WorldWideScience

Sample records for grain aeration systems

  1. Embedded system in Arduino platform with Fuzzy control to support the grain aeration decision

    Directory of Open Access Journals (Sweden)

    Albino Szesz Junior

    Full Text Available ABSTRACT: Aeration is currently the most commonly used technique to improve the drying and storage of grain, depending on temperature and water content of the grain, as of the temperature and relative humidity of the outside air. In order to monitor temperature and humidity of the grain mass, it is possible to have a network of sensors in the cells of both internal and external storage. Use of artificial intelligence through Fuzzy theory, has been used since the 60s and enables their application on various forms. Thus, it is observed that the aeration of grain in function of representing a system of controlled environment can be studied in relation to the application of this theory. Therefore, the aim of this paper is to present an embedded Fuzzy control system based on the mathematical model of CRUZ et al. (2002 and applied to the Arduino platform, for decision support in aeration of grain. For this, an embedded Arduino system was developed, which received the environmental values of temperature and humidity to then be processed in a Fuzzy controller and return the output as a recommendation to control the aeration process rationally. Comparing the results obtained from the graph presented by LASSERAN (1981 it was observed that the system is effective.

  2. Experimental silo-dryer-aerator for the storage of soybean grains

    Directory of Open Access Journals (Sweden)

    Paulo C. Coradi

    Full Text Available ABSTRACT This study aimed to verify the capacity of silo-dryer-aerator prototype equipment operating as a silo-storage-aerator for soybean quality analysis. Soybeans with water content of 17% (wet basis – w.b. were dried and stored in a silo-dryer-aerator system that was designed using a drying chamber, four independent storage cells, and a static capacity of 164 kg. Another batch of grains was stored in a silo-storage-aerator with a capacity of 1,200 kg. The experiment was set up in a completely randomized factorial 5 × 4 experimental design including five grain batches stored after being dried at 30, 40, and 50 °C (mixed grains were dried at three temperatures in the silo-dryer-aerator cells and one mixed grain batch stored in the silo-storage-aerator system under ambient air conditions for four storage times (zero, one, two, and three months. There was no difference between the grains stored in the silo-dryer-aerator and silo-storage-aerator at the end of the three-month storage in terms of the physico-chemical quality. The storage time associated with drying at 50 °C caused a reduction in the physical-chemical quality of the grains. The silo-dryer-aerator system was presented as a possible alternative to store soybean (Glycine max L. grains.

  3. New jet-aeration system using 'Supercavitation'.

    Science.gov (United States)

    Schmid, Andreas

    2010-03-01

    A newly developed fine bubble aeration system, by which air is transferred under supercavitation conditions, shows a clearly better performance than traditional, well-known aerators that rely on the jet-pump principle and its performance can be compared to oxygen transfer rates achieved in membrane and foil plate aerators. A prototype supercavitation aerator installed at a sewage treatment plant revealed an air input rate, which was about one third lower than that of the jet-pump system, which it replaced. In spite of this low air input rate, the daily demand of pure oxygen for the additionally installed membrane aeration system went down by approximately 49%, from the original level of about 1,200 m(3)/day to about 600 m(3)/day-and this over a test period of more than 7 months. The observed high oxygen transfer rates cannot be explained by traditional mass transfer mechanisms. It is assumed that a large amount of water being transferred into the gas phase by supercavitation contacting directly oxygen also in the gas phase and thereby overcoming mass transfer hindrances which might be favoured by hydroxyl radicals. With this new aerator, during the first 3 months of test phase, already more than 10,000 Euros had been saved because of the reduced pure oxygen demand.

  4. Acid mine water aeration and treatment system

    Science.gov (United States)

    Ackman, Terry E.; Place, John M.

    1987-01-01

    An in-line system is provided for treating acid mine drainage which basically comprises the combination of a jet pump (or pumps) and a static mixer. The jet pump entrains air into the acid waste water using a Venturi effect so as to provide aeration of the waste water while further aeration is provided by the helical vanes of the static mixer. A neutralizing agent is injected into the suction chamber of the jet pump and the static mixer is formed by plural sections offset by 90 degrees.

  5. Method of aeration disinfecting and drying grain in bulk and pretreating seeds and a transverse blow silo grain dryer therefor

    Science.gov (United States)

    Danchenko, Vitaliy G [Dnipropetrovsk, UA; Noyes, Ronald T [Stillwater, OK; Potapovych, Larysa P [Dnipropetrovsk, UA

    2012-02-28

    Aeration drying and disinfecting grain crops in bulk and pretreating seeds includes passing through a bulk of grain crops and seeds disinfecting and drying agents including an ozone and air mixture and surrounding air, subdividing the disinfecting and drying agents into a plurality of streams spaced from one another in a vertical direction, and passing the streams at different heights through levels located at corresponding heights of the bulk of grain crops and seeds transversely in a substantially horizontal direction.

  6. Radon in water aeration system operational performance

    International Nuclear Information System (INIS)

    Lamarre, B.L.

    1990-01-01

    North East Environmental Products, Inc. is a manufacturer of residential scale aeration systems for removal of radon and volatile organic chemicals from private water supplies. This paper is a review of the operational history of residential scale point of entry (POE) radon aeration systems. Emphasis is placed on the difficulties and solutions encountered in actual installations caused by both mechanical difficulties and water quality parameters. A summary of radon reduction efficiency is presented for wells with radon concentrations from 21,000 to 2,600,000 pCi/L. A discussion of customer concerns and attitudes is presented along with other areas for further technical improvement. Training techniques for dealers and installers are also discussed. An update of the current status of the radon in water industry includes current sales volumes as compared to the potential market and an update on the radon in water MCL standard setting process from an industry perspective

  7. PIV Study of Aeration Efficient of Stepped Spillway System

    Science.gov (United States)

    Abas, M. A.; Jamil, R.; Rozainy, M. R.; Zainol, M. A.; Adlan, M. N.; Keong, C. W.

    2017-06-01

    This paper investigates the three-dimensional (3D) simulation of Cascade aerator system using Lattice Boltzmann simulation and laboratory experiment was carried out to investigate the flow, aeration and cavitation in the spillway. Different configurations of stepped spillway are designed in this project in order to investigate the relationship between the configurations of stepped spillway and cavitation in the flow. The aeration in the stepped spillway will also be investigated. The experimental result will be compared with the simulated result at the end of this project. The figure of flow pattern at the 3rd step in simulation and experiment for Set 1 and Set 2 are look similar between LBM simulation and the experiment findings. This will provide a better understanding of the cavitation, aeration and flow in different configurations of the stepped spillway. In addition the occurrence of negative pressure region in the stepped spillway, increases the possibility of cavitation to occur. The cavitation will damage the structure of the stepped spillway. Furthermore, it also founds that increasing in barrier thickness of the stepped spillway will improve the aeration efficiency and reduce the cavitation in stepped spillway.

  8. Research on the Efficiency of Drinking Water Aeration Systems

    Directory of Open Access Journals (Sweden)

    Andrius Styra

    2011-02-01

    Full Text Available A number of modern iron removal systems used in individual houses do not work properly. One of the reasons could be inappropriate work of the aeration system. Therefore, the aim of this research is to analyze three types of jet pumps used in individual houses in Lithuania and compare the amount of sucked oxygen with demand for dissolved oxygen the amount of which is calculated. When summarizing the results of research, it was discovered that the ejector worked unstable when flow was low, and therefore stable operation require additional pressure.Article in Lithuanian

  9. Composting of tobacco plant waste by manual turning and forced aeration system

    OpenAIRE

    Nonglak Saithep

    2009-01-01

    The efficiency of tobacco plant waste composting, by the manual turning and the forced aeration system, was compared. Tobacco plant waste, cow manure, urea fertiliser, and a compost inoculum mixture at a 100:10:0.2:0.01 ratio respectively, with 60% (w/v) moisture content, were set up in piling forms. The piles of the manual turning system were provided with turning aeration by hand at intervals of 7 days during the composting process. For the forced aeration system, each pile was aerated by a...

  10. Composting of tobacco plant waste by manual turning and forced aeration system

    Directory of Open Access Journals (Sweden)

    Nonglak Saithep

    2009-05-01

    Full Text Available The efficiency of tobacco plant waste composting, by the manual turning and the forced aeration system, was compared. Tobacco plant waste, cow manure, urea fertiliser, and a compost inoculum mixture at a 100:10:0.2:0.01 ratio respectively, with 60% (w/v moisture content, were set up in piling forms. The piles of the manual turning system were provided with turning aeration by hand at intervals of 7 days during the composting process. For the forced aeration system, each pile was aerated by a 3-HP air pump with a flow rate of 19 litres min-1 for 15 minutes every morning and evening. The completely randomised design of turned and force-aerated piles was performed in triplicate. The composting activity of both systems during the composting period was measured by several parameters: temperature, pH, moisture content, C/N ratio, growth of microorganisms, cellulase activity, and nicotine degradation in the set-up piles. Both systems had similar temperature, pH, and moisture content conditions in the piles during the composting process. However, the forced aeration system was more advantageous for the growth of mesophilic and thermophilic microorganisms, for cellulase activity from cellulase-producing microorganisms, and for nicotine degradation, when compared to the manual turning system. In conclusion, the forced aeration system was more efficient than the manual turning system in composting and is a viable alternative method for the composting process.

  11. Development of a model for activated sludge aeration systems: linking air supply, distribution, and demand.

    Science.gov (United States)

    Schraa, Oliver; Rieger, Leiv; Alex, Jens

    2017-02-01

    During the design of a water resource recovery facility, it is becoming industry practice to use simulation software to assist with process design. Aeration is one of the key components of the activated sludge process, and is one of the most important aspects of modelling wastewater treatment systems. However, aeration systems are typically not modelled in detail in most wastewater treatment process modelling studies. A comprehensive dynamic aeration system model has been developed that captures both air supply and demand. The model includes sub-models for blowers, pipes, fittings, and valves. An extended diffuser model predicts both oxygen transfer efficiency within an aeration basin and pressure drop across the diffusers. The aeration system model allows engineers to analyse aeration systems as a whole to determine biological air requirements, blower performance, air distribution, control valve impacts, controller design and tuning, and energy costs. This enables engineers to trouble-shoot the entire aeration system including process, equipment and controls. It also allows much more realistic design of these highly complex systems.

  12. EFFECT OF HYDRAULIC AND GEOMETRICAL PROPERTIES ON STEPPED CASCADE AERATION SYSTEM

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    VEDHACHALAM RATHINAKUMAR

    2017-03-01

    Full Text Available Stepped cascade aeration system is commonly used to aerate the water and wastewater to increase the dissolved oxygen during pre and post treatment process. In the present research, experiments were conducted to evaluate the performance of a rectangular Cascade Aeration System with varying flow rates, risers and tread by maintaining constant width of the channel using water collected from reverse osmosis plant. The experiments were carried out with four different risers such as 0.15 m, 0.18 m, 0.225 m and 0.30 m. Each rise was investigated with five different tread of 0.60 m, 0.55 m, 0.50 m, 0.45 m and 0.40 m. Comprehensive experimental investigations were carried out for different hydraulic loading rates of 0.005 to 0.035 m3/s/m2. Results obtained from the experiments reveals that increasing dimensionless discharges promotes more aeration, attains a maximum up to dimensionless discharge= 2.22 and beyond this there was a significant decrease in aeration. In addition, the increased in number of steps significantly enhances air entertainment and surface fall rate in the Stepped Cascade Aeration System. A regression equation was derived by keeping aeration efficiency as response with dimensionless discharge and oxygen saturation concentration as influencing parameters. The dimension less discharge is a function of critical depth of the rectangular channel and step height, whereas oxygen saturation concentration represents the ratio of oxygen deficit and oxygen saturation concentration. Based on the experimental results, the optimum design and/or results such as number of steps (12 numbers and hydraulic loading rate (0.025 m3/s/m2 with fixed tread width of 0.6 m were identified to achieve maximum aeration rate (0.5-0.60 in Aeration system.

  13. A New Control and Design of PEM Fuel Cell System Powered Diffused Air Aeration System

    Directory of Open Access Journals (Sweden)

    Hassen T. Dorrah

    2012-06-01

    Full Text Available The goal of aquaculture ponds is to maximize production and profits while holding labor and management efforts to the minimum. Poor water quality in most ponds causes risk of fish kills, disease outbreaks which lead to minimization of pond production. Dissolved Oxygen (DO is considered to be among the most important water quality parameters in fish culture. Fish ponds in aquaculture farms are usually located in remote areas where grid lines are at far distance. Aeration of ponds is required to prevent mortality and to intensify production, especially when feeding is practical, and in warm regions. To increase pond production it is necessary to control dissolved oxygen. Aeration offers the most immediate and practical solution to water quality problems encountered at higher stocking and feeding rates. Many units of aeration system are electrical units so using a continuous, high reliability, affordable, and environmentally friendly power sources is necessary. Fuel cells have become one of the major areas of research in the academia and the industry. Aeration of water by using PEM fuel cell power is not only a new application of the renewable energy, but also, it provides an affordable method to promote biodiversity in stagnant ponds and lakes. This paper presents a new design and control of PEM fuel cell powered a diffused air aeration system for a shrimp farm in Mersa Matruh in Egypt. Also Artificial intelligence (AI control techniques are used to control the fuel cell output power by controlling its input gases flow rate. Moreover the mathematical modeling and simulation of PEM fuel cell is introduced. A comparative study is applied between the performance of fuzzy logic controller (FLC and neural network controller (NNC. The results show the effectiveness of NNC over FLC.

  14. Nitrogen removal in the bioreactor landfill system with intermittent aeration at the top of landfilled waste

    International Nuclear Information System (INIS)

    He Ruo; Shen Dongsheng

    2006-01-01

    High ammonia concentration of recycled landfill leachate makes it very difficult to treat. In this work, a vertical aerobic/anoxic/anaerobic lab-scale bioreactor landfill system, which was constructed by intermittent aeration at the top of landfilled waste, as a bioreactor for in situ nitrogen removal was investigated during waste stabilization. Intermittent aeration at the top of landfilled waste might stimulate the growth of nitrifying bacteria and denitrifying bacteria in the top and middle layers of waste. The nitrifying bacteria population for the landfill bioreactor with intermittent aeration system reached between10 6 and 10 8 cells/dry g waste, although it decreased 2 orders of magnitude on day 30, due to the inhibitory effect of the acid environment and high organic matter in the landfilled waste. The denitrifying bacteria population increased by between 4 and 13 orders of magnitude compared with conventional anaerobic landfilled waste layers. Leachate NO 3 - -N concentration was very low in both two experimental landfill reactors. After 105 days operation, leachate NH 4 + -N and TN concentrations for the landfill reactor with intermittent aeration system dropped to 186 and 289 mg/l, respectively, while they were still kept above 1000 mg/l for the landfill reactor without intermittent aerobic system. In addition, there is an increase in the rate of waste stabilization as well as an increase of 12% in the total waste settlement for the landfill reactor with intermittent aeration system

  15. Autonomous grain combine control system

    Science.gov (United States)

    Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

    2013-06-25

    A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

  16. A full-scale biological aerated filtration system application in the ...

    African Journals Online (AJOL)

    The treated wastewater characteristics are in compliance with the Egyptian law which regulates the discharge of industrial wastewater to the sewerage system. The results from each treatment process proved to be efficient for the treatment of such wastewater. Keywords: Paints wastewater treatment, Biological aerated filter ...

  17. Study of the liquid-film-forming apparatus as an alternative aeration system: design criteria and operating condition.

    Science.gov (United States)

    Hongprasith, Narapong; Imai, Tsuyoshi; Painmanakul, Pisut

    2017-06-01

    Aeration is an important factor in aquaculture systems because it is a vital condition for all organisms that live in water and respire aerobically. Generally, mechanical surface aerators are widely used in Thailand due to their advantage for increasing dissolved oxygen (DO) and for their horizontal mixing of aquaculture ponds with large surface areas. However, these systems still have some drawbacks, primarily the low oxygen transfer efficiency (OTE) and energy. Regarding this issue, alternative aeration systems should be studied and applied. Therefore, this research aims to study the aeration mechanism obtained by the diffused-air aeration combined with a liquid-film-forming apparatus (LFFA). The effect of gas flow rates, types, and patterns of aerator installation were investigated in an aquaculture pond of 10 m × 10 m × 1.5 m. The analytical parameters were volumetric mass transfer coefficient (k L a), OTE, and aeration efficiency (AE). From the results, the '4-D' with partitions was proposed as the suitable pattern for the LFFA installation. The advantage could be obtained from high energy performance with 1.2 kg/kW h of AE. Then, the operation conditions can be applied as a design guideline for this alternative aeration system in the aquaculture ponds.

  18. CHOICE THEORY OF CREEP DEFORMATION FOR EVALUATION OF LONG FINE-GRAINED AUTOCLAVED AERATED CONCRETE IN VIEW OF FACTORS CARBONIZATION

    Directory of Open Access Journals (Sweden)

    D. K-S. Bataev

    2015-01-01

    Full Text Available Experimental data on the effect of the age of autoclaved aerated concrete with and without carbonation factor to change its physical and mechanical characteristics, as well as by the amount of creep deformation and degree of reversibility. It was found that the solution of applied problems creep theory for structures of autoclaved aerated concrete, in accordance with their carbonation from the effects of atmospheric carbon dioxide, it is necessary to use the theory of elastic-creeping body on the basis of function creep measures in the form proposed by prof. S.V. Alexandrovsky. 

  19. Solar powered dugout aeration

    International Nuclear Information System (INIS)

    Murrell, S.

    2001-10-01

    Pasture dugouts are a significant source of water for livestock on the Canadian Prairies and as such, must maintain the best water quality possible. Aeration improves the water quality and is part of a good management plan to reduce overall water treatment costs. Although dugouts can be aerated naturally through wind and wave action and photosynthesis, this generally aerates only the top portion of the dugout. Artificial aeration by air injection into the lowest point of the dugout ensures that the water is oxygenated throughout the entire dugout. Solar aeration can be used in remote areas where grid power is not practical. With solar powered aeration systems, solar panels are used to generate the electrical power needed to run the compressor while storing excess energy in batteries. A solar aeration system includes solar panels, deep cycle batteries to store excess power, a control board with a regulator, a compressor, a weighed feeder hose, and an air diffuser. This publication presented the design of a solar aeration system and its cost. 1 tab., 3 figs

  20. Automatic system for quantification and visualization of lung aeration on chest computed tomography images: the Lung Image System Analysis - LISA

    Energy Technology Data Exchange (ETDEWEB)

    Felix, John Hebert da Silva; Cortez, Paulo Cesar, E-mail: jhsfelix@gmail.co [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia de Teleinformatica; Holanda, Marcelo Alcantara [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Hospital Universitario Walter Cantidio. Dept. de Medicina Clinica

    2010-12-15

    High Resolution Computed Tomography (HRCT) is the exam of choice for the diagnostic evaluation of lung parenchyma diseases. There is an increasing interest for computational systems able to automatically analyze the radiological densities of the lungs in CT images. The main objective of this study is to present a system for the automatic quantification and visualization of the lung aeration in HRCT images of different degrees of aeration, called Lung Image System Analysis (LISA). The secondary objective is to compare LISA to the Osiris system and also to specific algorithm lung segmentation (ALS), on the accuracy of the lungs segmentation. The LISA system automatically extracts the following image attributes: lungs perimeter, cross sectional area, volume, the radiological densities histograms, the mean lung density (MLD) in Hounsfield units (HU), the relative area of the lungs with voxels with density values lower than -950 HU (RA950) and the 15th percentile of the least density voxels (PERC15). Furthermore, LISA has a colored mask algorithm that applies pseudo-colors to the lung parenchyma according to the pre-defined radiological density chosen by the system user. The lungs segmentations of 102 images of 8 healthy volunteers and 141 images of 11 patients with Chronic Obstructive Pulmonary Disease (COPD) were compared on the accuracy and concordance among the three methods. The LISA was more effective on lungs segmentation than the other two methods. LISA's color mask tool improves the spatial visualization of the degrees of lung aeration and the various attributes of the image that can be extracted may help physicians and researchers to better assess lung aeration both quantitatively and qualitatively. LISA may have important clinical and research applications on the assessment of global and regional lung aeration and therefore deserves further developments and validation studies. (author)

  1. Automatic system for quantification and visualization of lung aeration on chest computed tomography images: the Lung Image System Analysis - LISA

    International Nuclear Information System (INIS)

    Felix, John Hebert da Silva; Cortez, Paulo Cesar; Holanda, Marcelo Alcantara

    2010-01-01

    High Resolution Computed Tomography (HRCT) is the exam of choice for the diagnostic evaluation of lung parenchyma diseases. There is an increasing interest for computational systems able to automatically analyze the radiological densities of the lungs in CT images. The main objective of this study is to present a system for the automatic quantification and visualization of the lung aeration in HRCT images of different degrees of aeration, called Lung Image System Analysis (LISA). The secondary objective is to compare LISA to the Osiris system and also to specific algorithm lung segmentation (ALS), on the accuracy of the lungs segmentation. The LISA system automatically extracts the following image attributes: lungs perimeter, cross sectional area, volume, the radiological densities histograms, the mean lung density (MLD) in Hounsfield units (HU), the relative area of the lungs with voxels with density values lower than -950 HU (RA950) and the 15th percentile of the least density voxels (PERC15). Furthermore, LISA has a colored mask algorithm that applies pseudo-colors to the lung parenchyma according to the pre-defined radiological density chosen by the system user. The lungs segmentations of 102 images of 8 healthy volunteers and 141 images of 11 patients with Chronic Obstructive Pulmonary Disease (COPD) were compared on the accuracy and concordance among the three methods. The LISA was more effective on lungs segmentation than the other two methods. LISA's color mask tool improves the spatial visualization of the degrees of lung aeration and the various attributes of the image that can be extracted may help physicians and researchers to better assess lung aeration both quantitatively and qualitatively. LISA may have important clinical and research applications on the assessment of global and regional lung aeration and therefore deserves further developments and validation studies. (author)

  2. Coupling of bio-PRB and enclosed in-well aeration system for remediation of nitrobenzene and aniline in groundwater.

    Science.gov (United States)

    Liu, Na; Ding, Feng; Wang, Liu; Liu, Peng; Yu, Xiaolong; Ye, Kang

    2016-05-01

    A laboratory-scale bio-permeable reactive barrier (bio-PRB) was constructed and combined with enclosed in-well aeration system to treat nitrobenzene (NB) and aniline (AN) in groundwater. Batch-style experiments were first conducted to evaluate the effectiveness of NB and AN degradation, using suspension (free cells) of degrading consortium and immobilized consortium by a mixture of perlite and peat. The NB and AN were completely degraded in 4 mg L(-1) when the aeration system was applied into the bio-PRB system. The NB and AN were effectively removed when the aeration system was functional in the bio-PRB. The removal efficiency decreased when the aeration system malfunctioned for 20 days, thus indicating that DO was an important factor for the degradation of NB and AN. The regain of NB and AN removal after the malfunction indicates the robustness of degradation consortium. No original organics and new formed by-products were observed in the effluent. The results indicate that NB and AN in groundwater can be completely mineralized in a bio-PRB equipped with enclosed in-well aeration system and filled with perlite and peat attached with degrading consortium.

  3. Water quality and bacteriology in an aquaculture facility equipped with a new aeration system

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, S.O.; Kulkarni, S.S.; Shirodkar, R.R.; Karekar, S.V.; PraveenKumar, R.; Sreepada, R.A.; Vogelsang, C.; LokaBharathi, P.A.

    .J., & Reyes F L. de los. (2005). Effects of Aeration Cycles on Nitrifying Bacterial Populations and Nitrogen Removal in Intermittently Aerated Reactors. Applied and Environmental Microbiology, 71(12), 8565-8572. Li, Q., Chen, B., Qu, k., Yuan, Y., Li, J...

  4. Nitrous oxide emissions from an intermittent aeration activated sludge system of an urban wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    William Z. de Mello

    2013-01-01

    Full Text Available This study investigated the emission of N2O during the sequential aerated (60-min and non-aerated (30-min stages of an intermittent aeration cycle in an activated sludge wastewater treatment plant (WWTP. N2O emission occurred during both stages; however, emission was much higher during aeration. Air stripping is the major factor controlling transfer of N2O from the sewage to the atmosphere. The N2O emissions exclusively from the aeration tank represented 0.10% of the influent total nitrogen load and the per capita emission factor was almost 3 times higher than that suggested by the IPCC for inventories of N2O emission from WWTPs.

  5. Improvement of Hydraulic and Water Quality Renovation Functions by Intermittent Aeration of Soil Treatment Areas in Onsite Wastewater Treatment Systems

    Directory of Open Access Journals (Sweden)

    David V. Kalen

    2010-12-01

    Full Text Available We tested intermittent aeration of the soil treatment area (STA of onsite wastewater treatment systems (OWTS for its ability to restore and maintain STA hydraulic flow and improve the water quality functions of conventional OWTS. Evaluation was conducted on hydraulically-failed conventional OWTS at three state-owned medical group homes in Washington County, RI, USA. Testing was conducted in two phases, with Phase I (before intermittent soil aeration (ISA comprising the first 6 months of the study, and Phase II (during ISA the remaining 7 months. Intermittent soil aeration restored STA hydraulic function in all three systems despite a marked reduction in the STA total infiltrative surface. Soil pore water was collected from 30 and 90 cm below the STA during both phases and analyzed for standard wastewater parameters. Although the STA infiltrative surface was reduced—and the contaminant load per unit of area increased—after installation of the ISA system, no differences were observed between phases in concentration of total N, NO3, total P, or dissolved organic carbon (DOC. Apparent removal rates—which do not account for dilution or differences in infiltrative area—for total N, total P, and DOC remained the same or improved during Phase II relative to the pre-operation phase. Furthermore, intermittent soil aeration enhanced actual removal rates —which do account for dilution and differences in infiltrative area. The effects of ISA on actual removal of contaminants from STE increased with increasing hydraulic load—a counterintuitive phenomenon, but one that has been previously observed in laboratory studies. The results of our study suggest that intermittent soil aeration can restore and maintain hydraulic flow in the STA and enhance carbon and nutrient removal in conventional OWTS.

  6. Feasibility study of an aeration treatment system in a raw water storage reservoir used as a potable water source

    OpenAIRE

    Fronk, Robert Charles

    1996-01-01

    The systems engineering process has been utilized to determine the feasibility of an aeration treatment system for a raw water storage reservoir used as a potable water source. This system will be used to ensure a consistently high quality of raw water by the addition of dissolved oxygen into the reservoir. A needs analysis establishes the importance and requirements for a consistently high quality of raw water used as a source for a potable water treatment facility. This s...

  7. Combination of Successive Alkalinity Producing System (SAPS) and Aeration for Passive Treatment of Highly Acidic Mine Drainage

    Science.gov (United States)

    Oh, C.; Ji, S.

    2015-12-01

    Passive treatment system has been widely used for remediation of mine drainage since its advantage of low installation and maintenance cost. The system, however, has also a disadvantage in assuring remediation and management efficiency if the drainage is highly acidic mine drainage. To remediate acid mine drainage (AMD) especially showing high acidity, passive treatment system which consists of successive alkalinity producing system (SAPS) and subsequent aeration pond was proposed and its mechanisms and efficiency was evaluated in this research. Target AMD was obtained from Waryong coal mine and showed typical characteristics of AMD having high metal concentration and low pH (acidity > 300 mg/L as CaCO3). Four experimental cases were conducted; untreated, treated with SAPS, treated with aeration, treated with SAPS and aeration to compare role and mechanism of each unit. Between organic matter and limestone layer which constitute SAPS, the former eliminated most of Fe(III) and Al in the AMD so that the latter was kept from being clogged by precipitates. Net acidity of the AMD rapidly decreased by supplement of alkalinity at the limestone layer. A primary function of SAPS, producing alkalinity constantly without clogging, was attained due to addition a portion of limestone particle into the organic matter layer. The discharge from SAPS had low ORP and DO values because of an anaerobic environment formed at the organic matter layer although its alkalinity was increased. This water quality was unfavorable for Fe(II) to be oxidized. Installation of aeration pond after SAPS, therefore, could be effective way of enhancing oxidation rate of Fe(II). Among the experimental cases, the combination of SAPS and aeration pond was only able to remediate the AMD. This concluded that to remediate highly acidic mine drainage with passive treatment system, three critical conditions were required; pre-precipitation of Fe(III) and Al at organic matter layer in SAPS, constant alkalinity

  8. SYSTEM OF PRECISE DOSING OF COAGULANT IN THE PULVERIZING AERATOR POWERED BY WIND USING FUZZY LOGIC

    Directory of Open Access Journals (Sweden)

    Andrzej Osuch

    2017-06-01

    Full Text Available One of the methods used to support land restoration lakes is the method of pulverizing aeration. Use of aerators powered exclusively by wind improves the condition of reservoirs, while not compromising the environment. The pulverizing aeration process drive is windy on the water aeration zone near bottom, while removing harmful gases anaerobic metabolism. Aerators of this type due to the unique method of operation also enable dosing of inactivation coagulants with oxygenated water to the depths of the lake. Mileage coagulant dosing can be made dependent on the speed of the wind, which has an impact on the performance of his work, because with the increase of wind speed dispensing valve coagulants should be stronger open. One of the methods for assessing the state of lakes is to measure water transparency. The softer visibility, the most likely state of the water is better. Dosage of coagulant so you can make the transparency of the water. Similarly, with increasing transparency water dispensing valve should be more covered up. Control of the drain valve dispenser coagulant can be simultaneously dependent on two factors. The study was designed method of control drain valve dispenser coagulant using fuzzy inference.

  9. Abnormal grain growth: a non-equilibrium thermodynamic model for multi-grain binary systems

    International Nuclear Information System (INIS)

    Svoboda, J; Fischer, F D

    2014-01-01

    Abnormal grain growth as the abrupt growth of a group of the largest grains in a multi-grain system is treated within the context of unequal retardation of grain growth due to the segregation of solute atoms from the bulk of the grains into the grain boundaries. During grain boundary migration, the segregated solute atoms are dragged under a small driving force or left behind the migrating grain boundary under a large driving force. Thus, the solute atoms in the grain boundaries of large grains, exhibiting a large driving force, can be released from the grain boundary. The mobility of these grain boundaries becomes significantly higher and abnormal grain growth is spontaneously provoked. The mean-field model presented here assumes that each grain is described by its grain radius and by its individual segregation parameter. The thermodynamic extremal principle is engaged to obtain explicit evolution equations for the radius and segregation parameter of each grain. Simulations of grain growth kinetics for various conditions of segregation with the same initial setting (100 000 grains with a given radius distribution) are presented. Depending on the diffusion coefficients of the solute in the grain boundaries, abnormal grain growth may be strongly or marginally pronounced. Solute segregation and drag can also significantly contribute to the stabilization of the grain structure. Qualitative agreement with several experimental results is reported. (paper)

  10. Design characteristics of Curved Blade Aerator w.r.t. aeration ...

    African Journals Online (AJOL)

    user

    To provide the required amount of oxygen, an aeration system is always ... and number of blades, depth of flow etc and physicochemical properties of the liquid. .... amounts to 29 cm with 12 blades (fiber strips) mounted on each aerator rotor.

  11. Comparisons Study of Phosphate Removal in Unaerated and Aerated High Calcium Steel Slag Filter System of Different pH Feed

    Directory of Open Access Journals (Sweden)

    Ahmad Siti Zu Nurain

    2017-01-01

    Full Text Available Excess phosphorus in water body will lead to eutrophication. This study investigated the phosphate removal efficiencies of unaerated and aerated filter systems using high composition of Calcium (Ca steel slag as the filter media at different pH values of the wastewater influents. Lab-scale filters were developed using 25 mg/L synthetic wastewater and weekly sampling was done to monitor the phosphate removal efficiencies together with the concentration of metals (Calcium (Ca and Magnesium (Mg. The results show that both unaerated and aerated systems have excellent phosphate removal efficiency at all acidic, neutral and alkaline pH feed, though unaerated systems removed slightly better compared to aerated systems; 76-98% and 69-97% respectively. The dominant phosphate removal mechanism for aerated systems was adsorption, meanwhilefor unaerated systems; both adsorption and precipitation for acidic and neutral pH, whileprecipitation was more dominant at basic pH. The performance of unaerated systems are slightly better compared to aerated systems, however, aerated systems are recommended to be applied when simultaneous removal of nutrients (phosphorus and nitrogen are concerned.

  12. New aeration systems for higher efficiency in mine water treatment in the Lausitz region; Einsatz neuer Belueftungssysteme zur Effizienzsteigerung bei der Grubenwasserbehandlung in der Lausitz

    Energy Technology Data Exchange (ETDEWEB)

    Janneck, E.; Glombitza, F. [G.E.O.S. Freiberg Ingenieurgesellschaft mbH, Freiberg (Germany); Schlee, K.; Arnold, I. [Vattenfall Europe Mining AG, Cottbus (Germany)

    2006-07-01

    The article presents experiences and results of the application of new aerator-systems in the mine water treatment. The processes of ferrous iron oxidation and sludge removal became more stable and efficiently by the application of the aerators. For the first time, spiral aerators were used in the Lower Lusatia lignite mining district to clean ferrous iron containing mine water. These devices lead to an enhanced iron oxidation rate under the existing conditions, where the oxygen diffusion is the rate determining step. Furthermore, the application caused increased throughput, optimal lime utilisation and better sludge thickening, which led to a higher efficiency of the mine water treatment. (orig.)

  13. Combination of Methoprene and Controlled Aeration to Manage Insects in Stored Wheat.

    Science.gov (United States)

    Liu, Samuel S; Arthur, Frank H; VanGundy, Douglas; Phillips, Thomas W

    2016-06-17

    A commercial formulation of the insect growth regulator methoprene was applied to wheat stored in small bins either alone or in combination with controlled aeration of the bins, to lower grain temperature for insect pest management of stored wheat. Grain temperatures were monitored and modified by a computer-controlled thermocouple system that also activated the aeration system at programmed set-points to move cool ambient air through the grain mass to lower grain temperature. Results from sampling insect populations in experimental storage bins along with laboratory mortality bioassays of insects placed on wheat taken from the bins over the course of the storage period showed that methoprene was very effective in controlling infestation by the externally-feeding stored grain insects Plodia interpunctella (Hübner), the Indian meal moth Tribolium castaneum (Herbst), the red flour beetle, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, and also for the internal-feeding pest Rhyzopertha dominica( Fauvel), the lesser grain borer. Methoprene did not give good control of the internal-feeding pest Sitophilus oryzae (L.), the rice weevil. Aeration alone was somewhat effective in suppressing insect population development, while methoprene alone or when combined with aeration greatly enhanced insect control. Commercial grain grading for industry quality standards at the end of the storage period confirmed the impact of insect suppression on maintaining high quality of the stored wheat. This field experiment shows that methoprene combined with aeration to cool grain can be effective for pest management of stored wheat in the southern plains of the United States of America.

  14. Combination of Methoprene and Controlled Aeration to Manage Insects in Stored Wheat

    Directory of Open Access Journals (Sweden)

    Samuel S. Liu

    2016-06-01

    Full Text Available A commercial formulation of the insect growth regulator methoprene was applied to wheat stored in small bins either alone or in combination with controlled aeration of the bins, to lower grain temperature for insect pest management of stored wheat. Grain temperatures were monitored and modified by a computer-controlled thermocouple system that also activated the aeration system at programmed set-points to move cool ambient air through the grain mass to lower grain temperature. Results from sampling insect populations in experimental storage bins along with laboratory mortality bioassays of insects placed on wheat taken from the bins over the course of the storage period showed that methoprene was very effective in controlling infestation by the externally-feeding stored grain insects Plodia interpunctella (Hübner, the Indian meal moth Tribolium castaneum (Herbst, the red flour beetle, Cryptolestes ferrugineus (Stephens, the rusty grain beetle, and also for the internal-feeding pest Rhyzopertha dominica( Fauvel, the lesser grain borer. Methoprene did not give good control of the internal-feeding pest Sitophilus oryzae (L., the rice weevil. Aeration alone was somewhat effective in suppressing insect population development, while methoprene alone or when combined with aeration greatly enhanced insect control. Commercial grain grading for industry quality standards at the end of the storage period confirmed the impact of insect suppression on maintaining high quality of the stored wheat. This field experiment shows that methoprene combined with aeration to cool grain can be effective for pest management of stored wheat in the southern plains of the United States of America.

  15. [Measurement and analysis of micropore aeration system's oxygenating ability under operation condition in waste water treatment plant].

    Science.gov (United States)

    Wu, Yuan-Yuan; Zhou, Xiao-Hong; Shi, Han-Chang; Qiu, Yong

    2013-01-01

    Using the aeration pool in the fourth-stage at Wuxi Lucun Waste Water Treatment Plant (WWTP) as experimental setup, off-gas method was selected to measure the oxygenating ability parameters of micropore aerators in a real WWTP operating condition and these values were compared with those in fresh water to evaluate the performance of the micropore aerators. Results showed that the micropore aerators which were distributed in different galleries of the aeration pool had significantly different oxygenating abilities under operation condition. The oxygenating ability of the micropore aerators distributed in the same gallery changed slightly during one day. Comparing with the oxygenating ability in fresh water, it decreased a lot in the real aeration pool, in more details, under the real WWTP operating condition, the values of oxygen transfer coefficient K(La) oxygenation capacity OC and oxygen utilization E(a) decreased by 43%, 57% and 76%, respectively.

  16. Cyber-physical system for a water reclamation plant: Balancing aeration, energy, and water quality to maintain process resilience

    Science.gov (United States)

    Zhu, Junjie

    Aeration accounts for a large fraction of energy consumption in conventional water reclamation plants (WRPs). Although process operations at older WRPs can satisfy effluent permit requirements, they typically operate with excess aeration. More effective process controls at older WRPs can be challenging as operators work to balance higher energy costs and more stringent effluent limitations while managing fluctuating loads. Therefore, understandings of process resilience or ability to quickly return to original operation conditions at a WRP are important. A state-of-art WRP should maintain process resilience to deal with different kinds of perturbations even after optimization of energy demands. This work was to evaluate the applicability and feasibility of cyber-physical system (CPS) for improving operation at Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) Calumet WRP. In this work, a process model was developed and used to better understand the conditions of current Calumet WRP, with additional valuable information from two dissolved oxygen field measurements. Meanwhile, a classification system was developed to reveal the pattern of historical influent scenario based on cluster analysis and cross-tabulation analysis. Based on the results from the classification, typical process control options were investigated. To ensure the feasibility of information acquisition, the reliability and flexibility of soft sensors were assessed to typical influent conditions. Finally, the process resilience was investigated to better balance influent perturbations, energy demands, and effluent quality for long-term operations. These investigations and evaluations show that although the energy demands change as the influent conditions and process controls. In general, aeration savings could be up to 50% from the level of current consumption; with a more complex process controls, the saving could be up to 70% in relatively steady-state conditions and at least 40

  17. Ferrous ion oxidations by ·H, ·OH and H2O2 in aerated FBX dosimetry system

    International Nuclear Information System (INIS)

    Gupta, B.L.; Nilekani, S.R.

    1998-01-01

    In the ferrous ion, benzoic acid and xylenol orange (FBX) dosimetric system, benzoic acid (BA) increases the G(Fe 3+ ) value. Xylenol orange (XO) controls the BA sensitized chain reaction as well as forms a complex with Fe 3+ . In the aerated FBX system each ·H, ·OH and H 2 O 2 oxidizes 8.5, 6.6 and 7.6 Fe 2+ ions, respectively; and these values respectively increase to 11.3, 7.6 and 8.6 in oxygenated solution. About 8% ·OH reacts with XO and the remaining with BA. The above fractional values are due to this competition. This ·OH reaction with XO oxidizes 1.8% and 2.1% ferrous ions only in aerated and oxygenated solutions, respectively. There is a competition between ·H reactions with O 2 and with BA, but both lead to the production of H 2 O 2 . The oxidation of Fe 2+ by ·OH reactions at different concentrations of H 2 O 2 is linear with absorbed dose while the ·H reactions make the oxidation of Fe 2+ non-linear with dose. This is due to competition reaction of H-adduct of BA between O 2 and Fe 3+

  18. The Effect of HLRs on Nitrogen Removal by Using a Pilot-scale Aerated Steel Slag System

    Directory of Open Access Journals (Sweden)

    Hamdan R.

    2017-01-01

    Full Text Available Discharge from domestic wastewater treatment plant amongst the main sources of nitrogen pollution in the environment. However, to remove nitrogen conventionally in domestic wastewater require high cost and complex chemical treatment method. Vertical flow aerated rock filter emerged as one of attractive alternative wastewater treatment method due to simplicity and compactness of the system. However, the application is yet to be developed in warm climate countries in particular Malaysia. Therefore, this study was conducted to investigate the effect of hydraulic loading rate (HLR to the performance of a pilot-scale Vertical Flow Aerated Rock Filter (VFARF in removing nitrogen from domestic wastewater using pilot-scale VFARF systems with steel slag as the filter media. Furthermore, this study has been designed to focus on the effects of two HLRs; 2.72 and 1.04 m3/m3.day. Influent and effluent of the filter systems were monitored biweekly basis for 11 weeks and analyzed for selected parameters. Results from this study shows that the VFARF with HLR 1.04 m3/m3.day has performed better in terms of removal ammonium-nitrogen and TKN as the system able to remove 90.4 ± 6.9%, 86.2 ± 10.7%, whilst the VFARF with 2.72 m3/m3.day remove 87.4 ± 9.9%, 80 ± 11.7%, respectively. From the observation, it can be concluded that nitrogen removal does affect by HLR as the removal in lower HLR system was higher due to high DO level in the VFARF system with 1.04 m3/m3.day which range from 4.5 to 5.1 mg/L whilst the DO level was slightly lower in the VFARF system with 2.72 m3/m3.day in the range of 3.7 to 4.5 mg/L.

  19. Comparison of compostable bags and aerated bins with conventional storage systems to collect the organic fraction of municipal solid waste from homes. a Catalonia case study.

    Science.gov (United States)

    Puyuelo, Belén; Colón, Joan; Martín, Patrícia; Sánchez, Antoni

    2013-06-01

    The separation of biowaste at home is key to improving, facilitating and reducing the operational costs of the treatment of organic municipal waste. The conventional method of collecting such waste and separating it at home is usually done by using a sealed bin with a plastic bag. The use of modern compostable bags is starting to be implemented in some European countries. These compostable bags are made of biodegradable polymers, often from renewable sources. In addition to compostable bags, a new model of bin is also promoted that has a perforated surface that, together with the compostable bag, makes the so-called "aerated system". In this study, different combinations of home collection systems have been systematically studied in the laboratory and at home. The results obtained quantitatively demonstrate that the aerated bin and compostable bag system combination is effective at improving the collection of biowaste without significant gaseous emissions and preparing the organic waste for further composting as concluded from the respiration indices. In terms of weight loss, temperature, gas emissions, respiration index and organic matter reduction, the best results were achieved with the aerated system. At the same time, a qualitative study of bin and bag combinations was carried in 100 homes in which more than 80% of the families participating preferred the aerated system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Palm oil mill effluent treatment using a two-stage microbial fuel cells system integrated with immobilized biological aerated filters.

    Science.gov (United States)

    Cheng, Jia; Zhu, Xiuping; Ni, Jinren; Borthwick, Alistair

    2010-04-01

    An integrated system of two-stage microbial fuel cells (MFCs) and immobilized biological aerated filters (I-BAFs) was used to treat palm oil mill effluent (POME) at laboratory scale. By replacing the conventional two-stage up-flow anaerobic sludge blanket (UASB) with a newly proposed upflow membrane-less microbial fuel cell (UML-MFC) in the integrated system, significant improvements on NH(3)-N removal were observed and direct electricity generation implemented in both MFC1 and MFC2. Moreover, the coupled iron-carbon micro-electrolysis in the cathode of MFC2 further enhanced treatment efficiency of organic compounds. The I-BAFs played a major role in further removal of NH(3)-N and COD. For influent COD and NH(3)-N of 10,000 and 125 mg/L, respectively, the final effluents COD and NH(3)-N were below 350 and 8 mg/L, with removal rates higher than 96.5% and 93.6%. The GC-MS analysis indicated that most of the contaminants were satisfactorily biodegraded by the integrated system. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. Composting of high moisture content swine manure with corncob in a pilot-scale aerated static bin system.

    Science.gov (United States)

    Zhu, Nengwu

    2006-10-01

    Pilot composting experiments of swine manure with corncob were conducted to evaluate the performance of the aerated static bin composting system. Effects of temperature control (60 and 70 degrees C) and moisture content (70% and 80%) were monitored on the composting by measuring physical and chemical indexes. The results showed that (1) the composting system could destroy pathogens, converted nitrogen from unstable ammonia to stable organic forms, and reduced the volume of waste; (2) significant difference of NH(4)(+)-N (P(12) = 0.074), and (NO(3)(-) + NO(2)(-))-N (P(12) = 0.085) was found between the temperature control treatments; (3) anaerobic reaction in the treatment with 80% moisture content resulted in significant difference of pH (P(23) = 0.006), total organic matter (P(23) = 0.003), and germination index (P(23) = 0.040) between 70% and 80%. Therefore, the optimum initial moisture content was less than 80% with the composting of swine manure and corncob by using the composting system.

  2. The extent of the influence and flux estimation of volatile mercury from the aeration pool in a typical coal-fired power plant equipped with a seawater flue gas desulfurization system

    International Nuclear Information System (INIS)

    Sun, Lumin; Feng, Lifeng; Yuan, Dongxing; Lin, Shanshan; Huang, Shuyuan; Gao, Liangming; Zhu, Yong

    2013-01-01

    Before being discharged, the waste seawater from the flue gas desulfurization system of coal-fired power plants contains a large amount of mercury, and is treated in aeration pools. During this aeration process, part of the mercury enters the atmosphere, but only very limited impact studies concerning this have been carried out. Taking a typical Xiamen power plant as an example, the present study targeted the elemental mercury emitted from the aeration pool. Concentrations of dissolved gaseous mercury as high as 1.14 ± 0.17 ng·L −1 were observed in the surface waste seawater in the aeration pool, and gaseous elemental mercury (GEM) as high as 10.94 ± 1.89 ng·m −3 was found in the air above the pool. To investigate the area affected by this GEM through air transfer, the total mercury in the dust and topsoil samples around the aeration pool were analyzed. Much higher values were found compared to those at a reference site. Environmental factors other than solar radiation had limited influence on the concentrations of the mercury species in the pool. A simulation device was built in our laboratory to study the flux of mercury from the aeration pool into the air. The results showed that more than 0.59 kg of mercury was released from the aeration pool every year, occupying 0.3% of the total mercury in the waste seawater. The transfer of mercury from water to air during the aeration pool and its environmental influence should not be ignored. - Highlights: ► High concentration of volatile mercury was observed in the aeration pool. ► More than 0.3% of total discharged Hg emitted from the pool into the air. ► Higher aeration rate resulted in more mercury emitted into the air. ► The dust and topsoil around the pool were polluted with the mercury

  3. Impacts of aeration management and polylactic acid addition on dissolved organic matter characteristics in intensified aquaponic systems.

    Science.gov (United States)

    Wu, Haiming; Zou, Yina; Lv, Jialong; Hu, Zhen

    2018-08-01

    Aquaponics as a potential alternative for conventional aquaculture industry has increasingly attracted worldwide attention in recent years. However, the sustainable application of aquaponics is facing a growing challenge. In particular, there is a pressing need to better understand and control the accumulation of dissolved organic matter (DOM) in aquaponics with the aim of optimizing nitrogen utilization efficiency. This study was aiming for assessing the characteristics of DOM in the culture water and the relationship with the nitrogen transformations in different intensified aquaponic systems with hydroponic aeration supplement and polylactic acid (PLA) addition. Two enhancing attempts altered the quantity of DOM in aquaponic systems significantly with a varying DOM content of 21.98-45.65 mg/L. The DOM could be represented by four identified fluorescence components including three humic -like materials (83-86%) and one tryptophan-like substance (14-17%). The fluorescence intensities of humic acid-like components were decreased significantly after the application of intensifying strategies, which indicating that two enhancing attempts possibly affected humic acid-like fluorescence. Variation of optical indices also suggested the reductions of water DOM which could be impacted by the enhancing nitrogen treatment processes. These findings will benefit the potential applications and sustainable operation of these strategies in aquaponics. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Mass balance of pent achloroni trobenzene-14c and metabolites in a closed aerated soil plant or soil-system

    International Nuclear Information System (INIS)

    Kamal, M.

    1984-01-01

    Two experiments were carried out with pentachloronitrobenzene- 14 C and soils with and without plants in a closed aerated laboratory system. In both experiments, degradation to 14 CO 2 within 16 or 53 days, respectively, was very low (=0,01% of initially applied 14 C). Volatilization loses were about 15% in the system with plants (16 days) and were negligible in the soil without plants (53 days). The uptake into plants within 16 days was 5.26% of initially applied 14 C(0.86% unchanged parent compound, 3.35% soluble metabolites, and 1.05% unextractable residues); the major portion of soluble metabolites was highly polar conjugates which were not characterized further. The radioactivity left in both soils after 16 or 53 days, respectively, considered of 57 or 37% unchanged parent compound, 10 or 42% soluble metabolites, and 13 or 25% soil-bound residues. In the soil without plants, the following conversion products were identified after 53 days: pentachloroaniline (18.7% of initially applied 14 C), pentachlorthioanisole (17.3%), pentachlorobenzene, and pentachlorophenylmethylsulphoxide (2.6% each). (author)

  5. A full-scale biological aerated filtration system application in the ...

    African Journals Online (AJOL)

    owner

    sedimentation of the wastewater for six hours reduced the COD, BOD, and TSS by 43, 26, and 76%, respectively. ... treatment system due to its advantages relative to other systems ... working hours (8 h) and the Table 1 shows the average and.

  6. Deflector plants turbine aeration

    International Nuclear Information System (INIS)

    Miller, D.E.; Sheppard, A.R.; Widener, D.W.

    1991-01-01

    Water quality requirements have become a focal point in recent re-licensing of hydroelectric projects. The Federal Energy Regulatory Commission has significantly increased the relevance of license conditions to insure that turbine discharges meet state or other specific criteria for dissolved oxygen (D.O.). Due to naturally occurring depletion of D.O. at increased depths in large reservoirs, water withdrawn from this strata may result in unacceptably low levels of D.O. Different researchers have evaluated various methods of improving D.O. content in hydro turbine discharges, including; diffusers, weirs, oxygen injection, and variations of turbine venting. The authors describe an approach called deflector plate turbine aeration. This computer based, engineered approach allows systems to be evaluated, designed, and installed with predictable performance and costs. Many experts in this field now agree that, to the extent practical, turbine venting offers the most dependable, maintenance free, and cost effective solution to the low D.O. problem. The approach presented in this paper has resulted in proven results

  7. Aerated Systems of the Type RH-RCl-Ethanol-Thymolsulphonphthalein Stable Low-Level Chemical Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Dvornik, I.; Zec, U.; Anic, A.; Ranogajec, F. [Institute Ruder Boskovic, Zagreb, Yugoslavia (Croatia)

    1967-03-15

    The characteristic of dosimeters described in this paper is concerned with the very sensitive colorimetric method of dose evaluation giving a fair sensitivity with low G(HC1). In addition, the systems are thermally stable and simple to manufacture. With photocolorimetric or spectrophotometric evaluation of about 100 rad the dosimetric: error can be as low as 1 rad, or lower. The examined technique of visual colorimetric evaluation at the same dose level gives the combined error of 10-20 rad, and up to {+-} 5 or 10% at 500 rad. Owing to the practically unlimited shelf life of dosimeters and visual colorimeters, and to the very low production costs of both devices, such chemical dosimeters could be of special interest for massive use as personal gamma dosimeters for wide populations, or as dosimeters for gamma and fast neutron dosimetric topography of nuclear accidents. With tetrachloroethylene and iso-octane G(HC1) has been found constant (8.4) for temperatures of between -10 and +35 Degree-Sign C and for dose-rates of between 80 and 80 000 rad/h. The upper dose limit of colorimetric evaluation is about 2000 rad. With other components G(HC1) can be lower and the range extends to higher doses. The colorimetric properties of the systems RH-ethanol-thymolsulphonphthalein, as well as some of the most interesting features of the production procedure, are described. The radiation chemical aspects are discussed briefly. (author)

  8. Streaming of interstellar grains in the solar system

    Science.gov (United States)

    Gustafson, B. A. S.; Misconi, N. Y.

    1979-01-01

    Results of a theoretical study of the interactions between interstellar grains streaming through the solar system and the solar wind are presented. It is shown that although elongated core-mantle interstellar particles of a characteristic radius of about 0.12 microns are subject to a greater force due to radiation pressure than to gravitational attraction, they are still able to penetrate deep inside the solar system. Calculations of particle trajectories within the solar system indicate substantial effects of the solar activity cycle as reflected in the interplanetary magnetic field on the distribution of 0.12- and 0.0005-micron interstellar grains streaming through the solar system, leading to a 50-fold increase in interstellar grain densities 3 to 4 AU ahead of the sun during years 8 to 17 of the solar cycle. It is noted that during the Solar Polar Mission, concentrations are expected which will offer the opportunity of detecting interstellar grains in the solar system.

  9. Experimental evaluation of the oxygen transfer in bubble aeration systems. Full scale experiences in lengthened activated sludge reactors

    International Nuclear Information System (INIS)

    Andreottola, G.; Ragazzi, M.; Tatano, F.

    1999-01-01

    The results of some full-scale oxygen transfer measurements conduced at the lengthened activate sludge tanks of two WWTPs of Trentino Region, are presented and discussed. As far at the tests in clean water are concerned, the non-liner regression method seems non accurate; important conclusion on the correlation between oxygen transfer process and typical parameters (i.e., fine-bubble diffusers, specific air flux) are derived. As far as the test in the wastewater is concerned, an increase of α-value from the inlet to the end of aeration tanks has been observed in the 'Andalo' WWTP [it

  10. Application of a simplified mathematical model to estimate the effect of forced aeration on composting in a closed system.

    Science.gov (United States)

    Bari, Quazi H; Koenig, Albert

    2012-11-01

    The aeration rate is a key process control parameter in the forced aeration composting process because it greatly affects different physico-chemical parameters such as temperature and moisture content, and indirectly influences the biological degradation rate. In this study, the effect of a constant airflow rate on vertical temperature distribution and organic waste degradation in the composting mass is analyzed using a previously developed mathematical model of the composting process. The model was applied to analyze the effect of two different ambient conditions, namely, hot and cold ambient condition, and four different airflow rates such as 1.5, 3.0, 4.5, and 6.0 m(3) m(-2) h(-1), respectively, on the temperature distribution and organic waste degradation in a given waste mixture. The typical waste mixture had 59% moisture content and 96% volatile solids, however, the proportion could be varied as required. The results suggested that the model could be efficiently used to analyze composting under variable ambient and operating conditions. A lower airflow rate around 1.5-3.0 m(3) m(-2) h(-1) was found to be suitable for cold ambient condition while a higher airflow rate around 4.5-6.0 m(3) m(-2) h(-1) was preferable for hot ambient condition. The engineered way of application of this model is flexible which allows the changes in any input parameters within the realistic range. It can be widely used for conceptual process design, studies on the effect of ambient conditions, optimization studies in existing composting plants, and process control. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Colloid formation in groundwater by subsurface aeration: characterisation of the geo-colloids and their counterparts

    NARCIS (Netherlands)

    Wolthoorn, A.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2004-01-01

    Subsurface aeration is used to oxidise Fe in situ in groundwater to make the water potable. In a groundwater system with pH > 7, subsurface aeration results in a non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove Fe in situ, the

  12. Abnormal grain growth: a non-equilibrium thermodynamic model for multi-grain binary systems

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jiří; Fischer, F. D.

    2014-01-01

    Roč. 22, č. 1 (2014), Art . No. 015013 ISSN 0965-0393 Institutional support: RVO:68081723 Keywords : grain boundary segregation * abnormal grain growth * theory * modelling * solute drag Subject RIV: BJ - Thermodynamics Impact factor: 2.167, year: 2014

  13. Evaluation of calcium cyanamide addition during co-composting of manure and maize straw in a forced-aeration static-pile system.

    Science.gov (United States)

    Simujide, Huasai; Aorigele, Chen; Wang, Chun-Jie; Zhang, Tian-Hua; Manda, Bai

    2016-01-01

    Composting is one of the most environmentally friendly treatments to inactivate pathogenic organisms or reduce them to acceptable levels. However, even under thermal conditions, some pathogenic organisms such as E. coli could exist for a long time in composting. Such great persistence may increase the possibility of outbreaks of these organisms and further increase the environmental load. Calcium cyanamide (CaCN 2 ) has recently been recognized to have the fungicidal effect on the pathogens of the soilborne diseases. So, the present study determined the effect of CaCN 2 addition on composting progress as an antimicrobial agent and an amendment during forced-aeration static-pile composting of cow manure, which was mainly aimed to inhibit the pathogens that had not been inactivated by heat during composting. The mixtures of dairy cow manure and maize straw with addition of 2 % CaCN 2 or no addition were composted for 63 days. The physical, chemical and biological changes in compost mixtures were examined during composting. The data were statistically analyzed using ANOVA procedure from SAS software (version 9.0). The results showed that the addition of CaCN 2 significantly increased the maximum temperature and lengthened the duration of the thermophilic phase, and increased the percent T-N but decreased C/N ratio. For microbiological test, the addition of CaCN 2 shortened the time to inactivate E. coli , and increased the total average population of thermophilic bacteria but did not significantly influence that of mesophilic bacteria. The results indicated that the addition of CaCN 2 , at least at the additive content of 2 % could benefit the thermophilic phase and the composting could quickly reach the sanitary standard during the composting of manure with maize straw in a forced-aeration static-pile system. This finding will contribute to solve the feces disposal problems.

  14. CFD simulation of fluid dynamic and biokinetic processes within activated sludge reactors under intermittent aeration regime.

    Science.gov (United States)

    Sánchez, F; Rey, H; Viedma, A; Nicolás-Pérez, F; Kaiser, A S; Martínez, M

    2018-08-01

    Due to the aeration system, biological reactors are the most energy-consuming facilities of convectional WWTPs. Many biological reactors work under intermittent aeration regime; the optimization of the aeration process (air diffuser layout, air flow rate per diffuser, aeration length …) is necessary to ensure an efficient performance; satisfying the effluent requirements with the minimum energy consumption. This work develops a CFD modelling of an activated sludge reactor (ASR) which works under intermittent aeration regime. The model considers the fluid dynamic and biological processes within the ASR. The biological simulation, which is transient, takes into account the intermittent aeration regime. The CFD modelling is employed for the selection of the aeration system of an ASR. Two different aeration configurations are simulated. The model evaluates the aeration power consumption necessary to satisfy the effluent requirements. An improvement of 2.8% in terms of energy consumption is achieved by modifying the air diffuser layout. An analysis of the influence of the air flow rate per diffuser on the ASR performance is carried out. The results show a reduction of 14.5% in the energy consumption of the aeration system when the air flow rate per diffuser is reduced. The model provides an insight into the aeration inefficiencies produced within ASRs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Response of cyanobacteria to the fountain-based water aeration system in Jeziorak Mały urban lake

    Directory of Open Access Journals (Sweden)

    Zębek Elżbieta

    2014-03-01

    Full Text Available This study of cyanobacteria phytoplankton was conducted from May to August in 2002, 2003 and 2005 during fountain-based water aeration in the pelagial of the Jeziorak Mały urban lake in Poland. Additional water mixing by this installation’s activity changed the cyanobacterial growth conditions. Although less of their proportion was noted in total phytoplankton abundance, higher mean abundance and biomass were recorded at the fountain than at the lake centre. Higher water temperature in the surface layer favoured cyanobacterial growth at the fountain, while higher iron concentration stimulated their development in the lake’s centre. This was supported by positive correlations between their abundance and these water parameters. Moreover, the fountain’s activity contributed to the cyanobacteria sinking in the water column. The higher abundance of cyanobacteria was found at 1m depth in May, July and August than in the fountain surface layer. Additional water mixing during fountain activity caused also a shift in their abundance maximum (C - June and F - August and contributed to intensive organic matter decomposition. These conditions promoted cyanobacterial nutrient uptake from the water at the fountain, and this is supported by the negative correlation between their abundance and orthophosphate and total nitrogen concentrations. Generally, water mixing during the fountain’s activity does not inhibit the growth of cyanobacteria. This phenomenon disturbed abundance dynamics of the cyanobacteria in summer months but didn’t contribute to their abundance decrease. It is important for these results to be considered in future management of shallow urban lakes.

  16. Parametrizing coarse grained models for molecular systems at equilibrium

    KAUST Repository

    Kalligiannaki, Evangelia; Chazirakis, A.; Tsourtis, A.; Katsoulakis, M. A.; Plechá č, P.; Harmandaris, V.

    2016-01-01

    Hierarchical coarse graining of atomistic molecular systems at equilibrium has been an intensive research topic over the last few decades. In this work we (a) review theoretical and numerical aspects of different parametrization methods (structural-based, force matching and relative entropy) to derive the effective interaction potential between coarse-grained particles. All methods approximate the many body potential of mean force; resulting, however, in different optimization problems. (b) We also use a reformulation of the force matching method by introducing a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (E. Kalligiannaki, et al., J. Chem. Phys. 2015). We apply and compare these methods to: (a) a benchmark system of two isolated methane molecules; (b) methane liquid; (c) water; and (d) an alkane fluid. Differences between the effective interactions, derived from the various methods, are found that depend on the actual system under study. The results further reveal the relation of the various methods and the sensitivities that may arise in the implementation of numerical methods used in each case.

  17. Parametrizing coarse grained models for molecular systems at equilibrium

    KAUST Repository

    Kalligiannaki, Evangelia

    2016-10-18

    Hierarchical coarse graining of atomistic molecular systems at equilibrium has been an intensive research topic over the last few decades. In this work we (a) review theoretical and numerical aspects of different parametrization methods (structural-based, force matching and relative entropy) to derive the effective interaction potential between coarse-grained particles. All methods approximate the many body potential of mean force; resulting, however, in different optimization problems. (b) We also use a reformulation of the force matching method by introducing a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (E. Kalligiannaki, et al., J. Chem. Phys. 2015). We apply and compare these methods to: (a) a benchmark system of two isolated methane molecules; (b) methane liquid; (c) water; and (d) an alkane fluid. Differences between the effective interactions, derived from the various methods, are found that depend on the actual system under study. The results further reveal the relation of the various methods and the sensitivities that may arise in the implementation of numerical methods used in each case.

  18. Effects of crystallographic orientation vs. grain interaction on slip systems

    DEFF Research Database (Denmark)

    Winther, Grethe

    . Such investigations reveal both similarities and differences. The present contribution gives an overview of a series of investigations, including transmission electron microscopy as well as three-dimensional x-ray diffraction on polycrystalline aluminium deformed to strains of 5-50%. The data are analysed focusing...... on the set of activated slip systems, more precisely whether the observed differences can be attributed to fluctuations in the relative activities of the same set of systems or whether activation of truly different systems is the origin of the variations between and within grains....

  19. Nitrogen-removal performance and community structure of nitrifying bacteria under different aeration modes in an oxidation ditch.

    Science.gov (United States)

    Guo, Chang-Zi; Fu, Wei; Chen, Xue-Mei; Peng, Dang-Cong; Jin, Peng-Kang

    2013-07-01

    Oxidation-ditch operation modes were simulated using sequencing batch reactors (SBRs) with alternate stirring and aerating. The nitrogen-removal efficiencies and nitrifying characteristics of two aeration modes, point aeration and step aeration, were investigated. Under the same air-supply capacity, oxygen dissolved more efficiently in the system with point aeration, forming a larger aerobic zone. The nitrifying effects were similar in point aeration and step aeration, where the average removal efficiencies of NH4(+) N were 98% and 96%, respectively. When the proportion of anoxic and oxic zones was 1, the average removal efficiencies of total nitrogen (TN) were 45% and 66% under point aeration and step aeration, respectively. Step aeration was more beneficial to both anoxic denitrification and simultaneous nitrification and denitrification (SND). The maximum specific ammonia-uptake rates (AUR) of point aeration and step aeration were 4.7 and 4.9 mg NH4(+)/(gMLVSS h), respectively, while the maximum specific nitrite-uptake rates (NUR) of the two systems were 7.4 and 5.3 mg NO2(-)-N/(gMLVSS h), respectively. The proportions of ammonia-oxidizing bacteria (AOB) to all bacteria were 5.1% under point aeration and 7.0% under step aeration, and the proportions of nitrite-oxidizing bacteria (NOB) reached 6.5% and 9.0% under point and step aeration, respectively. The dominant genera of AOB and NOB were Nitrosococcus and Nitrospira, which accounted for 90% and 91%, respectively, under point aeration, and the diversity of nitrifying bacteria was lower than under step aeration. Point aeration was selective of nitrifying bacteria. The abundance of NOB was greater than that of AOB in both of the operation modes, and complete transformation of NH4(+) N to NO3(-)-N was observed without NO2(-)-N accumulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. FROM ATOMISTIC TO SYSTEMATIC COARSE-GRAINED MODELS FOR MOLECULAR SYSTEMS

    KAUST Repository

    Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plechac, Petr

    2017-01-01

    The development of systematic (rigorous) coarse-grained mesoscopic models for complex molecular systems is an intense research area. Here we first give an overview of methods for obtaining optimal parametrized coarse-grained models, starting from

  1. CFD model of an aerating hydrofoil

    International Nuclear Information System (INIS)

    Scott, D; Sabourin, M; Beaulieu, S; Papillon, B; Ellis, C

    2014-01-01

    Improving water quality in the tailrace below hydroelectric dams has become a priority in many river systems. In warm climates, water drawn by the turbine from deep in a reservoir can be deficient in dissolved oxygen (DO), a critical element in maintaining a healthy aquatic ecosystem. Many different solutions have been proposed in order to increase the DO levels in turbine discharge, including: turbine aeration systems (adding air to the water through either the turbine hub, the periphery or through distributed aeration in the runner blades); bubble diffusers in the reservoir or in the tailrace; aerating weirs downstream of the dams; and surface water pumps in the reservoir near the dam. There is a significant potential to increase the effectiveness of these solutions by improving the way that oxygen is introduced into the water; better distributions of bubbles will result in better oxygen transfer. In the present study, a two-phase Computational Fluid Dynamics model has been formulated using a commercial code to study the distribution of air downstream of a simple aerating hydrofoil. The two-phase model uses the Eulerian-Eulerian approach. Appropriate relations are used to model the interphase forces, including the Grace drag force model, the Favre averaged drag force and the Sato enhanced eddy viscosity. The model is validated using experimental results obtained in the water tunnel at the University of Minnesota's Saint Anthony Falls Laboratory. Results are obtained for water velocities between 5 and 10 m/s, air flow rates between 0.5 and 1.5 sL/min and for angles of attack between 0° and -8°. The results of this study show that the CFD model provides a good qualitative comparison to the experimental results by well predicting the wake location at the different flow rates and angles of attack used

  2. Classification system for rain fed wheat grain cultivars using artificial ...

    African Journals Online (AJOL)

    Artificial neural network (ANN) models have found wide applications, including ... of grains is essential for various applications as wheat grain industry and cultivation. In order to classify the rain fed wheat cultivars using artificial neural network ...

