physics in naturally-fractured carbonate karst reservoirs in a simple and effective way. It certainly extends modeling and predicting capability in efficient development of this important type of reservoir.

  10. Hidden costs of antiretroviral treatment: the public health efficiency of drug packaging.

    Science.gov (United States)

    Andreu-Crespo, Àngels; Llibre, Josep M; Cardona-Peitx, Glòria; Sala-Piñol, Ferran; Clotet, Bonaventura; Bonafont-Pujol, Xavier

    2015-01-01

    While the overall percentage of unused antiretroviral medicines returned to the hospital pharmacy is low, their cost is quite high. Adverse events, treatment failure, pharmacokinetic interactions, pregnancy, or treatment simplification are common reasons for unplanned treatment changes. Socially inefficient antiretroviral packages prevent the reuse of drugs returned to the hospital pharmacy. We defined antiretroviral package categories based on the excellence of drug packaging and analyzed the number of pills and costs of drugs returned during a period of 1 year in a hospital-based HIV unit attending to 2,413 treated individuals. A total of 6,090 pills (34% of all returned antiretrovirals) - with a cost of 47,139.91 € - would be totally lost, mainly due to being packed up in the lowest efficiency packages. Newer treatments are packaged in low-excellence categories of packages, thus favoring the maintenance of these hidden costs in the near future. Therefore, costs of this low-efficiency drug packaging, where medication packages are started but not completed, in high-cost medications are substantial and should be properly addressed. Any improvement in the packaging by the manufacturer, and favoring the choice of drugs supplied through efficient packages (when efficacy, toxicity, and convenience are similar), should minimize the treatment expenditures paid by national health budgets.

  11. Analysis of the Unsteady Flow Field in a Centrifugal Compressor from Peak Efficiency to Near Stall with Full-Annulus Simulations

    Directory of Open Access Journals (Sweden)

    Yannick Bousquet

    2014-01-01

    Full Text Available This study concerns a 2.5 pressure ratio centrifugal compressor stage consisting of a splittered unshrouded impeller and a vaned diffuser. The aim of this paper is to investigate the modifications of the flow structure when the operating point moves from peak efficiency to near stall. The investigations are based on the results of unsteady three-dimensional simulations, in a calculation domain comprising all the blade. A detailed analysis is given in the impeller inducer and in the vaned diffuser entry region through time-averaged and unsteady flow field. In the impeller inducer, this study demonstrates that the mass flow reduction from peak efficiency to near stall leads to intensification of the secondary flow effects. The low momentum fluid accumulated near the shroud interacts with the main flow through a shear layer zone. At near stall condition, the interface between the two flow structures becomes unstable leading to vortices development. In the diffuser entry region, by reducing the mass flow, the high incidence angle from the impeller exit induces a separation on the diffuser vane suction side. At near stall operating point, vorticity from the separation is shed into vortex cores which are periodically formed and convected downstream along the suction side.

  12. STUDIES ON THE EFFICIENCY OF GRUNDWATER TREATMENT PROCESS WITH ADSORPTION ON ACTIVATED ALUMINA

    Directory of Open Access Journals (Sweden)

    Ewa Szatyłowicz

    2017-07-01

    Full Text Available The one of inorganic sorbents used in water treatment technology is activated alumina. Recommended by the European Commission to remove inorganic impurities, such as arsenic, fluoride, selenium and silicates. The adsorbent is usually applied in granular form, under flow conditions. It can become absorbent material increasingly used due to the presence of arsenic beside iron and manganese in groundwater intakes. The aim of the study was to evaluate the effectiveness of groundwater treatment in the technological system containing adsorption on activated alumina. The experiment was performed on test model CE 581 manufactured by G.U.N.T. Hamburg, in which can extract four treatment stages. The first stage is used in a gravel filter of grain size 1-2 mm, in the second sand filter of grain size 0.4-0.8 mm. The third and fourth phase includes two adsorbers. The first adsorber comprises activated alumina (Al2O3 and the other comprises a granular activated carbon. The study was conducted at different speeds of filtration: 5, 10 and 15 m/h. In the raw water samples and the purified water samples after each treatment step were determined the following parameters: pH, O2 concentration, electrolytic conductivity, SO42-, concentration, NO3- concentration, PO43- concentration, Cl-concentration, color, turbidity, iron and manganese concentration, CODMn, total hardness, calcium hardness, magnesium hardness, content of dissolved substances. Conducted research indicates that optimum filtration rate for most pollution is 15 m/h. Moreover, the presence of activated alumina has contributed to increasing the efficiency of nitrate (V and phosphate (V ions removal.

  13. Efficient H2O2/CH3COOH oxidative desulfurization/denitrification of liquid fuels in sonochemical flow-reactors.

    Science.gov (United States)

    Calcio Gaudino, Emanuela; Carnaroglio, Diego; Boffa, Luisa; Cravotto, Giancarlo; Moreira, Elizabeth M; Nunes, Matheus A G; Dressler, Valderi L; Flores, Erico M M

    2014-01-01

    The oxidative desulfurization/denitrification of liquid fuels has been widely investigated as an alternative or complement to common catalytic hydrorefining. In this process, all oxidation reactions occur in the heterogeneous phase (the oil and the polar phase containing the oxidant) and therefore the optimization of mass and heat transfer is of crucial importance to enhancing the oxidation rate. This goal can be achieved by performing the reaction in suitable ultrasound (US) reactors. In fact, flow and loop US reactors stand out above classic batch US reactors thanks to their greater efficiency and flexibility as well as lower energy consumption. This paper describes an efficient sonochemical oxidation with H2O2/CH3COOH at flow rates ranging from 60 to 800 ml/min of both a model compound, dibenzotiophene (DBT), and of a mild hydro-treated diesel feedstock. Four different commercially available US loop reactors (single and multi-probe) were tested, two of which were developed in the authors' laboratory. Full DBT oxidation and efficient diesel feedstock desulfurization/denitrification were observed after the separation of the polar oxidized S/N-containing compounds (S≤5 ppmw, N≤1 ppmw). Our studies confirm that high-throughput US applications benefit greatly from flow-reactors. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. High flux MWCNTs-interlinked GO hybrid membranes survived in cross-flow filtration for the treatment of strontium-containing wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lin; Lu, Ying [Key Laboratory of Biomass Chemical Engineering, Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027 (China); Liu, Ying-Ling [Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Li, Ming [Xi' an High-Tech Institute, Xi' an 710025 (China); Zhao, Hai-Yang [Key Laboratory of Biomass Chemical Engineering, Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027 (China); Hou, Li-An, E-mail: houla@cae.cn [Key Laboratory of Biomass Chemical Engineering, Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027 (China); Xi' an High-Tech Institute, Xi' an 710025 (China)

    2016-12-15

    Graphene oxide (GO)-based membranes provide an encouraging opportunity to support high separation efficiency for wastewater treatment. However, due to the relatively weak interaction between GO nanosheets, it is difficult for bare GO-based membranes to survive in cross-flow filtration. In addition, the permeation flux of the bare GO membrane is not high sufficiently due to its narrow interlayer spacing. In this study, GO membranes interlinked with multi-walled carbon nanotubes (MWCNTs) via covalent bonds were fabricated on modified polyacrylonitrile (PAN) supports by vacuum filtration. Due to the strong bonds between GO, MWCNTs and the PAN membrane, the membranes could be used for the treatment of simulated nuclear wastewater containing strontium via a cross-flow process. The result showed a high flux of 210.7 L/(m{sup 2} h) at 0.4 MPa, which was approximately 4 times higher than that of commercial nanofiltration membranes. The improved water permeation was attributed to the nanochannels created by the interlinked MWCNTs in the GO layers. In addition, the hybrid membrane exhibited a high rejection of 93.4% for EDTA-chelated Sr{sup 2+} in an alkaline solution, and could also be used to separate Na{sup +}/Sr{sup 2+} mixtures. These results indicate that the MWCNTs-interlinked GO membrane has promising prospects for application in radioactive waste treatment.

  15. Role of macrophyte and effect of supplementary aeration in up-flow constructed wetland-microbial fuel cell for simultaneous wastewater treatment and energy recovery.

    Science.gov (United States)

    Oon, Yoong-Ling; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Dahalan, Farrah Aini; Oon, Yoong-Sin; Lehl, Harvinder Kaur; Thung, Wei-Eng; Nordin, Noradiba

    2017-01-01

    This study investigates the role of plant (Elodea nuttallii) and effect of supplementary aeration on wastewater treatment and bioelectricity generation in an up-flow constructed wetland-microbial fuel cell (UFCW-MFC). Aeration rates were varied from 1900 to 0mL/min and a control reactor was operated without supplementary aeration. 600mL/min was the optimum aeration flow rate to achieve highest energy recovery as the oxygen was sufficient to use as terminal electron acceptor for electrical current generation. The maximum voltage output, power density, normalized energy recovery and Coulombic efficiency were 545.77±25mV, 184.75±7.50mW/m 3 , 204.49W/kg COD, 1.29W/m 3 and 10.28%, respectively. The variation of aeration flow rates influenced the NO 3 - and NH 4 + removal differently as nitrification and denitrification involved conflicting requirement. In terms of wastewater treatment performance, at 60mL/min aeration rate, UFCW-MFC achieved 50 and 81% of NO 3 - and NH 4 + removal, respectively. E. nuttallii enhanced nitrification by 17% and significantly contributed to bioelectricity generation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Separation efficiency of two waste polymer fibers for oily water treatment

    OpenAIRE

    Sokolović Dunja S.; Vulić Tatjana J.; Kiralj Arpad I.; Hadnađev-Kostić Milica S.; Sokolović Srđan S.

    2016-01-01

    This work is concerned with the efficiency of two different waste polymeric materials as the filter media in a laboratory-scale bed coalescer in the horizontal fluid flow mode, operating in a steady-state regime. The applied materials are: waste polyethylene terephthalate from textile industry, BA1 and waste polypropylene from carpet industry, PP. Using these compressible fiber polymeric materials, high bed porosity (up to 98%) could be obtained. The invest...

  17. A biodegradation and treatment of palm oil mill effluent (POME) using a hybrid up-flow anaerobic sludge bed (HUASB) Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Habeeb, S.A.; Latiff, AB. Aziz Abdul; Daud, Zawawi; Ahmad, Zulkifli [Faculty of Civil and Enviromental Engineering, University Tun Hussein Onn (Malaysia)

    2011-07-01

    Generally, anaerobic treatment has become a viable alternative in support of industrial wastewater treatment. Particularly, it is used in common to treat the palm oil mill effluent (POME). This study was carried out to assess the start-up performance of a bioreactor hybrid up-flow anaerobic sludge blanket (HUASB). Whereby, three identical reactors of 7.85-l capacity R1, R2, and R3 were operated for 57 days in order to provide two alienated comparisons. Identical operation conditions of organic loading rate (OLR) and hydraulic retention time (HRT) of 1.85 kg.m-3.day-1, and 2.6 day, respectively. R1 was operated in room temperature of 28{+-}2 C, and packed with palm oil shell as filter medium support. R2 was set with room temperature but packed with course gravel. R3 was provided with water bath system to adjust its temperature at 37{+-}1 C mesophilic, while its filter material had to be palm oil shell. During the whole operation period R3 was more efficient for organic materials, where a chemical oxygen demand (COD) removal efficiency of 82% was registered, while R1 and R2 were relatively less efficient of 78%, and 76%, respectively. Furthermore, TSS removal of R3 was also higher than R1, and R2 as registered 80%, 77% and 76%, respectively. On the other hand, turbidity and colour removal were not efficient and needed a post treatment. The seeded sludge was developed in each reactor as illustrated in this paper. Therefore, all reactors show favorable performance of anaerobic treatability of POME as well as good response of microbial species development.

  18. Flow Characteristics and Grain Size Distribution of Granular Gangue Mineral by Compaction Treatment

    Directory of Open Access Journals (Sweden)

    Ran Yuan

    2017-01-01

    Full Text Available A test system for water flow in granular gangue mineral was designed to study the flow characteristics by compaction treatment. With the increase of the compaction displacement, the porosity decreases and void in granular gangue becomes less. The main reason causing initial porosity decrease is that the void of larger size is filled with small particles. Permeability tends to decrease and non-Darcy flow factor increases under the compaction treatment. The change trend of flow characteristics shows twists and turns, which indicate that flow characteristics of granular gangue mineral are related to compaction level, grain size distribution, crushing, and fracture structure. During compaction, larger particles are crushed, which in turn causes the weight of smaller particles to increase, and water flow induces fine particles to migrate (weight loss; meanwhile, a sample with more weight of size (0–2.5 mm has a higher amount of weight loss. Water seepage will cause the decrease of some chemical components, where SiO2 decreased the highest in these components; the components decreased are more likely locked at fragments rather than the defect of the minerals. The variation of the chemical components has an opposite trend when compared with permeability.

  19. Evaluation of photodynamic treatment efficiency on glioblastoma cells received from malignant lesions: initial studies

    Science.gov (United States)

    Borisova, Ekaterina; Kyurkchiev, Dobroslav; Tumangelova-Yuzeir, Kalina; Angelov, Ivan; Genova-Hristova, Tsanislava; Semyachkina-Glushkovskaya, Oxana; Minkin, Krassimir

    2018-04-01

    Photodynamic therapy is well-established and extensively used method in treatment of different cancer types. This research reveals its potential in the treatment of cultivated human glioblastoma cells with adherent morphology. As the blood-brain barrier (BBB) permeability of the drugs is a significant problem that could not be solved easily for large biomolecules, we search for an appropriate low-molecular weight photosensitizer that could be applied for photodynamic treatment of glioblastoma cells. We used delta-aminolevulinic acid (5-ALA), which could pass BBB and plays the role of precursor of a protoporphyrin IX (PpIX) - photosensitizer, that is accumulated selectively in the tumour cells and could be a proper tool in PDT of glioblastoma. However, differences from patient to patient and between the cell activities could also lead to different effectiveness of the PDT treatment of the tumour areas. Therefore in our study we investigated not only the effect of using different fluence rates and light doses, but aims to establish more efficient values for further clinical applications for each sub-type of the GBM lesions. For the needs of PDT application an illumination device was developed in Laboratory of Biophotonics, BAS based on light-emitting diode (LED) matrix light sources for therapeutic application emitting at 635 nm. The device is optimized for PDT in combination with aminolevulinic acid/protoporphyrin IX applied as a photosensitizer drug. By the means of FACSCalibur flow cytometer (Becton Dickinson, USA) and Cell Quest Software was made evaluation of PDT effect on used human glioblastoma cells. Treatment of glioblastoma tumours continues to be a very serious issue and there is growing need in development of new concepts, methods and cancer-fighting strategies. PDT may contribute in accomplishing better results in cancer treatment and can be applied as well in combination with other techniques.

  20. UASB followed by Sub-Surface Horizontal Flow Phytodepuration for the Treatment of the Sewage Generated by a Small Rural Community

    Directory of Open Access Journals (Sweden)

    Massimo Raboni

    2014-10-01

    Full Text Available The paper presents the results of an experimental process designed for the treatment of the sewage generated by a rural community located in the north-east of Brazil. The process consists of a preliminary mechanical treatment adopting coarse screens and grit traps, followed by a biological treatment in a UASB reactor and a sub-surface horizontal flow phytodepuration step. The use of a UASB reactor equipped with a top cover, as well as of the phytodepuration process employing a porous medium, showed to present important health advantages. In particular, there were no significant odor emissions and there was no evidence of the proliferation of insects and other disease vectors. The plant achieved the following mean abatement efficiencies: 92.9% for BOD5, 79.2% for COD and 94% for Suspended Solids. With regard to fecal indicators average efficiencies of 98.8% for fecal coliforms and 97.9% for fecal enterococci were achieved. The UASB reactor showed an important role in achieving this result. The research was also aimed at evaluating the optimal operating conditions for the UASB reactor in terms of hydraulic load and organic volumetric loading. The achieved results hence indicated that the process may be highly effective for small rural communities in tropical and sub-tropical areas.

  1. High efficiency particulate removal with sintered metal filters

    International Nuclear Information System (INIS)

    Kirstein, B.E.; Paplawsky, W.J.; Pence, D.T.; Hedahl, T.G.

    1981-01-01

    Because of their particle removal efficiencies and durability, sintered metal filters have been chosen for high efficiency particulate air (HEPA) filter protection in the off-gas treatment system for the proposed Idaho National Engineering Laboratory Transuranic Waste Treatment Facility. Process evaluation of sintered metal filters indicated a lack of sufficient process design data to ensure trouble-free operation. Subsequence pilot scale testing was performed with flyash as the test particulate. The test results showed that the sintered metal filters can have an efficiency greater than 0.9999999 for the specific test conditions used. Stable pressure drop characteristics were observed in pulsed and reversed flow blowback modes of operation. Over 4900 hours of operation were obtained with operating conditions ranging up to approximately 90 0 C and 24 vol % water vapor in the gas stream

  2. Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp.

    Science.gov (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

    2015-05-01

    Cellulase treatment for decreasing viscosity and increasing Fock reactivity of dissolving pulp is a promising approach to reduce the use of toxic chemicals, such as hypochlorite in the dissolving pulp manufacturing process in the industry. Improving the cellulase treatment efficiency during the process is of practical interest. In the present study, the concept of using cationic polyacrylamide (CPAM) to enhance the cellulase treatment efficiency was demonstrated. This was mainly attributed to the increased cellulase adsorption onto cellulose fibers based on the patching/bridging mechanism. Results showed that the cellulase adsorption was increased by about 20% with the addition of 250 ppm of CPAM under the same conditions as those of the control. It was found that the viscosity decrease and Fock reactivity increase for the cellulase treatment was enhanced from using CPAM. The CPAM-assisted cellulase treatment concept may provide a practical alternative to the present hypochlorite-based technology for viscosity control in the industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Treatment of natural rubber processing wastewater using a combination system of a two-stage up-flow anaerobic sludge blanket and down-flow hanging sponge system.

    Science.gov (United States)

    Tanikawa, D; Syutsubo, K; Hatamoto, M; Fukuda, M; Takahashi, M; Choeisai, P K; Yamaguchi, T

    2016-01-01

    A pilot-scale experiment of natural rubber processing wastewater treatment was conducted using a combination system consisting of a two-stage up-flow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) reactor for more than 10 months. The system achieved a chemical oxygen demand (COD) removal efficiency of 95.7% ± 1.3% at an organic loading rate of 0.8 kg COD/(m(3).d). Bacterial activity measurement of retained sludge from the UASB showed that sulfate-reducing bacteria (SRB), especially hydrogen-utilizing SRB, possessed high activity compared with methane-producing bacteria (MPB). Conversely, the acetate-utilizing activity of MPB was superior to SRB in the second stage of the reactor. The two-stage UASB-DHS system can reduce power consumption by 95% and excess sludge by 98%. In addition, it is possible to prevent emissions of greenhouse gases (GHG), such as methane, using this system. Furthermore, recovered methane from the two-stage UASB can completely cover the electricity needs for the operation of the two-stage UASB-DHS system, accounting for approximately 15% of the electricity used in the natural rubber manufacturing process.

  4. Interdependences between flow patterns and oxygen entry in aeration tanks of wastewater treatment plants; Der Zusammenhang von Stroemungsstrukturen und Sauerstoffeintrag bei druckbeluefteten Belebungsbecken

    Energy Technology Data Exchange (ETDEWEB)

    Thiersch, B.

    2001-07-01

    The flow field, turbulence intensities and the distribution of the relative gas-holdup of aeration tanks of operating wastewater treatment plants were investigated experimentally with Acoustic-Doppler-Velocimeter probes. Based on the experimental results a hydrodynamical model in Euler-Euler-Formulation was developed and numerical studies of different tank and diffuser arrangements were performed. It was found that the flow pattern is mainly influenced by the gas sparger arrangement and the tank aspect-ratio. Combining the experimental and numerical results reasons for different aeration efficiencies were identified. Increasing the diffuser density changed the flow field from the spiral type to the cellular pattern with instable and dynamical structures. These flow patterns improved the aeration efficiency by increasing the residence time of the bubbles and the recirculating flows. (orig.) [German] In der vorliegenden Arbeit werden grundlegende Stroemungsstrukturen von druckbeluefteten Belebungsbecken anhand messtechnischer Untersuchungen der Geschwindigkeitsverteilungen, Turbulenzgroessen und relativer Gasgehaltsverteilungen von Belebungsbecken im Betriebszustand aufgezeigt. Vorab wird die Einsatzfaehigkeit von Akkustik-Doppler-Sonden in dispersen Zweiphasenstroemungen detailliert ueberprueft. Aufbauend auf den Messergebnissen wird ein numerisches Simulationsprogramm zur dynamischen Berechnung unterschiedlicher Beckenkonfigurationen entwickelt. Aus den experimentellen Ergebnissen in Verbindung mit den Berechnungsergebnissen sowie den Auswertungen frueherer Untersuchungen konnten hydromechanische Ursachen der unterschiedlichen Sauerstoffeintragseffizienz bei verschiedenen Beckenkonzeptionen abgeleitet werden. Dabei stellen die Anordnung sowie Gleichverteilung der Belueftungselemente sowie das Querschnittsverhaeltnis der Belebungsbecken die wesentlichen Einflussgroessen auf die Ausbildung der Stroemungsstrukturen dar. Mit zunehmender Belegungsdichte und

  5. APPLICATION OF PULSE-PERIODICAL MODE FOR IMPROVEMENT OF LASER TREATMENT EFFICIENCY

    Directory of Open Access Journals (Sweden)

    V. V. Apollonov

    2014-01-01

    Full Text Available The purpose of the paper is to estimate an application of pulse-periodical mode for improvement of laser treatment efficiency. Laser technologies have been widely used in the processes of material treatment with the purpose to provide them the required surface properties and also for high accuracy cutting of sheet materials. Application of complex treatment is of great interest and especially when it is used for worn-out surfaces with formation of a coating by gas-flame laying of powder mixture of specific composition and subsequent laser fusion.Increase of laser unit capacity is very important task for higher efficiency of laser technology application in mechanical engineering. Nowadays technological processes using lasers with high average power (more than 100 W have been applying only sources that are working in two modes, namely: continuous and pulse- periodical (P-P with pulse repetition rate from some units to several hundred hertz and pulse duration within dozens to hundreds of microseconds and even within milliseconds. On the other hand, in some cases shielding effect of plasma cloud formed during laser alloying, cladding or welding reduces the efficiency of laser treatment up to 50 % depending on plasma composition and laser beam length. High frequency P-P laser systems with high average power working in mode of Q-factor modulation allow to realize principally other mechanism of irradiation interaction with materials that is an ablation. In this case it is possible to provide local energy release both in space and time.The performed analysis has revealed that P-P mode of laser operation for a majority of treatment processes is much better and more efficient from energetic point of view in comparison with the continuous mode. On the basis of the developments it is possible to make a conclusion that there is a possibility to create laser systems working in high frequency P-P mode with high average power above hundreds watt.

  6. Super-compactor and grouting. Efficient and safe treatment of nuclear waste

    International Nuclear Information System (INIS)

    Li, Hongyou; Starke, Holger; Muetzel, Wolfgang; Winter, Marc

    2014-01-01

    The conditioning and volume reduction of nuclear waste are increasingly important factors throughout the world. Efficient and safe treatment of nuclear waste therefore plays a decisive role. Babcock Noell designed, manufactured and supplied a complete waste treatment facility for conditioning of the solid radioactive waste of a nuclear power plant to China. This facility consists of a Sorting Station, a Super-Compactor, a Grouting Unit with Capping Device and other auxiliary equipment which is described in more detail in the following article. This article gives an overview of the efficient and safe treatment of nuclear waste. Babcock Noell is a subsidiary of the Bilfinger Power Systems and has 40 years of experience in the field of design, engineering, construction, static and dynamic calculations, manufacturing, installation, commissioning, as well as in the service and operation of a wide variety of nuclear components and facilities worldwide.

  7. Study on cross-flow ultrafiltration for the radioactive liquid waste treatment

    International Nuclear Information System (INIS)

    Jung, K. H.; Jo, E. S.; Lee, D. G.; Lee, G. W.; Jung, K. J.

    2000-01-01

    The effect of the UF membranes on permeate flux was investigated in the ultrafiltration of dodecane (0.1v%) / water emulsion and dodecane-SDS-water emulsion in view of the treatment of radioactive oily emulsion liquid waste in the future. For variety of membranes, experiments in cross-flow modes have been performed at various pressure and different cross-flow velocities. Permeate flux decreased with the time and reached a constant steady-state value. Steady-state flux was found to be dependent by the hydrodynamic conditions but independent by the pressure. Flux decrease and rates of permeate flow resistance change have been analysed using a formulation of the equations illustrating the method of resistance mechanism recognition

  8. [The Probabilistic Efficiency Frontier: A Value Assessment of Treatment Options in Hepatitis C].

    Science.gov (United States)

    Mühlbacher, Axel C; Sadler, Andrew

    2017-06-19

    Background The German Institute for Quality and Efficiency in Health Care (IQWiG) recommends the concept of the efficiency frontier to assess health care interventions. The efficiency frontier supports regulatory decisions on reimbursement prices for the appropriate allocation of health care resources. Until today this cost-benefit assessment framework has only been applied on the basis of individual patient-relevant endpoints. This contradicts the reality of a multi-dimensional patient benefit. Objective The objective of this study was to illustrate the operationalization of multi-dimensional benefit considering the uncertainty in clinical effects and preference data in order to calculate the efficiency of different treatment options for hepatitis C (HCV). This case study shows how methodological challenges could be overcome in order to use the efficiency frontier for economic analysis and health care decision-making. Method The operationalization of patient benefit was carried out on several patient-relevant endpoints. Preference data from a discrete choice experiment (DCE) study and clinical data based on clinical trials, which reflected the patient and the clinical perspective, respectively, were used for the aggregation of an overall benefit score. A probabilistic efficiency frontier was constructed in a Monte Carlo simulation with 10000 random draws. Patient-relevant endpoints were modeled with a beta distribution and preference data with a normal distribution. The assessment of overall benefit and costs provided information about the adequacy of the treatment prices. The parameter uncertainty was illustrated by the price-acceptability-curve and the net monetary benefit. Results Based on the clinical and preference data in Germany, the interferon-free treatment options proved to be efficient for the current price level. The interferon-free therapies of the latest generation achieved a positive net cost-benefit. Within the decision model, these therapies

  9. Improving flow distribution in influent channels using computational fluid dynamics.

    Science.gov (United States)

    Park, No-Suk; Yoon, Sukmin; Jeong, Woochang; Lee, Seungjae

    2016-10-01

    Although the flow distribution in an influent channel where the inflow is split into each treatment process in a wastewater treatment plant greatly affects the efficiency of the process, and a weir is the typical structure for the flow distribution, to the authors' knowledge, there is a paucity of research on the flow distribution in an open channel with a weir. In this study, the influent channel of a real-scale wastewater treatment plant was used, installing a suppressed rectangular weir that has a horizontal crest to cross the full channel width. The flow distribution in the influent channel was analyzed using a validated computational fluid dynamics model to investigate (1) the comparison of single-phase and two-phase simulation, (2) the improved procedure of the prototype channel, and (3) the effect of the inflow rate on flow distribution. The results show that two-phase simulation is more reliable due to the description of the free-surface fluctuations. It should first be considered for improving flow distribution to prevent a short-circuit flow, and the difference in the kinetic energy with the inflow rate makes flow distribution trends different. The authors believe that this case study is helpful for improving flow distribution in an influent channel.

  10. Achieving Textbook Multigrid Efficiency for Hydrostatic Ice Sheet Flow

    KAUST Repository

    Brown, Jed; Smith, Barry; Ahmadia, Aron

    2013-01-01

    The hydrostatic equations for ice sheet flow offer improved fidelity compared with the shallow ice approximation and shallow stream approximation popular in today's ice sheet models. Nevertheless, they present a serious bottleneck because they require the solution of a three-dimensional (3D) nonlinear system, as opposed to the two-dimensional system present in the shallow stream approximation. This 3D system is posed on high-aspect domains with strong anisotropy and variation in coefficients, making it expensive to solve with current methods. This paper presents a Newton--Krylov multigrid solver for the hydrostatic equations that demonstrates textbook multigrid efficiency (an order of magnitude reduction in residual per iteration and solution of the fine-level system at a small multiple of the cost of a residual evaluation). Scalability on Blue Gene/P is demonstrated, and the method is compared to various algebraic methods that are in use or have been proposed as viable approaches.

  11. Achieving Textbook Multigrid Efficiency for Hydrostatic Ice Sheet Flow

    KAUST Repository

    Brown, Jed

    2013-03-12

    The hydrostatic equations for ice sheet flow offer improved fidelity compared with the shallow ice approximation and shallow stream approximation popular in today\\'s ice sheet models. Nevertheless, they present a serious bottleneck because they require the solution of a three-dimensional (3D) nonlinear system, as opposed to the two-dimensional system present in the shallow stream approximation. This 3D system is posed on high-aspect domains with strong anisotropy and variation in coefficients, making it expensive to solve with current methods. This paper presents a Newton--Krylov multigrid solver for the hydrostatic equations that demonstrates textbook multigrid efficiency (an order of magnitude reduction in residual per iteration and solution of the fine-level system at a small multiple of the cost of a residual evaluation). Scalability on Blue Gene/P is demonstrated, and the method is compared to various algebraic methods that are in use or have been proposed as viable approaches.

  12. Tracking the maximum efficiency point for the FC system based on extremum seeking scheme to control the air flow

    International Nuclear Information System (INIS)

    Bizon, Nicu

    2014-01-01

    Highlights: • The Maximum Efficiency Point (MEP) is tracked based on air flow rate. • The proposed Extremum Seeking (ES) control assures high performances. • About 10 kW/s search speed and 99.99% stationary accuracy can be obtained. • The energy efficiency increases with 3–12%, according to the power losses. • The control strategy is robust based on self-optimizing ES scheme proposed. - Abstract: An advanced control of the air compressor for the Proton Exchange Membrane Fuel Cell (PEMFC) system is proposed in this paper based on Extremum Seeking (ES) control scheme. The FC net power is mainly depended on the air and hydrogen flow rate and pressure, and heat and water management. This paper proposes to compute the optimal value for the air flow rate based on the advanced ES control scheme in order to maximize the FC net power. In this way, the Maximum Efficiency Point (MEP) will be tracked in real time, with about 10 kW/s search speed and a stationary accuracy of 0.99. Thus, energy efficiency will be close to the maximum value that can be obtained for a given PEMFC stack and compressor group under dynamic load. It is shown that the MEP tracking allows an increasing of the FC net power with 3–12%, depending on the percentage of the FC power supplied to the compressor and the level of the load power. Simulations shows that the performances mentioned above are effective

  13. Effect of Fixed Orthodontic Treatment on Salivary Flow, pH and Microbial Count

    Directory of Open Access Journals (Sweden)

    Sepideh Arab

    2016-08-01

    Full Text Available Objectives: The present study was designed to evaluate the changes in saliva properties and oral microbial flora in patients undergoing fixed orthodontic treatment.Materials and Methods: Two important saliva properties namely the salivary flow rate and pH as well as oral microbial flora were assessed in 30 orthodontic patients before starting fixed orthodontic treatment and after six, 12 and 18 weeks of treatment. Selective media, Sabouraud dextrose agar, Mitis salivarius agar and Rogosa agar were used for isolation of Candida albicans, Streptococcus mutans and Lactobacillus acidophilus, respectively. Statistical analysis was performed using Friedman and Dunn’s tests. P< 0.05 was considered statistically significant.Results: After six, 12 and 18 weeks of commencing fixed orthodontic treatment, the total colony counts of Candida albicans, Streptococcus mutans and Lactobacillus acidophilus showed a significant increase. The saliva pH decreased during the orthodontic treatment (P< 0.05 while the salivary flow did not change significantly. Conclusions: Fixed orthodontic treatment causes major changes in the saliva properties. The changes in oral microflora and saliva properties show the importance of caries preventive measures during orthodontic treatment.

  14. Passive flow regulators for drug delivery and hydrocephalus treatment

    Science.gov (United States)

    Chappel, E.; Dumont-Fillon, D.; Mefti, S.

    2014-03-01

    Passive flow regulators are usually intended to deliver or drain a fluid at a constant rate independently from pressure variations. New designs of passive flow regulators made of a stack of a silicon membrane anodically bonded to a Pyrex substrate are proposed. A first design has been built for the derivation of cerebrospinal fluid (CSF) towards peritoneum for hydrocephalus treatment. The device allows draining CSF at the patient production rate independently from postural changes. The flow rate is regulated at 20 ml/h in the range 10 to 40 mbar. Specific features to adjust in vivo the nominal flow rate are shown. A second design including high pressure shut-off feature has been made. The intended use is drug delivery with pressurized reservoir of typically 100 to 300 mbar. In both cases, the membrane comprises several holes facing pillars in the Pyrex substrate. These pillars are machined in a cavity which ensures a gap between the membrane and the pillars at rest. The fluid in the pressurized reservoir is directly in contact with the top surface of the membrane, inducing its deflection towards Pyrex substrate and closing progressively the fluidic pathway through each hole of the membrane. Since the membrane deflection is highly non-linear, FEM simulations have been performed to determine both radial position and diameter of the membrane holes that ensure a constant flow rate for a given range of pressure.

  15. Treatment of landfill leachate by irrigation of willow coppice - Plant response and treatment efficiency

    International Nuclear Information System (INIS)

    Aronsson, Paer; Dahlin, Torleif; Dimitriou, Ioannis

    2010-01-01

    Landfill leachates usually need to be treated before discharged, and using soil-plant systems for this has gained substantial interest in Sweden and in the UK. A three-year field study was conducted in central Sweden to quantify plant response, treatment efficiency and impact on groundwater quality of landfill leachate irrigation of short-rotation willow coppice (Salix). Two willow varieties were tested and four irrigation regimes in sixteen 400-m 2 plots. The willow plants did not react negatively, despite very high annual loads of nitrogen (≤2160 kg N/ha), chloride (≤8600 kg Cl/ha) and other elements. Mean annual growth was 1.5, 9.8 and 12.6 tonnes DM/ha during years 1-3. For one of two willow varieties tested, relative leaf length accurately predicted growth rate. Irrigation resulted in elevated groundwater concentrations of all elements applied. Treatment efficiency varied considerably for different elements, but was adequate when moderate loads were applied. - Short-rotation willow coppice was successfully used for treating a strong landfill leachate in central Sweden over three years.

  16. Recycling of waste bread as culture media for efficient biological treatment of wastewater

    International Nuclear Information System (INIS)

    Kim, Young-Ju; Kim, Pil-Jin; Kim, Ji-Hoon; Lee, Chang-Soo; Qureshi, T.I.

    2012-01-01

    Possibilities of recycling of waste bread as culture media for efficient biological treatment of wastewater were investigated. In order to get the highest growth of microorganism for increased contaminants' removal efficiency of the system, different compositions of waste bread and skim milk with and without adding Powdered Activated Carbon (PAC) were tested. Mixed waste bread compositions with added PAC showed relatively higher number of microorganisms than the compositions without added PAC. A composition of 40% mixed waste bread and 60% skim milk produced highest number of microorganisms with subsequent increased contaminants' removal efficiency of the system. 'Contrast' alone showed lower contaminants' removal efficiency than mixed bread compositions. Use of waste bread in the composition of skim milk reduced cost of using foreign source of nutrients in biological treatment of wastewater and also facilitated waste bread management through recycling. (author)

  17. Assessing the efficiency of an unplanted horizontal flow constructed wetland to reduce some emerging organic micropollutants. Preliminary results

    Science.gov (United States)

    Tapias, Josefina C.; Vila, Marta; Himi, Mahjoub; Salvadó, Victoria; Casas, Albert; Hidalgo, Manuela

    2017-04-01

    The presence of emerging organic contaminants (EOC) such as pharmaceutical and personal care products, pesticides or antiseptics in wastewater is an increasing concern worldwide due to their potential toxicological effects for humans and other living organisms. Because of their low concentration and persistence their removal using conventional treatment technologies is often incomplete and for this reason there is a growing interest for assessing the efficiency of alternative wastewater treatment technologies such as constructed wetlands (CWs). CWs are engineered systems for wastewater treatment plant (WWTP) designed to take advantage of many of the same processes that occur in natural wetlands, but within a more controlled environment. CWs are a cost-effective alternative to conventional wastewater treatment plants especially in the context of small communities with less than 2000 people equivalent. Our study has been conducted at the Verdú WWTP (Lleida, Catalonia, NE Spain). This system has a primary treatment consisting on three septic tanks in parallel with a volume of 50 m3 and three chambers each one. The primary effluent is distributed to four parallel horizontal subsurface flow (HSSF) CWs. Originally the system was planted with common reed (Phragmites australis), but currently after twelve years of service the system show evidences of clogging and then gravel bed was replaced and plants removed. After the HSSF CWs, there are two wastewater stabilization ponds (WSPs) followed by two smaller polishing horizontal HSSF CWs. Excellent overall treatment performance was exhibited on the elimination of conventional water quality parameters (93-98% average removal efficiency for TSS, COD, BOD5 and NTK), and its final effluent proved to comply with existing Spanish guidelines. Sampling has been conducted along two years at different seasons and examined EOC substances included analgesic and anti-inflammatory drugs (ibuprofen, diclofenac, and naproxene

  18. Small scale recirculating vertical flow constructed wetland (RVFCW) for the treatment and reuse of wastewater.

    Science.gov (United States)

    Gross, A; Sklarz, M Y; Yakirevich, A; Soares, M I M

    2008-01-01

    The quantity of freshwater available worldwide is declining, revealing a pressing need for its more efficient use. Moreover, in many developing countries and lightly populated areas, raw wastewater is discarded into the environment posing serious ecological and health problems. Unfortunately, this situation will persist unless low-cost, effective and simple technologies are brought in. The aim of this study is to present such a treatment method, a novel setup which is termed recirculating vertical flow constructed wetland (RVFCW). The RVFCW is composed of two components: (i) a three-layer bed consisting of planted organic soil over an upper layer of filtering media (i.e. tuff or beads) and a lower layer of limestone pebbles, and (ii) a reservoir located beneath the bed. Wastewater flows directly into the plant root zone and trickles down through the three-layer bed into the reservoir, allowing passive aeration. From the reservoir the water is recirculated back to the bed, several times, until the desired purification is achieved. The results obtained show that the RVFCW is an effective and convenient strategy to treat (domestic, grey and agro) wastewater for re-use in irrigation. The system performance is expected to be further improved once current optimization experiments and mathematical modeling studies are concluded. IWA Publishing 2008.

  19. Molecular Materials for Nonaqueous Flow Batteries with a High Coulombic Efficiency and Stable Cycling.

    Science.gov (United States)

    Milton, Margarita; Cheng, Qian; Yang, Yuan; Nuckolls, Colin; Hernández Sánchez, Raúl; Sisto, Thomas J

    2017-12-13

    This manuscript presents a working redox battery in organic media that possesses remarkable cycling stability. The redox molecules have a solubility over 1 mol electrons/liter, and a cell with 0.4 M electron concentration is demonstrated with steady performance >450 cycles (>74 days). Such a concentration is among the highest values reported in redox flow batteries with organic electrolytes. The average Coulombic efficiency of this cell during cycling is 99.868%. The stability of the cell approaches the level necessary for a long lifetime nonaqueous redox flow battery. For the membrane, we employ a low cost size exclusion cellulose membrane. With this membrane, we couple the preparation of nanoscale macromolecular electrolytes to successfully avoid active material crossover. We show that this cellulose-based membrane can support high voltages in excess of 3 V and extreme temperatures (-20 to 110 °C). These extremes in temperature and voltage are not possible with aqueous systems. Most importantly, the nanoscale macromolecular platforms we present here for our electrolytes can be readily tuned through derivatization to realize the promise of organic redox flow batteries.

  20. Asymmetric flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry for the quantification of quantum dots bioconjugation efficiency.

    Science.gov (United States)

    Menéndez-Miranda, Mario; Encinar, Jorge Ruiz; Costa-Fernández, José M; Sanz-Medel, Alfredo

    2015-11-27

    Hyphenation of asymmetric flow field-flow fractionation (AF4) to an on-line elemental detection (inductively coupled plasma-mass spectrometry, ICP-MS) is proposed as a powerful diagnostic tool for quantum dots bioconjugation studies. In particular, conjugation effectiveness between a "model" monoclonal IgG antibody (Ab) and CdSe/ZnS core-shell Quantum Dots (QDs), surface-coated with an amphiphilic polymer, has been monitored here by such hybrid AF4-ICP-MS technique. Experimental conditions have been optimized searching for a proper separation between the sought bioconjugates from the eventual free reagents excesses employed during the bioconjugation (QDs and antibodies). Composition and pH of the carrier have been found to be critical parameters to ensure an efficient separation while ensuring high species recovery from the AF4 channel. An ICP-MS equipped with a triple quadropole was selected as elemental detector to enable sensitive and reliable simultaneous quantification of the elemental constituents, including sulfur, of the nanoparticulated species and the antibody. The hyphenated technique used provided nanoparticle size-based separation, elemental detection, and composition analysis capabilities that turned out to be instrumental in order to investigate in depth the Ab-QDs bioconjugation process. Moreover, the analytical strategy here proposed allowed us not only to clearly identify the bioconjugation reaction products but also to quantify nanoparticle:antibodies bioconjugation efficiency. This is a key issue in future development of analytical and bioanalytical photoluminescent QDs applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. CAPILLARY BLOOD FLOW STATE ESTIMATION DURING PATIENTS TREATMENT WITH ORTODENTIC MECHANICAL APPLIANCES

    Directory of Open Access Journals (Sweden)

    D. A. Domenyuk

    2015-01-01

    Full Text Available Laser Doppler flowmetry was used to investigate the palatal muscosa capillary bloodflow in children aged 4.5-9 years with crowded teeth undergoing treatment with removable orthodontic appliances from cold-cured base polymers. The results obtained from the examination of the capillary blood flow based on the amplitude standard deviation, the variation coefficient, the amplitudes of vasomotor, breathing, and cardiorhythms, as well as the indices for active and passive mechanisms of blood flow modulation at the areas under study, showed that the hemodynamics indices in the palatal muscosa got disturbed a month after the treatment was started while the disturbances went even worse at later stages

  2. Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment.

    Science.gov (United States)

    Cambié, Dario; Bottecchia, Cecilia; Straathof, Natan J W; Hessel, Volker; Noël, Timothy

    2016-09-14

    Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous reactants. In this review, an up-to-date overview is given of photochemical transformations in continuous-flow reactors, including applications in organic synthesis, material science, and water treatment. In addition, the advantages of continuous-flow photochemistry are pointed out and a thorough comparison with batch processing is presented.

  3. Nitrogen Removal Efficiency at Centralized Domestic Wastewater Treatment Plants in Bangkok, Thailand

    Directory of Open Access Journals (Sweden)

    Pongsak Noophan

    2009-07-01

    Full Text Available In this study, influents and effluents from centralized domestic wastewater treatment systems in Bangkok (Rattanakosin, Dindaeng, Chongnonsi, Nongkhaem, and Jatujak were randomly collected in order to measure organic nitrogen plus ammonium-nitrogen (total Kjeldahl nitrogen, total organic carbon, total suspended solids, and total volatile suspended solids by using Standard Methods for the Examination of Water and Wastewater 1998. Characteristics of influent and effluent (primary data of the centralized domestic wastewater treatment system from the Drainage and Sewerage Department of Bangkok Metropolitan Administration were used to analyze efficiency of systems. Fluorescent in situ hybridization (FISH was used to identify specific nitrifying bacteria (ammonium oxidizing bacteria specific for Nitrosomonas spp. and nitrite oxidizing bacteria specific for Nitrobacter spp. and Nitrospira spp.. Although Nitrosomonas spp. and Nitrobacter spp. were found, Nitrospira spp. was most prevalent in the aeration tank of centralized wastewater treatment systems. Almost all of the centralized domestic wastewater treatment plants in Bangkok are designed for activated sludge type biological nutrient removal (BNR. However, low efficiency nitrogen removal was found at centralized wastewater treatment plants in Bangkok. Influent ratio of TOC:N at centralized treatment plant is less than 2.5. Centralized wastewater treatment systems have not always been used suitability and used successfully in some areas of Bangkok Thailand.

  4. Hidden costs of antiretroviral treatment: the public health efficiency of drug packaging

    Directory of Open Access Journals (Sweden)

    Andreu-Crespo À

    2015-08-01

    Full Text Available Àngels Andreu-Crespo,1,* Josep M Llibre,2,3,* Glòria Cardona-Peitx,1 Ferran Sala-Piñol,1 Bonaventura Clotet,2,4 Xavier Bonafont-Pujol1 1Pharmacy Department, 2HIV Unit and “Lluita contra la SIDA” Foundation, University Hospital Germans Trias i Pujol, Badalona, 3Universitat Autònoma de Barcelona, 4Universitat de Vic-Universitat Central de Catalunya (UVIC-UCC, Vic, Barcelona, Spain *These authors contributed equally to the work Abstract: While the overall percentage of unused antiretroviral medicines returned to the hospital pharmacy is low, their cost is quite high. Adverse events, treatment failure, pharmacokinetic interactions, pregnancy, or treatment simplification are common reasons for unplanned treatment changes. Socially inefficient antiretroviral packages prevent the reuse of drugs returned to the hospital pharmacy. We defined antiretroviral package categories based on the excellence of drug packaging and analyzed the number of pills and costs of drugs returned during a period of 1 year in a hospital-based HIV unit attending to 2,413 treated individuals. A total of 6,090 pills (34% of all returned antiretrovirals – with a cost of 47,139.91€ – would be totally lost, mainly due to being packed up in the lowest efficiency packages. Newer treatments are packaged in low-excellence categories of packages, thus favoring the maintenance of these hidden costs in the near future. Therefore, costs of this low-efficiency drug packaging, where medication packages are started but not completed, in high-cost medications are substantial and should be properly addressed. Any improvement in the packaging by the manufacturer, and favoring the choice of drugs supplied through efficient packages (when efficacy, toxicity, and convenience are similar, should minimize the treatment expenditures paid by national health budgets. Keywords: antiretroviral treatment, cost efficacy, drug packaging, treatment change

  5. Geometrically Flexible and Efficient Flow Analysis of High Speed Vehicles Via Domain Decomposition, Part 1: Unstructured-Grid Solver for High Speed Flows

    Science.gov (United States)

    White, Jeffery A.; Baurle, Robert A.; Passe, Bradley J.; Spiegel, Seth C.; Nishikawa, Hiroaki

    2017-01-01

    The ability to solve the equations governing the hypersonic turbulent flow of a real gas on unstructured grids using a spatially-elliptic, 2nd-order accurate, cell-centered, finite-volume method has been recently implemented in the VULCAN-CFD code. This paper describes the key numerical methods and techniques that were found to be required to robustly obtain accurate solutions to hypersonic flows on non-hex-dominant unstructured grids. The methods and techniques described include: an augmented stencil, weighted linear least squares, cell-average gradient method, a robust multidimensional cell-average gradient-limiter process that is consistent with the augmented stencil of the cell-average gradient method and a cell-face gradient method that contains a cell skewness sensitive damping term derived using hyperbolic diffusion based concepts. A data-parallel matrix-based symmetric Gauss-Seidel point-implicit scheme, used to solve the governing equations, is described and shown to be more robust and efficient than a matrix-free alternative. In addition, a y+ adaptive turbulent wall boundary condition methodology is presented. This boundary condition methodology is deigned to automatically switch between a solve-to-the-wall and a wall-matching-function boundary condition based on the local y+ of the 1st cell center off the wall. The aforementioned methods and techniques are then applied to a series of hypersonic and supersonic turbulent flat plate unit tests to examine the efficiency, robustness and convergence behavior of the implicit scheme and to determine the ability of the solve-to-the-wall and y+ adaptive turbulent wall boundary conditions to reproduce the turbulent law-of-the-wall. Finally, the thermally perfect, chemically frozen, Mach 7.8 turbulent flow of air through a scramjet flow-path is computed and compared with experimental data to demonstrate the robustness, accuracy and convergence behavior of the unstructured-grid solver for a realistic 3-D geometry on

  6. Efficiency of combined process of ozone and bio-filtration in the treatment of secondary effluent.

    Science.gov (United States)

    Tripathi, Smriti; Tripathi, B D

    2011-07-01

    The present work was aimed at studying the efficiency of the combined process of biofiltration with ozonation to improve the quality of secondary effluent. The secondary effluent from the Dinapur Sewage Treatment Plant Varanasi, India was used in this work. The process of biofiltration with the plant species of Eichornia crassipes and Lemna minor, at a flow rate of 262 ml min(-1) and plant density of 30 mg L(-1) for 48 h, in combination with the process of ozonation with ozone dose of 10 mg L(-1) and contact time of 5 min was applied. Results revealed that combined process was statistically most suitable for the highest degradation of physico-chemical and microbial parameters with improving BDOC value. The biofiltration process is able to remove highest percentage of toxic heavy metals from the secondary effluent without production of toxicity. This technique is highly recommendable for tropical wastewater where sewage is mixed with industrial effluents. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Changes in blood flow by local hypothermia and its application to cancer treatment

    International Nuclear Information System (INIS)

    Hong, Seong-Su; Higano, Shuichi; Ogawa, Yoshihiro; Nakamura, Mamoru; Hoshino, Humihiko

    1984-01-01

    Protective effects of local hypothermia on radiation dermatitis and mucositis were shown. It was considered that the main factor influencing radioprotection was decrease of local blood flow. Our examinations showed that blood flow of the skin and oral mucosa decreased while that of the tumors did not so change. Adequate results were obtained in the combined treatment of radiation and chemotherapy. (author)

  8. Increasing Water System Efficiency with Ultrafiltration Pre-treatment in Power Plants

    International Nuclear Information System (INIS)

    Majamaa, Katariina; Suarez, Javier; Gasia Eduard

    2012-09-01

    Water demineralization with reverse osmosis (RO) membranes has a long and successful history in water treatment for power plants. As the industry strives for more efficient, reliable and compact water systems, pressurized hollow-fiber ultrafiltration (UF) has become an increasingly appealing pre-treatment technology. Compared to conventional, non- membrane based pretreatments, ultrafiltration offers higher efficiency in the removal of suspended solids, microorganisms and colloidal matter, which are all common causes for operational challenges experienced in the RO systems. In addition, UF is more capable of handling varying feed water qualities and removes the risk of particle carry-over often seen with conventional filtration techniques. Ultrafiltration is a suitable treatment technology for various water types from surface waters to wastewater, and the more fluctuating or challenging the feed water source is, the better the benefits of UF are seen compared to conventional pretreatments. Regardless of the feed water type, ultrafiltration sustains a constant supply of high quality feed water to downstream RO, allowing a more compact and cost efficient RO system design with improved operational reliability. A detailed focus on the design and operational aspects and experiences of two plants is provided. These examples demonstrate both economical UF operation and tangible impact of RO process improvement. Experience from these plants can be leveraged to new projects. (authors)

  9. Importance of considering riparian vegetation requirements for the long-term efficiency of environmental flows in aquatic microhabitats

    Directory of Open Access Journals (Sweden)

    R. Rivaes

    2017-11-01

    Full Text Available Environmental flows remain biased toward the traditional biological group of fish species. Consequently, these flows ignore the inter-annual flow variability that rules species with longer lifecycles and therefore disregard the long-term perspective of the riverine ecosystem. We analyzed the importance of considering riparian requirements for the long-term efficiency of environmental flows. For that analysis, we modeled the riparian vegetation development for a decade facing different environmental flows in two case studies. Next, we assessed the corresponding fish habitat availability of three common fish species in each of the resulting riparian landscape scenarios. Modeling results demonstrated that the environmental flows disregarding riparian vegetation requirements promoted riparian degradation, particularly vegetation encroachment. Such circumstance altered the hydraulic characteristics of the river channel where flow depths and velocities underwent local changes of up to 10 cm and 40 cm s−1, respectively. Accordingly, after a decade of this flow regime, the available habitat area for the considered fish species experienced modifications of up to 110 % when compared to the natural habitat. In turn, environmental flows regarding riparian vegetation requirements were able to maintain riparian vegetation near natural standards, thereby preserving the hydraulic characteristics of the river channel and sustaining the fish habitat close to the natural condition. As a result, fish habitat availability never changed more than 17 % from the natural habitat.

