Science.gov

Sample records for additional performance parameters

  1. Effect of a phytogenic feed additive on performance, ovarian morphology, serum lipid parameters and egg sensory quality in laying hen

    PubMed Central

    Saki, Ali Asghar; Aliarabi, Hassan; Hosseini Siyar, Sayed Ali; Salari, Jalal; Hashemi, Mahdi

    2014-01-01

    This present study was conducted to evaluate the effects of dietary inclusion of 4, 8 and 12 g kg-1 phytogenic feed additives mixture on performance, egg quality, ovary parameters, serum biochemical parameters and yolk trimethylamine level in laying hens. The results of experiment have shown that egg weight was increased by supplementation of 12 g kg-1 feed additive whereas egg production, feed intake and feed conversion ratio (FCR) were not significantly affected. There were no significant differences in egg quality parameters by supplementation of phytogenic feed additive, whereas yolk trimethylamine level was decreased as the feed additive level increased. The sensory evaluation parameters did not differ significantly. No significant differences were found in serum cholesterol and triglyceride levels between the treatments but low- and high-density lipoprotein were significantly increased. Number of small follicles and ovary weight were significantly increased by supplementation of 12 g kg-1 feed additive. Overall, dietary supplementation of polyherbal additive increased egg weigh, improved ovary characteristics and declined yolk trimethylamine level. PMID:25610580

  2. Support vector machine to predict diesel engine performance and emission parameters fueled with nano-particles additive to diesel fuel

    NASA Astrophysics Data System (ADS)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive Support Vector Machine (SVM) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For SVM modelling, different values for radial basis function (RBF) kernel width and penalty parameters (C) were considered and the optimum values were then found. The results demonstrate that SVM is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve complete combustion of the fuel and reduce the exhaust emissions significantly.

  3. Gasoline additives, emissions, and performance

    SciTech Connect

    1995-12-31

    The papers included in this publication deal with the influence of fuel, additive, and hardware changes on a variety of vehicle performance characteristics. Advanced techniques for measuring these performance parameters are also described. Contents include: Fleet test evaluation of gasoline additives for intake valve and combustion chamber deposit clean up; A technique for evaluating octane requirement additives in modern engines on dynamometer test stands; A fleet test of two additive technologies comparing their effects on tailpipe emissions; Investigation into the vehicle exhaust emissions of high percentage ethanol blends; Variability in hydrocarbon speciation measurements at low emission (ULEV) levels; and more.

  4. Performance Boosting Additive

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mainstream Engineering Corporation was awarded Phase I and Phase II contracts from Goddard Space Flight Center's Small Business Innovation Research (SBIR) program in early 1990. With support from the SBIR program, Mainstream Engineering Corporation has developed a unique low cost additive, QwikBoost (TM), that increases the performance of air conditioners, heat pumps, refrigerators, and freezers. Because of the energy and environmental benefits of QwikBoost, Mainstream received the Tibbetts Award at a White House Ceremony on October 16, 1997. QwikBoost was introduced at the 1998 International Air Conditioning, Heating, and Refrigeration Exposition. QwikBoost is packaged in a handy 3-ounce can (pressurized with R-134a) and will be available for automotive air conditioning systems in summer 1998.

  5. Military display performance parameters

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Meyer, Frederick

    2012-06-01

    The military display market is analyzed in terms of four of its segments: avionics, vetronics, dismounted soldier, and command and control. Requirements are summarized for a number of technology-driving parameters, to include luminance, night vision imaging system compatibility, gray levels, resolution, dimming range, viewing angle, video capability, altitude, temperature, shock and vibration, etc., for direct-view and virtual-view displays in cockpits and crew stations. Technical specifications are discussed for selected programs.

  6. Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails

    PubMed Central

    Manafi, M.; Hedayati, M.; Khalaji, S.

    2016-01-01

    This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters. PMID:27189636

  7. Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails.

    PubMed

    Manafi, M; Hedayati, M; Khalaji, S

    2016-09-01

    This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters. PMID:27189636

  8. Tough, High-Performance, Thermoplastic Addition Polymers

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H.; Proctor, K. Mason; Gleason, John; Morgan, Cassandra; Partos, Richard

    1991-01-01

    Series of addition-type thermoplastics (ATT's) exhibit useful properties. Because of their addition curing and linear structure, ATT polymers have toughness, like thermoplastics, and easily processed, like thermosets. Work undertaken to develop chemical reaction forming stable aromatic rings in backbone of ATT polymer, combining high-temperature performance and thermo-oxidative stability with toughness and easy processibility, and minimizing or eliminating necessity for tradeoffs among properties often observed in conventional polymer syntheses.

  9. Does finger sense predict addition performance?

    PubMed

    Newman, Sharlene D

    2016-05-01

    The impact of fingers on numerical and mathematical cognition has received a great deal of attention recently. However, the precise role that fingers play in numerical cognition is unknown. The current study explores the relationship between finger sense, arithmetic and general cognitive ability. Seventy-six children between the ages of 5 and 12 participated in the study. The results of stepwise multiple regression analyses demonstrated that while general cognitive ability including language processing was a predictor of addition performance, finger sense was not. The impact of age on the relationship between finger sense, and addition was further examined. The participants were separated into two groups based on age. The results showed that finger gnosia score impacted addition performance in the older group but not the younger group. These results appear to support the hypothesis that fingers provide a scaffold for calculation and that if that scaffold is not properly built, it has continued differential consequences to mathematical cognition. PMID:26993292

  10. Diesel fuel detergent additive performance and assessment

    SciTech Connect

    Vincent, M.W.; Papachristos, M.J.; Williams, D.; Burton, J.

    1994-10-01

    Diesel fuel detergent additives are increasingly linked with high quality automotive diesel fuels. Both in Europe and in the USA, field problems associated with fuel injector coking or fouling have been experienced. In Europe indirect injection (IDI) light duty engines used in passenger cars were affected, while in the USA, a direct injection (DI) engine in heavy duty truck applications experienced field problems. In both cases, a fuel additive detergent performance test has evolved using an engine linked with the original field problem, although engine design modifications employed by the manufacturers have ensured improved operation in service. Increasing awareness of the potential for injector nozzle coking to cause deterioration in engine performance is coupled with a need to meet ever more stringent exhaust emissions legislation. These two requirements indicate that the use of detergency additives will continue to be associated with high quality diesel fuels. The paper examines detergency performance evaluated in a range of IDI and DI engines and correlates performance in the two most widely recognised test engines, namely the Peugeot 1.9 litre IDI, and Cummins L10 DI engines. 17 refs., 18 figs., 5 tabs.

  11. Simulating performance sensitivity of supercomputer job parameters.

    SciTech Connect

    Clearwater, Scott Harvey; Kleban, Stephen David

    2003-03-01

    We report on the use of a supercomputer simulation to study the performance sensitivity to systematic changes in the job parameters of run time, number of CPUs, and interarrival time. We also examine the effect of changes in share allocation and service ratio for job prioritization under a Fair Share queuing Algorithm to see the effect on facility figures of merit. We used log data from the ASCI supercomputer Blue Mountain and the ASCI simulator BIRMinator to perform this study. The key finding is that the performance of the supercomputer is quite sensitive to all the job parameters with the interarrival rate of the jobs being most sensitive at the highest rates and increasing run times the least sensitive job parameter with respect to utilization and rapid turnaround. We also find that this facility is running near its maximum practical utilization. Finally, we show the importance of the use of simulation in understanding the performance sensitivity of a supercomputer.

  12. Additional Investigations of Ice Shape Sensitivity to Parameter Variations

    NASA Technical Reports Server (NTRS)

    Miller, Dean R.; Potapczuk, Mark G.; Langhals, Tammy J.

    2006-01-01

    A second parameter sensitivity study was conducted at the NASA Glenn Research Center's Icing Research Tunnel (IRT) using a 36 in. chord (0.91 m) NACA-0012 airfoil. The objective of this work was to further investigate the feasibility of using ice shape feature changes to define requirements for the simulation and measurement of SLD and appendix C icing conditions. A previous study concluded that it was feasible to use changes in ice shape features (e.g., ice horn angle, ice horn thickness, and ice shape mass) to detect relatively small variations in icing spray condition parameters (LWC, MVD, and temperature). The subject of this current investigation extends the scope of this previous work, by also examining the effect of icing tunnel spray-bar parameter variations (water pressure, air pressure) on ice shape feature changes. The approach was to vary spray-bar water pressure and air pressure, and then evaluate the effects of these parameter changes on the resulting ice shapes. This paper will provide a description of the experimental method, present selected experimental results, and conclude with an evaluation of these results.

  13. Electrolyte additive for improved battery performance

    DOEpatents

    Bellows, Richard J.; Kantner, Edward

    1989-04-04

    In one embodiment of the present invention, there is provided an electrochemical cell having a metal bromine couple. The cell includes an electrode structure on which to deposit the metal of the couple and a counterelectrode at which to generate bromine. A microporous membrane separates the electrode and counterelectrode. Importantly, the aqueous electrolyte comprises an aqueous metal bromide solution containing a water soluble bromine complexing agent capable of forming a water immiscible complex with bromine and an additive capable of decreasing the wettability of the microporous separators employed in such cells by such water immiscible bromine complexes.

  14. Effects of black pepper (piper nigrum), turmeric powder (curcuma longa) and coriander seeds (coriandrum sativum) and their combinations as feed additives on growth performance, carcass traits, some blood parameters and humoral immune response of broiler chickens.

    PubMed

    Abou-Elkhair, R; Ahmed, H A; Selim, S

    2014-06-01

    Different herbs and spices have been used as feed additives for various purposes in poultry production. This study was conducted to assess the effect of feed supplemented with black pepper (Piper nigrum), turmeric powder (Curcuma longa), coriander seeds (Coriandrum sativum) and their combinations on the performance of broilers. A total of 210 (Cobb) one-d-old chicks were divided into seven groups of 30 birds each. The treatments were: a control group received no supplement, 0.5% black pepper (T1), 0.5% turmeric powder (T2), 2% coriander seeds (T3), a mixture of 0.5% black pepper and 0.5% turmeric powder (T4), a mixture of 0.5% black pepper and 2% coriander seed (T5), and a mixture of 0.5% black pepper, 0.5% turmeric powder and 2% coriander seeds (T6). Higher significant values of body weight gain during the whole period of 5 weeks (p<0.001) were observed in broilers on T1, T3, T5, and T6 compared to control. Dietary supplements with T1, T2, T3, and T6 improved the cumulative G:F of broilers during the whole period of 5 weeks (p<0.001) compared with control. The dressing percentage and edible giblets were not influenced by dietary supplements, while higher values of relative weight of the liver (p<0.05) were obtained in T5 and T6 compared to control. The addition of feed supplements in T5 and T6 significantly increased serum total protein and decreased serum glucose, triglycerides and alkaline phosphatase concentrations compared with the control group (p<0.05). Broilers on T6 showed significant decrease in the serum glutamate pyruvate transaminase concentration (p<0.05) compared to control. The broilers having T5 and T6 supplemented feed had relatively greater antibody titre (p<0.001) at 35 d of age than control. It is concluded that dietary supplements with black pepper or coriander seeds or their combinations enhanced the performance and health status of broiler chickens. PMID:25050023

  15. Battery performance enhancement with additions of bismuth

    NASA Astrophysics Data System (ADS)

    Manders, J. E.; Lam, L. T.; de Marco, R.; Douglas, J. D.; Pillig, R.; Rand, D. A. J.

    1994-02-01

    Automotive and valve-regulated batteries (VRBs) of typical commercial design have been constructed using positive and negative plates produced from leady oxide that is doped with 0.06 wt.% bismuth. The doping is performed by adding bismuth (III) oxide powder during the paste-mixing stage. Both battery designs have been subjected to endurance tests (automotive batteries: JIS cycle-life test; VRBs: repetitive 3-h discharge) in parallel with batteries that are similar in all respects but do not contain bismuth. A strategy and necessary hardware have been developed to measure the gassing properties of the VRBs during both charge and discharge. The procedure involves monitoring the internal pressure with high-precision pressure transducers. For automotive batteries, doping with bismuth produces no significant differences in JIS cycle life. By contrast, both the endurance and the capacity of VRBs are found to be enhanced by the presence of bismuth. Furthermore, bismuth reduces the build-up in gas pressure (mainly oxygen) in VRBs during constant-current charging. These results suggest that future specifications for leady oxide should include a minimum - rather than a maximum - bismuth content. In this respect, although studies performed to date show that significant advantages can be achieved with 0.06 wt.% bismuth in the active material, the optimum bismuth level has yet to be established.

  16. Self-calibration of terrestrial laser scanners: selection of the best geometric additional parameters

    NASA Astrophysics Data System (ADS)

    Lerma, J. L.; García-San-Miguel, D.

    2014-05-01

    Systematic errors are present in laser scanning system observations due to manufacturer imperfections, wearing over time, vibrations, changing environmental conditions and, last but not least, involuntary hits. To achieve maximum quality and rigorous measurements from terrestrial laser scanners, a least squares estimation of additional calibration parameters can be used to model the a priori unknown systematic errors and therefore improve output observations. The selection of the right set of additional parameters is not trivial and requires laborious statistical analysis. Based on this requirement, this article presents an approach to determine the best set of additional parameters which provides the best mathematical solution based on a dimensionless quality index. The best set of additional parameters is the one which provides the maximum quality index (i.e. minimum value) for the group of observables, exterior orientation parameters and reference points. Calibration performance is tested using both a phase shift continuous wave scanner, FARO PHOTON 880, and a pulse-based time-of-flight system, Leica HDS3000. The improvement achieved after the geometric calibration is 30% for the former and 70% for the latter.

  17. Non toxic additives for improved fabric filter performance

    SciTech Connect

    Bustard, C.J.; Baldrey, K.E.; Ebner, T.G.

    1995-11-01

    The overall objective of this three-phase Small Business innovative Research (SBIR) program funded by the Department of Energy pittsburgh Energy Technology Center (PETC) is to commercialize a technology based upon the use of non-toxic, novel flue gas conditioning agents to improve particulate air toxic control and overall fabric filter performance. The ultimate objective of the Phase II program currently in progress is to demonstrate that the candidate additives are successful at full-scale on flue gas from a coal-fired utility boiler. This paper covers bench-scale field tests conducted during the period February through May, 1995. The bench-scale additives testing was conducted on a flue gas slipstream taken upstream of the existing particulate control device at a utility power plant firing a Texas lignite coal. These tests were preceded by extensive testing with additives in the laboratory using a simulated flue gas stream and re-dispersed flyash from the same power plant. The bench-scale field testing was undertaken to demonstrate the performance with actual flue gas of the bet candidate additives previously identified in the laboratory. Results from the bench-scale tests will be used to establish operating parameters for a larger-scale demonstration on either a single baghouse compartment or a full baghouse at the same site.

  18. Performance Parameters Of A Kinestatic Charge Detector

    NASA Astrophysics Data System (ADS)

    DiBianca, Frank A.; Wagenaar, Douglas J.; Fetter, Joan E.; Tenney, Charles R.; Vance, Joseph E.; Bolz, Martha J.; McDaniel, David L.; Granfors, Paul

    1986-06-01

    The goal of developing an on-line electronic digital radiographic (EDR) system to replace conventional film-screen radiography (FSR) is important for at least two reasons. First, theoretical arguments show that EDR can have improved diagnostic quality, reduced patient dose and faster image accessibility than FSR. Secondly, the availability of EDR systems will remove the final impediment to the realization of the PACS concept inasmuch as FSR is the only major nonelectronic imaging modality left in the modern radiology department. The Kinestatic Charge Detector (KCD) has properties which make it a candidate for an on-line EDR systems-10. The KCD is a strip detector with high spatial resolution in two dimensions. However, mechanically and electronically, it operates like a one-dimensional detector. Thus, it can effectively scan on the order of 64 to 128 parallel x-ray lines simultaneously but with a 64 to 128-fold reduction in the number of actual detector cells and electronic channels. Moreover, this can be done at quantum detection efficiencies approaching unity. In this paper, theoretical calculations and experimental measurements of the performance parameters of a KCD are presented. Some of the particular parameters discussed include spatial, contrast, and temporal resolution.

  19. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  20. Effects of additional interfering signals on adaptive array performance

    NASA Technical Reports Server (NTRS)

    Moses, Randolph L.

    1989-01-01

    The effects of additional interference signals on the performance of a fully adaptive array are considered. The case where the number of interference signals exceeds the number of array degrees of freedom is addressed. It is shown how performance is affected as a function of the number of array elements, the number of interference signals, and the directivity of the array antennas. By using directive auxiliary elements, the performance of the array can be as good as the performance when the additional interference signals are not present.

  1. (Al, B)-ZSM-11 FCC additive performance

    SciTech Connect

    Hsing, L.H.; O`Young, C.L.

    1996-10-01

    ZSM-5 additive has been used extensively in the petroleum refining industry to enhance the light olefins production from the FCCU operation. In this paper, an FCC additive, (Al, B)-ZSM-11 was evaluated for its performance on a circulated FCC pilot unit. This additive was prepared by partially replacing the frame-work aluminum with boron, which in turn, will alternate its acid characteristics and performance as an FCC additive in promoting light olefin production. The (Al, B)-ZSM-11 additive increased C3=, C4=, and C5= yields, but was less effective in increasing C3=, C4= yields, particularly I-C4= than ZSM-5 additive. The (Al, B)-ZSM-11 additive increased branched C5= and decreased linear C5= yields resulting from skeletal isomerization. C5= and FC naphtha yields with (Al, B)-ZSM-11 additive are higher than those obtained with ZSM-5 additive indicating lower cracking of FC naphtha and C%= to lower olefins with (Al, B)-ZSM-11 additive than ZSM-5. The product selectivity difference between ZSM-5 and (Al, B)-ZSM-11 additives can be correlated with their respective acidity.