  3. GIS-based spatial decision support system for grain logistics management

    Science.gov (United States)

    Zhen, Tong; Ge, Hongyi; Jiang, Yuying; Che, Yi

    2010-07-01

    Grain logistics is the important component of the social logistics, which can be attributed to frequent circulation and the great quantity. At present time, there is no modern grain logistics distribution management system, and the logistics cost is the high. Geographic Information Systems (GIS) have been widely used for spatial data manipulation and model operations and provide effective decision support through its spatial database management capabilities and cartographic visualization. In the present paper, a spatial decision support system (SDSS) is proposed to support policy makers and to reduce the cost of grain logistics. The system is composed of two major components: grain logistics goods tracking model and vehicle routing problem optimization model and also allows incorporation of data coming from external sources. The proposed system is an effective tool to manage grain logistics in order to increase the speed of grain logistics and reduce the grain circulation cost.

  4. Effect of influent aeration on removal of organic matter from coffee processing wastewater in constructed wetlands.

    Science.gov (United States)

    Rossmann, Maike; Matos, Antonio Teixeira; Abreu, Edgar Carneiro; Silva, Fabyano Fonseca; Borges, Alisson Carraro

    2013-10-15

    The aim of the present study was to evaluate the influence of aeration and vegetation on the removal of organic matter in coffee processing wastewater (CPW) treated in 4 constructed wetlands (CWs), characterized as follows: (i) ryegrass (Lolium multiflorum) cultivated system operating with an aerated influent; (ii) non-cultivated system operating with an aerated influent, (iii) ryegrass cultivated system operating with a non-aerated influent; and (iv) non-cultivated system operating with a non-aerated influent. The lowest average chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) removal efficiencies of 87, 84 and 73%, respectively, were obtained in the ryegrass cultivated system operating with a non-aerated influent. However, ryegrass cultivation did not influence the removal efficiency of organic matter. Artificial aeration of the CPW, prior to its injection in the CW, did not improve the removal efficiencies of organic matter. On other hand it did contribute to increase the instantaneous rate at which the maximum COD removal efficiency was reached. Although aeration did not result in greater organic matter removal efficiencies, it is important to consider the benefits of aeration on the removal of the other compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Removal Efficiency of Nitrogen, Phosphorus and Heavy Metal by Intermittent Cycle Extended Aeration System from Municipal Wastewater (Yazd-ICEAS

    Directory of Open Access Journals (Sweden)

    Seyed Vahid Ghelmani

    2016-09-01

    Conclusion: The high removal efficiency of BOD5, TKN, and NH4+ showed that this advanced SBR system had an appropriate efficiency for nitrification. Phosphorus removal (TP had a lower efficiency than those of NH4+ and TKN, but it was within the environmental standard limits. On the other hand, in the advanced SBR the removal efficiency of heavy metals for Cd was not within the standard limits.

  6. Passively Aerated Composting of Straw-Rich Pig Manure : Effect of Compost Bed Porosity

    NARCIS (Netherlands)

    Veeken, A.H.M.; Wilde, de V.; Hamelers, H.V.M.

    2002-01-01

    Straw-rich manure from organic pig farming systems can be composted in passively aerated systems as the high application of straw results in a compost bed with good structure and porosity. The passively aerated composting process was simulated in one-dimensional reactors of 2 m3 for straw-rich

  7. A high sensitivity optically stimulated luminescence scanning system for measurement of single sand-sized grains

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Kohsiek, P.

    1999-01-01

    An instrument has been designed for the routine analysis of the optically stimulated luminescence signal from single grains of sand. The system is capable of analysing over 3000 individual grains in a single measurement sequence, and the OSL signal from each grain can be read in less than 3 s....... The design principles are described, along with preliminary measurements that illustrate the operation of the system and its capabilities....

  8. The impact of aeration on potato ( Solanum tuberosum L.) minituber ...

    African Journals Online (AJOL)

    Aeroponic systems are more effective than hydroponics for minituber production, as provided by the optimal system for root oxygenation. The study was conducted to improve conventional hydroponic systems by applying aeration so as to enhance potato minituber production yield via providing adequate oxygen in the root ...

  9. Ensuring sustainable grain legume-cereal cropping systems

    DEFF Research Database (Denmark)

    Bedoussac, Laurent; Journet, E-P; Hauggaard-Nielsen, Henrik

    2017-01-01

    health makes them a key rotation crop in the sustainable intensification and diversification of smallholder farming. This makes grain legumes a key food security crop. However, yields in developing countries are low as a result of such factors as the need for improved varieties of seed, poor seed......Grain legumes are widely cultivated, particularly for their dry seeds (known as pulses). Grain legumes are an important crop for a number of reasons. They are a rich source of protein and fibre, minerals and vitamins. In addition, their rapid growth and ability to fix nitrogen and improve soil...... distribution, the impact of pests and diseases, as well as vulnerability to poor soils, drought and other effects of climate change. This chapter summarises data from over 50 field experiments undertaken since 2001 on cereal-grain legume intercropping in 13 sites in southern and western France as well...

  10. Toward multiscale modelings of grain-fluid systems

    Science.gov (United States)

    Chareyre, Bruno; Yuan, Chao; Montella, Eduard P.; Salager, Simon

    2017-06-01

    Computationally efficient methods have been developed for simulating partially saturated granular materials in the pendular regime. In contrast, one hardly avoid expensive direct resolutions of 2-phase fluid dynamics problem for mixed pendular-funicular situations or even saturated regimes. Following previous developments for single-phase flow, a pore-network approach of the coupling problems is described. The geometry and movements of phases and interfaces are described on the basis of a tetrahedrization of the pore space, introducing elementary objects such as bridge, meniscus, pore body and pore throat, together with local rules of evolution. As firmly established local rules are still missing on some aspects (entry capillary pressure and pore-scale pressure-saturation relations, forces on the grains, or kinetics of transfers in mixed situations) a multi-scale numerical framework is introduced, enhancing the pore-network approach with the help of direct simulations. Small subsets of a granular system are extracted, in which multiphase scenario are solved using the Lattice-Boltzman method (LBM). In turns, a global problem is assembled and solved at the network scale, as illustrated by a simulated primary drainage.

  11. The development of furrower model blade to paddlewheel aerator for improving aeration efficiency

    Science.gov (United States)

    Bahri, Samsul; Praeko Agus Setiawan, Radite; Hermawan, Wawan; Zairin Junior, Muhammad

    2018-05-01

    The successful of intensive aquaculture is strongly influenced by the ability of the farmers to overcome the deterioration of water quality. The problem is low dissolved oxygen through aeration process. The aerator device which widely used in pond farming is paddle wheel aerator because it is the best aerator in aeration mechanism and usable driven power. However, this aerator still has a low performance of aeration, so that the cost of aerator operational for aquaculture is still high. Up to now, the effort to improve the performance of aeration was made by two-dimensional blade design. Obviously, it does not provide the optimum result due to the power requirements for aeration is directly proportional to the increase of aeration rate. The aim of this research is to develop three-dimensional model furrowed blades. Design of Furrower model blades was 1.6 cm diameter hole, 45º of vertical angle blade position and 30º of the horizontal position. The optimum performance furrowed model blades operated on the submerged blade 9 cm with 567.54 Watt of electrical power consumption and 4.322 m3 of splash coverage volume. The standard efficiency aeration is 2.72 kg O2 kWh-1. The furrowed model blades can improve the aeration efficiency of paddlewheel aerator.

  12. Treatment Wetland Aeration without Electricity? Lessons Learned from the First Experiment Using a Wind-Driven Air Pump

    Directory of Open Access Journals (Sweden)

    Johannes Boog

    2016-11-01

    Full Text Available Aerated treatment wetlands have become an increasingly recognized technology for treating wastewaters from domestic and various industrial origins. To date, treatment wetland aeration is provided by air pumps which require access to the energy grid. The requirement for electricity increases the ecological footprint of an aerated wetland and limits the application of this technology to areas with centralized electrical infrastructure. Wind power offers another possibility as a driver for wetland aeration, but its use for this purpose has not yet been investigated. This paper reports the first experimental trial using a simple wind-driven air pump to replace the conventional electric air blowers of an aerated horizontal subsurface flow wetland. The wind-driven air pump was connected to a two-year old horizontal flow aerated wetland which had been in continuous (24 h aeration since startup. The wind-driven aeration system functioned, however it was not specifically adapted to wetland aeration. As a result, treatment performance decreased compared to prior continuous aeration. Inconsistent wind speed at the site may have resulted in insufficient pressure within the aeration manifold, resulting in insufficient air supply to the wetland. This paper discusses the lessons learned during the experiment.

  13. Aspects concerning the quality of aeration for environmental friendly turbines

    Energy Technology Data Exchange (ETDEWEB)

    Bunea, F; Oprina, G [Hydrodynamics Department, National Institute for R and D in Electrical Engineering ICPE-CA, Splaiul Unirii, 313, Bucharest, 030138 (Romania); Houde, S; Ciocan, G D [Laboratoire de Machines Hydrauliques, Pavillon Adrien-Pouliot Universite Laval, 1065 rue de la medecine, Quebec G1V 0A6 (Canada); Baran, G; Pincovschi, I, E-mail: buneaflorentina@yahoo.co [Hydraulics, Hydraulic Machinery and Environmental Engineering Department, University Polytechnic of Bucharest, Splaiul Independentei, 313, Bucharest, 060042 (Romania)

    2010-08-15

    The hydro renewable energy provides a reliable power source; it does not pollute the air or land but affects the aquatic habitat due to low dissolved oxygen (DO) level in the water discharged from turbines. Hydro-turbines intake generally withdraws water from the bottom layer of the reservoirs with low DO level. In the different methods used for improving DO downstream the hydropower plants the volume of air is considered to be the main parameter of the injection. The energetic consumption is affected, in terms of loss of turbine efficiency due to air injection. The authors propose a study to show the importance of the quality of air injection, meaning bubble size, pressure loss on the aeration device etc. Different types of fine bubble aeration systems have been tested and compared. The capacity to predict the aeration by numerical simulation is analysed.

  14. Coarse-grained modeling of hybrid block copolymer system

    Science.gov (United States)

    Su, Yongrui

    This thesis is comprised of three major projects of my research. In the first project, I proposed a nanoparticle model and combined it with the Theoretically Informed Coarse Grained (TICG) model for pure polymer systems and the grand canonical slip springs model developed in our group to build a new model for entangled nanocomposites. With Molecule Dynamics(MD) simulation, I studied the mechanic properties of the nanocomposites, for example the influence of nanoparticles size and volume fraction on entanglements, the diffusion of polymers and nanoparticles, and the influence of nanoparticles size and volume fraction on viscosity et al.. We found that the addition of small-size nanoparticles reduces the viscosity of the nanocomposites, which is in contrary to what Einstein predicted a century ago. However, when particle increases its size to micrometers the Einstein predictions is recovered. From our simulation, we believe that small-size nanoparticles can more effectively decrease the entanglements of nanocomposites than larger particles. The free volume effect introduced by small-size nanoparticles also helps decrease the viscosity of the whole system. In the second project, I combined the Ohta-Kawasaki (OK) model [3] and the Covariance Matrix Adaptation Evolutionary Strategy(CMA-ES) to optimize the block copolymer blends self-assembly in the hole-shrink process. The aim is to predict the optimal composition and the optimal surface energy to direct the block copolymer blends self-assembly process in the confined hole. After optimization in the OK model, we calibrated the optimal results by the more reliable TICG model and got the same morphology. By comparing different optimization process, we found that the homopolymers which are comprised of the same monomers as either block of the block copolymer can form a perfect perforated hole and might have better performance than the pure block copolymer. While homopolymers which are comprised of a third-party monomers

  15. Autotrophic Nitrogen Removal in a Membrane-Aerated Biofilm Reactor Under Continuous Aeration: A Demonstration

    DEFF Research Database (Denmark)

    Gilmore, Kevin R.; Terada, Akihiko; Smets, Barth F.

    2013-01-01

    This work describes the successful coupling of partial nitrification (nitritation) and anaerobic ammonium oxidation in a membrane-aerated biofilm reactor (MABR) with continuous aeration. Controlling the relative surface loadings of oxygen versus ammonium prevented complete nitrite oxidation and a...

  16. Passively Aerated Composting of Straw-Rich Organic Pig Manure

    NARCIS (Netherlands)

    Veeken, A.H.M.; Wilde, de V.; Szanto, G.; Hamelers, H.V.M.

    2002-01-01

    In this study pig manure from organic farming systems is composted with passive aeration. Effectiveness of the composting process strongly depended on the density of the compost. Best results were observed at a density of 700 kg/m3, where both aerobic degradation and drying were adequate and

  17. Activity of some isoenzymatic systems in stored coffee grains

    Directory of Open Access Journals (Sweden)

    Reni Saath

    2014-02-01

    Full Text Available Considering the worldwide consumption of coffee, it is natural that throughout the history many people have dedicated the research to markers that contribute somehow on gauging its quality. This research aimed to evaluate the biochemical performance of arabica coffee during storage. Coffee in beans (natural and in parchment (pulped dried in concrete terrace and in dryer with heated air were packed in jute bags and stored in not controlled environmental conditions. Enzymatic activities of superoxide dismutase, catalase, peroxidase, polyphenoloxidase, esterase and lipoxygenase in coffee grains were evaluated at zero, three, six, nine and twelve months by means of electrophoresis. Independently of the drying method, the activity of isoenzymatic complexes highlighted deteriorative processes in stored grains of coffee. The treatments 60/40º C and 60º C used to reduce the water content imposed a greater stress condition, accelerated metabolism of natural coffee in the storage with decreased activity of defense mechanisms due to latent damage in these grains. Natural coffees are more sensible to high drying temperatures and its quality reduces faster than pulped coffee in the storage.

  18. Continuous primary fermentation of beer with yeast immobilized on spent grains : the effect of operational conditions

    OpenAIRE

    Brányik, Tomáš; Vicente, A. A.; Cruz, José Machado; Teixeira, J. A.

    2004-01-01

    A one-stage continuous primary beer fermentation with immobilized brewing yeast was studied. The objective of the work was to optimize the operational conditions (aeration and temperature) in terms of volumetric productivity and organoleptic quality of green beer. The system consisted of an internal-loop airlift reactor and a carrier material prepared from spent grains (a brewing by-product). An industrial wort and yeast strain were used. The immobilized biomass (in amounts from two to sevenf...

  19. Enhanced ethanol production from brewer's spent grain by a Fusarium oxysporum consolidated system

    Directory of Open Access Journals (Sweden)

    Christakopoulos Paul

    2009-02-01

    Full Text Available Abstract Background Brewer's spent grain (BG, a by-product of the brewing process, is attracting increasing scientific interest as a low-cost feedstock for many biotechnological applications. BG in the present study is evaluated as a substrate for lignocellulolytic enzyme production and for the production of ethanol by the mesophilic fungus Fusarium oxysporum under submerged conditions, implementing a consolidated bioconversion process. Fermentation experiments were performed with sugar mixtures simulating the carbohydrate content of BG in order to determine the utilization pattern that could be expected during the fermentation of the cellulose and hemicellulose hydrolysate of BG. The sugar mixture fermentation study focused on the effect of the initial total sugar concentration and on the effect of the aeration rate on fermenting performance of F. oxysporum. The alkali pretreatment of BG and different aeration levels during the ethanol production stage were studied for the optimization of the ethanol production by F. oxysporum. Results Enzyme yields as high as 550, 22.5, 6.5, 3225, 0.3, 1.25 and 3 U per g of carbon source of endoglucanase, cellobiohydrolase, β-D-glucosidase, xylanase, feruloyl esterase, β-D-xylosidase and α-L-arabinofuranosidase respectively, were obtained during the growth stage under optimized submerged conditions. An ethanol yield of 109 g ethanol per kg of dry BG was obtained with alkali-pretreated BG under microaerobic conditions (0.01 vvm, corresponding to 60% of the theoretical yield based on total glucose and xylose content of BG. Conclusion The enzymatic profile of the extracellular extract from F. oxysporum submerged cultures using BG and corn cob as the carbon source was proved efficient for a successful hydrolysis of BG. The fermentation study carried out using sugar mixtures simulating BG's carbohydrates content and consecutively alkali-pretreated and untreated BG, indicates that BG hydrolysis is the bottleneck

  20. Development and characterization of food-grade tracers for the global grain tracing and recall system.

    Science.gov (United States)

    Lee, Kyung-Min; Armstrong, Paul R; Thomasson, J Alex; Sui, Ruixiu; Casada, Mark; Herrman, Timothy J

    2010-10-27

    Tracing grain from the farm to its final processing destination as it moves through multiple grain-handling systems, storage bins, and bulk carriers presents numerous challenges to existing record-keeping systems. This study examines the suitability of coded caplets to trace grain, in particular, to evaluate methodology to test tracers' ability to withstand the rigors of a commercial grain handling and storage systems as defined by physical properties using measurement technology commonly applied to assess grain hardness and end-use properties. Three types of tracers to dispense into bulk grains for tracing the grain back to its field of origin were developed using three food-grade substances [processed sugar, pregelatinized starch, and silicified microcrystalline cellulose (SMCC)] as a major component in formulations. Due to a different functionality of formulations, the manufacturing process conditions varied for each tracer type, resulting in unique variations in surface roughness, weight, dimensions, and physical and spectroscopic properties before and after coating. The applied two types of coating [pregelatinized starch and hydroxypropylmethylcellulose (HPMC)] using an aqueous coating system containing appropriate plasticizers showed uniform coverage and clear coating. Coating appeared to act as a barrier against moisture penetration, to protect against mechanical damage of the surface of the tracers, and to improve the mechanical strength of tracers. The results of analysis of variance (ANOVA) tests showed the type of tracer, coating material, conditioning time, and a theoretical weight gain significantly influenced the morphological and physical properties of tracers. Optimization of these factors needs to be pursued to produce desirable tracers with consistent quality and performance when they flow with bulk grains throughout the grain marketing channels.

  1. Renewable energy for the aeration of wastewater ponds.

    Science.gov (United States)

    Hobus, I; Hegemann, W

    2003-01-01

    The application of a decentralised renewable energy supply for the aeration of wastewater ponds, and the influence of an unsteady oxygen supply on the specific conversion rate and biocoenose was investigated. With the discontinuous aeration the specific conversion rate is increased as compared to facultative ponds. The estimation of the microorganisms consortia was done with in situ hybridisation techniques. A significant shift in the bacteria population with the chosen specific probes for anaerobic, sulphate reducing and nitrifying bacteria could not be detected. Wastewater ponds have sufficient buffer volume to compensate for the fluctuating energy supply. But the efficiency of the energy supply of a photovoltaic plant decreases in shallow lakes (d photovoltaic and wind power plant, energy management, aeration system and wastewater pond, a simulation model was developed and tested. The application of renewable energy for the aeration of wastewater ponds is a useful alternative for the redevelopment of overloaded ponds as well as the construction of new wastewater ponds, especially in areas with an inadequate central electricity grid and a high availability of wind and solar energy.

  2. Instabilities in vertically vibrated fluid-grain systems.

    Science.gov (United States)

    King, P J; Lopez-Alcaraz, P; Pacheco-Martinez, H A; Clement, C P; Smith, A J; Swift, M R

    2007-03-01

    When a bed of fluid-immersed fine grains is exposed to vertical vibration a wealth of phenomena may be observed. At low frequencies a horizontal bed geometry is generally unstable and the bed breaks spatial symmetry, acquiring a tilt. At the same time it undergoes asymmetric granular convection. Fine binary mixtures may separate completely into layers or patterns of stripes. The separated regions may exhibit instabilities in which they undergo wave-like motion or exhibit quasi-periodic oscillations. We briefly review these and a number of related behaviours, identifying the physical mechanisms behind each. Finally, we discuss the magneto-vibratory separation of binary mixtures which results from exposing each component to a different effective gravity and describe the influence of a background fluid on this process.

  3. Development of micro tensile testing method in an FIB system for evaluating grain boundary strength

    International Nuclear Information System (INIS)

    Fujii, Katsuhiko; Fukuya, Koji

    2010-01-01

    A micro tensile testing method for evaluating grain boundary strength was developed. Specimens of 2 x 2 x 10μm having one grain boundary were made by focused ion beam (FIB) micro-processing and tensioned in an FIB system in situ. The load was measured from the deflection of the silicon cantilever. The method was applied to aged and unaged Fe-Mn-P alloy specimens with different level of grain boundary phosphorus segregation. The load at intergranular fracture decreased with increasing phosphorus segregation. (author)

  4. Characterization of Odorant Compounds from Mechanical Aerated Pile Composting and Static Aerated Pile Composting

    Directory of Open Access Journals (Sweden)

    Priyanka Kumari

    2016-04-01

    Full Text Available We studied airborne contaminants (airborne particulates and odorous compounds emitted from compost facilities in South Korea. There are primarily two different types of composting systems operating in Korean farms, namely mechanical aerated pile composting (MAPC and aerated static pile composting (SAPC. In this study, we analyzed various particulate matters (PM10, PM7, PM2.5, PM1, and total suspended particles, volatile organic compounds and ammonia, and correlated these airborne contaminants with microclimatic parameters, i.e., temperature and relative humidity. Most of the analyzed airborne particulates (PM7, PM2.5, and PM1 were detected in high concentration at SAPC facilities compered to MAPC; however these differences were statistically non-significant. Similarly, most of the odorants did not vary significantly between MAPC and SAPC facilities, except for dimethyl sulfide (DMS and skatole. DMS concentrations were significantly higher in MAPC facilities, whereas skatole concentrations were significantly higher in SAPC facilities. The microclimate variables also did not vary significantly between MAPC and SAPC facilities, and did not correlate significantly with most of the airborne particles and odorous compounds, suggesting that microclimate variables did not influence their emission from compost facilities. These findings provide insight into the airborne contaminants that are emitted from compost facilities and the two different types of composting agitation systems.

  5. Characterization of Odorant Compounds from Mechanical Aerated Pile Composting and Static Aerated Pile Composting.

    Science.gov (United States)

    Kumari, Priyanka; Lee, Joonhee; Choi, Hong-Lim

    2016-04-01

    We studied airborne contaminants (airborne particulates and odorous compounds) emitted from compost facilities in South Korea. There are primarily two different types of composting systems operating in Korean farms, namely mechanical aerated pile composting (MAPC) and aerated static pile composting (SAPC). In this study, we analyzed various particulate matters (PM10, PM7, PM2.5, PM1, and total suspended particles), volatile organic compounds and ammonia, and correlated these airborne contaminants with microclimatic parameters, i.e., temperature and relative humidity. Most of the analyzed airborne particulates (PM7, PM2.5, and PM1) were detected in high concentration at SAPC facilities compered to MAPC; however these differences were statistically non-significant. Similarly, most of the odorants did not vary significantly between MAPC and SAPC facilities, except for dimethyl sulfide (DMS) and skatole. DMS concentrations were significantly higher in MAPC facilities, whereas skatole concentrations were significantly higher in SAPC facilities. The microclimate variables also did not vary significantly between MAPC and SAPC facilities, and did not correlate significantly with most of the airborne particles and odorous compounds, suggesting that microclimate variables did not influence their emission from compost facilities. These findings provide insight into the airborne contaminants that are emitted from compost facilities and the two different types of composting agitation systems.

  6. Effects of snow grain shape on climate simulations: sensitivity tests with the Norwegian Earth System Model

    Directory of Open Access Journals (Sweden)

    P. Räisänen

    2017-12-01

    Full Text Available Snow consists of non-spherical grains of various shapes and sizes. Still, in radiative transfer calculations, snow grains are often treated as spherical. This also applies to the computation of snow albedo in the Snow, Ice, and Aerosol Radiation (SNICAR model and in the Los Alamos sea ice model, version 4 (CICE4, both of which are employed in the Community Earth System Model and in the Norwegian Earth System Model (NorESM. In this study, we evaluate the effect of snow grain shape on climate simulated by NorESM in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH is compared with another (NONSPH in which the snow shortwave single-scattering properties are based on a combination of three non-spherical snow grain shapes optimized using measurements of angular scattering by blowing snow. The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical case (0.77–0.78 in the visible region than in the spherical case ( ≈  0.89. Therefore, for the same effective snow grain size (or equivalently, the same specific projected area, the snow broadband albedo is higher when assuming non-spherical rather than spherical snow grains, typically by 0.02–0.03. Considering the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation with a global-mean top-of-the-model value of ca. −0.22 W m−2. Although this global-mean radiative effect is rather modest, the impacts on the climate simulated by NorESM are substantial. The global annual-mean 2 m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high latitudes. The climatic response is amplified by strong snow and sea ice feedbacks. It is further demonstrated that the effect of snow grain shape could be largely offset by adjusting the snow grain size. When assuming non-spherical snow grains with the parameterized grain

  7. Effects of snow grain shape on climate simulations: sensitivity tests with the Norwegian Earth System Model

    Science.gov (United States)

    Räisänen, Petri; Makkonen, Risto; Kirkevåg, Alf; Debernard, Jens B.

    2017-12-01

    Snow consists of non-spherical grains of various shapes and sizes. Still, in radiative transfer calculations, snow grains are often treated as spherical. This also applies to the computation of snow albedo in the Snow, Ice, and Aerosol Radiation (SNICAR) model and in the Los Alamos sea ice model, version 4 (CICE4), both of which are employed in the Community Earth System Model and in the Norwegian Earth System Model (NorESM). In this study, we evaluate the effect of snow grain shape on climate simulated by NorESM in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH) is compared with another (NONSPH) in which the snow shortwave single-scattering properties are based on a combination of three non-spherical snow grain shapes optimized using measurements of angular scattering by blowing snow. The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical case (0.77-0.78 in the visible region) than in the spherical case ( ≈ 0.89). Therefore, for the same effective snow grain size (or equivalently, the same specific projected area), the snow broadband albedo is higher when assuming non-spherical rather than spherical snow grains, typically by 0.02-0.03. Considering the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation with a global-mean top-of-the-model value of ca. -0.22 W m-2. Although this global-mean radiative effect is rather modest, the impacts on the climate simulated by NorESM are substantial. The global annual-mean 2 m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high latitudes. The climatic response is amplified by strong snow and sea ice feedbacks. It is further demonstrated that the effect of snow grain shape could be largely offset by adjusting the snow grain size. When assuming non-spherical snow grains with the parameterized grain size increased by ca. 70 %, the

  8. Influence of waterfall aeration and seasonal temperature variation on the iron and arsenic attenuation rates in an acid mine drainage system

    International Nuclear Information System (INIS)

    Chen, Chun-Jung; Jiang, Wei-Teh

    2012-01-01

    Dramatic seasonal changes in water chemistry and precipitate mineralogy associated with acid-mine drainage (AMD) in the waterfall and creek sections of the Chinkuashih area, northern Taiwan were investigated. Special attention has been paid to the kinetic effects of seasonal temperature variation and waterfall aeration. Precipitation of schwertmannite associated with removal of metals and As are indicated by delicate growth microstructures on precipitate surfaces, X-ray diffraction data, and downstream reductions of metal and As concentrations. Geochemical modeling suggested a downstream increase of the degree of saturation/supersaturation with respect to schwertmannite in the waterfall section, which can be attributed to high Fe 2+ oxidation rates. The waterfall section was characterized by high rates and model rate constants of Fe 2+ oxidation (6.1–6.7 × 10 −6 mol L −1 s −1 and 2.7–2.9 × 10 −2 s −1 ) and Fe (schwertmannite) precipitation (1.7–2.1 × 10 −6 mol L −1 s −1 and 3.5–4.1 × 10 −7 mol L −1 s −1 ). A high As sorption rate (4.7–6.3 × 10 −9 mol L −1 s −1 ) and low As distribution coefficient (7.9–11.8 × 10 −9 mol −1 L) were observed. The creek section showed up to 1–2 orders of magnitude slower rates and lower rate constants than the waterfall section and had seasonal variations comparable to those in areas polluted by AMD elsewhere. The summer rates were 4–5 times higher than the winter rates in the creek section, and are largely attributed to a temperature effect. In contrast, the seasonal differences in rate and rate constant were small in the waterfall section. Several factors associated with the waterfall aeration in addition to elevated temperature and As concentration enhanced Fe and As attenuation in the waterfall section. The waterfall effects on Fe precipitation rate were enhanced when the flow rate was large in the winter. Despite the remarkable removal of metals and As by the rapid

  9. Fine-Grained Access Control for Electronic Health Record Systems

    Science.gov (United States)

    Hue, Pham Thi Bach; Wohlgemuth, Sven; Echizen, Isao; Thuy, Dong Thi Bich; Thuc, Nguyen Dinh

    There needs to be a strategy for securing the privacy of patients when exchanging health records between various entities over the Internet. Despite the fact that health care providers such as Google Health and Microsoft Corp.'s Health Vault comply with the U.S Health Insurance Portability and Accountability Act (HIPAA), the privacy of patients is still at risk. Several encryption schemes and access control mechanisms have been suggested to protect the disclosure of a patient's health record especially from unauthorized entities. However, by implementing these approaches, data owners are not capable of controlling and protecting the disclosure of the individual sensitive attributes of their health records. This raises the need to adopt a secure mechanism to protect personal information against unauthorized disclosure. Therefore, we propose a new Fine-grained Access Control (FGAC) mechanism that is based on subkeys, which would allow a data owner to further control the access to his data at the column-level. We also propose a new mechanism to efficiently reduce the number of keys maintained by a data owner in cases when the users have different access privileges to different columns of the data being shared.

  10. Autonomous bed-sediment imaging-systems for revealing temporal variability of grain size

    Science.gov (United States)

    Buscombe, Daniel; Rubin, David M.; Lacy, Jessica R.; Storlazzi, Curt D.; Hatcher, Gerald; Chezar, Henry; Wyland, Robert; Sherwood, Christopher R.

    2014-01-01

    We describe a remotely operated video microscope system, designed to provide high-resolution images of seabed sediments. Two versions were developed, which differ in how they raise the camera from the seabed. The first used hydraulics and the second used the energy associated with wave orbital motion. Images were analyzed using automated frequency-domain methods, which following a rigorous partially supervised quality control procedure, yielded estimates to within 20% of the true size as determined by on-screen manual measurements of grains. Long-term grain-size variability at a sandy inner shelf site offshore of Santa Cruz, California, USA, was investigated using the hydraulic system. Eighteen months of high frequency (min to h), high-resolution (μm) images were collected, and grain size distributions compiled. The data constitutes the longest known high-frequency record of seabed-grain size at this sample frequency, at any location. Short-term grain-size variability of sand in an energetic surf zone at Praa Sands, Cornwall, UK was investigated using the ‘wave-powered’ system. The data are the first high-frequency record of grain size at a single location of a highly mobile and evolving bed in a natural surf zone. Using this technology, it is now possible to measure bed-sediment-grain size at a time-scale comparable with flow conditions. Results suggest models of sediment transport at sandy, wave-dominated, nearshore locations should allow for substantial changes in grain-size distribution over time-scales as short as a few hours.

  11. FROM ATOMISTIC TO SYSTEMATIC COARSE-GRAINED MODELS FOR MOLECULAR SYSTEMS

    KAUST Repository

    Harmandaris, Vagelis

    2017-10-03

    The development of systematic (rigorous) coarse-grained mesoscopic models for complex molecular systems is an intense research area. Here we first give an overview of methods for obtaining optimal parametrized coarse-grained models, starting from detailed atomistic representation for high dimensional molecular systems. Different methods are described based on (a) structural properties (inverse Boltzmann approaches), (b) forces (force matching), and (c) path-space information (relative entropy). Next, we present a detailed investigation concerning the application of these methods in systems under equilibrium and non-equilibrium conditions. Finally, we present results from the application of these methods to model molecular systems.

  12. 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.

  13. 3-D and quasi-2-D discrete element modeling of grain commingling in a bucket elevator boot system

    Science.gov (United States)

    Unwanted grain commingling impedes new quality-based grain handling systems and has proven to be an expensive and time consuming issue to study experimentally. Experimentally validated models may reduce the time and expense of studying grain commingling while providing additional insight into detail...

  14. Application of binomial and multinomial probability statistics to the sampling design process of a global grain tracing and recall system

    Science.gov (United States)

    Small, coded, pill-sized tracers embedded in grain are proposed as a method for grain traceability. A sampling process for a grain traceability system was designed and investigated by applying probability statistics using a science-based sampling approach to collect an adequate number of tracers fo...

  15. The Andatza coarse-grained turbidite system (westernmost Pyrenees: Stratigraphy, sedimentology and structural control

    Directory of Open Access Journals (Sweden)

    A. Bodego

    2017-06-01

    Full Text Available This is a field-based work that describes the stratigraphy and sedimentology of the Andatza Conglomerate Formation. Based on facies analysis three facies associations of a coarse-grained turbidite system and the related slope have been identified: (1 an inner fan of a turbidite system (or canyon and (2 a low- and (3 a high-gradient muddy slope respectively. The spatial distribution of the facies associations and the palaeocurrent analysis allow to interpret a depositional model for the Andatza Conglomerates consisting of an L-shaped, coarse-grained turbidite system, whose morphology was structurally controlled by synsedimentary basement-involved normal faults. The coarse-grained character of the turbidite system indicates the proximity of the source area, with the presence of a narrow shelf that fed the turbidite canyon from the north.

  16. Research About the Corosive Effects of FeCl3 in the Aeration Wastewater Basin

    Science.gov (United States)

    Panaitescu, C.; Petrescu, M. G.

    2018-01-01

    Biological aeration of industrial wastewater is a very impressive process in the treatment of wastewater. The involvement of chemical reagents in this process, however, implies the intensification of the corrosion processes due to both pollutants in the wastewater and the chemical reactions that occur when the coagulation / flocculation reagents are added. This paper explores the action of ferric chloride (FeCl3) on metallic parts in the aeration basin. The most affected structures are metal. At the classical basins the aeration systems were made of P295GH materials. The corrosion produced is uneven. The analysis of the high degree of corrosion was done according to the national and international standards. Finally, the paper supports the replacement of the existing aeration system with an anticorrosive material.

  17. Calibration and validation of coarse-grained models of atomic systems: application to semiconductor manufacturing

    Science.gov (United States)

    Farrell, Kathryn; Oden, J. Tinsley

    2014-07-01

    Coarse-grained models of atomic systems, created by aggregating groups of atoms into molecules to reduce the number of degrees of freedom, have been used for decades in important scientific and technological applications. In recent years, interest in developing a more rigorous theory for coarse graining and in assessing the predictivity of coarse-grained models has arisen. In this work, Bayesian methods for the calibration and validation of coarse-grained models of atomistic systems in thermodynamic equilibrium are developed. For specificity, only configurational models of systems in canonical ensembles are considered. Among major challenges in validating coarse-grained models are (1) the development of validation processes that lead to information essential in establishing confidence in the model's ability predict key quantities of interest and (2), above all, the determination of the coarse-grained model itself; that is, the characterization of the molecular architecture, the choice of interaction potentials and thus parameters, which best fit available data. The all-atom model is treated as the "ground truth," and it provides the basis with respect to which properties of the coarse-grained model are compared. This base all-atom model is characterized by an appropriate statistical mechanics framework in this work by canonical ensembles involving only configurational energies. The all-atom model thus supplies data for Bayesian calibration and validation methods for the molecular model. To address the first challenge, we develop priors based on the maximum entropy principle and likelihood functions based on Gaussian approximations of the uncertainties in the parameter-to-observation error. To address challenge (2), we introduce the notion of model plausibilities as a means for model selection. This methodology provides a powerful approach toward constructing coarse-grained models which are most plausible for given all-atom data. We demonstrate the theory and

  18. The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China

    Science.gov (United States)

    Ma, Hongbo; Nittrouer, Jeffrey A.; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J.; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

    2017-01-01

    Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams. PMID:28508078

  19. The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China.

    Science.gov (United States)

    Ma, Hongbo; Nittrouer, Jeffrey A; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

    2017-05-01

    Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams.

  20. Radon removal equipment based on aeration: A literature study of tests performed in Sweden between 1981 and 1996

    International Nuclear Information System (INIS)

    Mjoenes, L.

    2000-02-01

    In Sweden some principles to reduce the radon concentration in drinking water were tested in the beginning of the 1980s. Spray aeration under atmospheric pressure, diffused bubble aeration, aeration in the pressure tank and different combinations of these principles were studied. Aeration in the drill hole and adsorption on granulated activated char-coal were also tested. The best results, about 70 % reduction, were obtained with aeration in the pressure tank with a spray system combined with diffused air bubbling. The Oerebro project in the beginning of the 1990s included on site testing of five different aeration solutions: Aeration in the drill hole, aeration in the storage tank, ejector aeration, shallow tray aeration and packed column aeration. The radon removal efficiency varied between 20 % and 99 %. In 1994 a study intended to test the radon removal capacity of different water treatment equipment was performed. Six units of radon separators were included but most of the tested equipment was installed for other water treatment purposes. The performed measurements showed that the only types of equipment that reduce the radon concentration efficiently are radon separators and reverse osmosis filters. The radon removal capacity of the radon separators varied between 23 % and 97 %. In 1996 the nine most common radon separators on the Swedish market were tested. The results showed that the tested radon removal equipment worked well, although the technical quality and chosen technical solutions were not always the best. The radon removal capacity of the units participating in this test was in most cases between 96 and 99 %. In some cases the capacity exceeded 99 %. In order to reach this radon removal capacity the water must be recirculated in a storage tank under atmospheric pressure

  1. Radon removal equipment based on aeration: A literature study of tests performed in Sweden between 1981 and 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mjoenes, L

    2000-02-01

    In Sweden some principles to reduce the radon concentration in drinking water were tested in the beginning of the 1980s. Spray aeration under atmospheric pressure, diffused bubble aeration, aeration in the pressure tank and different combinations of these principles were studied. Aeration in the drill hole and adsorption on granulated activated char-coal were also tested. The best results, about 70 % reduction, were obtained with aeration in the pressure tank with a spray system combined with diffused air bubbling. The Oerebro project in the beginning of the 1990s included on site testing of five different aeration solutions: Aeration in the drill hole, aeration in the storage tank, ejector aeration, shallow tray aeration and packed column aeration. The radon removal efficiency varied between 20 % and 99 %. In 1994 a study intended to test the radon removal capacity of different water treatment equipment was performed. Six units of radon separators were included but most of the tested equipment was installed for other water treatment purposes. The performed measurements showed that the only types of equipment that reduce the radon concentration efficiently are radon separators and reverse osmosis filters. The radon removal capacity of the radon separators varied between 23 % and 97 %. In 1996 the nine most common radon separators on the Swedish market were tested. The results showed that the tested radon removal equipment worked well, although the technical quality and chosen technical solutions were not always the best. The radon removal capacity of the units participating in this test was in most cases between 96 and 99 %. In some cases the capacity exceeded 99 %. In order to reach this radon removal capacity the water must be recirculated in a storage tank under atmospheric pressure.

  2. PREPARATION OF ULTRA-LOW VOLUME WEIGHT AUTOCLAVED AERATED CONCRETE

    Directory of Open Access Journals (Sweden)

    Ondrej Koutny

    2016-12-01

    Full Text Available Autoclaved aerated concrete is a modern construction material that gains its popularity especially due to its thermal insulation performance resulting from low volume weight and porous structure with sufficient mechanical strength. Nowadays, there are attempts to use this material for thermal insulation purposes and to replace current systems, which have many disadvantages, mainly concerning durability. The key for improvement of thermal insulation properties is therefore obtaining a material based on autoclaved aerated concrete with extremely low volume weight (below 200 kg/m ³ ensuring good thermal isolation properties, but with sufficient mechanical properties to allow easy manipulation. This material can be prepared by foaming very fine powder materials such as silica fume or very finely ground sand. This paper deals with the possibilities of preparation and summarizes the basic requirements for successful preparation of such a material.

  3. Coarse Grained Molecular Dynamics Simulations of Transmembrane Protein-Lipid Systems

    Directory of Open Access Journals (Sweden)

    Peter Spijker

    2010-06-01

    Full Text Available Many biological cellular processes occur at the micro- or millisecond time scale. With traditional all-atom molecular modeling techniques it is difficult to investigate the dynamics of long time scales or large systems, such as protein aggregation or activation. Coarse graining (CG can be used to reduce the number of degrees of freedom in such a system, and reduce the computational complexity. In this paper the first version of a coarse grained model for transmembrane proteins is presented. This model differs from other coarse grained protein models due to the introduction of a novel angle potential as well as a hydrogen bonding potential. These new potentials are used to stabilize the backbone. The model has been validated by investigating the adaptation of the hydrophobic mismatch induced by the insertion of WALP-peptides into a lipid membrane, showing that the first step in the adaptation is an increase in the membrane thickness, followed by a tilting of the peptide.

  4. Greenhouse Gas Emissions Calculator for Grain and Biofuel Farming Systems

    Science.gov (United States)

    McSwiney, Claire P.; Bohm, Sven; Grace, Peter R.; Robertson, G. Philip

    2010-01-01

    Opportunities for farmers to participate in greenhouse gas (GHG) credit markets require that growers, students, extension educators, offset aggregators, and other stakeholders understand the impact of agricultural practices on GHG emissions. The Farming Systems Greenhouse Gas Emissions Calculator, a web-based tool linked to the SOCRATES soil…

  5. A prototype sensor system for the early detection of microbially linked spoilage in stored wheat grain

    Science.gov (United States)

    de Lacy Costello, B. P. J.; Ewen, R. J.; Gunson, H.; Ratcliffe, N. M.; Sivanand, P. S.; Spencer-Phillips, P. T. N.

    2003-04-01

    Sensors based on composites of metal oxides were fabricated and tested extensively under high-humidity and high-flow conditions with exposure to vapours reported to increase in the headspace of wheat grain (Triticum aestivum cv Hereward) colonized by fungi. The sensors that exhibited high sensitivity to target vapours combined with high stability were selected for inclusion into a four-sensor array prototype system. A sampling protocol aligned to parallel gas chromatography-mass spectrometry and human olfactory assessment studies was established for use with the sensor system. The sensor system was utilized to assess irradiated wheat samples that had been conditioned to 25% moisture content and inoculated with pathogens known to cause spoilage of grain in storage. These included the fungi Penicillium aurantiogriseum, Penicillium vulpinum, Penicillium verrucosum, Fusarium culmorum, Aspergillus niger, and Aspergillus flavus and the actinomycete, Streptomyces griseus. The sensor system successfully tracked the progress of the infections from a very early stage and the results were compared with human olfactory assessment panels run concurrently. A series of dilution studies were undertaken using previously infected grain mixed with sound grain, to improve the sensitivity and maximize the differentiation of the sensor system. An optimum set of conditions including incubation temperature, incubation time, sampling time, and flow rate were ascertained utilizing this method. The sensor system differentiated samples of sound grain from samples of sound grain with 1% (w/w) fungus infected grain added. Following laboratory trials, the prototype sensor system was evaluated in a commercial wheat grain intake facility. Thresholds calculated from laboratory tests were used to differentiate between sound and infected samples (classified by intake laboratory technicians) collected routinely from trucks delivering grain for use in food manufacture. All samples identified as having

  6. The Barley Grain Thioredoxin System – an Update

    Directory of Open Access Journals (Sweden)

    Per eHägglund

    2013-05-01

    Full Text Available Thioredoxin reduces disulfide bonds and play numerous important functions in plants. In cereal seeds, cytosolic h-type thioredoxin facilitates the release of energy reserves during the germination process and is recycled by NADPH-dependent thioredoxin reductase. This review presents a summary of the research conducted during the last ten years to elucidate the structure and function of the barley seed thioredoxin system at the molecular level combined with proteomic approaches to identify target proteins.

  7. A new database sub-system for grain-size analysis

    Science.gov (United States)

    Suckow, Axel

    2013-04-01

    Detailed grain-size analyses of large depth profiles for palaeoclimate studies create large amounts of data. For instance (Novothny et al., 2011) presented a depth profile of grain-size analyses with 2 cm resolution and a total depth of more than 15 m, where each sample was measured with 5 repetitions on a Beckman Coulter LS13320 with 116 channels. This adds up to a total of more than four million numbers. Such amounts of data are not easily post-processed by spreadsheets or standard software; also MS Access databases would face serious performance problems. The poster describes a database sub-system dedicated to grain-size analyses. It expands the LabData database and laboratory management system published by Suckow and Dumke (2001). This compatibility with a very flexible database system provides ease to import the grain-size data, as well as the overall infrastructure of also storing geographic context and the ability to organize content like comprising several samples into one set or project. It also allows easy export and direct plot generation of final data in MS Excel. The sub-system allows automated import of raw data from the Beckman Coulter LS13320 Laser Diffraction Particle Size Analyzer. During post processing MS Excel is used as a data display, but no number crunching is implemented in Excel. Raw grain size spectra can be exported and controlled as Number- Surface- and Volume-fractions, while single spectra can be locked for further post-processing. From the spectra the usual statistical values (i.e. mean, median) can be computed as well as fractions larger than a grain size, smaller than a grain size, fractions between any two grain sizes or any ratio of such values. These deduced values can be easily exported into Excel for one or more depth profiles. However, such a reprocessing for large amounts of data also allows new display possibilities: normally depth profiles of grain-size data are displayed only with summarized parameters like the clay

  8. AERATION OF THE ICE-COVERED WATER POOLS USING THE WAVE FLOW AERATOR

    Directory of Open Access Journals (Sweden)

    Solomin E.E

    2013-12-01

    Full Text Available This article describes the technical advantages and economic benefits of the ice-covered pool aeration plants consuming power from renewable energy sources. We made a comparative evaluation of the wave flow-aeration method and other methods of pool aeration. We showed the indexes and the characteristics of the wave flow-maker for aeration of ice-covered pools on the territory of Russia. We also made calculations of the economic benefits of aeration plants using the devices converting renewable energy. The project can be scaled and extended to the territory of the CIS, Europe, USA and Canada in the changing climate conditions and the variety of feed reservoirs around the world.

  9. Development of a red TL detection system for a single grain of quartz

    International Nuclear Information System (INIS)

    Yawata, T.; Hashimoto, T.

    2007-01-01

    Red thermoluminescence (RTL) of natural quartz grains offers many desirable properties for quaternary chronology and archaeological dating, although RTL measurements suffer from high thermal background due to black-body radiation on heating. To reduce the thermal background to as low a level as possible, a silver sample disc covered with a biotite plate with a sample hole was used in combination with a light guide, cluster heater, optical filters, and photomultiplier tube cooling to -20 deg. C in the present system. As a result, the thermal background decreased from 2x10 4 to 1000 cps in the temperature range 350-380 deg. C, resulting in a detection limit of approximately 100 cps, corresponding to the RTL signal from a single quartz grain (250-500μm) irradiated with 4.0 Gy. In addition, application of lower heating rates retarded the thermal quenching effect, resulting in high RTL signals, which are preferable for young or insensitive quartz samples. Using RTL measurements with the single quartz grain method under optimal RTL conditions, comparison of equivalent doses from artificially irradiated single quartz grains to the known dose was within the 20% measurement error. Based on equivalent dose determinations for single quartz grains, large irregularities on non-etched quartz surfaces might be very detrimental to the TL detection process. This result confirms that surface etching treatment is required to achieve reliable dating with high counting efficiency

  10. Soil water infiltration affected by biofuel and grain crop production systems in claypan landscape

    Science.gov (United States)

    The effect of soil management systems on water infiltration is very crucial within claypan landscapes to maximize production as well as minimize environmental risks. The objective of this study was to assess the effect of topsoil thickness on water infiltration in claypan soils for grain and biofuel...

  11. [The status of the body protective systems in children in atmospheric pollution by grain dust].

    Science.gov (United States)

    Mukhambetova, L Kh; Petrova, I V; Pinigin, M A; Leshchenko, G M; Shekhter, O V; Safiulin, A A; Astakhova, L F

    1998-01-01

    The use of noninvasive methods has revealed changes in the detoxification and immune systems in children exposed to grain dust-polluted ambient air. Impaired detoxification and immunity may be considered to be a manifestation of the common pathological mechanism responsible for reduced resistance to adverse factors and they lead to the increased risk of nonspecific infectious processes and allergy in the population.

  12. The effect of some growth regulators on enzyme systems in irradiated barley grain using disinfestation doses

    International Nuclear Information System (INIS)

    Bachman, S.

    1973-01-01

    Disinfestation doses of 20 to 100 krad may cause changes in the biological systems of barley grain and, therefore, may influence undesirably the technological quality of malted grain. The effect of some growth regulators on irradiated grain has been investigated. The experiments have been carried out on brewery barley var. Visa Breuns. Following growth-regulators were used: gibberellic acid (Polish preparation ''Gibrescol''), kinetin (6-furfurylo-aminopurin), CCC (2-chloroethyl trimethyl ammonium chloride), and betaine hydrochloride. By treating the irradiated barley with solutions of growth regulators it was possible to diminish the loss of enzyme activity. A ''regenerating'' effect of growth substances, mainly gibberellic acid and betain hydrochloride in 10 -4 M solutions, was observed. Amylolytic activity decreased immediately after irradiation but in samples treated with growth regulators it was higher than in those without regulators. The results may have a practical importance since gibberellic acid has just been introduced into the brewery industry. (F.J.)

  13. Landfill aeration for emission control before and during landfill mining.

    Science.gov (United States)

    Raga, Roberto; Cossu, Raffaello; Heerenklage, Joern; Pivato, Alberto; Ritzkowski, Marco

    2015-12-01

    The landfill of Modena, in northern Italy, is now crossed by the new high velocity railway line connecting Milan and Bologna. Waste was completely removed from a part of the landfill and a trench for the train line was built. With the aim of facilitating excavation and further disposal of the material extracted, suitable measures were defined. In order to prevent undesired emissions into the excavation area, the aerobic in situ stabilisation by means of the Airflow technology took place before and during the Landfill Mining. Specific project features involved the pneumatic leachate extraction from the aeration wells (to keep the leachate table low inside the landfill and increase the volume of waste available for air migration) and the controlled moisture addition into a limited zone, for a preliminary evaluation of the effects on process enhancement. Waste and leachate were periodically sampled in the landfill during the aeration before the excavation, for quality assessment over time; the evolution of biogas composition in the landfill body and in the extraction system for different plant set-ups during the project was monitored, with specific focus on uncontrolled migration into the excavation area. Waste biological stability significantly increased during the aeration (waste respiration index dropped to 33% of the initial value after six months). Leachate head decreased from 4 to 1.5m; leachate recirculation tests proved the beneficial effects of moisture addition on temperature control, without hampering waste aerobization. Proper management of the aeration plant enabled the minimization of uncontrolled biogas emissions into the excavation area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Radioactivity in houses built of aerated concrete based on alum shale

    International Nuclear Information System (INIS)

    Swedjemark, G.A.

    1980-01-01

    The highest activities in commonly used Swedish building materials are found in aerated concrete based on alum shale. The enhanced activity level is due to the high content of radium-226. The average activity concentration of radium-226 varies between different producers of aerated concrete based on alum shale from 700 Bq kg - (20 pCi g - ) to 2 400 Bq kg - (65 pCi g - ). Houses built in the same way with the same amounts of aerated concrete can therefore have very different gamma levels and very different concentrations of radon in the air with the same air exchange rate. Aerated concrete based on alum shale was used as a building material in Sweden from 1930 to 1975. The average concentration of radon daughters found in houses built of aerated concrete based to a major extent on alum shale is about 100 bq/m 3 (2.7 pCi 1 - ). The highest radon concentrations have been found in houses built entirely of aerated concrete based on alum shale. A group of 9 houses with natural draught ventilation systems has been investigated with regard to the concentration of radon, the equilibrium equivalent concentration of radon (EEC) and the gamma dose rate. The air exchange rates varied between the houses from 0.21 to 0.43 h - and the radon concentration from 540 Bq m - (15 pCi 1 - ) to 1 160 Bq m - (31 pCi 1 - ). The values given are averages for each house. (author)

  15. Iodine-infused aeration for hull fouling prevention: a vessel-scale study.

    Science.gov (United States)

    Dickenson, Natasha C; Krumholz, Jason S; Hunsucker, Kelli Z; Radicone, Michael

    2017-11-01

    Biofouling is a significant economic and ecological problem, causing reduced vessel performance and increases in fuel consumption and emissions. Previous research has shown iodine vapor (I 2 )-infused aeration to be an environmentally friendly method for deterring the settlement of fouling organisms. An aeration system was deployed on a vessel with hull sections coated with two types of antifoulant coatings, Intersleek ® 1100 (fouling-release) and Interspeed ® BRA-640 (ablative copper biocide), as well as an inert epoxy barrier coating, to assess the effectiveness of aeration in conjunction with common marine coatings. I 2 -infused aeration resulted in consistent reductions of 80-90% in hard fouling across all three coatings. Additionally, aeration reduced the soft fouling rate by 45-70% when used in conjunction with both Intersleek ® and Interspeed ® BRA versus those coatings alone. The results of this study highlight the contribution of I 2 -infused aeration as a standalone mechanism for fouling prevention or as a complement to traditional antifouling coatings.

  16. Grain boundary corrosion of copper canister material

    International Nuclear Information System (INIS)

    Fennell, P.A.H.; Graham, A.J.; Smart, N.R.; Sofield, C.J.

    2001-03-01

    The proposed design for a final repository for spent fuel and other long-lived residues in Sweden is based on the multi-barrier principle. The waste will be encapsulated in sealed cylindrical canisters, which will then be placed in granite bedrock and surrounded by compacted bentonite clay. The canister design is based on a thick cast inner container fitted inside a corrosion-resistant copper canister. During fabrication of the outer copper canisters there will be some unavoidable grain growth in the welded areas. As grains grow they will tend to concentrate impurities within the copper at the new grain boundaries. The work described in this report was undertaken to determine whether there is any possibility of enhanced corrosion at grain boundaries within the copper canister. The potential for grain boundary corrosion was investigated by exposing copper specimens, which had undergone different heat treatments and hence had different grain sizes, to aerated artificial bentonite-equilibrated groundwater with two concentrations of chloride, for increasing periods of time. The degree of grain boundary corrosion was determined by atomic force microscopy (AFM) and optical microscopy. AFM showed no increase in grain boundary 'ditching' for low chloride groundwater. In high chloride groundwater the surface was covered uniformly with a fine-grained oxide. No increases in oxide thickness were observed. No significant grain boundary attack was observed using optical microscopy either. The work suggests that in aerated artificial groundwaters containing chloride ions, grain boundary corrosion of copper is unlikely to adversely affect SKB's copper canisters

  17. Some effects of aeration on anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Bhywapathanapun, S

    1972-01-01

    The anaerobic digestion of meat works waste water is made possible by separating the sludge solids, after which necessary amounts of the concentrated sludge are returned to the digester. Sludge recirculation prolongs solid retention time in the digester. However, sludge separation by gravitational sedimentation is almost impossible because the sludge tends to rise with the continuous gassing. Therefore treatment of the sludge suspension prior to sedimentation is necessary for effective solid separation. The present study examined aeration degasification as a method for sludge suspension pretreatment and found that the rates of aeration of 0.75 to 1.0 VVM (0.12 to 0.16 cubic foot of air per gallon of mixed liquor per minute) were optimal for aeration degasification. The toxic effects on the anaerobic bacteria were small, daily gas production being reduced by only 5%.

  18. Path-space variational inference for non-equilibrium coarse-grained systems

    International Nuclear Information System (INIS)

    Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plecháč, Petr

    2016-01-01

    In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.

  19. Path-space variational inference for non-equilibrium coarse-grained systems

    Energy Technology Data Exchange (ETDEWEB)

    Harmandaris, Vagelis, E-mail: harman@uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete (Greece); Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), IACM/FORTH, GR-71110 Heraklion (Greece); Kalligiannaki, Evangelia, E-mail: ekalligian@tem.uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete (Greece); Katsoulakis, Markos, E-mail: markos@math.umass.edu [Department of Mathematics and Statistics, University of Massachusetts at Amherst (United States); Plecháč, Petr, E-mail: plechac@math.udel.edu [Department of Mathematical Sciences, University of Delaware, Newark, Delaware (United States)

    2016-06-01

    In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.

  20. Iron removal using an aerated granular filter

    Energy Technology Data Exchange (ETDEWEB)

    Cho, B.Y. [Dongguk University, Seoul (Republic of Korea). College of Engineering

    2005-10-01

    Laboratory scale experiments concerning iron removal from artificial raw water by an artificial filter using anthracite as filter media were conducted. The major findings were that iron oxidation and removal by an aerated filter is mainly a catalytic chemical reaction rather than a biological reaction. Further, iron removal does not perform effectively without aeration. Iron removal was very effective when the pH was weakly acidity. Iron oxide attached to the surface of the media is identified as ferrihydrite, which catalyzes the oxidation of iron as shown by Moessbauer spectra analysis.

  1. Shear reinforced beams in autoclaved aerated concrete

    DEFF Research Database (Denmark)

    Cornelius, Thomas

    2010-01-01

    Shear behaviour in concrete materials is very well documented, for normal density concrete materials. In this paper results of various tests on low density concrete materials like aerated autoclaved concrete (in the following denoted aircrete) will be presented and analyzed for different combinat....... Codes for designing prefabricated reinforced components of aircrete structures have adopted these recently developed approaches.......Shear behaviour in concrete materials is very well documented, for normal density concrete materials. In this paper results of various tests on low density concrete materials like aerated autoclaved concrete (in the following denoted aircrete) will be presented and analyzed for different...

  2. Innovative biological systems for anaerobic treatment of grain and food processing wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, P M

    1986-09-01

    The application of two innovative fixed film and suspended growth anaerobic biological systems to the treatment of grain and food processing wastewaters is discussed. A fluidized bed fixed film system and a suspended growth membrane system are described. The technical and economic factors dictating which system is selected for treatment of a specific industrial wastewater are discussed. Case history results from successful operation of full-scale, demonstration, and pilot-scale systems treating respectively, soy whey, cheese whey, and wheat flour processing wastewaters are presented.

  3. Quantitative Phase-Field Approach for Simulating Grain Growth in Anisotropic Systems with Arbitrary Inclination and Misorientation Dependence

    International Nuclear Information System (INIS)

    Moelans, N.; Blanpain, B.; Wollants, P.

    2008-01-01

    A phase-field approach for quantitative simulations of grain growth in anisotropic systems is introduced, together with a new methodology to derive appropriate model parameters that reproduce given misorientation and inclination dependent grain boundary energy and mobility in the simulations. The proposed model formulation and parameter choice guarantee a constant diffuse interface width and consequently give high controllability of the accuracy in grain growth simulations

  4. Effect of Ion Streaming on Diffusion of Dust Grains in Dissipative System

    Science.gov (United States)

    Begum, M.; Das, N.

    2018-01-01

    The presence of strong electric fields in the sheath region of laboratory complex plasma induces an ion drift and perturbs the field around dust grains. The downstream focusing of ions leads to the formation of oscillatory kind of attractive wake potential which superimpose with the normal Debye-Hückel (DH) potential. The structural properties of complex plasma and diffusion coefficient of dust grains in the presence of such a wake potential have been investigated using Langevin dynamics simulation in the subsonic regime of ion flow. The study reveals that the diffusion of dust grains is strongly affected by the ion flow, so that the diffusion changes its character in the wake potential to the DH potential dominant regimes. The dependence of the diffusion coefficient on the parameters, such as the neutral pressure, dust grain size, ion flow velocity, and Coulomb coupling parameter, have been calculated for the subsonic regime by using the Green-Kubo expression, which is based on the integrated velocity autocorrelation function. It is found that the diffusion and the structural property of the system is intimately connected with the interaction potential and significantly get affected in the presence of ion flow in the subsonic regime.

  5. Corn yield for silage and grains in different integrated crop-livestock systems

    Directory of Open Access Journals (Sweden)

    Laíse da Silveira Pontes

    Full Text Available Abstract In this study, the objective was to assess the influence of two doses of N (90 and 180 kg N ha-1, added to the winter pastures, two integrated crop-livestock systems (ICLS, with and without trees and five positions between the tree rows, on the corn (Zea mays L. quality and productivity, for silage and grain. Adopting the complete randomized block design, the treatments included three replicates. In 2006, following the 14 x 3 m spacing (currently with 158 trees ha-1 the trees were planted in 6 out of the 12 paddocks. While the corn was implemented during summer of 2013/2014, cattle grazing on the annual pasture was done during the prior winter, in both ICLS. Corn for silage was reaped at the R5 phenological stage, whereas for grains it was done at 176 days post seeding. For silage, the corn plants were grinded and then stocked in the experimental mini PVC silos. The silage varied slightly in quality along the positions between the tree rows. The differences observed between N levels in the dry matter, crude protein (CP and grain productivity are expressions of the residual effects of the winter fertilization. Silage quality was improved by the shade effect which minimized the acid detergent fiber and raised the CP, although it reduced the corn production for silage and grains by 52%. Some feasible techniques to reduce these losses are discussed.

  6. Oxygen demand for the stabilization of the organic fraction of municipal solid waste in passively aerated bioreactors

    International Nuclear Information System (INIS)

    Kasinski, Slawomir; Wojnowska-Baryla, Irena

    2014-01-01

    Highlights: • The use of an passively aerated reactor enables effective stabilization of OFMSW. • Convective air flow does not inhibit the aerobic stabilization of waste. • The use of an passively aerated reactor reduces the heat loss due to convection. • The volume of supplied air exceeds 1.7–2.88 times the microorganisms demand. - Abstract: Conventional aerobic waste treatment technologies require the use of aeration devices that actively transport air through the stabilized waste mass, which greatly increases operating costs. In addition, improperly operated active aeration systems, may have the adverse effect of cooling the stabilized biomass. Because active aeration can be a limiting factor for the stabilization process, passive aeration can be equally effective and less expensive. Unfortunately, there are few reports documenting the use of passive aeration systems in municipal waste stabilization. There have been doubts raised as to whether a passive aeration system provides enough oxygen to the organic matter mineralization processes. In this paper, the effectiveness of aeration during aerobic stabilization of four different organic fractions of municipal waste in a reactor with an integrated passive ventilation system and leachate recirculation was analyzed. For the study, four fractions separated by a rotary screen were chosen. Despite the high temperatures in the reactor, the air flow rate was below 0.016 m 3 /h. Using Darcy’s equation, theoretical values of the air flow rate were estimated, depending on the intensity of microbial metabolism and the amount of oxygen required for the oxidation of organic compounds. Calculations showed that the volume of supplied air exceeded the microorganisms demand for oxidation and endogenous activity by 1.7–2.88-fold

  7. MORPHOMETRIC CHARACTERIZATION OF THE SAND FRACTION IN A SAND GRAIN IMAGE CAPTURE SYSTEM1

    Directory of Open Access Journals (Sweden)

    Lucimar Arruda Viana

    Full Text Available ABSTRACT Morphology studies assume significant importance in analysis of phenomena of granular systems packaging, in particular with a view to the use of the technique of soil stabilization named particle size correction in forest roads. In this context, this study aimed to develop and operationalize a Sand Grain Image Capture System and, hereby, determine the morphological indices of the sand fractions of two sandy soils called João Pinheiro (JP and Cachoeira da Prata (CP. Soil samples, air-dried, were sieved (2.0 mm nominal mesh size for removal of gravels. The materials that passed through the sieve were subjected to dispersion, washing in 0.053 mm nominal mesh size sieve, removal of organic matter and iron oxides to obtain the clean sand fractions. Subsequently, each soil sample was sieved for separation into twelve classes, between the diameters of 0.149 mm and 1.190 mm, using a Rotap shaker. Next, tests were carried out to characterize the morphometric attributes of the twelve classes of sand fractions of the soils studied. For validation of the performance of the Sand Grain Image Capture System, the results were compared to those obtained using a standard procedure for image analysis. The analysis of the results led to the following conclusions: (i the sand fraction of the JP soil presented higher values for the morphometric indices roundness, elongation and compactness compared to sand fraction of the CP soil; and (ii the Sand Grain Image Capture System worked properly, with practicality.

  8. Effects of tailwater depth on spillway aeration

    African Journals Online (AJOL)

    2011-04-15

    Apr 15, 2011 ... Hydraulic structures such as spillways or weirs with their water-air controlling mechanisms are not only important for their structural properties but also for their effects on downstream ecology. Tailwater depth is an important factor affecting dissolved oxygen transfer and aeration rates of spillways. In this ...

  9. Grain size and shape analysis of the AD 1226 tephra layer, Reykjanes volcanic system

    Science.gov (United States)

    Ösp Magnúsdóttir, Agnes; Höskuldsson, Ármann; Larsen, Guðrún; Tumi Guðmunsson, Magnús; Sigurgeirsson, Magnús Á.

    2014-05-01

    Recent explosive eruptions in Iceland have drawn attention to long range tephra transport in the atmosphere. In Iceland tephra forming explosion eruptions are frequent, due to abundance of water. However, the volcanism on the island is principally basaltic. Volcanism along the Reykjanes Peninsula is divided into five distinct volcanic systems. Volcano-tectonic activity within these systems is periodic, with recurrence intervals in the range of 1 ka. Last volcano-tectonic sequence began around AD 940, shortly after settlement of Iceland, and lasted through AD 1340. During this period activity was characterized by basaltic fissure eruptions. Furthermore, this activity period on the Reykjanes peninsula began within the eastern most volcanic system and gradually moved towards the west across the peninsula. The 1226 eruption was a basaltic fissure eruption with in the Reykjanes volcanic system. The eruption began on land and gradually progressed towards the SW until the volcanic fissure extended into the sea. Water-magma interaction changed the eruption from effusive into explosive forming the largest tephra layer on the peninsula. Due to its close proximity to the Keflavik international airport and that of the capital of Iceland it is important to get an insight into, the characteristics, generation and distribution of such tephra deposits. In this eruption the tephra produced had an approximate volume of 0.1 km3 and covered an area of some 3500 km2 within the 0.5 cm isopach. Total grain size distribution of this tephra layer will be presented along with analysis of principal grain shapes of the finer portion of the tephra layer as a function of distance from the source. The tephra grain size is dominated by particles finer than 1 millimeter with an almost complete absence of large grains independent of distance from the source. Comprehensive understanding of the characteristics of tephra generated in this eruption can help us to understand hazards posed by future

  10. Removal of radon by aeration: testing of various aeration techniques for small water works. For European Commission under Contract No FI4PCT960054 TENAWA project

    International Nuclear Information System (INIS)

    Salonen, L.; Mehtonen, J.; Turunen, H.; Mjoenes, L.; Hagberg, N.; Raff, O.

    2002-12-01

    (diffused bubble, packed tower and spray nozzle aeration) and commercial aerators were studied in a number of Finnish, Swedish and German waterworks. Part of the aeration systems applied in the waterworks was originally designed for radon removal and the rest for removing Fe, Mn, CO 2 or H 2 S. Radon concentration in raw waters varied between 8 - 5 800 Bq/l. Diffused bubble aeration combined with spray aeration removed 98% of radon in one waterworks especially designed for radon removal. Very efficient radon removals (88 - 99%) were achieved in most waterworks using packed tower aeration whereas radon reduction using spray nozzle aeration varied in a larger range (67 - 98%). The efficiency of spray nozzle aeration can be improved easily in most plants if necessary. Various types of commercial aerators, although designed originally for radon removal in domestic use, can be applied efficiently (67 - 99%) also in small waterworks. The radon removals varied in large range (13 - 98%) in waterworks using aeration for removing Fe, Mn, CO 2 or H 2 S. Quite similar radon (about 85%) and CO 2 (about 75%) removals were achieved as a packed tower column was tested in pilot plant experiments. This agreed with the results obtained from different waterworks studied here. Practically all uranium (99.9%) was removed from water in one waterworks when a strong base anion exchanger was used. (orig.)

  11. Grain-A Java data analysis system for Total Data Readout

    International Nuclear Information System (INIS)

    Rahkila, P.