  10. Co and Fe-catalysts supported on sepiolite: effects of preparation conditions on their catalytic behaviors in high temperature gas flow treatment of dye.

    Science.gov (United States)

    Lin, Xiangfeng; Fang, Jian; Chen, Menglin; Huang, Zhi; Su, Chengyuan

    2016-08-01

    An efficient adsorbent/catalyst Co and Fe-catalysts loaded on sepiolite (Co-Fe/sepiolite) was successfully prepared for high temperature gas flow catalytic reaction by a simple impregnation method. The impact of preparation conditions (such as pH value of impregnation solution, impregnation time, calcination temperature, and time) on catalytic activity was studied. We found that the catalytic activity of Co-Fe/sepiolite was strongly influenced by all the investigated parameters. The regeneration efficiency (RE) was used to evaluate the catalytic activity. The RE is more noticeable at pH 5.0 of impregnation solution, impregnation time 18 h, calcination temperature 650 °C, and calcination time 3 h. This Co-Fe/sepiolite has great adsorption capacity in absorbing dye. It is used for an adsorbent to adsorb dye from wastewater solution under dynamic adsorption and saturated with dye, then regenerated with high temperature gas flow for adsorption/oxidation cycles. The Co-Fe/sepiolite acts as a catalyst to degrade the dye during regeneration under high temperature gas flow. Hence, the Co-Fe/sepiolite is not only an adsorbent but also a catalyst. The Co-Fe/sepiolite is more stable than sepiolite when applied in the treatment of plant's wastewater. The Co-Fe/sepiolite can be reused in adsorption-regeneration cycle. The results indicate the usability of the proposed combined process, dye adsorption on Co-Fe/sepiolite followed by the catalytic oxidation in high temperature gas flow.

  11. Biological nitrogen and carbon removal in a gravity flow biomass concentrator reactor for municipal sewage treatment.

    Science.gov (United States)

    Scott, Daniel; Hidaka, Taira; Campo, Pablo; Kleiner, Eric; Suidan, Makram T; Venosa, Albert D

    2013-01-01

    A novel membrane system, the Biomass Concentrator Reactor (BCR), was evaluated as an alternative technology for the treatment of municipal wastewater. Because the BCR is equipped with a membrane whose average poresize is 20 μm (18-28 μm), the reactor requires low-pressure differential to operate (gravity). The effectiveness of this system was evaluated for the removal of carbon and nitrogen using two identical BCRs, identified as conventional and hybrid, that were operated in parallel. The conventional reactor was operated under full aerobic conditions (i.e., organic carbon and ammonia oxidation), while the hybrid reactor incorporated an anoxic zone for nitrate reduction as well as an aerobic zone for organic carbon and ammonia oxidation. Both reactors were fed synthetic wastewater at a flow rate of 71 L d(-1), which resulted in a hydraulic retention time of 9 h. In the case of the hybrid reactor, the recycle flow from the aerobic zone to the anoxic zone was twice the feed flow rate. Reactor performance was evaluated under two solids retention times (6 and 15 d). Under these conditions, the BCRs achieved nearly 100% mixed liquor solids separation with a hydraulic head differential of less than 2.5 cm. The COD removal efficiency was over 90%. Essentially complete nitrification was achieved in both systems, and nitrogen removal in the hybrid reactor was close to the expected value (67%). Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Performance of a half-saturated vertical flow wetland packed with volcanic gravel in stormwater treatment.

    Science.gov (United States)

    Chen, Yaoping; Park, Kisoo; Niu, Siping; Kim, Youngchul

    2014-01-01

    A half-saturated pilot-scale wetland planted with Acorus calamus was built to treat urban stormwater. The design comprises a sedimentation tank for pretreatment, and a vertical flow volcanic gravel wetland bed equipped with a recirculation device. Eighteen rainfall events were monitored in 2012. The treatment system achieved total removal efficiencies of 99.4, 81, 50, and 86% for suspended solids, organic matter, nitrogen and phosphorus, respectively, and 29, 68, and 25% for copper, zinc, and lead, respectively, at a 3-day hydraulic residence time. In the wetland bed, the removal of ammonia, total nitrogen, and zinc were improved by recirculation. Plant uptake provided 18% of nitrogen removal and 39% of phosphorus removal. During the experimental stage, only 1.4% of the pore volume in substrate was reduced due to clogging, implying that the wetland can operate without clogging for a relatively long period.

  13. An efficient semi-implicit method for three-dimensional non-hydrostatic flows in compliant arterial vessels.

    Science.gov (United States)

    Fambri, Francesco; Dumbser, Michael; Casulli, Vincenzo

    2014-11-01

    Blood flow in arterial systems can be described by the three-dimensional Navier-Stokes equations within a time-dependent spatial domain that accounts for the elasticity of the arterial walls. In this article, blood is treated as an incompressible Newtonian fluid that flows through compliant vessels of general cross section. A three-dimensional semi-implicit finite difference and finite volume model is derived so that numerical stability is obtained at a low computational cost on a staggered grid. The key idea of the method consists in a splitting of the pressure into a hydrostatic and a non-hydrostatic part, where first a small quasi-one-dimensional nonlinear system is solved for the hydrostatic pressure and only in a second step the fully three-dimensional non-hydrostatic pressure is computed from a three-dimensional nonlinear system as a correction to the hydrostatic one. The resulting algorithm is robust, efficient, locally and globally mass conservative, and applies to hydrostatic and non-hydrostatic flows in one, two and three space dimensions. These features are illustrated on nontrivial test cases for flows in tubes with circular or elliptical cross section where the exact analytical solution is known. Test cases of steady and pulsatile flows in uniformly curved rigid and elastic tubes are presented. Wherever possible, axial velocity development and secondary flows are shown and compared with previously published results. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Efficiency calculation on 10 MW experimental steam turbine

    Directory of Open Access Journals (Sweden)

    Hoznedl Michal

    2018-01-01

    Full Text Available The paper deals with defining flow path efficiency of an experimental steam turbine by using measurement of flow, torque, pressures and temperatures. The configuration of the steam turbine flow path is briefly described. Measuring points and devices are defined. The paper indicates the advantages as well as disadvantages of flow path efficiency measurement using enthalpy and torque on the shaft. The efficiency evaluation by the help pressure and temperature measurement is influenced by flow parameter distribution and can provide different values of flow path efficiency. The efficiency determination by using of torque and mass flow measurement is more accurate and it is recommended for using. The disadvantage is relatively very complicated and expensive measuring system.

  15. Toward high-efficiency and detailed Monte Carlo simulation study of the granular flow spallation target

    Science.gov (United States)

    Cai, Han-Jie; Zhang, Zhi-Lei; Fu, Fen; Li, Jian-Yang; Zhang, Xun-Chao; Zhang, Ya-Ling; Yan, Xue-Song; Lin, Ping; Xv, Jian-Ya; Yang, Lei

    2018-02-01

    The dense granular flow spallation target is a new target concept chosen for the Accelerator-Driven Subcritical (ADS) project in China. For the R&D of this kind of target concept, a dedicated Monte Carlo (MC) program named GMT was developed to perform the simulation study of the beam-target interaction. Owing to the complexities of the target geometry, the computational cost of the MC simulation of particle tracks is highly expensive. Thus, improvement of computational efficiency will be essential for the detailed MC simulation studies of the dense granular target. Here we present the special design of the GMT program and its high efficiency performance. In addition, the speedup potential of the GPU-accelerated spallation models is discussed.

  16. [Metformin efficiency for the adolescent PCOS treatment].

    Science.gov (United States)

    Kedikova, S; Sirakov, M; Boyadzhieva, M

    2012-01-01

    PCOS is a polyglandular heterogenic metabolic condition, which frequency in adolescence is defined between 11-26%. There are some aspects of PCOS which can be seen in a regular puberty and vice versa. This makes the adolescent PCOS a condition which is rather complicated to diagnose as well as to treat. The pathophysiology of PCOS is not fully clarified, but is well established the fundamental role of the insulin resistance and the hyperinsulinemia. This fact explains the detailed investigations of the insulin sensitizers use for the PCOS treatment. Nevertheless there is insufficient experience with this medication group for the adolescent PCOS treatment in Bulgaria. To evaluate the Metformin efficiency for the adolescent PCOS treatment. This is a prospective study including 55 girls with menstrual irregularities aged between 13 and 18 years. None of the subjects had previously been diagnosed with any endocrine pathology or had received any hormonal treatment for at least three months prior to their evaluation. They have been evaluated according to the diagnostic criteria for PCOS in adolescence accepted in 2010. The incidence of PCOS in our research was 38.9%. In 66.7% of them the body mass index was higher than normal. Insulin resistance was diagnosed in 90.5%. The insulin resistance was improved in 80% of the PCOS patients after six months therapy with Metformin 2 x 850 mg/p.d. The menstrual function was regulated in 77.8% of the cases.

  17. Corrosion in Supercritical carbon Dioxide: Materials, Environmental Purity, Surface Treatments, and Flow Issues

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Anderson, Mark

    2013-12-10

    separately to high purity CO{sub 2}. Task 3: Evaluation of surface treatments on the corrosion performance of alloys in supercritical CO{sub 2}: Surface treatments can be very beneficial in improving corrosion resistance. Shot peening and yttrium and aluminum surface treatments will be investigated. Shot peening refines the surface grain sizes and promotes protective Cr-oxide layer formation. Both yttrium and aluminum form highly stable oxide layers (Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), which can get incorporated in the growing Fe-oxide layer to form an impervious complex oxide to enhance corrosion resistance. Task 4: Study of flow-assisted corrosion of select alloys in supercritical CO{sub 2} under a selected set of test conditions: To study the effects of flow-assisted corrosion, tests will be conducted in a supercritical CO{sub 2} flow loop. An existing facility used for supercritical water flow studies at the proposing university will be modified for use in this task. The system is capable of flow velocities up to 10 m/s and can operate at temperatures and pressures of up to 650°C and 20 MPa, respectively. All above tasks will be performed in conjunction with detailed materials characterization and analysis using scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS), x-ray diffraction (XRD), Auger electron spectroscopy (AES) techniques, and weight change measurements. Inlet and outlet gas compositions will be monitored using gas chromatography-mass spectrometry (GCMS).

  18. A new treatment of capillarity to improve the stability of IMPES two-phase flow formulation

    KAUST Repository

    Kou, Jisheng; Sun, Shuyu

    2010-01-01

    In this paper, we present an efficient numerical method for two-phase immiscible flow in porous media with different capillarity pressures. In highly heterogeneous permeable media, the saturation is discontinuous due to different capillary pressure

  19. A linked lake system beneath Thwaites Glacier, West Antarctica reveals an efficient mechanism for subglacial water flow.

    Science.gov (United States)

    Smith, B. E.; Gourmelen, N.; Huth, A.; Joughin, I. R.

    2016-12-01

    In this presentation we show the results of a multi-sensor survey of a system of subglacial lakes beneath Thwaites Glacier, West Antarctica. This is the first substantial active (meaning draining or filling on annual time scales) lake system detected under the fast-flowing glaciers of the Amundsen Coast. Altimetry data show that over the 2013 calendar year, four subglacial lakes drained, essentially simultaneously, with the bulk of the drainage taking place over the course the first three months of the year. The largest of the lakes appears to have drained around 3.7 km3 of water, with the others each draining less than 1 km3. The high-resolution radar surveys conducted in this area by NASA's IceBridge program allow detailed analysis of the subglacial hydrologic potential, which shows that the potential map in this area is characterized by small closed basins that should not, under the common assumption that water flow is directed down the gradient of the hydropotential, allow long-range water transport. The lakes' discharge demonstrates that, at least in some cases, water can flow out of apparently closed hydropotential basins. Combining a basal-flow routing map with a map of basal melt production suggests that the largest drainage event could recur as often as every 22 years, provided that overflow or leakage of mapped hydropotential basins allows melt water transport to refill the lake. An analysis of ice-surface speed records both around the lakes and at the Thwaites grounding line shows small changes in ice speed, but none clearly associated with the drainage event, suggesting that, at least in this area where subglacial melt is abundant, the addition of further water to the subglacial hydrologic system need not have any significant effect on ice flow. It is likely that the main impact of the lake system on the glacier is that as an efficient mechanism to remove meltwater from the system, it drains water that would otherwise flow through less efficient

  20. THE EFFECT OF THE REYNOLDS NUMBER OF AIR FLOW TO THE PARTICLE COLLECTION EFFICIENCY OF A FIBROUS FILTER MEDIUM WITH CYLINDRICAL SECTION

    Directory of Open Access Journals (Sweden)

    George P. Kouropoulos

    2014-01-01

    Full Text Available At this study an attempt for the theoretical approach of the Re ynolds number effect of air flow to the particle collection efficiency of a fibrous fil ter with cylindrical section will be made. Initially, a report of the air filtration models to fibrous filter media will be presented along with an explanation of both the parameters and the physical quantities which govern the air filtration process. Furthermore, the resul ting equation from the mathematical model will be applied to a real filter medium and the characteristic curves of filter efficiency will be drawn. The change of a filter medi um efficiency with regard to the Reynolds number of air flow that passes through the filt er, derived from the curves, will be studied. The general conclusion that we have is that as the Reynolds number of filtered air increases, the collection efficiency of the filter decreases.

  1. Investigation of TC and TSS Removal Efficiencies at Ahvaz West WTP Effluent Using the Land‒plant Treatment Process

    Directory of Open Access Journals (Sweden)

    Afshin Takdastan

    2015-12-01

    Full Text Available Although the conventional (primary and secondary treatment processes are known to remove up to 95–99% of some micro-organisms, they do not provide adequate treatment to make the effluent suitable for direct reuse, mainly due to the presence of high concentrations of pathogenic microorganisms. Obtaining reusable effluents, therefore, requires the use of processes that can be justified both technical and economic grounds. One such indigenous, low cost option is the land-plant process that can be used for advanced wastewater treatment. It is the objective of the present study to determine the efficiency of the local soil in Ahvaz and that of the vetiver plant in reducing the microbial load in the effluent from municipal wastewater treatment plants. A pilot study was thus carried out including three Lysimeters installed in West Ahvaz Wastewater Treatment Plant. Local soil was used in one Lysimeter, local soil with vetiver plant in the second one, and an artificial assortment of soil comprising local soil, silica sand (0.5-1mm, and sand (15-30mm in the third. In addition, the effluent from the secondary settling outlet at the WTP was transferred by pumping at the three filtration rates of 0.2, 0.6, and 1 ml/min into the system with three replications for each rate and samples were collected from both inlet and outlet flows. The average removal efficiencies of Total Suspended Solids (TSS and Total Coliform (TC in the effluent from the three Lysimeters with local soil with vetiver, local soil without vetiver, and artificial soil assortment for the filtration rate of 0.2 ml/min were: 67.75% and 99.7%, 58.33% and 99.6%, and 56.25% and 99.5%, respectively. For a filtration rate of 0.6 ml/min, these values were: 53.33% and 98.93%, 48.8 and 98.77%, and 47.68% and 98.64%. Finally, the values obtained for a filtration rate of 0.6 ml/min were: 50% and 93.96%, 46.42 and 91.34%, and 44/04% and 88/81%, respectively. The results from the study showed that the

  2. Improved modeling techniques for turbomachinery flow fields

    Energy Technology Data Exchange (ETDEWEB)

    Lakshminarayana, B. [Pennsylvania State Univ., University Park, PA (United States); Fagan, J.R. Jr. [Allison Engine Company, Indianapolis, IN (United States)

    1995-10-01

    This program has the objective of developing an improved methodology for modeling turbomachinery flow fields, including the prediction of losses and efficiency. Specifically, the program addresses the treatment of the mixing stress tensor terms attributed to deterministic flow field mechanisms required in steady-state Computational Fluid Dynamic (CFD) models for turbo-machinery flow fields. These mixing stress tensors arise due to spatial and temporal fluctuations (in an absolute frame of reference) caused by rotor-stator interaction due to various blade rows and by blade-to-blade variation of flow properties. These tasks include the acquisition of previously unavailable experimental data in a high-speed turbomachinery environment, the use of advanced techniques to analyze the data, and the development of a methodology to treat the deterministic component of the mixing stress tensor. Penn State will lead the effort to make direct measurements of the momentum and thermal mixing stress tensors in high-speed multistage compressor flow field in the turbomachinery laboratory at Penn State. They will also process the data by both conventional and conditional spectrum analysis to derive momentum and thermal mixing stress tensors due to blade-to-blade periodic and aperiodic components, revolution periodic and aperiodic components arising from various blade rows and non-deterministic (which includes random components) correlations. The modeling results from this program will be publicly available and generally applicable to steady-state Navier-Stokes solvers used for turbomachinery component (compressor or turbine) flow field predictions. These models will lead to improved methodology, including loss and efficiency prediction, for the design of high-efficiency turbomachinery and drastically reduce the time required for the design and development cycle of turbomachinery.

  3. Local flow management/profile descent algorithm. Fuel-efficient, time-controlled profiles for the NASA TSRV airplane

    Science.gov (United States)

    Groce, J. L.; Izumi, K. H.; Markham, C. H.; Schwab, R. W.; Thompson, J. L.

    1986-01-01

    The Local Flow Management/Profile Descent (LFM/PD) algorithm designed for the NASA Transport System Research Vehicle program is described. The algorithm provides fuel-efficient altitude and airspeed profiles consistent with ATC restrictions in a time-based metering environment over a fixed ground track. The model design constraints include accommodation of both published profile descent procedures and unpublished profile descents, incorporation of fuel efficiency as a flight profile criterion, operation within the performance capabilities of the Boeing 737-100 airplane with JT8D-7 engines, and conformity to standard air traffic navigation and control procedures. Holding and path stretching capabilities are included for long delay situations.

  4. Design, enhanced Thermal and Flow efficiency of a 2KW active magnetic regenerator

    DEFF Research Database (Denmark)

    Dallolio, Stefano; Eriksen, Dan; Engelbrecht, Kurt

    power of 1500 W over a temperature span of 25 K. This paper explains several details of the device, such as the design of the magnet, the regenerator housing and the flow system. In particular, this paper investigates the best geometry for the regenerator bed to achieve a thermal and mechanically...... efficient housing to be used in the AMR system. Particular attention has been given to the reduction of the parasitic losses through the regenerator housing: both heat leaks between the magnetocaloric material (MCM) and an adjacent iron ring and the surroundings through a lid on top of the regenerator...

  5. Following the money: Mapping the sources and funding flows of alcohol and other drug treatment in Australia.

    Science.gov (United States)

    Chalmers, Jenny; Ritter, Alison; Berends, Lynda; Lancaster, Kari

    2016-05-01

    The structures of health systems impact on patient outcomes. We present and analyse the first detailed mapping of who funds alcohol and other drug (AOD) treatment and the channels and intermediaries through which funding flows from the funding sources to treatment providers. The study involved a literature review of AOD treatment financing and existing diagrammatic representations of the structure of the Australian health system. We interviewed 190 key informants to particularise the AOD treatment sector, and undertook two case examples of government funded non-government organisations providing AOD treatment. Funding sources include the Australian and state and territory governments, philanthropy, fund-raising and clients themselves. While funding sources align with the health sector generally and the broader social services sector, the complexity of flows from source to treatment service and the number of intermediaries are noteworthy. So too are the many sources of funding drawn on by some treatment providers. Diversification is both beneficial and disadvantageous for non-government treatment providers, adding to administrative workloads, but smoothing the risk of funding shortfalls. Government funders benefit from sharing risk. Circuitous funding flows multiply the funding sources drawn on by services and put distance between the funding source and the service provider. This leads to concerns over lack of transparency about what is being purchased and challenges for the multiply funded service provider in maintaining programs and service models amid multiple and sometimes competing funding and accountability frameworks. [Chalmers J, Ritter A, Berends L, Lancaster K. Following the money: Mapping the sources and funding flows of alcohol and other drug treatment in Australia. Drug Alcohol Rev 2016;35:255-262]. © 2015 Australasian Professional Society on Alcohol and other Drugs.

  6. Enhanced fuel efficiency on tractor-trailers using synthetic jet-based active flow control

    Science.gov (United States)

    Amitay, Michael; Menicovich, David; Gallardo, Daniele

    2016-04-01

    The application of piezo-electrically-driven synthetic-jet-based active flow control to reduce drag on tractor-trailers was explored experimentally in wind tunnel testing as well as full-scale road tests. Aerodynamic drag accounts for more than 50% of the usable energy at highway speeds, a problem that applies primarily to trailer trucks. Therefore, a reduction in aerodynamic drag results in large saving of fuel and reduction in CO2 emissions. The active flow control technique that is being used relies on a modular system comprised of distributed, small, highly efficient actuators. These actuators, called synthetic jets, are jets that are synthesized at the edge of an orifice by a periodic motion of a piezoelectric diaphragm(s) mounted on one (or more) walls of a sealed cavity. The synthetic jet is zero net mass flux (ZNMF), but it allows momentum transfer to flow. It is typically driven near diaphragm and/or cavity resonance, and therefore, small electric input [O(10W)] is required. Another advantage of this actuator is that no plumbing is required. The system doesn't require changes to the body of the truck, can be easily reconfigured to various types of vehicles, and consumes small amounts of electrical power from the existing electrical system of the truck. Preliminary wind tunnel results showed up to 18% reduction in fuel consumption, whereas road tests also showed very promising results.

  7. Modeling of flow and reactive transport in IPARS

    KAUST Repository

    Wheeler, Mary Fanett

    2012-03-11

    In this work, we describe a number of efficient and locally conservative methods for subsurface flow and reactive transport that have been or are currently being implemented in the IPARS (Integrated Parallel and Accurate Reservoir Simulator). For flow problems, we consider discontinuous Galerkin (DG) methods and mortar mixed finite element methods. For transport problems, we employ discontinuous Galerkin methods and Godunov-mixed methods. For efficient treatment of reactive transport simulations, we present a number of state-of-the-art dynamic mesh adaptation strategies and implementations. Operator splitting approaches and iterative coupling techniques are also discussed. Finally, numerical examples are provided to illustrate the capability of IPARS to treat general biogeochemistry as well as the effectivity of mesh adaptations with DG for transport. © 2012 Bentham Science Publishers. All rights reserved.

  8. Improvement of the current efficiency of an Al-Zn-In anode by heat-treatment

    International Nuclear Information System (INIS)

    Lin, J.C.; Shih, H.C.

    1987-01-01

    Aluminum anodes, each having one of several heat-treatments [namely as-cast (A), furnace-cooled (B), quenched (C), and quenched and aged (D-1)] were electrically coupled to structural steels to provide cathodic protection. The electro-chemical potential of each galvanic couple depended on the type of heat-treatment: anodes A, B, and C exhibited a potential of -1.10V, and anode D-1 was somewhat less negative at -0.95V. Empirical relationships between galvanic current density and area ratio (AR), based on 120h tests, have been established. Surface examination showed that anodes A, B, and C corrode uniformly, whereas anode D-1 dissolves locally. Results showed that the current efficiency of a sacrificial aluminum anode is dependent on its microstructure, which is, in turn, affected by its heat-treatment. Both anodes A and B possessed an equilibrium precipitate of In and the corresponding efficiencies did not vary with time. However, anode C, and especially anode D-1, suffered from aging, and their efficiencies varied with time. The microstructure of anode C contained thermal defects such as dislocation loops, while anode D-1 contained both dislocation loops and microsegregates. Results confirm that as-cast and furnace-cooled anodes have the best efficiencies (94-98%), while quenched and aged anodes have significantly lower efficiencies

  9. Evaluation of the process performance of a down-flow hanging sponge reactor for direct treatment of domestic wastewater in Bangkok, Thailand.

    Science.gov (United States)

    Miyaoka, Yuma; Yoochatchaval, Wilasinee; Sumino, Haruhiko; Banjongproo, Pathan; Yamaguchi, Takashi; Onodera, Takashi; Okadera, Tomohiro; Syutsubo, Kazuaki

    2017-08-24

    This study assesses the performance of an aerobic trickling filter, down-flow hanging sponge (DHS) reactor, as a decentralized domestic wastewater treatment technology. Also, the characteristic eukaryotic community structure in DHS reactor was investigated. Long-term operation of a DHS reactor for direct treatment of domestic wastewater (COD = 150-170 mg/L and BOD = 60-90 mg/L) was performed under the average ambient temperature ranged from 28°C to 31°C in Bangkok, Thailand. Throughout the evaluation period of 550 days, the DHS reactor at a hydraulic retention time of 3 h showed better performance than the existing oxidation ditch process in the removal of organic carbon (COD removal rate = 80-83% and BOD removal rate = 91%), nitrogen compounds (total nitrogen removal rate = 45-51% and NH 4 + -N removal rate = 95-98%), and low excess sludge production (0.04 gTS/gCOD removed). The clone library based on the 18S ribosomal ribonucleic acid gene sequence revealed that phylogenetic diversity of 18S rRNA gene in the DHS reactor was higher than that of the present oxidation ditch process. Furthermore, the DHS reactor also demonstrated sufficient COD and NH 4 + -N removal efficiency under flow rate fluctuation conditions that simulates a small-scale treatment facility. The results show that a DHS reactor could be applied as a decentralized domestic wastewater treatment technology in tropical regions such as Bangkok, Thailand.

  10. Phase-contrast MRI versus numerical simulation to quantify hemodynamical changes in cerebral aneurysms after flow diverter treatment

    Science.gov (United States)

    Frolov, Sergey; Prothmann, Sascha; Liepsch, Dieter; Balasso, Andrea; Berg, Philipp; Kaczmarz, Stephan; Kirschke, Jan Stefan

    2018-01-01

    Cerebral aneurysms are a major risk factor for intracranial bleeding with devastating consequences for the patient. One recently established treatment is the implantation of flow-diverters (FD). Methods to predict their treatment success before or directly after implantation are not well investigated yet. The aim of this work was to quantitatively study hemodynamic parameters in patient-specific models of treated cerebral aneurysms and its correlation with the clinical outcome. Hemodynamics were evaluated using both computational fluid dynamics (CFD) and phase contrast (PC) MRI. CFD simulations and in vitro MRI measurements were done under similar flow conditions and results of both methods were comparatively analyzed. For preoperative and postoperative distribution of hemodynamic parameters, CFD simulations and PC-MRI velocity measurements showed similar results. In both cases where no occlusion of the aneurysm was observed after six months, a flow reduction of about 30-50% was found, while in the clinically successful case with complete occlusion of the aneurysm after 6 months, the flow reduction was about 80%. No vortex was observed in any of the three models after treatment. The results are in agreement with recent studies suggesting that CFD simulations can predict post-treatment aneurysm flow alteration already before implantation of a FD and PC-MRI could validate the predicted hemodynamic changes right after implantation of a FD. PMID:29304062

  11. Computational Flow Field in Energy Efficient Engine (EEE)

    Science.gov (United States)

    Miki, Kenji; Moder, Jeff; Liou, Meng-Sing

    2016-01-01

    In this paper, preliminary results for the recently-updated Open National Combustion Code (Open NCC) as applied to the EEE are presented. The comparison between two different numerical schemes, the standard Jameson-Schmidt-Turkel (JST) scheme and the advection upstream splitting method (AUSM), is performed for the cold flow and the reacting flow calculations using the RANS. In the cold flow calculation, the AUSM scheme predicts a much stronger reverse flow in the central recirculation zone. In the reacting flow calculation, we test two cases: gaseous fuel injection and liquid spray injection. In the gaseous fuel injection case, the overall flame structures of the two schemes are similar to one another, in the sense that the flame is attached to the main nozzle, but is detached from the pilot nozzle. However, in the exit temperature profile, the AUSM scheme shows a more uniform profile than that of the JST scheme, which is close to the experimental data. In the liquid spray injection case, we expect different flame structures in this scenario. We will give a brief discussion on how two numerical schemes predict the flame structures inside the EEE using different ways to introduce the fuel injection.

  12. High efficiency particulate removal with sintered metal filters

    International Nuclear Information System (INIS)

    Kirstein, B.E.; Paplawsky, W.J.; Pence, D.T.; Hedahl, T.G.

    1981-01-01

    Because of their particle removal efficiencies and durability, sintered metal filters have been chosen for HEPA filter protection in the off-gas treatment system for the proposed Idaho National Engineering Laboratory Transuranic Waste Treatment Facility. Process evaluation of sintered metal filters indicated a lack of sufficient process design data to assume trouble-free operation. Subsequent pilot-scale testing was performed with fly ash as the test particulate. The test results showed that the sintered metal filters can have an efficiency greater than 0.9999999 for the specific test conditions used. Stable pressure drop characteristics were observed in pulsed and reversed flow blowback modes of operation. Over 4900 hours of operation were obtained with operating conditions ranging up to approximately 90 0 C and 24 volume percent water vapor in the gas stream

  13. Internal Flow of Contra-Rotating Small Hydroturbine at Off- Design Flow Rates

    Science.gov (United States)

    SHIGEMITSU, Toru; TAKESHIMA, Yasutoshi; OGAWA, Yuya; FUKUTOMI, Junichiro

    2016-11-01

    Small hydropower generation is one of important alternative energy, and enormous potential lie in the small hydropower. However, efficiency of small hydroturbines is lower than that of large one. Then, there are demands for small hydroturbines to keep high performance in wide flow rate range. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance. In this research, performance of the contra-rotating small hydroturbine with 60mm casing diameter was investigated by an experiment and numerical analysis. Efficiency of the contra-rotating small hydroturbine was high in pico-hydroturbine and high efficiency could be kept in wide flow rate range, however the performance of a rear rotor decreased significantly in partial flow rates. Then, internal flow condition, which was difficult to measure experimentally, was investigated by the numerical flow analysis. Then, a relation between the performance and internal flow condition was considered by the numerical analysis result.

  14. Kinetic Energy Losses and Efficiency of an Axial Turbine Stage in Numerical Modeling of Unsteady Flows

    Directory of Open Access Journals (Sweden)

    A. S. Laskin

    2015-01-01

    Full Text Available The article presents the results of numerical investigation of kinetic energy (KE loss and blading efficiency of the single-stage axial turbine under different operating conditions, characterized by the ratio u/C0. The calculations are performed by stationary (Stage method and nonstationary (Transient method methods using ANSYS CFX. The novelty of this work lies in the fact that the numerical simulation of steady and unsteady flows in a turbine stage is conducted, and the results are obtained to determine the loss of KE, both separately by the elements of the flow range and their total values, in the stage efficiency as well. The results obtained are compared with the calculated efficiency according to one-dimensional theory.To solve these problems was selected model of axial turbine stage with D/l = 13, blade profiles of rotor and stator of constant cross-section, similar to tested ones in inverted turbine when = 0.3. The degree of reactivity ρ = 0.27, the rotor speed was varied within the range 1000 ÷ 1800 rev/min.Results obtained allow us to draw the following conclusions:1. The level of averaged coefficients of total KE losses in the range of from 0.48 to 0.75 is from 18% to 21% when calculating by the Stage method and from 21% to 25% by the Transient one.2. The level of averaged coefficients of KE losses with the output speed of in the specified range is from 9% to 13%, and almost the same when in calculating by Stage and Transient methods.3. Levels of averaged coefficients of KE loss in blade tips (relative to the differential enthalpies per stage are changed in the range: from 4% to 3% (Stage and are stored to be equal to 5% (Transient; from 5% to 6% (Stage and from 6% to 8% (Transient.4. Coefficients of KE losses in blade tips GV and RB are higher in calculations of the model stage using the Transient method than the Stage one, respectively, by = 1.5 ÷ 2.5% and = 4 ÷ 5% of the absolute values. These are values to characterize the KE

  15. The application of polyelectrolytes to improve liquid radwaste treatment system radionuclide removal efficiency

    International Nuclear Information System (INIS)

    Homyk, W.A.; Spall, M.J.; Vance, J.N.

    1990-01-01

    At nuclear plants, miscellaneous waste water treated in the liquid radwaste processing system contains a significant fraction of suspended particulate materials ranging in size from a few microns down to the submicron region. The fewer particles that typically exist as colloids are generally negatively charged by virtue of inorganic and organic anions absorbed onto the particle surfaces. Because many of the radionuclides exist as colloids and resist agglomeration and settling they are not easily removed by mechanical filtration or ion exchange processes. The colloidal materials will easily pass through most filters with conventional pore size ratings and through most ion exchange media. This leads to poor decontamination Factors (dFs) and higher radionuclide releases to the environment. A laboratory-scale testing program was conducted at Indian Point Unit No. 2 to determine the effectiveness of the use of organic polyelectrolytes to destabilize colloidal suspensions in liquid radwaste. Destabilizing colloidal suspensions will improve the removal efficiencies of the suspended material by typical filtration and ion exchange processes. The increased removal efficiencies will provide increased dFs in the liquid radwaste treatment system. The testing focused on identifying the specific organic polyelectrolytes and the associated dosages which would be effective in destabilizing the colloidal suspensions on actual waste water samples. The testing also examined the filtration characteristics of the water source to determine filter parameters such as: body feed material, body feed dosages, specific flow rates, etc., which would provide the basis for the design of filtration systems for these applications. The testing effort and the major conclusions from this investigation are given. 4 refs., 8 figs., 2 tabs

  16. Air flow optimization for energy efficient blower of biosafety cabinet class II A2

    Science.gov (United States)

    Ibrahim, M. D.; Mohtar, M. Z.; Alias, A. A.; Wong, L. K.; Yunos, Y. S.; Rahman, M. R. A.; Zulkharnain, A.; Tan, C. S.; Thayan, R.

    2017-04-01

    An energy efficient Biosafety Cabinet (BSC) has become a big challenge for manufacturers to develop BSC with the highest level of protection. The objective of research is to increase air flow velocity discharge from centrifugal blower. An aerodynamic duct shape inspired by the shape of Peregrine Falcon’s wing during diving flight is added to the end of the centrifugal blower. Investigation of air movement is determined by computational fluid dynamics (CFD) simulation. The results showed that air velocity can be increased by double compared to typical manufactured BSC and no air recirculation. As conclusion, a novel design of aerodynamic duct shape successfully developed and proved that air velocity can be increase naturally with same impeller speed. It can contribute in increasing energy efficiency of the centrifugal blower. It is vital to BSC manufacturer and can be apply to Heating, Air Ventilation and Air Conditioning (HVAC) industries.

  17. Nitrogen removal and nitrous oxide emission in surface flow constructed wetlands for treating sewage treatment plant effluent: Effect of C/N ratios.

    Science.gov (United States)

    Li, Ming; Wu, Haiming; Zhang, Jian; Ngo, Huu Hao; Guo, Wenshan; Kong, Qiang

    2017-09-01

    In order to design treatment wetlands with maximal nitrogen removal and minimal nitrous oxide (N 2 O) emission, the effect of influent C/N ratios on nitrogen removal and N 2 O emission in surface flow constructed wetlands (SF CWs) for sewage treatment plant effluent treatment was investigated in this study. The results showed that nitrogen removal and N 2 O emission in CWs were significantly affected by C/N ratio of influent. Much higher removal efficiency of NH 4 + -N (98%) and TN (90%) was obtained simultaneously in SF CWs at C/N ratios of 12:1, and low N 2 O emission (8.2mg/m 2 /d) and the percentage of N 2 O-N emission in TN removal (1.44%) were also observed. These results obtained in this study would be utilized to determine how N 2 O fluxes respond to variations in C/N ratios and to improve the sustainability of CWs for wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Highly efficient and energy-saving sectional treatment of landfill leachate with a synergistic system of biochemical treatment and electrochemical oxidation on a boron-doped diamond electrode

    International Nuclear Information System (INIS)

    Zhao Guohua; Pang Yaning; Liu Lei; Gao Junxia; Lv Baoying

    2010-01-01

    In this paper, a synergistic combination of the biochemical treatment and electrochemical oxidation (SBEO) of landfill leachate with sectional treatment on a boron-doped diamond (BDD) electrode is proposed. The first stage involves the synergistic system of biochemical treatment and electrochemical oxidation. Then, the second stage is followed by individual biochemical treatment. Comparisons among the SBEO, electrochemical oxidation, biochemical treatment and biochemical treatment with the pretreatment of electrochemical oxidation are made systematically, which show that this method is both highly efficient and energy-saving. The higher TOC removal and low energy cost on the BDD electrode can be explained by the conversion of the bio-refractory pollutants to biodegradable organics in the electrochemical oxidation process, improving the current efficiency and reducing the energy cost. The treated wastewater is degraded only with biochemical treatment in the second stage, which further improves efficiency and reduced the energy cost.

  19. Development of a down-flow hanging sponge reactor for the treatment of low strength sewage.

    Science.gov (United States)

    Yoochatchaval, Wilasinee; Onodera, Takashi; Sumino, Haruhiko; Yamaguchi, Takashi; Mizuochi, Motoyuki; Okadera, Tomohiro; Syutsubo, Kazuaki

    2014-01-01

    The process performance of a down-flow hanging sponge (DHS) reactor for treating low strength sewage (biochemical oxygen demand (BOD) 20-50 mg/L) was investigated in Bangkok, Thailand. The hydraulic retention time (HRT) was set at 4 h during the start-up period and was reduced to 1.5 h in a stepwise manner. Throughout the 300-day operational period, the DHS reactor shows high performance with respect to the removal of total suspended solid (>90% total suspended solid removal efficiency). No clogging of sponge media was observed in response to the self-digestion phenomena of the biofilm. At a HRT of 1.5 h, the BOD removal efficiency was sufficiently high (about 85%). The pathogen Escherichia coli and other coliform bacteria were removed almost completely as well (removal was 99.4% and 98.1%, respectively). Regarding the retained sludge activity measurement, the nitrite oxidation rate was higher than the ammonium oxidation rate (0.031 and 0.022 gram of nitrogen per gram of volatile suspended solids per day, respectively). In the 300 days of operation, the amount of excess sludge production was negligible. Thus, no sludge treatment system is required. Introduction of the DHS system in developing countries is recommended because this system requires a relatively small area, and has low electricity consumption and operation costs.

  20. Advanced porous electrodes with flow channels for vanadium redox flow battery

    Science.gov (United States)

    Bhattarai, Arjun; Wai, Nyunt; Schweiss, Ruediger; Whitehead, Adam; Lim, Tuti M.; Hng, Huey Hoon

    2017-02-01

    Improving the overall energy efficiency by reducing pumping power and improving flow distribution of electrolyte, is a major challenge for developers of flow batteries. The use of suitable channels can improve flow distribution through the electrodes and reduce flow resistance, hence reducing the energy consumption of the pumps. Although several studies of vanadium redox flow battery have proposed the use of bipolar plates with flow channels, similar to fuel cell designs, this paper presents the use of flow channels in the porous electrode as an alternative approach. Four types of electrodes with channels: rectangular open channel, interdigitated open cut channel, interdigitated circular poked channel and cross poked circular channels, are studied and compared with a conventional electrode without channels. Our study shows that interdigitated open channels can improve the overall energy efficiency up to 2.7% due to improvement in flow distribution and pump power reduction while interdigitated poked channel can improve up to 2.5% due to improvement in flow distribution.

  1. Understanding of the Interaction between Clearance Leakage Flow and Main Passage Flow in a VGT Turbine

    Directory of Open Access Journals (Sweden)

    Ben Zhao

    2015-02-01

    Full Text Available The clearance flow between the nozzle and endwall in a variable geometry turbine (VGT has been numerically investigated to understand the clearance effect on the VGT performance and internal flow. It was found that the flow rate through turbine increases but the turbine efficiency decreases with height of clearance. Detailed flow field analyses indicated that most of the efficiency loss resulting from the leakage flow occurs at the upstream of the rotor area, that is, in the nozzle endwall clearance and between the nozzle vanes. There are two main mechanisms associated with this efficiency loss. One is due to the formation of the local vortex flow structure between the clearance flow and the main flow. The other is due to the impact of the clearance flow on the main flow after the nozzle throat. This impact reduces the span of shockwave with increased shockwave magnitude by changing the trajectory of the main flow.

  2. Study of the efficiency of some water treatment unit that present in houses in Erbil city-Iraq

    Science.gov (United States)

    Toma, Janan. Jabbar.; Hanna, Aveen. Matti.

    2017-09-01

    Many people in Erbil city started more than two decade to put special treatment units in their houses to purified water to become safer for drinking uses. The aim of this study was determine the efficiency of six kind water treatment units which include (two replicate of Crystal Water Purifier, So-Safe Water Filter, R O Water Purifier, Kontec Water Purified and Al-Kawther Purified Water). Water samples were collected in two sites one before and other after treatment unit. Each sample was collect with three replication during May to October-2016. Analyzed for Major cations concentration (calcium, magnesium, sodium and potassium), anions concentration (nitrate and chloride) and hydrogen ion concentration (pH), electrical conductivity (EC), total dissolved solids (TDS), alkalinity and total hardness by using standard methods. The water quality index values for all raw water sample befor and after treatment was good and excellent respectively for drinking purposes. Efficiency of So-Safe Water Filter was 66.32% it means was more efficiency than others special water treatment units while in RO Water Purifier was 27.14%, means less efficiency than other water purifier water under this study. Values for major cations, anions and others chemicals characteristics in the water samples after treatment became lower concentrations than befor treatment, likely an indication that these were removed by treatment. According to guideline of world health organization all of variables except total hardness befor treatment are safe and suitable for drinking purposes.

  3. Experimental study of the efficiency of transformation of the dense plasma hypersonic flow kinetic energy into a radiation

    International Nuclear Information System (INIS)

    Kamrukov, A.S.; Kozlov, N.P.; Myshelov, E.P.; Protasov, Yu.S.

    1981-01-01

    Analysis of physical specific features of radiator where plasma heating is performed with tbermalization of directed kinetic energy of dense plasma flows accelerated electrodynamically up to hypersonic velocities during its shock deceleration, is given. It is shown that the plasma heating method considered has a number of principle advantages as compared with methods most disseminated now for generation of dense intensively radiating plasma (current heating exploding method) and suggests new possibilities for construction of selective high brightness radiat.ion sources of ultraviolet and far vacuum ultraviolet ranges of spectrum. Radiation gas dynamic processes of hypersonic plasma flow deceleration formed with magnetoplasma compressors have been experimentally investigated on their interaction with condenced matters in vacuum and basic thermodynamic parameters of shock compressed plasma have been determined. It is shown that the conversion process of kinetic energy of high-velocity plasma flows to radiation is accomplished at very high efficiency-integral luminescence of shock compressed plasma can reach approximately 90% of initial kinetic energy of flow [ru

  4. Experimental demonstration of the reverse flow catalytic membrane reactor concept for energy efficient syngas production. Part 2: Model development

    NARCIS (Netherlands)

    Smit, J.; Bekink, G.J.; Sint Annaland, van M.; Kuipers, J.A.M.

    2007-01-01

    In this contribution the technical feasibility of the reverse flow catalytic membrane reactor (RFCMR) concept with porous membranes for energy efficient syngas production is investigated. In earlier work an experimental proof of principle was already provided [Smit, J., Bekink, G.J., van Sint

  5. Efficiency enhancement of silicon nanowire solar cells by using UV/Ozone treatments and micro-grid electrodes

    Science.gov (United States)

    Chen, Junyi; Subramani, Thiyagu; Sun, Yonglie; Jevasuwan, Wipakorn; Fukata, Naoki

    2018-05-01

    Silicon nanowire solar cells were fabricated by metal catalyzed electroless etching (MCEE) followed by thermal chemical vapor deposition (CVD). In this study, we investigated two effects, a UV/ozone treatment and the use of a micro-grid electrodes, to enhance light absorption and reduce the optic losses in the solar cell device. The UV/ozone treatment successfully improved the conversion efficiency. The micro-grid electrodes were then applied in solar cell devices subjected to a back surface field (BSF) treatment and rapid thermal annealing (RTA). These effects improved the conversion efficiency from 9.4% to 10.9%. Moreover, to reduce surface recombination and improve the continuity of front electrodes, we optimized the etching time of the MCEE process, giving a high efficiency of 12.3%.

  6. Measuring and explaining eco-efficiencies of wastewater treatment plants in China: An uncertainty analysis perspective.

    Science.gov (United States)

    Dong, Xin; Zhang, Xinyi; Zeng, Siyu

    2017-04-01

    In the context of sustainable development, there has been an increasing requirement for an eco-efficiency assessment of wastewater treatment plants (WWTPs). Data envelopment analysis (DEA), a technique that is widely applied for relative efficiency assessment, is used in combination with the tolerances approach to handle WWTPs' multiple inputs and outputs as well as their uncertainty. The economic cost, energy consumption, contaminant removal, and global warming effect during the treatment processes are integrated to interpret the eco-efficiency of WWTPs. A total of 736 sample plants from across China are assessed, and large sensitivities to variations in inputs and outputs are observed for most samples, with only three WWTPs identified as being stably efficient. Size of plant, overcapacity, climate type, and influent characteristics are proven to have a significant influence on both the mean efficiency and performance sensitivity of WWTPs, while no clear relationships were found between eco-efficiency and technology under the framework of uncertainty analysis. The incorporation of uncertainty quantification and environmental impact consideration has improved the liability and applicability of the assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Evaluation of an up-flow anaerobic sludge bed (UASB) reactor containing diatomite and maifanite for the improved treatment of petroleum wastewater.

    Science.gov (United States)

    Chen, Chunmao; Liang, Jiahao; Yoza, Brandon A; Li, Qing X; Zhan, Yali; Wang, Qinghong

    2017-11-01

    Novel diatomite (R1) and maifanite (R2) were utilized as support materials in an up-flow anaerobic sludge bed (UASB) reactor for the treatment of recalcitrant petroleum wastewater. At high organic loadings (11kg-COD/m 3 ·d), these materials were efficient at reducing COD (92.7% and 93.0%) in comparison with controls (R0) (88.4%). Higher percentages of large granular sludge (0.6mm or larger) were observed for R1 (30.3%) and R2 (24.6%) compared with controls (22.6%). The larger portion of granular sludge provided a favorable habitat that resulted in greater microorganism diversity. Increased filamentous bacterial communities are believed to have promoted granular sludge formation promoting a conductive environment for stimulation methanogenic Archaea. These communities had enhanced pH tolerance and produced more methane. This study illustrates a new potential use of diatomite and maifanite as support materials in UASB reactors for increased efficiency when treating refractory wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Opportunities for Energy Efficiency and Open Automated Demand Response in Wastewater Treatment Facilities in California -- Phase I Report

    Energy Technology Data Exchange (ETDEWEB)

    Lekov, Alex; Thompson, Lisa; McKane, Aimee; Song, Katherine; Piette, Mary Ann

    2009-04-01

    This report summarizes the Lawrence Berkeley National Laboratory?s research to date in characterizing energy efficiency and automated demand response opportunities for wastewater treatment facilities in California. The report describes the characteristics of wastewater treatment facilities, the nature of the wastewater stream, energy use and demand, as well as details of the wastewater treatment process. It also discusses control systems and energy efficiency and automated demand response opportunities. In addition, several energy efficiency and load management case studies are provided for wastewater treatment facilities.This study shows that wastewater treatment facilities can be excellent candidates for open automated demand response and that facilities which have implemented energy efficiency measures and have centralized control systems are well-suited to shift or shed electrical loads in response to financial incentives, utility bill savings, and/or opportunities to enhance reliability of service. Control technologies installed for energy efficiency and load management purposes can often be adapted for automated demand response at little additional cost. These improved controls may prepare facilities to be more receptive to open automated demand response due to both increased confidence in the opportunities for controlling energy cost/use and access to the real-time data.