  2. BMI, a Performance Parameter for Speed Improvement

    PubMed Central

    Sedeaud, Adrien; Marc, Andy; Marck, Adrien; Dor, Frédéric; Schipman, Julien; Dorsey, Maya; Haida, Amal; Berthelot, Geoffroy; Toussaint, Jean-François

    2014-01-01

    The purpose of this study is to investigate the association between anthropometric characteristics and performance in all track and field running events and assess Body Mass Index (BMI) as a relevant performance indicator. Data of mass, height, BMI and speed were collected for the top 100 international men athletes in track events from 100 m to marathon for the 1996–2011 seasons, and analyzed by decile of performance. Speed is significantly associated with mass (r = 0.71) and BMI (r = 0.71) in world-class runners and moderately with height (r = 0.39). Athletes, on average were continuously lighter and smaller with distance increments. In track and field, speed continuously increases with BMI. In each event, performances are organized through physique gradients. «Lighter and smaller is better» in endurance events but «heavier and taller is better» for sprints. When performance increases, BMI variability progressively tightens, but it is always centered around a distance-specific optimum. Running speed is organized through biometric gradients, which both drives and are driven by performance optimization. The highest performance level is associated with narrower biometric intervals. Through BMI indicators, diversity is possible for sprints whereas for long distance events, there is a more restrictive aspect in terms of physique. BMI is a relevant indicator, which allows for a clear differentiation of athletes' capacities between each discipline and level of performance in the fields of human possibilities. PMID:24587266

  3. Friction Stir Additive Manufacturing: Route to High Structural Performance

    NASA Astrophysics Data System (ADS)

    Palanivel, S.; Sidhar, H.; Mishra, R. S.

    2015-03-01

    Aerospace and automotive industries provide the next big opportunities for additive manufacturing. Currently, the additive industry is confronted with four major challenges that have been identified in this article. These challenges need to be addressed for the additive technologies to march into new frontiers and create additional markets. Specific potential success in the transportation sectors is dependent on the ability to manufacture complicated structures with high performance. Most of the techniques used for metal-based additive manufacturing are fusion based because of their ability to fulfill the computer-aided design to component vision. Although these techniques aid in fabrication of complex shapes, achieving high structural performance is a key problem due to the liquid-solid phase transformation. In this article, friction stir additive manufacturing (FSAM) is shown as a potential solid-state process for attaining high-performance lightweight alloys for simpler geometrical applications. To illustrate FSAM as a high-performance route, manufactured builds of Mg-4Y-3Nd and AA5083 are shown as examples. In the Mg-based alloy, an average hardness of 120 HV was achieved in the built structure and was significantly higher than that of the base material (97 HV). Similarly for the Al-based alloy, compared with the base hardness of 88 HV, the average built hardness was 104 HV. A potential application of FSAM is illustrated by taking an example of a simple stiffener assembly.

  4. Additional field verification of convective scaling for the lateral dispersion parameter

    SciTech Connect

    Sakiyama, S.K.; Davis, P.A.

    1988-07-01

    The results of a series of diffusion trials over the heterogeneous surface of the Canadian Precambrian Shield provide additional support for the convective scaling of the lateral dispersion parameter. The data indicate that under convective conditions, the lateral dispersion parameter can be scaled with the convective velocity scale and the mixing depth. 10 references.

  5. Atlas performance and imploding liner parameter space

    SciTech Connect

    Reinovsky, R.; Lindemuth, I. R.; Atchison, W. L.; Cochrane, J. C. , Jr.; Faehl, R. J.

    2002-01-01

    Ultra-high magnetic fields have many applications in the confining and controlling plasmas and in exploring electron physics as manifested in the magnetic properties of materials. Another application of high fields is the acceleration of metal conductors to velocities higher than that achievable with conventional high explosive drive or gas guns. The Atlas pulse power system is the world's first pulse power system specifically designed to implode solid and near-solid density metal liners for use in pulse power hydrodynamic experiments. This paper describes the Atlas system during the first year of its operational life at Los Alamos, (comprising 10-15 implosion experiments); describes circuit models that adequately predicted the bulk kinematic behavior of liner implosions; and shows how those (now validated) models can be used to describe the range of parameters accessible through Atlas implosions.

  6. Metal-air cell with performance enhancing additive

    SciTech Connect

    Friesen, Cody A; Buttry, Daniel

    2015-11-10

    Systems and methods drawn to an electrochemical cell comprising a low temperature ionic liquid comprising positive ions and negative ions and a performance enhancing additive added to the low temperature ionic liquid. The additive dissolves in the ionic liquid to form cations, which are coordinated with one or more negative ions forming ion complexes. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. The ion complexes improve oxygen reduction thermodynamics and/or kinetics relative to the ionic liquid without the additive.

  7. Rheological parameters of dough with inulin addition and its effect on bread quality

    NASA Astrophysics Data System (ADS)

    Bojnanska, T.; Tokar, M.; Vollmannova, A.

    2015-04-01

    The rheological properties of enriched flour prepared with an addition of inulin were studied. The addition of inulin caused changes of the rheological parameters of the recorder curve. 10% and more addition significantly extended development time and on the farinogram were two peaks of consistency, what is a non-standard shape. With increasing addition of inulin resistance to deformation grows and dough is difficult to process, over 15% addition make dough short and unsuitable for making bread. Bread volume, the most important parameter, significantly decreased with inulin addition. Our results suggest a level of 5% inulin to produce a functional bread of high sensory acceptance and a level of 10% inulin produce a bread of satisfactory sensory acceptance. Bread with a level over 10% of inulin was unsatisfactory.

  8. Concurrently adjusting interrelated control parameters to achieve optimal engine performance

    DOEpatents

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2015-12-01

    Methods and systems for real-time engine control optimization are provided. A value of an engine performance variable is determined, a value of a first operating condition and a value of a second operating condition of a vehicle engine are detected, and initial values for a first engine control parameter and a second engine control parameter are determined based on the detected first operating condition and the detected second operating condition. The initial values for the first engine control parameter and the second engine control parameter are adjusted based on the determined value of the engine performance variable to cause the engine performance variable to approach a target engine performance variable. In order to cause the engine performance variable to approach the target engine performance variable, adjusting the initial value for the first engine control parameter necessitates a corresponding adjustment of the initial value for the second engine control parameter.

  9. 14 CFR 43.15 - Additional performance rules for inspections.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Additional performance rules for inspections. 43.15 Section 43.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Airworthiness of the manufacturer concerned: (1) The drive shafts or similar systems. (2) The main...

  10. Tough, high performance, addition-type thermoplastic polymers

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor)

    1992-01-01

    A tough, high performance polyimide is provided by reacting a triple bond conjugated with an aromatic ring in a bisethynyl compound with the active double bond in a compound containing a double bond activated toward the formation of a Diels-Adler type adduct, especially a bismaleimide, a biscitraconimide, or a benzoquinone, or mixtures thereof. Addition curing of this product produces a high linear polymeric structure and heat treating the highly linear polymeric structure produces a thermally stable aromatic addition-type thermoplastic polyimide, which finds utility in the preparation of molding compounds, adhesive compositions, and polymer matrix composites.

  11. Decoupling interrelated parameters for designing high performance thermoelectric materials.

    PubMed

    Xiao, Chong; Li, Zhou; Li, Kun; Huang, Pengcheng; Xie, Yi

    2014-04-15

    The world's supply of fossil fuels is quickly being exhausted, and the impact of their overuse is contributing to both climate change and global political unrest. In order to help solve these escalating problems, scientists must find a way to either replace combustion engines or reduce their use. Thermoelectric materials have attracted widespread research interest because of their potential applications as clean and renewable energy sources. They are reliable, lightweight, robust, and environmentally friendly and can reversibly convert between heat and electricity. However, after decades of development, the energy conversion efficiency of thermoelectric devices has been hovering around 10%. This is far below the theoretical predictions, mainly due to the interdependence and coupling between electrical and thermal parameters, which are strongly interrelated through the electronic structure of the materials. Therefore, any strategy that balances or decouples these parameters, in addition to optimizing the materials' intrinsic electronic structure, should be critical to the development of thermoelectric technology. In this Account, we discuss our recently developed strategies to decouple thermoelectric parameters for the synergistic optimization of electrical and thermal transport. We first highlight the phase transition, which is accompanied by an abrupt change of electrical transport, such as with a metal-insulator and semiconductor-superionic conductor transition. This should be a universal and effective strategy to optimize the thermoelectric performance, which takes advantage of modulated electronic structure and critical scattering across phase transitions to decouple the power factor and thermal conductivity. We propose that solid-solution homojunction nanoplates with disordered lattices are promising thermoelectric materials to meet the "phonon glass electron crystal" approach. The formation of a solid solution, coupled with homojunctions, allows for

  12. Development of additional tasks for the executive function performance test.

    PubMed

    Hahn, Bridget; Baum, Carolyn; Moore, Jennifer; Ehrlich-Jones, Linda; Spoeri, Susan; Doherty, Meghan; Wolf, Timothy J

    2014-01-01

    OBJECTIVE. The Executive Function Performance Test (EFPT) is a reliable and valid performance-based assessment of executive function for people with stroke. The objective of this study was to enhance the clinical utility of the EFPT by developing and testing additional tasks for the EFPT in the Alternate EFPT (aEFPT). METHOD. We performed a cross-sectional study with poststroke participants (n = 25) and healthy control participants (n = 25). All participants completed a neuropsychological assessment battery and both the EFPT and the aEFPT. RESULTS. No statistically significant differences were found between the EFPT and the aEFPT when examining total scores, construct scores, and two overall task scores. Correlations between the aEFPT and the neuropsychological measures were adequate to strong (r2s = .59-.83). CONCLUSION. The aEFPT tasks are comparable to the original EFPT tasks, providing occupational therapy practitioners with additional tasks that can be used clinically to identify performance-based executive function deficits in people with stroke. PMID:25397771

  13. Measuring Digital PCR Quality: Performance Parameters and Their Optimization.

    PubMed

    Lievens, A; Jacchia, S; Kagkli, D; Savini, C; Querci, M

    2016-01-01

    Digital PCR is rapidly being adopted in the field of DNA-based food analysis. The direct, absolute quantification it offers makes it an attractive technology for routine analysis of food and feed samples for their composition, possible GMO content, and compliance with labelling requirements. However, assessing the performance of dPCR assays is not yet well established. This article introduces three straightforward parameters based on statistical principles that allow users to evaluate if their assays are robust. In addition, we present post-run evaluation criteria to check if quantification was accurate. Finally, we evaluate the usefulness of Poisson confidence intervals and present an alternative strategy to better capture the variability in the analytical chain. PMID:27149415

  14. Measuring Digital PCR Quality: Performance Parameters and Their Optimization

    PubMed Central

    Lievens, A.; Jacchia, S.; Kagkli, D.; Savini, C.; Querci, M.

    2016-01-01

    Digital PCR is rapidly being adopted in the field of DNA-based food analysis. The direct, absolute quantification it offers makes it an attractive technology for routine analysis of food and feed samples for their composition, possible GMO content, and compliance with labelling requirements. However, assessing the performance of dPCR assays is not yet well established. This article introduces three straightforward parameters based on statistical principles that allow users to evaluate if their assays are robust. In addition, we present post-run evaluation criteria to check if quantification was accurate. Finally, we evaluate the usefulness of Poisson confidence intervals and present an alternative strategy to better capture the variability in the analytical chain. PMID:27149415

  15. Role of inorganic additives on the ballistic performance of gun propellant formulations.

    PubMed

    Damse, R S; Sikder, A K

    2008-06-15

    This paper explores the possibility of increasing the ballistic performance of gun propellant with the addition of inorganic additives viz. aluminium and ammonium perchlorate. Compositions based on propellant NQ containing additional aluminium and ammonium perchlorate in different parts were studied theoretically and experimentally. Performance in respect of ballistic parameters, sensitivity, thermal characteristics, thermal stability and mechanical properties are evaluated and compared with that of the conventional triple base propellant NQ. Experimental data on comparative study indicate that the compositions containing aluminium and ammonium perchlorate are superior to propellant NQ in respect of energy. PMID:18206299

  16. Tribological performance of ashless antiwear additives under extreme pressure conditions

    NASA Astrophysics Data System (ADS)

    Kim, Bohoon

    Zinc diakyl dithiophosphate (ZDDP) has been used in engine oil for several decades as an antiwear additive. However, ZDDP is the primary source of P, S and Zn in the exhaust, which results in frequent maintenance or replacement of exhaust gas treatment systems. The use of ashless additives is more desirable because of recent environmental regulations. The main goal of this research was to develop a fundamental understanding of how ashless compounds protect the tribological surface in comparison to ZDDP. X-ray absorption near edge structure spectroscopy (XANES) has been performed on tribo and thermal films in order to investigate the chemical properties of films generated from ashless antiwear additives like chemical structure as well as chemical composition. In order to achieve this objective, three approaches were used. First, the relationships between ashless thiophosphates and wear properties under extreme pressure were examined. Ashless antiwear additives properly form their tribofilms on the sliding steel surface, reacting with iron (Fe) which is originated from the substrate. The tribofilms consist of iron phosphates, iron sulfides, and iron sulfates that have lower reduced modulus and hardness compared to tribofilms from ZDDP. However, they are still sufficiently stiff to prevent asperity contact and provide antiwear behavior. In addition, the thickness of protective tribofilms formed with ashless thiophosphates was found to be thicker than the ones formed when ZDDP was used under identical tribological conditions. Secondly, in order to understand the mechanism of tribofilm generation of metal free additives, a fundamental understanding of thermal decomposition of ashless antiwear chemistries and their influence on thermal film formation was derived. The decomposed P- and S- containing products of ZDDP reacted with the metal surface and their own metal cations forming thermal films. In case of metal free dithiophosphates, sulfur species initially formed on

  17. Large capacitor performs as a distributed parameter pulse line

    NASA Technical Reports Server (NTRS)

    Gooding, T. J.

    1966-01-01

    Capacitor of extended foil construction performs as a distributed parameter pulse line in which current, amplitude, and period are readily controlled. The capacitor is used as the energy storage element in a pulsed plasma accelerator.

  18. Performance parameters in the design of flight motion simulators

    NASA Astrophysics Data System (ADS)

    Mitchell, Robert W.

    2012-06-01

    The desired test performance parameters influence the design of a Flight Motion Simulator (FMS) and affect its size, weight, power, electro-magnetic interference, noise, and vibration. A common desire is to specify requirements beyond the immediate need for future test programs. This may directly affect cost and schedule. Critical parameters that affect the FMS design are larger payload sizes, higher accuracies, and higher dynamic requirements. This paper provides a checklist of parameters and specification tradeoffs to be considered for the overall system performance requirements.

  19. Molecular-orbital coefficients for dinuclear polymethyne dyes in the effective additive parameter method

    SciTech Connect

    Dyadyusha, G.G.; Ushomirskii, M.M.

    1986-09-01

    A method previously proposed for determining the energy structure of a polymethyne dye with any terminal groups is used in considering formulas for the molecularorbital coefficients and the differences in the distribution on the atoms in the polymethyne chain for localized and delocalized energy levels, as well as the accuracy in calculating the molecular-orbital coefficients by means of a finite number of effective additive parameters. It is found that the localized states are important to the electron-density distribution on the chain atoms characteristic of the polymethyne dyes.