    2008-01-01

    Grain is a data analysis system developed to be used with the novel Total Data Readout data acquisition system. In Total Data Readout all the electronics channels are read out asynchronously in singles mode and each data item is timestamped. Event building and analysis has to be done entirely in the software post-processing the data stream. A flexible and efficient event parser and the accompanying software system have been written entirely in Java. The design and implementation of the software are discussed along with experiences gained in running real-life experiments

  12. Flexural Behaviour of Precast Aerated Concrete Panel (PACP with Added Fibrous Material: An Overview

    Directory of Open Access Journals (Sweden)

    Abdul Rahim Noor Hazlin

    2017-01-01

    Full Text Available The usage of precast aerated concrete panel as an IBS system has become the main alternative to conventional construction system. The usage of this panel system contributes to a sustainable and environmental friendly construction. This paper presents an overview of the precast aerated concrete panel with added fibrous material (PACP. PACP is fabricated from aerated foamed concrete with added Polypropylene fibers (PP. The influence of PP on the mechanical properties of PACP are studied and reviewed from previous research. The structural behaviour of precast concrete panel subjected to flexure load is also reviewed. It is found that PP has significant affects on the concrete mixture’s compressive stregth, tensile strength and flexural strength. It is also found that PP manage to control the crack propagation in the concrete panel.

  13. Influence of agitation speeds and aeration rates on the Xylanase activity of Aspergillus niger SS7

    Directory of Open Access Journals (Sweden)

    Yasser Bakri

    2011-08-01

    Full Text Available In this study, the effect of agitation and aeration rates on xylanase activity of Aspergillus niger SS7 in 3-litre stirred tank bioreactor was investigated. The agitation rates tested were 100, 200 and 300 rpm at each airflow rates of 0.5, 1.0 and 1.5 vvm. The maximum xylanase activity in mono- agitator system was at the agitation speed of 200 rpm and aeration rate of 1.0 vvm. In bi-agitator system, at low agitation speed (100 rpm, the xylanase activity was enhanced by 13% compared to mono- agitator system for an aeration rate of 1.0 vvm. Xylanase productivity in continuous culture was higher by approximately 3.5 times than in batch culture.

  14. Chemical Oxygen Demand abatement in sewage using Micro-Aeration Enhanced Ecological Floating Bed

    Science.gov (United States)

    Shi, Hongle; Zhou, Gaofeng; Liu, Yiqing; Tan, Jiancong; Fu, Yongsheng

    2018-02-01

    The traditional ecological floating bed combined with micro-aeration system and artificial medium was developed for the removal of contaminants and remediation of surface water. This micro-aeration enhanced ecological floating bed (MAEEFB) consisted of aeration unit, microbial processing unit and aquatic plant unit. Batch experiments were conducted in different operating conditions on the removal of chemical oxygen demand (COD) in the sewage using MAEEFB. The removal rate of COD by MAEEFB, enhanced ecological floating bed (EEFB) and traditional ecological floating bed (TEFB) in the same reaction conditions was 59.2%, 56.9% and 30.6%, respectively, indicating that the combination of micro-aeration system and artificial medium could enhance the removal efficiency of COD in TEFB. In MAEEFB, the aeration intensity should be designed reasonablely considering both treatment efficiency and operation cost. Only increasing the specific surface area of the packing cannot effectively improve the purification efficiency of water. Factors like packing material, ability of intercepting organics and complicated extent of microorganisms attaching on the packing should also be considered.

  15. Waste Stabilization Ponds and Aerated Lagoons Performance in Removal of Wastewater Indicator Microorganisms

    Directory of Open Access Journals (Sweden)

    Seyed ali Ghasemi

    2013-08-01

    Full Text Available In this work, the performance of two treatment plants in the City of Mashhad, one with an aerated lagoons system and the other one with waste stabilization ponds system were evaluated in regard to their efficiency in reduction of pathogenic microorganisms. For this purpose, over a period of one year (with 15-days intervals, samples were taken from the influent and effluent (prior to disinfection unit of the above mentioned treatment plants. The samples then were analyzed for parameters such as temperature, pH, density of total coliforms (TC and fecal coliforms (FC, dissolved oxygen and total suspended solids concentration. The results indicated that the aerated lagoons system was much more efficient in removal of indicator bacteria than the waste stabilization ponds during autumn and winter periods. However during the summer months, the waste stabilization ponds showed a higher efficiency in this regard. In general, the waste stabilization ponds system reduced the density of TC and FC by 0.21-2.15 log10 and 0.20-2.33 log10, respectively. In contrast, the levels of reduction in aerated lagoons system were in the range of 0.29-2.03 log10 for TC and 0.42-2.40 log10 for FC. Results indicated that solar intensity, pH and dissolved oxygen concentration were found to be the most significant parameters that reduced the microorganisms population in waste stabilization ponds, While, in the aerated lagoons system, the dissolved oxygen concentration in aerated basin and solar intensity play the most important role. In general, without receiving an adequate disinfection, the effluent from waste stabilization ponds and aerated lagoons cannot provide the microbiological standards required for irrigation of agricultural crops.

  16. The prevalence of deoxynivalenol and its derivatives in the spring wheat grain from different agricultural production systems in Lithuania.

    Science.gov (United States)

    Janaviciene, Sigita; Mankeviciene, Audrone; Suproniene, Skaidre; Kochiieru, Yuliia; Keriene, Ilona

    2018-02-22

    Deoxynivalenol (DON) together with two acetylated derivatives, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) occurs in cereal grains and their products. Co-occurrence of DON and acetylated derivatives in cereal grain is detected worldwide. Until now, DON and its derivatives have been considered equally toxic by health authorities. In this study, we analysed 103 samples of spring wheat grain, originating from the fields of different production systems in Lithuania, for the co-occurrence of type-B trichothecenes (DON, 3-ADON, 15-ADON). The samples were classified according to the production system-organic, sustainable and intensive. Mycotoxin levels in the spring wheat grain samples were determined by the HPLC method with UV detection. The type-B trichothecenes were found to be present at higher concentrations in the grain from the intensive production system. Eighty-one percent of the spring wheat grain samples from the intensive production system were co-contaminated with a combination of DON+3-ADON+15-ADON, 1% with DON+3-ADON. Additionally, DON+15-ADON and DON were found in 5% and 10% of the tested samples, respectively. Two percent of the samples were free from mycotoxins. In the grain samples from the sustainable production system, DON and a combination of DON+3-ADON showed a higher incidence - 47% and 23%, respectively. The samples with a combination of DON+3-ADON+15-ADON accounted for 18%. Completely different results were obtained from the analyses of organic grain samples. A large number of the organic spring wheat grain samples were contaminated with DON+3-ADON (55%) or DON (36%). The combination of DON+3-ADON+15-ADON was not present, while DON+15-ADON was present in 9% of the samples tested. The production systems did not lead to significant differences in mycotoxin levels, although a trend toward higher incidence and higher contamination was observed for the samples from the intensive and sustainable production systems.

  17. Decolorization of reactive dye using a photo-ferrioxalate system with brick grain-supported iron oxide

    International Nuclear Information System (INIS)

    Cheng, Hui-Pin; Huang, Yao-Hui; Lee, Changha

    2011-01-01

    The photocatalytic activity of a brick grain-supported iron oxide (denoted as B1) was tested for its activity to degrade Reactive Black 5 (RB5) in the presence of oxalic acid. B1 was obtained as a solid waste from a wastewater treatment plant, and characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N 2 adsorption/desorption isotherm analyses. The decolorization experiments were performed in a fluidized bed reactor with aeration under UV-A irradiation (λ = 365 nm). The effects of various factors such as solution pH, concentration of oxalic acid and dissolved oxygen on the decolorization of RB5 were evaluated considering the contributions of adsorption and photo-catalytic degradation. The role of dissolved iron in the removal of RB5 and the stability of B1 were also examined. In addition, the removal of TOC during the photo-catalytic reaction was monitored.

  18. Decolorization of reactive dye using a photo-ferrioxalate system with brick grain-supported iron oxide.

    Science.gov (United States)

    Cheng, Hui-Pin; Huang, Yao-Hui; Lee, Changha

    2011-04-15

    The photocatalytic activity of a brick grain-supported iron oxide (denoted as B1) was tested for its activity to degrade Reactive Black 5 (RB5) in the presence of oxalic acid. B1 was obtained as a solid waste from a wastewater treatment plant, and characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N(2) adsorption/desorption isotherm analyses. The decolorization experiments were performed in a fluidized bed reactor with aeration under UV-A irradiation (λ = 365 nm). The effects of various factors such as solution pH, concentration of oxalic acid and dissolved oxygen on the decolorization of RB5 were evaluated considering the contributions of adsorption and photo-catalytic degradation. The role of dissolved iron in the removal of RB5 and the stability of B1 were also examined. In addition, the removal of TOC during the photo-catalytic reaction was monitored. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Decolorization of reactive dye using a photo-ferrioxalate system with brick grain-supported iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hui-Pin [Department of Chemical Engineering, National Cheng Kung University, Tainan City 701, Taiwan (China); Huang, Yao-Hui, E-mail: yhhuang@mail.ncku.edu.tw [Department of Chemical Engineering, National Cheng Kung University, Tainan City 701, Taiwan (China); Lee, Changha, E-mail: clee@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon-ri, Eonyang-eup, Ulju-gun, Ulsan 698-805 (Korea, Republic of)

    2011-04-15

    The photocatalytic activity of a brick grain-supported iron oxide (denoted as B1) was tested for its activity to degrade Reactive Black 5 (RB5) in the presence of oxalic acid. B1 was obtained as a solid waste from a wastewater treatment plant, and characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N{sub 2} adsorption/desorption isotherm analyses. The decolorization experiments were performed in a fluidized bed reactor with aeration under UV-A irradiation ({lambda} = 365 nm). The effects of various factors such as solution pH, concentration of oxalic acid and dissolved oxygen on the decolorization of RB5 were evaluated considering the contributions of adsorption and photo-catalytic degradation. The role of dissolved iron in the removal of RB5 and the stability of B1 were also examined. In addition, the removal of TOC during the photo-catalytic reaction was monitored.

  20. A method to calculate flux distribution in reactor systems containing materials with grain structure

    International Nuclear Information System (INIS)

    Stepanek, J.

    1980-01-01

    A method is proposed to compute the neutron flux spatial distribution in slab, spherical or cylindrical systems containing zones with close grain structure of material. Several different types of equally distributed particles embedded in the matrix material are allowed in one or more zones. The multi-energy group structure of the flux is considered. The collision probability method is used to compute the fluxes in the grains and in an ''effective'' part of the matrix material. Then the overall structure of the flux distribution in the zones with homogenized materials is determined using the DPN ''surface flux'' method. Both computations are connected using the balance equation during the outer iterations. The proposed method is written in the code SURCU-DH. Two testcases are computed and discussed. One testcase is the computation of the eigenvalue in simplified slab geometry of an LWR container of one zone with boral grains equally distributed in an aluminium matrix. The second is the computation of the eigenvalue in spherical geometry of the HTR pebble-bed cell with spherical particles embedded in a graphite matrix. The results are compared to those obtained by repeated use of the WIMS Code. (author)

  1. Pilot scale experiment with MBR operated in intermittent aeration condition: analysis of biological performance.

    Science.gov (United States)

    Capodici, M; Di Bella, G; Di Trapani, D; Torregrossa, M

    2015-02-01

    The effect of intermittent aeration (IA) on a MBR system was investigated. The study was aimed at analyzing different working conditions and the influence of different IA cycles on the biological performance of the MBR pilot plant, in terms of organic carbon and ammonium removal as well as extracellular polymeric substances (EPSs) production. The membrane modules were placed in a separate compartment, continuously aerated. This configuration allowed to disconnect from the filtration stage the biological phenomena occurring into the IA bioreactor. The observed results highlighted good efficiencies, in terms of organic carbon and ammonium removal. It was noticed a significant soluble microbial products (SMPs) release, likely related to the higher metabolic stress that anoxic conditions exerted on the biomass. However, the proposed configuration, with the membranes in a separate compartment, allowed to reduce the EPSs in the membrane tank even during the non-aerated phase, thus lowering fouling development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Analysis Framework of China’s Grain Production System: A Spatial Resilience Perspective

    Directory of Open Access Journals (Sweden)

    Dazhuan Ge

    2017-12-01

    Full Text Available China’s grain production has transformed from absolute shortage to a current structural oversupply. High-intensity production introduced further challenges for the eco-environment, smallholder livelihood, and the man-land interrelationship. Driven by urban-rural transformation, research on food security patterns and grain production has expanded into a new field. To analyze the challenges and required countermeasures for China’s grain production system (GPS, this study constructed a theoretical GPS framework based on space resilience. Firstly, a new GPS concept was proposed and a functional system was established for protecting the regional food security, thus guaranteeing smallholder livelihood, stabilizing urban-rural transformation, and sustaining the eco-environment in terms of economic, social, and ecological attributes of the GPS. Secondly, based on a cross-scale interaction analysis that varied from a smallholder scale to a global scale, the systematic crisis of the GPS was analyzed. Thirdly, a cross-scale analytic framework of the GPS was formed from the perspective of spatial resilience, integrating both inner and external disturbance factors of the GPS. Both spatial heterogeneity and connectivity of internal and external disturbance factors are important contents of system space resilience. Finally, the hierarchy of spatial resilience of GPS became clear. The transformation of labor force and the land use transition form key thresholds of the GPS. In summary: based on protecting the basic functions of the GPS, the cross-scale effect of systematic disturbance factors and relevant countermeasures for spatial resilience are effectively influenced by the coordination of the interests of multiple stakeholders; spatial resilience is an effective analytical tool for GPS regulation, providing a reference for revealing the inherent mechanism and functional evolution of the GPS in the process of urban-rural transformation.

  3. The effects of micro-aeration on the phylogenetic diversity of microorganisms in a thermophilic anaerobic municipal solid-waste digester.

    Science.gov (United States)

    Tang, Yueqin; Shigematsu, Toru; Ikbal; Morimura, Shigeru; Kida, Kenji

    2004-05-01

    We demonstrated previously that micro-aeration allows construction of an effective thermophilic methane-fermentation system for treatment of municipal solid waste (MSW) without production of H(2)S. In the present study, we compared the microbial communities in a thermophilic MSW digester without aeration and with micro-aeration by fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE), phylogenetic analysis of libraries of 16S rRNA gene clones and quantitative real-time PCR. Moreover, we studied the activity of sulfate-reducing bacteria (SRB) by analysis of the transcription of the gene for dissimilatory sulfite reductase (dsr). Experiments using FISH revealed that microorganisms belonging to the domain Bacteria dominated in the digester both without aeration and with micro-aeration. Phylogenetic analysis based on 16S rRNA gene and analysis of bacteria by DGGE did not reveal any obvious difference within the microbial communities under the two aeration conditions, and bacteria affiliated with the phylum Firmicutes were dominant. In Archaea, the population of Methanosarcina decreased while the population of Methanoculleus increased as a result of micro-aerations as revealed by the analysis of 16S rRNA gene clones and quantitative real-time PCR. Reverse transcription and PCR (RT-PCR) demonstrated the transcription of dsrA not only in the absence of aeration but also in the presence of micro-aeration, even under conditions where no H(2)S was detected in the biogas. In conclusion, micro-aeration has no obvious effects on the phylogenetic diversity of microorganisms. Furthermore, the activity of SRBs in the digester was not repressed even though the concentration of H(2)S in the biogas was very low under the micro-aeration conditions.

  4. Fine grained event processing on HPCs with the ATLAS Yoda system

    CERN Document Server

    Calafiura, Paolo; The ATLAS collaboration; Guan, Wen; Maeno, Tadashi; Nilsson, Paul; Oleynik, Danila; Panitkin, Sergey; Tsulaia, Vakhtang; van Gemmeren, Peter; Wenaus, Torre

    2015-01-01

    High performance computing facilities present unique challenges and opportunities for HENP event processing. The massive scale of many HPC systems means that fractionally small utilizations can yield large returns in processing throughput. Parallel applications which can dynamically and efficiently fill any scheduling opportunities the resource presents benefit both the facility (maximal utilization) and the (compute-limited) science. The ATLAS Yoda system provides this capability to HENP-like event processing applications by implementing event-level processing in an MPI-based master-client model that integrates seamlessly with the more broadly scoped ATLAS Event Service. Fine grained, event level work assignments are intelligently dispatched to parallel workers to sustain full utilization on all cores, with outputs streamed off to destination object stores in near real time with similarly fine granularity, such that processing can proceed until termination with full utilization. The system offers the efficie...

  5. Computer vision system: a tool for evaluating the quality of wheat in a grain tank

    Science.gov (United States)

    Minkin, Uryi Igorevish; Panchenko, Aleksei Vladimirovich; Shkanaev, Aleksandr Yurievich; Konovalenko, Ivan Andreevich; Putintsev, Dmitry Nikolaevich; Sadekov, Rinat Nailevish

    2018-04-01

    The paper describes a technology that allows for automatizing the process of evaluating the grain quality in a grain tank of a combine harvester. Special recognition algorithm analyzes photographic images taken by the camera, and that provides automatic estimates of the total mass fraction of broken grains and the presence of non-grains. The paper also presents the operating details of the tank prototype as well as it defines the accuracy of the algorithms designed.

  6. Anaerobic digestion of grain stillage at high organic loading rates in three different reactor systems

    International Nuclear Information System (INIS)

    Schmidt, Thomas; Pröter, Jürgen; Scholwin, Frank; Nelles, Michael

    2013-01-01

    In this study the anaerobic digestion of grain stillage in three different reactor systems (continuous stirred tank reactor, anaerobic sequencing batch reactor, fixed bed reactor) with and without immobilization of microorganisms was investigated to evaluate the performance during increase of the organic loading rate (OLR) from 1 to 10 g of volatile solids (VS) per liter reactor volume and day and decrease of the hydraulic retention time (HRT) from 40 to 6 days. No significant differences have been observed between the performances of the three examined reactor systems. The changes in OLR and HRT caused a reduction of the specific biogas production (SBP) of about 25% from about 650 to 550 L kg −1 of VS but would also diminish the necessary digester volume and investment costs of about 75% compared to the state of the art. -- Highlights: ► It was shown that without immobilization of microorganisms low HRT's are possible. ► No significant differences have been observed between different digester designs. ► Trace element supplementation is obligatory with grain stillage as substrate

  7. Colloid formation in groundwater by subsurface aeration: characterisation of the geo-colloids and their counterparts

    International Nuclear Information System (INIS)

    Wolthoorn, Anke; Temminghoff, Erwin J.M.; Riemsdijk, Willem H. van

    2004-01-01

    Subsurface aeration is used to oxidise Fe in situ in groundwater to make the water potable. In a groundwater system with pH > 7, subsurface aeration results in a non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove Fe in situ, the formation of non-mobile Fe precipitate is the desired result. In addition to this intended effect, subsurface aeration may also strongly enhance the microbiological removal of NH 4 in the purification station. A hypothesis is that mobile Fe colloids may be the link between subsurface aeration and the positive effect on the microbiological removal of NH 4 . The objective of this study is to characterise the mobile Fe colloids and to derive a synthetic substitute for the naturally formed Fe colloids in order to be able to apply the Fe colloids as a management tool to enhance the removal of NH 4 in the process of producing drinking water from groundwater. At a purification station in The Netherlands natural Fe colloids from an aerated well were sampled. Furthermore, eight synthetic Fe colloids were prepared by oxidising synthetic solutions differing in elemental composition. The colloids were analysed using chemical analysis and electron microscopy (SEM and SEM-EDAX). The Fe colloids sampled in the field contained Fe, Ca, Na, PO 4 and Mn. Also in the synthetic Fe colloids PO 4 , Ca, Na and Mn were the most important elements next to Fe. Phosphate and dissolved organic C strongly influenced the morphology of the synthetic Fe colloids. When both the elemental composition and the morphology of the Fe colloids are taken into account, the synthetic Fe colloids formed in the synthetic solution containing Fe, Mn, PO 4 , SiO 4 and dissolved organic matter best match the Fe colloids from the field

  8. Colloid formation in groundwater by subsurface aeration: characterisation of the geo-colloids and their counterparts

    Energy Technology Data Exchange (ETDEWEB)

    Wolthoorn, Anke; Temminghoff, Erwin J.M.; Riemsdijk, Willem H. van

    2004-09-01

    Subsurface aeration is used to oxidise Fe in situ in groundwater to make the water potable. In a groundwater system with pH > 7, subsurface aeration results in a non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove Fe in situ, the formation of non-mobile Fe precipitate is the desired result. In addition to this intended effect, subsurface aeration may also strongly enhance the microbiological removal of NH{sub 4} in the purification station. A hypothesis is that mobile Fe colloids may be the link between subsurface aeration and the positive effect on the microbiological removal of NH{sub 4}. The objective of this study is to characterise the mobile Fe colloids and to derive a synthetic substitute for the naturally formed Fe colloids in order to be able to apply the Fe colloids as a management tool to enhance the removal of NH{sub 4} in the process of producing drinking water from groundwater. At a purification station in The Netherlands natural Fe colloids from an aerated well were sampled. Furthermore, eight synthetic Fe colloids were prepared by oxidising synthetic solutions differing in elemental composition. The colloids were analysed using chemical analysis and electron microscopy (SEM and SEM-EDAX). The Fe colloids sampled in the field contained Fe, Ca, Na, PO{sub 4} and Mn. Also in the synthetic Fe colloids PO{sub 4}, Ca, Na and Mn were the most important elements next to Fe. Phosphate and dissolved organic C strongly influenced the morphology of the synthetic Fe colloids. When both the elemental composition and the morphology of the Fe colloids are taken into account, the synthetic Fe colloids formed in the synthetic solution containing Fe, Mn, PO{sub 4}, SiO{sub 4} and dissolved organic matter best match the Fe colloids from the field.

  9. Simulating of Top-Cross system for enhancement of antioxidants in maize grain

    Directory of Open Access Journals (Sweden)

    Jelena Vancetovic

    2014-04-01

    Full Text Available Blue maize (Zea mays L. is grown for its high content of antioxidants. Conversion of yellow and white to blue maize is time consuming because several genes affect blue color. After each backcross selfing is needed for color to be expressed. In order to overcome the problem of time and effort needed for conversion to blue kernel color, we have set a pilot experiment simulating a Top-cross system for increasing antioxidants in maize grain. The idea is to alternately sow six rows of sterile standard quality hybrid and two rows of blue maize in commercial production. Five commercial ZP hybrids were crossed with a blue pop-corn population. Xenia effect caused by cross-pollination produced blue grain on all hybrids in the same year. Chemical analyses of the grains of five selfed original hybrids, five cross-pollinated hybrids and selfed blue popcorn pollinator were performed. Cross-fertilization with blue popcorn had different impact on antioxidant capacity and phytonutrients, increasing them significantly in some but not all cross-pollinated hybrids. Popcorn blue pollinator had higher values for all the analyzed traits than either selfed or cross-pollinated hybrids. Selfed vs. pollinated hybrids showed significant difference for total antioxidant capacity (p<0.1, total phenolics and total yellow pigments (p<0.01, with the increase of total phenolics and decrease of total yellow pigments in pollinated ones. Total flavonoids showed a little non-significant decrease in pollinated hybrids, while total anthocyanins were not detected in selfed yellow hybrids. Blue maize obtained this way has shown good potential for growing high quality phytonutrient genotypes.

  10. 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.

  11. Efeitos de sistemas de cultivo na densidade e macroporosidade do solo e no desenvolvimento radicular do milho em latossolo roxo Effects of tillage systems on bulk density, aeration porosity and root development of corn in a typic haplorthox soil

    Directory of Open Access Journals (Sweden)

    Paulo César Corsini

    1999-02-01

    Full Text Available Neste trabalho foram estudados os efeitos imediato e residual de dois sistemas de preparo na densidade e macroporosidade do solo e no desenvolvimento radicular do milho (Zea mays L., em camadas estruturalmente estabilizadas de um Latossolo Roxo, mantido por longo período sob plantio direto de milho. Os efeitos imediatos das operações envolvendo a subsolagem e a aração e gradagem aumentaram, em menos de um ano agrícola, a macroporosidade da camada superficial desse solo bem como o potencial de desenvolvimento radicular. Nesses tratamentos e nos três primeiros anos agrícolas, a adoção contínua do sistema de plantio direto diminuiu a porosidade de aeração do solo e o potencial de desenvolvimento radicular do milho. Os benefícios da manutenção desse sistema conservacionista nos valores de macroporosidade e densidade na camada superficial do solo iniciaram-se no quarto ano agrícola. A partir daí aumentaram, atingindo no oitavo ano agrícola consecutivo valores semelhantes aos imediatamente obtidos após as operações mecânicas realizadas na instalação do experimento. As relações entre desenvolvimento radicular, densidade e macroporosidade do solo foram estabelecidas por equações bem como por classes de desenvolvimento radicular.The objective of this study was to evaluate the immediate and the residual effects of soil preparation on bulk density, aeration porosity and root development relationships in stabilized structural layers of a typic Haplorthox soil due to long-term no-tillage system of corn (Zea mays L..The immediate effects of soil preparation to planting involving subsoiling, plowing, and disking improved soil macroporosity and root development for a short period of time. In these treatments and on the first three consecutive years, the adoption of continuous no-tillage management decreased soil macroporosity and root development. The long-term benefits of continuous no-tillage on soil macroporosity initiated at the

  12. An Application for the Improvement of the Transportation System of the Flour in a Grain Mill using "PID Compact"

    Directory of Open Access Journals (Sweden)

    Eugen Răduca

    2016-10-01

    Full Text Available The paper presents an application based on a PLC Simatic S7-1200, using the "PID_Compact" logical function, which can be used for the improvement of control systems. We also present a practical application: a system for the improvement of the transportation system of the flour in a grain mill using "PID Compact" .

  13. Formation of multiple stoichiometric phases in binary systems by combined bulk and grain boundary diffusion: Experiments and model

    International Nuclear Information System (INIS)

    Svoboda, J.; Fischer, F.D.; Schillinger, W.

    2013-01-01

    The thermodynamic extremal principle has been used by the authors to treat the evolution of binary and multicomponent systems under the assumption that all phases are nearly stoichiometric. Up to now only bulk diffusion has been taken into account. The concept is now extended to combined bulk and grain boundary diffusion possible in each newly formed phase. The grains are approximated by cylinders allowing interface diffusion along the top and bottom of the grains and grain boundary diffusion along the mantle with different interface/grain boundary diffusion coefficients. A consistent analysis yields an effective diffusion coefficient taking into account the combined interface/grain boundary and bulk diffusion of each individual component. The current concept is applied to the Cu–Sn couple which has been studied by a number of researchers. The results of simulations are compared with experiments at 200 °C on solid systems reported in the literature as well as with our experiments at 250 °C with liquid Sn.

  14. Integral parameters for characterizing water, energy, and aeration properties of soilless plant growth media

    Science.gov (United States)

    Chamindu Deepagoda, T. K. K.; Chen Lopez, Jose Choc; Møldrup, Per; de Jonge, Lis Wollesen; Tuller, Markus

    2013-10-01

    Over the last decade there has been a significant shift in global agricultural practice. Because the rapid increase of human population poses unprecedented challenges to production of an adequate and economically feasible food supply for undernourished populations, soilless greenhouse production systems are regaining increased worldwide attention. The optimal control of water availability and aeration is an essential prerequisite to successfully operate plant growth systems with soilless substrates such as aggregated foamed glass, perlite, rockwool, coconut coir, or mixtures thereof. While there are considerable empirical and theoretical efforts devoted to characterize water retention and aeration substrate properties, a holistic, physically-based approach considering water retention and aeration concurrently is lacking. In this study, the previously developed concept of integral water storage and energy was expanded to dual-porosity substrates and an analog integral oxygen diffusivity parameter was introduced to simultaneously characterize aeration properties of four common soilless greenhouse growth media. Integral parameters were derived for greenhouse crops in general, as well as for tomatoes. The integral approach provided important insights for irrigation management and for potential optimization of substrate properties. Furthermore, an observed relationship between the integral parameters for water availability and oxygen diffusivity can be potentially applied for the design of advanced irrigation and management strategies to ensure stress-free growth conditions, while conserving water resources.

  15. Mechanisms for naphthalene removal during electrolytic aeration.

    Science.gov (United States)

    Goel, Ramesh K; Flora, Joseph R V; Ferry, John

    2003-02-01

    Batch tests were performed to investigate chemical and physical processes that may result during electrolytic aeration of a contaminated aquifer using naphthalene as a model contaminant. Naphthalene degradation of 58-66% took place electrolytically and occurred at the same rates at a pH of 4 and 7. 1,4-naphthoquinone was identified as a product of the electrolysis. Stripping due to gases produced at the electrodes did not result in any naphthalene loss. Hydrogen peroxide (which may be produced at the cathode) did not have any effect on naphthalene, but the addition of ferrous iron (which may be present in aquifers) resulted in 67-99% disappearance of naphthalene. Chlorine (which may be produced from the anodic oxidation of chloride) can effectively degrade naphthalene at pH of 4, but not at a pH of 7. Mono-, di- and poly chloronaphthalenes were identified as oxidation products. Ferric iron coagulation (due to the oxidation of ferrous iron) did not significantly contribute to naphthalene loss. Overall, electrolytic oxidation and chemical oxidation due to the electrolytic by-products formed are significant abiotic processes that could occur and should be accounted for if bioremediation of PAH-contaminated sites via electrolytic aeration is considered. Possible undesirable products such as chlorinated compounds may be formed when significant amounts of chlorides are present.

  16. Radionuclide migration test using undisturbed aerated soil

    International Nuclear Information System (INIS)

    Yamamoto, Tadatoshi; Ohtsuka, Yoshiro; Ogawa, Hiromichi; Wadachi, Yoshiki

    1988-01-01

    As one of the most important part of safety assessment on the shallow land disposal of lowlevel radioactive waste, the radionuclide migration was studied using undisturbed soil samples, in order to evaluate an exact radionuclide migration in an aerated soil layer. Soil samples used in the migration test were coastal sand and loamy soil which form typical surface soil layers in Japan. The aqueous solution containing 60 CoCl 2 , 85 SrCl 2 and 137 CsCl was fed into the soil column and concentration of each radionuclide both in effluent and in soil was measured. Large amount of radionuclides was adsorbed on the surface of soil column and small amount of radionuclides moved deep into the soil column. Difference in the radionuclide profile was observed in the low concentration portion particularly. It is that some fractions of 60 Co and 137 Cs are stable in non-ionic form and move downward through the soil column together with water. The radionuclide distribution in the surface of soil column can be fairly predicted with a conventional migration equation for ionic radionuclides. As a result of radionuclide adsorption, both aerated soil layers of coastal sand and loamy soil have large barrier ability on the radionuclide migration through the ground. (author)

  17. Oxidation of magnetite in aerated aqueous media

    International Nuclear Information System (INIS)

    Taylor, P.; Owen, D.G.

    1993-04-01

    Metastable equilibria involving phases less stable than hematite can be significantly more oxidizing than the calculated equilibrium between well-crystallized hematite and magnetite. In this report, generalized solubility and stability relationships between magnetite and Fe 2 O 3 .xH 2 O phases are derived to describe the metastable equilibria. Experiments with synthetic magnetite powders in aerated aqueous solutions show that crystalline hematite is formed within days at temperatures above 100 C in pure water or solutions containing anions (e.g., Cl - , SO 4 2 - , HCO 3 - ) that do not form very strong surface complexes with iron oxides. In the presence of dissolved phosphate or silica, however, the dissolution-precipitation route to hematite is strongly inhibited, and maghemite is a persistent metastable product. Thus, phosphate or silica are expected to delay the approach to magnetite-hematite equilibrium in aerated groundwaters conditioned by magnetite. These findings are presented in the context of nuclear fuel waste disposal. (author). 63 refs., 1 tab., 11 figs

  18. Enhancement of ultrasonic disintegration of sewage sludge by aeration.

    Science.gov (United States)

    Zhao, He; Zhang, Panyue; Zhang, Guangming; Cheng, Rong

    2016-04-01

    Sonication is an effective way for sludge disintegration, which can significantly improve the efficiency of anaerobic digestion to reduce and recycle use of sludge. But high energy consumption limits the wide application of sonication. In order to improve ultrasonic sludge disintegration efficiency and reduce energy consumption, aeration was introduced. Results showed that sludge disintegration efficiency was improved significantly by combining aeration with ultrasound. The aeration flow rate, gas bubble size, ultrasonic density and aeration timing had impacts on sludge disintegration efficiency. Aeration that used in later stage of ultrasonic irradiation with low aeration flow rate, small gas bubbles significantly improved ultrasonic disintegration sludge efficiency. At the optimal conditions of 0.4 W/mL ultrasonic irradiation density, 30 mL/min of aeration flow rate, 5 min of aeration in later stage and small gas bubbles, ultrasonic sludge disintegration efficiency was increased by 45% and one third of ultrasonic energy was saved. This approach will greatly benefit the application of ultrasonic sludge disintegration and strongly promote the treatment and recycle of wastewater sludge. Copyright © 2015. Published by Elsevier B.V.

  19. Influence of aeration and lighting on biomass production and protein ...

    African Journals Online (AJOL)

    The influence aeration and light intensity could have on biomass production and protein biosynthesis in a Spirulina sp. isolated from an oil-polluted brackish water marsh is examined. Biomass, proximal composition and amino acid composition obtained from aerated cultures of the organism were compared with ...

  20. 21 CFR 880.6100 - Ethylene oxide gas aerator cabinet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide gas aerator cabinet. 880.6100... Miscellaneous Devices § 880.6100 Ethylene oxide gas aerator cabinet. (a) Identification. An ethyene oxide gas... required to remove residual ethylene oxide (ETO) from wrapped medical devices that have undergone ETO...

  1. Automatic Time Regulator for Switching on an Aeration Device for ...

    African Journals Online (AJOL)

    The need to aerate the pond at odd hours due to diurnal limit, save cost and human labor, necessitated the design of an automatic time regulator circuit, which controls the switching on and o of an aeration device at a pre determined and selected time interval (5mins., 10mins., 20mins., 30mins., and 40mins.) This design ...

  2. A Trade Study of Two Membrane-Aerated Biological Water Processors

    Science.gov (United States)

    Allada, Ram; Lange, Kevin; Vega. Leticia; Roberts, Michael S.; Jackson, Andrew; Anderson, Molly; Pickering, Karen

    2011-01-01

    Biologically based systems are under evaluation as primary water processors for next generation life support systems due to their low power requirements and their inherent regenerative nature. This paper will summarize the results of two recent studies involving membrane aerated biological water processors and present results of a trade study comparing the two systems with regards to waste stream composition, nutrient loading and system design. Results of optimal configurations will be presented.

  3. Otimização de sistema de autoaspiração de ar tipo Venturi para tratamento de água ferruginosa Optimization of auto-aspiration aeration system type Venturi for the treatment of ferruginous water

    Directory of Open Access Journals (Sweden)

    Jeferson S. Piccin

    2010-05-01

    Full Text Available Na confecção deste trabalho se utilizou a metodologia de superfície de resposta para otimizar o efeito do número de Reynolds, tempo de floculação e concentração de hipoclorito de sódio sobre a oxidação/floculação do ferro presente em águas subterrâneas em um sistema de aeração com autoaspiração de ar. O sistema se compunha de um vaso tipo Venturi, acoplado a um tubo de mistura para promover a oxigenação da água através da sucção do ar atmosférico. O mapeamento hidrodinâmico permitiu verificar as condições de operação no qual o sistema apresentou melhor eficiência de sucção de ar e menor consumo de energia, além de compará-las com as melhores condições a campo. Os resultados observados demonstraram que foi possível a remoção de 98,7% do ferro presente (residual ferro de 0,06 mg L-1 quando o sistema operou com número de Reynolds no estrangulamento do Venturi de 5,39 x 10(4, concentrações de hipoclorito de sódio de 38,4 mg L-1 e tempo de floculação 30 min. A metodologia de superfície de resposta foi satisfatória e permitiu otimizar as variáveis operacionais citadas.In this study the response surface methodology was used to optimize the effect of Reynolds number, flocculation time and sodium hypochlorite concentration on the iron oxidation/flocculation present in groundwaters in an aeration system with air auto-aspiration. This system was composed of a recipient type Venturi coupled to a mixture tube to promote the oxygenation of the water through the suction of the atmospheric air. The hydrodynamic mapping allowed the verification of the operation conditions in which the system presented the best air suction efficiency and energy consumption, and the comparison of the best field conditions. The observed results demonstrated that it was possible to remove 98.7% of present iron (residual iron of 0.06 mg L-1 when the system operated with Reynolds number of 5.39 x 10(4, sodium hypochlorite

  4. Grey-box modelling of aeration tank settling.

    Science.gov (United States)

    Bechman, Henrik; Nielsen, Marinus K; Poulsen, Niels Kjølstad; Madsen, Henrik

    2002-04-01

    A model of the concentrations of suspended solids (SS) in the aeration tanks and in the effluent from these during Aeration tank settling (ATS) operation is established. The model is based on simple SS mass balances, a model of the sludge settling and a simple model of how the SS concentration in the effluent from the aeration tanks depends on the actual concentrations in the tanks and the sludge blanket depth. The model is formulated in continuous time by means of stochastic differential equations with discrete-time observations. The parameters of the model are estimated using a maximum likelihood method from data from an alternating BioDenipho waste water treatment plant (WWTP). The model is an important tool for analyzing ATS operation and for selecting the appropriate control actions during ATS, as the model can be used to predict the SS amounts in the aeration tanks as well as in the effluent from the aeration tanks.

  5. A Fine-Grained Data Access Control System in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Boniface K. Alese

    2015-12-01

    Full Text Available The evolving realities of Wireless Sensor Network (WSN deployed to various terrain of life require serving multiple applications. As large amount of sensed data are distributed and stored in individual sensors nodes, the illegal access to these sensitive data can be devastating. Consequently, data insecurity becomes a big concern. This study, therefore, proposes a fine-grained access control system which only requires the right set of users to access a particular data, based on their access privileges in the sensor networks. It is designed using Priccess Protocol with Access policy formulation adopting the principle of Bell Lapadula model as well as Attribute-Based Encryption (ABE to control access to sensor data. The functionality of the proposed system is simulated using Netbeans. The performance analysis of the proposed system using execution time and size of the key show that the higher the key size, the harder it becomes for the attacker to hack the system. Additionally, the time taken for the proposed work is lesser which makes the work faster than the existing work. Consequently, a well secure interactive web-based application that could facilitates the field officers access to stored data in safe and secure manner is developed.

  6. Determination of pressure distribution in an aerated bed in a controlled pilot-scale compost reactor

    Energy Technology Data Exchange (ETDEWEB)

    Solowiej, P. [Warmia and Mazury Univ., Olsztyn (Poland)

    2010-07-01

    This study investigated the effectiveness of dealing with biological waste by composting. In particular, it examined the feasibility of recovering excess thermal energy produced in the process of composting biological waste in terms of mass and energy transport parameters required in the aerated compost bed. An experiment was performed in which a 100 dm{sup 3} adiabatic, leak-tight reactor equipped with a controlled aeration system was constructed to study the temperature and pressure distribution in the bed. Sensors were used to determine the amount and humidity of emitted gases under variable external physical conditions. The perforated bottom of the reactor allowed for bed aeration. As such, the humidity and heat were transported upwards, forced by the air pumped in and by natural convection. In terms of pressure distribution inside the composted and aerated bed, the study results showed that there were considerable differences in pressure for the selected places of the bed of the composted biological material. An increase in upwards pressure was observed in the heap throughout the experiment. Pressure differences in the same plane of the bed were also noted. The study results should facilitate the development of a model of mass and energy transport in a bed of composted material.

  7. Strongly coupled Coulomb systems with positive dust grains: thermal and UV-induced plasmas

    International Nuclear Information System (INIS)

    Samarian, A.A.

    2000-01-01

    Full text: A plasma containing macroscopic dust particles or grains (often referred to as a dusty or colloidal or complex plasma) has the feature that grains may be charged by electron or ion flux or by photo- or thermoelectron emission. Electron emission from a grain surface produces a positive charge; capture of electrons produces the reverse effect making the dust grains negatively charged. Most dusty plasma research is concerned with the ordered dust structures (so-called 'plasma crystal') in glow discharges. The dust grains in these experiments were found to carry a negative charge due to the higher mobility of electrons as compared to ions in the discharge plasma. In recent years, in parallel with the study of the properties of plasma crystals under discharge conditions, attempts to obtain a structure from positively charged dust grains have been made, and structure formation processes for various charging mechanisms, particularly thermoelectron emission and photoemission, have been investigated. In this paper we review the essential features of strongly coupled plasmas with positive dust grains. An ordered structure of CeO 2 grains has been experimentally observed in a combustion products jet. The grains were charged positively and suspended in the plasma flow. Their charge is about 10 3 a and the calculated value of a Coulomb coupling parameter Γ is >10, corresponding to a plasma liquid. The ordered structures of Al 2 O 3 dust grains in propellant combustion products plasma have been observed for the first time. These structures were found in the sheath boundary of condensation region. The obtained data let us estimate the value of parameter Γ =3-40, corresponding to the plasma liquid state. The possibility is studied of the formation of ordered dust grain structures in thermal plasma. The range of the required values of the coupling parameter Γ is calculated using the results of diagnostic measurements carried out in thermal plasma with grains of

  8. The geometry of generalized force matching and related information metrics in coarse-graining of molecular systems

    International Nuclear Information System (INIS)

    Kalligiannaki, Evangelia; Harmandaris, Vagelis; Katsoulakis, Markos A.; Plecháč, Petr

    2015-01-01

    Using the probabilistic language of conditional expectations, we reformulate the force matching method for coarse-graining of molecular systems as a projection onto spaces of coarse observables. A practical outcome of this probabilistic description is the link of the force matching method with thermodynamic integration. This connection provides a way to systematically construct a local mean force and to optimally approximate the potential of mean force through force matching. We introduce a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (e.g., reaction coordinates, end-to-end length of chains). Furthermore, we study the equivalence of force matching with relative entropy minimization which we derive for general non-linear coarse graining maps. We present in detail the generalized force matching condition through applications to specific examples in molecular systems

  9. The geometry of generalized force matching and related information metrics in coarse-graining of molecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Kalligiannaki, Evangelia, E-mail: ekalligian@tem.uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete, 70013 Heraklion (Greece); Harmandaris, Vagelis, E-mail: harman@uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete, 70013 Heraklion (Greece); Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), IACM/FORTH, GR-71110 Heraklion (Greece); Katsoulakis, Markos A., E-mail: markos@math.umass.edu [Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Plecháč, Petr, E-mail: plechac@math.udel.edu [Department of Mathematical Sciences, University of Delaware, Newark, Delaware 19716 (United States)

    2015-08-28

    Using the probabilistic language of conditional expectations, we reformulate the force matching method for coarse-graining of molecular systems as a projection onto spaces of coarse observables. A practical outcome of this probabilistic description is the link of the force matching method with thermodynamic integration. This connection provides a way to systematically construct a local mean force and to optimally approximate the potential of mean force through force matching. We introduce a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (e.g., reaction coordinates, end-to-end length of chains). Furthermore, we study the equivalence of force matching with relative entropy minimization which we derive for general non-linear coarse graining maps. We present in detail the generalized force matching condition through applications to specific examples in molecular systems.

  10. Experimental Study of Paddy Grain Drying in Continuous Recirculation System Pneumatic Conveyor

    Directory of Open Access Journals (Sweden)

    Prasetyo Totok

    2018-01-01

    Full Text Available Nowadays, paddy drying using conventional method is irrelevant to used. The increasing need of grain each year is one of the main factor that pushes scientist to invent new methods of drying paddy grain. The old method is unusefull since it takes up space, needed the sun as the drying media which causes a long drying time. One of the alternative of drying paddy grain is by using mechanic dryer. By using this dryer type, the process of drying takes faster comparing to the old method and the distribution of grain is supplied continuously. The dryer which uses pneumatic conveyor can be one of the solution due to its less energy consumption, a better drying result, and high drying capacity. The variable used to identify drying performance is temperature and loading weight. From the experiment, it is resulted that the best temperature for drying paddy grain is 60°C with the weight loading of 150 gram.

  11. Giant grains

    International Nuclear Information System (INIS)

    Leitch-Devlin, M.A.; Millar, T.J.; Williams, D.A.

    1976-01-01

    Infrared observations of the Orion nebula have been interpreted by Rowan-Robinson (1975) to imply the existence of 'giant' grains, radius approximately 10 -2 cm, throughout a volume about a parsec in diameter. Although Rowan-Robinson's model of the nebula has been criticized and the presence of such grains in Orion is disputed, the proposition is accepted, that they exist, and in this paper situations in which giant grains could arise are examined. It is found that, while a giant-grain component to the interstellar grain density may exist, it is difficult to understand how giant grains arise to the extent apparently required by the Orion nebula model. (Auth.)

  12. Development and evaluation of a geographic information retrieval system using fine grained toponyms

    Directory of Open Access Journals (Sweden)

    Damien Palacio

    2015-12-01

    Full Text Available Geographic information retrieval (GIR is concerned with returning information in response to an information need, typically expressed in terms of a thematic and spatial component linked by a spatial relationship. However, evaluation initiatives have often failed to show significant differences between simple text baselines and more complex spatially enabled GIR approaches. We explore the effectiveness of three systems (a text baseline, spatial query expansion, and a full GIR system utilizing both text and spatial indexes at retrieving documents from a corpus describing mountaineering expeditions, centred around fine grained toponyms. To allow evaluation, we use user generated content (UGC in the form of metadata associated with individual articles to build a test collection of queries and judgments. The test collection allowed us to demonstrate that a GIR-based method significantly outperformed a text baseline for all but very specific queries associated with very small query radii. We argue that such approaches to test collection development have much to offer in the evaluation of GIR.

  13. Implications of a North American grain marketing system for prairie transportation and elevators

    Science.gov (United States)

    1997-09-01

    The balance of this report will examine the experiences U.S. production agriculture has had with deregulation of the transportation industry. It will highlight the evolution of the procurement segment of grain marketing, concentrating on the wheat or...

  14. An Overview of Grain Growth Theories for Pure Single Phase Systems,

    Science.gov (United States)

    1986-10-01

    the fundamental causes for these distributions. This Blanc and Mocellin (1979) and Carnal and Mocellin (1981j set out to do. 7.1 Monte-Carlo Simulations...termed event B) (in 2-D) of 3-sided grains. (2) Neighbour-switching (termed event C). Blanc and Mocellin (1979) dealt with 2-D sections through...Kurtz and Carpay (1980a). 7.2 Analytical Method to Obtain fn Carnal and Mocellin (1981) obtained the distribution of grain coordination numbers in

  15. Time evolution of coarse-grained entropy in classical and quantum motions of strongly chaotic systems

    Science.gov (United States)

    Gu, Yan; Wang, Jiao

    1997-02-01

    We study relaxation of an ensemble of cat maps with initially localized phase-space distributions. Calculations of the coarse-grained entropy Sɛ ( t) for both classical and quantum motions are presented. It is shown that, within the relaxation period, both classical and quantum entropies increase with a nearly constant rate which can be identified as the largest Lyapunov exponent of the classical cat. After an empirical relaxation time, the time behavior for two entropies becomes different. While the classical entropy increases to the equilibrium entropy Seqm and stays there, its quantum analogue fluctuates incessantly around a mean overlineSɛ which is less than Seqm. We regard the entropy difference ΔS = S eqm - overlineSɛ as a measure of nonergodicity of the quantum motion of strongly chaotic systems and investigate its dependence on the Planck constant h. For fixed initial phase-space distributions, numerical results suggest that there is a scaling law ΔSαhβ with β ≈ 0.72 in the semiclassical regime.

  16. Dewaterability of sludge digested in extended aeration plants using ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-07-19

    Jul 19, 2010 ... extended aeration (EA) or anaerobic digestion were compared on full and lab scale sand drying ... Novak, 1999) and to the reduction of iron concentration in ... nutrient removal and provide semi-plug flow conditions to reduce.

  17. Aeration strategy for biofilm cultivation of the microalga Scenedesmus dimorphus.

    Science.gov (United States)

    Ji, Chunli; Wang, Junfeng; Liu, Tianzhong

    2015-10-01

    Biofilm cultivation of microalgae may be useful for biofuel production. However, many aspects for this cultivation method have not been well assessed. Accordingly, aeration strategy for biofilm cultivation of Scenedesmus dimorphus has been explored. Biomass, lipid and triacylglycerol (TAG) productivity in increased S. dimorphus as the CO2 concentration increased within 0.038-0.5% and kept constant with further increases. The biomass, lipid and TAG productivity increased with the speed increasing and an obvious threshold point was observed at 6.6 ml(-2) min(-1). The lipid and TAG content was unaffected by the aeration rate. Both the CO2 concentration as well as aeration speed affected the growth of S. dimorphus in biofilm cultivation. The optimized aeration strategy for biofilm cultivation was continuous air flow enriched with 1% CO2 (v/v) at 6.6 ml(-2) min(-1).

  18. Comparative study on the reactivity of Fe/Cu bimetallic particles and zero valent iron (ZVI) under different conditions of N2, air or without aeration.

    Science.gov (United States)

    Xiong, Zhaokun; Lai, Bo; Yang, Ping; Zhou, Yuexi; Wang, Juling; Fang, Shuping

    2015-10-30

    In order to further compare the degradation capacity of Fe(0) and Fe/Cu bimetallic system under different aeration conditions, the mineralization of PNP under different aeration conditions has been investigated thoroughly. The results show that the removal of PNP by Fe(0) or Fe/Cu system followed the pseudo-first-order reaction kinetics. Under the optimal conditions, the COD removal efficiencies obtained through Fe(0) or Fe/Cu system under different aeration conditions followed the trend that Fe/Cu (air)>Fe/Cu (N2: 0-30 min, air: 30-120 min)>control-Fe (air)>Fe/Cu (without aeration)>Fe/Cu (N2)>control-Fe (N2). It revealed that dissolved oxygen (DO) could improve the mineralization of PNP, and Cu could enhance the reactivity of Fe(0). In addition, the degradation of PNP was further analyzed by using UV-vis, FTIR and GC/MS, and the results suggest that Fe/Cu bimetallic system with air aeration could completely break the benzene ring and NO2 structure of PNP and could generate the nontoxic and biodegradable intermediate products. Meanwhile, most of these intermediate products were further mineralized into CO2 and H2O, which brought about a high COD removal efficiency (83.8%). Therefore, Fe/Cu bimetallic system with air aeration would be a promising process for toxic refractory industry wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A MATHEMATICAL MODEL OF OPTIMIZATION OF THE VOLUME OF MATERIAL FLOWS IN GRAIN PROCESSING INTEGRATED PRODUCTION SYSTEMS

    OpenAIRE

    Baranovskaya T. P.; Loyko V. I.; Makarevich O. A.; Bogoslavskiy S. N.

    2014-01-01

    The article suggests a mathematical model of optimization of the volume of material flows: the model for the ideal conditions; the model for the working conditions; generalized model of determining the optimal input parameters. These models optimize such parameters of inventory management in technology-integrated grain production systems, as the number of cycles supply, the volume of the source material and financial flows. The study was carried out on the example of the integrated system of ...

  20. An overview of molecular dynamics simulations of oxidized lipid systems, with a comparison of ELBA and MARTINI force fields for coarse grained lipid simulations

    DEFF Research Database (Denmark)

    Siani, Pablo; de Souza, R M; Dias, L G

    2016-01-01

    our new data of all-atom and coarse-grained simulations of hydroperoxidized lipid monolayer and bilayer systems and (iii) provide a comparison of the MARTINI and ELBA coarse grained force fields for lipid bilayer systems. We show that the better electrostatic treatment of interactions in ELBA is able...

  1. Incidence of secondary aeration in confined flames of high pressure premixed atmospheric burner

    International Nuclear Information System (INIS)

    Cadavid Sierra, Francisco Javier; Buitrago Garcia, Jorge Enrique; Velasquez, Daniel

    2002-01-01

    In this work an experimental study about the variables that affect the secondary aeration has been applied. The relationships with phenomena that affect the proper operation of the combustion chamber are discussed in detail. These phenomena are quenching, flame stabilization and the combustion product recirculation. A flexible combustion system developed to allow variations in the volume of combustion chamber, the area of secondary air entrance, the outlet of combustion products and the thermal output is presented. Also, the system could vary the inlet of primary air, though the study is carried out with maximal working area. The experimental setup allowed to compare and to find the influence of design parameters mentioned above on the secondary aeration and also to obtain the insight that the most important design parameters were combustion product outlet and the combustion intensity

  2. Study of test methods for radionuclide migration in aerated zone

    International Nuclear Information System (INIS)

    Li Shushen; Guo Zede; Wang Zhiming

    1993-01-01

    Aerated zone is an important natural barrier against transport of radionuclides released from disposal facilities of LLRW. This paper introduces study methods for radionuclide migration in aerated zone, including determination of water movement, laboratory simulation test, and field tracing test. For one purpose, results obtained with different methods are compared. These methods have been used in a five-year cooperative research project between CIRP and JAERI for an establishment of methodology for safety assessment on shallow land disposal of LLRW

  3. Groundwater Quality Improvement by Using Aeration and Filtration Methods

    OpenAIRE

    Nik N. Nik Daud; Nur H. Izehar; B. Yusuf; Thamer A. Mohamed; A. Ahsan

    2013-01-01

    An experiment was conducted using two aeration methods (water-into-air and air-into-water) and followed by filtration processes using manganese greensand material. The properties of groundwater such as pH, dissolved oxygen, turbidity and heavy metal concentration (iron and manganese) will be assessed. The objectives of this study are i) to determine the effective aeration method and ii) to assess the effectiveness of manganese greensand as filter media in removing iron an...

  4. Effect of aeration interval on oxygen consumption and GHG emission during pig manure composting.

    Science.gov (United States)

    Zeng, Jianfei; Yin, Hongjie; Shen, Xiuli; Liu, Ning; Ge, Jinyi; Han, Lujia; Huang, Guangqun

    2018-02-01

    To verify the optimal aeration interval for oxygen supply and consumption and investigate the effect of aeration interval on GHG emission, reactor-scale composting was conducted with different aeration intervals (0, 10, 30 and 50 min). Although O 2 was sufficiently supplied during aeration period, it could be consumed to  0.902), suggesting that lengthening the duration of aeration interval to some extent could effectively reduce GHG emission. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Desempenho de estratégias de aeração de milho armazenado: Fungos e condutividade elétrica Performance of aeration strategies for stored corn: Molds and electrical conductivity

    Directory of Open Access Journals (Sweden)

    Vânia R. G. Nascimento

    2012-01-01

    Full Text Available Objetivou-se, com o presente trabalho, avaliar e comparar o desempenho de três estratégias de aeração de milho armazenado quanto à ocorrência de fungos e à condutividade elétrica dos grãos. As estratégias avaliadas foram: aeração contínua; aeração noturna e aeração em condições de umidade de equilíbrio entre os grãos e o ar ambiente. Realizaram-se dois ensaios de aeração com grãos de milho secos (11% b.u. e úmidos (17% b.u.. Amostras de grãos foram retiradas durante os ensaios para contagem de fungos e medida da condutividade elétrica dos grãos. Grãos armazenados úmidos apresentaram maior ocorrência de fungos do que grãos armazenados secos. Observou-se que o Fusarium spp. apresentou contagens mais elevadas, o Penicillium spp. manifestou desenvolvimento e o Aspergillus spp. ocorreu com menor frequência. As estratégias de aeração empregadas não interferiram na condutividade elétrica dos grãos de milho armazenados, visto que não houve diferença significativa dos valores de condutividade elétrica entre os grãos submetidos a aeração e os grãos armazenados sem aeração.The aim of this study was to evaluate and to compare the performance of three aeration strategies for stored corn as for occurrence of molds and electrical conductivity of grain: continuous aeration; night aeration and aeration under equilibrium moisture content conditions between the grains and the ambient air. Two tests of aeration with dry corn grain (11% w.b. and wet corn (17% w.b. were done. Grain samples were taken during testing for counting of molds and measuring of electrical conductivity of grains. Wet corn stored had increased incidence of molds more than dry corn stored. It was observed that the Fusarium spp. showed higher scores, Penicillium spp. showed development and Aspergillus spp. occurred with lesser frequency. Aeration strategies employed did not affect the electrical conductivity of corn stored because there was no

  6. Systems study of fuels from grains and grasses. Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Benson, W.; Allen, A.; Athey, R.; McElroy, A.; Davis, M.; Bennett, M.

    1978-02-24

    The program reported on herein consists of a first phase analysis of the potential for significant and economically viable contributions to U.S. energy needs from grasses and grains by the photosynthetic production of biomass. The study does not include other cultivated crops such as sugar cane, sugar beets, cotton, tobacco, vegetables, fruits, etc. The scope of the study encompasses grain crop residues, whole plant biomass from grain crops and nongrain crops on cropland, and whole plant biomass from grasses on pasture, rangeland, and federal range. The basic approach to the study involves first an assessment of current total biomass generation from the various grasses and grains on cropland, pasture, range, and federal range, and aggregating the production by combinations of crop residues and whole plant biomass; second, evaluation of possibilities for introduction of new crops and expanding production to marginal or presently idle land; third, development of proposed reasonable scenarios for actually harvesting biomass from selected combinations of crop residues, forages and hays, and new crops from land now in production, plus additional marginal or underutilized land brought into production; and finally, assessment on national and regional or local scales of the production that might be affected by reasonable scenarios. This latter effort includes analysis of tentative possibilities for reallocating priorities and needs with regard to production of grain for export or for livestock production. The overall program includes a case study analysis of production economics for a representative farm of about 1,000 acres (405 ha) located in Iowa.

  7. Reaction and relaxation in a coarse-grained fluvial system following catchment-wide disturbance

    Science.gov (United States)

    Tunnicliffe, Jon; Brierley, Gary; Fuller, Ian C.; Leenman, Anya; Marden, Mike; Peacock, Dave

    2018-04-01

    The Waiapu River catchment (drainage area of 1734-km2) is one of the most prolific conveyors of sediment in the world, annually delivering roughly 35 Mt of fine material to the ocean from eroding gullies, hillslopes, and reworked sediment on valley floors. Tectonic and geologic influences, in combination with a dynamic climate influenced by tropical cyclones and clearance of vegetation from steep hillslopes, predisposes this region to high rates of erosion. The bedload sediment regime of the river is strongly influenced by several exceptionally large gullies and gully complexes that produce a coarse-grained, poorly sorted sediment mixture. Rapid abrasion and breakdown leads to high rates of suspended sediment yield. A wave of bedload material, manifesting as elevated bed levels and significant widening of active alluvial fills, has been triggered by large inputs of hillslope material from a few key tributary catchments following Cyclone Bola in 1988. We review the evidence for the relaxation process of the sedimentary system in the subsequent 29 years, appraising some of the legacy effects that may endure, as associated with reworking of the considerable alluvial stores within the Waiapu system. We use Structure-from-Motion (SfM) techniques and archival aerial photos to quantify changes in sediment storage at the base of two major gully systems in recent decades. A record of over 850 cross section surveys at 62 sites on 10 rivers throughout the catchment (1958-2017) indicates recent transition from a trend of continuous accumulation to downcutting and remobilisation of valley-bottom deposits. The channel cross sections provide a minimum estimate of sediment flux from source areas to the lower reaches of the river, giving a rudimentary but spatially extensive picture of the wave of material cascading through the drainage network. The largest impacts occur in the upper steepland rivers, closest to the landslide-derived sediment supply. Transport rates here, as

  8. Turbine Aeration Design Software for Mitigating Adverse Environmental Impacts Resulting From Conventional Hydropower Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Gulliver, John S. [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-03-01

    Conventional hydropower turbine aeration test-bed for computational routines and software tools for improving environmental mitigation technologies for conventional hydropower systems. In achieving this goal, we have partnered with Alstom, a global leader in energy technology development and United States power generation, with additional funding from the Initiative for Renewable Energy and the Environment (IREE) and the College of Science and Engineering (CSE) at the UMN

  9. Sequential Aeration of Membrane-Aerated Biofilm Reactors for High-Rate Autotrophic Nitrogen Removal: Experimental Demonstration

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Sun, Sheng-Peng; Lackner, Susanne

    2010-01-01

    One-stage autotrophic nitrogen (N) removal, requiring the simultaneous activity of aerobic and anaerobic ammonium oxidizing bacteria (AOB and AnAOB), can be obtained in spatially redox-stratified biofilms. However, previous experience with Membrane-Aerated Biofilm Reactors (MABRs) has revealed...... a difficulty in reducing the abundance and activity of nitrite oxidizing bacteria (NOB), which drastically lowers process efficiency. Here we show how sequential aeration is an effective strategy to attain autotrophic N removal in MABRs: Two separate MABRs, which displayed limited or no N removal under...... continuous aeration, could remove more than 5.5 g N/m2/day (at loads up to 8 g N/m2/day) by controlled variation of sequential aeration regimes. Daily averaged ratios of the surficial loads of O2 (oxygen) to NH4+ (ammonium) (LO2/LNH4) were close to 1.73 at this optimum. Real-time quantitative PCR based on 16...

  10. Intermittent Aeration Suppresses Nitrite-Oxidizing Bacteria in Membrane-Aerated Biofilms: A Model-Based Explanation

    DEFF Research Database (Denmark)

    Ma, Yunjie; Domingo Felez, Carlos; Plósz, Benedek G.

    2017-01-01

    . On the basis of dissolved oxygen (DO), ammonium, nitrite, and nitrate profiles within the biofilm and in the bulk, a 1-dimensional nitrifying biofilm model was developed and calibrated. The model was utilized to explore the potential mechanisms of NOB suppression associated with intermittent aeration...... nitritation, strategies to suppress nitrite-oxidizing bacteria (NOB) are needed, which are ideally grounded on an understanding of underlying mechanisms. In this study, a nitrifying MABR was operated under intermittent aeration. During eight months of operation, AOB dominated, while NOB were suppressed...... during intermittent aeration was mostly explained by periodic inhibition caused by free ammonia due to periodic transient pH upshifts. Dissolved oxygen limitation did not govern NOB suppression. Different intermittent aeration strategies were then evaluated for nitritation success in intermittently...

  11. Effect of Tillage Systems with Corn Residue on Grain Yield of Rapeseed in Moghan Region

    Directory of Open Access Journals (Sweden)

    J Taghinazhad

    2014-09-01

    Full Text Available This study carried out to evaluate the effect of different tillage systems on rapeseed yield (hayola 401 planted in corn residues. This experiment was done in Moghan region with clay soils during 2009-2012. Different seedbed preparation methods include MT: moldboard + disk tillage (conventional tillage was included, SCT: Stem Crusher + chisel + disk tandem harrow, STT: Stem Crusher + double-disc, CT: chisel + disk tillage and DD: two heavy disks. The experiment was conducted in a randomized complete block design with four replications. The results showed that soil bulk density in the 0-10 cm layer was not significant in different tillage treatments, but it was significantly higher than the conventional tillage in 10-20 cm depth. However, penetration resistance in 10-30 cm under DD was significantly higher than other treatments, but it was not significant in 0-10 cm layer among all tillage treatments. Thus, Comparison of the soil bulk density, penetration resistance, and plant establishment showed that the reduced tillage in canola seedbed preparation was effective. Besides, the surveys indicated that there was a significant different between MWD after primary and secondary tillage. The mean diameter weighted under SCT and DD, were 1.19 and 1.24 cm, respectively had the best status. The highest value and the worst status of this parameter observed for MT which was 1.92 cm. The highest rate of grain yield obtained by application of treatment SCT, and it was 2563.8 kg ha-1, The SCT treatment can be recommended as an effective canola bed preparation due to its significant saving in time and cost after corn harvesting.

  12. Microbial ecology and quality assurance in food fermentation systems. The case of kefir grains application.

    Science.gov (United States)

    Plessas, S; Alexopoulos, A; Voidarou, C; Stavropoulou, E; Bezirtzoglou, E

    2011-12-01

    Fermentation technology has become a modern method for food production the last decades as a process for enhancing product stability, safety and sensory standards. The main reason for this development is the increasing consumers' demand for safe and high quality food products. The above has led the scientific community to the thorough study for the appropriate selection of specific microorganisms with desirable properties such as bacteriocin production, and probiotic properties. The main food products produced through fermentation activity are bread, wine, beer cheese and other dairy products. The microorganisms conducting the above processes are mainly yeasts and lactic acid bacteria. The end products of carbohydrate catabolism by these microorganisms contribute not only to preservation as it was believed years ago, but also to the flavour, aroma and texture and to the increase of the nutritional quality by thereby helping determine unique product characteristics. Thus, controlling the function of specific microorganisms or the succession of microorganisms that dominate the microflora is therefore advantageous, because it can increase product quality, functionality and value. Throughout the process of the discovery of microbiological diversity in various fermented food systems, the development of starter culture technology has gained more scientific attention, and it could be used for the control of the manufacturing operation, and management of product quality. In the frame of this review the presentation of the quality enhancement of most consumed fermented food products around the world is attempted and the new trends in production of fermented food products, such as bread is discussed. The review is focused in kefir grains application in bread production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Aeration Strategies To Mitigate Nitrous Oxide Emissions from Single-Stage Nitritation/Anammox Reactors

    DEFF Research Database (Denmark)

    Domingo Felez, Carlos; Mutlu, A. Gizem; Jensen, Marlene Mark

    2014-01-01

    Autotrophic nitrogen removal is regarded as a resource efficient process to manage nitrogen-rich residual streams. However, nitrous oxide emissions of these processes are poorly documented and strategies to mitigate emissions unknown. In this study, two sequencing batch reactors performing single...... was noted when the duration of aeration was increased while decreasing air flow rate (10.9 +/- 3.2% Delta N2O/Delta TN). The extant ammonium oxidation activity (mgNH(4)(+)-N/gVSS.min) positively correlated with the specific N2O production rate (mgN(2)O-N/gVSS.min) of the systems. Operating under conditions......-stage nitritation/anammox were operated under different aeration strategies, gradually adjusted over six months. At constant but limiting oxygen loading, synthetic reject water was fed (0.75g-N/L.d) and high nitrogen removal efficiencies (83 +/- 5 and 88 +/- 2%) obtained. Dynamics of liquid phase nitrous (N2O...

  14. Measuring a critical stress for continuous prevention of marine biofouling accumulation with aeration.

    Science.gov (United States)

    Menesses, Mark; Belden, Jesse; Dickenson, Natasha; Bird, James

    2017-10-01

    When cleaning the hull of a ship, significant shear stresses are needed to remove established biofouling organisms. Given that there exists a link between the amount of time that fouling accumulates and the stress required to remove it, it is not surprising that more frequent grooming requires less shear stress. Yet, it is unclear if there is a minimum stress needed to prevent the growth of macrofouling in the limit of continuous grooming. This manuscript shows that single bubble stream aeration provides continuous grooming and prevents biofouling accumulation in regions where the average wall stress exceeds ~0.01 Pa. This value was found by comparing observations of biofouling growth from field studies with complementary laboratory measurements that probe the associated flow fields. These results suggest that aeration and other continuous grooming systems must exceed a wall stress of 0.01 Pa to prevent macrofouling accumulation.

