WorldWideScience

Sample records for solids loading rates

  1. Impact of Organic Loading Rate on Psychrophilic Anaerobic Digestion of Solid Dairy Manure

    Directory of Open Access Journals (Sweden)

    Noori M. Cata Saady

    2015-03-01

    Full Text Available Increasing the feed total solids to anaerobic digester improves the process economics and decreases the volume of liquid effluent from current wet anaerobic digestion. The objective of this study was to develop a novel psychrophilic (20 °C anaerobic digestion technology of undiluted cow feces (total solids of 11%–16%. Two sets of duplicate laboratory-scale sequence batch bioreactors have been operated at organic loading rates (OLR of 6.0 to 8.0 g total chemical oxygen demand (TCOD kg−1 inoculum day−1 (d−1 during 210 days. The results demonstrated that the process is feasible at treatment cycle length (TCL of 21 days; however, the quality of cow feces rather than the OLR had a direct influence on the specific methane yield (SMY. The SMY ranged between 124.5 ± 1.4 and 227.9 ± 4.8 normalized liter (NL CH4 kg−1 volatile solids (VS fed d−1. Substrate-to-inoculum mass ratio (SIR was 0.63 ± 0.05, 0.90 ± 0.09, and 1.06 ± 0.07 at OLR of 6.0, 7.0, and 8.0 g TCOD kg−1 inoculum d−1, respectively. No volatile fatty acids (VFAs accumulation has been observed which indicated that hydrolysis was the rate limiting step and VFAs have been consumed immediately. Bioreactors performance consistency in terms of the level of SMYs, VFAs concentrations at end of the TCL, pH stability and volatile solids reduction indicates a stable and reproducible process during the entire operation.

  2. Thermophilic co-digestion feasibility of distillers grains and swine manure: effect of C/N ratio and organic loading rate during high solid anaerobic digestion (HSAD).

    Science.gov (United States)

    Sensai, P; Thangamani, A; Visvanathan, C

    2014-01-01

    Anaerobic co-digestion of high solids containing distillers grains and swine manure (total solids, 27 +/- 2% and 18 +/- 2%, respectively) was evaluated in this study to assess the effect of C/N ratio and organic loading rate (OLR). Feed mixture was balanced to achieve a C/N ratio of 30/1 by mixing distillers grains and swine manure. Pilot-scale co-digestion of distillers grains and swine manure was carried out under thermophilic conditions in the continuous mode for seven different OLRs from R1 to R7 (3.5, 5, 6, 8, 10, 12 and 14 kg VS/m3 day) under high solid anaerobic digestion. The methane yield and volatile solid (VS) removal were consistent; ranging from 0.33 to 0.34 m3CH4/kg VS day and 50-53%, respectively, until OLR 8 kg VS/m3 day. After which methane yield and VS removal significantly decreased to 0.26 m3 CH4/kg VS day and 42%, respectively, when OLR was increased to 14 kg VS/m3 day. However, during operation, at OLR of 10 kg VS/m3 day, the methane yield and VS removal increased after the 19th day to 0.33 m3 CH4/kg VS day and 46%, respectively, indicating that a longer acclimatization period is required by methanogens at a higher loading rate.

  3. Characterization of Carbamazepine-Loaded Solid Lipid ...

    African Journals Online (AJOL)

    loaded solid lipid nanoparticles by RESS as well as their characterization has been achieved in this study. Keywords: Rapid expansion of supercritical fluid, Stearic acid, Solid lipid nanoparticles, Carbamazepine, Co-precipitation ...

  4. Optimisation of single-phase dry-thermophilic anaerobic digestion under high organic loading rates of industrial municipal solid waste: population dynamics.

    Science.gov (United States)

    Zahedi, S; Sales, D; Romero, L I; Solera, R

    2013-10-01

    Different high feed organic loading rates (OLRs) (from 5.7 g to 46.0 g TVS/l/d) or hydraulic retention times (HRTs) (from 15 d to 2 d) in single-phase dry-thermophilic anaerobic digestion (AD) of organic fraction municipal solid waste (OFMSW) were investigated. The specific gas production (SGP) values (0.25-0.53 m(3)/kg TVS) and the percentages of Eubacteria, Archaea, H2-utilising methanogens (HUMs) and acetate-utilising methanogens (AUMs) were stable within the ranges 80.2-91.1%, 12.4-18.5%, 4.4-9.8% and 5.5-10.9%, respectively. A HUM/AUM ratio greater than 0.7 seems to be necessary to maintain very low partial pressures of H2 required for dry AD process. Increasing OLR resulted in an increase in all the populations, except for propionate-utilising acetogens (PUAs). Optimal conditions were obtained at 3d HRT (OLR=30.7 g TVS/l/d), which is lower than the doubling time of acetogens and methanogens. The methane production (MP) was clearly higher than those reported in AD of OFMSW. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. High burn rate solid composite propellants

    Science.gov (United States)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  6. Working memory load modulates microsaccadic rate.

    Science.gov (United States)

    Dalmaso, Mario; Castelli, Luigi; Scatturin, Pietro; Galfano, Giovanni

    2017-03-01

    Microsaccades are tiny eye movements that individuals perform unconsciously during fixation. Despite that the nature and the functions of microsaccades are still lively debated, recent evidence has shown an association between these micro eye movements and higher order cognitive processes. Here, in two experiments, we specifically focused on working memory and addressed whether differential memory load could be reflected in a modulation of microsaccade dynamics. In Experiment 1, participants memorized a numerical sequence composed of either two (low-load condition) or five digits (high-load condition), appearing at fixation. The results showed a reduction in the microsaccadic rate in the high-load compared to the low-load condition. In Experiment 2, five red or green digits were always presented at fixation. Participants either memorized the color (low-load condition) or the five digits (high-load condition). Hence, visual stimuli were exactly the same in both conditions. Consistent with Experiment 1, microsaccadic rate was lower in the high-load than in the low-load condition. Overall, these findings reveal that an engagement of working memory can have an impact on microsaccadic rate, consistent with the view that microsaccade generation is pervious to top-down processes.

  7. Duration of load effects of solid wood

    DEFF Research Database (Denmark)

    Svensson, Staffan

    Test methods for studying the effect of long-term loading on the load carrying capacity of structural wood are discussed. The impact of sampling procedures on test results is investigated and is exemplified. It is concluded from this investigation that the sampling method has a significant impact...

  8. Loading rates in California inferred from aftershocks

    Directory of Open Access Journals (Sweden)

    C. Narteau

    2008-03-01

    Full Text Available We estimate the loading rate in southern California and the change in stress induced by a transient slip event across the San Andreas fault (SAF system in central California, using a model of static fatigue. We analyze temporal properties of aftershocks in order to determine the time delay before the onset of the power law aftershock decay rate. In creep-slip and stick-slip zones, we show that the rate of change of this delay is related to seismic and aseismic deformation across the SAF system. Furthermore, we show that this rate of change is proportional to the deficit of slip rate along the SAF. This new relationship between geodetic and seismological data is in good agreement with predictions from a Limited Power Law model in which the evolution of the duration of a linear aftershock decay rate over short time results from variations in the load of the brittle upper crust.

  9. Handball load and shoulder injury rate

    DEFF Research Database (Denmark)

    Møller, M.; Nielsen, R.O.; Attermann, J.

    2017-01-01

    Background Knowledge of injury patterns, an essential step towards injury prevention, is lacking in youth handball. Aim To investigate if an increase in handball load is associated with increased shoulder injury rates compared with a minor increase or decrease, and if an association is influenced...... by scapular control, isometric shoulder strength or glenohumeral range of motion (ROM). Methods 679 players (14-18 years) provided weekly reports on shoulder injury and handball load (training and competition hours) over 31 weeks using the SMS, phone and medical examination system. Handball load in a given...... week was categorised into (1) 60% relative to the weekly average amount of handball load the preceding 4 weeks. Assessment of shoulder isometric rotational and abduction strength, ROM and scapular control...

  10. Estimation of restaurant solid waste generation rates

    International Nuclear Information System (INIS)

    Heck, H.H.; Major, I.

    2002-01-01

    Most solid waste utilities try to create a billing schedule that is proportional to solid waste generation rates. This research was trying to determine if the current billing rate structure was appropriate or if a different rate structure should be implemented. A multiple regression model with forward stepwise addition was developed which accurately predicts weekly solid waste generation rates for restaurants. The model was based on a study of daily solid waste generation at twenty-one different businesses. The weight and volume of solid waste generated was measure daily for two weeks during the winter and two weeks during the summer. Researchers followed the collection truck and measured the volume and weight of the container contents. Data was collected on the following independent variables describing each establishment; weight of waste per collection, volume per collection, container utilization factor, building area, contract haulers bill, yearly property tax, yearly solid waste tax, average number of collections per week, type of restaurant, modal number of collections per week, storage container size, waste density, number of employees, number of hours open per week, and weekly collection capacity (collections per week times storage container size). Independent variables were added to the regression equation based on their partial correlation coefficient and confidence level. The regression equations developed had correlation coefficients of 0.87 to 1.00, which was much better than the correlation coefficient (0.84) of an existing model DeGeare and Ongerth (1971) and a correlation coefficient of 0.54 based on the current solid waste disposal tax. (author)

  11. Solids loading evaluation for HB-line scrap recovery filters

    International Nuclear Information System (INIS)

    Crowder, M.L.

    2000-01-01

    The HB-Line Scrap Recovery facility uses wire screen filters to remove solids from plutonium-containing solutions transferred from the slab tank dissolvers. At times, the accumulation of solids is large enough to cause blinding (i.e., pluggage) of the filters. If the solids contain undissolved plutonium, significant accumulation of fissile material could impact operations. To address this potential issue, experiments were performed to define the minimum solids required to completely blind a filter. The solids loading experiments were performed by arranging 25- and 10-microm HB-Line filters in series to simulate the equipment in the scrap recovery process. Separate tests were performed using coarse and fine glass frit and cerium oxide powder suspended in 35 wt% sodium nitrate solution using a small turbine mixer. The solution and solids were transferred from a reservoir through the filter housings by vacuum. In each case, the 25-microm filter blinded first and was full of wet cake. After drying and accounting for the sodium nitrate in the filter cake, the following results were obtained. The results of the solids loading tests demonstrated that at least 800 g of solids accumulated in the filter housing before flow stopped. The actual amount of collected material was dependent upon the physical properties of the solids such as density and particle size. The mass of solids collected by the blinded 25-microm filter increased when successively finer solids were used in the experiments. Based on these results, one should anticipate that filters in the HB-Line Scrap Recovery Facility have the potential to collect similar quantities of material before transfer of solution from the dissolvers is severely impacted

  12. Torque and Axial Loading Physics for Measuring Atmospheric Icing Load and Icing Rate

    OpenAIRE

    Mughal, Umair Najeeb; Virk, Muhammad Shakeel

    2015-01-01

    Measuring icing load and icing rate are important parameters for an atmospheric icing sensor. A new icing sensor has recently been designed and developed at Narvik University College for measuring atmospheric icing rate, icing load and icing type. Unlike the existing atmospheric icing sensors commercially available in market, which uses the axial loading for measuring icing load and icing rate, this new sensory system measures icing load and icing rate using the torque loading physics. The pe...

  13. Is earthquake rate in south Iceland modified by seasonal loading?

    Science.gov (United States)

    Jonsson, S.; Aoki, Y.; Drouin, V.

    2017-12-01

    Several temporarily varying processes have the potential of modifying the rate of earthquakes in the south Iceland seismic zone, one of the two most active seismic zones in Iceland. These include solid earth tides, seasonal meteorological effects and influence from passing weather systems, and variations in snow and glacier loads. In this study we investigate the influence these processes may have on crustal stresses and stressing rates in the seismic zone and assess whether they appear to be influencing the earthquake rate. While historical earthquakes in the south Iceland have preferentially occurred in early summer, this tendency is less clear for small earthquakes. The local earthquake catalogue (going back to 1991, magnitude of completeness M6+ earthquakes, which occurred in June 2000 and May 2008. Standard Reasenberg earthquake declustering or more involved model independent stochastic declustering algorithms are not capable of fully eliminating the aftershocks from the catalogue. We therefore inspected the catalogue for the time period before 2000 and it shows limited seasonal tendency in earthquake occurrence. Our preliminary results show no clear correlation between earthquake rates and short-term stressing variations induced from solid earth tides or passing storms. Seasonal meteorological effects also appear to be too small to influence the earthquake activity. Snow and glacier load variations induce significant vertical motions in the area with peak loading occurring in Spring (April-May) and maximum unloading in Fall (Sept.-Oct.). Early summer occurrence of historical earthquakes therefore correlates with early unloading rather than with the peak unloading or unloading rate, which appears to indicate limited influence of this seasonal process on the earthquake activity.

  14. 46 CFR 107.260 - Rated load test for cranes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Rated load test for cranes. 107.260 Section 107.260... INSPECTION AND CERTIFICATION Inspection and Certification § 107.260 Rated load test for cranes. (a) To meet the requirements in § 107.231(l), each crane must meet the following rated load test at both the...

  15. Demonstration of load rating capabilities through physical load testing : Sioux County bridge case study.

    Science.gov (United States)

    2013-08-01

    The objective of this work, Pilot Project - Demonstration of Capabilities and Benefits of Bridge Load Rating through Physical Testing, was to demonstrate the capabilities for load testing and rating bridges in Iowa, study the economic benefit of perf...

  16. Demonstration of load rating capabilities through physical load testing : Johnson County bridge case study.

    Science.gov (United States)

    2013-08-01

    The objective of this work, Pilot Project - Demonstration of Capabilities and Benefits of Bridge Load Rating through Physical Testing, was to demonstrate the capabilities for load testing and rating bridges in Iowa, study the economic benefit of perf...

  17. Demonstration of load rating capabilities through physical load testing : Ida County bridge case study.

    Science.gov (United States)

    2013-08-01

    The objective of this work, Pilot Project - Demonstration of Capabilities and Benefits of Bridge Load Rating through Physical Testing, was to demonstrate the capabilities for load testing and rating bridges in Iowa, study the economic benefit of perf...

  18. A high rate clarifier for load levelling in sewerage systems.

    Science.gov (United States)

    Jago, R A; Davey, A; Li, H

    2003-01-01

    The combining of chemically assisted clarification with a proprietary physical separation technology has led to a high rate process for clarifying flocculated sewage and other waste streams. This hybrid physico-chemical system, known as the CDS Fine Solids Separation (FSS) System, was developed over a two year period within a sewage treatment plant environment. This paper summarises the results of a recent field trial of the system with a Victorian water authority which experiences heavy loading of sewers in a coastal town during holiday periods. The trial sought to evaluate the FSS as a tool for smoothing the load on the 11 km long sewer to the sewage treatment plant (STP). The FSS system could possibly enable the costly augmentation of the sewer to be deferred, particularly as the capacity of the existing sewer pipe is satisfactory for most of the year. Water quality parameters were determined for a range of flowrates and operational conditions over a two month period. Large reductions were achieved in TSS, TP, FC, turbidity and BOD5, with only minimal reductions in NH3 and TON. These results showed that the FSS could meet the authority's objectives for load levelling and would provide a 20-25% increase in effective sewer capacity. The data are also discussed in terms of possible use of the effluent from the FSS for water reuse applications.

  19. Characterization of Celecoxib-Loaded Solid Lipid Nanoparticles ...

    African Journals Online (AJOL)

    system with several advantages, including enhanced physical stability, dual loading ability for lipophilic and .... where kp is the release rate constant at the elapsed time t, n is a constant, where the value of n ≤ 0.45 indicates .... CXB and the hydrocarbon chain of the esterified fatty acids in the lipids. Upon emulsification CXB.

  20. Mental load, heart rate and heart rate variability.

    NARCIS (Netherlands)

    Blitz, P.S.; Hoogstraten, J.; Mulder, G.

    1970-01-01

    "Several investigators have shown that diminished sinus arrhythmia can be seen as an indication of increased mental load. The present experiment deals with the influence of different levels of mental load, operationalized as the number of binary choices per minute, on the regularity of the heart

  1. Rating curve estimation of nutrient loads in Iowa rivers

    Science.gov (United States)

    Stenback, G.A.; Crumpton, W.G.; Schilling, K.E.; Helmers, M.J.

    2011-01-01

    Accurate estimation of nutrient loads in rivers and streams is critical for many applications including determination of sources of nutrient loads in watersheds, evaluating long-term trends in loads, and estimating loading to downstream waterbodies. Since in many cases nutrient concentrations are measured on a weekly or monthly frequency, there is a need to estimate concentration and loads during periods when no data is available. The objectives of this study were to: (i) document the performance of a multiple regression model to predict loads of nitrate and total phosphorus (TP) in Iowa rivers and streams; (ii) determine whether there is any systematic bias in the load prediction estimates for nitrate and TP; and (iii) evaluate streamflow and concentration factors that could affect the load prediction efficiency. A commonly cited rating curve regression is utilized to estimate riverine nitrate and TP loads for rivers in Iowa with watershed areas ranging from 17.4 to over 34,600km2. Forty-nine nitrate and 44 TP datasets each comprising 5-22years of approximately weekly to monthly concentrations were examined. Three nitrate data sets had sample collection frequencies averaging about three samples per week. The accuracy and precision of annual and long term riverine load prediction was assessed by direct comparison of rating curve load predictions with observed daily loads. Significant positive bias of annual and long term nitrate loads was detected. Long term rating curve nitrate load predictions exceeded observed loads by 25% or more at 33% of the 49 measurement sites. No bias was found for TP load prediction although 15% of the 44 cases either underestimated or overestimate observed long-term loads by more than 25%. The rating curve was found to poorly characterize nitrate and phosphorus variation in some rivers. ?? 2010 .

  2. Laboratory-scale method for enzymatic saccharification of lignocellulosic biomass at high-solids loadings

    Directory of Open Access Journals (Sweden)

    Dibble Clare J

    2009-11-01

    Full Text Available Abstract Background Screening new lignocellulosic biomass pretreatments and advanced enzyme systems at process relevant conditions is a key factor in the development of economically viable lignocellulosic ethanol. Shake flasks, the reaction vessel commonly used for screening enzymatic saccharifications of cellulosic biomass, do not provide adequate mixing at high-solids concentrations when shaking is not supplemented with hand mixing. Results We identified roller bottle reactors (RBRs as laboratory-scale reaction vessels that can provide adequate mixing for enzymatic saccharifications at high-solids biomass loadings without any additional hand mixing. Using the RBRs, we developed a method for screening both pretreated biomass and enzyme systems at process-relevant conditions. RBRs were shown to be scalable between 125 mL and 2 L. Results from enzymatic saccharifications of five biomass pretreatments of different severities and two enzyme preparations suggest that this system will work well for a variety of biomass substrates and enzyme systems. A study of intermittent mixing regimes suggests that mass transfer limitations of enzymatic saccharifications at high-solids loadings are significant but can be mitigated with a relatively low amount of mixing input. Conclusion Effective initial mixing to promote good enzyme distribution and continued, but not necessarily continuous, mixing is necessary in order to facilitate high biomass conversion rates. The simplicity and robustness of the bench-scale RBR system, combined with its ability to accommodate numerous reaction vessels, will be useful in screening new biomass pretreatments and advanced enzyme systems at high-solids loadings.

  3. Increased strength of concrete subject to high loading rates

    International Nuclear Information System (INIS)

    Curbach, M.

    1987-01-01

    Within the scope of this work various problems are discussed which occur in connection with concrete under high tensile loading rates (e.g. when a plane crashes on a nuclear power plant very high loads occur which act only for a very short time). Particularly the causes for the already frequently noticed increases in strength with increasing loading rates are investigated and also the question whether this increased strength can be taken into account when dimensioning a construction. (MM) [de

  4. Particle loading rates for HVAC filters, heat exchangers, and ducts.

    Science.gov (United States)

    Waring, M S; Siegel, J A

    2008-06-01

    The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

  5. Influence of sampling frequency and load calculation methods on quantification of annual river nutrient and suspended solids loads.

    Science.gov (United States)

    Elwan, Ahmed; Singh, Ranvir; Patterson, Maree; Roygard, Jon; Horne, Dave; Clothier, Brent; Jones, Geoffrey

    2018-01-11

    Better management of water quality in streams, rivers and lakes requires precise and accurate estimates of different contaminant loads. We assessed four sampling frequencies (2 days, weekly, fortnightly and monthly) and five load calculation methods (global mean (GM), rating curve (RC), ratio estimator (RE), flow-stratified (FS) and flow-weighted (FW)) to quantify loads of nitrate-nitrogen (NO 3 - -N), soluble inorganic nitrogen (SIN), total nitrogen (TN), dissolved reactive phosphorus (DRP), total phosphorus (TP) and total suspended solids (TSS), in the Manawatu River, New Zealand. The estimated annual river loads were compared to the reference 'true' loads, calculated using daily measurements of flow and water quality from May 2010 to April 2011, to quantify bias (i.e. accuracy) and root mean square error 'RMSE' (i.e. accuracy and precision). The GM method resulted into relatively higher RMSE values and a consistent negative bias (i.e. underestimation) in estimates of annual river loads across all sampling frequencies. The RC method resulted in the lowest RMSE for TN, TP and TSS at monthly sampling frequency. Yet, RC highly overestimated the loads for parameters that showed dilution effect such as NO 3 - -N and SIN. The FW and RE methods gave similar results, and there was no essential improvement in using RE over FW. In general, FW and RE performed better than FS in terms of bias, but FS performed slightly better than FW and RE in terms of RMSE for most of the water quality parameters (DRP, TP, TN and TSS) using a monthly sampling frequency. We found no significant decrease in RMSE values for estimates of NO 3 - N, SIN, TN and DRP loads when the sampling frequency was increased from monthly to fortnightly. The bias and RMSE values in estimates of TP and TSS loads (estimated by FW, RE and FS), however, showed a significant decrease in the case of weekly or 2-day sampling. This suggests potential for a higher sampling frequency during flow peaks for more precise

  6. Impact of measurement uncertainty from experimental load distribution factors on bridge load rating

    Science.gov (United States)

    Gangone, Michael V.; Whelan, Matthew J.

    2018-03-01

    Load rating and testing of highway bridges is important in determining the capacity of the structure. Experimental load rating utilizes strain transducers placed at critical locations of the superstructure to measure normal strains. These strains are then used in computing diagnostic performance measures (neutral axis of bending, load distribution factor) and ultimately a load rating. However, it has been shown that experimentally obtained strain measurements contain uncertainties associated with the accuracy and precision of the sensor and sensing system. These uncertainties propagate through to the diagnostic indicators that in turn transmit into the load rating calculation. This paper will analyze the effect that measurement uncertainties have on the experimental load rating results of a 3 span multi-girder/stringer steel and concrete bridge. The focus of this paper will be limited to the uncertainty associated with the experimental distribution factor estimate. For the testing discussed, strain readings were gathered at the midspan of each span of both exterior girders and the center girder. Test vehicles of known weight were positioned at specified locations on each span to generate maximum strain response for each of the five girders. The strain uncertainties were used in conjunction with a propagation formula developed by the authors to determine the standard uncertainty in the distribution factor estimates. This distribution factor uncertainty is then introduced into the load rating computation to determine the possible range of the load rating. The results show the importance of understanding measurement uncertainty in experimental load testing.

  7. Control of the flow rate in decreasing of the water load of peat production

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The retention capacity and control of the flow rate was studied in the Aqua-Peat research. The sedimentation ability of solid matter (peat particles), erosion, migration of the solid matter, and the functioning of the retention pipes located in the strip ditches and the sedimentation basins were measured in the research. Detection was also supplemented by laboratory scale models and by measurements made using them. A model, describing the solid matter erosion and migration on the mire, was compiled on the basis of the results. Migration of the solid matter is possible to reduce by pounding the water into the ditching. So there is more time for particles to settle before migration into watercources. By this method it is possible to reduce the solid matter loads caused by heavy rains and power-flows even by 88 %. If the flow control system is equipped with retainers and settling basins, the solid matter retention capacity can rise up to 93-97 %. The results have shown that the retention pipe retainers play more important role in reduction of solid matter load than sedimentation basins. A follow-up study was made using several types of retainers. A 5 cm thick siphon pipe appeared to be the best. The final selection of the retention pipes has, however, to be made as a compromise between the functioning of the drying process, production possibilities and solid matter retention. (1 ref., 2 figs.)

  8. Laboratory investigation of the loading rate effects in sand

    NARCIS (Netherlands)

    Huy, N.Q.; Van Tol, A.F.; Hölscher, P.

    2006-01-01

    In order to improve the interpretation of the quasi-static (e.g. Statnamic) pile load tests, a research project has been started to investigate effects of the loading rate on the bearing capacity of a pile in sand. A series of laboratory tests has been carried out. The testing program consists of a

  9. Enzymatic hydrolysis of biomass at high-solids loadings – A review

    International Nuclear Information System (INIS)

    Modenbach, Alicia A.; Nokes, Sue E.

    2013-01-01

    Enzymatic hydrolysis is the unit operation in the lignocellulose conversion process that utilizes enzymes to depolymerize lignocellulosic biomass. The saccharide components released are the feedstock for fermentation. When performed at high-solids loadings (≥15% solids, w/w), enzymatic hydrolysis potentially offers many advantages over conversions performed at low- or moderate-solids loadings, including increased sugar and ethanol concentrations and decreased capital and operating costs. The goal of this review is to provide a consolidated source of information on studies using high-solids loadings in enzymatic hydrolysis. Included in this review is a brief discussion of the limitations, such as a lack of available water, difficulty with mixing and handling, insufficient mass and heat transfer, and increased concentration of inhibitors, associated with the use of high solids, as well as descriptions and findings of studies that performed enzymatic hydrolysis at high-solids loadings. Reactors designed and/or equipped for improved handling of high-solids slurries are also discussed. Lastly, this review includes a brief discussion of some of the operations that have successfully scaled-up and implemented high-solids enzymatic hydrolysis at pilot- and demonstration-scale facilities. -- Highlights: •High solids enzymatic hydrolysis needed for conversion process to be cost-effective. •Limitations must be addressed before benefits of high-solid loadings fully realized. •Some success with high-solids loadings at pilot and demonstration scale

  10. Developing Representative Michigan Truck Configurations for Bridge Load Rating

    Science.gov (United States)

    2018-02-28

    The objective of this study is to recommend a rating process representative of Michigan load effects for legal and extended permit vehicles. For this study, high fidelity WIM data from 20 Michigan sites were analyzed. Using vehicle weight and configu...

  11. Sample intake position and loading rates from nonpoint source pollution

    Science.gov (United States)

    McGuire, P. E.; Daniel, T. C.; Stoffel, D.; Andraski, B.

    1980-01-01

    Paired water samples were simultaneously activated from two different vertical positions within the approach section of a flow-control structure to determine the effect of sample intake position on nonpoint runoff parameter concentrations and subsequent event loads. Suspended solids (SS), total phosphorus (TP) and organic plus exchangeable nitrogen [(Or+Ex)-N] were consistently higher throughout each runoff event when sampled from the floor of the approach section as opposed to those samples taken at midstage. Dissolved molybdate reactive phosphorus (DMRP) and ammonium (NH4-N) concentrations did not appear to be significantly affected by the vertical difference in intake position. However, the nitrate plus nitrite nitrogen [(NO3+NO2)-N] concentrations were much higher when sampled from the midstage position. Although the concentration differences between the two methods were not appreciable, when evaluated in terms of event loads, discrepancies were evident for all parameters. Midstage sampling produced event loads for SS, TP, (Or + Ex)-N, DMRP, NH4-N, and (NO3+NO2)-N that were 44,39,35,80,71, and 181%, respectively, of floor sampling loads. Differences in loads between the two methods are attributed to the midstage position, sampling less of the bed load. The correct position will depend on the objective; however, such differences should be recognized during the design phase of the monitoring program.

  12. Efficient field testing for load rating railroad bridges

    Science.gov (United States)

    Schulz, Jeffrey L.; Brett C., Commander

    1995-06-01

    As the condition of our infrastructure continues to deteriorate, and the loads carried by our bridges continue to increase, an ever growing number of railroad and highway bridges require load limits. With safety and transportation costs at both ends of the spectrum. the need for accurate load rating is paramount. This paper describes a method that has been developed for efficient load testing and evaluation of short- and medium-span bridges. Through the use of a specially-designed structural testing system and efficient load test procedures, a typical bridge can be instrumented and tested at 64 points in less than one working day and with minimum impact on rail traffic. Various techniques are available to evaluate structural properties and obtain a realistic model. With field data, a simple finite element model is 'calibrated' and its accuracy is verified. Appropriate design and rating loads are applied to the resulting model and stress predictions are made. This technique has been performed on numerous structures to address specific problems and to provide accurate load ratings. The merits and limitations of this approach are discussed in the context of actual examples of both rail and highway bridges that were tested and evaluated.

  13. Mechanics of arterial subfailure with increasing loading rate.

    Science.gov (United States)

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A

    2007-01-01

    Arterial subfailure leads to delayed symptomatology and high morbidity and mortality rates, particularly for the thoracic aorta and carotid arteries. Although arterial injuries occur during high-velocity automotive collisions, previous studies of arterial subfailure focused on quasi-static loading. This investigation subjected aortic segments to increasing loading rates to quantify effects on elastic, subfailure, and ultimate vessel mechanics. Sixty-two specimens were axially distracted, and 92% demonstrated subfailure before ultimate failure. With increasing loading rate, stress at initial subfailure and ultimate failure significantly increased, and strain at initial subfailure and ultimate failure significantly decreased. Present results indicate increased susceptibility for arterial subfailure and/or dissection under higher-rate extension. According to the present results, automotive occupants are at greater risk of arterial injury under higher velocity impacts due to greater body segment motions in addition to decreased strain tolerance to subfailure and catastrophic failure.

  14. Oridonin Loaded Solid Lipid Nanoparticles Enhanced Antitumor Activity in MCF-7 Cells

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2014-01-01

    Full Text Available Oridonin (ORI, a famous diterpenoid from Chinese herbal medicine, has drawn rising attention for its remarkable apoptosis and autophagy-inducing activity in human cancer therapy, while clinical application of ORI is limited by its strong hydrophobicity and rapid plasma clearance. The purpose of this study was to evaluate whether the antitumor activity of ORI could be enhanced by loading into solid lipid nanoparticles (SLNs. ORI-loaded SLNs were prepared by hot high pressure homogenization with narrow size distribution and good entrapment efficacy. MTT assay indicated that ORI-loaded SLNs enhanced the inhibition of proliferation against several human cancer cell lines including breast cancer MCF-7 cells, hepatocellular carcinoma HepG 2 cells, and lung carcinoma A549 cells compared with free ORI, while no significant enhancement of toxicity to human mammary epithelial MCF-10A cells was shown. Meanwhile, flow cytometric analysis demonstrated that ORI-SLNs induced more significant cell cycle arrest at S and decreased cell cycle arrest at G1/G0 phase in MCF-7 cells than bulk ORI solution. Hoechst 33342 staining and Annexin V/PI assay indicated that apoptotic rates of cells treated with ORI-loaded SLNs were higher compared with free ORI. In summary, our data indicated that SLNs may be a potential carrier for enhancing the antitumor effect of hydrophobic drug ORI.

  15. Loading rate effect on the fracture behaviour of highstrength concrete

    Directory of Open Access Journals (Sweden)

    Del Viso J.

    2010-06-01

    Full Text Available This research deals with the sensitivity of eight types of performancedesigned high-strength concrete to the loading rate. Variations in the composition of the concrete produce the desired performance, for instance having null shrinkage or being able to be pumped at elevated heights without segregation, but they also produce variations in the fracture properties that are reported in this paper. We performed tests at five loading rates spanning six orders of magnitude in the displacement rate, from 1.74 × 10-5 mm/s to 17.4 mm/s. Load-displacement curves show that their peak is higher as the displacement rate increases, whereas the corresponding displacement is almost constant. Fracture energy also increases, but only for loading rates higher than 0.01 mm/s. We use a formula based on a cohesive law with a viscous term to study the results. The correlation of the formula to the experimental results is good and it allows us to obtain the theoretical value for the fracture energy under strictly static conditions. In addition, both the fracture energy and the characteristic length of the concretes used in the study diminish as the compressive strength of their aggregates increases.

  16. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode and a semi-solid cathode. The semi-solid cathode includes a suspension of an active material of about 35% to about 75% by volume of an active material and about 0.5% to about 8% by volume of a conductive material in a non-aqueous liquid electrolyte. An ion-permeable membrane is disposed between the anode and the semi-solid cathode. The semi-solid cathode has a thickness of about 250 .mu.m to about 2,000 .mu.m, and the electrochemical cell has an area specific capacity of at least about 7 mAh/cm.sup.2 at a C-rate of C/4. In some embodiments, the semi-solid cathode slurry has a mixing index of at least about 0.9.

  17. Preparation and evaluation of carvedilol-loaded solid lipid ...

    African Journals Online (AJOL)

    Keywords: Carvedilol, Solid lipid nanoparticles, Antihypertensive, Sustained release. Tropical Journal of ... Lipid particles are of great importance to drug researchers and ... toxic for human use and officially recognized as a pharmaceutical ...

  18. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode, a semi-solid cathode that includes a suspension of an active material and a conductive material in a liquid electrolyte, and an ion permeable membrane disposed between the anode and the cathode. The semi-solid cathode has a thickness in the range of about 250 .mu.m-2,500 .mu.m, and the electrochemical cell has an area specific capacity of at least 5 mAh/cm.sup.2 at a C-rate of C/2.

  19. Motor operated valve testing and the 'rate of loading' phenomenon

    International Nuclear Information System (INIS)

    Black, B.R.

    1991-01-01

    This paper discusses valve design features which affect the ability to predict motor operated valve (MOV) performance and reviews factors which should be considered when selecting switch settings to limit stem loads. Considerable attention is given to the rate of loading phenomenon which affects the relationship between valve stem thrust and actuator spring pack deflection. Equations are developed, and testing is discussed which permit the construction of an MOV dynamic model. Factors which must be considered when maintaining switch settings correct throughout the life of the plant are discussed. And switch setting acceptance criteria for use with baseline Static and Design Basis testing are suggested

  20. Influence of different SSF conditions on ethanol production from corn stover at high solids loadings

    DEFF Research Database (Denmark)

    Gladis, Arne; Bondesson, Pia-Maria; Galbe, Mats

    2015-01-01

    In this study, three different kinds of simultaneous saccharification and fermentation (SSF) of washed pretreated corn stover with water-insoluble solids (WIS) content of 20% were investigated to find which one resulted in highest ethanol yield at high-solids loadings. The different methods were...

  1. Simultaneous Saccharification and Fermentation of Lactic Acid from Empty Fruit Bunch at High Solids Loading

    Directory of Open Access Journals (Sweden)

    Nursia Hassan

    2016-03-01

    Full Text Available The production of value-added chemicals from the bioconversion of lignocellulose biomass has been considered a promising venture. In this study, microwave, alkali-pretreated empty fruit bunch (EFB was used as the substrate, utilizing pelletized filamentous Rhizopus oryzae NRRL 395 and cellulolytic enzymes for lactic acid production in a fed-batch simultaneous saccharification and fermentation (SSF process. Insoluble solids generally do not affect the SSF process until a certain concentration is exceeded. To achieve a high lactic acid concentration in the broth, a high solids loading was required to allow a higher rate of glucose conversion. However, the results revealed a decrease in the final lactic acid yield when running SSF at a massive insoluble solids level. High osmotic pressure in the medium led to poor cellular performance and caused the Rhizopus oryzae pellets to break down, affecting the lactic acid production. To improve the process performance, a fed-batch operation mode was used. The fed-batch operation was shown to facilitate higher lactic acid yield, compared with the SSF batch mode. Enzyme feeding, as well as substrate feeding, was also investigated as a means of enabling a higher dry matter content, with a high glucose conversion in SSF of cellulose-rich EFB.

  2. Formulation and characterization of solid lipid nanoparticles loaded Neem oil for topical treatment of acne

    Directory of Open Access Journals (Sweden)

    V. Vijayan

    2013-01-01

    Conclusion: The result concluded that Neem oil loaded solid lipid nanoparticles with more lecithin content in their colloid exhibit sustained effect which satisfactorily produced the antibacterial action on Acne microbes. Therefore Neem oil loaded SLN was used successfully for prolonged treatment of Acne.

  3. Experimental investigation of bond strength under high loading rates

    Directory of Open Access Journals (Sweden)

    Michal Mathias

    2015-01-01

    Full Text Available The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw and the Joint Research Centre (JRC in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.

  4. Preparation and evaluation of carvedilol-loaded solid lipid ...

    African Journals Online (AJOL)

    The SLNs were characterized in terms of entrapment efficiency, particle size, zeta potential, polydispersity index, cytotoxicity, solid state characterization and drug release. The stability of the formulations was investigated by monitoring their properties for a period of 3 months. Results: The mean size of the nanoparticles was ...

  5. Development of strand burner for solid propellant burning rate studies

    International Nuclear Information System (INIS)

    Aziz, A; Mamat, R; Ali, W K Wan

    2013-01-01

    It is well-known that a strand burner is an apparatus that provides burning rate measurements of a solid propellant at an elevated pressure in order to obtain the burning characteristics of a propellant. This paper describes the facilities developed by author that was used in his studies. The burning rate characteristics of solid propellant have be evaluated over five different chamber pressures ranging from 1 atm to 31 atm using a strand burner. The strand burner has a mounting stand that allows the propellant strand to be mounted vertically. The strand was ignited electrically using hot wire, and the burning time was recorded by electronic timer. Wire technique was used to measure the burning rate. Preliminary results from these techniques are presented. This study shows that the strand burner can be used on propellant strands to obtain accurate low pressure burning rate data

  6. Dry fermentation of manure with straw in continuous plug flow reactor: Reactor development and process stability at different loading rates.

    Science.gov (United States)

    Patinvoh, Regina J; Kalantar Mehrjerdi, Adib; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

    2017-01-01

    In this work, a plug flow reactor was developed for continuous dry digestion processes and its efficiency was investigated using untreated manure bedded with straw at 22% total solids content. This newly developed reactor worked successfully for 230days at increasing organic loading rates of 2.8, 4.2 and 6gVS/L/d and retention times of 60, 40 and 28days, respectively. Organic loading rates up to 4.2gVS/L/d gave a better process stability, with methane yields up to 0.163LCH 4 /gVS added /d which is 56% of the theoretical yield. Further increase of organic loading rate to 6gVS/L/d caused process instability with lower volatile solid removal efficiency and cellulose degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Peptide-Loaded Solid Lipid Nanoparticles Prepared through Coacervation Technique

    Directory of Open Access Journals (Sweden)

    Marina Gallarate

    2011-01-01

    Full Text Available Stearic acid solid lipid nanoparticles were prepared according to a new technique, called coacervation. The main goal of this experimental work was the entrapment of peptide drugs into SLN, which is a difficult task, since their chemical characteristics (molecular weight, hydrophilicity, and stability hamper peptide-containing formulations. Insulin and leuprolide, chosen as model peptide drugs, were encapsulated within nanoparticles after hydrophobic ion pairing with anionic surfactants. Peptide integrity was maintained after encapsulation, and nanoparticles can act in vitro as a sustained release system for peptide.

  8. High-Pressure Burning Rate Studies of Solid Rocket Propellants

    Science.gov (United States)

    2013-01-01

    monopropellant burning rate. The self-de§agration rates of neat AP are plotted in Fig. 2 for both pressed pellets and single crystals. There is agreement...rate data from various investigators: 1 ¡ [2]; pressed pellets : 2 ¡ [3], 3 ¡ [4], and 4 ¡ [2]; and single crystals: 5 ¡ [5], and 6 ¡ [6]. Line ¡ AP...7]. Strand or window burners have had more use in the solid propellant community. There are numerous types and styles of combustion vessels, but they

  9. Measurement of blowdown flow rates using load cells

    International Nuclear Information System (INIS)

    Dolas, P.K.; Venkat Raj, V.; Ghosh, A.K.; Murty, L.G.K.; Muralidhar Rao, S.

    1980-01-01

    To establish a reliable method for measuring two-phase flow, experiments were planned for measurement of transient single phase flow rates from vessels using load cells. Suitability of lead-zirconate-titanate piezoelectric ceramic discs was examined. Discharge time constant of the disc used was low, leading to large measurement errors. Subsequently, experiments were carried out using strain gauge load cells and these were found satisfactory. The unsteady flow equation has been derived for the system under investigation. The equation has been solved numerically using the fourth order Runge-Kutta method and also by integrating it analytically. The experimental results are compared with the theoretical results and presented in this report. (auth.)

  10. Methane activation on palladium and mercury loaded solid supports

    Energy Technology Data Exchange (ETDEWEB)

    Kataja, K; Huuska, M; Karinto, K; Maijanen, A; Reinikainen, M; Kiviaho, J; Hase, A [VTT Chemical Technology, Espoo (Finland)

    1997-12-31

    Methane activation by non-radical method and especially possibilities to heterogenize the homogeneous non-radical system of Periana et al. was studied. Varied loadings of Pd and Hg were ion exchanged to acidic ZSM-5 zeolites with two different Si/A1 ratios. Activation was tested in tubular flow reactor and the outcoming gas was analyzed with quadrupole mass spectrometer. Catalysts, fresh and used, were characterized by XRF and XRD spectroscopies. The methane activation was observed on tested catalysts. However, the activation was concluded to occur mainly through radical reaction and only to some extent by the expected non-radical mechanism. (author) (9 refs.)

  11. Methane activation on palladium and mercury loaded solid supports

    Energy Technology Data Exchange (ETDEWEB)

    Kataja, K.; Huuska, M.; Karinto, K.; Maijanen, A.; Reinikainen, M.; Kiviaho, J.; Hase, A. [VTT Chemical Technology, Espoo (Finland)

    1996-12-31

    Methane activation by non-radical method and especially possibilities to heterogenize the homogeneous non-radical system of Periana et al. was studied. Varied loadings of Pd and Hg were ion exchanged to acidic ZSM-5 zeolites with two different Si/A1 ratios. Activation was tested in tubular flow reactor and the outcoming gas was analyzed with quadrupole mass spectrometer. Catalysts, fresh and used, were characterized by XRF and XRD spectroscopies. The methane activation was observed on tested catalysts. However, the activation was concluded to occur mainly through radical reaction and only to some extent by the expected non-radical mechanism. (author) (9 refs.)

  12. Space shuttle solid rocket booster water entry cavity collapse loads

    Science.gov (United States)

    Keefe, R. T.; Rawls, E. A.; Kross, D. A.

    1982-01-01

    Solid rocket booster cavity collapse flight measurements included external pressures on the motor case and aft skirt, internal motor case pressures, accelerometers located in the forward skirt, mid-body area, and aft skirt, as well as strain gages located on the skin of the motor case. This flight data yielded applied pressure longitudinal and circumferential distributions which compare well with model test predictions. The internal motor case ullage pressure, which is below atmospheric due to the rapid cooling of the hot internal gas, was more severe (lower) than anticipated due to the ullage gas being hotter than predicted. The structural dynamic response characteristics were as expected. Structural ring and wall damage are detailed and are considered to be attributable to the direct application of cavity collapse pressure combined with the structurally destabilizing, low internal motor case pressure.

  13. Complex stiffness formulation for the finite element analysis of anisotropic axisymmetric solids subjected to nonsymmetric loads

    International Nuclear Information System (INIS)

    Frater, J.; Lestingi, J.; Padovan, J.

    1977-01-01

    This paper describes the development of an improved semi-analytical finite element for the stress analysis of anisotropic axisymmetric solids subjected to nonsymmetric loads. Orthogonal functions in the form of finite Fourier exponential transforms, which satisfy the equations of equilibrium of the theory of elasticity for an anisotropic solid of revolution, are used to expand the imposed loadings and displacement field. It is found that the orthogonality conditions for the assumed solution reduce the theta-dependency, thus reducing the three dimensional problem to an infinite series of two dimensional problems. (Auth.)

  14. Simultaneous saccharification and ethanol fermentation at high corn stover solids loading in a helical stirring bioreactor.

    Science.gov (United States)

    Zhang, Jian; Chu, Deqiang; Huang, Juan; Yu, Zhanchun; Dai, Gance; Bao, Jie

    2010-03-01

    The higher ethanol titer inevitably requires higher solids loading during the simultaneous enzymatic saccharification and fermentation (SSF) using lignocellulose as the feedstock. The mixing between the solid lignocellulose and the liquid enzyme is crucially important. In this study, a bioreactor with a novel helical impeller was designed and applied to the SSF operation of the steam explosion pretreated corn stover under different solids loadings and different enzyme dosages. The performances using the helical impeller and the common Rushton impeller were compared and analyzed by measuring rheological properties and the mixing energy consumption. The results showed that the new designed stirring system had better performances in the saccharification yield, ethanol titer, and energy cost than those of the Rushton impeller stirring. The mixing energy consumption under different solids loadings and enzyme dosages during SSF operation were analyzed and compared to the thermal energy in the ethanol produced. A balance for achieving the optimal energy cost between the increased mixing energy cost and the reduced distillation energy cost at the high solids loading should be made. The potentials of the new bioreactor were tested under various SSF conditions for obtaining optimal ethanol yield and titer. (c) 2009 Wiley Periodicals, Inc.

  15. Dissolved-solids sources, loads, yields, and concentrations in streams of the conterminous United States

    Science.gov (United States)

    Anning, David W.; Flynn, Marilyn E.

    2014-01-01

    Recent studies have shown that excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, domestic, municipal, and industrial water users. Such effects motivated the U.S. Geological Survey’s National Water Quality Assessment Program to develop a SPAtially-Referenced Regression on Watershed Attributes (SPARROW) model that has improved the understanding of sources, loads, yields, and concentrations of dissolved solids in streams of the conterminous United States.

  16. Characterization of suspended solids and total phosphorus loadings from small watersheds in Wisconsin

    Science.gov (United States)

    Danz, Mari E.; Corsi, Steven R.; Graczyk, David J.; Bannerman, Roger T.

    2010-01-01

    Knowledge of the daily, monthly, and yearly distribution of contaminant loadings and streamflow can be critical for the successful implementation and evaluation of water-quality management practices. Loading data for solids (suspended sediment and total suspended solids) and total phosphorus and streamflow data for 23 watersheds were summarized for four ecoregions of Wisconsin: the Driftless Area Ecoregion, the Northern Lakes and Forests Ecoregion, the North Central Hardwoods Ecoregion, and the Southeastern Wisconsin Till Plains Ecoregion. The Northern Lakes and Forests and the North Central Hardwoods Ecoregions were combined into one region for analysis due to a lack of sufficient data in each region. Urban watersheds, all located in the Southeastern Wisconsin Till Plains, were analyzed separately from rural watersheds as the Rural Southeastern Wisconsin Till Plains region and the Urban Southeastern Wisconsin Till Plains region. Results provide information on the distribution of loadings and streamflow between base flow and stormflow, the timing of loadings and streamflow throughout the year, and information regarding the number of days in which the majority of the annual loading is transported. The average contribution to annual solids loading from stormflow periods for the Driftless Area Ecoregion was 84 percent, the Northern Lakes and Forests/North Central Hardwoods region was 71 percent, the Rural Southeastern Wisconsin Till Plains region was 70 percent, and the Urban Southeastern Wisconsin Till Plains region was 90 percent. The average contributions to annual total phosphorus loading from stormflow periods were 72, 49, 61, and 76 percent for each of the respective regions. The average contributions to annual streamflow from stormflow periods are 20, 23, 31, and 50 percent for each of the respective regions. In all regions, the most substantial loading contributions for solids were in the late winter (February through March), spring (April through May), and

  17. Buparvaquone loaded solid lipid nanoparticles for targeted delivery in theleriosis

    Directory of Open Access Journals (Sweden)

    Maheshkumar P Soni

    2014-01-01

    Full Text Available Background: Buparvaquone (BPQ, a hydroxynaphthoquinone derivative, has been investigated for the treatment of many infections and is recommended as the gold standard for the treatment of theileriosis. Theileriosis, an intramacrophage infection is localized mainly in reticuloendotheileial system (RES organs. The present study investigates development of solid lipid nanoparticles (SLN of BPQ for targeted delivery to the RES. Materials and Methods: BPQ SLN was prepared using melt method by adding a molten mixture into aqueous Lutrol F68 solution (80°C. Larger batches were prepared up to 6 g of BPQ with GMS: BPQ, 2:1. SLN of designed size were obtained using ultraturrax and high pressure homogenizer. A freeze and thaw study was used to optimize type and concentration of cryoprotectant with Sf: Mean particle size, Si: Initial particle size <1.3. Differential scanning calorimetry (DSC, powder X-ray diffraction (XRD and scanning electron microscope (SEM study was performed on optimized formulation. Formulation was investigated for in vitro serum stability, hemolysis and cell uptake study. Pharmacokinetic and biodistribution study was performed in Holtzman rat. Results: Based on solubility in lipid; glyceryl monostearate (GMS was selected for preparation of BPQ SLN. Batches of BPQ SLN were optimized for average particle size and entrapment efficiency at <100 mg solid content. A combination of Solutol HS-15 and Lutrol F68 at 2% w/v and greater enabled the desired Sf/Si < 1.3. Differential scanning calorimetry and powder X-ray diffraction revealed decrease in crystallinity of BPQ in BPQ SLN while, scanning electron microscope revealed spherical morphology. BPQ SLN revealed good stability at 4°C and 25°C. Low hemolytic potential (<8% and in vitro serum stability up to 5 h was observed. Cytotoxicity of SLN to the U937 cell was low. The macrophage cell line revealed high (52% uptake of BPQ SLN in 1 h suggesting the potential to RES uptake. SLN revealed

  18. Buparvaquone loaded solid lipid nanoparticles for targeted delivery in theleriosis

    Science.gov (United States)

    Soni, Maheshkumar P.; Shelkar, Nilakash; Gaikwad, Rajiv V.; Vanage, Geeta R.; Samad, Abdul; Devarajan, Padma V.

    2014-01-01

    Background: Buparvaquone (BPQ), a hydroxynaphthoquinone derivative, has been investigated for the treatment of many infections and is recommended as the gold standard for the treatment of theileriosis. Theileriosis, an intramacrophage infection is localized mainly in reticuloendotheileial system (RES) organs. The present study investigates development of solid lipid nanoparticles (SLN) of BPQ for targeted delivery to the RES. Materials and Methods: BPQ SLN was prepared using melt method by adding a molten mixture into aqueous Lutrol F68 solution (80°C). Larger batches were prepared up to 6 g of BPQ with GMS: BPQ, 2:1. SLN of designed size were obtained using ultraturrax and high pressure homogenizer. A freeze and thaw study was used to optimize type and concentration of cryoprotectant with Sf: Mean particle size, Si: Initial particle size Solutol HS-15 and Lutrol F68 at 2% w/v and greater enabled the desired Sf/Si < 1.3. Differential scanning calorimetry and powder X-ray diffraction revealed decrease in crystallinity of BPQ in BPQ SLN while, scanning electron microscope revealed spherical morphology. BPQ SLN revealed good stability at 4°C and 25°C. Low hemolytic potential (<8%) and in vitro serum stability up to 5 h was observed. Cytotoxicity of SLN to the U937 cell was low. The macrophage cell line revealed high (52%) uptake of BPQ SLN in 1 h suggesting the potential to RES uptake. SLN revealed longer circulation and biodistrbution study confirmed high RES uptake (75%) in RES organs like liver lung spleen etc. Conclusion: The high RES uptake suggests BPQ SLN as a promising approach for targeted and improved delivery in theileriosis. PMID:24459400

  19. Turnover rate of hypoxic cells in solid tumors

    International Nuclear Information System (INIS)

    Ljungkvist, A.S.E.; Bussink, J.; Rijken, P.F.J.W.; Van Der Kogel, A.J.

    2003-01-01

    Most solid tumors contain hypoxic cells, and both the amount and duration of tumor hypoxia has been shown to influence the effect of radiation treatment negatively. It is important to understand the dynamic processes within the hypoxic cell population in non-treated tumors, and the effect of different treatment modalities on the kinetics of hypoxic cells to be able to design optimal combined modality treatments. The turnover rate of hypoxic cells was analyzed in three different solid tumor models with a double bio-reductive hypoxic marker assay with sequential injection of the two hypoxic markers. Previously it was shown that this assay could be used to detect both a decrease and an increase of tumor hypoxia in relation to the tumor vasculature with high spatial resolution. In this study the first hypoxic marker, pimonidazole, was administered at variable times relative to tumor harvest, and the second hypoxic marker, CCI-103F, was injected at a fixed time before harvest. The hypoxic cell turnover rate was calculated as the loss of pimonidazole positive cells relative to CCI-103F. The murine C38 line had the fastest hypoxic turnover rate of 60% /24h and the human xenograft line SCCNij3 had the slowest hypoxic turnover rate of 30% /24 h. The hypoxic turnover rate was most heterogeneous in the SCCNij3 line that even contained viable groups of cells that had been hypoxic for at least 5 days. The human xenograft line MEC82 fell in between with a hypoxic turnover rate of 50% /24 h. The hypoxic cell turnover was related to the potential tumor volume doubling time (Tpot) with a Tpot of 26h in C38 and 103h in SCCNij3. The dynamics of hypoxic cells, quantified with a double hypoxic marker method, showed large differences in hypoxic cell turnover rate and were related to Tpot

  20. EFFECT OF SULFATE LOADING RATE AND ORGANIC LOADING RATE ON ANAEROBIC BAFFLED REACTORS USED FOR TREATMENT OF SANITARY LANDFILL LEACHATES

    Directory of Open Access Journals (Sweden)

    O. Burbano-Figueroa

    2015-06-01

    Full Text Available AbstractThis study investigated the effect of organic loading rate (OLR and sulfate loading rate (SLR on landfill leachate treatment by a lab-scale anaerobic baffled reactor (ABR. Landfill leachate contained a concentration of organic matter between 3966 and 5090 mg COD.L-1 and no detectable amounts of sulfate. Reactors were started-up by feeding them with iron-sulfate at a SLR of 0.05 g SO42-.L-1.day-1 (4 weeks. Factorial design and response surface techniques were used to evaluate and optimize the effects of these operating variables on COD removal. ABRs were operated at OLRs ranging from 0.30 up to 6.84 g COD.L-1.day-1 by changes in influent volumetric flow. SO42- was added to the influent at a SRL from 0.06 to 0.13 g SO42-.L-1.day-1. The highest value of COD removal (66% was reached at an OLR of 3.58 g COD.L-1.day-1 and SLR of 0.09 g SO4-2.L-1.day-1 with a COD/SO4-2 ratio of 40. Under these conditions sulfate is mainly used for molecular hydrogen consumption while organic matter is preferentially degraded via methanogesis.

  1. Development and evaluation of alginate-chitosan gastric floating beads loading with oxymatrine solid dispersion.

    Science.gov (United States)

    Liu, Yanhua; Chen, Lihong; Zhou, Chengming; Yang, Jianhong; Hou, Yanhui; Wang, Wenping

    2016-01-01

    Oxymatrine (OM) can be metabolized to matrine in gastrointestinal ileocecal valve after oral administration, which affects pharmacological activity and reduce bioavailability of OM. A type of multiple-unit alginate-chitosan (Alg-Cs) floating beads was prepared by the ionotropic gelation method for gastroretention delivery of OM. A solid dispersion technique was applied and incorporated into beads to enhance the OM encapsulation efficiency (EE) and sustain the drug release. The surface morphology and internal hollow structure of beads were evaluated using optical microscopy and scanning electron microscopy (SEM). The developed Alg-Cs beads were spherical in shape with hollow internal structure and had particle size of 3.49 ± 0.09 mm and 1.33 ± 0.09 mm for wet and dried beads. Over 84% of the optimized OM solid dispersion-loaded Alg-Cs beads were able to continuously float over the simulated gastric fluid for 12 h in vitro. The OM solid dispersion-loaded Alg-Cs beads showed drug EE of 67.07%, which was much higher than that of beads loading with pure OM. Compared with the immediate release of OM capsules and pure OM-loaded beads, the release of OM from solid dispersion-loaded Alg-Cs beads was in a sustained-release manner for 12 h. Prolonged gastric retention time of over 8.5 h was achieved for OM solid dispersion-loaded Alg-Cs floating beads in healthy rabbit in in vivo floating ability evaluated by X-ray imaging. The developed Alg-Cs beads loading with OM solid dispersion displayed excellent performance features characterized by excellent gastric floating ability, high drug EE and sustained-release pattern. The study illustrated the potential use of Alg-Cs floating beads combined with the solid dispersion technique for prolonging gastric retention and sustaining release of OM, which could provide a promising drug delivery system for gastric-specific delivery of OM for bioavailability enhancement.

  2. Non-linear analysis of solid propellant burning rate behavior

    Energy Technology Data Exchange (ETDEWEB)

    Junye Wang [Zhejiang Univ. of Technology, College of Mechanical and Electrical Engineering, Hanzhou (China)

    2000-07-01

    The parametric analysis of the thermal wave model of the non-steady combustion of solid propellants is carried out under a sudden compression. First, to observe non-linear effects, solutions are obtained using a computer under prescribed pressure variations. Then, the effects of rearranging the spatial mesh, additional points, and the time step on numerical solutions are evaluated. Finally, the behaviour of the thermal wave combustion model is examined under large heat releases (H) and a dynamic factor ({beta}). The numerical predictions show that (1) the effect of a dynamic factor ({beta}), related to the magnitude of dp/dt, on the peak burning rate increases as the value of beta increases. However, unsteady burning rate 'runaway' does not appear and will return asymptotically to ap{sup n}, when {beta}{>=}10.0. The burning rate 'runaway' is a numerical difficulty, not a solution to the models. (2) At constant beta and m, the amplitude of the burning rate increases with increasing H. However, the increase in the burning rate amplitude is stepwise, and there is no apparent intrinsic instability limit. A damped oscillation of burning rate occurs when the value of H is less. However, when H>1.0, the state of an intrinsically unstable model is composed of repeated, amplitude spikes, i.e. an undamped oscillation occurs. (3) The effect of the time step on the peak burning rate increases as H increases. (Author)

  3. Solid formation in piperazine rate-based simulation

    DEFF Research Database (Denmark)

    Gaspar, Jozsef; Thomsen, Kaj; von Solms, Nicolas

    2014-01-01

    of view but also from a modeling perspective. The present work develops a rate-based model for CO2 absorption and desorption modeling for gas-liquid-solid systems and it is demonstrated for the piperazine CO2 capture process. This model is an extension of the DTU CAPCO2 model to precipitating systems....... It uses the extended UNIQUAC thermodynamic model for phase equilibria and thermal properties estimation. The mass and heat transfer phenomena is implemented in a film model approach, based on second order reactions kinetics. The transfer fluxes are calculated using the concentration of the dissolved...

  4. Physicochemical characterization of tacrolimus-loaded solid dispersion with sodium carboxylmethyl cellulose and sodium lauryl sulfate.

    Science.gov (United States)

    Park, Young-Joon; Ryu, Dong-Sung; Li, Dong Xun; Quan, Qi Zhe; Oh, Dong Hoon; Kim, Jong Oh; Seo, Youn Gee; Lee, Young-Im; Yong, Chul Soon; Woo, Jong Soo; Choi, Han-Gon

    2009-06-01

    To develop a novel tacrolimus-loaded solid dispersion with improved solubility, various solid dispersions were prepared with various ratios of water, sodium lauryl sulfate, citric acid and carboxylmethylcellulose-Na using spray drying technique. The physicochemical properties of solid dispersions were investigated using scanning electron microscopy, differential scanning calorimetery and powder X-ray diffraction. Furthermore, their solubility and dissolution were evaluated compared to drug powder. The solid dispersion at the tacrolimus/CMC-Na/sodium lauryl sulfate/citric acid ratio of 3/24/3/0.2 significantly improved the drug solubility and dissolution compared to powder. The scanning electron microscopy result suggested that carriers might be attached to the surface of drug in this solid dispersion. Unlike traditional solid dispersion systems, the crystal form of drug in this solid dispersion could not be converted to amorphous form, which was confirmed by the analysis of DSC and powder X-ray diffraction. Thus, the solid dispersion system with water, sodium lauryl sulfate, citric acid and CMC-Na should be a potential candidate for delivering a poorly water-soluble tacrolimus with enhanced solubility and no convertible crystalline.

  5. Impact of socioeconomic status on municipal solid waste generation rate.

    Science.gov (United States)

    Khan, D; Kumar, A; Samadder, S R

    2016-03-01

    The solid waste generation rate was expected to vary in different socioeconomic groups due to many environmental and social factors. This paper reports the assessment of solid waste generation based on different socioeconomic parameters like education, occupation, income of the family, number of family members etc. A questionnaire survey was conducted in the study area to identify the different socioeconomic groups that may affect the solid waste generation rate and composition. The average waste generated in the municipality is 0.41 kg/capita/day in which the maximum waste was found to be generated by lower middle socioeconomic group (LMSEG) with average waste generation of 0.46 kg/capita/day. Waste characterization indicated that there was no much difference in the composition of wastes among different socioeconomic groups except ash residue and plastic. Ash residue is found to increase as we move lower down the socioeconomic groups with maximum (31%) in lower socioeconomic group (LSEG). The study area is a coal based city hence application of coal and wood as fuel for cooking in the lower socioeconomic group is the reason for high amount of ash content. Plastic waste is maximum (15%) in higher socioeconomic group (HSEG) and minimum (1%) in LSEG. Food waste is a major component of generated waste in almost every socioeconomic group with maximum (38%) in case of HSEG and minimum (28%) in LSEG. This study provides new insights on the role of various socioeconomic parameters on generation of household wastes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Preparation, characterization and pharmacokinetics of enrofloxacin-loaded solid lipid nanoparticles: influences of fatty acids.

    Science.gov (United States)

    Xie, Shuyu; Zhu, Luyan; Dong, Zhao; Wang, Xiaofang; Wang, Yan; Li, Xihe; Zhou, WenZhong

    2011-04-01

    Enrofloxacin-loaded solid lipid nanoparticles (SLN) were prepared using fatty acids (tetradecanoic acid, palmitic acid, stearic acid) as lipid matrix by hot homogenization and ultrasonication method. The effect of fatty acids on the characteristics and pharmacokinetics of the SLN were investigated. The results showed that the encapsulation efficiency and loading capacity of nanoparticles varied with fatty acids in the order of stearic acid>palmitic acid>tetradecanoic acid. Furthermore, stearic acid-SLN had larger particle size, bigger polydispersity index (PDI) and higher zeta potential compared with the other two fatty acid formulated SLN. The SLN showed sustained releases in vitro and the released enrofloxacin had the same antibacterial activity as that of the native enrofloxacin. Although in vitro release exhibited similar patterns, within 24 h the releasing rates of the three formulations were significantly different (tetradecanoic acid-SLN>palmitic acid-SLN>stearic acid-SLN). Pharmacokinetic study after a single dose of intramuscular administration to mice demonstrated that tetradecanoic acid-SLN, palmitic acid-SLN, and stearic acid-SLN increased the bioavailability by 6.79, 3.56 and 2.39 folds, and extended the mean residence time (MRT) of the drug from 10.60 h to 180.36, 46.26 and 19.09 h, respectively. These results suggest that the enrofloxacin-fatty acid SLN are promising formulations for sustained release while fatty acids had significant influences on the characteristics and performances of the SLN. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. Effect of loading rate on the compressive mechanics of the immature baboon cervical spine.

    Science.gov (United States)

    Elias, Paul Z; Nuckley, David J; Ching, Randal P

    2006-02-01

    Thirty-four cervical spine segments were harvested from 12 juvenile male baboons and compressed to failure at displacement rates of 5, 50, 500, or 5000 mm/s. Compressive stiffness, failure load, and failure displacement were measured for comparison across loading rate groups. Stiffness showed a significant concomitant increase with loading rate, increasing by 62% between rates of 5 and 5000 mm/s. Failure load also demonstrated an increasing relationship with loading rate, while displacement at failure showed no rate dependence. These data may help in the development of improved pediatric automotive safety standards and more biofidelic physical and computational models.

  8. Effect of loading rate on creep of phosphorous doped copper

    Energy Technology Data Exchange (ETDEWEB)

    Andersson-Oestling, Henrik C.M.; Sandstroem, Rolf (Swerea KIMAB (Sweden))

    2011-12-15

    Creep testing of copper intended for nuclear waste disposal has been performed on continuous creep tests machines at a temperature of 75 deg C. The loading time has been varied from 1 hour to 6 months. The rupture strain including both loading and creep strains does not differ from traditional dead weight lever creep test rigs. The loading strain increases with increasing loading time, at the expense of the creep strain. The time dependence of the creep strain has been modelled taking athermal plastic deformation and creep into account. During loading the contribution to the strain from the athermal plastic deformation dominates until the stress is close to the constant load level. When the constant load has been reached there is no more athermal strain and all of the strain comes from creep

  9. Measurement test on creep strain rate of uranium-zirconium solid solutions

    International Nuclear Information System (INIS)

    Ogata, Takanari; Akabori, Mitsuo; Ogawa, Toru

    1996-11-01

    In order to measure creep strain rate of a small specimen of U-Zr solid solution, authors proposed an estimation method which was based upon the stress relaxation after compression. It was applied to measurement test on creep strain rate of the U-10wt%Zr specimen in the temperature range of 757 to 911degC. It may be concluded that the proposed method is valid, provided that the strain is within the appropriate range and that sufficient amount of the load decrement is observed. The obtained creep rate of U-10wt%Zr alloy indicated significantly smaller value, compared to the experimental data for pure U metal and evaluated data for U-Pu-Zr alloy. However, more careful measurement is desired in future since the present data are thought to be influenced by the precipitations included in the specimen. (author)

  10. Temperature-controlled continuous production of all-trans retinoic acid-loaded solid lipid nanoparticles using static mixers

    Science.gov (United States)

    Shao, Wenyao; Yan, Mengwen; Chen, Tingting; Chen, Yuqing; Xiao, Zongyuan

    2017-04-01

    This work aims to develop a temperature-controlled continuous solvent emulsification-diffusion process to synthesize all-trans retinoic acid (ATRA)-loaded solid lipid nanoparticles (SLNs) using static mixers. ATRA-loaded SLNs of around 200 nm were obtained when the flow rates of the organic and aqueous phases were 50 ml min-1 and 500 ml min-1, respectively. It was found that the lipid concentration played a dominant role in the size of the obtained SLNs, and higher drug concentration resulted in relatively low entrapment efficiency. The encapsulation of ATRA in the SLNs was effective in improving its stability according to the photo-degradation test. The in vitro release of SLN was slow without an initial burst. This study demonstrates that the solvent emulsification-diffusion technique with static mixing is an effective method of producing SLNs, and could easily be scaled up for industrial applications. Highlights Higher lipid concentration leads to larger SLNs. SLN transformation occurs due to Ostwald ripening. The ATRA-loaded SLNs around 200 nm were successfully produced with static mixers. ATRA-loaded SLNs show better stability towards sunlight. ATRA in SLNs exhibited a relatively slow release rate without a significant initial burst.

  11. Loads of nitrate, phosphorus, and total suspended solids from Indiana watersheds

    Science.gov (United States)

    Bunch, Aubrey R.

    2016-01-01

    Transport of excess nutrients and total suspended solids (TSS) such as sediment by freshwater systems has led to degradation of aquatic ecosystems around the world. Nutrient and TSS loads from Midwestern states to the Mississippi River are a major contributor to the Gulf of Mexico Hypoxic Zone, an area of very low dissolved oxygen concentration in the Gulf of Mexico. To better understand Indiana’s contribution of nutrients and TSS to the Mississippi River, annual loads of nitrate plus nitrite as nitrogen, total phosphorus, and TSS were calculated for nine selected watersheds in Indiana using the load estimation model, S-LOADEST. Discrete water-quality samples collected monthly by the Indiana Department of Environmental Management’s Fixed Stations Monitoring Program from 2000–2010 and concurrent discharge data from the U. S. Geological Survey streamflow gages were used to create load models. Annual nutrient and TSS loads varied across Indiana by watershed and hydrologic condition. Understanding the loads from large river sites in Indiana is important for assessing contributions of nutrients and TSS to the Mississippi River Basin and in determining the effectiveness of best management practices in the state. Additionally, evaluation of loads from smaller upstream watersheds is important to characterize improvements at the local level and to identify priorities for reduction.

  12. Loading functions generated by solid explosive detonations inside concrete containment structures

    International Nuclear Information System (INIS)

    Freund, H.W.; Schumann, S.; Rischbieter, F.; Schmitz, C.

    1989-01-01

    Partial dismantling of concrete structures by controlled blasting is being considered for nuclear power reactor decommissioning /1,2/. Quantitative prediction of both the desired destructive effects and the side effects caused by the dynamic load is based on knowledge of the time dependent forces acting on the structure, availability of data abut the dynamic material properties, realistic structural models. This work describes investigations performed to obtain time dependent forces for the case where solid explosive charges embedded into concrete are being detonated. The resulting multi component loading function is shown to constitute a set of input data for pre-test safety calculations of the building vibrational response

  13. Apparatus and method for determining solids circulation rate

    Science.gov (United States)

    Ludlow, J Christopher [Morgantown, WV; Spenik, James L [Morgantown, WV

    2012-02-14

    The invention relates to a method of determining bed velocity and solids circulation rate in a standpipe experiencing a moving packed bed flow, such as the in the standpipe section of a circulating bed fluidized reactor The method utilizes in-situ measurement of differential pressure over known axial lengths of the standpipe in conjunction with in-situ gas velocity measurement for a novel application of Ergun equations allowing determination of standpipe void fraction and moving packed bed velocity. The method takes advantage of the moving packed bed property of constant void fraction in order to integrate measured parameters into simultaneous solution of Ergun-based equations and conservation of mass equations across multiple sections of the standpipe.