  20. Impact of Environmental Parameters on Marathon Running Performance

    PubMed Central

    El Helou, Nour; Tafflet, Muriel; Berthelot, Geoffroy; Tolaini, Julien; Marc, Andy; Guillaume, Marion; Hausswirth, Christophe; Toussaint, Jean-François

    2012-01-01

    Purpose The objectives of this study were to describe the distribution of all runners' performances in the largest marathons worldwide and to determine which environmental parameters have the maximal impact. Methods We analysed the results of six European (Paris, London, Berlin) and American (Boston, Chicago, New York) marathon races from 2001 to 2010 through 1,791,972 participants' performances (all finishers per year and race). Four environmental factors were gathered for each of the 60 races: temperature (°C), humidity (%), dew point (°C), and the atmospheric pressure at sea level (hPA); as well as the concentrations of four atmospheric pollutants: NO2 – SO2 – O3 and PM10 (μg.m−3). Results All performances per year and race are normally distributed with distribution parameters (mean and standard deviation) that differ according to environmental factors. Air temperature and performance are significantly correlated through a quadratic model. The optimal temperatures for maximal mean speed of all runners vary depending on the performance level. When temperature increases above these optima, running speed decreases and withdrawal rates increase. Ozone also impacts performance but its effect might be linked to temperature. The other environmental parameters do not have any significant impact. Conclusions The large amount of data analyzed and the model developed in this study highlight the major influence of air temperature above all other climatic parameter on human running capacity and adaptation to race conditions. PMID:22649525

  1. Extraction of bowing parameters from violin performance combining motion capture and sensors.

    PubMed

    Schoonderwaldt, E; Demoucron, M

    2009-11-01

    A method is described for measurement of a complete set of bowing parameters in violin performance. Optical motion capture was combined with sensors for accurate measurement of the main bowing parameters (bow position, bow velocity, bow acceleration, bow-bridge distance, and bow force) as well as secondary control parameters (skewness, inclination, and tilt of the bow). In addition, other performance features (moments of on/off in bow-string contact, string played, and bowing direction) were extracted. Detailed descriptions of the calculations of the bowing parameters, features, and calibrations are given. The described system is capable of measuring all bowing parameters without disturbing the player, allowing for detailed studies of musically relevant aspects of bow control and coordination of bowing parameters in bowed-string instrument performance. PMID:19894846

  2. Additional deleterious effects of alcohol consumption on sperm parameters and DNA integrity in diabetic mice.

    PubMed

    Pourentezari, M; Talebi, A R; Mangoli, E; Anvari, M; Rahimipour, M

    2016-06-01

    The aim of this study was to survey the impact of alcohol consumption on sperm parameters and DNA integrity in experimentally induced diabetic mice. A total of 32 adult male mice were divided into four groups: mice of group 1 served as control fed on basal diet, group 2 received streptozotocin (STZ) (200 mg kg(-1) , single dose, intraperitoneal) and basal diet, group 3 received alcohol (10 mg kg(-1) , water soluble) and basal diet, and group 4 received STZ and alcohol for 35 days. The cauda epididymidis of each mouse was dissected and placed in 1 ml of pre-warm Ham's F10 culture medium for 30 min. The swim-out spermatozoa were analysed for count, motility, morphology and viability. Sperm chromatin quality was evaluated with aniline blue, toluidine blue, acridine orange and chromomycin A3 staining. The results showed that all sperm parameters had significant differences (P < 0.05), also when sperm chromatin was assessed with cytochemical tests. There were significant differences (P < 0.001) between the groups. According to our results, alcohol and diabetes can cause abnormalities in sperm parameters and chromatin quality. In addition, alcohol consumption in diabetic mice can intensify sperm chromatin/DNA damage. PMID:26358836

  3. Transferability and additivity of dihedral parameters in polarizable and nonpolarizable empirical force fields.

    PubMed

    Zgarbová, Marie; Rosnik, Andreana M; Luque, F Javier; Curutchet, Carles; Jurečka, Petr

    2015-09-30

    Recent advances in polarizable force fields have revealed that major reparameterization is necessary when the polarization energy is treated explicitly. This study is focused on the torsional parameters, which are crucial for the accurate description of conformational equilibria in biomolecules. In particular, attention is paid to the influence of polarization on the (i) transferability of dihedral terms between molecules, (ii) transferability between different environments, and (iii) additivity of dihedral energies. To this end, three polarizable force fields based on the induced point dipole model designed for use in AMBER are tested, including two recent ff02 reparameterizations. Attention is paid to the contributions due to short range interactions (1-2, 1-3, and 1-4) within the four atoms defining the dihedral angle. The results show that when short range 1-2 and 1-3 polarization interactions are omitted, as for instance in ff02, the 1-4 polarization contribution is rather small and unlikely to improve the description of the torsional energy. Conversely, when screened 1-2 and 1-3 interactions are included, the polarization contribution is sizeable and shows potential to improve the transferability of parameters between different molecules and environments as well as the additivity of dihedral terms. However, to reproduce intramolecular polarization effects accurately, further fine-tuning of the short range damping of polarization is necessary. PMID:26224547

  4. Predicting Performance on a Firefighter's Ability Test from Fitness Parameters

    ERIC Educational Resources Information Center

    Michaelides, Marcos A.; Parpa, Koulla M.; Thompson, Jerald; Brown, Barry

    2008-01-01

    The purpose of this project was to identify the relationships between various fitness parameters such as upper body muscular endurance, upper and lower body strength, flexibility, body composition and performance on an ability test (AT) that included simulated firefighting tasks. A second intent was to create a regression model that would predict…

  5. Human transfer functions used to predict system performance parameters

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Automatic, parameter-tracking, model-matching technique compares the responses of a human operator with those of an analog computer model of a human operator to predict and analyze the performance of mechanical or electromechanical systems prior to construction. Transfer functions represent the input-output relation of an operator controlling a closed-loop system.

  6. The improvement of rechargeable lithium battery electrolyte performance with additives

    NASA Technical Reports Server (NTRS)

    Dominey, L. A.; Goldman, J. L.

    1990-01-01

    The deliberate introduction of additives like 2-methylfuran (2-MeF) is known to improve Li cycleability in cyclic ether electrolytes. The authors found that the proclivity of 2-MeF to polymerize in the bulk electrolyte or on a TiS2 cathode was inhibited by the addition of reduced oxygen species, such as O2- and OH-. Additionally, the polymerization of tetrahydrofuran and dioxolane and the destructive processes initiated by AsF6- decomposition to AsF5 and AsF3 were inhibited by the introduction of reduced oxygen species, particularly OH- at the 10-ppm to 100-ppm level.

  7. Resin additive improves performance of high-temperature hydrocarbon lubricants

    NASA Technical Reports Server (NTRS)

    Johnson, R. L.; Loomis, W. R.

    1971-01-01

    Paraffinic resins, in high temperature applications, improve strength of thin lubricant film in Hertzian contacts even though they do not increase bulk oil viscosity. Use of resin circumvents corrosivity and high volatility problems inherent with many chemical additives.

  8. AMT-200S Motor Glider Parameter and Performance Estimation

    NASA Technical Reports Server (NTRS)

    Taylor, Brian R.

    2011-01-01

    Parameter and performance estimation of an instrumented motor glider was conducted at the National Aeronautics and Space Administration Dryden Flight Research Center in order to provide the necessary information to create a simulation of the aircraft. An output-error technique was employed to generate estimates from doublet maneuvers, and performance estimates were compared with results from a well-known flight-test evaluation of the aircraft in order to provide a complete set of data. Aircraft specifications are given along with information concerning instrumentation, flight-test maneuvers flown, and the output-error technique. Discussion of Cramer-Rao bounds based on both white noise and colored noise assumptions is given. Results include aerodynamic parameter and performance estimates for a range of angles of attack.

  9. Performance Evaluation and Parameter Identification on DROID III

    NASA Technical Reports Server (NTRS)

    Plumb, Julianna J.

    2011-01-01

    The DROID III project consisted of two main parts. The former, performance evaluation, focused on the performance characteristics of the aircraft such as lift to drag ratio, thrust required for level flight, and rate of climb. The latter, parameter identification, focused on finding the aerodynamic coefficients for the aircraft using a system that creates a mathematical model to match the flight data of doublet maneuvers and the aircraft s response. Both portions of the project called for flight testing and that data is now available on account of this project. The conclusion of the project is that the performance evaluation data is well-within desired standards but could be improved with a thrust model, and that parameter identification is still in need of more data processing but seems to produce reasonable results thus far.

  10. Simulation verification techniques study. Task report 4: Simulation module performance parameters and performance standards

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Shuttle simulation software modules in the environment, crew station, vehicle configuration and vehicle dynamics categories are discussed. For each software module covered, a description of the module functions and operational modes, its interfaces with other modules, its stored data, inputs, performance parameters and critical performance parameters is given. Reference data sources which provide standards of performance are identified for each module. Performance verification methods are also discussed briefly.

  11. EP Additive Performance in Biobased vs. Paraffinic Base Oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of commercial extreme pressure (EP) additives containing sulfur, phosphorus, and chlorine were investigated for their EP properties in soybean (SBO) and paraffinic (PRFN) base oils. The investigations were conducted using a 4-ball (4B) and twist-compression (TC) tribometers. The concentra...

  12. Effects of Video Games as Reinforcers for Computerized Addition Performance.

    ERIC Educational Resources Information Center

    Axelrod, Saul; And Others

    1987-01-01

    Four 2nd-grade students completed addition problems on a computer, using video games as reinforcers. Two variable ratio schedules of reinforcement failed to increase student accuracy or the rate of correct responses. In a no-games reinforcement condition, students had more opportunities to respond and had a greater number of correct answers.…

  13. Performance and safety parameters for the high flux isotope reactor

    SciTech Connect

    Ilas, G.; Primm III, T.

    2012-07-01

    A Monte Carlo depletion model for the High Flux Isotope Reactor (HFIR) Cycle 400 and its use in calculating parameters of relevance to the reactor performance and safety during the reactor cycle are presented in this paper. This depletion model was developed to serve as a reference for the design of a low-enriched uranium (LEU) fuel for an ongoing study to convert HFIR from high-enriched uranium (HEU) to LEU fuel; both HEU and LEU depletion models use the same methodology and ENDF/B-VII nuclear data as discussed in this paper. The calculated HFIR Cycle 400 parameters, which are compared with measurement data from critical experiments performed at HFIR, data included in the HFIR Safety Analysis Report (SAR), or data reported by previous calculations, provide a basis for verification or updating of the corresponding SAR data. (authors)

  14. Performance and Safety Parameters for the High Flux Isotope Reactor

    SciTech Connect

    Ilas, Germina; Primm, Trent

    2012-01-01

    A Monte Carlo depletion model for the High Flux Isotope Reactor (HFIR) Cycle 400 and its use in calculating parameters of relevance to the reactor performance and safety during the reactor cycle are presented in this paper. This depletion model was developed to serve as a reference for the design of a low-enriched uranium (LEU) fuel for an ongoing study to convert HFIR from high-enriched uranium (HEU) to LEU fuel; both HEU and LEU depletion models use the same methodology and ENDV/B-VII nuclear data as discussed in this paper. The calculated HFIR Cycle 400 parameters, which are compared when available with measurement data from critical experiments performed at HFIR, data included in the HFIR Safety Analysis Report (SAR), or data reported by previous calculations, provide a basis for verification or updating of the corresponding SAR data.

  15. The influence of non-solvent addition on the independent and dependent parameters in roller electrospinning of polyurethane.

    PubMed

    Cengiz-Callioglu, Funda; Jirsak, Oldrich; Dayik, Mehmet

    2013-07-01

    This paper discusses the effects of 1,1,2,2 tetrachlorethylen (TCE) non-solvent addition on the independent (electrical conductivity, dielectric constant, surface tension and the theological properties of the solution etc.) and dependent parameters (number of Taylor cones per square meter (NTC/m2), spinning performance for one Taylor cone (SP/TC), total spinning performance (SP), fiber properties such as diameter, diameter uniformity, non-fibrous area) in roller electrospinning of polyurethane (PU). The same process parameters (voltage, distance of the electrodes, humidity, etc.) were applied for all solutions during the spinning process. According to the results, the effect of TCE non-solvent concentration on the dielectric constant, surface tension, rheological properties of the solution and also spinning performance was important statistically. Beside these results, TCE non-solvent concentration effects quality of fiber and nano web structure. Generally high fiber density, low non-fibrous percentage and uniform nanofibers were obtained from fiber morphology analyses. PMID:23901497

  16. Blind Source Parameters for Performance Evaluation of Despeckling Filters.

    PubMed

    Biradar, Nagashettappa; Dewal, M L; Rohit, ManojKumar; Gowre, Sanjaykumar; Gundge, Yogesh

    2016-01-01

    The speckle noise is inherent to transthoracic echocardiographic images. A standard noise-free reference echocardiographic image does not exist. The evaluation of filters based on the traditional parameters such as peak signal-to-noise ratio, mean square error, and structural similarity index may not reflect the true filter performance on echocardiographic images. Therefore, the performance of despeckling can be evaluated using blind assessment metrics like the speckle suppression index, speckle suppression and mean preservation index (SMPI), and beta metric. The need for noise-free reference image is overcome using these three parameters. This paper presents a comprehensive analysis and evaluation of eleven types of despeckling filters for echocardiographic images in terms of blind and traditional performance parameters along with clinical validation. The noise is effectively suppressed using the logarithmic neighborhood shrinkage (NeighShrink) embedded with Stein's unbiased risk estimation (SURE). The SMPI is three times more effective compared to the wavelet based generalized likelihood estimation approach. The quantitative evaluation and clinical validation reveal that the filters such as the nonlocal mean, posterior sampling based Bayesian estimation, hybrid median, and probabilistic patch based filters are acceptable whereas median, anisotropic diffusion, fuzzy, and Ripplet nonlinear approximation filters have limited applications for echocardiographic images. PMID:27298618

  17. Blind Source Parameters for Performance Evaluation of Despeckling Filters

    PubMed Central

    Biradar, Nagashettappa; Dewal, M. L.; Rohit, ManojKumar; Gowre, Sanjaykumar; Gundge, Yogesh

    2016-01-01

    The speckle noise is inherent to transthoracic echocardiographic images. A standard noise-free reference echocardiographic image does not exist. The evaluation of filters based on the traditional parameters such as peak signal-to-noise ratio, mean square error, and structural similarity index may not reflect the true filter performance on echocardiographic images. Therefore, the performance of despeckling can be evaluated using blind assessment metrics like the speckle suppression index, speckle suppression and mean preservation index (SMPI), and beta metric. The need for noise-free reference image is overcome using these three parameters. This paper presents a comprehensive analysis and evaluation of eleven types of despeckling filters for echocardiographic images in terms of blind and traditional performance parameters along with clinical validation. The noise is effectively suppressed using the logarithmic neighborhood shrinkage (NeighShrink) embedded with Stein's unbiased risk estimation (SURE). The SMPI is three times more effective compared to the wavelet based generalized likelihood estimation approach. The quantitative evaluation and clinical validation reveal that the filters such as the nonlocal mean, posterior sampling based Bayesian estimation, hybrid median, and probabilistic patch based filters are acceptable whereas median, anisotropic diffusion, fuzzy, and Ripplet nonlinear approximation filters have limited applications for echocardiographic images. PMID:27298618

  18. 14 CFR 43.15 - Additional performance rules for inspections.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Airworthiness of the manufacturer concerned: (1) The drive shafts or similar systems. (2) The main rotor transmission gear box for obvious defects. (3) The main rotor and center section (or the equivalent area). (4) The auxiliary rotor on helicopters. (c) Annual and 100-hour inspections. (1) Each person performing...

  19. Walking boosts your performance in making additions and subtractions

    PubMed Central

    Anelli, Filomena; Lugli, Luisa; Baroni, Giulia; Borghi, Anna M.; Nicoletti, Roberto

    2014-01-01

    Previous research demonstrates that the processing of spatial information and numerical magnitude are strictly interwoven. Recent studies also provide converging evidence that number processing is influenced by body movements. In the present study we further investigate this issue by focusing on whether and how motions experienced with the whole body can influence arithmetical calculations. We asked participants to make additions or subtractions while experiencing leftward and rightward motions. Data revealed the emergence of a congruency effect between the orientation inferred by the type of arithmetical calculations and the type of motions experienced along an horizontal axis. PMID:25566137

  20. Parameter Estimation for a Physically-Based Model Using Multi-Objective Approach Constrained With Additional Internal States

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Fenicia, F.; Savenije, H. H.

    2007-12-01

    . Therefore, in addition to the use of stream flow measurements for model calibration and uncertainty analysis, groundwater table gauging data were also used to help constrain parameter space. In model parameter identification, objective functions in favor of both high flows and low flows were employed to optimize the model performance. Results of this study show that parameters for subsurface processes are better identifiable than those for surface processes. This work also demonstrates that MOSCEM-UA is an efficient tool in parameter identification giving more insight to the structural behavior of the model.

  1. An additional performance of HTRS: the waste radiotoxicity minimisation.

    PubMed

    Cerullo, N; Bufalino, D; Forasassi, G; Lomonaco, G; Rocchi, P; Romanello, V

    2005-01-01

    The management of radioactive waste is a key issue for the present and future use of nuclear energy. In this frame, high temperature reactors (HTRs) have, among others, the capability to burn actinides. After a short introduction on HTRs, the performances of two MC-based burnup codes (Monte Carlo continuous energy burnup and MONTEBURNS) in assessing the ability of these reactors to burn actinides are compared. These codes are necessary for performing ultra-high burnup calculations on HTRs. The best one, in this specific case, results to be MONTEBURNS. It was analysed using HTRs loaded with the following: (1) 1st generation Pu, 600 equivalent full power days; (2) 2nd generation Pu, 645 equivalent full power days; and (iii) 33% 1st generation Pu and 67% Th, 705 equivalent full power days. Finally, it is possible to conclude that HTRs can reduce time when the waste is considered dangerous. Even if the amount of reduction does not solve the whole problem, it represents an important step in the management of radioactive waste. PMID:16381696

  2. Performance analysis of flexible DSSC with binder addition

    NASA Astrophysics Data System (ADS)

    Muliani, Lia; Hidayat, Jojo; Anggraini, Putri Nur

    2016-04-01

    Flexible DSSC is one of modification of DSSC based on its substrate. Operating at low temperature, flexible DSSC requires a binder to improve particles interconnection. This research was done to compare the morphology and performance of flexible DSSC that was produced with binder-added and binder-free. TiO2 powder, butanol, and HCl were mixed for preparation of TiO2 paste. Small amount of titanium isopropoxide as binder was added into the mixture. TiO2 paste was deposited on ITO-PET plastic substrate with area of 1x1 cm2 by doctor blade method. Furthermore, SEM, XRD, and BET characterization were done to analyze morphology and surface area of the TiO2 photoelectrode microstructures. Dyed TiO2 photoelectrode and platinum counter electrode were assembled and injected by electrolyte. In the last process, flexible DSSCs were illuminated by sun simulator to do J-V measurement. As a result, flexible DSSC containing binder showed higher performance with photoconversion efficiency of 0.31%.