  15. Settlement determination of operating moisture of autoclaved aerated concrete in different climatic zones

    Directory of Open Access Journals (Sweden)

    Pastushkov Pavel Pavlovich

    Full Text Available In the process of operation of buildings the moisture state of enveloping structures materials is changing depending on their construction features, properties of the material, temperature and moisture conditions in the premises, climatic conditions of the construction area. Moisture mode determines the operational properties of the enveloping structures of a building. It directly influences the thermal characteristics of enveloping structure and energy efficiency of the applied materials. The analysis of the methods for calculation of moisture behavior of enclosing structures is carried out. The research relevance of operational moisture of AAC is substantiated. Experimental studies and results of the sorption moisturizing and water vapor permeability of leading marks of aerated concrete are carried out. The authors offer the results of numerical calculations of the moisture behavior of aerated concrete in the walls with mark D400 with facade thermal insulation composite systems - with external plaster layers for different climatic zones of construction.

  16. Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Vogt, Josef Korbinian; Kristensen, Mette

    2017-01-01

    Objective To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. Design 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week...... dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory...... of whole grain consumed, in particular with intake of rye. Conclusion Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation....

  17. A coarse-graining approach for molecular simulation that retains the dynamics of the all-atom reference system by implementing hydrodynamic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Markutsya, Sergiy [Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Lamm, Monica H., E-mail: mhlamm@iastate.edu [Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011 (United States)

    2014-11-07

    We report on a new approach for deriving coarse-grained intermolecular forces that retains the frictional contribution that is often discarded by conventional coarse-graining methods. The approach is tested for water and an aqueous glucose solution, and the results from the new implementation for coarse-grained molecular dynamics simulation show remarkable agreement with the dynamics obtained from reference all-atom simulations. The agreement between the structural properties observed in the coarse-grained and all-atom simulations is also preserved. We discuss how this approach may be applied broadly to any existing coarse-graining method where the coarse-grained models are rigorously derived from all-atom reference systems.

  18. A coarse-graining approach for molecular simulation that retains the dynamics of the all-atom reference system by implementing hydrodynamic interactions

    International Nuclear Information System (INIS)

    Markutsya, Sergiy; Lamm, Monica H.

    2014-01-01

    We report on a new approach for deriving coarse-grained intermolecular forces that retains the frictional contribution that is often discarded by conventional coarse-graining methods. The approach is tested for water and an aqueous glucose solution, and the results from the new implementation for coarse-grained molecular dynamics simulation show remarkable agreement with the dynamics obtained from reference all-atom simulations. The agreement between the structural properties observed in the coarse-grained and all-atom simulations is also preserved. We discuss how this approach may be applied broadly to any existing coarse-graining method where the coarse-grained models are rigorously derived from all-atom reference systems

  19. A luminescence imaging system for the routine measurement of single-grain OSL dose distributions

    DEFF Research Database (Denmark)

    Kook, Myung Ho; Lapp, Torben; Murray, Andrew

    2015-01-01

    the potential of an electron multiplying charge-coupled device (EMCCD), providing extremely low level light detection. We characterize the performance of the device by discussing reproducibility and evaluating uncertainties in OSL signals. Finally we derive a typical single grain natural dose distribution...

  20. Systems study of fuels from grains and grasses. Quarterly progress report, July--October 1976

    Energy Technology Data Exchange (ETDEWEB)

    Benson, W.; Allen, A.; Athey, R.; McElroy, A.

    1976-11-15

    The specific objectives of the project are to determine on a geographic basis the current and potential USA production capability for grain and grass crops, to perform a preliminary screening of conversion processes, and to perform preliminary technical and economic feasibility analyses. The results obtained to date on biomass production, conversion processes, and data management are reported. (JSR)

  1. A Bayesian framework for adaptive selection, calibration, and validation of coarse-grained models of atomistic systems

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Kathryn, E-mail: kfarrell@ices.utexas.edu; Oden, J. Tinsley, E-mail: oden@ices.utexas.edu; Faghihi, Danial, E-mail: danial@ices.utexas.edu

    2015-08-15

    A general adaptive modeling algorithm for selection and validation of coarse-grained models of atomistic systems is presented. A Bayesian framework is developed to address uncertainties in parameters, data, and model selection. Algorithms for computing output sensitivities to parameter variances, model evidence and posterior model plausibilities for given data, and for computing what are referred to as Occam Categories in reference to a rough measure of model simplicity, make up components of the overall approach. Computational results are provided for representative applications.

  2. A Bayesian framework for adaptive selection, calibration, and validation of coarse-grained models of atomistic systems

    Science.gov (United States)

    Farrell, Kathryn; Oden, J. Tinsley; Faghihi, Danial

    2015-08-01

    A general adaptive modeling algorithm for selection and validation of coarse-grained models of atomistic systems is presented. A Bayesian framework is developed to address uncertainties in parameters, data, and model selection. Algorithms for computing output sensitivities to parameter variances, model evidence and posterior model plausibilities for given data, and for computing what are referred to as Occam Categories in reference to a rough measure of model simplicity, make up components of the overall approach. Computational results are provided for representative applications.

  3. Sol-gel synthesis and characterization of fine-grained ceramics in the alumina-titania system

    Energy Technology Data Exchange (ETDEWEB)

    Otterstein, E. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany)], E-mail: otterstein@physik1.uni-rostock.de; Karapetyan, G. [Institute of Chemistry, University of Rostock, Albert-Einstein-Strasse 3a, 18059 Rostock (Germany); Nicula, R. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany); Stir, M. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany); National Institute for Materials Physics, 105b Atomistilor Strasse, P.O.B. MG7, 077125 Bucharest-Magurele (Romania); Schick, C. [Institute of Physics, University of Rostock, Universitaetsplatz 3, 18051 Rostock (Germany); Burkel, E. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany)

    2008-02-05

    Fine-grained ceramics of the Al{sub 2}O{sub 3}-TiO{sub 2} system were synthesised by reactive sintering of sol-gel precursors (Al- and Ti-alkoxides). The thermal behaviour of the as-prepared xerogels was examined by thermal analysis and X-ray powder diffraction. Preliminary results concerning powder consolidation into bulk ceramic parts using spark plasma sintering (SPS) are discussed.

  4. Modeling of mixing in stirred bioreactors 4. mixing time for aerated bacteria, yeasts and fungus broths

    Directory of Open Access Journals (Sweden)

    Cascaval Dan

    2004-01-01

    Full Text Available The mixing time for bioreactors depends mainly on the rheoiogicai properties of the broths, the biomass concentration and morphology, mixing system characteristics and fermentation conditions. For quantifying the influence of these factors on the mixing efficiency for stirred bioreactors, aerated broths of bacteria (P. shermanii, yeasts (S. cerevisiae and fungi (P. chrysogenum, free mycelia and mycelial aggregates of different concentrations have been investigated using a laboratory bioreactor with a double turbine impeller. The experimental data indicated that the influence of the rotation speed, aeration rate and stirrer positions on the mixing intensity strongly differ from one system to another and must be correlated with the microorganism characteristics, namely: the biomass concentration and morphology. Moreover, compared with non-aerated broths, variations of the mixing time with the considered parameters are very different, due to the complex flow mechanism of gas-liquid dispersions. By means of the experimental data and using a multiregression analysis method some mathematical correlations for the mixing time of the general form: tm = a1*Cx2+a2*Cx+a3*IgVa+a4-N2+a5-N+a6/a7*L2+a8*L+a9 were established. The proposed equations offer good agreement with the experiments, the average deviation being ±6.7% - ±9.4 and are adequate for the flow regime Re < 25,000.

  5. Decentralized wastewater treatment using passively aerated biological filter.

    Science.gov (United States)

    Abou-Elela, Sohair I; Hellal, Mohamed S; Aly, Olfat H; Abo-Elenin, Salah A

    2017-10-13

    This study aimed to evaluate the efficiency of a novel pilot-scale passively aerated biological filter (PABF) as a low energy consumption system for the treatment of municipal wastewater. It consists of four similar compartments, each containing 40% of a non-woven polyester fabric as a bio-bed. The PABF was fed with primary treated wastewater under a hydraulic retention time (HRT) of 3.5 hr and a hydraulic loading rate of 5.5 m 2 /m 3 /d. The effect of media depth, HRT, dissolved oxygen (DO) and surface area of the media on the removal efficiency of pollutants was investigated. Results indicated that increasing media depth along the axis of the reactor and consequently increasing the HRT and DO resulted in great removal of different pollutants. A significant increase in the DO levels in the final effluent up to 6.7 mg/l resulted in good nitrification processes. Statistical analysis using SPSS showed that the reactor performance has significant removal efficiency (p filter systems.

  6. Evaluation of sequential aerated treatment of wastewater from hardboard mill

    Directory of Open Access Journals (Sweden)

    S. Videla

    1998-01-01

    Full Text Available Wastewater from a hardboard mill characterized by a high organic content (15-30 g/L COD was studied in a bench scale sequential aerated system in order to define a start up strategy. Inlet COD concentration varied from 0.5 to 25 g/L and the hydraulic retention time was maintained at 5 days. The sequential system proposed could reduce BOD, COD, TSS and phenol over 90% except when the inlet COD concentration was lower than 25 g/L.Água residual proveniente de uma indústria de tabuleiro de fibra dura caracterizada por ter um elevado conteúdo orgânico (15-30 g/L DQO foi estudada utilizando um sistema arejado seqüêncial de forma a definir uma estratégia de start up. A concentração de DQO na entrada do sistema variou na faixa de 0,5-25 g/L e o tempo de residência hidráulico foi mantido em 5 dias. O sistema seqüêncial proposto reduziu DBO, DQO, SST e fenol sobre 90% quando a concentração de DQO na entrada foi menor a 25 g/L.

  7. Origins of GEMS Grains

    Science.gov (United States)

    Messenger, S.; Walker, R. M.

    2012-01-01

    Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

  8. Soil Carbon Changes in Transitional Grain Crop Production Systems in South Dakota

    Science.gov (United States)

    Woodard, H. J.

    2004-12-01

    Corn-C (Zea Mays L.), soybean-S (Glycine max L.) and spring wheat-W (Triticum aestivum L.) crops were seeded as a component of either a C-S, S-W, or C-S-W crop rotation on silt-loam textured soils ranging from 3.0-5.0% organic matter. Conservation tillage(chisel plow-field cultivator) was applied to half of the plots. The other plots were direct seeded as a no-till (zero-tillage) treatment. Grain yield and surface crop residues were weighed from each treatment plot. Crop residue (stover and straw) was removed from half of the plots. After four years, soil samples were removed at various increments of depth and soil organic carbon (C) and nitrogen (N) was measured. The ranking of crop residue weights occurred by the order corn>>soybean>wheat. Surface residue accumulation was also greatest with residue treatments that were returned to the plots, those rotations in which maize was a component, and those without tillage. Mean soil organic carbon levels in the 0-7.5cm depth decreased from 3.41% to 3.19% (- 0.22%) with conventional tillage (chisel plow/field cultivator) as compared to a decrease from 3.19% to 3.05% (-0.14%) in plots without tillage over a four year period. Organic carbon in the 0-7.5cm depth decreased from 3.21% to 3.01% (- 0.20%) after residue removed as compared to a decrease from 3.39% to 3.23% (-0.17%) in plots without tillage applied after four years. The soil C:N ratio (0-7.5cm) decreased from 10.63 to 10.37 (-0.26 (unitless)) in the tilled plots over a four-year period. Soil C:N ratio at the 0-7.5cm depth decreased from 10.72 to 10.04 (-0.68) in the no-till plots over a four year period. Differences in the soil C:N ratio comparing residue removed and residue returned were similar (-0.51 vs. -0.43 respectively). These soils are highly buffered for organic carbon changes. Many cropping cycles are required to determine how soil carbon storage is significantly impacted by production systems.

  9. Aerated drilling cutting transport analysis in geothermal well

    Science.gov (United States)

    Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

    2017-12-01

    Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

  10. Impact of integrated nutrient management on growth and grain yield of wheat under irrigated cropping system

    International Nuclear Information System (INIS)

    Nawab, K.; Amanullah, A.; Shah, P.; Arif, M.; Khan, A.M.

    2011-01-01

    Field study was conducted during 2001-02 and 2002-03 to investigate the effect of cropping patterns and farm yard manure, potassium and zinc on the grain yield of wheat. Trials were conducted at Agricultural Research Farm, KPK Agricultural University Peshawar, Pakistan. Two factors cropping patterns and manures/fertilizers were studied in the experiment. Randomized complete block design was used with split plot arrangements and four replications having net plot size of 12 m/sup 2/. Wheat variety Ghaznavi-98 was sown in November soon after ploughing the soil at proper moisture level suitable for wheat seed germination. Five cropping patterns were allotted to main plots and the eight combinations of FYM, K and Zn to the sub-plots. Same plots were used for next year sowing. Effects of five cropping patterns i.e., rice-wheat, maize-wheat, sunflower-wheat, sorghum-wheat and pigeon pea-wheat and three organic and in-organic fertilizers (Farmyard Manure, Potassium and Zinc) on subsequent wheat crop were observed. Highest grain yield was obtained when wheat was planted after pigeon pea. Manures/fertilizer application (Farmyard Manure, Potassium and Zinc) produced significantly higher grain yield than the control plots. The findings of the present study revealed that leguminous crops can significantly increase the yield of succeeding crops. Thus use of Farmyard Manure, Potassium and Zinc should be included in integrated crop management approaches for sustainable agriculture. (author)

  11. Mechanisms and methods for biofouling prevention via aeration

    Science.gov (United States)

    Dickenson, Natasha; Henoch, Charles; Belden, Jesse

    2013-11-01

    Biofouling is a major problem for the Navy and marine industries, with significant economic and ecological consequences. Specifically, biofouling on immersed hull surfaces generates increased drag and thus requires increased fuel consumption to maintain speed. Considerable effort has been spent developing techniques to prevent and control biofouling, but with limited success. Control methods that have proven to be effective are costly, time consuming, or negatively affect the environment. Recently, aeration via bubble injection along submerged surfaces has been shown to achieve long-lasting antifouling effects, and is the only effective non-toxic method available. An understanding of the basic mechanisms by which bubble-induced flow impedes biofouling is lacking, but is essential for the design of large-scale systems. We present results from an experimental investigation of several bubble induced flow fields over an inclined plate with simultaneous measurements of the fluid velocity and bubble characteristics using Digital article Image Velocimetry and high speed digital video. Trajectories of representative larval organisms are also resolved and linked with the flow field measurements to determine the mechanisms responsible for biofouling prevention.

  12. Interstellar grains

    Energy Technology Data Exchange (ETDEWEB)

    Hoyle, F.; Wickramasinghe, N.C.

    1980-11-01

    Interstellar extinction of starlight was observed and plotted as a function of inverse wavelength. Agreement with the calculated effects of the particle distribution is shown. The main kinds of grain distinguished are: (1) graphite spheres of radius 0.02 microns, making up 10% of the total grain mass (2) small dielectric spheres of radius 0.04 microns making up 25% and (3) hollow dielectric cylinders containing metallic iron, with diameters of 2/3 microns making up 45%. The remaining 20% consists of other metals, metal oxides, and polysiloxanes. Absorption factor evidence suggests that the main dielectric component of the grains is organic material.

  13. Bubbling jet characteristics in an aeration tank; Aeration sonai kiho funryu no ryudo kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Kaji, M; Iguchi, M; Okita, K [Osaka University, Osaka (Japan). Faculty of Engineering; Nakatani, T [Kobe University, Kobe (Japan). Faculty of Engineering

    1996-11-25

    Laser Doppler velocimeter measurements were made to investigate bubbling jet characteristics in an aeration tank at a pressure of 200 kPa. The data were compared with previous measurements at atmospheric and reduced pressures. Bubble frequencies at the nozzle outlet were correlated with the mass flow rate of gas rather than the volumetric flow rate. In the far field where the buoyancy force of bubbles prevails, the axial and radial distributions of the mean velocity components, the r. m. s. values of turbulence components, the Reynolds shear stress and the skewness and flatness factors of the turbulence components obtained at an elevated pressure agreed well with those obtained at the atmospheric pressure for the same volumetric gas flow rate. Consequently, the liquid flow characteristics including the turbulence structure in the far field are not influenced by an increase in surface pressure as long as the volumetric gas flow rate is the same. 13 refs., 14 figs.

  14. Monitoring and modeling of nitrogen conversions in membrane-aerated biofilm reactors: Effects of intermittent aeration

    DEFF Research Database (Denmark)

    Ma, Yunjie

    Nitrogen can be removed from sewage by a variety of physicochemical and biological processes. Due to the high removal efficiency and relatively low costs, biological processes have been widely adopted for treating nitrogen-rich wastewaters. Among the biological technologies, biofilm processes show...... the membrane, whilst NH4+ is provid-ed from the bulk liquid phase. The counter substrate supply not only offers flexible aeration control, but also supports the development of a unique mi-crobial community and spatial structure inside the biofilm. In this study, lab-scale MABRs were operated under two types...... relevant biological N2O production pathways. Sensitive kinetic parameters were estimated with long-term bulk performance data. With the calibrated model, roles of HB and AnAOB were discussed and evaluated in mitigating N2O emissions in auto-trophic nitrogen removal MABRs. Moreover, I developed a 1-D...

  15. Studies of radon mitigation in well water by aeration

    International Nuclear Information System (INIS)

    Mafra, Karina Cristina; Paschuk, Sergei A.; Denyak, Valeriy; Reque, Marilson; Correa, Janine Nicolosi; Barbosa, Laercio

    2011-01-01

    The 222 Rn concentration in natural water in different countries usually is about few Bq/L and is the subject of the National legislation as well as International norms and recommendations. The United States Environmental Protection Agency (USEPA) established a limit of 11.1 Bq/L for the radon level in drinking water and this limit is considered as guideline in Canada and many countries of the European Union. This work presents the results of study of radon ( 222 Rn) concentration reduction in well water using the aeration process developed at the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR). The water samples were collected from a well at Pinheirinho region of Curitiba in 2011. Experimental setup was based on the Radon Monitor (AlphaGUARD). The 222 Rn concentration was analyzed using the software DataEXPERT by Genitron Instruments, taking into account the volume of water sample, its temperature, atmospheric pressure and the total volume of the air in the vessels. Initial concentration of radon in water samples was 28,67 Bq/L which is bigger than maximum concentration recommended by USEPA. The mitigation was performed by means of diffusion aeration of water samples of 15L during the time interval of 24 hours following a period of 4 days. The efficiency of aeration mitigation was controlled by comparing the activity of radon in aerated water with reference water samples that were not aerated. Obtained results show very satisfactory decrease of 222 Rn activity in water samples even after few hours of intense aeration. (author)

  16. Influence of rotor circumference speed on flotation cell aeration

    Energy Technology Data Exchange (ETDEWEB)

    Dedek, F; Bortlik, V

    1978-01-01

    Laboratory test results of flotation experiments conducted in Czechoslovakia with the use of coal flotation particles <0.5 mm are presented. Three different cells and rotors were used, type MS, Denver, VRF 2 with various rotor diameters ranging from 40 mm to 95 mm. Nine tables show the results with varying flotation time, circumferenial velocity, flotation reagents and aeration. Test procedures are discussed; main results are that circumferenial velocity cannot be used as a decisive parameter for cell aeration and flotation efficiency, and that a direct transfer of parameters cannot be made to flotation cells with a different design and to larger industrial equipment. (4 refs.) (In German)

  17. Thermal neutron pulsed parameters in non-hydrogenous systems. Experiment for lead grains

    International Nuclear Information System (INIS)

    Drozdowicz, K.; Gabanska, B.; Kosik, M.; Krynicka, E.; Woznicka, U.; Zaleski, T.

    1997-01-01

    In Czubek's method of measurement of the thermal neutron macroscopic absorption cross section a two-region geometry is applied where the investigated sample is surrounded by an external moderator. Both regions in the measurements made up till now were hydrogenous, which means the same type of the thermal neutron transport properties. In the paper a theoretical consideration to use non-hydrogenous materials as the samples is presented. Pulsed neutron measurements have been performed on homogeneous material in a geometry of the classic experiment with the variable geometric buckling. Two decay constants have been measured for different cylindrical samples of small lead grains (a lead shot). (author)

  18. Evaluation of design factors for a cascade aerator to enhance the efficiency of an oxidation pond for ferruginous mine drainage.

    Science.gov (United States)

    Oh, Chamteut; Ji, Sangwoo; Cheong, Youngwook; Yim, Giljae; Hong, Ji-Hye

    2016-10-01

    This research focused on the optimum design of a cascade aerator to enhance the efficiency of an oxidation pond in a passive treatment system for remediating ferruginous mine drainage. For this purpose, various aeration experiments with aerators of different drop heights (0-4 m) and formations (types A and B) were executed on mine drainage. Type A simply drops the mine drainage into the oxidation pond while type B sprays the mine drainage and retains it for 8 min in each step. The efficiency enhancement of the oxidation pond was strongly dependent on the increase in pH and DO of the mine drainage discharged into the pond. The water quality improved with the increase in drop height but especially showed better effect with type B. The reasons for this result were attributed to the increase of contact surface and retention time of the mine drainage. The cascade aerator, therefore, should be designed to be as high as possible with the assistance of spraying form and retention time of the mine drainage to maximize the efficiency of the oxidation pond. These effects could be evaluated by calculating required areas of the oxidation pond for 95% of Fe(2+) oxidation.

  19. Measurement of grain-boundary diffusion at low temperature by the surface-accumulation method. II. Results for gold-silver system

    International Nuclear Information System (INIS)

    Hwang, J.C.M.; Pan, J.D.; Balluffi, R.W.

    1979-01-01

    Grain-boundary diffusion rates in the gold-silver system were measured at relatively low temperatures by the surface-accumulation method which was analyzed in Paper I. The specimen was a polycrystalline gold film possessing columnar grains on which a silver layer was initially deposited epitaxially on one surface. During subsequent low-temperature annealing lattice diffusion was frozen out, and diffusion then occurred along the grain boundary and free-surface short circuits. The silver, therefore, diffused into the film from the silver layer along the boundaries, eventually reaching the opposite surface where it accumulated and was measured by Auger spectroscopy. The silver layer acted as an effective constant silver source, and grain-boundary diffusivities were calculated from the accumulation data. However, the exact location of the effective constant source in the silver layer could not be determined and this led to an uncertainty in the values of the grain-boundary diffusivities of a factor of 10. Lower- and upper-bound values were therefore described by D/sub b/(lower bound) =7.8 x 10 -6 exp(-0.62eV/kT) and D/sub b/(upper bound) =7.8 x 10 -5 exp(-0.62eV/kT) cm 2 /s in the temperature range 30--269 0 C. An examination of available grain-boundary diffusion data (including the present) suggests a tendency for the observed activation energy to decrease with decreasing temperature, and this was ascribed to a spectrum of activated jumps in the grain boundary and/or a spectrum of grain-boundary types in the specimen employed. The constant source behavior was tentatively ascribed, at least in part, to a grain-boundary ''Kirkendall effect'' resulting from the faster diffusion of silver than gold. The work indicates a need for increased understanding of the details of grain-boundary diffusion in alloys

  20. Dimensioning of aerated submerged fixed bed biofilm reactors ...

    African Journals Online (AJOL)

    The description of a biofilm mathematical model application for dimensioning an aerated fixed bed biofilm reactor (ASFBBR) for petrochemical wastewater polishing is presented. A simple one-dimensional model of biofilm, developed by P Harremöes, was chosen for this purpose. The model was calibrated and verified ...

  1. Tailwater concerns and the history of turbine aeration

    International Nuclear Information System (INIS)

    Bohac, C.E.; Ruane, R.J.

    1991-01-01

    All new proposals for hydropower development and many of the almost 300 hydroelectric projects which will be relicensed before 2000 will have to address the issue of minimum dissolved oxygen concentrations. This paper highlights some of the causes and concerns of low dissolved oxygen concentrations in releases from hydropower projects and describes the history of hydroturbine aeration for reaerating these releases

  2. A review and investigations of some properties of foamed aerated ...

    African Journals Online (AJOL)

    The properties investigated on foamed aerated concrete having a designed density of 1600kg/m3 were: workability, density, compressive strength, tensile strength, and the water absorption capacity. The results showed that at the designed density adopted for this work, the material was workable and repeatable.

  3. Non-autoclaved aerated concrete with mineral additives

    Science.gov (United States)

    Il'ina, L. V.; Rakov, M. A.

    2016-01-01

    We investigated the effect of joint grinding of Portland cement clinker, silica and carbonate components and mineral additives to specific surface of 280 - 300 m2/kg on the properties (strength, average density and thermal conductivity) of non-autoclaved aerated concrete, and the porosity of the hardened cement paste produced from Portland cement clinker with mineral additives. The joint grinding of the Portland cement clinker with silica and carbonate components and mineral additives reduces the energy consumption of non-autoclaved aerated concrete production. The efficiency of mineral additives (diopside, wollastonite) is due to the closeness the composition, the type of chemical bonds, physical and chemical characteristics (specific enthalpy of formation, specific entropy) to anhydrous clinker minerals and their hydration products. Considering the influence of these additions on hydration of clinker minerals and formation of hardened cement paste structure, dispersed wollastonite and diopside should be used as mineral additives. The hardness and, consequently, the elastic modulus of diopside are higher than that of hardened cement paste. As a result, there is a redistribution of stresses in the hardened cement paste interporous partitions and hardening, both the partitions and aerated concrete on the whole. The mineral additives introduction allowed to obtain the non-autoclaved aerated concrete with average density 580 kg/m3, compressive strength of 3.3 MPa and thermal conductivity of 0.131 W/(m.°C).

  4. Modelling and test of aeration tank settling (ATS)

    DEFF Research Database (Denmark)

    Nielsen, M. K.; Bechmann, H.; Henze, Mogens

    2000-01-01

    The use of aeration tank settling during high hydraulic loads on large wastewater treatment plants has previously been demonstrated as a reliable technique and proven valuable. The paper proposes a simplified deterministic model to predict the efficiency of the method. It is shown...

  5. Dewaterability of sludge digested in extended aeration plants using ...

    African Journals Online (AJOL)

    Dewaterability of unconditioned sludge digested in full scale and lab scale experiments using either extended aeration (EA) or anaerobic digestion were compared on full and lab scale sand drying beds. Sludge digested in EA plants resulted in improvement in sludge dewaterability compared to sludge digested ...

  6. PROJECT OF COAGULANT DISPENSER IN PULVERIZATION AERATOR WITH WIND DRIVE

    Directory of Open Access Journals (Sweden)

    Ewa Osuch

    2017-09-01

    Full Text Available Lakes are one of most important freshwater ecosystems, playing significant role in functioning of nature and human economy. Swarzędzkie Lake is good example of ecosystem, which in last half-century was exposed to the influence of strong anthropopressure. Direct inflow of sewage with large number of biogens coming to the lake with water of inflows caused distinct disturbance of its functioning. In autumn 2011 restoration begined on Swarzędzkie Lake for reduction of lake trophy and improvement of water quality. For achieving better and quicker effect, simultaneously combination of some methods was applied, among others method of oxygenation of over-bottom water with help of pulverization aerator and method of precise inactivation of phosphorus in water depths. Characterization and analysis of improved coagulant dispenser applying active substance only during work of pulverization aerator is the aim of this thesis. Principle of dispenser work, its structure and location in pulverization aerator were explained. It was stated, that introduction to water a factor initiating process of phosphorus inactivation causes significant reduction of mineral phosphorus in water and size of coagulant dose correlates with intensity of work of pulverization aerator with wind drive.

  7. Characterization and behaviour of Autoclaved Aerated Concrete before Autoclaving

    NARCIS (Netherlands)

    Straub, Chr.; Florea, M.V.A.; Brouwers, H.J.H.; Schmidt, Wolfram; Msinjili, Nsesheye Susan

    In order to achieve a high quality Autoclaved Aerated Concrete (AAC) product, certain steps need to be ensured: the characterization of the raw materials, a proper mixing and correct slurry behaviour to achieve a good green body during green curing. In the current research the emphasis is on all of

  8. Investigation of flashing de-aeration with and without recirculation

    International Nuclear Information System (INIS)

    Kjellstroem, B.; Toecksberg, B.

    1977-06-01

    A series of experiments with flashing de-areation has been carried out at the institute of Thermal Energytechnology of the Royal Institute of Technology in Stockholm. The results of the experiments with flashing de-areation without recirculation of the condensate show very low contents of dissolved oxygen in the de-aerated water. The results indicate that the de-aeration process is independent of the pressure. De-aeration efficiencies over 99 percent were measured. The continued experiments with recirculation of the condensate show a considerably deteriorated de-aeration performance together with a marked pressure dependency. A simple theoretical model has been formulated which explains these results. Comparisons between the experimental data and calculations with this model indicate that a conservative estimation of the oxygen content of the outgoing water can be obtained if the oxygen content of the recirculated condensate is calculated for the partial pressure of noncondensible gases equal to the total pressure in the condensor. It seems also possible to estimate a lower limit for the oxygen content of the outgoing water. The range of oxygen content between those limits is about a factor of 10 for the conditions investigated. Further studies of the uptake of oxygen during condensation seem necessary if a more accurate prediction is desired

  9. Translocation of aluminum to grain crops grown in different agricultural systems

    International Nuclear Information System (INIS)

    Khan, S.; Kazi, T.G.; Kolachi, N.F.; Afridi, H.I.

    2012-01-01

    The aim of this study was to evaluate the mobility and transport of Aluminum (AI) by shoot and grain crops (wheat and maize) grown on two different agricultural soil irrigated with water have high (lake water) and low levels (canal water) of AI. The total and bio available fractions (deionized water, 0.11 M CH/sub 3/COOH, 0.05 M ethylenediaminetetraacetic acid (EDT A) and 0.1 M HCl extractable) of Al in both understudied agricultural soils and correlate with respective total Al in the edible parts (grains) and non edible parts (Shoots) of wheat and maize. The All content in lake and canal water samples was found in the range of 750 - 1340 and 90 - 50 micro g/L respectively. The total and extractable Al in both agricultural soil samples, edible and non edible parts of wheat and maize were analysed by atomic absorption spectrometry after acid digestion in microwave oven. The edible and non edible part of both crops absorbed significantly high levels of Al grown on agricultural soil irrigated with lake water (SILW) as compared to those grown on soil irrigated with can water (SICW) had low level of A] (p< O.OI). The transfer factor of Al from soils to edible and non edible parts of wheat and maize were also evaluated. It was observed that the bioaccumulation of Al was found to be high in non edible parts of both crops grown in SILW. This study highlights the increased danger of growing food crops in the agricultural land continuously irrigated by A] contaminated lake water. (author)

  10. Porosimetric, Thermal and Strength Tests of Aerated and Nonaerated Concretes

    Science.gov (United States)

    Strzałkowski, Jarosław; Garbalińska, Halina

    2017-10-01

    The paper presents the results of porosimetry tests of lightweight concretes, obtained with three research methods. Impact of different porosity structures on the basic thermal and strength properties was also evaluated. Tests were performed, using the pressure gauge method on fresh concrete mixes, as well as using the mercury porosimetry test and optic RapidAir method on specimens prepared from mature composites. The study was conducted on lightweight concretes, based on expanded clay aggregate and fly ash aggregate, in two variants: with non-aerated and aerated cement matrix. In addition, two reference concretes, based on normal aggregate, were prepared, also in two variants of matrix aeration. Changes in thermal conductivity λ and volumetric specific heat cv throughout the first three months of curing of the concretes were examined. Additionally, tests for compressive strength on cubic samples were performed during the first three months of curing. It was found that the pressure gauge method, performed on a fresh mix, gave lowered values of porosity, compared to the other methods. The mercury porosity tests showed high sensitivity in evaluation of pores smaller than 30μm. Unfortunately, this technique is not suitable for analysing pores greater than 300μm. On the other hand, the optical method proves good in evaluation of large pores, greater than 300μm. The paper also presents results of correlation of individual methods of porosity testing. A consolidated graph of the pore structure, derived from both mercury and optical methods, was presented, too. For the all of six tested concretes, differential graphs of porosity, prepared with both methods, show a very broad convergence. The thermal test results indicate usefulness of aeration of the cement matrix of the composites based on lightweight aggregates for the further reduction of the thermal conductivity coefficient λ of the materials. The lowest values of the λ coefficient were obtained for the aerated

  11. Carbon and nutrient removal from on-site wastewater using extended-aeration activated sludge and ion exchange.

    Science.gov (United States)

    Safferman, Steven I; Burks, Bennette D; Parker, Robert A

    2004-01-01

    The need to improve on-site wastewater treatment processes is being realized as populations move into more environmentally sensitive regions and regulators adopt the total maximum daily load approach to watershed management. Under many conditions, septic systems do not provide adequate treatment; therefore, advanced systems are required. These systems must remove significant amounts of biochemical oxygen demand (BOD) and suspended solids, and substantially nitrify, denitrify, and remove phosphorus. Many existing advanced on-site wastewater systems effectively remove BOD, suspended solids, and ammonia, but few substantially denitrify and uptake phosphorus. The purpose of this research was to design and test modifications to an existing on-site wastewater treatment system to improve denitrification and phosphorus removal. The Nayadic (Consolidated Treatment Systems, Inc., Franklin, Ohio), an established, commercially available, extended-aeration, activated sludge process, was used to represent a typical existing system. Several modifications were considered based on a literature review, and the option with the best potential was tested. To improve denitrification, a supplemental treatment tank was installed before the Nayadic and a combination flow splitter, sump, and pump box with a recirculation system was installed after it. A recirculation pump returned a high proportion of the system effluent back to the supplemental treatment tank. Two supplemental treatment tank sizes, three flowrates, and three recirculation rates were tested. Actual wastewater was dosed as brief slugs to the system in accordance with a set schedule. Several ion-exchange resins housed in a contact column were tested on the effluent for their potential to remove phosphorus. Low effluent levels of five-day biochemical oxygen demand, suspended solids, and total nitrogen were achieved and substantial phosphorous removal was also achieved using a 3780-L supplemental treatment tank, a recirculation

  12. Removal of arsenic from contaminated groundwater with application of iron electrodissolution, aeration and sand filtration

    DEFF Research Database (Denmark)

    Kowalski, Krysztof; Arturi, Kasia; Søgaard, Erik Gydesen

    2014-01-01

    The results from a new water treatment system for arsenic removal are presented. The technology is based on the employment of an electrolytic iron dissolution and efficient aeration procedure prior to sand filtration. The treatment was introduced and investigated in a pilot scale plant and full......, there was a relationship where the higher applied current from the iron generator resulted in a better quality of the produced water. The long period of use also helped to determine a proper iron dosage (the Fe/As ratio 68 mg/mg) and identify carbonate scale formation in the electrochemical process. The electrolytic...

  13. Eco-functional intensification by cereal-grain legume intercropping in organic farming systems for increased yields, reduced weeds and improved grain protein concentration

    DEFF Research Database (Denmark)

    Bedoussac, Laurent; Journet, Étienne-Pascal; Hauggaard-Nielsen, Henrik

    2014-01-01

    Intercropping, i.e., simultaneously growing two (or more) species in the same field for a significant period of time but without necessarily concomitant sowing or harvest, is a practice aimed at eco-functional intensification. This chapter integrates a comprehensive amount of original data from...... field experiments conducted since 2001 on spring and winter cereal-grain legume intercrops in experimental and farm contexts in France and Denmark, in an attempt to generalise the findings and draw up common guidelines. We have shown that intercrops appear to be a useful agronomic solution for organic......, structure and manuring strategies. Consequently, it should be emphasized that: (i) the species and varietal traits suited to intercropping and organic farming will make it necessary to reconsider the varietal selection criteria; (ii) further mechanistic understanding of the behaviour of intercropping...

  14. Fate of low arsenic concentrations during full-scale aeration and rapid filtration.

    Science.gov (United States)

    Gude, J C J; Rietveld, L C; van Halem, D

    2016-01-01

    In the Netherlands, groundwater treatment commonly consists of aeration, with subsequent sand filtration without using chemical oxidants like chlorine. With arsenic (As) concentrations well below the actual guidelines of 10 μg As/L, groundwater treatment plants have been exclusively designed for the removal of iron (Fe), manganese and ammonium. The aim of this study was to investigate the As removal capacity at three of these groundwater treatment plants (10-26 μg As/L) in order to identify operational parameters that can contribute to lowering the filtrate As concentration to removal. Results showed that after aeration, As largely remained mobile in the supernatant water; even during extended residence times only 20-48% removal was achieved (with 1.4-4.2 mg/L precipitated Fe(II)). Speciation showed that the mobile As was in the reduced As(III) form, whereas, As(V) was readily adsorbed to the formed HFO flocs. In the filter bed, the remaining As(III) completely oxidized within 2 min of residence time and As removal efficiencies increased to 48-90%. Filter grain coating analysis showed the presence of manganese at all three treatment plants. It is hypothesized that these manganese oxides are responsible for the accelerated As(III) oxidation in the filter bed, leading to an increased removal capacity. In addition, pH adjustment from 7.8 to 7.0 has been found to improve the capacity for As(V) uptake by the HFO flocs in the filter bed. The overall conclusion is, that during groundwater treatment, the filter bed is crucial for rapid As(III) removal, indicating the importance to control the oxidation sequence of Fe and As for improved As removal efficiencies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Effective pine bark composting with the Dome Aeration Technology

    International Nuclear Information System (INIS)

    Trois, Cristina; Polster, Andreas

    2007-01-01

    In South Africa garden refuse is primarily disposed of in domestic landfills. Due to the large quantities generated, any form of treatment would be beneficial for volume reduction, waste stabilization and resource recovery. Dome Aeration Technology (DAT) is an advanced process for aerobic biological degradation of garden refuse and general waste [Paar, S., Brummack, J., Gemende, B., 1999a. Advantages of dome aeration in mechanical-biological waste treatment. In: Proceedings of the 7th International Waste Management and Landfill Symposium, Cagliari, 4-8 October 1999; Paar, S., Brummack, J., Gemende, B., 1999b. Mechanical-biological waste stabilization by the dome aeration method. Environment Protection Engineering 25 (3/99). Mollekopf, N., Brummack, J., Paar, S., Vorster, K., 2002. Use of the Dome Aeration Technology for biochemical stabilization of waste prior to landfilling. In: Proceedings of the Wastecon 2002, Waste Congress and Exhibition, Durban, South Africa.]. It is a non-reactor open windrow composting process, with the main advantage being that the input material needs no periodic turning. A rotting time of only 3-4 months indicates the high efficiency. Additionally, the low capital/operational costs, low energy inputs and limited plant requirements provide potential for use in aerobic refuse stabilization. The innovation in the DAT process is the passive aeration achieved by thermally driven advection through open windrows caused by temperature differences between the degrading material and the outside environment. This paper investigates the application of Dome Aeration Technology to pine bark composting as part of an integrated waste management strategy. A full-scale field experiment was performed at the Bisasar Road Landfill Site in Durban to assess the influence of climate, waste composition and operational conditions on the process. A test windrow was constructed and measurements of temperature and airflow through the material were taken. The process

  16. Coarse graining of entanglement classes in 2 ×m ×n systems

    Science.gov (United States)

    Hebenstreit, M.; Gachechiladze, M.; Gühne, O.; Kraus, B.

    2018-03-01

    We consider three-partite pure states in the Hilbert space C2⊗Cm⊗Cn and investigate to which states a given state can be locally transformed with a nonvanishing probability. Whenever the initial and final states are elements of the same Hilbert space, the problem can be solved via the characterization of the entanglement classes which are determined via stochastic local operations and classical communication (SLOCC). In the particular case considered here, the matrix pencil theory can be utilized to address this point. In general, there are infinitely many SLOCC classes. However, when considering transformations from higher to lower dimensional Hilbert spaces, an additional hierarchy among the classes can be found. This hierarchy of SLOCC classes coarse grains SLOCC classes which can be reached from a common resource state of higher dimension. We first show that a generic set of states in C2⊗Cm⊗Cn for n =m is the union of infinitely many SLOCC classes, which can be parameterized by m -3 parameters. However, for n ≠m there exists a single SLOCC class which is generic. Using this result, we then show that there is a full-measure set of states in C2⊗Cm⊗Cn such that any state within this set can be transformed locally to a full measure set of states in any lower dimensional Hilbert space. We also investigate resource states, which can be transformed to any state (not excluding any zero-measure set) in the smaller dimensional Hilbert space. We explicitly derive a state in C2⊗Cm⊗C2 m -2 which is the optimal common resource of all states in C2⊗Cm⊗Cm . We also show that for any n m .

  17. The Efficiency of Iron and Manganese Removal from Groundwater Using Tower Aeration

    Directory of Open Access Journals (Sweden)

    Meghdad Pirsaheb

    2012-09-01

    Full Text Available Groundwaters passing through different layers of soil and due to its water properties and its high solubility, contain elements and minerals of material in the soil that sometimes can be dangerous for the health of consumers or at least undesirable in terms of cognitive beautiful. Iron and manganese are from constitutive of the soil and rocks of the Earth's surface. Water penetration through soil and rock can minerals such as these elements have dissolved and bring them into solution. The problems of iron and manganese in groundwater in domestic installations, commercial, industrial and refineries are created, and because much of the community water supply from underground water supplies will be removed where iron and manganese concentrations exceeded it is necessary. In this study Tower aeration system performance for the removal of iron and manganese from groundwater sources have been studied. In this research, pilot column aeration tower design, implementation and was established. This system made of PVC with a diameter and height 150 cm and 15 cm which was filled with flexible pipe parts. The initial pH=5, 7 and 9 and the initial concentration of Fe and Mn 2, 3 and 4 mg/l of the output system, sampling was done.

  18. Whole-plant dynamic system of nitrogen use for vegetative growth and grain filling in rice plants (Oryza sativa L. as revealed through the production of 350 grains from a germinated seed over 150 days: a review and synthesis

    Directory of Open Access Journals (Sweden)

    Tadakatsu Yoneyama

    2016-08-01

    Full Text Available A single germinated rice (Oryza sativa L seed can produce 350 grains with the sequential development of 15 leaves on the main stem and 7 ‒ 10 leaves on 4 productive tillers (forming 5 panicles in total, using nitrogen (N taken up from the environment over a 150-day growing season. Nitrogen travels from uptake sites to the grain through growing organ-directed cycling among sequentially developed organs. Over the past 40 years, the dynamic system for N allocation during vegetative growth and grain filling has been elucidated through studies on N and 15N transport as well as enzymes and transporters involved. In this review, we synthesize the information obtained in these studies along the following main points: (1 During vegetative growth before grain-filling, about half of the total N in the growing organs, including young leaves, tillers, root tips and differentiating panicles is supplied via phloem from mature source organs such as leaves and roots, after turnover and remobilization of proteins, whereas the other half is newly taken up and supplied via xylem, with an efficient xylem-to-phloem transfer at stem nodes. Thus, the growth of new organs depends equally on both N sources. (2 A large fraction (as much as 80% of the grain N is derived largely from mature organs such as leaves and stems by degradation, including the autophagy pathway of chloroplast proteins (e.g., Rubisco. (3 Mobilized proteinogenic amino acids, including arginine, lysine, proline and valine, are derived mainly from protein degradation, with amino acid transporters playing a role in transferring these amino acids across cell membranes of source and sink organs, and enabling their efficient reutilization in the latter. On the other hand, amino acids such as glutamine, glutamic acid, γ-amino butyric acid, aspartic acid, and alanine are produced by assimilation of newly taken up N by roots and transported via xylem and phloem. The formation of 350 filled grains over 50

  19. Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial.

    Science.gov (United States)

    Roager, Henrik Munch; Vogt, Josef K; Kristensen, Mette; Hansen, Lea Benedicte S; Ibrügger, Sabine; Mærkedahl, Rasmus B; Bahl, Martin Iain; Lind, Mads Vendelbo; Nielsen, Rikke L; Frøkiær, Hanne; Gøbel, Rikke Juul; Landberg, Rikard; Ross, Alastair B; Brix, Susanne; Holck, Jesper; Meyer, Anne S; Sparholt, Morten H; Christensen, Anders F; Carvalho, Vera; Hartmann, Bolette; Holst, Jens Juul; Rumessen, Jüri Johannes; Linneberg, Allan; Sicheritz-Pontén, Thomas; Dalgaard, Marlene D; Blennow, Andreas; Frandsen, Henrik Lauritz; Villas-Bôas, Silas; Kristiansen, Karsten; Vestergaard, Henrik; Hansen, Torben; Ekstrøm, Claus T; Ritz, Christian; Nielsen, Henrik Bjørn; Pedersen, Oluf Borbye; Gupta, Ramneek; Lauritzen, Lotte; Licht, Tine Rask

    2017-11-01

    To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (pgut microbiome but reduced body weight and systemic low-grade inflammation. NCT01731366; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Physical properties of five grain dust types.

    OpenAIRE

    Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

    1986-01-01

    Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less tha...

  1. Autonomous Information Unit for Fine-Grain Data Access Control and Information Protection in a Net-Centric System

    Science.gov (United States)

    Chow, Edward T.; Woo, Simon S.; James, Mark; Paloulian, George K.

    2012-01-01

    As communication and networking technologies advance, networks will become highly complex and heterogeneous, interconnecting different network domains. There is a need to provide user authentication and data protection in order to further facilitate critical mission operations, especially in the tactical and mission-critical net-centric networking environment. The Autonomous Information Unit (AIU) technology was designed to provide the fine-grain data access and user control in a net-centric system-testing environment to meet these objectives. The AIU is a fundamental capability designed to enable fine-grain data access and user control in the cross-domain networking environments, where an AIU is composed of the mission data, metadata, and policy. An AIU provides a mechanism to establish trust among deployed AIUs based on recombining shared secrets, authentication and verify users with a username, X.509 certificate, enclave information, and classification level. AIU achieves data protection through (1) splitting data into multiple information pieces using the Shamir's secret sharing algorithm, (2) encrypting each individual information piece using military-grade AES-256 encryption, and (3) randomizing the position of the encrypted data based on the unbiased and memory efficient in-place Fisher-Yates shuffle method. Therefore, it becomes virtually impossible for attackers to compromise data since attackers need to obtain all distributed information as well as the encryption key and the random seeds to properly arrange the data. In addition, since policy can be associated with data in the AIU, different user access and data control strategies can be included. The AIU technology can greatly enhance information assurance and security management in the bandwidth-limited and ad hoc net-centric environments. In addition, AIU technology can be applicable to general complex network domains and applications where distributed user authentication and data protection are

  2. Effects of superoxide dismutase, dithiothreitol and formate ion on the inactivation of papain by hydroxyl and superoxide radicals in aerated solutions

    International Nuclear Information System (INIS)

    Lin, W.S.; Armstrong, D.A.

    1978-01-01

    Losses in enzyme activity and sulphydryl content have been studied in aerated papain solutions containing formate, superoxide dismutase and dithiothreitol. Both formate and dithiothreitol converted .OH to .0 2 -, whereas superoxide dismutase completely suppressed the inactivation by .0 2 -. Using results from all systems, the fraction of .0 2 - reactions with papain that caused inactivation of the enzyme was 0.33+-0.07. The results also showed that the fraction of .OH reactions, which cause inactivation of papain, is significantly higher in aerated than in oxygen-free solutions. (author)

  3. Computerized radioautographic grain counting

    International Nuclear Information System (INIS)

    McKanna, J.A.; Casagrande, V.A.

    1985-01-01

    In recent years, radiolabeling techniques have become fundamental assays in physiology and biochemistry experiments. They also have assumed increasingly important roles in morphologic studies. Characteristically, radioautographic analysis of structure has been qualitative rather than quantitative, however, microcomputers have opened the door to several methods for quantifying grain counts and density. The overall goal of this chapter is to describe grain counting using the Bioquant, an image analysis package based originally on the Apple II+, and now available for several popular microcomputers. The authors discuss their image analysis procedures by applying them to a study of development in the central nervous system

  4. Influence of Crop Nutrition on Grain Yield, Seed Quality and Water Productivity under Two Rice Cultivation Systems

    Directory of Open Access Journals (Sweden)

    Y.V. SINGH

    2013-03-01

    Full Text Available The system of rice intensification (SRI is reported to have advantages like lower seed requirement, less pest attack, shorter crop duration, higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation. With this background, SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute, New Delhi, India during two wet seasons (2009–2011. In the experiment laid out in a factorial randomized block design, two methods of rice cultivation [conventional transplanting (CT and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44 were used under seven crop nutrition treatments, viz. T1, 120 kg/hm2 N, 26.2 kg/hm2 P and 33 kg/hm2 K; T2, 20 t/hm2 farmyard manure (FYM; T3, 10 t/hm2 FYM + 60 kg/hm2 N; T4, 5 t/hm2 FYM + 90 kg/hm2 N; T5, 5 t/hm2 FYM + 60 kg/hm2 N + 1.5 kg/hm2 blue green algae (BGA; T6, 5 t/hm2 FYM + 60 kg/hm2 N + 1.0 t/hm2 Azolla, and T7, N0P0K0 (control, no NPK application to study the effect on seed quality, yield and water use. In SRI, soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2–3 cm was maintained during the reproductive phase of rice, however, in CT, standing water was maintained in crop growing season. Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI. Seed quality was superior in SRI as compared to CT. Integrated nutrient management (INM resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties. Grain yield attributes such as number of effective tillers per hill, panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone. Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer. The grain yield

  5. Sistema com aeração, decantação e filtragem para a melhoria da qualidade de água em irrigação localizada System with aeration, sedimentation and filtering for the improving of water quality in drip irrigation

    Directory of Open Access Journals (Sweden)

    Marco A. F. Lemos Filho

    2011-06-01

    Full Text Available A qualidade da água é muito importante para irrigação por gotejamento, pois ela escoa por pequenos bocais dos emissores, podendo ocorrer obstrução devido à deposição dos sólidos em suspensão. Portanto, antes da instalação do projeto, devem-se avaliar parâmetros de qualidade da água, para adotar medidas preventivas, evitando o risco de entupimento do sistema. Este trabalho teve como objetivo avaliar um sistema composto por aeradores com aspersores, sobre leito de pedra, para a precipitação dos íons Fe+2e Mn+2 em tanque de decantação, e um conjunto de filtragem composto por três filtros de areia e um de disco, em sistema de irrigação localizada. O trabalho foi realizado na Fazenda Alvorada, no município de Nova Granada - SP, no período de março a outubro de 2008. Foram realizadas determinações de variáveis físicas e químicas da água, ao longo do sistema de aeração, decantação e filtragem, o qual foi eficiente para a melhoria da qualidade de água, reduzindo os níveis de risco de entupimento de severo para médio e de médio para baixo. Oxigênio dissolvido, condutividade elétrica, pH, Fe+2e Fe+3 não diferenciaram a qualidade de água entre os pontos do sistema de tratamento, porém a turbidez, sólidos dissolvidos, sólidos em suspensão, ferro total e manganês total reduziram-se significativamente pelo uso do sistema proposto, melhorando a qualidade da água.Water quality is very important to drip irrigation, as it flows in small diameter holes, and may cause obstruction due to deposition of solid matter. Whence the water must be evaluated before installation of the project. Parameters related to water quality are essential to define conducting measures to avoid the risk of clogging the system. This study aimed to evaluate a system with sprinklers aeration on bedrock, for Fe+2and Mn total precipitation in sedimentation tank and a set of filtering consisting of three sand filters and a disk, installed in

  6. The effects of agitation and aeration on the production of gluconic acid by Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Dronawat, S.N.; Svihla, C.K.; Hanley, T.R. [Univ. of Louisville, KY (United States)

    1995-12-31

    The effects of agitation and aeration in the production of gluconic acid by Aspergillus niger from a glucose medium were investigated. Experiments were conducted at aeration rates of 5.0 and 10.0 L/min. Four different agitation speeds were investigated for each aeration rate. Gluconic acid concentration and biomass concentration were analyzed, and the rate of consumption of substrate by A. niger was noted. The main purpose of this work was to find the optimal conditions of agitation and aeration for the growth of A. niger and production of gluconic acid in submerged culture in a batch fermentor at a bench-top scale. The oxygen-transfer rates at different agitation and aeration rates were calculated. The gluconic acid concentration and rate of growth of A. niger increased with increase in the agitation and aeration rates.

  7. Violent breaking wave impacts. Part 3. Effects of scale and aeration

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Bullock, G. N.; Hogg, A. J.

    2015-01-01

    . The Bagnold-Mitsuyasu scaling law for the compression of an air pocket by a piston of incompressible water is rederived and generalised to 3D air pockets of arbitrary shape. Numerical results for wall pressure, force and impulse are then presented for a flip-through impact, a low-aeration impact and a high......The effects of scale and aeration on violent breaking wave impacts with trapped and entrained air are investigated both analytically and numerically. By dimensional analysis we show that the impact pressures for Froude scaled conditions prior to the impact depend on the scale and aeration level......-aeration impact, for nine scales and five levels of initial aeration. Two of these impact types trap a pocket of air at the wall. Among the findings of the paper is that for fixed initial aeration, impact pressures from the flip-through impact broadly follow Froude scaling. This is also the case for the two...

  8. Copy number ratios determined by two digital polymerase chain reaction systems in genetically modified grains

    Science.gov (United States)

    Pérez Urquiza, M.; Acatzi Silva, A. I.

    2014-02-01

    Three certified reference materials produced from powdered seeds to measure the copy number ratio sequences of p35S/hmgA in maize containing MON 810 event, p35S/Le1 in soybeans containing GTS 40-3-2 event and DREB1A/acc1 in wheat were produced according to the ISO Guides 34 and 35. In this paper, we report digital polymerase chain reaction (dPCR) protocols, performance parameters and results of copy number ratio content of genetically modified organisms (GMOs) in these materials using two new dPCR systems to detect and quantify molecular deoxyribonucleic acid: the BioMark® (Fluidigm) and the OpenArray® (Life Technologies) systems. These technologies were implemented at the National Institute of Metrology in Mexico (CENAM) and in the Reference Center for GMO Detection from the Ministry of Agriculture (CNRDOGM), respectively. The main advantage of this technique against the more-used quantitative polymerase chain reaction (qPCR) is that it generates an absolute number of target molecules in the sample, without reference to standards or an endogenous control, which is very useful when not much information is available for new developments or there are no standard reference materials in the market as in the wheat case presented, or when it was not possible to test the purity of seeds as in the maize case presented here. Both systems reported enhanced productivity, increased reliability and reduced instrument footprint. In this paper, the performance parameters and uncertainty of measurement obtained with both systems are presented and compared.

  9. Microfaunal indicators, Ciliophora phylogeny and protozoan population shifts in an intermittently aerated and fed bioreactor

    International Nuclear Information System (INIS)

    Ntougias, Spyridon; Tanasidis, Spartakos; Melidis, Paraschos

    2011-01-01

    Microfauna community structure was examined in the mixed liquor of a bench-scale bioreactor equipped with an intermittent aeration and feeding system. The reactor was operated under an intermittent aeration of 25 min in every 1 h and varying feeding conditions (0.264, 0.403 and 0.773 kg BOD 5 /m 3 d). A total of 14 protozoan and metazoan taxa were identified by microscopic examination. Sessile ciliates, followed by crawling ciliates, were the major protozoan groups under 0.403 kg BOD 5 /m 3 d organic loading conditions, while sessile ciliate population was remarkably increased under an organic loading of 0.773 kg BOD 5 /m 3 d. Principal Component Analysis and Pearson correlation coefficient tests were performed in order to reveal relationships between microfauna community and operational parameters. Ciliophora specific-18S rRNA gene clone library was constructed to identify ciliate diversity under 0.773 kg BOD 5 /m 3 d organic loading conditions. Ciliophora diversity consisted of members of Aspidiscidae, Epistylidae, Opisthonectidae and Vorticellidae, with the majority of the clones being associated with the species Vorticella fusca. At least one novel phylogenetic linkage among Ciliophora was identified. Comparisons made after molecular characterization and microscopic examination of Ciliophora community showed that the estimation of broad ciliate groups is useful for ecological considerations and evaluation of the operational conditions in wastewater treatment plants.

  10. Microfaunal indicators, Ciliophora phylogeny and protozoan population shifts in an intermittently aerated and fed bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Ntougias, Spyridon, E-mail: sntougia@env.duth.gr [Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi (Greece); Tanasidis, Spartakos; Melidis, Paraschos [Democritus University of Thrace, Department of Environmental Engineering, Laboratory of Wastewater Management and Treatment Technologies, Vas. Sofias 12, 67100 Xanthi (Greece)

    2011-02-28

    Microfauna community structure was examined in the mixed liquor of a bench-scale bioreactor equipped with an intermittent aeration and feeding system. The reactor was operated under an intermittent aeration of 25 min in every 1 h and varying feeding conditions (0.264, 0.403 and 0.773 kg BOD{sub 5}/m{sup 3} d). A total of 14 protozoan and metazoan taxa were identified by microscopic examination. Sessile ciliates, followed by crawling ciliates, were the major protozoan groups under 0.403 kg BOD{sub 5}/m{sup 3} d organic loading conditions, while sessile ciliate population was remarkably increased under an organic loading of 0.773 kg BOD{sub 5}/m{sup 3} d. Principal Component Analysis and Pearson correlation coefficient tests were performed in order to reveal relationships between microfauna community and operational parameters. Ciliophora specific-18S rRNA gene clone library was constructed to identify ciliate diversity under 0.773 kg BOD{sub 5}/m{sup 3} d organic loading conditions. Ciliophora diversity consisted of members of Aspidiscidae, Epistylidae, Opisthonectidae and Vorticellidae, with the majority of the clones being associated with the species Vorticella fusca. At least one novel phylogenetic linkage among Ciliophora was identified. Comparisons made after molecular characterization and microscopic examination of Ciliophora community showed that the estimation of broad ciliate groups is useful for ecological considerations and evaluation of the operational conditions in wastewater treatment plants.

  11. Treatment of Alkaline Stripped Effluent in Aerated Constructed Wetlands: Feasibility Evaluation and Performance Enhancement

    Directory of Open Access Journals (Sweden)

    Keli He

    2016-09-01

    Full Text Available Ammonium stripping has gained increasing interest for nitrogen recovery in anaerobically digested effluents. However, the stripped effluents often still do not meet discharge standards, having high pH and residual pollutants. Constructed wetlands (CWs are an easy to operate ecosystem and have a long history of application in treatment of wastewaters with extreme pH, such as acid mine drainage. However, knowledge of the mechanistic details involved in the use of CWs to treat high alkaline drainage, such as stripped effluent, is insufficient. This study explored the feasibility and effectiveness of using three sub-surface horizontal flow CWs to treat high alkaline stripped effluent (pH > 10. Two intensification strategies—intermittent aeration and effluent recirculation—were evaluated to enhance nitrogen depuration performance. The results show that the treatment of alkaline stripped effluent is feasible due to the high buffering capacity of the wetlands. Effluent recirculation combined with intermittent artificial aeration improves nitrogen removal, with 71% total nitrogen (TN removal. Ammonia volatilization from the surface of the wetlands in high alkaline conditions only contributed to 3% of the total removed ammonium. The microbial abundance and activity had significant diversity for the various enhancement strategies used in the constructed wetland systems. Anammox is an important process for nitrogen removal in CWs treating alkaline stripped effluent, and possible enhancements of this process should be investigated further.

  12. Systematic NMR Analysis of Stable Isotope Labeled Metabolite Mixtures in Plant and Animal Systems: Coarse Grained Views of Metabolic Pathways

    Science.gov (United States)

    Chikayama, Eisuke; Suto, Michitaka; Nishihara, Takashi; Shinozaki, Kazuo; Hirayama, Takashi; Kikuchi, Jun

    2008-01-01

    Background Metabolic phenotyping has become an important ‘bird's-eye-view’ technology which can be applied to higher organisms, such as model plant and animal systems in the post-genomics and proteomics era. Although genotyping technology has expanded greatly over the past decade, metabolic phenotyping has languished due to the difficulty of ‘top-down’ chemical analyses. Here, we describe a systematic NMR methodology for stable isotope-labeling and analysis of metabolite mixtures in plant and animal systems. Methodology/Principal Findings The analysis method includes a stable isotope labeling technique for use in living organisms; a systematic method for simultaneously identifying a large number of metabolites by using a newly developed HSQC-based metabolite chemical shift database combined with heteronuclear multidimensional NMR spectroscopy; Principal Components Analysis; and a visualization method using a coarse-grained overview of the metabolic system. The database contains more than 1000 1H and 13C chemical shifts corresponding to 142 metabolites measured under identical physicochemical conditions. Using the stable isotope labeling technique in Arabidopsis T87 cultured cells and Bombyx mori, we systematically detected >450 HSQC peaks in each 13C-HSQC spectrum derived from model plant, Arabidopsis T87 cultured cells and the invertebrate animal model Bombyx mori. Furthermore, for the first time, efficient 13C labeling has allowed reliable signal assignment using analytical separation techniques such as 3D HCCH-COSY spectra in higher organism extracts. Conclusions/Significance Overall physiological changes could be detected and categorized in relation to a critical developmental phase change in B. mori by coarse-grained representations in which the organization of metabolic pathways related to a specific developmental phase was visualized on the basis of constituent changes of 56 identified metabolites. Based on the observed intensities of 13C atoms of

  13. Influência das densidades de estocagem e sistemas de aeração sobre o peso e características de carcaça da tilápia do Nilo (Oreochromis niloticus Linnaeus, 1757 Influence of stocking densities and aeration systems on Nile tilapia (Oreochromis niloticus, 1757

    Directory of Open Access Journals (Sweden)

    Newton Castagnolli

    1998-10-01

    Full Text Available O experimento foi conduzido em nove tanques (38m2, durante 252 dias, com Oreochromis niloticus, revertidas para macho, pesando em média 16,3g, alimentadas com ração comercial (29,5% PB. Comparou-se a eficiência dos sistemas de aeração (A1=controle-sem aeração; A2=compressor radial e A3=chafariz, em três densidades de estocagem (D1=3 peixes/m3; D2=6 peixes/m3 e D3=9 peixes/m3, avaliadas através do peso final (PF dos peixes, peso de carcaça (PC, filé (PFI, pele (PP, gordura visceral (PGV e rendimentos de carcaça (RC e filé (RFI. O delineamento foi inteiramente casualizado, em esquema fatorial 3x3, com 30 repetições, sendo o peixe considerado a unidade experimental. O maior PF (530,27g e PC (431,22 foram obtidos na D1. O compressor radial (A2 foi significativamente mais eficiente do que os demais sistemas, para PF e PC, porém para PFI, somente foi significativamente mais eficiente na D2 (162,67g. O maior PGV (37,36g e PP (38,13g foram observados na D1 respectivamente, com A2 e A3. Para RC, não houve diferença entre as densidades e o A3 proporcionou o maior resultado, apesar de não diferir de A1. O RFI variou de 31,73% (A2D1 a 37,14% (A1D1 entre os tratamentos.A 252-day experiment was carried out in nine fish ponds with male sex-reversed Nile tilapia with 16.3g average weight and fed on commercial ration (29.5% crude protein. The efficiency of aeration systems (A1=non-aeration control; A2=radial compressor and A3=sprinkler was compared in three stocking densities (D1=3 fish/m3; D2=6 fish/m3 and D3=9 fish/m3, through the evaluation on their final weight (FW, carcass weight (CW, fillet weight (FIW, skin weight (SWO, visceral fat weight (VFW, carcass yield (CY and fillet yield (FIY. Plotting was completely randomized through a 3x3 factorial scheme, with 30 replications, and each fish was considered as an experimental unit. The heaviest FW (530.27g and CW (431.22g were obtained in D1. The radial compressor system was significantly

  14. Polyhydroxyalkanoate synthesis by mixed microbial consortia cultured on fermented dairy manure: Effect of aeration on process rates/yields and the associated microbial ecology.

    Science.gov (United States)

    Coats, Erik R; Watson, Benjamin S; Brinkman, Cynthia K

    2016-12-01

    Polyhydroxyalkanoates (PHAs) are biodegradable polymers that can substitute for petroleum-based plastics in a variety of applications. One avenue to commercial PHA production involves coupling waste-based synthesis with the use of mixed microbial consortia (MMC). In this regard, production requires maximizing the enrichment of a MMC capable of feast-famine PHA synthesis, with the metabolic response induced through imposition of aerobic-dynamic feeding (ADF) conditions. However, the concept of PHA production in complex matrices remains unrefined; process operational improvements are needed, along with an enhanced understanding of the MMC. Research presented herein investigated the effect of aeration on feast-famine PHA synthesis, with four independent aeration state systems studied; MMC were fed volatile fatty acid (VFA)-rich fermented dairy manure. Regardless of the aeration state, all MMC exhibited a feast-famine response based on observed carbon cycling. Moreover, there was no statistical difference in PHA synthesis rates, with q PHA ranging from 0.10 to 0.19 CmmolPHA gVSS -1 min -1 ; VFA uptake rates exhibited similar statistical indifferences. PHA production assessments on the enriched MMC resulted in maximum intracellular concentrations ranging from 22.5 to 90.7% (mgPHA mgVSS -1 ); at maximum concentration, the mean hydroxyvalerate mol content was 73 ± 0.6%. While a typical feast-famine dissolved oxygen (DO) pattern was observed at maximum aeration, less resolution was observed at decreasing aeration rates, suggesting that DO may not be an optimal process monitoring parameter. At lower aeration states, nitrogen cycling patterns, supported by molecular investigations targeting AOBs and NOBs, indicate that NO 2 and NO 3 sustained feast-famine PHA synthesis. Next-generation sequencing analysis of the respective MMC revealed numerous and diverse genera exhibiting the potential to achieve PHA synthesis, suggesting functional redundancy embedded in the diverse

  15. Managing soil microbial communities in grain production systems through cropping practices

    Science.gov (United States)

    Gupta, Vadakattu

    2013-04-01

    Cropping practices can significantly influence the composition and activity of soil microbial communities with consequences to plant growth and production. Plant type can affect functional capacity of different groups of biota in the soil surrounding their roots, rhizosphere, influencing plant nutrition, beneficial symbioses, pests and diseases and overall plant health and crop production. The interaction between different players in the rhizosphere is due to the plethora of carbon and nutritional compounds, root-specific chemical signals and growth regulators that originate from the plant and are modulated by the physico-chemical properties of soils. A number of plant and environmental factors and management practices can influence the quantity and quality of rhizodeposition and in turn affect the composition of rhizosphere biota communities, microbe-fauna interactions and biological processes. Some of the examples of rhizosphere interactions that are currently considered important are: proliferation of plant and variety specific genera or groups of microbiota, induction of genes involved in symbiosis and virulence, promoter activity in biocontrol agents and genes correlated with root adhesion and border cell quality and quantity. The observation of variety-based differences in rhizodeposition and associated changes in rhizosphere microbial diversity and function suggests the possibility for the development of varieties with specific root-microbe interactions targeted for soil type and environment i.e. designer rhizospheres. Spatial location of microorganisms in the heterogeneous field soil matrix can have significant impacts on biological processes. Therefore, for rhizosphere research to be effective in variable seasonal climate and soil conditions, it must be evaluated in the field and within a farming systems context. With the current focus on security of food to feed the growing global populations through sustainable agricultural production systems there is a

  16. Grass-clover undersowing affects nitrogen dynamics in a grain legume–cereal arable cropping system

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Mundus, Simon; Jensen, Erik Steen

    2012-01-01

    A field experiment was carried out in an arable organic cropping system and included a sequence with sole cropped fababean (Vicia faba L.), lupin (Lupinus angustifolius L.), pea (Pisum sativum L.), oat (Avena sativa L.) and pea–oat intercropping with or without an undersown perennial ryegrass...... N2 fixation and 15N labeling technique to determine the fate of pea and oat residue N recovery in the subsequent crop. The subsequent spring wheat and winter triticale crop yields were not significantly affected by the previous main crop, but a significant effect of catch crop undersowing...