  14. Characterization and Design of Zeolite Catalysts Solid Acidity, Shape Selectivity and Loading Properties

    CERN Document Server

    Niwa, Miki; Okumura, Kazu

    2010-01-01

    Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. Zeolite-based catalysts are used by industrial chemical companies in the interconversion of hydrocarbons and the alkylation of aromatic compounds. The current book deals with the characterization of specific properties of Zeolites and calculations for the design of catalysts. Measurements and utilization of solid acidity, shape selectivity, and loading properties, that are three prominent properties of a Zeolite catalyst, are treated in detail. These features concern chemical vapor deposition of silica, shape selectivity, loading properties, solid activity, Brønsted or Lewis character, ammonia temperature programmed desorption, control of the pore-opening size by chemical vapor deposition of silica and XAFS analysis of metals being highly dispersed inside and outside a framework.

  15. Dynamic analysis of solid propellant grains subjected to ignition pressurization loading

    Science.gov (United States)

    Chyuan, Shiang-Woei

    2003-11-01

    Traditionally, the transient analysis of solid propellant grains subjected to ignition pressurization loading was not considered, and quasi-elastic-static analysis was widely adopted for structural integrity because the analytical task gets simplified. But it does not mean that the dynamic effect is not useful and could be neglected arbitrarily, and this effect usually plays a very important role for some critical design. In order to simulate the dynamic response for solid rocket motor, a transient finite element model, accompanied by concepts of time-temperature shift principle, reduced integration and thermorheologically simple material assumption, was used. For studying the dynamic response, diverse ignition pressurization loading cases were used and investigated in the present paper. Results show that the dynamic effect is important for structural integrity of solid propellant grains under ignition pressurization loading. Comparing the effective stress of transient analysis and of quasi-elastic-static analysis, one can see that there is an obvious difference between them because of the dynamic effect. From the work of quasi-elastic-static and transient analyses, the dynamic analysis highlighted several areas of interest and a more accurate and reasonable result could be obtained for the engineer.

  16. Rotating solid foam reactors : mass transfer and reaction rate

    NARCIS (Netherlands)

    Tschentscher, R.

    2012-01-01

    In this thesis the performance and applicability of rotating solid foam stirrers is investigated. The stirrer consists, thereby of a solid, highly porous structure, which is used as stirrer and catalyst support simultaneously. The solid foam block occupies a large part of the reactor volume.

  17. Coupled Fluid-Solid Interaction Under Shock Wave Loading: Part II - Dynamic Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tipton, David Gregory [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Christon, Mark Allen [CTO Offce, Dassault Systµemes SIMULIA, Providence, RI (United States); Ingber, Marc Stuart [Univ. of New Mexico, Albuquerque, NM (United States). Department of Mechanical Engineering

    2009-07-01

    This article is the second of two that consider the treatment of fluid-solid interaction problems where the solid experiences wave loading and large bulk Lagrangian displacements. In part-I, we presented the formulation for the edge-based unstructured-grid Euler solver in the context of a discontinuous- Galerkin framework with the extensions used to treat internal fluid-solid interfaces. A super-sampled L2 projection was used to construct level-set data from the Lagrangian interface, and a narrow-band approach was used to identify and construct appropriate ghost data and boundary conditions at the fluid-solid interface. A series of benchmark problems were used to verify the treatment of the fluid-solid interface conditions with a static interface position. In this paper, we consider the treatment of dynamic interfaces and the associated large bulk Lagrangian displacements of the solid.We present the coupled dynamic fluid-solid system, and develop an explicit, monolithic treatment of the fully-coupled system. The conditions associated with moving interfaces and their implementation are discussed. A comparison of moving vs. fixed reference frames is used to verify the dynamic interface treatment. Lastly, a series of two and and three-dimensional projectile and shock-body interaction calculations are presented. Ultimately, the use of the Lagrangian interface position and a super-sampled projection for fast level-set construction, the narrow-band extraction of ghost data, and monolithic explicit solution algorithm has proved to be a computationally efficient means for treating shock induced fluid-solid interaction problems.

  18. Dynamic strength of rock with single planar joint under various loading rates at various angles of loads applied

    Directory of Open Access Journals (Sweden)

    Pei-Yun Shu

    2018-06-01

    Full Text Available Intact rock-like specimens and specimens that include a single, smooth planar joint at various angles are prepared for split Hopkinson pressure bar (SHPB testing. A buffer pad between the striker bar and the incident bar of an SHPB apparatus is used to absorb some of the shock energy. This can generate loading rates of 20.2–4627.3 GPa/s, enabling dynamic peak stresses/strengths and associated failure patterns of the specimens to be investigated. The effects of the loading rate and angle of load applied on the dynamic peak stresses/strengths of the specimens are examined. Relevant experimental results demonstrate that the failure pattern of each specimen can be classified as four types: Type A, integrated with or without tiny flake-off; Type B, slide failure; Type C, fracture failure; and Type D, crushing failure. The dynamic peak stresses/strengths of the specimens that have similar failure patterns increase linearly with the loading rate, yielding high correlations that are evident on semi-logarithmic plots. The slope of the failure envelope is the smallest for slide failure, followed by crushing failure, and that of fracture failure is the largest. The magnitude of the plot slope of the dynamic peak stress against the loading rate for the specimens that are still integrated after testing is between that of slide failure and crushing failure. The angle of application has a limited effect on the dynamic peak stresses/strengths of the specimens regardless of the failure pattern, but it affects the bounds of the loading rates that yield each failure pattern, and thus influences the dynamic responses of the single jointed specimen. Slide failure occurs at the lowest loading rate of any failure, but can only occur in single jointed specimen that allows sliding. Crushing failure is typically associated with the largest loading rate, and fracture failure may occur when the loading rate is between the boundaries for slide failure and crushing

  19. Composition, production rate and characterization of Greek dental solid waste.

    Science.gov (United States)

    Mandalidis, Alexandros; Topalidis, Antonios; Voudrias, Evangelos A; Iosifidis, Nikolaos

    2018-05-01

    The overall objective of this work is to determine the composition, characterization and production rate of Greek dental solid waste (DSW). This information is important to design and cost management systems for DSW, for safety and health considerations and for assessing environmental impact. A total of 141 kg of DSW produced by a total of 2542 patients in 20 dental practices from Xanthi, Greece was collected, manually separated and weighed over a period of four working weeks. The waste was separated in 19 sub fractions, which were classified in 2 major categories, according to Greek regulations: Domestic-type waste comprising 8% and hazardous waste comprising 92% by weight of total DSW. The latter was further classified in infectious waste, toxic waste and mixed type waste (infectious and toxic together), accounting for 88.5%, 3.5% and 0.03% of total DSW by weight, respectively. The overall unit production rates (mean ± standard error of the mean) were 381 ± 15 g/practice/d and 53.3 ± 1.4 g/patient/d for total DSW, 337 ± 14 g/practice/d and 46.6 ± 1.2 g/patient/d for total infectious DSW, 13.4 ± 0.7 g/practice/d and 2.1 ± 0.1 g/patient/d for total toxic DSW and 30.4 ± 2.5 g/practice/d and 4.6 ± 0.4 g/patient/d for domestic-type waste. Daily DSW production was correlated with daily number of patients and regression correlations were produced. DSW was subject to laboratory characterization in terms of bulk density, calorific value, moisture, ash and volatile solids content. Measured calorific values were compared to predictions from empirical models. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. The Effect of Rehearsal Rate and Memory Load on Verbal Working Memory

    OpenAIRE

    Fegen, David; Buchsbaum, Bradley R.; D’Esposito, Mark

    2014-01-01

    While many neuroimaging studies have investigated verbal working memory (WM) by manipulating memory load, the subvocal rehearsal rate at these various memory loads has generally been left uncontrolled. Therefore, the goal of this study was to investigate how mnemonic load and the rate of subvocal rehearsal modulate patterns of activity in the core neural circuits underlying verbal working memory. Using fMRI in healthy subjects, we orthogonally manipulated subvocal rehearsal rate and memory lo...

  1. Allostatic load and heart rate variability as health risk indicators.

    African Journals Online (AJOL)

    investigate the feasibility of inclusion of HRV indicators into allostatic load assessments and which HRV ... said to reflect stressor-induced activation of the two ... reduced in stress and said to be of prognostic value for ... Recruitment by a power point-illustrat- .... values (Total HRV and vagal activity dependent HRV) can.

  2. Experimental investigation on load capacity and wear rate of ...

    African Journals Online (AJOL)

    In this study, a boundary condition test was conducted on journal bearing materials (Al-Tin alloy and Lead-Bronze alloy) used in Peugeot and Toyota automobiles were examined at room temperature conditions. The results of experiments are presented in graphics which proves that the average loading capacities, PV factor ...

  3. Formulation, characterization and pharmacokinetics of praziquantel-loaded hydrogenated castor oil solid lipid nanoparticles.

    Science.gov (United States)

    Xie, Shuyu; Pan, Baoliang; Wang, Ming; Zhu, Luyan; Wang, Fenghua; Dong, Zhao; Wang, Xiaofang; Zhou, WenZhong

    2010-07-01

    The purpose of this study was to formulate praziquantel (PZQ)-loaded hydrogenated castor oil (HCO) solid lipid nanoparticles (SLN) to enhance the bioavailability and prolong the systemic circulation of the drug. PZQ was encapsulated into HCO nanoparticles by a hot homogenization and ultrasonication method. The physicochemical characteristics of SLN were investigated by optical microscope, scanning electron microscopy and photon correlation spectroscopy. Pharmacokinetics were studied after oral, subcutaneous and intramuscular administration in mice. The diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 344.0 +/- 15.1 nm, 0.31 +/- 0.08, -16.7 +/- 0.5 mV, 62.17 +/- 6.53% and 12.43 +/- 1.31%, respectively. In vitro release of PZQ-loaded HCO-SLN exhibited an initial burst release followed by a sustained release. SLN increased the bioavailability of PZQ by 14.9-, 16.1- and 2.6-fold, and extended the mean residence time of the drug from 7.6, 6.6 and 8.2 to 95.9, 151.6 and 48.2 h after oral, subcutaneous and intramuscular administration, respectively. The PZQ-loaded HCO-SLN could be a promising formulation to enhance the pharmacological activity of PZQ.

  4. Mechanical Behaviour of Bolted Joints Under Impact Rates of Loading

    Science.gov (United States)

    2012-01-01

    M. (1995). Bearing Strength of Autoclave and oven cured kevlar / epoxy laminates under static and dynamic loading. Compostes, 451-456. Kretsis, G...Joints in Glass Fibre/ Epoxy Laminates. Composites, Volume 16. No 2. Kolsky, H. (1949). An Investigation of the Mechanical Properties of Materials at...elongating the pulse width. The responses are read by the strain gages bonded on the incident and transmission bar with Vishay AE-10 epoxy . The gages

  5. Dissolution rate enhancement of repaglinide by solid dispersion

    African Journals Online (AJOL)

    Keywords: Diabetes, Solid dispersion, Repaglinide, Solubility, Dissolution, Burst release. Tropical Journal of ... high lipophilicity (logP = 3.97) and relatively low oral bioavailability (56 .... II drug, i.e., low soluble and high permeable in nature. As.

  6. Hansen solubility parameters (HSP) for prescreening formulation of solid lipid nanoparticles (SLN): in vitro testing of curcumin-loaded SLN in MCF-7 and BT-474 cell lines.

    Science.gov (United States)

    Doktorovova, Slavomira; Souto, Eliana B; Silva, Amélia M

    2018-01-01

    Curcumin, a phenolic compound from turmeric rhizome (Curcuma longa), has many interesting pharmacological effects, but shows very low aqueous solubility. Consequently, several drug delivery systems based on polymeric and lipid raw materials have been proposed to increase its bioavailability. Solid lipid nanoparticles (SLN), consisting of solid lipid matrix and a surfactant layer can load poorly water-soluble drugs, such as curcumin, deliver them at defined rates and enhance their intracellular uptake. In the present work, we demonstrate that, despite the drug's affinity to lipids frequently used in SLN production, the curcumin amount loaded in most SLN formulations may be too low to exhibit anticancer properties. The predictive curcumin solubility in solid lipids has been thoroughly analyzed by Hansen solubility parameters, in parallel with the lipid-screening solubility tests for a range of selected lipids. We identified the most suitable lipid materials for curcumin-loaded SLN, producing physicochemically stable particles with high encapsulation efficiency (>90%). Loading capacity of curcumin in SLN allowed preventing the cellular damage caused by cationic SLN on MCF-7 and BT-474 cells but was not sufficient to exhibit drug's anticancer properties. But curcumin-loaded SLN exhibited antioxidant properties, substantiating the conclusions that curcumin's effect in cancer cells is highly dose dependent.

  7. Development of Houttuynia cordata Extract-Loaded Solid Lipid Nanoparticles for Oral Delivery: High Drug Loading Efficiency and Controlled Release

    Directory of Open Access Journals (Sweden)

    Ju-Heon Kim

    2017-12-01

    Full Text Available Houttuynia cordata (H. cordata has been used for diuresis and detoxification in folk medicine as well as a herbal medicine with antiviral and antibacterial activities. H. cordata extract-loaded solid lipid nanoparticles (H-SLNs were prepared with various concentration of poloxamer 188 or poloxamer 407 by a hot homogenization and ultrasonication method. H-SLNs dispersion was freeze-dried with or without trehalose as a cryoprotectant. The physicochemical characteristics of H-SLNs were evaluated by dynamic laser scattering (DLS, differential scanning calorimetry (DSC, Fourier transform infrared spectroscopy (FT-IR, and scanning electron microscopy (SEM. Additionally, the in vitro release and in vitro cytotoxicity of H-SLNs were measured. Encapsulation efficiencies of H-SLNs (as quercitrin were 92.9–95.9%. The SEM images of H-SLNs showed that H-SLNs have a spherical morphology. DSC and FT-IR showed that there were no interactions between ingredients. The increased extent of particle size of freeze-dried H-SLNs with trehalose was significantly lower than that of H-SLNs without trehalose. H-SLNs provided sustained release of quercitrin from H. cordata extracts. Cell viability of Caco-2 cells was over 70% according to the concentration of various formulation. Therefore, it was suggested that SLNs could be good carrier for administering H. cordata extracts.

  8. An improved model for considering strain rate effects on reinforced concrete elements behavior under dynamic loads

    International Nuclear Information System (INIS)

    Sim, J.; Soroushian, P.

    1989-01-01

    An improved model for predicting the reinforced concrete element behavior under dynamic strain rates was developed using the layer modeling technique. The developed strain rate sensitive model for axial/flexural analysis of reinforced concrete elements was used to predict the test results, performed at different loading rates, and the predictions were reasonable. The developed analysis technique was used to study the loading rate sensitivity of reinforced concrete beams and columns with different geometry and material properties. Two design formulas for computing the loading rate dependent axial and flexural strengths of reinforced concrete sections are suggested

  9. Load and resistance factor rating (LRFR) in New York State : volume II.

    Science.gov (United States)

    2011-09-01

    This report develops a Load and Resistance Factor Rating (NYS-LRFR) methodology : for New York bridges. The methodology is applicable for the rating of existing : bridges, the posting of under-strength bridges, and checking Permit trucks. The : propo...

  10. Load and resistance factor rating (LRFR) in New York State : volume I.

    Science.gov (United States)

    2011-09-01

    This report develops a Load and Resistance Factor Rating (NYS-LRFR) methodology : for New York bridges. The methodology is applicable for the rating of existing : bridges, the posting of under-strength bridges, and checking Permit trucks. The : propo...

  11. Modelling of pile load tests in granular soils : Loading rate effects

    NARCIS (Netherlands)

    Nguyen, T.C.

    2017-01-01

    People have used pile foundations throughout history to support structures by transferring
    loads to deeper and stronger soil layers. One of the most important questions during the design of the pile foundation is the bearing capacity of the pile. The most reliable method for determining the

  12. Probing the impact of loading rate on the mechanical properties of viral nanoparticles

    NARCIS (Netherlands)

    Snijder, J.; Ivanovska, I.L.; Baclayon, M.; Roos, W.H.; Wuite, G.J.L.

    2012-01-01

    The effects of changes in the loading rate during the forced dissociation of single bonds have been studied for a wide variety of interactions. Less is known on the loading rate dependent behaviour of more complex systems that consist of multiple bonds. Here we focus on viral nanoparticles, in

  13. High-solids loading enzymatic hydrolysis of waste papers for biofuel production

    International Nuclear Information System (INIS)

    Wang, Lei; Templer, Richard; Murphy, Richard J.

    2012-01-01

    Highlights: ► Waste papers have great potential as a feedstock for bioethanol production. ► A wet blending step would significantly enhance enzymatic hydrolysis efficiency. ► High-solids loading saccharification was performed successfully on waste papers. ► Saccharification data were from four types of paper and two enzyme alternatives. ► Enzymatic hydrolysis kinetic models were validated by experimental data. -- Abstract: Waste papers (newspaper, office paper, magazines and cardboard in this study) with 50–73% (w/w oven dry weight) carbohydrate contents have considerable potential as raw materials for bioethanol production. A particle size reduction step of wet blending prior to enzymatic hydrolysis of newspaper was found to increase the glucan conversion efficiency by up to 10%. High-solids loading hydrolysis at 15% (w/w) of four types of paper using two enzyme alternatives, Celluclast 1.5L supplemented with Novozyme 188 and Cellic Ctec 1 (Novozymes A/S, Demark), at various enzyme concentrations were successfully performed in a lab-scale overhead-stirred reactor. This work has identified the relative saccharification performance for the four types of paper and shows office paper and cardboard to be more suitable for producing bioethanol than newspaper or magazine paper. The experimental data were also very well described by a modified, simple three parameter glucan and xylan hydrolysis model. These findings provide the possibility for incorporating this validated kinetic model into process designs required for commercial scale bioethanol production from waste paper resources.

  14. The High-Strain Rate Loading of Structural Biological Materials

    Science.gov (United States)

    Proud, W. G.; Nguyen, T.-T. N.; Bo, C.; Butler, B. J.; Boddy, R. L.; Williams, A.; Masouros, S.; Brown, K. A.

    2015-10-01

    The human body can be subjected to violent acceleration as a result of explosion caused by military ordinance or accident. Blast waves cause injury and blunt trauma can be produced by violent impact of objects against the human body. The long-term clinical manifestations of blast injury can be significantly different in nature and extent to those suffering less aggressive insult. Similarly, the damage seen in lower limbs from those injured in explosion incidents is in general more severe than those falling from height. These phenomena increase the need for knowledge of the short- and long-term effect of transient mechanical loading to the biological structures of the human body. This paper gives an overview of some of the results of collaborative investigation into blast injury. The requirement for time-resolved data, appropriate mechanical modeling, materials characterization and biological effects is presented. The use of a range of loading platforms, universal testing machines, drop weights, Hopkinson bars, and bespoke traumatic injury simulators are given.

  15. TMI-2 RCS activity and solids loading from aggressive defueling techniques

    International Nuclear Information System (INIS)

    Baston, V.F.; Hofstetter, K.J.

    1987-01-01

    One of the tasks performed in support of defueling operations has involved mechanical degradation of resolidified material (core crust layer) utilizing the core drilling equipment. Prior to actual drilling operations, an engineering estimate was made for the anticipated increase in radioactivity and particulate loading to the Three Mile Island Unit 2 (TMI-2) reactor coolant system (RCS). Predictions for RCS activity and particulate loading increases were important to evaluate the cleanup requirements for the defueling water cleanup system to minimize both the dose rates for defueling personnel and water turbidity

  16. The Effect of Organic Loading Rate on Milk WastewaterTreatment Using Sequencing Batch Reactor (SBR

    Directory of Open Access Journals (Sweden)

    Hooman Hajiabadi

    2009-09-01

    Full Text Available In this study, four aerobic sequencing batch reactors (SBRs were operated under the same conditions for the treatment of milk wastewater at different organic loading rates (OLRs. Cylindrical Plexiglas reactors were run for 56 days (including 21 days of acclimatization and 35 days of data gathering. Effective volume, influent wastewater flowrate, and sludge retention time (SRT of reactors were 5.5 L, 3.5 L/d, and 10 d, respectively. The average COD removal efficiency for the reactors R1, R2, R3, and R4 with influent OLRave values of 633, 929, 1915, and 3261 gCOD/m3d were 95, 96, 95, and 82 percent, respectively. The average effluent suspended solid (SS for all reactors was lower than 44 mg/L. Also, except for R4 with an average effluent turbidity of 270 NTU, other reactors met the Iranian wastewater emission standard (50 NTU. In addition, the average sludge volume index of reactors R1 to R3 was found to be lower than 67 mL/g. According to the results, the overall variation of COD removal efficiency versus influent OLR shows a decreasing rate with a correlation factor of 0.8 (R2.

  17. An analysis of representative heating load lines for residential HSPF ratings

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    This report describes an analysis to investigate representative heating loads for single-family detached homes using current EnergyPlus simulations (DOE 2014a). Hourly delivered load results are used to determine binned load lines using US Department of Energy (DOE) residential prototype building models (DOE 2014b) developed by Pacific Northwest National Laboratory (PNNL). The selected residential single-family prototype buildings are based on the 2006 International Energy Conservation Code (IECC 2006) in the DOE climate regions. The resulting load lines are compared with the American National Standards Institute (ANSI)/Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 210/240 (AHRI 2008) minimum and maximum design heating requirement (DHR) load lines of the heating seasonal performance factor (HSPF) ratings procedure for each region. The results indicate that a heating load line closer to the maximum DHR load line, and with a lower zero load ambient temperature, is more representative of heating loads predicted for EnergyPlus prototype residential buildings than the minimum DHR load line presently used to determine HSPF ratings. An alternative heating load line equation was developed and compared to binned load lines obtained from the EnergyPlus simulation results. The effect on HSPF of the alternative heating load line was evaluated for single-speed and two-capacity heat pumps, and an average HSPF reduction of 16% was found. The alternative heating load line relationship is tied to the rated cooling capacity of the heat pump based on EnergyPlus autosizing, which is more representative of the house load characteristics than the rated heating capacity. The alternative heating load line equation was found to be independent of climate for the six DOE climate regions investigated, provided an adjustable zero load ambient temperature is used. For Region IV, the default DOE climate region used for HSPF ratings, the higher load line results in an ~28

  18. Anaerobic co-digestion of food waste and dairy manure: effects of food waste particle size and organic loading rate.

    Science.gov (United States)

    Agyeman, Fred O; Tao, Wendong

    2014-01-15

    This study was to comprehensively evaluate the effects of food waste particle size on co-digestion of food waste and dairy manure at organic loading rates increased stepwise from 0.67 to 3 g/L/d of volatile solids (VS). Three anaerobic digesters were fed semi-continuously with equal VS amounts of food waste and dairy manure. Food waste was ground to 2.5 mm (fine), 4 mm (medium), and 8 mm (coarse) for the three digesters, respectively. Methane production rate and specific methane yield were significantly higher in the digester with fine food waste. Digestate dewaterability was improved significantly by reducing food waste particle size. Specific methane yield was highest at the organic loading rate of 2g VS/L/d, being 0.63, 0.56, and 0.47 L CH4/g VS with fine, medium, and coarse food waste, respectively. Methane production rate was highest (1.40-1.53 L CH4/L/d) at the organic loading rate of 3 g VS/L/d. The energy used to grind food waste was minor compared with the heating value of the methane produced. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Evaluation of hypericin-loaded solid lipid nanoparticles: physicochemical properties, photostability and phototoxicity.

    Science.gov (United States)

    Youssef, Tareq; Fadel, Maha; Fahmy, Rania; Kassab, Kawser

    2012-01-01

    Hypericin (HYP), a natural photosensitizer, has powerful photo-oxidizing ability, tumor-seeking characteristics, and minimal dark toxicity; nevertheless, it has proven high lipid solubility compared to its sparingly water soluble nature. Therefore, its formulation into solid lipid nanoparticles (SLNs) has attracted increasing attention as a potential drug-delivery carrier. Two HYP-loaded SLNs formulations were prepared utilizing microemulsion-based technique. Thereafter, the physicochemical properties of the formulations were investigated and evaluated. HYP-loaded SLNs showed spherical shape with mean particle size ranging from 200-300 nm for both formulations (FA and FB). The encapsulation efficiencies reached above 80% and FA showed significant higher encapsulation than FB (Phypericin and lipids forming the cores in both formulations. Spectroscopic measurements of the photostability study showed that hypericin encapsulation into SLNs improved its photostability, compared to free HYP in 0.1% ethanolic solution. However, photocytotoxicity studies on HepG2 cells revealed an evident inhibition of the photodynamic efficacy of HYP-loaded SLNs, compared to free HYP. In conclusion, although the elevated entrapment efficiency of HYP into SLNs increased its photostability, it decreased its phototoxicity which might be due to the quenching deactivation of HYP molecules resulting from SLN compactness and thickness structure. © 2012 Informa Healthcare USA, Inc.

  20. Lyophilized sponges loaded with curcumin solid lipid nanoparticles for buccal delivery: Development and characterization.

    Science.gov (United States)

    Hazzah, Heba A; Farid, Ragwa M; Nasra, Maha M A; El-Massik, Magda A; Abdallah, Ossama Y

    2015-08-15

    This study aimed to prepare and evaluate mucoadhesive sponges as dosage forms for delivering solid lipid nanoparticles. For this purpose curcumin (Cur) was formulated as solid nanoparticles (SLN) using Gelucire 50/13, and polaxomer 407. The prepared CurSLN dispersion was thickened with different mucoadhesive polymers. Different concentrations of glycerol, and mannitol of range (0.25-20%), and (0-1%), respectively were also examined. The formed gel was poured into oblong molds and freeze dried to form mucoadhesive sponge to be applied to the buccal mucosa. The prepared sponges were evaluated for their, in-vivo residence time, in-vitro and in-vivo drug release, and hydration capacity. Surface morphology for the different sponges were examined using SEM. TEM was also carried out for sponge fragments previously dispersed into water. Infrared spectroscopy was conducted to investigate interaction between used ingredients. The results showed that the CurSLN loaded HPMC, and Polycarbophil sponges showed 4, and 15 h in-vivo residence time, respectively, providing a considerable amount of curcumin into saliva. The incorporation of glycerol and mannitol at concentration of 1% provided elegant and flexible sponges. The SEM showed that the deposition of CurSLN differed according to the type of polymer used. TEM confirmed the integrity of liberated CurSLN from sponges. IR spectra showed an interaction between HPMC and poloxamer 407, which affected its behavior as a gelling agent. The obtained results provide an efficient approach for delivering solid lipid nanoparticles in a solid dosage form keeping the nanoparticle characters and integrity. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Dispersing Si{sub 3}N{sub 4} at high solids loading - applied to protein forming

    Energy Technology Data Exchange (ETDEWEB)

    Lyckfeldt, O.; Palmqvist, L. [Swedish Ceramic Inst., Goeteborg (Sweden); Poeydemenge, F. [ENSCI, Limoges (France)

    2002-07-01

    The dispersing of a Si{sub 3}N{sub 4} powder (UBE SN-E10) at high solids loading in aqueous media was investigated. The powder was used in the as-received (raw) state, after thermal (calcinations) and/or mechanical pre-treatments (ball milling{yields}freeze granulation{yields}freeze-drying). Slips were prepared using pH adjustment with NH{sub 4}OH or an addition of Tiron (low-M{sub w} sulphonic acid). Zeta potential measurements of diluted systems and rheological evaluations of concentrated suspensions were conducted. The effect of adding whey protein concentrate (WPC) was also studied. Zeta potential measurements showed a clear decrease in pH{sub iep} by calcination, whereas Tiron slightly increased the pH{sub iep} of calcined powder and decreased the pH{sub iep} of the as-received powder. Rheological data showed that pH adjustment to 10 was more efficient in stabilising the as-received powder than the calcined powder. pH adjustment was also considered to be the most important effect of adding small amounts of Tiron (0.08 wt%). However, for calcined powder, Tiron was shown to be equally efficient as pH adjustment. Pre-milling followed by freeze granulation/freeze-drying resulted in de-agglomerated powders with improved ability to rapidly disperse and, hence, extend the possibility of achieving extreme solids loadings. When approaching the practical limits in solids loading of these pre-milled powders, slips with 49.5 vol% of as-received and 46.6 vol% of calcined powders displayed clear shear thickening behaviour. However, addition of WPC (12 wt% based on water) significantly decreased the degree of shear thickening although the viscosity at lower shear rates increased. The gelling of WPC was distinct and rapid in suspensions with the two pre-milled powders, as-received stabilised at pH 10 and calcined stabilised with Tiron. (orig.)

  2. Novel sulpiride-loaded solid lipid nanoparticles with enhanced intestinal permeability

    Directory of Open Access Journals (Sweden)

    Ibrahim WM

    2013-12-01

    Full Text Available Waheed M Ibrahim,1 Abdullah H AlOmrani,2 Alaa Eldeen B Yassin31Drug Sector, Saudi Food and Drug Authority, 2Department of Pharmaceutics, College of Pharmacy, King Saud University, 3Department of Pharmaceutical Sciences, College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, Saudi ArabiaBackground: Solid lipid nanoparticles (SLN, novel drug delivery carriers, can be utilized in enhancing both intestinal permeability and dissolution of poorly absorbed drugs. The aim of this work was to enhance the intestinal permeability of sulpiride by loading into SLN.Methods: A unique ultrasonic melt-emulsification method with minimum stress conditions was used for the preparation of SLN. The mixture of the drug and the melted lipids was simply dispersed in an aqueous solution of a surfactant at a temperature that was 10°C higher than the melting points of the lipids using probe sonication, and was then simultaneously dispersed in cold water. Several formulation parameters were optimized, including the drug-to-lipid ratio, and the types of lipids and surfactants used. The produced SLN were evaluated for their particle size and shape, surface charge, entrapment efficiency, crystallinity of the drug and lipids, and the drug release profile. The rat everted sac intestine model was utilized to evaluate the change in intestinal permeability of sulpiride by loading into SLN.Results: The method adopted allowed successful preparation of SLN with a monodispersed particle size of 147.8–298.8 nm. Both scanning electron microscopic and atomic force microscopic images showed uniform spherical particles and confirmed the sizes determined by the light scattering technique. Combination of triglycerides with stearic acid resulted in a marked increase in zeta potential, entrapment efficiency, and drug loading; however, the particle size was increased. The type of surfactant used was critical for particle size

  3. High rate loading tests and impact tests of concrete and reinforcement

    International Nuclear Information System (INIS)

    Takeda, J.I.; Tachikawa, H.; Fujimoto, K.

    1982-01-01

    The responses of reinforced concrete structural members and structures subjected to impact or impulsive loadings are affected by the behavior of constituent concrete and reinforcement which are the synthesis of the rate effects and the contribution of propagating stress waves of them. The rate effects and the contribution of stress waves do not have the same tendency in the variation of magnitude of them with speed of impact or impulsive loadings. Therefore the rate effects, mentioned above, should be obtained by the tests minimized the effect of stress waves (high rate loading test). This paper deals with the testing techniques with high rate loadings and impact, and also reports the main results of these tests. (orig.) [de

  4. Multisized Inert Particle Loading for Solid Rocket Axial Combustion Instability Suppression

    Directory of Open Access Journals (Sweden)

    David R. Greatrix

    2012-01-01

    Full Text Available In the present investigation, various factors and trends, related to the usage of two or more sets of inert particles comprised of the same material (nominally aluminum but at different diameters for the suppression of axial shock wave development, are numerically predicted for a composite-propellant cylindrical-grain solid rocket motor. The limit pressure wave magnitudes at a later reference time in a given pulsed firing simulation run are collected for a series of runs at different particle sizes and loading distributions and mapped onto corresponding attenuation trend charts. The inert particles’ presence in the central core flow is demonstrated to be an effective means of instability symptom suppression, in correlating with past experimental successes in the usage of particles. However, the predicted results of this study suggest that one needs to be careful when selecting more than one size of particle for a given motor application.

  5. Analyzing the effects of mechanical and osmotic loading on glycosaminoglycan synthesis rate in cartilaginous tissues.

    Science.gov (United States)

    Gao, Xin; Zhu, Qiaoqiao; Gu, Weiyong

    2015-02-26

    The glycosaminoglycan (GAG) plays an important role in cartilaginous tissues to support and transmit mechanical loads. Many extracellular biophysical stimuli could affect GAG synthesis by cells. It has been hypothesized that the change of cell volume is a primary mechanism for cells to perceive the stimuli. Experimental studies have shown that the maximum synthesis rate of GAG is achieved at an optimal cell volume, larger or smaller than this level the GAG synthesis rate decreases. Based on the hypothesis and experimental findings in the literature, we proposed a mathematical model to quantitatively describe the cell volume dependent GAG synthesis rate in the cartilaginous tissues. Using this model, we investigated the effects of osmotic loading and mechanical loading on GAG synthesis rate. It is found our proposed mathematical model is able to well describe the change of GAG synthesis rate in isolated cells or in cartilage with variations of the osmotic loading or mechanical loading. This model is important for evaluating the GAG synthesis activity within cartilaginous tissues as well as understanding the role of mechanical loading in tissue growth or degeneration. It is also important for designing a bioreactor system with proper extracellular environment or mechanical loading for growing tissue at the maximum synthesis rate of the extracellular matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The effect of rehearsal rate and memory load on verbal working memory.

    Science.gov (United States)

    Fegen, David; Buchsbaum, Bradley R; D'Esposito, Mark

    2015-01-15

    While many neuroimaging studies have investigated verbal working memory (WM) by manipulating memory load, the subvocal rehearsal rate at these various memory loads has generally been left uncontrolled. Therefore, the goal of this study was to investigate how mnemonic load and the rate of subvocal rehearsal modulate patterns of activity in the core neural circuits underlying verbal working memory. Using fMRI in healthy subjects, we orthogonally manipulated subvocal rehearsal rate and memory load in a verbal WM task with long 45-s delay periods. We found that middle frontal gyrus (MFG) and superior parietal lobule (SPL) exhibited memory load effects primarily early in the delay period and did not exhibit rehearsal rate effects. In contrast, we found that inferior frontal gyrus (IFG), premotor cortex (PM) and Sylvian-parietal-temporal region (area Spt) exhibited approximately linear memory load and rehearsal rate effects, with rehearsal rate effects lasting through the entire delay period. These results indicate that IFG, PM and area Spt comprise the core articulatory rehearsal areas involved in verbal WM, while MFG and SPL are recruited in a general supervisory role once a memory load threshold in the core rehearsal network has been exceeded. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Enzymatic hydrolysis at high-solids loadings for the conversion of agave bagasse to fuel ethanol

    International Nuclear Information System (INIS)

    Caspeta, Luis; Caro-Bermúdez, Mario A.; Ponce-Noyola, Teresa; Martinez, Alfredo

    2014-01-01

    Highlights: • Conversion of agave bagasse to fuel ethanol. • Ethanosolv-pretreatment variables were statistically adjusted. • 91% of total sugars found in agave bagasse were recovered. • 225 g/L glucose from 30%-consistency hydrolysis using mini-reactors with peg-mixers. • 0.25 g of ethanol per g of dry agave bagasse was obtained. - Abstract: Agave bagasse is the lignocellulosic residue accumulated during the production of alcoholic beverages in Mexico and is a potential feedstock for the production of biofuels. A factorial design was used to investigate the effect of temperature, residence time and concentrations of acid and ethanol on ethanosolv pretreatment and enzymatic hydrolysis of agave bagasse. This method and the use of a stirred in-house-made mini-reactor increased the digestibility of agave bagasse from 30% observed with the dilute-acid method to 98%; also allowed reducing the quantity of enzymes used to hydrolyze samples with solid loadings of 30% w/w and glucose concentrations up to 225 g/L were obtained in the enzymatic hydrolysates. Overall this process allows the recovery of 91% of the total fermentable sugars contained in the agave bagasse (0.51 g/g) and 69% of total lignin as co-product (0.11 g/g). The maximum ethanol yield under optimal conditions using an industrial yeast strain for the fermentation was 0.25 g/g of dry agave bagasse, which is 86% of the maximum theoretical (0.29 g/g). The effect of the glucose concentration and solid loading on the conversion of cellulose to glucose is discussed, in addition to prospective production of about 50 million liters of fuel ethanol using agave bagasse residues from the tequila industry as a potential solution to the disposal problems

  8. Relationship Between Pretraining Subjective Wellness Measures, Player Load, and Rating-of-Perceived-Exertion Training Load in American College Football.

    Science.gov (United States)

    Govus, Andrew D; Coutts, Aaron; Duffield, Rob; Murray, Andrew; Fullagar, Hugh

    2018-01-01

    The relationship between pretraining subjective wellness and external and internal training load in American college football is unclear. To examine the relationship of pretraining subjective wellness (sleep quality, muscle soreness, energy, wellness Z score) with player load and session rating of perceived exertion (s-RPE-TL) in American college football players. Subjective wellness (measured using 5-point, Likert-scale questionnaires), external load (derived from GPS and accelerometry), and s-RPE-TL were collected during 3 typical training sessions per week for the second half of an American college football season (8 wk). The relationship of pretraining subjective wellness with player load and s-RPE training load was analyzed using linear mixed models with a random intercept for athlete and a random slope for training session. Standardized mean differences (SMDs) denote the effect magnitude. A 1-unit increase in wellness Z score and energy was associated with trivial 2.3% (90% confidence interval [CI] 0.5, 4.2; SMD 0.12) and 2.6% (90% CI 0.1, 5.2; SMD 0.13) increases in player load, respectively. A 1-unit increase in muscle soreness (players felt less sore) corresponded to a trivial 4.4% (90% CI -8.4, -0.3; SMD -0.05) decrease in s-RPE training load. Measuring pretraining subjective wellness may provide information about players' capacity to perform in a training session and could be a key determinant of their response to the imposed training demands American college football. Hence, monitoring subjective wellness may aid in the individualization of training prescription in American college football players.

  9. Development of novel sibutramine base-loaded solid dispersion with gelatin and HPMC: physicochemical characterization and pharmacokinetics in beagle dogs.

    Science.gov (United States)

    Lim, Hyun-Tae; Balakrishnan, Prabagar; Oh, Dong Hoon; Joe, Kwan Hyung; Kim, Young Ran; Hwang, Doo Hyung; Lee, Yong-Bok; Yong, Chul Soon; Choi, Han-Gon

    2010-09-15

    To develop a novel sibutramine base-loaded solid dispersion with enhanced solubility and bioavailability, various solid dispersions were prepared using a spray drying technique with hydrophilic polymers such as gelatin, HPMC and citric acid. Their solubility, thermal characteristics and crystallinity were investigated. The dissolution and pharmacokinetics of the sibutramine base-loaded solid dispersion were then compared with a sibutramine hydrochloride monohydrate-loaded commercial product (Reductil). The solid dispersions prepared with gelatin gave higher drug solubility than those prepared without gelatin, irrespective of the amount of polymer. The sibutramine base-loaded solid dispersions containing hydrophilic polymer and citric acid showed higher drug solubility compared to sibutramine base and sibutramine hydrochloride monohydrate. Among the formulations tested, the solid dispersion composed of sibutramine base/gelatin/HPMC/citric acid at the weight ratio of 1/0.8/0.2/0.5 gave the highest solubility of 5.03+/-0.24 mg/ml. Our DSC and powder X-ray diffraction results showed that the drug was present in an altered amorphous form in this solid dispersion. The difference factor (f(1)) values between solid dispersion and commercial product were 2.82, 6.65 and 6.31 at pH 1.2, 4.0 and 6.8, respectively. Furthermore, they had the similarity factor (f(2)) value of 65.68, 53.43 and 58.97 at pH 1.2, 4.0 and 6.8, respectively. Our results suggested that the solid dispersion and commercial product produced a similar correlation of dissolution profiles at all pH ranges. The AUC, C(max) and T(max) of the parent drug and metabolite I and II from the solid dispersion were not significantly different from those of the commercial product, suggesting that the solid dispersion might be bioequivalent to the commercial product in beagle dogs. Thus, the sibutramine base-loaded solid dispersion prepared with gelatin, HPMC and citric acid is a promising candidate for improving the

  10. 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

  11. Performance of a constructed wetland treating intensive shrimp aquaculture wastewater under high hydraulic loading rate

    International Nuclear Information System (INIS)

    Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y.; Chang, Y.-F.; Chen, Y.-M.; Shih, K.-C.

    2005-01-01

    A water treatment unit, mainly consisting of free water surface (FWS) and subsurface flow (SF) constructed wetland cells, was integrated into a commercial-scale recirculating aquaculture system for intensive shrimp culture. This study investigated performance of the treatment wetlands for controlling water quality. The results showed that the FWS-SF cells effectively removed total suspended solids (55-66%), 5-day biochemical oxygen demand (37-54%), total ammonia (64-66%) and nitrite (83-94%) from the recirculating water under high hydraulic loading rates (1.57-1.95 m/day). This led to a water quality that was suitable for shrimp culture and effluent that always satisfied the discharge standards. The area ratios of wetlands to culture tank being demonstrated (0.43) and calculated (0.096) in this study were both significantly lower than the reported values. Accordingly, a constructed wetland was technically and economically feasible for managing water quality of an intensive aquaculture system. - A constructed wetland was found to be technically and economically feasible for managing water quality of an intensive recirculating aquaculture system

  12. The effect of organic loading rate and retention time on hydrogen production from a methanogenic CSTR.

    Science.gov (United States)

    Pakarinen, O; Kaparaju, P; Rintala, J

    2011-10-01

    The possibility of shifting a methanogenic process for hydrogen production by changing the process parameters viz., organic loading rate (OLR) and hydraulic retention time (HRT) was evaluated. At first, two parallel semi-continuously fed continuously stirred tank reactors (CSTR) were operated as methanogenic reactors (M1 and M2) for 78 days. Results showed that a methane yield of 198-218 L/kg volatile solids fed (VS(fed)) was obtained when fed with grass silage at an OLR of 2 kgVS/m³/d and HRT of 30 days. After 78 days of operation, hydrogen production was induced in M2 by increasing the OLR from 2 to 10 kgVS/m³/d and shortening the HRT from 30 to 6 days. The highest H₂ yield of 42 L/kgVS(fed) was obtained with a maximum H₂ content of 24%. The present results thus demonstrate that methanogenic process can be shifted towards hydrogen production by increasing the OLR and decreasing HRT. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Loading of praziquantel in the crystal lattice of solid lipid nanoparticles - studies by DSC and SAXS

    Energy Technology Data Exchange (ETDEWEB)

    Souza, A.L.R.; Cassimiro, D.L.; Almeida, A.E.; Ribeiro, C.A.; Gremiao, M.P.D. [UNESP, Araraquara, SP (Brazil); Sarmento, V.H.V. [Universidade Federal de Sergipe (UFS), Itabaiana, SE (Brazil); Andreani, T.; Silva, A.M.; Souto, E.B. [Universidade de Tras-os-Montes e Alto Douro, Vila Real (Portugal)

    2012-07-01

    Full text: Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke infections that affect humans. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. In this work, solid lipid nanoparticles loaded with PZQ (PZQ-SLN) were prepared by a modified oil-in-water microemulsion method selecting stearic acid as lipid phase after solubility screening studies. The mean particle size (Z-Ave) and zeta potential (ZP) were 500 nm and -34.0 mV, respectively. Morphology and shape of PZQ-SLN were analysed by scanning electron microscopy revealing the presence of spherical particles with smooth surface. Differential scanning calorimetry suggested that SLN comprised a less ordered arrangement of crystals and the drug was molecularly dispersed in the lipid matrix. No supercooled melts were detected. The entrapment efficiency (EE) and loading capacity of PZQ, determined by high performance liquid chromatography, were 99.0 and 17.5, respectively. Effective incorporation of PZQ into the particles was confirmed by small angle X-ray scattering revealing the presence of a lipid lamellar structure. Stability parameters of PZQ-SLN stored at room temperature (25 deg C) and at 4 deg C were checked by analysing Z-Ave, ZP and the EE for a period of 60 days Results showed a relatively long-term physical stability after storage at 4 deg C, without drug expulsion. (author)

  14. Diffusion and Gas Conversion Analysis of Solid Oxide Fuel Cells at Loads via AC Impedance

    Directory of Open Access Journals (Sweden)

    Robert U. Payne

    2011-01-01

    Full Text Available Impedance measurements were conducted under practical load conditions in solid oxide fuel cells of differing sizes. For a 2 cm2 button cell, impedance spectra data were separately measured for the anode, cathode, and total cell. Improved equivalent circuit models are proposed and applied to simulate each of measured impedance data. Circuit elements related to the chemical and physical processes have been added to the total-cell model to account for an extra relaxation process in the spectra not measured at either electrode. The processes to which elements are attributed have been deduced by varying cell temperature, load current, and hydrogen concentration. Spectra data were also obtained for a planar stack of five 61 cm2 cells and the individual cells therein, which were fitted to a simplified equivalent circuit model of the total button cell. Similar to the button cell, the planar cells and stack exhibit a pronounced low-frequency relaxation process, which has been attributed to concentration losses, that is, the combined effects of diffusion and gas conversion. The simplified total-cell model approximates well the dynamic behavior of the SOFC cells and the whole stack.

  15. Loading of praziquantel in the crystal lattice of solid lipid nanoparticles - studies by DSC and SAXS

    International Nuclear Information System (INIS)

    Souza, A.L.R.; Cassimiro, D.L.; Almeida, A.E.; Ribeiro, C.A.; Gremiao, M.P.D.; Sarmento, V.H.V.; Andreani, T.; Silva, A.M.; Souto, E.B.

    2012-01-01

    Full text: Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke infections that affect humans. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. In this work, solid lipid nanoparticles loaded with PZQ (PZQ-SLN) were prepared by a modified oil-in-water microemulsion method selecting stearic acid as lipid phase after solubility screening studies. The mean particle size (Z-Ave) and zeta potential (ZP) were 500 nm and -34.0 mV, respectively. Morphology and shape of PZQ-SLN were analysed by scanning electron microscopy revealing the presence of spherical particles with smooth surface. Differential scanning calorimetry suggested that SLN comprised a less ordered arrangement of crystals and the drug was molecularly dispersed in the lipid matrix. No supercooled melts were detected. The entrapment efficiency (EE) and loading capacity of PZQ, determined by high performance liquid chromatography, were 99.0 and 17.5, respectively. Effective incorporation of PZQ into the particles was confirmed by small angle X-ray scattering revealing the presence of a lipid lamellar structure. Stability parameters of PZQ-SLN stored at room temperature (25 deg C) and at 4 deg C were checked by analysing Z-Ave, ZP and the EE for a period of 60 days Results showed a relatively long-term physical stability after storage at 4 deg C, without drug expulsion. (author)

  16. Diclofenac sodium-loaded solid lipid nanoparticles prepared by emulsion/solvent evaporation method

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dongfei; Jiang Sunmin [Nanjing Medical University, School of Pharmacy (China); Shen Hong [Nanjing Brain Hospital Affiliated to Nanjing Medical University, Neuro-Psychiatric Institute (China); Qin Shan; Liu Juanjuan; Zhang Qing; Li Rui, E-mail: chongloutougao@gmail.com; Xu Qunwei, E-mail: qunweixu@163.com [Nanjing Medical University, School of Pharmacy (China)

    2011-06-15

    The preparation of solid lipid nanoparticles (SLNs) suffers from the drawback of poor incorporation of water-soluble drugs. The aim of this study was therefore to assess various formulation and process parameters to enhance the incorporation of a water-soluble drug (diclofenac sodium, DS) into SLNs prepared by the emulsion/solvent evaporation method. Results showed that the entrapment efficiency (EE) of DS was increased to approximately 100% by lowering the pH of dispersed phase. The EE of DS-loaded SLNs (DS-SLNs) had been improved by the existence of cosurfactants and increment of PVA concentration. Stabilizers and their combination with PEG 400 in the dispersed phase also resulted in higher EE and drug loading (DL). EE increased and DL decreased as the phospholipid/DS ratio became greater, while the amount of DS had an opposite effect. Ethanol turned out to be the ideal solvent making DS-SLNs. EE and DL of DS-SLNs were not affected by either the stirring speed or the viscosity of aqueous and dispersed phase. According to the investigations, drug solubility in dispersion medium played the most important role in improving EE.

  17. Seismic Load Rating Procedure for Welded Steel Frames Oligo-cyclic Fatigue

    International Nuclear Information System (INIS)

    Ratiu, Mircea D.; Moisidis, Nicolae T.

    2004-01-01

    A dynamic load rating approach for seismic qualification of cold-formed steel welded frames is presented. Allowable seismic loads are developed from cyclic and monotonic tests of standard cold-formed steel components commonly used for piping and electrical raceway supports. The method permits simplified qualification of all connections of frame components through a single load comparison. Test input consists of rotation/cycles-to-failure data and monotonic moment/rotation data. Cyclic data are statistically evaluated to determine an acceptable maximum seismic rotation for the connection. The allowable seismic load is determined from the corresponding static rotation. Application to seismic qualification procedures is discussed. (authors)

  18. Optimization of methazolamide-loaded solid lipid nanoparticles for ophthalmic delivery using Box-Behnken design.

    Science.gov (United States)

    Wang, Fengzhen; Chen, Li; Jiang, Sunmin; He, Jun; Zhang, Xiumei; Peng, Jin; Xu, Qunwei; Li, Rui

    2014-09-01

    The purpose of the present study was to optimize methazolamide (MTZ)-loaded solid lipid nanoparticles (SLNs) which were used as topical eye drops by evaluating the relationship between design factors and experimental data. A three factor, three-level Box-Behnken design (BBD) was used for the optimization procedure, choosing the amount of GMS, the amount of phospholipid, the concentration of surfactant as the independent variables. The chosen dependent variables were entrapment efficiency, dosage loading, and particle size. The generated polynomial equations and response surface plots were used to relate the dependent and independent variables. The optimal nanoparticles were formulated with 100 mg GMS, 150 mg phospholipid, and 1% Tween80 and PEG 400 (1:1, w/v). A new formulation was prepared according to these levels. The observed responses were close to the predicted values of the optimized formulation. The particle size was 197.8 ± 4.9 nm. The polydispersity index of particle size was 0.239 ± 0.01 and the zeta potential was 32.7 ± 2.6 mV. The entrapment efficiency and dosage loading were about 68.39% and 2.49%, respectively. Fourier transform infrared spectroscopy (FT-IR) study indicated that the drug was entrapped in nanoparticles. The optimized formulation showed a sustained release followed the Peppas model. MTZ-SLNs showed significant prolonged decreasing intraocular pressure effect comparing with MTZ solution in vivo pharmacodynamics studies. The results of acute eye irritation study indicated that MTZ-SLNs and AZOPT both had no eye irritation. Furthermore, the MTZ-SLNs were suitable to be stored at low temperature (4 °C).

  19. Docetaxel-loaded solid lipid nanoparticles suppress breast cancer cells growth with reduced myelosuppression toxicity

    Directory of Open Access Journals (Sweden)

    Yuan Q

    2014-10-01

    Full Text Available Qing Yuan,1 Jing Han,1,2 Wenshu Cong,1 Ying Ge,3 Dandan Ma,1,3,4 Zhaoxia Dai,3,4 Yaping Li,5 Xiaolin Bi1,3,4 1CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 2School of Life Sciences, Anhui University, Hefei, 3Cancer Center, Institute of Cancer Stem Cell, Dalian Medical University, Dalian, 4Graduate School, Dalian Medical University, Dalian, 5Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People’s Republic of China Abstract: Docetaxel is an adjuvant chemotherapy drug widely used to treat multiple solid tumors; however, its toxicity and side effects limit its clinical efficacy. Herein, docetaxel-loaded solid lipid nanoparticles (DSNs were developed to reduce systemic toxicity of docetaxel while still keeping its anticancer activity. To evaluate its anticancer activity and toxicity, and to understand the molecular mechanisms of DSNs, different cellular, molecular, and whole genome transcription analysis approaches were utilized. The DSNs showed lower cytotoxicity compared with the commercial formulation of docetaxel (Taxotere® and induced more apoptosis at 24 hours after treatment in vitro. DSNs can cause the treated cancer cells to arrest in the G2/M phase in a dose-dependent manner similar to Taxotere. They can also suppress tumor growth very effectively in a mice model with human xenograft breast cancer. Systemic analysis of gene expression profiles by microarray and subsequent verification experiments suggested that both DSNs and Taxotere regulate gene expression and gene function, including DNA replication, DNA damage response, cell proliferation, apoptosis, and cell cycle regulation. Some of these genes expressed differentially at the protein level although their messenger RNA expression level was similar under Taxotere and DSN treatment. Moreover, DSNs improved the main side effect of Taxotere by greatly

  20. Development of novel cilostazol-loaded solid SNEDDS using a SPG membrane emulsification technique: Physicochemical characterization and in vivo evaluation.

    Science.gov (United States)

    Mustapha, Omer; Kim, Kyung Soo; Shafique, Shumaila; Kim, Dong Shik; Jin, Sung Giu; Seo, Youn Gee; Youn, Yu Seok; Oh, Kyung Taek; Lee, Beom-Jin; Park, Young Joon; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2017-02-01

    The objective of this study was to develop a novel solid self-nanoemulsifying drug delivery system (SNEDDS) using a membrane emulsification technique involving Shirasu porous glass (SPG) which produced very small and uniform emulsion droplets, resulting in enhanced solubility, dissolution and oral bioavailability of poorly water-soluble cilostazol. The effects of carriers on the drug solubility were assessed, and pseudo-ternary phase diagrams were plotted. Among the liquid SNEDDS formulations tested, the liquid SNEDDS composed of peceol (oil), Tween 20 (surfactant) and Labrasol (cosurfactant) at a weight ratio of 15/55/30, produced the smallest emulsion droplet size. The cilostazol-loaded liquid SNEDDS formulation was suspended in the distilled water and subjected to SPG membrane emulsification. Calcium silicate was added as a solid carrier in this liquid SNEDDS, completely suspended and spray-dried, leading to the production of a cilostazol-loaded solid SNEDDS. The emulsion droplet size, solubility and dissolution of the emulsified solid SNEDDS were assessed as compared to the solid SNEDDS prepared without emulsification. Moreover, the physicochemical characteristics and pharmacokinetics in rats were evaluated with the emulsified solid SNEDDS. The emulsified solid SNEDDS provided significantly smaller and more uniform nanoemulsions than did the non-emulsified solid SNEDDS. The emulsified solid SNEDDS showed significantly higher drug solubility and dissolution as compared to the non-emulsified solid SNEDDS. The crystalline drug in it was converted into the amorphous state. Moreover, in rats, it gave significantly higher initial plasma concentrations and AUC compared to the drug powder, suggesting its improved oral bioavailability of cilostazol. Thus, this novel solid SNEDDS developed using a membrane emulsification technique represents a potentially powerful oral delivery system for cilostazol. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Study of Acoustic Emission and Mechanical Characteristics of Coal Samples under Different Loading Rates

    Directory of Open Access Journals (Sweden)

    Huamin Li

    2015-01-01

    Full Text Available To study the effect of loading rate on mechanical properties and acoustic emission characteristics of coal samples, collected from Sanjiaohe Colliery, the uniaxial compression tests are carried out under various levels of loading rates, including 0.001 mm/s, 0.002 mm/s, and 0.005 mm/s, respectively, using AE-win E1.86 acoustic emission instrument and RMT-150C rock mechanics test system. The results indicate that the loading rate has a strong impact on peak stress and peak strain of coal samples, but the effect of loading rate on elasticity modulus of coal samples is relatively small. When the loading rate increases from 0.001 mm/s to 0.002 mm/s, the peak stress increases from 22.67 MPa to 24.99 MPa, the incremental percentage is 10.23%, and under the same condition the peak strain increases from 0.006191 to 0.007411 and the incremental percentage is 19.71%. Similarly, when the loading rate increases from 0.002 mm/s to 0.005 mm/s, the peak stress increases from 24.99 MPa to 28.01 MPa, the incremental percentage is 12.08%, the peak strain increases from 0.007411 to 0.008203, and the incremental percentage is 10.69%. The relationship between acoustic emission and loading rate presents a positive correlation, and the negative correlation relation has been determined between acoustic emission cumulative counts and loading rate during the rupture process of coal samples.

  2. Solid lipid nanoparticles by coacervation loaded with a methotrexate prodrug: preliminary study for glioma treatment.

    Science.gov (United States)

    Battaglia, Luigi; Muntoni, Elisabetta; Chirio, Daniela; Peira, Elena; Annovazzi, Laura; Schiffer, Davide; Mellai, Marta; Riganti, Chiara; Salaroglio, Iris Chiara; Lanotte, Michele; Panciani, Pierpaolo; Capucchio, Maria Teresa; Valazza, Alberto; Biasibetti, Elena; Gallarate, Marina

    2017-03-01

    Methotrexate-loaded biocompatible nanoparticles were tested for preliminary efficacy in glioma treatment. Behenic acid nanoparticles, prepared by the coacervation method, were loaded with the ester prodrug didodecylmethotrexate, which was previously tested in vitro against glioblastoma human primary cultures. Nanoparticle conjugation with an ApoE mimicking chimera peptide was performed to obtain active targeting to the brain. Biodistribution studies in healthy rats assessed the superiority of ApoE-conjugated formulation, which was tested on an F98/Fischer glioma model. Differences were observed in tumor growth rate (measured by MRI) between control and treated rats. In vitro tests on F98 cultured cells assessed their susceptibility to treatment, with consequent apoptosis, and allowed us to explain the apoptosis observed in glioma models.

  3. Behavior of quenched and tempered steels under high strain rate compression loading

    International Nuclear Information System (INIS)

    Meyer, L.W.; Seifert, K.; Abdel-Malek, S.

    1997-01-01

    Two quenched and tempered steels were tested under compression loading at strain rates of ε = 2.10 2 s -1 and ε = 2.10 3 s -1 . By applying the thermal activation theory, the flow stress at very high strain rates of 10 5 to 10 6 s -1 is derived from low temperature and high strain rate tests. Dynamic true stress - true strain behaviour presents, that stress increases with increasing strain until a maximum, then it decreases. Because of the adiabatic process under dynamic loading the maximum flow stress will occur at a lower strain if the strain rate is increased. Considering strain rate, strain hardening, strain rate hardening and strain softening, a constitutive equation with different additive terms is successfully used to describe the behaviour of material under dynamic compression loading. Results are compared with other models of constitutive equations. (orig.)

  4. Research on Acoustic Emission and Electromagnetic Emission Characteristics of Rock Fragmentation at Different Loading Rates

    Directory of Open Access Journals (Sweden)

    Fujun Zhao

    2018-01-01

    Full Text Available The relationships among the generation of acoustic emission, electromagnetic emission, and the fracture stress of rock grain are investigated, which are based on the mechanism of acoustic emission and electromagnetic emission produced in the process of indenting rock. Based on the relationships, the influence of loading rate on the characteristics of acoustic emission and electromagnetic emission of rock fragmentation is further discussed. Experiment on rock braking was carried out with three loading rates of 0.001 mm/s, 0.01 mm/s, and 0.1 mm/s. The results show that the phenomenon of acoustic emission and electromagnetic emission is produced during the process of loading and breaking rock. The wave forms of the two signals and the curve of the cutter indenting load show jumping characteristics. Both curves have good agreement with each other. With the increase of loading rate, the acoustic emission and electromagnetic emission signals are enhanced. Through analysis, it is found that the peak count rate, the energy rate of acoustic emission, the peak intensity, the number of pulses of the electromagnetic emission, and the loading rate have a positive correlation with each other. The experimental results agree with the theoretical analysis. The proposed studies can lead to an in-depth understanding of the rock fragmentation mechanism and help to prevent rock dynamic disasters.

  5. Leach rate characterization of solid radioactive waste forms

    International Nuclear Information System (INIS)

    Flynn, K.F.; Barletta, R.E.; Jardine, L.J.; Steindler, M.J.

    1978-01-01

    Leach rates were measured using distilled water on four types of waste forms: spray calcined waste mixed with silica and borosilicate glass and sintered, the same pulverized, the same in a lead matrix, and waste glass containing U. Twenty isotopes ranging from 22 Na to 239 Np were measured using activation analysis. Leach rates were also measured for a variety of matrix materials (Zircaloy, Al, Pb, glass, Pb 3 RE 6 (SiO 4 ) 6 ), using one isotope each. 2 tables

  6. Humid storage conditions increase the dissolution rate of diazepam from solid dispersions prepared by melt agglomeration

    DEFF Research Database (Denmark)

    Jørgensen, Anna Cecilia; Torstenson, Anette Seo

    2008-01-01

    The purpose of this study is to investigate the effect of cooling mode and storage conditions on the dissolution rate of a solid dispersion prepared by melt agglomeration. The aim has been to relate this effect to the solid state properties of the agglomerates. The cooling mode had an effect on t...

  7. Effects of Load and Speed on Wear Rate of Abrasive Wear for 2014 Al Alloy

    Science.gov (United States)

    Odabas, D.

    2018-01-01

    In this paper, the effects of the normal load and sliding speed on wear rate of two-body abrasive wear for 2014 Al Alloy were investigated in detail. In order to understand the variation in wear behaviour with load and speed, wear tests were carried out at a sliding distance of 11 m, a speed of 0.36 m/s, a duration of 30 s and loads in the range 3-11 N using 220 grit abrasive paper, and at a speed range 0.09-0.90 m/s, a load of 5 N and an average sliding distance of 11 m using abrasive papers of 150 grit size under dry friction conditions. Before the wear tests, solution treatment of the 2014 Al alloy was carried out at temperatures of 505 and 520 °C for 1 h in a muffle furnace and then quenched in cold water at 15 °C. Later, the ageing treatment was carried out at 185 °C for 8 h in the furnace. Generally, wear rate due to time increased linearly and linear wear resistance decreased with increasing loads. However, the wear rate was directly proportional to the load up to a critical load of 7 N. After this load, the slope of the curves decreased because the excessive deformation of the worn surface and the instability of the abrasive grains began to increase. When the load on an abrasive grain reaches a critical value, the groove width is about 0.17 of the abrasive grain diameter, and the abrasive grains begin to fail. The wear rate due to time increased slightly as the sliding speed increased in the range 0.09-0.90 m/s. The reason for this is that changes arising from strain rate and friction heating are expected with increasing sliding speeds.

  8. Comparison of three different types of cilostazol-loaded solid dispersion: Physicochemical characterization and pharmacokinetics in rats.

    Science.gov (United States)

    Mustapha, Omer; Kim, Kyung Soo; Shafique, Shumaila; Kim, Dong Shik; Jin, Sung Giu; Seo, Youn Gee; Youn, Yu Seok; Oh, Kyung Taek; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2017-06-01

    The aim of this research was to compare three different types of cilostazol-loaded solid dispersion system including solvent-evaporated, solvent-wetted and surface-attached solid dispersion. The effect of polymers and surfactants on the aqueous solubility of cilostazol was investigated, leading to the selection of polyvinylpyrrolidone (PVP) and sodium lauryl sulphate (SLS). Employing a spray-drying technique, numerous surface-attached, solvent-evaporated and solvent-wetted solid dispersions were prepared with various amounts PVP and SLS using water, 90% ethanol and acetone, respectively. Their physicochemical properties, solubility, dissolution and oral bioavailability in rats were assessed compared to the drug powder. Among each solid dispersion system tested, the surface-attached, solvent-evaporated and solvent-wetted solid dispersions composed of cilostazol, PVP and SLS at weight ratios of 3.0 : 0.75 : 1.5, 3.0 : 3.0 : 1.5 and 3.0 : 3.0 : 1.5, respectively, provided the highest drug solubility and dissolution. The solvent-evaporated solid dispersion gave homogeneous and very small spherical particles, in which the drug was changed to an amorphous state. In the solvent-wetted solid dispersion, the amorphous drug was attached to the polymer surface. Conversely, in the surface-attached solid dispersion, the carriers were adhered onto the surface of the unchanged crystalline drug. The solubility, dissolution and oral bioavailability were significantly increased in the order of solvent-evaporated>solvent-wetted>surface-attached>drug powder. Thus, the type of solid dispersion considerably affected the physicochemical properties, aqueous solubility and oral bioavailability. Furthermore, the cilostazol-loaded solvent-evaporated solid dispersion with the highest oral bioavailability would be actively recommended as a practical oral pharmaceutical product. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Integrated load distribution and production planning in series-parallel multi-state systems with failure rate depending on load

    International Nuclear Information System (INIS)

    Nourelfath, Mustapha; Yalaoui, Farouk

    2012-01-01

    A production system containing a set of machines (also called components) arranged according to a series-parallel configuration is addressed. A set of products must be produced in lots on this production system during a specified finite planning horizon. This paper presents a method for integrating load distribution decisions, and tactical production planning considering the costs of capacity change and the costs of unused capacity. The objective is to minimize the sum of capacity change costs, unused capacity costs, setup costs, holding costs, backorder costs, and production costs. The main constraints consist in satisfying the demand for all products over the entire horizon, and in not exceeding available repair resource. The production series-parallel system is modeled as a multi-state system with binary-state components. The proposed model takes into account the dependence of machines' failure rates on their load. Universal generating function technique can be used in the optimization algorithm for evaluating the expected system production rate in each period. We show how the formulated problem can be solved by comparing the results of several multi-product lot-sizing problems with capacity associated costs. The importance of integrating load distribution decisions and production planning is illustrated through numerical examples.

  10. Stability and antimicrobial effect of amikacin-loaded solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Solmaz Ghaffari

    2010-12-01

    Full Text Available Solmaz Ghaffari1, Jaleh Varshosaz1, Afrooz Saadat2, Fatemeh Atyabi21Department of Pharmaceutics, Faculty of Pharmacy and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; 2Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IranAbstract: Solid lipid nanoparticles (SLNs of amikacin were designed in this study for pulmonary delivery to reduce the dose or its administration intervals leading to reduction of its toxicities especially in long term treatment. Nanoparticles of amikacin were prepared from cholesterol by solvent diffusion technique and homogenization. The size, zeta potential, loading efficiency, and release profile of the nanoparticles were studied. The conventional broth macrodilution tube method was used to determine the minimum inhibitory concentration (MIC and minimum bacteriostatic concentration (MBC of amikacin SLNs with respect to Pseudomonas aeruginosa in vitro. To guarantee the stability of desired SLNs, they were lyophilized using cryoprotectants. Results showed that considering the release profile of amikacin from the studied nanocarrier, MIC and MBC of amikacin could be about two times less in SLNs of amikacin compared to the free drug. Therefore, fewer doses of amikacin in SLNs can clear the infection with less adverse effects and more safety. Particle size enlargement after lyophilization of desired SLNs after two months storage was limited in comparison with non-lyophilized particles, 996 and 194 nm, respectively. Zeta potential of lyophilized particles was increased to +17 mV from +4 mV before lyophilization. Storage of particles in higher temperature caused accelerated drug release.Keywords: amikacin, antimicrobial effects, Pseudomonas aeruginosa, solid lipid nanoparticles, stability

  11. Characterization, pharmacokinetics, and hypoglycemic effect of berberine loaded solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Xue M

    2013-12-01

    Full Text Available Mei Xue, Ming-xing Yang, Wei Zhang, Xiu-min Li, De-hong Gao, Zhi-min Ou, Zhi-peng Li, Su-huan Liu, Xue-jun Li, Shu-yu Yang Xiamen Diabetes Institute, The First Affiliated Hospital of Xiamen University, Xiamen, People’s Republic of China Abstract: The high aqueous solubility, poor permeability, and absorption of berberine (BBR result in its low plasma level after oral administration, which greatly limits its clinical application. BBR solid lipid nanoparticles (SLNs were prepared to achieve improved bioavailability and prolonged effect. Developed SLNs showed homogeneous spherical shapes, small size (76.8 nm, zeta potential (7.87 mV, encapsulation efficiency (58%, and drug loading (4.2%. The power of X-ray diffraction combined with 1H nuclear magnetic resonance spectroscopy was employed to analyze chemical functional groups and the microstructure of BBR-SLNs, and indicated that the drug was wrapped in a lipid carrier. Single dose (50 mg/kg oral pharmacokinetic studies in rats showed significant improvement (P<0.05 in the peak plasma concentration, area under the curve, and variance of mean residence time of BBR-SLNs when compared to BBR alone (P<0.05, suggesting improved bioavailability. Furthermore, oral administration of both BBR and BBR-SLNs significantly suppressed body weight gain, fasting blood glucose levels, and homeostasis assessment of insulin resistance, and ameliorated impaired glucose tolerance and insulin tolerance in db/db diabetic mice. BBR-SLNs at high dose (100 mg/kg showed more potent effects when compared to an equivalent dose of BBR. Morphologic analysis demonstrated that BBR-SLNs potentially promoted islet function and protected the islet from regeneration. In conclusion, our study demonstrates that by entrapping BBR into SLNs the absorption of BBR and its anti-diabetic action were effectively enhanced. Keywords: berberine, solid lipid nanoparticles, pharmacokinetic, hypoglycemic effect

  12. Optimization between heating load and entropy-production rate for endoreversible absorption heat-transformers

    International Nuclear Information System (INIS)

    Sun Fengrui; Qin Xiaoyong; Chen Lingen; Wu Chih

    2005-01-01

    For an endoreversible four-heat-reservoir absorption heat-transformer cycle, for which a linear (Newtonian) heat-transfer law applies, an ecological optimization criterion is proposed for the best mode of operation of the cycle. This involves maximizing a function representing the compromise between the heating load and the entropy-production rate. The optimal relation between the ecological criterion and the COP (coefficient of performance), the maximum ecological criterion and the corresponding COP, heating load and entropy production rate, as well as the ecological criterion and entropy-production rate at the maximum heating load are derived using finite-time thermodynamics. Moreover, compared with the heating-load criterion, the effects of the cycle parameters on the ecological performance are studied by numerical examples. These show that achieving the maximum ecological criterion makes the entropy-production rate decrease by 77.0% and the COP increase by 55.4% with only 27.3% heating-load losses compared with the maximum heating-load objective. The results reflect that the ecological criterion has long-term significance for optimal design of absorption heat-transformers

  13. Preparation and in Vivo Evaluation of a Dutasteride-Loaded Solid-Supersaturatable Self-Microemulsifying Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Min-Soo Kim

    2015-05-01

    Full Text Available The purpose of this study was to prepare a dutasteride-loaded solid-supersaturatable self-microemulsifying drug delivery system (SMEDDS using hydrophilic additives with high oral bioavailability, and to determine if there was a correlation between the in vitro dissolution data and the in vivo pharmacokinetic parameters of this delivery system in rats. A dutasteride-loaded solid-supersaturatable SMEDDS was generated by adsorption of liquid SMEDDS onto Aerosil 200 colloidal silica using a spray drying process. The dissolution and oral absorption of dutasteride from solid SMEDDS significantly increased after the addition of hydroxypropylmethyl cellulose (HPMC or Soluplus. Solid SMEDDS/Aerosil 200/Soluplus microparticles had higher oral bioavailability with 6.8- and 5.0-fold higher peak plasma concentration (Cmax and area under the concentration-time curve (AUC values, respectively, than that of the equivalent physical mixture. A linear correlation between in vitro dissolution efficiency and in vivo pharmacokinetic parameters was demonstrated for both AUC and Cmax values. Therefore, the preparation of a solid-supersaturatable SMEDDS with HPMC or Soluplus could be a promising formulation strategy to develop novel solid dosage forms of dutasteride.