  9. Survey on efficient linear solvers for porous media flow models on recent hardware architectures

    International Nuclear Information System (INIS)

    Anciaux-Sedrakian, Ani; Gratien, Jean-Marc; Guignon, Thomas; Gottschling, Peter

    2014-01-01

    In the past few years, High Performance Computing (HPC) technologies led to General Purpose Processing on Graphics Processing Units (GPGPU) and many-core architectures. These emerging technologies offer massive processing units and are interesting for porous media flow simulators may used for CO 2 geological sequestration or Enhanced Oil Recovery (EOR) simulation. However the crucial point is 'are current algorithms and software able to use these new technologies efficiently?' The resolution of large sparse linear systems, almost ill-conditioned, constitutes the most CPU-consuming part of such simulators. This paper proposes a survey on various solver and pre-conditioner algorithms, analyzes their efficiency and performance regarding these distinct architectures. Furthermore it proposes a novel approach based on a hybrid programming model for both GPU and many-core clusters. The proposed optimization techniques are validated through a Krylov subspace solver; BiCGStab and some pre-conditioners like ILU0 on GPU, multi-core and many-core architectures, on various large real study cases in EOR simulation. (authors)

  10. Kinetic studies on purification capability of channel flow type wastewater treatment plant

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, S [Fukui Institute of Technology, Fukui (Japan); Furukawa, K; Kim, J [Osaka Univ., Osaka (Japan). Faculty of Engineering

    1990-10-01

    In order to develop a wastewater treatment process of secondary effluent and a wastewater treatment process of a farm village, some experiments have been carried out using bench scale and full scale hydroponic type wastewater treatment plant. This wastewater treatment system mainly consists of water channels and hydroponic water tanks. The authors carried out of a kinetic study for purification capability of the water channels while assuring the growth of microorganism in the treatment scheme. It was shown experimentally that the channel flow type wastewater treatment plant had a high TOC removal capability regardless of the kind of contact material and treatment time. Activated sludge microorganism concentration in water channels was obtained by kinetic estimation from the measured effluent suspended solid concentration. Estimated amount of activated sludge in water channels comprised only 11.5-37.4 percent of the measured amounts of withdrawn sludge, indicating high photosynthesis production of algae in water channels. 8 refs., 4 figs., 5 tabs.

  11. Efficiency of Artemia cysts removal as a model invasive spore using a continuous microwave system with heat recovery.

    Science.gov (United States)

    Balasubramanian, Sundar; Ortego, Jeffrey; Rusch, Kelly A; Boldor, Dorin

    2008-12-15

    A continuous microwave system to treat ballast water inoculated with Artemia salina cysts as a model invasive spore was tested for its efficacy in inactivating the cysts present. The system was tested at two different flow rates (1 and 2 L x min(-1)) and two different power levels (2.5 and 4.5 kW). Temperature profiles indicate that the system could deliver heating loads in excess of 100 degrees C in a uniform and near-instantaneous manner when using a heat recovery system. Except for a power and flow rate combination of 2.5 kW and 2 L x min(-1), complete inactivation of the cysts was observed at all combinations at holding times below 100 s. The microwave treatment was better or equal to the control treatment in inactivating the cysts. Use of heat exchangers increased the power conversion efficiency and the overall efficiency of the treatment system. Cost economics analysis indicates that in the present form of development microwave treatment costs are higher than the existing ballast water treatment methods. Overall, tests results indicated that microwave treatment of ballast water is a promising method that can be used in conjunction with other methods to form an efficient treatment system that can prevent introduction of potentially invasive spore forming species in non-native waters.

  12. Carbon footprint of aerobic biological treatment of winery wastewater.

    Science.gov (United States)

    Rosso, D; Bolzonella, D

    2009-01-01

    The carbon associated with wastewater and its treatment accounts for approximately 6% of the global carbon balance. Within the wastewater treatment industry, winery wastewater has a minor contribution, although it can have a major impact on wine-producing regions. Typically, winery wastewater is treated by biological processes, such as the activated sludge process. Biomass produced during treatment is usually disposed of directly, i.e. without digestion or other anaerobic processes. We applied our previously published model for carbon-footprint calculation to the areas worldwide producing yearly more than 10(6) m(3) of wine (i.e., France, Italy, Spain, California, Argentina, Australia, China, and South Africa). Datasets on wine production from the Food and Agriculture Organisation were processed and wastewater flow rates calculated with assumptions based on our previous experience. Results show that the wine production, hence the calculated wastewater flow, is reported as fairly constant in the period 2005-2007. Nevertheless, treatment process efficiency and energy-conservation may play a significant role on the overall carbon-footprint. We performed a sensitivity analysis on the efficiency of the aeration process (alphaSOTE per unit depth, or alphaSOTE/Z) in the biological treatment operations and showed significant margin for improvement. Our results show that the carbon-footprint reduction via aeration efficiency improvement is in the range of 8.1 to 12.3%.

  13. An efficient and stable hydrodynamic model with novel source term discretization schemes for overland flow and flood simulations

    Science.gov (United States)

    Xia, Xilin; Liang, Qiuhua; Ming, Xiaodong; Hou, Jingming

    2017-05-01

    Numerical models solving the full 2-D shallow water equations (SWEs) have been increasingly used to simulate overland flows and better understand the transient flow dynamics of flash floods in a catchment. However, there still exist key challenges that have not yet been resolved for the development of fully dynamic overland flow models, related to (1) the difficulty of maintaining numerical stability and accuracy in the limit of disappearing water depth and (2) inaccurate estimation of velocities and discharges on slopes as a result of strong nonlinearity of friction terms. This paper aims to tackle these key research challenges and present a new numerical scheme for accurately and efficiently modeling large-scale transient overland flows over complex terrains. The proposed scheme features a novel surface reconstruction method (SRM) to correctly compute slope source terms and maintain numerical stability at small water depth, and a new implicit discretization method to handle the highly nonlinear friction terms. The resulting shallow water overland flow model is first validated against analytical and experimental test cases and then applied to simulate a hypothetic rainfall event in the 42 km2 Haltwhistle Burn, UK.

  14. Efficiency of ablative fractional Er: YAG (Erbium: Yttrium-Aluminum-Garnet laser treatment of epidermal and dermal benign skin lesions: A retrospective study

    Directory of Open Access Journals (Sweden)

    Erol Koç

    2014-03-01

    Full Text Available Background: Er: YAG lasers are precise ablation systems used in the treatment epidermal and dermal benign skin lesions. In this study, we restrospectively analysed efficiency of Er: YAG laser therapy in the treatment of epidermal and dermal benign skin lesions. Materials and Methods: We retrospectively investigated our clinical records of 116 patients treated with Er: YAG laser between April 2011 and April 2013. The clinical records of 103 patients (47 men, 56 women were included in our study. Of these 103 patients included in the study were xanthelasma, solar lentigo, epidermal nevus, seborrheic keratosis, nevus of ota, syringoma, cafe au lait macules (CALM and other than these. Treatment parameters, demographic features and before and after photographs of the lesions were investigated from patients’ records in order to evaluate efficiency of Er: YAG laser therapy. Results: Of these 103 patients included in the study were evaluated in 8 groups, described as xanthelasma (n=21, syringoma (n=17, solar lentigo (n=16, epidermal nevus (n=11, seborrheic keratosis (n=9, nevus of ota (n=5, CALM (n=3 and other than these (n=21. In the Er: YAG laser treatment, the average energy flow was 3-7 J/cm2, the average pulse duration was 300 ms, the average number of passes was 3-5 repeat, and the average pulse frequency was 3-7 Hz. While 4.9% of the patients showed no improvement, 59.2% showed marked improvement, 26.2% showed moderate improvement and 9.7% showed mild improvement. Treatment responses in xanthelasma, syringoma, epidermal nevus, solar lentigo and CALM lesions were statistically significant. Observed side effects were hyperpigmentation in 4 patients, hypopigmentation in 3 patients, hypertrophic scar in 2 patients and persistent erythema in one patient and the treatment was well tolerated by all the patients. Conclusion: Er: YAG laser is an effective and safe treatment option in the treatment of benign skin lesions especially in epidermal lesions.

  15. Numerical investigation of hub clearance flow in a Kaplan turbine

    Science.gov (United States)

    Wu, H.; Feng, J. J.; Wu, G. K.; Luo, X. Q.

    2012-11-01

    In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

  16. Numerical investigation of hub clearance flow in a Kaplan turbine

    International Nuclear Information System (INIS)

    Wu, H; Feng, J J; Wu, G K; Luo, X Q

    2012-01-01

    In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

  17. Intensive insulin treatment improves forearm blood flow in critically ill patients: a randomized parallel design clinical trial.

    Science.gov (United States)

    Žuran, Ivan; Poredos, Pavel; Skale, Rafael; Voga, Gorazd; Gabrscek, Lucija; Pareznik, Roman

    2009-01-01

    Intensive insulin treatment of critically ill patients was seen as a promising method of treatment, though recent studies showed that reducing the blood glucose level below 6 mmol/l had a detrimental outcome. The mechanisms of the effects of insulin in the critically ill are not completely understood. The purpose of the study was to test the hypothesis that intensive insulin treatment may influence forearm blood flow independently of global hemodynamic indicators. The study encompassed 29 patients of both sexes who were admitted to the intensive care unit due to sepsis and required artificial ventilation as the result of acute respiratory failure. 14 patients were randomly selected for intensive insulin treatment (Group 1; blood glucose concentration 4.4-6.1 mmol/l), and 15 were selected for conventional insulin treatment (Group 2; blood glucose level 7.0 mmol/l-11.0 mmol/l). At the start of the study (t0, beginning up to 48 hours after admittance and the commencement of artificial ventilation), at 2 hours (t1), 24 hours (t2), and 72 hours (t3) flow in the forearm was measured for 60 minutes using the strain-gauge plethysmography method. Student's t-test of independent samples was used for comparisons between the two groups, and Mann-Whitney's U-test where appropriate. Linear regression analysis and the Pearson correlation coefficient were used to determine the levels of correlation. The difference in 60-minute forearm flow at the start of the study (t0) was not statistically significant between groups, while at t2 and t3 significantly higher values were recorded in Group 1 (t2; Group 1: 420.6 +/- 188.8 ml/100 ml tissue; Group 2: 266.1 +/- 122.2 ml/100 ml tissue (95% CI 30.9-278.0, P = 0.02); t3; Group 1: 369.9 +/- 150.3 ml/100 ml tissue; Group 2: 272.6 +/- 85.7 ml/100 ml tissue (95% CI 5.4-190.0, P = 0.04). At t1 a trend towards significantly higher values in Group 1 was noted (P = 0.05). The level of forearm flow was related to the amount of insulin infusion (r

  18. Magnetic Heat Pump Containing Flow Diverters

    Science.gov (United States)

    Howard, Frank S.

    1995-01-01

    Proposed magnetic heat pump contains flow diverters for suppression of undesired flows. If left unchecked, undesired flows mix substantial amounts of partially heated and partially cooled portions of working fluid, effectively causing leakage of heat from heated side to cooled side. By reducing leakage of heat, flow diverters increase energy efficiency of magnetic heat pump, potentially offering efficiency greater than compressor-driven refrigerator.

  19. Liver volume, portal vein flow, and clearance of indocyanine green and antipyrine in hyperthyroidism before and after antithyroid treatment

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Sonne, J; Court-Payen, M

    1999-01-01

    The aim of the study was to examine liver volume, portal vein flow, and indocyanine green (ICG) and antipyrine clearance in hyperthyroidism before and after antithyroid drug treatment.......The aim of the study was to examine liver volume, portal vein flow, and indocyanine green (ICG) and antipyrine clearance in hyperthyroidism before and after antithyroid drug treatment....

  20. Improving the Efficiency of 3-D Hydrogeological Mixers: Dilution Enhancement Via Coupled Engineering-Induced Transient Flows and Spatial Heterogeneity

    Science.gov (United States)

    Di Dato, Mariaines; de Barros, Felipe P. J.; Fiori, Aldo; Bellin, Alberto

    2018-03-01

    Natural attenuation and in situ oxidation are commonly considered as low-cost alternatives to ex situ remediation. The efficiency of such remediation techniques is hindered by difficulties in obtaining good dilution and mixing of the contaminant, in particular if the plume deformation is physically constrained by an array of wells, which serves as a containment system. In that case, dilution may be enhanced by inducing an engineered sequence of injections and extractions from such pumping system, which also works as a hydraulic barrier. This way, the aquifer acts as a natural mixer, in a manner similar to the industrialized engineered mixers. Improving the efficiency of hydrogeological mixers is a challenging task, owing to the need to use a 3-D setup while relieving the computational burden. Analytical solutions, though approximated, are a suitable and efficient tool to seek the optimum solution among all possible flow configurations. Here we develop a novel physically based model to demonstrate how the combined spatiotemporal fluctuations of the water fluxes control solute trajectories and residence time distributions and therefore, the effectiveness of contaminant plume dilution and mixing. Our results show how external forcing configurations are capable of inducing distinct time-varying groundwater flow patterns which will yield different solute dilution rates.

  1. Efficient sampling algorithms for Monte Carlo based treatment planning

    International Nuclear Information System (INIS)

    DeMarco, J.J.; Solberg, T.D.; Chetty, I.; Smathers, J.B.

    1998-01-01

    Efficient sampling algorithms are necessary for producing a fast Monte Carlo based treatment planning code. This study evaluates several aspects of a photon-based tracking scheme and the effect of optimal sampling algorithms on the efficiency of the code. Four areas were tested: pseudo-random number generation, generalized sampling of a discrete distribution, sampling from the exponential distribution, and delta scattering as applied to photon transport through a heterogeneous simulation geometry. Generalized sampling of a discrete distribution using the cutpoint method can produce speedup gains of one order of magnitude versus conventional sequential sampling. Photon transport modifications based upon the delta scattering method were implemented and compared with a conventional boundary and collision checking algorithm. The delta scattering algorithm is faster by a factor of six versus the conventional algorithm for a boundary size of 5 mm within a heterogeneous geometry. A comparison of portable pseudo-random number algorithms and exponential sampling techniques is also discussed

  2. Influence of Low-Temperature Plasma Treatment on The Liquid Filtration Efficiency of Melt-Blown PP Nonwovens in The Conditions of Simulated Use of Respiratory Protective Equipment

    Directory of Open Access Journals (Sweden)

    Majchrzycka Katarzyna

    2017-06-01

    Full Text Available Filtering nonwovens produced with melt-blown technology are one of the most basic materials used in the construction of respiratory protective equipment (RPE against harmful aerosols, including bio- and nanoaerosols. The improvement of their filtering properties can be achieved by the development of quasi-permanent electric charge on the fibres. Usually corona discharge method is utilized for this purpose. In the presented study, it was assumed that the low-temperature plasma treatment could be applied as an alternative method for the manufacturing of conventional electret nonwovens for the RPE construction. Low temperature plasma treatment of polypropylene nonwovens was carried out with various process gases (argon, nitrogen, oxygen or air in a wide range of process parameters (gas flow velocity, time of treatment and power supplied to the reactor electrodes. After the modification, nonwovens were evaluated in terms of filtration efficiency of paraffin oil mist. The stability of the modification results was tested after 12 months of storage and after conditioning at elevated temperature and relative humidity conditions. Moreover, scanning electron microscopy and ATR-IR spectroscopy were used to assess changes in surface topography and chemical composition of the fibres. The modification of melt-blown nonwovens with nitrogen, oxygen and air plasma did not result in a satisfactory improvement of the filtration efficiency. In case of argon plasma treatment, up to 82% increase of filtration efficiency of paraffin oil mist was observed in relation to untreated samples. This effect was stable after 12 months of storage in normal conditions and after thermal conditioning in (70 ± 3°C for 24 h. The use of low-temperature plasma treatment was proven to be a promising improvement direction of filtering properties of nonwovens used for the protection of respiratory tract against harmful aerosols.

  3. Power Flow Distribution Strategy for Improved Power Electronics Energy Efficiency in Battery Storage Systems: Development and Implementation in a Utility-Scale System

    Directory of Open Access Journals (Sweden)

    Michael Schimpe

    2018-03-01

    Full Text Available Utility-scale battery storage systems typically consist of multiple smaller units contributing to the overall power dispatch of the system. Herein, the power distribution among these units is analyzed and optimized to operate the system with increased energy efficiency. To improve the real-life storage operation, a holistic system model for battery storage systems has been developed that enables a calculation of the energy efficiency. A utility-scale Second-Life battery storage system with a capacity of 3.3 MWh/3 MW is operated and evaluated in this work. The system is in operation for the provision of primary control reserve in combination with intraday trading for controlling the battery state of charge. The simulation model is parameterized with the system data. Results show that losses in power electronics dominate. An operational strategy improving the energy efficiency through an optimized power flow distribution within the storage system is developed. The power flow distribution strategy is based on the reduction of the power electronics losses at no-load/partial-load by minimizing their in-operation time. The simulation derived power flow distribution strategy is implemented in the real-life storage system. Field-test measurements and analysis prove the functionality of the power flow distribution strategy and reveal the reduction of the energy throughput of the units by 7%, as well as a significant reduction of energy losses in the units by 24%. The cost savings for electricity over the system’s lifetime are approximated to 4.4% of its investment cost.

  4. A comprehensive analysis of China's regional energy saving and emission reduction efficiency: From production and treatment perspectives

    International Nuclear Information System (INIS)

    Wu, Jie; Lv, Lin; Sun, Jiasen; Ji, Xiang

    2015-01-01

    Energy and environmental issues have recently aroused increasing interest in China and many approaches are used to evaluate energy and environmental performance. In this paper, a two-stage network DEA framework is applied to evaluate the efficiency of energy saving and emission reduction in China during the period of the eleventh five-year plan, from 2006 to 2010. In this study, economic activities are divided into production and treatment processes. This is different from previous research which generally focused on either environmental efficiency or energy efficiency, omitting the integration of energy and environmental measures. Today, energy saving and emission reduction are both parts of the basic state policy of China and are equally important. The empirical results in this study show that: (i) eastern China has the best energy saving and emission reduction efficiency, performing is better than western and central China. (ii) The efficiency of the production process in central China is better than that in western China while the western area performs better than the central area in term of treatment efficiency. (iii) Integrated efficiency of energy saving and emission reduction of China was relatively stable in the five years and the pollution treatment efficiency maintained a rising trend. -- Highlights: •We measured China's regional energy saving and emission reduction efficiency using two-stage DEA approach. •The production and treatment processes are incorporated in evaluation. •Eastern China performs best in terms of energy saving and emission reduction efficiency. •Integrated efficiency of energy saving and emission reduction of China kept a stable trend during 2006–2010

  5. Analysis of chemical reaction kinetics of depredating organic pollutants from secondary effluent of wastewater treatment plant in constructed wetlands.

    Science.gov (United States)

    Wang, Hao; Jiang, Dengling; Yang, Yong; Cao, Guoping

    2013-01-01

    Four subsurface constructed wetlands were built to treat the secondary effluent of a wastewater treatment plant in Tangshan, China. The chemical pollutant indexes of chemical oxygen demand (COD) were analyzed to evaluate the removal efficiency of organic pollutants from the secondary effluent of the wastewater treatment plant. In all cases, the subsurface constructed wetlands were efficient in treating organic pollutants. Under the same hydraulic loading condition, the horizontal flow wetlands exhibited better efficiency of COD removal than vertical flow wetlands: the removal rates in horizontal flow wetlands could be maintained at 68.4 ± 2.42% to 92.2 ± 1.61%, compared with 63.8 ± 1.19% to 85.0 ± 1.25% in the vertical flow wetlands. Meanwhile, the chemical reaction kinetics of organic pollutants was analyzed, and the results showed that the degradation courses of the four subsurface wetlands all corresponded with the first order reaction kinetics to a large extent.

  6. Parametric Study of High-Efficiency and Low-Emission Gas Burners

    Directory of Open Access Journals (Sweden)

    Shuhn-Shyurng Hou

    2013-01-01

    Full Text Available The objective of this study is to investigate the influence of three significant parameters, namely, swirl flow, loading height, and semi-confined combustion flame, on thermal efficiency and CO emissions of a swirl flow gas burner. We focus particularly on the effects of swirl angle and inclination angle on the performance of the swirl flow burner. The results showed that the swirl flow burner yields higher thermal efficiency and emits lower CO concentration than those of the conventional radial flow burner. A greater swirl angle results in higher thermal efficiency and CO emission. With increasing loading height, the thermal efficiency increases but the CO emission decreases. For a lower loading height (2 or 3 cm, the highest efficiency occurs at the inclination angle 15°. On the other hand, at a higher loading height, 4 cm, thermal efficiency increases with the inclination angle. Moreover, the addition of a shield can achieve a great increase in thermal efficiency, about 4-5%, and a decrease in CO emissions for the same burner (swirl flow or radial flow.

  7. Continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process: An efficient diesel treatment by injection of the aqueous phase.

    Science.gov (United States)

    Rahimi, Masoud; Shahhosseini, Shahrokh; Movahedirad, Salman

    2017-11-01

    A new continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process was developed in order to decrease energy and aqueous phase consumption. In this process the aqueous phase is injected below the horn tip leading to enhanced mixing of the phases. Diesel fuel as the oil phase with sulfur content of 1550ppmw and an appropriate mixture of hydrogen peroxide and formic acid as the aqueous phase were used. At the first step, the optimized condition for the sulfur removal has been obtained in the batch mode operation. Hence, the effect of more important oxidation parameters; oxidant-to-sulfur molar ratio, acid-to-sulfur molar ratio and sonication time were investigated. Then the optimized conditions were obtained using Response Surface Methodology (RSM) technique. Afterwards, some experiments corresponding to the best batch condition and also with objective of minimizing the residence time and aqueous phase to fuel volume ratio have been conducted in a newly designed double-compartment reactor with injection of the aqueous phase to evaluate the process in a continuous flow operation. In addition, the effect of nozzle diameter has been examined. Significant improvement on the sulfur removal was observed specially in lower sonication time in the case of dispersion method in comparison with the conventional contact between two phases. Ultimately, the flow pattern induced by ultrasonic device, and also injection of the aqueous phase were analyzed quantitatively and qualitatively by capturing the sequential images. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Propulsion efficiency and imposed flow fields of a copepod jump

    DEFF Research Database (Denmark)

    Jiang, H.; Kiørboe, Thomas

    2011-01-01

    Pelagic copepods jump to relocate, to attack prey and to escape predators. However, there is a price to be paid for these jumps in terms of their energy costs and the hydrodynamic signals they generate to rheotactic predators. Using observed kinematics of various types of jumps, we computed...... the imposed flow fields and associated energetics of jumps by means of computational fluid dynamics simulations by modeling the copepod as a self-propelled body. The computational fluid dynamics simulation was validated by particle image velocimetry data. The flow field generated by a repositioning jump...... the flow structure. The flow field associated with an escape jump sequence also includes two dominant vortex structures: one leading wake vortex generated as a result of the first jump and one around the body, but between these two vortex structures is an elongated, long-lasting flow trail with flow...

  9. Effect of Fixed Orthodontic Treatment on Salivary Flow, pH and Microbial Count.

    Science.gov (United States)

    Arab, Sepideh; Nouhzadeh Malekshah, Sepideh; Abouei Mehrizi, Ehsan; Ebrahimi Khanghah, Anita; Naseh, Roya; Imani, Mohammad Moslem

    2016-01-01

    The present study was designed to evaluate the changes in saliva properties and oral microbial flora in patients undergoing fixed orthodontic treatment. Two important saliva properties namely the salivary flow rate and pH as well as oral microbial flora were assessed in 30 orthodontic patients before starting fixed orthodontic treatment and after six, 12 and 18 weeks of treatment. Selective media, Sabouraud dextrose agar, Mitis salivarius agar and Rogosa agar were used for isolation of Candida albicans, Streptococcus mutans and Lactobacillus acidophilus, respectively. Statistical analysis was performed using Friedman and Dunn's tests. Porthodontic treatment, the total colony counts of Candida albicans, Streptococcus mutans and Lactobacillus acidophilus showed a significant increase. The saliva pH decreased during the orthodontic treatment (Porthodontic treatment causes major changes in the saliva properties. The changes in oral microflora and saliva properties show the importance of caries preventive measures during orthodontic treatment.

  10. Noninvasive determination of myocardial blood flow, oxygen consumption and efficiency in normal humans by carbon-11 acetate positron emission tomography imaging

    International Nuclear Information System (INIS)

    Porenta, G.; Cherry, S.; Czernin, J.; Brunken, R.; Kuhle, W.; Hashimoto, T.; Schelbert, H.R.

    1999-01-01

    The aims of this study were: (1) to measure noninvasively and near simultaneously myocardial blood flow, oxygen consumption, and contractile function and (2) to analyze myocardial energy expenditure and efficiency at rest and during dobutamine stress in normal humans. Dynamic and gated carbon-11 acetate positron emission tomography (PET) imaging was performed in 11 normal subjects. The initial uptake of 11 C-acetate was measured to estimate myocardial blood flow. Oxygen consumption was derived from the monoexponential slope of the 11 C-clearance curve recorded during myocardial washout. ECG-gated systolic and diastolic images were acquired during the peak myocardial 11 C activity to measure left ventricular radius, myocardial wall thickness, and long axis length. Myocardial oxygen consumption and parameters of cardiac geometry were used to determine myocardial energetics and cardiac efficiency by tension-area area analysis. Myocardial blood flow averaged 0.8±0.06 ml min -1 g -1 at rest and 1.48±0.15 ml min -1 g -1 during dobutamine stress. Oxygen delivery and consumption were 151±13 and 88±15 μl O 2 min -1 g -1 at rest and increased to 291±31 and 216±31 μl O 2 min -1 g -1 , respectively, during pharmacological stress (P 11 C acetate imaging provides the unique capability to study noninvasively determinants of myocardial energy delivery, expenditure, and efficiency. (orig.)

  11. Comparison of steam sterilization conditions efficiency in the treatment of Infectious Health Care Waste.

    Science.gov (United States)

    Maamari, Olivia; Mouaffak, Lara; Kamel, Ramza; Brandam, Cedric; Lteif, Roger; Salameh, Dominique

    2016-03-01

    Many studies show that the treatment of Infectious Health Care Waste (IHCW) in steam sterilization devices at usual operating standards does not allow for proper treatment of Infectious Health Care Waste (IHCW). Including a grinding component before sterilization allows better waste sterilization, but any hard metal object in the waste can damage the shredder. The first objective of the study is to verify that efficient IHCW treatment can occur at standard operating parameters defined by the contact time-temperature couple in steam treatment systems without a pre-mixing/fragmenting or pre-shredding step. The second objective is to establish scientifically whether the standard operation conditions for a steam treatment system including a step of pre-mixing/fragmenting were sufficient to destroy the bacterial spores in IHCW known to be the most difficult to treat. Results show that for efficient sterilization of dialysis cartridges in a pilot 60L steam treatment system, the process would require more than 20 min at 144°C without a pre-mixing/fragmenting step. In a 720L steam treatment system including pre-mixing/fragmenting paddles, only 10 min at 144°C are required to sterilize IHCW proved to be sterilization challenges such as dialysis cartridges and diapers in normal conditions of rolling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Carbon sequestration in surface flow constructed wetland after 12 years of swine wastewater treatment

    Science.gov (United States)

    Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbo...

  13. Use of a generalized Stokes number to determine the aerodynamic capture efficiency of non-Stokesian particles from a compressible gas flow

    Science.gov (United States)

    Israel, R.; Rosner, D. E.

    1983-01-01

    The aerodynamic capture efficiency of small but nondiffusing particles suspended in a high-speed stream flowing past a target is known to be influenced by parameters governing small particle inertia, departures from the Stokes drag law, and carrier fluid compressibility. By defining an effective Stokes number in terms of the actual (prevailing) particle stopping distance, local fluid viscosity, and inviscid fluid velocity gradient at the target nose, it is shown that these effects are well correlated in terms of a 'standard' (cylindrical collector, Stokes drag, incompressible flow, sq rt Re much greater than 1) capture efficiency curve. Thus, a correlation follows that simplifies aerosol capture calculations in the parameter range already included in previous numerical solutions, allows rational engineering predictions of deposition in situations not previously specifically calculated, and should facilitate the presentation of performance data for gas cleaning equipment and aerosol instruments.

  14. Seasonality as a Factor of Resort Treatment Efficiency of Patients with Cerebral Disorders

    Directory of Open Access Journals (Sweden)

    Aleksandr N. Bitsadze

    2012-11-01

    Full Text Available The article, basing on the results of examination of 369 patients with cerebrovascular disorders considers the features of seasonality impact on the cerebral haemodynamics correction and climatic balneotherapy efficiency in the course of subtropical balneotherapy resort treatment. The findings indicate the necessity to differentiate the approaches to patients with cerebrovascular disorders referral to resort treatment and climatic balneotherapy procedures prescription, considering both cerebral ischemia stage and seasonality.

  15. Evaluation of the treatment efficiencies of paper mill whitewaters in terms of organic composition and toxicity

    International Nuclear Information System (INIS)

    Latorre, Anna; Malmqvist, Asa; Lacorte, Silvia; Welander, Thomas; Barcelo, Damia

    2007-01-01

    The efficiency of several lab scale treatments (aerobic, anaerobic and ozone or combination of these) was evaluated using two packaging board mill whitewaters. The effect of the different treatments on the elimination of the organic load, the chemical oxygen demand (COD) and the toxicity was tested as well as the relationship between these parameters. Biocides, phenolic compounds, surfactants, plasticiziers and wood extractives were identified in untreated and treated whitewaters by liquid chromatography coupled with mass spectrometry (LC-MS) or gas chromatography coupled with mass spectrometry (GC-MS). A strong dependency on the water type and treatment efficiency was observed, being the combination of anaerobic and aerobic treatments the best option to reduce the organic contaminants in these waters, although in some cases, the toxicity did not decrease. However, ozone as post-treatment permitted a further reduction of organic compounds, toxicity and COD. - Aerobic and anaerobic treatments remove organic compounds in paper mill effluents but toxicity remains

  16. Visualizing the flow of evidence in network meta-analysis and characterizing mixed treatment comparisons.

    Science.gov (United States)

    König, Jochem; Krahn, Ulrike; Binder, Harald

    2013-12-30

    Network meta-analysis techniques allow for pooling evidence from different studies with only partially overlapping designs for getting a broader basis for decision support. The results are network-based effect estimates that take indirect evidence into account for all pairs of treatments. The results critically depend on homogeneity and consistency assumptions, which are sometimes difficult to investigate. To support such evaluation, we propose a display of the flow of evidence and introduce new measures that characterize the structure of a mixed treatment comparison. Specifically, a linear fixed effects model for network meta-analysis is considered, where the network estimates for two treatments are linear combinations of direct effect estimates comparing these or other treatments. The linear coefficients can be seen as the generalization of weights known from classical meta-analysis. We summarize properties of these coefficients and display them as a weighted directed acyclic graph, representing the flow of evidence. Furthermore, measures are introduced that quantify the direct evidence proportion, the mean path length, and the minimal parallelism of mixed treatment comparisons. The graphical display and the measures are illustrated for two published network meta-analyses. In these applications, the proposed methods are seen to render transparent the process of data pooling in mixed treatment comparisons. They can be expected to be more generally useful for guiding and facilitating the validity assessment in network meta-analysis. Copyright © 2013 John Wiley & Sons, Ltd.

  17. The use of polybenzimidazole membranes in vanadium redox flow batteries leading to increased coulombic efficiency and cycling performance

    International Nuclear Information System (INIS)

    Zhou, X.L.; Zhao, T.S.; An, L.; Wei, L.; Zhang, C.

    2015-01-01

    An issue with conventional vanadium redox flow batteries (VRFB) with Nafion membranes is the crossover of vanadium ions, resulting in low coulombic efficiency and rapid decay in capacity. In this work, a VRFB with a polybenzimidazole (PBI) membrane is tested and compared with the Nafion system. Results show that the PBI-based VRFB exhibits a substantially higher coulombic efficiency of up to 99% at current densities ranging from 20 mA cm −2 to 80 mA cm −2 . More importantly, it is demonstrated that the PBI-based VRFB has a capacity decay rate of as low as 0.3% per cycle, which is four times lower than that of the Nafion system (1.3% per cycle). The improved coulombic efficiency and cycling performance are attributed to the low crossover of vanadium ions through the PBI membrane

  18. Surface treatment by the ion flow from electron beam generated plasma in the forevacuum pressure range

    Directory of Open Access Journals (Sweden)

    Klimov Aleksandr

    2018-01-01

    Full Text Available The paper presents research results of peculiarities of gas ion flows usage and their generation from large plasma formation (>50 sq.cm obtained by electron beam ionization of gas in the forevacuum pressure range. An upgraded source was used for electron beam generation, which allowed obtaining ribbon electron beam with no transmitting magnetic field. Absence of magnetic field in the area of ion flow formation enables to obtain directed ion flows without distorting their trajectories. In this case, independent control of current and ion energy is possible. The influence of electron beam parameters on the parameters of beam plasma and ion flow – current energy and density – was determined. The results of alumina ceramics treatment with a beam plasma ions flow are given.

  19. Experimental study of the influence of flow passage subtle variation on mixed-flow pump performance

    Science.gov (United States)

    Bing, Hao; Cao, Shuliang

    2014-05-01

    In the mixed-flow pump design, the shape of the flow passage can directly affect the flow capacity and the internal flow, thus influencing hydraulic performance, cavitation performance and operation stability of the mixed-flow pump. However, there is currently a lack of experimental research on the influence mechanism. Therefore, in order to analyze the effects of subtle variations of the flow passage on the mixed-flow pump performance, the frustum cone surface of the end part of inlet contraction flow passage of the mixed-flow pump is processed into a cylindrical surface and a test rig is built to carry out the hydraulic performance experiment. In this experiment, parameters, such as the head, the efficiency, and the shaft power, are measured, and the pressure fluctuation and the noise signal are also collected. The research results suggest that after processing the inlet flow passage, the head of the mixed-flow pump significantly goes down; the best efficiency of the mixed-flow pump drops by approximately 1.5%, the efficiency decreases more significantly under the large flow rate; the shaft power slightly increases under the large flow rate, slightly decreases under the small flow rate. In addition, the pressure fluctuation amplitudes on both the impeller inlet and the diffuser outlet increase significantly with more drastic pressure fluctuations and significantly lower stability of the internal flow of the mixed-flow pump. At the same time, the noise dramatically increases. Overall speaking, the subtle variation of the inlet flow passage leads to a significant change of the mixed-flow pump performance, thus suggesting a special attention to the optimization of flow passage. This paper investigates the influence of the flow passage variation on the mixed-flow pump performance by experiment, which will benefit the optimal design of the flow passage of the mixed-flow pump.

  20. Innovative model-based flow rate optimization for vanadium redox flow batteries

    Science.gov (United States)

    König, S.; Suriyah, M. R.; Leibfried, T.

    2016-11-01

    In this paper, an innovative approach is presented to optimize the flow rate of a 6-kW vanadium redox flow battery with realistic stack dimensions. Efficiency is derived using a multi-physics battery model and a newly proposed instantaneous efficiency determination technique. An optimization algorithm is applied to identify optimal flow rates for operation points defined by state-of-charge (SoC) and current. The proposed method is evaluated against the conventional approach of applying Faraday's first law of electrolysis, scaled to the so-called flow factor. To make a fair comparison, the flow factor is also optimized by simulating cycles with different charging/discharging currents. It is shown through the obtained results that the efficiency is increased by up to 1.2% points; in addition, discharge capacity is also increased by up to 1.0 kWh or 5.4%. Detailed loss analysis is carried out for the cycles with maximum and minimum charging/discharging currents. It is shown that the proposed method minimizes the sum of losses caused by concentration over-potential, pumping and diffusion. Furthermore, for the deployed Nafion 115 membrane, it is observed that diffusion losses increase with stack SoC. Therefore, to decrease stack SoC and lower diffusion losses, a higher flow rate during charging than during discharging is reasonable.

  1. Analysis of small cyclones efficiency for primary treatment of incineration gases of radioactive wastes

    International Nuclear Information System (INIS)

    Halasz, M.R.T.; Massarani, G.

    2000-01-01

    The objective of this work is to develop an efficient gas treatment system, especially small diameter cyclones. The high efficiency justifies the interest in the application in radioactive wastes incinerators because it reduces the amount of radioactive ashes of other gas cleaning steps. The first stage of this work is to establish some promising configurations of high efficiency cyclones through modeling (neural networks). After construction of the equipment , the operation conditions of each small diameter cyclone were obtained and the viability of adaptation of a Post-cyclone (PoC) was also evaluated to increase the efficiency. The results show the effectiveness of the small diameter cyclone PoC set. The efficiency in optimized conditions can be higher than 98% for fine materials (D 50 s = 3,5 g/cm 3 ). (author)

  2. Influence of Fenton's reagent treatment on electrochemical properties of graphite felt for all vanadium redox flow battery

    International Nuclear Information System (INIS)

    Gao, Chao; Wang, NanFang; Peng, Sui; Liu, SuQin; Lei, Ying; Liang, XinXing; Zeng, ShanShan; Zi, HuiFang

    2013-01-01

    Highlights: ► Highly hydroxyl-functionalized graphite felt has been obtained through Fenton's reagent treatment. ► Fenton's reagent treatment involves only one step, works under ambient conditions and will never produce any toxic gas. ► The treated graphite felt exhibits superior electrochemical performance in comparison to the untreated one. -- Abstract: An environmental, economic and highly effective method for carbon fiber hydroxylated-functionalization based on Fenton's reagent treatment is used to improve the electrochemical activity of graphite felt (GF) as the positive electrode in all vanadium redox flow battery (VRFB). The effect of H 2 O 2 content in Fenton's reagent on the structure and electrochemical properties of GF is investigated. The scanning electron microscope (SEM) indicates that the surface of the treated GF is etched increasingly with the content of H 2 O 2 . The Fourier transformation infrared (FTIR) spectroscopy shows that the peak intensity of hydroxyl groups on the treated felt is increased with the H 2 O 2 concentration, which is further verified by X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the treated sample exhibits a higher electrochemical activity. A VRFB with the treated GF as electrodes exhibits higher coulombic, voltage and energy efficiency (98.8%, 75.1% and 74.2%) than that with the untreated GF (93.9%, 72.1% and 67.7%) at 60 mA cm −2 , and this method is even superior when compared with the reported methods

  3. Conditional Order-m Efficiency of Wastewater Treatment Plants: The Role of Environmental Factors

    Directory of Open Access Journals (Sweden)

    Ramón Fuentes

    2015-10-01

    Full Text Available The growing economic and environmental importance of managing water resources at a global level also entails greater efforts and interest in improving the functioning and efficiency of the increasingly more numerous wastewater treatment plants (WWTPs. In this context, this study analyzes the efficiency of a uniform sample of plants of this type located in the region of Valencia (Spain. The type of efficiency measure used for this (conditional order-m efficiency allows continuous and discrete contextual variables to be directly involved in the analysis and enables the assessment of their statistical significance and effect (positive or negative. The main findings of the study showed that the quality of the influent water and also the size and age of the plants had a significant influence on their efficiency levels. In particular, as regards the effect of such variables, the findings pointed to the existence of an inverse relationship between the quality of the influent water and the efficiency of the WWTPs. Also, a lower annual volume of treated water and more modern installations showed a positive influence. Additionally, the average efficiency levels observed turned out to be higher than those reported in previous studies.

  4. Efficiency of fenticonazole for the treatment of vaginal candidiasis

    Directory of Open Access Journals (Sweden)

    Živaljević Biljana

    2012-01-01

    Full Text Available Introduction. Uncomplicated vulvovaginal candidiasis appears in 75% women of reproductive age. The most frequent causes are Candida albicans (85-95% or C. glabrata, and infrequently C. krusei, C. tropicalis, C. parapsilosis, C. pseudotropicalis, etc. Objective. The aim of the study was to investigate efficiency and safety of fenticonazole for vaginal candidiasis treatment. Methods. Therapeutic effect of a single 600 mg fenticonasole vaginal capsule was observed in 417 women, aged 16-67, in five centers in Serbia. In all women, before the treatment, vaginal candidiasis was confirmed by testing of vaginal smear. Based on smear findings and associated symptoms observed on the 7th and 28th day after therapy administration, treatment results were evaluated. On the next day after drug application the patients recorded by using a questionnaire their own feelings on withdrawal symptoms and possible side effects in the period prior to the first control. Results. Control after seven days showed a statistically significant decrease of symptoms. In 385 women, vaginal smear was found negative to yeast and yeast blastospores. Within the first seven days after treatment 84 women had to repeat therapy due to the persistence of symptoms or positive vaginal smear. After 28 days we recorded full recovery in 392 patients, clinical improvement in eight, no change in 16, and deterioration in one patient only. Side effects were very seldom, mostly in the form of a slight redness of the vulva and vagina, and mild itching during several days. Conclusion. Our observations confirmed good efficacy and safety of fenticonazole in the treatment of vaginal candidiasis.

  5. [Efficiency of fenticonazole for the treatment of vaginal candidiasis].

    Science.gov (United States)

    2012-01-01

    Uncomplicated vulvovaginal candidiasis appears in 75% women of reproductive age. The most frequent causes are Candida albicans (85-95%) or C. glabrata, and infrequently C. krusei, C. tropicalis, C. parapsilosis, C. pseudotropicalis, etc. The aim of the study was to investigate efficiency and safety of fenticonazole for vaginal candidiasis treatment. Therapeutic effect of a single 600 mg fenticonasole vaginal capsule was observed in 417 women, aged 16-67, in five centers in Serbia. In all women, before the treatment, vaginal candidiasis was confirmed by testing of vaginal smear. Based on smear findings and associated symptoms observed on the 7th and 28th day after therapy administration, treatment results were evaluated. On the next day after drug application the patients recorded by using a questionnaire their own feelings on withdrawal symptoms and possible side effects in the period prior to the first control. Control after seven days showed a statistically significant decrease of symptoms. In 385 women, vaginal smear was found negative to yeast and yeast blastospores. Within the first seven days after treatment 84 women had to repeat therapy due to the persistence of symptoms or positive vaginal smear. After 28 days we recorded full recovery in 392 patients, clinical improvement in eight, no change in 16, and deterioration in one patient only. Side effects were very seldom, mostly in the form of a slight redness of the vulva and vagina, and mild itching during several days. Our observations confirmed good efficacy and safety of fenticonazole in the treatment of vaginal candidiasis.

  6. A water treatment case study for quantifying model performance with multilevel flow modeling

    Directory of Open Access Journals (Sweden)

    Emil K. Nielsen

    2018-05-01

    Full Text Available Decision support systems are a key focus of research on developing control rooms to aid operators in making reliable decisions and reducing incidents caused by human errors. For this purpose, models of complex systems can be developed to diagnose causes or consequences for specific alarms. Models applied in safety systems of complex and safety-critical systems require rigorous and reliable model building and testing. Multilevel flow modeling is a qualitative and discrete method for diagnosing faults and has previously only been validated by subjective and qualitative means. To ensure reliability during operation, this work aims to synthesize a procedure to measure model performance according to diagnostic requirements. A simple procedure is proposed for validating and evaluating the concept of multilevel flow modeling. For this purpose, expert statements, dynamic process simulations, and pilot plant experiments are used for validation of simple multilevel flow modeling models of a hydrocyclone unit for oil removal from produced water. Keywords: Fault Diagnosis, Model Validation, Multilevel Flow Modeling, Produced Water Treatment

  7. Evaluation of alternative flow sheets for upgrade of the Process Waste Treatment Plant

    International Nuclear Information System (INIS)

    Robinson, S.M.

    1991-04-01

    Improved chemical precipitation and/or ion-exchange (IX) methods are being developed at the Oak Ridge National Laboratory (ORNL) in an effort to reduce waste generation at the Process Waste Treatment Plant (PWTP). A wide variety of screening tests were performed on potential precipitation techniques and IX materials on a laboratory scale. Two of the more promising flow sheets have been tested on pilot and full scales. The data were modeled to determine the operating conditions and waste generation at plant-scale and used to develop potential flow sheets for use at the PWTP. Each flow sheet was evaluated using future-valve economic analysis and performance ratings (where numerical values were assigned to costs, process flexibility and simplicity, stage of development, waste reduction, environmental and occupational safety, post-processing requirements, and final waste form). The results of this study indicated that several potential flow sheets should be considered for further development, and more detailed cost estimates should be made before a final selection is made for upgrade of the PWTP. 19 refs., 52 figs., 22 tabs

  8. A framework to identify Pareto-efficient subdaily environmental flow constraints on hydropower reservoirs using a grid-wide power dispatch model

    Science.gov (United States)

    Olivares, Marcelo A.; Haas, Jannik; Palma-Behnke, Rodrigo; Benavides, Carlos

    2015-05-01

    Hydrologic alteration due to hydropeaking reservoir operations is a main concern worldwide. Subdaily environmental flow constraints (ECs) on operations can be promising alternatives for mitigating negative impacts. However, those constraints reduce the flexibility of hydropower plants, potentially with higher costs for the power system. To study the economic and environmental efficiency of ECs, this work proposes a novel framework comprising four steps: (i) assessment of the current subdaily hydrologic alteration; (ii) formulation and implementation of a short-term, grid-wide hydrothermal coordination model; (iii) design of ECs in the form of maximum ramping rates (MRRs) and minimum flows (MIFs) for selected hydropower reservoirs; and (iv) identification of Pareto-efficient solutions in terms of grid-wide costs and the Richard-Baker flashiness index for subdaily hydrologic alteration (SDHA). The framework was applied to Chile's main power grid, assessing 25 EC cases, involving five MIFs and five MRRs. Each case was run for a dry, normal, and wet water year type. Three Pareto-efficient ECs are found, with remarkably small cost increase below 2% and a SDHA improvement between 28% and 90%. While the case involving the highest MIF worsens the flashiness of another basin, the other two have no negative effect on other basins and can be recommended for implementation.

  9. Effectiveness of treatment with donepezil hydrochloride and changes in regional cerebral blood flow in patients with Alzheimer's disease

    International Nuclear Information System (INIS)

    Yoshida, Tsunetaka; Ha-Kawa, S.; Yoshimura, Masafumi; Nobuhara, Kenji; Kinoshita, Toshihiko; Sawada, Satoshi

    2007-01-01

    The objective of this study was to elucidate the relationship between the effects of donepezil hydrochloride (donepezil) and cerebral blood flow, and to evaluate the usefulness of cerebral blood flow imaging in assessing and predicting treatment effectiveness. The subjects were 29 outpatients (12 men and 17 women; age 50-82 years; mean age 69.2 years), who had received a diagnosis of Alzheimer's disease (AD). Efficacy was evaluated before donepezil administration; after 1 month, 3 months, and 6 months of drug administration; and at 1 year after completion of administration using the Japanese version of the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog), as a measure of cognitive function. The ADAS-cog has been frequently used to evaluate cognitive function in AD patients. Patients whose ADAS-cog scores improved by 3 or more points during the observation period were classified as responders, and those with no improvement were classified as nonresponders. 123 I-iofetamine (IMP) was used for single photon emission computed tomography cerebral blood flow scintigraphy. On the basis of ADAS-cog score improvement, 22 of the 29 patients were responders (7 men and 15 women; age 50-82 years; mean age 69.0 years) and seven were nonresponders (5 men and 2 women; age 61-80 years; mean age 70.0 years). The results indicate that a difference in cerebral blood flow responsiveness after 1 month of treatment distinguishes responders from nonresponders. After 1 month, blood flow was significantly decreased in all regions of nonresponders, whereas significant increases in blood flow were seen in the anterior frontal lobe and parietal lobe of responders. At that time point, blood flow in the basal ganglion differed significantly between the two groups, indicating that this difference in responsiveness after 1 month of treatment may distinguish responders from nonresponders. In cognitive function testing, the group that exhibited a complete response showed

  10. A single LipiFlow® Thermal Pulsation System treatment improves meibomian gland function and reduces dry eye symptoms for 9 months.

    Science.gov (United States)

    Greiner, Jack V

    2012-04-01

    To evaluate the effect of a single treatment with the LipiFlow(®) Thermal Pulsation System on signs of meibomian gland dysfunction (MGD) and dry eye symptoms over a 9-month period. Patients (n = 42 eyes, 21 subjects) diagnosed with MGD and dry eye symptoms were recruited for a non-significant risk, prospective, open-label, 1-month clinical trial. Patients received a single 12-minute treatment using the LipiFlow(®) Thermal Pulsation System on each eye. The LipiFlow(®) device applies heat to the conjunctival surfaces of the upper and lower inner eyelids while simultaneously applying pulsatile pressure to the outer eyelid surfaces to express the meibomian glands. Patient symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Standard Patient Evaluation for Eye Dryness (SPEED) dry eye questionnaires; tear break-up time was measured with the dry eye test (DET™); and meibomian gland function was evaluated using a standardized diagnostic expression technique. Data are presented for patient's pre-treatment (baseline) and at 1-month and 9-month post-treatment. Meibomian gland secretion scores improved significantly from baseline (4.4 ± 4.0) to 1-month post-treatment (11.3 ± 6.2; p dry eye disease, the LipiFlow(®) Thermal Pulsation System offers a technological advancement for the treatment of dry eye disease secondary to meibomian gland dysfunction. A single 12-minute LipiFlow(®) treatment results in up to 9 months of sustained improvement of meibomian gland function, tear break-up time and dry eye symptoms that are unparalleled with current dry eye treatments.

  11. Experimental demonstration of the reverse flow catalytic membrane reactor concept for energy efficient syngas production. Part 1: Influence of operating conditions

    NARCIS (Netherlands)

    Smit, J.; Bekink, G.J.; Sint Annaland, van M.; Kuipers, J.A.M.