  17. Liberal Entity Extraction: Rapid Construction of Fine-Grained Entity Typing Systems.

    Science.gov (United States)

    Huang, Lifu; May, Jonathan; Pan, Xiaoman; Ji, Heng; Ren, Xiang; Han, Jiawei; Zhao, Lin; Hendler, James A

    2017-03-01

    The ability of automatically recognizing and typing entities in natural language without prior knowledge (e.g., predefined entity types) is a major challenge in processing such data. Most existing entity typing systems are limited to certain domains, genres, and languages. In this article, we propose a novel unsupervised entity-typing framework by combining symbolic and distributional semantics. We start from learning three types of representations for each entity mention: general semantic representation, specific context representation, and knowledge representation based on knowledge bases. Then we develop a novel joint hierarchical clustering and linking algorithm to type all mentions using these representations. This framework does not rely on any annotated data, predefined typing schema, or handcrafted features; therefore, it can be quickly adapted to a new domain, genre, and/or language. Experiments on genres (news and discussion forum) show comparable performance with state-of-the-art supervised typing systems trained from a large amount of labeled data. Results on various languages (English, Chinese, Japanese, Hausa, and Yoruba) and domains (general and biomedical) demonstrate the portability of our framework.

  18. 75 FR 76254 - Official Performance and Procedural Requirements for Grain Weighing Equipment and Related Grain...

    Science.gov (United States)

    2010-12-08

    ... DEPARTMENT OF AGRICULTURE Grain Inspection, Packers and Stockyards Administration 7 CFR Part 802 [Docket GIPSA-2010-FGIS-0012] RIN 0580-AB19 Official Performance and Procedural Requirements for Grain Weighing Equipment and Related Grain Handling Systems AGENCY: Grain Inspection, Packers and Stockyards...

  19. Landfill aeration in the framework of a reclamation project in Northern Italy.

    Science.gov (United States)

    Raga, Roberto; Cossu, Raffaello

    2014-03-01

    In situ aeration by means of the Airflow technology was proposed for landfill conditioning before landfill mining in the framework of a reclamation project in Northern Italy. A 1-year aeration project was carried out on part of the landfill with the objective of evaluating the effectiveness of the Airflow technology for landfill aerobization, the evolution of waste biological stability during aeration and the effects on leachate and biogas quality and emissions. The main outcomes of the 1-year aeration project are presented in the paper. The beneficial effect of the aeration on waste biological stability was clear (63% reduction of the respiration index); however, the effectiveness of aeration on the lower part of the landfill is questionable, due to the limited potential for air migration into the leachate saturated layers. During the 1-year in situ aeration project approx. 275 MgC were discharged from the landfill body with the extracted gas, corresponding to 4.6 gC/kgDM. However, due to the presence of anaerobic niches in the aerated landfill, approx. 46% of this amount was extracted as CH4, which is higher than reported in other aeration projects. The O2 conversion quota was lower than reported in other similar projects, mainly due to the higher air flow rates applied. The results obtained enabled valuable recommendations to be made for the subsequent application of the Airflow technology to the whole landfill. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Bioreactor tests preliminary to landfill in situ aeration: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Raga, Roberto, E-mail: roberto.raga@unipd.it [ICEA Department, University of Padova. Via Marzolo, 9, 35131 Padova (Italy); Cossu, Raffaello [ICEA Department, University of Padova. Via Marzolo, 9, 35131 Padova (Italy)

    2013-04-15

    Highlights: ► Carbon and nitrogen mass balances in aerated landfill simulation reactors. ► Waste stabilization in aerated landfill simulation reactors. ► Effect of temperature on biodegradation processes in aerated landfills. - Abstract: Lab scale tests in bioreactor were carried out in the framework of the characterization studies of a landfill where in situ aeration (possibly followed by landfill mining) had been proposed as part of the novel waste management strategy in a region in northern Italy. The tests were run to monitor the effects produced by aerobic conditions at different temperatures on waste sampled at different depths in the landfill, with focus on the carbon and nitrogen conversion during aeration. Temperatures ranging from 35 to 45 °C were chosen, in order to evaluate possible inhibition of biodegradation processes (namely nitrification) at 45 °C in the landfill. The results obtained showed positive effects of the aeration on leachate quality and a significant reduction of waste biodegradability. Although a delay of biodegradation processes was observed in the reactor run at 45 °C, biodegradation rates increased after 2 months of aeration, providing very low values of the relevant parameters (as in the other aerated reactors) by the end of the study. Mass balances were carried out for TOC and N-NH{sub 4}{sup +}; the findings obtained were encouraging and provided evidence of the effectiveness of carbon and nitrogen conversion processes in the aerated landfill simulation reactors.

  1. DESAIN KONTROL AERATOR PADA INSTALASI PENGOLAHAN AIR LIMBAH SUWUNG DENGAN FUZZY LOGIC

    Directory of Open Access Journals (Sweden)

    I Made Mataram

    2010-12-01

    Full Text Available Limbah merupakan buangan yang dihasilkan dari suatu proses produksi baik industri maupun domestik (rumahtangga dan harus dikelola agar tidak menimbulkan pencemaran dan penurunan kualitas lingkungan. InstalasiPengolahan Air Limbah (IPAL merupakan suatu tempat pengolahan limbah yang bertempat di daerah Suwung.Pengolahan limbah cair dilakukan dengan menggunakan sistem kolam aerasi dan kolam sedimentasi.Pada proses aerasi yaitu proses reduksi BOD (Biological Oxygen Demand dan COD (Chemical OxygenDemand secara aerob digunakan aerator sebagai penghasil oksigen yaitu dengan cara menempatkan aerator didalam kolam aerasi sehingga menghasilkan oksigen berupa buih udara yang tercampur dengan air. Untuk IPALSuwung pengoperasian aerator masih dengan cara manual yaitu dioperasikan pada jam tertentu sehingga inputjumlah oksigen terkadang tidak sesuai dengan karakteristik input limbah yang diolah, maka diperlukan suatu sistemkontrol pengoperasian aerator yang dapat menghasilkan oksigen guna mereduksi COD secara tepat sesuai bakumutu limbahDalam penelitian ini dilakukan perencanaan desain kontrol pengoperasian aerator dengan fuzzy logic. Desainpengontrolan dengan menggunakan logika fuzzy pada pengoperasian aerator sudah dapat dibuat dan dapat bekerjasesuai dengan karateristik input/ouput limbah, ini terlihat dari lama operasi aerator yang bekerja sudah sesuaidengan input limbah. Penggunaan energi listrik dengan pengontrolan fuzzy pada pengoperasian aerator lebih rendahdibandingkan dengan penggunaan energi listrik pengoperasian secara manual, ini terlihat dari penggunaan energipengoperasian aerator manual dan fuzzy pada bulan Oktober 2010 yang memiliki selisih sebesar 6.693 kWh, bulanNovember 2010

  2. Bioreactor tests preliminary to landfill in situ aeration: A case study

    International Nuclear Information System (INIS)

    Raga, Roberto; Cossu, Raffaello

    2013-01-01

    Highlights: ► Carbon and nitrogen mass balances in aerated landfill simulation reactors. ► Waste stabilization in aerated landfill simulation reactors. ► Effect of temperature on biodegradation processes in aerated landfills. - Abstract: Lab scale tests in bioreactor were carried out in the framework of the characterization studies of a landfill where in situ aeration (possibly followed by landfill mining) had been proposed as part of the novel waste management strategy in a region in northern Italy. The tests were run to monitor the effects produced by aerobic conditions at different temperatures on waste sampled at different depths in the landfill, with focus on the carbon and nitrogen conversion during aeration. Temperatures ranging from 35 to 45 °C were chosen, in order to evaluate possible inhibition of biodegradation processes (namely nitrification) at 45 °C in the landfill. The results obtained showed positive effects of the aeration on leachate quality and a significant reduction of waste biodegradability. Although a delay of biodegradation processes was observed in the reactor run at 45 °C, biodegradation rates increased after 2 months of aeration, providing very low values of the relevant parameters (as in the other aerated reactors) by the end of the study. Mass balances were carried out for TOC and N-NH 4 + ; the findings obtained were encouraging and provided evidence of the effectiveness of carbon and nitrogen conversion processes in the aerated landfill simulation reactors

  3. Monitoring transitory profiles of leachate humic substances in landfill aeration reactors in mesophilic and thermophilic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Huanhuan [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Yin, Ke; Ge, Liya; Giannis, Apostolos [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); Chuan, Valerie W.L. [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Wang, Jing-Yuan, E-mail: JYWANG@ntu.edu.sg [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2015-04-28

    Highlights: • Polymerization and condensation of humic substances (HS) were enhanced by aeration. • Carboxylic group was enriched in HS by aeration presenting improved hydrophilicity. • Mobility of humic acid, as a result was enhanced by aeration especially in young landfill. • Waste age plays an important role in leachate management during aeration. - Abstract: The presence of humic substances (HS) in landfill leachate is of great interest because of their structural stability and potential toxicity. This study examined the effects of temperature and waste age on the transformation of HS during in situ aeration of bioreactor landfills. By establishing aerobic conditions, dissolved organic carbon (DOC) rapidly accumulated in the bioreactor leachate. Fractional analysis showed that the elevated concentration of humic acids (HAs) was primarily responsible for the increment of leachate strength. Further structural characterization indicated that the molecular weight (MW) and aromacity of HS were enhanced by aeration in conjunction with thermophilic temperature. Interestingly, elevation of HAs concentration was not observed in the aeration reactor with a prolonged waste age, as the mobility of HAs was lowered by the high MW derived from extended waste age. Based on these results, aeration may be more favorable in aged landfills, since dissolution of HAs could be minimized by the evolution to larger MW compared to young landfills. Moreover, increased operation temperature during aeration likely offers benefits for the rapid maturation of HS.

  4. Multilevel coarse graining and nano-pattern discovery in many particle stochastic systems

    International Nuclear Information System (INIS)

    Kalligiannaki, Evangelia; Katsoulakis, Markos A.; Plecháč, Petr; Vlachos, Dionisios G.

    2012-01-01

    In this work we propose a hierarchy of Markov chain Monte Carlo methods for sampling equilibrium properties of stochastic lattice systems with competing short and long range interactions. Each Monte Carlo step is composed by two or more sub-steps efficiently coupling coarse and finer state spaces. The method can be designed to sample the exact or controlled-error approximations of the target distribution, providing information on levels of different resolutions, as well as at the microscopic level. In both strategies the method achieves significant reduction of the computational cost compared to conventional Markov chain Monte Carlo methods. Applications in phase transition and pattern formation problems confirm the efficiency of the proposed methods.

  5. Automated grain extraction and classification by combining improved region growing segmentation and shape descriptors in electromagnetic mill classification system

    Science.gov (United States)

    Budzan, Sebastian

    2018-04-01

    In this paper, the automatic method of grain detection and classification has been presented. As input, it uses a single digital image obtained from milling process of the copper ore with an high-quality digital camera. The grinding process is an extremely energy and cost consuming process, thus granularity evaluation process should be performed with high efficiency and time consumption. The method proposed in this paper is based on the three-stage image processing. First, using Seeded Region Growing (SRG) segmentation with proposed adaptive thresholding based on the calculation of Relative Standard Deviation (RSD) all grains are detected. In the next step results of the detection are improved using information about the shape of the detected grains using distance map. Finally, each grain in the sample is classified into one of the predefined granularity class. The quality of the proposed method has been obtained by using nominal granularity samples, also with a comparison to the other methods.

  6. Influence of processing conditions on apparent viscosity and system parameters during extrusion of distiller's dried grains-based snacks.

    Science.gov (United States)

    Singha, Poonam; Muthukumarappan, Kasiviswanathan; Krishnan, Padmanaban

    2018-01-01

    A combination of different levels of distillers dried grains processed for food application (FDDG), garbanzo flour and corn grits were chosen as a source of high-protein and high-fiber extruded snacks. A four-factor central composite rotatable design was adopted to study the effect of FDDG level, moisture content of blends, extrusion temperature, and screw speed on the apparent viscosity, mass flow rate or MFR, torque, and specific mechanical energy or SME during the extrusion process. With increase in the extrusion temperature from 100 to 140°C, apparent viscosity, specific mechanical energy, and torque value decreased. Increase in FDDG level resulted in increase in apparent viscosity, SME and torque. FDDG had no significant effect (p > .5) on mass flow rate. SME also increased with increase in the screw speed which could be due to the higher shear rates at higher screw speeds. Screw speed and moisture content had significant negative effect ( p  extruder and the system parameters were affected by the processing conditions. This study will be useful for control of extrusion process of blends containing these ingredients for the development of high-protein high-fiber extruded snacks.

  7. Ionizing radiation for insect control in grain and grain products

    International Nuclear Information System (INIS)

    Tilton, E.W.; Brower, J.H.

    1987-01-01

    A technical review summarizes and discusses information on various aspects of the use of ionizing radiation for the control of insect infestation in grains and grain products. Topics include: the effects of ionizing radiation on insects infesting stored-grain products; the 2 main types of irradiators (electron accelerators; radioisotopes (e.g.: Co-60; Cs-137); dosimetry systems and methodology; variations in radiation resistance by stored-product pests; the proper selection of radiation dose; the effects of combining various treatments (temperature, infrared/microwave radiation, hypoxia, chemicals) with ionizing radiation; sublethal radiation for controlling bulk grain insects; the feeding capacity of irradiated insects; the susceptibility of insecticide-resistant insects to ionizing radiation; and the possible resistance of insects to ionizing radiation. Practical aspects of removing insects from irradiated grain also are discussed

  8. FINE PORE DIFFUSER SYSTEM EVALUATION FOR THE GREEN BAY METROPOLITAN SEWERAGE DISTRICT

    Science.gov (United States)

    The Green Bay Metropolitan Sewerage District retrofitted two quadrants of their activated sludge aeration system with ceramic and membrane fine pore diffusers to provide savings in energy usage compared to the sparged turbine aerators originally installed. Because significant di...

  9. Hybrid Quantum Mechanics/Molecular Mechanics/Coarse Grained Modeling: A Triple-Resolution Approach for Biomolecular Systems.

    Science.gov (United States)

    Sokkar, Pandian; Boulanger, Eliot; Thiel, Walter; Sanchez-Garcia, Elsa

    2015-04-14

    We present a hybrid quantum mechanics/molecular mechanics/coarse-grained (QM/MM/CG) multiresolution approach for solvated biomolecular systems. The chemically important active-site region is treated at the QM level. The biomolecular environment is described by an atomistic MM force field, and the solvent is modeled with the CG Martini force field using standard or polarizable (pol-CG) water. Interactions within the QM, MM, and CG regions, and between the QM and MM regions, are treated in the usual manner, whereas the CG-MM and CG-QM interactions are evaluated using the virtual sites approach. The accuracy and efficiency of our implementation is tested for two enzymes, chorismate mutase (CM) and p-hydroxybenzoate hydroxylase (PHBH). In CM, the QM/MM/CG potential energy scans along the reaction coordinate yield reaction energies that are too large, both for the standard and polarizable Martini CG water models, which can be attributed to adverse effects of using large CG water beads. The inclusion of an atomistic MM water layer (10 Å for uncharged CG water and 5 Å for polarizable CG water) around the QM region improves the energy profiles compared to the reference QM/MM calculations. In analogous QM/MM/CG calculations on PHBH, the use of the pol-CG description for the outer water does not affect the stabilization of the highly charged FADHOOH-pOHB transition state compared to the fully atomistic QM/MM calculations. Detailed performance analysis in a glycine-water model system indicates that computation times for QM energy and gradient evaluations at the density functional level are typically reduced by 40-70% for QM/MM/CG relative to fully atomistic QM/MM calculations.

  10. Sequentially aerated membrane biofilm reactors for autotrophic nitrogen removal: microbial community composition and dynamics

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Franck, Stephanie; Gülay, Arda

    2014-01-01

    Membrane-aerated biofilm reactors performing autotrophic nitrogen removal can be successfully applied to treat concentrated nitrogen streams. However, their process performance is seriously hampered by the growth of nitrite oxidizing bacteria (NOB). In this work we document how sequential aeration...

  11. Biofilm formation on membranes used for membrane aerated biological reactors, under different stress conditions

    International Nuclear Information System (INIS)

    Andrade-Molinar, C.; Ballinas-Casarrubias, M. L.; Solis-Martinez, F. J.; Rivera-Chavira, B. E.; Cuevas-Rodirguez, G.; Nevarez-Moorillon, G. V.

    2009-01-01

    Bacterial biofilm play an important role in wastewater treatment processes, and have been optimized in the membrane aerated biofilm reactors (MABR). In MABR, a hydrophobic membrane is used as support for the formation of biofilm, and supplements enough aeration to assure an aerobic process. (Author)

  12. Colonisation of winter wheat grain by Fusarium spp. and mycotoxin content as dependent on a wheat variety, crop rotation, a crop management system and weather conditions.

    Science.gov (United States)

    Czaban, Janusz; Wróblewska, Barbara; Sułek, Alicja; Mikos, Marzena; Boguszewska, Edyta; Podolska, Grażyna; Nieróbca, Anna

    2015-01-01

    Field experiments were conducted during three consecutive growing seasons (2007/08, 2008/09 and 2009/10) with four winter wheat (Triticum aestivum L.) cultivars - 'Bogatka', 'Kris', 'Satyna' and 'Tonacja' - grown on fields with a three-field crop rotation (winter triticale, spring barley, winter wheat) and in a four-field crop rotation experiment (spring wheat, spring cereals, winter rapeseed, winter wheat). After the harvest, kernels were surface disinfected with 2% NaOCl and then analysed for the internal infection by different species of Fusarium. Fusaria were isolated on Czapek-Dox iprodione dichloran agar medium and identified on the basis of macro- and micro-morphology on potato dextrose agar and synthetic nutrient agar media. The total wheat grain infection by Fusarium depended mainly on relative humidity (RH) and a rainfall during the flowering stage. Intensive rainfall and high RH in 2009 and 2010 in the period meant the proportions of infected kernels by the fungi were much higher than those in 2008 (lack of precipitation during anthesis). Weather conditions during the post-anthesis period changed the species composition of Fusarium communities internally colonising winter wheat grain. The cultivars significantly varied in the proportion of infected kernels by Fusarium spp. The growing season and type of crop rotation had a distinct effect on species composition of Fusarium communities colonising the grain inside. A trend of a higher percentage of the colonised kernels by the fungi in the grain from the systems using more fertilisers and pesticides as well as the buried straw could be perceived. The most frequent species in the grain were F. avenaceum, F. tricinctum and F. poae in 2008, and F. avenaceum, F. graminearum, F. tricinctum and F. poae in 2009 and 2010. The contents of deoxynivalenol and zearalenon in the grain were correlated with the percentage of kernels colonised by F. graminearum and were the highest in 2009 in the grain from the four

  13. MATHEMATICAL MODEL OF GRAIN MICRONIZATION

    Directory of Open Access Journals (Sweden)

    V. A. Afanas’ev

    2014-01-01

    Full Text Available Summary. During micronisation grain moisture evaporates mainly in decreasing drying rate period. Grain layer located on the surface of the conveyor micronisers will be regarded as horizontal plate. Due to the fact that the micronisation process the surface of the grain evaporates little moisture (within 2-7 % is assumed constant plate thickness. Because in the process of micronization grain structure is changing, in order to achieve an exact solution of the equations necessary to take into account changes thermophysical, optical and others. Equation of heat transfer is necessary to add a term that is responsible for the infrared heating. Because of the small thickness of the grain, neglecting the processes occurring at the edge of the grain, that is actually consider the problem of an infinite plate. To check the adequacy of the mathematical model of the process of micronisation of wheat grain moisture content must be comparable to the function of time, obtained by solving the system of equations with the measured experimental data of experience. Numerical solution of a system of equations for the period of decreasing drying rate is feasible with the help of the Maple 14, substituting the values of the constants in the system. Calculation of the average relative error does not exceed 7- 10 %, and shows a good agreement between the calculated data and the experimental values.

  14. The use of PCR assay for quality testing of grain of winter wheat cultivated in organic, integrated, conventional system and monoculture in phytopathological aspect

    Directory of Open Access Journals (Sweden)

    Aleksander Łukanowski

    2012-12-01

    Full Text Available The aim of experiments was to evaluate the occurrence of fungi on grain of winter wheat cv. Roma cultivated in four systems on the experimental fields owned by the Institute of Soil Science and Plant Cultivation. Among pathogenic species, fungi from genus Fusarium dominated. Their number was the lowest on grain harvested in organic system and the highest in integrated one. Saprotrophic species were represented mainly by Alternaria alternata, which occurred the most often in organic system. Determination of F. avenaceum, F. culmorum and F. poae with microscope was confirmed with a PCR assay. All isolates of F. culmorum and F. poae gave an amplification product of Tri 5 gene coding the possibility of trichocene production, while none of isolates of F. avenaceum.

  15. Management of microbial community composition, architecture and performance in autotrophic nitrogen removing bioreactors through aeration regimes

    DEFF Research Database (Denmark)

    Mutlu, A. Gizem

    to describe aggregation and architectural evolution in nitritation/anammox reactors, incorporating the possible influences of intermediates formed with intermittent aeration. Community analysis revealed an abundant fraction of heterotrophic types despite the absence of organic carbon in the feed. The aerobic...... and anaerobic ammonia oxidizing guilds were dominated by fast-growing Nitrosomonas spp. and Ca. Brocadia spp., while the nitrite oxidizing guild was dominated by high affinity Nitrospira spp. Emission of nitrous oxide (N2O) was evaluated from both reactors under dynamic aeration regimes. Contrary to the widely...... impacts could be isolated, increasing process understanding. It was demonstrated that aeration strategy can be used as a powerful tool to manipulate the microbial community composition, its architecture and reactor performance. We suggest operation via intermittent aeration with short aerated periods...

  16. Accelerated anaerobic hydrolysis rates under a combination of intermittent aeration and anaerobic conditions

    DEFF Research Database (Denmark)

    Jensen, T. R.; Lastra Milone, T.; Petersen, G.

    2017-01-01

    Anaerobic hydrolysis in activated return sludge was investigated in laboratory scale experiments to find if intermittent aeration would accelerate anaerobic hydrolysis rates compared to anaerobic hydrolysis rates under strict anaerobic conditions. The intermittent reactors were set up in a 240 h...... for calculating hydrolysis rates based on soluble COD were compared. Two-way ANOVA with the Bonferroni post-test was performed in order to register any significant difference between reactors with intermittent aeration and strictly anaerobic conditions respectively. The experiment demonstrated a statistically...... significant difference in favor of the reactors with intermittent aeration showing a tendency towards accelerated anaerobic hydrolysis rates due to application of intermittent aeration. The conclusion of the work is thus that intermittent aeration applied in the activated return sludge process (ARP) can...

  17. Direct measurement of anisotropy of interfacial free energy from grain boundary groove morphology in transparent organic metal analong systems

    Energy Technology Data Exchange (ETDEWEB)

    Rustwick, Bryce A. [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    Both academia and industry alike have paid close attention to the mechanisms of microstructural selection during the solidification process. The forces that give rise to and the principles which rule the natural selection of particular morphologies are important to understanding and controlling new microstructures. Interfacial properties play a very crucial role to the selection of such microstructure formation. In the solidification of a metallic alloy, the solid-liquid interface is highly mobile and responds to very minute changes in the local conditions. At this interface, the driving force must be large enough to drive solute diffusion, maintain local curvature, and overcome the kinetic barrier to move the interface. Therefore, the anisotropy of interfacial free energy with respect to crystallographic orientation is has a significant influence on the solidification of metallic systems. Although it is generally accepted that the solid-liquid interfacial free energy and its associated anisotropy are highly important to the overall selection of morphology, the confident measurement of these particular quantities remains a challenge, and reported values are scarce. Methods for measurement of the interfacial free energy include nucleation experiments and grain boundary groove experiments. The predominant method used to determine anisotropy of interfacial energy has been equilibrium shape measurement. There have been numerous investigations involving grain boundaries at a solid-liquid interface. These studies indicated the GBG could be used to describe various interfacial energy values, which affect solidification. Early studies allowed for an estimate of interfacial energy with respect to the GBG energy, and finally absolute interfacial energy in a constant thermal gradient. These studies however, did not account for the anisotropic nature of the material at the GBG. Since interfacial energy is normally dependent on orientation of the crystallographic plane of the

  18. Microbial community stratification in Membrane-Aerated Biofilm Reactors for Completely Autotrophic Nitrogen Removal

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Ruscalleda, Maël; Terada, Akihiko

    of bacterial granules or biofilms. In this sense, completely autotrophic nitrogen removal from high ammonium strength wastewater was achieved in a Membrane-Aereated Biofilm Reactor (MABR) in a single step. Here, a biofilm containing nitrifiers (Aerobic Ammonium and Nitrite Oxidizing Bacteria, AOB and NOB......, respectively) and Anaerobic Ammonium Oxidizing Bacteria (AnAOB) is grown on bubbleless aeration membranes to remove ammonium. Since oxygen permeates through the membrane-biofilm interface while ammonium diffuses into the biofilm from the biofilm-liquid interface, oxygen gradients can be established across...... the biofilm, allowing nitrogen removal in a single reactor by simultaneous activity of the mentioned biocatalysts. This work consists on the analysis of the microbial community existing in two laboratory-scale reactors operated for more than 300 days, which removed up to 5.5 g-N/m2/day. The system contained...

  19. Study on low intensity aeration oxygenation model and optimization for shallow water

    Science.gov (United States)

    Chen, Xiao; Ding, Zhibin; Ding, Jian; Wang, Yi

    2018-02-01

    Aeration/oxygenation is an effective measure to improve self-purification capacity in shallow water treatment while high energy consumption, high noise and expensive management refrain the development and the application of this process. Based on two-film theory, the theoretical model of the three-dimensional partial differential equation of aeration in shallow water is established. In order to simplify the equation, the basic assumptions of gas-liquid mass transfer in vertical direction and concentration diffusion in horizontal direction are proposed based on engineering practice and are tested by the simulation results of gas holdup which are obtained by simulating the gas-liquid two-phase flow in aeration tank under low-intensity condition. Based on the basic assumptions and the theory of shallow permeability, the model of three-dimensional partial differential equations is simplified and the calculation model of low-intensity aeration oxygenation is obtained. The model is verified through comparing the aeration experiment. Conclusions as follows: (1)The calculation model of gas-liquid mass transfer in vertical direction and concentration diffusion in horizontal direction can reflect the process of aeration well; (2) Under low-intensity conditions, the long-term aeration and oxygenation is theoretically feasible to enhance the self-purification capacity of water bodies; (3) In the case of the same total aeration intensity, the effect of multipoint distributed aeration on the diffusion of oxygen concentration in the horizontal direction is obvious; (4) In the shallow water treatment, reducing the volume of aeration equipment with the methods of miniaturization, array, low-intensity, mobilization to overcome the high energy consumption, large size, noise and other problems can provide a good reference.

  20. Sidestream Elevated Pool Aeration, a Technology for Improving Water Quality in Urban Rivers

    Science.gov (United States)

    Motta, D.; Garcia, T.; Abad, J. D.; Bombardelli, F. A.; Waratuke, A.; Garcia, M. H.

    2010-12-01

    Dissolved Oxygen (DO) levels are frequently depleted in rivers located in urban areas, as in the case of the Matanza-Riachuelo River in Buenos Aires, Argentina. This stream receives both domestic and industrial loads which have received minor or no treatment before being discharged into the water body. Major sources of pollution include, but are not limited, to leather and meat packing industries. Additionally, deep slow moving water in the river is associated with limited reaeration and facilitates deposition of organic-rich sediment, therefore exacerbating the DO consumption through sediment oxygen demand. In this study we assessed the efficiency of Sidestream Elevated Pool Aeration (SEPA) stations as a technology for alleviating conditions characterized by severely low DO levels. A SEPA station takes water from the stream at low DO concentrations, through a screw pump; then, water is transported to an elevated pool from where it flows over a series of weirs for water reaeration; finally, the aerated water is discharged back into the river sufficiently downstream from the intake point. This system mimics a phenomenon that occurs in mountain streams, where water is purified by bubbling over rocks. The impact of the use of SEPA stations on the DO concentrations in the Matanza-Riachuelo River was evaluated at both local and reach scales: this was done by deploying and monitoring an in situ pilot SEPA station, and by performing numerical modeling for the evaluation of the hydrodynamics in the SEPA station and the water quality in the reach where SEPA stations are planned to be implemented. An efficiency of aeration of 99% was estimated from DO measurements in the pilot SEPA, showing the potential of this technology for DO recovery in urban streams. Three-dimensional hydrodynamic modeling, besides assisting in the design of the pilot SEPA, has allowed for designing a prototype SEPA to be built soon. Finally, one-dimensional water quality modeling has provided the

  1. The Effect of Inoculation with Azotobacter and Nitrogen Levels on Grain and Corn Yield Components at Simultaneous Cropping System with Legumes

    Directory of Open Access Journals (Sweden)

    mohammad mirzakhani

    2017-09-01

    Full Text Available Introduction: Corn has been regarded as one of the important crops from the view point of both human and animal feeding resource. Intercropping defined as cultivation of two or more species together. The advantages of intercropping can be included: efficient use of water and sunlight, exchange of nutrients, weed competition reduction, reduction of pathogens and the increase of soil fertility. Research shows that intercropping combinations of legume–grass will increase forage quality. Because, grasses Grains have a lot of carbohydrates and legumes are rich in protein and vitamins. This study was conducted to evaluate the effect of inoculation with azotobacter and nitrogen levels on grain and corn yield components at simultaneous cropping system with legumes under the weather conditions of Markazi province. Materials and methods: This study was carried out at agricultural research field of Payame Noor University, Arak Branch during 2011. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Methods of plant nutrition (M0= inoculation with azotobacter, M1= inoculation with azotobacter + 37/5 Kg ha-1 of rare nitrogen with foliar application method, M2= inoculation with azotobacter + 150 Kg ha-1 of rare nitrogen mix with soil and simultaneous cropping treatment of legumes, [S1= corn + alfalfa (Medicago sativa L., S2= corn + bitter vetch (Lathyrus sativus L., S3= corn + mung bean (Vigna radiata L., S4= corn + chickpea (Cicer arientinum L., S5= corn + vetch (Vicia ervillia L. ] were assigned in plots. Each sub plot consisted of 4 rows, 6 m long with 60 cm between rows space and 20 cm between plants on the rows and S.C Apex hybrid was used. In this study characteristics such as: plant height, earing height, the number of grains per m-2, the number of rows per ear, the number of grains per row, surface of ear leaf, grain yield of corn, 1000 grain weight, harvest index of corn, nitrogen use

  2. Managing for Multifunctionality in Perennial Grain Crops

    Science.gov (United States)

    Ryan, Matthew R; Crews, Timothy E; Culman, Steven W; DeHaan, Lee R; Hayes, Richard C; Jungers, Jacob M; Bakker, Matthew G

    2018-01-01

    Abstract Plant breeders are increasing yields and improving agronomic traits in several perennial grain crops, the first of which is now being incorporated into commercial food products. Integration strategies and management guidelines are needed to optimize production of these new crops, which differ substantially from both annual grain crops and perennial forages. To offset relatively low grain yields, perennial grain cropping systems should be multifunctional. Growing perennial grains for several years to regenerate soil health before rotating to annual crops and growing perennial grains on sloped land and ecologically sensitive areas to reduce soil erosion and nutrient losses are two strategies that can provide ecosystem services and support multifunctionality. Several perennial cereals can be used to produce both grain and forage, and these dual-purpose crops can be intercropped with legumes for additional benefits. Highly diverse perennial grain polycultures can further enhance ecosystem services, but increased management complexity might limit their adoption. PMID:29662249

  3. Study on oxygen transfer by solid jet aerator with multiple openings

    Directory of Open Access Journals (Sweden)

    B.K. Shukla

    2018-04-01

    Full Text Available In the current study, two different sets of solid jet aerators having area of openings equal to 594.96 mm2 and 246.30 mm2 with rectangular nozzles having rounded ends were studied. Each set consisted of aerators having one, two, four and eight openings. The oxygenation performance of every model was studied for five different discharges of 1.11 l/s, 2.10 l/s, 2.96 l/s, 3.83 l/s and 4.69 l/s were studied. At low discharges, the aerator having lesser number of openings demonstrated more oxygen-transfer efficiency whereas at higher discharges, the aerator having more number of openings yielded more oxygenation-efficiency. Maximum value of oxygen-transfer efficiency of 21.53 kg-O2/kW-hr was obtained for the discharge of 1.11 l/s for single nozzle aerator; however the maximum oxygen-transfer factor of 2.0 × 10−2 s−1 was obtained at discharge of 4.69 l/s for aerator having eight numbers of openings having area of 594.96 mm2. On the other hand, maximum oxygen transfer efficiency of 10.93 kg-O2/kW-hr was demonstrated by aerator with single opening at a discharge of 1.11 l/s and maximum oxygen transfer factor of 7.83 × 10−3 s−1 was obtained from aerator with eight openings at a discharge of 4.69 l/s corresponding to set of aerators with area of openings equal to 246.30 mm2. Multiple non-linear regression modelling was applied to predict oxygen transfer of the aerators for different combinations of input parameters. At the end, the models were compared with conventional methods of aeration and were found to be competitive with traditional devices. Keywords: Plunging jet, Jet aerator, Oxygen transfer, Aeration, Dissolved oxygen

  4. Next Generation Snow Cover Mapping: Can Future Hyperspectral Satellite Spectrometer Systems Improve Subpixel Snow-covered Area and Grain Size in the Sierra Nevada?

    Science.gov (United States)

    Hill, R.; Calvin, W. M.; Harpold, A.

    2017-12-01

    Mountain snow storage is the dominant source of water for humans and ecosystems in western North America. Consequently, the spatial distribution of snow-covered area is fundamental to both hydrological, ecological, and climate models. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data were collected along the entire Sierra Nevada mountain range extending from north of Lake Tahoe to south of Mt. Whitney during the 2015 and 2016 snow-covered season. The AVIRIS dataset used in this experiment consists of 224 contiguous spectral channels with wavelengths ranging 400-2500 nanometers at a 15-meter spatial pixel size. Data from the Sierras were acquired on four days: 2/24/15 during a very low snow year, 3/24/16 near maximum snow accumulation, and 5/12/16 and 5/18/16 during snow ablation and snow loss. Building on previous retrieval of subpixel snow-covered area algorithms that take into account varying grain size we present a model that analyzes multiple endmembers of varying snow grain size, vegetation, rock, and soil in segmented regions along the Sierra Nevada to determine snow-cover spatial extent, snow sub-pixel fraction, and approximate grain size. In addition, varying simulated models of the data will compare and contrast the retrieval of current snow products such as MODIS Snow-Covered Area and Grain Size (MODSCAG) and the Airborne Space Observatory (ASO). Specifically, does lower spatial resolution (MODIS), broader resolution bandwidth (MODIS), and limited spectral resolution (ASO) affect snow-cover area and grain size approximations? The implications of our findings will help refine snow mapping products for planned hyperspectral satellite spectrometer systems such as EnMAP (slated to launch in 2019), HISUI (planned for inclusion on the International Space Station in 2018), and HyspIRI (currently under consideration).

  5. Cracking in autoclaved aerated concrete: Experimental investigation and XFEM modeling

    International Nuclear Information System (INIS)

    Ferretti, D.; Michelini, E.; Rosati, G.

    2015-01-01

    The paper aims to investigate and model cracking development in beams and deep-beams made of autoclaved aerated concrete (AAC). Fracture mechanics of AAC has been first studied by performing three-point bending tests on beams, similar to those commonly used for ordinary concrete elements. In some of these tests, crack growth has been also monitored by using ESPI laser technique. In this way, it has been possible to calibrate the main parameters of a proper cohesive law by means of extended finite element inverse analysis. Subsequently, cracking tests have been also performed on deep-beams, whose behavior is more representative of full scale walls. To validate the proposed cohesive law, deep-beam experimental behavior has been finally simulated through XFEM

  6. Cracking in autoclaved aerated concrete: Experimental investigation and XFEM modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, D., E-mail: daniele.ferretti@unipr.it [Department of Civil, Environmental, Land Management Engineering and Architecture, University of Parma, P.co Area delle Scienze 181/A, 43124 Parma (Italy); Michelini, E. [Department of Civil, Environmental, Land Management Engineering and Architecture, University of Parma, P.co Area delle Scienze 181/A, 43124 Parma (Italy); Rosati, G. [Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy)

    2015-01-15

    The paper aims to investigate and model cracking development in beams and deep-beams made of autoclaved aerated concrete (AAC). Fracture mechanics of AAC has been first studied by performing three-point bending tests on beams, similar to those commonly used for ordinary concrete elements. In some of these tests, crack growth has been also monitored by using ESPI laser technique. In this way, it has been possible to calibrate the main parameters of a proper cohesive law by means of extended finite element inverse analysis. Subsequently, cracking tests have been also performed on deep-beams, whose behavior is more representative of full scale walls. To validate the proposed cohesive law, deep-beam experimental behavior has been finally simulated through XFEM.

  7. Thermal conductivity of newspaper sandwiched aerated lightweight concrete panel

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Soon-Ching; Low, Kaw-Sai [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Wilayah Persekutuan (Malaysia)

    2010-12-15

    Investigation on the thermal conductivity of newspaper sandwiched aerated lightweight concrete (ALC) panels is the main purpose of this study. Various densities of ALC panels ranging from 1700, 1400 and 1100 kg/m{sup 3} with three different aerial intensities of newspaper sandwiched were produced. Investigation was limited to the effect of aerial intensity of newspaper sandwiched and the effect of density of ALC on thermal conductivity. It is found that the thermal conductivity of newspaper sandwiched ALC panels reduced remarkably compared to control ALC panels. The reduction was recorded at 18.0%, 21.8% and 20.7% correspond to densities of 1700, 1400 and 1100 kg/m{sup 3} with just a mere 0.05 g/cm{sup 2} aerial intensity of newspaper sandwiched. Newspaper sandwiched has a significant impact on the performance of thermal conductivity of ALC panels based on regression analysis. (author)

  8. Methane biofiltration using autoclaved aerated concrete as the carrier material.

    Science.gov (United States)

    Ganendra, Giovanni; Mercado-Garcia, Daniel; Hernandez-Sanabria, Emma; Boeckx, Pascal; Ho, Adrian; Boon, Nico

    2015-09-01

    The methane removal capacity of mixed methane-oxidizing bacteria (MOB) culture in a biofilter setup using autoclaved aerated concrete (AAC) as a highly porous carrier material was tested. Batch experiment was performed to optimize MOB immobilization on AAC specimens where optimum methane removal was obtained when calcium chloride was not added during bacterial inoculation step and 10-mm-thick AAC specimens were used. The immobilized MOB could remove methane at low concentration (~1000 ppmv) in a biofilter setup for 127 days at average removal efficiency (RE) of 28.7 %. Unlike a plug flow reactor, increasing the total volume of the filter by adding a biofilter in series did not result in higher total RE. MOB also exhibited a higher abundance at the bottom of the filter, in proximity with the methane gas inlet where a high methane concentration was found. Overall, an efficient methane biofilter performance could be obtained using AAC as the carrier material.

  9. Aeration-Controlled Formation of Acid in Heterolactic Fermentations

    DEFF Research Database (Denmark)

    Adler-Nissen, Jens

    1994-01-01

    fermentation processes should be analyzed as fed-batch fermentations with oxygen as the limiting substrate. Addition of fructose in limited amounts leads to the formation of one half mole of acetic acid for each mole fructose, thus offering an alternative mechanism for controlling acetic acid formation.......Controlled aeration of Leuconostoc mesenteroides was studied as a possible mechanism for control of the formation of acetic acid, a metabolite of major influence on the taste of lactic fermented foods. Fermentations were carried out in small scale in a medium in which growth was limited...... by the buffer capacity only. Ethanol and acetic acid formed during the fermentation were analyzed by rapid head space gas chromatography, and the ratio of the molar concentrations of these two volatiles quantitatively predicted the balance between the formation of acetic acid and lactic acid. The oxygen...

  10. Investigating the effect of multiple grain-grain interfaces on electric transport behavior of [50 wt% BaFe12O19-50 wt% Na0.5Bi0.5TiO3] magnetoelectric nanocomposite system

    Science.gov (United States)

    Pattanayak, Ranjit; Raut, Subhajit; Dash, Tapan; Mohapatra, Soumyaranjan; Muduli, Rakesh; Panigrahi, Simanchala

    2017-05-01

    Polycrystalline [50 wt% BaFe12O19 (BaM)-50 wt% Na0.5Bi0.5TiO3 (NBT)] particulate novel magnetoelectric nanocomposite system was successfully fabricated by solid state reaction technique. The Rietveld refinement of X-ray diffraction pattern was provided the evidence about the pure phase formation of desired nanocomposite system as well as the presence of both ferrimagnetic (FM) BaM & ferroelectric (FE) NBT phases separately. The Field Scanning Electron Micrograph (FESEM) and Scanning Tunneling Electron Micrograph (STEM) explored the information about grain size and connectivity of the composite system. The XPS study was helped to examine the presence of oxygen vacancy (Ov) as well as multi oxidation states of transition metal ions for nanocomposite system. In this report we have systematically examined the conduction mechanism of different interfaces (BaM-BaM, BaM-NBT and NBT-NBT) by the help of complex impedance spectroscopy technique. From our investigation it was observed that, different interfaces activates at different temperature ranges. Due to absence of OV, BaM-NBT interfaces conduction dominants over BaM-BaM interfaces conduction even at room temperature (RT). The mechanism behind the appeared high dielectric loss (tanδ) at RT which was reduced when NBT-NBT interfaces were activates at higher temperature was explained by Maxwell-Wagner type interfacial polarization concept.

  11. Litter aeration and spread of Salmonella in broilers.

    Science.gov (United States)

    Bodí, Sara González; Garcia, Arantxa Villagra; García, Santiago Vega; Orenga, Clara Marín

    2013-08-01

    Litter quality in the poultry sector is one of the main parameters of health, productivity, and animal welfare. Therefore, innovative management methods have been developed to improve the quality of litter. One of them is litter aeration (LA) by tumbling. However, there is little information related to the effect of this technique on the spreading of pathogens of public health importance such as Salmonella. In this context, the objective of this study was to determine the epidemiology of Salmonella in poultry farms, when serial LA were implemented during the rearing cycle of broilers. For this purpose, an experimental broiler farm with 3 identical rooms was used in the study. Two rooms were assigned to the LA treatment, and the other one served as the control room. Environmental samples were taken in poultry houses after LA in 4 consecutive weeks at the end of the cycle. All samples collected were analyzed according to the standards of the International Organization for Standardization (ISO 6579:2002, Annex D). The results of this study showed that in the control and treated rooms, the percentage of positive samples for Salmonella decreased in the first 3 LA sessions (LA 1, LA 2, and LA 3). However, in the last LA session of rearing (LA 4), the percentage of positive samples increased from 8.2 to 33.2% in the control room instead the treated rooms where the positive samples decreased (P = 0.017). Thus, the aeration of the litter as litter management technique in poultry broiler production does not increase the shedding or the spread of Salmonella throughout broiler houses. In addition, it could be an effective technique to reduce the infective pressure of this bacterium in several areas of the farm or in certain moments of the rearing period with more risk of multiplication and spreading of Salmonella.

  12. Biological iron oxidation by Gallionella spp. in drinking water production under fully aerated conditions.

    Science.gov (United States)

    de Vet, W W J M; Dinkla, I J T; Rietveld, L C; van Loosdrecht, M C M

    2011-11-01

    Iron oxidation under neutral conditions (pH 6.5-8) may be a homo- or heterogeneous chemically- or a biologically-mediated process. The chemical oxidation is supposed to outpace the biological process under slightly alkaline conditions (pH 7-8). The iron oxidation kinetics and growth of Gallionella spp. - obligatory chemolithotrophic iron oxidizers - were assessed in natural, organic carbon-containing water, in continuous lab-scale reactors and full-scale groundwater trickling filters in the Netherlands. From Gallionella cell numbers determined by qPCR, balances were made for all systems. The homogeneous chemical iron oxidation occurred in accordance with the literature, but was retarded by a low water temperature (13 °C). The contribution of the heterogeneous chemical oxidation was, despite the presence of freshly formed iron oxyhydroxides, much lower than in previous studies in ultrapure water. This could be caused by the adsorption of natural organic matter (NOM) on the iron oxide surfaces. In the oxygen-saturated natural water with a pH ranging from 6.5 to 7.7, Gallionella spp. grew uninhibited and biological iron oxidation was an important, and probably the dominant, process. Gallionella growth was not even inhibited in a full-scale filter after plate aeration. From this we conclude that Gallionella spp. can grow under neutral pH and fully aerated conditions when the chemical iron oxidation is retarded by low water temperature and inhibition of the autocatalytic iron oxidation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Grain Handling and Storage.

    Science.gov (United States)

    Harris, Troy G.; Minor, John

    This text for a secondary- or postecondary-level course in grain handling and storage contains ten chapters. Chapter titles are (1) Introduction to Grain Handling and Storage, (2) Elevator Safety, (3) Grain Grading and Seed Identification, (4) Moisture Control, (5) Insect and Rodent Control, (6) Grain Inventory Control, (7) Elevator Maintenance,…

  14. Grain Grading and Handling.

    Science.gov (United States)

    Rendleman, Matt; Legacy, James

    This publication provides an introduction to grain grading and handling for adult students in vocational and technical education programs. Organized in five chapters, the booklet provides a brief overview of the jobs performed at a grain elevator and of the techniques used to grade grain. The first chapter introduces the grain industry and…

  15. Ammonia-based feedforward and feedback aeration control in activated sludge processes.

    Science.gov (United States)

    Rieger, Leiv; Jones, Richard M; Dold, Peter L; Bott, Charles B

    2014-01-01

    Aeration control at wastewater treatment plants based on ammonia as the controlled variable is applied for one of two reasons: (1) to reduce aeration costs, or (2) to reduce peaks in effluent ammonia. Aeration limitation has proven to result in significant energy savings, may reduce external carbon addition, and can improve denitrification and biological phosphorus (bio-P) performance. Ammonia control for limiting aeration has been based mainly on feedback control to constrain complete nitrification by maintaining approximately one to two milligrams of nitrogen per liter of ammonia in the effluent. Increased attention has been given to feedforward ammonia control, where aeration control is based on monitoring influent ammonia load. Typically, the intent is to anticipate the impact of sudden load changes, and thereby reduce effluent ammonia peaks. This paper evaluates the fundamentals of ammonia control with a primary focus on feedforward control concepts. A case study discussion is presented that reviews different ammonia-based control approaches. In most instances, feedback control meets the objectives for both aeration limitation and containment of effluent ammonia peaks. Feedforward control, applied specifically for switching aeration on or off in swing zones, can be beneficial when the plant encounters particularly unusual influent disturbances.

  16. Optimization of aeration for biodiesel production by Scenedesmus obliquus grown in municipal wastewater.

    Science.gov (United States)

    Han, Song-Fang; Jin, Wenbiao; Tu, Renjie; Abomohra, Abd El-Fatah; Wang, Zhi-Han

    2016-07-01

    Despite the significant breakthroughs in research on microalgae as a feedstock for biodiesel, its production cost is still much higher than that of fossil diesel. One possible solution to overcome this problem is to optimize algal growth and lipid production in wastewater. The present study examines the optimization of pretreatment of municipal wastewater and aeration conditions in order to enhance the lipid productivity of Scenedesmus obliquus. Results showed that no significant differences were recorded in lipid productivity of S. obliquus grown in primary settled or sterilized municipal wastewater; however, ultrasound pretreatment of wastewater significantly decreased the lipid production. Whereas, aeration rates of 0.2 vvm significantly increased lipid content by 51 %, with respect to the non-aerated culture, which resulted in maximum lipid productivity (32.5 mg L(-1) day(-1)). Furthermore, aeration enrichment by 2 % CO2 resulted in increase of lipid productivity by 46 % over the CO2 non-enriched aerated culture. Fatty acid profile showed that optimized aeration significantly enhanced monounsaturated fatty acid production, composed mainly of C18:1, by 1.8 times over the non-aerated S. obliquus culture with insignificant changes in polyunsaturated fatty acid proportion; suggesting better biodiesel characteristics for the optimized culture.

  17. 3D-modelling of the thermal circumstances of a lake under artificial aeration

    Science.gov (United States)

    Tian, Xiaoqing; Pan, Huachen; Köngäs, Petrina; Horppila, Jukka

    2017-12-01

    A 3D-model was developed to study the effects of hypolimnetic aeration on the temperature profile of a thermally stratified Lake Vesijärvi (southern Finland). Aeration was conducted by pumping epilimnetic water through the thermocline to the hypolimnion without breaking the thermal stratification. The model used time transient equation based on Navier-Stokes equation. The model was fitted to the vertical temperature distribution and environmental parameters (wind, air temperature, and solar radiation) before the onset of aeration, and the model was used to predict the vertical temperature distribution 3 and 15 days after the onset of aeration (1 August and 22 August). The difference between the modelled and observed temperature was on average 0.6 °C. The average percentage model error was 4.0% on 1 August and 3.7% on 22 August. In the epilimnion, model accuracy depended on the difference between the observed temperature and boundary conditions. In the hypolimnion, the model residual decreased with increasing depth. On 1 August, the model predicted a homogenous temperature profile in the hypolimnion, while the observed temperature decreased moderately from the thermocline to the bottom. This was because the effect of sediment was not included in the model. On 22 August, the modelled and observed temperatures near the bottom were identical demonstrating that the heat transfer by the aerator masked the effect of sediment and that exclusion of sediment heat from the model does not cause considerable error unless very short-term effects of aeration are studied. In all, the model successfully described the effects of the aerator on the lake's temperature profile. The results confirmed the validity of the applied computational fluid dynamic in artificial aeration; based on the simulated results, the effect of aeration can be predicted.

  18. Design of high efficiency and energy saving aeration device for aquaculture

    Science.gov (United States)

    Liu, Sibo

    2017-03-01

    Energy efficient aeration device for aquaculture, in line with "by more than a generation, dynamic aeration" train of thought for technical design and improvement. Removable aeration terminal as the core, multi-level water to improve the method, the mobile fading pore aeration, intelligent mobile and open and close as the main function, aimed at solving the existing pond aeration efficiency, low energy consumption is high, the function of a single problem. From energy saving, efficiency, biological bacteria on the three directions, the aquaculture industry of energy conservation and emissions reduction. Device of the main advantages are: 1, original mobile fading aerator on the one hand, to expand the scope of work, playing a micro porous aeration of dissolved oxygen with high efficiency and to achieve "by more than a generation", on the other hand, through the sports equipment, stir the mixture of water, the water surface of photosynthesis of plants rich in dissolved oxygen input parts of the tank, compared to the stillness of the aerator can be more fully dissolved oxygen.2, through the opening of the pressure sensor indirect control device, can make the equipment timely and stop operation, convenient in use at the same time avoid the waste of energy.3, the biofilm suspension in aeration terminal, can be accomplished by nitration of microbial multi-level water improvement, still can make biofilm increase rate of netting in the movement process, the biological and mechanical aerobic promote each other, improve the efficiency of both. In addition, the device has small power consumption, low cost of characteristics. And have a certain degree of technical barriers, have their own intellectual property rights, and high degree of product market demand, easily accepted by customers, has a very high popularization value.

  19. Predictive coarse-graining

    Energy Technology Data Exchange (ETDEWEB)

    Schöberl, Markus, E-mail: m.schoeberl@tum.de [Continuum Mechanics Group, Technical University of Munich, Boltzmannstraße 15, 85748 Garching (Germany); Zabaras, Nicholas [Institute for Advanced Study, Technical University of Munich, Lichtenbergstraße 2a, 85748 Garching (Germany); Department of Aerospace and Mechanical Engineering, University of Notre Dame, 365 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Koutsourelakis, Phaedon-Stelios [Continuum Mechanics Group, Technical University of Munich, Boltzmannstraße 15, 85748 Garching (Germany)

    2017-03-15

    We propose a data-driven, coarse-graining formulation in the context of equilibrium statistical mechanics. In contrast to existing techniques which are based on a fine-to-coarse map, we adopt the opposite strategy by prescribing a probabilistic coarse-to-fine map. This corresponds to a directed probabilistic model where the coarse variables play the role of latent generators of the fine scale (all-atom) data. From an information-theoretic perspective, the framework proposed provides an improvement upon the relative entropy method and is capable of quantifying the uncertainty due to the information loss that unavoidably takes place during the coarse-graining process. Furthermore, it can be readily extended to a fully Bayesian model where various sources of uncertainties are reflected in the posterior of the model parameters. The latter can be used to produce not only point estimates of fine-scale reconstructions or macroscopic observables, but more importantly, predictive posterior distributions on these quantities. Predictive posterior distributions reflect the confidence of the model as a function of the amount of data and the level of coarse-graining. The issues of model complexity and model selection are seamlessly addressed by employing a hierarchical prior that favors the discovery of sparse solutions, revealing the most prominent features in the coarse-grained model. A flexible and parallelizable Monte Carlo – Expectation–Maximization (MC-EM) scheme is proposed for carrying out inference and learning tasks. A comparative assessment of the proposed methodology is presented for a lattice spin system and the SPC/E water model.

  20. 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

  1. Passive aeration composting of chicken litter: effects of aeration pipe orientation and perforation size on losses of compost elements.

    Science.gov (United States)

    Ogunwande, Gbolabo A; Osunade, James A

    2011-01-01

    A passive aeration composting study was undertaken to investigate the effects of aeration pipe orientation (PO) and perforation size (PS) on some physico-chemical properties of chicken litter (chicken manure + sawdust) during composting. The experimental set up was a two-factor completely randomised block design with two pipe orientations: horizontal (Ho) and vertical (Ve), and three perforation sizes: 15, 25 and 35 mm diameter. The properties monitored during composting were pile temperature, moisture content (MC), pH, electrical conductivity (EC), total carbon (C(T)), total nitrogen (N(T)) and total phosphorus (P(T)). Moisture level in the piles was periodically replenished to 60% for efficient microbial activities. The results of the study showed that optimum composting conditions (thermophilic temperatures and sanitation requirements) were attained in all the piles. During composting, both PO and PS significantly affected pile temperature, moisture level, pH, C(T) loss and P(T) gain. EC was only affected by PO while N(T) was affected by PS. Neither PO nor PS had a significant effect on the C:N ratio. A vertical pipe was effective for uniform air distribution, hence, uniform composting rate within the composting pile. The final values showed that PO of Ve and PS of 35 mm diameter resulted in the least loss in N(T). The PO of Ho was as effective as Ve in the conservation of C(T) and P(T). Similarly, the three PSs were equally effective in the conservation of C(T) and P(T). In conclusion, the combined effects of PO and PS showed that treatments Ve35 and Ve15 were the most effective in minimizing N(T) loss. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Grain legume-cereal intercropping: The practical application of diversity, competition and facilitation in arable and organic cropping systems

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Jørnsgaard, B.; Kinane, J.

    2008-01-01

    . Faba bean and lupin had lower yield stability than pea and fertilized barley. However, the different IC used environmental resources for plant growth up to 50% (LER=0.91-1.51) more effectively as compared to the respective SC, but with considerable variation over location, years and crops. The SC...... in Denmark over three consecutive cropping seasons including dual grain legume (pea, faba bean and lupin)-barley intercropping as compared to the respective sole crops (SC). Yield stability of intercrops (IC) was not greater than that of grain legume SC, with the exception of the IC containing faba bean......-15% compared to the corresponding SC. However, especially lupin was suppressed when intercropping, with a reduced N2-fixation from 15 to 5-6 g N m-2. The IC were particularly effective at suppressing weeds, capturing a greater share of available resources than SC. Weed infestation in the different crops...

  3. Computational Fluid Dynamics Modelling of Hydraulics and Sedimentation in Process Reactors during Aeration Tank Settling

    DEFF Research Database (Denmark)

    Jensen, M.D.; Ingildsen, P.; Rasmussen, Michael R.

    2006-01-01

    Aeration tank settling is a control method allowing settling in the process tank during highhydraulic load. The control method is patented. Aeration tank settling has been applied in several wastewater treatment plants using the present design of the process tanks. Some process tank designs...... and outletcausing a disruption of the sludge blanket at the outlet and thereby reducing the retention of sludge in theprocess tank. The model has allowed us to establish a clear picture of the problems arising at the plantduring aeration tank settling. Secondly, several process tank design changes have been...

  4. Modeling Slip System Strength Evolution in Ti 7Al Informed by In situ Grain Stress Measurements (Postprint)

    Science.gov (United States)

    2017-02-17

    incipient damage nucleation and growth , is that which comprises a local neighbor- hood of grains. Heterogeneities in the local intergranular stresses and...After yielding, there was a small drop in the flow stress to 525 MPa followed by work hardening to 535 MPa by the end of the test. Overall, the...collected on a large panel area detector that was located 756 mm downstream of the sample. The detector was a GE amorphous silicon area detector with 2048

  5. Physical properties of five grain dust types.

    Science.gov (United States)

    Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

    1986-01-01

    Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less than 100 micron of whole dust; bulk density; particle density; and ash content. PMID:3709482

  6. Computing the non-Markovian coarse-grained interactions derived from the Mori-Zwanzig formalism in molecular systems: Application to polymer melts

    Science.gov (United States)

    Li, Zhen; Lee, Hee Sun; Darve, Eric; Karniadakis, George Em

    2017-01-01

    Memory effects are often introduced during coarse-graining of a complex dynamical system. In particular, a generalized Langevin equation (GLE) for the coarse-grained (CG) system arises in the context of Mori-Zwanzig formalism. Upon a pairwise decomposition, GLE can be reformulated into its pairwise version, i.e., non-Markovian dissipative particle dynamics (DPD). GLE models the dynamics of a single coarse particle, while DPD considers the dynamics of many interacting CG particles, with both CG systems governed by non-Markovian interactions. We compare two different methods for the practical implementation of the non-Markovian interactions in GLE and DPD systems. More specifically, a direct evaluation of the non-Markovian (NM) terms is performed in LE-NM and DPD-NM models, which requires the storage of historical information that significantly increases computational complexity. Alternatively, we use a few auxiliary variables in LE-AUX and DPD-AUX models to replace the non-Markovian dynamics with a Markovian dynamics in a higher dimensional space, leading to a much reduced memory footprint and computational cost. In our numerical benchmarks, the GLE and non-Markovian DPD models are constructed from molecular dynamics (MD) simulations of star-polymer melts. Results show that a Markovian dynamics with auxiliary variables successfully generates equivalent non-Markovian dynamics consistent with the reference MD system, while maintaining a tractable computational cost. Also, transient subdiffusion of the star-polymers observed in the MD system can be reproduced by the coarse-grained models. The non-interacting particle models, LE-NM/AUX, are computationally much cheaper than the interacting particle models, DPD-NM/AUX. However, the pairwise models with momentum conservation are more appropriate for correctly reproducing the long-time hydrodynamics characterised by an algebraic decay in the velocity autocorrelation function.

  7. Treatment and re-use of urban sewage by means of aerated submerged biological filters and tertiary treatment; Depuracion y reutilizacion de las aguas residuales urbanas mediante filtros biologicos sumergidos aireados con tratamiento terciario

    Energy Technology Data Exchange (ETDEWEB)

    Mujal, F. J.

    2000-07-01

    The installations required for treating and re-using urban waste waters are reviewed. The treatment system put forward is called AERATED SURMERGED BIOLOGICAL FILTER AQUA PROCESS (S.B.F.). In this system, once that water has been clarified, it is treated biologically in an aerated reactor containing porous ceramic balls. After this it is filtered with silica+anthracite as a tertiary treatment. This technique minimize energy consumption and achieve optimum treatment performance at low running costs, as it requires little maintenance. Once the waste water has been treated in this way, the effluent is suitable for re-use to irrigate crops or infiltrate into underground aquifers. (Author)

  8. Grain boundary corrosion of copper canister weld material

    International Nuclear Information System (INIS)

    Gubner, Rolf; Andersson, Urban; Linder, Mats; Nazarov, Andrej; Taxen, Claes

    2006-01-01

    The proposed design for a final repository for spent fuel and other long-lived residues in Sweden is based on the multi-barrier principle. The waste will be encapsulated in sealed cylindrical canisters, which will then be placed in granite bedrock and surrounded by compacted bentonite clay. The canister design is based on a thick cast inner container fitted inside a corrosion-resistant copper canister. During fabrication of the outer copper canisters there will be some unavoidable grain growth in the welded areas. As grains grow, they will tend to concentrate impurities within the copper at the new grain boundaries. The work described in this report was undertaken to determine whether there is any possibility of enhanced corrosion at grain boundaries within the copper canister, based on the recommendations of the report SKB-TR--01-09 (INIS ref. 32025363). Grain boundary corrosion of copper is not expected to be a problem for the copper canisters in a repository. However, as one step in the experimental verification it is necessary to study grain boundary corrosion of copper in an environment where it may occur. A literature study aimed to find one or several solutions that are aggressive with respect to grain boundary corrosion of copper. Copper specimens cut from welds of real copper canisters where exposed to aerated ammonium hydroxide solution for a period of 14 days at 80 degrees C and 10 bar pressure. The samples were investigated prior to exposure using the scanning Kelvin probe technique to characterize anodic and cathodic areas on the samples. The degree of corrosion was determined by optical microscopy. No grain boundary corrosion could be observed in the autoclave experiments, however, a higher rate of corrosion was observed for the weld material compared to the base material. The work suggests that grain boundary corrosion of copper weld material is most unlikely to adversely affect SKB's copper canisters under the conditions in the repository

  9. Grain boundary corrosion of copper canister weld material

    Energy Technology Data Exchange (ETDEWEB)

    Gubner, Rolf; Andersson, Urban; Linder, Mats; Nazarov, Andrej; Taxen, Claes [Corrosion and Metals Research Inst. (KIMAB), Stockholm (Sweden)

    2006-01-15

    The proposed design for a final repository for spent fuel and other long-lived residues in Sweden is based on the multi-barrier principle. The waste will be encapsulated in sealed cylindrical canisters, which will then be placed in granite bedrock and surrounded by compacted bentonite clay. The canister design is based on a thick cast inner container fitted inside a corrosion-resistant copper canister. During fabrication of the outer copper canisters there will be some unavoidable grain growth in the welded areas. As grains grow, they will tend to concentrate impurities within the copper at the new grain boundaries. The work described in this report was undertaken to determine whether there is any possibility of enhanced corrosion at grain boundaries within the copper canister, based on the recommendations of the report SKB-TR--01-09 (INIS ref. 32025363). Grain boundary corrosion of copper is not expected to be a problem for the copper canisters in a repository. However, as one step in the experimental verification it is necessary to study grain boundary corrosion of copper in an environment where it may occur. A literature study aimed to find one or several solutions that are aggressive with respect to grain boundary corrosion of copper. Copper specimens cut from welds of real copper canisters where exposed to aerated ammonium hydroxide solution for a period of 14 days at 80 degrees C and 10 bar pressure. The samples were investigated prior to exposure using the scanning Kelvin probe technique to characterize anodic and cathodic areas on the samples. The degree of corrosion was determined by optical microscopy. No grain boundary corrosion could be observed in the autoclave experiments, however, a higher rate of corrosion was observed for the weld material compared to the base material. The work suggests that grain boundary corrosion of copper weld material is most unlikely to adversely affect SKB's copper canisters under the conditions in the repository.

  10. Nonlinear Modeling of Autoclaved Aerated Concrete Masonry Wall Strengthened using Ferrocement Sandwich Structure

    KAUST Repository

    M., Abdel-Mooty; M., El-Kashef; E., Fahmy; M., Abou-Zeid; M., Haroun

    2011-01-01

    Autoclaved Aerated Concrete (AAC) block are used mainly as non-load-bearing walls that provide heat insulation. This results in considerable saving in cooling energy particularly in hot desert environment with large variation of daily and seasonal

  11. Using a biological aerated filter to treat mixed water-borne volatile organic compounds and assessing its emissions

    Institute of Scientific and Technical Information of China (English)

    CHENG Wen-Hsi

    2009-01-01

    A biological aerated filter (BAF) was evaluated as a fixed-biofilm processes to remove water-borne volatile organic compounds (VOCs) from a multiple layer ceramic capacitor (MLCC) manufacturing plant in southern Taiwan.The components of VOC were identified to be toluene,1,2,4-trimethylbenzene,1,3,5-trimethylbenzene,bromodichloromethane and isopropanol (IPA).The full-scale BAF was constructed of two separate reactors in series,respectively using 10-cm and 15-cm diameter polypropylene balls as the packing materials and a successful preliminary bench-scale experiment was performed to feasibility.Performance results show that the BAF removed over 90% chemical oxygen demand (COD) from the influent with (1188 ± 605) mg/L of COD.A total organic loading of 2.76 kg biochemical oxygen demand (BOD)/(m~3 packing·d) was determined for the packed bed,in which the flow pattern approached that of a mixed flow.A limited VOC concentration of (0.97 ± 0.29) ppmv (as methane) was emitted from the BAF system.Moreover,the emission rate of VOC was calculated using the proposed formula,based on an air-water mass equilibrium relationship,and compared to the simulated results obtained using the Water 9 model.Both estimation approaches of calculation and model simulation using Water 9 evaluating VOC emissions reveal that 0.1% IPA (0.0031-0.0037 kg/d) was aerated into a gaseous phase,and 30% to 40% (0.006-0.008 kg/d) of the toluene was aerated.

  12. Effect of C/N ratio, aeration rate and moisture content on ammonia and greenhouse gas emission during the composting.

    Science.gov (United States)

    Jiang, Tao; Schuchardt, Frank; Li, Guoxue; Guo, Rui; Zhao, Yuanqiu

    2011-01-01

    Gaseous emission (N2O, CH4 and NH3) from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon (TOC) was lost in the form of CO2 and 0.8% to 7.5% of TOC emitted as CH4. Most of the nitrogen was lost in the form of NH3, which account for 9.6% to 32.4% of initial nitrogen. N2O was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH3 (p = 0.0189), CH4 (p = 0.0113) and N2O (p = 0.0493) emissions significantly. Higher aeration rates reduce the CH4 emission but increase the NH3 and N2O losses. C/N ratio could affect the NH3 (p = 0.0442) and CH4 (p = 0.0246) emissions significantly, but not the N2O. Lower C/N ratio caused higher NH3 and CH4 emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio.

  13. Ferroelectric domain continuity over grain boundaries

    DEFF Research Database (Denmark)

    Mantri, Sukriti; Oddershede, Jette; Damjanovic, Dragan

    2017-01-01

    Formation and mobility of domain walls in ferroelectric materials is responsible for many of their electrical and mechanical properties. Domain wall continuity across grain boundaries has been observed since the 1950's and is speculated to affect the grain boundary-domain interactions, thereby...... impacting macroscopic ferroelectric properties in polycrystalline systems. However detailed studies of such correlated domain structures across grain boundaries are limited. In this work, we have developed the mathematical requirements for domain wall plane matching at grain boundaries of any given...... orientation. We have also incorporated the effect of grain boundary ferroelectric polarization charge created when any two domains meet at the grain boundary plane. The probability of domain wall continuity for three specific grain misorientations is studied. Use of this knowledge to optimize processing...

  14. Rapid Startup and Loading of an Attached Growth, Simultaneous Nitrification/Denitrification Membrane Aerated Bioreactor

    Science.gov (United States)

    Meyer, Caitlin; Vega, Leticia

    2014-01-01

    The Membrane Aerated Bioreactor (MABR) is an attached-growth biological system for simultaneous nitrification and denitrification. This design is an innovative approach to common terrestrial wastewater treatments for nitrogen and carbon removal. Implementing a biologically-based water treatment system for long-duration human exploration is an attractive, low energy alternative to physiochemical processes. Two obstacles to implementing such a system are (1) the "start-up" duration from inoculation to steady-state operations and (2) the amount of surface area needed for the biological activity to occur. The Advanced Water Recovery Systems (AWRS) team at JSC explored these two issues through two tests; a rapid inoculation study and a wastewater loading study. Results from these tests demonstrate that the duration from inoculation to steady state can be reduced to two weeks and that the surface area to volume ratio baseline used in the Alternative Water Processor (AWP) test was higher than what was needed to remove the organic carbon and ammonium from the system.