  14. Preparation, characterization, and optimization of primaquine-loaded solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Omwoyo WN

    2014-08-01

    Full Text Available Wesley Nyaigoti Omwoyo,1,2 Bernhards Ogutu,3,4 Florence Oloo,3,5 Hulda Swai,6 Lonji Kalombo,6 Paula Melariri,6 Geoffrey Maroa Mahanga,2 Jeremiah Waweru Gathirwa3,4 1Department of Chemistry, Maasai Mara University, Narok, Kenya; 2Department of Chemistry, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya; 3Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya; 4Kenya Medical Research Institute, Nairobi, Kenya; 5Department of Chemical Sciences and Technology, Technical University of Kenya, Nairobi, Kenya; 6Department of Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract: Primaquine (PQ is one of the most widely used antimalarial drugs and is the only available drug that combats the relapsing form of malaria. PQ use in higher doses is limited by severe tissue toxicity including hematological- and gastrointestinal-related side effects. Nanoformulation of drugs in an appropriate drug carrier system has been extensively studied and shown to have the potential to improve bioavailability, thereby enhancing activity, reducing dose frequency, and subsequently reducing toxicity. The aim of this work was to design, synthesize, and characterize PQ-loaded solid lipid nanoparticles (SLNs (PQ-SLNs as a potential drug-delivery system. SLNs were prepared by a modified solvent emulsification evaporation method based on a water-in-oil-in-water (w/o/w double emulsion. The mean particle size, zeta potential, drug loading, and encapsulation efficiency of the PQ-SLNs were 236 nm, +23 mV, 14%, and 75%, respectively. The zeta potential of the SLNs changed dramatically, from -6.54 mV to +23.0 mV, by binding positively charged chitosan as surface modifier. A spherical morphology of PQ-SLNs was seen by scanning electron microscope. In vitro, release profile depicted a steady drug release over 72 hours. Differential scanning calorimeter thermograms demonstrated presence

  15. Photovoltaic systems for Malaysian islands: Effects of interest rates, diesel prices and load sizes

    International Nuclear Information System (INIS)

    Lau, K.Y.; Tan, C.W.; Yatim, A.H.M.

    2015-01-01

    Standalone diesel systems have been widely used on Malaysian islands due to the isolated locations of the islands. Nevertheless, the high diesel prices and the high cost of transporting diesel to islands cause the use of standalone diesel systems to be uneconomical. This study analyzes the feasibility of implementing PV (photovoltaic) systems as alternatives to standalone diesel systems by considering the effects of annual real interest rates, diesel prices and load sizes, using the HOMER (hybrid optimization of multiple energy resources) software. The results indicate that, at the ordinary diesel price of $ 0.61/L, low interest rates (0–3%) are desirable for the implementation of hybrid PV/diesel with battery systems over standalone diesel systems, regardless of the load sizes. Although different load sizes may affect the decisions on the implementation of PV systems at higher interest rates (6–9%), these effects become less pronounced as the price of diesel increases to $ 1.22/L or higher. Also, under high diesel prices, the choice of optimal system configurations obtained for small load sizes should be applicable for larger load sizes, albeit with different component ratings. Although the current study is intended for Malaysian islands, the findings can be generalized for other places with similar solar radiation levels. - Highlights: • Photovoltaic systems for Malaysian islands have been analyzed using HOMER. • Interest rates, diesel prices and load sizes affect optimal system configurations. • Effects of interest rates and load sizes reduce with increasing diesel prices. • Photovoltaic systems' implementation is feasible at high diesel prices. • The findings can be generalized for places with similar solar radiation levels

  16. A large deformation theory of solids subject to electromagnetic loads and its application

    International Nuclear Information System (INIS)

    Nishiguchi, I.; Sasaki, M.

    1993-01-01

    A large deformation theory of deformable solids is proposed in which the interaction with electromagnetic fields is taken into account. Weak forms of the Maxwell's equations in a fixed reference configuration together with the balance of momentum constitute the governing equations for our theory. The weak forms of the Maxwell's equations in a reference configuration can be derived by the direct transformation from spatial weak forms. The results coincide with the weak forms obtained from the local expressions by Lax and Nelson though we made a distinction between the covariant and contravariant vector explicitly. For the deformable body subject to the electromagnetic fields, weak forms of the Ampere's law and/or the Faraday's law, when combined with the weak form of the balance of momentum, can serve as the governing equations of the theory. As is known, however, these equations are not sufficient to describe the response of a specific material due to a given loading. As for the momentum balance, we need the dependency of stress on the deformation and objective constitutive equations of hyperelasticity, hypoelasticity and inelasticity are available. Parallel to these, objective constitutive equations for the electromagnetism are discussed. As an application of the theory, linearized equations for quasi-static deformation under magnetic field is derived based on the vector potential formulation. (author)

  17. Solid lipid nanoparticles loaded with edaravone for inner ear protection after noise exposure.

    Science.gov (United States)

    Gao, Gang; Liu, Ya; Zhou, Chang-Hua; Jiang, Ping; Sun, Jian-Jun

    2015-01-20

    Antioxidants and the duration of treatment after noise exposure on hearing recovery are important. We investigated the protective effects of an antioxidant substance, edaravone, and its slow-release dosage form, edaravone solid lipid nanoparticles (SLNs), in steady noise-exposed guinea pigs. SLNs loaded with edaravone were produced by an ultrasound technique. Edaravone solution or edaravone SLNs were administered by intratympanic or intravenous injection after the 1 st day of noise exposure. Guinea pigs were exposed to 110 dB sound pressure level (SPL) noise, centered at 0.25-4.0 kHz, for 4 days at 2 h/d. After noise exposure, the guinea pigs underwent auditory brainstem response (ABR) threshold measurements, reactive oxygen species (ROS) were detected in their cochleas with electron spin resonance (ESR), and outer hair cells (OHCs) were counted with silvernitrate (AgNO 3 ) staining at 1, 4, and 6 days. The ultrasound technique was able to prepare adequate edaravone SLNs with a mean particle size of 93.6 nm and entrapment efficiency of 76.7%. Acoustic stress-induced ROS formation and edaravone exerted a protective effect on the cochlea. Comparisons of hearing thresholds and ROS changes in different animal groups showed that the threshold shift and ROS generation were significantly lower in treated animals than in those without treatment, especially in the edaravone SLN intratympanic injection group. Edaravone SLNs show noticeable slow-release effects and have certain protective effects against noise-induced hearing loss (NIHL).

  18. Preparation and characterization of ketoprofen-loaded solid lipid nanoparticles made from beeswax and carnauba wax.

    Science.gov (United States)

    Kheradmandnia, Soheila; Vasheghani-Farahani, Ebrahim; Nosrati, Mohsen; Atyabi, Fatemeh

    2010-12-01

    Solid lipid nanoparticles (SLNs) have been proposed as suitable colloidal carriers for delivery of drugs with limited solubility. Ketoprofen as a model drug was incorporated into SLNs prepared from a mixture of beeswax and carnauba wax using Tween 80 and egg lecithin as emulsifiers. The characteristics of the SLNs with various lipid and surfactant composition were investigated. The mean particle size of drug-loaded SLNs decreased upon mixing with Tween 80 and egg lecithin as well as upon increasing total surfactant concentration. SLNs of 75 ± 4 nm with a polydispersity index of 0.2 ± 0.02 were obtained using 1% (vol/vol) mixed surfactant at a ratio of 60:40 Tween 80 to egg lecithin. The zeta potential of these SLNs varied in the range of -15 to -17 (mV), suggesting the presence of similar interface properties. High drug entrapment efficiency of 97% revealed the ability of SLNs to incorporate a poorly water-soluble drug such as ketoprofen. Differential scanning calorimetry thermograms and high-performance liquid chromatographic analysis indicated the stability of nanoparticles with negligible drug leakage after 45 days of storage. It was also found that nanoparticles with more beeswax content in their core exhibited faster drug release as compared with those containing more carnauba wax in their structure. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Bevacizumab loaded solid lipid nanoparticles prepared by the coacervation technique: preliminary in vitro studies

    Science.gov (United States)

    Battaglia, Luigi; Gallarate, Marina; Peira, Elena; Chirio, Daniela; Solazzi, Ilaria; Giordano, Susanna Marzia Adele; Gigliotti, Casimiro Luca; Riganti, Chiara; Dianzani, Chiara

    2015-06-01

    Glioblastoma, the most common primary brain tumor in adults, has an inauspicious prognosis, given that overcoming the blood-brain barrier is the major obstacle to the pharmacological treatment of brain tumors. As neoangiogenesis plays a key role in glioblastoma growth, the US Food and Drug Administration approved bevacizumab (BVZ), an antivascular endothelial growth factor antibody for the treatment of recurrent glioblastoma in patients whose the initial therapy has failed. In this experimental work, BVZ was entrapped in solid lipid nanoparticles (SLNs) prepared by the fatty-acid coacervation technique, thanks to the formation of a hydrophobic ion pair. BVZ activity, which was evaluated by means of four different in vitro tests on HUVEC cells, increased by 100- to 200-fold when delivered in SLNs. Moreover, SLNs can enhance the permeation of fluorescently labelled BVZ through an hCMEC/D3 cell monolayer—an in vitro model of the blood brain barrier. These results are promising, even if further in vivo studies are required to evaluate the effective potential of BVZ-loaded SLNs in glioblastoma treatment.

  20. Comparison of J estimating procedures for a solid subjected to bending loads

    International Nuclear Information System (INIS)

    Smith, E.

    1982-01-01

    A. Zahoor and M.F. Kanninen have recently developed a simple procedure for estimating the magnitude of the J-integral for through-wall cracks in pipes subjected to bending loads. This paper gives consideration to their procedure, but to check its predictions against available numerical results, it is explored in detail for the case of a crack in a solid deforming under plane-strain bending conditions. In this case, an implicit assumption in the procedure is that the plastic rotation depends on the ligament size, and not on any other geometrical dimension. This assumption is strictly valid only for deep cracks, and this paper shows the degree of inaccuracy obtained when it is applied to shallow cracks. The assumption is also shown to correlate with the existence of a unique relation, independent of geometrical parameters, between the ligament net-sectionstress and the J-integral, and also with the existence of C.E. Turner's plastic /eta/ factors. 12 refs

  1. Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique.

    Science.gov (United States)

    Phan, Xuan; Grisbrook, Tiffany L; Wernli, Kevin; Stearne, Sarah M; Davey, Paul; Ng, Leo

    2017-08-01

    This study aimed to determine if a quantifiable relationship exists between the peak sound amplitude and peak vertical ground reaction force (vGRF) and vertical loading rate during running. It also investigated whether differences in peak sound amplitude, contact time, lower limb kinematics, kinetics and foot strike technique existed when participants were verbally instructed to run quietly compared to their normal running. A total of 26 males completed running trials for two sound conditions: normal running and quiet running. Simple linear regressions revealed no significant relationships between impact sound and peak vGRF in the normal and quiet conditions and vertical loading rate in the normal condition. t-Tests revealed significant within-subject decreases in peak sound, peak vGRF and vertical loading rate during the quiet compared to the normal running condition. During the normal running condition, 15.4% of participants utilised a non-rearfoot strike technique compared to 76.9% in the quiet condition, which was corroborated by an increased ankle plantarflexion angle at initial contact. This study demonstrated that quieter impact sound is not directly associated with a lower peak vGRF or vertical loading rate. However, given the instructions to run quietly, participants effectively reduced peak impact sound, peak vGRF and vertical loading rate.

  2. A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.

    Science.gov (United States)

    Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

    2010-03-01

    The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. 2009 Elsevier Ltd. All rights reserved.

  3. Footwear Matters: Influence of Footwear and Foot Strike on Load Rates during Running.

    Science.gov (United States)

    Rice, Hannah M; Jamison, Steve T; Davis, Irene S

    2016-12-01

    Running with a forefoot strike (FFS) pattern has been suggested to reduce the risk of overuse running injuries, due to a reduced vertical load rate compared with rearfoot strike (RFS) running. However, resultant load rate has been reported to be similar between foot strikes when running in traditional shoes, leading to questions regarding the value of running with a FFS. The influence of minimal footwear on the resultant load rate has not been considered. This study aimed to compare component and resultant instantaneous loading rate (ILR) between runners with different foot strike patterns in their habitual footwear conditions. Twenty-nine injury-free participants (22 men, seven women) ran at 3.13 m·s along a 30-m runway, with their habitual foot strike and footwear condition. Ground reaction force data were collected. Peak ILR values were compared between three conditions; those who habitually run with an RFS in standard shoes, with an FFS in standard shoes, and with an FFS in minimal shoes. Peak resultant, vertical, lateral, and medial ILR were lower (P strike. When running with an FFS, peak posterior ILR were lower (P strike. Therefore, it appears that footwear alters the load rates during running, even with similar foot strike patterns.

  4. High rate composting of herbal pharmaceutical industry solid waste.

    Science.gov (United States)

    Ali, M; Duba, K S; Kalamdhad, A S; Bhatia, A; Khursheed, A; Kazmi, A A; Ahmed, N

    2012-01-01

    High rate composting studies of hard to degrade herbal wastes were conducted in a 3.5 m(3) capacity rotary drum composter. Studies were spread out in four trials: In trial 1 and 2, one and two turns per day rotation was observed, respectively, by mixing of herbal industry waste with cattle (buffalo) manure at a ratio of 3:1 on wet weight basis. In trial 3 inocula was added in raw waste to enhance the degradation and in trial 4 composting of a mixture of vegetable market waste and herbal waste was conducted at one turn per day. Results demonstrated that the operation of the rotary drum at one turn a day (trial 1) could provide the most conducive composting conditions and co-composting (trial 4) gave better quality compost in terms of temperature, moisture, nitrogen, and Solvita maturity index. In addition a FT-IR study also revealed that trial 1 and trial 4 gave quality compost in terms of stability and maturity due to the presence of more intense peaks in the aromatic region and less intense peaks were found in the aliphatic region compared with trial 2 and trial 3.

  5. Enhanced systemic exposure of saquinavir via the concomitant use of curcumin-loaded solid dispersion in rats.

    Science.gov (United States)

    Kim, Su-A; Kim, Sung-Whan; Choi, Hoo-Kyun; Han, Hyo-Kyung

    2013-08-16

    The present study aimed to evaluate the effect of curcumin-loaded solid dispersion on the pharmacokinetics of saquinavir in rats. Solid dispersion (SD) formulation was prepared with Solutol® HS15 to improve the solubility and bioavailability of curcumin. Subsequently, its inhibition effect on P-gp mediated cellular efflux was examined by using NCI/ADR-RES cells overexpressing P-gp. Compared to the untreated curcumin, SD formulation enhanced the cellular uptake of rhodamine-123, a P-gp substrate by approximately 3 folds in NCI/ADR-RES cells. The oral and intravenous pharmacokinetics of saquinavir were also determined in rats with/without curcumin in the different formulations. Compared to the control given saquinavir alone, curcumin-loaded solid dispersion significantly (p<0.05) increased the oral exposure of saquinavir in rats, while it did not affect the intravenous pharmacokinetics of saquinavir. The AUC and Cmax of oral saquinavir increased by 3.8- and 2.7-folds, respectively in the presence of curcumin-loaded solid dispersion. In contrast, the untreated curcumin did not affect the oral pharmacokinetics of saquinavir. These results suggest that SD formulation of curcumin should be effective to improve the in vivo effectiveness of curcumin as an absorption enhancer, leading to the improved oral exposure of saquinavir. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Rate of Loaded Sediments in Honda Bay, Puerto Princesa City, Palawan, Philippines

    Directory of Open Access Journals (Sweden)

    Joel Becira

    2006-06-01

    Full Text Available A study in Honda Bay, Puerto Princesa City, Palawan, Philippines was conducted to determine and compare the rate of loaded sediments of and among six sites in Honda Bay and during two seasons, and to discuss sedimentation rate in relation to selected environmental parameters commencing on April 2003 to November 2003.Results showed that the Babuyan River significantly contributed to the amounts of sediments being loaded to Honda Bay, Puerto Princesa City of which the amount of sediments loaded between the two sampling season and among the six sampling events had no significant difference. Sediment's color and texture affirmed the land-based activities in Babuyan and Mauyon watersheds, which eventually carried into the Bay during storm weather condition.The amount of trapped sediments in all stations is probably affected by the river's discharge capacity and the river's water velocity, although the duration sediment traps were mounted could also affect the measurement of sedimentation rate.

  7. Sigh rate and respiratory variability during mental load and sustained attention.

    Science.gov (United States)

    Vlemincx, Elke; Taelman, Joachim; De Peuter, Steven; Van Diest, Ilse; Van den Bergh, Omer

    2011-01-01

    Spontaneous breathing consists of substantial correlated variability: Parameters characterizing a breath are correlated with parameters characterizing previous and future breaths. On the basis of dynamic system theory, negative emotion states are predicted to reduce correlated variability whereas sustained attention is expected to reduce total respiratory variability. Both are predicted to evoke sighing. To test this, respiratory variability and sighing were assessed during a baseline, stressful mental arithmetic task, nonstressful sustained attention task, and recovery in between tasks. For respiration rate (excluding sighs), reduced total variability was found during the attention task, whereas correlated variation was reduced during mental load. Sigh rate increased during mental load and during recovery from the attention task. It is concluded that mental load and task-related attention show specific patterns in respiratory variability and sigh rate. Copyright © 2010 Society for Psychophysiological Research.

  8. Brittle materials at high-loading rates: an open area of research

    Science.gov (United States)

    Forquin, Pascal

    2017-01-01

    Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue of Philosophical Transactions A provides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  9. Textured insoles reduce vertical loading rate and increase subjective plantar sensation in overground running.

    Science.gov (United States)

    Wilkinson, Michael; Ewen, Alistair; Caplan, Nicholas; O'leary, David; Smith, Neil; Stoneham, Richard; Saxby, Lee

    2018-05-01

    The effect of textured insoles on kinetics and kinematics of overground running was assessed. 16 male injury-free-recreational runners attended a single visit (age 23 ± 5 yrs; stature 1.78 ± 0.06 m; mass 72.6 ± 9.2 kg). Overground 15-m runs were completed in flat, canvas plimsolls both with and without textured insoles at self-selected velocity on an indoor track in an order that was balanced among participants. Average vertical loading rate and peak vertical force (F peak ) were captured by force platforms. Video footage was digitised for sagittal plane hip, knee and ankle angles at foot strike and mid stance. Velocity, stride rate and length and contact and flight time were determined. Subjectively rated plantar sensation was recorded by visual scale. 95% confidence intervals estimated mean differences. Smallest worthwhile change in loading rate was defined as standardised reduction of 0.54 from a previous comparison of injured versus non-injured runners. Loading rate decreased (-25 to -9.3 BW s -1 ; 60% likely beneficial reduction) and plantar sensation was increased (46-58 mm) with the insole. F peak (-0.1 to 0.14 BW) and velocity (-0.02 to 0.06 m s -1 ) were similar. Stride length, flight and contact time were lower (-0.13 to -0.01 m; -0.02 to-0.01 s; -0.016 to -0.006 s) and stride rate was higher (0.01-0.07 steps s -1 ) with insoles. Textured insoles elicited an acute, meaningful decrease in vertical loading rate in short distance, overground running and were associated with subjectively increased plantar sensation. Reduced vertical loading rate could be explained by altered stride characteristics.

  10. The Influence of the Loading Rate on the Mechanical Properties of Drawing Steel Sheet

    Directory of Open Access Journals (Sweden)

    Buršák, M.

    2006-01-01

    Full Text Available The paper analyzes the influence of the loading rate in the interval from 1 to 1000 mm/min on the mechanical properties of drawing steel sheet H260LAD with the gauge of 1 mm, used for the manufacture of automotive parts, under tension and bending conditions. It describes the aspects of material characteristics under tension and bending conditions, while bending tests were made on notched specimens (a modified impact bending test. The paper presents knowledge that using a modified notch toughness test it is possible to achieve the pressability (formability characteristics corresponding to dynamic strain rates even under the static loading.

  11. Nitrogen removal in permeable woodchips filters affected by hydraulic loading rate and woodchips ratio

    DEFF Research Database (Denmark)

    Bruun, Jacob Druedahl; Kjærgaard, Charlotte; Hoffmann, Carl Christian

    2016-01-01

    response of mixed reactive media (woodchips-Seashells and woodchips-Filtralite mixtures) at two woodchips ratios (WR) to changes in the hydraulic loading rate (HLR). The tests implied continuous loading of aerated NO3-N spiked artificial drainage water and tritium (3H2O) breakthrough experiments. Flow...... normalized nitrate reduction rates were 0.35-3.97 g N m-3 L-1, corresponding to N- removal efficiencies of 5 to 74% depending on HLR and filter mixtures. At high HLR oxic conditions prevailed, thus N removal was restricted to the immobile domain, controlled by diffusion. At lower HLR, progressively lower...

  12. Response Load Extrapolation for Wind Turbines during Operation Based on Average Conditional Exceedance Rates

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Naess, Arvid; Saha, Nilanjan

    2011-01-01

    to cases where the Gumbel distribution is the appropriate asymptotic extreme value distribution. However, two extra parameters are introduced by which a more general and flexible class of extreme value distributions is obtained with the Gumbel distribution as a subclass. The general method is implemented...... within a hierarchical model where the variables that influence the loading are divided into ergodic variables and time-invariant non-ergodic variables. The presented method for statistical response load extrapolation was compared with the existing methods based on peak extrapolation for the blade out......The paper explores a recently developed method for statistical response load (load effect) extrapolation for application to extreme response of wind turbines during operation. The extrapolation method is based on average conditional exceedance rates and is in the present implementation restricted...

  13. Studies on rate equations for defects in irradiated solids using the local analysis method

    International Nuclear Information System (INIS)

    Carvalho e Camargo, M.U. de.

    1983-10-01

    The void formation and swelling phenomenon in material for nuclear reactors structures, mainly for fast reactors, has been studied by several authors. A simple calculation covering the basic instance of radiation damage in irradiated solid solution, using the local analysis in rate theory is presented here. A simple description of pratical and fundamental interest for the complex problem of solid solution under irradiation is given. (Author) [pt

  14. Brittle materials at high-loading rates: an open area of research

    Science.gov (United States)

    2017-01-01

    Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue of Philosophical Transactions A provides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’. PMID:27956517

  15. Solid Lipid Nanoparticles Loaded with Edaravone for Inner Ear Protection After Noise Exposure

    Directory of Open Access Journals (Sweden)

    Gang Gao

    2015-01-01

    Full Text Available Background: Antioxidants and the duration of treatment after noise exposure on hearing recovery are important. We investigated the protective effects of an antioxidant substance, edaravone, and its slow-release dosage form, edaravone solid lipid nanoparticles (SLNs, in steady noise-exposed guinea pigs. Methods: SLNs loaded with edaravone were produced by an ultrasound technique. Edaravone solution or edaravone SLNs were administered by intratympanic or intravenous injection after the 1 st day of noise exposure. Guinea pigs were exposed to 110 dB sound pressure level (SPL noise, centered at 0.25-4.0 kHz, for 4 days at 2 h/d. After noise exposure, the guinea pigs underwent auditory brainstem response (ABR threshold measurements, reactive oxygen species (ROS were detected in their cochleas with electron spin resonance (ESR, and outer hair cells (OHCs were counted with silvernitrate (AgNO 3 staining at 1, 4, and 6 days. Results: The ultrasound technique was able to prepare adequate edaravone SLNs with a mean particle size of 93.6 nm and entrapment efficiency of 76.7%. Acoustic stress-induced ROS formation and edaravone exerted a protective effect on the cochlea. Comparisons of hearing thresholds and ROS changes in different animal groups showed that the threshold shift and ROS generation were significantly lower in treated animals than in those without treatment, especially in the edaravone SLN intratympanic injection group. Conclusions: Edaravone SLNs show noticeable slow-release effects and have certain protective effects against noise-induced hearing loss (NIHL.

  16. IVABRADINE LOADED SOLID LIPID MICROPARTICLES: FORMULATION, CHARACTERIZATION AND OPTIMIZATION BY CENTRAL COMPOSITE ROTATABLE DESIGN.

    Science.gov (United States)

    Hanif, Muhammad; Khan, Hafeez Ullah; Afzal, Samina; Sher, Muhammad

    2017-01-01

    The current research focused on improvement of oral bioavailability and decrease in dosing frequency of ivabradine (Iva) in order to enhance patient compliance by formulating novel sustained release Iva loaded solid lipid microparticles (SLMs) with the help of melt emulsification technique. SLMs formulations were designed with the help of three level central composite rotatable design (CCRD) to study the impact of independent variables like lipid concentration, surfactant concentration and stirring speed on responses - percentage yield (Y,) and entrapment efficiency (Y2). Compatibility between the drug and bees wax (BW) was checked by conducting Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). SLMs were further evaluated for rheological behavior, zeta potential, particle size and for morphology by scanning'electron microscope (SEM). The release of drug from SLMs was conducted by USP type-Il apparatus at pH 1.2, pH 6.8 and data were analyzed by different kinetic models like zero order, first order, Higuchi model, Korsmeyer-Peppas and Hixon-Crowell models. The rheo- logical studies approved the good flow behavior of SLMs and spherical smooth surface of SLMs was observed from SEM. DSC, FTIR and XRD studies concluded the lack of any possible interaction between formulation components. The size-of SLMs ranged from 300 to 500 pm and zeta potential study showed the presence of higher negative charge (-30 to -52 mV). Response Y, varied from 53 to 90% and response Y2 ranged from 29 to 78% indicating the effect of formulation variables. The obtained outcomes were analyzed by second order polynomial equation and suggested quadratic model was also validated. SLMs released Iva from 54 to 90% at pH 6.8 and was significantly (p 0.05) affected by BW concentration. The release mechanism followed the zero order and Korsmeyer-Peppas (n 0.85) kinetic models suggesting slow erosion along with diffusion

  17. Curcumin loaded solid lipid nanoparticles ameliorate adjuvant-induced arthritis in rats.

    Science.gov (United States)

    Arora, R; Kuhad, A; Kaur, I P; Chopra, K

    2015-08-01

    Rheumatoid arthritis (RA), a chronic and systemic inflammation, results in destruction of joints and cartilages. Effectiveness of curcumin has been established in a wide variety of inflammatory disorders, but its utility as a therapeutic agent is limited by its poor absorption, rapid metabolism and fast systemic elimination. To apprehend these limitations, we propose to use highly bioavailable curcumin loaded solid lipid nanoparticles (C-SLNs) for the treatment of RA. In the present study, the protective effect of curcumin and its SLNs was evaluated in complete Freund's adjuvant (CFA)-induced arthritis in rats. Arthritic rats exhibited marked decrease in paw withdrawal threshold in Randall-Selitto and von Frey hair test along with decreased reaction time in hot plate. Arthritic rats also showed significant joint hyperalgesia, joint stiffness and increased paw volume along with marked decrease in mobility score. Arthritic rats showed a significant increase in blood leukocyte count, oxidative-nitrosative stress, tumour necrosis factor-α, C-reactive protein, cyclic citrullinated peptide antibody levels and radiological alterations in tibiotarsal joint. C-SLN administration (10 and 30 mg/kg), when compared with free curcumin (10 and 30 mg/kg), significantly and dose dependently ameliorated various symptoms of arthritis in rats, improved biochemical markers and preserved radiological alterations in joints of arthritic rats. The current findings suggest the protective potential of curcumin-SLNs in ameliorating CFA-induced arthritis in rats through attenuation of oxido-inflammatory and immunomodulatory cascade. Further, the results emphasize that SLNs are a novel approach to deliver curcumin into the inflamed joints and improve its biopharmaceutical performance. © 2014 European Pain Federation - EFIC®

  18. Canadian House Dust Study: Population-based concentrations, loads and loading rates of arsenic, cadmium, chromium, copper, nickel, lead, and zinc inside urban homes

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Pat E. [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Levesque, Christine [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Chénier, Marc; Gardner, H. David [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Jones-Otazo, Heather [Regions and Programs Branch, Health Canada, 180 Queen Street West, Toronto, ON, Canada M5V 3L7 (Canada); Petrovic, Sanya [Contaminated Sites Division, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Ave West, Ottawa, ON, Canada K1A 0K9 (Canada)

    2013-01-15

    The Canadian House Dust Study was designed to obtain nationally representative urban house dust metal concentrations (μg g{sup −1}) and metal loadings (μg m{sup −2}) for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Consistent sampling of active dust of known age and provenance (area sampled) also permitted the calculation of indoor loading rates (mg m{sup −2} day{sup −1} for dust and μg m{sup −2} day{sup −1} for metals) for the winter season (from 2007 to 2010) when houses are most tightly sealed. Geomean/median indoor dust loading rates in homes located more than 2 km away from industry of any kind (9.6/9.1 mg m{sup −2} day{sup −1}; n = 580) were significantly lower (p < .001) than geomean (median) dust loading rates in homes located within 2 km of industry (13.5/13.4 mg m{sup −2} day{sup −1}; n = 421). Proximity to industry was characterized by higher indoor metal loading rates (p < .003), but no difference in dust metal concentrations (.29 ≥ p ≤ .97). Comparisons of non-smokers' and smokers' homes in non-industrial zones showed higher metal loading rates (.005 ≥ p ≤ .038) in smokers' homes, but no difference in dust metal concentrations (.15 ≥ p ≤ .97). Relationships between house age and dust metal concentrations were significant for Pb, Cd and Zn (p < .001) but not for the other four metals (.14 ≥ p ≤ .87). All seven metals, however, displayed a significant increase in metal loading rates with house age (p < .001) due to the influence of higher dust loading rates in older homes (p < .001). Relationships between three measures of metals in house dust – concentration, load, and loading rate – in the context of house age, smoking behavior and urban setting consistently show that concentration data is a useful indicator of the presence of metal sources in the home, whereas dust mass is the overriding influence on metal loadings and loading rates

  19. Association between increase in vertical ground reaction force loading rate and pain level in women with patellofemoral pain after a patellofemoral joint loading protocol.

    Science.gov (United States)

    Briani, Ronaldo Valdir; Pazzinatto, Marcella Ferraz; Waiteman, Marina Cabral; de Oliveira Silva, Danilo; de Azevedo, Fábio Mícolis

    2018-04-11

    The etiology of patellofemoral pain (PFP) is thought to be the result of increased patellofemoral joint (PFJ) load and aberrant lower extremity mechanics, including altered vertical ground reaction forces (VGRF). However, few studies have investigated the association between an increase in pain and VGRF loading rates in the context of PFP. Thus, this study aimed to investigate the immediate effects of PFJ loading on pain and VGRF loading rate, and to see if there is a link between modification of both pain and VGRF loading rate during stair negotiation. Thirty-four women with PFP underwent VGRF analysis during stair negotiation under two conditions: with (condition 2) and without (condition 1) being previously submitted to a PFJ loading protocol in order to or not to exacerbate their knee pain, respectively. The VGRF loading rates were significantly higher in condition 2 (Mean ± standard deviation (SD)=4.0±0.6N/s) compared to condition 1 (Mean±SD=3.6±0.5N/s) during stair ascent and during stair descent (Mean±SD: condition 1=6.3±1.1N/s; condition 2=7.0±1.4N/s). In addition, VGRF loading rates were higher during stair descent compared to stair ascent in both conditions. There were significant correlations between the increase in pain and VGRF loading rate during both tasks. There seemed to be an important relation between the increase in pain and VGRF loading rates in women with PFP. Based on these findings, interventions aimed at reducing VGRF loading rates are important in the context of PFP. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Ji P

    2016-03-01

    Full Text Available Peng Ji, Tong Yu, Ying Liu, Jie Jiang, Jie Xu, Ying Zhao, Yanna Hao, Yang Qiu, Wenming Zhao, Chao WuCollege of Pharmacy, Liaoning Medical University, Jinzhou, Liaoning Province, People’s Republic of ChinaAbstract: Naringenin (NRG, a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only ~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide (MTT assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle

  1. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    Science.gov (United States)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  2. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    International Nuclear Information System (INIS)

    Pestchanyi, S; Landman, I; Garkusha, I; Makhlaj, V

    2011-01-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m - 2 causing surface melting and of 0.45 MJ m - 2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of N W ∼5×10 18 W per medium size ELM of 0.75 MJ m - 2 and 0.25 ms time duration has been estimated. The radiation cooling power of P rad =150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  3. Sound-Intensity Feedback During Running Reduces Loading Rates and Impact Peak.

    Science.gov (United States)

    Tate, Jeremiah J; Milner, Clare E

    2017-08-01

    Study Design Controlled laboratory study, within-session design. Background Gait retraining has been proposed as an effective intervention to reduce impact loading in runners at risk of stress fractures. Interventions that can be easily implemented in the clinic are needed. Objective To assess the immediate effects of sound-intensity feedback related to impact during running on vertical impact peak, peak vertical instantaneous loading rate, and vertical average loading rate. Methods Fourteen healthy, college-aged runners who ran at least 9.7 km/wk participated (4 male, 10 female; mean ± SD age, 23.7 ± 2.0 years; height, 1.67 ± 0.08 m; mass, 60.9 ± 8.7 kg). A decibel meter provided real-time sound-intensity feedback of treadmill running via an iPad application. Participants were asked to reduce the sound intensity of running while receiving continuous feedback for 15 minutes, while running at their self-selected preferred speed. Baseline and follow-up ground reaction force data were collected during overground running at participants' self-selected preferred running speed. Results Dependent t tests indicated a statistically significant reduction in vertical impact peak (1.56 BW to 1.13 BW, P≤.001), vertical instantaneous loading rate (95.48 BW/s to 62.79 BW/s, P = .001), and vertical average loading rate (69.09 BW/s to 43.91 BW/s, P≤.001) after gait retraining, compared to baseline. Conclusion The results of the current study support the use of sound-intensity feedback during treadmill running to immediately reduce loading rate and impact force. The transfer of within-session reductions in impact peak and loading rates to overground running was demonstrated. Decreases in loading were of comparable magnitude to those observed in other gait retraining methods. J Orthop Sports Phys Ther 2017;47(8):565-569. Epub 6 Jul 2017. doi:10.2519/jospt.2017.7275.

  4. Degradation of isobutanal at high loading rates in a compost biofilter.

    Science.gov (United States)

    Sercu, Bram; Demeestere, Kristof; Baillieul, Hans; Van Langenhove, Herman; Verstraete, Willy

    2005-08-01

    Biofiltration has been increasingly used for cleaning waste gases, mostly containing low concentrations of odorous compounds. To expand the application area of this technology, the biofiltration of higher pollutant loading rates has to be investigated. This article focuses on the biodegradation of isobutanal (IBAL) in a compost biofilter (BF) at mass loading rates between 211 and 4123 g/m3/day (30-590 ppm(v)). At mass loading rates up to 785 g/m3/day, near 100% removal efficiencies could be obtained. However, after increasing the loading rate to 1500-1900 g/m3/ day, the degradation efficiency decreased to 62-98%. In addition, a pH decrease and production of isobutanol (IBOL) and isobutyric acid (IBAC) were observed. This is the first report showing that an aldehyde can act as electron donor as well as acceptor in a BF. To study the effects of pH, compost moisture content, and electron acceptor availability on the biofiltration of IBAL, IBOL, and IBAC, additional batch and continuous experiments were performed. A pH of 5.2 reduced the IBAL degradation rate and inhibited the IBOL degradation, although adaptation of the microorganisms to low pH was observed in the BFs. IBAC was not degraded in the batch experiments. High moisture content (51%) initially had no effect on the IBOL production, although it negatively affected the IBAL elimination increasingly during a 21-day time-course experiment. In batch experiments, the reduction of IBAL to IBOL did not decrease when the amount of available electron acceptors (oxygen or nitrate) was increased. The IBAL removal efficiency at higher loading rates was limited by a combination of nutrient limitation, pH decrease, and dehydration, and the importance of each limiting factor depended on the influent concentration.

  5. Probabilistic concept to describe the influence of rate of loading on strength of concrete

    International Nuclear Information System (INIS)

    Mihashi, H.; Wittmann, F.H.

    1981-01-01

    Any reliability assessment of concrete structures is dependent on realistic assumptions on strength distribution. By means of experimental test series the most appropriate distribution function cannot be determined. In this contribution a theoretical concept to describe variability of strength of concrete will be presented. This approach is based on the characteristic composite structure. The structure of concrete is composed of aggregates and a binding agent i.e. porous hardened cement paste. Under formal conditions there are already big pores and cracks in the matrix as well as in the interface before a specimen is loaded. All structural defects can be assumed to be statistically distributed all over the specimen. If a load is applied cracks start to grow form the most critical structural defects. For a realistic estimation of the reliability of a secondary containment under impact loading conditions the influence of rate of loading on mean value and variability of strength is of major interest. The presented theory predicts that the mean strength increases with a power law as the rate of loading increases, while the coefficient of variation remains constant. A number of test series have been carried out to verify the theoretical concept. Different types of mortar (model concrete) and concrete have been included in the test program. Within the range of accuracy experimental results agree well with theoretical predictions. It can be concluded that the variability of macroscopic properties of concrete can be linked with the distribution of structural defects. Strength of concrete is best represented by a Weibull-type distribution function. The influence of rate of loading on strength can be experessed by means of a general rate process. (orig.)

  6. EFFECTS OF BURN RATE, WOOD SPECIES, MOISTURE CONTENT AND WEIGHT OF WOOD LOADED ON WOODSTOVE EMISSIONS

    Science.gov (United States)

    The report gives results of tests of four woodstove operating parameters (burn rate, wood moisture, wood load, and wood species) at two levels each using a half factorial experimental test design to determine statistically significant effects on the emission components CO, CO2, p...

  7. Effect of ventilation rate and board loading on formaldehyde concentration : a critical review of the literature

    Science.gov (United States)

    George E. Myers

    1984-01-01

    A critical literature review has been carried out on the influence of ventilation rate (N, hr.-1) and board loading (L, m2/m3) on steady state formaldehyde concentrations (Cs, ppm) resulting from particleboard and plywood emissions. Large differences exist among boards in the extent to which their formaldehyde concentrations change with N or L in laboratory chambers....

  8. Emission of formaldehyde by particleboard : effect of ventilation rate and loading on air-contamination levels

    Science.gov (United States)

    George E. Myers; Muneo Nagaoka

    1981-01-01

    Dynamic tests for determining the formaldehyde emission behavior of UF-bonded boards involve the measurement of formaldehyde concentration in the air within a vessel which contains a specified board loading L (m2 of board area per m3 of vessel free volume) and is being ventilated at a specified air exchange rate N (hr.-1). Such tests constitute a primary...

  9. The effect of loading rate on ductile fracture toughness and fracture surface roughness

    DEFF Research Database (Denmark)

    Osovski, S.; Srivastava, Akhilesh Kumar; Ponson, L.

    2015-01-01

    The variation of ductile crack growth resistance and fracture surface roughness with loading rate is modeled under mode I plane strain, small scale yielding conditions. Three-dimensional calculations are carried out using an elastic-viscoplastic constitutive relation for a progressively cavitatin...

  10. Loading rate and test temperature effects on fracture of in situ niobium silicide-niobium composites

    International Nuclear Information System (INIS)

    Rigney, J.D.; Lewandowski, J.J.

    1996-01-01

    Arc cast, extruded, and heat-treated in situ composites of niobium silicide (Nb 5 Si 3 ) intermetallic with niobium phases (primary--Nb p and secondary--Nb s ) exhibited high fracture resistance in comparison to monolithic Nb 5 Si 3 . In toughness tests conducted at 298 K and slow applied loading rates, the fracture process proceeded by the microcracking of the Nb 5 Si 3 and plastic deformation of the Nb p and Nb s phases, producing resistance-curve behavior and toughnesses of 28 MPa√m with damage zone lengths less than 500 microm. The effects of changes in the Nb p yield strength and fracture behavior on the measured toughnesses were investigated by varying the loading rates during fracture tests at both 77 and 298 K. Quantitative fractography was utilized to completely characterize each fracture surface created at 298 K in order to determine the type of fracture mode (i.e., dimpled, cleavage) exhibited by the Nb p . Specimens tested at either higher loading rates or lower test temperatures consistently exhibited a greater amount of cleavage fracture in the Nb p , while the Nb s always remained ductile. However, the fracture toughness values determined from experiments spanning six orders of magnitude in loading rate at 298 and 77 K exhibited little variation, even under conditions when the majority of Nb p phases failed by cleavage at 77 K. The changes in fracture mode with increasing loading rate and/or decreasing test temperature and their effects on fracture toughness are rationalized by comparison to existing theoretical models

  11. Effects of age and loading rate on equine cortical bone failure.

    Science.gov (United States)

    Kulin, Robb M; Jiang, Fengchun; Vecchio, Kenneth S

    2011-01-01

    Although clinical bone fractures occur predominantly under impact loading (as occurs during sporting accidents, falls, high-speed impacts or other catastrophic events), experimentally validated studies on the dynamic fracture behavior of bone, at the loading rates associated with such events, remain limited. In this study, a series of tests were performed on femoral specimens obtained post-mortem from equine donors ranging in age from 6 months to 28 years. Fracture toughness and compressive tests were performed under both quasi-static and dynamic loading conditions in order to determine the effects of loading rate and age on the mechanical behavior of the cortical bone. Fracture toughness experiments were performed using a four-point bending geometry on single and double-notch specimens in order to measure fracture toughness, as well as observe differences in crack initiation between dynamic and quasi-static experiments. Compressive properties were measured on bone loaded parallel and transverse to the osteonal growth direction. Fracture propagation was then analyzed using scanning electron and scanning confocal microscopy to observe the effects of microstructural toughening mechanisms at different strain rates. Specimens from each horse were also analyzed for dry, wet and mineral densities, as well as weight percent mineral, in order to investigate possible influences of composition on mechanical behavior. Results indicate that bone has a higher compressive strength, but lower fracture toughness when tested dynamically as compared to quasi-static experiments. Fracture toughness also tends to decrease with age when measured quasi-statically, but shows little change with age under dynamic loading conditions, where brittle "cleavage-like" fracture behavior dominates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Influence of mixing and solid concentration on sodium bicarbonate secondary nucleation rate in stirred tank

    Energy Technology Data Exchange (ETDEWEB)

    Wylock, C.; Debaste, F.; Haut, B. [Transfers, Interfaces and Processes - Chemical Engineering Unit, ULB, Brussels (Belgium); Gutierrez, V.; Delplancke-Ogletree, M.P. [Chemicals and Materials Department, ULB, Brussels (Belgium); Cartage, T. [Solvay SA, Brussels (Belgium)

    2010-09-15

    This work aims to investigate the influence of the solid concentration in suspension on the contact secondary nucleation rate of sodium bicarbonate crystallization in a stirred tank crystallizer and to show the necessity of a local description of the mixing for a nucleation rate influence study. Experiments and computational fluid dynamics (CFD) simulations are realized. Crystallization kinetic parameters are extracted from experimental data using a mass distribution fitting approach. CFD and the experimental results allow identifying that a mixing property correlated with the measurements of the secondary nucleation rate in the stirred tank crystallizer appears to be the turbulent dissipation rate on the edge of the impeller. Its influence and the influence of the solid concentration in the suspension on the secondary nucleation rate are estimated by the evaluation of their exponents in a kinetic law. The obtained exponent values are then discussed qualitatively. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. An attempt to explain strength increase due to high loading rates

    International Nuclear Information System (INIS)

    Eibl, J.; Curbach, M.

    1989-01-01

    Most materials such as steel, concrete, ceramics, polymers, etc. show an increase of strength due to high loading rates. A number of mathematical equations are available to describe this behaviour. Nevertheless the physical reasons for these observations are still unknown. The common behaviour of a number of materials leads to the assumption that at least some explanations are material independent. Due to this reason the results of the research done at the Institute for Concrete Structures in Karlsruhe are presented in this paper to furnish new ideas for the material research due to dynamic loading. (orig.)

  14. Rate-dependent response of superelastic Cu–Al–Mn alloy rods to tensile cyclic loads

    International Nuclear Information System (INIS)

    Araki, Yoshikazu; Maekawa, Nao; Omori, Toshihiro; Sutou, Yuji; Kainuma, Ryosuke; Ishida, Kiyohito

    2012-01-01

    We report the results of tensile cyclic loading tests conducted to examine the dependence of constitutive relations for superelastic Cu–Al–Mn alloy rods on loading rates. Recently, Cu–Al–Mn alloy rods with diameters up to 8 mm have been developed by the authors, and it has been demonstrated that these rods have excellent superelastic strains of more than 8%, which is comparable to Ni–Ti alloys and far superior to other Cu-based alloys. No information is available, however, on the rate dependence of constitutive relations for Cu–Al–Mn alloys. In this study, we prepare two Cu–Al–Mn alloy rod specimens, whose lengths and diameters are 150 mm and 8 mm, respectively. Their stress–strain relations are examined under the loading frequencies of 0.001, 0.5, and 1 Hz with constant strain amplitude of 4.5%. It was found from the tests that the maximum stress increase in Cu–Al–Mn alloys due to higher loading rate was less than 5%. Thermo-mechanical analysis predicts that stress increase in Cu–Al–Mn alloys is about 1/4 of that in Ni–Ti alloys, which agrees reasonably well with the experimental observations. Such low stress increase is highly desirable in the design of seismic devices such as dampers and isolators. (fast track communication)

  15. Development and characterization of solid dispersion of piroxicam for improvement of dissolution rate using hydrophilic carriers

    Directory of Open Access Journals (Sweden)

    Mohammad Barzegar-jalali

    2014-09-01

    Full Text Available Introduction: The main objective of this study was preparation and characterization of solid dispersion of piroxicam to enhance its dissolution rate. Methods: Solid dispersion formulations with different carriers including crospovidone, microcrystalline cellulose and Elaeagnus angustifolia fruit powder and with different drug: carrier ratios were prepared employing cogrinding method. Dissolution study of the piroxicam powders, physical mixtures and solid dispersions was performed in simulated gastric fluid and simulated intestinal fluid using USP Apparatus type II. The physical characterization of formulations were analyzed using powder X ray diffraction (PXRD, particle size analyzer and differential scanning calorimetry (DSC. Interactions between the drug and carriers were evaluated by Fourier transform infrared (FT-IR spectroscopic method. Results: It was revealed that all of three carriers increase the dissolution rate of piroxicam from physical mixtures and especially in solid dispersions compared to piroxicam pure and treated powders. PXRD and DSC results were confirmed the reduction of crystalline form of piroxicam. FT-IR analysis did not show any physicochemical interaction between drug and carriers in the solid dispersion formulations. Conclusion: Dissolution rate was dependent on the type and ratio of drug: carrier as well as pH of dissolution medium. Dissolution data of formulations were fitted well in to the linear Weibull as well as non-linear logistic and a suggested models.

  16. Evaluation of radiolabeled curcumin-loaded solid lipid nanoparticles usage as an imaging agent in liver-spleen scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Ayan, Arif Kursad [Department of Nuclear Medicine, Ataturk University, 25240 Erzurum (Turkey); Yenilmez, Ayse, E-mail: yenilmez2014@gmail.com [Department of Nanoscience and Nanoengineering, Ataturk University, 25240 Erzurum (Turkey); Department of Molecular Biology and Genetics, Erzurum Technical University, 25240 Erzurum (Turkey); Eroglu, Hayrettin [Department of Biomedical Engineering, Ataturk University, 25240 Erzurum (Turkey)

    2017-06-01

    Curcumin-loaded solid lipid nanoparticles (C-SLNs) were prepared using micro emulsion and ultrasonication methods in the first stage of this study to determine the role of C-SLN on liver-spleen scintigraphy. It was concluded that the curcumin that was encapsulated in solid lipid nanoparticles had a β′ polymorph structure according to the X-ray diffraction (XRD) analysis. İt was concluded that these particles were at nano scale according to the laser diffraction (LD) analysis. Fourier transform infrared spectroscopy (FT-IR) analysis suggested an interaction between the curcumin and the solid lipid matrix, and the curcumin was loaded on the solid lipid nanoparticles. Moreover, the particles were concluded to be spherical and at nanoscale according to the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. On the other hand, thermogravimetric analysis (TGA) suggested that the curcumin loaded solid nanoparticles were stable against the temperature. C-SLNs were labeled with Technetium-99 m ({sup 99m}Tc) radioisotope in the second stage of the study, then using scintigraphic methods in-vivo studies were performed on New Zealand rabbit and made a comparison with Phytate colloid, routinely used in liver-spleen scintigraphy. After analyzing the images and the biological distributions obtained from the experiments, uptake was observed in the liver and the spleen. Following from the experiment results, {sup 99m}Tc-labeled C-SLNs was concluded to be a possible imaging agent. In particular, it could be a new radiopharmaceutical alternative to {sup 99m}Tc-labeled compounds that are used in liver and spleen imaging in colloid scintigraphy. - Graphıcal abstract: Display Omitted - Hıghlıghts: • Curcumin-loaded solid lipid nanoparticles (C-SLNs) were prepared and examined characterization studies. • The C-SLNs were labeled with {sup 99m}Tc and made a comparison with Phytate colloid, routinely used in liver-spleen scintigraphy. • In vivo

  17. Acute toxicity study of tilmicosin-loaded hydrogenated castor oil-solid lipid nanoparticles

    Directory of Open Access Journals (Sweden)

    Xie Shuyu

    2011-11-01

    Full Text Available Abstract Background Our previous studies demonstrated that tilmicosin-loaded hydrogenated castor oil solid lipid nanoparticles (Til-HCO-SLN are a promising formulation for enhanced pharmacological activity and therapeutic efficacy in veterinary use. The purpose of this work was to evaluate the acute toxicity of Til-HCO-SLN. Methods Two nanoparticle doses were used for the study in ICR mice. The low dose (766 mg/kg.bw with tilmicosin 7.5 times of the clinic dosage and below the median lethal dose (LD50 was subcutaneously administered twice on the first and 7th day. The single high dose (5 g/kg.bw was the practical upper limit in an acute toxicity study and was administered subcutaneously on the first day. Blank HCO-SLN, native tilmicosin, and saline solution were included as controls. After medication, animals were monitored over 14 days, and then necropsied. Signs of toxicity were evaluated via mortality, symptoms of treatment effect, gross and microscopic pathology, and hematologic and biochemical parameters. Results After administration of native tilmicosin, all mice died within 2 h in the high dose group, in the low dose group 3 died after the first and 2 died after the second injections. The surviving mice in the tilmicosin low dose group showed hypoactivity, accelerated breath, gloomy spirit and lethargy. In contrast, all mice in Til-HCO-SLN and blank HCO-SLN groups survived at both low and high doses. The high nanoparticle dose induced transient clinical symptoms of treatment effect such as transient reversible action retardation, anorexy and gloomy spirit, increased spleen and liver coefficients and decreased heart coefficients, microscopic pathological changes of liver, spleen and heart, and minor changes in hematologic and biochemical parameters, but no adverse effects were observed in the nanoparticle low dose group. Conclusions The results revealed that the LD50 of Til-HCO-SLN and blank HCO-SLN exceeded 5 g/kg.bw and thus the

  18. Effect of the loading rate on compressive properties of goose eggs.

    Science.gov (United States)

    Nedomová, Š; Kumbár, V; Trnka, J; Buchar, J

    2016-03-01

    The resistance of goose (Anser anser f. domestica) eggs to damage was determined by measuring the average rupture force, specific deformation and rupture energy during their compression at different compression speeds (0.0167, 0.167, 0.334, 1.67, 6.68 and 13.36 mm/s). Eggs have been loaded between their poles (along X axis) and in the equator plane (Z axis). The greatest amount of force required to break the eggs was required when eggs were loaded along the X axis and the least compression force was required along the Z axis. This effect of the loading orientation can be described in terms of the eggshell contour curvature. The rate sensitivity of the eggshell rupture force is higher than that observed for the Japanese quail's eggs.

  19. [*C]octanoic acid breath test to measure gastric emptying rate of solids.

    Science.gov (United States)

    Maes, B D; Ghoos, Y F; Rutgeerts, P J; Hiele, M I; Geypens, B; Vantrappen, G

    1994-12-01

    We have developed a breath test to measure solid gastric emptying using a standardized scrambled egg test meal (250 kcal) labeled with [14C]octanoic acid or [13C]octanoic acid. In vitro incubation studies showed that octanoic acid is a reliable marker of the solid phase. The breath test was validated in 36 subjects by simultaneous radioscintigraphic and breath test measurements. Nine healthy volunteers were studied after intravenous administration of 200 mg erythromycin and peroral administration of 30 mg propantheline, respectively. Erythromycin significantly enhanced gastric emptying, while propantheline significantly reduced gastric emptying rates. We conclude that the [*C]octanoic breath test is a promising and reliable test for measuring the gastric emptying rate of solids.

  20. Effect of Bench Press Load Knowledge on Repetitions, Rating of Perceived Exertion, and Attentional Focus.

    Science.gov (United States)

    Beaudoin, Christina M; Cox, Zachary; Dundore, Tyler; Thomas, Tayler; Kim, Johnathon; Pillivant, Daniel

    2018-02-01

    Beaudoin, CM, Cox, Z, Dundore, T, Thomas, T, Kim, J, and Pillivant, D. Effect of bench press load knowledge on repetitions, rating of perceived exertion, and attentional focus. J Strength Cond Res 32(2): 514-519, 2018-Few studies have examined the role of the teleoanticipation during resistance training. The purpose of this study was to examine the effect of bench press (BP) load knowledge on repetitions completed, ratings of perceived exertion (RPEs), and attentional focus (% associative). Thirty-six recreationally active resistance-trained men (n = 25) and women (n = 11) participated in this study (age = 20.97 ± 1.87 years; ht = 174.12 ± 9.41 cm; and mass = 80.14 ± 14.03 kg). All subjects completed 3 testing sessions: (a) 1 repetition maximum (1RM) BP determination; (b) submaximal BP repetitions to fatigue known load (KL); and (c) submaximal BP repetitions to fatigue unknown load (UL). Known load and UL sessions were randomized and counterbalanced and both completed at 70% 1RM. An estimated weight ratio was computed using the subject's estimate of the UL weight relative to the KL weight. An independent samples t-test revealed no significant testing order difference for the estimated weight ratio. Two-way repeated-measures analysis of variances revealed no significant differences in the number of repetitions (p = 0.63), RPE (p = 0.18), or attentional focus (% associative) (p = 0.93) between the KL and UL conditions. Pearson correlations found a moderate positive association between KL repetitions completed and % associative focus when the UL was completed before the KL. Load knowledge did not influence the number of repetitions, RPE, or attentional focus while completing the BP. Further research examining the use of pacing strategies, RPE, and attentional focus during KL and UL conditions are warranted.

  1. Application of transient burning rate model of solid propellant in electrothermal-chemical launch simulation

    Directory of Open Access Journals (Sweden)

    Yan-jie Ni

    2016-04-01

    Full Text Available A 30 mm electrothermal-chemical (ETC gun experimental system is employed to research the burning rate characteristics of 4/7 high-nitrogen solid propellant. Enhanced gas generation rates (EGGR of propellants during and after electrical discharges are verified in the experiments. A modified 0D internal ballistic model is established to simulate the ETC launch. According to the measured pressure and electrical parameters, a transient burning rate law including the influence of EGGR coefficient by electric power and pressure gradient (dp/dt is added into the model. The EGGR coefficient of 4/7 high-nitrogen solid propellant is equal to 0.005 MW−1. Both simulated breech pressure and projectile muzzle velocity accord with the experimental results well. Compared with Woodley's modified burning rate law, the breech pressure curves acquired by the transient burning rate law are more consistent with test results. Based on the parameters calculated in the model, the relationship among propellant burning rate, pressure gradient (dp/dt and electric power is analyzed. Depending on the transient burning rate law and experimental data, the burning of solid propellant under the condition of plasma is described more accurately.

  2. Influence of organic loading rate on methane production in a CSTR from physicochemical sludge generated in a poultry slaughterhouse.

    Science.gov (United States)

    López-Escobar, Luis A; Martínez-Hernández, Sergio; Corte-Cano, Grisel; Méndez-Contreras, Juan M

    2014-01-01

    The influence of the increase of the organic loading rate (OLR) on methane production in a continuous stirred-tank reactor (CSTR) from physicochemical sludge generated in a poultry slaughterhouse was evaluated. Total solid (TS) to obtain OLR of 1, 5, 10 and 15 g VS L(-1) day(-1), with hydraulic retention times of 29, 6, 6 and 4, respectively, were conditioned. The results showed a decrease in pH levels and an increase in the theoretical volatile fatty acids (VFA). While the yield of methane production decreased from 0.48 to 0.10 LCH4/g VSremoved, respectively, the OLR-10 managed on average 38% removal of volatile solids (VS) and a yield biogas production of 0.81 Lbiogas g(-1) VSremoved and 1.35 L day(-1). This suggests that the OLR increases in an anaerobic system from physicochemical sludge only inhibits the methanogenic metabolism, because there is still substrate consumption and biogas production.

  3. Piping hydrodynamic loads for a PWR power up-rate with steam generator replacement

    International Nuclear Information System (INIS)

    Julie M Jarvis; Allen T Vieira; James M Gilmer

    2005-01-01

    Full text of publication follows: Pipe break hydrodynamic loads are calculated for various systems in a PWR for a Power Up-rate (PUR) with a Steam Generator Replacement (SGR). PUR with SGR can change the system pressures, mass flowrates and pipe routing/configuration. These changes can alter the steam generator piping steam/water hammer loads. This paper discusses the need to benchmark against the original design basis, the use of different modeling techniques, and lessons learned. Benchmarking for licensing in the United States is vital in consideration of 10CFR50.59 and other licensing and safety issues. RELAP5 and its force post-processor R5FORCE are used to model the transient loads for various piping systems such as main feedwater and blowdown systems. Other modeling applications, including the Bechtel GAFT program, are used to evaluate loadings in the main steam piping. Forces are calculated for main steam turbine stop valve closure, feedwater pipe breaks and subsequent check valve slam, and blowdown isolation valve closure. These PUR/SGR forces are compared with the original design basis forces. Modeling techniques discussed include proper valve closure modeling, sonic velocity changes due to pipe material changes, and two phase flow effects. Lessons learned based on analyses done for several PWR PUR with SGR are presented. Lessons learned from these analyses include choosing the optimal replacement piping size and routing to improve system performance without resulting in excessive piping loads. (authors)

  4. An estimation of finger-tapping rates and load capacities and the effects of various factors.

    Science.gov (United States)

    Ekşioğlu, Mahmut; İşeri, Ali

    2015-06-01

    The aim of this study was to estimate the finger-tapping rates and finger load capacities of eight fingers (excluding thumbs) for a healthy adult population and investigate the effects of various factors on tapping rate. Finger-tapping rate, the total number of finger taps per unit of time, can be used as a design parameter of various products and also as a psychomotor test for evaluating patients with neurologic problems. A 1-min tapping task was performed by 148 participants with maximum volitional tempo for each of eight fingers. For each of the tapping tasks, the participant with the corresponding finger tapped the associated key in the standard position on the home row of a conventional keyboard for touch typing. The index and middle fingers were the fastest fingers for both hands, and little fingers the slowest. All dominant-hand fingers, except little finger, had higher tapping rates than the fastest finger of the nondominant hand. Tapping rate decreased with age and smokers tapped faster than nonsmokers. Tapping duration and exercise had also significant effect on tapping rate. Normative data of tapping rates and load capacities of eight fingers were estimated for the adult population. In designs of psychomotor tests that require the use of tapping rate or finger load capacity data, the effects of finger, age, smoking, and tapping duration need to be taken into account. The findings can be used for ergonomic designs requiring finger-tapping capacity and also as a reference in psychomotor tests. © 2015, Human Factors and Ergonomics Society.

  5. A quantitative approach to the loading rate of seismogenic sources in Italy

    Science.gov (United States)

    Caporali, Alessandro; Braitenberg, Carla; Montone, Paola; Rossi, Giuliana; Valensise, Gianluca; Viganò, Alfio; Zurutuza, Joaquin

    2018-06-01

    To investigate the transfer of elastic energy between a regional stress field and a set of localized faults, we project the stress rate tensor inferred from the Italian GNSS (Global Navigation Satellite Systems) velocity field onto faults selected from the Database of Individual Seismogenic Sources (DISS 3.2.0). For given Lamé constants and friction coefficient, we compute the loading rate on each fault in terms of the Coulomb failure function (CFF) rate. By varying the strike, dip and rake angles around the nominal DISS values, we also estimate the geometry of planes that are optimally oriented for maximal CFF rate. Out of 86 Individual Seismogenic Sources (ISSs), all well covered by GNSS data, 78-81 (depending on the assumed friction coefficient) load energy at a rate of 0-4 kPa yr-1. The faults displaying larger CFF rates (4-6 ± 1 kPa yr-1) are located in the central Apennines and are all characterized by a significant strike-slip component. We also find that the loading rate of 75% of the examined sources is less than 1 kPa yr-1 lower than that of optimally oriented faults. We also analysed 2016 August 24 and October 30 central Apennines earthquakes (Mw 6.0-6.5, respectively). The strike of their causative faults based on seismological and tectonic data and the geodetically inferred strike differ by <30°. Some sources exhibit a strike oblique to the direction of maximum strain rate, suggesting that in some instances the present-day stress acts on inherited faults. The choice of the friction coefficient only marginally affects this result.

  6. A quantitative approach to the loading rate of seismogenic sources in Italy

    Science.gov (United States)

    Caporali, Alessandro; Braitenberg, Carla; Montone, Paola; Rossi, Giuliana; Valensise, Gianluca; Viganò, Alfio; Zurutuza, Joaquin

    2018-03-01

    To investigate the transfer of elastic energy between a regional stress field and a set of localized faults we project the stress rate tensor inferred from the Italian GNSS velocity field onto faults selected from the Database of Individual Seismogenic Sources (DISS 3.2.0). For given Lamé constants and friction coefficient we compute the loading rate on each fault in terms of the Coulomb Failure Function (CFF) rate. By varying the strike, dip and rake angles around the nominal DISS values, we also estimate the geometry of planes that are optimally oriented for maximal CFF rate. Out of 86 Individual Seismogenic Sources (ISSs), all well covered by GNSS data, 78 to 81 (depending on the assumed friction coefficient) load energy at a rate of 0-4 kPa/yr. The faults displaying larger CFF rates (4 to 6 ± 1 kPa/yr) are located in the central Apennines and are all characterized by a significant strike-slip component. We also find that the loading rate of 75 per cent of the examined sources is less than 1 kPa/yr lower than that of optimally oriented faults. We also analyzed the 24 August and 30 October 2016, central Apennines earthquakes (Mw 6.0-6.5 respectively). The strike of their causative faults based on seismological and tectonic data and the geodetically inferred strike differ by < 30°. Some sources exhibit a strike oblique to the direction of maximum strain rate, suggesting that in some instances the present-day stress acts on inherited faults. The choice of the friction coefficient only marginally affects this result.

  7. Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

    Science.gov (United States)

    Azizi, Mohammad Ali; Brouwer, Jacob

    2017-10-01

    A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

  8. Original communication: Basal metabolic rate in children with a solid tumor

    NARCIS (Netherlands)

    Broeder, den E.; Oeseburg, B.; Lippens, R.J.J.; Staveren, van W.A.; Sengers, R.C.A.; Hof, van 't M.A.; Tolboom, J.J.M.

    2001-01-01

    Objective: To study the level of and changes in basal metabolic rate (BMR) in children with a solid tumour at diagnosis and during treatment in order to provide a more accurate estimate of energy requirements for nutritional support. Design: An observational study. Setting: Tertiary care at the

  9. Phonon conductivity and relaxation rate in solids with disturbances by the Green function method

    International Nuclear Information System (INIS)

    Singh, M.

    1980-09-01

    In this present article we have established an expression for the temperature dependence of the lattice thermal conductivity of solids with harmonic disturbances. The relaxation rate for scattering of phonons with point defect is also derived. We will apply the Kubo-correlation function formalism for the thermal conductivity, and the double time temperature dependent Green function technique for the evaluation of correlation functions

  10. Effect of loading rate variation on soybean protein wastewater treatment by UASB reactor

    Science.gov (United States)

    Sun, Yi; Li, Yongfeng; Guo, Zi-rui; Jiao, An-ying; Han, Wei; Yang, Chuan-ping

    2010-11-01

    In order to improve the efficiency and evaluate the feasibility of anaerobic digestion for treatment of soybean protein wastewater. The stability and performance of the Up-Flow Anaerobic Sludge Blanket (UASB) process was investigated at different organic loading rates (OLRS) and hydraulic retention times over 200 days. When chemical oxygen demand (COD) reached maximum, the loading rate was adjusted in a small way and indicators such as VFA, pH and COD in effluent as well as gas production are observed. These experimental results clearly showed that, the most proper corresponding organic loading rate (OLR) and hydraulic retention time were 6 kg/ (m3ṡd) (COD = 6000 mg/L) and 24 h respectively. Up to 85% of COD was removed and the CH4 production rate of 3.2 m3/(m3ṡd) was obtained. The produced biogas contained 72% of CH4. In the mean time, anaerobic sludge multiplies more faster and exiguous particles appeared. Granules with diameter 1-3 mm.

  11. Brain targeting effect of camptothecin-loaded solid lipid nanoparticles in rat after intravenous administration

    DEFF Research Database (Denmark)

    Martins, S. M.; Sarmento, B.; Nunes, C.

    2013-01-01

    studies against glioma and macrophage human cell lines revealed that camptothecin-loaded SLN induced cell death with the lowest maximal inhibitory concentration (IC50) values, revealing higher antitumour activity of camptothecin-loaded SLN against gliomas. Furthermore, in vivo biodistribution studies...

  12. Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approaches.

    Science.gov (United States)

    Madureira, Ana Raquel; Nunes, Sara; Campos, Débora A; Fernandes, João C; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Maria Manuela; Reis, Flávio

    2016-01-01

    Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications.

  13. Direct determination of bulk etching rate for LR-115-II solid state ...

    Indian Academy of Sciences (India)

    The thickness of the removed layer of the LR-115-II solid state nuclear track detector during etching is measured directly with a rather precise instrument. Dependence of bulk etching rate on temperature of the etching solution is investigated. It has been found that the bulk etching rate is 3.2 m/h at 60°C in 2.5 N NaOH of ...

  14. Rate dependent inelastic behavior of polycrystalline solids using a dislocation model

    International Nuclear Information System (INIS)

    Werne, R.W.; Kelly, J.M.

    1980-01-01

    A rate dependent theory of polycrystalline plasticity is presented in which the solid is modeled as an isotropic continuum with internal variables. The rate of plastic deformation is shown to be a function of the deviatoric portion of the Cauchy stress tensor as well as two scalar internal variables. The scalar internal variables, which are the dislocation density and mobile fraction, are governed by rate equations which reflect the evolution of microstructural processes. The model has been incorporated into a two dimensional finite element code and several example multidimensional problems are presented which exhibit the rate dependence of the material model

  15. Solid lipid nanoparticles loaded with insulin by sodium cholate-phosphatidylcholine-based mixed micelles: preparation and characterization.

    Science.gov (United States)

    Liu, Jie; Gong, Tao; Wang, Changguang; Zhong, Zhirong; Zhang, Zhirong

    2007-08-01

    Solid lipid nanoparticles (SLNs) loaded with insulin-mixed micelles (Ins-MMs) were prepared by a novel reverse micelle-double emulsion method, in which sodium cholate (SC) and soybean phosphatidylcholine (SPC) were employed to improve the liposolubility of insulin, and the mixture of stearic acid and palmitic acid were employed to prepare insulin loaded solid lipid nanoparticles (Ins-MM-SLNs). Some of the formulation parameters were optimized to obtain high quality nanoparticles. The particle size and zeta potential measured by photon correlation spectroscopy (PCS) were 114.7+/-4.68 nm and -51.36+/-2.04 mV, respectively. Nanospheres observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed extremely spherical shape. The entrapment efficiency (EE%) and drug loading capacity (DL%) determined with high performance liquid chromatogram (HPLC) by modified ultracentrifuge method were 97.78+/-0.37% and 18.92+/-0.07%, respectively. Differential scanning calorimetry (DSC) of Ins-MM-SLNs indicated no tendency of recrystallisation. The core-shell drug loading pattern of the SLNs was confirmed by fluorescence spectra and polyacrylamide gel electrophoresis (PAGE) which also proved the integrity of insulin after being incorporated into lipid carrier. The drug release behavior was studied by in situ and externally sink method and the release pattern of drug was found to follow Weibull and Higuchi equations. Results of stability evaluation showed a relatively long-term stability after storage at 4 degrees C for 6 months. In conclusion, SLNs with small particle size, excellent physical stability, high entrapment efficiency, good loading capacity for protein drug can be produced by this novel reverse micelle-double emulsion method in present study.