  3. Experimental investigation of design parameters on dry powder inhaler performance.

    PubMed

    Ngoc, Nguyen Thi Quynh; Chang, Lusi; Jia, Xinli; Lau, Raymond

    2013-11-30

    The study aims to investigate the impact of various design parameters of a dry powder inhaler on the turbulence intensities generated and the performance of the dry powder inhaler. The flow fields and turbulence intensities in the dry powder inhaler are measured using particle image velocimetry (PIV) techniques. In vitro aerosolization and deposition a blend of budesonide and lactose are measured using an Andersen Cascade Impactor. Design parameters such as inhaler grid hole diameter, grid voidage and chamber length are considered. The experimental results reveal that the hole diameter on the grid has negligible impact on the turbulence intensity generated in the chamber. On the other hand, hole diameters smaller than a critical size can lead to performance degradation due to excessive particle-grid collisions. An increase in grid voidage can improve the inhaler performance but the effect diminishes at high grid voidage. An increase in the chamber length can enhance the turbulence intensity generated but also increases the powder adhesion on the inhaler wall. PMID:24055597

  4. Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

    NASA Technical Reports Server (NTRS)

    Jansen, Ralph H.; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

    2016-01-01

    The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  5. Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

    NASA Technical Reports Server (NTRS)

    Jansen, Ralph; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

    2015-01-01

    The purpose of this presentation is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  6. Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

    NASA Technical Reports Server (NTRS)

    Jansen, Ralph H.; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

    2015-01-01

    The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  7. [Determination of seven additives in polymer products by ultra performance supercritical fluid chromatography].

    PubMed

    Zhang, Yun; Du, Zhenxia

    2014-01-01

    A method for rapid determination of seven commonly used additives in polymer products by ultra performance supercritical fluid chromatography (UPSFC)-photodiode array detector (PDA) was developed. In this experiment, the detection wavelength was set at 220 nm. After the important parameters of UPSFC, such as the diluting solvent, mobile phase additive, column temperature, automatic back pressure regulator (ABPR) and flow rate were investigated, the optimized conditions were acquired as follows: n-hexane/isopropanol (1/1, v/v) was chosen as the diluting solvent, the mixture of methanol/acetonitrile (1/1, v/v) as the mobile phase additive, 2 mL/min as the flow rate, 50 degrees C as the column temperature, 12.41 - 13.79 MPa as the ABPR. Under these conditions, seven additives were separated in 5 min, and full baseline separation was achieved. The real sample was pretreated by microwave-assisted extraction (MAE) and analyzed by UPSFC-PDA. The seven additives can be detected with the recoveries of 69.9% - 118.9%, and the relative standard deviations (RSDs, n = 9) were less than 10%. This method is simple, fast with good selectivity and suitable for the analysis of the additives in polymer products. PMID:24783869

  8. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium.

    PubMed

    Amin Yavari, S; Chai, Y C; Böttger, A J; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2015-06-01

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20V anodizing time: 30min to 3h) are used for anodizing porous titanium structures that were later heat treated at 500°C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500°C improve the cell culture response of porous titanium. PMID

  9. Method and system for monitoring and displaying engine performance parameters

    NASA Technical Reports Server (NTRS)

    Abbott, Terence S. (Inventor); Person, Jr., Lee H. (Inventor)

    1991-01-01

    The invention is a method and system for monitoring and directly displaying the actual thrust produced by a jet aircraft engine under determined operating conditions and the available thrust and predicted (commanded) thrust of a functional model of an ideal engine under the same determined operating conditions. A first set of actual value output signals representative of a plurality of actual performance parameters of the engine under the determined operating conditions is generated and compared with a second set of predicted value output signals representative of the predicted value of corresponding performance parameters of a functional model of the engine under the determined operating conditions to produce a third set of difference value output signals within a range of normal, caution, or warning limit values. A thrust indicator displays when any one of the actual value output signals is in the warning range while shaping function means shape each of the respective difference output signals as each approaches the limit of the respective normal, caution, and warning range limits.

  10. Key parameters controlling the performance of catalytic motors

    NASA Astrophysics Data System (ADS)

    Esplandiu, Maria J.; Afshar Farniya, Ali; Reguera, David

    2016-03-01

    The development of autonomous micro/nanomotors driven by self-generated chemical gradients is a topic of high interest given their potential impact in medicine and environmental remediation. Although impressive functionalities of these devices have been demonstrated, a detailed understanding of the propulsion mechanism is still lacking. In this work, we perform a comprehensive numerical analysis of the key parameters governing the actuation of bimetallic catalytic micropumps. We show that the fluid motion is driven by self-generated electro-osmosis where the electric field originates by a proton current rather than by a lateral charge asymmetry inside the double layer. Hence, the surface potential and the electric field are the key parameters for setting the pumping strength and directionality. The proton flux that generates the electric field stems from the proton gradient induced by the electrochemical reactions taken place at the pump. Surprisingly the electric field and consequently the fluid flow are mainly controlled by the ionic strength and not by the conductivity of the solution, as one could have expected. We have also analyzed the influence of the chemical fuel concentration, electrochemical reaction rates, and size of the metallic structures for an optimized pump performance. Our findings cast light on the complex chemomechanical actuation of catalytic motors and provide important clues for the search, design, and optimization of novel catalytic actuators.

  11. Key parameters controlling the performance of catalytic motors.

    PubMed

    Esplandiu, Maria J; Afshar Farniya, Ali; Reguera, David

    2016-03-28

    The development of autonomous micro/nanomotors driven by self-generated chemical gradients is a topic of high interest given their potential impact in medicine and environmental remediation. Although impressive functionalities of these devices have been demonstrated, a detailed understanding of the propulsion mechanism is still lacking. In this work, we perform a comprehensive numerical analysis of the key parameters governing the actuation of bimetallic catalytic micropumps. We show that the fluid motion is driven by self-generated electro-osmosis where the electric field originates by a proton current rather than by a lateral charge asymmetry inside the double layer. Hence, the surface potential and the electric field are the key parameters for setting the pumping strength and directionality. The proton flux that generates the electric field stems from the proton gradient induced by the electrochemical reactions taken place at the pump. Surprisingly the electric field and consequently the fluid flow are mainly controlled by the ionic strength and not by the conductivity of the solution, as one could have expected. We have also analyzed the influence of the chemical fuel concentration, electrochemical reaction rates, and size of the metallic structures for an optimized pump performance. Our findings cast light on the complex chemomechanical actuation of catalytic motors and provide important clues for the search, design, and optimization of novel catalytic actuators. PMID:27036470

  12. Effect of an Additional, Parallel Capacitor on Pulsed Inductive Plasma Accelerator Performance

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Sivak, Amy D.; Balla, Joseph V.

    2011-01-01

    A model of pulsed inductive plasma thrusters consisting of a set of coupled circuit equations and a one-dimensional momentum equation has been used to study the effects of adding a second, parallel capacitor into the system. The equations were nondimensionalized, permitting the recovery of several already-known scaling parameters and leading to the identification of a parameter that is unique to the particular topology studied. The current rise rate through the inductive acceleration coil was used as a proxy measurement of the effectiveness of inductive propellant ionization since higher rise rates produce stronger, potentially better ionizing electric fields at the coil face. Contour plots representing thruster performance (exhaust velocity and efficiency) and current rise rate in the coil were generated numerically as a function of the scaling parameters. The analysis reveals that when the value of the second capacitor is much less than the first capacitor, the performance of the two-capacitor system approaches that of the single-capacitor system. In addition, as the second capacitor is decreased in value the current rise rate can grow to be twice as great as the rise rate attained in the single capacitor case.

  13. The effects of scene content parameters, compression, and frame rate on the performance of analytics systems

    NASA Astrophysics Data System (ADS)

    Tsifouti, A.; Triantaphillidou, S.; Larabi, M. C.; Doré, G.; Bilissi, E.; Psarrou, A.

    2015-01-01

    In this investigation we study the effects of compression and frame rate reduction on the performance of four video analytics (VA) systems utilizing a low complexity scenario, such as the Sterile Zone (SZ). Additionally, we identify the most influential scene parameters affecting the performance of these systems. The SZ scenario is a scene consisting of a fence, not to be trespassed, and an area with grass. The VA system needs to alarm when there is an intruder (attack) entering the scene. The work includes testing of the systems with uncompressed and compressed (using H.264/MPEG-4 AVC at 25 and 5 frames per second) footage, consisting of quantified scene parameters. The scene parameters include descriptions of scene contrast, camera to subject distance, and attack portrayal. Additional footage, including only distractions (no attacks) is also investigated. Results have shown that every system has performed differently for each compression/frame rate level, whilst overall, compression has not adversely affected the performance of the systems. Frame rate reduction has decreased performance and scene parameters have influenced the behavior of the systems differently. Most false alarms were triggered with a distraction clip, including abrupt shadows through the fence. Findings could contribute to the improvement of VA systems.

  14. Performance and Probabilistic Verification of Regional Parameter Estimates for Conceptual Rainfall-runoff Models

    NASA Astrophysics Data System (ADS)

    Franz, K.; Hogue, T.; Barco, J.

    2007-12-01

    Identification of appropriate parameter sets for simulation of streamflow in ungauged basins has become a significant challenge for both operational and research hydrologists. This is especially difficult in the case of conceptual models, when model parameters typically must be "calibrated" or adjusted to match streamflow conditions in specific systems (i.e. some of the parameters are not directly observable). This paper addresses the performance and uncertainty associated with transferring conceptual rainfall-runoff model parameters between basins within large-scale ecoregions. We use the National Weather Service's (NWS) operational hydrologic model, the SACramento Soil Moisture Accounting (SAC-SMA) model. A Multi-Step Automatic Calibration Scheme (MACS), using the Shuffle Complex Evolution (SCE), is used to optimize SAC-SMA parameters for a group of watersheds with extensive hydrologic records from the Model Parameter Estimation Experiment (MOPEX) database. We then explore "hydroclimatic" relationships between basins to facilitate regionalization of parameters for an established ecoregion in the southeastern United States. The impact of regionalized parameters is evaluated via standard model performance statistics as well as through generation of hindcasts and probabilistic verification procedures to evaluate streamflow forecast skill. Preliminary results show climatology ("climate neighbor") to be a better indicator of transferability than physical similarities or proximity ("nearest neighbor"). The mean and median of all the parameters within the ecoregion are the poorest choice for the ungauged basin. The choice of regionalized parameter set affected the skill of the ensemble streamflow hindcasts, however, all parameter sets show little skill in forecasts after five weeks (i.e. climatology is as good an indicator of future streamflows). In addition, the optimum parameter set changed seasonally, with the "nearest neighbor" showing the highest skill in the

  15. Tensiomyography parameters and jumping and sprinting performance in Brazilian elite soccer players.

    PubMed

    Gil, Saulo; Loturco, Irineu; Tricoli, Valmor; Ugrinowitsch, Carlos; Kobal, Ronaldo; Abad, Cesar Cavinato Cal; Roschel, Hamilton

    2015-09-01

    Tensiomyography has been suggested as an indirect marker of muscle stiffness, which is associated with strength/power performance. Therefore, it is reasonable to suggest that tensiomyography parameters could be associated with power-related motor tasks. The purpose of this study was to investigate the association between tensiomyography parameters (from rectus and biceps femoris) and jumping and sprinting abilities in elite soccer players. In addition, we used tensiomyography parameters to compare the lateral symmetry between dominant and non-dominant legs. Twenty elite soccer players (age: 23.3 ± 4.8 years; height: 183.5 ± 6.6 cm; weight: 77.8 ± 7.5 kg) volunteered to participate in the study. Significant moderate negative correlations between biceps femoris displacement and contact time (r = -0.5, p = 0.03), rectus femoris displacement and contact time (r = -0.51, p = 0.02), and a significant moderate correlation between biceps femoris displacement and reactive strength index (r = 0.5, p = 0.03) were found. There were no correlations between tensiomyography parameters and power-related motor tasks. In addition, no differences in tensiomyography parameters between dominant and non-dominant legs were found. Our data suggest that tensiomyography parameters are not associated with power-related motor tasks performance in elite soccer players. PMID:26271313

  16. An Efficient Data Partitioning to Improve Classification Performance While Keeping Parameters Interpretable.

    PubMed

    Korjus, Kristjan; Hebart, Martin N; Vicente, Raul

    2016-01-01

    Supervised machine learning methods typically require splitting data into multiple chunks for training, validating, and finally testing classifiers. For finding the best parameters of a classifier, training and validation are usually carried out with cross-validation. This is followed by application of the classifier with optimized parameters to a separate test set for estimating the classifier's generalization performance. With limited data, this separation of test data creates a difficult trade-off between having more statistical power in estimating generalization performance versus choosing better parameters and fitting a better model. We propose a novel approach that we term "Cross-validation and cross-testing" improving this trade-off by re-using test data without biasing classifier performance. The novel approach is validated using simulated data and electrophysiological recordings in humans and rodents. The results demonstrate that the approach has a higher probability of discovering significant results than the standard approach of cross-validation and testing, while maintaining the nominal alpha level. In contrast to nested cross-validation, which is maximally efficient in re-using data, the proposed approach additionally maintains the interpretability of individual parameters. Taken together, we suggest an addition to currently used machine learning approaches which may be particularly useful in cases where model weights do not require interpretation, but parameters do. PMID:27564393

  17. An Efficient Data Partitioning to Improve Classification Performance While Keeping Parameters Interpretable

    PubMed Central

    Korjus, Kristjan; Hebart, Martin N.; Vicente, Raul

    2016-01-01

    Supervised machine learning methods typically require splitting data into multiple chunks for training, validating, and finally testing classifiers. For finding the best parameters of a classifier, training and validation are usually carried out with cross-validation. This is followed by application of the classifier with optimized parameters to a separate test set for estimating the classifier’s generalization performance. With limited data, this separation of test data creates a difficult trade-off between having more statistical power in estimating generalization performance versus choosing better parameters and fitting a better model. We propose a novel approach that we term “Cross-validation and cross-testing” improving this trade-off by re-using test data without biasing classifier performance. The novel approach is validated using simulated data and electrophysiological recordings in humans and rodents. The results demonstrate that the approach has a higher probability of discovering significant results than the standard approach of cross-validation and testing, while maintaining the nominal alpha level. In contrast to nested cross-validation, which is maximally efficient in re-using data, the proposed approach additionally maintains the interpretability of individual parameters. Taken together, we suggest an addition to currently used machine learning approaches which may be particularly useful in cases where model weights do not require interpretation, but parameters do. PMID:27564393

  18. Scaling Performance Assessments: A Comparison of One-Parameter and Two-Parameter Partial Credit Models.

    ERIC Educational Resources Information Center

    Fitzpatrick, Anne R.; And Others

    1996-01-01

    One-parameter (1PPC) and two-parameter partial credit (2PPC) models were compared using real and simulated data with constructed response items present. Results suggest that the more flexible three-parameter logistic-2PPC model combination produces better model fit than the combination of the one-parameter logistic and the 1PPC models. (SLD)

  19. Performance Parameters and Characterizations of Nanocrystals: A Brief Review.

    PubMed

    Chogale, Manasi M; Ghodake, Vinod N; Patravale, Vandana B

    2016-01-01

    Poor bioavailability of drugs associated with their poor solubility limits the clinical effectiveness of almost 40% of the newly discovered drug moieties. Low solubility, coupled with a high log p value, high melting point and high dose necessitates exploration of alternative formulation strategies for such drugs. One such novel approach is formulation of the drugs as "Nanocrystals". Nanocrystals are primarily comprised of drug and surfactants/stabilizers and are manufactured by "top-down" or "bottom-up" methods. Nanocrystals aid the clinical efficacy of drugs by various means such as enhancement of bioavailability, lowering of dose requirement, and facilitating sustained release of the drug. This effect is dependent on the various characteristics of nanocrystals (particle size, saturation solubility, dissolution velocity), which have an impact on the improved performance of the nanocrystals. Various sophisticated techniques have been developed to evaluate these characteristics. This article describes in detail the various characterization techniques along with a brief review of the significance of the various parameters on the performance of nanocrystals. PMID:27589788

  20. Effect of several geometric parameters on the static internal performance of three nonaxisymmetric nozzle concepts

    NASA Technical Reports Server (NTRS)

    Berrier, B. L.; Re, R. J.

    1979-01-01

    Effects of several geometric parameters on the internal performance of nonaxisymmetric convergent-divergent, single-ramp expansion, and wedge nozzles were investigated at nozzle pressure ratios up to approximately 10. In addition, two different thrust-vectoring schemes were investigated with the wedge nozzle. The results indicated that as with conventional round nozzles, peak nonaxisymmetric nozzle, internal performance occurred near the nozzle pressure ratio required for fully expanded exhaust flow. Nozzle sidewall length or area generally had little effect on the internal performance of the nozzles investigated.