  15. 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.

  16. Study on water infiltration in loess aerated zone at CIRP's field test site

    International Nuclear Information System (INIS)

    Du Zhongde; Zhao Yingjie; Ni Dongqi; Ma Binghui; Xu Zhaoyi; Tadao Tanaka; Masayuki Mukai

    2000-01-01

    Vertical joints and large pores existing uniquely in loess cause difference between loess and other homogenous soil media in water infiltration. Field test of water infiltration in loess aerated zone of and analysis with hydraulic theory of soil concludes that for the loess aerated zone of vertical joints existing in it makes little contribution to water infiltration under unsaturated condition, and large pores in the media would significantly retard water infiltration

  17. Low frequency aeration of pig slurry affects slurry characteristics and emissions of greenhouse gases and ammonia.

    Science.gov (United States)

    Calvet, Salvador; Hunt, John; Misselbrook, Tom H

    2017-07-01

    Low frequency aeration of slurries may reduce ammonia (NH 3 ) and methane (CH 4 ) emissions without increasing nitrous oxide (N 2 O) emissions. The aim of this study was to quantify this potential reduction and to establish the underlying mechanisms. A batch experiment was designed with 6 tanks with 1 m 3 of pig slurry each. After an initial phase of 7 days when none of the tanks were aerated, a second phase of 4 weeks subjected three of the tanks to aeration (2 min every 6 h, airflow 10 m 3  h -1 ), whereas the other three tanks remained as a control. A final phase of 9 days was established with no aeration in any tank. Emissions of NH 3 , CH 4 , carbon dioxide (CO 2 ) and N 2 O were measured. In the initial phase no differences in emissions were detected, but during the second phase aeration increased NH 3 emissions by 20% with respect to the controls (8.48 vs. 7.07 g m -3  [slurry] d -1 , P emissions were 40% lower in the aerated tanks (2.04 vs. 3.39 g m -3  [slurry] d -1 , P emissions remained after the aeration phase had finished. No effect was detected for CO 2 , and no relevant N 2 O emissions were detected during the experiment. Our results demonstrate that low frequency aeration of stored pig slurry increases slurry pH and increases NH 3 emissions.

  18. Start-Up and Aeration Strategies for a Completely Autotrophic Nitrogen Removal Process in an SBR

    Directory of Open Access Journals (Sweden)

    Xiaoling Zhang

    2017-01-01

    Full Text Available The start-up and performance of the completely autotrophic nitrogen removal via nitrite (CANON process were examined in a sequencing batch reactor (SBR with intermittent aeration. Initially, partial nitrification was established, and then the DO concentration was lowered further, surplus water in the SBR with high nitrite was replaced with tap water, and continuous aeration mode was turned into intermittent aeration mode, while the removal of total nitrogen was still weak. However, the total nitrogen (TN removal efficiency and nitrogen removal loading reached 83.07% and 0.422 kgN/(m3·d, respectively, 14 days after inoculating 0.15 g of CANON biofilm biomass into the SBR. The aggregates formed in SBR were the mixture of activated sludge and granular sludge; the volume ratio of floc and granular sludge was 7 : 3. DNA analysis showed that Planctomycetes-like anammox bacteria and Nitrosomonas-like aerobic ammonium oxidization bacteria were dominant bacteria in the reactor. The influence of aeration strategies on CANON process was investigated using batch tests. The result showed that the strategy of alternating aeration (1 h and nonaeration (1 h was optimum, which can obtain almost the same TN removal efficiency as continuous aeration while reducing the energy consumption, inhibiting the activity of NOB, and enhancing the activity of AAOB.

  19. The aeration period of a model nuclear waste repository

    International Nuclear Information System (INIS)

    Sharland, S.M.; Tasker, P.W.

    1987-02-01

    We have constructed a model of the evolution of oxygen in a cement backfill which includes both its depletion through the canister corrosion reactions and its migration in the cement pores. The results indicate that the duration in which mild steel waste canisters may be subject to localised corrosion is very much shorter than the intended lifetime of the repository components, provided there is no external source of oxygen. For canisters spaced 1.2m apart, the model predicts a maximum aeration period of approximately 65 years, assuming high oxygen content and diffusivity in the backfill and low leakage current on the canisters (0.01 μA cm -2 ). In such a case a reducing environment is established throughout the backfill within this period. Under conditions of more restricted oxygen transport, reducing conditions are still established within a relatively short time in the immediate vicinity of the canisters, but the oxidation potential elsewhere in the backfill is then controlled by the uniform corrosion rate of the canisters. (author)

  20. Comparative test on nuclide migration in aerated zone

    International Nuclear Information System (INIS)

    Li Shushen; Zhao Yingjie; Wu Qinghua; Wang Zhiming; Hao Janzhong; Ji Shaowei; Guo Liangtian; Guo Zhiming

    2002-01-01

    In order to study the influence of different tracer source layer material on nuclide migration behavior, the comparative test on stable elements Sr, Nd and Ce migration in aerated loess zone was carried out using loess and arenaceous quartz as the tracer source layer materials respectively. The test lasted 470 days. During the test, four times of sampling were done. The testing results indicate that under artificial sprinkling of 5 mm/h and 3 h/d, Nd and Ce not only in loess tracer source layer but also in arenaceous quartz tracer source layer did not obviously downwards migrated. Concentration peak of Sr for loess layer migrated down about 15 cm in 470 d (mass center moved down about 10 cm) but for arenaceous quartz layer the concentration peak of Sr did not obviously migrated down (mass center moved down about 2.7 cm). The test results show that very thin arenaceous quartz layer with thickness of 7 mm is also able to shield unsaturated water flow obviously. This is the main reason why the nuclides in arenaceous quartz layer migrate down slowly

  1. DECREASE OF SOLIDS IN GRAY WATER BY AERATION PROCESS

    Directory of Open Access Journals (Sweden)

    Gerardo Alonso Torres-Avalos

    2017-07-01

    Full Text Available The activated sludge process is a biological treatment consisting basically of agitation and aeration of a waste water mixture and a selected microorganisms sludge. The oxidation of organic matter was determined with several tests such as BOD5 (Biochemical Oxygen Demand, TSS (Total Sedimented Solids, SS (Sediment Solids, TDS (Total Dissolved Solids, FVS (fixed and volatile solids and finally a measurement of treated water turbidity. The results obtained for the reduction of the organic load during the first two days of treatment (samples 1, 2 and 3 are visible in each of the organic loading tests; during the last two days according to the samples 4 and 5 the solids showed an increase in organic load. The related organoleptic properties such as color showed a notable decrease. As for the tests performed at pH show a change, samples 1, 2 and 3 approaching a range where they are neutral and the last two samples (4 and 5 the pH has an elevation until it becomes alkaline. The efficiency of the method used for the treatment of residual water during the first days reduced the organic load with a variation of TS and TSS of 760, 569 ppm respectively. This is a viable alternative since this is a low cost method with short term results because organoleptic properties such as odor and color were lost during the first day of treatment.

  2. Hydroxyl radical induced degradation of salicylates in aerated aqueous solution

    International Nuclear Information System (INIS)

    Szabó, László; Tóth, Tünde; Homlok, Renáta; Rácz, Gergely; Takács, Erzsébet; Wojnárovits, László

    2014-01-01

    Ionizing radiation induced degradation of acetylsalicylic acid, its hydrolysis product salicylic acid and a salicylic acid derivative 5-sulpho-salicylic acid, was investigated in dilute aqueous solutions by UV–vis spectrophotometry, HPLC separation and diode-array or MS/MS detection, chemical oxygen demand, total organic carbon content and by Vibrio fischeri toxicity measurements. Hydroxyl radicals were shown to degrade these molecules readily, and first degradation products were hydroxylated derivatives in all cases. Due to the by-products, among them hydrogen peroxide, the toxicity first increased and then decreased with the absorbed dose. With prolonged irradiation complete mineralization was achieved. - Highlights: • In OH induced reactions of salicylates first products are hydroxylated derivatives. • With prolonged irradiation dihydroxy derivatives also form. • In aerated solutions the one-electron oxidant OH induces 3–4 oxidations. • Toxicity first increases and then decreases with dose mainly due to H 2 O 2 formation. • The toxicity in tap water is smaller than in pure water

  3. Microbiota of kefir grains

    Directory of Open Access Journals (Sweden)

    Tomislav Pogačić

    2013-03-01

    Full Text Available Kefir grains represent the unique microbial community consisting of bacteria, yeasts, and sometimes filamentous moulds creating complex symbiotic community. The complexity of their physical and microbial structures is the reason that the kefir grains are still not unequivocally elucidated. Microbiota of kefir grains has been studied by many microbiological and molecular approaches. The development of metagenomics, based on the identification without cultivation, is opening new possibilities for identification of previously nonisolated and non-identified microbial species from the kefir grains. Considering recent studies, there are over 50 microbial species associated with kefir grains. The aim of this review is to summarise the microbiota composition of kefir grains. Moreover, because of technological and microbiological significance of the kefir grains, the paper provides an insight into the microbiological and molecular methods applied to study microbial biodiversity of kefir grains.

  4. Alternating anoxic feast/aerobic famine condition for improving granular sludge formation in sequencing batch airlift reactor at reduced aeration rate.

    Science.gov (United States)

    Wan, Junfeng; Bessière, Yolaine; Spérandio, Mathieu

    2009-12-01

    In this study the influence of a pre-anoxic feast period on granular sludge formation in a sequencing batch airlift reactor is evaluated. Whereas a purely aerobic SBR was operated as a reference (reactor R2), another reactor (R1) was run with a reduced aeration rate and an alternating anoxic-aerobic cycle reinforced by nitrate feeding. The presence of pre-anoxic phase clearly improved the densification of aggregates and allowed granular sludge formation at reduced air flow rate (superficial air velocity (SAV)=0.63cms(-1)). A low sludge volume index (SVI(30)=45mLg(-1)) and a high MLSS concentration (9-10gL(-1)) were obtained in the anoxic/aerobic system compared to more conventional results for the aerobic reactor. A granular sludge was observed in the anoxic/aerobic system whilst only flocs were observed in the aerobic reference even when operated at a high aeration rate (SAV=2.83cms(-1)). Nitrification was maintained efficiently in the anoxic/aerobic system even when organic loading rate (OLR) was increased up to 2.8kgCODm(-3)d(-1). In the contrary nitrification was unstable in the aerobic system and dropped at high OLR due to competition between autotrophic and heterotrophic growth. The presence of a pre-anoxic period positively affected granulation process via different mechanisms: enhancing heterotrophic growth/storage deeper in the internal anoxic layer of granule, reducing the competition between autotrophic and heterotrophic growth. These processes help to develop dense granular sludge at a moderate aeration rate. This tends to confirm that oxygen transfer is the most limiting factor for granulation at reduced aeration. Hence the use of an alternative electron acceptor (nitrate or nitrite) should be encouraged during feast period for reducing energy demand of the granular sludge process.

  5. Effect of FYM, potassium and zinc on phenology and grain yield of wheat in rain fed cropping systems

    International Nuclear Information System (INIS)

    Nawab, K.; Amanullah; Arif, M.; Shah, P.; Khan, M.A.; Khan, K.

    2011-01-01

    Little work has been done on potassium (K) and zinc (Zn) in combination with farm yard manure (FYM) under rain fed conditions of NWFP. This study was designed to examine the effects of un-irrigated cropping patterns and organic and in-organic fertilizers on wheat crop. Field experiments were conducted to investigate the effect of cropping patterns and farm yard manure, potassium and zinc on phenology and grain yield of wheat under rain fed (barani or un-irrigated) conditions at Agricultural Research Station, Serai Naurang Bannu for two years during 2001-02 and 2002-03. The experiment was designed in RCB design with split arrangements. Two factors were studied in the experiment. Effects of five cropping patterns i.e., fallow-wheat, groundnut-wheat, mungbean-wheat, sorghum-wheat and pigeon pea-wheat and three organic and in-organic fertilizers on subsequent wheat crop were observed. Data revealed that both the cropping patterns and manures/fertilizers had non-significant effect on days to anthesis, seed fill duration and days to maturity of wheat. Highest grain yield (3194 kg ha/sup -1/ wheat following mungbean produced more yield and wheat following groundnut produced less yield under dry land conditions. The present findings revealed that pigeon pea-wheat cropping pattern seems to be more sustainable in terms of yield under rain fed conditions and use of FYM, K and Zn should be included in integrated crop management approaches for sustainable crop production. (Author)

  6. Rapid manganese removal from mine waters using an aerated packed-bed bioreactor.

    Science.gov (United States)

    Johnson, Karen L; Younger, Paul L

    2005-01-01

    In the UK, the Environmental Quality Standard for manganese has recently been lowered to 30 microg/L (annual average), which is less than the UK Drinking Water Inspectorate's Maximum Permitted Concentration Value (50 microg/L). Current passive treatment systems for manganese removal operate as open-air gravel-bed filters, designed to maximize either influent light and/or dissolved oxygen. This requires large areas of land. A novel enhanced bioremediation treatment system for manganese removal has been developed that consists of a passively aerated subsurface gravel bed. The provision of air at depth and the use of catalytic substrates help overcome the slow kinetics usually associated with manganese oxidation. With a residence time of only 8 h and an influent manganese concentration of approximately 20 mg/L, >95% of the manganese was removed. The treatment system also operates successfully at temperatures as low as 4 degrees C and in total darkness. These observations have positive implications for manganese treatment using this technique in both colder climates and where large areas of land are unavailable. Furthermore, as the operation of this passive treatment system continually generates fresh manganese oxyhydroxide, which is a powerful sorbent for most pollutant metals, it potentially has major ancillary benefits as a removal process for other metals, such as zinc.

  7. A review of modeling approaches in activated sludge systems

    African Journals Online (AJOL)

    use

    Key words: Mathematical modeling, water, wastewater, wastewater treatment plants, activated sludge systems. INTRODUCTION ... sedimentation processes which take place in the aeration ...... activated sludge waste water treatment systems.

  8. Grain boundary segregation and intergranular failure

    International Nuclear Information System (INIS)

    White, C.L.

    1980-01-01

    Trace elements and impurities often segregate strongly to grain boundaries in metals and alloys. Concentrations of these elements at grain boundaries are often 10 3 to 10 5 times as great as their overall concentration in the alloy. Because of such segregation, certain trace elements can exert a disproportionate influence on material properties. One frequently observed consequence of trace element segregation to grain boundaries is the occurrence of grain boundary failure and low ductility. Less well known are incidences of improved ductility and inhibition of grain boundary fracture resulting from trace element segregation to grain boundaries in certain systems. An overview of trace element segregation and intergranular failure in a variety of alloy systems as well as preliminary results from studies on Al 3% Li will be presented

  9. Microbial Community Structure of a Leachfield Soil: Response to Intermittent Aeration and Tetracycline Addition

    Directory of Open Access Journals (Sweden)

    David A. Potts

    2013-04-01

    Full Text Available Soil-based wastewater treatment systems, or leachfields, rely on microbial processes for improving the quality of wastewater before it reaches the groundwater. These processes are affected by physicochemical system properties, such as O2 availability, and disturbances, such as the presence of antimicrobial compounds in wastewater. We examined the microbial community structure of leachfield mesocosms containing native soil and receiving domestic wastewater under intermittently-aerated (AIR and unaerated (LEACH conditions before and after dosing with tetracycline (TET. Community structure was assessed using phospholipid fatty acid analysis (PLFA, analysis of dominant phylotypes using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR–DGGE, and cloning and sequencing of 16S rRNA genes. Prior to dosing, the same PLFA biomarkers were found in soil from AIR and LEACH treatments, although AIR soil had a larger active microbial population and higher concentrations for nine of 32 PLFA markers found. AIR soil also had a larger number of dominant phylotypes, most of them unique to this treatment. Dosing of mesocosms with TET had a more marked effect on AIR than LEACH soil, reducing the size of the microbial population and the number and concentration of PLFA markers. Dominant phylotypes decreased by ~15% in response to TET in both treatments, although the AIR treatment retained a higher number of phylotypes than the LEACH treatment. Fewer than 10% of clones were common to both OPEN ACCESS Water 2013, 5 506 AIR and LEACH soil, and fewer than 25% of the clones from either treatment were homologous with isolates of known genus and species. These included human pathogens, as well as bacteria involved in biogeochemical transformations of C, N, S and metals, and biodegradation of various organic contaminants. Our results show that intermittent aeration has a marked effect on the size and structure of the microbial community that develops in

  10. Investigation on flow pattern by submersible mechanical aerator aused in anaerobic-aerobic tank. Kenki koki ken'yo suichu aerator ni yoru sonai ryudo no chosa kensho

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, M; Inoue, H; Kamei, T; Kato, N [Ebara Corp., Tokyo (Japan)

    1994-01-20

    As explained in the present report, flow pattern was verified in a submersible aerator tank for both anaerobic and aerobic wastewater treatment (submersible plant for the mechanical agitation and aeration). The verification was made in a water passage of the sewage treatment plant. The flowing was conditioned as per the measurement of both flow velocity and activated sludge concentration. The submersible aerator was installed so that balance might be kept in ventilating pressure between it and the diffusing plate. The flowing on the tank bottom was stabilized by installing a special guide at the outlet of aerator. The result was as follows: in both tanks during the anaerobic operation, the flow velocity was 0.15m/s as a whole and higher than the standard of 0.1m/s on the tank bottom. Under the tank top and at the middle of tank height, the flow velocity is lower than that on the tank bottom and the intake of dissolved oxygen is weak. In both tanks during the aerobic operation, the flow velocity as a whole is higher than that during the anaerobic operation. It is attributable to the airlift effect. The flow pattern during the aerobic operation is characterized by the flow which is generated, by airlift effect, under the tank top toward the wall. Then, that flow effectively works for the flowing on the tank bottom. Hardly dispersed, the pollutant concentration indicates that the flowing is sufficient in the tank. 4 refs., 6 figs., 3 tabs.

  11. Effects of aeration and internal recycle flow on nitrous oxide emissions from a modified Ludzak-Ettinger process fed with glycerol.

    Science.gov (United States)

    Song, Kang; Suenaga, Toshikazu; Harper, Willie F; Hori, Tomoyuki; Riya, Shohei; Hosomi, Masaaki; Terada, Akihiko

    2015-12-01

    Nitrous oxide (N2O) is emitted from a modified Ludzak-Ettinger (MLE) process, as a primary activated sludge system, which requires mitigation. The effects of aeration rates and internal recycle flow (IRF) ratios on N2O emission were investigated in an MLE process fed with glycerol. Reducing the aeration rate from 1.5 to 0.5 L/min increased gaseous the N2O concentration from the aerobic tank and the dissolved N2O concentration in the anoxic tank by 54.4 and 53.4 %, respectively. During the period of higher aeration, the N2O-N conversion ratio was 0.9 % and the potential N2O reducers were predominantly Rhodobacter, which accounted for 21.8 % of the total population. Increasing the IRF ratio from 3.6 to 7.2 decreased the N2O emission rate from the aerobic tank and the dissolved N2O concentration in the anoxic tank by 56 and 48 %, respectively. This study suggests effective N2O mitigation strategies for MLE systems.

  12. Crescimento de juvenis de pacu em tanques com aeração noturna - DOI: 10.4025/actascianimsci.v25i1.2122 Growth of pacu juveniles in nightly aerated system - DOI: 10.4025/actascianimsci.v25i1.2122

    Directory of Open Access Journals (Sweden)

    Evoy Zaniboni Filho

    2003-04-01

    Full Text Available O presente estudo avalia o efeito de duas densidades de estocagem (20 e 40 peixes/m2 e da aeração noturna da água dos tanques de cultivo do pacu Piaractus mesopotamicus (Holmberg, 1887. Um total de 12 tanques com fundo de terra e paredes de alvenaria foram utilizados em 4 tratamentos com 3 repetições cada. Foram utilizados alevinos com 30 dias de idade, pesando em média 1,93 ± 1,70g, e o experimento foi conduzido durante 60 dias. A aeração noturna possibilitou a obtenção de valores médios de oxigênio de 5,6 ± 0,5 e 5,8 ± 0,5mg O2/l para as densidades de 20 e 40 peixes/m2, enquanto nos tanques sem a aeração os valores de oxigênio foram de 4,3 ± 0,7 e 3,4 ± 0,7mg O2/l, respectivamente. A biomassa foi o único parâmetro que aumentou com a aeração noturna, enquanto que a sobrevivência e o crescimento apresentaram efeitos discretos.The present study evaluated the effects of two stocking densities (20 and 40 fish/m2 and nightly aeration on water quality and growth of pacu, Piaractus mesopotamicus (Holmberg, 1887. Twelve ponds with concrete walls and earthen bottom were used to set 4 treatments with 3 repetitions each. 30-day old fish with average weight (mean standard ± deviation of 1.93 ± 1.70g in the beginning of the experiment were observed for 60 days. Nightly aeration promoted 5.6 ± 0.5 and 5.8 ± 0.5mg O2/l at dawn in the population densities of 20 and 40 fish/m2, while the unaerated ponds allowed 4.3 ± 0.7 and 3.4 ± 0.7mg O2/l for these densities, respectively. Fish biomass was the only biological parameter increased by nightly aeration, while discrete effects were observed in growth and survival.

  13. Role of Fusobacterium nucleatum and Coaggregation in Anaerobe Survival in Planktonic and Biofilm Oral Microbial Communities during Aeration

    Science.gov (United States)

    Bradshaw, David J.; Marsh, Philip D.; Watson, G. Keith; Allison, Clive

    1998-01-01

    Coaggregation is a well-characterized phenomenon by which specific pairs of oral bacteria interact physically. The aim of this study was to examine the patterns of coaggregation between obligately anaerobic and oxygen-tolerant species that coexist in a model oral microbial community. Obligate anaerobes other than Fusobacterium nucleatum coaggregated only poorly with oxygen-tolerant species. In contrast, F. nucleatum was able to coaggregate not only with both oxygen-tolerant and other obligately anaerobic species but also with otherwise-noncoaggregating obligate anaerobe–oxygen-tolerant species pairs. The effects of the presence or absence of F. nucleatum on anaerobe survival in both the biofilm and planktonic phases of a complex community of oral bacteria grown in an aerated (gas phase, 200 ml of 5% CO2 in air · min−1) chemostat system were then investigated. In the presence of F. nucleatum, anaerobes persisted in high numbers (>107 · ml−1 in the planktonic phase and >107 · cm−2 in 4-day biofilms). In an equivalent culture in the absence of F. nucleatum, the numbers of black-pigmented anaerobes (Porphyromonas gingivalis and Prevotella nigrescens) were significantly reduced (P ≤ 0.001) in both the planktonic phase and in 4-day biofilms, while the numbers of facultatively anaerobic bacteria increased in these communities. Coaggregation-mediated interactions between F. nucleatum and other species facilitated the survival of obligate anaerobes in aerated environments. PMID:9746571

  14. Rapid Start-up and Loading of an Attached Growth, Simultaneous Nitrification/Denitrification Membrane Aerated Bioreactor

    Science.gov (United States)

    Meyer, Caitlin E.; Pensinger, Stuart; Pickering, Karen D.; Barta, Daniel; Shull, Sarah A.; Vega, Letticia M.; Christenson, Dylan; Jackson, W. Andrew

    2015-01-01

    Membrane aerated bioreactors (MABR) are attached-growth biological systems used for simultaneous nitrification and denitrification to reclaim water from waste. This design is an innovative approach to common terrestrial wastewater treatments for nitrogen and carbon removal and implementing a biologically-based water treatment system for long-duration human exploration is an attractive, low energy alternative to physiochemical processes. Two obstacles to implementing such a system are (1) the "start-up" duration from inoculation to steady-state operations and (2) the amount of surface area needed for the biological activity to occur. The Advanced Water Recovery Systems (AWRS) team at JSC explored these two issues through two tests; a rapid inoculation study and a wastewater loading study. Results from these tests demonstrate that the duration from inoculation to steady state can be reduced to under two weeks, and that despite low ammonium removal rates, the MABRs are oversized.

  15. Influence of housing system, grain type, and particle size on Salmonella colonization and shedding of broilers fed triticale or corn-soybean meal diets.

    Science.gov (United States)

    Santos, F B O; Sheldon, B W; Santos, A A; Ferket, P R

    2008-03-01

    Salmonella colonization in poultry may be influenced by grain type and particle size. Broilers reared either in nonlitter cage-based housing or in a conventionally floored litter house from 0 to 42 d were assigned to 1 of 4 dietary treatments: 1) ground corn-soybean meal (C, 560 microm), 2) coarsely ground corn-soybean meal (CC, >1,700 microm), 3) ground triticale-soybean meal (T, 560 microm), or 4) whole triticale-soybean meal (WT). A 4-strain cocktail of Salmonella enterica was orally gavaged into each chick at placement. Growth performance, cecal and fecal Salmonella populations, gizzard and proventriculus pH, intestinal size, jejunum histomorphometry, and carcass yields were measured. Broilers responded differently to the dietary treatments according to the housing system used. At 42 d, birds reared on litter and fed ground grain had greater BW than those fed coarse grain (2.87 vs. 2.71 kg), whereas cage-reared broilers fed ground triticale were heavier than those fed corn (2.75 vs. 2.64 kg). Broilers raised on litter had a better feed conversion ratio than those raised in cages (1.71 vs. 1.81 g/g). Independent of the housing system, relative eviscerated carcass weights of birds fed T and C were heavier than those of CC- and WT-fed broilers (762 vs. 752 g/kg). Generally, the jejunum villus area and mucosal depth were larger, whereas the small intestine was lighter and shorter in broilers raised on litter. Relative gizzard weights of broilers raised on litter and fed the coarser diets were heavier than those of broilers reared in cages and fed finely ground diets. Feeding whole or coarsely ground grains decreased cecal Salmonella populations in 42-d-old broilers (3.8, 3.9, 4.4, and 4.4 log most probable number/g for CC, WT, C, and T, respectively). Additionally, 42-d-old broilers reared on litter had lower cecal Salmonella populations than those in cages (3.8 vs. 4.4 log most probable number/g). In conclusion, as a feed ingredient, triticale is a good

  16. Ambient iron-mediated aeration (IMA) for water reuse.

    Science.gov (United States)

    Deng, Yang; Englehardt, James D; Abdul-Aziz, Samer; Bataille, Tristan; Cueto, Josenrique; De Leon, Omar; Wright, Mary E; Gardinali, Piero; Narayanan, Aarthi; Polar, Jose; Tomoyuki, Shibata

    2013-02-01

    Global water shortages caused by rapidly expanding population, escalating water consumption, and dwindling water reserves have rendered water reuse a strategically significant approach to meet current and future water demand. This study is the first to our knowledge to evaluate the technical feasibility of iron-mediated aeration (IMA), an innovative, potentially economical, holistic, oxidizing co-precipitation process operating at room temperature, atmospheric pressure, and neutral pH, for water reuse. In the IMA process, dissolved oxygen (O₂) was continuously activated by zero-valent iron (Fe⁰) to produce reactive oxygen species (ROS) at ambient pH, temperature, and pressure. Concurrently, iron sludge was generated as a result of iron corrosion. Bench-scale tests were conducted to study the performance of IMA for treatment of secondary effluent, natural surface water, and simulated contaminated water. The following removal efficiencies were achieved: 82.2% glyoxylic acid, ~100% formaldehyde as an oxidation product of glyoxylic acid, 94% of Ca²⁺ and associated alkalinity, 44% of chemical oxygen demand (COD), 26% of electrical conductivity (EC), 98% of di-n-butyl phthalate (DBP), 80% of 17β-estradiol (E2), 45% of total nitrogen (TN), 96% of total phosphorus (TP), 99.8% of total Cr, >90% of total Ni, 99% of color, 3.2 log removal of total coliform, and 2.4 log removal of E. Coli. Removal was attributed principally to chemical oxidation, precipitation, co-precipitation, coagulation, adsorption, and air stripping concurrently occurring during the IMA treatment. Results suggest that IMA is a promising treatment technology for water reuse. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Effects of intermittent and continuous aeration on accelerative stabilization and microbial population dynamics in landfill bioreactors.

    Science.gov (United States)

    Sang, Nguyen Nhu; Soda, Satoshi; Inoue, Daisuke; Sei, Kazunari; Ike, Michihiko

    2009-10-01

    Performance and microbial population dynamics in landfill bioreactors were investigated in laboratory experiments. Three reactors were operated without aeration (control reactor, CR), with cyclic 6-h aeration and 6-h non-aeration (intermittently aerated reactor, IAR), and with continuous aeration (continuously aerated reactor, CAR). Each reactor was loaded with high-organic solid waste. The performance of IAR was highest among the reactors up to day 90. The respective solid weight, organic matter content, and waste volume on day 90 in the CR, IAR, and CAR were 50.9, 39.1, and 47.5%; 46.5, 29.3 and 35.0%; and 69, 38, and 53% of the initial values. Organic carbon and nitrogen compounds in leachate in the IAR and the CAR showed significant decreases in comparison to those in the CR. The most probable number (MPN) values of fungal 18S rDNA in the CAR and the IAR were higher than those in the CR. Terminal restriction fragment length polymorphism analysis showed that unique and diverse eubacterial and archaeal communities were formed in the IAR. The intermittent aeration strategy was favorable for initiation of solubilization of organic matter by the aerobic fungal populations and the reduction of the acid formation phase. Then the anaerobic H(2)-producing bacteria Clostridium became dominant in the IAR. Sulfate-reducing bacteria, which cannot use acetate/sulfate but which instead use various organics/sulfate as the electron donor/acceptor were also dominant in the IAR. Consequently, Methanosarcinales, which are acetate-utilizing methanogens, became the dominant archaea in the IAR, where high methane production was observed.

  18. Nonlinear Modeling of Autoclaved Aerated Concrete Masonry Wall Strengthened using Ferrocement Sandwich Structure

    KAUST Repository

    M., Abdel-Mooty

    2011-01-01

    Autoclaved Aerated Concrete (AAC) block are used mainly as non-load-bearing walls that provide heat insulation. This results in considerable saving in cooling energy particularly in hot desert environment with large variation of daily and seasonal temperatures. However, due to the relatively low strength there use load bearing walls is limited to single storey and low-rise construction. A system to enhance the strength of the AAC masonry wall in resisting both inplane vertical and combined vertical and lateral loads using ferrocement technology is proposed in this research. The proposed system significantly enhances the load carrying capacity and stiffness of the AAC wall without affecting its insulation characteristics. Ferrocement is made of cement mortar reinforced with closely spaced wire mesh. Full scale wall specimens with height of 2100mm and width of 1820mm were tested with different configuration of ferrocement. A finite elementmodel is developed and verified against the experimentalwork. The results of the finite element model correlates well with the experimental results.

  19. Yields and Nutritional of Greenhouse Tomato in Response to Different Soil Aeration Volume at two depths of Subsurface drip irrigation

    Science.gov (United States)

    Li, Yuan; Niu, Wenquan; Dyck, Miles; Wang, Jingwei; Zou, Xiaoyang

    2016-01-01

    This study investigated the effects of 4 aeration levels (varied by injection of air to the soil through subsurface irrigation lines) at two subsurface irrigation line depths (15 and 40 cm) on plant growth, yield and nutritional quality of greenhouse tomato. In all experiments, fruit number, width and length, yield, vitamin C, lycopene and sugar/acid ratio of tomato markedly increased in response to the aeration treatments. Vitamin C, lycopene, and sugar/acid ratio increased by 41%, 2%, and 43%, respectively, in the 1.5 times standard aeration volume compared with the no-aeration treatment. An interaction between aeration level and depth of irrigation line was also observed with yield, fruit number, fruit length, vitamin C and sugar/acid ratio of greenhouse tomato increasing at each aeration level when irrigation lines were placed at 40 cm depth. However, when the irrigation lines were 15 cm deep, the trend of total fruit yields, fruit width, fruit length and sugar/acid ratio first increased and then decreased with increasing aeration level. Total soluble solids and titrable acid decreased with increasing aeration level both at 15 and 40 cm irrigation line placement. When all of the quality factors, yields and economic benefit are considered together, the combination of 40 cm line depth and “standard” aeration level was the optimum combination. PMID:27995970

  20. Optimizing aeration rates for minimizing membrane fouling and its effect on sludge characteristics in a moving bed membrane bioreactor

    International Nuclear Information System (INIS)

    Rahimi, Yousef; Torabian, Ali; Mehrdadi, Naser; Habibi-Rezaie, Mehran; Pezeshk, Hamid; Nabi-Bidhendi, Gholam-Reza

    2011-01-01

    Research highlights: → There is an optimum aeration rate in the MBMBR process compartments. → Optimum aeration rate maximizes nutrients removal. → Optimum aeration rate minimizes membrane fouling. → Both aeration rates in MBBR and membrane compartment can affect on membrane permeability. - Abstract: In MBR processes, sufficient aeration is necessary to maintain sustainable flux and to retard membrane fouling. Membrane permeability, sludge characteristics, nutrient removal and biomass growth at various air flow rates in the membrane and moving bed biofilm reactor (MBBR) compartments were studied in a pilot plant. The highest nitrogen and phosphorous removal rates were found at MBBR aeration rates of 151 and 85 L h -1 and a specific aeration demand per membrane area (SAD m ) of 1.2 and 0.4m air 3 m -2 h -1 , respectively. A linear correlation was found between the amount of attached biofilm and the nutrient removal rate. The aeration rate in the MBBR compartment and SAD m significantly influenced the sludge characteristics and membrane permeability. The optimum combination of the aeration rate in the MBBR compartment and SAD m were 151 L h -1 and 0.8-1.2m air 3 m membrane -2 h -1 , respectively.

  1. Impact of post-infiltration soil aeration at different growth stages of sub-surface trickle-irrigated tomato plants

    Science.gov (United States)

    Li, Yuan; Jia, Zong-xia; Niu, Wen-Quan; Wang, Jing-wei

    2016-07-01

    Sensitivity to low rhizosphere soil aeration may change over time and therefore plant response may also depend on different growth stages of a crop. This study quantified effects of soil aeration during 5 different periods, on growth and yield of trickle-irrigated potted single tomato plants. Irrigation levels were 0.6 to 0.7 (low level) or 0.7 to 0.8 (high level) of total water holding capacity of the pots. Soil was aerated by injecting 2.5 l of air into each pot through the drip tubing immediately after irrigation. Fresh fruit yield, above ground plant dry weight, plant height, and leaf area index response to these treatments were measured. For all these 4 response variables, means of post-infiltration aeration between 58 to 85 days after sowing were 13.4, 43.5, 13.7, and 37.7% higher than those for the non-aerated pots, respectively. The results indicated that: post-infiltration soil aeration can positively impact the yield and growth of sub-surface trickle-irrigated potted tomato plants; positive effects on plant growth can be obtained with aeration during the whole growth period or with aeration for partial periods; positive growth effects of partial periods of aeration appears to persist and result in yield benefit.

  2. Optimizing aeration rates for minimizing membrane fouling and its effect on sludge characteristics in a moving bed membrane bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Yousef, E-mail: yrahimi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Torabian, Ali, E-mail: atorabi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Mehrdadi, Naser, E-mail: mehrdadi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Habibi-Rezaie, Mehran, E-mail: mhabibi@khayam.ut.ac.ir [Department of Biotechnology, Faculty of Biology, College of Science, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Pezeshk, Hamid, E-mail: pezeshk@khayam.ut.ac.ir [Department of Statistics, Faculty of Mathematics and Computer, College of Science, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of); Nabi-Bidhendi, Gholam-Reza, E-mail: ghhendi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave., Tehran (Iran, Islamic Republic of)

    2011-02-28

    Research highlights: {yields} There is an optimum aeration rate in the MBMBR process compartments. {yields} Optimum aeration rate maximizes nutrients removal. {yields} Optimum aeration rate minimizes membrane fouling. {yields} Both aeration rates in MBBR and membrane compartment can affect on membrane permeability. - Abstract: In MBR processes, sufficient aeration is necessary to maintain sustainable flux and to retard membrane fouling. Membrane permeability, sludge characteristics, nutrient removal and biomass growth at various air flow rates in the membrane and moving bed biofilm reactor (MBBR) compartments were studied in a pilot plant. The highest nitrogen and phosphorous removal rates were found at MBBR aeration rates of 151 and 85 L h{sup -1} and a specific aeration demand per membrane area (SAD{sub m}) of 1.2 and 0.4m{sub air}{sup 3} m{sup -2} h{sup -1}, respectively. A linear correlation was found between the amount of attached biofilm and the nutrient removal rate. The aeration rate in the MBBR compartment and SAD{sub m} significantly influenced the sludge characteristics and membrane permeability. The optimum combination of the aeration rate in the MBBR compartment and SAD{sub m} were 151 L h{sup -1} and 0.8-1.2m{sub air}{sup 3}m{sub membrane}{sup -2} h{sup -1}, respectively.

  3. Dynamics of interplanetary dust grains

    International Nuclear Information System (INIS)

    Lamy, P.L.

    1975-01-01

    The interaction of spherical grains of various materials-three silicates (quartz, obsidian and andesite), water-ice and iron - whose radii lie in the micronic and submicronic range with the interplanetary medium is solved. This includes: the interaction with the solar radiation field which is solved using Mie scattering theory and taking into account the precise dependence of the optical properties of the five materials upon wavelength; the interaction with the solar wind: corpuscular tangential drag is found to be always important and may even be larger than the Poynting-Robertson drag; the interaction with the interplanetary magnetic field is investigated in terms of a diffusion or random walk through a series of electromagnetic scatterings, leading to a Chapman-Komolgorov equation (i.e., a generalized Liouville equation). Numerical results are presented for these interactions spanning the entire solar system with circularity of elliptical orbits, direct or retrograde, with grains of various materials and sizes and giving -probably for the first time - a clear global picture of the interaction of dust grains with the interplanetary medium. The dynamics of the grains is then investigated using the theory of general perturbations and the numerical integration of trajectories of circum-solar grains

  4. DEVELOPMENT OF GRAIN MARKET IN UKRAINE

    Directory of Open Access Journals (Sweden)

    Aleksandr Maslak

    2015-11-01

    Full Text Available The subject of the research is a set of theoretical, methodological and practical fundamentals of organizational and economic functioning are integrated agricultural formations in the grain market of Ukraine. The methodological basis of research is the complex analysis of economic processes in the grain market in Ukraine and the world. During research we used such methods as method of systematization and comparison, statistic, economic, balance, constructive, target-oriented, and the methods of induction and deduction, analogy and comparison. Main aim of this article is the analysis of the situation on the grain market in Ukraine, defining the role of integrated agricultural formations in this market, improving the organizational-economic mechanism of its functioning, identifies ways of improving the competitiveness of Ukraine among world exporters of grain. Using results of the studies we examined trends grain market in Ukraine; influence of businesses in grain production; analysis of constraints to improve production efficiency of grain; defined domestic (internal needs of grain in Ukraine; assessed the status and expediency transformation infrastructure of the grain market of Ukraine; defined priority directions of development of the grain market in Ukraine. As a result of the preparation of articles, it is obtained the following conclusions: Ukraine is the world's largest producers and exporters of grain, the production of integrated agricultural units to a third of the total grain; technical condition of farm does not meet the needs of production; the domestic market is unable to provide the existing demand for grain production, contributing to export growth; Ukraine has a number of problems due to increased grain production, namely the shortage of storage capacity for the storage of grain, limited performance transshipment of grain in port elevators and imperfection and depreciation of transport systems; solving the existing problems is

  5. Corrosion behavior of electrodeposited Co-Fe alloys in aerated solutions

    Energy Technology Data Exchange (ETDEWEB)

    Chansena, A. [Research Unit on Corrosion, College of Data Storage Innovation, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand); Sutthiruangwong, S., E-mail: sutha.su@kmitl.ac.th [Department of Chemistry, Faculty of Science, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand); Research Unit on Corrosion, College of Data Storage Innovation, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand)

    2017-05-01

    Co-Fe alloy is an important component for reader-writer in hard disk drive. The surface of the alloy is exposed to the environment both in gas phase and in liquid phase during manufacturing process. The study of corrosion behavior of Co-Fe alloys can provide useful fundamental data for reader-writer production planning especially when corrosion becomes a major problem. The corrosion study of electrodeposited Co-Fe alloys from cyclic galvanodynamic polarization was performed using potentiodynamic polarization technique. The composition of electrodeposited Co-Fe alloys was determined by X-ray fluorescence spectrometry. The patterns from X-ray diffractometer showed that the crystal structure of electrodeposited Co-Fe alloys was body-centered cubic. A vibrating sample magnetometer was used for magnetic measurements. The saturation magnetization (M{sub s}) was increased and the intrinsic coercivity (H{sub ci}) was decreased with increasing Fe content. The corrosion rate study was performed in aerated deionized water and aerated acidic solutions at pH 3, 4 and 5. The corrosion rate diagram for Co-Fe alloys was constructed. It was found that the corrosion rate of Co-Fe alloys was increased with increasing Fe content in both aerated deionized water and aerated acidic solutions. In aerated pH 3 solution, the Co-Fe alloy containing 78.8% Fe showed the highest corrosion rate of 7.7 mm yr{sup −1} with the highest M{sub s} of 32.0 A m{sup 2} kg{sup −1}. The corrosion rate of the alloy with 23.8% Fe was at 1.1 mm yr{sup −1} with M{sub s} of 1.2 A m{sup 2} kg{sup −1}. In aerated deionized water, the alloy with the highest Fe content of 78.5% still showed the highest corrosion rate of 0.0059 mm yr{sup −1} while the alloy with the lowest Fe content of 20.4% gave the lowest corrosion rate of 0.0045 mm yr{sup −1}. - Highlights: • The aeration during corrosion measurement simulates reader-writer head production environment. • The corrosion rate diagram for Co-Fe alloys

  6. Emerging quasi-0D states at vanishing total entropy of the 1D hard sphere system: A coarse-grained similarity to the car parking problem

    Science.gov (United States)

    Frusawa, Hiroshi

    2014-05-01

    A coarse-grained system of one-dimensional (1D) hard spheres (HSs) is created using the Delaunay tessellation, which enables one to define the quasi-0D state. It is found from comparing the quasi-0D and 1D free energy densities that a frozen state due to the emergence of quasi-0D HSs is thermodynamically more favorable than fluidity with a large-scale heterogeneity above crossover volume fraction of ϕc=e/(1+e)=0.731⋯ , at which the total entropy of the 1D state vanishes. The Delaunay-based lattice mapping further provides a similarity between the dense HS system above ϕc and the jamming limit in the car parking problem.

  7. Emerging quasi-0D states at vanishing total entropy of the 1D hard sphere system: A coarse-grained similarity to the car parking problem

    International Nuclear Information System (INIS)

    Frusawa, Hiroshi

    2014-01-01

    A coarse-grained system of one-dimensional (1D) hard spheres (HSs) is created using the Delaunay tessellation, which enables one to define the quasi-0D state. It is found from comparing the quasi-0D and 1D free energy densities that a frozen state due to the emergence of quasi-0D HSs is thermodynamically more favorable than fluidity with a large-scale heterogeneity above crossover volume fraction of ϕ c =e/(1+e)=0.731⋯ , at which the total entropy of the 1D state vanishes. The Delaunay-based lattice mapping further provides a similarity between the dense HS system above ϕ c and the jamming limit in the car parking problem.

  8. Aerated biofilters with multiple-level air injection configurations to enhance biological treatment of methane emissions.

    Science.gov (United States)

    Farrokhzadeh, Hasti; Hettiaratchi, J Patrick A; Jayasinghe, Poornima; Kumar, Sunil

    2017-09-01

    Aiming to improve conventional methane biofilter performance, a multiple-level aeration biofilter design is proposed. Laboratory flow-through column experiments were conducted to evaluate three actively-aerated methane biofilter configurations. Columns were aerated at one, two, and three levels of the bed depth, with air introduced at flow rates calculated from methane oxidation reaction stoichiometry. Inlet methane loading rates were increased in five stages between 6 and 18mL/min. The effects of methane feeding rate, levels of aeration, and residence time on methane oxidation rates were determined. Samples collected after completion of flow-through experiments were used to determine methane oxidation kinetic parameters, V max , K m , and methanotrophic community distribution across biofilter columns. Results obtained from mixed variances analysis and response surfaces, as well as methanotrophic activity data, suggested that, biofilter column with two aeration levels has the most even performance over time, maintaining 85.1% average oxidation efficiency over 95days of experiments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Production of environmentally friendly aerated concrete with required construction and operational properties

    Directory of Open Access Journals (Sweden)

    Tkach Evgeniya

    2018-01-01

    Full Text Available The purpose of these studies is to justify the feasibility of recycling different types of industrial waste instead of conventional expensive raw materials in production of environmentally friendly aerated concrete with required construction and operational properties. The impact of wastes from various industries on the environmental condition of affected areas, as well as the results of their environmental assessment were analyzed to determine whether these wastes could be used in production of high-performance building materials. The assessment of industrial wastes in aerated concrete production suggests that industrial wastes of hazard class IV can be recycled to produce aerated concrete. An environmentally friendly method for large-scale waste recycling, including a two-step environmentally sustainable mechanism, was developed. The basic quality indicators of the modified aerated concrete proved that the environmental safety could be enhanced by strengthening the structure, increasing its uniformity and improving thermal insulation properties. The modified non-autoclaved aerated concrete products with improved physical and operational properties were developed. They have the following properties: density – D700; class of concrete – B3.5; thermal transmittance coefficient – 0.143 W/(m·°C; frost resistance – F75.

  10. Maximization of beta-galactosidase production: a simultaneous investigation of agitation and aeration effects.

    Science.gov (United States)

    Alves, Fernanda Germano; Filho, Francisco Maugeri; de Medeiros Burkert, Janaína Fernandes; Kalil, Susana Juliano

    2010-03-01

    In this work, the agitation and aeration effects in the maximization of the beta-galactosidase production from Kluyveromyces marxianus CCT 7082 were investigated simultaneously, in relation to the volumetric enzyme activity and the productivity, as well as the analysis of the lactose consumption and production of glucose, and galactose of this process. Agitation and aeration effects were studied in a 2 L batch stirred reactor. A central composite design (2(2) trials plus three central points) was carried out. Agitation speed varied from 200 to 500 rpm and aeration rate from 0.5 to 1.5 vvm. It has been shown in this study that the volumetric enzyme production was strongly influenced by mixing conditions, while aeration was shown to be less significant. Linear models for activity and productivity due to agitation and aeration were obtained. The favorable condition was 500 rpm and 1.5 vvm, which lead to the best production of 17 U mL(-1) for enzymatic activity, 1.2 U mL(-1) h(-1) for productivity in 14 h of process, a cellular concentration of 11 mg mL(-1), and a 167.2 h(-1) volumetric oxygen transfer coefficient.

  11. Hybrid system: Heat pump-solar air dryer for grains; Sistema hibrido: bomba de calor - calentador solar de aire para el secado de productos agricolas

    Energy Technology Data Exchange (ETDEWEB)

    Soto Gomez, Willfredo [Instituto Tecnologico de Tijuana, Tijuana (Mexico); Ortega Herrera, Jose Angel [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)

    2000-07-01

    Design, building, operation and evaluation energy wise of a hybrid experimental type, with heat pump, that uses no chloride, does not destroy the ozone layer. It is solar air dryer for grains. In this research we dry rice. It has tree systems: 1.- A mechanical compression heat pump, 2.- An air solar heater, and 3.- An agriculture products dryer. The drying capacity is 20 pounds of grain /day, with a median daily solar radiation. The costs is approximately U.S. $ 6 000.00. The heat pump used 22 refrigerant first, and now works with refrigerant SUVA 9000. This refrigerant will be available this year in the I.S., it is one of the ecological class that substitutes the chlorofluorocarbonates. [Spanish] Se disena, construye, opera, y evalua energeticamente, un sistema hibrido tipo experimental, con bomba de calor que utiliza refrigerante que no contiene cloro, y no destruye la capa de ozono y un calentador solar de aire, para secar granos. En este trabajo secamos arroz. Se compone de tres sistemas: 1.- Bomba de calor por compresion mecanica, 2.- Calentador solar de aire, 3.- Secador de productos agricolas. La capacidad de secado es de 10 Kilos de granos/dia promedio. Tiene un costo aproximado de $ 60 000. La bomba de calor utiliza refrigerante 22 en una primera generacion, y actualmente opera con un refrigerante SUVA 9000, en una segunda generacion, este refrigerante se comercializara en este ano, en la Union Americana, pertenece a la familia de los llamados refrigerantes ecologicos, sustitutos de los clorofluorocarbonados.

  12. About oxide dispersion particles chemical compatibility with areas coherent dissipation/sub-grains of bcc-alloys in Fe - (Cr, V, Mo, W systems

    Directory of Open Access Journals (Sweden)

    Udovsky A.

    2016-01-01

    Full Text Available A concept of partial magnetic moments (PMM of the iron atoms located in the first ч four coordination spheres (1÷4 CS for bcc lattice have been introduced based on analysis of results obtained by quantum-mechanical calculations (QMC for volume dependence of the average magnetic moment ferromagnetic (FM Fe. The values of these moments have been calculated for pure bcc Fe and bcc - Fe-Cr alloys. This concept has been used to formulate a three sub-lattice model for binary FM alloys of the Fe-M systems (M is an alloying paramagnetic element. Physical reason for sign change dependence of the short-range order and mixing enthalpy obtained by QMCs for Fe-(Cr, V bcc phases has been found. Using this model it has been predicted that static displacements of Fe - atoms in alloy matrix increase with increasing the of CS number and result in reducing of the area of coherent dissipation (ACD size with growth of the dimension factor (DF in the Fe-(Cr, V, Mo, W systems in agreement with the X-ray experiments. It has been shown theoretically that anisotropy of spin- density in bcc lattice Fe and DF in binary Fe - (Cr, V, Mo, W systems is main factor for origins of segregations on small angle boundaries of ACD and sub-grains boundaries To prevent the coagulation of both ACD and sub-grains, and to increase the strength of alloys, it is advisable to add oxide dispersion particles into ferrite steel taking into account their chemical compatibility and coherent interfacing with the crystalline lattice of a ferrite matrix. Application of phase diagrams for binary and ternary the Fe-(Y, Zr-O systems to verify chemical compatibility of oxide dispersion particles with ferrite matrix have been discussed

  13. Measurements of N2O and CH4 from the aerated composting of food waste

    International Nuclear Information System (INIS)

    He, Y.; Sun, T.; Inamori, Y.; Mizuochi, M.; Kong, H.; Iwami, N.

    2000-01-01

    Emissions of N 2 O and CH 4 from an aerated composting system were investigated using small-scale simulated reactors. The results show relatively high emissions of N 2 O at the beginning of composting, in proportion to the application amount of food waste. After 2 days, the N 2 O emission decreased to 0.53 ppmv on average, near to the background level in the atmosphere (0.45 ppmv). The addition of composted cattle manure increased N 2 O emissions not only at the beginning of composting, but also during the later period and resulted in two peak emission curves. Good correlation was observed between the N 2 O concentration at the air outlet and NO 2 - concentration in waste, suggesting a generation pathway for N 2 O from NO 2 - to N 2 O. Methane was only detected in treatments containing composted cattle manure. The high emission of methane illustrates the involvement of anoxic/anaerobic microorganisms with the addition of composted manure. The result suggests the existence of anoxic or anaerobic microsite inside the waste particles even though ventilation was employed during the composting process

  14. Compaction of cereal grain

    OpenAIRE

    Wychowaniec, J.; Griffiths, I.; Gay, A.; Mughal, A.

    2013-01-01

    We report on simple shaking experiments to measure the compaction of a column of Firth oat grain. Such grains are elongated anisotropic particles with a bimodal polydispersity. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical shaking evolve to a dense state with evidence of nematic-like structure at the surface of the confining tube. This is accompanied by an increase in the packing fraction of the grain.

  15. Evolution of interstellar grains

    International Nuclear Information System (INIS)

    Greenberg, J.M.

    1984-01-01

    The principal aim of this chapter is to derive the properties of interstellar grains as a probe of local physical conditions and as a basis for predicting such properties as related to infrared emissivity and radiative transfer which can affect the evolution of dense clouds. The first sections will develop the criteria for grain models based directly on observations of gas and dust. A summary of the chemical evolution of grains and gas in diffuse and dense clouds follows. (author)

  16. Microbiota of kefir grains

    OpenAIRE

    Tomislav Pogačić; Sanja Šinko; Šimun Zamberlin; Dubravka Samaržija

    2013-01-01

    Kefir grains represent the unique microbial community consisting of bacteria, yeasts, and sometimes filamentous moulds creating complex symbiotic community. The complexity of their physical and microbial structures is the reason that the kefir grains are still not unequivocally elucidated. Microbiota of kefir grains has been studied by many microbiological and molecular approaches. The development of metagenomics, based on the identification without cultivation, is opening new possibilities f...

  17. Grain boundary migration

    International Nuclear Information System (INIS)

    Dimitrov, O.

    1975-01-01

    Well-established aspects of grain-boundary migration are first briefly reviewed (influences of driving force, temperature, orientation and foreign atoms). Recent developments of the experimental methods and results are then examined, by considering the various driving of resistive forces acting on grain boundaries. Finally, the evolution in the theoretical models of grain-boundary motion is described, on the one hand for ideally pure metals and, on the other hand, in the presence of solute impurity atoms [fr

  18. Inspection of copper canisters for spent nuclear fuel by means of ultrasonic array system. Modelling, defect detection and grain noise estimation

    International Nuclear Information System (INIS)

    Wu Ping; Stepinski, T.

    1998-07-01

    The work presented in the report has been split into three overlapping tasks which have the following objectives: (1) development of beam-forming tools, and verification of modeling tools; (2) investigation of detection and resolution limits; (3) evaluation of attenuation, estimation and suppression of grain noise. For beam-forming tools, a method of designing steered and/or focused beams in immersed solids is presented based on geometrical acoustics. Presently, the beam designs are only related to delays but not to apodization. These focused, steered beams are intended to be used for sizing defects and inspecting the regions close to canisters outer walls. The modeling tool developed previously for simulating elastic fields radiated by planar arrays into immersed solids has been verified by comparing with the results obtained from PASS, a software developed by Dr. Didier Cassereau, France. The results from our modeling tool are in excellent agreement with those from PASS. Since the array coming with the ALLIN ultrasonic array system is not planar, but cylindrically curved in elevation, and it works not in transmission mode, but in pulse echo mode, the above modeling tool for the planar arrays cannot be applied directly. Therefore, the modeling tool has been upgraded for the ALLIN array. The theory underlying this modeling tool is the extended angular spectrum approach (ASA) which was developed based on the conventional ASA that only applies to planar sources. Experimental verification of the modeling tool has shown that the results from the tool agree very well with the measurements. To quantify the fields from the ALLIN array and to facilitate the comparison of simulated results with the measured ones, the ALLIN array system has been calibrated based on the existing functionality, and an analytical model has been proposed for simulating measured acoustic echo pulses. To investigate the detection and resolution limits, we have carried out a series of experiments

  19. Effect of aerated concrete blockwork joints on the heat transfer performance uniformity

    Science.gov (United States)

    Pukhkal, Viktor; Murgul, Vera

    2018-03-01

    Analysis of data on the effect of joints of the aerated concrete blocks on the heat transfer uniformity of exterior walls was carried out. It was concluded, that the values of the heat transfer performance uniformity factor in the literature sources were obtained for the regular fragment of a wall construction by approximate addition of thermal conductivities. Heat flow patterns for the aerated concrete exterior walls amid different values of the thermal conductivity factors and design ambient air temperature of -26 °C were calculated with the use of "ELCUT" software for modelling of thermal patterns by finite element method. There were defined the values for the heat transfer performance uniformity factor, reduced total thermal resistance and heat-flux density for the exterior walls. The calculated values of the heat transfer performance uniformity factors, as a function of the coefficient of thermal conductivity of aerated concrete blocks, differ from the known data by a more rigorous thermal and physical substantiation.

  20. [Research of aeration with bio-film technology to treat urban landscape water].

    Science.gov (United States)

    Song, Ying-Wei; Nie, Zhi-Dan; Nian, Yue-Gang; Huang, Min-Sheng; Huang, Jian-Jun; Yan, Hai-Hong; Zhang, Yang

    2008-01-01

    Research of the aeration with bio-film technology was carried out to treat scenic water of a sanatorium in Beijing. The aim of the research was improving the water habitat by increasing the transparency and reducing the concentration of N and P. The equipments were set in a 5,000 m2 water area, which combined the plug flow jet aerator with the elastic biological filler. The research indicated that the transparency increased from 25 cm to 120 cm by the technology. The removal efficiencies of NH4(+)-N, NO3(-)-N and TP were 86.6% , 90% and 73.3%, but there was only 22.4% for TN. The concentration of DO increased from 4.3 mg/L to 7 mg/L. In a word, the aeration with bio-film technology was an effective measure to improve the water habitat by increasing the transparency.

  1. Thermal Response Of An Aerated Concrete Wall With Micro-Encapsulated Phase Change Material

    Science.gov (United States)

    Halúzová, Dušana

    2015-06-01

    For many years Phase Change Materials (PCM) have attracted attention due to their ability to store large amounts of thermal energy. This property makes them a candidate for the use of passive heat storage. In many applications, they are used to avoid the overheating of the temperature of an indoor environment. This paper describes the behavior of phase change materials that are inbuilt in aerated concrete blocks. Two building samples of an aerated concrete wall were measured in laboratory equipment called "twin-boxes". The first box consists of a traditional aerated concrete wall; the second one has additional PCM micro-encapsulated in the wall. The heat flux through the wall was measured and compared to simulation results modeled in the ESP-r program. This experimental measurement provides a foundation for a model that can be used to analyze further building constructions.

  2. CO-COMPOSTING LIMBAH PADAT BELTPRESS DAN JERAMI PADI DENGAN AERATED STATIC PILE

    Directory of Open Access Journals (Sweden)

    Nastiti Siswi Indrasti

    2017-07-01

    Full Text Available Solid waste from beltpress machine in wastewater treatment plant is produced as much as 1,25 tons/day but hasnot been utilized, causing unpleasant odour and requires a high cost for disposal. Composting is one of alternative technology that can be applied to solve the problem. The objectives of this research were to examine the influence of the initial C/N value and aeration rate to the rate of co-composting process in reaching the C/N value that corresponds to SNI 19-7030-2004, and to characterize the compost produced. The research design used was factorial Complete Random Design (CRD with two factors and two repetitions. The first factor was C/N value, consisted of 25; 30; 35 and the second factor was aeration rate, consisted of 0; 0,4; 0,8 L/min.kg of dry material. Composting was done using 30 L reactor by giving active intermittent aeration for 1 hour/day during the first 7 days of composting. Effects of initial C/N value and aeration rate were significantly different (P0.05 on pH value. Lower initial C/N value and higher aeration rate attained standard C/N value fastest. The best treatment based on the conformity with SNI 19-7030-2004 was initial C/N25 with aeration rate 0,8 L/minute.kg dry matter. The compost produced met the SNI standards in macro elements, trace elements,and other elements, but didnot qualify the pH value and moisture content.

  3. Modelling nitrous oxide emissions from mown-grass and grain-cropping systems: Testing and sensitivity analysis of DailyDayCent using high frequency measurements.

    Science.gov (United States)

    Senapati, Nimai; Chabbi, Abad; Giostri, André Faé; Yeluripati, Jagadeesh B; Smith, Pete

    2016-12-01

    The DailyDayCent biogeochemical model was used to simulate nitrous oxide (N 2 O) emissions from two contrasting agro-ecosystems viz. a mown-grassland and a grain-cropping system in France. Model performance was tested using high frequency measurements over three years; additionally a local sensitivity analysis was performed. Annual N 2 O emissions of 1.97 and 1.24kgNha -1 year -1 were simulated from mown-grassland and grain-cropland, respectively. Measured and simulated water filled pore space (r=0.86, ME=-2.5%) and soil temperature (r=0.96, ME=-0.63°C) at 10cm soil depth matched well in mown-grassland. The model predicted cumulative hay and crop production effectively. The model simulated soil mineral nitrogen (N) concentrations, particularly ammonium (NH 4 + ), reasonably, but the model significantly underestimated soil nitrate (NO 3 - ) concentration under both systems. In general, the model effectively simulated the dynamics and the magnitude of daily N 2 O flux over the whole experimental period in grain-cropland (r=0.16, ME=-0.81gNha -1 day -1 ), with reasonable agreement between measured and modelled N 2 O fluxes for the mown-grassland (r=0.63, ME=-0.65gNha -1 day -1 ). Our results indicate that DailyDayCent has potential for use as a tool for predicting overall N 2 O emissions in the study region. However, in-depth analysis shows some systematic discrepancies between measured and simulated N 2 O fluxes on a daily basis. The current exercise suggests that the DailyDayCent may need improvement, particularly the sub-module responsible for N transformations, for better simulating soil mineral N, especially soil NO 3 - concentration, and N 2 O flux on a daily basis. The sensitivity analysis shows that many factors such as climate change, N-fertilizer use, input uncertainty and parameter value could influence the simulation of N 2 O emissions. Sensitivity estimation also helped to identify critical parameters, which need careful estimation or site

  4. Microscopic determination of the PuO2 grain size and pore size distribution of MOX pellets with an image analysis system

    International Nuclear Information System (INIS)

    Vandezande, J.

    2000-01-01

    The industrial way to obtain the Pu distribution in a MOX pellet is by Image Analysis. The PuO 2 grains are made visible by alpha-autoradiography. Along with the Pu distribution the pore structure is an item which is examined, the latter is determined on the unetched sample. After the visualization of the sample structure, the sample is evaluated with an Image Analysis System. Each image is enhanced and a distinction is made between the objects to be measured and the matrix. The relevant parameters are then analyzed. When the overall particle distribution is wanted, all identified particles are measured and classified in size groups, based on a logarithmic scale. The possible conversion of two-dimensional diameters to three-dimensional diameters is accomplished by application of the Saltykov algorithm. When a single object is of interest, the object is selected interactively, and the result is reported to the user. (author)

  5. Improved Aeration Process - Catalytic Role Of The Iron Oxides In Arsenic Oxidation And Coprecipitation

    DEFF Research Database (Denmark)

    Kowalski, Krysztof; Søgaard, Erik Gydesen

    2013-01-01

    Demands for a better drinking water quality, especially concerning arsenic, a compound with many adverse health effects, put a pressure on the utilities to ensure the best treatment technologies that meet nowadays and possible future quality standards. The aim of this paper is to introduce...... an improved aeration process that can also help in developing better arsenic removal treatment. The results present advantages of arsenic oxidation in an aeration process in the presence of ferrihydrite surface that have been shown to adsorb arsenic simultaneously to its oxidation. The presence...

  6. Utilizing whey protein isolate and polysaccharide complexes to stabilize aerated dairy gels.

    Science.gov (United States)

    O'Chiu, Emily; Vardhanabhuti, Bongkosh

    2017-05-01

    Heated soluble complexes of whey protein isolate (WPI) with polysaccharides may be used to modify the properties of aerated dairy gels, which could be formulated into novel-textured high-protein desserts. The objective of this study was to determine the effect of polysaccharide charge density and concentration within a WPI-polysaccharide complex on the physical properties of aerated gels. Three polysaccharides having different degrees of charge density were chosen: low-methoxyl pectin, high-methoxyl type D pectin, and guar gum. Heated complexes were prepared by heating the mixed dispersions (8% protein, 0 to 1% polysaccharide) at pH 7. To form aerated gels, 2% glucono-δ-lactone was added to the dispersions of skim milk powder and heated complex and foam was generated by whipping with a handheld frother. The foam set into a gel as the glucono-δ-lactone acidified to a final pH of 4.5. The aerated gels were evaluated for overrun, drainage, gel strength, and viscoelastic properties. Without heated complexes, stable aerated gels could not be formed. Overrun of aerated gel decreased (up to 73%) as polysaccharide concentration increased from 0.105 to 0.315% due to increased viscosity, which limited air incorporation. A negative relationship was found between percent drainage and dispersion viscosity. However, plotting of drainage against dispersion viscosity separated by polysaccharide type revealed that drainage decreased most in samples with high-charge-density, low-methoxyl pectin followed by those with low-charge-density, high-methoxyl type D pectin. Aerated gels with guar gum (no charge) did not show improvement to stability. Rheological results showed no significant difference in gelation time among samples; therefore, stronger interactions between WPI and high-charge-density polysaccharide were likely responsible for increased stability. Stable dairy aerated gels can be created from WPI-polysaccharide complexes. High-charge-density polysaccharides, at

  7. Computational Fluid Dynamics Modelling of Hydraulics and Sedimentation in Process Reactors During Aeration Tank Settling

    DEFF Research Database (Denmark)

    Dam Jensen, Mette; Ingildsen, Pernille; Rasmussen, Michael R.

    2005-01-01

    Aeration Tank Settling is a control method alowing settling in the process tank during high hydraulic load. The control method is patented. Aeration Tank Settling has been applied in several waste water treatment plant's using present design of the process tanks. Some process tank designs have...... shown to be more effective than others. To improve the design of less effective plants Computational Fluid Dynamics (CFD) modelling of hydraulics and sedimentation has been applied. The paper discusses the results at one particular plant experiencing problems with partly short-circuiting of the inlet...

  8. The Application of EIS and PIV Methods to the Measurement of Aerated Flow

    Directory of Open Access Journals (Sweden)

    Fejfarová M.

    2013-04-01

    Full Text Available The paper describes measurements in the aerated water medium using modern methods PIV (Particle Image Velocimetry and EIS (Electrical Impedance Spectrometry, which are applied in the Laboratory of Water Management Research (LVV of the Department of Water Structures (UVST at the Faculty of Civil Engineering (FAST of Brno University of Technology (VUT. Measurements of the water medium were carried out for three different aeration intensities at special experimental workplaces. The experiment was focused on the capability of the methods to monitor the air content in the water.

  9. Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Vogt, Josef K; Kristensen, Mette

    2018-01-01

    OBJECTIVE: To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. DESIGN: 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week...... dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory.......0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did...

  10. Extremely 54Cr- and 50Ti-rich Presolar Oxide Grains in a Primitive Meteorite: Formation in Rare Types of Supernovae and Implications for the Astrophysical Context of Solar System Birth

    Science.gov (United States)

    Nittler, Larry R.; O’D. Alexander, Conel M.; Liu, Nan; Wang, Jianhua

    2018-04-01

    We report the identification of 19 presolar oxide grains from the Orgueil CI meteorite with substantial enrichments in 54Cr, with 54Cr/52Cr ratios ranging from 1.2 to 56 times the solar value. The most enriched grains also exhibit enrichments at mass-50, most likely due in part to 50Ti, but close-to-normal or depleted 53Cr/52Cr ratios. There is a strong inverse relationship between 54Cr enrichment and grain size; the most extreme grains are all attractive, as these likely occur much more frequently than high-density SN Ia, and their evolutionary timescales (∼20 Myr) are comparable to those of molecular clouds. Self-pollution of the Sun’s parent cloud from an ECSN may explain the heterogeneous distribution of n-rich isotopic anomalies in planetary materials, including a recently reported dichotomy in Mo isotopes in the solar system. The stellar origins of three grains with solar 54Cr/52Cr, but anomalies in 50Cr or 53Cr, as well as of a grain enriched in 57Fe, are unclear.