  16. Formulation and characterization of hydrophilic drug diclofenac sodium-loaded solid lipid nanoparticles based on phospholipid complexes technology.

    Science.gov (United States)

    Liu, Dongfei; Chen, Li; Jiang, Sunmin; Zhu, Shuning; Qian, Yong; Wang, Fengzhen; Li, Rui; Xu, Qunwei

    2014-03-01

    To successfully prepare the diclofenac sodium (DS)-loaded solid lipid nanoparticles (SLNs), phospholipid complexes (PCs) technology was applied here to improve the liposolubility of DS. Solid lipid nanoparticles (SLNs) loaded with phospholipid complexes (PCs) were prepared by the modified emulsion/solvent evaporation method. DS could be solubilized effectively in the organic solvents with the existence of phospholipid and apparent partition coefficient of DS in PCs increased significantly. X-ray diffraction analysis suggested that DS in PCs was either molecularly dispersed or in an amorphous form. However, no significant difference was observed between the Fourier transform infrared spectroscopy (FT-IR) spectra of physical mixture and that of PCs. Particles with small sizes, narrow polydispersity indexes and high entrapment efficiencies could be obtained with the addition of PCs. Furthermore, according to the transmission electron microscopy, a core-shell structure was likely to be formed. The presence of PCs caused the change of zeta potential and retarded the drug release of SLNs, which indicated that phospholipid formed multilayers around the solid lipid core of SLNs. Both FT-IR and differential scanning calorimetry analysis also illustrated that some weak interactions between DS and lipid materials might take place during the preparation of SLNs. In conclusion, the model hydrophilic drug-DS can be formulated into the SLNs with the help of PCs.

  17. Reactivity and reaction rate studies on the fourth loading of ZENITH

    International Nuclear Information System (INIS)

    Cameron, I.R.; Freemantle, R.G.; Reed, D.L.; Wilson, D.J.

    1963-08-01

    The determination of the excess reactivity, control rod worths, prompt neutron lifetime, flux fine structure, and reaction rates of various nuclides for the fourth loading of the heated zero energy reactor ZENITH is described. The core contains 7.76 kg of U235, giving a carbon/U235 atom ratio of 7578, and forms the most dilute of the range studied. Comparisons of the experimental results with calculations using multigroup diffusion codes are presented. (author)

  18. Reactivity and reaction rate studies on the fourth loading of ZENITH

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, I R; Freemantle, R G; Reed, D L; Wilson, D J [General Reactor Physics Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1963-08-15

    The determination of the excess reactivity, control rod worths, prompt neutron lifetime, flux fine structure, and reaction rates of various nuclides for the fourth loading of the heated zero energy reactor ZENITH is described. The core contains 7.76 kg of U235, giving a carbon/U235 atom ratio of 7578, and forms the most dilute of the range studied. Comparisons of the experimental results with calculations using multigroup diffusion codes are presented. (author)

  19. Loading Rate Effects on the One-Dimensional Compressibility of Four Partially Saturated Soils

    Science.gov (United States)

    1986-12-01

    representations are referred to as constitutive models. Numerous constitutive models incorporating loading rate effects have been developed ( Baladi and Rohani...and probably more indicative of the true values of applied pressure and average strain produced during the test. A technique developed by Baladi and...Sand," Technical Report No. AFWL-TR-66-146, Air Force Weapons Laboratory, Kirtland Air Force Base, New Mexico, June, 1967. 4. Baladi , George Y., and

  20. Two Coupled Queues with Vastly Different Arrival Rates: Critical Loading Case

    Directory of Open Access Journals (Sweden)

    Charles Knessl

    2011-01-01

    Full Text Available We consider two coupled queues with a generalized processor sharing service discipline. The second queue has a much smaller Poisson arrival rate than the first queue, while the customer service times are of comparable magnitude. The processor sharing server devotes most of its resources to the first queue, except when it is empty. The fraction of resources devoted to the second queue is small, of the same order as the ratio of the arrival rates. We assume that the primary queue is heavily loaded and that the secondary queue is critically loaded. If we let the small arrival rate to the secondary queue be O(ε, where 0≤ε≪1, then in this asymptotic limit the number of customers in the first queue will be large, of order O(ε-1, while that in the second queue will be somewhat smaller, of order O(ε-1/2. We obtain a two-dimensional diffusion approximation for this model and explicitly solve for the joint steady state probability distribution of the numbers of customers in the two queues. This work complements that in (Morrison, 2010, which the second queue was assumed to be heavily or lightly loaded, leading to mean queue lengths that were O(ε-1 or O(1, respectively.

  1. Aging and loading rate effects on the mechanical behavior of equine bone

    Science.gov (United States)

    Kulin, Robb M.; Jiang, Fengchun; Vecchio, Kenneth S.

    2008-06-01

    Whether due to a sporting accident, high-speed impact, fall, or other catastrophic event, the majority of clinical bone fractures occur under dynamic loading conditions. However, although extensive research has been performed on the quasi-static fracture and mechanical behavior of bone to date, few high-quality studies on the fracture behavior of bone at high strain rates have been performed. Therefore, many questions remain regarding the material behavior, including not only the loading-rate-dependent response of bone, but also how this response varies with age. In this study, tests were performed on equine femoral bone taken post-mortem from donors 6 months to 28 years of age. Quasi-static and dynamic tests were performed to determine the fracture toughness and compressive mechanical behavior as a function of age at varying loading rates. Fracture paths were then analyzed using scanning confocal and scanning-electron microscopy techniques to assess the role of various microstructural features on toughening mechanisms.

  2. Estimated dissolved-solids loads and trends at selected streams in and near the Uinta Basin, Utah, Water Years 1989–2013

    Science.gov (United States)

    Thiros, Susan A.

    2017-03-23

    The U.S. Geological Survey (USGS), in cooperation with the Colorado River Basin Salinity Control Forum, studied trends in dissolved-solids loads at selected sites in and near the Uinta Basin, Utah. The Uinta Basin study area includes the Duchesne River Basin and the Middle Green River Basin in Utah from below Flaming Gorge Reservoir to the town of Green River.Annual dissolved-solids loads for water years (WY) 1989 through 2013 were estimated for 16 gaging stations in the study area using streamflow and water-quality data from the USGS National Water Information System database. Eight gaging stations that monitored catchments with limited or no agricultural land use (natural subbasins) were used to assess loads from natural sources. Four gaging stations that monitored catchments with agricultural land in the Duchesne River Basin were used to assess loads from agricultural sources. Four other gaging stations were included in the dissolved-solids load and trend analysis to help assess the effects of agricultural areas that drain to the Green River in the Uinta Basin, but outside of the Duchesne River Basin.Estimated mean annual dissolved-solids loads for WY 1989–2013 ranged from 1,520 tons at Lake Fork River above Moon Lake, near Mountain Home, Utah (UT), to 1,760,000 tons at Green River near Green River, UT. The flow-normalized loads at gaging stations upstream of agricultural activities showed no trend or a relatively small change. The largest net change in modeled flow-normalized load was -352,000 tons (a 17.8-percent decrease) at Green River near Green River, UT.Annual streamflow and modeled dissolved-solids loads at the gaging stations were balanced between upstream and downstream sites to determine how much water and dissolved solids were transported to the Duchesne River and a section of the Green River, and how much was picked up in each drainage area. Mass-balance calculations of WY 1989–2013 mean annual dissolved-solids loads at the studied sites show

  3. Dynamic Behavior of AA2519-T8 Aluminum Alloy Under High Strain Rate Loading in Compression

    Science.gov (United States)

    Olasumboye, A. T.; Owolabi, G. M.; Odeshi, A. G.; Yilmaz, N.; Zeytinci, A.

    2018-02-01

    In this study, the effects of strain rate on the dynamic behavior, microstructure evolution and hence, failure of the AA2519-T8 aluminum alloy were investigated under compression at strain rates ranging from 1000 to 3500 s-1. Cylindrical specimens of dimensions 3.3 mm × 3.3 mm (L/D = 1) were tested using the split-Hopkinson pressure bar integrated with a digital image correlation system. The microstructure of the alloy was assessed using optical and scanning electron microscopes. Results showed that the dynamic yield strength of the alloy is strain rate dependent, with the maximum yield strength attained by the material being 500 MPa. The peak flow stress of 562 MPa was attained by the material at 3500 s-1. The alloy also showed a significant rate of strain hardening that is typical of other Al-Cu alloys; the rate of strain hardening, however, decreased with increase in strain rate. It was determined that the strain rate sensitivity coefficient of the alloy within the range of high strain rates used in this study is approximately 0.05 at 0.12 plastic strain; a more significant value than what was reported in literature under quasi-static loading. Micrographs obtained showed potential sites for the evolution of adiabatic shear band at 3500 s-1, with a characteristic circular-shaped surface profile comprising partially dissolved second phase particles in the continuous phase across the incident plane of the deformed specimen. The regions surrounding the site showed little or no change in the size of particles. However, the constituent coarse particles were observed as agglomerations of fractured pieces, thus having a shape factor different from those contained in the as-received alloy. Since the investigated alloy is a choice material for military application where it can be exposed to massive deformation at high strain rates, this study provides information on its microstructural and mechanical responses to such extreme loading condition.

  4. Assessment of the contribution of sewer deposits to suspended solids loads in combined sewer systems during rain events.

    Science.gov (United States)

    Hannouche, A; Chebbo, G; Joannis, C

    2014-04-01

    Within the French observatories network SOERE "URBIS," databases of continuous turbidity measurements accumulating hundreds of events and many dry weather days are available for two sites with different features (Clichy in Paris and Ecully in Lyon). These measurements, converted into total suspended solids (TSS) concentration using TSS-turbidity relationships and combined with a model of runoff event mean concentration, enable the assessment of the contribution of sewer deposits to wet weather TSS loads observed at the outlet of the two watersheds. Results show that the contribution of sewer deposits to wet weather suspended solid's discharges is important but variable (between 20 and 80 % of the mass at the outlet depending on the event), including a site allegedly free of (coarse) sewer deposits. The uncertainties associated to these results are assessed too.

  5. Novel dual-reverse thermosensitive solid lipid nanoparticle-loaded hydrogel for rectal administration of flurbiprofen with improved bioavailability and reduced initial burst effect.

    Science.gov (United States)

    Din, Fakhar Ud; Mustapha, Omer; Kim, Dong Wuk; Rashid, Rehmana; Park, Jong Hyuck; Choi, Ju Yeon; Ku, Sae Kwang; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

    2015-08-01

    The purpose of this study was to develop novel solid lipid nanoparticle (SLN)-loaded dual-reverse thermosensitive hydrogel (DRTH) for rectal administration of flurbiprofen with improved bioavailability and reduced initial burst effect. The flurbiprofen-loaded SLNs were prepared by hot homogenisation technique, after optimising the amounts of lipid mixture (tricaprin and triethanolamine in 8:2 weight ratio), drug and surfactant. The flurbiprofen-loaded thermosensitive SLN composed of drug, lipid mixture and surfactant at a weight ratio of 10/15/1.3 was a solid at room temperature, and changed to liquid form at physiological temperature due to its melting point of about 32°C. This SLN gave the mean particle size of about 190nm and entrapment efficiency of around 90%. The DRTHs were prepared by adding this flurbiprofen-loaded thermosensitive SLN in various poloxamer solutions. Their rheological characterisation, release and stability were investigated while a morphological and pharmacokinetic study was performed after its rectal administration to rats compared with the drug and hydrogel. Poloxamer 188 and SLN decreased the gelation temperature and gelation time, but increased the viscosity at 25°C, gel strength and mucoadhesive force of DRTHs. In particular, the DRTH composed of [SLN/P 407/P 188 (10%/15%/25%)] with the gelation temperature of about 35°C existed as liquid at room temperature, but gelled at 30-36°C, leading to opposite reversible property of SLN. Thus, it was easy to administer rectally, and it gelled rapidly inside the body. This DRTH gave a significantly increased dissolution rate of the drug as compared to the flurbiprofen, but significantly retarded as compared to the hydrogel, including the initial dissolution rate. Moreover, this DRTH gave significantly higher plasma concentration and 7.5-fold AUC values compared to the drug, and lower initial plasma concentration and Cmax value compared to the hydrogel due to reduced initial burst effect. No

  6. Strain rate dependency of bovine trabecular bone under impact loading at sideways fall velocity.

    Science.gov (United States)

    Enns-Bray, William S; Ferguson, Stephen J; Helgason, Benedikt

    2018-05-03

    There is currently a knowledge gap in scientific literature concerning the strain rate dependent properties of trabecular bone at intermediate strain rates. Meanwhile, strain rates between 10 and 200/s have been observed in previous dynamic finite element models of the proximal femur loaded at realistic sideways fall speeds. This study aimed to quantify the effect of strain rate (ε̇) on modulus of elasticity (E), ultimate stress (σ u ), failure energy (U f ), and minimum stress (σ m ) of trabecular bone in order to improve the biofidelity of material properties used in dynamic simulations of sideways fall loading on the hip. Cylindrical cores of trabecular bone (D = 8 mm, L gauge  = 16 mm, n = 34) from bovine proximal tibiae and distal femurs were scanned in µCT (10 µm), quantifying apparent density (ρ app ) and degree of anisotropy (DA), and subsequently impacted within a miniature drop tower. Force of impact was measured using a piezoelectric load cell (400 kHz), while displacement during compression was measured from high speed video (50,000 frames/s). Four groups, with similar density distributions, were loaded at different impact velocities (0.84, 1.33, 1.75, and 2.16 m/s) with constant kinetic energy (0.4 J) by adjusting the impact mass. The mean strain rates of each group were significantly different (p < 0.05) except for the two fastest impact speeds (p = 0.09). Non-linear regression models correlated strain rate, DA, and ρ app with ultimate stress (R 2  = 0.76), elastic modulus (R 2  = 0.63), failure energy (R 2  = 0.38), and minimum stress (R 2  = 0.57). These results indicate that previous estimates of σ u could be under predicting the mechanical properties at strain rates above 10/s. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Dry anaerobic digestion of food waste and cardboard at different substrate loads, solid contents and co-digestion proportions.

    Science.gov (United States)

    Capson-Tojo, Gabriel; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Delgenès, Jean-Philippe; Escudié, Renaud

    2017-06-01

    The increasing food waste production calls for developing efficient technologies for its treatment. Anaerobic processes provide an effective waste valorization. The influence of the initial substrate load on the performance of batch dry anaerobic co-digestion reactors treating food waste and cardboard was investigated. The load was varied by modifying the substrate to inoculum ratio (S/X), the total solids content and the co-digestion proportions. The results showed that the S/X was a crucial parameter. Within the tested values (0.25, 1 and 4gVS·gVS -1 ), only the reactors working at 0.25 produced methane. Methanosarcina was the main archaea, indicating its importance for efficient methanogenesis. Acidogenic fermentation was predominant at higher S/X, producing hydrogen and other metabolites. Higher substrate conversions (≤48%) and hydrogen yields (≤62mL·gVS -1 ) were achieved at low loads. This study suggests that different value-added compounds can be produced in dry conditions, with the initial substrate load as easy-to-control operational parameter. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Semi-continuous anaerobic digestion of solid poultry slaughterhouse waste: effect of hydraulic retention time and loading.

    Science.gov (United States)

    Salminen, Esa A; Rintala, Jukka A

    2002-07-01

    We studied the effect of hydraulic retention time (HRT) and loading on anaerobic digestion of poultry slaughterhouse wastes, using semi-continuously fed, laboratory-scale digesters at 31 degrees C. The effect on process performance was highly significant: Anaerobic digestion appeared feasible with a loading of up to 0.8 kg volatile solids (VS)/m3 d and an HRT of 50-100 days. The specific methane yield was high, from 0.52 to 0.55 m3/kg VS(added). On the other hand, at a higher loading, in the range from 1.0 to 2.1 kg VS/m3 d, and a shorter HRT, in the range from 25 to 13 days, the process appeared inhibited and/or overloaded, as indicated by the accumulation of volatile fatty acids and long-chain fatty acids and the decline in the methane yield. However, the inhibition was reversible. The nitrogen in the feed, ca. 7.8% of total solids (TS), was organic nitrogen with little ammonia present, whereas in the digested material ammonia accounted for 52-67% (up to 3.8 g/l) of total nitrogen. The TS and VS removals amounted to 76% and 64%, respectively. Our results show that on a continuous basis under the studied conditions and with a loading of up to 0.8 kg VS/m3 d metric ton (wet weight) of the studied waste mixture could yield up to 140 m3 of methane.

  9. Influence of solvent evaporation rate and formulation factors on solid dispersion physical stability.

    Science.gov (United States)

    Wu, Jian X; Yang, Mingshi; Berg, Frans van den; Pajander, Jari; Rades, Thomas; Rantanen, Jukka

    2011-12-18

    New chemical entities (NCEs) often show poor water solubility necessitating solid dispersion formulation. The aim of the current study is to employ design of experiments in investigating the influence of one critical process factor (solvent evaporation rate) and two formulation factors (PVP:piroxicam ratio (PVP:PRX) and PVP molecular weight (P(MW))) on the physical stability of PRX solid dispersion prepared by the solvent evaporation method. The results showed the rank order of an increase in factors contributing to a decrease in the extent of PRX nucleation being evaporation rate>PVP:PRX>P(MW). The same rank order was found for the decrease in the extent of PRX crystal growth in PVP matrices from day 0 up to day 12. However, after 12days the rank became PVP:PRX>evaporation rate>P(MW). The effects of an increase in evaporation rate and PVP:PRX ratio in stabilizing PRX were of the same order of magnitude, while the effect from P(MW) was much smaller. The findings were confirmed by XRPD. FT-IR showed that PRX recrystallization in the PVP matrix followed Ostwald's step rule, and an increase in the three factors all led to increased hydrogen bonding interaction between PRX and PVP. The present study showed the applicability of the Quality by Design approach in solid dispersion research, and highlights the need for multifactorial analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Load rate dependence of the mechanical properties of thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Zotov, Nikolay; Eggeler, Gunther [Institut fuer Werkstoffe, Ruhr Universitaet Bochum, 44780 Bochum (Germany); Bartsch, Marion [Institut fuer Werkstoff-Forschung, DLR Koeln, 51147 Koeln (Germany)

    2009-07-01

    Thermal barrier coatings (TBC), composed of yttrium-stabilized zirconia (YSZ) ceramic top coat (TC) and intermetallic NiCoCrAlY bond coat (BC) are commonly used as protective coatings of Ni-based high temperature gas engine components. Nanoindentation techniques are increasingly applied for determining the TBC mechanical properties on a nanometre scale. However, little is known about the load-rate dependence of the mechanical properties, which is important for better understanding of cyclic thermal fatigue experiments. Nanoindentations with different load rates omega were performed on polished cross-sections of TBC, deposited by EB-PVD on IN625 substrates (S), using a XP Nanoindenter (MTS) equipped with Berkovich diamond tip. The Young's modulus (E) of the TC is independent of omega, while E for the BC and the S decreases with omega. The hardness (H) of the TC and the BC increases, while H for the S decreases with omega. From the dependence of H on omega, creep power-law exponents c = 0.24(11) and c = 0.023(6) for the TC and the BC were determined. For all TBC components, a decrease with omega of the power-law exponents n and m, describing the loading and unloading nanoindentation curves, is observed.

  11. Direct Numerical Simulations of Microstructure Effects During High-Rate Loading of Additively Manufactured Metals

    Science.gov (United States)

    Battaile, Corbett; Owen, Steven; Moore, Nathan

    2017-06-01

    The properties of most engineering materials depend on the characteristics of internal microstructures and defects. In additively manufactured (AM) metals, these can include polycrystalline grains, impurities, phases, and significant porosity that qualitatively differ from conventional engineering materials. The microscopic details of the interactions between these internal defects, and the propagation of applied loads through the body, act in concert to dictate macro-observable properties like strength and compressibility. In this work, we used Sandia's ALEGRA finite element software to simulate the high-strain-rate loading of AM metals from laser engineered net shaping (LENS) and thermal spraying. The microstructural details of the material were represented explicitly, such that internal features like second phases and pores are captured and meshed as individual entities in the computational domain. We will discuss the dependence of the high-strain-rate mechanical properties on microstructural characteristics such as the shapes, sizes, and volume fractions of second phases and pores. In addition, we will examine how the details of the microstructural representation affect the microscopic material response to dynamic loads, and the effects of using ``stair-step'' versus conformal interfaces smoothed via the SCULPT tool in Sandia's CUBIT software. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US DOE NNSA under contract DE-AC04-94AL85000.

  12. Evolution of the fracture process zone in high-strength concrete under different loading rates

    Directory of Open Access Journals (Sweden)

    Cámara M.

    2010-06-01

    Full Text Available For cementitious materials, the inelastic zone around a crack tip is termed as fracture process zone (FPZ and dominated by complicated mechanism, such as microcracking, crack deflection, bridging, crack face friction, crack tip blunting by voids, crack branching, and so on. Due to the length of the FPZ is related with the characteristic length of the cementitious materials, the size, extent and location of the FPZ has been the object of countless research efforts for several decades. For instance, Cedolin et al. [1] have used an optical method based on the moiré interferometry to determine FPZ in concrete. Castro-Montero et al. [2] have applied the method of holographic interferometry to mortar to study the extension of the FPZ. The advantage of the interferometry method is that the complete FPZ can be directly observed on the surface of the sample. Swartz et al. [3] has adopted the dye penetration technique to illustrate the changing patterns observed as the crack progress from the tensile side to the compression side of the beam. Moreover, acoustic emission (AE is also an experimental technique well suited for monitoring fracture process. Haidar et al. [4] and Maji et al. [5] have studied the relation between acoustic emission characteristics and the properties of the FPZ. Compared with the extensive research on properties of the FPZ under quasi-static loading conditions, much less information is available on its dynamic characterization, especially for high-strength concrete (HSC. This paper presents the very recent results of an experimental program aimed at disclosing the loading rate effect on the size and velocity of the (FPZ in HSC. Eighteen three-point bending specimens were conducted under a wide range of loading rates from from 10-4 mm/s to 103 mm/s using either a servo-hydraulic machine or a self-designed drop-weight impact device. The beam dimensions were 100 mm 100 mm in cross section, and 420 mm in length. The initial notch

  13. Radiometric determination of dilute inhomogeneous solids loading in pneumatic conveying systems

    International Nuclear Information System (INIS)

    Yong Yan; Byrne, Ben; Coulthard, John

    1994-01-01

    The application of γ-ray attenuation methods to non-intrusive measurement of the solids content in pneumatic flow lines is discussed. An instrument employing a broad single-beam interrogation geometry and a single-element detector with uniform sensitivity profile is described. It is designed primarily for metering pulverized coal, where the solids concentration is typically very low, and also often highly inhomogeneous. A detailed analysis of the factors affecting measurement accuracy is presented, together with results obtained from laboratory tests. (author)

  14. Direct Load Control (DLC) Considering Nodal Interrupted Energy Assessment Rate (NIEAR) in Restructured Power Systems

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Wang, Peng; Goel, Lalit

    2010-01-01

    is used as the bids from the ACL customers, is utilized to determine the direct monetary compensation to the ACL customers. The proposed scheme was investigated for the PoolCo electricity market. The optimal DLC scheme is determined based on the minimum system operating cost which is comprised......A direct load control (DLC) scheme of air conditioning loads (ACL) considering direct monetary compensation to ACL customers for the service interruption caused by the DLC program is proposed in this paper for restructured power systems. The nodal interrupted energy assessment rate (NIEAR), which...... of the system energy cost, the system spinning reserve cost and the compensation cost to the ACL customers. Dynamic programming (DP) was used to obtain the optimal DLC scheme. The IEEE reliability test system (RTS) was studied to illustrate the proposed DLC scheme....

  15. Efficient loading of primary alcohols onto a solid phase using a trityl bromide linker

    DEFF Research Database (Denmark)

    Crestey, François; Ottesen, Lars Korsgaard; Jaroszewski, Jerzy Witold

    2008-01-01

    The Letter describes an improved, rapid and mild strategy for the loading of primary alcohols onto a polystyrene trityl resin via a highly reactive trityl bromide linker. This protocol facilitates an efficient resin loading even of acid-sensitive or heat-labile alcohols, which otherwise require...... expensive or non-commercial resin types. Secondary alcohols were only attached in moderate to low yields, while attempts to load a tertiary alcohol expectedly failed. Importantly, selective attachment of diols via a primary alcohol group in the presence of more hindered alcohol groups proved possible....... The effects of activation time and reagent excess as well as alcohol structure were investigated. This improved method provides a convenient access to O-linked resin-bound N-Fmoc-protected amino alcohols that may be employed in SPS of peptides with C-terminal alcohol functionalities. In the case...

  16. Phenomenological rate process theory for the storage of atomic H in solid Hsub(2)sup(*)

    International Nuclear Information System (INIS)

    Rosen, G.

    1976-01-01

    A phenomenological rate process theory is developed for the storage and rapid recombination of atomic hydrogen fuel radical in a crystalline molecular hydrogen solid at temperatures in the range o.1K(<=)T(<=K. It is shown that such a theory can account quantitatively for the recently observed dependence of the storage time on the storage temperature, for the maximum concentration of trapped H atom, and for the time duration of the energy release in the tritium decay experiments of Webeler

  17. Analysis of field usage failure rate data for plastic encapsulated solid state devices

    Science.gov (United States)

    1981-01-01

    Survey and questionnaire techniques were used to gather data from users and manufacturers on the failure rates in the field of plastic encapsulated semiconductors. It was found that such solid state devices are being successfully used by commercial companies which impose certain screening and qualification procedures. The reliability of these semiconductors is now adequate to support their consideration in NASA systems, particularly in low cost systems. The cost of performing necessary screening for NASA applications was assessed.

  18. Characterization of naproxen-loaded solid SMEDDSs prepared by spray drying: the effect of the polysaccharide carrier and naproxen concentration.

    Science.gov (United States)

    Čerpnjak, Katja; Zvonar, Alenka; Vrečer, Franc; Gašperlin, Mirjana

    2015-05-15

    The purpose of this study was to prepare solid SMEDDS (sSMEDDS) particles produced by spray-drying using maltodextrin (MD), hypromellose (HPMC), and a combination of the two as a solid carrier. Naproxen (NPX) as the model drug was dissolved (at 6% concentration) or partially suspended (at 18% concentration) in a liquid SMEDDS composed of Miglyol(®) 812, Peceol™, Gelucire(®) 44/14, and Solutol(®) HS 15. Among the sSMEDDSs tested, the MD-based sSMEDDSs (with a granular, smooth-surfaced, microspherical appearance) preserved the self-microemulsifying properties of liquid SMEDDSs and exhibited dissolution profiles similar to those of liquid SMEDDSs, irrespective of the concentration of NPX. In contrast, HPMC-based sSMEDDSs (irregular-shaped microparticles) exhibited slightly prolonged release times due to the polymeric nature of the carrier. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), and Raman mapping analysis confirmed molecularly dissolved NPX (at 6% of drug loading), whereas at 18% NPX loading drug is partially molecularly dissolved and partially in the crystalline state. Copyright © 2015. Published by Elsevier B.V.

  19. Effect of Chamber Pressurization Rate on Combustion and Propagation of Solid Propellant Cracks

    Science.gov (United States)

    Yuan, Wei-Lan; Wei, Shen; Yuan, Shu-Shen

    2002-01-01

    area of the propellant grain satisfies the designed value. But cracks in propellant grain can be generated during manufacture, storage, handing and so on. The cracks can provide additional surface area for combustion. The additional combustion may significantly deviate the performance of the rocket motor from the designed conditions, even lead to explosive catastrophe. Therefore a thorough study on the combustion, propagation and fracture of solid propellant cracks must be conducted. This paper takes an isolated propellant crack as the object and studies the effect of chamber pressurization rate on the combustion, propagation and fracture of the crack by experiment and theoretical calculation. deformable, the burning inside a solid propellant crack is a coupling of solid mechanics and combustion dynamics. In this paper, a theoretical model describing the combustion, propagation and fracture of the crack was formulated and solved numerically. The interaction of structural deformation and combustion process was included in the theoretical model. The conservation equations for compressible fluid flow, the equation of state for perfect gas, the heat conducting equation for the solid-phase, constitutive equation for propellant, J-integral fracture criterion and so on are used in the model. The convective burning inside the crack and the propagation and fracture of the crack were numerically studied by solving the set of nonlinear, inhomogeneous gas-phase governing equations and solid-phase equations. On the other hand, the combustion experiments for propellant specimens with a precut crack were conducted by RTR system. Predicted results are in good agreement with experimental data, which validates the reasonableness of the theoretical model. Both theoretical and experimental results indicate that the chamber pressurization rate has strong effects on the convective burning in the crack, crack fracture initiation and fracture pattern.

  20. Impact of hydraulic and carbon loading rates of constructed wetlands on contaminants of emerging concern (CECs) removal

    International Nuclear Information System (INIS)

    Sharif, Fariya; Westerhoff, Paul; Herckes, Pierre

    2014-01-01

    Constructed wetlands remove trace organic contaminants via synergistic processes involving plant biomass that include hydrolysis, volatilization, sorption, biodegradation, and photolysis. Wetland design conditions, such as hydraulic loading rates (HLRs) and carbon loading rates (CLRs), influence these processes. Contaminant of emerging concern (CEC) removal by wetland plants was investigated at varying HLRs and CLRs. Rate constants and parameters obtained from batch-scale studies were used in a mechanistic model to evaluate the effect of these two loading rates on CEC removal. CLR significantly influenced CEC removal when wetlands were operated at HLR >5 cm/d. High values of CLR increased removal of estradiol and carbamazepine but lowered that of testosterone and atrazine. Without increasing the cumulative HLR, operating two wetlands in series with varying CLRs could be a way to improve CEC removal. -- Highlights: • A fate-predictive model was developed to evaluate the effect of loading rates on CEC removal in constructed wetlands. • Carbon loading rates (CLRs) can influence CEC removal when wetlands are operated at higher hydraulic loading rates (HLRs). • The effect of CLRs varies among CECs with different physico-chemical properties. • Combination of wetlands with different CLRs can optimize CEC removal without changing the net HLR. -- This article evaluates the effect of design loading rates on contaminant of emerging concern (CEC) removal in constructed wetlands

  1. An urban observatory for quantifying phosphorus and suspended solid loads in combined natural and stormwater conveyances.

    Science.gov (United States)

    Melcher, Anthony A; Horsburgh, Jeffery S

    2017-06-01

    Water quality in urban streams and stormwater systems is highly dynamic, both spatially and temporally, and can change drastically during storm events. Infrequent grab samples commonly collected for estimating pollutant loadings are insufficient to characterize water quality in many urban water systems. In situ water quality measurements are being used as surrogates for continuous pollutant load estimates; however, relatively few studies have tested the validity of surrogate indicators in urban stormwater conveyances. In this paper, we describe an observatory aimed at demonstrating the infrastructure required for surrogate monitoring in urban water systems and for capturing the dynamic behavior of stormwater-driven pollutant loads. We describe the instrumentation of multiple, autonomous water quality and quantity monitoring sites within an urban observatory. We also describe smart and adaptive sampling procedures implemented to improve data collection for developing surrogate relationships and for capturing the temporal and spatial variability of pollutant loading events in urban watersheds. Results show that the observatory is able to capture short-duration storm events within multiple catchments and, through inter-site communication, sampling efforts can be synchronized across multiple monitoring sites.

  2. Nuclear heat-load limits for above-grade storage of solid transuranium wastes

    International Nuclear Information System (INIS)

    Clontz, B.G.

    1978-06-01

    Nuclear safety and heat load limits were established for above-grade storage of transuranium (TRU) wastes. Nuclear safety limits were obtained from a study by J.L. Forstner and are summarized. Heat load limits are based on temperature calculations for TRU waste drums stored in concrete containers (hats), and results are summarized. Waste already in storage is within these limits. The limiting factors for individual drum heat load limits were (1) avoidance of temperatures in excess of 190 0 F (decomposition temperature of anion resin) when anion resin is present in a concrete hat, and (2) avoidance of temperatures in excess of 450 0 F (ignition temperature of paper) at any point inside a waste drum. The limiting factor for concrete had heat load limits was avoidance of temperatures in excess of 265 0 F (melt point of high density polyethylene) at the drum liners. A temperature profile for drums and hats filled to recommended limits is shown. Equations and assumptions used were conservative

  3. High Strain Rate Deformation Mechanisms of Body Centered Cubic Material Subjected to Impact Loading

    Science.gov (United States)

    Visser, William

    Low carbon steel is the most common grade of structural steel used; it has carbon content of 0.05% to 0.25% and very low content of alloying elements. It is produced in great quantities and provides material properties that are acceptable for many engineering applications, particularly in the construction industry in which low carbon steel is widely used as the strengthening phase in civil structures. The overall goal of this dissertation was to investigate the deformation response of A572 grade 50 steel when subjected to impact loading. This steel has a 0.23% by weight carbon content and has less than 2% additional alloying elements. The deformation mechanisms of this steel under shock loading conditions include both dislocation motion and twin formation. The goal of this work was achieved by performing experimental, analytical and numerical research in three integrated tasks. The first is to determine the relationship between the evolution of deformation twins and the impact pressure. Secondly, a stress criterion for twin nucleation during high strain rate loading was developed which can account for the strain history or initial dislocation density. Lastly, a method was applied for separating the effects of dislocations and twins generated by shock loading in order to determine their role in controlling the flow stress of the material. In this regard, the contents of this work have been categorically organized. First, the active mechanisms in body centered cubic (BCC) low carbon steel during shock loading have been determined as being a composed of the competing mechanisms of dislocations and deformation twins. This has been determined through a series of shock loading tests of the as-received steel. The shock loading tests were done by plate impact experiments at several impact pressures ranging from 2GPa up to 13GPa using a single stage light gas gun. A relationship between twin volume fraction and impact pressure was determined and an analytical model was

  4. The failure of brittle materials under overall compression: Effects of loading rate and defect distribution

    Science.gov (United States)

    Paliwal, Bhasker

    The constitutive behaviors and failure processes of brittle materials under far-field compressive loading are studied in this work. Several approaches are used: experiments to study the compressive failure behavior of ceramics, design of experimental techniques by means of finite element simulations, and the development of micro-mechanical damage models to analyze and predict mechanical response of brittle materials under far-field compression. Experiments have been conducted on various ceramics, (primarily on a transparent polycrystalline ceramic, aluminum oxynitride or AlON) under loading rates ranging from quasi-static (˜ 5X10-6) to dynamic (˜ 200 MPa/mus), using a servo-controlled hydraulic test machine and a modified compression Kolsky bar (MKB) technique respectively. High-speed photography has also been used with exposure times as low as 20 ns to observe the dynamic activation, growth and coalescence of cracks and resulting damage zones in the specimen. The photographs were correlated in time with measurements of the stresses in the specimen. Further, by means of 3D finite element simulations, an experimental technique has been developed to impose a controlled, homogeneous, planar confinement in the specimen. The technique can be used in conjunction with a high-speed camera to study the in situ dynamic failure behavior of materials under confinement. AlON specimens are used for the study. The statically pre-compressed specimen is subjected to axial dynamic compressive loading using the MKB. Results suggest that confinement not only increases the load carrying capacity, it also results in a non-linear stress evolution in the material. High-speed photographs also suggest an inelastic deformation mechanism in AlON under confinement which evolves more slowly than the typical brittle-cracking type of damage in the unconfined case. Next, an interacting micro-crack damage model is developed that explicitly accounts for the interaction among the micro-cracks in

  5. Risk of solid cancer in low dose-rate radiation epidemiological studies and the dose-rate effectiveness factor.

    Science.gov (United States)

    Shore, Roy; Walsh, Linda; Azizova, Tamara; Rühm, Werner

    2017-10-01

    Estimated radiation risks used for radiation protection purposes have been based primarily on the Life Span Study (LSS) of atomic bomb survivors who received brief exposures at high dose rates, many with high doses. Information is needed regarding radiation risks from low dose-rate (LDR) exposures to low linear-energy-transfer (low-LET) radiation. We conducted a meta-analysis of LDR epidemiologic studies that provide dose-response estimates of total solid cancer risk in adulthood in comparison to corresponding LSS risks, in order to estimate a dose rate effectiveness factor (DREF). We identified 22 LDR studies with dose-response risk estimates for solid cancer after minimizing information overlap. For each study, a parallel risk estimate was derived from the LSS risk model using matching values for sex, mean ages at first exposure and attained age, targeted cancer types, and accounting for type of dosimetric assessment. For each LDR study, a ratio of the excess relative risk per Gy (ERR Gy -1 ) to the matching LSS ERR risk estimate (LDR/LSS) was calculated, and a meta-analysis of the risk ratios was conducted. The reciprocal of the resultant risk ratio provided an estimate of the DREF. The meta-analysis showed a LDR/LSS risk ratio of 0.36 (95% confidence interval [CI] 0.14, 0.57) for the 19 studies of solid cancer mortality and 0.33 (95% CI 0.13, 0.54) when three cohorts with only incidence data also were added, implying a DREF with values around 3, but statistically compatible with 2. However, the analyses were highly dominated by the Mayak worker study. When the Mayak study was excluded the LDR/LSS risk ratios increased: 1.12 (95% CI 0.40, 1.84) for mortality and 0.54 (95% CI 0.09, 0.99) for mortality + incidence, implying a lower DREF in the range of 1-2. Meta-analyses that included only cohorts in which the mean dose was LDR data provide direct evidence regarding risk from exposures at low dose rates as an important complement to the LSS risk estimates used

  6. Tensile characterisation of the aorta across quasi-static to blast loading strain rates

    Science.gov (United States)

    Magnus, Danyal; Proud, William; Haller, Antoine; Jouffroy, Apolline

    2017-06-01

    The dynamic tensile failure mechanisms of the aorta during Traumatic Aortic Injury (TAI) are poorly understood. In automotive incidents, where the aorta may be under strains of the order of 100/s, TAI is the second largest cause of mortality. In these studies, the proximal descending aorta is the most common site where rupture is observed. In particular, the transverse direction is most commonly affected due to the circumferential orientation of elastin, and hence the literature generally concentrates upon axial samples. This project extends these dynamic studies to the blast loading regime where strain-rates are of the order of 1000/s. A campaign of uniaxial tensile experiments are conducted at quasi-static, intermediate (drop-weight) and high (tensile Split-Hopkinson Pressure Bar) strain rates. In each case, murine and porcine aorta models are considered and the extent of damage assessed post-loading using histology. Experimental data will be compared against current viscoelastic models of the aorta under axial stress. Their applicability across strain rates will be discussed. Using a multi-disciplinary approach, the conditions applied to the samples replicate in vivo conditions, employing a blood simulant-filled tubular specimen surrounded by a physiological solution.

  7. Rate-independent dissipation and loading direction effects in compressed carbon nanotube arrays

    International Nuclear Information System (INIS)

    Raney, J R; Fraternali, F; Daraio, C

    2013-01-01

    Arrays of nominally-aligned carbon nanotubes (CNTs) under compression deform locally via buckling, exhibit a foam-like, dissipative response, and can often recover most of their original height. We synthesize millimeter-scale CNT arrays and report the results of compression experiments at different strain rates, from 10 −4 to 10 −1 s −1 , and for multiple compressive cycles to different strains. We observe that the stress–strain response proceeds independently of the strain rate for all tests, but that it is highly dependent on loading history. Additionally, we examine the effect of loading direction on the mechanical response of the system. The mechanical behavior is modeled using a multiscale series of bistable springs. This model captures the rate independence of the constitutive response, the local deformation, and the history-dependent effects. We develop here a macroscopic formulation of the model to represent a continuum limit of the mesoscale elements developed previously. Utilizing the model and our experimental observations we discuss various possible physical mechanisms contributing to the system’s dissipative response. (paper)

  8. Simultaneous optimization of the cavity heat load and trip rates in linacs using a genetic algorithm

    Directory of Open Access Journals (Sweden)

    Balša Terzić

    2014-10-01

    Full Text Available In this paper, a genetic algorithm-based optimization is used to simultaneously minimize two competing objectives guiding the operation of the Jefferson Lab’s Continuous Electron Beam Accelerator Facility linacs: cavity heat load and radio frequency cavity trip rates. The results represent a significant improvement to the standard linac energy management tool and thereby could lead to a more efficient Continuous Electron Beam Accelerator Facility configuration. This study also serves as a proof of principle of how a genetic algorithm can be used for optimizing other linac-based machines.

  9. Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.

    Science.gov (United States)

    Lewis, Ryan C; Gaffney, Shannon H; Le, Matthew H; Unice, Ken M; Paustenbach, Dennis J

    2012-09-01

    Workers handle catalysts extensively at petroleum refineries throughout the world each year; however, little information is available regarding the airborne concentrations and plausible exposures during this type of work. In this paper, we evaluated the airborne concentrations of 15 metals and total dust generated during solid catalyst loading and unloading operations at one of the largest petroleum refineries in the world using historical industrial hygiene samples collected between 1989 and 2006. The total dust and metals, which included aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, platinum, silicon, silver, vanadium, and zinc, were evaluated in relation to the handling of four different types of solid catalysts associated with three major types of catalytic processes. Consideration was given to the known components of the solid catalysts and any metals that were likely deposited onto them during use. A total of 180 analytical results were included in this analysis, representing 13 personal and 54 area samples. Of the long-term personal samples, airborne concentrations of metals ranged from refinery and perhaps other modern refineries during the timeframe examined. Copyright © 2011 Elsevier GmbH. All rights reserved.

  10. A multilayered thick cylindrical shell under internal pressure and thermal loads applicable to solid propellant rocket motors

    Energy Technology Data Exchange (ETDEWEB)

    Renganathan, K.; Nageswara Rao, B.; Jana, M.K. [Vikram Sarabhai Space Centre, Trivandrum (India). Structural Engineering Group

    2000-09-01

    A solid propellant rocket motor can be considered to be made of various circumferential layers of different properties. A simple procedure is described here to obtain an analytical solution for the general case of multilayered thick cyclindrical shell for internal pressure and thermal loads. This analytical procedure is useful in the preliminary design analysis of solid propellant rocket motors. Since solid propellant material is of viscoelastic behaviour an approximate viscoelastic solution methodology for the multilayered shell is described for estimation of time dependent solutions of propellant grain in a rocket motor. The analytical solution for a two layer reinforced thick cylindrical shell available in the literature is shown to be a special case of the present analytical solution. The results from the present analytical solution for multilayers is found to be in good agreement with FEA results. (orig.) [German] Der grundlegende Aufbau von Feststoffraketenmotoren kann auf einen Zylinder aus mehreren Schichten mit unterschiedlichen Eigenschaften zurueckgefuehrt werden. Eine einfache Berechnungsprozedur fuer die analytische Loesung des allgemeinen Falles eines mehrschichtigen Zylinders unter innerem Druck und thermischer Belastung wird hier vorgestellt. Diese analytische Methodik ist fuer den Auslegungsprozess von Feststoffraketenmotoren von grundlegender Bedeutung. Das viskoelastische Fliessverhalten des festen Brennstoffes, das den zeitlichen Ablauf des Verbrennungsprozesses wesentlich bestimmt, wird durch ein Naeherungsverfahren gut erfasst. Ein in der Literatur enthaltenes spezielles Ergebnis fuer einen zweischaligen verstaerkten Zylinder ergibt sich als Sonderfall der hier vorgestellten Methodik. Die analytisch erhaltenen Loesungen fuer mehrschichtige Aufbauten sind in guter Uebereinstimmung mit mittels der FEM ermittelten Ergebnisse. (orig.)

  11. In vivo evaluation of the efficacy of albendazole sulfoxide and albendazole sulfoxide loaded solid lipid nanoparticles against hydatid cyst.

    Science.gov (United States)

    Ahmadnia, Sara; Moazeni, Mohammad; Mohammadi-Samani, Soliman; Oryan, Ahmad

    2013-10-01

    Cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus, which in this disease the metacestode develop in visceral organs especially liver and lungs. The disease is present worldwide and affects humans as well as herbivores including cattle, sheep, camels, horses and others. Benzimidazole carbamate derivatives, such as mebendazole and albendazole, are currently used for chemotherapeutic treatment of CE in inoperable patients and have to be applied in high doses for extended periods of time, and therefore adverse side effects are frequently observed. This study was designed to evaluate and compare the in vivo effects of 0.5 mg/kg, BID, albendazole sulfoxide (ricobendazole) and two different therapeutic regimens of 0.5 mg/kg BID and 2 mg/kg every 48 h of albendazole sulfoxide loaded solid lipid nanoparticles. Albendazole sulfoxide loaded solid lipid nanoparticles was prepared by solvent diffusion-evaporation method. Fifty Balb/c mice were infected by intraperitoneal injection of protoscoleces and 8 months post infection, the infected mice were treated for 15 days with the above mentioned regimens. They were then euthanized and the size and weight of the cysts as well as their ultrastructural changes were investigated. Although the cysts showed reduced size and weight in the treated animals but these reductions were not statistically significant. The cysts in the animals which received albendazole sulfoxide loaded SLN every 48 h showed more ultrastructural modification. However, these ultrastructural changes should be supported by further biochemical and molecular studies before introducing it as an efficient therapeutic regimen for treatment of human and animal hydatid disease. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Solid state pump lasers with high power and high repetition rate

    International Nuclear Information System (INIS)

    Oba, Masaki; Kato, Masaaki; Arisawa, Takashi

    1995-01-01

    We built a laser diode pumped solid state green laser (LDPSSGL) rated at high repetition rate. Two laser heads are placed in one cavity with a rotator in between to design to avoid thermal lensing and thermal birefringence effect. Although average green laser power higher than 10 W was obtained at 1 kHz repetition rate with pulse width of 20-30 nsec, the beam quality was so much deteriorated that energy efficiency was as low as 2 %. Learning from this experience that high power oscillator causes a lot of thermal distortion not only in the laser rod but also in the Q-switch device, we proceeded to built a oscillator/amplifier system. A low power oscillator has a slab type crystal in the cavity. As a result spatial distribution of laser power was extremely improved. As we expect that the high repetition rate solid state laser should be CW operated Q-switch type laser from the view point of lifetime of diode lasers, a conventional arc lamp pumped CW Q-switch green YAG laser of which the repetition rate is changeable from 1 kHz to 5 kHz and the pulse width is 250-570 nsec was also tested to obtain pumping characteristics of a dye laser as a function of power, pulse width etc., and dye laser pulse width of 100-130 nsec were obtained. (author)

  13. Solid lipid nanoparticles loaded with iron to overcome barriers for treatment of iron deficiency anemia

    Directory of Open Access Journals (Sweden)

    Hosny KM

    2015-01-01

    Full Text Available Khaled Mohamed Hosny,1,2 Zainy Mohammed Banjar,3 Amani H Hariri,4 Ali Habiballah Hassan5 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni Suef University, Beni Suef, Egypt; 3Department of Clinical Biochemistry, Faculty of medicine, King Abdulaziz University, Jeddah, Saudi Arabia; 4Consultant Obstetrics and Gynecology, Hera Genaral Hospital, Makkah, Saudi Arabia; 5Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: According to the World Health Organization, 46% of the world’s children suffer from anemia, which is usually treated with iron supplements such as ferrous sulfate. The aim of this study was to prepare iron as solid lipid nanoparticles, in order to find an innovative way for alleviating the disadvantages associated with commercially available tablets. These limitations include adverse effects on the digestive system resulting in constipation and blood in the stool. The second drawback is the high variability in the absorption of iron and thus in its bioavailability. Iron solid lipid nanoparticles (Fe-SLNs were prepared by hot homogenization/ultrasonication. Solubility of ferrous sulfate in different solid lipids was measured, and effects of process variables such as the surfactant type and concentration, homogenization and ultrasonication times, and charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release and in vivo pharmacokinetics were studied in rabbits. Results indicated that Fe-SLNs consisted of 3% Compritol 888 ATO, 1% Lecithin, 3% Poloxamer 188, and 0.2% dicetylphosphate, with an average particle size of 25 nm with 92.3% entrapment efficiency. In vivo pharmacokinetic study revealed more than fourfold enhanced bioavailability. In

  14. Novel formulation and evaluation of a Q10-loaded solid lipid nanoparticle cream: in vitro and in vivo studies

    Directory of Open Access Journals (Sweden)

    Farboud ES

    2011-03-01

    Full Text Available Effat Sadat Farboud, Saman Ahmad Nasrollahi, Zahra TabbakhiDepartment of Pharmaceutics, School of Pharmacy, Tehran University of Medical Sciences, Tehran, IranAbstract: Solid lipid nanoparticles (SLNs of coenzyme Q10 (CoQ10 were formulated by a high-pressure homogenization method. The best formulation of SLN dispersion consisted of 13% lipid (cetyl palmitate or stearic acid, 8% surfactant (Tween 80 or Tego Care 450, and water. Stability tests, particle size analysis, differential scanning calorimetry, transmission electron microscopy, and release study were conducted to find the best formulation. A simple cream of CoQ10 and a cream containing CoQ10-loaded SLNs were prepared and compared on volunteers aged 20–30 years. SLNs with particle size between 50 nm and100 nm exhibited the most suitable stability. In vitro release profiles of CoQ10 from simple cream, SLN alone, and CoQ10-loaded SLN cream showed prolonged release for SLNs compared with the simple cream, whereas there was no significant difference between SLN alone and SLN in cream. In vitro release studies also demonstrated that CoQ10-loaded SLN and SLN cream possessed a biphasic release pattern in comparison with simple cream. In vivo skin hydration and elasticity studies on 25 volunteers suggested good dermal penetration and useful activity of Q10 on skin as a hydratant and antiwrinkle cream.Keywords: coenzyme Q10, SLN, release study 

  15. The hydrolytic stage in high solids temperature phased anaerobic digestion improves the downstream methane production rate.

    Science.gov (United States)

    Buffière, P; Dooms, M; Hattou, S; Benbelkacem, H

    2018-07-01

    The role of the hydrolytic stage in high solids temperature phased anaerobic digestion was investigated with a mixture of cattle slurry and maize silage with variable ratios (100, 70 and 30% volatile solids coming from cattle slurry). It was incubated for 48 h at 37, 55, 65 and 72 °C. Soluble chemical oxygen demand and biochemical methane potential were measured at 0, 24 and 48 h. Higher temperatures improved the amount of solubilized COD, which confirmed previously reported results. Nevertheless, solubilization mostly took place during the first 24 h. The rate of methane production in post-hydrolysis BMPs increased after 48 h hydrolysis time, but not after 24 h. The first order kinetic constant rose by 40% on average. No correlation was observed between soluble COD and downstream methane production rate, indicating a possible modification of the physical structure of the particulate solids during the hydrolytic stage. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Digital image processing based mass flow rate measurement of gas/solid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Song Ding; Peng Lihui; Lu Geng; Yang Shiyuan [Tsinghua National Laboratory for Information Science and Technology, Department of Automation, Tsinghua University, Beijing, 100084 (China); Yan Yong, E-mail: lihuipeng@tsinghua.edu.c [University of Kent, Canterbury, Kent CT2 7NT (United Kingdom)

    2009-02-01

    With the rapid growth of the process industry, pneumatic conveying as a tool for the transportation of a wide variety of pulverized and granular materials has become widespread. In order to improve plant control and operational efficiency, it is essential to know the parameters of the particle flow. This paper presents a digital imaging based method which is capable of measuring multiple flow parameters, including volumetric concentration, velocity and mass flow rate of particles in the gas/solid two phase flow. The measurement system consists of a solid state laser for illumination, a low-cost CCD camera for particle image acquisition and a microcomputer with bespoke software for particle image processing. The measurements of particle velocity and volumetric concentration share the same sensing hardware but use different exposure time and different image processing methods. By controlling the exposure time of the camera a clear image and a motion blurred image are obtained respectively. The clear image is thresholded by OTSU method to identify the particles from the dark background so that the volumetric concentration is determined by calculating the ratio between the particle area and the total area. Particle velocity is derived from the motion blur length, which is estimated from the motion blurred images by using the travelling wave equation method. The mass flow rate of particles is calculated by combining the particle velocity and volumetric concentration. Simulation and experiment results indicate that the proposed method is promising for the measurement of multiple parameters of gas/solid two-phase flow.

  17. Digital image processing based mass flow rate measurement of gas/solid two-phase flow

    International Nuclear Information System (INIS)

    Song Ding; Peng Lihui; Lu Geng; Yang Shiyuan; Yan Yong

    2009-01-01

    With the rapid growth of the process industry, pneumatic conveying as a tool for the transportation of a wide variety of pulverized and granular materials has become widespread. In order to improve plant control and operational efficiency, it is essential to know the parameters of the particle flow. This paper presents a digital imaging based method which is capable of measuring multiple flow parameters, including volumetric concentration, velocity and mass flow rate of particles in the gas/solid two phase flow. The measurement system consists of a solid state laser for illumination, a low-cost CCD camera for particle image acquisition and a microcomputer with bespoke software for particle image processing. The measurements of particle velocity and volumetric concentration share the same sensing hardware but use different exposure time and different image processing methods. By controlling the exposure time of the camera a clear image and a motion blurred image are obtained respectively. The clear image is thresholded by OTSU method to identify the particles from the dark background so that the volumetric concentration is determined by calculating the ratio between the particle area and the total area. Particle velocity is derived from the motion blur length, which is estimated from the motion blurred images by using the travelling wave equation method. The mass flow rate of particles is calculated by combining the particle velocity and volumetric concentration. Simulation and experiment results indicate that the proposed method is promising for the measurement of multiple parameters of gas/solid two-phase flow.

  18. Ammonia threshold for inhibition of anaerobic digestion of thin stillage and the importance of organic loading rate.

    Science.gov (United States)

    Moestedt, Jan; Müller, Bettina; Westerholm, Maria; Schnürer, Anna

    2016-03-01

    Biogas production from nitrogen-rich feedstock results in release of ammonia (NH3), causing inhibition of the microbial process. The reported threshold ammonia value for stable biogas production varies greatly between studies, probably because of differences in operating conditions. Moreover, it is often difficult to separate the effect of ammonia inhibition from that of organic loading rate (OLR), as these two factors are often interrelated. This study attempted to distinguish the effects of ammonia and OLR by analysis of two laboratory-scale biogas reactors operating with thin stillage and subjected to an increase in free ammonia (from 0.30 to 1.1 g L(-1)) either by addition of an external nitrogen source (urea) or by increasing the OLR (3.2-6.0 g volatile solids L(-1) d(-1)). The results showed that ammonia concentration was detrimental for process performance, with the threshold for stability in both processes identified as being about 1 g NH3-N L(-1), irrespective of OLR. Analysis of the methanogenic community showed limited differences between the two reactors on order level and a clear increase in the abundance of Methanomicrobiales, particularly Methanoculleus sp., in response to increasing ammonia concentration. Further comprehensive molecular analysis revealed that diverse Methanoculleus species dominated in the reactors at a given ammonia level at different OLR. The acetogenic community was clearly affected by both ammonia concentration and OLR, suggesting that the volatile fatty acid load in relation to the higher OLR was important for the dynamics of this community. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  19. Effect of orientation and loading rate on compression behavior of small-scale Mo pillars

    International Nuclear Information System (INIS)

    Schneider, A.S.; Clark, B.G.; Frick, C.P.; Gruber, P.A.; Arzt, E.

    2009-01-01

    Recently, much work has focused on the size effect in face centered cubic (fcc) structures, however few pillar studies have focused on body centered cubic (bcc) metals. This paper explores the role of bcc crystal structure on the size effect, through compression testing of [001] and [235] Molybdenum (Mo) small-scale pillars manufactured by focused ion beam (FIB). The pillar diameters ranged from 200 nm to 5 μm. Results show that the relationship between yield stress and diameter exhibits an inverse relationship (σ y ∝ d -0.22 for [001] Mo and σ y ∝ d -0.34 for [235] Mo) weaker than that observed for face centered cubic (fcc) metals (σ y ∝ d -0.6to-1.0 ). Additional tests at various loading rates revealed that small-scale Mo pillars exhibit a strain rate sensitivity similar to bulk Mo.

  20. Fracture toughness evaluation of small notched specimen in consideration of notch effect and loading rate

    International Nuclear Information System (INIS)

    Lee, Baik Woo; Kwon, Dong Il; Jang, Jae Il

    2000-01-01

    Notch effect and loading rate dependency on fracture toughness were considered when evaluating fracture toughness of small notched specimens using the instrumented impact test. Notch effect was analyzed into stress redistribution effect and stress relaxation with a viewpoint of stress triaxiality. Stress redistribution effect was corrected by introducing effective crack length, which was the sum of actual crack length and plastic zone size. Stress relaxation effect was also corrected using elastic stress concentration factor, which would decrease if plastic deformation occurred. As a result, corrected fracture toughness of the notched specimen was very consistent with the reference fracture toughness obtained using precracked specimen. In addition, limiting notch root radius, below which fracture toughness was independent of notch radius, was observed and discussed. Loading rate dependency on fracture toughness, which was obtained from the static three point bending test and the instrumented impact test, was also discussed with stress field in plastic zone ahead of a notch and fracture based on stress control mechanism. (author)

  1. Fatigue crack growth rate of API X70 steel pipelines under spectrum loading

    International Nuclear Information System (INIS)

    Beden, S.M.; Abdullah, S.; Ariffin, A.K.

    2012-01-01

    Pipelines offer the most efficient way to transport bulk quantities of gas and oil, either from points of production to storage locations or from storage locations to distributed points of end use. As one of the main materials of west–east gas transmission pipes, X70 pipelines usually serve under variable amplitude loading (VAL). Base on the importance of in-service API X70 pipelines, it is important for the safe operation of this system to know its behaviour under VAL. This paper focuses on the ability of using the NASGRO model to predict the fatigue crack growth (FCG), based on investigation with the modified Wheeler model and experimental data. The results show that the NASGRO model give a fatigue life near by to that published in literatures and also showed the FCG rate response of X70 pipeline steels when exposed to VAL with different overload values. Extra modification to the NASGRO model may lead to better representing of FCG rate. Highlights: ► The assessment of fatigue crack propagation under different load histories are proposed and presented in this paper. ► Due to lack of knowledge in the related area, as yet no universal model exists. ► The output was based on both simulation and experiments. The simulation part was carried out based on the NASGRO model. ► This work focus on fatigue crack growth (FCG) and fatigue life based on the comparison with the previous work.

  2. Time-Dependent Behaviors of Granite: Loading-Rate Dependence, Creep, and Relaxation

    Science.gov (United States)

    Hashiba, K.; Fukui, K.

    2016-07-01

    To assess the long-term stability of underground structures, it is important to understand the time-dependent behaviors of rocks, such as their loading-rate dependence, creep, and relaxation. However, there have been fewer studies on crystalline rocks than on tuff, mudstone, and rock salt, because the high strength of crystalline rocks makes the detection of their time-dependent behaviors much more difficult. Moreover, studies on the relaxation, temporal change of stress and strain (TCSS) conditions, and relations between various time-dependent behaviors are scarce for not only granites, but also other rocks. In this study, previous reports on the time-dependent behaviors of granites were reviewed and various laboratory tests were conducted using Toki granite. These tests included an alternating-loading-rate test, creep test, relaxation test, and TCSS test. The results showed that the degree of time dependence of Toki granite is similar to other granites, and that the TCSS resembles the stress-relaxation curve and creep-strain curve. A viscoelastic constitutive model, proposed in a previous study, was modified to investigate the relations between the time-dependent behaviors in the pre- and post-peak regions. The modified model reproduced the stress-strain curve, creep, relaxation, and the results of the TCSS test. Based on a comparison of the results of the laboratory tests and numerical simulations, close relations between the time-dependent behaviors were revealed quantitatively.

  3. Quantification of protein backbone hydrogen-deuterium exchange rates by solid state NMR spectroscopy

    International Nuclear Information System (INIS)

    Lopez del Amo, Juan-Miguel; Fink, Uwe; Reif, Bernd

    2010-01-01

    We present the quantification of backbone amide hydrogen-deuterium exchange rates (HDX) for immobilized proteins. The experiments make use of the deuterium isotope effect on the amide nitrogen chemical shift, as well as on proton dilution by deuteration. We find that backbone amides in the microcrystalline α-spectrin SH3 domain exchange rather slowly with the solvent (with exchange rates negligible within the individual 15 N-T 1 timescales). We observed chemical exchange for 6 residues with HDX exchange rates in the range from 0.2 to 5 s -1 . Backbone amide 15 N longitudinal relaxation times that we determined previously are not significantly affected for most residues, yielding no systematic artifacts upon quantification of backbone dynamics (Chevelkov et al. 2008b). Significant exchange was observed for the backbone amides of R21, S36 and K60, as well as for the sidechain amides of N38, N35 and for W41ε. These residues could not be fit in our previous motional analysis, demonstrating that amide proton chemical exchange needs to be considered in the analysis of protein dynamics in the solid-state, in case D 2 O is employed as a solvent for sample preparation. Due to the intrinsically long 15 N relaxation times in the solid-state, the approach proposed here can expand the range of accessible HDX rates in the intermediate regime that is not accessible so far with exchange quench and MEXICO type experiments.

  4. Preparation and characterization of solid lipid nanoparticles loaded with frankincense and myrrh oil

    Directory of Open Access Journals (Sweden)

    Shi F

    2012-04-01

    Full Text Available Feng Shi, Ji-Hui Zhao, Ying Liu, Zhi Wang, Yong-Tai Zhang, Nian-Ping FengSchool of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of ChinaAbstract: The aim of the present study was to prepare solid lipid nanoparticles (SLNs for the oral delivery of frankincense and myrrh essential oils (FMO. Aqueous dispersions of SLNs were successfully prepared by a high-pressure homogenization method using Compritol 888 ATO as the solid lipid and soybean lecithin and Tween 80 as the surfactants. The properties of the SLNs such as particle size, zeta potential (ZP, and drug encapsulation efficiency (EE were investigated. The morphology of SLNs was observed by transmission electron microscopy (TEM. The crystallinity of the formulation was analyzed by differential scanning calorimetry (DSC and X-ray diffraction (XRD. In addition, drug evaporation release and antitumor activity were also studied. Round SLNs with a mean size of 113.3 ± 3.6 nm, a ZP of -16.8 ± 0.4 mV, and an EE of 80.60% ± 1.11% were obtained. DSC and XRD measurements revealed that less ordered structures were formed in the inner cores of the SLN particles. Evaporation loss of the active components in FMO could be reduced in the SLNs. Furthermore, the SLN formulation increased the antitumor efficacy of FMO in H22-bearing Kunming mice. Hence, the presented SLNs can be used as drug carriers for hydrophobic oil drugs extracted from traditional Chinese medicines.Keywords: solid lipid nanoparticles, frankincense oil, myrrh oil, evaporation release, antitumor activity, traditional Chinese medicine

  5. Measuring Cognitive Load during Simulation-Based Psychomotor Skills Training: Sensitivity of Secondary-Task Performance and Subjective Ratings

    Science.gov (United States)

    Haji, Faizal A.; Khan, Rabia; Regehr, Glenn; Drake, James; de Ribaupierre, Sandrine; Dubrowski, Adam

    2015-01-01

    As interest in applying cognitive load theory (CLT) to the study and design of pedagogic and technological approaches in healthcare simulation grows, suitable measures of cognitive load (CL) are needed. Here, we report a two-phased study investigating the sensitivity of subjective ratings of mental effort (SRME) and secondary-task performance…

  6. Volatile fatty acids production from food waste: effects of pH, temperature, and organic loading rate.

    Science.gov (United States)

    Jiang, Jianguo; Zhang, Yujing; Li, Kaimin; Wang, Quan; Gong, Changxiu; Li, Menglu

    2013-09-01

    The effects of pH, temperature, and organic loading rate (OLR) on the acidogenesis of food waste have been determined. The present study investigated their effects on soluble chemical oxygen demand (SCOD), volatile fatty acids (VFAs), volatile solids (VS), and ammonia nitrogen (NH4(+)-N). Both the concentration and yield of VFAs were highest at pH 6.0, acetate and butyrate accounted for 77% of total VFAs. VFAs concentration and the VFA/SCOD ratio were highest, and VS levels were lowest, at 45 °C, but the differences compared to the values at 35 °C were slight. The concentrations of VFAs, SCOD, and NH4(+)-N increased as OLR increased, whereas the yield of VFAs decreased from 0.504 at 5 g/Ld to 0.306 at 16 g/Ld. Acetate and butyrate accounted for 60% of total VFAs. The percentage of acetate and valerate increased as OLR increased, whereas a high OLR produced a lower percentage of propionate and butyrate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Sustainable organic loading rate and energy recovery potential of mesophilic anaerobic membrane bioreactor for municipal wastewater treatment

    KAUST Repository

    Wei, Chunhai

    2014-08-01

    The overall performance of a mesophilic anaerobic membrane bioreactor (AnMBR) for synthetic municipal wastewater treatment was investigated under a range of organic loading rate (OLR). A very steady and high chemical oxygen demand (COD) removal (around 98%) was achieved over a broad range of volumetric OLR of 0.8-10gCOD/L/d. The sustainable volumetric and sludge OLR satisfying a permeate COD below 50mg/L for general reuse was 6gCOD/L/d and 0.63gCOD/gMLVSS (mixed liquor volatile suspended solids)/d, respectively. At a high sludge OLR of over 0.6gCOD/gMLVSS/d, the AnMBR achieved high methane production of over 300ml/gCOD (even approaching the theoretical value of 382ml/gCOD). A low biomass production of 0.015-0.026gMLVSS/gCOD and a sustainable flux of 6L/m2/h were observed. The integration of a heat pump and forward osmosis into the mesophilic AnMBR process would be a promising way for net energy recovery from typical municipal wastewater in a temperate area. © 2014 Elsevier Ltd.

  8. Sustainable organic loading rate and energy recovery potential of mesophilic anaerobic membrane bioreactor for municipal wastewater treatment

    KAUST Repository

    Wei, Chunhai; Harb, Moustapha; Amy, Gary L.; Hong, Pei-Ying; Leiknes, TorOve

    2014-01-01

    The overall performance of a mesophilic anaerobic membrane bioreactor (AnMBR) for synthetic municipal wastewater treatment was investigated under a range of organic loading rate (OLR). A very steady and high chemical oxygen demand (COD) removal (around 98%) was achieved over a broad range of volumetric OLR of 0.8-10gCOD/L/d. The sustainable volumetric and sludge OLR satisfying a permeate COD below 50mg/L for general reuse was 6gCOD/L/d and 0.63gCOD/gMLVSS (mixed liquor volatile suspended solids)/d, respectively. At a high sludge OLR of over 0.6gCOD/gMLVSS/d, the AnMBR achieved high methane production of over 300ml/gCOD (even approaching the theoretical value of 382ml/gCOD). A low biomass production of 0.015-0.026gMLVSS/gCOD and a sustainable flux of 6L/m2/h were observed. The integration of a heat pump and forward osmosis into the mesophilic AnMBR process would be a promising way for net energy recovery from typical municipal wastewater in a temperate area. © 2014 Elsevier Ltd.

  9. Improved drug loading and antibacterial activity of minocycline-loaded PLGA nanoparticles prepared by solid/oil/water ion pairing method

    Science.gov (United States)

    Kashi, Tahereh Sadat Jafarzadeh; Eskandarion, Solmaz; Esfandyari-Manesh, Mehdi; Marashi, Seyyed Mahmoud Amin; Samadi, Nasrin; Fatemi, Seyyed Mostafa; Atyabi, Fatemeh; Eshraghi, Saeed; Dinarvand, Rassoul

    2012-01-01

    Background Low drug entrapment efficiency of hydrophilic drugs into poly(lactic-co-glycolic acid) (PLGA) nanoparticles is a major drawback. The objective of this work was to investigate different methods of producing PLGA nanoparticles containing minocycline, a drug suitable for periodontal infections. Methods Different methods, such as single and double solvent evaporation emulsion, ion pairing, and nanoprecipitation were used to prepare both PLGA and PEGylated PLGA nanoparticles. The resulting nanoparticles were analyzed for their morphology, particle size and size distribution, drug loading and entrapment efficiency, thermal properties, and antibacterial activity. Results The nanoparticles prepared in this study were spherical, with an average particle size of 85–424 nm. The entrapment efficiency of the nanoparticles prepared using different methods was as follows: solid/oil/water ion pairing (29.9%) > oil/oil (5.5%) > water/oil/water (4.7%) > modified oil/water (4.1%) > nano precipitation (0.8%). Addition of dextran sulfate as an ion pairing agent, acting as an ionic spacer between PEGylated PLGA and minocycline, decreased the water solubility of minocycline, hence increasing the drug entrapment efficiency. Entrapment efficiency was also increased when low molecular weight PLGA and high molecular weight dextran sulfate was used. Drug release studies performed in phosphate buffer at pH 7.4 indicated slow release of minocycline from 3 days to several weeks. On antibacterial analysis, the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles was at least two times lower than that of the free drug. Conclusion Novel minocycline-PEGylated PLGA nanoparticles prepared by the ion pairing method had the best drug loading and entrapment efficiency compared with other prepared nanoparticles. They also showed higher in vitro antibacterial activity than the free drug. PMID:22275837

  10. Assessment of dissolved-solids loading to the Colorado River in the Paradox Basin between the Dolores River and Gypsum Canyon, Utah

    Science.gov (United States)

    Shope, Christopher L.; Gerner, Steven J.