  1. Effects of noise and mental task performance upon changes in cerebral blood flow parameters

    PubMed Central

    Nowakowska-Kotas, Marta; Pokryszko-Dragan, Anna; Brodowski, Mirosław; Szydło, Mariusz; Podemski, Ryszard

    2015-01-01

    The objectives of this paper were to determine whether traffic noise influences the parameters of cerebral blood flow (CBF) measured by functional transcranial Doppler sonography (fTCD) during the performance of mental tasks, and to see whether impact of noise on CBF changes with age. The study comprised 36 healthy volunteers, 22 women and 14 men, aged 25-49 years. The fTCD was performed using a fixed 2-MHz probe, aiming for an evaluation of mean velocity (MFV) and the pulsatility index (PI) in the middle cerebral artery (MCA) on both sides. Subsequently, fTCD was monitored: At rest; during performance of the Paced Auditory Serial Addition Test (PASAT); during exposure to traffic noise; and during concomitant exposure to noise and PASAT performance. MFV and PI were compared for particular conditions and correlated with age. During exposure to noise, flow parameters did not change significantly. PASAT performance in silence increased MFV and decreased PI in MCA on both sides. During PASAT performance, on exposure to noise, MCV and PI changed significantly only in the left MCA. However, values of MFV were significantly lower during noise than in silence. Correlations with age were noted for velocities in the right MCA during PASAT performance in silence and for PI on both sides during PASAT performed in noise conditions. Noise impairs the CBF during mental tasks. A comparison of changes in CBF parameters correlated with age suggests that the involvement of the nondominant hemisphere in managing with noise effects increases with age. PMID:26572702

  2. Effects of noise and mental task performance upon changes in cerebral blood flow parameters.

    PubMed

    Nowakowska-Kotas, Marta; Pokryszko-Dragan, Anna; Brodowski, Mirosław; Szydło, Mariusz; Podemski, Ryszard

    2015-01-01

    The objectives of this paper were to determine whether traffic noise influences the parameters of cerebral blood flow (CBF) measured by functional transcranial Doppler sonography (fTCD) during the performance of mental tasks, and to see whether impact of noise on CBF changes with age. The study comprised 36 healthy volunteers, 22 women and 14 men, aged 25-49 years. The fTCD was performed using a fixed 2-MHz probe, aiming for an evaluation of mean velocity (MFV) and the pulsatility index (PI) in the middle cerebral artery (MCA) on both sides. Subsequently, fTCD was monitored: At rest; during performance of the Paced Auditory Serial Addition Test (PASAT); during exposure to traffic noise; and during concomitant exposure to noise and PASAT performance. MFV and PI were compared for particular conditions and correlated with age. During exposure to noise, flow parameters did not change significantly. PASAT performance in silence increased MFV and decreased PI in MCA on both sides. During PASAT performance, on exposure to noise, MCV and PI changed significantly only in the left MCA. However, values of MFV were significantly lower during noise than in silence. Correlations with age were noted for velocities in the right MCA during PASAT performance in silence and for PI on both sides during PASAT performed in noise conditions. Noise impairs the CBF during mental tasks. A comparison of changes in CBF parameters correlated with age suggests that the involvement of the nondominant hemisphere in managing with noise effects increases with age. PMID:26572702

  3. Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

    NASA Astrophysics Data System (ADS)

    Turczyk, Sascha

    2016-04-01

    The determination of | V cb | using inclusive and exclusive (semi-)leptonic decays exhibits a long-standing tension of varying O(3σ ) significance. For the inclusive determination the decay rate is expanded in 1/ m b using heavy quark expansion, and from moments of physical observables the higher order heavy quark parameters are extracted from experimental data in order to assess | V cb | from the normalisation. The drawbacks are high correlations both theoretically as well as experimentally among these observables. We will scrutinise the inclusive determination in order to add a new and less correlated observable. This observable is related to the decay angle of the charged lepton and can help to constrain the important heavy quark parameters in a new way. It may validate the current seemingly stable extraction of | V cb | from inclusive decays or hints to possible issues, and even may be sensitive to New Physics operators.

  4. Scatterometry performance improvement by parameter and spectrum feed-forward

    NASA Astrophysics Data System (ADS)

    Li, Jie; Zangooie, Shahin; Boinapally, Karthik; Zou, Xi; Hu, Jiangtao; Liu, Zhuan; Yedur, Sanjay; Wilkens, Peter; Ver, Avraham; Cohen, Robert; Khamsepour, Babak

    2014-04-01

    Optical critical dimension (OCD) metrology using scatterometry has been widely adopted for fast and non-destructive in-line process control and yield improvement. Recently there has been increased interest in metrology performance enhancement through a holistic approach. We investigate the benefits of feed-forward of metrology information from prior process steps using samples from magnetic hard disk drive manufacturing. The scatterometry targets are composed of rather isolated gratings that are designed to have better correlation with device features. Two gratings, one with pitch ≍ 10CD, and the other with pitch ≍ 15CD, are measured at post develop and post reactive ion etch (RIE) steps. Two methods: parameter feed-forward (PFF) and spectrum feedforward (SFF) are studied in which the measurement results or spectrum collected on the blanket target at photo step are fed forward to the measurements on the grating structures at post develop or post RIE step. Compared with standard measurement without FF, for the more isolated grating at photo step, both PFF and SFF improve CD correlation from R2=0.96 to R2=0.975 using CD-SEM results measured on device as the reference. Dynamic precision and fleet measurement precision are improved by 20-60%. For post RIE step, PFF and SFF significantly improve CD correlation from R2=0.95, slope=1.09 to R2=0.975, slope=1.03 for the denser grating, and from R2=0.90, slope=0.79 to R2=0.96, slope=0.96 for the more isolated grating. Dynamic precision is generally improved by 20-40%. It is observed that both PFF and SFF are equally efficient in reducing parameter correlation for the application studied here.

  5. Investigation of measureable parameters that correlate with automatic target recognition performance in synthetic aperture sonar

    NASA Astrophysics Data System (ADS)

    Gazagnaire, Julia; Cobb, J. T.; Isaacs, Jason

    2015-05-01

    There is a desire in the Mine Counter Measure community to develop a systematic method to predict and/or estimate the performance of Automatic Target Recognition (ATR) algorithms that are detecting and classifying mine-like objects within sonar data. Ideally, parameters exist that can be measured directly from the sonar data that correlate with ATR performance. In this effort, two metrics were analyzed for their predictive potential using high frequency synthetic aperture sonar (SAS) images. The first parameter is a measure of contrast. It is essentially the variance in pixel intensity over a fixed partition of relatively small size. An analysis was performed to determine the optimum block size for this contrast calculation. These blocks were then overlapped in the horizontal and vertical direction over the entire image. The second parameter is the one-dimensional K-shape parameter. The K-distribution is commonly used to describe sonar backscatter return from range cells that contain a finite number of scatterers. An Ada-Boosted Decision Tree classifier was used to calculate the probability of classification (Pc) and false alarm rate (FAR) for several types of targets in SAS images from three different data sets. ROC curves as a function of the measured parameters were generated and the correlation between the measured parameters in the vicinity of each of the contacts and the ATR performance was investigated. The contrast and K-shape parameters were considered separately. Additionally, the contrast and K-shape parameter were associated with background texture types using previously labeled high frequency SAS images.

  6. Effect of argon addition on plasma parameters and dust charging in hydrogen plasma

    SciTech Connect

    Kakati, B. Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.; Saxena, Y. C.

    2014-10-28

    Experimental results on effect of adding argon gas to hydrogen plasma in a multi-cusp dusty plasma device are reported. Addition of argon modifies plasma density, electron temperature, degree of hydrogen dissociation, dust current as well as dust charge. From the dust charging profile, it is observed that the dust current and dust charge decrease significantly up to 40% addition of argon flow rate in hydrogen plasma. But beyond 40% of argon flow rate, the changes in dust current and dust charge are insignificant. Results show that the addition of argon to hydrogen plasma in a dusty plasma device can be used as a tool to control the dust charging in a low pressure dusty plasma.

  7. Radiation processing of thermoplastic starch by blending aromatic additives: Effect of blend composition and radiation parameters

    NASA Astrophysics Data System (ADS)

    Khandal, Dhriti; Mikus, Pierre-Yves; Dole, Patrice; Coqueret, Xavier

    2013-03-01

    This paper reports on the effects of electron beam (EB) irradiation on poly α-1,4-glucose oligomers (maltodextrins) in the presence of water and of various aromatic additives, as model blends for gaining a better understanding at a molecular level the modifications occurring in amorphous starch-lignin blends submitted to ionizing irradiation for improving the properties of this type of bio-based thermoplastic material. A series of aromatic compounds, namely p-methoxy benzyl alcohol, benzene dimethanol, cinnamyl alcohol and some related carboxylic acids namely cinnamic acid, coumaric acid, and ferulic acid, was thus studied for assessing the ability of each additive to counteract chain scission of the polysaccharide and induce interchain covalent linkages. Gel formation in EB-irradiated blends comprising of maltodextrin was shown to be dependent on three main factors: the type of aromatic additive, presence of glycerol, and irradiation dose. The chain scission versus grafting phenomenon as a function of blend composition and dose were studied using Size Exclusion Chromatography by determining the changes in molecular weight distribution (MWD) from Refractive Index (RI) chromatograms and the presence of aromatic grafts onto the maltodextrin chains from UV chromatograms. The occurrence of crosslinking was quantified by gel fraction measurements allowing for ranking the cross-linking efficiency of the additives. When applying the method to destructurized starch blends, gel formation was also shown to be strongly affected by the moisture content of the sample submitted to irradiation. The results demonstrate the possibility to tune the reactivity of tailored blend for minimizing chain degradation and control the degree of cross-linking.

  8. 20 CFR 666.110 - May a Governor require additional indicators of performance?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false May a Governor require additional indicators of performance? 666.110 Section 666.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... State Measures of Performance § 666.110 May a Governor require additional indicators of performance?...

  9. 20 CFR 666.110 - May a Governor require additional indicators of performance?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false May a Governor require additional indicators of performance? 666.110 Section 666.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... State Measures of Performance § 666.110 May a Governor require additional indicators of performance?...

  10. 20 CFR 666.110 - May a Governor require additional indicators of performance?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false May a Governor require additional indicators of performance? 666.110 Section 666.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... State Measures of Performance § 666.110 May a Governor require additional indicators of performance?...

  11. 20 CFR 666.110 - May a Governor require additional indicators of performance?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false May a Governor require additional indicators of performance? 666.110 Section 666.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... of Performance § 666.110 May a Governor require additional indicators of performance? Yes,...

  12. 20 CFR 666.110 - May a Governor require additional indicators of performance?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false May a Governor require additional indicators of performance? 666.110 Section 666.110 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... of Performance § 666.110 May a Governor require additional indicators of performance? Yes,...

  13. Effect of Geometric Parameters on the Performance of P-Type Junctionless Lateral Gate Transistors

    PubMed Central

    Larki, Farhad; Dehzangi, Arash; Md Ali, Sawal Hamid; Jalar, Azman; Islam, Md. Shabiul; Hamidon, Mohd Nizar; Majlis, Burhanuddin Yeop

    2014-01-01

    This paper examines the impact of two important geometrical parameters, namely the thickness and source/drain extensions on the performance of low doped p-type double lateral gate junctionless transistors (DGJLTs). The three dimensional Technology Computer-Aided Design simulation is implemented to calculate the characteristics of the devices with different thickness and source/drain extension and based on that, the parameters such as threshold voltage, transconductance and resistance in saturation region are analyzed. In addition, simulation results provide a physical explanation for the variation of device characteristics given by the variation of geometric parameters, mainly based on investigation of the electric field components and the carries density variation. It is shown that, the variation of the carrier density is the main factor which affects the characteristics of the device when the device's thickness is varied. However, the electric field is mainly responsible for variation of the characteristics when the source/drain extension is changed. PMID:24743692

  14. TCP performance in ATM networks: ABR parameter tuning and ABR/UBR comparisons

    SciTech Connect

    Chien Fang; Lin, A.

    1996-02-27

    This paper explores two issues on TOP performance over ATM networks: ABR parameter tuning and performance comparison of binary mode ABR with enhanced UBR services. Of the fifteen parameters defined for ABR, two parameters dominate binary mode ABR performance: Rate Increase Factor (RIF) and Rate Decrease Factor (RDF). Using simulations, we study the effects of these two parameters on TOP over ABR performance. We compare TOP performance with different ABR parameter settings in terms of through-puts and fairness. The effects of different buffer sizes and LAN/WAN distances are also examined. We then compare TOP performance with the best ABR parameter setting with corresponding UBR service enhanced with Early Packet Discard and also with a fair buffer allocation scheme. The results show that TOP performance over binary mode ABR is very sensitive to parameter value settings, and that a poor choice of parameters can result in ABR performance worse than that of the much less expensive UBR-EPD scheme.

  15. Clock performance as a critical parameter in navigation satellite systems

    NASA Technical Reports Server (NTRS)

    Anderle, R. J.

    1978-01-01

    The high performance of available oscillators has permitted the development of invaluable navigation and geodetic satellite systems. However, still higher performance oscillators would further improve the accuracy or flexibility of the systems.

  16. Superposition-additive approach: thermodynamic parameters of clusterization of monosubstituted alkanes at the air/water interface.

    PubMed

    Vysotsky, Yu B; Belyaeva, E A; Fomina, E S; Fainerman, V B; Aksenenko, E V; Vollhardt, D; Miller, R

    2011-12-21

    The applicability of the superposition-additive approach for the calculation of the thermodynamic parameters of formation and atomization of conjugate systems, their dipole electric polarisabilities, molecular diamagnetic susceptibilities, π-electron circular currents, as well as for the estimation of the thermodynamic parameters of substituted alkanes, was demonstrated earlier. Now the applicability of the superposition-additive approach for the description of clusterization of fatty alcohols, thioalcohols, amines, carboxylic acids at the air/water interface is studied. Two superposition-additive schemes are used that ensure the maximum superimposition of the graphs of the considered molecular structures including the intermolecular CH-HC interactions within the clusters. The thermodynamic parameters of clusterization are calculated for dimers, trimers and tetramers. The calculations are based on the values of enthalpy, entropy and Gibbs' energy of clusterization calculated earlier using the semiempirical quantum chemical PM3 method. It is shown that the proposed approach is capable of the reproduction with sufficiently enough accuracy of the values calculated previously. PMID:22042000

  17. Optimization of laser butt welding parameters with multiple performance characteristics

    NASA Astrophysics Data System (ADS)

    Sathiya, P.; Abdul Jaleel, M. Y.; Katherasan, D.; Shanmugarajan, B.

    2011-04-01

    This paper presents a study carried out on 3.5 kW cooled slab laser welding of 904 L super austenitic stainless steel. The joints have butts welded with different shielding gases, namely argon, helium and nitrogen, at a constant flow rate. Super austenitic stainless steel (SASS) normally contains high amount of Mo, Cr, Ni, N and Mn. The mechanical properties are controlled to obtain good welded joints. The quality of the joint is evaluated by studying the features of weld bead geometry, such as bead width (BW) and depth of penetration (DOP). In this paper, the tensile strength and bead profiles (BW and DOP) of laser welded butt joints made of AISI 904 L SASS are investigated. The Taguchi approach is used as a statistical design of experiment (DOE) technique for optimizing the selected welding parameters. Grey relational analysis and the desirability approach are applied to optimize the input parameters by considering multiple output variables simultaneously. Confirmation experiments have also been conducted for both of the analyses to validate the optimized parameters.

  18. Evaluation of potential performance additives for the advanced lithium bromide chiller

    SciTech Connect

    Reiner, R.H.; Del Cul, W.; Perez-Blanco, H.; Ally, M.R.; Zaltash, A.

    1991-04-01

    The effectiveness and stability of potential heat-and-mass transfer (performance) additives for an advanced lithium bromide (LiBr) chiller were evaluated in a series of experimental studies. These studies of additive effectiveness and stability were necessary because many currently used performance additives decompose at the high generator temperatures (220{degrees}C to 260{degrees}C) desired for this particular advanced LiBr chiller. For example, one common performance additive, 2-ethyl-l-hexanol (2EH), reacts with the corrosion inhibitor, lithium chromate (Li{sub 2}CrO{sub 4}), even at moderate generator temperatures ({ge}180{degrees}C). These stability problems can be mitigated by using less reactive corrosion inhibitors such as lithium molybdate (Li{sub 2}MoO{sub 4}) and by using more stable performance additives such as 1-heptanol (HEP) or 1H,1H,7H-dodecafluoro-1-heptanol (DFH). There seems to be a trade-off between additive stability and effectiveness: the most effective performance additives are not the most stable additives. These studies indicate that HEP or DFH may be effective additives in the advanced LiBr chiller if Li{sub 2}MoO{sub 4} is used as a corrosion inhibitor.

  19. Effect of Operating Parameters and Chemical Additives on Crystal Habit and Specific Cake Resistance of Zinc Hydroxide Precipitates

    SciTech Connect

    Alwin, Jennifer Louise

    1999-08-01

    The effect of process parameters and chemical additives on the specific cake resistance of zinc hydroxide precipitates was investigated. The ability of a slurry to be filtered is dependent upon the particle habit of the solid and the particle habit is influenced by certain process variables. The process variables studied include neutralization temperature, agitation type, and alkalinity source used for neutralization. Several commercially available chemical additives advertised to aid in solid/liquid separation were also examined in conjunction with hydroxide precipitation. A statistical analysis revealed that the neutralization temperature and the source of alkalinity were statistically significant in influencing the specific cake resistance of zinc hydroxide precipitates in this study. The type of agitation did not significantly effect the specific cake resistance of zinc hydroxide precipitates. The use of chemical additives in conjunction with hydroxide precipitation had a favorable effect on the filterability. The morphology of the hydroxide precipitates was analyzed using scanning electron microscopy.

  20. High Energy Density Additives for Hybrid Fuel Rockets to Improve Performance and Enhance Safety

    NASA Technical Reports Server (NTRS)

    Jaffe, Richard L.