  11. Analysis of Process Gases and Trace Contaminants in Membrane-Aerated Gaseous Effluent Streams.

    Science.gov (United States)

    Coutts, Janelle L.; Lunn, Griffin Michael; Meyer, Caitlin E.

    2015-01-01

    In membrane-aerated biofilm reactors (MABRs), hollow fibers are used to supply oxygen to the biofilms and bulk fluid. A pressure and concentration gradient between the inner volume of the fibers and the reactor reservoir drives oxygen mass transport across the fibers toward the bulk solution, providing the fiber-adhered biofilm with oxygen. Conversely, bacterial metabolic gases from the bulk liquid, as well as from the biofilm, move opposite to the flow of oxygen, entering the hollow fiber and out of the reactor. Metabolic gases are excellent indicators of biofilm vitality, and can aid in microbial identification. Certain gases can be indicative of system perturbations and control anomalies, or potentially unwanted biological processes occurring within the reactor. In confined environments, such as those found during spaceflight, it is important to understand what compounds are being stripped from the reactor and potentially released into the crew cabin to determine the appropriateness or the requirement for additional mitigation factors. Reactor effluent gas analysis focused on samples provided from Kennedy Space Center's sub-scale MABRs, as well as Johnson Space Center's full-scale MABRs, using infrared spectroscopy and gas chromatography techniques. Process gases, such as carbon dioxide, oxygen, nitrogen, nitrogen dioxide, and nitrous oxide, were quantified to monitor reactor operations. Solid Phase Microextraction (SPME) GC-MS analysis was used to identify trace volatile compounds. Compounds of interest were subsequently quantified. Reactor supply air was examined to establish target compound baseline concentrations. Concentration levels were compared to average ISS concentration values and/or Spacecraft Maximum Allowable Concentration (SMAC) levels where appropriate. Based on a review of to-date results, current trace contaminant control systems (TCCS) currently on board the ISS should be able to handle the added load from bioreactor systems without the need

  12. Startup of a Partial Nitritation-Anammox MBBR and the Implementation of pH-Based Aeration Control.

    Science.gov (United States)

    Klaus, Stephanie; Baumler, Rick; Rutherford, Bob; Thesing, Glenn; Zhao, Hong; Bott, Charles

    2017-06-01

      The single-stage deammonification moving bed biofilm reactor (MBBR) is a process for treating high strength nitrogen waste streams. In this process, partial nitritation and anaerobic ammonia oxidation (anammox) occur simultaneously within a biofilm attached to plastic carriers. An existing tank at the James River Treatment Plant (76 ML/d) in Newport News, Virginia was modified to install a sidestream deammonification MBBR process. This was the second sidestream deammonification process in North America and the first MBBR type installation. After 4 months the process achieved greater than 85% ammonia removal at the design loading rate of 2.4 g /m2·d (256 kg /d) signaling the end of startup. Based on observations during startup and process optimization phases, a novel pH-based control system was developed that maximizes ammonium removal and results in stable aeration and effluent alkalinity.

  13. Statistical Theory of Normal Grain Growth Revisited

    International Nuclear Information System (INIS)

    Gadomski, A.; Luczka, J.

    2002-01-01

    In this paper, we discuss three physically relevant problems concerning the normal grain growth process. These are: Infinite vs finite size of the system under study (a step towards more realistic modeling); conditions of fine-grained structure formation, with possible applications to thin films and biomembranes, and interesting relations to superplasticity of materials; approach to log-normality, an ubiquitous natural phenomenon, frequently reported in literature. It turns out that all three important points mentioned are possible to be included in a Mulheran-Harding type behavior of evolving grains-containing systems that we have studied previously. (author)

  14. Grain refinement control in TIG arc welding

    Science.gov (United States)

    Iceland, W. F.; Whiffen, E. L. (Inventor)

    1975-01-01

    A method for controlling grain size and weld puddle agitation in a tungsten electrode inert gas welding system to produce fine, even grain size and distribution is disclosed. In the method the frequency of dc welding voltage pulses supplied to the welding electrode is varied over a preselected frequency range and the arc gas voltage is monitored. At some frequency in the preselected range the arc gas voltage will pass through a maximum. By maintaining the operating frequency of the system at this value, maximum weld puddle agitation and fine grain structure are produced.

  15. Experimental evaluation of the oxygen transfer in bubble aeration systems. Full scale experiences in lengthened activated sludge reactors; Valutazione sperimantale del trasferimento dell'ossigeno in sistemi di aerazione a bolle fini. Esperienza a scala reale in reattori a fanghi attivi a forma allungata

    Energy Technology Data Exchange (ETDEWEB)

    Andreottola, G.; Ragazzi, M.; Tatano, F. [Trento Univ. (Italy). Dipt. di Ingegneria Civile. Ist. di Ingegneria Sanitaria-Ambientale

    1999-06-01

    The results of some full-scale oxygen transfer measurements conduced at the lengthened activate sludge tanks of two WWTPs of Trentino Region, are presented and discussed. As far at the tests in clean water are concerned, the non-liner regression method seems non accurate; important conclusion on the correlation between oxygen transfer process and typical parameters (i.e., fine-bubble diffusers, specific air flux) are derived. As far as the test in the wastewater is concerned, an increase of {alpha}-value from the inlet to the end of aeration tanks has been observed in the 'Andalo' WWTP. [Italian] Vengono presentati e discussi i risultati di alcune prove di ossigenazione a scala reale condotte presso due impianti di depurazione del Trentino. Con riferimento alle prove di acqua pulita, il metodo di elaborazione dati tramite regressione non lineare ai minimi quadrati e' apparso piu' preciso; inoltre si sono dedotti importanti considerazioni sulla correlazione tra processo di trasferimento dell'ossigeno e alcuni parametri di influenza (densita' diffusori, profondita' d'acqua, fouling diffusori, portata d'aria). La prova in liquame condotta presso l'impianto 'Andalo', ha rilevato un andamento crescente del fattore di correzione {alpha} verso 'in-out' di vasca.

  16. FAM-FMC system as an alternative element of the software used in a grain and flour milling enterprise

    Directory of Open Access Journals (Sweden)

    Szymon T. Dziuba

    2014-10-01

    Full Text Available Processes of computerization have become a standard in contemporary production plant methods. Implementation of these processes is aimed at limiting activities which had up to that point, been performed manually. Dedicated computer systems are being developed according to the requirements imposed on concrete enterprises with consideration of their manufacturing specificity. These adjusted systems facilitate and accelerate production and improve its performance while helping maintain a consistent level of quality for the final product. Flour mill laboratories use the software to record and facilitate computation of the measurements. This study is aimed at analysing the potential for implementation of the FAM-FMC system as a tool to support production of flour with parameters that match specific customer expectations.

  17. Alcohol production from sterilized and non-sterilized molasses by Saccharomyces cerevisiae immobilized on brewer's spent grains in two types of continuous bioreactor systems

    International Nuclear Information System (INIS)

    Kopsahelis, Nikolaos; Bosnea, Loulouda; Bekatorou, Argyro; Tzia, Constantina; Kanellaki, Maria

    2012-01-01

    In this work an integrated cost effective system for continuous alcoholic fermentation of a cheap raw material (molasses) is described, involving yeast immobilized by a simple method on brewer's spent grains, able to ferment in the temperature range 30–40 °C, and two types of bioreactors, a Multistage Fixed Bed Tower (MFBT) and a Packed Bed reactor (PB). The MFBT bioreactor gave better results regarding ethanol concentration, productivity and conversion. Furthermore, the use of sterilized and non-sterilized molasses, fed in two similar MFBT bioreactors, showed that ethanol concentration (kg m −3 ) was significantly (p −3 at 35 °C and 44.2–48.2 kg m −3 at 40 °C), compared to sterilized molasses, where ethanol concentration ranged from 35.6 to 46.6 kg m −3 at 35 °C and 30.8–44.2 kg m −3 at 40 °C. During 32 days of continuous operation using non-sterilized molasses no contamination was observed. Industrialization of the proposed system seems to have a potential, mainly due to its high fermentation efficiency and the obtained high operational stability. -- Highlights: ► An integrated cost effective system for continuous alcoholic fermentation. ► Efficient conversion of non-sterilized molasses to ethanol. ► No need for additional treatments to prevent contamination. ► Results showed high fermentation efficiency and high operational stability.

  18. Composite wastewater treatment by aerated electrocoagulation and modified peroxi-coagulation processes.

    Science.gov (United States)

    Kumar, Abhijeet; Nidheesh, P V; Suresh Kumar, M

    2018-08-01

    Treatment of composite wastewater generating from the industrial estates is a great challenge. The present study examines the applicability of aerated electrocoagulation and modified peroxi-coagulation processes for removing color and COD from composite wastewater. Iron plates were used as anodes and cathodes in both electrochemical processes and experiments were carried out in a working volume of 2 L. Aeration enhanced the efficiency of electrocoagulation process significantly. More than 50% of COD and 60% of color were removed after 1 h of electrocoagulation process operated at pH 3 and applied voltage of 1 V. Efficiency of the modified peroxi-coagulation process was significantly higher than that of aerated electrocoagulation. COD and color removal efficiencies of the modified peroxi-coagulation process were found as 77.7% and 97%, respectively after 1 h of electrolysis operated at 1 V, solution pH 3 and 50 mM hydrogen peroxide addition. This improved efficiency of modified peroxi-coagulation compared to aerated electrocoagulation is mainly due to the attack of in-situ generated hydroxyl radicals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Investigation of aeration rate on Uranium bio leaching in internal airlift bioreactor

    International Nuclear Information System (INIS)

    Zolala, M. R.; Safdari, S. J.; Haghighi Asl, A.; Rashidi, A.

    2012-01-01

    Uranium is leached from the uranium ore of the second anomaly of Saghand by the Acidithiobacillus ferroxidans bacteria in an internal airlift bio-reactor. This study has been made to find the effect of aeration rate as well as its optimal value. The experiments have been carried out at 4 aeration rates to find the best recovery results in the least possible time duration. The results showed that the most percentage of the uranium recovery is in the superficial gas velocity of 0.010 m/s. The recovery at this aeration rate has an efficiency of more than 95 p ercent i n 11 days. Also, the best range for aeration study in the airlift bio-reactor is calculated with a minimum value of 0.0065 m/s which is the critical value of the uranium particle suspension as well as the maximum value of 0.015 m/s. The stress on the bacteria increases the recovery time process in velocities of more than 0.015 m/s.

  20. Optimization and control of the activated sludge process by adaptation of aeration tank volume

    Energy Technology Data Exchange (ETDEWEB)

    Staud, R

    1982-04-01

    Purpose of full scale studies conducted at a municipal wastewater treatment plant at Schwetzingen, Germany, was to optimize the activated sludge treatment process. Influent loading fluctuations were answered by operating a distinct number of the four parallel treatment plant units (aeration tank/clarifier) present. During the intermediate period of time the aerators were also switched off, and the activated sludge was kept anaerobically. The purpose of this particular technique is to equalize the nutrient supply of the microorganisms to gain an improved metabolic potential, as well as to decrease the energy demand for aeration. A mathematical algorithm for process control was developed to accomplish this technique. Initial parameters are inflow rate, MLSS and plateau-BOD to evaluate the substrate concentration. The results of the full scale studies prove the practicability of this concept. Equalization of the F:M ratio fluctuations leads to an increase of the average substrate loading but not to any decrease in the overall process efficiency. Anaerobic sludge storage did not cause any problem. Odor problems could be handled by limitation of the storage period to 24 hours. As far as energy consumption for aeration is concerned a decrease by 47% percent could be achieved.

  1. Effect of micro-aeration on anaerobic digestion of primary sludge under septic tank conditions.

    Science.gov (United States)

    Diak, James; Örmeci, Banu; Kennedy, Kevin J

    2013-04-01

    Micro-aeration, which refers to the addition of very small amounts of air, is a simple technology that can potentially be incorporated in septic tanks to improve the digestion performance. The purpose of this study was to investigate and compare the effects of micro-aeration on anaerobic digestion of primary sludge under septic tank conditions. 1.6 L batch reactor experiments were carried out in duplicate using raw primary sludge, with 4.1 % total solids, and diluted primary sludge, with 2.1 % total solids. Reactors were operated for 5 weeks at room temperature to simulate septic tank conditions. Micro-aeration rate of 0.00156 vvm effectively solubilised chemical oxygen demand (COD) and improved the subsequent degradation of COD. Micro-aeration also increased the generation of ammonia and soluble proteins, but did not improve the reduction in total and volatile solids, or the reduction in carbohydrates. Experiments using diluted sludge samples showed similar trends as the experiments with raw sludge, which suggest that initial solids concentration did not have a significant effect on the degradation of primary sludge under septic tank conditions.

  2. Scanning electron microscopy of autoclaved aerated concrete with supplementary raw materials

    NARCIS (Netherlands)

    Straub, C.; Florea, M.V.A.; Brouwers, H.J.H.; Nisperos, Arturo G.; Pöllmann, Herbert

    Microscopy is a key analysis technology for the understanding of the achieved properties of building materials. In the case of Autoclaved Aerated Concrete (AAC) it is even more important due to the phase transformation during the hydrothermal hardening. The incorporation of substitution materials in

  3. EVALUATING THE COSTS OF PACKED-TOWER AERATION AND GAC FOR CONTROLLING SELECTED ORGANICS

    Science.gov (United States)

    This article focuses on a preliminary cost analysis that compares liquid-phase granular activated carbon (GAC) treatment with packed-tower aeration (PTA) treatment, with and without air emissions control. The sensitivity of cost to design and operating variables is also discussed...

  4. Circulation induced by diffused aeration in a shallow lake | Toné ...

    African Journals Online (AJOL)

    Field surveys were carried out to investigate the surface jet flows and the resulting circulation patterns generated by diffused aeration in a shallow lake. In conrast to previous studies, the experimental conditions included point-source bubble plumes with very high air flow rates (100–400 L/min) relative to the shallow water ...

  5. Sodium carbonate activated slag as cement replacement in autoclaved aerated concrete

    NARCIS (Netherlands)

    Yuan, B.; Straub, C.; Segers, S.; Yu, Q.; Brouwers, H.J.H.

    2017-01-01

    This paper aims to study the suitability of fully replacing cement by sodium carbonate activated slag in producing autoclaved aerated concrete (AAC). The material properties of the product are characterized in terms of green strength development, mechanical properties, pore related properties such

  6. Feasibility study of a V-shaped pipe for passive aeration composting.

    Science.gov (United States)

    Ogunwande, Gbolabo A

    2011-03-01

    A V-shaped (Vs) pipe was improvised for composting of chicken litter in passive aeration piles. Three piles, equipped with horizontal (Ho), vertical (Ve) and Vs pipes were set up. The three treatments were replicated thrice. The effects of the aeration pipe on the physico-chemical properties of chicken litter and air distribution within the composting piles were investigated during composting. The properties monitored were temperature, pH, electrical conductivity, moisture content, total carbon, total nitrogen, total phosphorus and carbon-to-nitrogen ratio. Moisture level in the piles was replenished fortnightly to 60% during composting. The results of the study showed that all the piles attained the optimum temperature range (40-65°C) for effective composting and satisfied the requirements for sanitation. The non-significant (p > 0.05) temperature difference within the piles with Ve and Vs pipes indicated that these pipes were effective for uniform air distribution within the pile. The aeration pipe had significant (p ≤ 0.05) effect on pile temperature, pre-replenishment moisture content, pH and total phosphorus. In conclusion, the study showed that the Vs pipe is feasible and effective for passive aeration composting.

  7. Physio-Microstructural Properties of Aerated Cement Slurry for Lightweight Structures

    Science.gov (United States)

    Salem, Talal; Hamadna, Sameer; Darsanasiri, A. G. N. D.; Soroushian, Parviz; Balchandra, Anagi; Al-Chaar, Ghassan

    2018-01-01

    Cementitious composites, including ferrocement and continuous fiber reinforced cement, are increasingly considered for building construction and repair. One alternative in processing of these composites is to infiltrate the reinforcement (continuous fibers or chicken mesh) with a flowable cementitious slurry. The relatively high density of cementitious binders, when compared with polymeric binders, are a setback in efforts to introduce cementitious composites as lower-cost, fire-resistant, and durable alternatives to polymer composites. Aeration of the slurry is an effective means of reducing the density of cementitious composites. This approach, however, compromises the mechanical properties of cementitious binders. An experimental program was undertaken in order to assess the potential for production of aerated slurry with a desired balance of density, mechanical performance, and barrier qualities. The potential for nondestructive monitoring of strength development in aerated cementitious slurry was also investigated. This research produced aerated slurries with densities as low as 0.9 g/cm3 with viable mechanical and barrier qualities for production of composites. The microstructure of these composites was also investigated. PMID:29649163

  8. Application of glass recycling by-products in Autoclaved Aerated Concrete

    NARCIS (Netherlands)

    Straub, Chr.; Florea, M.V.A.; Brouwers, H.J.H.; Schmidt, Wolfram; Msinjili, Nsesheye Susan

    Autoclaved Aerated Concrete (AAC) is a construction material with a large range of applications. In order to generate more sustainable materials, the possibility of the incorporation of by-products and left-over-materials from various processes is investigated. The focus of this research is the

  9. Fe(II) oxidation kinetics and Fe hydroxyphosphate precipitation upon aeration of anaerobic (ground)water

    NARCIS (Netherlands)

    van der Grift, B.; Griffioen, J.; Behrends, T.; Wassen, M.J.; Schot, P.P.; Osté, Leonard

    2015-01-01

    Exfiltration of anaerobic Fe-rich groundwater into surface water plays an important role in controlling the transport of phosphate (P) from agricultural areas to the sea. Previous laboratory and field studies showed that Fe(II) oxidation upon aeration leads to effective immobilization of dissolved P

  10. Kansas Agents Study Grain Marketing

    Science.gov (United States)

    Schoeff, Robert W.

    1973-01-01

    Author is an extension specialist in feed and grain marketing for Kansas State University. He describes a tour set up to educate members of the Kansas Grain and Feed Dealers' Association in the area of grain marketing and exporting. (GB)

  11. Field study of nitrous oxide production with in situ aeration in a closed landfill site.

    Science.gov (United States)

    Nag, Mitali; Shimaoka, Takayuki; Nakayama, Hirofumi; Komiya, Teppei; Xiaoli, Chai

    2016-03-01

    Nitrous oxide (N(2)O) has gained considerable attention as a contributor to global warming and depilation of stratospheric ozone layer. Landfill is one of the high emitters of greenhouse gas such as methane and N(2)O during the biodegradation of solid waste. Landfill aeration has been attracted increasing attention worldwide for fast, controlled and sustainable conversion of landfills into a biological stabilized condition, however landfill aeration impel N(2)O emission with ammonia removal. N(2)O originates from the biodegradation, or the combustion of nitrogen-containing solid waste during the microbial process of nitrification and denitrification. During these two processes, formation of N(2)O as a by-product from nitrification, or as an intermediate product of denitrification. In this study, air was injected into a closed landfill site and investigated the major N(2)O production factors and correlations established between them. The in-situ aeration experiment was carried out by three sets of gas collection pipes along with temperature probes were installed at three different distances of one, two and three meter away from the aeration point; named points A-C, respectively. Each set of pipes consisted of three different pipes at three different depths of 0.0, 0.75 and 1.5 m from the bottom of the cover soil. Landfill gases composition was monitored weekly and gas samples were collected for analysis of nitrous oxide concentrations. It was evaluated that temperatures within the range of 30-40°C with high oxygen content led to higher generation of nitrous oxide with high aeration rate. Lower O(2) content can infuse N(2)O production during nitrification and high O(2) inhibit denitrification which would affect N(2)O production. The findings provide insights concerning the production potentials of N(2)O in an aerated landfill that may help to minimize with appropriate control of the operational parameters and biological reactions of N turnover. Investigation of

  12. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suyun [Department of Environmental and Low-Carbon Science, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai (China); Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong); Selvam, Ammaiyappan [Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong); Wong, Jonathan W.C., E-mail: jwcwong@hkbu.edu.hk [Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region (Hong Kong)

    2014-02-15

    Highlights: • Effect of micro-aeration on acidogenesis and hydrolysis of food waste was investigated. • Micro-aeration at 258 L-air/kg TS/d increased the VFAs production 3-fold. • High aeration leads to loss of substrate through microbial biomass and respiration. • Optimum aeration increased methane recovery while high aeration intensity reduced methane yield. - Abstract: Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35 °C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21–27% and 38–64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH{sub 4}/g VS{sub added} in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO{sub 2} respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.

  13. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste

    International Nuclear Information System (INIS)

    Xu, Suyun; Selvam, Ammaiyappan; Wong, Jonathan W.C.

    2014-01-01

    Highlights: • Effect of micro-aeration on acidogenesis and hydrolysis of food waste was investigated. • Micro-aeration at 258 L-air/kg TS/d increased the VFAs production 3-fold. • High aeration leads to loss of substrate through microbial biomass and respiration. • Optimum aeration increased methane recovery while high aeration intensity reduced methane yield. - Abstract: Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35 °C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21–27% and 38–64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH 4 /g VS added in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO 2 respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste

  14. Whole Grains and Fiber

    Science.gov (United States)

    ... for Physical Activity in Children My Family Health Tree What's that you're drinking? Get Active with ... grains. When grocery shopping, an easy way to identify healthy food choices is to look for the ...

  15. 6 Grain Yield

    African Journals Online (AJOL)

    create a favourable environment for rice ... developing lines adaptable to many ... have stable, not too short crop duration with ..... Analysis of variance of the effect of site and season on maturity, grain yield and plant ..... and yield components.

  16. Spatiotemporal Aeration and Lung Injury Patterns Are Influenced by the First Inflation Strategy at Birth.

    Science.gov (United States)

    Tingay, David G; Rajapaksa, Anushi; Zonneveld, C Elroy; Black, Don; Perkins, Elizabeth J; Adler, Andy; Grychtol, Bartłomiej; Lavizzari, Anna; Frerichs, Inéz; Zahra, Valerie A; Davis, Peter G

    2016-02-01

    Ineffective aeration during the first inflations at birth creates regional aeration and ventilation defects, initiating injurious pathways. This study aimed to compare a sustained first inflation at birth or dynamic end-expiratory supported recruitment during tidal inflations against ventilation without intentional recruitment on gas exchange, lung mechanics, spatiotemporal regional aeration and tidal ventilation, and regional lung injury in preterm lambs. Lambs (127 ± 2 d gestation), instrumented at birth, were ventilated for 60 minutes from birth with either lung-protective positive pressure ventilation (control) or as per control after either an initial 30 seconds of 40 cm H2O sustained inflation (SI) or an initial stepwise end-expiratory pressure recruitment maneuver during tidal inflations (duration 180 s; open lung ventilation [OLV]). At study completion, molecular markers of lung injury were analyzed. The initial use of an OLV maneuver, but not SI, at birth resulted in improved lung compliance, oxygenation, end-expiratory lung volume, and reduced ventilatory needs compared with control, persisting throughout the study. These changes were due to more uniform inter- and intrasubject gravity-dependent spatiotemporal patterns of aeration (measured using electrical impedance tomography). Spatial distribution of tidal ventilation was more stable after either recruitment maneuver. All strategies caused regional lung injury patterns that mirrored associated regional volume states. Irrespective of strategy, spatiotemporal volume loss was consistently associated with up-regulation of early growth response-1 expression. Our results show that mechanical and molecular consequences of lung aeration at birth are not simply related to rapidity of fluid clearance; they are also related to spatiotemporal pressure-volume interactions within the lung during inflation and deflation.

  17. Numerical and experimental investigation of the self-inducing turbine aeration capacity

    International Nuclear Information System (INIS)

    Achouri, Ryma; Dhaouadi, Hatem; Mhiri, Hatem; Bournot, Philippe

    2014-01-01

    Highlights: • Numerical and experimental study of k L a coefficient of a self-inducing turbine. • Validation of experimental results. • Numerical study of k L a variation with the variation of impeller submersion and blade inclination. • Numerical study of the flow field and hydrodynamic parameters. - Abstract: Self-inducing turbines are a model of mixers that ensure the aeration of a fluid field without using a sparger and a surface aerator. Nevertheless, this type of turbines remain quite complicated in terms of behavior of the fluid within the tank, and its actual aeration capacity varies depending on the type of turbine used. The studied turbine is self-inducing and made of three blades and each blade contains five holes. In this work, we evaluated experimentally – using the technique of dynamic oxygenation and deoxygenating – the aeration capacity of our impeller by calculating the volumetric mass transfer coefficient k L a for various submergences and various inclination angles of the blade. This work was then validated by a numerical modeling using the commercial code Fluent, and the flow within the tank as well as the evolution of the hydrodynamic parameters was also studied. The simulation is steady state with a VOF multiphase model and the realizable k–ε turbulence model. We finally concluded that k L a decreases with the increase of the inclination angle and with the increase of the submergence of our turbine. We could also study the hydrodynamic parameters of the flow such as the power number, the aeration number and the shear rate

  18. Dating recent floodplain sediments in the Hawkesbury-Nepean River system, eastern Australia using single-grain quartz OSL

    DEFF Research Database (Denmark)

    Sim, Anna K.; Thomsen, Kristina Jørkov; Murray, K.J.

    2014-01-01

    Two fluvial sediment cores taken from a floodplain of the Hawkesbury-Nepean River system in the Sydney region, eastern Australia are dated using Optically Stimulated Luminescence (OSL) to provide a reliable chronology essential for the management and planning of water resources. Nine charcoal 14C...... in an average apparent age overestimation of ~200 years, which is significant for these samples, but negligible for sediments older than a few thousand years. The intention is that the chronology obtained in this study will be used in conjunction with a proxy flood record, derived from floodplain sediments...

  19. Ethanol production in an immobilized-cell column reactor: The effects of micro-aeration and dual feeds

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K

    1988-01-01

    Immobilized Saccharomyces cerevesiae cells adsorbed onto wood chips in a packed-bed bioreactor were used for ethanol fermentation from glucose solution. In aerobic and anaerobic batch experiments, an increase in initial glucose concentration resulted in a reduction of the specific growth rate, but no apparent glucose inhibition was found at initial glucose concentrations of ca <120 g/l. Since it is inevitable to use high substrate concentration to obtain high product concentration, experiments were performed in an immobilized-cell reactor (ICR) to examine any improvements achieved by a dual-feed mode over a continuous ICR system. The dual scheme can provide the same total amount of substrate while keeping the maximum substrate concentration to which the cells are exposed to about half of that in the single-feed case. In the dual-feed ICR, the ethanol production rate was 15% higher than that of the single-fed ICR. Experiments in skewed and vertical ICRs were performed to observe the difference in CO{sub 2} bubble removal; the bubbles were smoothly released in the skewed ICR compared to significant CO{sub 2} accumulation in the vertical ICR, and a biomass buildup on the wood surface was also observed. The experimental results indicate that trace amounts of dissolved oxygen stimulated fermentation rates, with one experiment showing a 31% improvement in ethanol productivity using aeration. At a controlled aeration rate, cells were observed to flocculate naturally onto the wood surface. Plugging of the void spaces, due to excess cell growth and intermittent CO{sub 2} holdup, was observed to begin at the base of the packed bed and progressed upward with time, thus undesirable channelling of liquid flow occurred. 200 refs., 76 figs., 21 tabs.

  20. Simultaneous improvement of waste gas purification and nitrogen removal using a novel aerated vertical flow constructed wetland.

    Science.gov (United States)

    Zhang, Xinwen; Hu, Zhen; Ngo, Huu Hao; Zhang, Jian; Guo, Wenshan; Liang, Shuang; Xie, Huijun

    2018-03-01

    Insufficient oxygen supply is identified as one of the major factors limiting organic pollutant and nitrogen (N) removal in constructed wetlands (CWs). This study designed a novel aerated vertical flow constructed wetland (VFCW) using waste gas from biological wastewater treatment systems to improve pollutant removal in CWs, its potential in purifying waste gas was also identified. Compared with unaerated VFCW, the introduction of waste gas significantly improved NH 4 + -N and TN removal efficiencies by 128.48 ± 3.13% and 59.09 ± 2.26%, respectively. Furthermore, the waste gas ingredients, including H 2 S, NH 3 , greenhouse gas (N 2 O) and microbial aerosols, were remarkably reduced after passing through the VFCW. The removal efficiencies of H 2 S, NH 3 and N 2 O were 77.78 ± 3.46%, 52.17 ± 2.53%, and 87.40 ± 3.89%, respectively. In addition, the bacterial and fungal aerosols in waste gas were effectively removed with removal efficiencies of 42.72 ± 3.21% and 47.89 ± 2.82%, respectively. Microbial analysis results revealed that the high microbial community abundance in the VFCW, caused by the introduction of waste gas from the sequencing batch reactor (SBR), led to its optimized nitrogen transformation processes. These results suggested that the VFCW intermittently aerated with waste gas may have potential application for purifying wastewater treatment plant effluent and waste gas, simultaneously. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Spatio-temporal changes in water quality in an eutrophic lake with artificial aeration

    Directory of Open Access Journals (Sweden)

    Ferral Anabella

    2017-12-01

    Full Text Available In this work we present novel results concerning water quality changes in an eutrophic water body connected with an artificial aeration system installed in it. Sixty one in-situ and laboratory measurements of biogeochemical variables were recorded monthly between October 2008 and June 2011 to evaluate temporal and spatial changes in San Roque reservoir (Argentina. t-Student mean difference tests, carried out over the whole period, showed with 95% confidence that a monitoring point located at the centre of the water body is representative of the chemical behaviour of the reservoir. Thermal stratification was observed in all sampling sites in the summer, but the frequency of these episodes was markedly lower in bubbling zones. Mean chlorophyll-a concentrations were 58.9 μg·dm−3 and 117.0 μg·dm−3 in the absence and in the presence of thermocline respectively. According to the t-Student test, this difference was significant, with p < 0.001. Phosphate release from sediments was corroborated under hypoxia conditions. ANOVA one way analysis did not show significant spatial differences for any variable. Mean normalize spatial index (MENSI was developed to compare data from different regions affected by high temporal variability. It proved to be useful to quantify spatial differences. Structure analysis of temporal series was used to scrutinize both chemical and spatial association successfully. Three chemically different zones were determined in the reservoir. This study demonstrated that spatial comparisons by means of marginal statistics may not be an adequate method when high temporal variation is present. In such a case, temporal structure analysis has to be considered.

  2. Computerized pattern recognition used for grain counting in high resolution autoradiographs with low grain densities

    NARCIS (Netherlands)

    Schellart, N. A.; Zweijpfenning, R. C.; van Marle, J.; Huijsmans, D. P.

    1986-01-01

    Using a video-image system coupled to a minicomputer with commercial image handling software, autoradiographic grains displayed in dark-field are counted with a fast (ca. 3.5 min for 120,000 microns 2) and reliable (false scores less than 5%) grain-recognizing FORTRAN program executed in the users

  3. Comparing the effects of feeding a grain- or a fish meal-based diet on water quality, waste production, and rainbow trout Oncorhynchus mykiss performance within low exchange water recirculating aquaculture systems

    Science.gov (United States)

    Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...

  4. Impact fracture experiments simulating interstellar grain-grain collisions

    Science.gov (United States)

    Freund, Friedemann; Chang, Sherwood; Dickinson, J. Thomas

    1990-01-01

    Oxide and silicate grains condensing during the early phases of the formation of the solar system or in the outflow of stars are exposed to high partial pressures of the low-z elements H, C, N and O and their simple gaseous compounds. Though refractory minerals are nominally anhydrous and non-carbonate, if they crystallize in the presence of H2O, N2 and CO or CO2 gases, they dissolve traces of the gaseous components. The question arises: How does the presence of dissolved gases or gas components manifest itself when grain-grain collisions occur. What are the gases emitted when grains are shattered during a collision event. Researchers report on fracture experiments in ultrahigh vacuum (UHV, approximately less than 10 to the -8th power mbar) designed to measure (by means of a quadrupole mass spectrometer, QMS, with microns to ms time resolution) the emission of gases and vapors during and after impact (up to 1.5 sec). Two terrestrial materials were chosen which represent structural and compositional extremes: olivine (San Carlos, AZ), a densely packed Mg-Fe(2+) silicate from the upper mantle, available as 6 to 12 mm single crystals, and obsidian (Oregon), a structurally open, alkaline-SiO2-rich volcanic glass. In the olivine crystals OH- groups have been identified spectroscopically, as well as H2 molecules. Obsidian is a water-rich glass containing OH- besides H2O molecules. Olivine from the mantle often contains CO2, either as CO2-rich fluid in fluid inclusions or structurally dissolved or both. By analogy to synthetic glasses CO2 in the obsidian may be present in form of CO2 molecules in voids of molecular dimensions, or as carbonate anions, CO3(2-). No organic molecules have been detected spectroscopically in either material. Results indicate that refractory oxide/silicates which contain dissolved traces of the H2O and CO/CO2 components but no spectroscopically detectable traces of organics may release complex H-C-O (possibly H-C-N-O) molecules upon fracture

  5. Drought stress variability in ancient Near Eastern agricultural systems evidenced by δ13C in barley grain.

    Science.gov (United States)

    Riehl, Simone; Pustovoytov, Konstantin E; Weippert, Heike; Klett, Stefan; Hole, Frank

    2014-08-26

    The collapse and resilience of political systems in the ancient Near East and their relationship with agricultural development have been of wide interest in archaeology and anthropology. Despite attempts to link the archaeological evidence to local paleoclimate data, the precise role of environmental conditions in ancient agricultural production remains poorly understood. Recently, stable isotope analysis has been used for reconstructing site-specific ancient growing conditions for crop species in semiarid and arid landscapes. To open the discussion of the role of regional diversity in past agricultural production as a factor in societal development, we present 1.037 new stable carbon isotope measurements from 33 archaeological sites and modern fields in the geographic area of the Fertile Crescent, spanning the Aceramic Neolithic [10,000 calibrated years (cal) B.C.] to the later Iron Age (500 cal B.C.), alongside modern data from 13 locations. Our data show that drought stress was an issue in many agricultural settlements in the ancient Near East, particularly in correlation with the major Holocene climatic fluctuations, but its regional impact was diverse and influenced by geographic factors. Although cereals growing in the coastal areas of the northern Levant were relatively unaffected by Holocene climatic fluctuations, farmers of regions further inland had to apply irrigation to cope with increased water stress. However, inland agricultural strategies showed a high degree of variability. Our findings suggest that regional differences in climatic effects led to diversified strategies in ancient subsistence and economy even within spatially limited cultural units.

  6. Film grain synthesis and its application to re-graining

    Science.gov (United States)

    Schallauer, Peter; Mörzinger, Roland

    2006-01-01

    Digital film restoration and special effects compositing require more and more automatic procedures for movie regraining. Missing or inhomogeneous grain decreases perceived quality. For the purpose of grain synthesis an existing texture synthesis algorithm has been evaluated and optimized. We show that this algorithm can produce synthetic grain which is perceptually similar to a given grain template, which has high spatial and temporal variation and which can be applied to multi-spectral images. Furthermore a re-grain application framework is proposed, which synthesises based on an input grain template artificial grain and composites this together with the original image content. Due to its modular approach this framework supports manual as well as automatic re-graining applications. Two example applications are presented, one for re-graining an entire movie and one for fully automatic re-graining of image regions produced by restoration algorithms. Low computational cost of the proposed algorithms allows application in industrial grade software.

  7. Bedload transport measurements with impact plate geophones in two Austrian mountain streams (Fischbach and Ruetz): system calibration, grain size estimation, and environmental signal pick-up

    Science.gov (United States)

    Rickenmann, Dieter; Fritschi, Bruno

    2017-10-01

    The Swiss plate geophone system is a bedload surrogate measuring technique that has been installed in more than 20 streams, primarily in the European Alps. Here we report about calibration measurements performed in two mountain streams in Austria. The Fischbach and Ruetz gravel-bed streams are characterized by important runoff and bedload transport during the snowmelt season. A total of 31 (Fischbach) and 21 (Ruetz) direct bedload samples were obtained during a 6-year period. Using the number of geophone impulses and total transported bedload mass for each measurement to derive a calibration function results in a strong linear relation for the Fischbach, whereas there is only a poor linear calibration relation for the Ruetz measurements. Instead, using geophone impulse rates and bedload transport rates indicates that two power law relations best represent the Fischbach data, depending on transport intensity; for lower transport intensities, the same power law relation is also in reasonable agreement with the Ruetz data. These results are compared with data and findings from other field sites and flume studies. We further show that the observed coarsening of the grain size distribution with increasing bedload flux can be qualitatively reproduced from the geophone signal, when using the impulse counts along with amplitude information. Finally, we discuss implausible geophone impulse counts that were recorded during periods with smaller discharges without any bedload transport, and that are likely caused by vehicle movement very near to the measuring sites.

  8. Determination of the Removal Efficiency of Linear Alkyl Benzene Sulphonate Acids (LAS in Fixed Bed Aeration Tank and Conventional Activated Sludge

    Directory of Open Access Journals (Sweden)

    Asghar Ebrahimi

    2011-03-01

    Full Text Available Linear Alkyl Benzene Sulphonate Acids (LAS are one of the anionic surfactants that are produced and used in large quantities in different countries and find their way into the natural environment through sewer systems. These compounds may potentially cause environmental hazards in such surface waters as rivers. It is, therefore, necessary to remove as much of these compounds as possible by biological processes in wastewater treatment plants. For this purpose, four parallel biological reactors were constructed that used the conventional activated sludge and aeration tanks with fixed bed on the bench scale in order to evaluate the removal efficiency of LAS. The reactors were operated under conditions similar to domestic wastewater treatment plants. Parameters of interest were measured according to standard methods and ANOVA and T-test were used for the statistical analysis of the data. The results showed that aeration tanks with fixed beds yielded higher values of LAS and COD removal and air consumption compared to the conventional activated sludge system. It was shown that the two systems studied achieved LAS removal efficiencies of 96% and 94% for an influent LAS concentration of 5 mg/L. Further, it was found that the effluents from both systems satisfied water quality standards for discharge into surface waters (

  9. Grain boundary structure and properties

    International Nuclear Information System (INIS)

    Balluffi, R.W.

    1979-01-01

    An attempt is made to distinguish those fundamental aspects of grain boundaries which should be relevant to the problem of the time dependent fracture of high temperature structural materials. These include the basic phenomena which are thought to be associated with cavitation and cracking at grain boundaries during service and with the more general microstructural changes which occur during both processing and service. A very brief discussion of the current state of our knowledge of these fundamentals is given. Included are the following: (1) structure of ideal perfect boundaries; (2) defect structure of grain boundaries; (3) diffusion at grain boundaries; (4) grain boundaries as sources/sinks for point defects; (5) grain boundary migration; (6) dislocation phenomena at grain boundaries; (7) atomic bonding and cohesion at grain boundaries; (8) non-equilibrium properties of grain boundaries; and (9) techniques for studying grain boundaries

  10. Radiation disinfestation of grain

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-10-15

    A panel was convened by the International Atomic Energy Agency to consider ways of applying radiation to grain handling and insect control, and to make recommendations on the advisability and nature of any future action in this field. Among other subjects, the panel discussed the use of electron accelerators and gamma radiation for grain disinfestation as well as problems of radiation entomology and wholesomeness of irradiated grain. After reviewing the present state of knowledge regarding radiation disinfestation of grain, the experts agreed that pilot plant operations be initiated as soon as practicable in order to evaluate the use of irradiation plants under practical conditions in their entomological, engineering and economic aspects. They recommended that research effort be directed towards solving certain fundamental problems related to the proposed pilot plant projects; such as rapid methods for differentiation between sterile insects and normal ones; study of the metabolism of irradiated immature stages of insects in relation to the heating of treated grain; research into possible induction of radiation resistance; irradiation susceptibility of insects which show resistance to conventional insecticides; and study of methods of sensitizing insects to irradiation damage. It was also pointed out that the distribution of irradiated food for human consumption was controlled in most countries under present legislative procedures, and no country had yet approved radiation treatment of cereals. The experts recommended that countries in a position to submit evidence to their appropriate authorities regarding the wholesomeness of irradiated cereals should be encouraged to do so as soon as possible. Regarding the engineering aspects of irradiation pilot plant projects, the experts noted that the process could be automated and operated safely. Electron accelerators and cobalt sources could be used for all the throughput rates utilized in most conventional grain

  11. Radiation disinfestation of grain

    International Nuclear Information System (INIS)

    1962-01-01

    A panel was convened by the International Atomic Energy Agency to consider ways of applying radiation to grain handling and insect control, and to make recommendations on the advisability and nature of any future action in this field. Among other subjects, the panel discussed the use of electron accelerators and gamma radiation for grain disinfestation as well as problems of radiation entomology and wholesomeness of irradiated grain. After reviewing the present state of knowledge regarding radiation disinfestation of grain, the experts agreed that pilot plant operations be initiated as soon as practicable in order to evaluate the use of irradiation plants under practical conditions in their entomological, engineering and economic aspects. They recommended that research effort be directed towards solving certain fundamental problems related to the proposed pilot plant projects; such as rapid methods for differentiation between sterile insects and normal ones; study of the metabolism of irradiated immature stages of insects in relation to the heating of treated grain; research into possible induction of radiation resistance; irradiation susceptibility of insects which show resistance to conventional insecticides; and study of methods of sensitizing insects to irradiation damage. It was also pointed out that the distribution of irradiated food for human consumption was controlled in most countries under present legislative procedures, and no country had yet approved radiation treatment of cereals. The experts recommended that countries in a position to submit evidence to their appropriate authorities regarding the wholesomeness of irradiated cereals should be encouraged to do so as soon as possible. Regarding the engineering aspects of irradiation pilot plant projects, the experts noted that the process could be automated and operated safely. Electron accelerators and cobalt sources could be used for all the throughput rates utilized in most conventional grain

  12. Spectro-Polarimetry of Fine-Grained Ice and Dust Surfaces Measured in the Laboratory to Study Solar System Objects and Beyond

    Science.gov (United States)

    Poch, O.; Cerubini, R.; Pommerol, A.; Thomas, N.; Schmid, H. M.; Potin, S.; Beck, P.; Schmitt, B.; Brissaud, O.; Carrasco, N.; Szopa, C.; Buch, A.

    2017-12-01

    The polarization of the light is very sensitive to the size, morphology, porosity and composition of the scattering particles. As a consequence, polarimetric observations could significantly complement observations performed in total light intensity, providing additional constraints to interpret remote sensing observations of Solar System and extra-solar objects. This presentation will focus on measurements performed in the laboratory on carefully characterized surface samples, providing reference data that can be used to test theoretical models and predict or interpret spectro-polarimetric observations. Using methods developed in the Laboratory for Outflow Studies of Sublimating Materials (LOSSy) at the University of Bern, we produce well-characterized and reproducible surfaces made of water ice particles having different grain sizes and porosities, as well as mineral/organic dusts, pure or mixed together, as analogues of planetary or small bodies surfaces. These surface samples are illuminated with a randomly polarized light source simulating the Sun. The polarization of their scattered light is measured at multiple phase angles and wavelengths, allowing to study the shape of the polarimetric phase curves and their spectral dependence, with two recently developed setups: The POLarimeter for Icy Samples (POLICES), at the University of Bern, allows the measurement of the weak polarization of ice surfaces from 400 to 800 nm, with direct application to icy satellites. Using a precision Stokes polarimeter, this setup is also used to study the spectral variations of circular polarization in the light scattered by biotic versus abiotic surfaces. The Spectrogonio radiometer with cHanging Angles for Detection Of Weak Signals (SHADOWS), at IPAG (University of Grenoble Alpes), measures linear polarization spectra from 0.35 to 5 μm in the light scattered by dark meteorite powders or icy samples, with application to primitive objects of the Solar System (asteroids, comets).

  13. Effect of light and aeration on the metamorphosis rate from nauplii to protozoea and larval quality of Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Hadja Radtke Nunes

    2010-06-01

    Full Text Available In order to determine the optimal ranges of the factors light intensity and aeration that reflect the best rate of metamorphosis from nauplii to the first protozoea stage of Litopenaeus vannamei, and also the highest quality of the larvae, two separate experiments were carried out. The nauplii were exposed to four different light intensities (0; 5,000; 10,000; and 15,000 lux and four aeration conditions (static, low, medium and strong. The data were subjected to one-way ANOVA (significance level of 5%, followed by Tukey test for comparison of means. There were no significant differences between the percentages of metamorphosis under the different conditions of light and aeration that were tested (P>0.05. However, the score of the quality of the larvae was significantly lower (P<0.05 for the condition of continuous darkness (0 lux and the treatment with low intensity of aeration compared to other treatments in both experiments.

  14. Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

    Science.gov (United States)

    Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa

    2014-01-01

    The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern. PMID:24696646

  15. Sequentially aerated membrane biofilm reactors for autotrophic nitrogen removal: microbial community composition and dynamics

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Franck, Stephanie; Gülay, Arda

    2014-01-01

    Membrane-aerated biofilm reactors performing autotrophic nitrogen removal can be successfully applied to treat concentrated nitrogen streams. However, their process performance is seriously hampered by the growth of nitrite oxidizing bacteria (NOB). In this work we document how sequential aeration...... (rich in oxygen) and AnAOB in regions neighbouring the liquid phase. Both communities were separated by a transition region potentially populated by denitrifying heterotrophic bacteria. AOB and AnAOB bacterial groups were more abundant and diverse than NOB, and dominated by the r......-strategists Nitrosomonas europaea and Ca. Brocadia anammoxidans, respectively. Taken together, the present work presents tools to better engineer, monitor and control the microbial communities that support robust, sustainable and efficient nitrogen removal....

  16. Mechanical properties of lightweight aerated concrete with different aluminium powder content

    Directory of Open Access Journals (Sweden)

    Shabbar Rana

    2017-01-01

    Full Text Available Aerated concrete is produced by introducing gas into a concrete, the amount dependent upon the requirements for strength. One method to achieve this is by using powdered aluminium which reacts with the calcium hydroxide produced upon hydration of the cement. The aim of the current study was to investigate the influence of the powder content on the mechanical properties of aerated concrete namely; compressive and flexural strengths, modulus of elasticity, density and porosity. The results indicated that an increase in aluminium content caused a decrease in the compressive and tensile strengths. It also produced a decrease in the modulus of elasticity. When the aluminium content increased, the density decreased and the porosity increased.

  17. THE INFLUENCE OF A HALLOYSITE ADDITIVE ON THE PERFORMANCE OF AUTOCLAVED AERATED CONCRETE

    Directory of Open Access Journals (Sweden)

    Z. Owsiak

    2015-03-01

    Full Text Available This paper presents the results from the tests of autoclaved aerated concrete with halloysite as a cement additive. Good pozzolanic properties make it a suitable material to be used as a partial replacement of a portion of cement. Basic physical and mechanical properties of the composites with various mineral content are discussed. The compressive strength test results indicate an increase in strength of the AAC containing 2.5 % and 5 % halloysite relative to the reference specimen. Thermal conductivity and density values remained at the same level. Observations of the microstructure in the scanning electron microscope confirmed the results from the XRD tests. Anhydrite was observed in addition to tobermorite. The results from the tests of the autoclaved aerated concretes in which halloysite was incorporated as 7.5 % and 10 % cement replacement showed an increase in compressive strength, density and thermal conductivity values.

  18. Sistemas de manejo de plantas daninhas no desenvolvimento e na produtividade da soja Burndown systems on growth and grain yield in soybeans in Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    Jamil Constantin

    2009-01-01

    glyphosate occurred within 48 hours prior to sowing. The trials were developed in 2003/2004 growing season, in six localities in Paraná State: Sertãozinho, Campo Mourão, Iretama, Pitanga, Boa Esperança, and Mamborê, in areas with high density of weeds preceding no-till soybean sowing. Evaluations related to weed control and soybean development and grain yield were performed. MA burndown systems provided improved control of weeds after crop emergence. Soybean plants from AP areas were shorter, in comparison to ME, evidencing a delay in the shoot growth. Reduction of grain yield was verified for all localities when AP burndown system was adopted, with reductions between 15% and 50%.

  19. Autoclaved aerated concrete : shaping the evolution of residential construction in the United States.

    OpenAIRE

    Bukoski, Steven C.

    1998-01-01

    CIVINS (Civilian Institutions) Thesis document Precast Autoclaved Aerated Concrete (AAC) is a proven construction material used in Europe for over 70 years. Introduced to the United States in 1990, construction thus far is limited to commercial and custom borne applications. Premium benefits include energy efficiency and resistance to natural disaster and pests. Despite being the leading residential construction material in Europe and Japan, lumber is the leading material of choice in the ...

  20. Temperature control of paddy bulk storage with aeration-thermosyphon heat pipe

    International Nuclear Information System (INIS)

    Dussadee, Natthawud; Punsaensri, Tammasak; Kiatsiriroat, Tanongkiat

    2007-01-01

    A technology of an aeration-thermosyphon heat pipe is developed for controlling paddy temperature in a paddy bulk silo. A prototype of paddy bulk storage of 1000 kg has a set of copper tubes with steel fins embedded in the paddy bed. The total heat transfer area of the tubes with fins is 16 m 2 . The tubes act as the evaporator of a thermosyphon heat pipe and absorb heat resulting from the paddy respiration. The thermosyphon has a total condenser area of 12.2 m 2 that is exposed to ambient air. At the bottom of the silo, ambient air is fed upward through the paddy bed for the aeration. The initial moisture content of the paddy is around 12.8% wet basis. A mathematical model to predict the paddy bed temperature in the silo with the hybrid aeration-thermosyphon is developed, and the results agree very well with the experimental data. The operating period of its blower could be found from the simulation. The blower is on when the paddy bed temperature, T b , is over or equal to 28 deg. C and the difference temperature between the bed and the ambient, T d , is over or equal to 1 deg. C. The appropriate evaporator area should be over 8 m 2 . At the area of 8 m 2 , the operation time of the blower is 8-9% of the annual period compared with 30-40% for normal aeration alone. The monthly paddy bed temperature could be maintained between 24 and 27 deg. C under the climate of Chiang Mai, Thailand

  1. Effect of aeration on the fermentative activity of Saccharomyces cerevisiae cultured in apple juice

    OpenAIRE

    Estela-Escalante, W.; Rychtera, M.; Melzoch, K.; Hatta-Sakoda, B.

    2012-01-01

    The influence of aeration on the fermentative activity of Saccharomyces cerevisiaeRTVE V 15-1-416 was studied in order to evaluate the synthesis of fermentation by-products. To achieve this, the strain was cultured in Erlenmeyer flasks and bioreactor containing sterilized and aroma removed apple juice. The chemical compounds produced during fermentations in shaken (200 min-¹) and static (without agitation) flasks and bioreactor, all in batch mode, were determined by GC and HPLC. The results s...

  2. Moniliformin in Norwegian grain

    NARCIS (Netherlands)

    Uhlig, S.; Torp, M.; Jarp, J.; Parich, A.; Gutleb, A.C.; Krska, R.

    2004-01-01

    Norwegian grain samples (73 oats, 75 barley, 83 wheat) from the 2000-02 growing seasons were examined for contamination with moniliformin, and the association between the fungal metabolite and the number of kernels infected with common Fusaria was investigated. Before quantification of moniliformin

  3. Effect of aerated concrete blockwork joints on the heat transfer performance uniformity

    Directory of Open Access Journals (Sweden)

    Pukhkal Viktor

    2018-01-01

    Full Text Available Analysis of data on the effect of joints of the aerated concrete blocks on the heat transfer uniformity of exterior walls was carried out. It was concluded, that the values of the heat transfer performance uniformity factor in the literature sources were obtained for the regular fragment of a wall construction by approximate addition of thermal conductivities. Heat flow patterns for the aerated concrete exterior walls amid different values of the thermal conductivity factors and design ambient air temperature of -26 °C were calculated with the use of “ELCUT” software for modelling of thermal patterns by finite element method. There were defined the values for the heat transfer performance uniformity factor, reduced total thermal resistance and heat-flux density for the exterior walls. The calculated values of the heat transfer performance uniformity factors, as a function of the coefficient of thermal conductivity of aerated concrete blocks, differ from the known data by a more rigorous thermal and physical substantiation.

  4. Properties of Agro-Industrial Aerated Concrete as Potential Thermal Insulation for Building

    Directory of Open Access Journals (Sweden)

    Aminudin Eeydzah

    2016-01-01

    Full Text Available The present paper is aiming to provide an actual state of the development of non autoclaved Agro-Industrial aerated concrete by using multiple ashes as improvement of thermal behavior for building. The feasibility of Agro-Industrial wastes as lightweight concrete by utilizing the Palm Oil Fuel Ash (POFA as binder replacement and bottom ash as fine aggregate was investigated in this paper. Portland cement, bottom ash, aluminum powder and lime (Ca(OH2 were used in this study. The POFA was used to replace Portland cement and Hydrated Lime at 0%, 5%, 10% and 15% by weight and aluminum powder was added at 0.75% dry weight in order to form bubbles. The compressive strength, water absorption, porosity and the thermal conductivity test were carried out after the concrete were water cured for 7 days and later being exposed to the air and water until 28days. The results show that the 20% replacements give the optimum strength of 7.143MPa and 30% give the best thermal conductivity with 0.48W/mK. Hence, this study aim, was to develop an agro-industrial aerated concrete good in insulation but having an optimum strength. Hence, it has been found that the more the percentage of POFA is added the lower the thermal conductivity since the pore structure is increasing and by the optimization done, 30% replacement has been chosen as the best mix design for Agro-Industrial Aerated Concrete.

  5. Relationship between respiratory quotient, nitrification, and nitrous oxide emissions in a forced aerated composting process

    Energy Technology Data Exchange (ETDEWEB)

    Tsutsui, Hirofumi, E-mail: jm-tsutsuih@kochi-u.ac.jp [Research and Education Faculty, Natural Sciences Cluster, Agriculture Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan); Japan Science and Technology Agency, CREST (Japan); Fujiwara, Taku [Research and Education Faculty, Natural Sciences Cluster, Agriculture Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan); Japan Science and Technology Agency, CREST (Japan); Inoue, Daisuke [Department of Health Science, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara-Minami, Kanagawa (Japan); Japan Science and Technology Agency, CREST (Japan); Ito, Ryusei [Department of Environmental Engineering, Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido (Japan); Japan Science and Technology Agency, CREST (Japan); Matsukawa, Kazutsugu [Research and Education Faculty, Multidisciplinary Science Cluster, Life and Environmental Medicine Science Unit, Kochi University, B200 Monobe, Nankoku, Kochi (Japan); Japan Science and Technology Agency, CREST (Japan); Funamizu, Naoyuki [Department of Environmental Engineering, Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido (Japan); Japan Science and Technology Agency, CREST (Japan)

    2015-08-15

    Highlights: • RQ can be an indicator of N{sub 2}O emission in forced aerated composting process. • Emission of N{sub 2}O with nitrification was observed with RQ decrease. • Mass balances demonstrated the RQ decrease was caused by nitrification. • Conversion ratio of oxidized ammonia and total N to N{sub 2}O were ∼2.7%. - Abstract: We assessed the relationship between respiratory quotient (RQ) and nitrification and nitrous oxide (N{sub 2}O) emission in forced aerated composting using lab-scale reactors. Relatively high RQ values from degradation of readily degradable organics initially occurred. RQ then stabilized at slightly lower values, then decreased. Continuous emission of N{sub 2}O was observed during the RQ decrease. Correlation between nitrification and N{sub 2}O emission shows that the latter was triggered by nitrification. Mass balances demonstrated that the O{sub 2} consumption of nitrification (∼24.8 mmol) was slightly higher than that of CO{sub 2} emission (∼20.0 mmol), indicating that the RQ decrease was caused by the occurrence of nitrification. Results indicate that RQ is a useful index, which not only reflects the bioavailability of organics but also predicts the occurrence of nitrification and N{sub 2}O emission in forced aerated composting.

  6. Delayed ultraviolet light-induced cessation of respiration by inadequate aeration of Escherichia coli

    International Nuclear Information System (INIS)

    Joshi, J.G.; Swenson, P.A.; Schenley, R.L.

    1977-01-01

    Inadequately aerated Escherichia coli B/r cultures did not shut their respiration off 60 min after ultraviolet light (52 J/m 2 at 254 nm) as they did when well supplied with oxygen. Since cessation of respiration is associated with cell death, the result suggested that oxygen toxicity by superoxide radicals generated by cell metabolism might be responsible for cell death. The specific activity of superoxide dismutase, which scavenges O 2 - radicals, increased twofold after 90 min of adequate aeration, but the specific activity of catalase remained constant. Respiration and viability of irradiated cells were affected not at all by the presence of superoxide dismutase and only slightly by the presence of catalase. Metal ions such as Mn 2+ and Fe 2+ , inducers of superoxide dismutase, had no effect on respiration and viability. When irradiated cells were incubated under N 2 for 90 min, the respiration, growth, and viability time-course responses were the same as for cells not exposed to anaerobiosis. We conclude that superoxide anions generated at the time of irradiation play no part in cessation of respiration and cell death and that inadequate aeration or anaerobiosis delays the ultraviolet light-induced synthesis of proteins responsible for the irreversible cessation of respiration

  7. Effects of Aeration Treatment on γ-Aminobutyric Acid Accumulation in Germinated Tartary Buckwheat (Fagopyrum tataricum

    Directory of Open Access Journals (Sweden)

    Yuanxin Guo

    2016-01-01

    Full Text Available To explore the optimum condition of γ-aminobutyric acid (GABA accumulation in germinated tartary buckwheat, effects of some factors including aeration treatment, physiological indexes, air flow rate, culture temperature, and pH value of cultivating solution under hypoxia on GABA in germinated tartary buckwheat were investigated. The results showed that the dark cultures with distilled water at 30°C, 2 days, and aeration stress with 1.0 L/min air flow rate at 30°C were optimal for GABA accumulation. Under these conditions, the predicted content of GABA was up to 371.98 μg/g DW. The analysis of correlation indicated that there was a significant correlation (P<0.01 between GABA accumulation and physiological indexes. Box-Behnken experimental analysis revealed that optimal conditions with aeration treatment for GABA accumulation in germinated tartary buckwheat were air flow rate of 1.04 L/min, culture temperature of 31.25°C, and a pH value of 4.21. Under these conditions, the GABA content was predicted as high as 386.20 μg/g DW, which was close to the measured value (379.00±9.30 μg/g DW. The variance analysis and validation test suggested that this established regression model could predict GABA accumulation in tartary buckwheat during germination.

  8. Greenhouse gas production and efficiency of planted and artificially aerated constructed wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Maltais-Landry, Gabriel [Departement des sciences biologiques, Universite de Montreal 90, rue Vincent-D' Indy, Montreal (Ciheam), H2V 2S9 (Canada); Institut de recherche en biologie vegetale, Universite de Montreal 4101, rue Sherbrooke Est, Montreal (Ciheam), H1X 2B2 (Canada)], E-mail: gabriel.maltais-landry@umontreal.ca; Maranger, Roxane [Departement des sciences biologiques, Universite de Montreal 90, rue Vincent-D' Indy, Montreal (Ciheam), H2V 2S9 (Canada)], E-mail: r.maranger@umontreal.ca; Brisson, Jacques [Departement des sciences biologiques, Universite de Montreal 90, rue Vincent-D' Indy, Montreal (Ciheam), H2V 2S9 (Canada); Institut de recherche en biologie vegetale, Universite de Montreal 4101, rue Sherbrooke Est, Montreal (Ciheam), H1X 2B2 (Canada)], E-mail: jacques.brisson@umontreal.ca; Chazarenc, Florent [Institut de recherche en biologie vegetale, Universite de Montreal 4101, rue Sherbrooke Est, Montreal (Ciheam), H1X 2B2 (Canada)

    2009-03-15

    Greenhouse gas (GHG) emissions by constructed wetlands (CWs) could mitigate the environmental benefits of nutrient removal in these man-made ecosystems. We studied the effect of 3 different macrophyte species and artificial aeration on the rates of nitrous oxide (N{sub 2}O), carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) production in CW mesocosms over three seasons. CW emitted 2-10 times more GHG than natural wetlands. Overall, CH{sub 4} was the most important GHG emitted in unplanted treatments. Oxygen availability through artificial aeration reduced CH{sub 4} fluxes. Plant presence also decreased CH{sub 4} fluxes but favoured CO{sub 2} production. Nitrous oxide had a minor contribution to global warming potential (GWP < 15%). The introduction of oxygen through artificial aeration combined with plant presence, particularly Typha angustifolia, had the overall best performance among the treatments tested in this study, including lowest GWP, greatest nutrient removal, and best hydraulic properties. - Methane is the main greenhouse gas produced in constructed wetlands and oxygen availability is the main factor controlling fluxes.

  9. Bubble growth as a means to measure dissolved nitrogen concentration in aerated water

    Science.gov (United States)

    Ando, Keita; Yamashita, Tatsuya

    2017-11-01

    Controlling the amount of dissolved gases in water is important, for example, to food processing; it is essential to quantitatively evaluate dissolved gas concentration. The concentration of dissolved oxygen (DO) can be measured by commercial DO meters, but that of dissolved nitrogen (DN) cannot be obtained easily. Here, we propose a means to measure DN concentration based on Epstein-Plesset-type analysis of bubble growth under dissolved gas supersaturation. DO supersaturation in water is produced by oxygen microbubble aeration. The diffusion-driven growth of bubbles nucleated at glass surfaces in contact with the aerated water is first observed. The observed growth is then compared to the extended Epstein-Plesset theory that considers Fick's mass transfer of both DO and DN across bubble interfaces; in this comparison, the unknown DN concentration is treated as a fitting parameter. Comparisons between the experiment and the theory suggest, as expected, that DN can be effectively purged by oxygen microbubble aeration. This study was supported in part by the Mizuho Foundation for the Promotion of Science and by a MEXT Grant-in-Aid for the Program for Leading Graduate Schools.

  10. Computational fluid dynamics modelling of hydraulics and sedimentation in process reactors during aeration tank settling.

    Science.gov (United States)

    Jensen, M D; Ingildsen, P; Rasmussen, M R; Laursen, J

    2006-01-01

    Aeration tank settling is a control method allowing settling in the process tank during high hydraulic load. The control method is patented. Aeration tank settling has been applied in several waste water treatment plants using the present design of the process tanks. Some process tank designs have shown to be more effective than others. To improve the design of less effective plants, computational fluid dynamics (CFD) modelling of hydraulics and sedimentation has been applied. This paper discusses the results at one particular plant experiencing problems with partly short-circuiting of the inlet and outlet causing a disruption of the sludge blanket at the outlet and thereby reducing the retention of sludge in the process tank. The model has allowed us to establish a clear picture of the problems arising at the plant during aeration tank settling. Secondly, several process tank design changes have been suggested and tested by means of computational fluid dynamics modelling. The most promising design changes have been found and reported.

  11. Computational fluid dynamics simulations of membrane filtration process adapted for water treatment of aerated sewage lagoons.

    Science.gov (United States)

    Cano, Grégory; Mouahid, Adil; Carretier, Emilie; Guasp, Pascal; Dhaler, Didier; Castelas, Bernard; Moulin, Philippe

    2015-01-01

    The aim of this study is to apply the membrane bioreactor technology in an oxidation ditch in submerged conditions. This new wastewater filtration process will benefit rural areas (membranes developed without support are immersed in an aeration well and work in suction mode. The development of the membrane without support and more precisely the performance of spacers are approached by computational fluid dynamics in order to provide the best compromise between pressure drop/flow velocity and permeate flux. The numerical results on the layout and the membrane modules' geometry in the aeration well indicate that the optimal configuration is to install the membranes horizontally on three levels. Membranes should be connected to each other to a manifold providing a total membrane area of 18 m². Loss rate compared to the theoretical throughput is relatively low (less than 3%). Preliminary data obtained by modeling the lagoon provide access to its hydrodynamics, revealing that recirculation zones can be optimized by making changes in the operating conditions. The experimental validation of these results and taking into account the aeration in the numerical models are underway.

  12. Optimization of Biological Treatment of an Industrial Wastewater in an Intermittent Aeration Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Azar Asadi

    2015-11-01

    Full Text Available In this paper, the simultaneous removal of carbon and nutrients (nitrogen and phosphorus from Faraman’s industrial wastewater (FIW in a time-based sequencing batch reactor (SBR was investigated. The experiments were conducted based on a central composite design (CCD and analyzed using the response surface methodology (RSM. Reaction and aeration times were selected for the purposes of analyzing, modeling, and optimizing the process. Nine dependent parameters were monitored as process responses. The region of exploration for the process was taken as the area enclosed by the boundaries of reaction time (12-36 h and aeration time (40-60 min/h. Reaction time was found to be the most effective variable and showed a decreasing impact on the total chemical oxygen demand (TCOD, slowly-biodegradable chemical oxygen demand (sbCOD, total nitrogen (TN, and total phosphorus (TP removal efficiencies. The optimum operating conditions were determined in the range of 12 to 16 h for the reaction time and 40 to 60 min/h for the aeration time.

  13. Impacts of aeration and active sludge addition on leachate recirculation bioreactor

    International Nuclear Information System (INIS)

    Dong Jun; Zhao Yongsheng; Henry, Rotich K.; Hong Mei

    2007-01-01

    Stabilization of municipal solid waste (MSW) is affected by moisture, nutrients, oxygen, pH and accumulation of inhibitory fermentation products, etc. Optimization of these parameters could create a favorable environment that promotes the rapid development of the desired microbial population and acceleration of decomposition of MSW. The objectives of this work was to determine the feasibility of enhancing phase separation through intermittent aeration strategy throughout the treatment process; to demonstrate the potential of active sludge for in situ nitrogen removal; to examine the efficiency and evaluate the possibility of in situ removal of contaminants from leachate. The results indicate that the removal ratio of COD, BOD 5 , NH 4 + and total nitrogen are over 80, 81, 75, and 74%, respectively, in the leachate recirculation reactors with aeration; the removal efficiency of NH 4 + and total nitrogen of the reactor which were added active sludge were 88 and 84%, respectively. Therefore, aeration strategy has positive impacts on the solid waste stabilization; addition of active sludge in reactor is favorable for the remediation of the nitrogen; using landfill itself for in situ attenuating the contaminants from leachate is feasible

  14. The response of archaeal species to seasonal variables in a subtropical aerated soil: insight into the low abundant methanogens.

    Science.gov (United States)

    Xie, Wei; Jiao, Na; Ma, Cenling; Fang, Sa; Phelps, Tommy J; Zhu, Ruixin; Zhang, Chuanlun

    2017-08-01

    Archaea are cosmopolitan in aerated soils around the world. While the dominance of Thaumarchaeota has been reported in most soils, the methanogens are recently found to be ubiquitous but with low abundances in the aerated soil globally. However, the seasonal changes of Archaea community in the aerated soils are still in the mist. In this study, we investigated the change of Archaea in the context of environmental variables over a period of 12 months in a subtropical soil on the Chongming Island, China. The results showed that Nitrososphaera spp. were the dominant archaeal population while the methanogens were in low proportions but highly diverse (including five genera: Methanobacterium, Methanocella, Methanosaeta, Methanosarcina, and Methanomassiliicoccus) in the aerated soil samples determined by high throughput sequencing. A total of 126 LSA correlations were found in the dataset including all the 72 archaeal OTUs and 8 environmental factors. A significance index defined as the pagerank score of each OTU divided by its relative abundance was used to evaluate the significance of each OTU. The results showed that five out of 17 methanogen OTUs were significantly positively correlated with temperature, suggesting those methanogens might increase with temperature rather than being dormant in the aerated soils. Given the metabolic response of methanogens to temperature under aerated soil conditions, their contribution to the global methane cycle warrants evaluation.