    2014-01-01

    Salinity loads throughout the Colorado River Basin have been a concern over recent decades due to adverse impacts on population, natural resources, and regional economics. With substantial financial resources and various reclamation projects, the salt loading to Lake Powell and associated total dissolved-solids concentrations in the Lower Colorado River Basin have been substantially reduced. The Colorado River between its confluence with the Dolores River and Lake Powell traverses a physiographic area where saline sedimentary formations and evaporite deposits are prevalent. However, the dissolved-solids loading in this area is poorly understood due to the paucity of water-quality data. From 2003 to 2011, the U.S. Geological Survey in cooperation with the U.S. Bureau of Reclamation conducted four synoptic sampling events to quantify the salinity loading throughout the study reach and evaluate the occurrence and impacts of both natural and anthropogenic sources. The results from this study indicate that under late-summer base-flow conditions, dissolved-solids loading in the reach is negligible with the exception of the Green River, and that variations in calculated loads between synoptic sampling events are within measurement and analytical uncertainties. The Green River contributed approximately 22 percent of the Colorado River dissolved-solids load, based on samples collected at the lower end of the study reach. These conclusions are supported by water-quality analyses for chloride and bromide, and the results of analyses for the stable isotopes of oxygen and deuterium. Overall, no significant sources of dissolved-solids loading from tributaries or directly by groundwater discharge, with the exception of the Green River, were identified in the study area.

  11. The effect of loading rate on pile bearing capacity of saturated sand

    NARCIS (Netherlands)

    Archeewa, E.

    2005-01-01

    Pile load tests are commonly used by engineers to determine its bearing capacity. At present, there are three methods of pile load tests: the static, the dynamic and the quasi-static test. The static pile load test is done by applying an axial load on the pile with a long duration. The dynamic and

  12. Ventilation rate in equilibrium factor measurements with solid state nuclear track detectors (SSNTD)

    International Nuclear Information System (INIS)

    Gil, L.R.; Leitao, R.M.S.; Marques, A.; Rivera, A.

    1994-08-01

    Ventilation rate values are calculated from track density measurements in solid state nuclear track detectors (SSNTD), both when ventilation is the main cause of radioactive disequilibrium in radon progeny and when it shares importance with other agents. The method consists in exposing a SSNTD of high intrinsic efficiency (CR-39) in filtered and unfiltered conditions and, in addition, covered with a thin Aluminium foil, to stop alpha particles from 218 Po and 222 Rn. No calibrations are required but, when necessary, independent measurements of the loss rates of radioactivity to aerosol and to walls have to perform. Ventilation rates depend upon geometry detection efficiencies for alpha particles, here obtained by Monte Carlo simulation, taking into account the space distribution of emission positions. This may lead to sizeable corrections in ventilation and equilibrium factor values. Since geometric detection efficiencies depend upon alpha-particle ranges in air, the influences of barometric variables are also discussed. (author). 7 refs

  13. Experimental study on composite solid propellant material burning rate using algorithm MATLAB

    Directory of Open Access Journals (Sweden)

    Thunaipragasam Selvakumaran

    2016-01-01

    Full Text Available In rocketry application, now-a-days instead of monopropellants slowly composite propellants are introduced. Burning rate of a solid state composite propellant depends on many factors like oxidizer-binder ratio, oxidizer particle size and distribution, particle size and its distribution, pressure, temperature, etc. Several researchers had taken the mass varied composite propellant. In that, the ammonium perchlorate mainly varied from 85 to 90%. This paper deals with the oxidizer rich propellant by allowing small variation of fuel cum binder ranging from 2%, 4%, 6%, and 8% by mass. Since the percent of the binder is very less compared to the oxidizer, the mixture remains in a powder form. The powder samples are used to make a pressed pellet. Experiments were conducted in closed window bomb set-up at pressures of 2, 3.5, and 7 MN/m2. The burning rates are calculated from the combustion photography (images taken by a high-speed camera. These images were processed frame by frame in MATLAB, detecting the edges in the images of the frames. The burning rate is obtained as the slope of the linear fit from MATLAB and observed that the burn rate increases with the mass variation of constituents present in solid state composite propellant. The result indicates a remarkable increase in burn rate of 26.66%, 20%, 16.66%, and 3.33% for Mix 1, 2, 3, 4 compared with Mix 5 at 7 MN/m2. The percentage variations in burn rate between Mix 1 and Mix 5 at 2, 3.5, and 7 MN/m2 are 25.833%, 32.322%, and 26.185%, respectively.

  14. A quantitative theory of solid tumor growth, metabolic rate and vascularization.

    Directory of Open Access Journals (Sweden)

    Alexander B Herman

    Full Text Available The relationships between cellular, structural and dynamical properties of tumors have traditionally been studied separately. Here, we construct a quantitative, predictive theory of solid tumor growth, metabolic rate, vascularization and necrosis that integrates the relationships between these properties. To accomplish this, we develop a comprehensive theory that describes the interface and integration of the tumor vascular network and resource supply with the cardiovascular system of the host. Our theory enables a quantitative understanding of how cells, tissues, and vascular networks act together across multiple scales by building on recent theoretical advances in modeling both healthy vasculature and the detailed processes of angiogenesis and tumor growth. The theory explicitly relates tumor vascularization and growth to metabolic rate, and yields extensive predictions for tumor properties, including growth rates, metabolic rates, degree of necrosis, blood flow rates and vessel sizes. Besides these quantitative predictions, we explain how growth rates depend on capillary density and metabolic rate, and why similar tumors grow slower and occur less frequently in larger animals, shedding light on Peto's paradox. Various implications for potential therapeutic strategies and further research are discussed.

  15. SDOF models for reinforced concrete beams under impulsive loads accounting for strain rate effects

    Energy Technology Data Exchange (ETDEWEB)

    Stochino, F., E-mail: fstochino@unica.it [Department of Civil and Environmental Engineering and Architecture, University of Cagliari, Via Marengo 2, 09123 Cagliari (Italy); Carta, G., E-mail: giorgio_carta@unica.it [Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Via Marengo 2, 09123 Cagliari (Italy)

    2014-09-15

    Highlights: • Flexural failure of reinforced concrete beams under blast and impact loads is studied. • Two single degree of freedom models are formulated to predict the beam response. • Strain rate effects are taken into account for both models. • The theoretical response obtained from each model is compared with experimental data. • The two models give a good estimation of the maximum deflection at collapse. - Abstract: In this paper, reinforced concrete beams subjected to blast and impact loads are examined. Two single degree of freedom models are proposed to predict the response of the beam. The first model (denoted as “energy model”) is developed from the law of energy balance and assumes that the deformed shape of the beam is represented by its first vibration mode. In the second model (named “dynamic model”), the dynamic behavior of the beam is simulated by a spring-mass oscillator. In both formulations, the strain rate dependencies of the constitutive properties of the beams are considered by varying the parameters of the models at each time step of the computation according to the values of the strain rates of the materials (i.e. concrete and reinforcing steels). The efficiency of each model is evaluated by comparing the theoretical results with experimental data found in literature. The comparison shows that the energy model gives a good estimation of the maximum deflection of the beam at collapse, defined as the attainment of the ultimate strain in concrete. On the other hand, the dynamic model generally provides a smaller value of the maximum displacement. However, both approaches yield reliable results, even though they are based on some approximations. Being also very simple to implement, they may serve as an useful tool in practical applications.

  16. Discrete dislocation plasticity analysis of loading rate-dependent static friction.

    Science.gov (United States)

    Song, H; Deshpande, V S; Van der Giessen, E

    2016-08-01

    From a microscopic point of view, the frictional force associated with the relative sliding of rough surfaces originates from deformation of the material in contact, by adhesion in the contact interface or both. We know that plastic deformation at the size scale of micrometres is not only dependent on the size of the contact, but also on the rate of deformation. Moreover, depending on its physical origin, adhesion can also be size and rate dependent, albeit different from plasticity. We present a two-dimensional model that incorporates both discrete dislocation plasticity inside a face-centred cubic crystal and adhesion in the interface to understand the rate dependence of friction caused by micrometre-size asperities. The friction strength is the outcome of the competition between adhesion and discrete dislocation plasticity. As a function of contact size, the friction strength contains two plateaus: at small contact length [Formula: see text], the onset of sliding is fully controlled by adhesion while for large contact length [Formula: see text], the friction strength approaches the size-independent plastic shear yield strength. The transition regime at intermediate contact size is a result of partial de-cohesion and size-dependent dislocation plasticity, and is determined by dislocation properties, interfacial properties as well as by the loading rate.

  17. Hierarchical Load Tracking Control of a Grid-connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    DEFF Research Database (Denmark)

    Li, Yonghui; Wu, Qiuwei; Zhu, Haiyu

    2015-01-01

    efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active...... power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model......Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject...

  18. Preparation, characterization, and optimization of altretamine-loaded solid lipid nanoparticles using Box-Behnken design and response surface methodology.

    Science.gov (United States)

    Gidwani, Bina; Vyas, Amber

    2016-01-01

    The objective of the present study was to prepare solid lipid nanoparticles (SLNs) of altretamine (ALT) by the hot homogenization and ultrasonication method. The study was conducted using the Box-Behnken design (BBD), with a 3(3) design and a total of 17 experimental runs, performed in combination with response surface methodology (RSM). The SLNs were evaluated for mean particle size, entrapment efficiency, and drug-loading. The optimized formulation, with a desirability factor of 0.92, was selected and characterized. In vitro release studies showed a biphasic release pattern from the SLNs for up to 24 h. The results of % EE (93.21 ± 1.5), %DL (1.15 ± 0.6), and mean diameter of (100.6 ± 2.1) nm, were very close to the predicted values.

  19. Solid State Track Recorder fission rate measurements at high neutron fluence and high temperature

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Roberts, J.H.; Gold, R.

    1985-01-01

    Solid State Track Recorder (SSTR) techniques have been used to measure 239-Pu, 235-U, and 237-Np fission rates for total neutron fluences approaching 5 x 10 17 n/cm 2 at temperatures in the range 680 to 830 0 F. Natural quartz crystal SSTRs were used to withstand the high temperature environment and ultra low-mass fissionable deposits of the three isotopes were required to yield scannable track densities at the high neutron fluences. The results of these high temperature, high neutron fluence measurements are reported

  20. Enhanced oxygen reduction activity and solid oxide fuel cell performance with a nanoparticles-loaded cathode.

    Science.gov (United States)

    Zhang, Xiaomin; Liu, Li; Zhao, Zhe; Tu, Baofeng; Ou, Dingrong; Cui, Daan; Wei, Xuming; Chen, Xiaobo; Cheng, Mojie

    2015-03-11

    Reluctant oxygen-reduction-reaction (ORR) activity has been a long-standing challenge limiting cell performance for solid oxide fuel cells (SOFCs) in both centralized and distributed power applications. We report here that this challenge has been tackled with coloading of (La,Sr)MnO3 (LSM) and Y2O3 stabilized zirconia (YSZ) nanoparticles within a porous YSZ framework. This design dramatically improves ORR activity, enhances fuel cell output (200-300% power improvement), and enables superior stability (no observed degradation within 500 h of operation) from 600 to 800 °C. The improved performance is attributed to the intimate contacts between nanoparticulate YSZ and LSM particles in the three-phase boundaries in the cathode.

  1. Luteolin-loaded solid lipid nanoparticles synthesis, characterization, & improvement of bioavailability, pharmacokinetics in vitro and vivo studies

    Science.gov (United States)

    Dang, Hao; Meng, Murtaza Hasan Weiwei; Zhao, Haiwei; Iqbal, Javed; Dai, Rongji; Deng, Yulin; Lv, Fang

    2014-04-01

    Luteolin (LU, 5,7,3',4'-tetrahydroxyflavone) most active compound in Chinese herbal flavones has been acting as a antimicrobial, anti-inflammatory, anti-cancer, and antimutagen. However, its poor bioavailability, hydrophobicity, and pharmacokinetics restrict clinical application. Here in this study, LU-loaded solid lipid nanoparticles have been prepared by hot-microemulsion ultrasonic technique to improve the bioavailability & pharmacokinetics of compound. LU-loaded solid lipid nanoparticle size was confirmed by particle size analyzer with range from 47 to 118 nm, having zepta potential -9.2 mV and polydisperse index 0.247, respectively. Round-shaped SLNPs were obtained by using transmission electron microscope, and encapsulation efficiency 74.80 % was calculated by using HPLC. Both in vitro and vivo studies, LC-MS/MS technique was used for quantification of Luteolin in rat. The T max value of drug with LU-SLNs after the administration was Ten times shorter than pure Luteolin suspension administration. C max value of drug after the administration of LU-SLNs was five times higher than obtained with native drug suspension. Luteolin with SLNs has increased the half-life approximately up to 2 h. Distribution and clearance of drug with SLNs were significantly decreased by 2.16-10.57 fold, respectively. In the end, the relative bioavailability of SLNs has improved about 4.89 compared to Luteolin with SLNs. From this study, it can be concluded that LU-SLNs have not only great potential for improving solubility but also increased the drug concentration in plasma. Furthermore, use of LC-MS/MS for quantification of LU-SLNs in rat plasma is reliable and of therapeutic usefulness, especially for neurodegenerative and cancerous disorders in humans.

  2. Effect of liquid-to-solid lipid ratio on characterizations of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) for transdermal administration.

    Science.gov (United States)

    Song, Aihua; Zhang, Xiaoshu; Li, Yanting; Mao, Xinjuan; Han, Fei

    2016-08-01

    The aim of this study is to evaluate the effect of liquid-to-solid lipid ratio on properties of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), and to clarify the superiority of NLCs over SLNs for transdermal administration. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, differential scanning calorimetry, X-ray diffractometry, in vitro percutaneous permeation profile, and stability of SLNs and NLCs were compared. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, and in vitro percutaneous permeation amount of the developed NLCs were all 78%, >35, and >240 μg/cm(2), respectively, however, for SLNs were 280 nm, -29.11 mV, 63.2%, 32.54, and 225.9 μg/cm(2), respectively. After 3 months storage at 4 °C and 25 °C, almost no significant differences between the evaluated parameters of NLCs were observed. However, for SLNs, particle size was increased to higher than 300 nm (4 °C and 25 °C), drug encapsulation efficiency was decreased to 51.2 (25 °C), in vitro occlusion factor was also decreased to lower than 25 (4 °C and 25 °C), and the cumulative amount was decreased to 148.9 μg/cm(2) (25 °C) and 184.4 μg/cm(2) (4 °C), respectively. And DSC and XRD studies indicated that not only the crystalline peaks of the encapsulated flurbiprofen disappeared but also obvious difference between samples and bulk Compritol® ATO 888 was seen. It could be concluded that liquid-to-solid lipid ratio has significant impact on the properties of SLNs and NLCs, and NLCs showed better stability than SLNs. Therefore, NLCs might be a better option than SLNs for transdermal administration.

  3. Effect of Degeneration on Fluid-Solid Interaction within Intervertebral Disk Under Cyclic Loading - A Meta-Model Analysis of Finite Element Simulations.

    Science.gov (United States)

    Nikkhoo, Mohammad; Khalaf, Kinda; Kuo, Ya-Wen; Hsu, Yu-Chun; Haghpanahi, Mohammad; Parnianpour, Mohamad; Wang, Jaw-Lin

    2015-01-01

    The risk of low back pain resulted from cyclic loadings is greater than that resulted from prolonged static postures. Disk degeneration results in degradation of disk solid structures and decrease of water contents, which is caused by activation of matrix digestive enzymes. The mechanical responses resulted from internal solid-fluid interactions of degenerative disks to cyclic loadings are not well studied yet. The fluid-solid interactions in disks can be evaluated by mathematical models, especially the poroelastic finite element (FE) models. We developed a robust disk poroelastic FE model to analyze the effect of degeneration on solid-fluid interactions within disk subjected to cyclic loadings at different loading frequencies. A backward analysis combined with in vitro experiments was used to find the elastic modulus and hydraulic permeability of intact and enzyme-induced degenerated porcine disks. The results showed that the averaged peak-to-peak disk deformations during the in vitro cyclic tests were well fitted with limited FE simulations and a quadratic response surface regression for both disk groups. The results showed that higher loading frequency increased the intradiscal pressure, decreased the total fluid loss, and slightly increased the maximum axial stress within solid matrix. Enzyme-induced degeneration decreased the intradiscal pressure and total fluid loss, and barely changed the maximum axial stress within solid matrix. The increase of intradiscal pressure and total fluid loss with loading frequency was less sensitive after the frequency elevated to 0.1 Hz for the enzyme-induced degenerated disk. Based on this study, it is found that enzyme-induced degeneration decreases energy attenuation capability of disk, but less change the strength of disk.

  4. Bioethanol production: an integrated process of low substrate loading hydrolysis-high sugars liquid fermentation and solid state fermentation of enzymatic hydrolysis residue.

    Science.gov (United States)

    Chu, Qiulu; Li, Xin; Ma, Bin; Xu, Yong; Ouyang, Jia; Zhu, Junjun; Yu, Shiyuan; Yong, Qiang

    2012-11-01

    An integrated process of enzymatic hydrolysis and fermentation was investigated for high ethanol production. The combination of enzymatic hydrolysis at low substrate loading, liquid fermentation of high sugars concentration and solid state fermentation of enzymatic hydrolysis residue was beneficial for conversion of steam explosion pretreated corn stover to ethanol. The results suggested that low substrate loading hydrolysis caused a high enzymatic hydrolysis yield; the liquid fermentation of about 200g/L glucose by Saccharomyces cerevisiae provided a high ethanol concentration which could significantly decrease cost of the subsequent ethanol distillation. A solid state fermentation of enzymatic hydrolysis residue was combined, which was available to enhance ethanol production and cellulose-to-ethanol conversion. The results of solid state fermentation demonstrated that the solid state fermentation process accompanied by simultaneous saccharification and fermentation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Fabrication, appraisal, and transdermal permeation of sildenafil citrate-loaded nanostructured lipid carriers versus solid lipid nanoparticles

    Science.gov (United States)

    Elnaggar, Yosra SR; El-Massik, Magda A; Abdallah, Ossama Y

    2011-01-01

    Although sildenafil citrate (SC) is used extensively for erectile dysfunction, oral delivery of SC encounters many obstacles. Furthermore, the physicochemical characteristics of this amphoteric drug are challenging for delivery system formulation and transdermal permeation. This article concerns the assessment of the potential of nanomedicine for improving SC delivery and transdermal permeation. SC-loaded nanostructured lipid carriers (NLCs) and solid lipid nanoparticles (SLNs) were fabricated using a modified high-shear homogenization technique. Nanoparticle optimization steps included particle size analysis, entrapment efficiency (EE) determination, freeze-drying and reconstitution, differential scanning calorimetry, in vitro release, stability study and high-performance liquid chromatography analysis. Transdermal permeation of the nanocarriers compared with SC suspension across human skin was assessed using a modified Franz diffusion cell assembly. Results revealed that SLNs and NLCs could be optimized in the nanometric range (180 and 100 nm, respectively) with excellent EE (96.7% and 97.5%, respectively). Nanoparticles have significantly enhanced in vitro release and transdermal permeation of SC compared with its suspensions. Furthermore, transdermal permeation of SC exhibited higher initial release from both SLN and NLC formulations followed by controlled release, with promising implications for faster onset and longer drug duration. Nanomedicines prepared exhibited excellent physical stability for the study period. Solid nanoparticles optimized in this study successfully improved SC characteristics, paving the way for an efficient topical Viagra® product. PMID:22238508

  6. Microwave-assisted microemulsion technique for production of miconazole nitrate- and econazole nitrate-loaded solid lipid nanoparticles.

    Science.gov (United States)

    Shah, Rohan M; Eldridge, Daniel S; Palombo, Enzo A; Harding, Ian H

    2017-08-01

    The microwave-assisted production of solid lipid nanoparticles (SLNs) is a novel technique reported recently by our group. The small particle size, solid nature and use of physiologically well-tolerated lipid materials make SLNs an interesting and potentially efficacious drug carrier. The main purpose of this research work was to investigate the suitability of microwave-assisted microemulsion technique to encapsulate selected ionic drug substances such as miconazole nitrate and econazole nitrate. The microwave-produced SLNs had a small size (250-300nm), low polydispersity (microwave-produced SLNs. Data fitting of drug release data revealed that the release of both drugs from microwave-produced SLNs was governed by non-Fickian diffusion indicating that drug release was both diffusion- and dissolution- controlled. Anti-fungal efficacy of drug-loaded SLNs was evaluated on C. albicans. The cell viability studies showed that cytotoxicity of SLNs was concentration-dependent. These encouraging results suggest that the microwave-assisted procedure is suitable for encapsulation of ionic drugs and that microwave-produced SLNs can act as potential carriers of antifungal drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Miconazole-loaded solid lipid nanoparticles: formulation and evaluation of a novel formula with high bioavailability and antifungal activity

    Directory of Open Access Journals (Sweden)

    Aljaeid BM

    2016-01-01

    Full Text Available Bader Mubarak Aljaeid,1 Khaled Mohamed Hosny1,2 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni Suef University, Beni Suef, Egypt Background and objective: Miconazole is a broad-spectrum antifungal drug that has poor aqueous solubility (<1 µg/mL; as a result, a reduction in its therapeutic efficacy has been reported. The aim of this study was to formulate and evaluate miconazole-loaded solid lipid nanoparticles (MN-SLNs for oral administration to find an innovative way to alleviate the disadvantages associated with commercially available capsules. Methods: MN-SLNs were prepared by hot homogenization/ultrasonication. The solubility of miconazole in different solid lipids was measured. The effect of process variables, such as surfactant types, homogenization and ultrasonication times, and the charge-inducing agent on the particle size, zeta potential, and encapsulation efficiency were determined. Furthermore, in vitro drug release, antifungal activity against Candida albicans, and in vivo pharmacokinetics were studied in rabbits. Results: The MN-SLN, consisting of 1.5% miconazole, 2% Precirol ATO5, 2.5% Cremophor RH40, 0.5% Lecinol, and 0.1% Dicetylphosphate, had an average diameter of 23 nm with a 90.2% entrapment efficiency. Furthermore, the formulation of MN-SLNs enhanced the antifungal activity compared with miconazole capsules. An in vivo pharmacokinetic study revealed that the bioavailability was enhanced by >2.5-fold. Conclusion: MN-SLN was more efficient in the treatment of candidiasis with enhanced oral bioavailability and could be a promising carrier for the oral delivery of miconazole. Keywords: miconazole, Precirol ATO5, solid lipid nanoparticles, encapsulation, Cremophor RH40, antifungal activity

  8. Inactivation of bacterial pathogenic load in compost against vermicompost of organic solid waste aiming to achieve sanitation goals: A review.

    Science.gov (United States)

    Soobhany, Nuhaa; Mohee, Romeela; Garg, Vinod Kumar

    2017-06-01

    Waste management strategies for organic residues, such as composting and vermicomposting, have been implemented in some developed and developing countries to solve the problem of organic solid waste (OSW). Yet, these biological treatment technologies do not always result in good quality compost or vermicompost with regards to sanitation capacity owing to the presence of bacterial pathogenic substances in objectionable concentrations. The presence of pathogens in soil conditioners poses a potential health hazard and their occurrence is of particular significance in composts and/or vermicomposts produced from organic materials. Past and present researches demonstrated a high-degree of agreement that various pathogens survive after the composting of certain OSW but whether similar changes in bacterial pathogenic loads arise during vermitechnology has not been thoroughly elucidated. This review garners information regarding the status of various pathogenic bacteria which survived or diffused after the composting process compared to the status of these pathogens after the vermicomposting of OSW with the aim of achieving sanitation goals. This work is also indispensable for the specification of compost quality guidelines concerning pathogen loads which would be specific to treatment technology. It was hypothesized that vermicomposting process for OSW can be efficacious in sustaining the existence of pathogenic organisms most specifically; human pathogens under safety levels. In summary, earthworms can be regarded as a way of obliterating pathogenic bacteria from OSW in a manner equivalent to earthworm gut transit mechanism which classifies vermicomposting as a promising sanitation technique in comparison to composting processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Characterization and evaluation of 5-fluorouracil-loaded solid lipid nanoparticles prepared via a temperature-modulated solidification technique.

    Science.gov (United States)

    Patel, Meghavi N; Lakkadwala, Sushant; Majrad, Mohamed S; Injeti, Elisha R; Gollmer, Steven M; Shah, Zahoor A; Boddu, Sai Hanuman Sagar; Nesamony, Jerry

    2014-12-01

    The aim of this research was to advance solid lipid nanoparticle (SLN) preparation methodology by preparing glyceryl monostearate (GMS) nanoparticles using a temperature-modulated solidification process. The technique was reproducible and prepared nanoparticles without the need of organic solvents. An anticancer agent, 5-fluorouracil (5-FU), was incorporated in the SLNs. The SLNs were characterized by particle size analysis, zeta potential analysis, differential scanning calorimetry (DSC), infrared spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), drug encapsulation efficiency, in vitro drug release, and in vitro cell viability studies. Particle size of the SLN dispersion was below 100 nm, and that of redispersed lyophilizates was ~500 nm. DSC and infrared spectroscopy suggested that the degree of crystallinity did not decrease appreciably when compared to GMS. TEM and AFM images showed well-defined spherical to oval particles. The drug encapsulation efficiency was found to be approximately 46%. In vitro drug release studies showed that 80% of the encapsulated drug was released within 1 h. In vitro cell cultures were biocompatible with blank SLNs but demonstrated concentration-dependent changes in cell viability to 5-FU-loaded SLNs. The 5-FU-loaded SLNs can potentially be utilized in an anticancer drug delivery system.

  10. Dosimetric advancement of high-dose-rate after-loading 192Ir source

    International Nuclear Information System (INIS)

    Zhang Shuxu; Li Wenhua; Xu Hairong

    2004-01-01

    High-dose-rate (HDR) 192 Ir source is a nuclide commonly used in the brachytherapy system. The basic dosimetry data of the near source area is usually measured by pin ion chambers or TLD techniques, but these methods have a lower spatial resolution than Electron spin resonance (ESR) dosimetry which has a spatial resolution of 156 μm, and the Monte Carlo photon transport simulations are taken as the golden standard of those measures. The precision in two-dimensional dose distribution measured by GafChromic film is reported to be 1.0%. In vivo dosimetry using TLD during HDR intracavitary after-loading brachytherapy is a good predictor of late rectal complications. The accuracy of magnetic resonance imaging (MRI) Fricke-gel dosimetry for three-dimensional dose distribution is about 2.5% with a spatial resolution of 1.56 mm. The optical computed tomography polymer gel dosimetry has a unique advance than MRI gel dosimetry

  11. Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring

    International Nuclear Information System (INIS)

    Oh, Sung Ha; Choi, Bok Lok

    2014-01-01

    This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses

  12. Strain rate dependent orthotropic properties of pristine and impulsively loaded porcine temporomandibular joint disk.

    Science.gov (United States)

    Beatty, M W; Bruno, M J; Iwasaki, L R; Nickel, J C

    2001-10-01

    The purpose of this study was to characterize the tensile stress-strain behavior of the porcine temporomandibular joint (TMJ) disk with respect to collagen orientation and strain rate dependency. The apparent elastic modulus, ultimate tensile strength, and strain at maximum stress were measured at three elongation rates (0.5, 50, and 500 mm/min) for dumbbell-shaped samples oriented along either anteroposterior or mediolateral axes of the disks. In order to study the effects of impact-induced fissuring on the mechanical behavior, the same properties were measured along each orientation at an elongation rate of 500 mm/min for disks subjected to impulsive loads of 0.5 N. s. The results suggested a strongly orthotropic nature to the healthy pristine disk. The values for the apparent modulus and ultimate strength were 10-fold higher along the anteroposterior axis (p disks for either orientation (p > 0.05). The results demonstrated the importance of choosing an orthotropic model for the TMJ disk to conduct finite element modeling, to develop failure criteria, and to construct tissue-engineered replacements. Impact-induced fissuring requires further study to determine if the TMJ disk is orthotropic with respect to fatigue.

  13. Using Pulse Rate in Estimating Workload Evaluating a Load Mobilizing Activity

    Directory of Open Access Journals (Sweden)

    Juan Alberto Castillo

    2014-06-01

    Full Text Available Introduction: The pulse rate is a direct indicator of the state of the cardiovascular system, in ad-dition to being an indirect indicator of the energy expended in performing a task. The pulse of a person is the number of pulses recorded in a peripheral artery per unit time; the pulse appears as a pressure wave moving along the blood vessels, which are flexible, “in large arterial branches, speed of 7-10 m/s in the small arteries, 15 to 35 m/s”. Materials and methods: The aim of this study was to assess heart rate, using the technique of recording the frequency of the pulse, oxy-gen consumption and observation of work activity in the estimation of the workload in a load handling task for three situations: lift/transfer/deposit; before, during and after the task the pulse rate is recorded for 24 young volunteers (10 women and 14 men under laboratory conditions. We performed a gesture analysis of work activity and lifting and handling strategies. Results: We observed an increase between initial and final fp in both groups and for the two tasks, a dif¬ference is also recorded in the increase in heart rate of 17.5 for charging 75 % of the participants experienced an increase in fp above 100 lat./min. Par 25 kg, registered values indicate greater than 114 lat./min and 17.5 kg than 128 lat./min values. Discussion: The pulse rate method is recommended for its simplicity of use for operational staff, supervisors and managers and indus¬trial engineers not trained in the physiology method can also be used by industrial hygienists.

  14. Crack nucleation in solid materials under external load - simulations with the Discrete Element Method

    Directory of Open Access Journals (Sweden)

    Klejment Piotr

    2018-01-01

    Full Text Available Numerical analysis of cracking processes require an appropriate numerical technique. Classical engineering approach to the problem has its roots in the continuum mechanics and is based mainly on the Finite Element Method. This technique allows simulations of both elastic and large deformation processes, so it is very popular in the engineering applications. However, a final effect of cracking - fragmentation of an object at hand can hardly be described by this approach in a numerically efficient way since it requires a solution of a problem of nontrivial evolving in time boundary conditions. We focused our attention on the Discrete Element Method (DEM, which by definition implies “molecular” construction of the matter. The basic idea behind DEM is to represent an investigated body as an assemblage of discrete particles interacting with each other. Breaking interaction bonds between particles induced by external forces imeditelly implies creation/evolution of boundary conditions. In this study we used the DEM approach to simulate cracking process in the three dimensional solid material under external tension. The used numerical model, although higly simplified, can be used to describe behaviour of such materials like thin films, biological tissues, metal coatings, to name a few.

  15. The influence of gas–solid reaction kinetics in models of thermochemical heat storage under monotonic and cyclic loading

    International Nuclear Information System (INIS)

    Nagel, T.; Shao, H.; Roßkopf, C.; Linder, M.; Wörner, A.; Kolditz, O.

    2014-01-01

    Highlights: • Detailed analysis of cyclic and monotonic loading of thermochemical heat stores. • Fully coupled reactive heat and mass transport. • Reaction kinetics can be simplified in systems limited by heat transport. • Operating lines valid during monotonic and cyclic loading. • Local integral degree of conversion to capture heterogeneous material usage. - Abstract: Thermochemical reactions can be employed in heat storage devices. The choice of suitable reactive material pairs involves a thorough kinetic characterisation by, e.g., extensive thermogravimetric measurements. Before testing a material on a reactor level, simulations with models based on the Theory of Porous Media can be used to establish its suitability. The extent to which the accuracy of the kinetic model influences the results of such simulations is unknown yet fundamental to the validity of simulations based on chemical models of differing complexity. In this article we therefore compared simulation results on the reactor level based on an advanced kinetic characterisation of a calcium oxide/hydroxide system to those obtained by a simplified kinetic model. Since energy storage is often used for short term load buffering, the internal reactor behaviour is analysed under cyclic partial loading and unloading in addition to full monotonic charge/discharge operation. It was found that the predictions by both models were very similar qualitatively and quantitatively in terms of thermal power characteristics, conversion profiles, temperature output, reaction duration and pumping powers. Major differences were, however, observed for the reaction rate profiles themselves. We conclude that for systems not limited by kinetics the simplified model seems sufficient to estimate the reactor behaviour. The degree of material usage within the reactor was further shown to strongly vary under cyclic loading conditions and should be considered when designing systems for certain operating regimes

  16. Combustion and fuel loading characteristics of Hanford Site transuranic solid waste

    International Nuclear Information System (INIS)

    Greenhalgh, W.O.

    1994-01-01

    The Waste Receiving and Processing (WRAP) Facility is being designed for construction in the north end of the Central Waste Complex. The WRAP Facility will receive, store, and process radioactive solid waste of both transuranic (TRU) and mixed waste (mixed radioactive-chemical waste) categories. Most of the waste is in 208-L (55-gal) steel drums. Other containers such as wood and steel boxes, and various sized drums will also be processed in the facility. The largest volume of waste and the type addressed in this report is TRU in 208-L (55-gal) drums that is scheduled to be processed in the Waste Receiving and Processing Facility Module 1 (WRAP 1). Half of the TRU waste processed by WRAP 1 is expected to be retrieved stored waste and the other half newly generated waste. Both the stored and new waste will be processed to certify it for permanent storage in the Waste Isolation Pilot Plant (WIPP) or disposal. The stored waste will go through a process of retrieval, examination, analysis, segregation, repackaging, relabeling, and documentation before certification and WIPP shipment. Newly generated waste should be much easier to process and certify. However, a substantial number of drums of both retrievable and newly generated waste will require temporary storage and handling in WRAP. Most of the TRU waste is combustible or has combustible components. Therefore, the presence of a substantial volume of drummed combustible waste raises concern about fire safety in WRAP and similar waste drum storage facilities. This report analyzes the fire related characteristics of the expected WRAP TRU waste stream

  17. Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approaches

    Directory of Open Access Journals (Sweden)

    Madureira AR

    2016-08-01

    Full Text Available Ana Raquel Madureira,1 Sara Nunes,2 Débora A Campos,1 João C Fernandes,2 Cláudia Marques,3 Monica Zuzarte,2 Beatriz Gullón,1 Luís M Rodríguez-Alcalá,1 Conceição Calhau,3,4 Bruno Sarmento,5–7 Ana Maria Gomes,1 Maria Manuela Pintado,1 Flávio Reis2 1Catholic University of Portugal, CBQF – Center for Biotechnology and Fine Chemistry – Associate Laboratory, Faculty of Biotechnology, Porto, Portugal; 2Laboratory of Pharmacology and Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI, Faculty of Medicine, and CNC.IBILI Consortium, University of Coimbra, Coimbra, Portugal; 3Department of Biochemistry, Faculty of Medicine, University of Porto, Porto, Portugal; 4Center for Health Technology and Services Research (CINTESIS, Porto, Portugal; 5Department of Pharmaceutical Sciences, Institute of Health Sciences-North, CESPU, Gandra, Portugal; 6“I3S” Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal; 7INEB, Institute of Biomedical Engineering, University of Porto, Porto, Portugal Abstract: Rosmarinic acid (RA possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL were evaluated for cell (lymphocytes viability, necrosis and apoptosis, and antioxidant

  18. Predicting fractional bed load transport rates: Application of the Wilcock‐Crowe equations to a regulated gravel bed river

    Science.gov (United States)

    Gaeuman, David; Andrews, E.D.; Krause, Andreas; Smith, Wes

    2009-01-01

    Bed load samples from four locations in the Trinity River of northern California are analyzed to evaluate the performance of the Wilcock‐Crowe bed load transport equations for predicting fractional bed load transport rates. Bed surface particles become smaller and the fraction of sand on the bed increases with distance downstream from Lewiston Dam. The dimensionless reference shear stress for the mean bed particle size (τ*rm) is largest near the dam, but varies relatively little between the more downstream locations. The relation between τ*rm and the reference shear stresses for other size fractions is constant across all locations. Total bed load transport rates predicted with the Wilcock‐Crowe equations are within a factor of 2 of sampled transport rates for 68% of all samples. The Wilcock‐Crowe equations nonetheless consistently under‐predict the transport of particles larger than 128 mm, frequently by more than an order of magnitude. Accurate prediction of the transport rates of the largest particles is important for models in which the evolution of the surface grain size distribution determines subsequent bed load transport rates. Values of τ*rm estimated from bed load samples are up to 50% larger than those predicted with the Wilcock‐Crowe equations, and sampled bed load transport approximates equal mobility across a wider range of grain sizes than is implied by the equations. Modifications to the Wilcock‐Crowe equation for determining τ*rm and the hiding function used to scale τ*rm to other grain size fractions are proposed to achieve the best fit to observed bed load transport in the Trinity River.

  19. Strain-rate effect on initial crush stress of irregular honeycomb under dynamic loading and its deformation mechanism

    Science.gov (United States)

    Wang, Peng; Zheng, Zhijun; Liao, Shenfei; Yu, Jilin

    2018-02-01

    The seemingly contradictory understandings of the initial crush stress of cellular materials under dynamic loadings exist in the literature, and a comprehensive analysis of this issue is carried out with using direct information of local stress and strain. Local stress/strain calculation methods are applied to determine the initial crush stresses and the strain rates at initial crush from a cell-based finite element model of irregular honeycomb under dynamic loadings. The initial crush stress under constant-velocity compression is identical to the quasi-static one, but less than the one under direct impact, i.e. the initial crush stresses under different dynamic loadings could be very different even though there is no strain-rate effect of matrix material. A power-law relation between the initial crush stress and the strain rate is explored to describe the strain-rate effect on the initial crush stress of irregular honeycomb when the local strain rate exceeds a critical value, below which there is no strain-rate effect of irregular honeycomb. Deformation mechanisms of the initial crush behavior under dynamic loadings are also explored. The deformation modes of the initial crush region in the front of plastic compaction wave are different under different dynamic loadings.

  20. Results of radiation therapy for uterine cervical cancer using high dose rate remote after loading system

    International Nuclear Information System (INIS)

    Ogawa, Yoshihiro; Nemoto, Kenji

    2003-01-01

    In Japan, radiotherapy with high dose rate remote after loading system (HDR-RALS) for intracavitary brachytherapy is the standard treatment for more than 30 years. This report showed the usefulness of HDR-RALS for uterine cervical cancer. From 1980 through 1999, 442 patients with uterine cervical cancers (stage I: 66, stage II: 161, stage III: 165, stage IV: 50) were treated. Radiotherapy was performed both external teletherapy and HDR-RALS. Overall survival rate at 5 years was 60.2%. The 5-year actuarial incidence of all complications was 16.4%. The 5-year actuarial incidence of all complications in cases treated with the sum doses of whole pelvic irradiation (without central shield) and RALS up to 49 Gy, 50 to 59 Gy or larger doses were 7.5%, 11.0% and 25.2%, respectively. Radiation therapy using HDR-RALS was very effective. While the dose of whole pelvic irradiation was increased, the actuarial incidence of all complications was increased. (author)

  1. Influence of solid loading on D-xylose production through dilute sulphuric acid hydrolysis of olive stones

    Directory of Open Access Journals (Sweden)

    Cuevas, M.

    2015-09-01

    Full Text Available The selective hydrolysis of hemicellulose from olive stones was attempted in order to achieve a maximum D-xylose yield. For this aim, batch hydrolysis was conducted under different operating conditions of temperature, acid concentration and solid loading. Firstly, distilled water, sulphuric acid and nitric acid were assessed as hydrolytic agents at different temperatures (200, 205, 210 and 220 °C and at a fixed acid concentration (0.025 M. Sulphuric acid and 200 °C were selected for the subsequent dilute acid hydrolysis optimization based on the obtained D-xylose yields. The combined influence of solid loading (from 29.3 to 170.7 g olive stones into 300 mL acid solution and sulphuric acid concentration (0.006–0.034 M on the release of D-xylose was then estimated by response surface methodology. According to a statistical analysis, both parameters had significant interaction effects on D-xylose production. The results illustrated that the higher the solid loading, the higher the required acid concentration. The decrease in the solid/liquid ratio in the reactor had a positive effect on D-xylose extraction and on the amount of acid used. The optimum solid loading and sulphuric acid concentration were determined to be 50 g (solid/liquid ratio 1/6 and 0.016 M, respectively. Under these conditions, the predicted D-xylose yield (expressed as g of sugar per 100 g of dry matter fed was 20.4 (87.2% of maximum attainable.Se ha desarrollado una hidrólisis selectiva de la fracción hemicelulósica del hueso de aceituna con el fin de obtener el máximo rendimiento de D-xilosa. Para ello las hidrólisis se llevaron a cabo en un reactor discontinuo a distintas condiciones de temperatura, concentración de ácido y carga de sólidos. En primer lugar se evaluó la capacidad hidrolítica del agua destilada y de los ácidos nítrico y sulfúrico a distintas temperaturas (200, 205, 210 y 220°C manteniendo fija la concentración de ácido (0,025 M. A partir de

  2. Measurement of peak impact loads differ between accelerometers - Effects of system operating range and sampling rate.

    Science.gov (United States)

    Ziebart, Christina; Giangregorio, Lora M; Gibbs, Jenna C; Levine, Iris C; Tung, James; Laing, Andrew C

    2017-06-14

    A wide variety of accelerometer systems, with differing sensor characteristics, are used to detect impact loading during physical activities. The study examined the effects of system characteristics on measured peak impact loading during a variety of activities by comparing outputs from three separate accelerometer systems, and by assessing the influence of simulated reductions in operating range and sampling rate. Twelve healthy young adults performed seven tasks (vertical jump, box drop, heel drop, and bilateral single leg and lateral jumps) while simultaneously wearing three tri-axial accelerometers including a criterion standard laboratory-grade unit (Endevco 7267A) and two systems primarily used for activity-monitoring (ActiGraph GT3X+, GCDC X6-2mini). Peak acceleration (gmax) was compared across accelerometers, and errors resulting from down-sampling (from 640 to 100Hz) and range-limiting (to ±6g) the criterion standard output were characterized. The Actigraph activity-monitoring accelerometer underestimated gmax by an average of 30.2%; underestimation by the X6-2mini was not significant. Underestimation error was greater for tasks with greater impact magnitudes. gmax was underestimated when the criterion standard signal was down-sampled (by an average of 11%), range limited (by 11%), and by combined down-sampling and range-limiting (by 18%). These effects explained 89% of the variance in gmax error for the Actigraph system. This study illustrates that both the type and intensity of activity should be considered when selecting an accelerometer for characterizing impact events. In addition, caution may be warranted when comparing impact magnitudes from studies that use different accelerometers, and when comparing accelerometer outputs to osteogenic impact thresholds proposed in literature. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  3. A clean measurement of the hydrogen retardation of the rate of solid phase epitaxy in silicon

    International Nuclear Information System (INIS)

    Liu, A.C.Y.; McCallum, J.C.

    1999-01-01

    The rate retarding effects of the impurity hydrogen on solid phase epitaxy (SPE) in silicon have yet to be completely understood. Existing measurements of this behaviour do not coincide exactly, however, several features have attained prominence. Firstly, a linear decrease in the SPE rate is detected up until a certain concentration of hydrogen. Subsequent to this point the rate remains almost constant at around half the intrinsic rate. It is conjectured that the hydrogen bonds to and passivates the defects whose agency enables the incorporation of atoms from the amorphous phase to the crystalline. This rate reduction increases until the defect population is saturated. At this point the reduction in rate ceases. Secondly, a dependence on temperature has not been consolidated, in contrast with the trends observed with the doping species. Here a method is proposed for producing a controlled concentration of hydrogen for the advancing amorphous/crystalline interface to encounter during epitaxy. A bubble layer is formed in crystalline silicon approximately 0.6μm beneath the surface through the implantation of hydrogen at 65 keV with fluences of 4 x 10 16 /cm 2 and 3 x 10 16 /cm 2 and annealing for 1 hour at 850 deg C in dry argon. The anneal doesn't out gas all the introduced hydrogen, leaving a remnant gas pressure in the bubbles. The hydrogen implants at the two fluences should yield two samples with different amounts of hydrogen trapped in the bubbles. A buried amorphous layer is created to encompass the bubble layer containing this residual contaminant through silicon self implantation at appropriate energies and fluences. The progress of the front interface of the buried amorphous layer is monitored by time resolved reflectivity (TRR) as SPE is effected at various temperatures

  4. Enhancement of ethanol production from green liquor-ethanol-pretreated sugarcane bagasse by glucose-xylose cofermentation at high solid loadings with mixed Saccharomyces cerevisiae strains.

    Science.gov (United States)

    You, Yanzhi; Li, Pengfei; Lei, Fuhou; Xing, Yang; Jiang, Jianxin

    2017-01-01

    Efficient cofermentation of glucose and xylose is necessary for economically feasible bioethanol production from lignocellulosic biomass. Here, we demonstrate pretreatment of sugarcane bagasse (SCB) with green liquor (GL) combined with ethanol (GL-Ethanol) by adding different GL amounts. The common Saccharomyces cerevisiae (CSC) and thermophilic S. cerevisiae (TSC) strains were used and different yeast cell mass ratios (CSC to TSC) were compared. The simultaneous saccharification and cofermentation (SSF/SSCF) process was performed by 5-20% (w/v) dry substrate (DS) solid loadings to determine optimal conditions for the co-consumption of glucose and xylose. Compared to previous studies that tested fermentation of glucose using only the CSC, we obtained higher ethanol yield and concentration (92.80% and 23.22 g/L) with 1.5 mL GL/g-DS GL-Ethanol-pretreated SCB at 5% (w/v) solid loading and a CSC-to-TSC yeast cell mass ratio of 1:2 (w/w). Using 10% (w/v) solid loading under the same conditions, the ethanol concentration increased to 42.53 g/L but the ethanol yield decreased to 84.99%. In addition, an increase in the solid loading up to a certain point led to an increase in the ethanol concentration from 1.5 mL GL/g-DS-pretreated SCB. The highest ethanol concentration (68.24 g/L) was obtained with 15% (w/v) solid loading, using a CSC-to-TSC yeast cell mass ratio of 1:3 (w/w). GL-Ethanol pretreatment is a promising pretreatment method for improving both glucan and xylan conversion efficiencies of SCB. There was a competitive relationship between the two yeast strains, and the glucose and xylose utilization ability of the TSC was better than that of the CSC. Ethanol concentration was obviously increased at high solid loading, but the yield decreased as a result of an increase in the viscosity and inhibitor levels in the fermentation system. Finally, the SSCF of GL-Ethanol-pretreated SCB with mixed S. cerevisiae strains increased ethanol concentration and was an

  5. Influence of load and sliding velocity on wear resistance of solid-lubricant composites of ultra-high molecular weight polyethylene

    Science.gov (United States)

    Panin, S. V.; Kornienko, L. A.; Buslovich, D. G.; Alexenko, V. O.; Ivanova, L. R.

    2017-12-01

    To determine the limits of the operation loading intervals appropriate for the use of solid lubricant UHMWPE composites in tribounits for mechanical engineering and medicine, the tribotechnical properties of UHMWPE blends with the optimum solid lubricant filler content (polytetrafluoroethylene, calcium stearate, molybdenum disulfide, colloidal graphite, boron nitride) are studied under dry sliding friction at different velocities (V = 0.3 and 0.5 m/s) and loads (P = 60 and 140 N). It is shown that the wear resistance of solid lubricant UHMWPE composites at moderate sliding velocities (V = 0.3 m/s) and loads (P = 60 N) increases 2-3 times in comparison with pure UHMWPE, while at high load P = 140 N wear resistance of both neat UHMWPE and its composites is reduced almost twice. At high sliding velocities and loads (up to P = 140 N), multiple increasing of the wear of pure UHMWPE and its composites takes place (by the factor of 5 to 10). The operational conditions of UHMWPE composites in tribounits in engineering and medicine are discussed.

  6. The Effect of Loading Rate on Hydraulic Fracturing in Synthetic Granite - a Discrete Element Study

    Science.gov (United States)

    Tomac, I.; Gutierrez, M.

    2015-12-01

    rock plays a significant role in fracture propagation velocity. Fluid viscosity effects are similar to the loading rate effects, because in both cases the rapid buildup of the pressure in the wellbore in absence of the inflow of the fluid into initiated fracture causes induction of multiple simultaneous fracture branches at the wellbore wall.

  7. Preparation, characterization, and pharmacokinetics of tilmicosin- and florfenicol-loaded hydrogenated castor oil-solid lipid nanoparticles.

    Science.gov (United States)

    Ling, Z; Yonghong, L; Changqing, S; Junfeng, L; Li, Z; Chunyu, J; Xianqiang, L

    2017-06-01

    To effectively control bovine mastitis, tilmicosin (TIL)- and florfenicol (FF)-loaded solid lipid nanoparticles (SLN) with hydrogenated castor oil (HCO) were prepared by a hot homogenization and ultrasonication method. In vitro antibacterial activity, properties, and pharmacokinetics of the TIL-FF-SLN were studied. The results demonstrated that TIL and FF had a synergistic or additive antibacterial activity against Streptococcus dysgalactiae, Streptococcus uberis, and Streptococcus agalactiae. The size, polydispersity index, and zeta potential of nanoparticles were 289.1 ± 13.7 nm, 0.31 ± 0.05, and -26.7 ± 1.3 mV, respectively. The encapsulation efficiencies for TIL and FF were 62.3 ± 5.9% and 85.1 ± 5.2%, and the loading capacities for TIL and FF were 8.2 ± 0.6% and 3.3 ± 0.2%, respectively. The TIL-FF-SLN showed no irritation in the injection site and sustained release in vitro. After medication, TIL and FF could maintain about 0.1 μg/mL for 122 and 6 h. Compared to the control solution, the SLN increased the area under the concentration-time curve (AUC 0-t ), elimination half-life (T ½ke ), and mean residence time (MRT) of TIL by 33.09-, 23.29-, and 37.53-fold, and 1.69-, 5.00-, and 3.83-fold for FF, respectively. These results of this exploratory study suggest that the HCO-SLN could be a useful system for the delivery of TIL and FF for bovine mastitis therapy. © 2016 John Wiley & Sons Ltd.

  8. The seating mechanics of head-neck modular tapers in vitro: Load-displacement measurements, moisture, and rate effects.

    Science.gov (United States)

    Ouellette, Eric S; Shenoy, Aarti A; Gilbert, Jeremy L

    2018-04-01

    The mechanically assisted crevice corrosion performance of head-neck modular tapers is a significant concern in orthopedic biomaterials. Fretting crevice corrosion processes in modular tapers are thought to be influenced by a wide array of factors including seating mechanics of the junction, hence there is a need for in vitro test methods that can assess their performance. This study presented a test method to directly measure the load-displacement seating mechanics of modular tapers and used this method to compare the seating mechanics for different tapers, moisture, seating loads and seating rates. Seating mechanics were explored whereby the instantaneous load-displacement behavior of the head seating onto the neck is captured and used to define the mechanics of seating. Two distinct taper design/material combinations were assembled wet or dry using axially applied loads (500, 1,000, 2,000, and 4,000 N) at two loading rates of 100 and 10 4  N/s (n = 5 for each condition) using a servohydraulic test frame. The results showed that pull-off strength scaled with seating load and ranged between 43% and 68% of seating load depending on sample and wetness. Tapers seated wet had higher pull-off strengths (2,200 ± 300 N) than those seated dry (1,800 ± 200 N, p mechanics (load-displacement plots) varied due to sample type and due to wetness with differences in seating energy, seating stiffness, and seating displacement. These results show the detailed mechanics of seating during assembly and provide significant insight into the complex interplay of factors associated with even "ideal" seating (axial, quasistatic) loading. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1164-1172, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Effect of Degeneration on Fluid–Solid Interaction within Intervertebral Disk Under Cyclic Loading – A Meta-Model Analysis of Finite Element Simulations

    Science.gov (United States)

    Nikkhoo, Mohammad; Khalaf, Kinda; Kuo, Ya-Wen; Hsu, Yu-Chun; Haghpanahi, Mohammad; Parnianpour, Mohamad; Wang, Jaw-Lin

    2015-01-01

    The risk of low back pain resulted from cyclic loadings is greater than that resulted from prolonged static postures. Disk degeneration results in degradation of disk solid structures and decrease of water contents, which is caused by activation of matrix digestive enzymes. The mechanical responses resulted from internal solid–fluid interactions of degenerative disks to cyclic loadings are not well studied yet. The fluid–solid interactions in disks can be evaluated by mathematical models, especially the poroelastic finite element (FE) models. We developed a robust disk poroelastic FE model to analyze the effect of degeneration on solid–fluid interactions within disk subjected to cyclic loadings at different loading frequencies. A backward analysis combined with in vitro experiments was used to find the elastic modulus and hydraulic permeability of intact and enzyme-induced degenerated porcine disks. The results showed that the averaged peak-to-peak disk deformations during the in vitro cyclic tests were well fitted with limited FE simulations and a quadratic response surface regression for both disk groups. The results showed that higher loading frequency increased the intradiscal pressure, decreased the total fluid loss, and slightly increased the maximum axial stress within solid matrix. Enzyme-induced degeneration decreased the intradiscal pressure and total fluid loss, and barely changed the maximum axial stress within solid matrix. The increase of intradiscal pressure and total fluid loss with loading frequency was less sensitive after the frequency elevated to 0.1 Hz for the enzyme-induced degenerated disk. Based on this study, it is found that enzyme-induced degeneration decreases energy attenuation capability of disk, but less change the strength of disk. PMID:25674562

  10. The Influence of Loading Rate and Variable Temperatures on Microbial Communities in Anaerobic Digesters

    Directory of Open Access Journals (Sweden)

    Richard J. Ciotola

    2014-02-01

    Full Text Available The relationship between seasonal temperatures, organic loading rate (OLR and the structure of archaeal communities in anaerobic digesters was investigated. Previous studies have often assessed archaeal community structure at fixed temperatures and constant OLRs, or at variable temperatures not characteristic of temperate climates. The goal of this study was to determine the maximum OLR that would maintain a balanced microbial ecosystem during operation in a variable temperature range expected in a temperate climate (27–10 °C. Four-liter laboratory digesters were operated in a semi-continuous mode using dairy cow manure as the feedstock. At OLRs of 1.8 and 0.8 kg VS/m3·day the digesters soured (pH < 6.5 as a result of a decrease in temperature. The structure of the archaeal community in the sour digesters became increasingly similar to the manure feedstock with gains in the relative abundance of hydrogenotrophic methanogens. At an OLR of 0.3 kg VS/m3·day the digesters did not sour, but the archaeal community was primarily hydrogenotrophic methanogens. Recommendations for operating an ambient temperature digester year round in a temperate climate are to reduce the OLR to at least 0.3 kg VS/m3·day in colder temperatures to prevent a shift to the microbial community associated with the sour digesters.

  11. Effects of organic loading rate on biogas production from macroalgae: Performance and microbial community structure.

    Science.gov (United States)

    Sun, Meng-Ting; Fan, Xiao-Lei; Zhao, Xiao-Xian; Fu, Shan-Fei; He, Shuai; Manasa, M R K; Guo, Rong-Bo

    2017-07-01

    Macroalgae biomass has been considered as a promising feedstock for biogas production. In order to improve the efficiency of anaerobic digestion (AD) of macroalgae, semi-continuous fermentation was conducted to examine the effects of organic loading rate (OLR) on biogas production from Macrocystis pyrifer. Results showed that, under OLRs of 1.37, 2.74, 4.12 and 6.85kgVS substrate /(m 3 ·d), the average unit biogas yields were 438.9, 477.3, 480.1 and 188.7mL/(gVS substrate d), respectively. It indicated that biogas production was promoted by the increased OLR in an appropriate range while inhibited by the OLR beyond the appropriate range. The investigation on physical-chemical parameters revealed that unfavorable VFAs concentration, pH and salinity might be the main causes for system failure due to the overrange OLR, while the total phenols failed to reach the inhibitory concentration. Microbial community analysis demonstrated that several bacterial and archaeal phyla altered with increase in OLR apparently. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Operative correction of judoists’ training loads on the base of on-line monitoring of heart beats rate

    Directory of Open Access Journals (Sweden)

    Yong Qiang Liu

    2015-04-01

    Full Text Available Purpose: ensure increase of effectiveness of training process’s control by means of operative correction of training loads of different qualification judo wrestlers’ heart beats rate indicators. Material: the research was conducted on the base of Brest SCJSOR № 1. Judo wrestlers of different sport qualification (age 17-19 years old, n=15 participated in the research. Monitoring of judo wrestlers’ heart beats rate was carried out with the help of system “Polar”. Results: we have found factorial structure of functional fitness in every profile of sportsmen. Model characteristics of judo wrestlers were supplemented with the most important sides of functional fitness. Analysis of indicators of restoration effectiveness indicators (REI in both groups of judo wrestlers showed high level of organism’s responsiveness to training load of special and power orientation in comparison with speed power load. We have worked out algorithm of operative correction of training loads by indicators of heart beats rate in training process, depending on orientation and intensity of loads’ physiological influence on judo wrestler. Conclusions: Telemetric on-line monitoring of sportsman’s heart beats rate and calculation of REI permit to objectively assess effectiveness of training’s construction and of micro-cycle in total and detect in due time the trend to development of over-loading and failure of adaptation.

  13. Operative correction of judoists’ training loads on the base of on-line monitoring of heart beats rate

    Directory of Open Access Journals (Sweden)

    Liu Yong Qiang

    2015-02-01

    Full Text Available Purpose: ensure increase of effectiveness of training process’s control by means of operative correction of training loads of different qualification judo wrestlers’ heart beats rate indicators. Material: the research was conducted on the base of Brest SCJSOR № 1. Judo wrestlers of different sport qualification (age 17-19 years old, n=15 participated in the research. Monitoring of judo wrestlers’ heart beats rate was carried out with the help of system “Polar”. Results: we have found factorial structure of functional fitness in every profile of sportsmen. Model characteristics of judo wrestlers were supplemented with the most important sides of functional fitness. Analysis of indicators of restoration effectiveness indicators (REI in both groups of judo wrestlers showed high level of organism’s responsiveness to training load of special and power orientation in comparison with speed power load. We have worked out algorithm of operative correction of training loads by indicators of heart beats rate in training process, depending on orientation and intensity of loads’ physiological influence on judo wrestler. Conclusions: Telemetric on-line monitoring of sportsman’s heart beats rate and calculation of REI permit to objectively assess effectiveness of training’s construction and of micro-cycle in total and detect in due time the trend to development of over-loading and failure of adaptation.

  14. Oxidation rates of carbon and nitrogen in char residues from solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Karlstroem, O.

    2013-06-01

    Computational fluid dynamics (CFD) modeling is an important tool in designing new combustion systems. By using CFD modeling, entire combustion systems can be modeled and the emissions and the performance can be predicted. CFD modeling can also be used to develop new and better combustion systems from an economical and environmental point of view. In CFD modeling of solid fuel combustion, the combustible fuel is generally treated as single fuel particles. One of the limitations with the CFD modeling concerns the sub-models describing the combustion of single fuel particles. Available models in the scientific literature are in many cases not suitable as submodels for CFD modeling since they depend on a large number of input parameters and are computationally heavy. In this thesis CFD-applicable models are developed for the combustion of single fuel particles. The single particle models can be used to improve the combustion performance in various combustion devices or develop completely new technologies. The investigated fields are oxidation of carbon (C) and nitrogen (N) in char residues from solid fuels. Modeled char-C oxidation rates are compared to experimental oxidation rates for a large number of pulverized solid fuel chars under relevant combustion conditions. The experiments have been performed in an isothermal plug flow reactor operating at 1123-1673 K and 3-15 vol.% O{sub 2}. In the single particle model, the char oxidation is based on apparent kinetics and depends on three fuel specific parameters: apparent pre-exponential factor, apparent activation energy, and apparent reaction order. The single particle model can be incorporated as a sub-model into a CFD code. The results show that the modeled char oxidation rates are in good agreement with experimental char oxidation rates up to around 70% of burnout. Moreover, the results show that the activation energy and the reaction order can be assumed to be constant for a large number of bituminous coal chars

  15. Magnetic Solid Phase Extraction and Removal of Five Cationic Dyes from Aqueous Solution Using Magnetite Nanoparticle Loaded Platanusorientalis Waste Leaves

    Directory of Open Access Journals (Sweden)

    Elaheh Madrakian

    2016-12-01

    Full Text Available This paper reports on synthesis of a magnetic adsorbent for wastewater treatment purposes. In this regard, platanus orientalis waste leaves were chosen as a cheap material for preparing the magnetic adsorbent by loading magnetite nanoparticles on it. The synthesized adsorbent was characterized using scanning electron microscope and X-ray diffractometer. Then, it was used for magnetic solid phase extraction and removal of five cationic dyes including methyl violet (MV, methylene blue (MB, malachite green (MG, crystal violet (CV, and neutral red (NR from aqueous solution as a model application. Different important factors affecting the adsorption process were optimized, and the results showed that under the optimized conditions (pH 10 for CV, MV, MB, and MG; pH 6 for NR; adsorbent dosage, 20 mg; agitation time, 25 min efficient removal of the investigated dyes (adsorption capacities between of 89-133 mg g-1 is achievable using the synthesized adsorbent. Furthermore, the reusability experiments showed that the adsorbent could be reused at least ten cycles without any significant loss in its sorption behavior.

  16. Preparation of oridonin-loaded solid lipid nanoparticles and studies on them in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Dianrui [College of Life Science and Technology, Beijing University of Chemical Technology, 15 Bei Sanhuan Donglu, Beijing 100029 (China); Tan Tianwei [College of Life Science and Technology, Beijing University of Chemical Technology, 15 Bei Sanhuan Donglu, Beijing 100029 (China); Gao Lei [Department of Pharmaceutics, College of Pharmacy, Shandong University, 44 Wenhua Xilu, Jinan 250012 (China)

    2006-12-14

    Oridonin, a lipophilic Chinese medicine, has very low oral bioavailability due to its poor solubility. Solid lipid nanoparticle (SLN) delivery systems of oridonin have been formed using stearic acid, soybean lecithin and pluronic F{sub 68} in our studies to overcome this problem. Emulsion evaporation-solidification at low temperature was used to prepare SLN dispersions. The particle size and morphology were examined by transmission electron microscopy (TEM), and the zeta potential was measured by a television micro-electrophoresis apparatus. Process and formulation variables have been studied and optimized on the basis of entrapment efficiency. Differential scanning calorimetry (DSC) and powder x-ray diffraction (PXRD) studies were performed to characterize the state of the drug. In vitro release studies were performed in phosphate-buffer solution (PBS) (pH 7.4). The tissue distribution in mice and the pharmacokinetics in rabbits were studied to evaluate the tissue targeted property of SLNs. Stable SLN formulations of oridonin having a mean size range of 15-35 nm and mean zeta potential -45.07 mV were developed. More than 40% oridonin was entrapped in SLNs. DSC and PXRD analysis showed that oridonin is dispersed in SLNs in an amorphous state. The release pattern of the drug was analysed and found to follow the Higuchi equations. In vivo studies demonstrated that oridonin-loaded SLNs obviously increased the concentration of oridonin in liver, lung and spleen, while its distribution in heart and kidney decreased.

  17. Hierarchical Load Tracking Control of a Grid-Connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    Directory of Open Access Journals (Sweden)

    Yonghui Li

    2015-03-01

    Full Text Available Based on the benchmark solid oxide fuel cell (SOFC dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject to the constraints of fuel utilization factor, stack temperature and output active power. The optimal operating conditions of the grid-connected SOFC were obtained by solving the NLP problem considering the power consumed by the air compressor. With the optimal operating conditions of the SOFC for the maximum efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model.

  18. Flexible solid-state symmetric supercapacitors based on MnO2 nanofilms with high rate capability and long cyclability

    Science.gov (United States)

    Wu, Lingxia; Li, Ruizhi; Guo, Junling; Zhou, Cheng; Zhang, Wenpei; Wang, Chong; Huang, Yu; Li, Yuanyuan; Liu, Jinping

    2013-08-01

    Flexible solid-state symmetric supercapacitor was fabricated using MnO2 nanofilms growing directly on carbon cloth as the electrodes and PVA/H3PO4 gel as the electrolyte/separator. The device can be operated at a stable cell-voltage up to 1.4 V, obviously larger than that of conventional solid-state symmetric supercapacitors (≤1 V). It exhibited excellent rate capability with a scan rate as high as 20 V s-1 and a long cyclability (˜60000 cycles) even under severe mechanical deformation. The charge storage mechanism at different scan rates was also quantitatively analyzed.

  19. Flexible solid-state symmetric supercapacitors based on MnO2 nanofilms with high rate capability and long cyclability

    Directory of Open Access Journals (Sweden)

    Lingxia Wu

    2013-08-01

    Full Text Available Flexible solid-state symmetric supercapacitor was fabricated using MnO2 nanofilms growing directly on carbon cloth as the electrodes and PVA/H3PO4 gel as the electrolyte/separator. The device can be operated at a stable cell-voltage up to 1.4 V, obviously larger than that of conventional solid-state symmetric supercapacitors (≤1 V. It exhibited excellent rate capability with a scan rate as high as 20 V s−1 and a long cyclability (∼60000 cycles even under severe mechanical deformation. The charge storage mechanism at different scan rates was also quantitatively analyzed.

  20. Impact of Exchange Rate Movements, Global Economic Activity, and the BDI Volatility on Loaded Port Cargo Throughput in South Korea

    Directory of Open Access Journals (Sweden)

    Chang Beom Kim

    2016-12-01

    Full Text Available This study examines the effects of exchange rate movements, global economic activity, and the volatility of the Baltic Dry Index (BDI on South Korea's loaded port cargo throughput, based on monthly data for the period from January 2000 to October 2014. The results indicate that the BDI volatility has a negative effect on the loaded cargo throughput, while increases in the nominal exchange rate and in global economy activity have a positive effect. In addition, the error correction model results show that the error correction term is statistically significant with the negative sign.

  1. Tensile behaviour of natural fibres. Effect of loading rate, temperature and humidity on the “accommodation” phenomena

    Directory of Open Access Journals (Sweden)

    Placet V.

    2010-06-01

    Full Text Available The use of natural fibres in high performance composite requires an accurate understanding of the mechanical behaviour of the fibres themselves. As for all biobased materials, the mechanical properties of natural fibres depend generally on the testing rate and on the environmental conditions. In addition, natural fibres as hemp for example exhibit a particular mechanism of stiffness increase and accommodation phenomena under cyclic loading. Loading rate, temperature and humidity effects on the viscoelastic properties of hemp fibres were investigated in this work. The collected results clearly emphasis the involvement of time-dependant and mechano-sorptive mechanisms.

  2. SU-D-209-01: Can Fluoroscopic Air-Kerma Rates Be Reliably Measured with Solid-State Meters?

    International Nuclear Information System (INIS)

    Feng, C; Thai, L; Wagner, L; Ozus, B

    2016-01-01

    Purpose: Ionization chambers remain the standard for calibration of air-kerma rate measuring devices. Despite their strong energy-dependent response, solid state radiation detectors are increasingly used, primarily due to their efficiency in making standardized measurements. To test the reliability of these devices in measuring air-kerma rates, we compared ion chambers measurements with solid-state measurements for various mobile fluoroscopes operated at different beam qualities and air-kerma rates. Methods: Six mobile fluoroscopes (GE OEC models 9800 and 9900) were used to generate test beams. Using various field sizes and dose rate controls, copper attenuators and a lead attenuator were placed at the image receptor in varying combinations to generate a range of air-kerma rates. Air-kerma rates at 30 centimeters from the image receptors were measured using two 6-cm"3 ion chambers with electrometers (Radcal, models 1015 and 9015) and two with solid state detectors (Unfors Xi and Raysafe X2). No error messages occurred during measurements. However, about two months later, one solid-state device stopped working and was replaced by the manufacturer. Two out of six mobile fluoroscopic units were retested with the replacement unit. Results: Generally, solid state and ionization chambers agreed favorably well, with two exceptions. Before replacement of the detector, the Xi meter when set in the “RF High” mode deviated from ion chamber readings by factors of 2 and 10 with no message indicating error in measurement. When set in the “RF Low” mode, readings were within −4% to +3%. The replacement Xi detector displayed messages alerting the user when settings were not compatible with air-kerma rates. Conclusion: Air-kerma rates can be measured favorably well using solid-state devices, but users must be aware of the possibility that readings can be grossly in error with no discernible indication for the deviation.

  3. SU-D-209-01: Can Fluoroscopic Air-Kerma Rates Be Reliably Measured with Solid-State Meters?

    Energy Technology Data Exchange (ETDEWEB)

    Feng, C; Thai, L; Wagner, L [The University of Texas Health Science Center at Houston, Houston, TX (United States); Ozus, B [CHI St Luke’s Health, Baylor St Luke’s Medical Center, Houston, TX (United States)

    2016-06-15

    Purpose: Ionization chambers remain the standard for calibration of air-kerma rate measuring devices. Despite their strong energy-dependent response, solid state radiation detectors are increasingly used, primarily due to their efficiency in making standardized measurements. To test the reliability of these devices in measuring air-kerma rates, we compared ion chambers measurements with solid-state measurements for various mobile fluoroscopes operated at different beam qualities and air-kerma rates. Methods: Six mobile fluoroscopes (GE OEC models 9800 and 9900) were used to generate test beams. Using various field sizes and dose rate controls, copper attenuators and a lead attenuator were placed at the image receptor in varying combinations to generate a range of air-kerma rates. Air-kerma rates at 30 centimeters from the image receptors were measured using two 6-cm{sup 3} ion chambers with electrometers (Radcal, models 1015 and 9015) and two with solid state detectors (Unfors Xi and Raysafe X2). No error messages occurred during measurements. However, about two months later, one solid-state device stopped working and was replaced by the manufacturer. Two out of six mobile fluoroscopic units were retested with the replacement unit. Results: Generally, solid state and ionization chambers agreed favorably well, with two exceptions. Before replacement of the detector, the Xi meter when set in the “RF High” mode deviated from ion chamber readings by factors of 2 and 10 with no message indicating error in measurement. When set in the “RF Low” mode, readings were within −4% to +3%. The replacement Xi detector displayed messages alerting the user when settings were not compatible with air-kerma rates. Conclusion: Air-kerma rates can be measured favorably well using solid-state devices, but users must be aware of the possibility that readings can be grossly in error with no discernible indication for the deviation.