    2014-01-01

    We propose a conceptual study of prototype strained hydrocarbon molecules as high energy density additives for hybrid rocket fuels to boost the performance of these rockets without compromising safety and reliability. Use of these additives could extend the range of applications for which hybrid rockets become an attractive alternative to conventional solid or liquid fuel rockets. The objectives of the study were to confirm and quantify the high enthalpy of these strained molecules and to assess improvement in rocket performance that would be expected if these additives were blended with conventional fuels. We confirmed the chemical properties (including enthalpy) of these additives. However, the predicted improvement in rocket performance was too small to make this a useful strategy for boosting hybrid rocket performance.

  1. Investigation into Spectral Parameters as they Impact CPV Module Performance

    SciTech Connect

    Muller, M.; Marion, B.; Kurtz, S.; Rodriguez, J.

    2011-03-01

    The CPV industry is well aware that performance of triple junction cells depends on spectral conditions but there is a lack of data quantifying this spectral dependence at the module level. This paper explores the impact of precipitable water vapor, aerosol optical depth (AOD), and optical air mass on multiple CPV module technologies on-sun in Golden, CO.

  2. Assembling probabilistic performance parameters of shale-gas wells

    USGS Publications Warehouse

    Cook, Troy; Charpentier, Ronald R.

    2010-01-01

    Shale-gas well productivity estimates in USGS assessments from 1995 to present are based on studies that require decline curve fits and analysis to a large sample or to all wells within a particular assessment unit. Probabilistic type curves can be created on nearly any size well group and were designed for use within a resource context. The probabilistic type curve was designed to improve on the familiar format of a deterministic type curve by showing the full range of production possibilities for a given group of wells. Additional information was added to make certain components, such as data density and nonproducing wells, more explicit.

  3. Guidebook for performance assessment parameters used in the Waste Isolation Pilot Plant compliance certification application. Volume 2: Appendices

    SciTech Connect

    Howarth, S.M.; Martell, M.A.; Weiner, R.; Lattier, C.

    1998-06-01

    The Waste Isolation Pilot Plant (WIPP) Compliance Certification Application (CCA) Performance Assessment (PA) Parameter Database and its ties to supporting information evolved over the course of two years. When the CCA was submitted to the Environmental Protection Agency (EPA) in October 1996, information such as identification of parameter value or distribution source was documented using processes established by Sandia National Laboratories WIPP Quality Assurance Procedures. Reviewers later requested additional supporting documentation, links to supporting information, and/or clarification for many parameters. This guidebook is designed to document a pathway through the complex parameter process and help delineate flow paths to supporting information for all WIPP CCA parameters. In addition, this report is an aid for understanding how model parameters used in the WIPP CCA were developed and qualified. To trace the source information for a particular parameter, a dual-route system was established. The first route uses information from the Parameter Records package as it existed when the CCA calculations were run. The second route leads from the EPA Parameter Database to additional supporting information.

  4. Guidebook for performance assessment parameters used in the Waste Isolation Pilot Plant compliance certification application. Volume 1: Main report

    SciTech Connect

    Howarth, S.M.; Martell, M.A.; Weiner, R.; Lattier, C.

    1998-06-01

    The Waste Isolation Pilot Plant (WIPP) Compliance Certification Application (CCA) Performance Assessment (PA) Parameter Database and its ties to supporting information evolved over the course of two years. When the CCA was submitted to the Environmental Protection Agency (EPA) in October 1996, information such as identification of parameter value or distribution source was documented using processes established by Sandia National Laboratories WIPP Quality Assurance Procedures. Reviewers later requested additional supporting documentation, links to supporting information, and/or clarification for many parameters. This guidebook is designed to document a pathway through the complex parameter process and help delineate flow paths to supporting information for all WIPP CCA parameters. In addition, this report is an aid for understanding how model parameters used in the WIPP CCA were developed and qualified. To trace the source information for a particular parameter, a dual-route system was established. The first route uses information from the Parameter Records Package as it existed when the CCA calculations were run. The second route leads from the EPA Parameter Database to additional supporting information.

  5. The effect of additional design parameters on the LQR based design of a control/structural system

    NASA Technical Reports Server (NTRS)

    Bainum, Peter M.; Xu, Jianke

    1990-01-01

    A multiobjective cost function that includes a form of the standard LQR regulator cost and its partial variation with respect to the additional design parameters is presented in connection with the design of an orbiting control/structural system. Simple models of uniform solid and tubular beams are demonstrated with two typical additional payload masses, i.e., symmetrically distributed and asymmetrically distributed, with respect to the center of the beam. By regarding the transient response of pitch angle and free-free beam deformations in the orbital plane, the optimal outer diameter of the beam and all feedback control can be determined by numerical analysis with this multicriterial approach. It is concluded that the multicriteria design approach should give better results from both the structural designer's and the control designer's standpoints.

  6. Determination of the Performance Parameters of a Spectrophotometer: An Advanced Experiment.

    ERIC Educational Resources Information Center

    Cope, Virgil W.

    1978-01-01

    Describes an advanced analytical chemistry laboratory experiment developed for the determination of the performance parameters of a spectrophotometer. Among the parameters are the baseline linearity with wavelength, wavelength accuracy and respectability, stray light, noise level and pen response time. (HM)

  7. Regression analysis of technical parameters affecting nuclear power plant performances

    SciTech Connect

    Ghazy, R.; Ricotti, M. E.; Trueco, P.

    2012-07-01

    Since the 80's many studies have been conducted in order to explicate good and bad performances of commercial nuclear power plants (NPPs), but yet no defined correlation has been found out to be totally representative of plant operational experience. In early works, data availability and the number of operating power stations were both limited; therefore, results showed that specific technical characteristics of NPPs were supposed to be the main causal factors for successful plant operation. Although these aspects keep on assuming a significant role, later studies and observations showed that other factors concerning management and organization of the plant could instead be predominant comparing utilities operational and economic results. Utility quality, in a word, can be used to summarize all the managerial and operational aspects that seem to be effective in determining plant performance. In this paper operational data of a consistent sample of commercial nuclear power stations, out of the total 433 operating NPPs, are analyzed, mainly focusing on the last decade operational experience. The sample consists of PWR and BWR technology, operated by utilities located in different countries, including U.S. (Japan)) (France)) (Germany)) and Finland. Multivariate regression is performed using Unit Capability Factor (UCF) as the dependent variable; this factor reflects indeed the effectiveness of plant programs and practices in maximizing the available electrical generation and consequently provides an overall indication of how well plants are operated and maintained. Aspects that may not be real causal factors but which can have a consistent impact on the UCF, as technology design, supplier, size and age, are included in the analysis as independent variables. (authors)

  8. Failure of the addition of fresh seminal plasma to cryopreserved-thawed sperm to improve semen parameters.

    PubMed

    Check, D J; Check, M L; Bollendorf, A; Check, J H

    1993-01-01

    Previous data has shown that subnormal motility in some semen specimens can be improved by the addition of fresh human seminal plasma (HSP). However, if the HSP was first frozen the motility-enhancing factor was lost. We hypothesized that some of the reduction in sperm motility of cryopreserved-thawed sperm may be related to damage of the "motility-enhancing factor" of HSP. This study evaluated whether the addition of fresh HSP could improve the motility of frozen-thawed sperm. Each frozen-thawed specimen was evaluated for motile density and hypoosmotic swelling and then divided into two aliquots. Equal volumes of HSP, human tubal fluid (HTF), and control media were added and the semen parameters were reevaluated. The mean scores for motile density and percent motility did not change compared with baseline thawed volumes with either HSP or HTF additives. There were some isolated cases that did improve with either HSP (21%) or HTF (14%). Future studies are needed to determine whether this improvement is coincidental or consistent, and to determine whether at least some individuals can benefit from the addition of fresh HSP to frozen-thawed sperm. PMID:8215691

  9. Evaluation of Yucca schidigera extract as feed additive on performance of broiler chicks in winter season

    PubMed Central

    Sahoo, Sarada Prasanna; Kaur, Daljeet; Sethi, A. P. S.; Sharma, A.; Chandra, M.

    2015-01-01

    Aim: Yucca schidigera extract has been successfully used as feed additives in the poultry industry. It enhances the growth and productivity in broiler production. Hence, the present study was designed to analyze the effect of Y. schidigera extract in growth, carcass quality and behavior along with its economical utility in broiler rearing. Materials and Methods: Total, 120 numbers of day-old broiler chicks of equal sex ratio were randomly divided into Yucca supplemented treatment and control group, each having 60 birds in three replications of 20 numbers. The feeding management and rearing conditions were similar for all the groups as per the standard except the Yucca supplementation in the treatment group @ 125 mg/kg of feed. The parameters with respect to growth, carcass, behavior, and litter content were recorded as per standard procedures. Results: The Yucca supplementation can effectively enhance growth of 173 g in 6th week by utilizing lesser feed intake than control group, which ultimately proves better feed conversion rate, protein efficiency ratio, and energy efficiency ratio in broiler production. Eviscerated weight of 58.50% for the treatment group was significantly higher (p<0.05) than 54.10% in the control group. The breast meat yield of Yucca group (32.23%) was significantly higher (p<0.05) than control (30.33%). More frequency of agonistic behavioral expressions was noticed in the control group than the treatment group. A profit of 43.68% was received by usage of Yucca supplementation in the diet on live weight basis. Numerically, lower percentage of moisture was present in Yucca treated group than the control. Conclusion: From this study, it can be concluded that Yucca supplementation has an important role in augmenting broiler‘s growth performance, efficiency to utilize feed, protein and energy, and survivability. Hence, use of Yucca powder in broiler ration could be beneficial to maintain the litter quality, which directly enhances the

  10. Role of anaerobic fungi in wheat straw degradation and effects of plant feed additives on rumen fermentation parameters in vitro.

    PubMed

    Dagar, S S; Singh, N; Goel, N; Kumar, S; Puniya, A K

    2015-01-01

    In the present study, rumen microbial groups, i.e. total rumen microbes (TRM), total anaerobic fungi (TAF), avicel enriched bacteria (AEB) and neutral detergent fibre enriched bacteria (NEB) were evaluated for wheat straw (WS) degradability and different fermentation parameters in vitro. Highest WS degradation was shown for TRM, followed by TAF, NEB and least by AEB. Similar patterns were observed with total gas production and short chain fatty acid profiles. Overall, TAF emerged as the most potent individual microbial group. In order to enhance the fibrolytic and rumen fermentation potential of TAF, we evaluated 18 plant feed additives in vitro. Among these, six plant additives namely Albizia lebbeck, Alstonia scholaris, Bacopa monnieri, Lawsonia inermis, Psidium guajava and Terminalia arjuna considerably improved WS degradation by TAF. Further evaluation showed A. lebbeck as best feed additive. The study revealed that TAF plays a significant role in WS degradation and their fibrolytic activities can be improved by inclusion of A. lebbeck in fermentation medium. Further studies are warranted to elucidate its active constituents, effect on fungal population and in vivo potential in animal system. PMID:25391347

  11. Relationships between blood lactate parameters and endurance performance

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Charilaos

    The purpose of this study was to determine if one lactate threshold definition, as determined from an incremental maximal exercise test, correlates the best with the average speed of running during two different distances (10 km and 21.1 km). Thirteen well-trained runners (age: 30.9 +/- 2.2 yrs; height: 179.9 +/- 1.2 cm; weight: 70.5 +/- 1.8 kg; body fat: 8.5 +/- 1.0%; V˙O2max: 65.3 +/- 1.0 ml·kg -1·min-1) completed an incremental maximal exercise test to determine their individual lactate profile, one 10 km and one half marathon time trial (TT) on a treadmill. During these trials, oxygen consumption, heart rate, and blood responses were measured. Blood samples were collected through a venous catheter placed in an antecubital vein to determine lactate responses. Correlation coefficients between the running velocity at the different LT definitions and the average running speed during each time trial were calculated using Pearson's correlation coefficient. A dependent t-test was used to determine statistical difference for the mean lactate response between the two running distances and a two-way ANOVA was used to determine the difference between trials over time. All the lactate threshold definitions were significantly correlated (r ≥ 0.59; p < 0.05) with both distances. The LTlog was the definition with the highest correlation for both 10 km time trial (r = 0.926) and the half marathon (r = 0.906). The mean lactate concentration during the 10 km time trial (3.52 +/- 0.4 mmol/L) was significantly higher than the mean lactate concentration during the half marathon (1.86 +/- 0.3 mmol/L). These results indicate that any point on the lactate profile curve correlates with running performance with LTlog providing the highest correlation. However, the LT log was not the best indicator for each individual for each distance, indicating that there is a need to consider individual differences.

  12. Hematological parameters in Polish mixed breed rabbits with addition of meat breed blood in the annual cycle.

    PubMed

    Tokarz-Deptuła, B; Niedźwiedzka-Rystwej, P; Adamiak, M; Hukowska-Szematowicz, B; Trzeciak-Ryczek, A; Deptuła, W

    2015-01-01

    In the paper we studied haematologic values, such as haemoglobin concentration, haematocrit value, thrombocytes, leucocytes: lymphocytes, neutrophils, basophils, eosinophils and monocytes in the pheral blood in Polish mixed-breeds with addition of meat breed blood in order to obtain the reference values which are until now not available for this animals. In studying this indices we took into consideration the impact of the season (spring, summer, autumn, winter), and sex of the animals. The studies have shown a high impact of the season of the year on those rabbits, but only in spring and summer. Moreover we observed that the sex has mean impact on the studied values of haematological parameters in those rabbits. According to our knowledge, this is the first paper on haematologic values in this widely used group of rabbits, so they may serve as reference values. PMID:26812808

  13. Optimal welding parameters for very high power ultrasonic additive manufacturing of smart structures with aluminum 6061 matrix

    NASA Astrophysics Data System (ADS)

    Wolcott, Paul J.; Hehr, Adam; Dapino, Marcelo J.

    2014-03-01

    Ultrasonic additive manufacturing (UAM) is a recent solid state manufacturing process that combines ad- ditive joining of thin metal tapes with subtractive milling operations to generate near net shape metallic parts. Due to the minimal heating during the process, UAM is a proven method of embedding Ni-Ti, Fe-Ga, and PVDF to create active metal matrix composites. Recently, advances in the UAM process utilizing 9 kW very high power (VHP) welding has improved bonding properties, enabling joining of high strength materials previously unweldable with 1 kW low power UAM. Consequently, a design of experiments study was conducted to optimize welding conditions for aluminum 6061 components. This understanding is critical in the design of UAM parts containing smart materials. Build parameters, including weld force, weld speed, amplitude, and temperature were varied based on a Taguchi experimental design matrix and tested for me- chanical strength. Optimal weld parameters were identi ed with statistical methods including a generalized linear model for analysis of variance (ANOVA), mean e ects plots, and interaction e ects plots.

  14. Effect of combinations of additives on the performance of lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Santee, Stuart; Xiao, Ang; Yang, Li; Gnanaraj, Joe; Lucht, Brett L.

    Commercial lithium-ion batteries have excellent performance at room temperature for a few years. However, the calendar life and thermal stability (>50 °C) need to be improved for many applications, including electric vehicles. We have conducted an investigation of the effect of thermal stabilizing additives, including dimethyl acetamide, vinylene carbonate, and lithium bis(oxalato) borate, on the performance of lithium ion batteries stored at 70 °C for one month. The reactions of the lithium hexafluorophosphate/carbonate electrolyte, with and without electrolyte additives, with the surface of the electrodes after initial formation cycling have been analyzed via a combination of IR-ATR and XPS.

  15. Effect of Fuel Additives on Spray Performance of Alternative Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2015-11-01

    Role of alternative fuels on reducing the combustion pollutants is gaining momentum in both land and air transport. Recent studies have shown that addition of nanoscale metal particles as fuel additives to liquid fuels have a positive effect not only on their combustion performance but also in reducing the pollutant formation. However, most of those studies are still in the early stages of investigation with the addition of nanoparticles at low weight percentages. Such an addition can affect the hydrodynamic and thermo-physical properties of the fuel. In this study, the near nozzle spray performance of gas-to-liquid jet fuel with and without the addition of alumina nanoparticles are investigated at macro- and microscopic levels using optical diagnostic techniques. At macroscopic level, the addition of nanoparticles is seen to enhance the sheet breakup process when compared to that of the base fuel. Furthermore, the microscopic spray characteristics such as droplet size and velocity are also found to be affected. Although the addition of nanoscale metal particles at low weight percentages does not affect the bulk fluid properties, the atomization process is found to be affected in the near nozzle region. Funded by Qatar National Research Fund.

  16. [Influence Additional Cognitive Tasks on EEG Beta Rhythm Parameters during Forming and Testing Set to Perception of the Facial Expression].