  15. The effect of aeration on the removal of wastewater-derived pharmaceutical residues from groundwater - a laboratory study.

    Science.gov (United States)

    Burke, Victoria; Duennbier, Uwe; Massmann, Gudrun

    2013-01-01

    Several studies on waste- or drinking water treatment processes as well as on groundwater have recently shown that some pharmaceutical residues (PRs) are redox-sensitive. Hence, their (bio)degradation depends on the redox conditions prevalent in the aquifer. Groundwater, providing raw water for drinking water production, is often anoxic and aeration is a widespread treatment method applied mainly to eliminate unwanted iron and manganese from the water. As a side-effect, aeration may trigger the elimination of PRs. Within the present study the influence of aeration on the fate of a number of wastewater derived analgesics and their residues as well as several antimicrobial compounds was investigated. For this purpose, anoxic groundwater was transferred into stainless steel tanks, some of which were aerated while others were continuously kept anoxic. Results prove that the degradation of six phenazone type compounds is dependent on oxygen availability and compounds are efficiently removed under oxic conditions only. Concerning the antimicrobials, doxycycline and trimethoprim were better removed during aeration, whereas a slightly improved removal under anoxic conditions was observed for clindamycin, roxithromycin and clarithromycin. The study provides first laboratory proof of the redox-sensitivity of several organic trace pollutants. In addition, results demonstrate that aeration is an effective treatment for the elimination of a number of wastewater derived PRs.

  16. Increased Production of Hydrogen Peroxide by Lactobacillus delbrueckii subsp. bulgaricus upon Aeration: Involvement of an NADH Oxidase in Oxidative Stress

    Science.gov (United States)

    Marty-Teysset, C.; de la Torre, F.; Garel, J.-R.

    2000-01-01

    The growth of Lactobacillus delbrueckii subsp. bulgaricus (L. delbrueckii subsp. bulgaricus) on lactose was altered upon aerating the cultures by agitation. Aeration caused the bacteria to enter early into stationary phase, thus reducing markedly the biomass production but without modifying the maximum growth rate. The early entry into stationary phase of aerated cultures was probably related to the accumulation of hydrogen peroxide in the medium. Indeed, the concentration of hydrogen peroxide in aerated cultures was two to three times higher than in unaerated ones. Also, a similar shift from exponential to stationary phase could be induced in unaerated cultures by adding increasing concentrations of hydrogen peroxide. A significant fraction of the hydrogen peroxide produced by L. delbrueckii subsp. bulgaricus originated from the reduction of molecular oxygen by NADH catalyzed by an NADH:H2O2 oxidase. The specific activity of this NADH oxidase was the same in aerated and unaerated cultures, suggesting that the amount of this enzyme was not directly regulated by oxygen. Aeration did not change the homolactic character of lactose fermentation by L. delbrueckii subsp. bulgaricus and most of the NADH was reoxidized by lactate dehydrogenase with pyruvate. This indicated that NADH oxidase had no (or a very small) energetic role and could be involved in eliminating oxygen. PMID:10618234

  17. A field study on phytoremediation of dredged sediment contaminated by heavy metals and nutrients: the impacts of sediment aeration.

    Science.gov (United States)

    Wu, Juan; Yang, Lihua; Zhong, Fei; Cheng, Shuiping

    2014-12-01

    Compared to traditional chemical or physical treatments, phytoremediation has proved to be a cost-effective and environmentally sound alternative for remediation of contaminated dredged sediment. A field study was conducted in a sediment disposal site predominantly colonized by Typha angustifolia under different sediment moisture conditions to estimate the phytoremediation effects of dredged sediment. The moisture content was 37.30 % and 48.27 % in aerated and waterlogged sediment, respectively. Total nitrogen (TN) content was higher in the waterlogged sediment than in the aerated sediment. The total Cd contents were lower in aerated sediment, which was mainly resulted from the lower exchangeable fraction of Cd. The bioaccumulation of P, Cu and Pb in T. angustifolia was promoted by waterlogging, and the belowground tissue concentrations and accumulation factors (AFs) of Cu were higher than that of other metals, which can be explained by that Cu is an essential micronutrient for plants. Consistent with many previous studies, T. angustifolia showed higher metal levels in roots than in above-ground tissues at both the sediment conditions. Due to the improved biomass produced in the aerated sediment, the removals of nutrients and the metals by plant harvest were higher from aerated sediment than from waterlogged sediment. It was indicated that maintaining the dredged sediment aerated can avoid release risk and plant uptake of metals, while the opposite management option can promote phytoextraction of these contaminants.

  18. Why do interstellar grains exist

    International Nuclear Information System (INIS)

    Seab, C.G.; Hollenbach, D.J.; Mckee, C.F.; Tielens, A.G.G.M.

    1986-01-01

    There exists a discrepancy between calculated destruction rates of grains in the interstellar medium and postulated sources of new grains. This problem was examined by modelling the global life cycle of grains in the galaxy. The model includes: grain destruction due to supernovae shock waves; grain injection from cool stars, planetary nebulae, star formation, novae, and supernovae; grain growth by accretion in dark clouds; and a mixing scheme between phases of the interstellar medium. Grain growth in molecular clouds is considered as a mechanism or increasing the formation rate. To decrease the shock destruction rate, several new physical processes, such as partial vaporization effects in grain-grain collisions, breakdown of the small Larmor radius approximation for betatron acceleration, and relaxation of the steady-state shock assumption are included

  19. Comparing cost and process performance of activated sludge (AS) and biological aerated filters (BAF) over ten years of full sale operation.

    Science.gov (United States)

    Hansen, R; Thogersen, T; Rogalla, F

    2007-01-01

    In the early 1990s, the Wastewater Treatment Plant (WWTP) of Frederikshavn, Denmark, was extended to meet new requirements for nutrient removal (8 mg/L TN, 1.5 mg TP/L) as well as to increase its average daily flow to 16,500 m(3)/d (4.5 MGD). As the most economical upgrade of the existing activated sludge (AS) plant, a parallel biological aerated filter (BAF) was selected, and started up in 1995. Running two full scale processes in parallel for over ten years on the same wastewater and treatment objectives enabled a direct comparison in relation to operating performance, costs and experience. Common pretreatment consists of screening, an aerated grit and grease removal and three primary settlers with chemical addition. The effluent is then pumped to the two parallel biological treatment stages, AS with recirculation and an upflow BAF with floating media. The wastewater is a mixture of industrial and domestic wastewater, with a dominant discharge of fish processing effluent which can amount to 50% of the flow. The maximum hydraulic load on the pretreatment section as a whole is 1,530 m(3)/h. Approximately 60% of the sewer system is combined with a total of 32 overflow structures. To avoid the direct discharge of combined sewer overflows into the receiving waters, the total hydraulic wet weather capacity of the plant is increased to 4,330 m(3)/h, or 6 times average flow. During rain, some of the raw sewage can be directed through a stormwater bypass to the BAF, which can be modified in its operation to accommodate various treatment needs: either using simultaneous nitrification/denitrification in all filters with recirculation introducing bottom aeration with full nitrification in some filters for storm treatment and/or post-denitrification in one filter. After treatment, the wastewater is discharged to the Baltic Sea through a 500 m outfall. The BAF backwash sludge, approximately 1,900 m(3) per 24 h in dry weather, is redirected to the AS plant. Primary settler

  20. The impact of aeration on potato (Solanum tuberosum L.) minituber ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-03-18

    Mar 18, 2015 ... 2Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, Malaysia. 3Department of ... aeroponic systems in potato minituber production showed ...... seed as an important factor for growth and total yield.

  1. Direct imaging of grain boundaries

    International Nuclear Information System (INIS)

    Gronsky, R.

    1979-09-01

    There are currently two types of microscopes which, in principle, are capable of imaging atom positions at grain boundaries. One, the field ion microscope (FIM), yields a projection of the specimen surface (approximately stereographic) by field ionization of an imaging gas at protruding atom sites, and provides topographic information in high-index pole regions which may be interpreted atom-by-atom. The other, a transmission electron microscope (TEM), yields a projection (approximately linear) of the entire specimen thickness by electron optical imaging, and provides atomic resolution detail throughout the illuminated area. In this paper, both methods are described and compared, using examples from practical materials systems

  2. Sistemas de produção de grãos e incidência de plantas daninhas Weed incidence in grain production systems

    Directory of Open Access Journals (Sweden)

    G.S.A Castro

    2011-01-01

    Full Text Available O sistema de semeadura direta e os diferentes sistemas de produção nele adotados podem contribuir para a supressão de plantas infestantes. Em razão disso, o objetivo do presente trabalho foi avaliar o controle de plantas daninhas em função de diferentes sistemas de produção de grãos. Os tratamentos utilizados foram: I. Sistema "safra-pousio" - soja/ pousio/milho/pousio/arroz/pousio/soja; II. Sistema "safra-adubo verde" - soja/milheto/ milho/guandu/arroz/crotalária/soja; III. Sistema "safra-safrinha" - soja/aveia-branca/milho/ feijão-da-seca/arroz/mamona/soja; IV. Sistema "safra - forrageira"- soja + braquiária/milho + braquiária/arroz + braquiária/soja. Em novembro de 2009 (após três safras agrícolas, foi realizado o levantamento de plantas daninhas infestantes. Para isso, foi utilizado um quadro (0,3 x 0,3 m, lançado aleatoriamente quatro vezes dentro de cada parcela. As plantas foram identificadas, bem como feita a determinação do número total das espécies invasoras, da massa seca e da porcentagem de controle das espécies de acordo com o sistema de produção. Foi realizada ainda a análise fitossociológica da comunidade de plantas daninhas infestantes. Os sistemas safra-adubo verde, safra-safrinha e safra-forrageira apresentaram bom controle de plantas infestantes quando comparados ao sistema safra-pousio. Portanto, a presença de algum tipo de cobertura é importante para manter as características do solo favorável e um bom controle de plantas invasoras.Tillage and other agricultural production systems can contribute to weed suppression. Thus, the objective of this study was to evaluate weed control using different grain production systems. The treatments were: I. "Harvest-fallow" System- soybean/fallow/corn/fallow/rice/ fallow/soybean; II. "Harvest-green manure" System-soybean/millet/maize/pigeon pea/rice/ Crotalaria/soybean; III. "Harvest-out of season" System-soy/white oats/corn/dry bean/rice/castor oil

  3. Grain Boundary Segregation in Metals

    CERN Document Server

    Lejcek, Pavel

    2010-01-01

    Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

  4. Grain destruction in interstellar shocks

    International Nuclear Information System (INIS)

    Seab, C.G.; Shull, J.M.

    1984-01-01

    One of the principal methods for removing grains from the Interstellar Medium is to destroy them in shock waves. Previous theoretical studies of shock destruction have generally assumed only a single size and type of grain; most do not account for the effect of the grain destruction on the structure of the shock. Earlier calculations have been improved in three ways: first, by using a ''complete'' grain model including a distribution of sizes and types of grains; second, by using a self-consistent shock structure that incorporates the changing elemental depletions as the grains are destroyed; and third, by calculating the shock-processed ultraviolet extinction curves for comparison with observations. (author)

  5. Dust grain charging in a wake of other grains

    International Nuclear Information System (INIS)

    Miloch, W. J.; Block, D.

    2012-01-01

    The charging of dust grain in the wake of another grains in sonic and supersonic collisionless plasma flows is studied by numerical simulations. We consider two grains aligned with the flow, as well as dust chains and multiple grain arrangements. It is found that the dust charge depends significantly on the flow speed, distance between the grains, and the grain arrangement. For two and three grains aligned, the charges on downstream grains depend linearly on the flow velocity and intergrain distance. The simulations are carried out with DiP3D, a three dimensional particle-in-cell code with both electrons and ions represented as numerical particles [W. J. Miloch et al., Phys. Plasmas 17, 103703 (2010)].

  6. Hydrodynamic cavitation: a bottom-up approach to liquid aeration

    NARCIS (Netherlands)

    Raut, J.S.; Stoyanov, S.D.; Duggal, C.; Pelan, E.G.; Arnaudov, L.N.; Naik, V.M.

    2012-01-01

    We report the use of hydrodynamic cavitation as a novel, bottom-up method for continuous creation of foams comprising of air microbubbles in aqueous systems containing surface active ingredients, like proteins or particles. The hydrodynamic cavitation was created using a converging-diverging nozzle.

  7. Technical Note: Field-observed angles of repose for stored grain in the United States

    Science.gov (United States)

    Bulk grain angle of repose (AoR) is a key parameter for inventorying grain, predicting flow characteristics, and designing bins and grain handling systems. The AoR is defined for two cases, piling (dynamic) or emptying (static), and usually varies with grain type. The objective of this study was to ...

  8. Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Vogt, Josef Korbinian; Kristensen, Mette

    2017-01-01

    Objective To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. Design 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week d...

  9. Biaxial magnetic grain alignment

    International Nuclear Information System (INIS)

    Staines, M.; Genoud, J.-Y.; Mawdsley, A.; Manojlovic, V.

    2000-01-01

    Full text: We describe a dynamic magnetic grain alignment technique which can be used to produce YBCO thick films with a high degree of biaxial texture. The technique is, however, generally applicable to preparing ceramics or composite materials from granular materials with orthorhombic or lower crystal symmetry and is therefore not restricted to superconducting applications. Because magnetic alignment is a bulk effect, textured substrates are not required, unlike epitaxial coated tape processes such as RABiTS. We have used the technique to produce thick films of Y-247 on untextured silver substrates. After processing to Y-123 the films show a clear enhancement of critical current density relative to identically prepared untextured or uniaxially textured samples. We describe procedures for preparing materials using magnetic biaxial grain alignment with the emphasis on alignment in epoxy, which can give extremely high texture. X-ray rocking curves with FWHM of as little as 1-2 degrees have been measured

  10. Evolution of grain structure in nickel oxide scales

    International Nuclear Information System (INIS)

    Atkinson, H.V.

    1987-01-01

    In systems such as the oxidation of nickel, in which grain-boundary diffusion in the oxide can control the rate of oxidation, understanding of the factors governing the grain structure is of importance. High-purity mechanically polished polycrystalline nickel was oxidized at 700 0 C, 800 0 C, and 1000 0 C for times up to 20 hr in 1 atm O 2 . The scale microstructures were examined by parallel and transverse cross section transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Texture coefficients were found by x-ray diffraction (XRD). Each grain in the transverse section grain boundary networks was systematically analyzed for width parallel to the Ni-NiO interface and perpendicular length, for boundary radius of curvature and for number of sides. The variation of these parameters with depth in the scale was examined. In particular, grains were increasingly columnar (i.e., with ratio of grain length to width > 1) at higher temperatures and longer times. Columnar grain boundaries tended to be fairly static; the columnar grain width was less than the rate controlling grain size predicted from the oxidation rate. The mean boundary curvature per grain provided a guide to the tendency for grain growth, except in the region of the Ni-NiO interface, where the boundaries were thought to be pinned

  11. Grain Boundary Complexions

    Science.gov (United States)

    2014-05-01

    Cantwell et al. / Acta Materialia 62 (2014) 1–48 challenging from a scientific perspective, but it can also be very technologically rewarding , given the...energy) is a competing explanation that remains to be explored. Strategies to drive the grain boundary energy toward zero have produced some success...Thompson AM, Soni KK, Chan HM, Harmer MP, Williams DB, Chabala JM, et al. J Am Ceram Soc 1997;80:373. [172] Behera SK. PhD dissertation, Materials Science

  12. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentation demand; the optimizaton of value of agricultural crops; and the efficiencies of combining related industries. Ahydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grain can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural- environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  13. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (Ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentaton demand; the optimization of value of agricultureal crops; and the efficiencies of combining related industries. Anhydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grains can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural-environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  14. Grain preservation in SSSR

    International Nuclear Information System (INIS)

    Trisviatski, L.A.

    1973-01-01

    First the importance of cereals collected in the S.S.S.R., the reason why the government had to put in practice a storage chain, composed of large capacity store houses (200 000 metric tonnes, or more) is reminded. When climatic conditions result in wet harvested grains, cereals are dried either in state enterprise dryers (32 to 50 tonnes/hour) or in kolkhozes' dryers (2 to 16 tonnes/hour). A new type of drying with recycling, has been developped, economizing 10 to 15 p. 100. Then the possibilities offered by the technique of partial drying of very wet grains are studied and the preservation processes using fresh ventilation, or hot ventilation with drying effect are described. The question of silage of wet grains destined to animal consumption is then examined as well as preservation by sodium pyrosulfide; the use of propionic acid, little developped in SSSR, is studied now, just as storage with inert gas. The struggle technics against insects, either with chemical agents, or with irradiation are described. Finally the modalities of technicians formation, specialized in preservation, are discussed [fr

  15. Origins of amorphous interstellar grains

    International Nuclear Information System (INIS)

    Hasegawa, H.

    1984-01-01

    The existence of amorphous interstellar grains has been suggested from infrared observations. Some carbon stars show the far infrared emission with a lambda -1 wavelength dependence. Far infrared emission supposed to be due to silicate grains often show the lambda -1 wavelength dependence. Mid infrared spectra around 10 μm have broad structure. These may be due to the amorphous silicate grains. The condition that the condensed grains from the cosmic gas are amorphous is discussed. (author)

  16. Photoelectric charging of dust grains

    International Nuclear Information System (INIS)

    Ignatov, A. M.

    2009-01-01

    Photoemission from the surface of a dust grain in vacuum is considered. It is shown that the cutoff in the energy spectrum of emitted electrons leads to the formation of a steady-state electron cloud. The equation describing the distribution of the electric potential in the vicinity of a dust grain is solved numerically. The dust grain charge is found as a function of the grain size.

  17. Transformation and fate of 2,4,6-trinitrotoluene (TNT) in anaerobic bioslurry reactors under various aeration schemes: implications for the decontamination of soils.

    Science.gov (United States)

    Newcombe, David A; Crawford, Ronald L

    2007-12-01

    Energetic compounds have been used in a variety of industrial and military applications worldwide leading to widespread environmental contamination. Many of these compounds are toxic and resist degradation by oxidative enzymes resulting in a need for alternative remediation methods. It has been shown that trinitrotoluene (TNT)-contaminated soil subjected to treatment in strictly anaerobic bioreactors results in tight binding of TNT transformation products to soil organic matter. The research presented here examined the fate of TNT and its metabolites in bioreactors under three different aeration regimes. In all treatment regimes, the typical metabolites of aminodinitrotoluenes and diaminonitrotoluenes were observed prior to irreversible binding into the soil fraction of the slurry. Significant transformation of TNT into organic acids or simple diols, as others report in prior work, was not observed in any of the treatments and is an unlikely fate of TNT in anaerobic soil slurries. These results indicate that aeration does not dramatically affect transformation or fate of TNT in reactor systems that receive a rich carbon source but does affect the rate at which metabolites become tightly bound to the soil. The most rapid transformations and lowest redox potentials were observed in reactors in which an aerobic headspace was maintained suggesting that aerobes play a role in establishing conditions that are most conducive to TNT reduction.

  18. The Variation Characteristic of Sulfides and VOSc in a Source Water Reservoir and Its Control Using a Water-Lifting Aerator

    Directory of Open Access Journals (Sweden)

    Jian-Chao Shi

    2016-04-01

    Full Text Available Sulfides and volatile organic sulfur compounds (VOSc in water are not only malodorous but also toxic to humans and aquatic organisms. They cause serious deterioration in the ecological environment and pollute drinking water sources. In the present study, a source water reservoir—Zhoucun Reservoir in East China—was selected as the study site. Through a combination of field monitoring and in situ release experiments of sulfides, the characteristics of seasonal variation and distribution of sulfides and VOSc in the reservoir were studied, and the cause of the sulfide pollution was explained. The results show that sulfide pollution was quite severe in August and September 2014 in the Zhoucun Reservoir, with up to 1.59 mg·L−1 of sulfides in the lower layer water. The main source of sulfides is endogenous pollution. VOSc concentration correlates very well with that of sulfides during the summer, with a peak VOSc concentration of 44.37 μg·L−1. An installed water-lifting aeration system was shown to directly oxygenate the lower layer water, as well as mix water from the lower and the upper layers. Finally, the principle and results of controlling sulfides and VOSc in reservoirs using water-lifting aerators are clarified. Information about sulfides and VOSc fluctuation and control gained in this study may be applicable to similar reservoirs, and useful in practical water quality improvement and pollution prevention.

  19. Removal of radon by aeration testing of various aeration techniques for small water works. For European Commission under Contract No FI4PCT960054 TENAWA project

    CERN Document Server

    Salonen, L; Mehtonen, J; Mjoenes, L; Raff, O; Turunen, H

    2002-01-01

    Capability of various aeration techniques to remove radon from water in small waterworks was studied as a part of project (Treatment Techniques for Removing Natural Radionuclides from Drinking Water), which was carried out during 1997-1999 on a cost-shared basis (contract No. F14PCT960054) with The European Commission (CEC) under the supervision of the Directorate-General XII Radiation Protection Research Unit. In TENAWA project both laboratory and field experiments were performed in order to find reliable methods and equipment for removing natural radionuclides from ground water originating either from private wells or small waterworks. Because such techniques are more often needed in private households than at waterworks, the main emphasis of the research was aimed to solve the water treatment problems related to the private water supplies, especially bedrock wells. Radon was the most important radionuclide to be removed from water at waterworks whereas the removal of other radionuclides ( sup 2 sup 3 sup 4...

  20. Weed Population Dynamics, Water Productivity and Grain Yield of Durum Wheat (Triticum durum L. in No-Tillage and Conventional Tillage Systems

    Directory of Open Access Journals (Sweden)

    Mehdi Mojab

    2016-09-01

    and broadleaved weed densities were recorded at 30 days after the beginning of crop emergence. Wheat grain yield was calculated at harvest time. Comparison of the means was conducted based on protected LSD (PLSD at 0.05 significant levels. Results and Discussion: Tillage systems indicated a significant effect on wheat density. The average number of crop seedlings in no-tillage plots was 27 % higher than in the conventional tillage plots. Maintaining crop residues on the soil surface provided a better site for crop germination and emergence. The response to tillage system and year effects varied depending on the weed species. Results showed that the effect of tillage systems, year and their interactions were significant on the density of Lolium temulentum and Sinapis arvensis, while in the case of Phalaris minor and Hordeum spontaneum just the tillage regimen significantly influenced the weed density. L. temulentum and S. arvensis plants showed an almost similar pattern in their response to tillage systems and year effects. The density of these two species significantly decreased under no-tillage system compared with conventional tillage operations. Moreover, their densities in conventional tillage plots were significantly greater in the second year of the experiment than the first year. The lower seedling emergence of P. minor and H. spontaneum under no-tillage circumstances is not surprising, as crop residues prevent from reaching the light on the soil surface and the light requirement for germination of these species has been reported in several studies. The water productivity of the no-tillage plots was greater than of the conventional ones at both two years of the experiment. Preservation of wheat residues on the soil surface decreases soil temperature via shading and causes reduces the evaporation rate from the soil surface. Although there was no significant difference between wheat yields in the two growing seasons under conventional tillage environment, wheat

  1. Storing Peanuts in Grain Bags

    Science.gov (United States)

    A study was executed to determine the potential of storing farmers stock peanuts and shelled peanuts for crushing in hermetically sealed grain bags. The objectives of the study were to evaluate equipment for loading and unloading the grain bags, the capacity of the grain bags, and the changes in qu...

  2. Modelling of the Bubble Size Distribution in an Aerated Stirred Tank: Theoretical and Numerical Comparison of Different Breakup Models

    Directory of Open Access Journals (Sweden)

    Kálal Zbyněk

    2014-09-01

    Full Text Available The main topic of this study is the mathematical modelling of bubble size distributions in an aerated stirred tank using the population balance method. The air-water system consisted of a fully baffled vessel with a diameter of 0.29 m, which was equipped with a six-bladed Rushton turbine. The secondary phase was introduced through a ring sparger situated under the impeller. Calculations were performed with the CFD software CFX 14.5. The turbulent quantities were predicted using the standard k-ε turbulence model. Coalescence and breakup of bubbles were modelled using the MUSIG method with 24 bubble size groups. For the bubble size distribution modelling, the breakup model by Luo and Svendsen (1996 typically has been used in the past. However, this breakup model was thoroughly reviewed and its practical applicability was questioned. Therefore, three different breakup models by Martínez-Bazán et al. (1999a, b, Lehr et al. (2002 and Alopaeus et al. (2002 were implemented in the CFD solver and applied to the system. The resulting Sauter mean diameters and local bubble size distributions were compared with experimental data.

  3. Quality of Brazil nuts stored in forced aeration silos

    Directory of Open Access Journals (Sweden)

    David Aquino da Costa

    2016-06-01

    Full Text Available ABSTRACT The traditional system of collection and storage of Brazil nut compromises seriously the quality of these almonds as it contributes to the high incidence of contaminants, like fungi of the genus Aspergillus, which can produce aflatoxins. In this study, the objective was to evaluate the influence of the storage period in studied conditions, on the physicochemical characteristics and on the microbiological contamination of Brazil nuts. The experimental was designed as completely randomized, considering as treatments the storage period (0 - control, 30, 60, 90, 120 and 150 days with four replicates of 3 kg of Brazil nuts each. The samples were submitted to physicochemical and microbiological analysis. It was observed that almonds submitted to the storage had their moisture content reduced by 78.2% at 150 days of storage, however, this reduction was not fast enough to avoid surface contamination by filamentous and potentially aflatoxins producing fungi. The critical period of contamination occurred on the first 30 days of storage when there was an increase of the studied fungi, as well as B1 and total aflatoxin. The studied storage conditions were four times more effective in reducing the product moisture content than the traditional methods, however, pre-drying is necessary to avoid contamination of the product.

  4. An Evaluation of Coarse-Grained Locking for Multicore Microkernels

    OpenAIRE

    Elphinstone, Kevin; Zarrabi, Amirreza; Danis, Adrian; Shen, Yanyan; Heiser, Gernot

    2016-01-01

    The trade-off between coarse- and fine-grained locking is a well understood issue in operating systems. Coarse-grained locking provides lower overhead under low contention, fine-grained locking provides higher scalability under contention, though at the expense of implementation complexity and re- duced best-case performance. We revisit this trade-off in the context of microkernels and tightly-coupled cores with shared caches and low inter-core migration latencies. We evaluate performance on ...

  5. Post-IR IRSL290 dating of K-rich feldspar sand grains in a wind-dominated system on Sardinia

    DEFF Research Database (Denmark)

    Andreucci, S.; Sechi, D.; Buylaert, Jan-Pieter

    2017-01-01

    The reliability of a post-IR elevated temperature IRSL (290 °C; pIRIR290) is tested on wind-blown, sand-sized (180–250 μm) K-rich feldspar grains. The pIRIR290 ages were compared with quartz SAR-OSL data, other independent age controls and historical information. Three study areas along the coast....... The pIRIR290 ages indicate an offset up to ∼1000 years. We can conclude that the pIRIR290 method on sand-sized K-feldspar grains shows great promise for samples at or beyond the quartz OSL age limit but should not be applied to Late Holocene or modern deposits....

  6. The Ethanol-Chlorobenzene Aerated System as a New High-Level Dosimeter for Routine Measurements; Le Systeme Ethanol-Chlorobenzene Aere Utilise Comme Dosimetre pour les Mesures Courantes de Fortes Doses; Aehrirovannaya sistema ehtanola-khlorobenzola v kachestve novogo dozimetra vysokogo urovnya dlya provedeniya obychnykh izmerenij; Dosimetro de Etanol-Clorobenceno Saturado de Aire para la Determinacion de Intensidades Elevadas

    Energy Technology Data Exchange (ETDEWEB)

    Dvornik, I.; Zec, U.; Ranogajec, F. [Institute ' ' Ruder Boskovic' ' , Zagreb, Yugoslavia (Croatia)

    1966-11-15

    The radiolytic hydrogen chloride yield for {sup 60}Co gamma radiation measured as a function of dose (0.05 to 100 Mrad), dose-rate (0.5 to 2500 rad sec{sup -1}) and chlorobenzene (CB) concentration is found to be 5 {+-} 0.1 for CB concentrations between 20 and 40% in a broad range of experimental conditions. The yield is only slightly sensitive to normal impurities. Analytical and lower-grade components give yields reproducible within a few per cent of this value if 4% water and about 2X 10{sup -3} M benzene and acetaldehyde or acetone are initially present. Higher dosimetric accuracy is obtained if the exact G(Cl{sup -}) is determined for given materials by calibration with the Fricke dosimeter. With 4% CB and 4 Degree-Sign Inverted-Exclamation-Mark o water all grades of ethanol give G(Cl{sup -}) = 3.65 {+-} 0.05, irrespective of additives. The effect of variation of the water content within {+-} 1% is negligible. The hydrogen chloride concentration in the whole dose range is determined by mercurimetric or alkali- metric titration directly in the irradiated sample with an accuracy of one per cent or better. Incomplete experiments with fast electrons have proved that similar systems are of possible interest for calibration and control of industrial irradiations with intense electron beams. The simplicity of preparation and analysis together with the broad range (covered by only one analytical method) and high overall accuracy give to the new dosimeter all the qualities of the almost unique tool for dosimetric calibration of sources and routine control of industrial radiation processing. (author) [French] On constate que la quantite d'acide chlorhydrique radiolytique produite par des rayons gamma emis par le {sup 60}Co, mesuree en fonction de la dose (0,05 a 100 Mrad), du debit de dose (0,5 a 2500 rad-s{sup -1}) et de la concentration du chlorobenzene (CB), est de 5 {+-} 0,1 pour des concentrations de CB comprises entre 20 et 40% dans un tres large eventail de

  7. Effects of Aeration of Sawdust Cultivation Bags on Hyphal Growth of Lentinula edodes.

    Science.gov (United States)

    Lee, Hwa-Yong; Ham, Eun-Ju; Yoo, Young-Jin; Kim, Eui-Sung; Shim, Kyu-Kwang; Kim, Myung-Kon; Koo, Chang-Duck

    2012-09-01

    The effects of aeration through lid filters on the hyphal growth of Lentinula edodes (oak mushroom) in sawdust cultivation bags were investigated. The aeration treatment levels were traditional 27 mm hole cotton plugs, cotton balls and combinations of seven hole sizes × two hole positions (up and under) in the lids covering plastic bags containing 1.4 kg sawdust medium at 63% moisture that had been autoclaved for one hour and inoculated with sawdust spawn of L. edodes strain 921. Aeration treatment effects were measured based on the CO(2) concentration at the 15th wk, as well as the hyphal growth rate and degree of weight loss of bags every 14 days for 15 wk. In bags with traditional cotton plugs, the CO(2) concentration was 3.8 ± 1.3%, daily mean hyphal growth was 2.3 ± 0.6 mm and daily mean weight loss was 0.84 ± 0.26 g. In the bags with 15 mm diameter holes, the CO(2) concentration was 6.0 ± 1.6%, daily hyphal growth was 2.8 ± 0.2 mm and daily weight loss was 0.86 ± 0.4 g. The bags with 15 mm holes had a higher CO(2) concentration and lower water loss than bags with other hole sizes, but the hyphal growth was not significantly different from that of other bags. The weight loss of bags increased proportionally relative to the lid hole sizes. Taken together, these results indicate that traditional cotton plugs are economically efficient, but 15 mm hole lids are the most efficient at maintaining hyphal growth and controlling water loss while allowing CO(2) emissions.

  8. Grain Interactions in Crystal Plasticity

    International Nuclear Information System (INIS)

    Boyle, K.P.; Curtin, W.A.

    2005-01-01

    The plastic response of a sheet metal is governed by the collective response of the underlying grains. Intragranular plasticity depends on intrinsic variables such as crystallographic orientation and on extrinsic variables such as grain interactions; however, the role of the latter is not well understood. A finite element crystal plasticity formulation is used to investigate the importance of grain interactions on intragranular plastic deformation in initially untextured polycrystalline aggregates. A statistical analysis reveals that grain interactions are of equal (or more) importance for determining the average intragranular deviations from the applied strain as compared to the orientation of the grain itself. Furthermore, the influence of the surrounding grains is found to extend past nearest neighbor interactions. It is concluded that the stochastic nature of the mesoscale environment must be considered for a proper understanding of the plastic response of sheet metals at the grain-scale

  9. The Effect of Water Deficit stress on Osmotic Metabolites and Anti Oxidant System and Grain and Oil Yield of Amaranth CV. Koniz

    Directory of Open Access Journals (Sweden)

    Mehrdad Yarnia

    2015-01-01

    Full Text Available Drought is one of the most important environmental stresses that highly affect crop growth and yield. But the response of crops to stress depending on the timing of crop growth stages is different. The purpose of this study was to investigate effect of different levels of water stress (irrigation after 50, 80, 110, 140 and 170 mm evaporation from pan on different stages of Amaranth growth (establishment, branching, flowering and grain filling. To find the effects of water deficit stress on this plant it was decided to determine its protein percentage, oil and grain yields under drought stress. Evaluation of physiological characteristics as to the extent of osmotic adjustment and antioxidant activity was also carried out. Results showed that water deficit stress,depending on the severity and duration of stress, caused a reduction between between a minimum of 10 to a maximum of 89 percent in yield, 28 to 70 percent in harvest index, 12 to 32 percent in grain protein and 29 to 97 percent in oil yield. This indicates the high sensitivity of grain and oil yields to severe and prolonged drought stresses. Changes in osmotic substances (proline and soluble carbohydrates showed that this crop under water stress conditions increased proline and soluble carbohydrates by 31 and 50 percents, respectively. Thus, if could be said that under severe droughts the ability of crops to cops with drought will be reduced. Similarly, amaranth, to cope with water stress, increases the amount of antioxidant enzymes like catalase, peroxidase and super oxid dismutase up to 53, 23 and 79%, respectively. Higher amount of super oxid dismutase enzyme produce as the result of drought stress may play an important role to cope with reactive oxygen species and oxidative stresses.

  10. The effect of grain boundary chemistry on the slip transmission process through grain boundaries in Ni3Al

    International Nuclear Information System (INIS)

    Robertson, I.M.; Lee, T.C.; Subramanian, R.; Birnbaum, H.K.

    1992-01-01

    This paper reports on the conditions established in disordered FCC systems for predicting the slip system that will be activated by a grain boundary to relieve a local stress concentration that have been applied to the ordered FCC alloy Ni 3 Al. The slip transfer behavior in hypo-stoichiometric Ni 3 Al with (0.2 at. %B) and without boron was directly observed by performing the deformation experiments in situ in the transmission electron microscope. In the boron-free and boron-doped alloys, lattice dislocations were incorporated in the grain boundary, but did not show evidence of dissociation to grain boundary dislocations or of movement in the grain boundary plane. The stress concentration associated with the dislocation pileup at the grain boundary are relieved by the emission of dislocations from the grain boundary in the boron-doped alloy. The slip system initiated in the adjoining grain obeyed the conditions established for disordered FCC systems. In the boron-free alloy, the primary stress relief mechanism was grain-boundary cracking, although dislocation emission from the grain boundary also occurred and accompanied intergranular crack advance

  11. EXPERIMENTAL STUDY ON THE GAS-LIQUID FLOW IN THE MEMBRANE MICROPORE AERATION BIOREACTOR

    Directory of Open Access Journals (Sweden)

    DONG LIU

    2008-12-01

    Full Text Available Particle Image Velocimetry (PIV has been developed to measure the typical two-phase flow of various work conditions in Membrane Micropore Aeration Bioreactor (MMAB. The fluid phase is separated out using image processing techniques, which provides accurate measurements for the Bioreactor’s flow field, and makes it possible for quantitative analysis of the momentum exchange, heat exchange and the process of micro-admixture. The experimental method PIV used in this paper can preferably measure the complex flow in the reactor and initiates a new approach for the bioreactor design which mainly depends on experience at present.

  12. Study on soil-water retention curves for loess aerated zone

    International Nuclear Information System (INIS)

    Guo Zede; Cheng Jinru; Deng An; Masayuki Mukai; Hideo Kamiyama

    2000-01-01

    The author introduces the measuring method and results of soil-water retention curves of 46 samples taken from ground surface to water table of 28 m depth at CIRP's Field Test Site. The results indicate that the soil-water retention characteristics vary significantly with depth, and the loess-aerated zone at the site can be divided into five layers. From the results, unsaturated hydraulic parameters are deduced, such as conductivity, specific water capacity and equivalent pore diameter. The water velocity calculated from these parameters is satisfactorily consistent with that one obtained from 3 H tracing test carried out at the site

  13. Determination of re-aeration coefficients on high mountain rivers using nuclear techniques

    International Nuclear Information System (INIS)

    Fajardo, Marco

    2001-01-01

    The rivers Machangara and Guayllabamba in Quito, Ecuador, currently are highly polluted, mainly due to human and industrial residues from the city. The objective of this survey is to establish the dynamics of dissolved oxygen in these rivers using the Krypton 85 method to determine the re aeration coefficient in representative sectors of the rivers. In addition, conventional test tracers establish mean flow speed and flow longitudinal dispersion coefficients. The results of this study will be useful for future water quality modelling of these rivers, in order to define their behaviour and auto depurative capacity to treat sludge waters from Quito

  14. Ozone aeration impact on the maturation phase in the process of green waste composting

    Directory of Open Access Journals (Sweden)

    Gliniak Maciej

    2018-01-01

    Full Text Available The paper presents work results on optimization of stabilization phase in the biomass composting process. In these studies, it was examined the influence of two doses of ozone (10 and 20 mgO3·dm-3 in the air used for aeration of stabilization. The results showed the ability to reduce compost maturation time by more than 50%. Application of these ozone doses resulted in a reduction of organic matter content in the stabilizer by 30 to 60%, while reduction of moisture in the material by 20%.

  15. Interplay between grain structure and protein adsorption on functional response of osteoblasts: ultrafine-grained versus coarse-grained substrates.

    Science.gov (United States)

    Misra, R D K; Nune, C; Pesacreta, T C; Somani, M C; Karjalainen, L P

    2013-01-01

    The rapid adsorption of proteins is the starting and primary biological response that occurs when a biomedical device is implanted in the physiological system. The biological response, however, depends on the surface characteristics of the device. Considering the significant interest in nano-/ultrafine surfaces and nanostructured coatings, we describe here, the interplay between grain structure and protein adsorption (bovine serum albumin: BSA) on osteoblasts functions by comparing nanograined/ultrafine-grained (NG/UFG) and coarse-grained (CG: grain size in the micrometer range) substrates by investigating cell-substrate interactions. The protein adsorption on NG/UFG surface was beneficial in favorably modulating biological functions including cell attachment, proliferation, and viability, whereas the effect was less pronounced on protein adsorbed CG surface. Additionally, immunofluorescence studies demonstrated stronger vinculin signals associated with actin stress fibers in the outer regions of the cells and cellular extensions on protein adsorbed NG/UFG surface. The functional response followed the sequence: NG/UFG(BSA) > NG/UFG > CG(BSA) > CG. The differences in the cellular response on bare and protein adsorbed NG/UFG and CG surfaces are attributed to cumulative contribution of grain structure and degree of hydrophilicity. The study underscores the potential advantages of protein adsorption on artificial biomedical devices to enhance the bioactivity and regulate biological functions. Copyright © 2012 Wiley Periodicals, Inc.

  16. Combination of ozonation, activated carbon, and biological aerated filter for advanced treatment of dyeing wastewater for reuse.

    Science.gov (United States)

    Zou, Xiao-Ling

    2015-06-01

    Laboratorial scale experiments were performed to investigate and evaluate the performance and removal characteristics of organics, color, and genotoxicity by an integrated process including ozonation, activated carbon (AC), and biological aerated filter (BAF) for recycling biotreated dyeing wastewater (BTDW) collected from a cotton textile factory. Influent chemical oxygen demand (COD) in the range of 156 - 252 mg/L, 5-day biochemical oxygen demand (BOD5) of 13.5 - 21.7 mg/L, and color of 58 - 76° were observed during the 20-day continuous operation. Outflows with average COD of 43 mg/L, BOD5 of 6.6 mg/L, and color of 5.6° were obtained after being decontaminated by the hybrid system with ozone dosage of 0.25 mg O3applied/mg COD0, 40 min ozonation contact time, 30 min hydraulic retention time (HRT) for AC treatment, and 2.5 h HRT for BAF treatment. More than 82 % of the genotoxicity of BTDW was eliminated in the ozonation unit. The genotoxicity of the BAF effluent was less than 1.33 μg 4-nitroquinoline-N-oxide/L. Ozonation could change the organics molecular structures, destroy chromophores, increase the biodegradability, and obviously reduce the genotoxicity of BTDW. Results showed that the combined process could guarantee water reuse with high quality.

  17. Phase field simulation of grain growth in porous uranium dioxide

    International Nuclear Information System (INIS)

    Ahmed, Karim; Pakarinen, Janne; Allen, Todd; El-Azab, Anter

    2014-01-01

    Graphical abstract: Display Omitted -- Abstract: A novel phase field model has been developed to investigate grain growth in porous polycrystalline UO 2 . Based on a system of Cahn–Hilliard and Allen–Cahn equations, the model takes into consideration both the curvature driven grain boundary motion and pore migration by surface diffusion. As such, the model accounts for the interaction between pore and grain boundary kinetics, which tends to retard the growth process. The phase field model parameters are found in terms of measurable material properties. Hence, quantitative results that can be compared with experiments were obtained. The model has been used to investigate the effect of porosity on the kinetics of grain growth in UO 2 . It is found that, as the amount of porosity increases, grain growth in UO 2 gradually changes from boundary controlled growth to pore controlled growth. For high porosity levels, the grain growth completely stops after a short evolution time. It is also found that the inhomogeneous distribution of pores leads to abnormal grain growth even without taking into account the anisotropy in grain boundary energy and mobility. The effects of porosity, temperature and initial microstructure on grain growth were thoroughly investigated. The model predictions are in good agreement with published experimental results of grain growth in UO 2

  18. Coarse grained model for semiquantitative lipid simulations

    NARCIS (Netherlands)

    Marrink, SJ; de Vries, AH; Mark, AE

    2004-01-01

    This paper describes the parametrization of a new coarse grained (CG) model for lipid and surfactant systems. Reduction of the number of degrees of freedom together with the use of short range potentials makes it computationally very efficient. Compared to atomistic models a gain of 3-4 orders of

  19. Cycling of grain legume residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1995-01-01

    Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initial...... management methods in order to conserve grain legume residue N sources within the soil-plant system....

  20. The Martini Coarse-Grained Force Field

    NARCIS (Netherlands)

    Periole, X.; Marrink, S.J.; Monticelli, Luca; Salonen, Emppu

    2013-01-01

    The Martini force field is a coarse-grained force field suited for molecular dynamics simulations of biomolecular systems. The force field has been parameterized in a systematic way, based on the reproduction of partitioning free energies between polar and apolar phases of a large number of chemical

  1. Comparison of alternative beef production systems based on forage finishing or grain-forage diets with or without growth promotants: 2. Meat quality, fatty acid composition, and overall palatability.

    Science.gov (United States)

    Faucitano, L; Chouinard, P Y; Fortin, J; Mandell, I B; Lafrenière, C; Girard, C L; Berthiaume, R

    2008-07-01

    Five beef cattle management regimens were evaluated for their effect on meat quality, fatty acid composition, and overall palatability of the longis-simus dorsi (LD) muscle in Angus cross steers. A 98-d growing phase was conducted using grass silage with or without supplementation of growth promotants (Revalor G and Rumensin) or soybean meal. Dietary treatments in the finishing phase were developed with or without supplementation of growth promotants based on exclusive feeding of forages with no grain supplementation, or the feeding of grain:forage (70:30) diets. Growth promotants increased (P forages increased the proportion of cis-9, cis-12, cis-15 C18:3 as well as several other isomers of the n-3 family and decreased in the ratio of n-6 to n-3 fatty acids in the LD muscle as compared with supplementing grain (P forage-based diet increased (P Forage feeding also increased the proportion of cis-9, trans-11 C18:2 (P forage-finishing and growth promotants-free beef production system.

  2. Efficient removal of perfluorooctane sulfonate from aqueous film-forming foam solution by aeration-foam collection.

    Science.gov (United States)

    Meng, Pingping; Deng, Shubo; Maimaiti, Ayiguli; Wang, Bin; Huang, Jun; Wang, Yujue; Cousins, Ian T; Yu, Gang

    2018-07-01

    Aqueous film-forming foams (AFFFs) used in fire-fighting are one of the main contamination sources of perfluorooctane sulfonate (PFOS) to the subterranean environment, requiring high costs for remediation. In this study, a method that combined aeration and foam collection was presented to remove PFOS from a commercially available AFFF solution. The method utilized the strong surfactant properties of PFOS that cause it to be highly enriched at air-water interfaces. With an aeration flow rate of 75 mL/min, PFOS removal percent reached 96% after 2 h, and the PFOS concentration in the collected foam was up to 6.5 mmol/L, beneficial for PFOS recovery and reuse. Increasing the aeration flow rate, ionic strength and concentration of co-existing surfactant, as well as decreasing the initial PFOS concentration, increased the removal percents of PFOS by increasing the foam volume, but reduced the enrichment of PFOS in the foams. With the assistance of a co-existing hydrocarbon surfactant, PFOS removal percent was above 99.9% after aeration-foam collection for 2 h and the enrichment factor exceeded 8400. Aeration-foam collection was less effective for short-chain perfluoroalkyl substances due to their relatively lower surface activity. Aeration-foam collection was found to be effective for the removal of high concentrations of PFOS from AFFF-contaminated wastewater, and the concentrated PFOS in the collected foam can be reused. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Quantum theory of multiscale coarse-graining.

    Science.gov (United States)

    Han, Yining; Jin, Jaehyeok; Wagner, Jacob W; Voth, Gregory A

    2018-03-14

    Coarse-grained (CG) models serve as a powerful tool to simulate molecular systems at much longer temporal and spatial scales. Previously, CG models and methods have been built upon classical statistical mechanics. The present paper develops a theory and numerical methodology for coarse-graining in quantum statistical mechanics, by generalizing the multiscale coarse-graining (MS-CG) method to quantum Boltzmann statistics. A rigorous derivation of the sufficient thermodynamic consistency condition is first presented via imaginary time Feynman path integrals. It identifies the optimal choice of CG action functional and effective quantum CG (qCG) force field to generate a quantum MS-CG (qMS-CG) description of the equilibrium system that is consistent with the quantum fine-grained model projected onto the CG variables. A variational principle then provides a class of algorithms for optimally approximating the qMS-CG force fields. Specifically, a variational method based on force matching, which was also adopted in the classical MS-CG theory, is generalized to quantum Boltzmann statistics. The qMS-CG numerical algorithms and practical issues in implementing this variational minimization procedure are also discussed. Then, two numerical examples are presented to demonstrate the method. Finally, as an alternative strategy, a quasi-classical approximation for the thermal density matrix expressed in the CG variables is derived. This approach provides an interesting physical picture for coarse-graining in quantum Boltzmann statistical mechanics in which the consistency with the quantum particle delocalization is obviously manifest, and it opens up an avenue for using path integral centroid-based effective classical force fields in a coarse-graining methodology.

  4. Quantum theory of multiscale coarse-graining

    Science.gov (United States)

    Han, Yining; Jin, Jaehyeok; Wagner, Jacob W.; Voth, Gregory A.

    2018-03-01

    Coarse-grained (CG) models serve as a powerful tool to simulate molecular systems at much longer temporal and spatial scales. Previously, CG models and methods have been built upon classical statistical mechanics. The present paper develops a theory and numerical methodology for coarse-graining in quantum statistical mechanics, by generalizing the multiscale coarse-graining (MS-CG) method to quantum Boltzmann statistics. A rigorous derivation of the sufficient thermodynamic consistency condition is first presented via imaginary time Feynman path integrals. It identifies the optimal choice of CG action functional and effective quantum CG (qCG) force field to generate a quantum MS-CG (qMS-CG) description of the equilibrium system that is consistent with the quantum fine-grained model projected onto the CG variables. A variational principle then provides a class of algorithms for optimally approximating the qMS-CG force fields. Specifically, a variational method based on force matching, which was also adopted in the classical MS-CG theory, is generalized to quantum Boltzmann statistics. The qMS-CG numerical algorithms and practical issues in implementing this variational minimization procedure are also discussed. Then, two numerical examples are presented to demonstrate the method. Finally, as an alternative strategy, a quasi-classical approximation for the thermal density matrix expressed in the CG variables is derived. This approach provides an interesting physical picture for coarse-graining in quantum Boltzmann statistical mechanics in which the consistency with the quantum particle delocalization is obviously manifest, and it opens up an avenue for using path integral centroid-based effective classical force fields in a coarse-graining methodology.

  5. Hydrogen peroxide-enhanced iron-mediated aeration for the treatment of mature landfill leachate.

    Science.gov (United States)

    Deng, Yang; Englehardt, James D

    2008-05-01

    Municipal landfill leachate is being disallowed for biological treatment by some sewer authorities due to its recalcitrance and corrosiveness, and therefore physicochemical treatment may be needed. In this paper, hydrogen peroxide-enhanced iron (Fe(0))-mediated aeration (IMA) was studied as an alternative for the treatment of mature landfill leachate. Bench-scale Taguchi array screening tests and full factorial tests were conducted. Iron grade, initial pH, H(2)O(2) addition rate, and aeration rate significantly influenced both overall chemical oxygen demand (COD) removal and iron consumption. In the enhanced IMA-treated leachate at an initial pH of 8.2, COD was reduced by 50% due to oxidation and coagulation, a level almost equivalent to those obtained by Fenton treatment. Meanwhile, the 5-day biochemical oxygen demand (BOD(5))/COD ratio was increased from 0.02 to 0.17. In particular, the effect of initial pH became minor at H(2)O(2) addition rate greater than the theoretical demand for complete oxidation of organics by H(2)O(2). In addition, 83% of 300 mg/L ammonia nitrogen and 38% of 8.30 mS/cm electrical conductivity were removed when the initial pH was not adjusted. Based on these results, the process appears suitable for treatment of mature leachate.

  6. Eco-toxicological studies of diesel and biodiesel fuels in aerated soil

    International Nuclear Information System (INIS)

    Lapinskiene, Asta; Martinkus, Povilas; Rebzdaite, Vilija

    2006-01-01

    The goal of this study was to compare diesel fuel to biodiesel fuel by determining the toxicity of analyzed materials and by quantitatively evaluating the microbial transformation of these materials in non-adapted aerated soil. The toxicity levels were determined by measuring the respiration of soil microorganisms as well as the activity of soil dehydrogenases. The quantitative evaluation of biotransformation of analyzed materials was based on the principle of balancing carbon in the following final products: (a) carbon dioxide; (b) humus compounds; (c) the remainder of non-biodegraded analyzed material; and (d) intermediate biodegradation products and the biomass of microorganisms. The results of these studies indicate that diesel fuel has toxic properties at concentrations above 3% (w/w), while biodiesel fuel has none up to a concentration of 12% (w/w). The diesel fuel is more resistant to biodegradation and produces more humus products. The biodiesel is easily biotransformed. - The comparison of diesel and biodiesel fuels' eco-toxicological parameters in non-adapted aerated soil is relevant when considering the effects of these substances on the environment in cases of accidental spills

  7. Removal of Iron and Manganese Using Cascade Aerator and Limestone Roughing Filter

    Directory of Open Access Journals (Sweden)

    Mohd Sanusi Azrin

    2016-01-01

    Full Text Available Combination between oxidation and filtration can be used for removing iron and manganese from groundwater especially when the concentrations of these metals were high. This study focused on the effectiveness of the cascade aerator and the size of the limestone filter media to remove iron and manganese from groundwater. Water samples used for this study were collected from orphanage home, Rumah Nur Kasih, Taiping. Universiti Sains Malaysia (USM has provided a tube well of 15 m depth and 150 mm diameter for the orphanage home. However, the water cannot be used for domestic consumption due to high amount of iron and manganese at 6.48 and 1.9 mg/L which exceeded the drinking water standard of 0.3 and 0.1 mg/L respectively. Using laboratory physical model, the study has shown that the removals of iron and manganese have reduce the concentration until 0.17 and 0.2 mg/L respectively. Thus, the results from this study which utilize cascade aerator and limestone roughing filter could be implemented on site for the community to use the ground water for domestic purposes.

  8. Functioning of microbial complexes in aerated layers of a highmoor peat bog

    Science.gov (United States)

    Golovchenko, A. V.; Bogdanova, O. Yu.; Stepanov, A. L.; Polyanskaya, L. M.; Zvyagintsev, D. G.

    2010-09-01

    Monitoring was carried out using the luminescent-microscopic method of the abundance parameters of different groups of microorganisms in a monolith and in the mixed layers of a highmoor peat bog (oligotrophic residual-eutrophic peat soil) in a year-long model experiment. The increase of the aeration as a result of mixing of the layers enhanced the activity of the soil fungi. This was attested to by the following changes: the increase of the fungal mycelium length by 6 times and of the fungal biomass by 4 times and the double decrease of the fraction of spores in the fungal complex. The response of the fungal complex to mixing was different in the different layers of the peat bog. The maximal effect was observed in the T1 layer and the minimal one in the T2 layer. The emission of CO2 in the mixed samples was 1.5-2 times higher than that from the undisturbed peat samples. In contrast with the fungi, the bacteria and actinomycetes were not affected by the aeration of the highmoor layers.

  9. Effect of auxotrophies on yeast performance in aerated fed-batch reactor

    Energy Technology Data Exchange (ETDEWEB)

    Landi, Carmine; Paciello, Lucia [Dept. Ingegneria Industriale, Universita di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Salerno (Italy); Alteriis, Elisabetta de [Dept. Biologia Strutturale e Funzionale, Universita degli Studi di Napoli ' Federico II' , Via Cinthia, 80100 Napoli (Italy); Brambilla, Luca [Dept. Biotecnologie e Bioscienze, Universita Milano-Bicocca, Piazza della Scienza, 20126 Milano (Italy); Parascandola, Palma, E-mail: pparascandola@unisa.it [Dept. Ingegneria Industriale, Universita di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Salerno (Italy)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer The paper contributes to fill the gap existing between the basic and applied research. Black-Right-Pointing-Pointer Mathematical model sheds light on the physiology of auxotrophic yeast strains. Black-Right-Pointing-Pointer Yeast behavior in fed-batch is influenced by biological and environmental determinants. Black-Right-Pointing-Pointer Process optimization would make possible the production of heterologous proteins which are not yet on the market. -- Abstract: A systematic investigation on the effects of auxotrophies on the performance of yeast in aerated fed-batch reactor was carried out. Six isogenic strains from the CEN.PK family of Saccharomyces cerevisiae, one prototroph and five auxotrophs, were grown in aerated fed-batch reactor using the same operative conditions and a proper nutritional supplementation. The performance of the strains, in terms of final biomass decreased with increasing the number of auxotrophies. Auxotrophy for leucine exerted a profound negative effect on the performance of the strains. Accumulation of reactive oxygen species (ROS) in the cells of the strain carrying four auxotrophies and its significant viability loss, were indicative of an oxidative stress response induced by exposure of cells to the environmental conditions. The mathematical model was fundamental to highlight how the carbon flux, depending on the number and type of auxotrophies, was diverted towards the production of increasingly large quantities of energy for maintenance.

  10. Effect of auxotrophies on yeast performance in aerated fed-batch reactor

    International Nuclear Information System (INIS)

    Landi, Carmine; Paciello, Lucia; Alteriis, Elisabetta de; Brambilla, Luca; Parascandola, Palma

    2011-01-01

    Highlights: ► The paper contributes to fill the gap existing between the basic and applied research. ► Mathematical model sheds light on the physiology of auxotrophic yeast strains. ► Yeast behavior in fed-batch is influenced by biological and environmental determinants. ► Process optimization would make possible the production of heterologous proteins which are not yet on the market. -- Abstract: A systematic investigation on the effects of auxotrophies on the performance of yeast in aerated fed-batch reactor was carried out. Six isogenic strains from the CEN.PK family of Saccharomyces cerevisiae, one prototroph and five auxotrophs, were grown in aerated fed-batch reactor using the same operative conditions and a proper nutritional supplementation. The performance of the strains, in terms of final biomass decreased with increasing the number of auxotrophies. Auxotrophy for leucine exerted a profound negative effect on the performance of the strains. Accumulation of reactive oxygen species (ROS) in the cells of the strain carrying four auxotrophies and its significant viability loss, were indicative of an oxidative stress response induced by exposure of cells to the environmental conditions. The mathematical model was fundamental to highlight how the carbon flux, depending on the number and type of auxotrophies, was diverted towards the production of increasingly large quantities of energy for maintenance.

  11. Cytosine modifications after gamma irradiation in aerated aqueous solution of Escherichia coli DNA

    International Nuclear Information System (INIS)

    Polverelli, M.

    1983-04-01

    After gamma irradiation of cytosine in aerated aqueous solution and utilization of various spectrometric methods (mass spectrometry, proton nuclear magnetic resonance and infrared spectrometry) about ten new radiolysis products were identified. The formation of N-glycolylbiuret in H 2 18 O aqueous solution of irradiated cytosine at pH 4,5 indicated that the preferred 18 OH hydroxyl radical attack was at C-5. The formation of trans 1-carbamoyl-4,5 dihydroxyimidazolidin-2 oxo which is the major product after cytosine pyrimidine ring rearrangement took place preferentially at neutral pH, while N-glycolylbiuret predominated at pH 4,5. The deamination pathway was predominant when cytosine was irradiated at acidic pH values (pH 2 ) or in copper complexes. The development of a new acid hydrolysis method using fluorhydric acid stabilized in pyridine made easier the evaluation of cytosine modifications after gamma irradiation in aerated aqueous solution of E. Coli DNA- 14 C-2 cytosine. This hydrolytic agent removed the modified bases from the polynucleotidic chain. A difference was found between the proportion of radiolytic products removed by acid hydrolysis and by irradiation of the free base in solution [fr

  12. Sustained Aeration of Infant Lungs (SAIL) trial: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Foglia, Elizabeth E; Owen, Louise S; Thio, Marta; Ratcliffe, Sarah J; Lista, Gianluca; Te Pas, Arjan; Hummler, Helmut; Nadkarni, Vinay; Ades, Anne; Posencheg, Michael; Keszler, Martin; Davis, Peter; Kirpalani, Haresh

    2015-03-15

    Extremely preterm infants require assistance recruiting the lung to establish a functional residual capacity after birth. Sustained inflation (SI) combined with positive end expiratory pressure (PEEP) may be a superior method of aerating the lung compared with intermittent positive pressure ventilation (IPPV) with PEEP in extremely preterm infants. The Sustained Aeration of Infant Lungs (SAIL) trial was designed to study this question. This multisite prospective randomized controlled unblinded trial will recruit 600 infants of 23 to 26 weeks gestational age who require respiratory support at birth. Infants in both arms will be treated with PEEP 5 to 7 cm H2O throughout the resuscitation. The study intervention consists of performing an initial SI (20 cm H20 for 15 seconds) followed by a second SI (25 cm H2O for 15 seconds), and then PEEP with or without IPPV, as needed. The control group will be treated with initial IPPV with PEEP. The primary outcome is the combined endpoint of bronchopulmonary dysplasia or death at 36 weeks post-menstrual age. www.clinicaltrials.gov , Trial identifier NCT02139800 , Registered 13 May 2014.

  13. Performance of Submerged Aerated Biofilters for Wastewater Treatment and Excess Biological Sludge Production

    Directory of Open Access Journals (Sweden)

    Mohammad A. Baghapour

    2007-01-01

    Full Text Available Minimizing sludge production in the treatment facility is a reasonable measure to reduce waste in sewage treatment, especially as regards excess biological sludge. In this regard, submerged aerated filters' (SAFs have recently found increasing applications in treatment facilities. Thanks to their treatment mechanism, they have greatly contributed to reduction of waste production and, thereby, to reduced treatment costs. Biomass growths of both attached and suspended types take place in these filters. However, little attention has been paid to suspended sludge production and to its relationship with the physical properties of the filter. The design and application criterion for these filters is the organic loadings on unit of area or unit of volume of the media used in these filters. In this study, four filters with different physical properties and different specific areas were loaded with synthetic wastewater made of low-fat dry milk powder for five different hydraulic retention times to evaluate excess sludge production rates in submerged aerated filters. It was shown that increasing specific area increased SCOD removal efficiency up to a maximum level in saturated growths after which point the removal efficiency remained unchanging or decreased. The results also revealed that decreased hydraulic retention times increased sludge production rates in all the study columns and that media with higher porosity levels produced less excess sludge despite lower pollutant removal efficiency.

  14. Influence of addition of calcium sulfate dihydrate on drying of autoclaved aerated concrete

    Science.gov (United States)

    Małaszkiewicz, Dorota; Chojnowski, Jacek

    2017-11-01

    The quality of the autoclaved aerated concrete (AAC) strongly depends on the chemical composition of the raw materials, as well as on the process of the hydrothermal reaction during autoclaving. Performance parameters depend on material structure: fine micron-scale matrix porosity generated by the packing of thin tobermorite plates and coarse aeration pores arising from the foaming of wet mix. In this study the binder varied in calcium sulfate dihydrate (CaSO4ṡ2H2O) content. Five series of AAC specimens were produced, with gypsum content 0; 0.55; 1.15; 2.3 and 3.5% of dry mass respectively. AAC units were produced in UNIPOL technology. The study presents experimental results of AAC moisture stabilization. The initial moisture content was determined directly after autoclaving. Slower drying process was observed for samples containing over 2% of gypsum. Whereas other performance parameters, compressive and tensile strength, as well as water absorption and capillary rise, were significantly better comparing to the reference AAC samples.

  15. Coarse-graining complex dynamics

    DEFF Research Database (Denmark)

    Sibani, Paolo

    2013-01-01

    Continuous Time Random Walks (CTRW) are widely used to coarse-grain the evolution of systems jumping from a metastable sub-set of their configuration space, or trap, to another via rare intermittent events. The multi-scaled behavior typical of complex dynamics is provided by a fat...... macroscopic variables all produce identical long time relaxation behaviors. Hence, CTRW shed no light on the link between microscopic and macroscopic dynamics. We then highlight how a more recent approach, Record Dynamics (RD) provides a viable alternative, based on a very different set of physical ideas......: while CTRW make use of a renewal process involving identical traps of infinite size, RD embodies a dynamical entrenchment into a hierarchy of traps which are finite in size and possess different degrees of meta-stability. We show in particular how RD produces the stretched exponential, power...

  16. Quality evaluation of carbonaceous industrial by-products and its effect on properties of autoclave aerated concrete

    Science.gov (United States)

    Fomina, E. V.; Lesovik, V. S.; Fomin, A. E.; Kozhukhova, N. I.; Lebedev, M. S.

    2018-03-01

    Argillite is a carbonaceous industrial by-product that is a potential source in environmentally friendly and source-saving construction industry. In this research, chemical and mineral composition as well as particle size distribution of argillite were studied and used to develop autoclave aerated concrete as partial substitute of quartz sand. Effect of the argillite as a mineral admixture in autoclave aerated concrete was investigated in terms of compressive and tensile strength, density, heat conductivity etc. The obtained results demonstrated an efficiency of argillite as an energy-saving material in autoclave construction composites.

  17. Grain Flow at High Stresses

    Science.gov (United States)

    McSaveney, M. J.

    2015-12-01

    The transport mechanism of rapid long-runout rock avalanches was a hotly debated topic when I came on the scene in 1967. So how come it is still debated today? My explanation is that it is the expected outcome of peer review, poor comprehension, and technological advances outpacing intellectual advances. Why think about the problem when we can model it! So let us think about the problem. Shreve thought that rock avalanches fell upon and trapped a layer of air. What physics was he thinking about? It is how feathers and tissue papers fall. When my rock avalanches fly, they fly like unlubricated bricks using the physics of projectiles and ballistics. But the main transport mechanism is not flight. The dominant impression from watching a rock avalanche in motion is of fluid flow, as Heim described it in 1882. A rock avalanche is a very large grain flow. Bagnold studied dispersive grain flows, but why should one assume that rock avalanches are dispersive grain flows as many do. The more common grain flow type is a dense grain flow and rock avalanches are dense grain flows in which the weight can and does generate very high stresses at grain contacts. Brittle rock deforms elastically up to its compressive strength, whereupon it breaks, releasing elastic strain as transient elastic strain (seismic energy to a seismologist, acoustic energy to a physicist). Melosh and others have shown that acoustic energy can fluidize a grain mass. There is no exotic physics behind grain flow at high stress. When grains break, the released elastic strain has to go somewhere, and it goes somewhere principally by transmission though grain contacts. Depending on the state of stress at the grain contact, the contact will pass the stress or will slip at conventional values of Coulomb friction. Enough thinking! A physical model of the entire process is too big for any laboratory. So whose numerical model will do it?

  18. Grain dust and the lungs.

    Science.gov (United States)

    Chan-Yeung, M.; Ashley, M. J.; Grzybowski, S.

    1978-01-01

    Grain dust is composed of a large number of materials, including various types of grain and their disintegration products, silica, fungi, insects and mites. The clinical syndromes described in relation to exposure to grain dust are chronic bronchitis, grain dust asthma, extrinsic allergic alveolitis, grain fever and silo-filler's lung. Rhinitis and conjunctivitis are also common in grain workers. While the concentration and the quality of dust influence the frequency and the type of clinical syndrome in grain workers, host factors are also important. Of the latter, smoking is the most important factor influencing the frequency of chronic bronchitis. The role of atopy and of bronchial hyperreactivity in grain dust asthma has yet to be assessed. Several well designed studies are currently being carried out in North America not only to delineate the frequency of the respiratory abnormalities, the pathogenetic mechanisms and the host factors, but also to establish a meaningful threshold limit concentration for grain dust. Images p1272-a PMID:348288

  19. Synthesis and thermoelectric properties of fine-grained FeVSb system half-Heusler compound polycrystals with high phase purity

    International Nuclear Information System (INIS)

    Zou Minmin; Li Jingfeng; Guo Peijun; Kita, Takuji

    2010-01-01

    Nearly single-phased FeVSb half-Heusler compound thermoelectric materials with fine grains of diameter 100-200 nm were prepared from their elemental powders by combining mechanical alloying (MA) and spark plasma sintering. The resultant bulk samples showed a relatively low room-temperature electrical resistivity on the order of 10 μΩm, and a moderate negative Seebeck coefficient with a maximum value of -175 μV K -1 at 300 0 C. It was found that proper excessive addition of V relative to the stoichiometric composition (FeVSb) during MA enhanced the phase purity and hence the power factor of the spark plasma sintered samples, resulting in a large power factor value of 2480 μW m -1 K -2 when the elemental powders were mixed with the composition FeV 1.15 Sb. Its thermal conductivity was significantly reduced mainly due to refined grain sizes, resulting in a high dimensionless figure of merit ZT of 0.31 at a low-to-mid temperature (300 0 C) as for undoped half-Heusler compounds.

  20. Modelling of grain refinement driven by negative grain boundary energy

    Czech Academy of Sciences Publication Activity Database

    Fischer, F. D.; Zickler, G. A.; Svoboda, Jiří

    2017-01-01

    Roč. 97, č. 23 (2017), s. 1963-1977 ISSN 1478-6435 R&D Projects: GA ČR(CZ) GA15-06390S Institutional support: RVO:68081723 Keywords : grain refinement * grain nucleation * distribution concept * jump on distribution function Subject RIV: BJ - Thermodynamics OBOR OECD: Thermodynamics Impact factor: 1.505, year: 2016