  4. Stress-associated cardiovascular reaction masks heart rate dependence on physical load in mice.

    Science.gov (United States)

    Andreev-Andrievskiy, A A; Popova, A S; Borovik, A S; Dolgov, O N; Tsvirkun, D V; Custaud, M; Vinogradova, O L

    2014-06-10

    When tested on the treadmill mice do not display a graded increase of heart rate (HR), but rather a sharp shift of cardiovascular indices to high levels at the onset of locomotion. We hypothesized that under test conditions cardiovascular reaction to physical load in mice is masked with stress-associated HR increase. To test this hypothesis we monitored mean arterial pressure (MAP) and heart rate in C57BL/6 mice after exposure to stressful stimuli, during spontaneous locomotion in the open-field test, treadmill running or running in a wheel installed in the home cage. Mice were treated with β1-adrenoblocker atenolol (2mg/kg ip, A), cholinolytic ipratropium bromide (2mg/kg ip, I), combination of blockers (A+I), anxiolytic diazepam (5mg/kg ip, D) or saline (control trials, SAL). MAP and HR in mice increased sharply after handling, despite 3weeks of habituation to the procedure. Under stressful conditions of open field test cardiovascular parameters in mice were elevated and did not depend on movement speed. HR values did not differ in I and SAL groups and were reduced with A or A+I. HR was lower at rest in D pretreated mice. In the treadmill test HR increase over speeds of 6, 12 and 18m/min was roughly 1/7-1/10 of HR increase observed after placing the mice on the treadmill. HR could not be increased with cholinolytic (I), but was reduced after sympatholytic (A) or A+I treatment. Anxiolytic (D) reduced heart rate at lower speeds of movement and its overall effect was to unmask the dependency of HR on running speed. During voluntary running in non-stressful conditions of the home cage HR in mice linearly increased with increasing running speeds. We conclude that in test situations cardiovascular reactions in mice are governed predominantly by stress-associated sympathetic activation, rendering efforts to evaluate HR and MAP reactions to workload unreliable. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Calibration of track detectors and measurement of radon exhalation rate from solid samples

    International Nuclear Information System (INIS)

    Singh, Ajay Kumar; Jojo, P.J.; Prasad, Rajendra; Khan, A.J.; Ramachandran, T.V.

    1997-01-01

    CR-39 and LR-115 type II track detectors to be used for radon exhalation measurements have been calibrated. The configurations fitted with detectors in Can technique in the open cup mode are cylindrical plastic cup (PC) and conical plastic cup (CPC). The experiment was performed in radon exposure chamber having monodisperse aerosols of 0.2 μm size, to find the relationship between track density and the radon concentration. The calibration factors for PC and CPC type dosimeters with LR-115 type II detector were found to be 0.056 and 0.083 tracks cm -2 d -1 (Bqm -3 ) -1 respectively, while with CR-39 detector the values were 0.149 and 0.150 tracks cm -2 d -1 (Bq m -3 ) -1 . Employing the Can technique, measurements of exhalation rates from solid samples used as construction materials, are undertaken. Radon exhalation rate is found to be minimum in cement samples while in fly ash it is not enhanced as compared to coal samples. (author)

  6. MHz repetition rate solid-state driver for high current induction accelerators

    International Nuclear Information System (INIS)

    Brooksby, C; Caporaso, G; Goerz, D; Hanks, R; Hickman, B; Kirbie, H; Lee, B; Saethre, R.

    1999-01-01

    A research team from the Lawrence Livermore National Laboratory and Bechtel Nevada Corporation is developing an all solid-state power source for high current induction accelerators. The original power system design, developed for heavy-ion fusion accelerators, is based on the simple idea of using an array of field effect transistors to switch energy from a pre-charged capacitor bank to an induction accelerator cell. Recently, that idea has been expanded to accommodate the greater power needs of a new class of high-current electron accelerators for advanced radiography. For this purpose, we developed a 3-stage induction adder that uses over 4,000 field effect transistors to switch peak voltages of 45 kV at currents up to 4.8 kA with pulse repetition rates of up to 2 MHz. This radically advanced power system can generate a burst of five or more pulses that vary from 200 ns to 2 ampersand micro;s at a duty cycle of up to 25%. Our new source is precise, robust, flexible, and exceeds all previous drivers for induction machines by a factor of 400 in repetition rate and a factor of 1000 in duty cycle

  7. Estimation of Subjective Mental Work Load Level with Heart Rate Variability by Tolerance to Driver's Mental Load

    Science.gov (United States)

    Yokoi, Toshiyuki; Itoh, Michimasa; Oguri, Koji

    Most of the traffic accidents have been caused by inappropriate driver's mental state. Therefore, driver monitoring is one of the most important challenges to prevent traffic accidents. Some studies for evaluating the driver's mental state while driving have been reported; however driver's mental state should be estimated in real-time in the future. This paper proposes a way to estimate quantitatively driver's mental workload using heart rate variability. It is assumed that the tolerance to driver's mental workload is different depending on the individual. Therefore, we classify people based on their individual tolerance to mental workload. Our estimation method is multiple linear regression analysis, and we compare it to NASA-TLX which is used as the evaluation method of subjective mental workload. As a result, the coefficient of correlation improved from 0.83 to 0.91, and the standard deviation of error also improved. Therefore, our proposed method demonstrated the possibility to estimate mental workload.

  8. Handball load and shoulder injury rate: a 31-week cohort study of 679 elite youth handball players.

    Science.gov (United States)

    Møller, M; Nielsen, R O; Attermann, J; Wedderkopp, N; Lind, M; Sørensen, H; Myklebust, G

    2017-02-01

    Knowledge of injury patterns, an essential step towards injury prevention, is lacking in youth handball. To investigate if an increase in handball load is associated with increased shoulder injury rates compared with a minor increase or decrease, and if an association is influenced by scapular control, isometric shoulder strength or glenohumeral range of motion (ROM). 679 players (14-18 years) provided weekly reports on shoulder injury and handball load (training and competition hours) over 31 weeks using the SMS, phone and medical examination system. Handball load in a given week was categorised into (1) 60% relative to the weekly average amount of handball load the preceding 4 weeks. Assessment of shoulder isometric rotational and abduction strength, ROM and scapular control was performed at baseline and midseason. An increase in handball load by >60% was associated with greater shoulder injury rate (HR 1.91; 95% CI 1.00 to 3.70, p=0.05) compared with the reference group. The effect of an increase in handball load between 20% and 60% was exacerbated among players with reduced external rotational strength (HR 4.0; 95% CI 1.1 to 15.2, p=0.04) or scapular dyskinesis (HR 4.8; 95% CI 1.3 to 18.3, p=0.02). Reduced external rotational strength exacerbated the effect of an increase above 60% (HR 4.2; 95% CI 1.4 to 12.8, p=0.01). A large increase in weekly handball load increases the shoulder injury rate in elite youth handball players; particularly, in the presence of reduced external rotational strength or scapular dyskinesis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Development of free-flowing peppermint essential oil-loaded hollow solid lipid micro- and nanoparticles via atomization with carbon dioxide.

    Science.gov (United States)

    Yang, Junsi; Ciftci, Ozan Nazim

    2016-09-01

    The main objective of this study was to overcome the issues related to the volatility and strong smell that limit the efficient utilization of essential oils as "natural" antimicrobials in the food industry. Peppermint essential oil-loaded hollow solid lipid micro- and nanoparticles were successfully formed using a novel "green" method based on atomization of CO 2 -expanded lipid mixture. The highest essential oil loading efficiency (47.5%) was achieved at 50% initial essential oil concentration at 200bar expansion pressure and 50μm nozzle diameter, whereas there was no significant difference between the loading efficiencies (35%-39%) at 5%, 7%, 10%, and 20% initial essential oil concentrations (p>0.05). Particles generated at all initial essential oil concentrations were spherical but increasing the initial essential oil concentration to 20% and 50% generated a less smooth particle surface. After 4weeks of storage, 61.2%, 42.5%, 0.2%, and 2.0% of the loaded essential oil was released from the particles formed at 5%, 10%, 20%, and 50% initial essential oil concentrations, respectively. This innovative simple and clean process is able to form spherical hollow micro- and nanoparticles loaded with essential oil that can be used as food grade antimicrobials. These novel hollow solid lipid micro- and nanoparticles are alternatives to the solid lipid nanoparticles, and overcome the issues associated with the solid lipid nanoparticles. The dry free-flowing products make the handling and storage more convenient, and the simple and clean process makes the scaling up more feasible. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Initial foot contact and related kinematics affect impact loading rate in running.

    Science.gov (United States)

    Breine, Bastiaan; Malcolm, Philippe; Van Caekenberghe, Ine; Fiers, Pieter; Frederick, Edward C; De Clercq, Dirk

    2017-08-01

    This study assessed kinematic differences between different foot strike patterns and their relationship with peak vertical instantaneous loading rate (VILR) of the ground reaction force (GRF). Fifty-two runners ran at 3.2 m · s -1 while we recorded GRF and lower limb kinematics and determined foot strike pattern: Typical or Atypical rearfoot strike (RFS), midfoot strike (MFS) of forefoot strike (FFS). Typical RFS had longer contact times and a lower leg stiffness than Atypical RFS and MFS. Typical RFS showed a dorsiflexed ankle (7.2 ± 3.5°) and positive foot angle (20.4 ± 4.8°) at initial contact while MFS showed a plantar flexed ankle (-10.4 ± 6.3°) and more horizontal foot (1.6 ± 3.1°). Atypical RFS showed a plantar flexed ankle (-3.1 ± 4.4°) and a small foot angle (7.0 ± 5.1°) at initial contact and had the highest VILR. For the RFS (Typical and Atypical RFS), foot angle at initial contact showed the highest correlation with VILR (r = -0.68). The observed higher VILR in Atypical RFS could be related to both ankle and foot kinematics and global running style that indicate a limited use of known kinematic impact absorbing "strategies" such as initial ankle dorsiflexion in MFS or initial ankle plantar flexion in Typical RFS.

  11. Advanced bridge safety initiative, task 1 : development of improved analytical load rating procedures for flat-slab concrete bridges - a thesis and guidelines.

    Science.gov (United States)

    2010-01-01

    Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

  12. Effects of temperature and organic loading rate on the performance and microbial community of anaerobic co-digestion of waste activated sludge and food waste.

    Science.gov (United States)

    Gou, Chengliu; Yang, Zhaohui; Huang, Jing; Wang, Huiling; Xu, Haiyin; Wang, Like

    2014-06-01

    Anaerobic co-digestion of waste activated sludge and food waste was investigated semi-continuously using continuously stirred tank reactors. Results showed that the performance of co-digestion system was distinctly influenced by temperature and organic loading rate (OLR) in terms of gas production rate (GPR), methane yield, volatile solids (VS) removal efficiency and the system stability. The highest GPR at 55 °C was 1.6 and 1.3 times higher than that at 35 and 45 °C with the OLR of 1 g VSL(-1)d(-1), and the corresponding average CH₄ yields were 0.40, 0.26 and 0.30 L CH₄ g(-1)VSadded, respectively. The thermophilic system exhibited the best load bearing capacity at extremely high OLR of 7 g VSL(-1)d(-1), while the mesophilic system showed the best process stability at low OLRs (< 5 g VSL(-1)d(-1)). Temperature had a more remarkable effect on the richness and diversity of microbial populations than the OLR. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Comparison of heavy metal loads in stormwater runoff from major and minor urban roads using pollutant yield rating curves

    International Nuclear Information System (INIS)

    Davis, Brett; Birch, Gavin

    2010-01-01

    Trace metal export by stormwater runoff from a major road and local street in urban Sydney, Australia, is compared using pollutant yield rating curves derived from intensive sampling data. The event loads of copper, lead and zinc are well approximated by logarithmic relationships with respect to total event discharge owing to the reliable appearance of a first flush in pollutant mass loading from urban roads. Comparisons of the yield rating curves for these three metals show that copper and zinc export rates from the local street are comparable with that of the major road, while lead export from the local street is much higher, despite a 45-fold difference in traffic volume. The yield rating curve approach allows problematic environmental data to be presented in a simple yet meaningful manner with less information loss. - A simple method for representing data onroad runoff pollution allows comparisons among dissimilar sites and could form the basis for a pollution database.

  14. Effect of loading rate on dynamic fracture of reaction bonded silicon nitride

    Science.gov (United States)

    Liaw, B. M.; Kobayashi, A. S.; Emery, A. F.

    1986-01-01

    Wedge-loaded, modified tapered double cantilever beam (WL-MTDCB) specimens under impact loading were used to determine the room temperature dynamic fracture response of reaction bonded silicon nitride (RBSN). The crack extension history, with the exception of the terminal phase, was similar to that obtained under static loading. Like its static counterpart, a distinct crack acceleration phase, which was not observed in dynamic fracture of steel and brittle polymers, was noted. Unlike its static counterpart, the crack continued to propagate at nearly its terminal velocity under a low dynamic stress intensity factor during the terminal phase of crack propagation. These and previously obtained results for glass and RBSN show that dynamic crack arrest under a positive dynamic stress intensity factor is unlikely in static and impact loaded structural ceramics.

  15. Effects of feeding and organism loading rate on PCB accumulation by Lumbriculus variegatus in sediment bioaccumulation testing

    Science.gov (United States)

    Sediment bioaccumulation test methods published by USEPA and ASTM in 2000 specify that the Lumbriculus variegatus, a freshwater oligochaete, should not be fed during the 28-day exposure and recommends an organism loading rate of total organic carbon in sediment to organism dry we...

  16. The Effect of Soldier Marching, Rucksack Load, and Heart Rate on Marksmanship

    Science.gov (United States)

    2017-04-01

    has demonstrated that marksmanship is a complex task that can be modified by both physiological and psychological processes (Helin, Sihvonen...complete the march with Rucksack load due to an ankle injury sustained on the cross-country march, and par- tial data from his Rucksack visit was...that carrying heavier loads results in physiologic changes. A multilevel logistic regression controlling for the multiple observations (shots

  17. Ammonia and nitrite removal rates in a closed recirculating-water system, under three load rates of rainbow trout Oncorhynchus mykiss

    OpenAIRE

    Arredondo-Figueroa, J. L.; Ingle de la Mora, G; Guerrero-Legarreta, I; Ponce-Palafox, J. T.; Barriga-Sosa, I. de los A.

    2007-01-01

    Nitrification and denitrification rates of inorganic nitrogen were studied in a closed recirculating-water system, comparing three load rates of rainbow trout Oncorhynchus mykiss (89, 156 and 194 kg in each tank with two repetitions). Six self-cleaning water circular fish tanks with a volume of 4.3 m³ were used, maintaining a 3.94 m³/day of average flow rate and constant aeration. A total of 371 rainbow trout, 524 ± 8 g initial wet weight were introduced in the system and fed with a commercia...

  18. The efficacy of Isotretinoin-loaded solid lipid nanoparticles in comparison to Isotrex® on acne treatment

    Directory of Open Access Journals (Sweden)

    Shiva Golmohammadzadeh

    2013-01-01

    Full Text Available Abstract: Topical retinoids are considered as the first line therapy in the treatment of acne vulgaris, but they are associated with cutaneous irritation. In this study, isotretinoin-loaded solid lipid nanoparticles(IT-SLN were prepared to treat the mild to moderate acne. Also using IT-SLN would minimize IT adverse effects in comparison to commercial product, Isotrex®. This study was conducted to prepare and characterize IT-SLN and assessing the efficiency of IT-SLN comparing to Isotrex® acne. IT-SLN was prepared using hot high pressure homogenization method.  IT-SLN contained 0.05% IT in 5% of lipid phase (Glyceryl monostearate- GMS and tween 80 (2.5 % w/v was used as surfactant in the aqueous phase. IT-SLN was characterized by particle size analyzing, differential scanning calorimetry and transmission electron microscopy. Encapsulation efficacy was also obtained using spectrophotometry. The efficacy of IT-SLN was evaluated in a randomized, single-blind, parallel-group study and compared with Isotrex®. Forty patients encountered in the study and divided in two groups. Treatment regimen was once-nightly topical administration accompanied with topical administration of clindamycin 2% solution twice a day for 8 weeks. The particle size of IT-SLN was around 60 nm with PDI of 0.4 and zeta potential was about -40 mV. Encapsulation efficacy of IT in SLN in crystalline form was 84±0.21%. IT-SLN produced significantly better treatment than Isotrex® in both non-inflammatory and inflammatory lesions according to its recovery percent after 8 weeks. Also IT-SLN gained better global assessment scores. Our results showed that IT-SLN had higher efficacy than Isotrex® to clear non-inflammatory and inflammatory lesions.

  19. Enhanced intracellular delivery and antibacterial efficacy of enrofloxacin-loaded docosanoic acid solid lipid nanoparticles against intracellular Salmonella.

    Science.gov (United States)

    Xie, Shuyu; Yang, Fei; Tao, Yanfei; Chen, Dongmei; Qu, Wei; Huang, Lingli; Liu, Zhenli; Pan, Yuanhu; Yuan, Zonghui

    2017-01-23

    Enrofloxacin-loaded docosanoic acid solid lipid nanoparticles (SLNs) with different physicochemical properties were developed to enhance activity against intracellular Salmonella. Their cellular uptake, intracellular elimination and antibacterial activity were studied in RAW 264.7 cells. During the experimental period, SLN-encapsulated enrofloxacin accumulated in the cells approximately 27.06-37.71 times more efficiently than free drugs at the same extracellular concentration. After incubation for 0.5 h, the intracellular enrofloxacin was enhanced from 0.336 to 1.147 μg/mg of protein as the sizes of nanoparticles were increased from 150 to 605 nm, and from 0.960 to 1.147 μg/mg of protein when the charge was improved from -8.1 to -24.9 mv. The cellular uptake was more significantly influenced by the size than it was by the charge, and was not affected by whether the charge was positive or negative. The elimination of optimal SLN-encapsulated enrofloxacin from the cells was significantly slower than that of free enrofloxacin after removing extracellular drug. The inhibition effect against intracellular Salmonella CVCC541 of 0.24 and 0.06 μg/mL encapsulated enrofloxacin was stronger than 0.6 μg/mL free drug after all of the incubation periods and at 48 h, respectively. Docosanoic acid SLNs are thus considered as a promising carrier for intracellular bacterial treatment.

  20. The study of solid circulation rate in a compartmented fluidized bed gasifier (CFBG)

    Science.gov (United States)

    Wee, S. K.; Pok, Y. W.; Law, M. C.; Lee, V. C. C.

    2016-06-01

    Biomass waste has been abundantly available in Malaysia since the booming of palm oil industry. In order to tackle this issue, gasification is seen a promising technology to convert waste into energy. In view of the heat requirement for endothermic gasification reaction as well as the complex design and operation of multiple fluidized beds, compartmented fluidized bed gasifier (CFBG) with the combustor and the gasifier as separate compartments is proposed. As such, solid circulation rate (SCR) is one of the essential parameters for steady gasification and combustion to be realized in their respective compartments. Experimental and numerical studies (CFD) on the effect of static bed height, main bed aeration, riser aeration and v-valve aeration on SCR have been conducted in a cold- flow CFBG model with only river sand as the fluidizing medium. At lower operating range, the numerical simulations under-predict the SCR as compared to that of the experimental results. Also, it predicts slightly different trends over the range. On the other hand, at higher operating range, the numerical simulations are able to capture those trends as observed in the experimental results at the lower operating range. Overall, the numerical results compare reasonably well with that of the experimental works.

  1. Evaluation of Burning Test Rate Method for Flammable Solids to Increase air-Cargo Safety.

    Science.gov (United States)

    Lukežič, Marjan; Marinšek, Marjan; Faganeli, Jadran

    2010-03-01

    This paper deals with a standard classification procedure for readily combustible solids and their assignment to the relevant packing groups according to international air-cargo legislation and regulations. The current International Air Transport Association and United Nations Orange Book regulations were used on chemically similar substances: hexamethylenetetramine and Dancook ignition briquettes, which are both assigned into the same Packing Group III. To critically evaluate the degree of hazard both chemicals present, a standard burning test rate as well as thermogravimetry, differential scanning calorimetry and evolved gas analysis measurements were performed. It was shown that relatively small changes in the chemical composition of the material may have essential influence on the package group determination. Taking into account all the facts collected in the experimental work, it was concluded that ignition briquettes will undergo spontaneous combustion if exposed to elevated temperatures and, from this point of view, represent higher risk than hexamethylenetetramine during air transportation. Therefore, ignition briquettes should be classified into Packing Group II.

  2. The effects of xylazine, detomidine, acepromazine and butorphanol on equine solid phase gastric emptying rate.

    Science.gov (United States)

    Sutton, D G M; Preston, T; Christley, R M; Cohen, N D; Love, S; Roussel, A J

    2002-07-01

    The aim of this study was to measure the effects of specific commonly used sedative protocols on equine solid phase gastric emptying rate, using the 13C-octanoic acid breath test (13C-OABT). The gastric emptying of a standard 13C-labelled test meal was measured once weekly in 8 mature horses over two 4 week treatment periods. Each horse acted as its own control. In treatment Period 1, saline (2 ml i.v.), xylazine (0.5 mg/kg i.v.), detomidine (0.01 mg/kg i.v.) or detomidine/butorphanol combination (0.01/0.02 mg/kg i.v.) was administered in randomised order after ingestion of the test meal. During treatment Period 2, test meal consumption was followed by saline, xylazine (1.0 mg/kg i.v.), or detomidine (0.03 mg/kg i.v.) administration, or preceded by acepromazine (0.05 mg/kg i.m.) in randomised order. The 13C:12C ratio of sequential expiratory breath samples was determined by isotope ratio mass spectrometry, and used to measure the gastric half-emptying time, t 1/2, and duration of the lag phase, t lag, for each of the 64 tests. In treatment Period 1, detomidine/butorphanol prolonged both t 1/2 and t lag with respect to xylazine 0.5 mg/kg and the saline control (P detomidine 0.03 mg/kg delayed each parameter with respect to saline, acepromazine and xylazine 1.0 mg/kg (P detomidine on gastric emptying rate was dose related (P<0.05). These findings may have clinical significance for case selection when these agents are used for purposes of sedation and/or analgesia.

  3. Primary and secondary effects of real-time feedback to reduce vertical loading rate during running.

    Science.gov (United States)

    Baggaley, M; Willy, R W; Meardon, S A

    2017-05-01

    Gait modifications are often proposed to reduce average loading rate (AVLR) during running. While many modifications may reduce AVLR, little work has investigated secondary gait changes. Thirty-two rearfoot runners [16M, 16F, 24.7 (3.3) years, 22.72 (3.01) kg/m 2 , >16 km/week] ran at a self-selected speed (2.9 ± 0.3 m/s) on an instrumented treadmill, while 3D mechanics were calculated via real-time data acquisition. Real-time visual feedback was provided in a randomized order to cue a forefoot strike (FFS), a minimum 7.5% decrease in step length, or a minimum 15% reduction in AVLR. AVLR was reduced by FFS (mean difference = 26.4 BW/s; 95% CI = 20.1, 32.7; P < 0.001), shortened step length (8.4 BW/s; 95% CI = 2.9, 14.0; P = 0.004), and cues to reduce AVLR (14.9 BW/s; 95% CI = 10.2, 19.6; P < 0.001). FFS, shortened step length, and cues to reduce AVLR all reduced eccentric knee joint work per km [(-48.2 J/kg*m; 95% CI = -58.1, -38.3; P < 0.001), (-35.5 J/kg*m; 95% CI = -42.4, 28.6; P < 0.001), (-23.1 J/kg*m; 95% CI = -33.3, -12.9; P < 0.001)]. However, FFS and cues to reduce AVLR also increased eccentric ankle joint work per km [(54.49 J/kg*m; 95% CI = 45.3, 63.7; P < 0.001), (9.20 J/kg*m; 95% CI = 1.7, 16.7; P = 0.035)]. Potentially injurious secondary effects associated with FFS and cues to reduce AVLR may undermine their clinical utility. Alternatively, a shortened step length resulted in small reductions in AVLR, without any potentially injurious secondary effects. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Organic loading rates affect composition of soil-derived bacterial communities during continuous, fermentative biohydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yonghua; Bruns, Mary Ann [Department of Crop and Soil Sciences, The Pennsylvania State University, University Park, PA 16802 (United States); Zhang, Husen; Salerno, Michael; Logan, Bruce E. [Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2008-11-15

    Bacterial community composition during steady-state, fermentative H{sub 2} production was compared across a range of organic loading rates (OLRs) of 0.5-19 g COD l{sup -1} h{sup -1} in a 2-l continuous flow reactor at 30 C. The varied OLRs were achieved with glucose concentrations of 2.5-10 g l{sup -1} and hydraulic retention times of 1-10 h. The synthetic wastewater feed was amended with L-cysteine and maintained at a pH of 5.5. For each run at a given glucose concentration, the reactor was inoculated with an aliquot of well-mixed agricultural topsoil that had been heat-treated to reduce numbers of vegetative cells. At OLRs less than 2 g COD l{sup -1} h{sup -1}, DNA sequences from ribosomal RNA intergenic spacer analysis profiles revealed more diverse and variable populations (Selenomonas, Enterobacter, and Clostridium spp.) than were observed above 2 g COD l{sup -1} h{sup -1} (Clostridium spp. only). An isolate, LYH1, was cultured from a reactor sample (10 g glucose l{sup -1} at a 10-h HRT) on medium containing L-cysteine. In confirming H{sub 2} production by LYH1 in liquid batch culture, lag periods for H{sub 2} production in the presence and absence of L-cysteine were 5 and 50 h, respectively. The 16S rRNA gene sequence of LYH1 indicated that the isolate was a Clostridium sp. affiliated with RNA subcluster Ic, with >99% similarity to Clostridium sp. FRB1. In fluorescent in situ hybridization tests, an oligonucleotide probe complementary to the 16S rRNA of LYH1 hybridized with 90% of cells observed at an OLR of 2 g COD h{sup -1}, compared to 26% of cells at an OLR of 0.5 g COD l{sup -1} h{sup -1}. An OLR of 2 g COD l{sup -1} h{sup -1} appeared to be a critical threshold above which clostridia were better able to outcompete Enterobacteriaceae and other organisms in the mixed soil inoculum. Our results are discussed in light of other biohydrogen studies employing pure cultures and mixed inocula. (author)

  5. Effect of organic loading rate on fermentative hydrogen production from continuous stirred tank and membrane bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Lihong [Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4 (Canada); Bagley, David M. [Department of Civil and Architectural Engineering, Dept. 3295, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071 (United States); Liss, Steven N. [Department of Environmental Biology, University of Guelph, 50 Stone Road, Guelph, Ontario, N1G 2W1 (Canada)

    2009-05-15

    The influence of organic loading rates (OLRs) on the performance of fermentative hydrogen-producing bioreactors operating in continuous stirred tank reactor (CSTR) and membrane bioreactor (MBR) modes was examined. Five OLRs were examined, ranging from 4.0 to 30 g COD L{sup -1} d{sup -1}, with influent glucose concentrations ranging from 1.3 to 10 g COD L{sup -1}. At OLRs up to 13 g COD L{sup -1} d{sup -1}, all influent glucose was utilized and the H{sub 2} yield was not significantly influenced by OLR, although the yield in the CSTR mode was significantly higher than that in the MBR mode, 1.25 versus 0.97 mol H{sub 2} (mol Gluc. Conv.){sup -1}, respectively. At an OLR of 30 g COD L{sup -1} d{sup -1}, both reactor modes were overloaded with respect to glucose utilization and also had significantly higher H{sub 2} yields of 1.77 and 1.49 mol H{sub 2} (mol Gluc. Conv.){sup -1} for the CSTR and MBR modes, respectively, versus the underloaded operation. At the intermediate OLR of 22 g COD L{sup -1} d{sup -1}, the H{sub 2} yield was maximized at 1.78 mol H{sub 2} (mol Gluc. Conv.){sup -1} for both the CSTR and MBR operation. Overall H{sub 2} production was 50% higher in the MBR mode, 0.78 versus 0.51 moles d{sup -1}, because the CSTR mode was overloaded with respect to glucose utilization at this OLR. These results suggest that an optimum OLR that maximizes H{sub 2} yield and H{sub 2} production may be near the OLR that causes overload with respect to substrate utilization. Additionally, while the CSTR mode is easier to operate and provides higher H{sub 2} yields at underloaded and overloaded OLRs, the MBR mode may be preferable when operating near the optimum OLR. (author)

  6. Application of Galerkin meshfree methods to nonlinear thermo-mechanical simulation of solids under extremely high pulsed loading

    International Nuclear Information System (INIS)

    Ibáñez, Daniel Iglesias; García Orden, Juan C.; Brañas, B.; Carmona, J.M.; Molla, J.

    2013-01-01

    Highlights: • The paper presents a novel application of meshfree methods, valid for its implementation on a multibody framework. • Coupled nonlinear thermo-mechanical formulation is detailed and described in the reference configuration, as this allows to compute the shape functions only once. • We show the conditions in which future information induces inefficiency. • Beam parameters are the only information needed to apply the thermal load. • The solution procedure takes charge of updating the volumetric heat rate as the body moves and deforms. -- Abstract: Beam facing elements of the International Fusion Materials Irradiation Facility (IFMIF) Linear Particle Accelerator prototype (LIPAc) must stop 5–40 MeV D + ions with a peak current of 125 mA. The duty cycle of the beam loading varies from 0.1% to 100% (CW), depending on the device, with the ions being stopped in the first hundreds microns of the beam facing material. For intermediate duty cycles up to CW, the thermal load can be considered a heat flux load on the boundary, but this approximation gets too conservative as the duty cycle is reduced because the thermal diffusion becomes more important. Instant heat flux produced by the beam can reach up to 3 GW/m 2 in elements such as the beam dump and slits during short times of hundredths of microseconds. In these cases, the accuracy of the volumetric heat generation is critical for obtaining realistic results. Meshfree Galerkin methods discretize a continuum using scattered nodes. As opposed to FEM, no predefined connectivity is needed between the nodes, so C ∞ (infinitely differentiable) locally supported shape functions can be used to approximate both the trial and the test functions. This feature makes these type of methods well suited for those problems where the domain experiences very large deformations or has high gradients of the state variables. Radial basis (RBF) and moving least squares (MLS) functions have been applied to the

  7. A Spike Neural Controller for Traffic Load Parameter with Priority-Based Rate in Wireless Multimedia Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadia Adnan Shiltagh

    2015-11-01

    Full Text Available Wireless Multimedia Sensor Networks (WMSNs are a type of sensor network that contains sensor nodes equipped with cameras, microphones; therefore the WMSNS are able to produce multimedia data such as video and audio streams, still images, and scalar data from the surrounding environment. Most multimedia applications typically produce huge volumes of data, this leads to congestion. To address this challenge, This paper proposes Modify Spike Neural Network control for Traffic Load Parameter with Exponential Weight of Priority Based Rate Control algorithm (MSNTLP with EWBPRC. The Modify Spike Neural Network controller (MSNC can calculate the appropriate traffic load parameter μ for each parent node and then use in the EWPBRC algorithm to estimate the transmission rate of parent nodes and then assign a suitable transmission rate for each child node. A comparative study between (MSNTLP with EWBPRC and fuzzy logic controller for traffic load parameter with Exponential Weight of Priority Based Rate Control algorithm (FTLP with EWBPRC algorithm shows that the (MSNTLP with EWBPRC is more efficient than (FTLP with EWBPRC algorithm in terms of packet loss, queue delay and throughput. Another comparative study between (MSNTLP with EWBPRC and EWBPRC with fixed traffic load parameter (µ shows that the MSNTLP with EWBPRC is more efficient than EWBPRC with fixed traffic load parameter (µ in terms of packet loss ratio and queue delay. A simulation process is developed and tested using the network simulator _2 (NS2 in a computer having the following properties: windows 7 (64-bit, core i7, RAM 8GB, hard 1TB.

  8. Automation-aided Task Loads Index based on the Automation Rate Reflecting the Effects on Human Operators in NPPs

    International Nuclear Information System (INIS)

    Lee, Seungmin; Seong, Poonghyun; Kim, Jonghyun

    2013-01-01

    Many researchers have found that a high automation rate does not guarantee high performance. Therefore, to reflect the effects of automation on human performance, a new estimation method of the automation rate that considers the effects of automation on human operators in nuclear power plants (NPPs) was suggested. These suggested measures express how much automation support human operators but it cannot express the change of human operators' workload, whether the human operators' workload is increased or decreased. Before considering automation rates, whether the adopted automation is good or bad might be estimated in advance. In this study, to estimate the appropriateness of automation according to the change of the human operators' task loads, automation-aided task loads index is suggested based on the concept of the suggested automation rate. To insure plant safety and efficiency on behalf of human operators, various automation systems have been installed in NPPs, and many works which were previously conducted by human operators can now be supported by computer-based operator aids. According to the characteristics of the automation types, the estimation method of the system automation and the cognitive automation rate were suggested. The proposed estimation method concentrates on the effects of introducing automation, so it directly express how much the automated system support human operators. Based on the suggested automation rates, the way to estimate how much the automated system can affect the human operators' cognitive task load is suggested in this study. When there is no automation, the calculated index is 1, and it means there is no change of human operators' task load

  9. Automation-aided Task Loads Index based on the Automation Rate Reflecting the Effects on Human Operators in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seungmin; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jonghyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-05-15

    Many researchers have found that a high automation rate does not guarantee high performance. Therefore, to reflect the effects of automation on human performance, a new estimation method of the automation rate that considers the effects of automation on human operators in nuclear power plants (NPPs) was suggested. These suggested measures express how much automation support human operators but it cannot express the change of human operators' workload, whether the human operators' workload is increased or decreased. Before considering automation rates, whether the adopted automation is good or bad might be estimated in advance. In this study, to estimate the appropriateness of automation according to the change of the human operators' task loads, automation-aided task loads index is suggested based on the concept of the suggested automation rate. To insure plant safety and efficiency on behalf of human operators, various automation systems have been installed in NPPs, and many works which were previously conducted by human operators can now be supported by computer-based operator aids. According to the characteristics of the automation types, the estimation method of the system automation and the cognitive automation rate were suggested. The proposed estimation method concentrates on the effects of introducing automation, so it directly express how much the automated system support human operators. Based on the suggested automation rates, the way to estimate how much the automated system can affect the human operators' cognitive task load is suggested in this study. When there is no automation, the calculated index is 1, and it means there is no change of human operators' task load.

  10. Batch and multi-step fed-batch enzymatic saccharification of Formiline-pretreated sugarcane bagasse at high solid loadings for high sugar and ethanol titers.

    Science.gov (United States)

    Zhao, Xuebing; Dong, Lei; Chen, Liang; Liu, Dehua

    2013-05-01

    Formiline pretreatment pertains to a biomass fractionation process. In the present work, Formiline-pretreated sugarcane bagasse was hydrolyzed with cellulases by batch and multi-step fed-batch processes at 20% solid loading. For wet pulp, after 144 h incubation with cellulase loading of 10 FPU/g dry solid, fed-batch process obtained ~150 g/L glucose and ~80% glucan conversion, while batch process obtained ~130 g/L glucose with corresponding ~70% glucan conversion. Solid loading could be further increased to 30% for the acetone-dried pulp. By fed-batch hydrolysis of the dried pulp in pH 4.8 buffer solution, glucose concentration could be 247.3±1.6 g/L with corresponding 86.1±0.6% glucan conversion. The enzymatic hydrolyzates could be well converted to ethanol by a subsequent fermentation using Saccharomices cerevisiae with ethanol titer of 60-70 g/L. Batch and fed-batch SSF indicated that Formiline-pretreated substrate showed excellent fermentability. The final ethanol concentration was 80 g/L with corresponding 82.7% of theoretical yield. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. An empirical model for prediction of household solid waste generation rate - A case study of Dhanbad, India.

    Science.gov (United States)

    Kumar, Atul; Samadder, S R

    2017-10-01

    Accurate prediction of the quantity of household solid waste generation is very much essential for effective management of municipal solid waste (MSW). In actual practice, modelling methods are often found useful for precise prediction of MSW generation rate. In this study, two models have been proposed that established the relationships between the household solid waste generation rate and the socioeconomic parameters, such as household size, total family income, education, occupation and fuel used in the kitchen. Multiple linear regression technique was applied to develop the two models, one for the prediction of biodegradable MSW generation rate and the other for non-biodegradable MSW generation rate for individual households of the city Dhanbad, India. The results of the two models showed that the coefficient of determinations (R 2 ) were 0.782 for biodegradable waste generation rate and 0.676 for non-biodegradable waste generation rate using the selected independent variables. The accuracy tests of the developed models showed convincing results, as the predicted values were very close to the observed values. Validation of the developed models with a new set of data indicated a good fit for actual prediction purpose with predicted R 2 values of 0.76 and 0.64 for biodegradable and non-biodegradable MSW generation rate respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Determining the effect of solid and liquid vectors on the gaseous interfacial area and oxygen transfer rates in two-phase partitioning bioreactors

    International Nuclear Information System (INIS)

    Quijano, Guillermo; Rocha-Rios, Jose; Hernandez, Maria; Villaverde, Santiago; Revah, Sergio; Munoz, Raul; Thalasso, Frederic

    2010-01-01

    The effect of liquid and solid transfer vectors (silicone oil and Desmopan, respectively) on the gaseous interfacial area (a g ) was evaluated in a two-phase partitioning bioreactor (TPPB) using fresh mineral salt medium and the cultivation broth of a toluene degradation culture (Pseudomonas putida DOT-T1E cultures continuously cultivated with and without silicone oil at low toluene loading rates). Higher values of a g were recorded in the presence of both silicone oil and Desmopan compared to the values obtained in the absence of a vector, regardless of the aqueous medium tested (1.6 and 3 times higher, respectively, using fresh mineral salt medium). These improvements in a g were well correlated to the oxygen mass transfer enhancements supported by the vectors (1.3 and 2.5 for liquid and solid vectors, respectively, using fresh medium). In this context, oxygen transfer rates of 2.5 g O 2 L -1 h -1 and 1.3 g O 2 L -1 h -1 were recorded in the presence of Desmopan and silicone oil, respectively, which are in agreement with previously reported values in literature. These results suggest that mass transfer enhancements in TPPBs might correspond to an increase in a g rather than to the establishment of a high-performance gas/vector/water transfer pathway.

  13. Determining the effect of solid and liquid vectors on the gaseous interfacial area and oxygen transfer rates in two-phase partitioning bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Quijano, Guillermo [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y de Estudios, Avanzados del IPN (Cinvestav), Apdo. Postal 14-740, 07360 Mexico, D.F. (Mexico); Rocha-Rios, Jose [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Departamento de Ingenieria de Procesos e Hidraulica (IPH), Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 Mexico, D.F. (Mexico); Hernandez, Maria; Villaverde, Santiago [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Revah, Sergio [Departamento de Procesos y Tecnologia, Universidad Autonoma Metropolitana-Cuajimalpa, c/o IPH, UAM-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 Mexico, D.F. (Mexico); Munoz, Raul, E-mail: mutora@iq.uva.es [Departmento de Ingenieria Quimica y Tecnologia del Medio Ambiente, Universidad de Valladolid, Paseo del Prado de la Magdalena, s/n, 47005 Valladolid (Spain); Thalasso, Frederic [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y de Estudios, Avanzados del IPN (Cinvestav), Apdo. Postal 14-740, 07360 Mexico, D.F. (Mexico)

    2010-03-15

    The effect of liquid and solid transfer vectors (silicone oil and Desmopan, respectively) on the gaseous interfacial area (a{sub g}) was evaluated in a two-phase partitioning bioreactor (TPPB) using fresh mineral salt medium and the cultivation broth of a toluene degradation culture (Pseudomonas putida DOT-T1E cultures continuously cultivated with and without silicone oil at low toluene loading rates). Higher values of a{sub g} were recorded in the presence of both silicone oil and Desmopan compared to the values obtained in the absence of a vector, regardless of the aqueous medium tested (1.6 and 3 times higher, respectively, using fresh mineral salt medium). These improvements in a{sub g} were well correlated to the oxygen mass transfer enhancements supported by the vectors (1.3 and 2.5 for liquid and solid vectors, respectively, using fresh medium). In this context, oxygen transfer rates of 2.5 g O{sub 2} L{sup -1} h{sup -1} and 1.3 g O{sub 2} L{sup -1} h{sup -1} were recorded in the presence of Desmopan and silicone oil, respectively, which are in agreement with previously reported values in literature. These results suggest that mass transfer enhancements in TPPBs might correspond to an increase in a{sub g} rather than to the establishment of a high-performance gas/vector/water transfer pathway.

  14. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    Science.gov (United States)

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Improved estimates of filtered total mercury loadings and total mercury concentrations of solids from potential sources to Sinclair Inlet, Kitsap County, Washington

    Science.gov (United States)

    Paulson, Anthony J.; Conn, Kathleen E.; DeWild, John F.

    2013-01-01

    Previous investigations examined sources and sinks of mercury to Sinclair Inlet based on historic and new data. This included an evaluation of mercury concentrations from various sources and mercury loadings from industrial discharges and groundwater flowing from the Bremerton naval complex to Sinclair Inlet. This report provides new data from four potential sources of mercury to Sinclair Inlet: (1) filtered and particulate total mercury concentrations of creek water during the wet season, (2) filtered and particulate total mercury releases from the Navy steam plant following changes in the water softening process and discharge operations, (3) release of mercury from soils to groundwater in two landfill areas at the Bremerton naval complex, and (4) total mercury concentrations of solids in dry dock sumps that were not affected by bias from sequential sampling. The previous estimate of the loading of filtered total mercury from Sinclair Inlet creeks was based solely on dry season samples. Concentrations of filtered total mercury in creek samples collected during wet weather were significantly higher than dry weather concentrations, which increased the estimated loading of filtered total mercury from creek basins from 27.1 to 78.1 grams per year. Changes in the concentrations and loading of filtered and particulate total mercury in the effluent of the steam plant were investigated after the water softening process was changed from ion-exchange to reverse osmosis and the discharge of stack blow-down wash began to be diverted to the municipal water-treatment plant. These changes reduced the concentrations of filtered and particulate total mercury from the steam plant of the Bremerton naval complex, which resulted in reduced loadings of filtered total mercury from 5.9 to 0.15 grams per year. Previous investigations identified three fill areas on the Bremerton naval complex, of which the western fill area is thought to be the largest source of mercury on the base

  16. Reconceptualizing perceptual load as a rate problem: The role of time in the allocation of selective attention.

    Science.gov (United States)

    Li, Zhi; Xin, Keyun; Li, Wei; Li, Yanzhe

    2018-04-30

    In the literature about allocation of selective attention, a widely studied question is when will attention be allocated to information that is clearly irrelevant to the task at hand. The present study, by using convergent evidence, demonstrated that there is a trade-off between quantity of information present in a display and the time allowed to process it. Specifically, whether or not there is interference from irrelevant distractors depends not only on the amount of information present, but also on the amount of time allowed to process that information. When processing time is calibrated to the amount of information present, irrelevant distractors can be selectively ignored successfully. These results suggest that the perceptual load in the load theory of selective attention (i.e., Lavie, 2005) should be thought about as a dynamic rate problem rather than a static capacity limitation. The authors thus propose that rather than conceiving of perceptual load as a quantity of information, they should consider it as a quantity of information per unit of time. In other words, it is the relationship between the quantity of information in the task and the time for processing the information that determines the allocation of selective attention. Thus, the present findings extended load theory, allowing it to explain findings that were previously considered as counter evidence of load theory. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  17. The Coupled Effect of Loading Rate and Grain Size on Tensile Strength of Sandstones under Dynamic Disturbance

    Directory of Open Access Journals (Sweden)

    Miao Yu

    2017-01-01

    Full Text Available It is of significance to comprehend the effects of rock microstructure on the tensile strength under different loading rates caused by mining disturbance. So, in this paper, three kinds of sandstones drilled from surrounding rocks in Xiao Jihan Coal to simulate the in situ stress state, whose average grain size is 30 μm (fine grain, FG, 105 μm (medium grain, MG, and 231 μm (Coarse grain, CG, are selected with the calculation of optical microscopic technique and moreover processed to Brazilian disc (BD to study the mechanical response of samples. The dynamic Brazilian tests of samples with three kinds of grain sizes are conducted with the Split Hopkinson Pressure Bar (SHPB driven by pendulum hammer, which can produce four different velocities (V=2.0 m/s, 2.5 m/s, 3.3 m/s, and 4.2 m/s when the incident bar is impacted by pendulum hammer. The incident wave produced by pendulum hammer is a slowly rising stress wave, which allows gradual stress accumulation in the specimen and maintains the load at both ends of the specimen in an equilibrium state. The results show that the dynamic strength of three kinds of BD samples represented loading rates dependence, and FG sandstones are more sensitive for loading rates than MG and CG samples. Moreover, the peak strength is observed to increase linearly with an increasing stress rates, and the relationship between the dynamic BD strength and stress rates can be built through a linear equation. Finally, the failure modes of different grain sizes are discussed and explained by microfailure mechanism.

  18. Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xiao, E-mail: liuxiao07@mails.tsinghua.edu.cn [School of Environment, Tsinghua University, Beijing 100084 (China); Wang Wei; Shi Yunchun; Zheng Lei [School of Environment, Tsinghua University, Beijing 100084 (China); Gao Xingbao [Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Qiao Wei [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhou Yingjun [Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540 (Japan)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. Black-Right-Pointing-Pointer System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m{sup 3} d){sup -1} were analyzed. Black-Right-Pointing-Pointer A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and HRT of 15d. Black-Right-Pointing-Pointer With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. Black-Right-Pointing-Pointer The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2-8.0 kg volatile solid (VS) (m{sup 3} d){sup -1}, with VS reduction rates of 61.7-69.9%, and volumetric biogas production of 0.89-5.28 m{sup 3} (m{sup 3} d){sup -1}. A maximum methane production rate of 2.94 m{sup 3} (m{sup 3} d){sup -1} was achieved at OLR of 8.0 kg VS (m{sup 3} d){sup -1} and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m{sup 3} d){sup -1}. This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

  19. Pilot-scale anaerobic co-digestion of municipal biomass waste and waste activated sludge in China: Effect of organic loading rate

    International Nuclear Information System (INIS)

    Liu Xiao; Wang Wei; Shi Yunchun; Zheng Lei; Gao Xingbao; Qiao Wei; Zhou Yingjun

    2012-01-01

    Highlights: ► Co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) was examined on a pilot-scale reactor. ► System performance and stability under OLR of 1.2, 2.4, 3.6, 4.8, 6.0 and 8.0 kg VS (m 3 d) −1 were analyzed. ► A maximum methane production rate of 2.94 m 3 (m 3 d) −1 was achieved at OLR of 8.0 kg VS (m 3 d) −1 and HRT of 15d. ► With the increasing OLRs, pH values, VS removal rate and methane concentration decreased and VFA increased. ► The changing of biogas production rate can be a practical approach to monitor and control anaerobic digestion system. - Abstract: The effects of organic loading rate on the performance and stability of anaerobic co-digestion of municipal biomass waste (MBW) and waste activated sludge (WAS) were investigated on a pilot-scale reactor. The results showed that stable operation was achieved with organic loading rates (OLR) of 1.2–8.0 kg volatile solid (VS) (m 3 d) −1 , with VS reduction rates of 61.7–69.9%, and volumetric biogas production of 0.89–5.28 m 3 (m 3 d) −1 . A maximum methane production rate of 2.94 m 3 (m 3 d) −1 was achieved at OLR of 8.0 kg VS (m 3 d) −1 and hydraulic retention time of 15 days. With increasing OLRs, the anaerobic reactor showed a decrease in VS removal rate, average pH value and methane concentration, and a increase of volatile fatty acid concentration. By monitoring the biogas production rate (BPR), the anaerobic digestion system has a higher acidification risk under an OLR of 8.0 kg VS (m 3 d) −1 . This result remarks the possibility of relating bioreactor performance with BPR in order to better understand and monitor anaerobic digestion process.

  20. Anti-inflammatory effects and hepatotoxicity of Tripterygium-loaded solid lipid nanoparticles on adjuvant-induced arthritis in rats.

    Science.gov (United States)

    Xue, Mei; Jiang, Zhen-zhou; Wu, Tao; Li, Ji; Zhang, Liang; Zhao, Yan; Li, Xue-jun; Zhang, Lu-Yong; Yang, Shu-yu

    2012-08-15

    Tripterygium wilfordii Hook f. (TWHF) has been demonstrated to have anti-inflammatory, immunosuppressive effects and its clinical use was restricted to some extent due to some toxic effects on the digestive, urogenital, and blood circulatory systems, especially the male reproductive system. In the previous study, we had confirmed that TWHF-loaded solid lipid nanoparticles (SLN) have protective effects on male reproductive toxicity in rats. Anti-inflammatory effects and hepatotoxicity of TWHF-SLN remain to be unidentified. The present study was focused on the anti-inflammatory effect of complete Freund's adjuvant-induced arthritis in rats treated with TWHF-SLN as well as the effects of SLN delivery system on decreasing the hepatotoxicity induced by tripterygium. Sixty-four healthy male rats were randomly divided into eight groups with eight rats each. From day 18 after FCA injection, TWHF-SLN group (120, 60, 30 mg/kg) and TWHF group (120, 60, 30 mg/kg) were administered by oral gavage for 24 consecutive days. The control group was with saline and model control group was without any treatment. The volume of the right hind paws was evaluated at 0, 4, 8, 12, 18, 24, 30, 36 and 42 days post-injection of FCA by a home-made connected device. The serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT), total bilirubin (TBIL) and albumin (ALB) levels were evaluated by an autoanalyzer. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) malondialdehyde (MDA) and xanthine oxidase (XOD) levels were determined using commercial kits. The PG level in sera was examined by double antibody sandwich method. Tissue histopathology was evaluated with hematoxylin and eosin (H&E). The results show that TWHF-SLN can significantly reduce rat paw volume at 60 mg/kg (psystem can enhance the anti-inflammatory activity of TWHF, and meanwhile has a protective effect against TWHF

  1. Flow time analysis of load management late arrival discrete time queueing system with dual service rate using hypo geometrical distribution

    International Nuclear Information System (INIS)

    Shah, S.A.; Shah, W.; Shaikh, F.K.

    2012-01-01

    Flow time analysis is a powerful concept to analyze the flow time of any arriving customer in any system at any instant. A load management mechanism can be employed very effectively in any queueing system by utilizing a system which provides probability of dual service rate. In this paper, we develop and demonstrate the flow and service processes transition diagram to determine the flow time of a customer in a load management late arrival state dependent finite discrete time queueing system with dual service rate where customers are hypo geometrically distributed. We compute the probability mass function of each starting state and total probability mass function. The obtained analytical results are validated with simulation results for varying values of arrival and service probabilities. (author)

  2. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Joshy, K.S. [Department of Chemistry, CMS College Kottayam, Kerala (India); International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sharma, Chandra P. [Division of Biosurface Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Science and Technology, Poojappura, Thiruvananthapuram, Kerala (India); Kalarikkal, Nandakumar [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sandeep, K. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Thomas, Sabu, E-mail: sabuchathukulam@yahoo.co.uk [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Pothen, Laly A. [Department of Chemistry, Bishop Moore College, Mavelikkara, Kerala (India)

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake.

  3. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells

    International Nuclear Information System (INIS)

    Joshy, K.S.; Sharma, Chandra P.; Kalarikkal, Nandakumar; Sandeep, K.; Thomas, Sabu; Pothen, Laly A.

    2016-01-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake

  4. Study on solid-liquid two-phase unsteady flow characteristics with different flow rates in screw centrifugal pump

    International Nuclear Information System (INIS)

    Li, R N; Wang, H Y; Han, W; Shen, Z J; Ma, W

    2013-01-01

    The screw centrifugal pump is used as an object, and the unsteady numerical simulation of solid-liquid two-phase flow is carried out under different flow rate conditions in one circle by choosing the two-phase flow of sand and water as medium, using the software FLUENT based on the URANS equations, combining with sliding mesh method, and choosing the Mixture multiphase flow model and the SIMPLE algorithm. The results show that, with the flow rate increasing, the change trends for the pressure on volute outlet are almost constant, the fluctuation trends of the impeller axial force have a little change, the pressure and the axial force turn to decrease on the whole, the radial force gradually increases when the impeller maximum radius passes by half a cycle near the volute outlet, and the radial force gradually decreases when the maximum radius passes by the other half a cycle in a rotation cycle. The distributions of the solid particles are very uneven under a small flow rate condition on the face. The solid particles under a big flow rate condition are distributed more evenly than the ones under a small flow rate condition on the back. The theoretical basis and reference are provided for improving its working performance

  5. Evaluation of percutaneous absorption of the repellent diethyltoluamide and the sunscreen ethylhexyl p-methoxycinnamate-loaded solid lipid nanoparticles: an in-vitro study.

    Science.gov (United States)

    Puglia, Carmelo; Bonina, Francesco; Castelli, Francesco; Micieli, Dorotea; Sarpietro, Maria Grazia

    2009-08-01

    Diethyltoluamide and ethylhexyl p-methoxycinnamate (OMC) are two active ingredients in insect repellent and sunscreen products, respectively. The concurrent application of these two substances often increases their systemic absorption, compromising the safety and efficiency of the cosmetic product. In this study, diethyltoluamide and OMC were incorporated into solid lipid nanoparticles, a colloidal drug delivery system, to reduce percutaneous absorption and avoid toxic effects and also maintain the efficacy of the two active compounds on the skin surface for a long duration. Solid lipid nanoparticles were prepared based on an ultrasonication technique and characterized by differential scanning calorimetry (DSC) analyses. In-vitro studies determined the percutaneous absorption of diethyltoluamide and OMC. DSC data carried out on unloaded and diethyltoluamide- and/or OMC-loaded solid lipid nanoparticles highlighted that diethyltoluamide and OMC modified the temperature and the enthalpy change associated to the calorimetric peak of solid lipid nanoparticles. The concurrent presence of the two compounds in the solid lipid nanoparticles caused a synergic effect, indicating that the lipid matrix of nanoparticles guaranteed a high encapsulation of both diethyltoluamide and OMC. Results from the in-vitro study demonstrated that the particles were able to reduce the skin permeation of the two cosmetic ingredients in comparison with an oil-in-water emulsion. This study has provided supplementary evidence as to the potential of lipid nanoparticles as carriers for topical administration of cosmetic active compounds.

  6. Docetaxel-loaded solid lipid nanoparticles as a basis for a targeted and dose-sparing personalized breast cancer treatment strategy

    Directory of Open Access Journals (Sweden)

    Danilova NV

    2015-03-01

    Full Text Available Natalia V Danilova,1,2 Zhomart R Kalzhanov,3 Nina A Nefedova,2 Pavel G Mal’kov,2 Ioannis P Kosmas,1,4 Marina Y Eliseeva,1,5 Ospan A Mynbaev1,5,6 1International Translational Medicine and Biomodeling Research Team, MIPT Center for Human Physiology, Laboratory of Cellular and Molecular Technologies, Moscow Institute of Physics and Technology, State University, 2Department of Physiology and Basic Pathology, Faculty of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia; 3Department of Human Metabolism, Academic Unit of Reproductive and Developmental Medicine, Sheffield University, Sheffield, UK; 4Department of Obstetrics and Gynecology, Ioannina State General Hospital G Chatzikosta, Ioannina, Greece; 5Department of Obstetrics, Gynecology and Reproductive Medicine, Peoples’ Friendship University of Russia, 6Laboratory of Immunology, Moscow State University of Medicine and Dentistry named after AI Evdokimov, Moscow, Russia The long-term survival rate of patients with breast cancer was improved by the application of systemic adjuvant chemotherapy,1 although the primary breast cancer treatment strategy consists of mastectomy with lymphadenectomy and radiotherapy followed by breast reconstruction.2–5 Unfortunately, most adjuvant chemotherapeutic agents trigger major side effects.1,6 Therefore, we have read with great interest an article in the International Journal of Nanomedicine on the design of docetaxel-loaded solid lipid nanoparticles (DSNs aimed at reducing the systemic toxicity of standardized docetaxel treatment.7 Read the original article 

  7. Strain rate dependent deformation and failure behavior of laser welded DP780 steel joint under dynamic tensile loading

    International Nuclear Information System (INIS)

    Liu, Yang; Dong, Danyang; Wang, Lei; Chu, Xi; Wang, Pengfei; Jin, Mengmeng

    2015-01-01

    Laser welded DP steel joints are used widely in the automotive industry for weight reduction. Understanding the deformation and fracture behavior of the base metal (BM) and its welded joint (WJ), especially at high strain rates, is critical for the design of vehicle structures. This paper is concerned with the effects of strain rate on the tensile properties, deformation and fracture behavior of the laser welded DP780 steel joint. Quasi-static and dynamic tensile tests were performed on the WJ and BM of the DP780 steel using an electromechanical universal testing machine and a high-speed tensile testing machine over a wide range of strain rate (0.0001–1142 s −1 ). The microstructure change and microhardness distribution of the DP780 steel after laser welding were examined. Digital image correlation (DIC) and high-speed photography were employed for the strain measurement of the DP780 WJ during dynamic tensile tests. The DP780 WJ is a heterogeneous structure with hardening in fusion zone (FZ) and inner heat-affected zone (HAZ), and softening in outer HAZ. The DP780 BM and WJ exhibit positive strain rate dependence on the YS and UTS, which is smaller at lower strain rates and becomes larger with increasing strain rate, while ductility in terms of total elongation (TE) tends to increase under dynamic loading. Laser welding leads to an overall reduction in the ductility of the DP780 steel. However, the WJ exhibits a similar changing trend of the ductility to that of the BM with respect to the strain rate over the whole strain rate range. As for the DP780 WJ, the distance of tensile failure location from the weld centerline decreases with increasing strain rate. The typical ductile failure characteristics of the DP780 BM and WJ do not change with increasing strain rate. DIC measurements reveal that the strain localization starts even before the maximum load is attained in the DP780 WJ and gradual transition from uniform strains to severely localized strains occurs

  8. Strain rate dependent deformation and failure behavior of laser welded DP780 steel joint under dynamic tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang, E-mail: liuyang@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Dong, Danyang, E-mail: dongdanyang@mail.neu.edu.cn [College of Science, Northeastern University, Shenyang 110819 (China); Wang, Lei, E-mail: wanglei@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Chu, Xi, E-mail: chuxi.ok@163.com [College of Science, Northeastern University, Shenyang 110819 (China); Wang, Pengfei, E-mail: wpf1963871400@163.com [College of Science, Northeastern University, Shenyang 110819 (China); Jin, Mengmeng, E-mail: 24401878@163.com [College of Science, Northeastern University, Shenyang 110819 (China)

    2015-03-11

    Laser welded DP steel joints are used widely in the automotive industry for weight reduction. Understanding the deformation and fracture behavior of the base metal (BM) and its welded joint (WJ), especially at high strain rates, is critical for the design of vehicle structures. This paper is concerned with the effects of strain rate on the tensile properties, deformation and fracture behavior of the laser welded DP780 steel joint. Quasi-static and dynamic tensile tests were performed on the WJ and BM of the DP780 steel using an electromechanical universal testing machine and a high-speed tensile testing machine over a wide range of strain rate (0.0001–1142 s{sup −1}). The microstructure change and microhardness distribution of the DP780 steel after laser welding were examined. Digital image correlation (DIC) and high-speed photography were employed for the strain measurement of the DP780 WJ during dynamic tensile tests. The DP780 WJ is a heterogeneous structure with hardening in fusion zone (FZ) and inner heat-affected zone (HAZ), and softening in outer HAZ. The DP780 BM and WJ exhibit positive strain rate dependence on the YS and UTS, which is smaller at lower strain rates and becomes larger with increasing strain rate, while ductility in terms of total elongation (TE) tends to increase under dynamic loading. Laser welding leads to an overall reduction in the ductility of the DP780 steel. However, the WJ exhibits a similar changing trend of the ductility to that of the BM with respect to the strain rate over the whole strain rate range. As for the DP780 WJ, the distance of tensile failure location from the weld centerline decreases with increasing strain rate. The typical ductile failure characteristics of the DP780 BM and WJ do not change with increasing strain rate. DIC measurements reveal that the strain localization starts even before the maximum load is attained in the DP780 WJ and gradual transition from uniform strains to severely localized strains

  9. Enhancement of glomerular filtration rate and renal plasma flow by oral glucose load in well controlled insulin-dependent diabetics

    DEFF Research Database (Denmark)

    Sandahl Christiansen, J; Christensen, C K; Hermansen, K

    1986-01-01

    Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured in 27 patients with uncomplicated insulin-dependent diabetes (IDDM) before and after an oral glucose load of 1.1 g glucose/kg body wt. In the 18 patients showing near-normoglycaemia (blood glucose less than or equal to 8....... No changes in blood pressure or urinary albumin excretion rates took place in either group. The reduction in plasma protein and in plasma growth hormone concentration were similar in the two groups. No change was seen in plasma arginine vasopressin concentration. There was no difference in the qualitative...

  10. Pediatric Solid-Organ Transplant Recipients Carry Chronic Loads of Epstein-Barr Virus Exclusively in the Immunoglobulin D-Negative B-Cell Compartment

    Science.gov (United States)

    Rose, Camille; Green, Michael; Webber, Steven; Ellis, Demetrius; Reyes, Jorges; Rowe, David

    2001-01-01

    Solid-organ transplant recipients are at risk for development of lymphoproliferative diseases. The purpose of this study was to examine the distribution of Epstein-Barr virus (EBV) load in the peripheral blood of pediatric transplant recipients who had become chronic viral load carriers (>8 copies/105 lymphocytes for >2 months). A total of 19 patients with viral loads ranging from 20 to 5,000 viral genome copies/105 lymphocytes were studied. Ten patients had no previous diagnosis of posttransplant lymphoproliferative disease (PT-LPD), while nine had recovered from a diagnosed case of PT-LPD. No portion of the peripheral blood viral load was detected in the cell-free plasma fraction. Viral DNA was found in a population of cells characterized as CD19hi and immunoglobulin D negative, a phenotype that is consistent with the virus being carried exclusively in the memory B-cell compartment of the peripheral blood. There was no difference in the compartmentalization based upon either the level of the viral load or the past diagnosis of an episode of PT-LPD. These results have implications for the design of tests to detect EBV infection and for the interpretation and use of positive EBV PCR assays in the management of transplant recipients. PMID:11283064

  11. Groundwater and surface-water interaction, water quality, and processes affecting loads of dissolved solids, selenium, and uranium in Fountain Creek near Pueblo, Colorado, 2012–2014

    Science.gov (United States)

    Arnold, L. Rick; Ortiz, Roderick F.; Brown, Christopher R.; Watts, Kenneth R.

    2016-11-28

    In 2012, the U.S. Geological Survey, in cooperation with the Arkansas River Basin Regional Resource Planning Group, initiated a study of groundwater and surface-water interaction, water quality, and loading of dissolved solids, selenium, and uranium to Fountain Creek near Pueblo, Colorado, to improve understanding of sources and processes affecting loading of these constituents to streams in the Arkansas River Basin. Fourteen monitoring wells were installed in a series of three transects across Fountain Creek near Pueblo, and temporary streamgages were established at each transect to facilitate data collection for the study. Groundwater and surface-water interaction was characterized by using hydrogeologic mapping, groundwater and stream-surface levels, groundwater and stream temperatures, vertical hydraulic-head gradients and ratios of oxygen and hydrogen isotopes in the hyporheic zone, and streamflow mass-balance measurements. Water quality was characterized by collecting periodic samples from groundwater, surface water, and the hyporheic zone for analysis of dissolved solids, selenium, uranium, and other selected constituents and by evaluating the oxidation-reduction condition for each groundwater sample under different hydrologic conditions throughout the study period. Groundwater loads to Fountain Creek and in-stream loads were computed for the study area, and processes affecting loads of dissolved solids, selenium, and uranium were evaluated on the basis of geology, geochemical conditions, land and water use, and evapoconcentration.During the study period, the groundwater-flow system generally contributed flow to Fountain Creek and its hyporheic zone (as a single system) except for the reach between the north and middle transects. However, the direction of flow between the stream, the hyporheic zone, and the near-stream aquifer was variable in response to streamflow and stage. During periods of low streamflow, Fountain Creek generally gained flow from

  12. Influence of solids concentration on the sedimentation rate of the mud in the aggregate industry

    Directory of Open Access Journals (Sweden)

    Benigno Leyva-de la Cruz

    2016-12-01

    Full Text Available The objective of this investigation is to determine, for the mud resulting from the wash process in the Jobo community arid industry in Sagua de Tánamo, the impact of solids percent on the theoretical sedimentation velocity that is predicted by the Stokes velocity Law. Samples of the discharge pipeline and the mud sedimentation area were analyzed from granulometric, density and solids concentration points of view. The solids percentage variable (S was analyzed in four scenarios (4, 12, 20 and 28 % and time (t was evaluated at intervals of 20 minutes for 5 hours. The behavior of mud sedimentation was characterized through the sedimentation velocity. The results indicate that the Stokes velocity law does not apply for estimating the mud sedimentation velocity with a 95% confidence. Therefore, a correction function is obtained for the Stokes velocity law expressed through the polynomial mathematical model of second degree.

  13. Influence of loading rate and modes on infiltration of treated wastewater in soil-based constructed wetland.

    Science.gov (United States)

    Bisone, Sara; Gautier, Mathieu; Masson, Matthieu; Forquet, Nicolas

    2017-01-01

    Over the last 10 years soil-based constructed wetlands for discharge of treated wastewater (TWW) are commonly presented as a valuable option to provide tertiary treatment. The uncomplete knowledge in soil modifications and a lack of clear design practices laid the foundation of this work. The aim of this study was to determine optimal hydraulic loads and to observe the main critical parameters affecting treating performances and hydraulic loads acceptance. For this purpose, a soil rich in clay and backfill was chosen to perform column infiltration tests with TWW. Two loading rates and two loading modes were compared to study the influence of an intermittent feeding. Inlet and outlet waters were periodically analysed and columns were instrumented with balances, tensiometers, O 2 and temperature probes. Soil physico-chemical characteristics were also taken into account to better understand the modification of the soil. One of the main expectations of tertiary treatment is to improve phosphate removal. A particular attention was thus given to phosphorus retention. The interest of an intermittent feeding in presence of a soil with high clay content was showed. This study highlighted that an intermittent feeding could make possible the use of a clay-rich soil for water infiltration.

  14. Benthic Uptake Rate due to Hyporheic Exchange: The Effects of Streambed Morphology for Constant and Sinusoidally Varying Nutrient Loads

    Directory of Open Access Journals (Sweden)

    Daniele Tonina

    2015-01-01

    Full Text Available Hyporheic exchange carries reactive solutes, which may include biological oxygen demand (BOD, dissolved oxygen (DO and reactive dissolved inorganic nitrogen (Nr, into the sediment, where biochemical reactions consume DO. Here, we study the impact of streambed morphology, stream-reactive solute loads and their diel oscillations on the DO benthic uptake rate (BUR due to hyporheic processes. Our model solves the hyporheic flow field and the solute transport equations analytically, within a Lagrangian framework, considering advection, longitudinal diffusion and reactions modeled as first order kinetics. The application of the model to DO field measurements over a gravel bar-pool sequence shows a good match with measured DO concentrations with an overall agreement of 58% and a kappa index of 0.46. We apply the model to investigate the effects of daily constant and sinusoidally time varying stream BOD, DO and Nr loads and of the morphodynamic parameters on BUR. Our modeling results show that BUR varies as a function of bedform size and of nutrient loads and that the hyporheic zone may consume up to 0.06% of the stream DO at the pool-riffle bedform scale. Daily oscillations of stream BOD and DO loads have small effects on BUR, but may have an important influence on local hyporheic processes and organisms’ distribution.

  15. Response of Jupiter's Aurora to Plasma Mass Loading Rate Monitored by the Hisaki Satellite During Volcanic Eruptions at Io

    Science.gov (United States)

    Kimura, T.; Hiraki, Y.; Tao, C.; Tsuchiya, F.; Delamere, P. A.; Yoshioka, K.; Murakami, G.; Yamazaki, A.; Kita, H.; Badman, S. V.; Fukazawa, K.; Yoshikawa, I.; Fujimoto, M.

    2018-03-01

    The production and transport of plasma mass are essential processes in the dynamics of planetary magnetospheres. At Jupiter, it is hypothesized that Io's volcanic plasma carried out of the plasma torus is transported radially outward in the rotating magnetosphere and is recurrently ejected as plasmoid via tail reconnection. The plasmoid ejection is likely associated with particle energization, radial plasma flow, and transient auroral emissions. However, it has not been demonstrated that plasmoid ejection is sensitive to mass loading because of the lack of simultaneous observations of both processes. We report the response of plasmoid ejection to mass loading during large volcanic eruptions at Io in 2015. Response of the transient aurora to the mass loading rate was investigated based on a combination of Hisaki satellite monitoring and a newly developed analytic model. We found that the transient aurora frequently recurred at a 2-6 day period in response to a mass loading increase from 0.3 to 0.5 t/s. In general, the recurrence of the transient aurora was not significantly correlated with the solar wind, although there was an exceptional event with a maximum emission power of 10 TW after the solar wind shock arrival. The recurrence of plasmoid ejection requires the precondition that an amount comparable to the total mass of magnetosphere, 1.5 Mt, is accumulated in the magnetosphere. A plasmoid mass of more than 0.1 Mt is necessary in case that the plasmoid ejection is the only process for mass release.