    PubMed

    Yakovenko, I A; Cheremushkin, E A; Kozlov, M K

    2015-01-01

    The research of changes of a beta rhythm parameters on condition of working memory loading by extension of a interstimuli interval between the target and triggering stimuli to 16 sec is investigated on 70 healthy adults in two series of experiments with set to a facial expression. In the second series at the middle of this interval for strengthening of the load was entered the additional cognitive task in the form of conditioning stimuli like Go/NoGo--circles of blue or green color. Data analysis of the research was carried out by means of continuous wavelet-transformation on the basis of "mather" complex Morlet-wavelet in the range of 1-35 Hz. Beta rhythm power was characterized by the mean level, maxima of wavelet-transformation coefficient (WLC) and latent periods of maxima. Introduction of additional cognitive task to pause between the target and triggering stimuli led to essential increase in absolute values of the mean level of beta rhythm WLC and relative sizes of maxima of beta rhythm WLC. In the series of experiments without conditioning stimulus subjects with large number of mistakes (from 6 to 40), i.e. rigid set, in comparison with subjects with small number of mistakes (to 5), i.e. plastic set, at the forming stage were characterized by higher values of the mean level of beta rhythm WLC. Introduction of the conditioning stimuli led to smoothing of intergroup distinctions throughout the experiment. PMID:26601500

  17. Strategies and Performance in Elementary Students' Three-Digit Mental Addition

    ERIC Educational Resources Information Center

    Csíkos, Csaba

    2016-01-01

    The focus of this study is the relationship between students' performance in mental calculation and the strategies they use when solving three-digit mental addition problems. The sample comprises 78 4th grade students (40 boys and 38 girls). Their mean age was 10 years and 4 months. The main novelties of the current research include (1)…

  18. Effect of additives on electrochemical performance of lithium nickel cobalt manganese oxide at high temperature

    NASA Astrophysics Data System (ADS)

    Kang, Kyoung Seok; Choi, Suneui; Song, JunHo; Woo, Sang-Gil; Jo, Yong Nam; Choi, Jungkyu; Yim, Taeeun; Yu, Ji-Sang; Kim, Young-Jun

    2014-05-01

    Lithium-nickel-cobalt-manganese oxide, Li[NixCoyMnz]O2 (NCM) is a low-cost cathode material with a high capacity and a moderately high rate capability, however, it still suffers from poor electrochemical performance. In this study, several types of additives are attempted to enhance the surface stability of high-Ni-content (Ni ≥ 60%) cathodes and the most effective additive turns out to be PS. The cycle performance in the presence of 2% PS is much improved at a high temperature of 60 °C: (1) 98.9% of its initial capacity is preserved, (2) the increase in thickness is only 17.9%, preventing undesired swellings, and (3) gases are not generated in large amounts with the internal pressure being 56.4 kPa. The FT-IR spectroscopy results suggest that the surface of the cathode in the presence of 2% PS is covered with a film of alkyl sulfone components (RSOSR and RSO2SR), which is possibly formed by the electrochemical oxidation of PS. The current results confirm that the electrochemical performance of Ni-rich cathodes can be improved via the appropriate use of additives. They also indicate that among the tested additive candidates in this study, PS is highly desirable for enhancing the electrochemical performance of Ni-rich cathodes.

  19. Efficacy of a feed-additive antibacterial combination for improving feedlot cattle performance and health.

    PubMed Central

    Gallo, G F; Berg, J L

    1995-01-01

    The effectiveness of a feed-additive antimicrobial combination for improving feedlot performance and health was tested using 4325 high-risk feeder calves randomly allocated to a control group or an experimental group. The experimental group received the conventional ration plus a feed additive containing 700 mg per head/day of chlortetracycline and sulfamethazine from arrival at the feedlot to day 56 of the feeding period. The inclusion of the feed additive to the ration significantly improved average daily gain for days 0-28 (P = 0.0163) and 0-56 (P = 0.0001), and the feed conversion for days 0-28 (P = 0.0061) and 0-56 (P = 0.0004). Additionally, the use of the feed additive significantly reduced the rate of bovine respiratory disease morbidity for days 0-28 (P = 0.0014) and 0-56 (P = 0.0001), the rate of relapses and mortality for days 0-56 (P = 0.0151 and P = 0.0209, respectively), and the rate of animals diagnosed with chronic respiratory disease for days 0-28 and 0-56 (P = 0.0009 and P = 0.0002, respectively). Performance and health improvements produced by the use of the feed additive were cost-effective. PMID:7600512

  20. Effects of montmorillonite addition on the performance of starch-based wood adhesive.

    PubMed

    Li, Zhaofeng; Wang, Jian; Li, Caiming; Gu, Zhengbiao; Cheng, Li; Hong, Yan

    2015-01-22

    Effects of montmorillonite (MMT) addition on the performance of corn starch-based wood adhesive were investigated. It was found that MMT addition could enhance the shear strength of the starch-based wood adhesive. The shear strength of the adhesive with 5% (w/w, dry starch basis) MMT reached 10.6 MPa in the dry state, which was almost twice that of the same adhesive without MMT. Addition of 5% MMT also produced an approximately 1.2-fold increase in the shear strength in the wet state. Although this addition caused an increase in the viscosity, the resulting adhesive retained both good mobility and viscosity stability during storage. MMT also enhanced the shear-thinning and solid-like behaviors of the adhesive, compared with the adhesive without MMT. Finally, MMT addition improved the thermal stability of the adhesive. In conclusion, addition of MMT to starch-based wood adhesives can improve their overall performance, enhancing their value as alternatives for traditional petrochemical-based wood adhesives. PMID:25439910

  1. Effect of buoyancy and power design parameters on hybrid airship performance

    NASA Technical Reports Server (NTRS)

    Talbot, P. D.; Gelhausen, P. A.

    1983-01-01

    The effects of several design parameters on the performance of hybrid airships having rotors and propellers were examined with a simple mathematical model. The parameters included buoyancy ratio, Froude number, ratio of rotor power to total power, and rotor shaft tilt. Performance variations resulting from changes in these parameters were calculated, and are presented and discussed. Performance quantities included best climb rate, equivalent vehicle L/D, and maximum speed. Performance at all speeds between hover and maximum speed was found to be sensitive to power distribution between rotors and propellers, and to rotor shaft tilt.

  2. Effects of structure parameters on the sensor performance of photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Xiao, Rui; Rong, Zhen; Pang, Yuanfeng; Bo, Xiaochen

    2015-02-01

    A simple and compact sensor based on a photonic crystal fiber (PCF) for the in-situ detection of fluorescence signals with high sensitivity is demonstrated. Several different kinds of PCF probes are studied. The effect of PCF parameters on sensitivity and the guiding mechanisms are analyzed, and the performance of PCF probes is experimentally evaluated by measuring the fluorescence signal of Cy3 dye. In addition, the detection sensitivity of the hollow-core PCF probe and the flat-tippedmulti-mode fiber probe is compared. The experimental results show that the hollow-core PCF probe provides a greater than five-fold increase in detection sensitivity compared with direct measurements by a flat-tippedmulti-mode fiber probe, which shows its potential for wide applications to in-situ detection in the medical, forensic, biological, geological, and environmental fields with high sensitivity.

  3. Pyramidal Fin Arrays Performance Using Streamwise Anisotropic Materials by Cold Spray Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Cormier, Yannick; Dupuis, Philippe; Jodoin, Bertrand; Corbeil, Antoine

    2016-01-01

    This work evaluates the thermal and hydrodynamic performance of pyramidal fin arrays produced using cold spray as an additive manufacturing process. Near-net-shaped pyramidal fin arrays of pure aluminum, pure nickel, and stainless steel 304 were manufactured. Fin array characterization such as fin porosity level and surface roughness evaluation was performed. The thermal conductivities of the three different coating materials were measured by laser flash analysis. The results obtained show a lower thermal efficiency for stainless steel 304, whereas the performances of the aluminum and nickel fin arrays are similar. This result is explained by looking closely at the fin and substrate roughness induced by the cold gas dynamic additive manufacturing process. The multi-material fin array sample has a better thermal efficiency than stainless steel 304. The work demonstrates the potential of the process to produce streamwise anisotropic fin arrays as well as the benefits of such arrays.

  4. Evaluating mixtures of 14 hygroscopic additives to improve antibody microarray performance.

    PubMed

    Bergeron, Sébastien; Laforte, Veronique; Lo, Pik-Shan; Li, Huiyan; Juncker, David

    2015-11-01

    Microarrays allow the miniaturization and multiplexing of biological assays while only requiring minute amounts of samples. As a consequence of the small volumes used for spotting and the assays, evaporation often deteriorates the quality, reproducibility of spots, and the overall assay performance. Glycerol is commonly added to antibody microarray printing buffers to decrease evaporation; however, it often decreases the binding of antibodies to the surface, thereby negatively affecting assay sensitivity. Here, combinations of 14 hygroscopic chemicals were used as additives to printing buffers for contact-printed antibody microarrays on four different surface chemistries. The ability of the additives to suppress evaporation was quantified by measuring the residual buffer volume in open quill pins over time. The seven best additives were then printed either individually or as a 1:1 mixture of two additives, and the homogeneity, intensity, and reproducibility of both the spotted protein and of a fluorescently labeled analyte in an assay were quantified. Among the 28 combinations on the four slides, many were found to outperform glycerol, and the best additive mixtures were further evaluated by changing the ratio of the two additives. We observed that the optimal additive mixture was dependent on the slide chemistry, and that it was possible to increase the binding of antibodies to the surface threefold compared to 50 % glycerol, while decreasing whole-slide coefficient of variation to 5.9 %. For the two best slides, improvements were made for both the limit of detection (1.6× and 5.9×, respectively) and the quantification range (1.2× and 2.1×, respectively). The additive mixtures identified here thus help improve assay reproducibility and performance, and might be beneficial to all types of microarrays that suffer from evaporation of the printing buffers. PMID:26345442

  5. Influence of electrolyte co-additives on the performance of dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Stergiopoulos, Thomas; Rozi, Evangelia; Karagianni, Chaido-Stefania; Falaras, Polycarpos

    2011-12-01

    The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs). The most effective additives are 4- tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work, we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high as 8% were obtained.

  6. Ultimate strength performance of tankers associated with industry corrosion addition practices

    NASA Astrophysics Data System (ADS)

    Kim, Do Kyun; Kim, Han Byul; Zhang, Xiaoming; Li, Chen Guang; Paik, Jeom Kee

    2014-09-01

    In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSRH) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures

  7. Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system.

    PubMed

    Serna-Galvis, Efraím A; Silva-Agredo, Javier; Giraldo-Aguirre, Ana L; Torres-Palma, Ricardo A

    2015-08-15

    Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20-60 W), dissolved gas (air, Ar and He), pH (3-11) and initial concentration of fluoxetine (2.9-162.0 μmol L(-1)). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe(2+)) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. PMID:25912531

  8. Nano-Fe as feed additive improves the hematological and immunological parameters of fish, Labeo rohita H.

    NASA Astrophysics Data System (ADS)

    Behera, T.; Swain, P.; Rangacharulu, P. V.; Samanta, M.

    2014-08-01

    An experiment was conducted to compare the effects of iron oxide nanoparticles ( T 1) and ferrous sulfate ( T 2) on Indian major carp, Labeo rohita H. There were significant differences ( P < 0.05) in the final weight of T 1 and T 2 compared with the control. Survival rates were not affected by the dietary treatments. Fish fed a basal diet (control) showed lower ( P < 0.05) iron content in muscle compared to T 1 and T 2. Furthermore, the highest value ( P < 0.05) of iron content was observed in T 1. In addition, RBCs and hemoglobin levels were significantly higher in T 1 as compared to other treated groups. Different innate immune parameters such as respiratory burst activity, bactericidal activity and myeloperoxidase activity were higher in nano-Fe-treated diet ( T 1) as compared to other iron source ( T 2) and control in 30 days post-feeding. Moreover, nano-Fe appeared to be more effective ( P < 0.05) than ferrous sulfate in increasing muscle iron and hemoglobin contents. Dietary administration of nano-Fe did not cause any oxidative damage, but improved antioxidant enzymatic activities (SOD and GSH level) irrespective of different iron sources in the basal diet.

  9. A study of the effects of an additional sound source on RASS performance

    SciTech Connect

    Coulter, R.L.

    1998-12-31

    The Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site of the Atmospheric Radiation Measurements (ARM) Program continuously operates a nine panel 915 MHz wind profiler with Radio Acoustic Sounding System (RASS), measuring wind profiles for 50 minutes and virtual temperature profiles for the remaining 10 minutes during each hour. It is well recognized that one of the principal limits on RASS performance is high horizontal wind speed that moves the acoustic wave front sufficiently to prevent the microwave energy produced by the radar and scattered from the acoustic wave from being reflected back t the radar antenna. With this limitation in mind, the ARM program purchased an additional, portable acoustic source that could be mounted on a small trailer and placed in strategic locations to enhance the RASS performance (when it was not being used for spare parts). A test of the resulting improvement in RASS performance was performed during the period 1995--1997.

  10. The use of performance parameters in monitoring the safety of dams experiencing alkali-aggregate reaction

    SciTech Connect

    Veesaert, C.J.; LaBoon, J.H.

    1995-12-31

    As the Bureau of Reclamation (Reclamation) moves away from design and construction of new water resource projects toward optimizing the management of existing water resource projects, monitoring the condition of high risk structures such as dams becomes very important. To address this need, Reclamation has developed a logical approach of monitoring the safety of a dam over time. This approach analyzes visual and instrumentation performance parameters unique to each dam, Performance parameters specify the expected performance (behavior) of both embankment and concrete dams, including those concrete dams effected by alkali-aggregate reaction. This paper presents an overview of the concept of performance parameters in monitoring the safety of dams, which have experienced alkali-aggregate reaction. Three case studies are presented to illustrate the use of performance parameters in monitoring a dam`s behavior over time, relative to the effects of alkali-aggregate reaction.

  11. Antisolvent precipitation of novel xylitol-additive crystals to engineer tablets with improved pharmaceutical performance.

    PubMed

    Kaialy, Waseem; Maniruzzaman, Mohammad; Shojaee, Saeed; Nokhodchi, Ali

    2014-12-30

    The purpose of this work was to develop stable xylitol particles with modified physical properties, improved compactibility and enhanced pharmaceutical performance without altering polymorphic form of xylitol. Xylitol was crystallized using antisolvent crystallization technique in the presence of various hydrophilic polymer additives, i.e., polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) at a range of concentrations. The crystallization process did not influence the stable polymorphic form or true density of xylitol. However, botryoidal-shaped crystallized xylitols demonstrated different particle morphologies and lower powder bulk and tap densities in comparison to subangular-shaped commercial xylitol. Xylitol crystallized without additive and xylitol crystallized in the presence of PVP or PVA demonstrated significant improvement in hardness of directly compressed tablets; however, such improvement was observed to lesser extent for xylitol crystallized in the presence of PEG. Crystallized xylitols produced enhanced dissolution profiles for indomethacin in comparison to original xylitol. The influence of additive concentration on tablet hardness was dependent on the type of additive, whereas an increased concentration of all additives provided an improvement in the dissolution behavior of indomethacin. Antisolvent crystallization using judiciously selected type and concentration of additive can be a potential approach to prepare xylitol powders with promising physicomechanical and pharmaceutical properties. PMID:25447824

  12. Determining System Parameters for Optimal Performance of Hybrid DS/FFH Spread-Spectrum

    SciTech Connect

    Ma, Xiao; Olama, Mohammed M; Kuruganti, Phani Teja; Smith, Stephen Fulton; Djouadi, Seddik M

    2012-01-01

    In recent years there has been great interest in using hybrid spread-spectrum (HSS) techniques for commercial applications, particularly in the Smart Grid, in addition to their use in military communications because they accommodate high data rates with high link integrity, even in the presence of significant multipath effects and interfering signals. A highly useful form of this transmission technique for many types of command, control, and sensing applications is the specific code-related combination of standard direct sequence (DS) modulation with "fast" frequency hopping (FFH), denoted hybrid DS/FFH, wherein multiple frequency hops occur within a single data-bit time. In this paper, an optimization problem is formulated that maximizes the DS/FFH communication system performance in terms of probability of bit error and solves for the system design parameters. The objective function is non-convex and can be solved by applying the Karush-Kuhn-Tucker conditions. System design parameters of interest are the length of the DS code sequence, number of frequency hopping channels, number of channels corrupted by wide-band jamming, and number of hops per bit. The proposed formulation takes into account the effects from wide-band and partial-band jamming, multi-user interference and/or varying degrees of Rayleigh and Rician multipath fading. Numerical results are presented to demonstrate the method s viability.

  13. Use of pyrocatechol violet as an effective redox additive for highly promoting the supercapacitor performances

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Nie, Yong Fu; Chen, Xiang Ying; Xiao, Zheng Hui; Zhang, Zhong Jie

    2016-08-01

    In present work, we demonstrate a simple but effective redox additive of pyrocatechol violet (abbr. PCV) to largely promote the capacitive performances especially when carried out in three different kinds of electrolytes (H2SO4, Na2SO4 and KOH), mostly due to its fast electron and proton transfer occurring in the electrode/electrolyte interface. It reveals that the PCV dosage incorporated into electrolyte plays a crucial role in the determination of capacitive performance. When conducted in a two-electrode system, incorporating 0.06 mol L-1 PCV into 1 mol L-1 H2SO4 can achieve large capacitance up to 200 F g-1, which is almost 2.06 times than the one without the addition of PCV; besides, the corresponding energy density is of 28 Wh kg-1 (also increasing 2 times). What's more, PCV has been extended as the redox additive in other electrolytes such as Na2SO4 and KOH, and remarkable promotion in capacitance and energy density also occur, well evincing the high efficiency and universal applicability of PCV for the large promotion of supercapacitors' performances due to its prominent electrochemical reversibility and high solubility.

  14. Performance of peaky template matching under additive white Gaussian noise and uniform quantization

    NASA Astrophysics Data System (ADS)

    Horvath, Matthew S.; Rigling, Brian D.