    2007-01-01

    In this contribution the technical feasibility of the reverse flow catalytic membrane reactor (RFCMR) concept with porous membranes for energy efficient syngas production is investigated. In earlier work an experimental proof of principle was already provided [Smit, J., Bekink, G.J., van Sint

  12. Review: Efficiency of physical and chemical treatments on the inactivation of dairy bacteriophages

    Directory of Open Access Journals (Sweden)

    Daniela Marta Guglielmotti

    2012-01-01

    Full Text Available Bacteriophages can cause great economic losses due to fermentation failure in dairy plants. Hence, physical and chemical treatments of raw material and/or equipment are mandatory to maintain phage levels as low as possible. Regarding thermal treatments used to kill pathogenic bacteria or achieve longer shelf-life of dairy products, neither low temperature long time (LTLT nor high temperature short time (HTST pasteurization were able to inactivate most lactic acid bacteria (LAB phages. Even though most phages did not survive 90ºC for 2 min, there were some that resisted 90ºC for more than 15 min (conditions suggested by the International Dairy Federation, IDF, for complete phage destruction. Among biocides tested, ethanol showed variable effectiveness in phage inactivation, since only phages infecting dairy cocci and Lactobacillus helveticus were reasonably inactivated by this alcohol, whereas isopropanol was in all cases highly ineffective. In turn, peracetic acid has consistently proved to be very fast and efficient to inactivate dairy phages, whereas efficiency of sodium hypochlorite was variable, even among different phages infecting the same LAB species. Both alkaline chloride foam and ethoxylated nonylphenol with phosphoric acid were remarkably efficient, trait probably related to their highly alkaline or acidic pH values in solution, respectively. Photocatalysis using UV light and TiO2 has been recently reported as a feasible option to industrially inactivate phages infecting diverse LAB species. Processes involving high pressure were barely used for phage inactivation, but until now most studied phages revealed high resistance to these treatments. To conclude, and given the great phage diversity found on dairies, it is always advisable to combine different anti-phage treatments (biocides, heat, high pressure, photocatalysis, rather than using them separately at extreme conditions.

  13. Efficient multigrid computation of steady hypersonic flows

    NARCIS (Netherlands)

    Koren, B.; Hemker, P.W.; Murthy, T.K.S.

    1991-01-01

    In steady hypersonic flow computations, Newton iteration as a local relaxation procedure and nonlinear multigrid iteration as an acceleration procedure may both easily fail. In the present chapter, same remedies are presented for overcoming these problems. The equations considered are the steady,

  14. Domestic wastewater treatment using multi-electrode continuous flow MFCs with a separator electrode assembly design

    KAUST Repository

    Ahn, Yongtae; Logan, Bruce E.

    2012-01-01

    Treatment of domestic wastewater using microbial fuel cells (MFCs) will require reactors with multiple electrodes, but this presents unique challenges under continuous flow conditions due to large changes in the chemical oxygen demand (COD

  15. Atomizing industrial gas-liquid flows – Development of an efficient hybrid VOF-LPT numerical framework

    International Nuclear Information System (INIS)

    Ström, Henrik; Sasic, Srdjan; Holm-Christensen, Olav; Shah, Louise Jivan

    2016-01-01

    Highlights: • Modelling of turbulent atomizing gas-liquid flows in real industrial devices. • A combined VOF-LPT framework with statistical coupling. • Regions of separated and dispersed multiphase flow treated simultaneously. • Statistical model based on a limited amount of highly resolved VOF data. - Abstract: Atomizing gas-liquid flows are used in industrial applications where high interphase heat and mass transfer rates and good mixing are of primary importance. Today, there is no single mathematical framework available to predict the entire liquid breakup process at an acceptable computational cost for a typical problem of industrial size. In this work, we develop a volume-of-fluid (VOF) framework that is combined with Lagrangian particle tracking (LPT) to take advantage of the respective strengths of these two approaches. The two frameworks are coupled via a statistical model that enables a transition from the VOF to the LPT formulation using input data about the primary breakup process obtained from detailed VOF simulations in dedicated switching zones. LPT-to-VOF transitions are handled directly by analyzing the proximity of LPT parcels to larger VOF structures. The combined framework is specifically designed to accommodate situations where atomization occurs in several locations simultaneously and when separated and dispersed turbulent gas-liquid flows co-exist in the same industrial unit. The procedure in which the statistical model is derived is presented and discussed, its performance is verified and the computational efficiency of the combined VOF-LPT model is assessed. Finally, the application of the coupled framework to the simulation of an industrial gas-liquid mixer with four separate atomization regions is presented.

  16. Improving the sludge disintegration efficiency of sonication by combining with alkalization and thermal pre-treatment methods.

    Science.gov (United States)

    Şahinkaya, S; Sevimli, M F; Aygün, A

    2012-01-01

    One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization > sono-thermal pre-treatment > sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

  17. High efficiency, variable geometry, centrifugal cryogenic pump

    International Nuclear Information System (INIS)

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-01-01

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions

  18. Improvement of biological nitrogen removal with nitrate-dependent Fe(II) oxidation bacterium Aquabacterium parvum B6 in an up-flow bioreactor for wastewater treatment.

    Science.gov (United States)

    Zhang, Xiaoxin; Li, Ang; Szewzyk, Ulrich; Ma, Fang

    2016-11-01

    Aquabacterium parvum strain B6 exhibited efficient nitrate-dependent Fe(II) oxidation ability using nitrate as an electron acceptor. A continuous up-flow bioreactor that included an aerobic and an anoxic section was constructed, and strain B6 was added to the bioreactor as inocula to explore the application of microbial nitrate-dependent Fe(II) oxidizing (NDFO) efficiency in wastewater treatment. The maximum NRE (anoxic section) and TNRE of 46.9% and 79.7%, respectively, could be obtained at a C/N ratio of 5.3:1 in the influent with HRT of 17. Meanwhile, the taxonomy composition of the reactor was assessed, as well. The NDFO metabolism of strain B6 could be expected because of its relatively dominant position in the anoxic section, whereas potential heterotrophic nitrification and aerobic denitrification developed into the prevailing status in the aerobic section after 50days of continuous operation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Methods for compressible multiphase flows and their applications

    Science.gov (United States)

    Kim, H.; Choe, Y.; Kim, H.; Min, D.; Kim, C.

    2018-06-01

    This paper presents an efficient and robust numerical framework to deal with multiphase real-fluid flows and their broad spectrum of engineering applications. A homogeneous mixture model incorporated with a real-fluid equation of state and a phase change model is considered to calculate complex multiphase problems. As robust and accurate numerical methods to handle multiphase shocks and phase interfaces over a wide range of flow speeds, the AUSMPW+_N and RoeM_N schemes with a system preconditioning method are presented. These methods are assessed by extensive validation problems with various types of equation of state and phase change models. Representative realistic multiphase phenomena, including the flow inside a thermal vapor compressor, pressurization in a cryogenic tank, and unsteady cavitating flow around a wedge, are then investigated as application problems. With appropriate physical modeling followed by robust and accurate numerical treatments, compressible multiphase flow physics such as phase changes, shock discontinuities, and their interactions are well captured, confirming the suitability of the proposed numerical framework to wide engineering applications.

  20. The Impact of Psycho-Education on in Vitro Fertilisation Treatment Efficiency.

    Science.gov (United States)

    Belevska, Jana

    2015-01-01

    The aim of the study was to examine the efficiency of psycho-education of candidates for the IVF in stress, anxiety and depression decreasing, and the impact of the psycho educative techniques on the successfulness of the treatment. A random sample of 64 candidates for IVF treatment is divided in two groups: control group without psycho-education (32 candidates) and intervention group of 32 candidates included in psycho-education. Depression, anxiety and stress scale (DASS) was used as a psychometric test. It's a multiple choice, self-reported inventory for measuring the levels of stress, anxiety and severity of depression. For statistic evaluation SPSS software was used. The study shows that the intervention group included in psycho-education has a signifycantly lower scores on stress (t = 3.201, p stress decreasing, as well as significant impact in the successfulness of the treatment. It was pointed out that psychological support of candidates for IVF is important for the lessening of the negative emotional reactions of candidates as well as for the successfulness of the treatment.

  1. A hybrid hydrostatic and non-hydrostatic numerical model for shallow flow simulations

    Science.gov (United States)

    Zhang, Jingxin; Liang, Dongfang; Liu, Hua

    2018-05-01

    Hydrodynamics of geophysical flows in oceanic shelves, estuaries, and rivers, are often studied by solving shallow water model equations. Although hydrostatic models are accurate and cost efficient for many natural flows, there are situations where the hydrostatic assumption is invalid, whereby a fully hydrodynamic model is necessary to increase simulation accuracy. There is a growing concern about the decrease of the computational cost of non-hydrostatic pressure models to improve the range of their applications in large-scale flows with complex geometries. This study describes a hybrid hydrostatic and non-hydrostatic model to increase the efficiency of simulating shallow water flows. The basic numerical model is a three-dimensional hydrostatic model solved by the finite volume method (FVM) applied to unstructured grids. Herein, a second-order total variation diminishing (TVD) scheme is adopted. Using a predictor-corrector method to calculate the non-hydrostatic pressure, we extended the hydrostatic model to a fully hydrodynamic model. By localising the computational domain in the corrector step for non-hydrostatic pressure calculations, a hybrid model was developed. There was no prior special treatment on mode switching, and the developed numerical codes were highly efficient and robust. The hybrid model is applicable to the simulation of shallow flows when non-hydrostatic pressure is predominant only in the local domain. Beyond the non-hydrostatic domain, the hydrostatic model is still accurate. The applicability of the hybrid method was validated using several study cases.

  2. Ibuprofen removal in horizontal subsurface flow constructed wetlands: treatment performance and fungal community dynamics.

    Science.gov (United States)

    Zhang, Dongqing; Luo, Jinxue; Lee, Zarraz May Ping; Gersberg, Richard M; Liu, Yu; Tan, Soon Keat; Ng, Wun Jern

    2016-01-01

    The treatment performance of ibuprofen (IBP)-enriched wastewater by horizontal subsurface flow constructed wetlands planted with cattail (Typha angustifolia) and unplanted control mesocosms was investigated. Removal efficiencies of IBP were significantly (p fungal community in these wetland systems. The overall diversity of the fungal community was reduced under the IBP exposure. Taxonomic analysis revealed that 62.2% of the fungal sequences were affiliated with Basidiomycota, followed by Ascomycota (37.4%) at the phylum level. Uncultured fungus (48.2%), Chaetomium sp. (14.2%), Aspergillus sp. (12.4%), Trichoderma sp. (5.7%), Cladosporium sp. (5.4%), and Emericellopsis sp. (5.2%) were identified as dominant genera. At the genus level, a distinct profile of the fungal community in the IBP-enriched mesocosms was observed as compared to the control beds, and as well specific fungal genera were enhanced in the planted beds, regardless of IBP enrichment. However, despite these differences, the composition of the fungal community (as measured by Bray-Curtis similarity) was mostly unaffected by the significant IBP enrichment. On the other hand, a consistent similarity pattern of fungal community structure in the planted mesocosms suggests that the presence of higher macrophytes in the wetland systems may well help shape the fungal community structure.

  3. Vortex flow structures and interactions for the optimum thrust efficiency of a heaving airfoil at different mean angles of attack

    Energy Technology Data Exchange (ETDEWEB)

    Martín-Alcántara, A.; Fernandez-Feria, R. [Universidad de Málaga, Andalucía Tech, E. T. S. Ingeniería Industrial, Dr Ortiz Ramos s/n, 29071 Málaga (Spain); Sanmiguel-Rojas, E. [Área de Mecánica de Fluidos, Universidad de Jaén, Campus de las Lagunillas, 23071 Jaén (Spain)

    2015-07-15

    The thrust efficiency of a two-dimensional heaving airfoil is studied computationally for a low Reynolds number using a vortex force decomposition. The auxiliary potentials that separate the total vortex force into lift and drag (or thrust) are obtained analytically by using an elliptic airfoil. With these auxiliary potentials, the added-mass components of the lift and drag (or thrust) coefficients are also obtained analytically for any heaving motion of the airfoil and for any value of the mean angle of attack α. The contributions of the leading- and trailing-edge vortices to the thrust during their down- and up-stroke evolutions are computed quantitatively with this formulation for different dimensionless frequencies and heave amplitudes (St{sub c} and St{sub a}) and for several values of α. Very different types of flows, periodic, quasi-periodic, and chaotic described as St{sub c}, St{sub a}, and α, are varied. The optimum values of these parameters for maximum thrust efficiency are obtained and explained in terms of the interactions between the vortices and the forces exerted by them on the airfoil. As in previous numerical and experimental studies on flapping flight at low Reynolds numbers, the optimum thrust efficiency is reached for intermediate frequencies (St{sub c} slightly smaller than one) and a heave amplitude corresponding to an advance ratio close to unity. The optimal mean angle of attack found is zero. The corresponding flow is periodic, but it becomes chaotic and with smaller average thrust efficiency as |α| becomes slightly different from zero.

  4. Review of Constructed Subsurface Flow vs. Surface Flow Wetlands

    International Nuclear Information System (INIS)

    HALVERSON, NANCY

    2004-01-01

    The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the water level below the top of the rock or gravel media, thus minimizing human and ecological exposure. Subsurface flow wetlands demonstrate higher rates of contaminant removal per unit of land than surface flow (free water surface) wetlands, therefore subsurface flow wetlands can be smaller while achieving the same level of contaminant removal. Wetlands remove metals using a variety of processes including filtration of solids, sorption onto organic matter, oxidation and hydrolysis, formation of carbonates, formation of insoluble sulfides, binding to iron and manganese oxides, reduction to immobile forms by bacterial activity, and uptake by plants and bacteria. Metal removal rates in both subsurface flow and surface flow wetlands can be high, but can vary greatly depending upon the influent concentrations and the mass loading rate. Removal rates of greater than 90 per cent for copper, lead and zinc have been demonstrated in operating surface flow and subsurface flow wetlands. The constituents that exceed NPDES limits at outfalls H-02 a nd H

  5. Two-year survey of specific hospital wastewater treatment and its impact on pharmaceutical discharges.

    Science.gov (United States)

    Wiest, Laure; Chonova, Teofana; Bergé, Alexandre; Baudot, Robert; Bessueille-Barbier, Frédérique; Ayouni-Derouiche, Linda; Vulliet, Emmanuelle

    2018-04-01

    It is well known that pharmaceuticals are not completely removed by conventional activated sludge wastewater treatment plants. Hospital effluents are of major concern, as they present high concentrations of pharmaceutically active compounds. Despite this, these specific effluents are usually co-treated with domestic wastewaters. Separate treatment has been recommended. However, there is a lack of information concerning the efficiency of separate hospital wastewater treatment by activated sludge, especially on the removal of pharmaceuticals. In this context, this article presents the results of a 2-year monitoring of conventional parameters, surfactants, gadolinium, and 13 pharmaceuticals on the specific study site SIPIBEL. This site allows the characterization of urban and hospital wastewaters and their separate treatment using the same process. Flow proportional sampling, solid-phase extraction, and liquid chromatography coupled with tandem mass spectrometry were used in order to obtain accurate data and limits of quantification consistent with ultra-trace detection. Thanks to these consolidated data, an in-depth characterization of urban and hospital wastewaters was realized, as well as a comparison of treatment efficiency between both effluents. Higher concentrations of organic carbon, AOX, phosphates, gadolinium, paracetamol, ketoprofen, and antibiotics were observed in hospital wastewaters compared to urban wastewaters. Globally higher removals were observed in the hospital wastewater treatment plant, and some parameters were shown to be of high importance regarding removal efficiencies: hydraulic retention time, redox conditions, and ambient temperature. Eleven pharmaceuticals were still quantified at relevant concentrations in hospital and urban wastewaters after treatment (e.g., up to 1 μg/L for sulfamethoxazole). However, as the urban flow was about 37 times higher than the hospital flow, the hospital contribution appeared relatively low compared to

  6. Non invasive blood flow assessment in diabetic foot ulcer using laser speckle contrast imaging technique

    Science.gov (United States)

    Jayanthy, A. K.; Sujatha, N.; Reddy, M. Ramasubba; Narayanamoorthy, V. B.

    2014-03-01

    Measuring microcirculatory tissue blood perfusion is of interest for both clinicians and researchers in a wide range of applications and can provide essential information of the progress of treatment of certain diseases which causes either an increased or decreased blood flow. Diabetic ulcer associated with alterations in tissue blood flow is the most common cause of non-traumatic lower extremity amputations. A technique which can detect the onset of ulcer and provide essential information on the progress of the treatment of ulcer would be of great help to the clinicians. A noninvasive, noncontact and whole field laser speckle contrast imaging (LSCI) technique has been described in this paper which is used to assess the changes in blood flow in diabetic ulcer affected areas of the foot. The blood flow assessment at the wound site can provide critical information on the efficiency and progress of the treatment given to the diabetic ulcer subjects. The technique may also potentially fulfill a significant need in diabetic foot ulcer screening and management.

  7. Modification of SrTiO3 single-crystalline surface after plasma flow treatment

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Alexandr A.; Weissbach, Torsten; Leisegang, Tilmann; Meyer, Dirk C. [Institut fuer Strukturphysik, Technische Universitaet Dresden, 01062 Dresden (Germany); Kulagin, Nikolay A. [Kharkiv National University for Radioelectronics, av. Shakespeare 6-48, 61045 Kharkiv (Ukraine); Langer, Enrico [Institut fuer Festkoerperphysik, Technische Universitaet Dresden, 01062 Dresden (Germany)

    2009-07-01

    Surface of pure and transition metal-doped SrTiO3(STO) single crystals before and after hydrogen plasma-flow treatment (energy of 5..20 J/cm2) is investigated by wide-angle X-ray diffraction (WAXRD), fluorescence X-ray absorption near edge structure (XANES) and scanning electron microscopy (SEM) techniques. Plasma treatment results in the formation of a textured polycrystalline layer at the surface of the single-crystalline samples with different orientation. The formation of the quasi-ordered structures consisting of nanoscale-sized pyramids is observed by SEM. XANES evidences the change of the valency of the part of Ti4+ to Ti3+ due to the plasma treatment. The data obtained together with results of X-ray spectroscopy measurements gives evidences of the change of stoichiometry of the STO samples resulting in a change of their physical properties after plasma treatment.

  8. Towards multi-phase flow simulations in the PDE framework Peano

    KAUST Repository

    Bungartz, Hans-Joachim

    2011-07-27

    In this work, we present recent enhancements and new functionalities of our flow solver in the partial differential equation framework Peano. We start with an introduction including an overview of the Peano development and a short description of the basic concepts of Peano and the flow solver in Peano concerning the underlying structured but adaptive Cartesian grids, the data structure and data access optimisation, and spatial and time discretisation of the flow solver. The new features cover geometry interfaces and additional application functionalities. The two geometry interfaces, a triangulation-based description supported by the tool preCICE and a built-in geometry using geometry primitives such as cubes, spheres, or tetrahedra allow for the efficient treatment of complex and changing geometries, an essential ingredient for most application scenarios. The new application functionality concerns a coupled heat-flow problem and two-phase flows. We present numerical examples, performance and validation results for these new functionalities. © 2011 Springer-Verlag.

  9. An efficient framework for photon Monte Carlo treatment planning

    International Nuclear Information System (INIS)

    Fix, Michael K; Manser, Peter; Frei, Daniel; Volken, Werner; Mini, Roberto; Born, Ernst J

    2007-01-01

    Currently photon Monte Carlo treatment planning (MCTP) for a patient stored in the patient database of a treatment planning system (TPS) can usually only be performed using a cumbersome multi-step procedure where many user interactions are needed. This means automation is needed for usage in clinical routine. In addition, because of the long computing time in MCTP, optimization of the MC calculations is essential. For these purposes a new graphical user interface (GUI)-based photon MC environment has been developed resulting in a very flexible framework. By this means appropriate MC transport methods are assigned to different geometric regions by still benefiting from the features included in the TPS. In order to provide a flexible MC environment, the MC particle transport has been divided into different parts: the source, beam modifiers and the patient. The source part includes the phase-space source, source models and full MC transport through the treatment head. The beam modifier part consists of one module for each beam modifier. To simulate the radiation transport through each individual beam modifier, one out of three full MC transport codes can be selected independently. Additionally, for each beam modifier a simple or an exact geometry can be chosen. Thereby, different complexity levels of radiation transport are applied during the simulation. For the patient dose calculation, two different MC codes are available. A special plug-in in Eclipse providing all necessary information by means of Dicom streams was used to start the developed MC GUI. The implementation of this framework separates the MC transport from the geometry and the modules pass the particles in memory; hence, no files are used as the interface. The implementation is realized for 6 and 15 MV beams of a Varian Clinac 2300 C/D. Several applications demonstrate the usefulness of the framework. Apart from applications dealing with the beam modifiers, two patient cases are shown. Thereby

  10. Unified Analysis of Multi-Chamber Contact Tanks and Mixing Efficiency Based on Vorticity Field. Part I: Hydrodynamic Analysis

    Directory of Open Access Journals (Sweden)

    Ender Demirel

    2016-11-01

    Full Text Available Multi-chamber contact tanks have been extensively used in industry for water treatment to provide potable water to communities, which is essential for human health. To evaluate the efficiency of this treatment process, flow and tracer transport analysis have been used in the literature using Reynolds averaged Navier–Stokes (RANS and large-eddy simulations (LES. The purpose of this study is two-fold. First a unifying analysis of the flow field is presented and similarities and differences in the numerical results that were reported in the literature are discussed. Second, the vorticity field is identified as the key parameter to use in separating the mean flow (jet zone and the recirculating zones. Based on the concepts of vorticity gradient and flexion product, it is demonstrated that the separation of the recirculation zone and the jet zone, fluid-fluid flow separation, is possible. The separation of the recirculation zones and vortex core lines are characterized using the definition of the Lamb vector. The separated regions are used to characterize the mixing efficiency in the chambers of the contact tank. This analysis indicates that the recirculation zone and jet zone formation are three-dimensional and require simulations over a long period of time to reach stability. It is recognized that the characteristics of the jet zones and the recirculation zones are distinct for each chamber and they follow a particular pattern and symmetry between the alternating chambers. Hydraulic efficiency coefficients calculated for each chamber show that the chambers having an inlet adjacent to the free surface may be designed to have larger volumes than the chambers having wall bounded inlets to improve the efficiency of the contact tank. This is a simple design alternative that would increase the efficiency of the system. Other observations made through the chamber analysis are also informative in redefining the characteristics of the efficiency of the

  11. Efficient Brownian Dynamics of rigid colloids in linear flow fields based on the grand mobility matrix

    Science.gov (United States)

    Palanisamy, Duraivelan; den Otter, Wouter K.

    2018-05-01

    We present an efficient general method to simulate in the Stokesian limit the coupled translational and rotational dynamics of arbitrarily shaped colloids subject to external potential forces and torques, linear flow fields, and Brownian motion. The colloid's surface is represented by a collection of spherical primary particles. The hydrodynamic interactions between these particles, here approximated at the Rotne-Prager-Yamakawa level, are evaluated only once to generate the body's (11 × 11) grand mobility matrix. The constancy of this matrix in the body frame, combined with the convenient properties of quaternions in rotational Brownian Dynamics, enables an efficient simulation of the body's motion. Simulations in quiescent fluids yield correct translational and rotational diffusion behaviour and sample Boltzmann's equilibrium distribution. Simulations of ellipsoids and spherical caps under shear, in the absence of thermal fluctuations, yield periodic orbits in excellent agreement with the theories by Jeffery and Dorrepaal. The time-varying stress tensors provide the Einstein coefficient and viscosity of dilute suspensions of these bodies.

  12. Fluorescence spectroscopy as a tool for determination of organic matter removal efficiency at water treatment works

    Directory of Open Access Journals (Sweden)

    M. Z. Bieroza

    2010-04-01

    Full Text Available Organic matter (OM in drinking water treatment is a common impediment responsible for increased coagulant and disinfectant dosages, formation of carcinogenic disinfection-by products, and microbial re-growth in distribution system. The inherent heterogeneity of OM implies the utilization of advanced analytical techniques for its characterization and assessment of removal efficiency. Here, the application of simple fluorescence excitation-emission technique to OM characterization in drinking water treatment is presented. The fluorescence data of raw and clarified water was obtained from 16 drinking water treatment works. The reduction in fulvic-like fluorescence was found to significantly correlate with OM removal measured with total organic carbon (TOC. Fluorescence properties, fulvic- and tryptophan-like regions, were found to discriminate OM fractions of different removal efficiencies. The results obtained in the study show that fluorescence spectroscopy provides a rapid and accurate characterization and quantification of OM fractions and indication of their treatability in conventional water treatment.

  13. Resilience and reliability of compact vertical-flow treatment wetlands designed for tropical climates.

    Science.gov (United States)

    Lombard-Latune, R; Pelus, L; Fina, N; L'Etang, F; Le Guennec, B; Molle, P

    2018-06-10

    Most of the tropical areas have sanitation problems to contend with. The French system of vertical-flow treatment wetlands (FS-VFTW) fed with raw wastewater could be a good water and sludge management solution. The purpose-adapted tropical design can reduce area requirement to below 1 m 2 /population equivalents (p.e.). The Taupinière FS-VFTW on Martinique Island was built according to this design, with one stage but with a saturated layer at the bottom of the filter and a simplified trickling filter (TF) added for further treatment to meet the high performances targeted. Unsaturated/saturated vertical-flow filters (US/S FS-VFTW) have shown improved performances on total nitrogen, carbon and suspended solids removal in temperate climates, but the performances in tropical conditions remain unknown. Here, we report on real-world-operation in the French Overseas Territories (FOT), the reliability and performances of this VFCW tropical-design. The system experienced loading conditions ranging from 30% to 165% of nominal carbonaceous biological oxygen demand (BOD 5 ), as well as tropical rainstorms that brought over 7 times the nominal hydraulic load. Over a period of 3 years, 29 campaigns collected 24-h flow-proportional samples at each treatment stage (raw wastewater, FS-VFTW outlet, TF outlet). When applied loads were close to nominal values, the US/S FS-VFTW itself guarantees 85/90/60/50% removal and 125/25/40/50 mg/L at the outlet for chemical oxygen demand (COD)/total suspended solids (TSS)/total Kjeldahl nitrogen (TKN)/total nitrogen (TN), respectively. By comparison with US/S systems in mainland France, it appears that the warmer tropical-climate temperatures facilitate both nitrification and denitrification kinetics. Performances in overload conditions confirm that the US/S FS-VFTW remains robust and reliable although COD and TKN removal are impacted, especially after strong tropical rain events. By adding a simple compact trickling filter to a US/S FS

  14. An efficient flow-based botnet detection using supervised machine learning

    DEFF Research Database (Denmark)

    Stevanovic, Matija; Pedersen, Jens Myrup

    2014-01-01

    Botnet detection represents one of the most crucial prerequisites of successful botnet neutralization. This paper explores how accurate and timely detection can be achieved by using supervised machine learning as the tool of inferring about malicious botnet traffic. In order to do so, the paper...... introduces a novel flow-based detection system that relies on supervised machine learning for identifying botnet network traffic. For use in the system we consider eight highly regarded machine learning algorithms, indicating the best performing one. Furthermore, the paper evaluates how much traffic needs...... to accurately and timely detect botnet traffic using purely flow-based traffic analysis and supervised machine learning. Additionally, the results show that in order to achieve accurate detection traffic flows need to be monitored for only a limited time period and number of packets per flow. This indicates...

  15. Restoration of the contrast of cerebral blood flows by the spatial deconvolution method

    International Nuclear Information System (INIS)

    Compingt, D.L.; Philippon, B.L.

    1982-01-01

    The measurement of regional cerebral blood flows (rCBF) with a gamma camera during xenon-133 inhalation necessitates collimators with high efficiency. Their spatial resolutions are weak: on the images given by a F.W.H.M. collimator (25 mm to 5 cm depth of water), the contrast restoration method by the ponctual dispersion function (P.D.F.) is used. The convolution product (Image)=(Object)*(P.D.F.) is resolved by a bidimensional Fast Fourier Transform treatment. The high frequencies are eliminated by a progressive filtration. The rCBF is calculated with Obrist's method. The Initial Slope Index is only used. A rCBF image with the calculator is also realized. The numerical values are compared with the normal treatment (N) without contrast restoration and after restoration. 22 patients are so treated after severe cerebral strokes. The hemispheric average of the flows according to the 2 treatments is unchanged (difference: 1.1%). The contrast between higher and lower flow areas is increasing by 73% after contrast restoration (significant difference: p [fr

  16. Analysis of copper losses throughout weak acid effluent flows generated during off-gas treatment in the New Copper Smelter RTB Bor

    Directory of Open Access Journals (Sweden)

    Dragana Ivšić-Bajčeta

    2013-09-01

    Full Text Available The previous inadequate treatment of off-gas in RTB Bor in Serbia has resulted in serious pollution of the environment and the possibly high losses of copper through the effluent flows. The project of New Copper Smelter RTB Bor, besides the new flash smelting furnace (FSF and the reconstruction of Pierce-Smith converter (PSC, includes more effective effluent treatment. Paper presents an analysis of the new FSF and PSC off-gas treatment, determination of copper losses throughout generated wastewaters and discussion of its possible valorization. Assumptions about the solubility of metals phases present in the FSF and PSC off-gas, obtained by the treatment process simulation, were compared with the leaching results of flue dusts. Determined wastewaters characteristics indicate that the PSC flow is significantly richer in copper, mostly present in insoluble metallic/sulfide form, while the FSF flow has low concentration of copper in the form of completely soluble oxide/sulfate. The possible scenario for the copper valorization, considering arsenic and lead as limiting factors, is the separation of the FSF and PSC flows, return of the metallic/sulfide solid phase to the smelting process and recovery from the sulfate/oxide liquid phase.

  17. Polymer electrolyte fuel cells: flow field for efficient air operation

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F N; Tsukada, A; Haas, O; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    A new flow field was designed for a polymer electrolyte fuel cell stack with an active area of 200 cm{sup 2} for operation at low air stoichiometry and low air over pressure. Optimum of gas flow and channel dimensions were calculated based on the required pressure drop in the fluid. Single cells and a bi-cell stack with the new flow field show an improved current/voltage characteristic when operated at low air stoichiometries as compared to that of the previous non optimized design. (author) 4 figs., 3 refs.

  18. 3D Numerical Investigation of the Flow Pattern in Settling Basins by SSIIM2 Software

    Directory of Open Access Journals (Sweden)

    Edris Merufinia

    2017-01-01

    Full Text Available Settling basins are considered as a major and important component in conventional water treatment processes. The high cost of constructing these basins accounts for approximately 30% of the total capital investment of water treatment plants. Hence, it is essential to model and optimize their performance beforehand. In settling and sedimentation basins, different areas of flow including secondary and rotational flows occur due to the velocity gradient. Such phenomena cause short paths, increase flow stationary and dead zones, and change the mixing rates of the flow, which collectively prevent laminar conditions to be created for the sedimentation process, and thereby reduce process efficiency. The remedy is to reduce as far as possible the dead zones in the flow. The first step to optimize a settling basin is to calculate accurately the velocity field and the volume of rotation zones. The present study presents the numerical simulation of a flow in a rectangular basin. Continuity and Navier-Stokes equations are solved using finite volume method. A 3D flow simulation is performed using the standard k-ε turbulence model for settling basins with and without baffles. Finally, the numerical results obtained are compared with experimental results reported elsewhere.

  19. Aeration to degas CO{sub 2}, increase pH, and increase iron oxidation rates for efficient treatment of net alkaline mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, C.S.; Dennis, A.; Kahler, A. [Bucknell University, Lewisburg, PA (United States). Dept. of Geology

    2009-07-15

    Passive treatment systems for mine drainage use no energy other than gravity, but they require greater area than active treatment systems. Researchers are considering 'hybrid' systems that have passive and active components for increased efficiency, especially where space limitations render passive-only technology ineffective. Flow-through reactor field experiments were conducted at two large net-alkaline anthracite mine discharges in central Pennsylvania. Assuming an Fe removal rate of 20 g m{sup -2} day{sup -1} and Fe loading from field data, 3.6 x 10{sup 3} and 3.0 x 10{sup 4} m{sup 2} oxidation ponds would be required for the passive treatment of Site 21 and Packer 5 discharges, respectively. However, only a small area is available at each site. This paper demonstrates aeration to drive off CO{sub 2}, increase pH, and increase Fe(II) oxidation rates, enabling treatment within a small area compared to passive treatment methods, and introduces a geochemical model to accurately predict these rates as well as semi-passive treatment system sizing parameters. Iron(II) oxidation modeling of actively aerated systems predicted that a 1-m deep pond with 10 times less area than estimated for passive treatment would lower Fe(II) concentrations to less than 1 mg L-1 at summer and winter temperatures for both sites. The use of active aeration for treatment Of CO{sub 2}-rich, net-alkaline discharges (including partially treated effluent from anoxic limestone drains) can result in considerably reduced treatment area for oxidation and may lower treatment costs, but settling of Fe hydroxides was not considered in this study. The reduced capital cost for earthmoving will need to be compared to energy and maintenance costs for aeration.

  20. Research of Workflow Efficiency in HighEnthalpy Air Flow Compact Generators

    Directory of Open Access Journals (Sweden)

    V. Yu. Aleksandrov

    2015-01-01

    Full Text Available To test the combustion chambers (CC of high-speed ramjet engine (ramjet it is necessary to create the inlet conditions as realistic as possible, including the stagnation temperature T0, the Mach number M0, and the total airflow pressure p0. To achieve T0 = 1000 ... 2000 K is possible using a high-enthalpy airflow generator (HAG providing the fired air-heating and oxygen balance compensation.Due to strict weight and size restrictions imposed by the test conditions of the ramjet CC and bench equipment, there is a need to reduce HAG size and weight. For small HAG the relevant tasks are to organize effective workflow and ensure combustion stability, which can be solved directly at the developmental testing stage.The characteristic criterion of the workflow efficiency in HAG is the completed physicochemical combustion processes of the working fluid components. This is due to the fact that in the testing process a possible after-burning component of the working fluid in the flow path of the ramjet CC has a significant impact on the studied characteristics of the engine, thereby having a detrimental effect on the quality of the experiment.The examination of the workflow efficiency in HAG showed that the use of hydrogen as a fuel allows us to achieve a high degree of completing the physicochemical processes and reaching the specified conditions at the CC inlet to the ramjet under test. The use of hydrocarbon fuels reduces the completion degree of the workflow process in HAG and is accompanied by the development of pressure pulsations.The data obtained can be used when developing various HAGs, including those intended for testing the CC of ramjets for the prospective aircrafts.

  1. Modeling of Aircraft Deicing Fluid Induced Biochemical Oxygen Demand in Subsurface-Flow Constructed Treatment Wetlands

    Science.gov (United States)

    2009-03-01

    Jukka A. Rintala, Christof Holliger, and Alla N. Nozhevnikova. “Evaluation of Kinetic Coefficients Using Intergrated Monod and Haldane Models for...Rousseau, Diederik P. L., Peter A Vanrolleghem, and Niels De Pauw. “Model-Based Design of Horizontal Subsurface Flow constructed Treatment

  2. Techno-economical efficiency and productivity change of wastewater treatment plants: the role of internal and external factors.

    Science.gov (United States)

    Hernández-Sancho, F; Molinos-Senante, M; Sala-Garrido, R

    2011-12-01

    Efficiency and productivity are important measures for identifying best practice in businesses and optimising resource-use. This study analyses how these two measures change across the period 2003-2008 for 196 wastewater treatment plants (WWTPs) in Spain, by using the benchmarking methods of Data Envelopment Analysis and the Malmquist Productivity Index. To identify which variables contribute to the sustainability of the WWTPs, differences in efficiency scores and productivity indices for external factors are also investigated. Our results indicate that both efficiency and productivity decreased over the five years. We verify that the productivity drop is primarily explained by technical change. Furthermore, certain external variables affected WWTP efficiency, including plant size, treatment technology and energy consumption. However, plants with low energy consumption are the only ones which improve their productivity. Finally, the benchmarking analyses proved to be useful as management tools in the wastewater sector, by providing vital information for improving the sustainability of plants.

  3. Two passive groundwater treatment installations at DOE facilities

    International Nuclear Information System (INIS)

    Barton, W.D.; Craig, P.M.; Stone, W.C.

    1997-01-01

    Groundwater is being successfully treated by reactive media at two DOE sites. Passive treatment utilizing containerized treatment media has been installed on a radioactive groundwater seep at Oak Ridge National Lab, Oak Ridge, Tennessee, and on a TCE plume at the Portsmouth Gaseous Diffusion Plant in Piketon, Ohio. In both applications, flow is conducted by gravity through canisters of reactive treatment media. The canister-based treatment installation at ORNL utilizes a natural sodium-chabazite zeolite to remove radiological cations (Sr, Cs) from contaminated groundwater at greater than 99.9% efficiency. Portsmouth is currently conducting tests on three different types of treatment media for reductive dehalogenation of TCE

  4. Thermal treatment of starch slurry in Couette-Taylor flow apparatus

    Directory of Open Access Journals (Sweden)

    Hubacz Robert

    2017-09-01

    Full Text Available In this paper, thermal processing of starch slurry in a Couette-Taylor flow (CTF apparatus was investigated. Gelatinized starch dispersion, after treatment in the CTF apparatus, was characterized using such parameters like starch granule diameters (or average diameter, starch granule swelling degree (quantifying the amount of water absorbed by starch granules and concentration of dissolved starch. These parameters were affected mostly by the process temperature, although the impact of the axial flow or rotor rotation on them was also observed. Moreover, the analysis of results showed a relatively good correlation between these parameters, as well as, between those parameter and apparent viscosity of gelatinized starch dispersion. Meanwhile, the increase in the value of the apparent viscosity and in shear-tinning behaviour of dispersion was associated with the progress of starch processing in the CTF apparatus. Finally, the CTF apparatuses of different geometries were compared using numerical simulation of the process. The results of the simulation indicated that the apparatus scaling-up without increasing the width of the gap between cylinders results in higher mechanical energy consumption per unit of processed starch slurry.

  5. Heterogeneous photocatalysis for air and water treatment: Fundamental needs for quantum efficiency enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Ollis, D.F. [North Carolina State Univ., Raleigh, NC (United States)

    1996-09-01

    In the remediation industries, a useful treatment technology must be {open_quotes}general, robust, and cheap{close_quotes}. Among oxidation processes, heterogeneous photocatalysis is now broadly demonstrated to destroy common water and air contaminants. The potential process uses of highly stable titania, long lived lamps (one year), and room temperature operation, indicating a simple and robust process. We are left to address the third criterion: Can photocatalysis be {open_quotes}cheap{close_quotes}? In both liquid phase and gas phase treatment and purification by photocatalysis, it is established that the primary barrier to commercialization is often cost. Cost in return is dominated by the efficiency with which solar or lamp photons are harvested for productive light, and subsequent dark, reactions. This paper therefore defines fundamental needs in photocatalysis for pollution control in terms of activities which could lead to quantum efficiency enhancement. We first recall three related definitions. The quantum yield (QY) is the ratio of molecules of reactant converted per photon absorbed, a fundamental quantity. A less fundamental, but more easily measured variable is the quantum efficiency (QE), the ratio of molecules converted per photon entering the reactor. A third variable is the energy required per order of magnitude pollutant reduction, or EEO, a definition which provides for easy energy cost comparisons among different technologies. Each measure cited here reflects the photon, and thus the electrical, cost of this photochemistry.

  6. Electrocoagulation efficiency of the tannery effluent treatment using aluminium electrodes.

    Science.gov (United States)

    Espinoza-Quiñones, Fernando R; Fornari, Marilda M T; Módenes, Aparecido N; Palácio, Soraya M; Trigueros, Daniela E G; Borba, Fernando H; Kroumov, Alexander D

    2009-01-01

    An electro-coagulation laboratory scale system using aluminium plates electrodes was studied for the removal of organic and inorganic pollutants as a by-product from leather finishing industrial process. A fractional factorial 2(3) experimental design was applied in order to obtain optimal values of the system state variables. The electro-coagulation (EC) process efficiency was based on the chemical oxygen demand (COD), turbidity, total suspended solid, total fixed solid, total volatile solid, and chemical element concentration values. Analysis of variance (ANOVA) for final pH, total fixed solid (TFS), turbidity and Ca concentration have confirmed the predicted models by the experimental design within a 95% confidence level. The reactor working conditions close to real effluent pH (7.6) and electrolysis time in the range 30-45 min were enough to achieve the cost effective reduction factors of organic and inorganic pollutants' concentrations. An appreciable improvement in COD removal efficiency was obtained for electro-coagulation treatment. Finally, the technical-economical analysis results have clearly shown that the electro-coagulation method is very promising for industrial application.

  7. Nitrogen regulation of transpiration controls mass-flow acquisition of nutrients.

    Science.gov (United States)

    Matimati, Ignatious; Verboom, G Anthony; Cramer, Michael D

    2014-01-01

    Transpiration may enhance mass-flow of nutrients to roots, especially in low-nutrient soils or where the root system is not extensively developed. Previous work suggested that nitrogen (N) may regulate mass-flow of nutrients. Experiments were conducted to determine whether N regulates water fluxes, and whether this regulation has a functional role in controlling the mass-flow of nutrients to roots. Phaseolus vulgaris were grown in troughs designed to create an N availability gradient by restricting roots from intercepting a slow-release N source, which was placed at one of six distances behind a 25 μm mesh from which nutrients could move by diffusion or mass-flow (termed 'mass-flow' treatment). Control plants had the N source supplied directly to their root zone so that N was available through interception, mass-flow, and diffusion (termed 'interception' treatment). 'Mass-flow' plants closest to the N source exhibited 2.9-fold higher transpiration (E), 2.6-fold higher stomatal conductance (gs), 1.2-fold higher intercellular [CO2] (Ci), and 3.4-fold lower water use efficiency than 'interception' plants, despite comparable values of photosynthetic rate (A). E, gs, and Ci first increased and then decreased with increasing distance from the N source to values even lower than those of 'interception' plants. 'Mass-flow' plants accumulated phosphorus and potassium, and had maximum concentrations at 10mm from the N source. Overall, N availability regulated transpiration-driven mass-flow of nutrients from substrate zones that were inaccessible to roots. Thus when water is available, mass-flow may partially substitute for root density in providing access to nutrients without incurring the costs of root extension, although the efficacy of mass-flow also depends on soil nutrient retention and hydraulic properties.

  8. Energy efficient SDN commodity switch based practical flow forwarding method

    KAUST Repository

    AlGhadhban, Amer

    2016-07-04

    Recent SDN researches suffer from over-accumulation of unhealthy flow-load. Instead, we leverage the SDN controller network view to encode the end-to-end path information into the packet address. Our solution EncPath significantly reduces the flow-table size and the number of control messages. Consequently, the power consumption of network switches is in orders of magnitude less than other evaluated solutions. It also provides flow management flexibility and scalability. We compare EncPath with single and multipath routing solutions and single path solution. Also, we operated them in proactive and reactive modes. We find that EncPath flow entries in core switches in a multihomed fat-tree with 144 hosts is approximately 1000 times smaller than Equal-Cost MultiPath (ECMP) and random routing. Additionally, the number of control messages to setup the network is reduced by a factor of 200×. This, consequently, affords data-plane and control-plane devices space to process other tasks. © 2016 IEEE.

  9. Treatment of atrazine in nursery irrigation runoff by a constructed wetland.

    Science.gov (United States)

    Runes, Heather B; Jenkins, Jeffrey J; Moore, James A; Bottomley, Peter J; Wilson, Bruce D

    2003-02-01

    To investigate the treatment capability of a surface flow wetland at a container nursery near Portland, Oregon, atrazine was introduced during simulated runoff events. Treatment efficiency was evaluated as the percent atrazine recovered (as percent of applied) in the water column at the wetland's outlet. Atrazine treatment efficiency at the outlet of the constructed wetland during a 7-d period ranged from 18-24% in 1998 (experiments 1-3) and 16-17% in 1999 (experiments 4 and 5). Changes in total flow, or frequency and intensity of runoff events did not affect treatment. For experiment 6 in 1999, where the amount, frequency, and duration of runoff events exceeded all other experiments, treatment was compromised. For all experiments, deethylatrazine (DEA) and deisopropylatrazine (DIA) accounted for 13-21% of the initial application. Hydroxyatrazine (HA) was rarely detected in the water. Organic carbon adsorption coefficients (Koc) were determined from batch equilibrium sorption isotherms with wetland sediment, and they decreased in the order of HA > DIA > atrazine > DEA. Static water-sediment column experiments indicated that sorption is an important mechanism for atrazine loss from water passing through the constructed wetland. The results of the MPN assay indicated the existence in the wetland of a low-density population of microorganisms with the potential to mineralize atrazine's ethyl side chain.

  10. Septage unit treatment by sludge treatment reed beds for easy management and reuse: performance and design considerations.

    Science.gov (United States)

    Kim, Boram; Bel, Thomas; Bourdoncle, Pascal; Dimare, Jocelyne; Troesch, Stéphane; Molle, Pascal

    2018-01-01

    Sustainable treatment and management of fecal sludge in rural areas require adapted solutions. Rustic and simple operating processes such as sludge treatment reed beds (STRB) have been increasingly considered for this purpose. The biggest full scale (2,600 m 2 of STRB) septage treatment unit in France had been built in Nègrepelisse with the final objectives of reusing treated sludge and leachates for agriculture spreading and tree irrigation, respectively. The aim of this investigation was to validate the treatment chain of this installation. The obtained field data showed firstly that the overall removal efficiencies of STRB were satisfactory and stable. Removal rates higher than 98% for chemical oxygen demand and suspended solids and a 95% for Kjeldahl nitrogen represented so far a beneficial septage treatment by STRB. The highlighted necessity of a suitable complementary leachate treatment (before tree irrigation) justified the presence of the second stage of vertical flow constructed wetland. The sludge deposit drying and mineralization efficiencies were on the right track. According to hydrotextural diagram analysis, surface deposit was however found to have high deformability probably due to the youth of the installation. An in-depth understanding of STRB system needs continuous long-term studies.

  11. Optimization of operating parameters of hybrid vertical down-flow constructed wetland systems for domestic sewerage treatment.

    Science.gov (United States)

    Huang, Zhujian; Zhang, Xianning; Cui, Lihua; Yu, Guangwei

    2016-09-15

    In this work, three hybrid vertical down-flow constructed wetland (HVDF-CW) systems with different compound substrates were fed with domestic sewage and their pollutants removal performance under different hydraulic loading and step-feeding ratio was investigated. The results showed that the hydraulic loading and step-feeding ratio were two crucial factors determining the removal efficiency of most pollutants, while substrate types only significantly affected the removal of COD and NH4(+)-N. Generally, the lower the hydraulic loading, the better removal efficiency of all contaminants, except for TN. By contrast, the increase of step-feeding ratio would slightly reduce the removal rate of ammonium and TP but obviously promoted the TN removal. Therefore, the optimal operation of this CWs could be achieved with low hydraulic loading combined with 50% of step-feeding ratio when TN removal is the priority, whereas medium or low hydraulic loading without step-feeding would be suitable when TN removal is not taken into consideration. The obtained results in this study can provide us with a guideline for design and optimization of hybrid vertical flow constructed wetland systems to improve the pollutants removal from domestic sewage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Immediate Flow Disruption as a Prognostic Factor After Flow Diverter Treatment: Long-Term Experience with the Pipeline Embolization Device.

    Science.gov (United States)

    Dodier, Philippe; Frischer, Josa M; Wang, Wei-Te; Auzinger, Thomas; Mallouhi, Ammar; Serles, Wolfgang; Gruber, Andreas; Knosp, Engelbert; Bavinzski, Gerhard

    2018-05-01

    To report long-term results after Pipeline Embolization Device (PED) implantation, characterize complex and standard aneurysms comprehensively, and introduce a modified flow disruption scale. We retrospectively reviewed a consecutive series of 40 patients harboring 59 aneurysms treated with 54 PEDs. Aneurysm complexity was assessed using our proposed classification. Immediate angiographic results were analyzed using previously published grading scales and our novel flow disruption scale. According to our new definition, 46 (78%) aneurysms were classified as complex. Most PED interventions were performed in the paraophthalmic and cavernous internal carotid artery segments. Excellent neurologic outcome (modified Rankin Scale 0 and 1) was observed in 94% of patients. Our data showed low permanent procedure-related mortality (0%) and morbidity (3%) rates. Long-term angiographic follow-up showed complete occlusion in 81% and near-total obliteration in a further 14%. Complete obliteration after deployment of a single PED was achieved in all standard aneurysms with 1-year follow-up. Our new scale was an independent predictor of aneurysm occlusion in a multivariable analysis. All aneurysms with a high flow disruption grade showed complete occlusion at follow-up regardless of PED number or aneurysm complexity. Treatment with the PED should be recognized as a primary management strategy for a highly selected cohort with predominantly complex intracranial aneurysms. We further show that a priori assessment of aneurysm complexity and our new postinterventional angiographic flow disruption scale predict occlusion probability and may help to determine the adequate number of per-aneurysm devices. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Subsurface flow constructed wetlands for the treatment of wastewater from different sources. Design and operation

    OpenAIRE

    Torrens Armengol, Antonina

    2016-01-01

    The aim of the thesis is to examine the viability of the subsurface constructed wetlands for the treatment of wastewater derived from three different sources (treatment ponds, pig farms and car wash facilities), and to evaluate the influence of design (size, type and depth of media, presence of Phragmites australis) and operational parameters (hydraulic load, dosing and feeding modes) on treatment efficiency and hydraulic behavior. Several studies were done in the framework of different ...

  14. Effect of Orifice Nozzle Design and Input Power on Two-Phase Flow and Mass Transfer Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hei Cheon [Chonnam Nat’l Univ., Gwangju (Korea, Republic of)

    2016-04-15

    It is necessary to investigate the input power as well as the mass transfer characteristics of the aeration process in order to improve the energy efficiency of an aerobic water treatment. The objective of this study is to experimentally investigate the effect of orifice nozzle design and input power on the flow and mass transfer characteristics of a vertical two-phase flow. The mass ratio, input power, volumetric mass transfer coefficient, and mass transfer efficiency were calculated using the measured data. It was found that as the input power increases the volumetric mass transfer coefficient increases, while the mass ratio and mass transfer efficiency decrease. The mass ratio, volumetric mass transfer coefficient, and mass transfer efficiency were higher for the orifice configuration with a smaller orifice nozzle area ratio. An empirical correlation was proposed to estimate the effect of mass ratio, input power, and Froude number on the volumetric mass transfer coefficient.