  16. Fracture Energy of Plain Concrete Beams at Different Rates of Loading

    DEFF Research Database (Denmark)

    Ulfkjær, J. P.; Hansen, Lars Pilegaard; Madsen, S. H.

    . The beams are tested in a closed loop servo controlled materials testing system. The experimental results for these preliminary tests show that the bending tensile strength is increasing with the displacement rate and that the fracture energy is constant at lower displacement rates and then increasing...

  17. Some contributions to the high strain rate deformation of solids and the thermally activated deformation of wood

    International Nuclear Information System (INIS)

    Ferguson, W George

    2009-01-01

    The behaviour of metals as a function of rate of loading, strain rate, and temperature is discussed in terms of previous work by the author. Strain rates range from 10 -3 s -1 , obtained in a standard tensile testing machine, to 10 2 s -1 obtained in a hydraulic piston driven machine and up to 10 4 s -1 , very high strain rates with a Kolsky split Hopkinson bar using shear type loading. At rates less 10 3 s -1 the strength is a function of strain rate and temperature, is thermally activated and governed by the stress-assisted thermal activation of dislocations across short-range barriers in the crystal. At very high strain rates however the behaviour is controlled by interaction of dislocations with either phonons or electrons, giving a strength proportional to strain rate. The compressive strength of small clear samples of wood, Pinus radiata and Kahikatea, determined over the strain rate range 10 -3 s -1 to 10 3 s -1 as a function of strain rate, temperature and moisture content shows the behaviour to again be thermally activated with the strength a function of stain rate, temperature and moisture content. A rate theory of deformation is developed where the yield behaviour of wood is assumed to result from the stress-assisted thermally activated motion of elementary fibrils over short-range barriers. The moisture is assumed to affect the bond energy between elementary fibrils and the barrier energy is taken to be a linear decreasing function of increasing moisture content and the moisture to act like a plasticiser in separating the elementary fibrils. The theory more than adequately explains the observed behaviour.

  18. Changes in patellofemoral pain resulting from repetitive impact landings are associated with the magnitude and rate of patellofemoral joint loading.

    Science.gov (United States)

    Atkins, Lee T; James, C Roger; Yang, Hyung Suk; Sizer, Phillip S; Brismée, Jean-Michel; Sawyer, Steven F; Powers, Christopher M

    2018-03-01

    Although a relationship between elevated patellofemoral forces and pain has been proposed, it is unknown which joint loading variable (magnitude, rate) is best associated with pain changes. The purpose of this study was to examine associations among patellofemoral joint loading variables and changes in patellofemoral pain across repeated single limb landings. Thirty-one females (age: 23.5(2.8) year; height: 166.8(5.8) cm; mass: 59.6(8.1) kg) with PFP performed 5 landing trials from 0.25 m. The dependent variable was rate of change in pain obtained from self-reported pain scores following each trial. Independent variables included 5-trial averages of peak, time-integral, and average and maximum development rates of the patellofemoral joint reaction force obtained using a previously described model. Pearson correlation coefficients were calculated to evaluate individual associations between rate of change in pain and each independent variable (α = 0.05). Stepwise linear multiple regression (α enter  = 0.05; α exit  = 0.10) was used to identify the best predictor of rate of change in pain. Subjects reported an average increase of 0.38 pain points with each landing trial. Although, rate of change in pain was positively correlated with peak force (r = 0.44, p = 0.01), and average (r = 0.41, p = 0.02) and maximum force development rates (r = 0.39, p = 0.03), only the peak force entered the predictive model explaining 19% of variance in rate of change in pain (r 2  = 0.19, p = 0.01). Peak patellofemoral joint reaction force was the best predictor of the rate of change in pain following repetitive singe limb landings. The current study supports the theory that patellofemoral joint loading contributes to changes in patellofemoral pain. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. A study on the strength of an armour-grade aluminum under high strain-rate loading

    Science.gov (United States)

    Appleby-Thomas, G. J.; Hazell, P. J.

    2010-06-01

    The aluminum alloy 5083 in tempers such as H32 and H131 is an established light-weight armour material. While its dynamic response under high strain-rates has been investigated elsewhere, little account of the effect of material orientation has been made. In addition, little information on its strength under such loadings is available in the literature. Here, both the longitudinal and lateral components of stress have been measured using embedded manganin stress gauges during plate-impact experiments on samples with the rolling direction aligned both orthogonal and parallel to the impact axis. The Hugoniot elastic limit, spall, and shear strengths were investigated for incident pressures in the range 1-8 GPa, providing an insight into the response of this alloy under shock loading. Further, the time dependence of lateral stress behind the shock front was investigated to give an indication of material response.

  20. Strain Rate Dependent Deformation of a Polymer Matrix Composite with Different Microstructures Subjected to Off-Axis Loading

    Directory of Open Access Journals (Sweden)

    Xiaojun Zhu

    2014-01-01

    Full Text Available This paper aims to investigate the comprehensive influence of three microstructure parameters (fiber cross-section shape, fiber volume fraction, and fiber off-axis orientation and strain rate on the macroscopic property of a polymer matrix composite. During the analysis, AS4 fibers are considered as elastic solids, while the surrounding PEEK resin matrix exhibiting rate sensitivities are described using the modified Ramaswamy-Stouffer viscoplastic state variable model. The micromechanical method based on generalized model of cells has been used to analyze the representative volume element of composites. An acceptable agreement is observed between the model predictions and experimental results found in the literature. The research results show that the stress-strain curves are sensitive to the strain rate and the microstructure parameters play an important role in the behavior of polymer matrix.

  1. Effect Of Adding Sago Flour In Yoghurt Based On Viscosity, Overrun, Melting Rate And Total Solid Of Yoghurt Ice Cream

    Directory of Open Access Journals (Sweden)

    Ika Ayu Wijayanti

    2017-03-01

    Full Text Available The purpose of this research was to find out the best concentration of adding sago flour in yoghurt based on viscosity, overrun, melting rate and total solid of yoghurt ice cream. The experiment was designed by Completely Randomized Design (CRD using four treatments were 0 %, 2 %, 4 %, 6 % from volume of fresh milk and four replication. The data were analyzed by using Analysis of Variance (ANOVA and continued by Duncan’s Multiple Range Test (DMRT. Result of this research showed that concentration of adding sago flour in yoghurt gave highly significant difference effect (P<0.01 on viscosity, overrun, melting rate and total solid of yoghurt ice cream. It can be concluded that the adding of sago flour 2% in yoghurt gave the best result with the viscosity was 1750.75 cP, overrun was 25.14%, melting rate was 39.13 minutes/50 g, total solid was 36.20% and gave the best quality of yoghurt ice cream.

  2. Household solid waste generation rate and physical composition analysis: case of Sekondi-Takoradi Metropolis in the western region, Ghana

    Directory of Open Access Journals (Sweden)

    Eugene Atta Nyankson

    2015-06-01

    Full Text Available Sekondi-Takoradi Metropolis, one of the rapidly expanding cities of Ghana has been facing serious problems with solid waste management. This is mainly due to the lack of available information about the types and quantity of solid waste generation in the area. Hence, the objective of this study was to determine the rate of household solid waste generation and its composition in the aforesaid city. The methodology and procedures for this study were derived from the Standard Test Method for Determination of the Composition of Unprocessed MSW (ASTM D 5231-92. All samples were hand sorted into 6 waste categories (paper, plastic, organics, metals, glass, and other waste. The study revealed that by weight, organic wastes constitutes the largest proportion of household solid waste (38% followed by 19% plastics, 7% papers, 4% metals, 4% glass and 28% other wastes (comprising of sand, stones, ash, inert substances. The rate of daily waste generation per capita in the low, middle and high income households were 0.27±0.19, 0.4±0.19 and 0.58±0.24 kg/cap/day, respectively. The study revealed that there is no waste treatment or recovery facility established within the metropolis hence no significant waste recovery and reuse activities exist. The study showed that more than 38 % of the waste generated in Sekondi-Takoradi Metropolis is decomposable organic matter that can be re-used through composting as well as 34% of the waste having recycling potential thereby considerably mitigating the solid waste problem. DOI: http://dx.doi.org/10.3126/ije.v4i2.12644 International Journal of Environment Vol.4(2 2015: 221-235

  3. Quality control of 192Ir high dose rate after loading brachytherapy dose veracity

    International Nuclear Information System (INIS)

    Feng Zhongsu; Xu Xiao; Liu Fen

    2008-01-01

    Recently, 192 Ir high dose rate (HDR) afterloading are widely used in brachytherapy. The advantage of using HDR systems over low dose rate systems are shorter treatment time and higher fraction dose. To guarantee the veracity of the delivery dose, several quality control methods are deseribed in this work. With these we can improve the position precision, time precision and dose precision of the brachytherapy. (authors)

  4. Intracavitary after loading techniques, advantages and disadvantages with high and low dose-rate methods

    International Nuclear Information System (INIS)

    Walstam, Rune

    1980-01-01

    Even though suggested as early as 1903, it is only when suitable sealed gamma sources became available, afterloading methods could be developed for interstitial as well as intracavitary work. Manual afterloading technique can be used only for low dose rate irradiation, while remote controlled afterloading technique can be used for both low and high dose-rate irradiation. Afterloading units used at the Karolinska Institute, Stockholm, are described, and experience of their use is narrated briefly. (M.G.B.)

  5. Optimal Load-Tracking Operation of Grid-Connected Solid Oxide Fuel Cells through Set Point Scheduling and Combined L1-MPC Control

    Directory of Open Access Journals (Sweden)

    Siwei Han

    2018-03-01

    Full Text Available An optimal load-tracking operation strategy for a grid-connected tubular solid oxide fuel cell (SOFC is studied based on the steady-state analysis of the system thermodynamics and electrochemistry. Control of the SOFC is achieved by a two-level hierarchical control system. In the upper level, optimal setpoints of output voltage and the current corresponding to unit load demand is obtained through a nonlinear optimization by minimizing the SOFC’s internal power waste. In the lower level, a combined L1-MPC control strategy is designed to achieve fast set point tracking under system nonlinearities, while maintaining a constant fuel utilization factor. To prevent fuel starvation during the transient state resulting from the output power surging, a fuel flow constraint is imposed on the MPC with direct electron balance calculation. The proposed control schemes are testified on the grid-connected SOFC model.

  6. Ductile fracture mechanism of low-temperature In-48Sn alloy joint under high strain rate loading.

    Science.gov (United States)

    Kim, Jong-Woong; Jung, Seung-Boo

    2012-04-01

    The failure behaviors of In-48Sn solder ball joints under various strain rate loadings were investigated with both experimental and finite element modeling study. The bonding force of In-48Sn solder on an Ni plated Cu pad increased with increasing shear speed, mainly due to the high strain-rate sensitivity of the solder alloy. In contrast to the cases of Sn-based Pb-free solder joints, the transition of the fracture mode from a ductile mode to a brittle mode was not observed in this solder joint system due to the soft nature of the In-48Sn alloy. This result is discussed in terms of the relationship between the strain-rate of the solder alloy, the work-hardening effect and the resulting stress concentration at the interfacial regions.

  7. Development of high repetition rate ultra-short pulse solid state lasers pumped by laser diodes

    International Nuclear Information System (INIS)

    Ueda, Ken-ichi; Lu, Jianren; Takaichi, Kazunori; Yagi, Hideki; Yanagitani, Takakimi; Kaminskii, Alexander; Kawanaka, Junji

    2004-01-01

    A novel technique for ceramic lasers has been developed recently. Self-energy-driven sintering of nano-and micro particles created the fully transparent Nd:YAG ceramics. The ceramic YAG demonstrated high efficiency operation (optical-to-optical conversion of 60% in end pumping) and solid-phase crystals growth and the possible scaling were investigated principally. Typical performance of ceramic YAG laser has been reviewed. The present status and future prospect of the ceramic lasers technologies were discussed. (author)

  8. Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

    Directory of Open Access Journals (Sweden)

    D. Chaitanya Kumar Rao

    2016-08-01

    Full Text Available Nano-catalysts containing copper–cobalt oxides (Cu–Co–O have been synthesized by the citric acid (CA complexing method. Copper (II nitrate and Cobalt (II nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope (SEM, Energy Dispersive Spectroscopy (EDS and Fourier Transform Infrared Spectroscopy (FTIR methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, CuCo-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of CuCo-I nano-catalyst.

  9. Solid Propellant Subscale Burning Rate Analysis Methods for US and Selected NATO Facilities

    Science.gov (United States)

    2002-01-01

    impossibility of the center of a particle lying closer than its radius from a solid boundary, * Due to surface tension and sedimentation (tends to level...34 effect (for bottom cast or bayonet cast grains) may consist of sedimentation of larger particles against the walls during casting flow, with the...February 2000. 91 Ratti A., "Metodi di Riduzione Dati Balistici per i Boosters a Propellente Solido di Ariane-4 e di Ariane-5," M.Sc. Thesis in Aerospace

  10. Sustained-release diclofenac potassium-loaded solid lipid microparticle based on solidified reverse micellar solution: in vitro and in vivo evaluation.

    Science.gov (United States)

    Chime, Salome Amarachi; Attama, Anthony Amaechi; Builders, Philip F; Onunkwo, Godswill C

    2013-01-01

    To formulate sustained-release diclofenac potassium-loaded solid lipid microparticles (SLMs) based on solidified reverse micellar solution (SRMS) and to evaluate the in vitro and in vivo properties. SRMS consisting of mixtures of Phospholipon® 90H and Softisan® 154 were used to formulate diclofenac potassium-loaded SLMs. Characterization based on the particle size and morphology, stability and encapsulation efficiency (EE%) were carried out on the SLMs. In vitro release was carried out in simulated intestinal fluid (pH 7.5). Anti-inflammatory and ulcerogenic properties were studied using rats. Maximum EE% of 95%, 94% and 93% were obtained for SLMs formulated with SRMS 1:1, 2:1 and 1:2, respectively. In vitro release showed about 85-90% drug release at 13 h. Diclofenac potassium-loaded SLMs showed good anti-inflammatory and gastro-protective properties. Diclofenac potassium-loaded SLMs based on SRMS could be used orally or parenterally under controlled conditions, for once daily administration.

  11. Selectivity control of photosensitive structures based on gallium arsenide phosphide solid solutions by changing the rate of surface recombination

    International Nuclear Information System (INIS)

    Tarasov, S A; Andreev, M Y; Lamkin, I A; Solomonov, A V

    2016-01-01

    In this paper, we demonstrate the effect of surface recombination on spectral sensitivity of structures based on gallium arsenide phosphide solid solutions. Simulation of the effect for structures based on a p-n junction and a Schottky barrier was carried out. Photodetectors with different rates of surface recombination were fabricated by using different methods of preliminary treatment of the semiconductor surface. We experimentally demonstrated the possibility to control photodetector selectivity by altering the rate of surface recombination. The full width at half maximum was reduced by almost 4 times, while a relatively small decrease in sensitivity at the maximum was observed. (paper)

  12. Relationships between rating-of-perceived-exertion- and heart-rate-derived internal training load in professional soccer players: a comparison of on-field integrated training sessions.

    Science.gov (United States)

    Campos-Vazquez, Miguel Angel; Mendez-Villanueva, Alberto; Gonzalez-Jurado, Jose Antonio; León-Prados, Juan Antonio; Santalla, Alfredo; Suarez-Arrones, Luis

    2015-07-01

    To describe the internal training load (ITL) of common training sessions performed during a typical week and to determine the relationships between different indicators of ITL commonly employed in professional football (soccer). Session-rating-of-perceived-exertion TL (sRPE-TL) and heart-rate- (HR) derived measurements of ITL as Edwards TL and Stagno training impulses (TRIMPMOD) were used in 9 players during 3 periods of the season. The relationships between them were analyzed in different training sessions during a typical week: skill drills/circuit training + small-sided games (SCT+SSGs), ball-possession games+technical-tactical exercises (BPG+TTE), tactical training (TT), and prematch activation (PMa). HR values obtained during SCT+SSGs and BPG+TTE were substantially greater than those in the other 2 sessions, all the ITL markers and session duration were substantially greater in SCT+SSGs than in any other session, and all ITL measures in BPG+TTE were substantially greater than in TT and PMa sessions. Large relationships were found between HR>80% HRmax and HR>90% HRmax vs sRPE-TL during BPG+TTE and TT sessions (r=.61-.68). Very large relationships were found between Edwards TL and sRPE-TL and between TRIMPMOD and sRPE-TL in sessions with BPG+TTE and TT (r=.73-.87). Correlations between the different HR-based methods were always extremely large (r=.92-.98), and unclear correlations were observed for other relationships between variables. sRPE-TL provided variable-magnitude within-individual correlations with HR-derived measures of training intensity and load during different types of training sessions typically performed during a week in professional soccer. Caution should be applied when using RPE- or HR-derived measures of exercise intensity/load in soccer training interchangeably.

  13. Dislocation-drag contribution to high-rate plastic deformation in shock-loaded tantalum

    International Nuclear Information System (INIS)

    Tonks, D.L.; Hixson, R.S.; Johnson, J.N.; Gray, G.T. III

    1994-01-01

    Time-resolved plastic waves in plate-impact experiments give information on the relationship between applied shear stress and plastic strain rate at low plastic strain. This information is essentially different from that obtained at intermediate strain rates using Hopkins on bar techniques, because in the former case the material deformation state is driven briefly into the regime dominated by dislocation drag rather than thermal activation. Two VISAR records of the particle velocity at the tantalum/sapphire (window) interface are obtained for symmetric impact producing peak in situ longitudinal stresses of approximately 75 kbar and 111 kbar. The risetimes of the plastic waves are about 100 ns and 60 ns, respectively, with peak strain rates of about 2x10 5 /s and 1x10 6 /s, respectively, as determined by weak-shock analysis [Wallace, Phys. Rev. B 22, 1487 (1980), and Tonks, Los Alamos DataShoP Report LA-12068-MS (1991)]. These data show a much stronger dependence of plastic strain rate on applied shear stress than previously predicted by linear viscous drag models in combination with thermal activation through a large Peierls barrier. The data also show complex evolution of the mobile dislocation density during early stages of high-rate plastic flow. This measurement and analysis aid significantly in establishing the fundamental picture of dynamic deformation of BCC metals and the evolution of the internal material state at early times following shock compression. copyright 1994 American Institute of Physics

  14. Study of the effect of political measures on the citizen participation rate in recycling and on the environmental load reduction

    International Nuclear Information System (INIS)

    Matsui, Yasuhiro; Tanaka, Masaru; Ohsako, Masahiro

    2007-01-01

    Obtaining the cooperation of citizens to participate in separate waste collection is essential to create a recycling-oriented society. In this research, the degree of change in the citizen participation rate, which occurs when the contents of political measures such as the raising of awareness, provision of information, and the conditions of collection services were changed, was estimated together with the effect on the reduction in environmental load. A questionnaire survey was conducted, targeted at residents of Itabashi Ward, while logistic regression analyses were also conducted to create predictive models for recycling behavior, and sensitivity analyses of the models were carried out to estimate the increase in citizen participation rate achievable through the implementation of various political measures. It was found that the effect of 'thorough perception of information' was the largest, followed by 'minimization of evaluation of trouble' and 'thorough perception of efficacy of measures.' The effect of the improvement in the citizen participation rate on the reduction in environmental load was also evaluated quantitatively by life cycle inventory analyses. It was indicated that 'maximization of perception of information' had the greatest effect. However, the reduction effect with 'paper packs' and 'PET bottles' was relatively small compared with that of 'bottles/cans.'

  15. A software reconfigurable optical multiband UWB system utilizing a bit-loading combined with adaptive LDPC code rate scheme

    Science.gov (United States)

    He, Jing; Dai, Min; Chen, Qinghui; Deng, Rui; Xiang, Changqing; Chen, Lin

    2017-07-01

    In this paper, an effective bit-loading combined with adaptive LDPC code rate algorithm is proposed and investigated in software reconfigurable multiband UWB over fiber system. To compensate the power fading and chromatic dispersion for the high frequency of multiband OFDM UWB signal transmission over standard single mode fiber (SSMF), a Mach-Zehnder modulator (MZM) with negative chirp parameter is utilized. In addition, the negative power penalty of -1 dB for 128 QAM multiband OFDM UWB signal are measured at the hard-decision forward error correction (HD-FEC) limitation of 3.8 × 10-3 after 50 km SSMF transmission. The experimental results show that, compared to the fixed coding scheme with the code rate of 75%, the signal-to-noise (SNR) is improved by 2.79 dB for 128 QAM multiband OFDM UWB system after 100 km SSMF transmission using ALCR algorithm. Moreover, by employing bit-loading combined with ALCR algorithm, the bit error rate (BER) performance of system can be further promoted effectively. The simulation results present that, at the HD-FEC limitation, the value of Q factor is improved by 3.93 dB at the SNR of 19.5 dB over 100 km SSMF transmission, compared to the fixed modulation with uncoded scheme at the same spectrum efficiency (SE).

  16. Formation of nitrous oxide in a gradient of oxygenation and nitrogen loading rate during denitrification of nitrite and nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Gong, You-Kui; Peng, Yong-Zhen [School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Yang, Qing, E-mail: gykren@163.com [School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China); Wu, Wei-Min [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090 (China); Wang, Shu-Ying [School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer The correlation of DO to N{sub 2}O emission under denitrification via nitrite was confirmed. Black-Right-Pointing-Pointer The higher nitrite ratio in NO{sub x} (nitrite and nitrate) caused the more N{sub 2}O emission. Black-Right-Pointing-Pointer Reactor feed mode and nitrite loading rate had significant impact on N{sub 2}O emission which was related to nitrite level. - Abstract: Nitrous oxide (N{sub 2}O) emission has been observed during denitrification of nitrate via nitrite as intermediate. With a laboratory-scale reactor (2.4 L), the N{sub 2}O emission was characterized under a gradient of DO concentration from 0 to 0.7 mg/L, different ratio of nitrite versus nitrate and different nitrite feed mode. The N{sub 2}O emission was influenced by the level of dissolved oxygen (DO) and nitrite accumulation. The higher DO level and the higher ratio of nitrite versus nitrate resulted in the higher N{sub 2}O emission. Using nitrite as sole electron acceptor at the same loading rate, the sequence of N{sub 2}O emission with three different feed modes was: pulse > step-wise > continuous feed. The N{sub 2}O emitted in pulse feed reactors was 3.1-4.2 and 8.2-11.7 folds of that in the step-wise feed and continuous feed reactors, respectively. With continuous feed mode, the impact of DO concentration on the mass of N{sub 2}O emitted was limited while the higher N{sub 2}O emission occurred at the higher nitrite loading rate.

  17. Effect of sucrose polyesters on crystallization rate of vegetable ghee: solid fat content study

    Directory of Open Access Journals (Sweden)

    Ibrahim Nasir, Mohammad

    2003-12-01

    Full Text Available Crystallization rate of partial hydrogenated blend of soybean oil and cottonseed oil used for making vegetable ghee (vanaspati was investigated, by solid fat content (SFC using pulsed nuclear magnetic resonance (p-NMR. The effects of adding sucrose fatty acid esters or sucrose polyesters (SPE on the crystallization rate of the blend fat were studied. Sucrose tetrastearate DK ester F-10 (stearate 70% - palmitate 30% was added to the fat at different concentration, namely 0.5% and 1.0%. Blank sample and sample containing 0.5% and 1.0% DK ester F-10 / (DK F-10 were chosen to measure the change in SFC at constant temperature of 15ºC for a period of 25 hr. Five determinations of SFC were taken to the fat samples during the 25 hr i.e. 2,5,9,13 and 25th hr. SFC vs. time of crystallization of the three samples showed continuous increasing in SFC in all samples during the 25 hr, with sharp increasing at the first two hours. Samples containing 0.0% and 0.5% DK F-10, showed no significant difference in SFC during the first thirteen hours, while sample containing 1.0% DK F-10, showed higher SFC than the other two samples, through out the period. The amount of SFC for 1.0% DK F-10 sample at the 13th hour is equal to the SFC of the blank (0.0% sample at the 25th hour. Melting point of the same samples increased with the increasing DK F-10 concentration in the fat samples. The results of SFC make it sure that the addition of 1.0% DK F- 10 will shorten the time required for the crystallization of vegetable ghee while the addition of 0.5% will not have significant effect.Se ha investigado, mediante el contenido en grasa sólida (SFC por resonancia magnética nuclear pulsada (p-NMR, la velocidad de cristalización de mezcla de aceite de la soja y aceite de semilla del algodón parcialmente hidrogenada utilizada en la elaboración de ghee vegetal (vanaspati. Se han estudiado los efectos de añadir ésteres de sacarosa de ácidos grasos o poliésteres de

  18. Pretreatment methods to obtain pumpable high solid loading wood–water slurries for continuous hydrothermal liquefaction systems

    DEFF Research Database (Denmark)

    Dãrãbana, Iulia-Maria; Rosendahl, Lasse Aistrup; Pedersen, Thomas Helmer

    2015-01-01

    Feedstock pretreatment is a prerequisite step for continuous processing of lignocellulosic biomass through HTL, in order to facilitate the pumpability of biomass aqueous slurries. Until now, HTL feedstock pumpability could only be achieved at solid mass content below 15%. In this work, two...... pretreatment methods to obtain wood-based slurries with more than 20% solid mass content, for continuous processing in HTL systems, are proposed. The effect of biomass particle size and pretreatment method on the feedstock pumpability is analyzed. The experimental results show that pumpable wood-based slurries...

  19. Optimization of the RF cavity heat load and trip rates for CEBAF at 12 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, He [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Freyberger, Arne P. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Krafft, Geoffrey A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Terzic, Balsa P. [Old Dominion Univ., Norfolk, VA (United States)

    2017-05-01

    The Continuous Electron Beam Accelerator Facility at JLab has 200 RF cavities in the north linac and the south linac respectively after the 12 GeV upgrade. The purpose of this work is to simultaneously optimize the heat load and the trip rate for the cavities and to reconstruct the pareto-optimal front in a timely manner when some of the cavities are turned down. By choosing an efficient optimizer and strategically creating the initial gradients, the pareto-optimal front for no more than 15 cavities down can be re-established within 20 seconds.

  20. Fracture and strain rate behavior of airplane fuselage materials under blast loading

    NARCIS (Netherlands)

    Mediavilla Varas, J.; Soetens, F.; Kroon, E.; Aanhold, van J.E.; Meulen, van der O.R.; Sagimon, M.

    2010-01-01

    The dynamic behavior of three commonly used airplane fuselage materials is investigated, namely of Al2024-T3, Glare-3 and CFRP. Dynamic tensile tests using a servo-hydraulic and a light weight shock testing machine (LSM) have been performed. The results showed no strain rate effect on Al2024-T3 and

  1. Fracture and strain rate behavior of airplane fuselage materials under blast loading

    NARCIS (Netherlands)

    Mediavilla Varas, J.; Soetens, F.; Kroon, E.; Aanhold, J.E. van; Meulen, O.R. van der; Sagimon, M.

    2010-01-01

    The dynamic behavior of three commonly used airplane fuselage materials is investigated, namely of Al2024-T3, Glare-3 and CFRP. Dynamic tensile tests using a servo-hydraulic and a light weight shock testing machine (LSM) have been performed. The results showed no strain rate effect on Al2024-T3 and

  2. Influence of the menstrual cycle and of menopause on the gastric emptying rate of solids in female volunteers

    International Nuclear Information System (INIS)

    Mones, J.; Carrio, I.; Calabuig, R.; Estorch, M.; Sainz, S.; Berna, L.; Vilardell, F.

    1993-01-01

    The aim of this study was to assess the influence of the normal menstrual cycle and of menopause on the gastric emptying rate of solids. Gastric emptying was studied in 15 premenopausal and ten postmenopausal women with an isotopic technique after the ingestion of a radiolabelled test meal. Premenopausal women were studied twice: Within 1 week prior to menses and again 1 week after onset of menses. Postmenopausal women were studied only once. The emptying curves of the solid component of the meal fitted a linear model. The half-emptying time was 78±5 min during the follicular phase, 75±7 min during the luteal phase and 76±6 min in postmenopausal women (differences not statistically significant). The mean percentages of the meal retained in the stomach at different time intervals were also similar in the three groups. These results suggest that the menstrual cycle does not influence the gastric emptying rate of solids, which remains unchanged in relation to the follicular phase or after menopause. (orig.)

  3. Influence of the menstrual cycle and of menopause on the gastric emptying rate of solids in female volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Mones, J. (Dept. of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain)); Carrio, I. (Dept. of Nuclear Medicine, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain)); Calabuig, R. (Dept. of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain)); Estorch, M. (Dept. of Nuclear Medicine, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain)); Sainz, S. (Dept. of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain)); Berna, L. (Dept. of Nuclear Medicine, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain)); Vilardell, F. (Dept. of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma de Barcelona (Spain))

    1993-07-01

    The aim of this study was to assess the influence of the normal menstrual cycle and of menopause on the gastric emptying rate of solids. Gastric emptying was studied in 15 premenopausal and ten postmenopausal women with an isotopic technique after the ingestion of a radiolabelled test meal. Premenopausal women were studied twice: Within 1 week prior to menses and again 1 week after onset of menses. Postmenopausal women were studied only once. The emptying curves of the solid component of the meal fitted a linear model. The half-emptying time was 78[+-]5 min during the follicular phase, 75[+-]7 min during the luteal phase and 76[+-]6 min in postmenopausal women (differences not statistically significant). The mean percentages of the meal retained in the stomach at different time intervals were also similar in the three groups. These results suggest that the menstrual cycle does not influence the gastric emptying rate of solids, which remains unchanged in relation to the follicular phase or after menopause. (orig.)

  4. Nanoindentation study of size effect and loading rate effect on mechanical properties of a thin film metallic glass Cu49.3Zr50.7

    International Nuclear Information System (INIS)

    Pang Jianjun; Tan Mingjen; Liew, K.M.; Shearwood, Christopher

    2012-01-01

    A binary metallic glass (MG) Cu 49.3 Zr 50.7 in the form of thin film was successfully grown on a Si (1 0 0) substrate by magnetron sputtering. The mechanical properties, specifically, hardness and modulus at various peak loads and loading rates were characterized through instrumented nanoindentation. Unlike other metallic glasses showing an indentation size effect (ISE), the composition of this study does not have an ISE, which is phenomenologically the result of the negligible length scale according to the strain gradient plasticity model. The proportional specimen resistance model is applicable to the load-displacement behaviors and suggests that the frictional effect is too small to contribute to the ISE. The occurrence of plasticity depends on loading rates and can be delayed so that the displacement during the load holding segment increases logarithmically. In addition, the hardness and modulus are both dependent on the loading rates as well, i.e., they increase as the loading rate increases up to 0.1 mN/s and then hold constant, which is independent of creep time (≤100 s). These loading-rate-dependent behaviors are interpreted as the result of viscoelastic effect rather than free volume kinetics.

  5. Estimation of physical work load by statistical analysis of the heart rate in a conveyor-belt worker.

    Science.gov (United States)

    Kontosic, I; Vukelić, M; Pancić, M; Kunisek, J

    1994-12-01

    Physical work load was estimated in a female conveyor-belt worker in a bottling plant. Estimation was based on continuous measurement and on calculation of average heart rate values in three-minute and one-hour periods and during the total measuring period. The thermal component of the heart rate was calculated by means of the corrected effective temperature, for the one-hour periods. The average heart rate at rest was also determined. The work component of the heart rate was calculated by subtraction of the resting heart rate and the heart rate measured at 50 W, using a regression equation. The average estimated gross energy expenditure during the work was 9.6 +/- 1.3 kJ/min corresponding to the category of light industrial work. The average estimated oxygen uptake was 0.42 +/- 0.06 L/min. The average performed mechanical work was 12.2 +/- 4.2 W, i.e. the energy expenditure was 8.3 +/- 1.5%.

  6. Recent advances in the design of drug-loaded polymeric implants for the treatment of solid tumors.

    Science.gov (United States)

    Wadee, Ameena; Pillay, Viness; Choonara, Yahya E; du Toit, Lisa C; Penny, Clement; Ndesendo, Valence M K; Kumar, Pradeep; Murphy, Caragh S

    2011-10-01

    The effective treatment of solid tumors continues to be a great challenge to clinicians, despite the development of novel drugs. In order to improve the clinical efficacy of existing chemotherapeutic agents, researchers have considered the possibility of site-specific solid tumor treatment. The greatest advantage of localized delivery is the significantly fewer side effects experienced by patients. Recently, in situ forming implants have attracted considerable interest. These polymeric systems are injected as solutions into tumor sites and the injected solution forms an implant as a result of local environmental stimuli and hence removes the need for surgical implantation. This review summarizes the attempts that have been made to date in the development of polymeric implants for the treatment of solid tumors. Both in situ forming implants and preformed implants, fabricated using natural and synthetic polymers, are described. In addition, the peri- or intra-tumoral delivery of chemotherapeutic agents based on implants inserted surgically into the affected region is also discussed along with a short coverage of implants having an undesirable initial burst release effect. Although these implants have been shown to improve the treatment of various solid tumors, the ideal implant that is able to deliver high doses of chemotherapeutics to the tumor site, over prolonged periods with relatively few side effects on normal tissue, is yet to be formulated.

  7. Influence of step rate and quadriceps load distribution on patellofemoral cartilage contact pressures during running.

    Science.gov (United States)

    Lenhart, Rachel L; Smith, Colin R; Vignos, Michael F; Kaiser, Jarred; Heiderscheit, Bryan C; Thelen, Darryl G

    2015-08-20

    Interventions used to treat patellofemoral pain in runners are often designed to alter patellofemoral mechanics. This study used a computational model to investigate the influence of two interventions, step rate manipulation and quadriceps strengthening, on patellofemoral contact pressures during running. Running mechanics were analyzed using a lower extremity musculoskeletal model that included a knee with six degree-of-freedom tibiofemoral and patellofemoral joints. An elastic foundation model was used to compute articular contact pressures. The lower extremity model was scaled to anthropometric dimensions of 22 healthy adults, who ran on an instrumented treadmill at 90%, 100% and 110% of their preferred step rate. Numerical optimization was then used to predict the muscle forces, secondary tibiofemoral kinematics and all patellofemoral kinematics that would generate the measured primary hip, knee and ankle joint accelerations. Mean and peak patella contact pressures reached 5.0 and 9.7MPa during the midstance phase of running. Increasing step rate by 10% significantly reduced mean contact pressures by 10.4% and contact area by 7.4%, but had small effects on lateral patellar translation and tilt. Enhancing vastus medialis strength did not substantially affect pressure magnitudes or lateral patellar translation, but did shift contact pressure medially toward the patellar median ridge. Thus, the model suggests that step rate tends to primarily modulate the magnitude of contact pressure and contact area, while vastus medialis strengthening has the potential to alter mediolateral pressure locations. These results are relevant to consider in the design of interventions used to prevent or treat patellofemoral pain in runners. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. High-rate polyaniline/carbon-cloth electrodes: effect of mass loading on the pseudocapacitive performance

    Czech Academy of Sciences Publication Activity Database

    Tomšík, Elena; Ivanko, Iryna; Kohut, Olena; Hromádková, Jiřina

    2017-01-01

    Roč. 4, č. 11 (2017), s. 2884-2890 ISSN 2196-0216 R&D Projects: GA ČR(CZ) GA15-14791S Grant - others:OPPK(XE) CZ.2.16/3.1.00/21545 Program:OPPK Institutional support: RVO:61389013 Keywords : pseudocapacitors * polyaniline * high charge-discharge rate Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.136, year: 2016

  9. Physiochemical Characterization and Release Rate Studies of SolidDispersions of Ketoconazole with Pluronic F127 and PVP K-30

    Science.gov (United States)

    Kumar, Pankaj; Mohan, Chander; KanamSrinivasan Uma Shankar, Mara; Gulati, Monica

    2011-01-01

    In the present study solid dispersions of the antifungal drug Ketoconazole were prepared with Pluronic F-127 and PVP K-30 with an intention to improve its dissolution properties. Investigations of the properties of the dispersions were performed using release studies, Differential scanning calorimetery (DSC), X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR). The results obtained showed that the rate of dissolution of Ketoconazole was considerably improved when formulated in solid dispersions with PVP K-30 and Pluronic F-127 as compared with pure drug and physical mixtures. The results from DSC and XRD studies showed the transition of crystalline nature of drug to amorphous form, while FTIR studies demonstrated the absence of drug-carriers interaction. PMID:24250403

  10. Formation of the prebiotic molecule NH2CHO on astronomical amorphous solid water surfaces: accurate tunneling rate calculations.

    Science.gov (United States)

    Song, Lei; Kästner, Johannes

    2016-10-26

    Investigating how formamide forms in the interstellar medium is a hot topic in astrochemistry, which can contribute to our understanding of the origin of life on Earth. We have constructed a QM/MM model to simulate the hydrogenation of isocyanic acid on amorphous solid water surfaces to form formamide. The binding energy of HNCO on the ASW surface varies significantly between different binding sites, we found values between ∼0 and 100 kJ mol -1 . The barrier for the hydrogenation reaction is almost independent of the binding energy, though. We calculated tunneling rate constants of H + HNCO → NH 2 CO at temperatures down to 103 K combining QM/MM with instanton theory. Tunneling dominates the reaction at such low temperatures. The tunneling reaction is hardly accelerated by the amorphous solid water surface compared to the gas phase for this system, even though the activation energy of the surface reaction is lower than the one of the gas-phase reaction. Both the height and width of the barrier affect the tunneling rate in practice. Strong kinetic isotope effects were observed by comparing to rate constants of D + HNCO → NHDCO. At 103 K we found a KIE of 231 on the surface and 146 in the gas phase. Furthermore, we investigated the gas-phase reaction NH 2 + H 2 CO → NH 2 CHO + H and found it unlikely to occur at cryogenic temperatures. The data of our tunneling rate constants are expected to significantly influence astrochemical models.

  11. Targeting the Endocannabinoid/CB1 Receptor System For Treating Major Depression Through Antidepressant Activities of Curcumin and Dexanabinol-Loaded Solid Lipid Nanoparticles

    Directory of Open Access Journals (Sweden)

    Xiaolie He

    2017-08-01

    Full Text Available Background/Aims: This study investigated the underlying mechanisms of the antidepressant effects of curcumin and dexanabinol-loaded solid lipid nanoparticles in corticosterone-induced cell and mice depression models. Methods: Curcumin and dexanabinol-loaded solid lipid nanoparticles (Cur/SLNs-HU-211 were synthesized via an emulsifcation and low-temperature solidification method. Antidepressant activities of nanoparticles in a corticosterone-induced major depression model were investigated by MTT assay, cellular uptake by flow cytometry, behaviour by Forced Swimming Test and rotarod test, neurotransmitters by High Performance Liquid Chromatography, Western blotting, qPCR and immunofluorescence. Results: Treatment with Cur/SLNs-HU-211 induced greater dopamine (DA/5-hydroxytryptamine (5-HT release with reduced corticosterone-induced apoptotic cell death in PC12 cells. Additionally, in vivo Cur/SLNs-HU-211 significantly induced recovery from depressive behaviour with increased DA/5-HT levels, CB1 mRNA levels and CB1, p-MEK1 and p-ERK1/2 protein expression levels in the hippocampus and striatum. Cur/SLNs-HU-211 improved CB1 expression and inspired the proliferation of astrocytes in the hippocampus and striatum, exerted neuroprotective effects by preventing corticosterone -induced BDNF/NeuN expression reduction. Conclusion: Our study implies that Cur/SLNs-HU-211 may be a useful approach for treatment of major depression.

  12. Use of 198 Au, with surface labelling, in the study of solid transport by bed load in large natural channels

    International Nuclear Information System (INIS)

    Nakahira, S.

    1987-01-01

    The present study aims to present a method of measuring the bed load transport using a radioisotope technique in large natural channels. This study describes the basic principles of radioisotope application in this field, emphasizing the use of 198 Au for surface labelling of a natural sediment. Moreover, it presents the theoretical aspects, critical analysis, recommendations and comments on the methodology proposed. (author)

  13. High strain rate deformation and fracture of the magnesium alloy Ma2-1 under shock wave loading

    Science.gov (United States)

    Garkushin, G. V.; Kanel', G. I.; Razorenov, S. V.

    2012-05-01

    This paper presents the results of measurements of the dynamic elastic limit and spall strength under shock wave loading of specimens of the magnesium alloy Ma2-1 with a thickness ranging from 0.25 to 10 mm at normal and elevated (to 550°C) temperatures. From the results of measurements of the decay of the elastic precursor of a shock compression wave, it has been found that the plastic strain rate behind the front of the elastic precursor decreases from 2 × 105 s-1 at a distance of 0.25 mm to 103 s-1 at a distance of 10 mm. The plastic strain rate in a shock wave is one order of magnitude higher than that in the elastic precursor at the same value of the shear stress. The spall strength of the alloy decreases as the solidus temperature is approached.

  14. Effect of trace element addition and increasing organic loading rates on the anaerobic digestion of cattle slaughterhouse wastewater.

    Science.gov (United States)

    Schmidt, Thomas; McCabe, Bernadette K; Harris, Peter W; Lee, Seonmi

    2018-05-18

    In this study, anaerobic digestion of slaughterhouse wastewater with the addition of trace elements was monitored for biogas quantity, quality and process stability using CSTR digesters operated at mesophilic temperature. The determination of trace element concentrations was shown to be deficient in Fe, Ni, Co, Mn and Mo compared to recommendations given in the literature. Addition of these trace elements resulted in enhanced degradation efficiency, higher biogas production and improved process stability. Higher organic loading rates and lower hydraulic retention times were achieved in comparison to the control digesters. A critical accumulation of volatile fatty acids was observed at an organic loading rate of 1.82 g L -1  d -1 in the control compared to 2.36 g L -1  d -1 in the digesters with trace element addition. The improved process stability was evident in the final weeks of experimentation, in which control reactors produced 84% less biogas per day compared to the reactors containing trace elements. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Evaluation of rapid methods for in-situ characterization of organic contaminant load and biodegradation rates in winery wastewater.

    Science.gov (United States)

    Carvallo, M J; Vargas, I; Vega, A; Pizarro, G; Pizarr, G; Pastén, P

    2007-01-01

    Rapid methods for the in-situ evaluation of the organic load have recently been developed and successfully implemented in municipal wastewater treatment systems. Their direct application to winery wastewater treatment is questionable due to substantial differences between municipal and winery wastewater. We critically evaluate the use of UV-VIS spectrometry, buffer capacity testing (BCT), and respirometry as rapid methods to determine organic load and biodegradation rates of winery wastewater. We tested three types of samples: actual and treated winery wastewater, synthetic winery wastewater, and samples from a biological batch reactor. Not surprisingly, respirometry gave a good estimation of biodegradation rates for substrate of different complexities, whereas UV-VIS and BCT did not provide a quantitative measure of the easily degradable sugars and ethanol, typically the main components of the COD in the influent. However, our results strongly suggest that UV-VIS and BCT can be used to identify and estimate the concentration of complex substrates in the influent and soluble microbial products (SMP) in biological reactors and their effluent. Furthermore, the integration of UV-VIS spectrometry, BCT, and mathematical modeling was able to differentiate between the two components of SMPs: substrate utilization associated products (UAP) and biomass associated products (BAP). Since the effluent COD in biologically treated wastewaters is composed primarily by SMPs, the quantitative information given by these techniques may be used for plant control and optimization.

  16. Mass concentration coupled with mass loading rate for evaluating PM_2_._5 pollution status in the atmosphere: A case study based on dairy barns

    International Nuclear Information System (INIS)

    Joo, HungSoo; Park, Kihong; Lee, Kwangyul; Ndegwa, Pius M.

    2015-01-01

    This study investigated particulate matter (PM) loading rates and concentrations in ambient air from naturally ventilated dairy barns and also the influences of pertinent meteorological factors, traffic, and animal activities on mass loading rates and mass concentrations. Generally, relationships between PM_2_._5 concentration and these parameters were significantly poorer than those between the PM loading rate and the same parameters. Although ambient air PM_2_._5 loading rates correlated well with PM_2_._5 emission rates, ambient air PM_2_._5 concentrations correlated poorly with PM_2_._5 concentrations in the barns. A comprehensive assessment of PM_2_._5 pollution in ambient air, therefore, requires both mass concentrations and mass loading rates. Emissions of PM_2_._5 correlated strongly and positively with wind speed, temperature, and solar radiation (R"2 = 0.84 to 0.99) and strongly but negatively with relative humidity (R"2 = 0.93). Animal activity exhibited only moderate effect on PM_2_._5 emissions, while traffic activity did not significantly affect PM_2_._5 emissions. - Highlights: • Sink PM_2_._5 loading rates correlate well with source PM_2_._5 emission rates. • Sink PM_2_._5 concentrations correlate poorly with source PM_2_._5 concentrations. • Mass loading rate complements mass concentration in appraising sink PM_2_._5 status. • PM_2_._5 emissions is dependent on wind speed, temp, solar strength, and RH. • Cow traffic activity affects PM_2_._5 emissions, while traffic activity does not. - Both PM mass loading rate and concentrations are required for comprehensive assessment of pollution potential of PM released into the atmosphere.

  17. Measuring Load on Working Memory: The Use of Heart Rate as a Means of Measuring Chemistry Students' Cognitive Load

    Science.gov (United States)

    Cranford, Kristen N.; Tiettmeyer, Jessica M.; Chuprinko, Bryan C.; Jordan, Sophia; Grove, Nathaniel P.

    2014-01-01

    Information processing provides a powerful model for understanding how learning occurs and highlights the important role that cognitive load plays in this process. In instances in which the cognitive load of a problem exceeds the available working memory, learning can be seriously hindered. Previously reported methods for measuring cognitive load…

  18. Loading rate effects on strength and fracture toughness of pipe steels used in Task 1 of the IPIRG program

    International Nuclear Information System (INIS)

    Marschall, C.W.; Landow, M.P.; Wilkowski, G.M.

    1993-10-01

    Material characterization tests were conducted on laboratory specimens machined from pipes to determine the effect of dynamic loading (i.e., rates comparable to those for high amplitude seismic events) on tensile properties and fracture resistance at 288 C (550 F). Specimens were fabricated from seven different pipes, including carbon steels and stainless steels (both base metal and weld metal), which were to be subjected to full-scale pipe tests in IPIRG Task 1.0. For the stainless steels tested at 288 C (550 F), tensile strength was unchanged, while yield strength and fracture resistance were increased. The increase in fracture resistance was modest for the wrought base metals and substantial for the weld metal and the cast base metal. The carbon steels tested were sensitive to dynamic strain aging, and hence the strength and toughness was affected by both temperature and strain rate effects. The carbon steel base metal and welds exhibited ultimate tensile strength values at 288 C (550 F) that were greater than at room temperature. Furthermore, the ultimate tensile strength at 288 C (550 F) was lowered significantly by increased strain rate and, in the carbon steel base metals, increased strain rate also lowered the fracture resistance, substantially in the base metal of one pipe. In comparing these results to the IPIRG pipe test results to date, it was found that the trends of these tests agree well with the Subtask 1.2 quasi-static and dynamic pipe fracture experiments. Loads measured in the Subtask 1.1 pipe experiments were, however, somewhat higher than would have been expected by the trends observed in the laboratory tests

  19. Interim report on the state-of-the-art of solid-state motor controllers. Part 4. Failure-rate and failure-mode data

    International Nuclear Information System (INIS)

    Jaross, R.A.

    1983-09-01

    An assessment of the reliability of solid-state motor controllers for nuclear power plants is made. Available data on failure-rate and failure-mode data for solid-state motor controllers based on industrial operating experience is meager; the data are augmented by data on other solid-state power electronic devices that are shown to have components similar to those found in solid-state motor controllers. In addition to large nonnuclear solid-state adjustable-speed motor drives, the reliability of nuclear plant inverter systems and high-voltage solid-state dc transmission-line converters is assessed. Licensee Event Report analyses from several sources, the open literature, and personal communications are used to determine the realiability of solid-state devices typical of those expected to be used in nuclear power plants in terms of failures per hour

  20. Duration of off-loading and recurrence rate in Charcot osteo-arthropathy treated with less restrictive regimen with removable walker

    DEFF Research Database (Denmark)

    Christensen, Tomas M; Gade-Rasmussen, Birthe; Pedersen, Lis W

    2013-01-01

    Recent literature on acute diabetic Charcot osteoarthropathy (CA) reports unusually long periods of off-loading. Data suggest that this might increase the re-currence rate. Subsequently we evaluated the influence of duration of off-loading on the risk of required re-casting....

  1. Variable EBV DNA Load Distributions and Heterogeneous EBV mRNA Expression Patterns in the Circulation of Solid Organ versus Stem Cell Transplant Recipients

    Directory of Open Access Journals (Sweden)

    A. E. Greijer

    2012-01-01

    Full Text Available Epstein-Barr virus (EBV driven post-transplant lymphoproliferative disease (PTLD is a heterogeneous and potentially life-threatening condition. Early identification of aberrant EBV activity may prevent progression to B-cell lymphoma. We measured EBV DNA load and RNA profiles in plasma and cellular blood compartments of stem cell transplant (SCT; n=5, solid organ transplant recipients (SOT; n=15, and SOT having chronic elevated EBV-DNA load (n=12. In SCT, EBV DNA was heterogeneously distributed, either in plasma or leukocytes or both. In SOT, EBV DNA load was always cell associated, predominantly in B cells, but occasionally in T cells (CD4 and CD8 or monocytes. All SCT with cell-associated EBV DNA showed BARTs and EBNA1 expression, while LMP1 and LMP2 mRNA was found in 1 and 3 cases, respectively. In SOT, expression of BARTs was detected in all leukocyte samples. LMP2 and EBNA1 mRNA was found in 5/15 and 2/15, respectively, but LMP1 mRNA in only 1, coinciding with severe PTLD and high EBV DNA. Conclusion: EBV DNA is differently distributed between white cells and plasma in SOT versus SCT. EBV RNA profiling in blood is feasible and may have added value for understanding pathogenic virus activity in patients with elevated EBV-DNA.

  2. Application of subsurface wastewater infiltration system to on-site treatment of domestic sewage under high hydraulic loading rate

    Directory of Open Access Journals (Sweden)

    Ying-hua Li

    2015-01-01

    Full Text Available In order to enhance the hydraulic loading rate (HLR of a subsurface wastewater infiltration system (SWIS used in treating domestic sewage, the intermittent operation mode was employed in the SWIS. The results show that the intermittent operation mode contributes to the improvement of the HLR and the pollutant removal rate. When the wetting-drying ratio (RWD was 1.0, the pollutant removal rate increased by (13.6 ± 0.3% for NH3-N, (20.7 ± 1.1% for TN, (18.6 ± 0.4% for TP, (12.2 ± 0.5% for BOD, (10.1 ± 0.3% for COD, and (36.2 ± 1.2% for SS, compared with pollutant removal rates under the continuous operation mode. The pollutant removal rate declined with the increase of the HLR. The effluent quality met The Reuse of Urban Recycling Water – Water Quality Standard for Scenic Environment Use (GB/T 18921-2002 even when the HLR was as high as 10 cm/d. Hydraulic conductivity, oxidation reduction potential (ORP, the quantity of nitrifying bacteria, and the pollutant removal rate of NH3-N increased with the decrease of the RWD. For the pollutant removal rates of TP, BOD, and COD, there were no significant difference (p < 0.05 under different RWDs. The suggested RWD was 1.0. Relative contribution of the pretreatment and SWIS to the pollutant removal was examined, and more than 80% removal of NH3-N, TN, TP, COD, and BOD occurred in the SWIS.

  3. Extremely fast increase in the organic loading rate during the co-digestion of rapeseed oil and sewage sludge in a CSTR--characterization of granules formed due to CaO addition to maintain process stability.

    Science.gov (United States)

    Kasina, M; Kleyböcker, A; Michalik, M; Würdemann, H

    2015-01-01

    In a co-digestion system running with rapeseed oil and sewage sludge, an extremely fast increase in the organic loading rate was studied to develop a procedure to allow for flexible and demand-driven energy production. The over-acidification of the digestate was successfully prevented by calcium oxide dosage, which resulted in granule formation. Mineralogical analyses revealed that the granules were composed of insoluble salts of long chain fatty acids and calcium and had a porous structure. Long chain fatty acids and calcium formed the outer cover of granules and offered interfaces on the inside thereby enhancing the growth of biofilms. With granule size and age, the pore size increased and indicated degradation of granular interfaces. A stable biogas production up to the organic loading rate of 10.4 kg volatile solids m(-3) d(-1) was achieved although the hydrogen concentration was not favorable for propionic acid degradation. However, at higher organic loading rates, unbalanced granule formation and degradation were observed. Obviously, the adaption time for biofilm growth was too short to maintain the balance, thereby resulting in a low methane yield.

  4. Pharmaceutical removal in tropical subsurface flow constructed wetlands at varying hydraulic loading rates.

    Science.gov (United States)

    Zhang, Dong Qing; Gersberg, Richard M; Hua, Tao; Zhu, Junfei; Tuan, Nguyen Anh; Tan, Soon Keat

    2012-04-01

    Determining the fate of emerging organic contaminants in an aquatic ecosystem is important for developing constructed wetlands (CWs) treatment technology. Experiments were carried out in subsurface flow CWs in Singapore to evaluate the fate and transport of eight pharmaceutical compounds. The CW system included three parallel horizontal subsurface flow CWs and three parallel unplanted beds fed continuously with synthetic wastewater at different hydraulic retention times (HRTs). The findings of the tests at 2-6 d HRTs showed that the pharmaceuticals could be categorized as (i) efficiently removed compounds with removal higher than 85% (ketoprofen and salicylic acid); (ii) moderately removed compounds with removal efficiencies between 50% and 85% (naproxen, ibuprofen and caffeine); and (iii) poorly removed compounds with efficiency rate lower than 50% (carbamazepine, diclofenac, and clofibric acid). Except for carbamazepine and salicylic acid, removal efficiencies of the selected pharmaceuticals showed significant (pcaffeine, ketoprofen and clofibric acid were found to follow first order decay kinetics with decay constants higher in the planted beds than the unplanted beds. Correlations between pharmaceutical removal efficiencies and log K(ow) were not significant (p>0.05), implying that their removal is not well related to the compound's hydrophobicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Influence of Loading Rate on the Calibration of Instrumented Charpy Strikers

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; Scibetta, M.; McColskey, D.; McCowan, C.

    2009-01-15

    One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. The conventional approach for establishing an analytical relationship between strain gage output and force applied to the transducer is the static calibration, which is preferably performed with the striker installed in the pendulum assembly. However, the response of an instrumented striker under static force application may sometimes differ significantly from its dynamic performance during an actual Charpy test. This is typically reflected in a large difference between absorbed energy returned by the pendulum encoder (KV) and calculated under the instrumented force/displacement test record (Wt). Such difference can be either minimized by optimizing the striker design or analytically removed by adjusting forces and displacements until KV = Wt (the so-called 'Dynamic Force Adjustment'). This study investigates the influence of increasing force application rates on the force/voltage characteristics of two instrumented strikers, one at NIST in Boulder, CO and one at SCK-CEN in Mol, Belgium.

  6. Effects of Surface Inclination on the Vertical Loading Rates and Landing Pattern during the First Attempt of Barefoot Running in Habitual Shod Runners

    OpenAIRE

    An, W.; Rainbow, M. J.; Cheung, R. T. H.

    2015-01-01

    Barefoot running has been proposed to reduce vertical loading rates, which is a risk factor of running injuries. Most of the previous studies evaluated runners on level surfaces. This study examined the effect of surface inclination on vertical loading rates and landing pattern during the first attempt of barefoot running among habitual shod runners. Twenty habitual shod runners were asked to run on treadmill at 8.0?km/h at three inclination angles (0?; +10?; ?10?) with and without their usua...

  7. THE EFFECTS OF DIFFERENT WORK-LOADING APPLIED TO THE WORKERS THAT WORK PRODUCING OF SHIRT TO THE SEAM FAULT RATES

    Directory of Open Access Journals (Sweden)

    Önder YÜCEL

    2001-03-01

    Full Text Available Human efficiency is of big importance in the clothing industry. So as to provide high quality and productivity stabilized work –loading must be given to the workers that work in the cloth production lines. In addition to it, the kind of work must be paid attention in the studies to be done on stabilized work-loading. The aim of this study is to determine the effects of different work-loading to the seam fault rates. For this purpose, four different work-loading had been applied to the workers and determined seam faults on the clothes had been recorded. As a result of this study, seam fault rates in the different work-loading had been evaluated.

  8. Effect of Five-Finger Shoes on Vertical Ground Reaction Force Loading Rates and Perceived Comfort during the Stance Phase of the Running

    Directory of Open Access Journals (Sweden)

    Seyede Zeynab Hoseini

    2016-06-01

    Full Text Available Objective:  Increased vertical ground reaction force loading rates and lack of comfort footwear in the early stance phase can increase the risk of overuse injuries. The purpose of this study was to investigate the effect of Five-finger shoes on vertical ground reaction force loading rate and perceived comfort during the stance phase of running. Methods: 15 male students (aged 24 ± 5/24 years, weight 75/8 ± 4/61 kg, height 178/6 ± 6/64 cm were selected. Subjects were asked to run over a force plate, in control shoe, five finger shoe and barefoot conditions. Loading rate using the slope of the vertical reaction force and perceived comfort were determined using a visual analogue scale. One factor repeated measures ANOVA was used to test the loading rate hypothesis and Paired t-tests was used to test the meaningfulness of perceived comfort (P<0/05. Results: The effect of shoes on loading rate was found to be not significant (P=0.1. However, comfort of control shoes increased by 10. 92% as compared to that of five-finger shoes (P=0.001.  Conclusion: The loading rate of five-finger shoes is the same as that of barefoot during running; however, as subjects did not perceive them as comfortable as regular shoes are five-finger shoes cannot be advised as a desirable choice in exercises.

  9. Enhancement of glomerular filtration rate and renal plasma flow by oral glucose load in well controlled insulin-dependent diabetics

    DEFF Research Database (Denmark)

    Sandahl Christiansen, J; Christensen, C K; Hermansen, K

    1986-01-01

    Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured in 27 patients with uncomplicated insulin-dependent diabetes (IDDM) before and after an oral glucose load of 1.1 g glucose/kg body wt. In the 18 patients showing near-normoglycaemia (blood glucose less than or equal to 8...... mmol/l) before the glucose challenge the increase in blood glucose from 4.2 +/- 1.7 to 15.2 +/- 2.3 mmol/l was accompanied by an enhancement of GFR from 128 +/- 15 to 132 +/- 14 ml/min X 1.73 m2 (2p = 0.030) and of RPF from 534 +/- 116 to 562 +/- 105 ml/min X 1.73 m2 (2p = 0.023). By contrast oral...... glucose load to the nine patients with hyperglycaemia (greater than 8 mmol/l) during baseline conditions raising blood glucose from 11.9 +/- 2.0 to 19.6 +/- 1.5 mmol/l was accompanied by a reduction in GFR from 149 +/- 15 to 139 +/- 9 ml/min X 1.73 m2 (2p less than 0.001) while RPF was unchanged...

  10. Progress in generating fracture data base as a function of loading rate and temperature using small-scale tests

    International Nuclear Information System (INIS)

    Couque, H.; Hudak, S.J. Jr.

    1993-01-01

    Structural integrity assessment of nuclear pressure vessels requires small specimen fracture testing to generate data over a wide range of material loading, and temperature conditions. Small scale testing is employed since extensive testing is required including small radiation embrittled samples from nuclear surveillance capsules. However, current small scale technology does not provide the needed dynamic fracture toughness relevant to the crack arrest/reinitiation events that may occur during pressurized thermal shock transients following emergency shutdown. This paper addresses the generation of this much needed dynamic toughness data using a novel experimental-computational approach involving a coupled pressure bars (CPB) technique and a viscoplastic dynamic fracture code. CPB data have been generated to testing temperatures never before reached: 37 to 100 degrees C -- 60 to 123 degrees C above the nil ductility transition temperature. Fracture behavior of pressure vessel steel from lower shelf to upper shelf temperatures and previous toughness estimates for the 10 6 MPa√m s -1 loading rate regime are assessed in light of the new CPB data. 26 refs., 14 figs., 3 tabs

  11. Effects of regular away travel on training loads, recovery, and injury rates in professional Australian soccer players.

    Science.gov (United States)

    Fowler, Peter; Duffield, Rob; Waterson, Adam; Vaile, Joanna

    2015-07-01

    The current study examined the acute and longitudinal effects of regular away travel on training load (TL), player wellness, and injury surrounding competitive football (soccer) matches. Eighteen male professional football players, representing a team competing in the highest national competition in Australia, volunteered to participate in the study. Training loads, player wellness and injury incidence, rate, severity, and type, together with the activity at the time of injury, were recorded on the day before, the day of, and for 4 d after each of the 27 matches of the 2012-13 season. This included 14 home and 13 away matches, further subdivided based on the midpoint of the season into early (1-13) and late competition (14-27) phases. While TLs were significantly greater on day 3 at home compared with away during the early competition phase (P=.03), no other significant effects of match location were identified (P>.05). Total TL and mean wellness over the 6 d surrounding matches and TL on day 3 were significantly reduced during the late compared with the early competition phase at home and away (P.05), training missed due to injury was 60% and 50% greater during the late than during the early competition phase at home and away, respectively. In conclusion, no significant interactions between match location and competition phase were evident during the late competition phase, which suggests that away travel had negligible cumulative effects on the reduction in player wellness in the latter half of the season.

  12. The heart rate increase at the onset of high-work intensity exercise is accelerated by central blood volume loading.

    Science.gov (United States)

    Miyamoto, Tadayoshi; Oshima, Yoshitake; Ikuta, Komei; Kinoshita, Hiroshi

    2006-01-01

    Using a water immersion (WI) method, the combined effect of central blood volume (CBV) loading and work intensity on the time course of heart rate (HR) at the onset of upright dynamic exercise was investigated. Seven males cranked a cycle ergometer for 12 min using their un-immersed arms at low-, moderate- and high-work intensities, followed by a 12-min rest. For WI, the pre-exercise resting cardiac output increased by 36%, while HR decreased by 22% [from 76.8 (10.4) to 59.6 (9.8) beats/min]. WI also increased the high-frequency (HF, 0.15-0.40 Hz) component of the HR variability, suggesting an increased vagal activity. During the initial 2 min of the exercise period at low-work intensity, HR increased by 34.9 and 25.8% in the WI and control conditions, respectively. These were 117 and 73% at high-work intensity, indicating more accelerated HR with WI than the control. The plasma norepinephrine concentration increased less during high-work intensity exercise during WI, as compared to exercise during control conditions. In conclusion, the HR increase at the onset of high-work intensity exercise is accelerated by CBV loading but not at low intensity, possibly reflecting vago-sympathetic interaction and reduced baroreflex sensitivity.

  13. Exfoliation rate of mammary epithelial cells in milk on bovine mastitis caused by Staphylococcus aureus is associated with bacterial load.

    Science.gov (United States)

    Nagasawa, Yuya; Kiku, Yoshio; Sugawara, Kazue; Tanabe, Fuyuko; Hayashi, Tomohito

    2018-01-01

    The exfoliation rate of mammary epithelial cells (MECs) in milk is affected by physiological, breeding and environmental factors. Little is known about the relationship between the MEC exfoliation into milk and mammary-infected Staphylococcus aureus (S. aureus) load on bovine mastitis caused by S. aureus. The aim of this study was to investigate the relationship between S. aureus load and the proportion of MEC exfoliation in milk using five substantial bovine mastitis models. In 64 randomly extracted milk samples from udders at 3-21 days after S. aureus infusion, there were various samples with different numbers of S. aureus counts and somatic cell counts. No significant correlations were found between the S. aureus counts and somatic cell count (r = 0.338). In contrast, a significant correlation was noted between S. aureus counts and the proportion of cytokeratin-positive cells in the milk from the infused udders (r = 0.734, P mastitis udders caused by S. aureus may contribute to reduced milk yield. © 2017 Japanese Society of Animal Science.

  14. Biogas production from solid pineapple waste

    Energy Technology Data Exchange (ETDEWEB)

    Tanticharoen, M.; Bhumiratana, S.; Tientanacom, S.; Pengsobha, L.

    1984-01-01

    Solid pineapple waste composed of shell and core was used as substrate in anaerobic fermentation producing CH4. The experiments were carried out using four 30-L vessels and no mixing, a 200-L plug-flow reactor, and a 5-cubic m stirred tank. Because of high acidity of the substrate, the loading rate is as low as 2.5 g dry solid added/L-day. The average gas yield is 0.3-0.5 L/g dry substrate. A pretreatment of wet solid with sludge effluent prior loading to the digester resulted in better stability of the biodigester than without pretreatment. These studies showed that loading rate can be much higher than those previously used. The 2-stage process was tested to determine a conversion efficiency of high loading and at much shorter reactor retention times. The results of the entire program indicated that biogas production from cannery pineapple waste is technically feasible.

  15. Municipal solid waste generation rates and its management at Yusmarg forest ecosystem, a tourist resort in Kashmir.

    Science.gov (United States)

    Bhat, Rouf Ahmad; Nazir, Rumisa; Ashraf, Samia; Ali, Mudasir; Bandh, Suhaib A; Kamili, Azra N

    2014-02-01

    The present study was carried out at Yusmarg, a forest ecosystem and tourist resort, in the Kashmir valley during 2012 with the objectives of determining the municipal solid waste (MSW) generation rates per capita and on a daily basis, and assessing the existing MSW system. It was estimated that daily generation of MSW at Yusmarg by tourists, as well as residents, was 107.74 kg; on average, the MSW generated at each site was about 36.48 kg/day. The per capita generation of MSW was highest (0.97 kg/person/day) at site 1 followed by 0.288 kg/person/day at site 2 and 0.201 kg/person/day at site 3, with an average per capita MSW generation rate of 0.484 kg/person/day. Manual segregation of the collected wastes showed that it comprised some recyclable, combustible, compostable and inert materials. Among the different waste categories, 56% of waste was recyclable materials, 29% was compostable wastes, 9% was combustible wastes and 6% was inert materials. The present study infers that MSW management in Yusmarg was inappropriate, and infrastructure, skilled manpower and a proper scientific disposal mechanism is lacking in the area. In order to conserve the forest wealth of the area there is a great need to focus on the solid waste problem of the tourist resort.

  16. Solid dispersions, part II: new strategies in manufacturing methods for dissolution rate enhancement of poorly water-soluble drugs.

    Science.gov (United States)

    Bikiaris, Dimitrios N

    2011-12-01

    The absorption of poorly water-soluble drugs, when presented in the crystalline state to the gastrointestinal tract, is typically dissolution rate-limited, and according to BCS these drugs belong mainly to class II. Both dissolution kinetics and solubility are particle size dependent. Nowadays, various techniques are available to the pharmaceutical industry for dissolution rate enhancement of such drugs. Among such techniques, nanosuspensions and drug formulation in solid dispersions are those with the highest interest. This review discusses strategies undertaken over the last 10 years, which have been applied for the dissolution enhancement of poorly water-soluble drugs; such processes include melt mixing, electrospinning, microwave irradiation and the use of inorganic nanoparticles. Many problems in this field still need to be solved, mainly the use of toxic solvents, and for this reason the use of innovative new procedures and materials will increase over the coming years. Melt mixing remains extremely promising for the preparation of SDs and will probably become the most used method in the future for the preparation of solid drug dispersions.

  17. One-step electrochemically expanded graphite foil for flexible all-solid supercapacitor with high rate performance

    International Nuclear Information System (INIS)

    Li, Han-Yu; Yu, Yao; Liu, Lang; Liu, Lin; Wu, Yue

    2017-01-01

    Flexible solid-state supercapacitors (SSCs) as a candidate for energy storage source, have been attracting intensive attention. Graphene-based materials for SSCs have been widely studied. However, most reported preparation methods for graphene-based materials are energy-consuming, time-consuming and environmentally hazardous, what’s more, the assembling of SSCs need additives, such as current collectors, flexible substrates. So, it is necessary to develop simpler and greener attempts to achieve high-performance, cost-effective, substrates/additives-free and flexible electrodes for SSC devices. Herein, we reported a green and facile one-step process of electrochemical oxidation and expansion in salt solution to activate graphite foil (GF) for fabricating expanded graphite foil (EGF). The EGF electrode with unique structure and high conductivity showed high supercapacitor performance of 65 mF cm −2 , remarkable rate-capability maintaining at a level of 80% even at a current density of 20 mA cm −2 and excellent cycling stability with ∼95% capacitance remaining after 10000 cycles at a current density of 20 mA cm −2 . Moreover, a symmetric flexible all-solid supercapacitor (SSC) device was integrated using EGFs without any current collectors and additives. The flexible EGF-based device showed a high capacitance capacity of 30.5 mF cm −2 , excellent rate performance and good cycle stability which make it holds promise for applications in flexible, portable and wearable electronic devices.

  18. Solid State Track Recorder fission rate measurements in low power light water reactor pressure vessel mockups

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Roberts, J.H.; Kellogg, L.S.

    1985-01-01

    The results of extensive SSTR measurements made at the Pool Critical Assembly (PCA) facility at Oak Ridge National Laboratory have been reported previously. Measurements were made at key locations in PCA which is an idealized mockup of the water gap, thermal shield, pressure vessel geometry of a light water reactor. Recently, additional SSTR fission rate measurements have been carried out for 237-Np, 238-U, and 235-U in key locations in the NESTOR Shielding and Dosimetry Improvement Program (NESDIP) mockup facility located at Winfrith, England. NESDIP is a replica of the PCA facility, and comparisons will be made between PCA and NESDIP measurements. The results of measurements made at the engineering mockup at the VENUS critical assembly at CEN/SCK, Mol, Belgium will also be reported. Measurements were made at selected radial and azimuthal locations in VENUS, which models the in-core and near-core regions of a pressurized water reactor. Comparisons of absolute SSTR fission rates with absolute fission rates made with the Mol miniature fission chamber will be reported. Absolute fission rate comparisons have also been made between the NBS fission chamber, radiometric fission foils, and SSTRs, and these results will be summarized

  19. Biogas-pH automation control strategy for optimizing organic loading rate of anaerobic membrane bioreactor treating high COD wastewater.

    Science.gov (United States)

    Yu, Dawei; Liu, Jibao; Sui, Qianwen; Wei, Yuansong

    2016-03-01

    Control of organic loading rate (OLR) is essential for anaerobic digestion treating high COD wastewater, which would cause operation failure by overload or less efficiency by underload. A novel biogas-pH automation control strategy using the combined gas-liquor phase monitoring was developed for an anaerobic membrane bioreactor (AnMBR) treating high COD (27.53 g·L(-1)) starch wastewater. The biogas-pH strategy was proceeded with threshold between biogas production rate >98 Nml·h(-1) preventing overload and pH>7.4 preventing underload, which were determined by methane production kinetics and pH titration of methanogenesis slurry, respectively. The OLR and the effluent COD were doubled as 11.81 kgCOD·kgVSS(-1)·d(-1) and halved as 253.4 mg·L(-1), respectively, comparing with a constant OLR control strategy. Meanwhile COD removal rate, biogas yield and methane concentration were synchronously improved to 99.1%, 312 Nml·gCODin(-1) and 74%, respectively. Using the biogas-pH strategy, AnMBR formed a "pH self-regulation ternary buffer system" which seizes carbon dioxide and hence provides sufficient buffering capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Effect of load, area of contact, and contact stress on the wear mechanisms of a bonded solid lubricant film

    Science.gov (United States)

    Fusaro, R. L.

    1980-01-01

    A pin on disk type of friction and wear apparatus was used to study the effect of load, contact stress and rider area of contact on the friction and wear properties of polyimide bonded graphite fluoride films. Different rider area contacts were obtained by initially generating flats (with areas of 0.0035, 0.0071, 0.0145, and 0.0240 cm) on 0.476-cm radius hemispherically tipped riders. Different projected contact stresses were obtained by applying loads of 2.5- to 58.8-N to the flats. Two film wear mechanisms were observed. The first was found to be a linear function of contact stress and was independent of rider area of contact. The second was found to increase exponentially as the stress increased. The second also appeared to be a function of rider contact area. Wear equations for each mechanism were empirically derived from the experimental data. In general, friction coefficients increased with increasing rider contact area and with sliding duration. This was related to the build up of thick rider transfer films.

  1. Physico-chemical characterisation, cytotoxic activity, and biocompatibility studies of tamoxifen-loaded solid lipid nanoparticles prepared via a temperature-modulated solidification method.

    Science.gov (United States)

    Lakkadwala, Sushant; Nguyen, Sanko; Lawrence, Joseph; Nauli, Surya M; Nesamony, Jerry

    2014-01-01

    Solid lipid nanoparticles (SLNs) can efficiently and efficaciously incorporate anti-cancer agents. To prepare and characterise tamoxifen (TAM)-loaded SLNs. Glyceryl monostearate, Tween-80, and trehalose were used in SLNs. SLNs were tested via dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Characterisation studies revealed SLNs of about 540 nm with a negative surface charge and confirmed the entrapment of TAM in the SLNs. The entrapment efficiency was estimated to be 60%. The in vitro drug release profile demonstrated a gradual increase followed by a release plateau for several days. A drug concentration-dependent increase in cytotoxic activity was observed when the SLNs were evaluated in cell cultures. Biocompatible and stable lyophilised SLNs were successfully prepared and found to possess properties that may be utilised in an anti-cancer drug delivery system.

  2. LHI (low head safety injection) emergency cooling pump test for the EPR trademark in operation with solid matter loaded water

    International Nuclear Information System (INIS)

    Ganzmann, I.; Schulte, C.

    2010-01-01

    Emergency cooling pumps are essential and indispensable components of the NPP safety philosophy. In case of a loss-of coolant accident solid matter (debris: fibrous insulation material, concrete dust, pigment particles) might be released into the coolant, LHSI (low head safety injection) pumps have to ensure their performance capacity for a certain amount of debris without damage or loss of power. The authors describe the development of a test facility. The LHSI was tested in continuous operation over a time period of 14 days with a debris content of 1500 ppm (90% mineral wool fibers, 3% concrete dust, 3% pigment particles, 4% microporous insulation material). The pump did not show any damage or loss of hydraulic power. Further tests including thermoshock conditions (temperature changes of 160 C) are planned.

  3. Rating of Perceived Exertion for Quantification of Training and Combat Loads During Combat Sport-Specific Activities: A Short Review.

    Science.gov (United States)

    Slimani, Maamer; Davis, Philip; Franchini, Emerson; Moalla, Wassim

    2017-10-01

    The aim of this short review was to summarize data pertaining to the rating of perceived exertion (RPE) methods (RPE value and session-RPE) during combat sport-specific activities (i.e., competition and training) based on many factors, including contest type (i.e., official vs. simulated vs. training), combat rounds, age of participants and muscle groups, and their correlation with physiological variables (i.e., blood lactate concentration [La] and heart rate [HR]). The current review shows higher RPE in a match of mixed martial arts (MMAs) than Brazilian jiu-jitsu and kickboxing matches and during the competitive period compared with the precompetitive period. This could be explained by the longer duration of bouts, the higher percentage contribution of aerobic metabolism in MMA than other combat sports and contest type differences (simulated vs. official matches). Thus, this review found significant correlations between RPE or session-RPE, [La] and HR. Particularly, there was a stronger correlation between RPE and [La] during official striking (r = 0.81) than grappling combat sports matches (r = 0.53). In addition, a variation of correlation (moderate to large) between session-RPE and HR-based methods has been reported (i.e., Edwards' training load [r ranged between 0.58 and 0.95] and Banister training impulse [r ranged between 0.52 and 0.86]). Specifically, stronger correlation was apparent in combat sport competition that required a much higher percentage contribution of aerobic metabolism (e.g., karate) and in adult athletes than anaerobic-based combat sports (e.g., taekwondo) and young athletes, respectively. Indeed, the current review highlights that the correlations between session-RPE and HR-based methods were higher during official competition than training sessions. Session-RPE was affected by participants' competitive level, the intensity of session (high vs. low), the training modalities (tactical-technical vs. technical-development vs. simulated

  4. Glomerular Filtration Rate Estimation in Renal and Non-Renal Solid Organ Transplantation

    DEFF Research Database (Denmark)

    Hornum, Mads; Feldt-Rasmussen, Bo

    2017-01-01

    Following transplantation (TX) of both renal and non-renal organs, a large proportion of patients have renal dysfunction. There are multiple causes for this. Chronic nephrotoxicity and high doses of calcineurin inhibitors are important factors. Preoperative and perioperative factors like...... or estimates of renal function in these patients, in order to accurately and safely dose immunosuppressive medication and perform and adjust the treatment and prophylaxis of renal dysfunction. This is a short overview and discussion of relevant studies and possible caveats of estimated glomerular filtration...... rate methods for use in renal and non-renal TX....

  5. Degradation rates in thermophilic sludge processing - the liquid and the solid way

    Energy Technology Data Exchange (ETDEWEB)

    Mihaltz, P.; Kovacs, R.; Csikor, Zs.; Dahab, M.F.

    2003-07-01

    Two promising and well known techniques for sludge stabilization and pathogen destruction, the composting and autothermal thermophilic aerobic digestion (ATAD, often referred to as ''liquid composting'') have not yet undergone a comparative parallel study. This comparison is presented in this paper to identify - sometimes unusually (e.g. up to 30 mg O{sub 2} /gVS h) high - degradation rates, their main influencing parameters. For the ATAD we developed a well fitting modified two-substrate kinetic model quantitatively describing this process feature too - the clear signs of two substrate degradation also appears in most own and literature composting records. However compost process modelling needs as a prerequisite the clarification of the controlling transport mechanisms. Experimental conclusions suggest the dual role of local VS limitation closely connected with, but being behind the strong observed oxygen limitation, what is proposed for the explanation of composting process rates - essentially based on specific surface area controlled transport phenomena, justifying efforts to conduct the process at lower (<20 to 25%) moisture content and higher (>1000 1/m) specific surface area levels. (author)

  6. Studies on reducing the thermal loads of solar-pumped solid state lasers; Taiyoko reiki laser no netsufuka teigen ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K; Yugami, H; Naito, H; Arashi, H [Tohoku University, Sendai (Japan)

    1997-11-25

    It was intended to reduce the thermal loads of solar-pumped solid state lasers (highly densified solar light is irradiated directly onto a laser medium to cause excitation. No electric power is required for the excitation.). For this purpose, experiments were performed by using a selective permeation film. Solar light includes wavelengths not effective for excitation, which causes heat generation and thermal loads such as lens heating effect and thermal stress compounded refraction, degrading the laser beam quality. The Nd:YAG was used as a laser medium, and a multi-layered film (composed of SiO2 and TiO2) which cuts wavelength below 500 nm as a selective permeation film to cut light having wavelengths not required for excitation. A laser transmitting experiment revealed that the slope efficiency is improved by 27% as compared to not using the film. Beam fluctuation was improved to 45%. Using the selective permeation film has realized more efficient conversion of the solar light into a beam with better quality. The results for calculation of heat lens effect by using temperature distribution simulation showed good agreement with experimental values. Using the selective permeation film can suppress the maximum temperature of a laser rod to 68%, as well as the thermal stress. 9 figs., 2 tabs.

  7. Suspended-sediment concentrations, loads, total suspended solids, turbidity, and particle-size fractions for selected rivers in Minnesota, 2007 through 2011

    Science.gov (United States)

    Ellison, Christopher A.; Savage, Brett E.; Johnson, Gregory D.

    2014-01-01

    Sediment-laden rivers and streams pose substantial environmental and economic challenges. Excessive sediment transport in rivers causes problems for flood control, soil conservation, irrigation, aquatic health, and navigation, and transports harmful contaminants like organic chemicals and eutrophication-causing nutrients. In Minnesota, more than 5,800 miles of streams are identified as impaired by the Minnesota Pollution Control Agency (MPCA) due to elevated levels of suspended sediment. The U.S. Geological Survey, in cooperation with the MPCA, established a sediment monitoring network in 2007 and began systematic sampling of suspended-sediment concentrations (SSC), total suspended solids (TSS), and turbidity in rivers across Minnesota to improve the understanding of fluvial sediment transport relations. Suspended-sediment samples collected from 14 sites from 2007 through 2011 indicated that the Zumbro River at Kellogg in the driftless region of southeast Minnesota had the highest mean SSC of 226 milligrams per liter (mg/L) followed by the Minnesota River at Mankato with a mean SSC of 193 mg/L. During the 2011 spring runoff, the single highest SSC of 1,250 mg/L was measured at the Zumbro River. The lowest mean SSC of 21 mg/L was measured at Rice Creek in the northern Minneapolis- St. Paul metropolitan area. Total suspended solids (TSS) have been used as a measure of fluvial sediment by the MPCA since the early 1970s; however, TSS concentrations have been determined to underrepresent the amount of suspended sediment. Because of this, the MPCA was interested in quantifying the differences between SSC and TSS in different parts of the State. Comparisons between concurrently sampled SSC and TSS indicated significant differences at every site, with SSC on average two times larger than TSS concentrations. The largest percent difference between SSC and TSS was measured at the South Branch Buffalo River at Sabin, and the smallest difference was observed at the Des Moines

  8. The effects of working memory load and attention refocusing on delay discounting rates in alcohol use disorder with comorbid antisocial personality disorder.

    Science.gov (United States)

    Gunn, Rachel L; Gerst, Kyle R; Lake, Allison J; Finn, Peter R

    2018-02-01

    Executive working memory capacity (eWMC) is central to adaptive decision-making. Research has revealed reduced eWMC and higher rates of impulsive decision making in individuals with alcohol use disorders (AUDs: DSM-IV Alcohol Dependence of Alcohol Abuse) and antisocial psychopathology (AP). Recent work has shown that placing a load on working memory (WM) further increases impulsive decision making on the delay discounting (DD) task in those with AUDs and AP. The current study examined the effects of an attention refocusing manipulation to offset the effects of this WM-load on DD rates in control subjects, those with AUDs without AP, and AUDs with AP (AUD-AP). Results revealed that 1) the AUD-AP group had higher DD rates (i.e., more impulsive decision-making) than the AUD group, followed by controls, and 2) attention refocusing after a load is placed on WM was associated with lower DD rates compared to the load without refocusing in both AUD groups, but not controls. Results suggest that refocusing attention after a cognitive load may be an effective cognitive strategy for reducing the impulsivity-enhancing effects of cognitive load on decision making in individuals with AUDs and AP. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. SOUND TRANSMISSION LOSS OF A DOUBLE-LEAF SOLID-MICROPERFORATED PARTITION UNDER NORMAL INCIDENCE OF ACOUSTIC LOADING

    Directory of Open Access Journals (Sweden)

    Ahmad Yusuf Ismail

    2011-12-01

    Full Text Available 0 0 1 332 1894 International Islamic University 15 4 2222 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} The micro-perforated panel (MPP is recently well-known as an alternative ‘green‘ sound absorber replacing the conventional porous materials. Constructed from a solid panel which provides a non-abrassive structure and also an optically attractive surface, there gives a feasibility to implement such a panel inside a vehicle cabin. This paper is the preliminary study to investigate the sound transmission loss (TL of a solid panel coupled with a micro-perforated panel to form a doube-leaf partition which is already known as a lightweigth stucture for noise insulation in vehicles and buildings. The mathematical model for the TL subjected to normal incidence of acoustic excitation is derived. The results show that its performance substantially improves at the troublesome frequency of mass-air-mass resonance which occurs in the conventional double-leaf solid partition. This is important particularly for the noise source predominant at low frequencies. This can also be controlled by tuning the hole size and number as well as the air gap between the panels.  ABSTRAK: Panel bertebuk mikro (micro-perforated panel (MPP kebelakangan ini dikenali sebagai alternatif penyerap bunyi yang mesra alam menggantikan bahan berliang lazim. Dibina daripada satu panel padu yang memberikan satu struktur tak lelas dan juga satu permukaan yang menarik, ia memberikan kemungkinan penggunaan panel tersebut di dalam kabin kenderaan. Tesis ini merupakan kajian permulaan dalam mengkaji hilang pancaran bunyi

  10. Effect of organic loading rate on anaerobic treatment of slaughterhouse wastewater in a fluidised-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Borja, R. [Consejo Superior de Investigaciones Cientificas, Seville (Spain). Inst. de la Grasa; Banks, C.J.; Zhengjian Wang [Manchester Univ. (United Kingdom). Inst. of Science and Technology

    1995-09-01

    COD removal efficiencies in the range 75.0-98.9% were achieved in an aerobic fluidised-bed reactor treating slaughterhouse wastewater, when evaluated at organic loading rates (OLR) of between 2.9 and 54.0 g COD/l.d, hydraulic retention times (HRT) of between 0.5 and 8 h and feed COD concentrations of between 250 and 4500 mg/l. More than 94% of feed COD could be removed up to OLR of about 27 g COD/l.d. Up to 0.320 litres of methane were produced per gram of COD removed and this methane production rate was independent of the OLR applied in this investigation. Volatile fatty acid (VFA) concentration in the reactor increased sharply at an OLR of about 30 g COD/l.d and, therefore, sufficient alkalinity should be provided to prevent pH from dropping to an undesirable level. The anaerobic fluidised-bed system can be operated at a significantly higher liquid throughput than other previously reported systems while maintaining its excellent efficiency. (Author)

  11. Different organic loading rates on the biogas production during the anaerobic digestion of rice straw: A pilot study.

    Science.gov (United States)

    Zhou, Jun; Yang, Jun; Yu, Qing; Yong, Xiaoyu; Xie, Xinxin; Zhang, Lijuan; Wei, Ping; Jia, Honghua

    2017-11-01

    The aim of this work was to investigate the mesophilic methane fermentation of rice straw at different organic loading rates (OLRs) in a 300m 3 bioreactor. It was found that biogas production increased when the OLR was below 2.00kg VS substrate /(m 3 ·d). The average volumetric biogas production reached 0.86m 3 /(m 3 ·d) at an OLR of 2.00kg VS substrate /(m 3 ·d). Biogas production rate was 323m 3 /t dry rice straw over the whole process. The pH, chemical oxygen demand, volatile fatty acid, and NH 4 + -N concentrations were all in optimal range at different OLRs. High-throughput sequencing analysis indicated that Firmicutes, Fibrobacteres, and Spirochaetes predominated in straw samples. Chloroflexi, Proteobacteria, and Planctomycetes were more abundant in the slurry. The hydrogenotrophic pathway was the main biochemical pathway of methanogenesis in the reactor. This study provides new information regarding the OLR and the differences in the spatial distribution of specific microbiota in a rice straw biogas plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Glomerular Filtration Rate Estimation in Renal and Non-Renal Solid Organ Transplantation

    DEFF Research Database (Denmark)

    Hornum, Mads; Feldt-Rasmussen, Bo

    2017-01-01

    Following transplantation (TX) of both renal and non-renal organs, a large proportion of patients have renal dysfunction. There are multiple causes for this. Chronic nephrotoxicity and high doses of calcineurin inhibitors are important factors. Preoperative and perioperative factors like hyperten......Following transplantation (TX) of both renal and non-renal organs, a large proportion of patients have renal dysfunction. There are multiple causes for this. Chronic nephrotoxicity and high doses of calcineurin inhibitors are important factors. Preoperative and perioperative factors like...... hypertension, hypotension, drugs and infections may play a causative role as well. Organ-specific causes include hepatorenal syndrome, cirrhosis, low cardiac function, low respiratory function and diabetes developed both before and after TX. It is important to be able to perform precise and valid measurements...... rate methods for use in renal and non-renal TX....

  13. Curcumin-loaded self-nanomicellizing solid dispersion system: part I: development, optimization, characterization, and oral bioavailability.

    Science.gov (United States)

    Parikh, Ankit; Kathawala, Krishna; Song, Yunmei; Zhou, Xin-Fu; Garg, Sanjay

    2018-05-29

    Curcumin (CUR) is considered as one of the most bioactive molecules ever discovered from nature due to its proven anti-inflammatory and antioxidant in both preclinical and clinical studies. Despite its proven safety and efficacy, the clinical translation of CUR into a useful therapeutic agent is still limited due to its poor oral bioavailability. To overcome its limitation and enhance oral bioavailability by improving its aqueous solubility, stability, and intestinal permeability, a novel CUR formulation (NCF) was developed using the self-nanomicellizing solid dispersion strategy. From the initial screening of polymers for their potential to improve the solubility and stability, Soluplus (SOL) was selected. The optimized NCF demonstrated over 20,000-fold improvement in aqueous solubility as a result of amorphization, hydrogen bonding interaction, and micellization determined using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance, dynamic light scattering, and transmission electron microscopy. Moreover, the greater stabilizing effect in alkaline pH and light was observed. Furthermore, significant enhancement of dissolution and permeability of CUR across everted sacs of rat small intestine were noticed. Pharmacokinetic studies demonstrated that the oral bioavailability of CUR was increased 117 and 17-fold in case of NCF and physical mixture of CUR and SOL compared to CUR suspension. These results suggest NCF identified as a promising new approach for repositioning of CUR for pharmaceutical application by enhancing the oral bioavailability of CUR. The findings herein stimulate further in vivo evaluations and clinical tests of NCF.

  14. Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa; Melek, Esra [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

    2008-11-30

    Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation-preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions (k = 3, N = 21) were 1.14 {mu}g L{sup -1} for copper, 2.01 {mu}g L{sup -1} for iron and 0.14 {mu}g L{sup -1} for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin-multimineral tablet, dialysis solutions, natural waters and some food samples.

  15. The ecological effects of different loading rates of metalaxyl on microbial biomass in unplanted and planted soils under field conditions

    Directory of Open Access Journals (Sweden)

    M. Mansourzadeh

    2016-05-01

    Full Text Available Fungicides are most widely used pesticides in Iran and the world. Application of fungicides may affect the populations and activity of soil microorganisms, particularly fungi, with a consequence for soil fertility and crop growth. In the current study, the effects of different levels of metalaxyl on soil microbial biomass carbon (C and nitrogen (N, microbial biomass C/N ratio and metabolic quotient under field conditions were assessed. Two levels of metalaxyl (30 and 60 kg.ha-1 were applied in planted soils with corn and unplanted calcareous soils, using a split-plots experiment in a completely randomized design with three replications. The C and N contents in soil microbial biomass as well as metabolic quotient were measured at 30 and 90 days after the onset of the experiment. Results showed that in cultivated soils metalaxyl application at 30 kg.ha-1 increased (15-80% significantly (p≤0.01 the amounts of microbial biomass C and N at both intervals (except microbial biomass C at 90 days compared to the control soil (0 kg.ha-1, while in uncultivated soils both microbial biomass C and N reduced by almost 1-34%. Microbial biomass C/N ratios in unplanted soils decreased (15 and 53% with increasing loading rates of metalaxyl, without a clear effect in cultivated soils. On the other hand, metabolic quotient values reduced (48% at 30 and 60 kg.ha-1 metalaxyl in corn-cultivated soils when compared to untreated soils while in uncultivated soils metalaxyl rate at 30 kg.a-1 had the greatest values at 30 days, and increased with increasing the levels of metalaxyl at 90 days. In summary, application of metalaxyl can either reduce or increase soil biological indices, and the direction and changes are depended upon the application rate of metalaxyl, time elapsed since metalaxyl application and the presence or absence of plant.

  16. A method for the measurement of fission rates in fast neutron fields using solid state track detectors

    International Nuclear Information System (INIS)

    Hansen, W.; Vogel, W.

    1984-04-01

    Solid state track detectors (SSTDs) are increasingly used for the registration of radiation in different fields of nuclear physics. Because of their small sizes and masses and the absence of any electronics during exposure SSTDs do not cause distortions in the system to be investigated and are useful for measurements at such places being difficult of access. The elaboration of a method is described for fission rate measurements in fast neutron fields applying SSTDs and different fissionable isotopes which were electrodeposited on stainless steel backings. Experiences of the electrodeposition and results of quality checks are presented. The evaluation of the etched tracks is performed with spark counter technique. The dependence of the counting result on essential influence parameters is discussed. (author)

  17. An All-Solid-State High Repetiton Rate Titanium:Sapphire Laser System For Resonance Ionization Laser Ion Sources

    Science.gov (United States)

    Mattolat, C.; Rothe, S.; Schwellnus, F.; Gottwald, T.; Raeder, S.; Wendt, K.

    2009-03-01

    On-line production facilities for radioactive isotopes nowadays heavily rely on resonance ionization laser ion sources due to their demonstrated unsurpassed efficiency and elemental selectivity. Powerful high repetition rate tunable pulsed dye or Ti:sapphire lasers can be used for this purpose. To counteract limitations of short pulse pump lasers, as needed for dye laser pumping, i.e. copper vapor lasers, which include high maintenance and nevertheless often only imperfect reliability, an all-solid-state Nd:YAG pumped Ti:sapphire laser system has been constructed. This could complement or even replace dye laser systems, eliminating their disadvantages but on the other hand introduce shortcomings on the side of the available wavelength range. Pros and cons of these developments will be discussed.

  18. Investigation of the Maximum Spin-Up Coefficients of Friction Obtained During Tests of a Landing Gear Having a Static-Load Rating of 20,000 Pounds

    Science.gov (United States)

    Batterson, Sidney A.

    1959-01-01

    An experimental investigation was made at the Langley landing loads track to obtain data on the maximum spin-up coefficients of friction developed by a landing gear having a static-load rating of 20,000 pounds. The forward speeds ranged from 0 to approximately 180 feet per second and the sinking speeds, from 2.7 feet per second to 9.4 feet per second. The results indicated the variation of the maximum spin-up coefficient of friction with forward speed and vertical load. Data obtained during this investigation are also compared with some results previously obtained for nonrolling tires to show the effect of forward speed.

  19. Composition, Production Rate and Management of Dental Solid Waste in 2017 in Birjand, Iran

    Directory of Open Access Journals (Sweden)

    Habibe Momeni

    2018-01-01

    Full Text Available Background: The presence of toxic and pathogenic agents in the dental waste products has made it to be classified as “hazardous waste.” Objective: To assess dental waste production rate and composition and approaches used to manage these waste products in 2017 in Birjand, Iran. Methods: 48 dental clinics were evaluated in two months of 2017. Sampling was performed from each clinic 3 times a week. Samples were manually divided into 5 categories of chemical-pharmaceutical, infectious, semi-household, sharp and cutting materials, and toxic waste products, and weighed. A checklist containing 25 questions was used to evaluate the aspects of waste management in dental clinics. Results: The total amount of waste products generated in dental clinics was 7848.02 kg/ year in which semi-household waste had the highest quantity (4263.411 kg/year and toxic waste had the lowest quantity (9.275 kg/year. Components with the highest amounts in dentistry waste products were nylon gloves (16.7%, paper and cardboard (13.4%, latex gloves (10.8%, and pharmaceuticals (10.2%. Waste separation was restricted to sharp and cutting waste. More than half (57% of dental units were equipped with amalgam filter. Fixing solutions were directly discharged to sewage in 48.6% of clinics. There was no program to reduce waste generation in 54% of the clinics. Autoclave was the main tool for sterilizing dental instruments. Conclusion: This study showed a remarkable share of recyclable materials in the composition of dental waste and lack of special approach to manage waste in dental clinics. It is necessary to plan for minimizing generation of, separating, and recycling waste at source.

  20. Composition, Production Rate and Management of Dental Solid Waste in 2017 in Birjand, Iran.

    Science.gov (United States)

    Momeni, Habibe; Tabatabaei Fard, Seyyedeh Fatemeh; Arefinejad, Aliye; Afzali, Afsane; Talebi, Farkhonde; Rahmanpour Salmani, Elham

    2018-01-01

    The presence of toxic and pathogenic agents in the dental waste products has made it to be classified as "hazardous waste." To assess dental waste production rate and composition and approaches used to manage these waste products in 2017 in Birjand, Iran. 48 dental clinics were evaluated in two months of 2017. Sampling was performed from each clinic 3 times a week. Samples were manually divided into 5 categories of chemical-pharmaceutical, infectious, semi-household, sharp and cutting materials, and toxic waste products, and weighed. A checklist containing 25 questions was used to evaluate the aspects of waste management in dental clinics. The total amount of waste products generated in dental clinics was 7848.02 kg/ year in which semi-household waste had the highest quantity (4263.411 kg/year) and toxic waste had the lowest quantity (9.275 kg/year). Components with the highest amounts in dentistry waste products were nylon gloves (16.7%), paper and cardboard (13.4%), latex gloves (10.8%), and pharmaceuticals (10.2%). Waste separation was restricted to sharp and cutting waste. More than half (57%) of dental units were equipped with amalgam filter. Fixing solutions were directly discharged to sewage in 48.6% of clinics. There was no program to reduce waste generation in 54% of the clinics. Autoclave was the main tool for sterilizing dental instruments. This study showed a remarkable share of recyclable materials in the composition of dental waste and lack of special approach to manage waste in dental clinics. It is necessary to plan for minimizing generation of, separating, and recycling waste at source.

  1. Vitamin E TPGS emulsified vinorelbine bitartrate loaded solid lipid nanoparticles (SLN): Formulation development, optimization and in vitro characterization.

    Science.gov (United States)

    Maurya, Lakshmi; Rajamanickam, Vijayakumar Mahalingam; Narayan, Gopeshwar; Singh, Sanjay

    2018-04-08

    Vinorelbine bitartrate (VRL), a semi synthetic vinca alkaloid approved for breast cancer, has been proved to beneficial as first line and subsequent therapies. However, it's hydrophilic and thermo labile nature provides hindrance to oral clinical translation. The current work focused on the application of DOE a modern statistical optimization tool for the development and optimization of a solid lipid nanoparticle (SLN) formulation that can encapsulate hydrophilic and thermolabile Vinorelbine bitartrate (VRL) to a maximum extent without compromising integrity and anticancer activity of the drug. SLNs were prepared by solvent diffusion technique employing Taguchi orthogonal array design with optimized formulation and process variables. The emulsifying nature and low melting point of glyceryl mono-oleate (GMO) were exploited to enhance entrapment and minimizing temperature associated degradation, respectively. Moreover, two types of surfactants, Vitamin E TPGS (TPGS) and Poloxamer-188 were utilized to obtain TPGS-VRL-SLNs and PL-VRL-SLNs, respectively. The SLNs were characterized for various physicochemical properties, in-vitro drug release kinetics and anticancer activity by MTT assay on MCF-7 cancer cell lines. The SLNs were found to be spherical in shape with entrapment efficiency (EE) up to 58 %. In-vitro release studies showed biphasic release pattern following Korsemeyer peppas model with fickian release kinetics. Results of MTT assay revealed that TPGS-VRL-SLNs and PL-VRL-SLNs were 39.5 and 18.5 fold more effective, respectively, compared to the pristine VRL. DOE approach was successfully applied for the development of VRL-SLNs. Enhanced entrapment and anticancer efficacy of TPGS-VRL-SLN can be attributed to emulsifying nature of GMO and inherent cytotoxic nature of TPGS, respectively, which synergizes with VRL. Therefore, TPGS associated SLNs may be potential carrier in cancer chemotherapeutics. Copyright© Bentham Science Publishers; For any queries, please

  2. A Bayesian approach to infer nitrogen loading rates from crop and land-use types surrounding private wells in the Central Valley, California

    Science.gov (United States)

    Ransom, Katherine M.; Bell, Andrew M.; Barber, Quinn E.; Kourakos, George; Harter, Thomas

    2018-05-01

    This study is focused on nitrogen loading from a wide variety of crop and land-use types in the Central Valley, California, USA, an intensively farmed region with high agricultural crop diversity. Nitrogen loading rates for several crop types have been measured based on field-scale experiments, and recent research has calculated nitrogen loading rates for crops throughout the Central Valley based on a mass balance approach. However, research is lacking to infer nitrogen loading rates for the broad diversity of crop and land-use types directly from groundwater nitrate measurements. Relating groundwater nitrate measurements to specific crops must account for the uncertainty about and multiplicity in contributing crops (and other land uses) to individual well measurements, and for the variability of nitrogen loading within farms and from farm to farm for the same crop type. In this study, we developed a Bayesian regression model that allowed us to estimate land-use-specific groundwater nitrogen loading rate probability distributions for 15 crop and land-use groups based on a database of recent nitrate measurements from 2149 private wells in the Central Valley. The water and natural, rice, and alfalfa and pasture groups had the lowest median estimated nitrogen loading rates, each with a median estimate below 5 kg N ha-1 yr-1. Confined animal feeding operations (dairies) and citrus and subtropical crops had the greatest median estimated nitrogen loading rates at approximately 269 and 65 kg N ha-1 yr-1, respectively. In general, our probability-based estimates compare favorably with previous direct measurements and with mass-balance-based estimates of nitrogen loading. Nitrogen mass-balance-based estimates are larger than our groundwater nitrate derived estimates for manured and nonmanured forage, nuts, cotton, tree fruit, and rice crops. These discrepancies are thought to be due to groundwater age mixing, dilution from infiltrating river water, or denitrification

  3. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    International Nuclear Information System (INIS)

    Mothilal, T.; Pitchandi, K.

    2015-01-01

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%

  4. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Mothilal, T. [T. J. S. Engineering College, Gummidipoond (India); Pitchandi, K. [Sri Venkateswara College of Engineering, Sriperumbudur (India)

    2015-10-15

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%.

  5. Organic loading rate impact on biohydrogen production and microbial communities at anaerobic fluidized thermophilic bed reactors treating sugarcane stillage.

    Science.gov (United States)

    Santos, Samantha Christine; Rosa, Paula Rúbia Ferreira; Sakamoto, Isabel Kimiko; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

    2014-05-01

    This study aimed to evaluate the effect of high organic loading rates (OLR) (60.0-480.00 kg COD m(-3)d(-1)) on biohydrogen production at 55°C, from sugarcane stillage for 15,000 and 20,000 mg CODL(-1), in two anaerobic fluidized bed reactors (AFBR1 and AFBR2). It was obtained, for H2 yield and content, a decreasing trend by increasing the OLR. The maximum H2 yield was observed in AFBR1 (2.23 mmol g COD added(-1)). The volumetric H2 production was proportionally related to the applied hydraulic retention time (HRT) of 6, 4, 2 and 1h and verified in AFBR1 the highest value (1.49 L H2 h(-1)L(-1)). Among the organic acids obtained, there was a predominance of lactic acid (7.5-22.5%) and butyric acid (9.4-23.8%). The microbial population was set with hydrogen-producing fermenters (Megasphaera sp.) and other organisms (Lactobacillus sp.). Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Organic loading rate effect on the acidogenesis of cheese whey: a comparison between UASB and SBR reactors.

    Science.gov (United States)

    Calero, R; Iglesias-Iglesias, R; Kennes, C; Veiga, M C

    2017-09-16

    Volatile fatty acids (VFA) production and degree of acidification (DA) were investigated in the anaerobic treatment of cheese whey by comparison of two processes: a continuous process using a laboratory upflow anaerobic sludge blanket (UASB) reactor and a discontinuous process using a sequencing batch reactor (SBR). The main purpose of this work was to study the organic loading rate (OLR) effect on the yield of VFA in two kinds of reactors. The predominant products in the acidogenic process in both reactors were: acetate, propionate, butyrate and valerate. The maximum DA obtained was 98% in an SBR at OLR of 2.7 g COD L -1 d -1 , and 97% in the UASB at OLR at 15.1 g COD L -1 d -1 . The results revealed that the UASB reactor was more efficient at a medium OLR with a higher VFA yield, while with the SBR reactor, the maximum acidification was obtained at a lower OLR with changes in the VFA profile at different OLRs applied.

  7. A new islanding detection technique for multiple mini hydro based on rate of change of reactive power and load connecting strategy

    International Nuclear Information System (INIS)

    Laghari, J.A.; Mokhlis, H.; Bakar, A.H.A.; Karimi, M.

    2013-01-01

    Highlights: • The requirement of DG interconnection with existing power system is discussed. • Various islanding detection techniques are discussed with their merits and demerits. • New islanding detection strategy is proposed for multiple mini hydro type DGs. • The proposed strategy is based on dq/dt and load connecting strategy. • The effectiveness of strategy is verified on various other cases. - Abstract: The interconnection of distributed generation (DG) into distribution networks is undergoing a rapid global expansion. It enhances the system’s reliability, while simultaneously reduces pollution problems related to the generation of electrical power. To fully utilize the benefits of DGs, certain technical issues need to be addressed. One of the most important issues in this context is islanding detection. This paper presents a new islanding detection technique that is suitable for multiple mini-hydro type DG units. The proposed strategy is based on the rate of change of reactive power and load connecting strategy to detect islanding within the system. For a large power mismatch, islanding is detected by rate of change of reactive power only. However, for a close power mismatch, the rate of change of reactive power initiates a load connecting strategy, which in turn alters the load on the distribution network. This load variation in the distribution network causes a variation in the rate of change of reactive power, which is utilized to distinguish islanding and other events. The simulation results show that the proposed strategy is effective in detecting islanding occurrence in a distribution network

  8. Fatigue life assessment of thin-walled welded joints under non-proportional load-time histories by the shear stress rate integral approach

    Directory of Open Access Journals (Sweden)

    A. Bolchoun

    2016-10-01

    Full Text Available Fatigue life tests under constant and variable amplitude loadings were performed on the tube-tube thin-walled welded specimens made of magnesium (AZ31 and AZ61 alloys. The tests included pure axial, pure torsional and combined in-phase and out-of-phase loadings with the load ratio  RR " ", " " 1  . For the tests with variable amplitude loads a Gaußdistributed loading spectrum with S L 4 5 10  cycles was used. Since magnesium welds show a fatigue life reduction under out-of-phase loads, a stress-based method, which takes this behavior into account, is proposed. The out-of-phase loading results in rotating shear stress vectors in the section planes, which are not orthogonal to the surface. This fact is used in order to provide an out-of-phase measure of the load. This measure is computed as an area covered by the shear stress vectors in all planes over a certain time interval, its computation involves the shear stress and the shear stress rate vectors in the individual planes. Fatigue life evaluation for the variable amplitudes loadings is performed using the Palmgren-Miner linear damage accumulation, whereas the total damage of every cycle is split up into two components: the amplitude component and the out-of-phase component. In order to compute the two components a modification of the rainflow counting method, which keeps track of the time intervals, where the cycles occur, must be used. The proposed method also takes into account different slopes of the pure axial and the pure torsional Wöhler-line by means of a Wöhler-line interpolation for combined loadings

  9. Transferrin-loaded nido-carborane liposomes. Synthesis and intracellular targeting to solid tumors for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Nakamura, Hiroyuki; Miyajima, Yusuke; Kuwata, Yasuhiro; Maruyama, Kazuo; Masunaga, Shinichiro; Ono, Koji

    2006-01-01

    The boron ion cluster lipids, as a double-tailed boron lipid synthesized from heptadecanol, formed stable liposomes at 25% molar ratio toward DSPC with cholesterol. Transferrin was able to be introduced on the surface of boron liposomes (Tf-PEG-CL liposomes) by the coupling of transferrin to the PEG-CO 2 H moieties of PEG-CL liposomes. The biodistribution of Tf-PEG-CL liposomes showed that Tf-PEG-CL liposomes accumulated in tumor tissues and stayed there for a sufficiently long time to increase tumor:blood concentration ratio. A 10 B concentration of 22 ppm in tumor tissues was achieved by the injection of Tf-PEG-CL liposome at 7.2 mg/kg body weight 10 B in tumor-bearing mice. After neutron irradiation, the average survival rate of mice not treated with Tf-PEG-CL liposomes was 21 days, whereas that of the treated mice was 31 days. Longer survival rates were observed in the mice treated with Tf-PEG-CL liposomes; one of them even survived for 52 days after BNCT. (author)

  10. Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe rate at Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

    Energy Technology Data Exchange (ETDEWEB)

    Takan, Gokhan; Guldu, Ozge Kozgus; Medine, Emin Ilker [Ege Univ., Izmir (Turkey). Dept. of Nuclear Applications

    2017-06-01

    Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe rate at Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe rate at Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe rate at Au) nanoparticles and radiolabeled with {sup 131}I to combine magnetic targeted drug delivery and radiotherapy. Fe rate at Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe rate at Au nanoparticles (Fe rate at Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe rate at Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

  11. Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe rate at Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

    International Nuclear Information System (INIS)

    Takan, Gokhan; Guldu, Ozge Kozgus; Medine, Emin Ilker

    2017-01-01

    Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe rate at Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe rate at Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe rate at Au) nanoparticles and radiolabeled with "1"3"1I to combine magnetic targeted drug delivery and radiotherapy. Fe rate at Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe rate at Au nanoparticles (Fe rate at Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe rate at Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

  12. Effects of Surface Inclination on the Vertical Loading Rates and Landing Pattern during the First Attempt of Barefoot Running in Habitual Shod Runners

    Science.gov (United States)

    An, W.; Rainbow, M. J.; Cheung, R. T. H.

    2015-01-01

    Barefoot running has been proposed to reduce vertical loading rates, which is a risk factor of running injuries. Most of the previous studies evaluated runners on level surfaces. This study examined the effect of surface inclination on vertical loading rates and landing pattern during the first attempt of barefoot running among habitual shod runners. Twenty habitual shod runners were asked to run on treadmill at 8.0 km/h at three inclination angles (0°; +10°; −10°) with and without their usual running shoes. Vertical average rate (VALR) and instantaneous loading rate (VILR) were obtained by established methods. Landing pattern was decided using high-speed camera. VALR and VILR in shod condition were significantly higher (p running, but not in barefoot condition (p > 0.382). There was no difference (p > 0.413) in the landing pattern among all surface inclinations. Only one runner demonstrated complete transition to non-heel strike landing in all slope conditions. Reducing heel strike ratio in barefoot running did not ensure a decrease in loading rates (p > 0.15). Conversely, non-heel strike landing, regardless of footwear condition, would result in a softer landing (p < 0.011). PMID:26258133

  13. Effects of Surface Inclination on the Vertical Loading Rates and Landing Pattern during the First Attempt of Barefoot Running in Habitual Shod Runners

    Directory of Open Access Journals (Sweden)

    W. An

    2015-01-01

    Full Text Available Barefoot running has been proposed to reduce vertical loading rates, which is a risk factor of running injuries. Most of the previous studies evaluated runners on level surfaces. This study examined the effect of surface inclination on vertical loading rates and landing pattern during the first attempt of barefoot running among habitual shod runners. Twenty habitual shod runners were asked to run on treadmill at 8.0 km/h at three inclination angles (0°; +10°; −10° with and without their usual running shoes. Vertical average rate (VALR and instantaneous loading rate (VILR were obtained by established methods. Landing pattern was decided using high-speed camera. VALR and VILR in shod condition were significantly higher (p0.382. There was no difference (p>0.413 in the landing pattern among all surface inclinations. Only one runner demonstrated complete transition to non-heel strike landing in all slope conditions. Reducing heel strike ratio in barefoot running did not ensure a decrease in loading rates (p>0.15. Conversely, non-heel strike landing, regardless of footwear condition, would result in a softer landing (p<0.011.

  14. Effects of Surface Inclination on the Vertical Loading Rates and Landing Pattern during the First Attempt of Barefoot Running in Habitual Shod Runners.

    Science.gov (United States)

    An, W; Rainbow, M J; Cheung, R T H

    2015-01-01

    Barefoot running has been proposed to reduce vertical loading rates, which is a risk factor of running injuries. Most of the previous studies evaluated runners on level surfaces. This study examined the effect of surface inclination on vertical loading rates and landing pattern during the first attempt of barefoot running among habitual shod runners. Twenty habitual shod runners were asked to run on treadmill at 8.0 km/h at three inclination angles (0°; +10°; -10°) with and without their usual running shoes. Vertical average rate (VALR) and instantaneous loading rate (VILR) were obtained by established methods. Landing pattern was decided using high-speed camera. VALR and VILR in shod condition were significantly higher (p running, but not in barefoot condition (p > 0.382). There was no difference (p > 0.413) in the landing pattern among all surface inclinations. Only one runner demonstrated complete transition to non-heel strike landing in all slope conditions. Reducing heel strike ratio in barefoot running did not ensure a decrease in loading rates (p > 0.15). Conversely, non-heel strike landing, regardless of footwear condition, would result in a softer landing (p < 0.011).

  15. Effects of Organic Loading Rate on the Performance of a Pressurized Anaerobic Filter in Two-Phase Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Yuling Chen

    2014-02-01

    Full Text Available The effect of organic loading rate (OLR on a pressurized anaerobic filter was studied in a laboratory two-phase anaerobic digestion system. The anaerobic filter was operated successively at two working pressures (9 bar and 1.5 bar. The OLR(COD for each pressure was increased from 5 to 17.5 kg·m−3·day−1. The best performance of the reactor at 9 bar was observed at OLR(COD of 12.5 kg·m−3·day−1 and hydraulic retention time (HRT of 1.8 day, with specific biogas productivity (SBP of 5.3 L·L−1·day−1 and COD degradation grade of 90.6%. At higher OLRs and shorter HRTs, the process became unstable. In contrast, there was no indication of digester failure during the experiments at 1.5 bar. The SBP peaked at OLR(COD of 17.5 kg·m−3·day−1 with 8.2 L·L−1·day−1, where COD degradation grade was 90.4%. The biogas collected from the reactor at 9 bar and 1.5 bar contained approximately 74.5% CH4 and 66.2% CH4, respectively, regardless of OLR variation. At OLR(COD of 5–12.5 kg·m−3·day−1, the reactor at 9 bar had the same specific methane yield as at 1.5 bar, which was in the range of 0.31–0.32 LN·g−1COD. Raising the working pressure in the reactor resulted in an increase of methane content of the produced biogas. However, the low pH value (approximately 6.5 inside the reactor, induced by high CO2 partial pressure seemed to limit the reactor performance at high OLRs and short HRT.

  16. Evaluation of bond strength and load deflection rate of multi-stranded fixed retainer wires: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Renu Sarah Samson

    2018-01-01

    Full Text Available Background: Fixed orthodontic retainers must be well retained on the tooth surfaces, allow physiologic movement of teeth and exert minimal forces on the teeth to be retained. Previous studies analyzed the bond strength and amount of deflection caused due to the debonding force but not the magnitude of force needed for unit deformation. Aims: This study aims to evaluate and compare the bond strength and load deflection rate (LDR of three different fixed retainer wires. Materials and Methods: The wires were divided into three Groups: A – three-stranded twisted ligature wire, B – Bond-A-Braid (Reliance Orthodontics, and C – three-stranded twisted lingual retainer wire (3M Unitek. Twenty models were prepared for each group with a passive 15 mm long lingual retainer wire bonded to two lower incisors. An occlusogingival force was applied to the wire until it debonded. For LDR, three-point bending test was done at 0.5 mm deflection. These forces were measured using a Universal Instron Testing Machine. Statistical Analysis: Mean bond strength/LDR and pairwise comparisons were analyzed with one-way ANOVA and Tukey's honest significant difference post hoc test, respectively. Results: Group C exhibited the highest mean bond strength and LDR of 101.17N and 1.84N, respectively. The intergroup comparisons were all statistically significant. Conclusion: Compared to the other two wire types, Group C might be better retained on the teeth due to its higher bond strength. With its relatively higher LDR value, it may resist deformation from occlusal forces, thereby reducing inadvertent tooth movement and yet remain flexible enough to allow physiologic tooth movements.

  17. Preparation and evaluation of azithromycin binary solid dispersions using various polyethylene glycols for the improvement of the drug solubility and dissolution rate

    Directory of Open Access Journals (Sweden)

    Ehsan Adeli

    Full Text Available ABSTRACT Azithromycin is a water-insoluble drug, with a very low bioavailability. In order to increase the solubility and dissolution rate, and consequently increase the bioavailability of poorly-soluble drugs (such as azithromycin, various techniques can be applied. One of such techniques is "solid dispersion". This technique is frequently used to improve the dissolution rate of poorly water-soluble compounds. Owing to its low solubility and dissolution rate, azithromycin does not have a suitable bioavailability. Therefore, the main purpose of this investigation was to increase the solubility and dissolution rate of azithromycin by preparing its solid dispersion, using different Polyethylene glycols (PEG. Preparations of solid dispersions and physical mixtures of azithromycin were made using PEG 4000, 6000, 8000, 12000 and 20000 in various ratios, based on the solvent evaporation method. From the studied drug release profile, it was discovered that the dissolution rate of the physical mixture, as the well as the solid dispersions, were higher than those of the drug alone. There was no chemical incompatibility between the drug and polymer from the observed Infrared (IR spectra. Drug-polymer interactions were also investigated using Differential Scanning Calorimetry (DSC, Powder X-Ray Diffraction (PXRD and Scanning Election Microscopy (SEM. In conclusion, the dissolution rate and solubility of azithromycin were found to improve significantly, using hydrophilic carriers, especially PEG 6000.

  18. Gadolinium-Loaded Solid Lipid Nanoparticles as a Tumor-Absorbable Contrast Agent for Early Diagnosis of Colorectal Tumors Using Magnetic Resonance Colonography.

    Science.gov (United States)

    Sun, Jihong; Zhang, Shizheng; Jiang, Shaojie; Bai, Weixian; Liu, Fei; Yuan, Hong; Ji, Jiansong; Luo, Jingfeng; Han, Guocan; Chen, Lumin; Jin, Yin; Hu, Peng; Yu, Lei; Yang, Xiaoming

    2016-09-01

    Magnetic resonance (MR) contrast agents focusing on special functions are required to improve cancer diagnosis, particularly in the early stages. Here, we designed multifunctional solid lipid nanoparticles (SLNs) with simultaneous loading of gadolinium (Gd) diethylenetriaminepentaacetic acid (Gd-DTPA) and octadecylamine fluorescein isothiocyanate (FITC) to obtain Gd-FITC-SLNs as a tumor-absorbable nanoparticle contrast agent for the histological confirmation of MR imaging (MRI) findings. Colorectal tumors were evaluated in vitro and in vivo via direct uptake of this contrast agent, which displayed reasonable T1 relaxivity and no significant cytotoxicity at the experimental concentrations in human colon carcinoma cells (HT29) and mouse colon carcinoma cells (CT26). In vitro cell uptake experiments demonstrated that contrast agent absorption by the two types of cancer cells was concentration-dependent in the safe concentration range. During in vivo MRI, transrectal infusion of Gd-FITC-SLNs showed more significant enhancement at the tumor site compared with the infusion of Gd-DTPA in female C57/BL mice with azoxymethane/dextran sulfate sodium-induced colorectal highgrade intraepithelial neoplasia. Subsequent confocal fluorescence microscopy demonstrated Gd-FITC-SLNs as highly concentrated green fluorescent spots distributed from the tumor capsule into the tumor. This study establishes the "proof-of-principle" of a new MRI technique wherein colorectal tumors are enhanced via direct absorption or uptake of the nanoparticle contrast agent.

  19. Gas chromatographic determination of polycyclic aromatic hydrocarbons in water and smoked rice samples after solid-phase microextraction using multiwalled carbon nanotube loaded hollow fiber.

    Science.gov (United States)

    Matin, Amir Abbas; Biparva, Pourya; Gheshlaghi, Mohammad

    2014-12-29

    A novel solid-phase microextraction fiber was prepared based on multiwalled carbon nanotubes (MWCNTs) loaded on hollow fiber membrane pores. Stainless steel wire was used as unbreakable support. The major advantages of the proposed fiber are its (a) high reproducibility due to the uniform structure of the hollow fiber membranes, (b) high extraction capacity related to the porous structure of the hollow fiber and outstanding adsorptive characteristics of MWCNTs. The proposed fiber was applied for the microextraction of five representative polycyclic aromatic hydrocarbons (PAHs) from aqueous media (river and hubble-bubble water) and smoked rice samples followed by gas chromatographic determination. Analytical merits of the method, including high correlation coefficients [(0.9963-0.9992) and (0.9982-0.9999)] and low detection limits [(9.0-13.0ngL(-1)) and (40.0-150.0ngkg(-1))] for water and rice samples, respectively, made the proposed method suitable for the ultra-trace determination of PAHs. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Association between minor loading vein architecture and light- and CO2-saturated rates of photosynthetic oxygen evolution among Arabidopsis thaliana ecotypes from different latitudes

    Directory of Open Access Journals (Sweden)

    Christopher M Cohu

    2013-07-01

    Full Text Available Through microscopic analysis of veins and assessment of light- and CO2-saturated rates of photosynthetic oxygen evolution, we investigated the relationship between minor loading vein anatomy and photosynthesis of mature leaves in three ecotypes of Arabidopsis thaliana grown under four different combinations of temperature and photon flux density (PFD. All three ecotypes exhibited greater numbers and cross-sectional area of phloem cells as well as higher photosynthesis rates in response to higher PFD and especially lower temperature. The Swedish ecotype exhibited the strongest response to these conditions, the Italian ecotype the weakest response, and the Col-0 ecotype exhibited an intermediate response. Among all three ecotypes, strong linear relationships were found between light- and CO2-saturated rates of photosynthetic oxygen evolution and the number and area of either sieve elements or of companion and phloem parenchyma cells in foliar minor loading veins, with the Swedish ecotype showing the highest number of cells in minor loading veins (and largest minor veins coupled with unprecedented high rates of photosynthesis. Linear, albeit less significant, relationships were also observed between number and cross-sectional area of tracheids per minor loading vein versus light- and CO2-saturated rates of photosynthetic oxygen evolution. We suggest that sugar distribution infrastructure in the phloem is co-regulated with other features that set the upper limit for photosynthesis. The apparent genetic differences among Arabidopsis ecotypes should allow for future identification of the gene(s involved in augmenting sugar-loading and -transporting phloem cells and maximal rates of photosynthesis.

  1. Pilot project - demonstration of capabilities and benefits of bridge load rating through physical testing : tech transfer summary.

    Science.gov (United States)

    2013-08-01

    This project demonstrated the capabilities for load testing bridges in Iowa, developed and presented a webinar to local and state engineers, and produced a spreadsheet and benefit evaluation matrix that others can use to preliminarily assess where br...

  2. Determination of trace amounts of plutonium in environmental samples by RIMS using a high repetition rate solid state laser system

    International Nuclear Information System (INIS)

    Gruening, C.; Kratz, J.V.; Trautmann, N.; Waldek, A.; Huber, G.; Passler, G.; Wendt, K.

    2001-01-01

    A reliable and easy to handle high repetition rate solid state laser system has been set up for routine applications of Resonance Ionization Mass Spectrometry (RIMS). It consists of three Titanium-Sapphire (Ti:Sa) lasers pumped by one Nd:YAG laser, providing up to 3 W of tunable laser light each in a wavelength range from 725 nm to 895 nm. The isotope shifts for 238 Pu to 244 Pu have been measured in an efficient ionization scheme with λ 1 =420.76 nm, λ 2 =847.28 nm and λ 3 =767.53 nm. An overall detection efficiency of the RIMS apparatus of ε=1x10 -5 is routinely reached, resulting in a detection limit of 2x10 6 atoms (0.8 fg) of plutonium. The isotopic compositions of synthetic samples and the NIST standard reference material SRM996 were measured. The content of 238 Pu to 242 Pu has been determined in dust samples from the surroundings of a nuclear power plant and 244 Pu was determined in urine samples for the National Radiation Protection Board (NRPB), U.K. Routine operation of plutonium ultratrace detection could thus be established

  3. Effect of increasing nitrobenzene loading rates on the performance of anaerobic migrating blanket reactor and sequential anaerobic migrating blanket reactor/completely stirred tank reactor system

    International Nuclear Information System (INIS)

    Kuscu, Ozlem Selcuk; Sponza, Delia Teresa

    2009-01-01

    A laboratory scale anaerobic migrating blanket reactor (AMBR) reactor was operated at nitrobenzene (NB) loading rates increasing from 3.33 to 66.67 g NB/m 3 day and at a constant hydraulic retention time (HRT) of 6 days to observe the effects of increasing NB concentrations on chemical oxygen demand (COD), NB removal efficiencies, bicarbonate alkalinity, volatile fatty acid (VFA) accumulation and methane gas percentage. Moreover, the effect of an aerobic completely stirred tank reactor (CSTR) reactor, following the anaerobic reactor, on treatment efficiencies was also investigated. Approximately 91-94% COD removal efficiencies were observed up to a NB loading rate of 30.00 g/m 3 day in the AMBR reactor. The COD removal efficiencies decreased from 91% to 85% at a NB loading rate of 66.67 g/m 3 day. NB removal efficiencies were approximately 100% at all NB loading rates. The maximum total gas, methane gas productions and methane percentage were found to be 4.1, 2.6 l/day and 59%, respectively, at a NB loading rate of 30.00 g/m 3 day. The optimum pH values were found to be between 7.2 and 8.4 for maximum methanogenesis. The total volatile fatty acid (TVFA) concentrations in the effluent were 110 and 70 mg/l in the first and second compartments at NB loading rates as high as 66.67 and 6.67 g/m 3 day, respectively, while they were measured as zero in the effluent of the AMBR reactor. In this study, from 180 mg/l NB 66 mg/l aniline was produced in the anaerobic reactor while aniline was completely removed and transformed to 2 mg/l of cathechol in the aerobic CSTR reactor. Overall COD removal efficiencies were found to be 95% and 99% for NB loading rates of 3.33 and 66.67 g/m 3 day in the sequential anaerobic AMBR/aerobic CSTR reactor system, respectively. The toxicity tests performed with Photobacterium phosphoreum (LCK 480, LUMIStox) and Daphnia magna showed that the toxicity decreased with anaerobic/aerobic sequential reactor system from the influent, anaerobic and to

  4. Application of spatial and non-spatial data analysis in determination of the factors that impact municipal solid waste generation rates in Turkey

    International Nuclear Information System (INIS)

    Keser, Saniye; Duzgun, Sebnem; Aksoy, Aysegul

    2012-01-01

    Highlights: ► Spatial autocorrelation exists in municipal solid waste generation rates for different provinces in Turkey. ► Traditional non-spatial regression models may not provide sufficient information for better solid waste management. ► Unemployment rate is a global variable that significantly impacts the waste generation rates in Turkey. ► Significances of global parameters may diminish at local scale for some provinces. ► GWR model can be used to create clusters of cities for solid waste management. - Abstract: In studies focusing on the factors that impact solid waste generation habits and rates, the potential spatial dependency in solid waste generation data is not considered in relating the waste generation rates to its determinants. In this study, spatial dependency is taken into account in determination of the significant socio-economic and climatic factors that may be of importance for the municipal solid waste (MSW) generation rates in different provinces of Turkey. Simultaneous spatial autoregression (SAR) and geographically weighted regression (GWR) models are used for the spatial data analyses. Similar to ordinary least squares regression (OLSR), regression coefficients are global in SAR model. In other words, the effect of a given independent variable on a dependent variable is valid for the whole country. Unlike OLSR or SAR, GWR reveals the local impact of a given factor (or independent variable) on the waste generation rates of different provinces. Results show that provinces within closer neighborhoods have similar MSW generation rates. On the other hand, this spatial autocorrelation is not very high for the exploratory variables considered in the study. OLSR and SAR models have similar regression coefficients. GWR is useful to indicate the local determinants of MSW generation rates. GWR model can be utilized to plan waste management activities at local scale including waste minimization, collection, treatment, and disposal. At global

  5. An Integrated Instrumentation System for Velocity, Concentration and Mass Flow Rate Measurement of Solid Particles Based on Electrostatic and Capacitance Sensors

    Directory of Open Access Journals (Sweden)

    Jian Li

    2015-12-01

    Full Text Available The online and continuous measurement of velocity, concentration and mass flow rate of pneumatically conveyed solid particles for the high-efficiency utilization of energy and raw materials has become increasingly significant. In this paper, an integrated instrumentation system for the velocity, concentration and mass flow rate measurement of dense phase pneumatically conveyed solid particles based on electrostatic and capacitance sensorsis developed. The electrostatic sensors are used for particle mean velocity measurement in combination with the cross-correlation technique, while the capacitance sensor with helical surface-plate electrodes, which has relatively homogeneous sensitivity distribution, is employed for the measurement of particle concentration and its capacitance is measured by an electrostatic-immune AC-based circuit. The solid mass flow rate can be further calculated from the measured velocity and concentration. The developed instrumentation system for velocity and concentration measurement is verified and calibrated on a pulley rig and through static experiments, respectively. Finally the system is evaluated with glass beads on a gravity-fed rig. The experimental results demonstrate that the system is capable of the accurate solid mass flow rate measurement, and the relative error is within −3%–8% for glass bead mass flow rates ranging from 0.13 kg/s to 0.9 kg/s.

  6. Study on MnCl_2/CaCl_2–NH_3 two-stage solid sorption freezing cycle for refrigerated trucks at low engine load in summer

    International Nuclear Information System (INIS)

    Gao, P.; Zhang, X.F.; Wang, L.W.; Wang, R.Z.; Li, D.P.; Liang, Z.W.; Cai, A.F.

    2016-01-01

    Graphical abstract: A MnCl_2/CaCl_2–NH_3 two-stage solid sorption freezing cycle driven by the engine exhaust gas is proposed for refrigerated trucks. - Highlights: • A two-stage adsorption freezing system is designed and constructed for the refrigerated truck. • Composite adsorbents of MnCl_2 and CaCl_2 with the matrix of ENG-TSA are developed. • The average refrigerating capacity of 2.2 kW in the adsorption process is obtained. • The chilled air outlet temperature of the evaporator is controlled at about −5 °C. • The COP is 0.13 when the heating and refrigerating temperatures are 230 °C and −5 °C. - Abstract: A novel MnCl_2/CaCl_2–NH_3 two-stage solid sorption freezing cycle is designed and established for the refrigerated truck with the rated power of 80 kW. The conventional sorption/desorption process and the resorption process are combined in the two-stage cycle. Theoretical analysis shows that such a cycle could adapt to the low heat source temperature and the high cooling temperature of the sorption beds very well, which is quite essential for the truck when the running speed and the load are low in summer. The expanded natural graphite treated with sulfuric acid (ENG-TSA) is chosen as the matrix, and composite adsorbents of MnCl_2/ENG-TSA and CaCl_2/ENG-TSA are developed. The hot air heated by the electric heater is used to simulate the engine exhaust gas to drive the system. When the hot air, the ambient air and the refrigerating temperature are 230 °C, 30 °C and −5 °C, respectively, the average refrigerating capacity is 2.2 kW in the sorption process. Correspondingly, the COP and SCP are 0.13 and 91.7 W/kg, respectively. The average refrigerating capacity of 1.1 kW in one cycle is gotten, which could meet the required refrigerating capacity of the light refrigerated truck at the low engine load engine in summer.

  7. Fracto-mechanoluminescent light emission of EuD4TEA-PDMS composites subjected to high strain-rate compressive loading

    Science.gov (United States)

    Ryu, Donghyeon; Castaño, Nicolas; Bhakta, Raj; Kimberley, Jamie

    2017-08-01

    The objective of this study is to understand light emission characteristics of fracto-mechanoluminescent (FML) europium tetrakis(dibenzoylmethide)-triethylammonium (EuD4TEA) crystals under high strain-rate compressive loading. As a sensing material that can play a pivotal role for the self-powered impact sensor technology, it is important to understand transformative light emission characteristics of the FML EuD4TEA crystals under high strain-rate compressive loading. First, EuD4TEA crystals were synthesized and embedded into polydimethylsiloxane (PDMS) elastomer to fabricate EuD4TEA-PDMS composite test specimens. Second, the prepared EuD4TEA-PDMS composites were tested using the modified Kolsky bar setup equipped with a high-speed camera. Third, FML light emission was captured to yield 12 bit grayscale video footage, which was processed to quantify the FML light emission. Finally, quantitative parameters were generated by taking into account pixel values and population of pixels of the 12 bit grayscale images to represent FML light intensity. The FML light intensity was correlated with high strain-rate compressive strain and strain rate to understand the FML light emission characteristics under high strain-rate compressive loading that can result from impact occurrences.

  8. Ultrasonic assisted dispersive solid-phase microextraction of Eriochrome Cyanine R from water sample on ultrasonically synthesized lead (II) dioxide nanoparticles loaded on activated carbon: Experimental design methodology.

    Science.gov (United States)

    Bahrani, Sonia; Ghaedi, Mehrorang; Mansoorkhani, Mohammad Javad Khoshnood; Asfaram, Arash; Bazrafshan, Ali Akbar; Purkait, Mihir Kumar

    2017-01-01

    The present research focus on designing an appropriate dispersive solid-phase microextraction (UA-DSPME) for preconcentration and determination of Eriochrome Cyanine R (ECR) in aqueous solutions with aid of sonication using lead (II) dioxide nanoparticles loaded on activated carbon (PbO-NPs-AC). This material was fully identified with XRD and SEM. Influence of pH, amounts of sorbent, type and volume of eluent, and sonication time on response properties were investigated and optimized by central composite design (CCD) combined with surface response methodology using STATISTICA. Among different solvents, dimethyl sulfoxide (DMSO) was selected as an efficient eluent, which its combination by present nanoparticles and application of ultrasound waves led to enhancement in mass transfer. The predicted maximum extraction (100%) under the optimum conditions of the process variables viz. pH 4.5, eluent 200μL, adsorbent dosage 2.5mg and 5min sonication was close to the experimental value (99.50%). at optimum conditions some experimental features like wide 5-2000ngmL -1 ECR, low detection limit (0.43ngmL -1 , S/N=3:1) and good repeatability and reproducibility (relative standard deviation, <5.5%, n=12) indicate versatility in successful applicability of present method for real sample analysis. Investigation of accuracy by spiking known concentration of ECR over 200-600ngmL -1 gave mean recoveries from 94.850% to 101.42% under optimal conditions. The procedure was also applied for the pre-concentration and subsequent determination of ECR in tap and waste waters. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Investigation of column flotation process on sulphide ore using 2-electrode capacitance sensor: The effect of air flow rate and solid percentage

    Science.gov (United States)

    Haryono, Didied; Harjanto, Sri; Wijaya, Rifky; Oediyani, Soesaptri; Nugraha, Harisma; Huda, Mahfudz Al; Taruno, Warsito Purwo

    2018-04-01

    Investigation of column flotation process on sulphide ore using 2-electrode capacitance sensor is presented in this paper. The effect of air flow rate and solid percentage on column flotation process has been experimentally investigated. The purpose of this paper is to understand the capacitance signal characteristic affected by the air flow rate and the solid percentage which can be used to determine the metallurgical performance. Experiments were performed using a laboratory column flotation cell which has a diameter of 5 cm and the total height of 140 cm. The sintered ceramic sparger and wash water were installed at the bottom and above of the column. Two-electrode concave type capacitance sensor was also installed at a distance of 50 cm from the sparger. The sensor was attached to the outer wall of the column, connected to data acquisition system, manufactured by CTECH Labs Edwar Technology and personal computer for further data processing. Feed consisting ZnS and SiO2 with the ratio of 3:2 was mixed with some reagents to make 1 litre of slurry. The slurry was fed into the aerated column at 100 cm above the sparger with a constant rate and the capacitance signals were captured during the process. In this paper, 7.5 and 10% of solid and 2-4 L/min of air flow rate with 0.5 L/min intervals were used as independent variables. The results show that the capacitance signal characteristics between the 7.5 and 10% of solid are different at any given air flow rate in which the 10% solid produced signals higher than those of 7.5%. Metallurgical performance and capacitance signal exhibit a good correlation.

  10. An investigation of the forces within the tibiae at typical blast loading rates – with different boots

    CSIR Research Space (South Africa)

    Pandelani, T

    2014-06-01

    Full Text Available In this study, the responses of the HIII and MiL-Lx surrogate legs were evaluated at several blast loading conditions using the Modified Lower Limb Impactor. The impact tests were conducted using a lower limb impactor with the leg mounted vertically...

  11. A Decade of Improvements for Solid Oxide Electrolysis Cells. Long-Term Degradation Rate from 40%/Kh to 0.4 % Kh

    DEFF Research Database (Denmark)

    Hauch, Anne; Brodersen, Karen; Chen, Ming

    2016-01-01

    Solid oxide electrolysis cells (SOEC) have the potential for efficient large-scale conversion from electrical energy to chemical energy stored in fuels, such as hydrogen or synthetic hydrocarbon fuels by use of well-known catalysis processes. Key issues for the break-through of this technology...... are to provide inexpensive, reliable, high performing and long-term stable SOEC for stack and system applications. At DTU Energy (formerly Department of Fuel Cells and Solid State Chemistry, Risø National Laboratory), research within SOEC for more than a decade has led to long-term degradation rates on cell...

  12. Calculation of the Intensity of electrical field at the end of the loaded path in the solid-state nuclear track detectors by using the numerical calculation of Laplace equations

    International Nuclear Information System (INIS)

    Kolahdooz, M.; Abotalebi, A.; Sheikh Aleslam, F.

    2011-01-01

    The goal of this article is calculation of the electric field at the end of loaded path in solid-state track detectors. For the calculation, Laplace-Equation has been solved numerically. By solving the equation, upon considering a specific potential at the boundary of the region, in addition to calculating the electric field at the end of path, the parameters which are affecting the electric field have also been investigated.

  13. The effect of the cooling rate during quenching, electron bombardment and plastic deformation on the kinetics of a solid solution disintegration in iron-copper alloys

    International Nuclear Information System (INIS)

    Fedorov, G.B.; Zhukov, V.P.; Braun, A.G.; Smirnov, E.A.

    1974-01-01

    From the electroresistivity variation at 77 0 K, the influence of nonequilibrium point defect density and of complexes and dislocations on the decay process of the iron-copper solid solution is determined. Owing to high quenching rate of thin foils, isochrones of their electroconductivity curves appear shifted by about 200 0 C to lower temperatures. For quenched and irradiated specimens at 200-250 0 C a sharp retardation of electroconductivity decline is observed due to a zone stage. The plastic deformation (15%) leads to a partial suppression of that stage. Both irradiation and deformation initiate the process of copper separation from the solid solution, the latter being the stronger, the more copper is in the solid solution

  14. The design of a modified lower limb impactor to assess lower limb injury at typical blast loading rates

    CSIR Research Space (South Africa)

    Pandelani, T

    2014-01-01

    Full Text Available tibia peak force averaged 5154 N and ranged from 5013 N to 5161 N. The MiL-Lx leg’s biomechanical response demonstrated high repeatability with a standard deviation of 137 N for the tibia peak load. Discussion Figure 6 shows the comparison... towards understanding the mechanism of injury. Conclusions The experimental apparatus presented here allows for biomechanical lower limbs surrogates to be tested at various postures, and offers an independent test-bed for assessing the bio...

  15. An Adaptive, Multi-Rate Linear Quadratic Regulator for a Shipboard MVDC Distribution System with Constant Power Loads

    Science.gov (United States)

    2017-09-01

    investigation into the factors which most strongly influence ROA size would be instructive. The genetic algorithm could be modified to assess ROA size and an...DISTRIBUTION SYSTEM WITH CONSTANT POWER LOADS 5. FUNDING NUMBERS REL95 REK4K 6. AUTHOR(S) Adam J. Mills 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS...ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING /MONITORING AGENCY NAME(S) AND

  16. Experimental investigation of the failure envelope of unidirectional carbon-epoxy composite under high strain rate transverse and off-axis tensile loading

    Directory of Open Access Journals (Sweden)

    Kuhn Peter

    2015-01-01

    Full Text Available The mechanical response of the carbon-epoxy material system HexPly IM7