  15. Aeration to degas CO2, increase pH, and increase iron oxidation rates for efficient treatment of net alkaline mine drainage

    International Nuclear Information System (INIS)

    Kirby, C.S.; Dennis, A.; Kahler, A.

    2009-01-01

    Passive treatment systems for mine drainage use no energy other than gravity, but they require greater area than active treatment systems. Researchers are considering 'hybrid' systems that have passive and active components for increased efficiency, especially where space limitations render passive-only technology ineffective. Flow-through reactor field experiments were conducted at two large net-alkaline anthracite mine discharges in central Pennsylvania. Assuming an Fe removal rate of 20 g m -2 day -1 and Fe loading from field data, 3.6 x 10 3 and 3.0 x 10 4 m 2 oxidation ponds would be required for the passive treatment of Site 21 and Packer 5 discharges, respectively. However, only a small area is available at each site. This paper demonstrates aeration to drive off CO 2 , increase pH, and increase Fe(II) oxidation rates, enabling treatment within a small area compared to passive treatment methods, and introduces a geochemical model to accurately predict these rates as well as semi-passive treatment system sizing parameters. Both net-alkaline discharges were suboxic with a pH of ∼5.7, Fe(II) concentration of ∼16 mg L -1 , and low Mn and Al concentrations. Flow rates were ∼4000 L min -1 at Site 21 and 15,000 L min -1 at Packer 5. Three-h aeration experiments with flow rates scaled to a 14-L reactor resulted in pH increases from 5.7 to greater than 7, temperature increases from 12 to 22 deg. C, dissolved O 2 increases to saturation with respect to the atmosphere, and Fe(II) concentration decreases from 16 to -1 . A 17,000-L pilot-scale reactor at Site 21 produced similar results although aeration was not as complete as in the smaller reactor. Two non-aerated experiments at Site 21 with 13 and 25-h run times resulted in pH changes of ≤0.2 and Fe(II) concentration decreases of less than 3 mg L -1 . An Fe(II) oxidation model written in a differential equation solver matched the field experiments very well using field-measured pH, temperature, dissolved O 2

  16. Potentials for Improvement of Resource Efficiency in Printed Circuit Board Manufacturing: A Case Study Based on Material Flow Cost Accounting

    Directory of Open Access Journals (Sweden)

    Yi-Xuan Wang

    2017-05-01

    Full Text Available The pursuit of sustainable resource use by manufacturing companies is driven by resource scarcity, environmental awareness, and cost savings potentials. To address these issues, Material Flow Cost Accounting (MFCA has been developed and applied as an effective environmental management tool. Within MFCA’s general allocation, the accounts of products and losses are overrated by weight or volume. However, such a method is incompatible with Printed Circuit Board (PCB manufacturing because of industry characteristics in which primary inputs and products are measured by area. Based on MFCA, this case study systematically established several linear cost calculation models along the production process for capturing the actual waste flows as well as performing cost-benefit analysis. The recognition of previously ignored losses offered the incentive to find appropriate indicators to conduct cost-benefit analysis on hotspots for losses. Loss identification and analysis indicated that machining and wiring are the necessities and priorities of process optimization for resource efficiency improvement measures. Therefore, this research could not only advance the achievement of a profitable and sustainable production while improving resource efficiency at the source but could also provide support for decision making in PCB manufacturing.

  17. PIV measurements of the flow at the inlet of a turbocharger centrifugal compressor with recirculation casing treatment near the inducer

    Science.gov (United States)

    Gancedo, Matthieu; Gutmark, Ephraim; Guillou, Erwann

    2016-02-01

    Turbocharging reciprocating engines is a viable solution in order to meet the new regulations for emissions and fuel efficiency in part because turbochargers allow to use smaller, more efficient engines (downsizing) while maintaining power. A major challenge is to match the flow range of a dynamic turbomachine (the centrifugal compressor in the turbocharger) with a positive displacement pump (the engine) as the flow range of the latter is typically higher. The operating range of the compressor is thus of prime interest. At low mass flow rate (MFR), the compressor range is limited by the occurrence of surge. To control and improve it, numerous and varied methods have been used. Yet, an automotive application requires that the solution remains relatively simple and preferably passive. A common feature that has been demonstrated to improve the surge line is the use of flow recirculation in the inducer region through a circumferential bleed slot around the shroud, also called "ported shroud", similar to what has been developed for axial compressors in the past. The compressor studied here features such a device. In order to better understand the effect of the recirculation slot on the compressor functioning, flow measurements were performed at the inlet using particle image velocimetry and the results were correlated with pressure measurements nearby. Measurements were taken on a compressor with and without recirculation and across the full range of normal operation and during surge using a phase-locking method to obtain average flow fields throughout the entire surge cycle. When the recirculation is blocked, it was found that strong backflow develops at low MFR perturbing the incoming flow and inducing significant preswirl. The slot eliminated most of the backflow in front of the inducer making the compressor operation more stable. The measurements performed during surge showed strong backflow occurring periodically during the outlet pressure drop and when the

  18. ENHANCEMENT OF PHENOL REMOVAL EFFICIENCY IN DORA REFINERY WASTEWATER TREATMENT PLANT

    Directory of Open Access Journals (Sweden)

    Salah F. Sharif

    2013-05-01

    Full Text Available Because the sanctions imposed on Iraq by the United Nations, programmed maintenance and wearing parts replacement has not been performed according to schedules in DORA Refinery Wastewater Unit, which resulted in higher phenol content and BOD5 in effluents disposed to river. The investigations showed that two main reasons were behind this problem: Firstly, increased emissions of hydrocarbons in the complexity of refinery equipment and Secondly, the decreased efficiency of the aerators in the biological. During the last few months, phenol average concentration in the effluent, after biological treatment was found to be between 0.06-0.13 mg/L, while COD was exceeding 110 mg/L after treatment in the same period. Considerable enhancement, has been indicated recently, after the following performances: First: Recycling wastewater from some heat exchangers, and the segregation of low and high strength of wastewaters, Second: Minimizing emissions of hydrocarbons from fluid catalytic cracking and steam cracking, Third: Replacement of driving motors of the aerators in the biological treatment unit. After replacement of these units, a significant decrease in phenol concentration was obtained in purified water (0.03-0.05 mg/L and COD of 60 mg/L before the tertiary treatment. It is concluded that a better quality of effluents has been obtained after a series of emissions control and wastewater treatment unit equipment maintenance performances.

  19. Mass flows and removal of antibiotics in two municipal wastewater treatment plants.

    Science.gov (United States)

    Li, Bing; Zhang, Tong

    2011-05-01

    The mass flows and removal of 20 antibiotics of seven classes in two wastewater treatment plants (WWTPs) of Hong Kong were investigated in different seasons of a whole year, using bihourly 24h flow proportional composite samples. Antibiotics were detected at concentrations of 3.2-1718, 1.3-1176 and 1.1-233ngL(-1) in influents, secondary and disinfection effluents. Total daily discharges of all the detected antibiotics from effluents of Shatin and Stanley WWTPs were 470-710 and 3.0-5.2gd(-1), respectively. Ampicillin, cefalexin, sulfamethoxazole, sulfadiazine, sulfamethazine, chlortetracycline and vancomycin were effectively (52-100%) eliminated by activated sludge process while ampicillin and cefalexin were effectively (91-99%) eliminated by disinfection. Bihourly variation analysis showed that concentrations of the major antibiotics in influents varied more significantly in Stanley WWTP which served small communities. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. An evaluation of the performance and optimization of a new wastewater treatment technology: the air suction flow-biofilm reactor.

    Science.gov (United States)

    Forde, P; Kennelly, C; Gerrity, S; Collins, G; Clifford, Eoghan

    2015-01-01

    In this laboratory study, a novel wastewater treatment technology, the air suction flow-biofilm reactor (ASF-BR) - a sequencing batch biofilm reactor technology with a passive aeration mechanism - was investigated for its efficiency in removing organic carbon, nitrogen and phosphorus, from high-strength synthetic wastewaters. A laboratory-scale ASF-BR comprising 2 reactors, 350 mm in diameter and 450 mm in height, was investigated over 2 studies (Studies 1 and 2) for a total of 430 days. Study 1 lasted a total of 166 days and involved a 9-step sequence alternating between aeration, anoxic treatment and settlement. The cycle time was 12.1 h and the reactors were operated at a substrate loading rate of 3.60 g filtered chemical oxygen demand (CODf)/m2 media/d, 0.28 g filtered total nitrogen (TNf)/m2 media/d, 0.24 g ammonium-nitrogen (NH4-N)/m2 media/d and 0.07 g ortho-phosphate (PO4-P)/m2 media/d. The average removal rates achieved during Study 1 were 98% CODf, 88% TNf, 97% NH4-N and 35% PO4-P. During Study 2 (264 days), the unit was operated at a loading rate of 2.49 g CODf/m2 media/d, 0.24 g TNf/m2 media/d, 0.20 g NH4-N/m2 media/d and 0.06 PO4-P/m2 media/d. The energy requirement during this study was reduced by modifying the treatment cycle in include fewer pumping cycles. Removal rates in Study 2 averaged 97% CODf, 86% TNf, 99% NH4-N and 76% PO4-P. The excess sludge production of the system was evaluated and detailed analyses of the treatment cycles were carried out. Biomass yields were estimated at 0.09 g SS/g CODf, removed and 0.21 g SS/g CODf, removed for Studies 1 and 2, respectively. Gene analysis showed that the use of a partial vacuum did not affect the growth of ammonia-oxidizing bacteria. The results indicate that the ASF-BR and passive aeration technologies can offer efficient alternatives to existing technologies.

  1. Treatment Wetlands

    OpenAIRE

    Dotro, Gabriela; Langergraber, Günter; Molle, Pascal; Nivala, Jaime; Puigagut, Jaume; Stein, Otto; Von Sperling, Marcos

    2017-01-01

    Overview of Treatment Wetlands; Fundamentals of Treatment Wetlands; Horizontal Flow Wetlands; Vertical Flow Wetlands; French Vertical Flow Wetlands; Intensified and Modified Wetlands; Free Water Surface Wetlands; Other Applications; Additional Aspects.

  2. The effect of water availability on stand-level productivity, transpiration, water use efficiency and radiation use efficiency of field-grown willow clones

    International Nuclear Information System (INIS)

    Linderson, Maj-Lena; Iritz, Zinaida; Lindroth, Anders

    2007-01-01

    The effect of water availability on stand-level productivity, transpiration, water use efficiency (WUE) and radiation use efficiency (RUE) is evaluated for different willow clones at stand level. The measurements were made during the growing season 2000 in a 3-year-old plantation in Scania, southernmost Sweden. Six willow clones were included in the study: L78183, SW Rapp, SW Jorunn, SW Jorr, SW Tora and SW Loden. All clones were exposed to two water treatments: rain-fed, non-irrigated treatment and reduced water availability by reduced soil water recharge. Field measurements of stem sap-flow and biometry are up-scaled to stand transpiration and stand dry substance production and used to assess WUE. RUE is estimated from the ratio between the stand dry substance production and the accumulated absorbed photosynthetic active radiation over the growing season. The total stand transpiration rate for the 5 months lies between 100 and 325 mm, which is fairly low compared to the Penman-Monteith transpiration for willow, reaching 400-450 mm for the same period. Mean WUE of all clones and treatments is 5.3 g/kg, which is high compared to earlier studies, while average RUE is 0.31 g/mol, which is slightly low compared to other results. Generally, all clones, except for Jorunn, seem to be better off concerning biomass production, WUE and RUE than the reference clone. Jorr, Jorunn and Loden also seem to be able to cope with the reduced water availability with increase in the water use efficiency. Tora performs significantly better than the other clones concerning both growth and efficiency in light and water use, but the effect of the dry treatment on stem growth shows sensitivity to water availability. The reduced stem growth could be due to a change in allocation patterns

  3. Efficiency estimation methods of chemical radiation treatment of patients with disseminated cervicalcancer

    International Nuclear Information System (INIS)

    Yivankova, V.S.; Nesterenko, T.M.; Khranovs'ka, N.M.; Baranovs'ka, L.M.; Khrulenko, T.V.; Shevchenko, G.M.

    2014-01-01

    The Department of Radiation Oncology, National Cancer Institute developed methods chemoradiotherapy (CRT) patients with locally advanced cancers of the cervix (cervical cancer MR). Before treatment patients underwent complex examination, including DNA index determination by laser DNA flow cytometry based on biopsies of the cervix. During concomitant radiotherapy were used cytotoxic drugs in radiomodifying doses. Conducted to investigate the possibility of monitoring the effectiveness of treatment at the subcellular level. The treatment and analysis of the clinical and instrumental monitoring data in 79 patients with MR of cervical cancer (63 patients studied and 16 - control group). Effectiveness of CRT was evaluated by the degree of tumor regression, the dynamics of indicators DNA status of cervical cells and severity of toxic effects. Analysis of the direct method results CRT showed that the dynamics of DNA clones of tumor status correlates with clinical data obtained in response to cytotoxic therapy MR cervical cancer. Positive response of tumors in patients with cervical cancer MR after a full course chemoradiation increased by 25,0 % in comparison with standard methods. Toxic effects of treatment on the number and severity of patients in the study group did not differ from the control group, did not exceed the second degree

  4. Kansas City plant ultraviolet/ozone/hydrogen peroxide groundwater treatment system overview

    International Nuclear Information System (INIS)

    Stites, M.E.; Hughes, R.F.

    1992-01-01

    The Kansas City Plant (KCP) has committed to the utilization of a groundwater treatment system, for removal of volatile organic compounds (VOCs), that discharges a minimal amount of pollutants to the environment. An advanced oxidation process (AOP) system utilizing ozone, ultraviolet radiation, and hydrogen peroxide serves in this capacity. Packed tower aeration and activated carbon filtration are listed as best available technologies (BATs) by the Environmental Protection Agency (EPA) for the removal of VOCs in water. The disadvantage to these BATs is that they transfer the VOCs from the water medium to the air or carbon media respectively. Operation of the system began in May 1988 at a flow rate of 22.7 liters per minute (lpm) (6 gallons per minute (gpm)). An additional 102.2 lpm (27 gpm) of flow were added in October 1990. Various efforts to optimize and track the treatment unites efficiency have been carried out. A maximum influent reading of 26,590 parts per billion (ppb) of total VOCs has been recorded. Following the addition of flows, removal efficiency has averaged approximately 95%. Both air and water effluents are factored into this calculation. (author)

  5. Pharmaceutical and personal care products in domestic wastewater and their removal in anaerobic treatment systems: Septic tank – up flow anaerobic filter.

    Directory of Open Access Journals (Sweden)

    Juan Pablo Arrubla Vélez

    2016-01-01

    Full Text Available In several countries around the world, Pharmaceutical and Personal Care Products (PPCPs exist in aquatic environments, a fact that increases the awareness within the scientific community with respect to their possible fate and environment effects. This research presents a preliminary monitoring of use, consumption and presence of PPCPs in wastewater from a treatment plant in a rural area of Pereira (Colombia. Domestic sewage is treated in a septic tank followed by an Up-Flow Anaerobic Filter and its effluent is discharged into the Otún River, upstream of the water intake of the supply system of the city. The compounds monitored in this research included ibuprofen, naproxen, diclofenac, aspirin, ketoprofen, caffeine, galaxolide, tonalide and dihydrojasmonate. An adapted method of multi-residue analysis was used, which is based on solid phase extraction with hydrophilic-lipophilic balance cartridges, and determination by gas chromatography-mass spectrometry. The removal efficiencies demonstrated that the treatment plant could eliminate less than 50% of dihydrojasmonate, diclofenac and galaxolide existing in wastewater; concentration of aspirin, naproxen and tonalide could only be reduced in 15%; and caffeine, ibuprofen and ketoprofen were not removed. Results provided basic information to decide over the necessity of complementary treatments for effluents from systems with the mentioned units.

  6. Nasal high flow therapy: a novel treatment rather than a more expensive oxygen device

    Directory of Open Access Journals (Sweden)

    Eleni Ischaki

    2017-09-01

    Full Text Available Nasal high flow is a promising novel oxygen delivery device, whose mechanisms of action offer some beneficial effects over conventional oxygen systems. The administration of a high flow of heated and humidified gas mixture promotes higher and more stable inspiratory oxygen fraction values, decreases anatomical dead space and generates a positive airway pressure that can reduce the work of breathing and enhance patient comfort and tolerance. Nasal high flow has been used as a prophylactic tool or as a treatment device mostly in patients with acute hypoxaemic respiratory failure, with the majority of studies showing positive results. Recently, its clinical indications have been expanded to post-extubated patients in intensive care or following surgery, for pre- and peri-oxygenation during intubation, during bronchoscopy, in immunocompromised patients and in patients with “do not intubate” status. In the present review, we differentiate studies that suggest an advantage (benefit from other studies that do not suggest an advantage (no benefit compared to conventional oxygen devices or noninvasive ventilation, and propose an algorithm in cases of nasal high flow application in patients with acute hypoxaemic respiratory failure of almost any cause.

  7. Resource recovery from residual household waste: An application of exergy flow analysis and exergetic life cycle assessment

    DEFF Research Database (Denmark)

    Laner, David; Rechberger, Helmut; De Soete, Wouter

    2015-01-01

    Exergy is based on the Second Law of thermodynamics and can be used to express physical and chemical potential and provides a unified measure for resource accounting. In this study, exergy analysis was applied to four residual household waste management scenarios with focus on the achieved resource...... of the waste treatment system under investigation and (ii) exergetic life cycle assessment (LCA) using the Cumulative Exergy Extraction from the Natural Environment (CEENE) as a method for resource accounting. Scenario efficiencies of around 17-27% were found based on the exergy flow analysis (higher...... with the functionality of a material. In addition, the definition of appropriate waste system boundaries is critical for the exergy efficiencies derived from the flow analysis, as it is constrained by limited information available about the composition of flows in the system as well as about secondary production...

  8. Microbial Removal Efficiency of UV in Tehran Shahid Mahallati Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Reza Dabbagh

    2009-03-01

    Full Text Available Shahid Mahallati Wastewater Treatment Plant was selected for installing a UV disinfection unit to investigate its germicidal effect on microbial removal. Low pressure mercury lamps were used to generate germicidal ultraviolet radiation (UV-C. The UV system was operated over a period of 6 months that included both warm and cold seasons. A maximum UV disinfection efficiency of 14.4m3/h was recorded for the system on the basis of design criteria within turbidity ranges of 9 to 32 NTU. The minimum UV dose applied in the UV unit was 40000 µW.s/cm2 and the highest bacterial density in the UV unit influent was 5.6*107. Effluent total coliform or fecal coliform enumeration after exposure to UV ray showed the microbial density decreasing from four logs, or 99.99%, to as high as six logs, or 99.9999% removal efficiency, under different conditions. Effluent microbial densities in terms of total and fecal coliforms were below 1000MPN/100mL and 400MPN/100mL, respectively. These values comply with wastewater discharge or agricultural irrigation standards according to Iran Department of Environment. From our results, it is concluded that UV disinfection may be an effective technique for wastewater disinfection in Iranian wastewater treatment plants.

  9. Fast Postmoisture Treatment of Luminescent Perovskite Films for Efficient Light-Emitting Diodes.

    Science.gov (United States)

    Wang, Haoran; Li, Xiaomin; Yuan, Mingjian; Yang, Xuyong

    2018-04-01

    Despite the recent advances in the performance of perovskite light-emitting diodes (PeLEDs), the effects of water on the perovskite emissive layer and its electroluminescence are still unclear, even though it has been previously demonstrated that moisture has a significant impact on the quality of perovskite films in the fabrication process of perovskite solar cells and is a prerequisite for obtaining high-performance PeLEDs. Here, the effects of postmoisture on the luminescent CH 3 NH 3 PbBr 3 (MAPbBr 3 ) perovskite films are systematically investigated. It is found that postmoisture treatment can efficiently control the morphology and growth of perovskite films and only a fast moisture exposure at a 60% high relative humidity results in significantly improved crystallinity, carrier lifetime, and photoluminescence quantum yield of perovskite films. With the optimized moisture-treated perovskite films, a high-performance PeLED is fabricated, exhibiting a maximum current efficiency of 20.4 cd A -1 , which is an almost 20-fold enhancement when compared with perovskite films without moisture treatment. The results provide valuable insights into the moisture-assisted growth of luminescent perovskite films and will aid in the development of high-performance perovskite light-emitting devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Towards a Highly Efficient Meshfree Simulation of Non-Newtonian Free Surface Ice Flow: Application to the Haut Glacier d'Arolla

    Science.gov (United States)

    Shcherbakov, V.; Ahlkrona, J.

    2016-12-01

    In this work we develop a highly efficient meshfree approach to ice sheet modeling. Traditionally mesh based methods such as finite element methods are employed to simulate glacier and ice sheet dynamics. These methods are mature and well developed. However, despite of numerous advantages these methods suffer from some drawbacks such as necessity to remesh the computational domain every time it changes its shape, which significantly complicates the implementation on moving domains, or a costly assembly procedure for nonlinear problems. We introduce a novel meshfree approach that frees us from all these issues. The approach is built upon a radial basis function (RBF) method that, thanks to its meshfree nature, allows for an efficient handling of moving margins and free ice surface. RBF methods are also accurate and easy to implement. Since the formulation is stated in strong form it allows for a substantial reduction of the computational cost associated with the linear system assembly inside the nonlinear solver. We implement a global RBF method that defines an approximation on the entire computational domain. This method exhibits high accuracy properties. However, it suffers from a disadvantage that the coefficient matrix is dense, and therefore the computational efficiency decreases. In order to overcome this issue we also implement a localized RBF method that rests upon a partition of unity approach to subdivide the domain into several smaller subdomains. The radial basis function partition of unity method (RBF-PUM) inherits high approximation characteristics form the global RBF method while resulting in a sparse system of equations, which essentially increases the computational efficiency. To demonstrate the usefulness of the RBF methods we model the velocity field of ice flow in the Haut Glacier d'Arolla. We assume that the flow is governed by the nonlinear Blatter-Pattyn equations. We test the methods for different basal conditions and for a free moving

  11. Transcatheter embolization for high blood flow vascular malformations of oral maxillofacial region

    International Nuclear Information System (INIS)

    Sun Zengtao; Liu Zuoqin; Li Jijun; Tang Jun; Shang Jianqiang; Chen Jie

    2007-01-01

    Objective: To explore the treatment and efficiency of high blood flow vascular malformations of oral maxillofacial region with super-selective arterial embolization. Methods: 18 cases underwent angiography of the head and neck before treatment and then followed by super-selective catheterization with microcatheter to embolize the feeding vessels of the vascular malformations with PVA. 8 cases underwent surgical excision within 72 hours after the embolization and the other 10 cases passed through the arterial radical emboliztion treatment. Results: Technical success ratio reached 100% with no complications causing skin necrosis or incorrect arterial embolization else where in the skull. All 8 cases undergone preoperative embolization showed obviously less bleeding, easier removal of the mass and reduction of operation time. 10 cases with radical arterial embolization manifested reduction of swelling and improvement of organ function within 1 to 24 months after the procedure. 5 patients were cured with only once operation, 4 cases with twice operation and 1 with the thrice. Conclusions: Aterial embolization is a safe and effective method in the treatment of high blood flow vascular malformations of oral maxillofacial region. (authors)

  12. Data on wastewater treatment plant by using wetland method, Babol, Iran

    Directory of Open Access Journals (Sweden)

    Yousef Dadban Shahamat

    2018-02-01

    Full Text Available Date in this paper highlights the applications of constructed horizontal surface flow (HF-CW wetland with two different local plants (Louis latifoila and Phragmites -australis (Cav. Trin at the wastewater treatment plant in Babol city. This system was designed as an advanced treatment unit in field scale after the treatment plant. Parameters such as Total Dissolved Solid (TDS, Total Suspended Solid (TSS, Turbidity, Biological Oxygen Demand (BOD and Chemical Oxygen Demand (COD, were investigated. The result shows that treatment efficiency increases with the passage of time. The efficiency of Phragmites planted setups in open environment was fairly good for all studied parameters (28.6% of TDS, 94.4% for TSS, 79.8% for turbidity, 93.7% for BOD and 82.6% for COD. The efficiency of the latifoila set up was also good, but lower than that of Phragmites (26.5% of TDS, 76.9% for TSS, 71.5% for turbidity, 79.1 for BOD and 68.8% for COD. In brief, the obtained dates show that using local plants in (HF-CW wetland not only effectively reduces various contaminants from the effluent of the wastewater according to Effluent Guideline regulations (WHO & EPA, but it is also a cost- effective and environmentally friendly method. Also, it was calculated that in full scale operation [time (1 day and a depth (0.3 m], 8 ha of wetland was needed. Keywords: BOD, Babol, COD, Horizontal subsurface flow wetland, TSS, TSD

  13. A ghost-cell immersed boundary method for flow in complex geometry

    International Nuclear Information System (INIS)

    Tseng, Y.-H.; Ferziger, Joel H.

    2003-01-01

    An efficient ghost-cell immersed boundary method (GCIBM) for simulating turbulent flows in complex geometries is presented. A boundary condition is enforced through a ghost cell method. The reconstruction procedure allows systematic development of numerical schemes for treating the immersed boundary while preserving the overall second-order accuracy of the base solver. Both Dirichlet and Neumann boundary conditions can be treated. The current ghost cell treatment is both suitable for staggered and non-staggered Cartesian grids. The accuracy of the current method is validated using flow past a circular cylinder and large eddy simulation of turbulent flow over a wavy surface. Numerical results are compared with experimental data and boundary-fitted grid results. The method is further extended to an existing ocean model (MITGCM) to simulate geophysical flow over a three-dimensional bump. The method is easily implemented as evidenced by our use of several existing codes

  14. Parking Lot Runoff Quality and Treatment Efficiency of a Stormwater-Filtration Device, Madison, Wisconsin, 2005-07

    Science.gov (United States)

    Horwatich, Judy A.; Bannerman, Roger T.

    2010-01-01

    To evaluate the treatment efficiency of a stormwater-filtration device (SFD) for potential use at Wisconsin Department of Transportation (WisDOT) park-and-ride facilities, a SFD was installed at an employee parking lot in downtown Madison, Wisconsin. This type of parking lot was chosen for the test site because the constituent concentrations and particle-size distributions (PSDs) were expected to be similar to those of a typical park-and-ride lot operated by WisDOT. The objective of this particular installation was to reduce loads of total suspended solids (TSS) in stormwater runoff to Lake Monona. This study also was designed to provide a range of treatment efficiencies expected for a SFD. Samples from the inlet and outlet were analyzed for 33 organic and inorganic constituents, including 18 polycyclic aromatic hydrocarbons (PAHs). Samples were also analyzed for physical properties, including PSD. Water-quality samples were collected for 51 runoff events from November 2005 to August 2007. Samples from all runoff events were analyzed for concentrations of suspended sediment (SS). Samples from 31 runoff events were analyzed for 15 constituents, samples from 15 runoff events were analyzed for PAHs, and samples from 36 events were analyzed for PSD. The treatment efficiency of the SFD was calculated using the summation of loads (SOL) and the efficiency ratio methods. Constituents for which the concentrations and (or) loads were decreased by the SFD include TSS, SS, volatile suspended solids, total phosphorous (TP), total copper, total zinc, and PAHs. The efficiency ratios for these constituents are 45, 37, 38, 55, 22, 5, and 46 percent, respectively. The SOLs for these constituents are 32, 37, 28, 36, 23, 8, and 48 percent, respectively. The SOL for chloride was -21 and the efficiency ratio was -18. Six chemical constituents or properties-dissolved phosphorus, chemical oxygen demand, dissolved zinc, total dissolved solids, dissolved chemical oxygen demand, and

  15. flowClust: a Bioconductor package for automated gating of flow cytometry data

    Directory of Open Access Journals (Sweden)

    Lo Kenneth

    2009-05-01

    Full Text Available Abstract Background As a high-throughput technology that offers rapid quantification of multidimensional characteristics for millions of cells, flow cytometry (FCM is widely used in health research, medical diagnosis and treatment, and vaccine development. Nevertheless, there is an increasing concern about the lack of appropriate software tools to provide an automated analysis platform to parallelize the high-throughput data-generation platform. Currently, to a large extent, FCM data analysis relies on the manual selection of sequential regions in 2-D graphical projections to extract the cell populations of interest. This is a time-consuming task that ignores the high-dimensionality of FCM data. Results In view of the aforementioned issues, we have developed an R package called flowClust to automate FCM analysis. flowClust implements a robust model-based clustering approach based on multivariate t mixture models with the Box-Cox transformation. The package provides the functionality to identify cell populations whilst simultaneously handling the commonly encountered issues of outlier identification and data transformation. It offers various tools to summarize and visualize a wealth of features of the clustering results. In addition, to ensure its convenience of use, flowClust has been adapted for the current FCM data format, and integrated with existing Bioconductor packages dedicated to FCM analysis. Conclusion flowClust addresses the issue of a dearth of software that helps automate FCM analysis with a sound theoretical foundation. It tends to give reproducible results, and helps reduce the significant subjectivity and human time cost encountered in FCM analysis. The package contributes to the cytometry community by offering an efficient, automated analysis platform which facilitates the active, ongoing technological advancement.

  16. Effects of iron and calcium carbonate on contaminant removal efficiencies and microbial communities in integrated wastewater treatment systems.

    Science.gov (United States)

    Zhao, Zhimiao; Song, Xinshan; Zhang, Yinjiang; Zhao, Yufeng; Wang, Bodi; Wang, Yuhui

    2017-12-01

    In the paper, we explored the influences of different dosages of iron and calcium carbonate on contaminant removal efficiencies and microbial communities in algal ponds combined with constructed wetlands. After 1-year operation of treatment systems, based on the high-throughput pyrosequencing analysis of microbial communities, the optimal operating conditions were obtained as follows: the ACW10 system with Fe 3+ (5.6 mg L -1 ), iron powder (2.8 mg L -1 ), and CaCO 3 powder (0.2 mg L -1 ) in influent as the adjusting agents, initial phosphorus source (PO 4 3- ) in influent, the ratio of nitrogen to phosphorus (N/P) of 30 in influent, and hydraulic retention time (HRT) of 1 day. Total nitrogen (TN) removal efficiency and total phosphorus (TP) removal efficiency were improved significantly. The hydrolysis of CaCO 3 promoted the physicochemical precipitation in contaminant removal. Meanwhile, Fe 3+ and iron powder produced Fe 2+ , which improved contaminant removal. Iron ion improved the diversity, distribution, and metabolic functions of microbial communities in integrated treatment systems. In the treatment ACW10, the dominant phylum in the microbial community was PLANCTOMYCETES, which positively promoted nitrogen removal. After 5 consecutive treatments in ACW10, contaminant removal efficiencies for TN and TP respectively reached 80.6% and 57.3% and total iron concentration in effluent was 0.042 mg L -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Material flow cost accounting as a tool for improved resource efficiency in the hotel sector: A case of emerging market

    Directory of Open Access Journals (Sweden)

    Celani John Nyide

    2016-12-01

    Full Text Available Material Flow Cost Accounting (MFCA is one of the Environmental Management Accounting (EMA tools that has been developed to enable environmentally and economically efficient material usage and thus improve resource efficiency. However, the use of this tool to improve resource efficiency in the South African hotel sector remains unknown. An exploratory study, qualitative in nature, was conducted using a single case study with embedded units approach. A Hotel Management Group that met the selection criteria formed part of this study. In-depth interviews were conducted with 10 participants and additional documents were analysed. The investigated hotels have developed technologies that provide an environmental account in both physical and monetary units which constitute the use of MFCA to improve resource efficiencies. However, the study established a number of factors that affect the implementation of MFCA by the hotel sector in a South African context

  18. Retrograde Transvenous Ethanol Embolization of High-flow Peripheral Arteriovenous Malformations

    International Nuclear Information System (INIS)

    Linden, Edwin van der; Baalen, Jary M. van; Pattynama, Peter M. T.

    2012-01-01

    Purpose: To report the clinical efficiency and complications in patients treated with retrograde transvenous ethanol embolization of high-flow peripheral arteriovenous malformations (AVMs). Retrograde transvenous ethanol embolization of high-flow AVMs is a technique that can be used to treat AVMs with a dominant outflow vein whenever conventional interventional procedures have proved insufficient. Methods: This is a retrospective study of the clinical effectiveness and complications of retrograde embolization in five patients who had previously undergone multiple arterial embolization procedures without clinical success. Results: Clinical outcomes were good in all patients but were achieved at the cost of serious, although transient, complications in three patients. Conclusion: Retrograde transvenous ethanol embolization is a highly effective therapy for high-flow AVMs. However, because of the high complication rate, it should be reserved as a last resort, to be used after conventional treatment options have failed.

  19. Transverse correlation: An efficient transverse flow estimator - initial results

    DEFF Research Database (Denmark)

    Holfort, Iben Kraglund; Henze, Lasse; Kortbek, Jacob

    2008-01-01

    , a standard deviation of 1.64% and a bias of 1.13% are obtained for a beam to flow angle of 90 degrees. Using the same setup a standard deviation of 2.21% and a bias of 1.07% are obtained for a beam to flow angle of 75 degrees. Using 20 emissions a standard deviation of 3.4% and a bias of 2.06% are obtained...... at 45 degrees. The method performs stable down to a signal-to-noise ratio of 0 dB, where a standard deviation of 5.5% and a bias of 1.2% is achieved....

  20. Industrial energy-flow management

    International Nuclear Information System (INIS)

    Lampret, Marko; Bukovec, Venceslav; Paternost, Andrej; Krizman, Srecko; Lojk, Vito; Golobic, Iztok

    2007-01-01

    Deregulation of the energy market has created new opportunities for the development of new energy-management methods based on energy assets, risk management, energy efficiency and sustainable development. Industrial energy-flow management in pharmaceutical systems, with a responsible approach to sustainable development, is a complex task. For this reason, an energy-information centre, with over 14,000 online measured data/nodes, was implemented. This paper presents the energy-flow rate, exergy-flow rate and cost-flow rate diagrams, with emphasis on cost-flow rate per energy unit or exergy unit of complex pharmaceutical systems

  1. LES of stratified-wavy flows using novel near-interface treatment

    Science.gov (United States)

    Karnik, Aditya; Kahouadji, Lyes; Chergui, Jalel; Juric, Damir; Shin, Seungwon; Matar, Omar K.

    2017-11-01

    The pressure drop in horizontal stratified wavy flows is influenced by interfacial shear stress. The near-interface behavior of the lighter phase is akin to that near a moving wall. We employ a front-tracking code, Blue, to simulate and capture the near-interface behaviour of both phases. Blue uses a modified Smagorinsky LES model incorporating a novel near-interface treatment for the sub-grid viscosity, which is influenced by damping due to the wall-like interface, and enhancement of the turbulent kinetic energy (TKE) due to the interfacial waves. Simulations are carried out for both air-water and oil-water stratified configurations to demonstrate the applicability of the present method. The mean velocities and tangential Reynolds stresses are compared with experiments for both configurations. At the higher Re, the waves penetrate well into the buffer region of the boundary layer above the interface thus altering its dynamics. Previous attempts to capture the secondary structures associated with such flows using RANS or standard LES methodologies have been unsuccessful. The ability of the present method to reproduce these structures is due to the correct estimation of the near-interface TKE governing energy transfer from the normal to tangential directions. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).

  2. Energy savings by reduced mixing in aeration tanks: results from a full scale investigation and long term implementation at Avedoere wastewater treatment plant.

    Science.gov (United States)

    Sharma, A K; Guildal, T; Thomsen, H R; Jacobsen, B N

    2011-01-01

    The aim of this project was to investigate the potential of reducing number of mixers in the biological treatment process and thereby achieve energy and economical savings and contribute to cleaner environment. The project was carried out at Avedoere wastewater treatment plant and a full scale investigation was conducted to study the effect of reduced mixing on flow velocity, suspended solid sedimentation, concentration gradients of oxygen and SS with depth and treatment efficiency. The only negative effect observed was on flow velocity; however the velocity was above the critical velocity. The plant has been operating with 50% of its designed number of mixers since September 2007 and long term results also confirm that reduced mixing did not have any negative effect on treatment efficiency. The estimated yearly electricity saving is 0.75 GWh/year.

  3. High efficiency and low cost preparation of size controlled starch nanoparticles through ultrasonic treatment and precipitation.

    Science.gov (United States)

    Chang, Yanjiao; Yan, Xiaoxia; Wang, Qian; Ren, Lili; Tong, Jin; Zhou, Jiang

    2017-07-15

    The purpose of this work was to develop an approach to produce size controlled starch nanoparticles (SNPs), via precipitation with high efficiency and low cost. High concentration starch aqueous pastes (up to 5wt.%) were treated by ultrasound. Viscosity measurements and size exclusion chromatography characterization revealed that, after 30min ultrasonic treatment, viscosity of the starch pastes decreased two orders of magnitude and the weight average molecular weight of the starch decreased from 8.4×10 7 to 2.7×10 6 g/mol. Dynamic light scattering measurements and scanning electron microscopy observations showed that the SNPs prepared from the starch pastes with ultrasonic treatments were smaller (∼75nm) and more uniform. Moreover, SNPs could be obtained using less non-solvents. X-ray diffraction results indicated that effect of the ultrasonic treatment on crystalline structure of the SNPs was negligible. Ultrasound can be utilized to prepare smaller SNPs through nanoprecipitation with higher efficiency and lower cost. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Experimental procedure for the determination of counting efficiency and sampling flow rate of a grab-sampling working level meter

    International Nuclear Information System (INIS)

    Grenier, M.; Bigu, J.

    1982-07-01

    The calibration procedures used for a working level meter (WLM) of the grab-sampling type are presented in detail. The WLM tested is a Pylon WL-1000C working level meter and it was calibrated for radon/thoron daughter counting efficiency (E), for sampling pump flow rate (Q) and other variables of interest. For the instrument calibrated at the Elliot Lake Laboratory, E was 0.22 +- 0.01 while Q was 4.50 +- 0.01 L/min

  5. Factors influencing arsenic and nitrate removal from drinking water in a continuous flow electrocoagulation (EC) process

    International Nuclear Information System (INIS)

    Kumar, N. Sanjeev; Goel, Sudha

    2010-01-01

    An experimental study was conducted under continuous flow conditions to evaluate some of the factors influencing contaminant removal by electrocoagulation (EC). A bench-scale simulation of drinking water treatment was done by adding a filtration column after a rectangular EC reactor. Contaminant removal efficiency was determined for voltages ranging from 10 to 25 V and a comparative study was done with distilled water and tap water for two contaminants: nitrate and arsenic(V). Maximum removal efficiency was 84% for nitrate at 25 V and 75% for arsenic(V) at 20 V. No significant difference in contaminant removal was observed in tap water versus distilled water. Increase in initial As(V) concentration from 1 ppm to 2 ppm resulted in a 10% increase in removal efficiency. Turbidity in the EC reactor effluent was 52 NTU and had to be filtered to achieve acceptable levels of final turbidity (5 NTU) at steady-state. The flow regime in the continuous flow reactor was also evaluated in a tracer study to determine whether it is a plug flow reactor (PFR) or constantly stirred tank reactor (CSTR) and the results show that this reactor was close to an ideal CSTR, i.e., it was fairly well-mixed.

  6. Factors influencing arsenic and nitrate removal from drinking water in a continuous flow electrocoagulation (EC) process

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, N. Sanjeev [Civil Engineering Department, IIT Kharagpur, Kharagpur 721302 (India); Goel, Sudha, E-mail: sudhagoel@civil.iitkgp.ernet.in [Civil Engineering Department, IIT Kharagpur, Kharagpur 721302 (India)

    2010-01-15

    An experimental study was conducted under continuous flow conditions to evaluate some of the factors influencing contaminant removal by electrocoagulation (EC). A bench-scale simulation of drinking water treatment was done by adding a filtration column after a rectangular EC reactor. Contaminant removal efficiency was determined for voltages ranging from 10 to 25 V and a comparative study was done with distilled water and tap water for two contaminants: nitrate and arsenic(V). Maximum removal efficiency was 84% for nitrate at 25 V and 75% for arsenic(V) at 20 V. No significant difference in contaminant removal was observed in tap water versus distilled water. Increase in initial As(V) concentration from 1 ppm to 2 ppm resulted in a 10% increase in removal efficiency. Turbidity in the EC reactor effluent was 52 NTU and had to be filtered to achieve acceptable levels of final turbidity (5 NTU) at steady-state. The flow regime in the continuous flow reactor was also evaluated in a tracer study to determine whether it is a plug flow reactor (PFR) or constantly stirred tank reactor (CSTR) and the results show that this reactor was close to an ideal CSTR, i.e., it was fairly well-mixed.

  7. [Reflections about the efficiency criteria for cancer treatments during marketing authorization application].

    Science.gov (United States)

    Jeannin, Noémie; Blois-Da Conceição, Stéphanie; Protière, Christel

    2013-03-01

    Although clear and validated recommendations exist concerning the evaluation of cancer treatments at the international level, the criteria retained to obtain the marketing authorization (MA) are multiple and heterogeneous. This qualitative survey explores the opinion related to the assessment of cancer treatment among the several concerned population. By the way of semi-structured interviews, our aim was to elicit perceptions toward the criteria which should be retained during the process of MA, by patients, oncologists, members of the pharmaceutical industry, health decision-makers and general population. Our survey emphasizes the variability of the significations associated with the criteria of efficiency of cancer treatments according to the characteristics of the respondents. We also have observed some common expectations from patients and oncologists toward the economic and political aspect, but also from the whole respondents toward the importance of the comfort of the patients. Lastly, the necessity to define specific criteria related to clinical cases emerges.

  8. The effect of mixing-vane arrangements in a subchannel turbulent flow

    International Nuclear Information System (INIS)

    Ikeno, Tsutomu; Murata, Tamotsu; Kajishima, Takeo

    2006-01-01

    Large eddy simulation (LES) of developed turbulent flows in a rod bundle was carried out for four spacer designs. The mixing-vanes attached at the spacer were inclined at 30degC or 20deg; they were arranged to promote the swirling or convective flow. These arrangements are possible elements to compose an actual rod bundle. Our LES technique with a consistent higher-order immersed boundary method and a one-equation dynamic sub-grid scale model contributed to an efficient treatment of the complex wall configurations of rods and spacers. The computational results reasonably reproduced experimental results for the drag coefficient and the decay rate of swirling flow. The profiles of the axial velocities and the turbulence intensities indicated reasonable trend for the turbulent flow in the rod bundle. The effect of mixing-vane arrangement on the lateral flows was successfully clarified: the cross flow took the longer way on the rod surface than the swirling flow and then was more significantly influenced by momentum diffusion at the no-slip wall. Therefore, the largely inclined mixing-vanes promoted the cross flow only in the neighborhood of the spacer, the swirling flow inside a subchannel could reach farther downstream than the cross flow. (author)

  9. ``Living off the land'': resource efficiency of wetland wastewater treatment

    Science.gov (United States)

    Nelson, M.; Odum, H. T.; Brown, M. T.; Alling, A.

    Bioregenerative life support technologies for space application are advantageous if they can be constructed using locally available materials, and rely on renewable energy resources, lessening the need for launch and resupply of materials. These same characteristics are desirable in the global Earth environment because such technologies are more affordable by developing countries, and are more sustainable long-term since they utilize less non-renewable, imported resources. Subsurface flow wetlands (wastewater gardens™) were developed and evaluated for wastewater recycling along the coast of Yucatan. Emergy evaluations, a measure of the environmental and human economic resource utilization, showed that compared to conventional sewage treatment, wetland wastewater treatment systems use far less imported and purchased materials. Wetland systems are also less energy-dependent, lessening dependence on electrical infrastructure, and require simpler maintenance since the system largely relies on the ecological action of microbes and plants for their efficacy. Detailed emergy evaluations showed that wetland systems use only about 15% the purchased emergy of conventional sewage systems, and that renewable resources contribute 60% of total emergy used (excluding the sewage itself) compared to less than 1% use of renewable resources in the high-tech systems. Applied on a larger scale for development in third world countries, wetland systems would require 1/5 the electrical energy of conventional sewage treatment (package plants), and save 2/3 of total capital and operating expenses over a 20-year timeframe. In addition, there are numerous secondary benefits from wetland systems including fiber/fodder/food from the wetland plants, creation of ecosystems of high biodiversity with animal habitat value, and aesthestic/landscape enhancement of the community. Wetland wastewater treatment is an exemplar of ecological engineering in that it creates an interface ecosystem to handle

  10. Study of flow profile distortions and efficiency in counter pressure moderated partial filling micellar electrokinetic chromatography in relation to the relative buffer zone lengths.

    Science.gov (United States)

    Michalke, Daniela; Welsch, Thomas

    2002-06-25

    The influence of the relative buffer zone lengths on the efficiency was investigated in partial filling micellar electrokinetic chromatography using sodium dodecyl sulfate as separation additive. Varying relative zone lengths were obtained by applying identical initial separation zone lengths but different total lengths of the capillaries. Plate numbers of a homologous series of omega-phenylalcohols were measured to indicate the effect of both a changing relative zone length during the run and a counter pressure applied on the cathodic buffer reservoir. The magnitude and the course of these plate numbers are discussed on the basis of models for flow profile superposition and flow profile deformation which are caused by an intersegmental pressure arising at the boundary between the two buffer zones with different electroosmotic flow velocities. Calculation of the intersegmental pressure and of the resulting laminar flow components in the buffer zones on the basis of some equations for electroosmotic and hydrodynamic flow supported the interpretation that a long background buffer zone should be avoided

  11. Water flow induced transport of Pseudomonas fluorescens cells through soil columns as affected by inoculant treatment

    NARCIS (Netherlands)

    Hekman, W.E.; Heijnen, C.E.; Trevors, J.T.; Elsas, van J.D.

    1994-01-01

    Water flow induced transport of Pseudomonas fluorescens cells through soil columns was measured as affected by the inoculant treatment. Bacterial cells were introduced into the topsoil of columns, either encapsulated in alginate beads of different types or mixed with bentonite clay in concentrations

  12. Domestic wastewater treatment using multi-electrode continuous flow MFCs with a separator electrode assembly design

    KAUST Repository

    Ahn, Yongtae

    2012-10-11

    Treatment of domestic wastewater using microbial fuel cells (MFCs) will require reactors with multiple electrodes, but this presents unique challenges under continuous flow conditions due to large changes in the chemical oxygen demand (COD) concentration within the reactor. Domestic wastewater treatment was examined using a single-chamber MFC (130 mL) with multiple graphite fiber brush anodes wired together and a single air cathode (cathode specific area of 27 m2/m3). In fed-batch operation, where the COD concentration was spatially uniform in the reactor but changed over time, the maximum current density was 148 ± 8 mA/m2 (1,000 Ω), the maximum power density was 120 mW/m2, and the overall COD removal was >90 %. However, in continuous flow operation (8 h hydraulic retention time, HRT), there was a 57 % change in the COD concentration across the reactor (influent versus effluent) and the current density was only 20 ± 13 mA/m2. Two approaches were used to increase performance under continuous flow conditions. First, the anodes were separately wired to the cathode, which increased the current density to 55 ± 15 mA/m2. Second, two MFCs were hydraulically connected in series (each with half the original HRT) to avoid large changes in COD among the anodes in the same reactor. The second approach improved current density to 73 ± 13 mA/m2. These results show that current generation from wastewaters in MFCs with multiple anodes, under continuous flow conditions, can be improved using multiple reactors in series, as this minimizes changes in COD in each reactor. © 2012 Springer-Verlag Berlin Heidelberg.

  13. Geometry of power flows and convex-relaxed power flows in distribution networks with high penetration of renewables

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei; Zhao, Haoran

    2016-01-01

    Renewable energies are increasingly integrated in electric distribution networks and will cause severe overvoltage issues. Smart grid technologies make it possible to use coordinated control to mitigate the overvoltage issues and the optimal power flow (OPF) method is proven to be efficient...... in the applications such as curtailment management and reactive power control. Nonconvex nature of the OPF makes it difficult to solve and convex relaxation is a promising method to solve the OPF very efficiently. This paper investigates the geometry of the power flows and the convex-relaxed power flows when high...

  14. Numerical flow analysis of axial flow compressor for steady and unsteady flow cases

    Science.gov (United States)

    Prabhudev, B. M.; Satish kumar, S.; Rajanna, D.

    2017-07-01

    Performance of jet engine is dependent on the performance of compressor. This paper gives numerical study of performance characteristics for axial compressor. The test rig is present at CSIR LAB Bangalore. Flow domains are meshed and fluid dynamic equations are solved using ANSYS package. Analysis is done for six different speeds and for operating conditions like choke, maximum efficiency & before stall point. Different plots are compared and results are discussed. Shock displacement, vortex flows, leakage patterns are presented along with unsteady FFT plot and time step plot.

  15. ETV REPORT: EVALUATION OF HYDROMETRICS, INC., HIGH EFFICIENCY REVERSE OSMOSIS (HERO™) INDUSTRIAL WASTEWATER TREATMENT SYSTEM

    Science.gov (United States)

    Hydrometrics, founded in 1979 and located in Helena, MT, manufactures a commercial-ready High Efficiency Reverse Osmosis (HERO™) industrial wastewater treatment system. The system uses a three-stage reverse osmosis process to remove and concentrate metals for recovery while prod...

  16. Performance evaluation of the sulfur-redox-reaction-activated up-flow anaerobic sludge blanket and down-flow hanging sponge anaerobic/anoxic sequencing batch reactor system for municipal sewage treatment.

    Science.gov (United States)

    Hatamoto, Masashi; Ohtsuki, Kota; Maharjan, Namita; Ono, Shinya; Dehama, Kazuya; Sakamoto, Kenichi; Takahashi, Masanobu; Yamaguchi, Takashi

    2016-03-01

    A sulfur-redox-reaction-activated up-flow anaerobic sludge blanket (UASB) and down-flow hanging sponge (DHS) system, combined with an anaerobic/anoxic sequencing batch reactor (A2SBR), has been used for municipal sewage treatment for over 2 years. The present system achieved a removal rate of 95±14% for BOD, 74±22% for total nitrogen, and 78±25% for total phosphorus, including low water temperature conditions. Sludge conversion rates during the operational period were 0.016 and 0.218 g-VSS g-COD-removed(-1) for the UASB, and DHS, respectively, which are similar to a conventional UASB-DHS system, which is not used of sulfur-redox-reaction, for sewage treatment. Using the sulfur-redox reaction made advanced treatment of municipal wastewater with minimal sludge generation possible, even in winter. Furthermore, the occurrence of a unique phenomenon, known as the anaerobic sulfur oxidation reaction, was confirmed in the UASB reactor under the winter season. Copyright © 2016. Published by Elsevier Ltd.

  17. A novel aerated surface flow constructed wetland using exhaust gas from biological wastewater treatment: Performance and mechanisms.

    Science.gov (United States)

    Zhang, Xinwen; Hu, Zhen; Zhang, Jian; Fan, Jinlin; Ngo, Huu Hao; Guo, Wenshan; Zeng, Chujun; Wu, Yiwen; Wang, Siyuan

    2018-02-01

    In this study, a novel aerated surface flow constructed wetland (SFCW) using exhaust gas from biological wastewater treatment was investigated. Compared with un-aerated SFCW, the introduction of exhaust gas into SFCW significantly improved NH 4 + -N, TN and COD removal efficiencies by 68.30 ± 2.06%, 24.92 ± 1.13% and 73.92 ± 2.36%, respectively. The pollutants removal mechanism was related to the microbial abundance and the highest microbial abundance was observed in the SFCW with exhaust gas because of the introduction of exhaust gas from sequencing batch reactor (SBR), and thereby optimizing nitrogen transformation processes. Moreover, SFCW would significantly mitigate the risk of exhaust gas pollution. SFCW removed 20.00 ± 1.23%, 34.78 ± 1.39%, and 59.50 ± 2.33% of H 2 S, NH 3 and N 2 O in the exhaust gas, respectively. And 31.32 ± 2.23% and 32.02 ± 2.86% of bacterial and fungal aerosols in exhaust gas were also removed through passing SFCW, respectively. Copyright © 2017. Published by Elsevier Ltd.

  18. [Catheter-related bladder discomfort after urological surgery: importance of the type of surgery and efficiency of treatment by clonazepam].

    Science.gov (United States)

    Maro, S; Zarattin, D; Baron, T; Bourez, S; de la Taille, A; Salomon, L

    2014-09-01

    Bladder catheter can induce a Catheter-Related Bladder Discomfort (CRBD). Antagonist of muscarinic receptor is the gold standard treatment. Clonazepam is an antimuscarinic, muscle relaxing oral drug. The aim of this study is to look for a correlation between the type of surgical procedure and the existence of CRBD and to evaluate the efficiency of clonazepam. One hundred patients needing bladder catheter were evaluated. Sexe, age, BMI, presence of diabetes, surgical procedure and existence of CRBD were noted. Pain was evaluated with analogic visual scale. Timing of pain, need for specific treatment by clonazepam and its efficiency were noted. Correlation between preoperative data, type of surgical procedure, existence of CRBD and efficiency of treatment were evaluated. There were 79 men and 21 women (age: 65.9 years, BMI: 25.4). Twelve patients presented diabetes. Surgical procedure concerned prostate in 39 cases, bladder in 19 cases (tumor resections), endo-urology in 20 cases, upper urinary tract in 12 cases (nephrectomy…) and lower urinary tract in 10 cases (sphincter, sub-uretral tape). Forty patients presented CRBD, (pain 4.5 using VAS). This pain occurred 0.6 days after surgery. No correlation was found between preoperative data and CRBD. Bladder resection and endo-urological procedures were surgical procedures which procured CRBD. Clonazepam was efficient in 30 (75 %) out of 40 patients with CRBD. However, it was less efficient in case of bladder tumor resection. CRBD is frequent and occurred immediately after surgery. Bladder resection and endo-urology were the main surgical procedures which induced CRBD. Clonazepam is efficient in 75 %. Bladder resection is the surgical procedure which is the most refractory to treatment. 5. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. Design and implementation of an intensified coprecipitation reactor for the treatment of liquid radioactive wastes

    International Nuclear Information System (INIS)

    Flouret, Julie; Barre, Yves; Muhr, Herve; Plasari, Edouard

    2013-01-01

    The coprecipitation is a robust and inexpensive process for the treatment of important volumes of low and intermediate radioactive level liquid wastes. Its major inconvenient is the huge volume of sludge generated. The purpose of this work is to optimize the industrial coprecipitation continuous process by achieving the following objectives: - maximize the decontamination efficiency; - minimize the volume of sludge generated by the process; - reduce the treatment cost decreasing the installation volume. An innovative reactor with an infinite recycling ratio was therefore designed. It is a multifunctional reactor composed of two zones: a perfectly mixed precipitation zone and a classifier to perform liquid-solid separation. The experiments are focused on the coprecipitation of strontium by barium sulphate. The effluent containing sulphate ions and the barium nitrate solution are injected in the reaction zone where strontium and barium co-precipitate as sulphates. The produced solid phase is returned into the reaction zone by the classifier and goes out slowly from the reactor bottom with a residence time much higher than the liquid phase. This creates both a high concentration of solid phase in the reaction zone and a high efficiency of decontamination. The experimental conditions simulate the industrial effluents. The total treatment flow rate is 17 L/h, with an effluent flow rate of 16 L/h and a reactive flow rate of 1 L/h, hence a mean residence time of 10 minutes. In these experimental conditions, the molar ratio sulphate/barium after mixing corresponds to 4.9. These conditions are used in the reprocessing plant of La Hague. The decontamination factor reached in these experimental conditions is excellent: DF = 1500. The decontamination factor obtained with the classical continuous process is only equal to 60. Different process parameters are studied in order to optimize the reactor/classifier: residence time, barium nitrate flow rate and racking flow rate. The

  20. MXS-Chaining: A Highly Efficient Cloning Platform for Imaging and Flow Cytometry Approaches in Mammalian Systems.

    Directory of Open Access Journals (Sweden)

    Hanna L Sladitschek

    Full Text Available The continuous improvement of imaging technologies has driven the development of sophisticated reporters to monitor biological processes. Such constructs should ideally be assembled in a flexible enough way to allow for their optimization. Here we describe a highly reliable cloning method to efficiently assemble constructs for imaging or flow cytometry applications in mammalian cell culture systems. We bioinformatically identified a list of restriction enzymes whose sites are rarely found in human and mouse cDNA libraries. From the best candidates, we chose an enzyme combination (MluI, XhoI and SalI: MXS that enables iterative chaining of individual building blocks. The ligation scar resulting from the compatible XhoI- and SalI-sticky ends can be translated and hence enables easy in-frame cloning of coding sequences. The robustness of the MXS-chaining approach was validated by assembling constructs up to 20 kb long and comprising up to 34 individual building blocks. By assessing the success rate of 400 ligation reactions, we determined cloning efficiency to be 90% on average. Large polycistronic constructs for single-cell imaging or flow cytometry applications were generated to demonstrate the versatility of the MXS-chaining approach. We devised several constructs that fluorescently label subcellular structures, an adapted version of FUCCI (fluorescent, ubiquitination-based cell cycle indicator optimized to visualize cell cycle progression in mouse embryonic stem cells and an array of artificial promoters enabling dosage of doxycyline-inducible transgene expression. We made publicly available through the Addgene repository a comprehensive set of MXS-building blocks comprising custom vectors, a set of fluorescent proteins, constitutive promoters, polyadenylation signals, selection cassettes and tools for inducible gene expression. Finally, detailed guidelines describe how to chain together prebuilt MXS-building blocks and how to generate new

  1. Pharmaceutical removal in tropical subsurface flow constructed wetlands at varying hydraulic loading rates.

    Science.gov (United States)

    Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Tuan, Nguyen Anh; Tan, Soon Keat

    2012-04-01

    Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2-6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (pcaffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log K(ow) were not significant (p>0.05), implying that their removal is not well related to the compound's hydrophobicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Critical parameters in the production of ceramic pot filters for household water treatment in developing countries.

    Science.gov (United States)

    Soppe, A I A; Heijman, S G J; Gensburger, I; Shantz, A; van Halem, D; Kroesbergen, J; Wubbels, G H; Smeets, P W M H

    2015-06-01

    The need to improve the access to safe water is generally recognized for the benefit of public health in developing countries. This study's objective was to identify critical parameters which are essential for improving the performance of ceramic pot filters (CPFs) as a point-of-use water treatment system. Defining critical production parameters was also relevant to confirm that CPFs with high-flow rates may have the same disinfection capacity as pots with normal flow rates. A pilot unit was built in Cambodia to produce CPFs under controlled and constant conditions. Pots were manufactured from a mixture of clay, laterite and rice husk in a small-scale, gas-fired, temperature-controlled kiln and tested for flow rate, removal efficiency of bacteria and material strength. Flow rate can be increased by increasing pore sizes and by increasing porosity. Pore sizes were increased by using larger rice husk particles and porosity was increased with larger proportions of rice husk in the clay mixture. The main conclusions: larger pore size decreases the removal efficiency of bacteria; higher porosity does not affect the removal efficiency of bacteria, but does influence the strength of pots; flow rates of CPFs can be raised to 10-20 L/hour without a significant decrease in bacterial removal efficiency.

  3. Integrating sequencing batch reactor with bio-electrochemical treatment for augmenting remediation efficiency of complex petrochemical wastewater.

    Science.gov (United States)

    Yeruva, Dileep Kumar; Jukuri, Srinivas; Velvizhi, G; Naresh Kumar, A; Swamy, Y V; Venkata Mohan, S

    2015-01-01

    The present study evaluates the sequential integration of two advanced biological treatment methods viz., sequencing batch reactor (SBR) and bioelectrochemical treatment systems (BET) for the treatment of real-field petrochemical wastewater (PCW). Initially two SBR reactors were operated in aerobic (SBR(Ae)) and anoxic (SBR(Ax)) microenvironments with an organic loading rate (OLR) of 9.68 kg COD/m(3)-day. Relatively, SBR(Ax) showed higher substrate degradation (3.34 kg COD/m(3)-day) compared to SBR(Ae) (2.9 kg COD/m(3)-day). To further improve treatment efficiency, the effluents from SBR process were fed to BET reactors. BET(Ax) depicted higher SDR (1.92 kg COD/m(3)-day) with simultaneous power generation (17.12 mW/m(2)) followed by BET(Ae) (1.80 kg COD/m(3)-day; 14.25 mW/m(2)). Integrating both the processes documented significant improvement in COD removal efficiency due to the flexibility of combining multiple microenvironments sequentially. Results were supported with GC-MS and FTIR, which confirmed the increment in biodegradability of wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. COMPARATIVE EFFICIENCIES STUDY OF SLOT MODEL AND MOUSE MODEL IN PRESSURISED PIPE FLOW

    Directory of Open Access Journals (Sweden)

    Saroj K. Pandit

    2014-01-01

    Full Text Available The flow in sewers is unsteady and variable between free-surfac e to full pipe pressurized flow. Sewers are designed on the basis of free surf ace flow (gravity flow however they may carry pressurized flow. Preissmann Slot concep t is widely used numerical approach in unsteady free surface-pressurized flow as it provides the advantage of using free surface flow as a single type flow. Slo t concept uses the Saint- Venant’s equations as a basic equation for one-dimensional unst eady free surface flow. This paper includes two different numerical models using Saint Venant’s equations. The Saint Venant’s e quations of continuity and momen tum are solved by the Method of Characteristics and presented in forms for direct substitution into FORTRAN programming for numerical analysis in the first model. The MOUSE model carries out computation of unsteady flows which is founde d on an implicit, finite difference numerical solut ion of the basic one dimension al Saint Venant’s equations of free surface flow. The simulation results are comp ared to analyze the nature and degree of errors for further improvement.

  5. Quantifying and improving the efficiency of Gamma Knife treatment plans for brain metastases: results of a 1-year audit.

    Science.gov (United States)

    Wright, Gavin; Hatfield, Paul; Loughrey, Carmel; Reiner, Beatrice; Bownes, Peter

    2014-12-01

    A method for quantifying the efficiency of Gamma Knife treatment plans for metastases was previously implemented by the authors to retrospectively identify the least efficient plans and has provided insights into improved planning strategies. The aim of the current work was to ascertain whether those insights led to improved treatment plans. Following completion of the initial study, a 1-year audit of metastasis plans created at St. James's Institute of Oncology was carried out. Audited recent plans were compared with the earlier plans of the initial study, in terms of their efficiency and dosimetric quality. The statistical significance of any differences between relevant plan parameters was quantified by Mann-Whitney U-tests. Comparisons were made between all plans and repeated for a reduced set of plans from which the smallest lesions treated with a single 4-mm shot were excluded. The plan parameters compared were a plan efficiency index (PEI), the number of shots, Paddick conformity index (PCI), gradient index (GI), and percent coverage (of the lesion by the prescription isodose). A total of 157 metastatic lesions were included in the audit and were compared with 241 in the initial study. In a comparison of all cases, the audited plans achieved a higher median PEI score than did the earlier plans from the initial study (1.08 vs 1.02), indicating improved efficiency of the audited plans. When the smallest lesions (for which there was little scope for varying plan strategy) were discounted, the improvement in median PEI score was greater (1.23 vs 1.03, p planning strategy yielding these efficiency improvements did not rely on the use of significantly fewer shots (median 11 vs 11 shots, p = 0.924), nor did it result in significant detriment to dosimetric quality (median coverage 99% vs 99%, median PCI 0.84 vs 0.83, p = 0.449, and median GI 2.72 vs 2.67, p = 0.701, audited plans vs initial plans, respectively). Choice of planning strategy can substantially affect

  6. Sulfur flow in a soil-plant system-effects of long-term treatment history and soil properties

    DEFF Research Database (Denmark)

    Boye, Kristin; Eriksen, Jørgen; Nilsson, Ingvar

    2010-01-01

    deficiency, reduced biomass production and lower total S uptake by the rye grass. The isotopic measurements revealed that more than two thirds of the plant S was derived from non-labeled soil organic S, even in the + S treatment, and that all organic S pools (physically unprotected/protected and residual...... organic S) in the soil were involved in the S transformations. The long-term FYM treatment had resulted in higher S cycling rates and a slightly higher resistance to S deficiency than the CR treatment. The influence of soil type on S flow patterns was important, but probably only partly related...

  7. Efficiency of Moringa oleifera Seeds for Treatment of Laundry Wastewater

    Directory of Open Access Journals (Sweden)

    Al-Gheethi AA

    2017-01-01

    Full Text Available Laundry wastewater has simple characteristics in which the detergents compounds are the main constitutes. But these compounds have adverse effects on the aquatic organisms in the natural water bodies which received these wastes without treatment. Few studies were conducted on these wastes because it represent a small part of the total wastewater generated from different human activities. Moreover, the coagulation process for laundry wastewater might be effective to remove of detergents compounds. Therefore, in the present study, the efficiency of coagulation process by using chemical (ferrous sulphate and natural coagulants (Moringa oleifera seeds were investigated. The raw laundry wastewater samples were collected from laundromat located at Taman Universiti, Parit Raja. The characteristics of these wastes were determined and then the wastewater was subjected for the treatment process consisted of three units including aeration, coagulation and sedimentation process. The chemical and natural coagulants were used with four dosage (30, 60, 90 and 120 mg L−1 and the coagulation process was carried out at room temperature (25±2ºC for one hour. The results revealed that the laundry wastewater have high concentrations of turbidity (57.8-68.1 NTU and Chemical Oxygen Demand (COD (423-450 mg L−1 with pH value between 7.96 and 8.37. M. oleifera seeds exhibited high efficiency for removal of turbidity (83.63% with 120 mg L−1 of dosage, while 30 mg L−1 of FeSO4 was the best for removal of COD (54.18%. However, both parameters still more than Standard B for wastewater disposal suggesting the need to increase the period of coagulation process with M. oleifera seeds or to subject of the treated effluents for a secondary coagulation process with natural coagulant products to improve the characteristics of laundry wastewater without a secondary products as that generated with the chemical coagulants.

  8. Oxygen profile and clogging in vertical flow sand filters for on-site wastewater treatment.

    Science.gov (United States)

    Petitjean, A; Forquet, N; Boutin, C

    2016-04-01

    13 million people (about 20% of the population) use on-site wastewater treatment in France. Buried vertical sand filters are often built, especially when the soil permeability is not sufficient for septic tank effluent infiltration in undisturbed soil. Clogging is one of the main problems deteriorating the operation of vertical flow filters for wastewater treatment. The extent of clogging is not easily assessed, especially in buried vertical flow sand filters. We suggest examining two possible ways of detecting early clogging: (1) NH4-N/NO3-N outlet concentration ratio, and (2) oxygen measurement within the porous media. Two pilot-scale filters were equipped with probes for oxygen concentration measurements and samples were taken at different depths for pollutant characterization. Influent and effluent grab-samples were taken three times a week. The systems were operated using batch-feeding of septic tank effluent. Qualitative description of oxygen transfer processes under unclogged and clogged conditions is presented. NH4-N outlet concentration appears to be useless for early clogging detection. However, NO3-N outlet concentration and oxygen content allows us to diagnose the early clogging of the system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Improving mixing efficiency in a closed circuit water flow rig for ...

    African Journals Online (AJOL)

    . ... pulse velocity method, indicating that the flow meters functioned correctly. The modified rig with scaled-up mixing techniques could serve as platform for training in evaluating mixing vessels and flow meters in industrial process plants.

  10. Wastewater treatment in horizontal subsurface flow constructed wetlands using different media (setup stage

    Directory of Open Access Journals (Sweden)

    Abdel Razik A. Zidan

    2015-04-01

    Full Text Available Wastewater treatment through horizontal subsurface flow (HSSF constructed wetlands (CWs using three different treatment media (gravel, pieces of plastic pipes, and shredded tire rubber chips were investigated in Samaha village, Dakahliya, Egypt. The study focused on the wetland setup stage during the first months of its operation (setup stage. In this stage media porosity, bacterial biofilm, and plant roots growth were in progress and it was prior to the operational steady state stage. Objectives of this paper are to study the change in media porosity of HSSF wetland cells in order to estimate duration of wetland setup stage, and to evaluate the use of different bed media on biological oxygen demand (BOD, chemical oxygen demand (COD and total suspended solids (TSS treatment. The results showed that after 180 days of operation, the wetland cells had reached steady porosity and had started stable treatment. Also performance of plastic media bed in pollutants reduction was better than gravel and rubber beds and gravel media was in advanced than rubber media.

  11. [Differences in cerebral blood flow following risperidone treatment in children with autistic disorder].

    Science.gov (United States)

    Ozdemir, Dilşad Foto; Karabacak, Neşe Ilgin; Akkaş, Burcu; Akdemir, Ozgür; Unal, Fatih; Senol, Selahattin

    2009-01-01

    Functional changes in the brains of autistic children due to risperidone treatment and theirs relationship to the symptom clusters are yet unknown. In this autistic disorder case series we aimed to comparatively evaluate the clinical findings before and after risperidone treatment, and regional cerebral blood flow (rCBF) findings with 99mTc-hexamethylpropyleneamine oxime (HMPAO) brain SPECT. Eleven autistic patients (age range: 6-7 years; 4 girls, 7 boys) received risperidone therapy (1.5-2.5 mg d(-1)) and were followed-up for 3 months. All the patients underwent neurologic examinations, psychometric examinations, and SPECT imaging, both at the start of risperidone treatment and 3 months after the treatment started. Clinical observations, and the observations of parents and teachers were recorded. These results were compared with cerebral perfusion indices obtained from SPECT data. After 3 months of treatment changes in rCBF were observed in various regions and to varying degrees. We observed relationships between clinical symptoms and pre-therapy rCBF findings, and between clinical improvement and rCBF changes. Findings in the present case series are the first to demonstrate a relationship between clinical improvement and regional perfusion patterns after risperidone treatment. We think that these findings may contribute to the understanding of the neurofunctional mechanisms and hypothetical models of autism.

  12. EFFICIENCY OF PRE-TREATMENT OF LEACHATE FROM MUNICIPAL WASTE DUMPS BY GASEOUS DESORPTION (STRIPPING OF AMMONIA

    Directory of Open Access Journals (Sweden)

    Justyna Koc-Jurczyk

    2017-05-01

    Full Text Available The paper studies the efficiency of pre-treatment of landfill leachate by gaseous desorption of ammonia. The research was done on a municipal non-hazardous waste dump in Krosno (Sub-Carpathian Province, Poland. The pretreatment provided a favorable BOD5/COD ratio in leachate. Also concentrations of 16 PAHs and heavy metals did not exceed the legal limits. However, gaseous desorption of ammonia was insufficiently efficient in recovering ammonia nitrogen from leachate.

  13. A Numerical Study on the Improvement of Suction Performance and Hydraulic Efficiency for a Mixed-Flow Pump Impeller

    Directory of Open Access Journals (Sweden)

    Sung Kim

    2014-01-01

    Full Text Available This paper describes a numerical study on the improvement of suction performance and hydraulic efficiency of a mixed-flow pump by impellers. The design of these impellers was optimized using a commercial CFD (computational fluid dynamics code and DOE (design of experiments. The design variables of meridional plane and vane plane development were defined for impeller design. In DOE, variables of inlet part were selected as main design variables in meridional plane, and incidence angle was selected in vane plane development. The verification of the experiment sets that were generated by 2k factorial was done by numerical analysis. The objective functions were defined as the NPSHre (net positive suction head required, total efficiency, and total head of the impellers. The importance of the geometric design variables was analyzed using 2k factorial designs. The interaction between the NPSHre and total efficiency, according to the meridional plane and incidence angle, was discussed by analyzing the 2k factorial design results. The performance of optimally designed model was verified by experiments and numerical analysis and the reliability of the model was retained by comparison of numerical analysis and comparative analysis with the reference model.

  14. Perfluoroalkyl substances (PFASs) in wastewater treatment plants and drinking water treatment plants: Removal efficiency and exposure risk.

    Science.gov (United States)

    Pan, Chang-Gui; Liu, You-Sheng; Ying, Guang-Guo

    2016-12-01

    Perfluoroalkyl substances (PFASs) are a group of chemicals with wide industrial and commercial applications, and have been received great attentions due to their persistence in the environment. The information about their presence in urban water cycle is still limited. This study aimed to investigate the occurrence and removal efficiency of eighteen PFASs in wastewater treatment plants (WWTPs) and drinking water plants (DWTPs) with different treatment processes. The results showed that both perfluorobutane sulfonic acid (PFBS) and perfluorooctane sulfonic acid (PFOS) were the predominant compounds in the water phase of WWTPs and DWTPs, while PFOS was dominant in dewatered sludge of WWTPs. The average total PFASs concentrations in the three selected WWTPs were 19.6-232 ng/L in influents, 15.5-234 ng/L in effluents, and 31.5-49.1 ng/g dry weight in sludge. The distribution pattern of PFASs differed between the wastewater and sludge samples, indicating strong partition of PFASs with long carbon chains to sludge. In the WWTPs, most PFASs were not eliminated efficiently in conventional activated sludge treatment, while the membrane bio-reactor (MBR) and Unitank removed approximately 50% of long chain (C ≥ 8) perfluorocarboxylic acids (PFCAs). The daily mass loads of total PFASs in WWTPs were in the range of 1956-24773 mg in influent and 1548-25085 mg in effluent. PFASs were found at higher concentrations in the wastewater from plant A with some industrial wastewater input than from the other two plants (plant B and plant C) with mainly domestic wastewater sources. Meanwhile, the average total PFASs concentrations in the two selected DWTPs were detected at 4.74-14.3 ng/L in the influent and 3.34-13.9 ng/L in the effluent. In DWTPs, only granular activated carbon (GAC) and powder activated carbon (PAC) showed significant removal of PFASs. The PFASs detected in the tap water would not pose immediate health risks in the short term exposure. The findings from this

  15. Accurate and efficient calculation of response times for groundwater flow

    Science.gov (United States)

    Carr, Elliot J.; Simpson, Matthew J.

    2018-03-01

    We study measures of the amount of time required for transient flow in heterogeneous porous media to effectively reach steady state, also known as the response time. Here, we develop a new approach that extends the concept of mean action time. Previous applications of the theory of mean action time to estimate the response time use the first two central moments of the probability density function associated with the transition from the initial condition, at t = 0, to the steady state condition that arises in the long time limit, as t → ∞ . This previous approach leads to a computationally convenient estimation of the response time, but the accuracy can be poor. Here, we outline a powerful extension using the first k raw moments, showing how to produce an extremely accurate estimate by making use of asymptotic properties of the cumulative distribution function. Results are validated using an existing laboratory-scale data set describing flow in a homogeneous porous medium. In addition, we demonstrate how the results also apply to flow in heterogeneous porous media. Overall, the new method is: (i) extremely accurate; and (ii) computationally inexpensive. In fact, the computational cost of the new method is orders of magnitude less than the computational effort required to study the response time by solving the transient flow equation. Furthermore, the approach provides a rigorous mathematical connection with the heuristic argument that the response time for flow in a homogeneous porous medium is proportional to L2 / D , where L is a relevant length scale, and D is the aquifer diffusivity. Here, we extend such heuristic arguments by providing a clear mathematical definition of the proportionality constant.

  16. Two-Dimensional Cutting (TDC Vitrectome: In Vitro Flow Assessment and Prospective Clinical Study Evaluating Core Vitrectomy Efficiency versus Standard Vitrectome

    Directory of Open Access Journals (Sweden)

    Mitrofanis Pavlidis

    2016-01-01

    Full Text Available Purpose. To evaluate comparative aspiration flow performance and also vitrectomy operating time efficiency using a double-cutting open port vitreous cutting system incorporated in a two-dimensional cutting (TDC, DORC International vitrectome design versus standard vitreous cutter. Methods. In vitro investigations compared aspiration flow rates in artificial vitreous humor at varying cutter speeds and vacuum levels using a TDC vitrectome and a standard vitrectome across different aspiration pump systems. A prospective single-centre clinical study evaluated duration of core vitrectomy in 80 patients with macular pucker undergoing 25-gauge or 27-gauge vitrectomy using either a TDC vitrectome at 16,000 cuts per minute (cpm or standard single-cut vitrectome, combined with a Valve Timing intelligence (VTi pump system (EVA, DORC International. Results. Aspiration flow rates remained constant independent of TDC vitrectome cut rate, while flow rates decreased linearly at higher cutter speeds using a classic single-blade vitrectome. Mean duration of core vitrectomy surgeries using a TDC vitreous cutter system was significantly (p<0.001 shorter than the mean duration of core vitrectomy procedures using a single-cut vitrectome of the same diameter (reduction range, 34%–50%. Conclusion. Vitrectomy surgery performed using a TDC vitrectome was faster than core vitrectomy utilizing a standard single-action vitrectome at similar cut speeds.

  17. Abatement vs. treatment for efficient diffuse source water pollution management in terrestrial-marine systems.

    Science.gov (United States)

    Roebeling, P C; Cunha, M C; Arroja, L; van Grieken, M E

    2015-01-01

    Marine ecosystems are affected by water pollution originating from coastal catchments. The delivery of water pollutants can be reduced through water pollution abatement as well as water pollution treatment. Hence, sustainable economic development of coastal regions requires balancing of the marginal costs from water pollution abatement and/or treatment and the associated marginal benefits from marine resource appreciation. Water pollution delivery reduction costs are, however, not equal across abatement and treatment options. In this paper, an optimal control approach is developed and applied to explore welfare maximizing rates of water pollution abatement and/or treatment for efficient diffuse source water pollution management in terrestrial-marine systems. For the case of diffuse source dissolved inorganic nitrogen water pollution in the Tully-Murray region, Queensland, Australia, (agricultural) water pollution abatement cost, (wetland) water pollution treatment cost and marine benefit functions are determined to explore welfare maximizing rates of water pollution abatement and/or treatment. Considering partial (wetland) treatment costs and positive water quality improvement benefits, results show that welfare gains can be obtained, primarily, through diffuse source water pollution abatement (improved agricultural management practices) and, to a minor extent, through diffuse source water pollution treatment (wetland restoration).

  18. A Finite Difference, Semi-implicit, Equation-of-State Efficient Algorithm for the Compositional Flow Modeling in the Subsurface: Numerical Examples

    KAUST Repository

    Saavedra, Sebastian

    2012-07-01

    The mathematical model that has been recognized to have the more accurate approximation to the physical laws govern subsurface hydrocarbon flow in reservoirs is the Compositional Model. The features of this model are adequate to describe not only the performance of a multiphase system but also to represent the transport of chemical species in a porous medium. Its importance relies not only on its current relevance to simulate petroleum extraction processes, such as, Primary, Secondary, and Enhanced Oil Recovery Process (EOR) processes but also, in the recent years, carbon dioxide (CO2) sequestration. The purpose of this study is to investigate the subsurface compositional flow under isothermal conditions for several oil well cases. While simultaneously addressing computational implementation finesses to contribute to the efficiency of the algorithm. This study provides the theoretical framework and computational implementation subtleties of an IMplicit Pressure Explicit Composition (IMPEC)-Volume-balance (VB), two-phase, equation-of-state, approach to model isothermal compositional flow based on the finite difference scheme. The developed model neglects capillary effects and diffusion. From the phase equilibrium premise, the model accounts for volumetric performances of the phases, compressibility of the phases, and composition-dependent viscosities. The Equation of State (EoS) employed to approximate the hydrocarbons behaviour is the Peng Robinson Equation of State (PR-EOS). Various numerical examples were simulated. The numerical results captured the complex physics involved, i.e., compositional, gravitational, phase-splitting, viscosity and relative permeability effects. Regarding the numerical scheme, a phase-volumetric-flux estimation eases the calculation of phase velocities by naturally fitting to phase-upstream-upwinding. And contributes to a faster computation and an efficient programming development.

  19. Efficiency of a natural wetland for effluent polishing of a septic tank

    Directory of Open Access Journals (Sweden)

    Z. Yousefi

    2014-04-01

    Full Text Available Wetlands now days apply as a polishing system for the classical wastewater treatment, in addition of different usages. Usually wetland systems are inexpensive methods vs. expensive high technology treatment systems. Objective of this study is an evaluation of natural wetland treatment in polishing of a septic effluent. Research duration works extended for 10 months on a natural wetland system in Pardis of Mazandaran University of medical sciences and eastern north of health faculty. Wastewater quality index such as pH, EC, BOD, COD, TSS, Nitrate, Phosphorus, Ammonia and Temperature performed on the samples of influent and effluent of the system. The study showed the system works as a buffering system for flow and pH. Results indicated that average of BOD5 and TSS efficiency were 67.70and 83%, respectively. Efficiency of COD was 65.26 and 80 % for a Low and moderate strength influent respectively. Average of phosphorus, NH3 and Nitrate in effluent were 0.032 mg/L, 7.18 and 0.036 mg/L, respectively. Efficiency of ammonia and Phosphorus were slightly increased in best condition. Based on this study result, natural wetland can be success in BOD, COD, and TSS removal of the classical septic tank, but for nitrogen and Phosphorus removal do not have considerable effects.

  20. Assessment of ovarian stromal blood flow after metformin treatment in women with polycystic ovary syndrome.

    Science.gov (United States)

    Makled, Ahmed K; El Sherbiny, Mohamed; Elkabarity, Rania

    2014-04-01

    To authenticate the effect of metformin treatment on ovarian stromal blood flow in women with polycystic ovary syndrome (PCOS) using 3-dimensional (3D) power Doppler. The current case-control study was conducted at Ain Shams University Maternity Hospital. A total of 60 women diagnosed to have PCOS were included as group 1. Another 40 fertile women who were recruited from outpatient clinic for contraception without PCOS with regular menstrual cycles were included as control group (group 2). All women underwent 3D power Doppler evaluations of ovarian stroma. Anthropometric, hormonal and biochemical criteria were also measured. All women in group 1 received metformin hydrochloride 500 mg tablets, which were started in a step-up maneuver every 5 days, from one to three tablets per day. The same parameters were also measured after the 3 months duration of treatment. A total of 100 women were finally analyzed. At the start of the study, there were no statistically significant differences between group 1 and group 2 and regarding age and body mass index, but the waist/hip ratio and Ferriman-Gallwey scoring were statistically different between the 2 groups. The mean ovarian volume and stromal volume were significantly larger in group 1. 3D power Doppler indices [the vascularization index (VI), the flow index (FI) and the (VFI) vascularization-flow index] were much higher in group 1 than in group 2 (1.38 ± 0.76 vs. 4.69 ± 1.37, P treatment significantly reduce VI, FI and VFI (4.69 ± 1.37 vs. 2.95 ± 1.52, P < 0.05, 32.66 ± 4.37 vs. 29.48 ± 4.98, P < 0.05 and 1.54 ± 0.69 vs. 1.21 ± 0.7 P < 0.05, respectively). Using Receiver operator characteristic, there was no cut-off value of VI, FI or VFI to detect ovulation in women of PCOS. Metformin seems to have a beneficial effect in normal weight PCO women via correcting ovarian stromal blood flow and hormonal profiles.

  1. Numerical simulation of the debris flow dynamics with an upwind scheme and specific friction treatment

    Science.gov (United States)

    Sánchez Burillo, Guillermo; Beguería, Santiago; Latorre, Borja; Burguete, Javier

    2014-05-01

    means of the Nash-Shutcliffe statistic [10]. This error estimation can be used to calibrate the input friction coefficients, providing an efficient tool for risk analysis in many regions of the world and specially in areas with steep topographic gradients such as mountain ranges, heavily incised river networks, coastal cliffs, etc. References: [1] H. J. Koerner, "Reichweite und geschwindigkeit von bergstürzen und fleisschneelawinen". Rock Mechanics, 8, 225-256 (1976) [2] P. J. McLellan and P. K. Kaiser, "Application of a two-parameter model to rock avalanches in the mackenzine mountains". 4th International Symposium on Landslides, 135-140 (1984). [3] A. Kent and O. Hungr, "Runout characteristics of debris from dump failures in mountainous terrain: stage 2: analysis, modelling and prediction". British Columbia Mine Waste Rock Pile Research Committee and CANMET (1995). [4] O. Hungr and S. G. Evans, "Rock avalanche runout prediction using a dynamic model". 7th International Symposium on Landslides, 233-238 (1996). [5] D. Rickenmann and T. Koch, "Comparison of debris flow modelling approaches". First International Conference on Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment. ASCE, ed. New York. C.L. Chen (1997). [6] P. Bertolo and G. F. Wieczorek, "Calibration of numerical models for small debris flows in Yosemite Valley, California, USA". Natural Hazards in Earth System Sciences (5) 993-1001 (2005). [7] S. Beguería and Th. J. van Asch and J. P. Malet and S. Gröndahl, "A GIS-based numerical model for simulating the kinematics of mud and debris flows over complex terrain". Natural Hazards in Earth System Sciences (9) 1897-1909 (2009). [8] G. Sánchez Burillo, S. Beguería, B. Latorre and J. Burguete, "Numerical treatment of the friction term in upwind schemes in debris flow runout modelling". ASCE Journal of Hydraulic Engineering (sent for publication). [9] A. Voellmy, Über die Zerstörungskraft von Lawinen. Schweizer. Bauzeitung (1955). [10] J. E

  2. Use of flow-diverting stents as salvage treatment following failed stent-assisted embolization of intracranial aneurysms.

    Science.gov (United States)

    Heiferman, Daniel M; Billingsley, Joshua T; Kasliwal, Manish K; Johnson, Andrew K; Keigher, Kiffon M; Frudit, Michel E; Moftakhar, Roham; Lopes, Demetrius K

    2016-07-01

    Flow-diverting stents, including the Pipeline embolization device (PED) and Silk, have been beneficial in the treatment of aneurysms previously unable to be approached via endovascular techniques. Recurrent aneurysms for which stent-assisted embolization has failed are a therapeutic challenge, given the existing intraluminal construct with continued blood flow into the aneurysm. We report our experience using flow-diverting stents in the repair of 25 aneurysms for which stent-assisted embolization had failed. Nineteen (76%) of these aneurysms at the 12-month follow-up showed improved Raymond class occlusion, with 38% being completely occluded, and all aneurysms demonstrated decreased filling. One patient developed a moderate permanent neurologic deficit. Appropriate stent sizing, proximal and distal construct coverage, and preventing flow diverter deployment between the previously deployed stent struts are important considerations to ensure wall apposition and prevention of endoleak. Flow diverters are shown to be a reasonable option for treating previously stented recurrent cerebral aneurysms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  3. A parallel offline CFD and closed-form approximation strategy for computationally efficient analysis of complex fluid flows

    Science.gov (United States)

    Allphin, Devin

    Computational fluid dynamics (CFD) solution approximations for complex fluid flow problems have become a common and powerful engineering analysis technique. These tools, though qualitatively useful, remain limited in practice by their underlying inverse relationship between simulation accuracy and overall computational expense. While a great volume of research has focused on remedying these issues inherent to CFD, one traditionally overlooked area of resource reduction for engineering analysis concerns the basic definition and determination of functional relationships for the studied fluid flow variables. This artificial relationship-building technique, called meta-modeling or surrogate/offline approximation, uses design of experiments (DOE) theory to efficiently approximate non-physical coupling between the variables of interest in a fluid flow analysis problem. By mathematically approximating these variables, DOE methods can effectively reduce the required quantity of CFD simulations, freeing computational resources for other analytical focuses. An idealized interpretation of a fluid flow problem can also be employed to create suitably accurate approximations of fluid flow variables for the purposes of engineering analysis. When used in parallel with a meta-modeling approximation, a closed-form approximation can provide useful feedback concerning proper construction, suitability, or even necessity of an offline approximation tool. It also provides a short-circuit pathway for further reducing the overall computational demands of a fluid flow analysis, again freeing resources for otherwise unsuitable resource expenditures. To validate these inferences, a design optimization problem was presented requiring the inexpensive estimation of aerodynamic forces applied to a valve operating on a simulated piston-cylinder heat engine. The determination of these forces was to be found using parallel surrogate and exact approximation methods, thus evidencing the comparative

  4. Efficiency of electrical coagulation process using aluminum electrodes for municipal wastewater treatment: a case study at Karaj wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Samad Gholami Yengejeh

    2017-05-01

    Full Text Available Background: The reuse of treated municipal wastewater is an important source of water for different purposes. This study evaluated the efficiency of the electrocoagulation process in removing turbidity, total suspended solids (TSS, chemical oxygen demand (COD, nitrate, and phosphate from wastewater at the treatment facility in Karaj, Iran. Methods: This experimental study was performed at a pilot scale and in a batch system. A 4-liter tank made from safety glass with 4 plate electrodes made from aluminum was unipolarly connected to a direct current power supply with a parallel arrangement. Wastewater samples were taken from the influent at the Karaj wastewater treatment facility. Rates of turbidity, TSS, COD, nitrate, and phosphate removal under different conditions were determined. Results: The highest efficiency of COD, TSS, nitrate, turbidity, and phosphate elimination was achieved at a voltage of 30 volts and a reaction time of 30 minutes. The rates were 88.43%, 87.39%, 100%, 80.52%, and 82.69%, respectively. Conclusion: Based on the results of this study, electrocoagulation is an appropriate method for use in removing nitrate, phosphate, COD, turbidity, and TSS from wastewater.

  5. Streptavidin-functionalized capillary immune microreactor for highly efficient chemiluminescent immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhanjun [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China); Zong Chen [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Ju Huangxian, E-mail: hxju@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Yan Feng, E-mail: yanfeng2007@sohu.com [Jiangsu Institute of Cancer Prevention and Cure, Nanjing 210009 (China)

    2011-11-07

    Highlights: {yields} A novel capillary immune microreactor was proposed for highly efficient flow-through chemiluminescent immunoassay. {yields} The microreactor was prepared by functionalizing capillary inner wall with streptavidin for capture of biotinylated antibody. {yields} The proposed immunoassay method showed wide dynamic range, good reproducibility, stability and practicality. {yields} The microreactor was low-cost and disposable, and possessed several advantages over the conventional immunoreactors. - Abstract: A streptavidin functionalized capillary immune microreactor was designed for highly efficient flow-through chemiluminescent (CL) immunoassay. The functionalized capillary could be used as both a support for highly efficient immobilization of antibody and a flow cell for flow-through immunoassay. The functionalized inner wall and the capture process were characterized using scanning electron microscopy. Compared to conventional packed tube or thin-layer cell immunoreactor, the proposed microreactor showed remarkable properties such as lower cost, simpler fabrication, better practicality and wider dynamic range for fast CL immunoassay with good reproducibility and stability. Using {alpha}-fetoprotein as model analyte, the highly efficient CL flow-through immunoassay system showed a linear range of 3 orders of magnitude from 0.5 to 200 ng mL{sup -1} and a low detection limit of 0.1 ng mL{sup -1}. The capillary immune microreactor could make up the shortcoming of conventional CL immunoreactors and provided a promising alternative for highly efficient flow-injection immunoassay.

  6. Workflow efficiency for the treatment planning process in CT-guided high-dose-rate brachytherapy for cervical cancer.

    Science.gov (United States)

    Michaud, Anthony L; Benedict, Stanley; Montemayor, Eliseo; Hunt, Jon Paul; Wright, Cari; Mathai, Mathew; Mayadev, Jyoti S

    2016-01-01

    To investigate process efficiency, we present a prospective investigation of the treatment planning phase of image-guided brachytherapy (BT) for cervical cancer using a specific checklist. From October 2012 to January 2014, 76 BT procedures were consecutively performed. Prospective data on the CT-based treatment planning process was collected using a specific checklist which details the following steps: (1) dosimetry planning, (2) physician review start, (3) physician review time, (4) dosimetry processing, (5) physics review start, (6) physics review, and (7) procedural pause. Variables examined included the use of a pre-BT MRI, clinic duty conflicts, resident teaching, and the use of specific BT planners. Analysis was performed using descriptive statistics, t-test, and analysis of variance. Seventy-five prospectively gathered checklists comprised this analysis. The mean time for treatment planning was 95 minutes (med 94, std 18). The mean intervals in the above steps were (1) = 42, (2) = 5, (3) = 19, (4) = 10, (5) = 6, (6) = 13, and (7) = 26 minutes. There was no statistical difference in patients who had a pre-BT MRI. Resident teaching did not influence time, p = 0.17. Treatment planning time was decreased with a specific planner, p = 0.0015. A skillful team approach is required for treatment planning efficiency in image-guided BT. We have found that the specific BT planners can have a significant effect on the overall planning efficiency. We continue to examine clinical and workflow-related factors that will enhance our safety and workflow process with BT. Published by Elsevier Inc.

  7. Dissolved methane oxidation and competition for oxygen in down-flow hanging sponge reactor for post-treatment of anaerobic wastewater treatment

    OpenAIRE

    Hatamoto, Masashi; Miyauchi, Tomo; Kindaichi, Tomonori; Ozaki, Noriatsu; Ohashi, Akiyoshi

    2011-01-01

    Post-treatment of anaerobic wastewater was undertaken to biologically oxidize dissolved methane, with the aim of preventing methane emission. The performance of dissolved methane oxidation and competition for oxygen among methane, ammonium, organic matter, and sulfide oxidizing bacteria were investigated using a lab-scale closed-type down-flow hanging sponge (OHS) reactor. Under the oxygen abundant condition of a hydraulic retention time of 2 h and volumetric air supply rate of 12.95 m(3)-air...

  8. 梳子坝对土石流之防治效率%The Controlling Efficiency of Slit Dam for Debris Flow Disaster

    Institute of Scientific and Technical Information of China (English)

    连惠邦; 柴钫武; 柯志宗

    2001-01-01

    Using mass conservation law of debris flow which passing through a slit dam and laboratory experiments, this paper has established three primary efficiency parameters: the sediment flow-out ratio, sediment concentration ratio, and sediment storage rate behind the slit dam. These efficiency parameters are developed to evaluate the effectiveness of the slit dam in retarding the debris flow and to design the height and spacing of posts and the location of a slit dam or a series of slit dams.%梳子坝是一种透过性坝体,可以有效地防止土石流之危害。因此,本研究经由土石流通过梳子坝的质量守恒定律和渠槽试验,分别建立土砂流出率、泥砂体积浓度比及贮砂率等三种主要的效率参数,作为评估梳子坝防治土石流之效率,并据以发展出一种简单的设计模式,可以用来设计单一梳子坝的高度、开口间距及总开口宽度等坝体几何因子。

  9. Study of plasma-chemical NO-containing gas flow for treatment of wounds and inflammatory processes.

    Science.gov (United States)

    Pekshev, Alexander V; Shekhter, Anatoly B; Vagapov, Andrey B; Sharapov, Nikolay A; Vanin, Anatoly F

    2018-02-28

    This work is aimed at exhaustive and detailed study of chemical, physical and physico-chemical characteristics of NO-containing gas flow (NO-CGF) generated by a plasma-chemical generator of Plason device, which has been used in medical practice for more than 15 years for effectively healing wound and inflammatory conditions with exogenous nitric oxide (NO-therapy). Data was obtained on spatial structure of the gas flow, and values of its local parameters in axial and radial directions, such as nitric oxide content, velocity, temperature and mass flow density of nitric oxide, providing altogether the effectiveness of treatment by the exogenous NO-therapy method, were determined experimentally and by computations. It was demonstrated that plasma-chemical synthesis of NO from atmospheric air in a low direct current (DC) arc provides a high mass flow of nitric oxide at the level of 1.6-1.8 mg/s, while in the area of impact of NO-CGF on the biological tissue, on its axis, NO content is 400-600 ppm, flow velocity about 5 m/s, nitric oxide mass flow density 0.25-0.40 mg/(s·cm 2 ), temperature 40-60 °C. Tendencies were determined for designing new devices for further experimental biological and medical research in the field of NO-therapy: lowering the temperature of NO-CGF to ambient temperature will enable variation, in experiments, of the affecting flow parameters in a wide range up to their maximum values: NO content up to 2000 ppm, velocity up to 20 m/s, nitric oxide mass flow density up to 2.5 mg/(s·cm 2 ). Copyright © 2017. Published by Elsevier Inc.

  10. Energy savings by reduced mixing in aeration tanks: Results from a full scale investigation and long term implementation at Avedoere wastewater treatment plant

    DEFF Research Database (Denmark)

    Sharma, Anitha Kumari; Guildal, T.; Thomsen, H.R.

    2011-01-01

    investigation was conducted to study the effect of reduced mixing on flow velocity, suspended solid sedimentation, concentration gradients of oxygen and SS with depth and treatment efficiency. The only negative effect observed was on flow velocity; however the velocity was above the critical velocity. The plant...

  11. Dense Array Optimization of Cross-Flow Turbines

    Science.gov (United States)

    Scherl, Isabel; Strom, Benjamin; Brunton, Steven; Polagye, Brian

    2017-11-01

    Cross-flow turbines, where the axis of rotation is perpendicular to the freestream flow, can be used to convert the kinetic energy in wind or water currents to electrical power. By taking advantage of mean and time-resolved wake structures, the optimal density of an array of cross-flow turbines has the potential for higher power output per unit area of land or sea-floor than an equivalent array of axial-flow turbines. In addition, dense arrays in tidal or river channels may be able to further elevate efficiency by exploiting flow confinement and surface proximity. In this work, a two-turbine array is optimized experimentally in a recirculating water channel. The spacing between turbines, as well as individual and coordinated turbine control strategies are optimized. Array efficiency is found to exceed the maximum efficiency for a sparse array (i.e., no interaction between turbines) for stream-wise rotor spacing of less than two diameters. Results are discussed in the context of wake measurements made behind a single rotor.

  12. TECHNOLOGICAL PROCESS ASSESSMENT OF THE DRINKING WATER TREATMENT AT TARGU-MURES WATER TREATMENT PLANT

    Directory of Open Access Journals (Sweden)

    CORNELIA DIANA HERTIA

    2011-03-01

    Full Text Available This paper intends to assess the technological process of obtaining drinking water at Targu-Mures water treatment plant. The assessment was performed before changing the technological process and four months were chosen to be analized during 2008: January, April, July and October for its efficiency analysis on treatment steps. Mures River is the water source for the water treatment plant, being characterized by unsteady flow and quality parameters with possible important variability in a very short period of time. The treatment technological process is the classic one, represented by coagulation, sedimentation, filtration and disinfection, but also prechlorination was constantly applied as additional treatment during 2008. Results showed that for the measured parameters, raw water at the water treatment plant fits into class A3 for surface waters, framing dictated by the bacterial load. The treatment processes efficiency is based on the performance calculation for sedimentation, filtration, global and for disinfection, a better conformation degree of technological steps standing out in January in comparison to the other three analyzed months. A variable non-compliance of turbidity and residual chlorine levels in the disinfected water was observed constantly. Previous treatment steps managed to maintain a low level of oxidisability, chlorine consumption and residual chlorine levels being also low. 12% samples were found inconsistent with the national legislation in terms of bacteriological quality. Measures for the water treatment plant retechnologization are taken primarily for hyperchlorination elimination, which currently constitutes a discomfort factor (taste, smell, and a generating factor of chlorination by-products.

  13. PDF modeling of turbulent flows on unstructured grids

    Science.gov (United States)

    Bakosi, Jozsef

    In probability density function (PDF) methods of turbulent flows, the joint PDF of several flow variables is computed by numerically integrating a system of stochastic differential equations for Lagrangian particles. Because the technique solves a transport equation for the PDF of the velocity and scalars, a mathematically exact treatment of advection, viscous effects and arbitrarily complex chemical reactions is possible; these processes are treated without closure assumptions. A set of algorithms is proposed to provide an efficient solution of the PDF transport equation modeling the joint PDF of turbulent velocity, frequency and concentration of a passive scalar in geometrically complex configurations. An unstructured Eulerian grid is employed to extract Eulerian statistics, to solve for quantities represented at fixed locations of the domain and to track particles. All three aspects regarding the grid make use of the finite element method. Compared to hybrid methods, the current methodology is stand-alone, therefore it is consistent both numerically and at the level of turbulence closure without the use of consistency conditions. Since both the turbulent velocity and scalar concentration fields are represented in a stochastic way, the method allows for a direct and close interaction between these fields, which is beneficial in computing accurate scalar statistics. Boundary conditions implemented along solid bodies are of the free-slip and no-slip type without the need for ghost elements. Boundary layers at no-slip boundaries are either fully resolved down to the viscous sublayer, explicitly modeling the high anisotropy and inhomogeneity of the low-Reynolds-number wall region without damping or wall-functions or specified via logarithmic wall-functions. As in moment closures and large eddy simulation, these wall-treatments provide the usual trade-off between resolution and computational cost as required by the given application. Particular attention is focused on

  14. Integrated soft sensor model for flow control.

    Science.gov (United States)

    Aijälä, G; Lumley, D

    2006-01-01

    Tighter discharge permits often require wastewater treatment plants to maximize utilization of available facilities in order to cost-effectively reach these goals. Important aspects are minimizing internal disturbances and using available information in a smart way to improve plant performance. In this study, flow control throughout a large highly automated wastewater treatment plant (WWTP) was implemented in order to reduce internal disturbances and to provide a firm foundation for more advanced process control. A modular flow control system was constructed based on existing instrumentation and soft sensor flow models. Modules were constructed for every unit process in water treatment and integrated into a plant-wide model. The flow control system is used to automatically control recirculation flows and bypass flows at the plant. The system was also successful in making accurate flow estimations at points in the plant where it is not possible to have conventional flow meter instrumentation. The system provides fault detection for physical flow measuring devices. The module construction allows easy adaptation for new unit processes added to the treatment plant.

  15. Fluid Flow Behaviour under Different Gases and Flow Rate during Gas Metal Arc Welding

    OpenAIRE

    Jaison Peter

    2013-01-01

    Gas metal arc welding (GMAW) is a highly efficient and fast process for fabricating high quality weld. High quality welds are fabricated by proper selection of consumable includes gas and filler metals. The optimum flow rate of gas will ensure the proper quality of weld. In this project, a fluid flow behavior of different flow rate is modeled and the change quality will be studied.

  16. Gasification: in search of efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Whysall, M. [UOP N.V., Antwerp (Belgium)

    2007-07-01

    Gasification of low cost feed stocks such as coal and heavy residues enables the supply of synthesis gas, hydrogen, power and utilities at a lower cost relative to conventional methodologies. The resulting synthesis gas can be used, after cleaning and sulphur removal, as a fuel or to produce other chemicals such as ammonia, methanol, or Fischer-Tropsch liquids. The paper covers coal and residue upgrading through the use of gasification, conversion and hydroprocessing and its integration with synthesis gas treatment and hydrogen recovery. Residue conversion choices can be influenced by hydrogen cost which can be controlled by integrating hydrogen production, recovery and purification into the gasification complex. Flow-schemes that maximize generation efficiency and minimize capital and operating costs and offer possibilities for CO{sub 2} capture are discussed. 3 figs.

  17. Efficient Parallel Algorithms for Unsteady Incompressible Flows

    KAUST Repository

    Guermond, Jean-Luc; Minev, Peter D.

    2013-01-01

    The objective of this paper is to give an overview of recent developments on splitting schemes for solving the time-dependent incompressible Navier–Stokes equations and to discuss possible extensions to the variable density/viscosity case. A particular attention is given to algorithms that can be implemented efficiently on large parallel clusters.

  18. Design and characterization of a device to quantify the magnetic drug targeting efficiency of magnetic nanoparticles in a tube flow phantom by magnetic particle spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Radon, Patricia, E-mail: patricia.radon@ptb.de; Löwa, Norbert; Gutkelch, Dirk; Wiekhorst, Frank

    2017-04-01

    The aim of magnetic drug targeting (MDT) is to transfer a therapeutic drug coupled to magnetic nanoparticles (MNP) to desired disease locations (e.g. tumor region) with the help of magnetic field gradients. To transfer the MDT approach into clinical practice a number of important issues remain to be solved. We developed and characterized an in-vitro flow phantom to provide a defined and reproducible MDT environment. The tube system of the flow phantom is directed through the detection coil of a magnetic particle spectroscopy (MPS) device to determine the targeting efficiency. MPS offers an excellent temporal resolution of seconds and an outstanding specific sensitivity of some nanograms of iron. In the flow phantom different MNP types, magnet geometries and tube materials can be employed to vary physical parameters like diameter, flow rate, magnetic targeting gradient, and MNP properties. - Highlights: • Flow phantom for magnetic targeting. • MPS for quantitative MNP detection. • ng detection limit for MNP.

  19. Chemical characterization of milk after treatment with thermal (HTST and UHT) and nonthermal (turbulent flow ultraviolet) processing technologies.

    Science.gov (United States)

    Cappozzo, Jack C; Koutchma, Tatiana; Barnes, Gail

    2015-08-01

    As a result of growing interest to nonthermal processing of milk, the purpose of this study was to characterize the chemical changes in raw milk composition after exposure to a new nonthermal turbulent flow UV process, conventional thermal pasteurization process (high-temperature, short-time; HTST), and their combinations, and compare those changes with commercially UHT-treated milk. Raw milk was exposed to UV light in turbulent flow at a flow rate of 4,000L/h and applied doses of 1,045 and 2,090 J/L, HTST pasteurization, and HTST in combination with UV (before or after the UV). Unprocessed raw milk, HTST-treated milk, and UHT-treated milk were the control to the milk processed with the continuous turbulent flow UV treatment. The chemical characterization included component analysis and fatty acid composition (with emphasis on conjugated linoleic acid) and analysis for vitamin D and A and volatile components. Lipid oxidation, which is an indicator to oxidative rancidity, was evaluated by free fatty acid analysis, and the volatile components (extracted organic fraction) by gas chromatography-mass spectrometry to obtain mass spectral profile. These analyses were done over a 14-d period (initially after treatment and at 7 and 14 d) because of the extended shelf-life requirement for milk. The effect of UV light on proteins (i.e., casein or lactalbumin) was evaluated qualitatively by sodium dodecyl sulfate-PAGE. The milk or liquid soluble fraction was analyzed by sodium dodecyl sulfate-PAGE for changes in the protein profile. From this study, it appears that continuous turbulent flow UV processing, whether used as a single process or in combination with HTST did not cause any statistically significant chemical changes when compared with raw milk with regard to the proximate analysis (total fat, protein, moisture, or ash), the fatty acid profile, lipid oxidation with respect to volatile analysis, or protein profile. A 56% loss of vitamin D and a 95% loss of vitamin A

  20. The Design Method of Axial Flow Runners Focusing on Axial Flow Velocity Uniformization and Its Application to an Ultra-Small Axial Flow Hydraulic Turbine

    Directory of Open Access Journals (Sweden)

    Yasuyuki Nishi

    2016-01-01

    Full Text Available We proposed a portable and ultra-small axial flow hydraulic turbine that can generate electric power comparatively easily using the low head of open channels such as existing pipe conduits or small rivers. In addition, we proposed a simple design method for axial flow runners in combination with the conventional one-dimensional design method and the design method of axial flow velocity uniformization, with the support of three-dimensional flow analysis. Applying our design method to the runner of an ultra-small axial flow hydraulic turbine, the performance and internal flow of the designed runner were investigated using CFD analysis and experiment (performance test and PIV measurement. As a result, the runners designed with our design method were significantly improved in turbine efficiency compared to the original runner. Specifically, in the experiment, a new design of the runner achieved a turbine efficiency of 0.768. This reason was that the axial component of absolute velocity of the new design of the runner was relatively uniform at the runner outlet in comparison with that of the original runner, and as a result, the negative rotational flow was improved. Thus, the validity of our design method has been verified.

  1. The effect of combined treatment with transcranial direct current stimulation on cerebral blood flow in patients with cerebral palsy

    Directory of Open Access Journals (Sweden)

    K. V. Yatsenko

    2017-02-01

    Full Text Available There is a close link between the activity of the brain and cerebral blood supply. Transcranial direct current stimulation (tDCS modulates the activity of the cerebral cortex and thus affects the cerebral blood flow. The aim of the study was to investigate the effect of combined treatment with tDCS on cerebral blood flow in patients with cerebral palsy (CP. Materials and Methods. 60 patients with various forms of cerebral palsy were examined and received the course of treatment. The comparison group was formed from 30 children who received the course of basic medical and rehabilitation procedures. The main group included 30 children who, in addition to the same therapy, received a course of tDCS. A transcranial Doppler ultrasound examination of head blood vessels was used for the study of cerebral hemodynamics in children with cerebral palsy before and after combined treatment with tDCS. Results. tDCS reduced asymmetry coefficient of blood flow velocity in the middle cerebral arteries (MCA by 12.3 %, whereas in the comparison group only by 2.5 %; in the anterior cerebral artery (ACA – 9.5 %, while in the comparison group – 0.8 %. tDCS significantly reduced the high mean blood flow velocity per cycle (MFV in the basilar artery (BA, MCA and ACA (21.7 %, 18.3 % and 7.8 %, respectively; in the comparison group no statistically significant positive dynamics was observed. tDCS significantly increased the low MVF in the BA, MCA and ACA (29.7 %, 21.2 % and 9.7 % respectively; a statistically significant increase of MVF by 9.9 % was only in the CMA in the comparison group of patients. Conclusions. Our data indicate that the use of tDCS in the combined treatment of CP patients improves cerebral hemodynamics in 87 % of patients, in contrast to 52 % in the comparison group. The addition of transcranial direct current stimulation method to the complex treatment of patients with cerebral palsy improves the effectiveness of treatment and may also

  2. Resource recovery from residual household waste: An application of exergy flow analysis and exergetic life cycle assessment.

    Science.gov (United States)

    Laner, David; Rechberger, Helmut; De Soete, Wouter; De Meester, Steven; Astrup, Thomas F

    2015-12-01

    Exergy is based on the Second Law of thermodynamics and can be used to express physical and chemical potential and provides a unified measure for resource accounting. In this study, exergy analysis was applied to four residual household waste management scenarios with focus on the achieved resource recovery efficiencies. The calculated exergy efficiencies were used to compare the scenarios and to evaluate the applicability of exergy-based measures for expressing resource quality and for optimizing resource recovery. Exergy efficiencies were determined based on two approaches: (i) exergy flow analysis of the waste treatment system under investigation and (ii) exergetic life cycle assessment (LCA) using the Cumulative Exergy Extraction from the Natural Environment (CEENE) as a method for resource accounting. Scenario efficiencies of around 17-27% were found based on the exergy flow analysis (higher efficiencies were associated with high levels of material recycling), while the scenario efficiencies based on the exergetic LCA lay in a narrow range around 14%. Metal recovery was beneficial in both types of analyses, but had more influence on the overall efficiency in the exergetic LCA approach, as avoided burdens associated with primary metal production were much more important than the exergy content of the recovered metals. On the other hand, plastic recovery was highly beneficial in the exergy flow analysis, but rather insignificant in exergetic LCA. The two approaches thereby offered different quantitative results as well as conclusions regarding material recovery. With respect to resource quality, the main challenge for the exergy flow analysis is the use of exergy content and exergy losses as a proxy for resource quality and resource losses, as exergy content is not per se correlated with the functionality of a material. In addition, the definition of appropriate waste system boundaries is critical for the exergy efficiencies derived from the flow analysis, as it

  3. Efficient C1-continuous phase-potential upwind (C1-PPU) schemes for coupled multiphase flow and transport with gravity

    Science.gov (United States)

    Jiang, Jiamin; Younis, Rami M.

    2017-10-01

    In the presence of counter-current flow, nonlinear convergence problems may arise in implicit time-stepping when the popular phase-potential upwinding (PPU) scheme is used. The PPU numerical flux is non-differentiable across the co-current/counter-current flow regimes. This may lead to cycles or divergence in the Newton iterations. Recently proposed methods address improved smoothness of the numerical flux. The objective of this work is to devise and analyze an alternative numerical flux scheme called C1-PPU that, in addition to improving smoothness with respect to saturations and phase potentials, also improves the level of scalar nonlinearity and accuracy. C1-PPU involves a novel use of the flux limiter concept from the context of high-resolution methods, and allows a smooth variation between the co-current/counter-current flow regimes. The scheme is general and applies to fully coupled flow and transport formulations with an arbitrary number of phases. We analyze the consistency property of the C1-PPU scheme, and derive saturation and pressure estimates, which are used to prove the solution existence. Several numerical examples for two- and three-phase flows in heterogeneous and multi-dimensional reservoirs are presented. The proposed scheme is compared to the conventional PPU and the recently proposed Hybrid Upwinding schemes. We investigate three properties of these numerical fluxes: smoothness, nonlinearity, and accuracy. The results indicate that in addition to smoothness, nonlinearity may also be critical for convergence behavior and thus needs to be considered in the design of an efficient numerical flux scheme. Moreover, the numerical examples show that the C1-PPU scheme exhibits superior convergence properties for large time steps compared to the other alternatives.

  4. Treatment of back flow fluids from shale gas exploration with recovery of uranium

    International Nuclear Information System (INIS)

    Gajda, D.; Zakrzewska-Koltuniewicz, G.; Abramowska, A.; Kiegiel, K.; Niescior-Borowinska, P.; Miskiewicz, A.; Olszewska, W.; Kulisa, K.; Samszynski, Z.; Drzewicz, P.; Konieczynska, M.

    2015-01-01

    Shale gas exploitation is the cause of many social protests. According to the protesters gas extraction technology threatens the environment: it consumes huge amounts of water, creates danger of poisoning drinking water, the formation of toxic wastewater, air contamination, noise, etc. Hydro-fracturing fluids could also leach radioactive isotopes e.g. uranium from the rock. The upper content of the main elements found in examined back flow fluids in Poland are the following: chlorine: 100.00 Kg/m 3 , sodium: 40.00 kg/m 3 , potassium: 0.90 kg/m 3 , lithium: 0.15 kg/m 3 , magnesium: 2.00 kg/m 3 , calcium: 20.00 kg/m 3 , strontium: 0.80 kg/m 3 and cesium: 0.06 kg/m 3 while the upper content of trace elements are the following: uranium: 3.5 g/m 3 , lanthanum: 12.4 g/m 3 , vanadium: 1.3 g/m 3 , yttrium: 1.3 g/m 3 , molybdenum: 2.0 g/m 3 and manganese: 9.7 g/m 3 . The recovery of uranium, and other valuable metals, from back flow fluids will reduce an environmental impact of hydro-fracturing process. This poster details the treatment of back flow fluids in Poland allowing rare earth elements and uranium recovery

  5. Characterization of wastewater treatment by two microbial fuel cells in continuous flow operation.

    Science.gov (United States)

    Kubota, Keiichi; Watanabe, Tomohide; Yamaguchi, Takashi; Syutsubo, Kazuaki

    2016-01-01

    A two serially connected single-chamber microbial fuel cell (MFC) was applied to the treatment of diluted molasses wastewater in a continuous operation mode. In addition, the effect of series and parallel connection between the anodes and the cathode on power generation was investigated experimentally. The two serially connected MFC process achieved 79.8% of chemical oxygen demand removal and 11.6% of Coulombic efficiency when the hydraulic retention time of the whole process was 26 h. The power densities were 0.54, 0.34 and 0.40 W m(-3) when electrodes were in individual connection, serial connection and parallel connection modes, respectively. A high open circuit voltage was obtained in the serial connection. Power density decreased at low organic loading rates (OLR) due to the shortage of organic matter. Power generation efficiency tended to decrease as a result of enhancement of methane fermentation at high OLRs. Therefore, high power density and efficiency can be achieved by using a suitable OLR range.

  6. Evaluation of coronary blood flow reserve by 13N-NH3 positron emission computed tomography (PET) with dipyridamole in the treatment of hypertension with the ACE inhibitor (Cilazapril)

    International Nuclear Information System (INIS)

    Masuda, Daisuke; Nohara, Ryuji; Tamaki, Nagara

    2000-01-01

    The purpose of this study was to evaluate the effect of treatment with an angiotensin-converting enzyme (ACE) inhibitor (Cilazapril) for early hypertensive patients in terms of coronary blood flow reserve evaluated by 13 NH 3 -positron emission tomography (PET). Before and after 12 weeks of ACE inhibitor treatment, 13 NH 3 -PET with dipyridamole provocation test was performed, and definite myocardial perfusion and coronary flow reserve (CFR) were calculated. Compared to our normal subjects previously reported (2.61±0.74), average coronary flow reserve was decreased (1.70±0.64 in hypertensive patients), and improved after treatment (1.77±0.52), but not significantly. Of 12 patients, five (42%) showed improved coronary flow reserve from 1.34 to 1.99 without a significant change in the resting flow. Only one patient (8%) showed deterioration after the ACE inhibitor treatment. The coronary vascular resistance (CVR) after ACE inhibitor treatment of the patients with CFR <2.0 decreased significantly compared with those with CFR ≥2.0 (p<0.03). These results indicate that hypertensive patients at the early stage show decreased coronary flow reserve despite having normal resting flow. Treatment with an ACE inhibitor (Cilazapril) for 12 weeks improved coronary flow reserve in 42% of our patients. The CVR of the patients with CFR <2.0 showed improvement compared to those with CFR ≥2.0. This result indicates that an ACE inhibitor (e.g., Cilazapril) should be one of the choices for improving CFR if hypertensive patients in early stage show signs of ischemia or diastolic dysfunction, which may be one of the sequels of reserve restriction. (author)

  7. Control of occupational exposure to phenol in industrial wastewater treatment plant of a petroleum refinery in Alexandria, Egypt: An intervention application case study.

    Science.gov (United States)

    Zaki, Gehan R; El-Marakby, Fadia A; Ramadan, Alaa El-Din K; Issa, Ahmed I; Nofal, Faten H

    2016-11-01

    Phenol exposure is one of the hazards in the industrial wastewater treatment basin of any refinery. It additively interacts with hydrogen sulfide emitted from the wastewater basin. Consequently, its concentration should be greatly lower than its threshold limit value. The present study aimed at controlling occupational exposure to phenol in the work environment of wastewater treatment plant in a refinery by reducing phenolic compounds in the industrial wastewater basin. This study was conducted on both laboratory and refinery scales. The first was completed by dividing each wastewater sample from the outlets of different refinery units into three portions; the first was analyzed for phenolic compounds. The second and third were for laboratory scale charcoal and bacterial treatments. The two methods were compared regarding their simplicities, design, and removal efficiencies. Accordingly, bacterial treatment by continuous flow of sewage water containing Pseudomonas Aeruginosa was used for refinery scale treatment. Laboratory scale treatment of phenolic compounds revealed higher removal efficiency of charcoal [100.0(0.0) %] than of bacteria [99.9(0.013) %]. The refinery scale bacterial treatment was [99.8(0.013) %] efficient. Consequently, level of phenol in the work environment after refinery-scale treatment [0.069(0.802) mg/m(3)] was much lower than that before [5.700(26.050) mg/m(3)], with removal efficiency of [99.125(2.335) %]. From the present study, we can conclude that bacterial treatment of phenolic compounds in industrial wastewater of the wastewater treatment plant using continuous flow of sewage water containing Pseudomonas Aeruginosa reduces the workers' exposure to phenol.

  8. Improving efficiency and safety in external beam radiation therapy treatment delivery using a Kaizen approach.

    Science.gov (United States)

    Kapur, Ajay; Adair, Nilda; O'Brien, Mildred; Naparstek, Nikoleta; Cangelosi, Thomas; Zuvic, Petrina; Joseph, Sherin; Meier, Jason; Bloom, Beatrice; Potters, Louis

    Modern external beam radiation therapy treatment delivery processes potentially increase the number of tasks to be performed by therapists and thus opportunities for errors, yet the need to treat a large number of patients daily requires a balanced allocation of time per treatment slot. The goal of this work was to streamline the underlying workflow in such time-interval constrained processes to enhance both execution efficiency and active safety surveillance using a Kaizen approach. A Kaizen project was initiated by mapping the workflow within each treatment slot for 3 Varian TrueBeam linear accelerators. More than 90 steps were identified, and average execution times for each were measured. The time-consuming steps were stratified into a 2 × 2 matrix arranged by potential workflow improvement versus the level of corrective effort required. A work plan was created to launch initiatives with high potential for workflow improvement but modest effort to implement. Time spent on safety surveillance and average durations of treatment slots were used to assess corresponding workflow improvements. Three initiatives were implemented to mitigate unnecessary therapist motion, overprocessing of data, and wait time for data transfer defects, respectively. A fourth initiative was implemented to make the division of labor by treating therapists as well as peer review more explicit. The average duration of treatment slots reduced by 6.7% in the 9 months following implementation of the initiatives (P = .001). A reduction of 21% in duration of treatment slots was observed on 1 of the machines (P Kaizen approach has the potential to improve operational efficiency and safety with quick turnaround in radiation therapy practice by addressing non-value-adding steps characteristic of individual department workflows. Higher effort opportunities are identified to guide continual downstream quality improvements. Copyright © 2017 American Society for Radiation Oncology. Published by

  9. Effect of self recirculation casing treatment on the performance of a turbocharger centrifugal compressor

    Science.gov (United States)

    Gancedo, Matthieu

    Increase in emission regulations in the transport industry brings the need to have more efficient engines. A path followed by the automobile industry is to downsize the size of the internal combustion engine and increase the air density at the intake to keep the engine power when needed. Typically a centrifugal compressor is used to force the air into the engine, it can be powered from the engine shaft (superchargers) or extracting energy contained into the hot exhaust gases with a turbine (turbochargers). The flow range of the compressor needs to match the one of the engine. However compressors mass flow operating range is limited by choke on the high end and surge on the low end. In order to extend the operation at low mass flow rates, the use of passive devices for turbocharger centrifugal compressors was explored since the late 80's. Hence, casing treatments including flow recirculation from the inducer part of the compressor have been shown to move the surge limit to lower flows. Yet, the working mechanisms are still not well understood and thus, to optimize the design of this by-pass system, it is necessary to determine the nature of the changes induced by the device both on the dynamic stability of the pressure delivery and on the flow at the inlet. The compressor studied here features a self-recirculating casing treatment at the inlet. The recirculation passage could be blocked to carry a direct comparison between the cases with and without the flow feature. To grasp the effect on compressor stability, pressure measurements were taken in the different constituting elements of the compressor. The study of the mean pressure variations across the operating map showed that the tongue region is a limiting element. Dynamic pressure measurements revealed that the instabilities generated near the inducer when the recirculation is blocked increase the overall instability levels at the compressor outlet and propagating pressure waves starting at the tongue occurred

  10. Myocardial blood flow and its transit time, oxygen utilization, and efficiency of highly endurance-trained human heart.

    Science.gov (United States)

    Heinonen, Ilkka; Kudomi, Nobuyuki; Kemppainen, Jukka; Kiviniemi, Antti; Noponen, Tommi; Luotolahti, Matti; Luoto, Pauliina; Oikonen, Vesa; Sipilä, Hannu T; Kopra, Jaakko; Mononen, Ilkka; Duncker, Dirk J; Knuuti, Juhani; Kalliokoski, Kari K

    2014-07-01

    Highly endurance-trained athlete's heart represents the most extreme form of cardiac adaptation to physical stress, but its circulatory alterations remain obscure. In the present study, myocardial blood flow (MBF), blood mean transit time (MTT), oxygen extraction fraction (OEF) and consumption (MVO2), and efficiency of cardiac work were quantified in highly trained male endurance athletes and control subjects at rest and during supine cycling exercise using [(15)O]-labeled radiotracers and positron emission tomography. Heart rate and MBF were lower in athletes both at rest and during exercise. OEF increased in response to exercise in both groups, but was higher in athletes (70 ± 21 vs. 63 ± 11 % at rest and 86 ± 13 vs. 73 ± 10 % during exercise). MTT was longer and vascular resistance higher in athletes both at rest and during exercise, but arterial content of 2,3-diphosphoglycerate (oxygen affinity) was unchanged. MVO2 per gram of myocardium trended (p = 0.08) lower in athletes both at rest and during exercise, while myocardial efficiency of work and MVO2 per beat were not different between groups. Arterial levels of free fatty acids were ~twofold higher in athletes likely leading to higher myocardial fatty acid oxidation and hence oxygen cost, which may have blunted the bradycardia-induced decrease in MVO2. Finally, the observed group differences in MBF, OEF, MTT and vascular resistance remained significant also after they were controlled for differences in MVO2. In conclusion, in highly endurance-trained human heart, increased myocardial blood transition time enables higher oxygen extraction levels with a lower myocardial blood flow and higher vascular resistance. These physiological adaptations to exercise training occur independently of the level of oxygen consumption and together with training-induced bradycardia may serve as mechanisms to increase functional reserve of the human heart.

  11. Comparison of the efficiencies of attached- versus suspended-growth SBR systems in the treatment of recycled paper mill wastewater.

    Science.gov (United States)

    Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Abu Hasan, Hassimi; Abd Rahim, Reehan Adnee

    2015-11-01

    The complexity of residual toxic organics from biologically treated effluents of pulp and paper mills is a serious concern. To date, it has been difficult to choose the best treatment technique because each of the available options has advantages and drawbacks. In this study, two different treatment techniques using laboratory-scale aerobic sequencing batch reactors (SBRs) were tested with the same real recycled paper mill effluent to evaluate their treatment efficiencies. Two attached-growth SBRs using granular activated carbon (GAC) with and without additional biomass and a suspended-growth SBR were used in the treatment of real recycled paper mill effluent at a chemical oxygen demand (COD) level in the range of 800-1300 mg/L, a fixed hydraulic retention time of 24 h and a COD:N:P ratio of approximately 100:5:1. The efficiency of this biological treatment process was studied over a 300-day period. The six most important wastewater quality parameters, namely, chemical oxygen demand (COD), turbidity, ammonia (expressed as NH3-N), phosphorus (expressed as PO4(3)-P), colour, and suspended solids (SS), were measured to compare the different treatment techniques. It was determined that these processes were able to almost completely and simultaneously eliminate COD (99%) and turbidity (99%); the removals of NH3-N (90-100%), PO4(3)-P (66-78%), colour (63-91%), and SS (97-99%) were also sufficient. The overall performance results confirmed that an attached-growth SBR system using additional biomass on GAC is a promising configuration for wastewater treatment in terms of performance efficiency and process stability under fluctuations of organic load. Hence, this hybrid system is recommended for the treatment of pulp and paper mill effluents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Self Cleaning High Efficiency Particulate Air (HEPA) Filtration without Interrupting Process Flow - 59347

    International Nuclear Information System (INIS)

    Chadwick, Chris

    2012-01-01

    The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research suggests that the then costs to the Department of Energy (DOE), based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft 3 /min, cleanable, stainless HEPA could be commercially available for $5, 000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15, 000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

  13. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system...... is implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V...

  14. Importance of food waste pre-treatment efficiency for global warming potential in life cycle assessment of anaerobic digestion systems

    DEFF Research Database (Denmark)

    Carlsson, My; Naroznova, Irina; Møller, Jacob

    2015-01-01

    treatment of the refuse. The objective of this study was to investigate how FW pre-treatment efficiency impacts the environmental performance of waste management, with respect to global warming potential (GWP). The modeling tool EASETECH was used to perform consequential LCA focusing on the impact...

  15. ESTIMATION OF EFFICIENCY OF MACHINERY FOR PRE-SOWING TREATMENT OF RADISH SEEDS FOR SEED PRODUCTION

    Directory of Open Access Journals (Sweden)

    S. M. Sirota

    2016-01-01

    Full Text Available The results of pre-sowing treatment of radish seeds aimed at increasing of seed production, yield and its productivity in protected area are presented. The density fractionation of radish seeds by gravity separator is recommended for improvement of planting material quality and increasing of utilization efficiency of frame area.

  16. Efficiency and stability of the DSBGK method

    KAUST Repository

    Li, Jun

    2012-07-09

    Recently, the DSBGK method (Note: the original name DS-BGK is changed to DSBGK for simplicity) was proposed to reduce the stochastic noise in simulating rarefied gas flows at low velocity. Its total computational time is almost independent of the magnitude of deviation from equilibrium state. It was verified by the DSMC method in different benchmark problems over a wide range of Kn number. Some simulation results of the closed lid-driven cavity flow, thermal transpiration flow and the open channel flow by the DSBGK method are given here to show its efficiency and numerical stability. In closed problems, the density distribution is subject to unphysical fluctuation due to the absence of density constraint at the boundary. Thus, many simulated molecules are employed by DSBGK simulations to improve the stability and reduce the magnitude of fluctuation. This increases the memory usage remarkably but has small influence to the efficiency of DSBGK simulations. In open problems, the DSBGK simulation remains stable when using about 10 simulated molecules per cell because the fixed number densities at open boundaries eliminate the unphysical fluctuation. Small modification to the CLL reflection model is introduced to further improve the efficiency slightly.

  17. Efficiency and stability of the DSBGK method

    KAUST Repository

    Li, Jun

    2012-01-01

    Recently, the DSBGK method (Note: the original name DS-BGK is changed to DSBGK for simplicity) was proposed to reduce the stochastic noise in simulating rarefied gas flows at low velocity. Its total computational time is almost independent of the magnitude of deviation from equilibrium state. It was verified by the DSMC method in different benchmark problems over a wide range of Kn number. Some simulation results of the closed lid-driven cavity flow, thermal transpiration flow and the open channel flow by the DSBGK method are given here to show its efficiency and numerical stability. In closed problems, the density distribution is subject to unphysical fluctuation due to the absence of density constraint at the boundary. Thus, many simulated molecules are employed by DSBGK simulations to improve the stability and reduce the magnitude of fluctuation. This increases the memory usage remarkably but has small influence to the efficiency of DSBGK simulations. In open problems, the DSBGK simulation remains stable when using about 10 simulated molecules per cell because the fixed number densities at open boundaries eliminate the unphysical fluctuation. Small modification to the CLL reflection model is introduced to further improve the efficiency slightly.

  18. Simulation-based patient flow analysis in an endoscopy unit

    DEFF Research Database (Denmark)

    Koo, Pyung-Hoi; Nielsen, Karl Brian; Jang, Jaejin

    2010-01-01

    One of the major elements in improving efficiency of healthcare services is patient flow. Patients require a variety of healthcare resources as they receive healthcare services. Poor management of patient flow results in long waiting time of patients, under/over utilization of medical resources......, low quality of care and high healthcare cost. This article addresses patient flow problems at a Gastrointestinal endoscopy unit. We attempt to analyze the main factors that contribute to the inefficient patient flow and process bottlenecks and to propose efficient patient scheduling and staff...

  19. Analysis of energy efficiency and energy consumption costs: a case study for regional wastewater treatment plant in Malaysia

    Directory of Open Access Journals (Sweden)

    Nor Azuana Ramli

    2017-03-01

    Full Text Available The objective of this study is to analyze the possibilities of increasing energy efficiency in the central region wastewater treatment plant by focusing on two aspects: biogas production and prediction of energy production. The analysis is based on one of the biggest central region wastewater treatment plants in Malaysia. After studying the energy efficiency, which consists of optimization of energy consumption and enhancing gas generation, the prediction of power consumption is performed using an autoregressive integrated moving average (ARIMA model. The prediction results are compared with the linear regression method. Comparison shows that even though the total cost of savings is greater by using linear regression, the prediction through ARIMA is more accurate and has smaller root mean square error. The implementation of these two aspects managed to increase energy efficiency by 10% of energy recovery that could further reduce electricity cost and reduction of sludge cake disposal off site. The study recommends other aspects, such as modification in setting up the frequency of variable speed drive for aerators and blowers and optimizing number of feeds into train unit processes within aeration tanks in increasing energy efficiency.

  20. Microbial community composition of a down-flow hanging sponge (DHS) reactor combined with an up-flow anaerobic sludge blanket (UASB) reactor for the treatment of municipal sewage.

    Science.gov (United States)

    Kubota, Kengo; Hayashi, Mikio; Matsunaga, Kengo; Iguchi, Akinori; Ohashi, Akiyoshi; Li, Yu-You; Yamaguchi, Takashi; Harada, Hideki

    2014-01-01

    The microbial community composition of a down-flow hanging sponge (DHS) reactor in an up-flow anaerobic sludge blanket (UASB)-DHS system used for the treatment of municipal sewage was investigated. The clone libraries showed marked differences in microbial community composition at different reactor heights and in different seasons. The dominant phylotypes residing in the upper part of the reactor were likely responsible for removing organic matters because a significant reduction in organic matter in the upper part was observed. Quantification of the amoA genes revealed that the proportions of ammonia oxidizing bacteria (AOB) varied along the vertical length of the reactor, with more AOB colonizing the middle and lower parts of the reactor than the top of the reactor. The findings indicated that sewage treatment was achieved by a separation of microbial habitats responsible for organic matter removal and nitrification in the DHS reactor. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Through-flow analysis of steam turbines operating under partial admission

    International Nuclear Information System (INIS)

    Delabriere, H.; Werthe, J.M.

    1993-05-01

    In order to produce electric energy with improved efficiency, Electricite de France has to check the performances of equipment proposed by manufacturers. In the specific field of steam turbines, one of the main tools of analysis is the quasi 3D through flow computer code CAPTUR, which enables the calculation of all the aerothermodynamic parameters in a steam turbine. The last development that has been performed on CAPTUR is the extension to a calculation of a flow within a turbine operating under partial admission. For such turbines, it is now possible to calculate an internal flow field, and determine the efficiency, in a much more accurate way than with previous methods, which consist in an arbitrary efficiency correction on an averaged 1D flow calculation. From the aerodynamic point of view, partial admission involves specific losses in the first stage, then expansion and turbulent mixing just downstream of the first stage. Losses in the first stage are of very different types: windage, pumping and expansion at the ends of an admission sector. Their values have been estimated, with help of experimental results, and then expressed as a slow down coefficient applied to the relative velocity at the blade outlet. As for the flow downstream the first stage, a computational analysis has been made with specific 2D and 3D codes. It has led to define the numerical treatment established in the CAPTUR code. Some problems had to be solved to make compatible a quasi 3D formulation, making an average in the azimutal direction and using a streamline curvature method, with an absolute 3D phenomenon. Certain limitations of the working conditions were first adopted, but a generalization is on hand. The calculation of a nuclear HP steam turbine operating under partial admission has been performed. Calculation results are in good accordance with tests results, especially as regards the expansion line along the stages. The code CAPTUR will be particularly useful for the calculation

  2. A novel flow battery: A lead acid battery based on an electrolyte with soluble lead(II). Part IX: Electrode and electrolyte conditioning with hydrogen peroxide

    Science.gov (United States)

    Collins, John; Li, Xiaohong; Pletcher, Derek; Tangirala, Ravichandra; Stratton-Campbell, Duncan; Walsh, Frank C.; Zhang, Caiping

    Extended cycling of a soluble lead acid battery can lead to problems due to an imbalance in the coulombic efficiency leading to deposits of Pb and PbO2 on the electrodes. Periodic addition of hydrogen peroxide to the electrolyte of the soluble lead acid flow battery largely overcomes several operational problems seen during extended cycling, using a 10 cm × 10 cm parallel plate flow cell. It is shown that this treatment greatly extends the number of cycles that can be achieved with a reasonable energy-, voltage-, and charge efficiency of 54-66%, 71%, and 77-91%.

  3. A novel flow battery: A lead acid battery based on an electrolyte with soluble lead(II). Part IX: Electrode and electrolyte conditioning with hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Collins, John; Stratton-Campbell, Duncan [C-Tech Innovation Ltd., Capenhurst, Chester CH1 6EH (United Kingdom); Li, Xiaohong; Tangirala, Ravichandra; Walsh, Frank C.; Zhang, Caiping [Energy Technology Research Group, School of Engineering Sciences, University of Southampton, Highfield, University Road, Southampton SO17 1BJ (United Kingdom); Pletcher, Derek [Electrochemistry and Surface Science Group, School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2010-05-01

    Extended cycling of a soluble lead acid battery can lead to problems due to an imbalance in the coulombic efficiency leading to deposits of Pb and PbO2 on the electrodes. Periodic addition of hydrogen peroxide to the electrolyte of the soluble lead acid flow battery largely overcomes several operational problems seen during extended cycling, using a 10 cm x 10 cm parallel plate flow cell. It is shown that this treatment greatly extends the number of cycles that can be achieved with a reasonable energy-, voltage-, and charge efficiency of 54-66%, 71%, and 77-91%. (author)

  4. Environmental risk assessment of effluents as a whole emerging contaminant: Efficiency of alternative tertiary treatments for wastewater depuration.

    Science.gov (United States)

    Díaz-Garduño, B; Pintado-Herrera, M G; Biel-Maeso, M; Rueda-Márquez, J J; Lara-Martín, P A; Perales, J A; Manzano, M A; Garrido-Pérez, C; Martín-Díaz, M L

    2017-08-01

    Emerging contaminants (ECs) and regulated compounds (RCs) from three different WWTP effluents were measured in the current study. The efficiency of two tertiary treatments, Photobiotreatment (PhtBio) and Multi-Barrier Treatment (MBT), for removing contaminants was determined. Results indicated different percentages of removal depending on the treatment and the origin of the effluent. Risk Quotients (RQs) were determined for different species of algae, Daphnia, and fish. RQ results revealed diverse risk values depending on the bioindicator species. Tonalide, galaxolide (fragrances), and ofloxacin (antibiotic) were the most persistent and harmful substances in tested effluents. "Negligible risk" category was reached since a wide diversity of ECs were removed by MBT with high removal percentages. Contrarily, PhtBio was effective only in the depuration of certain chemical compounds, and its efficiency depended on the composition of the raw effluent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Science.gov (United States)

    Cary, Robert E.

    2015-12-08

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  6. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Robert B.

    2018-04-17

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  7. An efficient immersed boundary-lattice Boltzmann method for the hydrodynamic interaction of elastic filaments

    Science.gov (United States)

    Tian, Fang-Bao; Luo, Haoxiang; Zhu, Luoding; Liao, James C.; Lu, Xi-Yun

    2012-01-01

    We have introduced a modified penalty approach into the flow-structure interaction solver that combines an immersed boundary method (IBM) and a multi-block lattice Boltzmann method (LBM) to model an incompressible flow and elastic boundaries with finite mass. The effect of the solid structure is handled by the IBM in which the stress exerted by the structure on the fluid is spread onto the collocated grid points near the boundary. The fluid motion is obtained by solving the discrete lattice Boltzmann equation. The inertial force of the thin solid structure is incorporated by connecting this structure through virtual springs to a ghost structure with the equivalent mass. This treatment ameliorates the numerical instability issue encountered in this type of problems. Thanks to the superior efficiency of the IBM and LBM, the overall method is extremely fast for a class of flow-structure interaction problems where details of flow patterns need to be resolved. Numerical examples, including those involving multiple solid bodies, are presented to verify the method and illustrate its efficiency. As an application of the present method, an elastic filament flapping in the Kármán gait and the entrainment regions near a cylinder is studied to model fish swimming in these regions. Significant drag reduction is found for the filament, and the result is consistent with the metabolic cost measured experimentally for the live fish. PMID:23564971

  8. An efficient immersed boundary-lattice Boltzmann method for the hydrodynamic interaction of elastic filaments

    Science.gov (United States)

    Tian, Fang-Bao; Luo, Haoxiang; Zhu, Luoding; Liao, James C.; Lu, Xi-Yun

    2011-08-01

    We have introduced a modified penalty approach into the flow-structure interaction solver that combines an immersed boundary method (IBM) and a multi-block lattice Boltzmann method (LBM) to model an incompressible flow and elastic boundaries with finite mass. The effect of the solid structure is handled by the IBM in which the stress exerted by the structure on the fluid is spread onto the collocated grid points near the boundary. The fluid motion is obtained by solving the discrete lattice Boltzmann equation. The inertial force of the thin solid structure is incorporated by connecting this structure through virtual springs to a ghost structure with the equivalent mass. This treatment ameliorates the numerical instability issue encountered in this type of problems. Thanks to the superior efficiency of the IBM and LBM, the overall method is extremely fast for a class of flow-structure interaction problems where details of flow patterns need to be resolved. Numerical examples, including those involving multiple solid bodies, are presented to verify the method and illustrate its efficiency. As an application of the present method, an elastic filament flapping in the Kármán gait and the entrainment regions near a cylinder is studied to model fish swimming in these regions. Significant drag reduction is found for the filament, and the result is consistent with the metabolic cost measured experimentally for the live fish.

  9. Test Program for High Efficiency Gas Turbine Exhaust Diffuser

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Thomas R.

    2009-12-31

    This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust geometry. Importantly, low frequency diffuser noise was reduced by 5 dB or more, compared to the baseline. Appolicability to other diffuser geometries is yet to be demonstrated.

  10. Comparison in decoloration efficiency among radiation, ultraviolet ray and Fenton oxidation treatment for aqueous solution of dyes

    International Nuclear Information System (INIS)

    Shimokawa, Toshishige; Sawai, Takeshi

    1984-01-01

    To establish the methods of oxidation and decomposition treatment for dyeing waste water, the processes by radiation, ultraviolet ray and Fenton oxidation were examined comparatively for the decoloration efficiency. The dyes tested were commercially available reactive dyes, RBO-3R, DBR-BB, MBY-6GS and RBB-R. In the radiation process, the dye solution was irradiated with gamma ray of cobalt-60 while blowing air through it. Radiation process and Fenton oxidation were excellent for decoloration. Ultraviolet ray was low in the treatment efficiency, so it is not practical. In the radiation process, the addition of a reagent and the adjustment of pH are not required unlike the case of the Fenton oxidation process. Its continuous operation is also possible, so it is a highly practical means. (Mori, K.)

  11. Mathematics model of filtration efficiency of moisture separator for nuclear reactors

    International Nuclear Information System (INIS)

    Zhang Zhenzhong; Jiang Feng; Huang Yunfeng

    2010-01-01

    In order to study the filtration mechanism of the moisture separator for water droplet of 5∼10μm, this paper set up a physical model. For the mixed meshes, they can be classified into three types: standard meshes, bur meshes and middle meshes. For all fibers of the wire meshes and vertical fibers of standard mixed meshes, a Kuwabara flow field is used to track the particle to get the inertial impaction efficiency and then calculate the total filtration efficiency of the meshes. For other fibers, besides the Kuwabara flow field, an around-flat flow field is added to calculate the efficiency. Lastly, the total efficiency of the moisture separator according to the equation of the filtration efficiency for the filters in series is compared with the experimental data. The result shows that, under the standard condition,the calculation value is consistent with the experimental efficiency data. (authors)

  12. Renewable Wood Pulp Paper Reactor with Hierarchical Micro/Nanopores for Continuous-Flow Nanocatalysis.

    Science.gov (United States)

    Koga, Hirotaka; Namba, Naoko; Takahashi, Tsukasa; Nogi, Masaya; Nishina, Yuta

    2017-06-22

    Continuous-flow nanocatalysis based on metal nanoparticle catalyst-anchored flow reactors has recently provided an excellent platform for effective chemical manufacturing. However, there has been limited progress in porous structure design and recycling systems for metal nanoparticle-anchored flow reactors to create more efficient and sustainable catalytic processes. In this study, traditional paper is used for a highly efficient, recyclable, and even renewable flow reactor by tailoring the ultrastructures of wood pulp. The "paper reactor" offers hierarchically interconnected micro- and nanoscale pores, which can act as convective-flow and rapid-diffusion channels, respectively, for efficient access of reactants to metal nanoparticle catalysts. In continuous-flow, aqueous, room-temperature catalytic reduction of 4-nitrophenol to 4-aminophenol, a gold nanoparticle (AuNP)-anchored paper reactor with hierarchical micro/nanopores provided higher reaction efficiency than state-of-the-art AuNP-anchored flow reactors. Inspired by traditional paper materials, successful recycling and renewal of AuNP-anchored paper reactors were also demonstrated while high reaction efficiency was maintained. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  13. Removal of iron and manganese using biological roughing up flow filtration technology.

    Science.gov (United States)

    Pacini, Virginia Alejandra; María Ingallinella, Ana; Sanguinetti, Graciela

    2005-11-01

    The removal of iron and manganese from groundwater using biological treatment methods is almost unknown in Latin America. Biological systems used in Europe are based on the process of double rapid biofiltration during which dissolved oxygen and pH need to be strictly controlled in order to limit abiotic iron oxidation. The performance of roughing filter technology in a biological treatment process for the removal of iron and manganese, without the use of chemical agents and under natural pH conditions was studied. Two pilot plants, using two different natural groundwaters, were operated with the following treatment line: aeration, up flow roughing filtration and final filtration (either slow or rapid). Iron and manganese removal efficiencies were found to be between 85% and 95%. The high solid retention capability of the roughing filter means that it is possible to remove iron and manganese simultaneously by biotic and abiotic mechanisms. This system combines simple, low-cost operation and maintenance with high iron and manganese removal efficiencies, thus constituting a technology which is particularly suited to small waterworks.

  14. Centrifugal compressor tip clearance and impeller flow

    Energy Technology Data Exchange (ETDEWEB)

    Jaatinen-Varri, Ahti; Tiainen, Jonna; Turunen-Saaresti, Teemu; Gronman, Aki; Ameli, Alireza; Backman, Jari [Laboratory of Fluid Dynamics, LUT School of Energy Systems, Lappeenranta University of Technology, Lappeenranta (Finland); Engeda, Abraham [Turbomachinery Laboratory, Dept. of Mechanical Engineering, Michigan State University, East Lansing (United States)

    2016-11-15

    Compressors consume a considerable portion of the electricity used in the industrial sector. Hence, improvements in compressor efficiency lead to energy savings and reduce environmental impacts. The efficiency of an unshrouded centrifugal compressor suffers from leakage flow over the blade tips. The effect of tip leakage flow on the passage flow differs between the full and splitter blade passages. In this study, the differences in the flow fields between the full and splitter blade passages were studied numerically in detail. An industrial high-speed compressor with a design pressure ratio of 1.78 was modelled. Numerical studies were conducted with six different tip clearances and three different diffuser widths. The results show that increasing tip clearance considerably increases the reversed flow into the impeller with an unpinched diffuser. The reversed flow then partly mixes into the flow in the same blade passage it entered the impeller and the rest migrates over the blade, mixing with the tip clearance flow. Furthermore, as the reversed and clearance flow mix into the wake, the wake is weakened. As pinch reduces both the reversed flow and clearance flow, the passage wakes are stronger with pinches. However, the pinch is beneficial as the losses at the impeller outlet decrease.

  15. Centrifugal compressor tip clearance and impeller flow

    International Nuclear Information System (INIS)

    Jaatinen-Varri, Ahti; Tiainen, Jonna; Turunen-Saaresti, Teemu; Gronman, Aki; Ameli, Alireza; Backman, Jari; Engeda, Abraham

    2016-01-01

    Compressors consume a considerable portion of the electricity used in the industrial sector. Hence, improvements in compressor efficiency lead to energy savings and reduce environmental impacts. The efficiency of an unshrouded centrifugal compressor suffers from leakage flow over the blade tips. The effect of tip leakage flow on the passage flow differs between the full and splitter blade passages. In this study, the differences in the flow fields between the full and splitter blade passages were studied numerically in detail. An industrial high-speed compressor with a design pressure ratio of 1.78 was modelled. Numerical studies were conducted with six different tip clearances and three different diffuser widths. The results show that increasing tip clearance considerably increases the reversed flow into the impeller with an unpinched diffuser. The reversed flow then partly mixes into the flow in the same blade passage it entered the impeller and the rest migrates over the blade, mixing with the tip clearance flow. Furthermore, as the reversed and clearance flow mix into the wake, the wake is weakened. As pinch reduces both the reversed flow and clearance flow, the passage wakes are stronger with pinches. However, the pinch is beneficial as the losses at the impeller outlet decrease

  16. An integrated anaerobic digestion and UV photocatalytic treatment of distillery wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Apollo, Seth [Department of Chemical Engineering, Vaal University of Technology, Private Bag X021, Vanderbijlpark 1900 (South Africa); Onyango, Maurice S. [Department of Chemical and Metallurgical Engineering, Tshwane University of Technology, Pretoria, Private Bag X680, Pretoria 0001 (South Africa); Ochieng, Aoyi, E-mail: ochienga@vut.ac.za [Department of Chemical Engineering, Vaal University of Technology, Private Bag X021, Vanderbijlpark 1900 (South Africa)

    2013-10-15

    Highlights: • Integrated AD and photodegradation is suitable for treatment of distillery effluent. • AD process is effective in COD and BOD reduction but not colour removal. • UV photodegradation is efficient in colour and DON removal. • UV photodegradation as a post treatment technique achieved high efficiencies. • UV pre-treatment inhibited biogas production in the succeeding anaerobic process. -- Abstract: Anaerobic up-flow fixed bed reactor and annular photocatalytic reactor were used to study the efficiency of integrated anaerobic digestion (AD) and ultraviolet (UV) photodegradation of real distillery effluent and raw molasses wastewater (MWW). It was found that UV photodegradation as a stand-alone technique achieved colour removal of 54% and 69% for the distillery and MWW, respectively, with a COD reduction of <20% and a negligible BOD reduction. On the other hand, AD as a single treatment technique was found to be effective in COD and BOD reduction with efficiencies of above 75% and 85%, respectively, for both wastewater samples. However, the AD achieved low colour removal efficiency, with an increase in colour intensity of 13% recorded when treating MWW while a colour removal of 51% was achieved for the distillery effluent. The application of UV photodegradation as a pre-treatment method to the AD process reduced the COD removal and biogas production efficiency. However, an integration in which UV photodegradation was employed as a post-treatment to the AD process achieved high COD removal of above 85% for both wastewater samples, and colour removal of 88% for the distillery effluent. Thus, photodegradation can be employed as a post-treatment technique to an AD system treating distillery effluent for complete removal of the biorecalcitrant and colour imparting compounds.

  17. An integrated anaerobic digestion and UV photocatalytic treatment of distillery wastewater

    International Nuclear Information System (INIS)

    Apollo, Seth; Onyango, Maurice S.; Ochieng, Aoyi

    2013-01-01

    Highlights: • Integrated AD and photodegradation is suitable for treatment of distillery effluent. • AD process is effective in COD and BOD reduction but not colour removal. • UV photodegradation is efficient in colour and DON removal. • UV photodegradation as a post treatment technique achieved high efficiencies. • UV pre-treatment inhibited biogas production in the succeeding anaerobic process. -- Abstract: Anaerobic up-flow fixed bed reactor and annular photocatalytic reactor were used to study the efficiency of integrated anaerobic digestion (AD) and ultraviolet (UV) photodegradation of real distillery effluent and raw molasses wastewater (MWW). It was found that UV photodegradation as a stand-alone technique achieved colour removal of 54% and 69% for the distillery and MWW, respectively, with a COD reduction of <20% and a negligible BOD reduction. On the other hand, AD as a single treatment technique was found to be effective in COD and BOD reduction with efficiencies of above 75% and 85%, respectively, for both wastewater samples. However, the AD achieved low colour removal efficiency, with an increase in colour intensity of 13% recorded when treating MWW while a colour removal of 51% was achieved for the distillery effluent. The application of UV photodegradation as a pre-treatment method to the AD process reduced the COD removal and biogas production efficiency. However, an integration in which UV photodegradation was employed as a post-treatment to the AD process achieved high COD removal of above 85% for both wastewater samples, and colour removal of 88% for the distillery effluent. Thus, photodegradation can be employed as a post-treatment technique to an AD system treating distillery effluent for complete removal of the biorecalcitrant and colour imparting compounds

  18. Efficiency of Magnetic Field Treatment on Pressure Sores in Bedridden Patients

    Directory of Open Access Journals (Sweden)

    Ferda Özdemir

    2011-09-01

    Full Text Available Objective: Pressure sores are an important source of complications in patients who are immobilized and bedridden. We aimed to investigate the efficiency of magnetic field treatment in pressure sores. Material and Methods: This was a randomized, double blind controlled design study. 20 patients in the study group received magneto-therapy, once a day for 30 minutes and with 150G, keeping to the BTL09 magnetotherapy device’s program. In the control group, 20 patients received the dressing only once a day. The surface areas of the pressure sores were evaluated at the onset of the treatment (1st day, and on the 7th and 15th days.Results: When within group comparisons were conducted, a significant difference was observed between the 1st and 7th day, 7th and 15th day, and 1st and 15th day measures in both the groups in terms of the scar area. The average healing time for the treatment group was 10.80±4.06 (6-20 days, and the average healing time for the control group was 18.85±9.75 (5-32 days. There was a statistically significant difference between the two groups (z=-2.114, p=0.034. Also, there was a significant difference in the scar area between the two groups in the 15th day measure (z=-3.818, p=0.000.Conclusion: The healing process of the tissue can be accelerated.with the use of magnetotherapy in the treatment of pressure sores of stage II and III,

  19. Cash flow forecasting model for nuclear power projects

    International Nuclear Information System (INIS)

    Liu Wei; Guo Jilin

    2002-01-01

    Cash flow forecasting is very important for owners and contractors of nuclear power projects to arrange the capital and to decrease the capital cost. The factors related to contractor cash flow forecasting are analyzed and a cash flow forecasting model is presented which is suitable for both contractors and owners. The model is efficiently solved using a cost-schedule data integration scheme described. A program is developed based on the model and verified with real project data. The result indicates that the model is efficient and effective

  20. Suppression of turbulent resistivity in turbulent Couette flow

    Science.gov (United States)

    Si, Jiahe; Colgate, Stirling A.; Sonnenfeld, Richard G.; Nornberg, Mark D.; Li, Hui; Colgate, Arthur S.; Westpfahl, David J.; Romero, Van D.; Martinic, Joe

    2015-07-01

    Turbulent transport in rapidly rotating shear flow very efficiently transports angular momentum, a critical feature of instabilities responsible both for the dynamics of accretion disks and the turbulent power dissipation in a centrifuge. Turbulent mixing can efficiently transport other quantities like heat and even magnetic flux by enhanced diffusion. This enhancement is particularly evident in homogeneous, isotropic turbulent flows of liquid metals. In the New Mexico dynamo experiment, the effective resistivity is measured using both differential rotation and pulsed magnetic field decay to demonstrate that at very high Reynolds number rotating shear flow can be described entirely by mean flow induction with very little contribution from correlated velocity fluctuations.

  1. Suppression of turbulent resistivity in turbulent Couette flow

    Energy Technology Data Exchange (ETDEWEB)

    Si, Jiahe, E-mail: jsi@nmt.edu; Sonnenfeld, Richard G.; Colgate, Arthur S.; Westpfahl, David J.; Romero, Van D.; Martinic, Joe [New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801 (United States); Colgate, Stirling A.; Li, Hui [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Nornberg, Mark D. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2015-07-15

    Turbulent transport in rapidly rotating shear flow very efficiently transports angular momentum, a critical feature of instabilities responsible both for the dynamics of accretion disks and the turbulent power dissipation in a centrifuge. Turbulent mixing can efficiently transport other quantities like heat and even magnetic flux by enhanced diffusion. This enhancement is particularly evident in homogeneous, isotropic turbulent flows of liquid metals. In the New Mexico dynamo experiment, the effective resistivity is measured using both differential rotation and pulsed magnetic field decay to demonstrate that at very high Reynolds number rotating shear flow can be described entirely by mean flow induction with very little contribution from correlated velocity fluctuations.

  2. Suppression of turbulent resistivity in turbulent Couette flow

    International Nuclear Information System (INIS)

    Si, Jiahe; Sonnenfeld, Richard G.; Colgate, Arthur S.; Westpfahl, David J.; Romero, Van D.; Martinic, Joe; Colgate, Stirling A.; Li, Hui; Nornberg, Mark D.

    2015-01-01

    Turbulent transport in rapidly rotating shear flow very efficiently transports angular momentum, a critical feature of instabilities responsible both for the dynamics of accretion disks and the turbulent power dissipation in a centrifuge. Turbulent mixing can efficiently transport other quantities like heat and even magnetic flux by enhanced diffusion. This enhancement is particularly evident in homogeneous, isotropic turbulent flows of liquid metals. In the New Mexico dynamo experiment, the effective resistivity is measured using both differential rotation and pulsed magnetic field decay to demonstrate that at very high Reynolds number rotating shear flow can be described entirely by mean flow induction with very little contribution from correlated velocity fluctuations

  3. Evaluation of laser therapy and alpha-lipoic acid for the treatment of burning mouth syndrome: a randomized clinical trial.

    Science.gov (United States)

    Barbosa, Natália Guimarães; Gonzaga, Amanda Katarinny Goes; de Sena Fernandes, Luzia Leiros; da Fonseca, Aldilane Gonçalves; Queiroz, Salomão Israel Monteiro Lourenço; Lemos, Telma Maria Araújo Moura; da Silveira, Éricka Janine Dantas; de Medeiros, Ana Miryam Costa

    2018-03-03

    The aim of this study was to evaluate the efficacy of low-level laser therapy (LLLT) and alpha-lipoic acid (ALA) in the treatment of burning mouth syndrome (BMS) and secondary oral burning (SOB) by unstimulated sialometry, symptom assessment, and measurement of salivary TNF-α levels. Forty-four patients were randomized into four treatment groups: BMS/laser (n = 10), BMS/ALA (n = 5), SOB/laser (n = 15), and SOB/ALA (n = 14). The control group consisted of eight healthy female subjects. Unstimulated salivary flow was measured before and after treatment, and the collected saliva was stored at - 20 °C for the analysis of TNF-α. Symptoms were evaluated before and after treatment using a pain visual analog scale. Most patients were women (81.8%) during menopause (72.2%). LLLT and ALA were efficient in increasing salivary flow only in BMS but provided symptom relief in both conditions. TNF-α levels did not differ between patients with BMS and SOB or between those patients and the control group. No differences were observed in posttreatment TNF-α levels in either condition. The results of this study suggest that LLLT and ALA are efficient therapies in reducing burning mouth symptoms, with LLLT being more efficient than ALA.

  4. Optical diagnostics of intermittent flows

    DEFF Research Database (Denmark)

    Okulov, V.L.; Naumov, I.V.; Sørensen, Jens Nørkær

    2007-01-01

    The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle...... is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for azimuthal...

  5. Thermo-fluid dynamics of two-phase flow

    CERN Document Server

    Ishii, Mamoru; Ishii, Mamoru; Ishii, M

    2006-01-01

    Provides a very systematic treatment of two phase flow problems from a theoretical perspectiveProvides an easy to follow treatment of modeling and code devlopemnt of two phase flow related phenomenaCovers new results of two phase flow research such as coverage of fuel cells technology.

  6. Dynamic water allocation policies improve the global efficiency of storage systems

    Science.gov (United States)

    Niayifar, Amin; Perona, Paolo

    2017-06-01

    Water impoundment by dams strongly affects the river natural flow regime, its attributes and the related ecosystem biodiversity. Fostering the sustainability of water uses e.g., hydropower systems thus implies searching for innovative operational policies able to generate Dynamic Environmental Flows (DEF) that mimic natural flow variability. The objective of this study is to propose a Direct Policy Search (DPS) framework based on defining dynamic flow release rules to improve the global efficiency of storage systems. The water allocation policies proposed for dammed systems are an extension of previously developed flow redistribution rules for small hydropower plants by Razurel et al. (2016).The mathematical form of the Fermi-Dirac statistical distribution applied to lake equations for the stored water in the dam is used to formulate non-proportional redistribution rules that partition the flow for energy production and environmental use. While energy production is computed from technical data, riverine ecological benefits associated with DEF are computed by integrating the Weighted Usable Area (WUA) for fishes with Richter's hydrological indicators. Then, multiobjective evolutionary algorithms (MOEAs) are applied to build ecological versus economic efficiency plot and locate its (Pareto) frontier. This study benchmarks two MOEAs (NSGA II and Borg MOEA) and compares their efficiency in terms of the quality of Pareto's frontier and computational cost. A detailed analysis of dam characteristics is performed to examine their impact on the global system efficiency and choice of the best redistribution rule. Finally, it is found that non-proportional flow releases can statistically improve the global efficiency, specifically the ecological one, of the hydropower system when compared to constant minimal flows.

  7. Efficiency analysis system of material management

    Directory of Open Access Journals (Sweden)

    Bogusław Śliwczyński

    2012-12-01

    Full Text Available Background: Significant scope of enterprise's efficiency management is improving of material management process both the strategic and operational level. The complexity of material flow processes can lead to a threat such as distraction and disintegration of analysis focusing on many different factors influenced on effective sourcing and procurement management, transport and warehousing processes, inventory management, working capital and cash flow management. Material and methods: The presented article focuses on multidimensional and multi-criteria analysis of material management efficiency that is considered as decision support system. Authors have presented results of the research regarding ineffective material management confirm insufficient analytical supporting in various decisions of procurement operations. Results and conclusions: Based on research results authors presented in the article model of efficiency analysis system of material management.

  8. A simple and efficient outflow boundary condition for the incompressible Navier–Stokes equations

    Directory of Open Access Journals (Sweden)

    Yibao Li

    2017-01-01

    Full Text Available Many researchers have proposed special treatments for outlet boundary conditions owing to lack of information at the outlet. Among them, the simplest method requires a large enough computational domain to prevent or reduce numerical errors at the boundaries. However, an efficient method generally requires special treatment to overcome the problems raised by the outlet boundary condition used. For example, mass flux is not conserved and the fluid field is not divergence-free at the outlet boundary. Overcoming these problems requires additional computational cost. In this paper, we present a simple and efficient outflow boundary condition for the incompressible Navier–Stokes equations, aiming to reduce the computational domain for simulating flow inside a long channel in the streamwise direction. The proposed outflow boundary condition is based on the transparent equation, where a weak formulation is used. The pressure boundary condition is derived by using the Navier–Stokes equations and the outlet flow boundary condition. In the numerical algorithm, a staggered marker-and-cell grid is used and temporal discretization is based on a projection method. The intermediate velocity boundary condition is consistently adopted to handle the velocity–pressure coupling. Characteristic numerical experiments are presented to demonstrate the robustness and accuracy of the proposed numerical scheme. Furthermore, the agreement of computational results from small and large domains suggests that our proposed outflow boundary condition can significantly reduce computational domain sizes.

  9. A novel flow diverter(Tubridge) for the treatment of recurrent aneurysms: A single-center experience

    International Nuclear Information System (INIS)

    Zhang, Yong Xin; Huang, Qing Hai; Fang, Yibin; Yang, Peng Fei; Xu, Yi; Hong Bo; Liu, Jian Min

    2017-01-01

    The Tubridge flow diverter (FD) is a novel device aimed at reconstructing the parent artery and occluding complex aneurysms. Retreatment of recurrent aneurysms using the FD is challenging. We report our initial experience in the repair of aneurysm recurrence with the FD. A database was reviewed prospectively, and 8 patients with 8 recurrent aneurysms (mean size, 16.7 mm) were identified. Four aneurysms had previously ruptured. The previous aneurysm treatment consisted of coiling in 1 aneurysm and single-stent-assisted coiling in 7 aneurysms. The procedural complications and clinical and angiographic outcomes were analyzed. Six aneurysms were treated by using a single Tubridge FD alone, while the remaining 2 were treated with FD + coiling. The immediate results of the 8 aneurysms were that they all showed incomplete occlusion. Neither major ischemic nor hemorrhagic complications occurred; however, 1 patient experienced a vasospasm. Follow-up angiographies were available for 7 aneurysms; the mean follow-up was 16.9 months (7–36 months). Five aneurysms were completely occluded, whereas 2 had a residual neck. Severe asymptomatic stenosis of 1 parent artery of a vertebral artery dissecting aneurysm was found. All visible branches covered by the FD were patent. All patients were clinically assessed as having attained a favorable outcome (modified Rankin Scale score ≤ 2) at discharge and follow-up. In selected patients, the Tubridge FD can provide a safe and efficient option for the retreatment of recurrent aneurysms. Nevertheless, attention should be paid to several technical points

  10. A novel flow diverter(Tubridge) for the treatment of recurrent aneurysms: A single-center experience

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yong Xin; Huang, Qing Hai; Fang, Yibin; Yang, Peng Fei; Xu, Yi; Hong Bo; Liu, Jian Min [Dept. of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai (China)

    2017-09-15

    The Tubridge flow diverter (FD) is a novel device aimed at reconstructing the parent artery and occluding complex aneurysms. Retreatment of recurrent aneurysms using the FD is challenging. We report our initial experience in the repair of aneurysm recurrence with the FD. A database was reviewed prospectively, and 8 patients with 8 recurrent aneurysms (mean size, 16.7 mm) were identified. Four aneurysms had previously ruptured. The previous aneurysm treatment consisted of coiling in 1 aneurysm and single-stent-assisted coiling in 7 aneurysms. The procedural complications and clinical and angiographic outcomes were analyzed. Six aneurysms were treated by using a single Tubridge FD alone, while the remaining 2 were treated with FD + coiling. The immediate results of the 8 aneurysms were that they all showed incomplete occlusion. Neither major ischemic nor hemorrhagic complications occurred; however, 1 patient experienced a vasospasm. Follow-up angiographies were available for 7 aneurysms; the mean follow-up was 16.9 months (7–36 months). Five aneurysms were completely occluded, whereas 2 had a residual neck. Severe asymptomatic stenosis of 1 parent artery of a vertebral artery dissecting aneurysm was found. All visible branches covered by the FD were patent. All patients were clinically assessed as having attained a favorable outcome (modified Rankin Scale score ≤ 2) at discharge and follow-up. In selected patients, the Tubridge FD can provide a safe and efficient option for the retreatment of recurrent aneurysms. Nevertheless, attention should be paid to several technical points.

  11. Three-dimensional lattice Boltzmann model for compressible flows.

    Science.gov (United States)

    Sun, Chenghai; Hsu, Andrew T

    2003-07-01

    A three-dimensional compressible lattice Boltzmann model is formulated on a cubic lattice. A very large particle-velocity set is incorporated in order to enable a greater variation in the mean velocity. Meanwhile, the support set of the equilibrium distribution has only six directions. Therefore, this model can efficiently handle flows over a wide range of Mach numbers and capture shock waves. Due to the simple form of the equilibrium distribution, the fourth-order velocity tensors are not involved in the formulation. Unlike the standard lattice Boltzmann model, no special treatment is required for the homogeneity of fourth-order velocity tensors on square lattices. The Navier-Stokes equations were recovered, using the Chapman-Enskog method from the Bhatnagar-Gross-Krook (BGK) lattice Boltzmann equation. The second-order discretization error of the fluctuation velocity in the macroscopic conservation equation was eliminated by means of a modified collision invariant. The model is suitable for both viscous and inviscid compressible flows with or without shocks. Since the present scheme deals only with the equilibrium distribution that depends only on fluid density, velocity, and internal energy, boundary conditions on curved wall are easily implemented by an extrapolation of macroscopic variables. To verify the scheme for inviscid flows, we have successfully simulated a three-dimensional shock-wave propagation in a box and a normal shock of Mach number 10 over a wedge. As an application to viscous flows, we have simulated a flat plate boundary layer flow, flow over a cylinder, and a transonic flow over a NACA0012 airfoil cascade.

  12. Boolean logic analysis for flow regime recognition of gas–liquid horizontal flow

    International Nuclear Information System (INIS)

    Ramskill, Nicholas P; Wang, Mi

    2011-01-01

    In order to develop a flowmeter for the accurate measurement of multiphase flows, it is of the utmost importance to correctly identify the flow regime present to enable the selection of the optimal method for metering. In this study, the horizontal flow of air and water in a pipeline was studied under a multitude of conditions using electrical resistance tomography but the flow regimes that are presented in this paper have been limited to plug and bubble air–water flows. This study proposes a novel method for recognition of the prevalent flow regime using only a fraction of the data, thus rendering the analysis more efficient. By considering the average conductivity of five zones along the central axis of the tomogram, key features can be identified, thus enabling the recognition of the prevalent flow regime. Boolean logic and frequency spectrum analysis has been applied for flow regime recognition. Visualization of the flow using the reconstructed images provides a qualitative comparison between different flow regimes. Application of the Boolean logic scheme enables a quantitative comparison of the flow patterns, thus reducing the subjectivity in the identification of the prevalent flow regime

  13. Chemical-looping combustion in a reverse-flow fixed bed reactor

    International Nuclear Information System (INIS)

    Han, Lu; Bollas, George M.

    2016-01-01

    A reverse-flow fixed bed reactor concept for CLC (chemical-looping combustion) is explored. The limitations of conventional fixed bed reactors, as applied to CLC, are overcome by reversing the gas flow direction periodically to enhance the mixing characteristics of the bed, thus improving oxygen carrier utilization and energy efficiency with respect to power generation. The reverse-flow reactor is simulated by a dusty-gas model and compared with an equivalent fixed bed reactor without flow reversal. Dynamic optimization is used to calculate conditions at which each reactor operates at maximum energy efficiency. Several cases studies illustrate the benefits of reverse-flow operation for the CLC with CuO and NiO oxygen carriers and methane and syngas fuels. The results show that periodic reversal of the flow during reduction improves the contact between the fuel and unconverted oxygen carrier, enabling the system to suppress unwanted catalytic reactions and axial temperature and conversion gradients. The operational scheme presented reduces the fluctuations of temperature during oxidation and increases the high-temperature heat produced by the process. CLC in a reverse-flow reactor has the potential to achieve higher energy efficiency than conventional fixed bed CLC reactors, when integrated with a downstream gas turbine of a combined cycle power plant. - Highlights: • Reverse-flow fixed bed CLC reactors for combined cycle power systems. • Dynamic optimization tunes operation of batch and transient CLC systems. • The reverse-flow CLC system provides stable turbine-ready gas stream. • Reverse-flow CLC fixed bed reactor has superior CO 2 capture and thermal efficiency.

  14. Phase Resolved Angular Velocity Control of Cross Flow Turbines

    Science.gov (United States)

    Strom, Benjamin; Brunton, Steven; Polagye, Brian

    2015-11-01

    Cross flow turbines have a number of operational advantages for the conversion of kinetic energy in marine or fluvial currents, but they are often less efficient than axial flow devices. Here a control scheme is presented in which the angular velocity of a cross flow turbine with two straight blades is prescribed as a function of azimuthal blade position, altering the time-varying effective angle of attack. Flume experiments conducted with a scale model turbine show approximately an 80% increase in turbine efficiency versus optimal constant angular velocity and constant resistive torque control schemes. Torque, drag, and lateral forces on one- and two-bladed turbines are analyzed and interpreted with bubble flow visualization to develop a simple model that describes the hydrodynamics responsible for the observed increase in mean efficiency. Challenges associated with implementing this control scheme on commercial-scale devices are discussed. If solutions are found, the performance increase presented here may impact the future development of cross flow turbines.

  15. Novel patch modelling method for efficient simulation and prediction uncertainty analysis of multi-scale groundwater flow and transport processes

    Science.gov (United States)

    Sreekanth, J.; Moore, Catherine

    2018-04-01

    The application of global sensitivity and uncertainty analysis techniques to groundwater models of deep sedimentary basins are typically challenged by large computational burdens combined with associated numerical stability issues. The highly parameterized approaches required for exploring the predictive uncertainty associated with the heterogeneous hydraulic characteristics of multiple aquifers and aquitards in these sedimentary basins exacerbate these issues. A novel Patch Modelling Methodology is proposed for improving the computational feasibility of stochastic modelling analysis of large-scale and complex groundwater models. The method incorporates a nested groundwater modelling framework that enables efficient simulation of groundwater flow and transport across multiple spatial and temporal scales. The method also allows different processes to be simulated within different model scales. Existing nested model methodologies are extended by employing 'joining predictions' for extrapolating prediction-salient information from one model scale to the next. This establishes a feedback mechanism supporting the transfer of information from child models to parent models as well as parent models to child models in a computationally efficient manner. This feedback mechanism is simple and flexible and ensures that while the salient small scale features influencing larger scale prediction are transferred back to the larger scale, this does not require the live coupling of models. This method allows the modelling of multiple groundwater flow and transport processes using separate groundwater models that are built for the appropriate spatial and temporal scales, within a stochastic framework, while also removing the computational burden associated with live model coupling. The utility of the method is demonstrated by application to an actual large scale aquifer injection scheme in Australia.

  16. Channel flow and trichloroethylene treatment in a partly iron-filled fracture: Experimental and model results

    Science.gov (United States)

    Cai, Zuansi; Merly, Corrine; Thomson, Neil R.; Wilson, Ryan D.; Lerner, David N.

    2007-08-01

    Technical developments have now made it possible to emplace granular zero-valent iron (Fe 0) in fractured media to create a Fe 0 fracture reactive barrier (Fe 0 FRB) for the treatment of contaminated groundwater. To evaluate this concept, we conducted a laboratory experiment in which trichloroethylene (TCE) contaminated water was flushed through a single uniform fracture created between two sandstone blocks. This fracture was partly filled with what was intended to be a uniform thickness of iron. Partial treatment of TCE by iron demonstrated that the concept of a Fe 0 FRB is practical, but was less than anticipated for an iron layer of uniform thickness. When the experiment was disassembled, evidence of discrete channelised flow was noted and attributed to imperfect placement of the iron. To evaluate the effect of the channel flow, an explicit Channel Model was developed that simplifies this complex flow regime into a conceptualised set of uniform and parallel channels. The mathematical representation of this conceptualisation directly accounts for (i) flow channels and immobile fluid arising from the non-uniform iron placement, (ii) mass transfer from the open fracture to iron and immobile fluid regions, and (iii) degradation in the iron regions. A favourable comparison between laboratory data and the results from the developed mathematical model suggests that the model is capable of representing TCE degradation in fractures with non-uniform iron placement. In order to apply this Channel Model concept to a Fe 0 FRB system, a simplified, or implicit, Lumped Channel Model was developed where the physical and chemical processes in the iron layer and immobile fluid regions are captured by a first-order lumped rate parameter. The performance of this Lumped Channel Model was compared to laboratory data, and benchmarked against the Channel Model. The advantages of the Lumped Channel Model are that the degradation of TCE in the system is represented by a first

  17. Effect on Non-Newtonian Rheology on Mixing in Taylor-Couette Flow

    Science.gov (United States)

    Cagney, Neil; Balabani, Stavroula

    2017-11-01

    Mixing processes within many industry applications are strongly affected by the rheology of the working fluid. This is particularly relevant for pharmaceutical, food and waste treatment industries, where the working fluids are often strongly non-Newtonian, and significant variations in rheology between batches may occur. We approach the question of how rheology affects mixing by focussing on a the classical case of Taylor-Couette flow, which exhibits a number of instabilities and flow regimes as a function of Reynolds number. We examine Taylor-Couette flow generated for a range of aqueous solutions of xantham gum or corn starch, such that the rheology varies from shear-thinning to shear-thickening. For each case, we measure the power consumption using a torque meter and the flow field using high speed, time-resolved Particle-Image Velocimetry. The mixing characteristics are quantified using a number of Lagrangian and Eulerian approaches, including the coarse grained density method and vortex strength. By comparing these metrics to the power number, we discuss how the mixing efficiency (ratio of mixing effectiveness to power input) varies with the flow index of the fluid.

  18. A MODIFIED DECOMPOSITION METHOD FOR SOLVING NONLINEAR PROBLEM OF FLOW IN CONVERGING- DIVERGING CHANNEL

    Directory of Open Access Journals (Sweden)

    MOHAMED KEZZAR

    2015-08-01

    Full Text Available In this research, an efficient technique of computation considered as a modified decomposition method was proposed and then successfully applied for solving the nonlinear problem of the two dimensional flow of an incompressible viscous fluid between nonparallel plane walls. In fact this method gives the nonlinear term Nu and the solution of the studied problem as a power series. The proposed iterative procedure gives on the one hand a computationally efficient formulation with an acceleration of convergence rate and on the other hand finds the solution without any discretization, linearization or restrictive assumptions. The comparison of our results with those of numerical treatment and other earlier works shows clearly the higher accuracy and efficiency of the used Modified Decomposition Method.

  19. Efficient simulations of fluid flow coupled with poroelastic deformations in pleated filters

    KAUST Repository

    Calo, Victor M.; Iliev, Dimitar; Iliev, Oleg; Kirsch, Ralf; Lakdawala, Zahra; Printsypar, Galina

    2015-01-01

    model describes a free fluid flow coupled with a flow in porous media in a domain that contains the filtering media. To discretize the complex computational domain we use quadrilateral boundary fitted grids which resolve porous-fluid interfaces

  20. High-energy redox-flow batteries with hybrid metal foam electrodes.

    Science.gov (United States)

    Park, Min-Sik; Lee, Nam-Jin; Lee, Seung-Wook; Kim, Ki Jae; Oh, Duk-Jin; Kim, Young-Jun

    2014-07-09

    A nonaqueous redox-flow battery employing [Co(bpy)3](+/2+) and [Fe(bpy)3](2+/3+) redox couples is proposed for use in large-scale energy-storage applications. We successfully demonstrate a redox-flow battery with a practical operating voltage of over 2.1 V and an energy efficiency of 85% through a rational cell design. By utilizing carbon-coated Ni-FeCrAl and Cu metal foam electrodes, the electrochemical reactivity and stability of the nonaqueous redox-flow battery can be considerably enhanced. Our approach intoduces a more efficient conversion of chemical energy into electrical energy and enhances long-term cell durability. The cell exhibits an outstanding cyclic performance of more than 300 cycles without any significant loss of energy efficiency. Considering the increasing demands for efficient energy storage, our achievement provides insight into a possible development pathway for nonaqueous redox-flow batteries with high energy densities.

  1. The use of novel flow diverting device Tubridge for the treatment of intracranial aneurysms: initial experience

    International Nuclear Information System (INIS)

    Yang Pengfei; Liu Jianmin; Huang Qinghai; Xu Yi; Hong Bo; Zhao Wenyuan; Li Qiang; Fang Yibin; Zhang Yuhui

    2011-01-01

    Objective: To preliminarily evaluate the feasibility, efficacy and safety of the novel flow diverting device, Tubridge, in treating intracranial aneurysms. Methods: The novel flow diverting device, Tubridge, was employed to treat intracranial aneurysms in 14 patients with a mean age of (52.4±10.2) years. A total of 14 intracranial aneurysms were detected in 14 patients, including 13 un-ruptured aneurysms and one ruptured aneurysms. The technical results and clinical data were analyzed. Results: A total of 18 flow diverters were implanted. The flow diverter was successfully conveyed and delivered in all patients, with a technical success rate of 100%. Six aneurysms were treated with the flow diverter together with the coils. Of the six aneurysms, complete obliteration of the aneurysm was obtained in 2 (Raymond grade Ⅰ), remnant of neck was seen in 1 (Raymond grade Ⅱ) and residual aneurysm sac was found in 3 (Raymond grade Ⅲ) cases. Eight aneurysms were treated with flow diverter implantation alone. After the procedure, marked decrease in contrast filling of the aneurysm sac was seen in 3 aneurysms, while the change in contrast filling pattern of the aneurysm sac as well as the obvious retention of contrast in the aneurysm sac could be detected in all cases. No procedure-related hemorrhagic or ischemic complications occurred. The mRS score at the time of discharge was 0 (n=13) or 1 (n=1). Conclusion: For the treatment of some special type intracranial aneurysms, the use of Tubridge flow diverter is clinically feasible, its effect is immediate and satisfactory with higher safety in short term. However, its long-term efficacy and safety need to be further evaluated. (authors)

  2. Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system.

    Science.gov (United States)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

    2017-08-01

    Aniline-containing wastewater can cause significant environmental problems and threaten the humans's life. However, rapid degradation of aniline with cost-efficient methods remains a challenge. In this work, a novel microbial electrolysis cell with bipolar membrane was integrated with Fenton reaction (MEC-Fenton) for efficient treatment of real wastewater containing a high concentration (4460 ± 52 mg L -1 ) of aniline. In this system, H 2 O 2 was in situ electro-synthesized from O 2 reduction on the graphite cathode and was simultaneously used as source of OH for the oxidation of aniline wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h -1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing efficient mineralization of aniline. The applicability of bipolar membrane MEC-Fenton system was successfully demonstrated with actual aniline wastewater. Moreover, energy balance showed that the system could be a promising technology for removal of biorefractory organic pollutants from wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Evaluation of constructed wetland treatment performance for winery wastewater.

    Science.gov (United States)

    Grismer, Mark E; Carr, Melanie A; Shepherd, Heather L

    2003-01-01

    Rapid expansion of wineries in rural California during the past three decades has created contamination problems related to winery wastewater treatment and disposal; however, little information is available about performance of on-site treatment systems. Here, the project objective was to determine full-scale, subsurface-flow constructed wetland retention times and treatment performance through assessment of water quality by daily sampling of total dissolved solids, pH, total suspended solids, chemical oxygen demand (COD), tannins, nitrate, ammonium, total Kjeldahl nitrogen, phosphate, sulfate, and sulfide across operating systems for winery wastewater treatment. Measurements were conducted during both the fall crush season of heavy loading and the spring following bottling and racking operations at the winery. Simple decay model coefficients for these constituents as well as COD and tannin removal efficiencies from winery wastewater in bench-scale reactors are also determined. The bench-scale study used upward-flow, inoculated attached-growth (pea-gravel substrate) reactors fed synthetic winery wastewater. Inlet and outlet tracer studies for determination of actual retention times were essential to analyses of treatment performance from an operational subsurface-flow constructed wetland that had been overloaded due to failure to install a pretreatment system for suspended solids removal. Less intensive sampling conducted at a smaller operational winery wastewater constructed wetland that had used pretreatment suspended solids removal and aeration indicated that the constructed wetlands were capable of complete organic load removal from the winery wastewater.

  4. Optimization of non-thermal plasma efficiency in the simultaneous elimination of benzene, toluene, ethyl-benzene, and xylene from polluted airstreams using response surface methodology.

    Science.gov (United States)

    Najafpoor, Ali Asghar; Jonidi Jafari, Ahmad; Hosseinzadeh, Ahmad; Khani Jazani, Reza; Bargozin, Hasan

    2018-01-01

    Treatment with a non-thermal plasma (NTP) is a new and effective technology applied recently for conversion of gases for air pollution control. This research was initiated to optimize the efficient application of the NTP process in benzene, toluene, ethyl-benzene, and xylene (BTEX) removal. The effects of four variables including temperature, initial BTEX concentration, voltage, and flow rate on the BTEX elimination efficiency were investigated using response surface methodology (RSM). The constructed model was evaluated by analysis of variance (ANOVA). The model goodness-of-fit and statistical significance was assessed using determination coefficients (R 2 and R 2 adj ) and the F-test. The results revealed that the R 2 proportion was greater than 0.96 for BTEX removal efficiency. The statistical analysis demonstrated that the BTEX removal efficiency was significantly correlated with the temperature, BTEX concentration, voltage, and flow rate. Voltage was the most influential variable affecting the dependent variable as it exerted a significant effect (p < 0.0001) on the response variable. According to the achieved results, NTP can be applied as a progressive, cost-effective, and practical process for treatment of airstreams polluted with BTEX in conditions of low residence time and high concentrations of pollutants.

  5. Numerical and Experimental Study of Pump Sump Flows

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chuang

    2014-01-01

    Full Text Available The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

  6. Interface-Resolving Simulation of Collision Efficiency of Cloud Droplets

    Science.gov (United States)

    Wang, Lian-Ping; Peng, Cheng; Rosa, Bodgan; Onishi, Ryo

    2017-11-01

    Small-scale air turbulence could enhance the geometric collision rate of cloud droplets while large-scale air turbulence could augment the diffusional growth of cloud droplets. Air turbulence could also enhance the collision efficiency of cloud droplets. Accurate simulation of collision efficiency, however, requires capture of the multi-scale droplet-turbulence and droplet-droplet interactions, which has only been partially achieved in the recent past using the hybrid direct numerical simulation (HDNS) approach. % where Stokes disturbance flow is assumed. The HDNS approach has two major drawbacks: (1) the short-range droplet-droplet interaction is not treated rigorously; (2) the finite-Reynolds number correction to the collision efficiency is not included. In this talk, using two independent numerical methods, we will develop an interface-resolved simulation approach in which the disturbance flows are directly resolved numerically, combined with a rigorous lubrication correction model for near-field droplet-droplet interaction. This multi-scale approach is first used to study the effect of finite flow Reynolds numbers on the droplet collision efficiency in still air. Our simulation results show a significant finite-Re effect on collision efficiency when the droplets are of similar sizes. Preliminary results on integrating this approach in a turbulent flow laden with droplets will also be presented. This work is partially supported by the National Science Foundation.

  7. Comparative study of turbulence model performance for axisymmetric sudden expansion flow

    International Nuclear Information System (INIS)

    Bae, Youngmin; Kim, Young In; Kim, Keung Koo; Yoon, Juhyeon

    2013-01-01

    In this study, the performance of turbulence models in predicting the turbulent flow in an axisymmetric sudden expansion with an expansion ratio of 4 is assessed for a Reynolds number of 5.6 Χ 10 4 . The comparisons show that the standard k-ε and RSM models provide the best agreement with the experimental data, whereas the standard k-ω model gives poor predictions. Owing to its computational efficiency, the Reynolds Averaged Navier-Stokes (RANS) approach has been widely used for the prediction of turbulent flows and associated pressure losses in a variety of internal flow systems such as a diffuser, orifice, converging nozzle, and pipes with sudden expansion. However, the lack of a general turbulence model often leads to limited applications of a RANS approach, i. e., the accuracy and validity of solutions obtained from RANS equations vary with the turbulence model, flow regime, near-wall treatment, and configuration of the problem. In light of the foregoing, a large amount of turbulence research has been conducted to assess the performance of existing turbulence models for different flow fields. In this paper, the turbulent flow in an axisymmetric sudden expansion is numerically investigated for a Reynolds number of 5.6 Χ 10 4 , with the aim of examining the performance of several turbulence models

  8. Debris filtering efficiency and its effect on long term cooling capability

    International Nuclear Information System (INIS)

    Jung, Min-Su; Kim, Kyu-Tae

    2013-01-01

    Highlights: • Debris filtering efficiencies for two debris filter designs used in PWRs are provided. • Various debris used in the tests are selected to simulate actual debris found in PWRs. • Debris filter efficiency is explained by flow-hole size and grid strap height. • The effect of debris filters on flow blockage during LTC after a LOCA is described. -- Abstract: A cutting-edge debris-filter designs, Protective Grid (P-grid) and Guardian Grid (G-grid) attached to the upper part of bottom nozzle, have been employed for the PWRs in Korea since 2000s to protect the fuel from debris-induced fuel failures. The debris-filter efficiency of the P-grid and G-grid designs is improved by relatively smaller flow areas formed by the grid straps and dimples. The debris-filter efficiency of the P-grid design is further improved by the relatively smaller flow-hole bottom nozzle. The debris-filter flow tests employing eighteen debris types showed that the debris-filter efficiencies of the P-grid and G-grid designs are 91 and 96%, respectively, while that of the SYS80 fuel design having only the standard flow-hole bottom nozzle is 26%. The slightly better debris-filter efficiency of the G-grid design against the P-grid design may be explained by relatively smaller flow areas at the G-grid dimple region as well as by the relatively longer solid end plug and the higher G-grid strap. The P-grid design may capture circular shapes of debris larger than 3.44 mm in diameter at the flow holes formed by the P-grid dimples, whereas the G-grid design may capture circular shapes of debris larger than 2.54 mm in diameter at the flow holes formed by the G-grid dimples. The aforementioned difference in the debris-filter efficiency between the P-grid and G-grid designs may be predicted by the solid modeling technique generating three-dimensional flow paths. Using the minimum flow-hole areas generated by the P-grid and G-grid designs, on the other hand, the effect of debris injected from

  9. An implicit multigrid algorithm for computing hypersonic, chemically reacting viscous flows

    International Nuclear Information System (INIS)

    Edwards, J.R.

    1996-01-01

    An implicit algorithm for computing viscous flows in chemical nonequilibrium is presented. Emphasis is placed on the numerical efficiency of the time integration scheme, both in terms of periteration workload and overall convergence rate. In this context, several techniques are introduced, including a stable, O(m 2 ) approximate factorization of the chemical source Jacobian and implementations of V-cycle and filtered multigrid acceleration methods. A five species-seventeen reaction air model is used to calculate hypersonic viscous flow over a cylinder at conditions corresponding to flight at 5 km/s, 60 km altitude and at 11.36 km/s, 76.42 km altitude. Inviscid calculations using an eleven-species reaction mechanism including ionization are presented for a case involving 11.37 km/s flow at an altitude of 84.6 km. Comparisons among various options for the implicit treatment of the chemical source terms and among different multilevel approaches for convergence acceleration are presented for all simulations

  10. Combination of microfluidic high-throughput production and parameter screening for efficient shaping of gold nanocubes using Dean-flow mixing.

    Science.gov (United States)

    Thiele, Matthias; Knauer, Andrea; Malsch, Daniéll; Csáki, Andrea; Henkel, Thomas; Köhler, J Michael; Fritzsche, Wolfgang

    2017-04-11

    Metal nanoparticles and their special optical properties, the so-called localized surface plasmon resonance (LSPR), facilitate many applications in various fields. Due to the strong dependency of the LSPR on particle geometry, their synthesis is a challenging and time-consuming procedure especially for non-spherical shapes. In contrast, micromixers offer new experimental approaches and therefore enable the simplification of several processes. By using a zigzag micromixer (Dean-Flow-Mixer, DFM) that induces Dean-flow secondary flow patterns, we theoretically and experimentally show the mixing efficiency. Thus, we highlight the advantages of using it in the multistep synthesis of Au nanoparticles. Based on a narrow size distribution of Au nanocubes and an increased yield in combination with higher reproducibility, we depict the need for and advantage of the DFM to control the incubation times during the growth process. We further show that, by using the DFM, easy and very fast Au nanocube edge length tuning (53 nm, 58 nm, 70 nm and 75 nm) is possible by simultaneously reducing the consumption of the materials by up to 95%. We finally demonstrate the versatile abilities by using the DFM for parameter screening on examples of different halides and accessible bromide in the growth solutions. Therefore, we highlight the optimal concentration for the different growth regimes and the influences on the Au nanoparticle morphology (spheres, cubes and rods) and their defined shaping.

  11. Numerical prediction of Pelton turbine efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Jott, D; Mez' nar, P; Lipej, A, E-mail: dragicajost@turboinstitut.s [Turbointtitut, Rovtnikova 7, Ljubljana, 1210 (Slovenia)

    2010-08-15

    This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-{omega} SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.

  12. Numerical prediction of Pelton turbine efficiency

    Science.gov (United States)

    Jošt, D.; Mežnar, P.; Lipej, A.

    2010-08-01

    This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-ω SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.

  13. Numerical prediction of Pelton turbine efficiency

    International Nuclear Information System (INIS)

    Jott, D; Mez'nar, P; Lipej, A

    2010-01-01

    This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-ω SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.

  14. Technical efficiency of rural primary health care system for diabetes treatment in Iran: a stochastic frontier analysis.

    Science.gov (United States)

    Qorbani, Mostafa; Farzadfar, Farshad; Majdzadeh, Reza; Mohammad, Kazem; Motevalian, Abbas

    2017-01-01

    Our aim was to explore the technical efficiency (TE) of the Iranian rural primary healthcare (PHC) system for diabetes treatment coverage rate using the stochastic frontier analysis (SFA) as well as to examine the strength and significance of the effect of human resources density on diabetes treatment. In the SFA model diabetes treatment coverage rate, as a output, is a function of health system inputs (Behvarz worker density, physician density, and rural health center density) and non-health system inputs (urbanization rate, median age of population, and wealth index) as a set of covariates. Data about the rate of self-reported diabetes treatment coverage was obtained from the Non-Communicable Disease Surveillance Survey, data about health system inputs were collected from the health census database and data about non-health system inputs were collected from the census data and household survey. In 2008, rate of diabetes treatment coverage was 67% (95% CI: 63%-71%) nationally, and at the provincial level it varied from 44% to 81%. The TE score at the national level was 87.84%, with considerable variation across provinces (from 59.65% to 98.28%).Among health system and non-health system inputs, only the Behvarz density (per 1000 population)was significantly associated with diabetes treatment coverage (β (95%CI): 0.50 (0.29-0.70), p  < 0.001). Our findings show that although the rural PHC system can considered efficient in diabetes treatment at the national level, a wide variation exists in TE at the provincial level. Because the only variable that is predictor of TE is the Behvarz density, the PHC system may extend the diabetes treatment coverage by using this group of health care workers.

  15. Vegetated treatment area (VTAs efficiencies for E. coli and nutrient removal on small-scale swine operations

    Directory of Open Access Journals (Sweden)

    R. Daren Harmel

    2018-06-01

    Full Text Available As small-scale animal feeding operations work to manage their byproducts and avoid regulation, they need practical, cost-effective methods to reduce environmental impact. One such option is using vegetative treatment areas (VTAs with perennial grasses to treat runoff; however, research is limited on VTA effectiveness as a waste management alternative for smaller operations. This study evaluated the efficiencies of VTAs in reducing bacteria and nutrient runoff from small-scale swine operations in three counties in Central Texas. Based on 4 yr of runoff data, the Bell and Brazos VTAs significantly reduced loads and concentrations of E. coli and nutrients (except NO3-N and had treatment efficiencies of 73–94%. Most notably, the Bell VTA reduced loads of E. coli, NH4-N, PO4-P, total N, and total P similar to that of the background (control. In spite of significant reductions, runoff from the Brazos VTA had higher concentrations and loads than the control site, especially following installation of concrete pens and increased pen washing, which produced standing water and increased E. coli and nutrient influx. The Robertson VTA produced fewer significant reductions and had lower treatment efficiencies (29–69%; however, E. coli and nutrient concentrations and loads leaving this VTA were much lower than observed at the Bell and Brazos County sites due to alternative solids management and enclosed pens. Based on these results and previous research, VTAs can be practical, effective waste management alternatives for reducing nutrient and bacteria losses from small-scale animal operations, but only if properly designed and managed. Keywords: Bacteria, Nutrients, Swine manure, Waste management, Water quality

  16. Measuring mixing efficiency in experiments of strongly stratified turbulence

    Science.gov (United States)

    Augier, P.; Campagne, A.; Valran, T.; Calpe Linares, M.; Mohanan, A. V.; Micard, D.; Viboud, S.; Segalini, A.; Mordant, N.; Sommeria, J.; Lindborg, E.

    2017-12-01

    Oceanic and atmospheric models need better parameterization of the mixing efficiency. Therefore, we need to measure this quantity for flows representative of geophysical flows, both in terms of types of flows (with vortices and/or waves) and of dynamical regimes. In order to reach sufficiently large Reynolds number for strongly stratified flows, experiments for which salt is used to produce the stratification have to be carried out in a large rotating platform of at least 10-meter diameter.We present new experiments done in summer 2017 to study experimentally strongly stratified turbulence and mixing efficiency in the Coriolis platform. The flow is forced by a slow periodic movement of an array of large vertical or horizontal cylinders. The velocity field is measured by 3D-2C scanned horizontal particles image velocimetry (PIV) and 2D vertical PIV. Six density-temperature probes are used to measure vertical and horizontal profiles and signals at fixed positions.We will show how we rely heavily on open-science methods for this study. Our new results on the mixing efficiency will be presented and discussed in terms of mixing parameterization.

  17. Method of improving the decontaminating efficiency of ruthenium in evaporating treatment of nitric acid

    International Nuclear Information System (INIS)

    Kubota, Kanya; Yamana, Hajime; Takeda, Seiichiro.

    1984-01-01

    Purpose: To significantly improve the ruthenium removing efficiency in a nitric acid solution in an acid recovery system for the recovery of nitric acid from nitric acid liquid wastes through evaporating condensation. Method: Upon evaporating treatment of nitric acid solution containing ruthenium by supplying and heating the solution to a nitric acid evaporating device, hydrazine is previously added to the nitric acid solution. Hydrazine and intermediate reaction product of hydrazine such as azide causes a reduction reaction with intermediate reaction product of ruthenium tetraoxide to suppress the oxidation of ruthenium and thereby improve the decontaminating efficiency of ruthenium. The amount of hydrazine to be added is preferably between 20 - 500 mg/l and most suitably between 200 - 2000 mg/l per one liter of the liquid in the evaporating device. (Seki, T.)

  18. Design of combination biofilter and subsurface constructed wetland-multilayer filtration with vertical flow type using Vetiveria zizanioides (akar wangi)

    Science.gov (United States)

    Astuti, A. D.; Lindu, M.; Yanidar, R.; Faruq, M.

    2018-01-01

    As environmental regulation has become stricter in recent years, there is an increasing concern about the issue of wastewater treatment in urban areas. Senior High School as center of student activity has a potential source to generated domestic wastewater from toilet, bathroom and canteen. Canteen wastewater contains high-organic content that to be treated before discharged. Based on previous research the subsurface constructed wetland-multilayer filtration with vertical flow is an attractive alternative to provide efficient treatment of canteen wastewater. The effluent concentration complied with regulation according to [9]. Due to limited land, addition of preliminary treatment such as the presence of biofilter was found to improve the performance. The aim of this study was to design combination biofilter and subsurface constructed wetland-multilayer filtration with vertical flow type using vetiveria zizanioides (akar wangi) treating canteen wastewater. Vetiveria zizanioides (akar wangi) is used because from previous research, subsurface constructed wetland-multilayer filtration (SCW-MLF) with vertical flow type using vetiveria zizanioides (akar wangi) can be an alternative canteen wastewater treatment that is uncomplicated in technology, low cost in operational and have a beautiful landscape view, besides no odors or insects were presented during the operation.

  19. Potential of development of the mechanical-biological waste treatment; Entwicklungspotenzial der Mechanisch-Biologischen Abfallbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Grundmann, Thomas; Balhar, Michael [ASA e.V., Ennigerloh (Germany); Abfallwirtschaftsgesellschaft des Kreises Warendorf mbH, Ennigerloh (Germany)

    2013-03-01

    The Consortium Material-Specific Waste Treatment eV (Ennigerloh, Federal Republic of Germany) is an association of plant operators having the opinion that an economic and ecologic waste treatment only can be guaranteed by material-specific processes permanently. Due to the specific treatment processes in plants with mechanical-biological waste treatment (MBA) material flows are resulting being available for the recycling or exploitation. Under this aspect, the authors of the contribution under consideration report on the development potential of the mechanical-biological waste treatment. The state of the art of the technology of mechanical-biological waste treatment in Germany as well as the contribution of this technology to the resource protection and climate protection are described. Further aspects of this contribution are the increase of the energy efficiency and reduction of emissions; further development of the efficient sorting technology; development of integrated total conceptions - MBA-sites as centres for the production of renewable energies.

  20. Aeroacoustics of T-junction merging flow.

    Science.gov (United States)

    Lam, G C Y; Leung, R C K; Tang, S K

    2013-02-01

    This paper reports a numerical study of the aeroacoustics of merging flow at T-junction. The primary focus is to elucidate the acoustic generation by the flow unsteadiness. The study is conducted by performing direct aeroacoustic simulation approach, which solves the unsteady compressible Navier-Stokes equations and the perfect gas equation of state simultaneously using the conservation element and solution element method. For practical flows, the Reynolds number based on duct width is usually quite high (>10(5)). In order to properly account for the effects of flow turbulence, a large eddy simulation methodology together with a wall modeling derived from the classical logarithm wall law is adopted. The numerical simulations are performed in two dimensions and the acoustic generation physics at different ratios of side-branch to main duct flow velocities VR (=0.5,0.67,1.0,2.0) are studied. Both the levels of unsteady interactions of merging flow structures and the efficiency of acoustic generation are observed to increase with VR. Based on Curle's analogy, the major acoustic source is found to be the fluctuating wall pressure induced by the flow unsteadiness occurred in the downstream branch. A scaling between the wall fluctuating force and the efficiency of the acoustic generation is also derived.