    2015-05-01

    Peaky template matching (PTM) is a special case of a general algorithm known as multinomial pattern matching originally developed for automatic target recognition of synthetic aperture radar data. The algorithm is a model- based approach that first quantizes pixel values into Nq = 2 discrete values yielding generative Beta-Bernoulli models as class-conditional templates. Here, we consider the case of classification of target chips in AWGN and develop approximations to image-to-template classification performance as a function of the noise power. We focus specifically on the case of a uniform quantization" scheme, where a fixed number of the largest pixels are quantized high as opposed to using a fixed threshold. This quantization method reduces sensitivity to the scaling of pixel intensities and quantization in general reduces sensitivity to various nuisance parameters difficult to account for a priori. Our performance expressions are verified using forward-looking infrared imagery from the Army Research Laboratory Comanche dataset.

  15. Performance on paced serial addition tasks indicates an associative network for calculation.

    PubMed

    Hiscock, M; Caroselli, J S; Kimball, L E; Panwar, N

    2001-06-01

    Although paced serial addition (PSA) tasks are considered to be tests of general information-processing capacity, recent work suggests that performance on such tasks is influenced by arithmetic-specific variables. We designed two visual PSA experiments to determine whether the performance of normal adults would support predictions derived from the cognitive psychology of calculation. Experiment 1 showed that mixing familiar (Arabic numeral) and less familiar (Roman numeral) stimulus formats reduced scores below the averaged scores for pure Arabic and Roman lists. The Roman-Arabic order of addends was more difficult than the Arabic-Roman order. Experiment 2, which involved only Arabic numerals as addends, showed that performance could be impaired by constraining the trial-to-trial variability of sums. The results of both experiments confirm the importance of arithmetic-specific variables in PSA and provide support for an associative network model of calculation. In addition, the findings implicate interference from extraneous addends and responses as the performance-limiting factor. PMID:11404809

  16. A study on the performance of synthetic type charts when process parameters are estimated

    NASA Astrophysics Data System (ADS)

    You, Huay Woon; Khoo, Michael Boon Chong; Teh, Sin Yin

    2015-10-01

    There are two types of synthetic charts for monitoring the process mean, i.e. synthetic X ¯ chart and synthetic double sampling X ¯ chart (SDS X ¯ chart). In most applications, the process parameters, such as the in-control mean and the in-control standard deviation are usually unknown. Under such circumstances, both these process parameters need to be estimated from an in-control Phase I dataset. Thus, it is vital to study the performance of these charts when the process parameters are unknown. In this paper, the performance of two synthetic type charts with estimated process parameters will be studied. The average number of observations to signal (ANOS) criterion will be used to evaluate the performances of these charts. This study shows that the performances of synthetic type charts are significantly affected by the estimation of process parameters. Furthermore, a large number of Phase I samples is required so that the synthetic type charts with estimated process parameters will have reasonable performances as their corresponding known process parameters counterparts, especially when the sample size and size of process mean shift is small.

  17. Adaptive neuro-fuzzy inference system (ANFIS) to predict CI engine parameters fueled with nano-particles additive to diesel fuel

    NASA Astrophysics Data System (ADS)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive neuro-fuzzy inference system (ANFIS) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For ANFIS modelling, Gaussian curve membership function (gaussmf) and 200 training epochs (iteration) were found to be optimum choices for training process. The results demonstrate that ANFIS is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve combustion of the fuel and reduce the exhaust emissions significantly.

  18. Performance evaluation and parameter sensitivity of energy-harvesting shock absorbers on different vehicles

    NASA Astrophysics Data System (ADS)

    Guo, Sijing; Liu, Yilun; Xu, Lin; Guo, Xuexun; Zuo, Lei

    2016-07-01

    Traditional shock absorbers provide favourable ride comfort and road handling by dissipating the suspension vibration energy into heat waste. In order to harvest this dissipated energy and improve the vehicle fuel efficiency, many energy-harvesting shock absorbers (EHSAs) have been proposed in recent years. Among them, two types of EHSAs have attracted much attention. One is a traditional EHSA which converts the oscillatory vibration into bidirectional rotation using rack-pinion, ball-screw or other mechanisms. The other EHSA is equipped with a mechanical motion rectifier (MMR) that transforms the bidirectional vibration into unidirectional rotation. Hereinafter, they are referred to as NonMMR-EHSA and MMR-EHSA, respectively. This paper compares their performances with the corresponding traditional shock absorber by using closed-form analysis and numerical simulations on various types of vehicles, including passenger cars, buses and trucks. Results suggest that MMR-EHSA provides better ride performances than NonMMR-EHSA, and that MMR-EHSA is able to improve both the ride comfort and road handling simultaneously over the traditional shock absorber when installed on light-damped, heavy-duty vehicles. Additionally, the optimal parameters of MMR-EHSA are obtained for ride comfort. The optimal solutions ('Pareto-optimal solutions') are also obtained by considering the trade-off between ride comfort and road handling.

  19. Improvement of capacitive performances of symmetric carbon/carbon supercapacitors by addition of nanostructured polypyrrole powder

    NASA Astrophysics Data System (ADS)

    Benhaddad, L.; Gamby, J.; Makhloufi, L.; Pailleret, A.; Pillier, F.; Takenouti, H.

    2016-03-01

    A nanostructured polypyrrole powder was synthesized in a previous work from the oxidation of pyrrole by a nanostructured MnO2 powder used simultaneously as an oxidizing agent and a sacrificial template in a redox heterogeneous mechanism. In this study, this original PPy powder was used as an active additive material with different ratio in carbon/carbon symmetrical supercapacitors whose performances were studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) using a Swagelok-type cell. From the EIS spectra, the complex capacitance was extracted using a model involving two Cole-Cole type complex capacitances linked in series. The specific capacitance values evaluated by EIS and cyclic voltammetry are in a good agreement between them. The results show that the addition of nanostructured polypyrrole powder improves significantly the specific capacitance of the carbon electrode and consequently the performances of carbon/carbon supercapacitors. The original and versatile synthesis method used to produce this polypyrrole powder appears to be attractive for large scale production of promising additives for electrode materials of supercapacitors.

  20. Comparison of the tribology performance of nano-diesel soot and graphite particles as lubricant additives

    NASA Astrophysics Data System (ADS)

    Zhang, Zu-chuan; Cai, Zhen-bing; Peng, Jin-fang; Zhu, Min-hao

    2016-02-01

    The tribology behavior of exhaust diesel soot as a lubricant additive was investigated and then compared with that of a selection of commercial nano-graphite particles. Specifically, 0.01 wt% particles were dispersed in PAO4 oil with 1 wt% sorbitan monooleate (Span 80) as a dispersing agent, and wear tests based on the ball against plate mode were conducted at various temperatures. Different analytical techniques (e.g. transmission electron, scanning electron and infrared microscopy; energy dispersive x-ray and Raman spectroscopy; and charge measurement) were employed to characterize the chemistry and morphology of the additives and their tribology performance. The oil containing only 0.01 wt% diesel soot clearly improved wear resistance over 60 °C. In particular, at 100 °C the wear rate decreased by approximately 90% compared to the function of base oil. In the same test conditions, diesel soot exhibited better anti-wear performance than nano-graphite at high temperatures. The potential measure showed that the nano-graphite had positive charge and the diesel soot had negative charge. Electrochemical action may play an important role in the lubricant mechanisms of diesel soot and graphite as oil additives.

  1. Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters

    NASA Technical Reports Server (NTRS)

    Karmali, M. S.; Phatak, A. V.

    1982-01-01

    Results of a study to investigate, by means of a computer simulation, the performance sensitivity of helicopter IMC DSAL operations as a function of navigation system parameters are presented. A mathematical model representing generically a navigation system is formulated. The scenario simulated consists of a straight in helicopter approach to landing along a 6 deg glideslope. The deceleration magnitude chosen is 03g. The navigation model parameters are varied and the statistics of the total system errors (TSE) computed. These statistics are used to determine the critical navigation system parameters that affect the performance of the closed-loop navigation, guidance and control system of a UH-1H helicopter.

  2. Improving the performance of ammonia-water absorption cycles using salt additives and membranes

    SciTech Connect

    Ibrahim, O.M.; Barnett, S.M.; Balamuru, V.G.

    1997-12-31

    This paper proposes a new design of an ammonia-water absorption refrigeration cycle for low-temperature heat sources such as solar energy and waste heat. The proposed cycle uses a salt additive to shift the chemical equilibrium toward more effective separation of ammonia molecules from aqueous solution (i.e., salting out). Since salt additives can affect all aspects of the absorption cycle, membranes have been chosen to control the flow of ions in the cycle and limit their effects to the generation side. This paper describes an absorption cycle that uses membrane separation processes, such as reverse osmosis, dialysis, and electrodialysis. To optimize the performance of the cycle, however, the membranes and salts must be carefully chosen.

  3. Winter-time CO2 addition in high rate algal mesocosms for enhanced microalgal performance.

    PubMed

    Sutherland, Donna L; Montemezzani, Valerio; Mehrabadi, Abbas; Craggs, Rupert J

    2016-02-01

    Carbon limitation in domestic wastewater high rate algal ponds is thought to constrain microalgal photo-physiology and productivity and CO2 augmentation is often used to overcome this limitation in summer. However, the implications of carbon limitation during winter are poorly understood. This paper investigates the effects of 0.5%, 2%, 5% and 10% CO2 addition on the winter-time performance of wastewater microalgae in high rate algal mesocosms. Performance was measured in terms of light absorption, photosynthetic efficiency, biomass production and nutrient removal rates, along with community composition. Varying percentage CO2 addition and associated change in culture pH resulted in 3 distinct microalgal communities. Light absorption by the microalgae increased by up to 144% with CO2 addition, while a reduction in the package effect meant that there was less internal self-shading thereby increasing the efficiency of light absorption. Carbon augmentation increased the maximum rate of photosynthesis by up to 172%, which led to increased microalgal biovolume by up to 181% and an increase in total organic biomass for all treatments except 10% CO2. While 10% CO2 improved light absorption and photosynthesis this did not translate to enhanced microalgal productivity. Increased microalgal productivity with CO2 addition did not result in increased dissolved nutrient (nitrogen and phosphorus) removal. This experiment demonstrated that winter-time carbon augmentation up to 5% CO2 improved microalgal light absorption and utilisation, which ultimately increased microalgal biomass and is likely to enhance total annual microalgal areal productivity in HRAPs. PMID:26707731

  4. Measures of GCM Performance as Functions of Model Parameters Affecting Clouds and Radiation

    NASA Astrophysics Data System (ADS)

    Jackson, C.; Mu, Q.; Sen, M.; Stoffa, P.

    2002-05-01

    This abstract is one of three related presentations at this meeting dealing with several issues surrounding optimal parameter and uncertainty estimation of model predictions of climate. Uncertainty in model predictions of climate depends in part on the uncertainty produced by model approximations or parameterizations of unresolved physics. Evaluating these uncertainties is computationally expensive because one needs to evaluate how arbitrary choices for any given combination of model parameters affects model performance. Because the computational effort grows exponentially with the number of parameters being investigated, it is important to choose parameters carefully. Evaluating whether a parameter is worth investigating depends on two considerations: 1) does reasonable choices of parameter values produce a large range in model response relative to observational uncertainty? and 2) does the model response depend non-linearly on various combinations of model parameters? We have decided to narrow our attention to selecting parameters that affect clouds and radiation, as it is likely that these parameters will dominate uncertainties in model predictions of future climate. We present preliminary results of ~20 to 30 AMIPII style climate model integrations using NCAR's CCM3.10 that show model performance as functions of individual parameters controlling 1) critical relative humidity for cloud formation (RHMIN), and 2) boundary layer critical Richardson number (RICR). We also explore various definitions of model performance that include some or all observational data sources (surface air temperature and pressure, meridional and zonal winds, clouds, long and short-wave cloud forcings, etc...) and evaluate in a few select cases whether the model's response depends non-linearly on the parameter values we have selected.

  5. Enhanced performance of polymer:fullerene bulk heterojunction solar cells upon graphene addition

    SciTech Connect

    Robaeys, Pieter Dierckx, Wouter; Dexters, Wim; Spoltore, Donato; Drijkoningen, Jeroen; Bonaccorso, Francesco; Bourgeois, Emilie; D'Haen, Jan; Haenen, Ken; Manca, Jean V.; Nesladek, Milos; Liesenborgs, Jori; Van Reeth, Frank; Lombardo, Antonio; Ferrari, Andrea C.

    2014-08-25

    Graphene has potential for applications in solar cells. We show that the short circuit current density of P3HT (Poly(3-hexylthiophene-2,5-diyl):PCBM((6,6)-Phenyl C61 butyric acid methyl ester) solar cells is enhanced by 10% upon the addition of graphene, with a 15% increase in the photon to electric conversion efficiency. We discuss the performance enhancement by studying the crystallization of P3HT, as well as the electrical transport properties. We show that graphene improves the balance between electron and hole mobilities with respect to a standard P3HT:PCBM solar cell.

  6. Greek research reactor performance characteristics after addition of beryllium reflector and LEU fuel

    SciTech Connect

    Deen, J.R.; Snelgrove, J.L.; Papastergiou, C.

    1992-12-31

    The GRR-1 is a 5-MW pool-type, light-water-moderated and-cooled reactor fueled with MTR-type fuel elements. Recently received Be reflector blocks will soon be added to the core to add additional reactivity until fresh LEU fuel arrives. REBUS-3 xy fuel cycle analyses, using burnup dependent cross sections, were performed to assist in fuel management decisions for the water- and Be-reflected HEU nonequilibrium cores. Cross sections generated by EPRI-CELL have been benchmarked to identical VIM Monte Carlo models. The size of the Be-reflected LEU core has been reduced to 30 elements compared to 35 for the HEU water-reflected core, and an equilibrium cycle calculation has been performed.

  7. Greek research reactor performance characteristics after addition of beryllium reflector and LEU fuel

    SciTech Connect

    Deen, J.R.; Snelgrove, J.L. ); Papastergiou, C. )

    1992-01-01

    The GRR-1 is a 5-MW pool-type, light-water-moderated and-cooled reactor fueled with MTR-type fuel elements. Recently received Be reflector blocks will soon be added to the core to add additional reactivity until fresh LEU fuel arrives. REBUS-3 xy fuel cycle analyses, using burnup dependent cross sections, were performed to assist in fuel management decisions for the water- and Be-reflected HEU nonequilibrium cores. Cross sections generated by EPRI-CELL have been benchmarked to identical VIM Monte Carlo models. The size of the Be-reflected LEU core has been reduced to 30 elements compared to 35 for the HEU water-reflected core, and an equilibrium cycle calculation has been performed.

  8. Physiological and performance changes from the addition of a sprint interval program to wrestling training.

    PubMed

    Farzad, Babak; Gharakhanlou, Reza; Agha-Alinejad, Hamid; Curby, David G; Bayati, Mahdi; Bahraminejad, Morteza; Mäestu, Jarek

    2011-09-01

    Increasing the level of physical fitness for competition is the primary goal of any conditioning program for wrestlers. Wrestlers often need to peak for competitions several times over an annual training cycle. Additionally, the scheduling of these competitions does not always match an ideal periodization plan and may require a modified training program to achieve a high level of competitive fitness in a short-time frame. The purpose of this study was to examine the effects of 4 weeks of sprint-interval training (SIT) program, on selected aerobic and anaerobic performance indices, and hormonal and hematological adaptations, when added to the traditional Iranian training of wrestlers in their preseason phase. Fifteen trained wrestlers were assigned to either an experimental (EXP) or a control (CON) group. Both groups followed a traditional preparation phase consisting of learning and drilling technique, live wrestling and weight training for 4 weeks. In addition, the EXP group performed a running-based SIT protocol. The SIT consisted of 6 35-m sprints at maximum effort with a 10-second recovery between each sprint. The SIT protocol was performed in 2 sessions per week, for the 4 weeks of the study. Before and after the 4-week training program, pre and posttesting was performed on each subject on the following: a graded exercise test (GXT) to determine VO(2)max, the velocity associated with V(2)max (νVO(2)max), maximal ventilation, and peak oxygen pulse; a time to exhaustion test (T(max)) at their νVO(2)max; and 4 successive Wingate tests with a 4-minute recovery between each trial for the determination of peak and mean power output (PPO, MPO). Resting blood samples were also collected at the beginning of each pre and posttesting period, before and after the 4-week training program. The EXP group showed significant improvements in VO(2)max (+5.4%), peak oxygen pulse (+7.7%) and T(max) (+32.2%) compared with pretesting. The EXP group produced significant increases

  9. A Method to Evaluate Additional Waste Forms to Optimize Performance of the HLW Repository

    SciTech Connect

    D. Gombert; L. Lauerhass

    2006-02-01

    The DOE high-level waste (HLW) disposal system is based on decisions made in the 1970s. The de facto Yucca Mountain WAC for HLW, contained in the Waste Acceptance System Requirements Document (WASRD), and the DOE-EM Waste Acceptance Product Specification for Vitrified High Level Waste Forms (WAPS) tentatively describes waste forms to be interred in the repository, and limits them to borosilicate glass (BSG). It is known that many developed waste forms are as durable as or better than environmental assessment or “EA”-glass. Among them are the salt-ceramic and metallic waste forms developed at ANL-W. Also, iron phosphate glasses developed at University of Missouri show promise in stabilizing the most refractory materials in Hanford HLW. However, for any of this science to contribute, the current Total System Performance Assessment model must be able to evaluate the additional waste form to determine potential impacts on repository performance. The results can then support the technical bases required in the repository license application. A methodology is proposed to use existing analysis models to evaluate potential additional waste forms for disposal without gathering costly material specific degradation data. The concept is to analyze the potential impacts of waste form chemical makeup on repository performance assuming instantaneous waste matrix dissolution. This assumption obviates the need for material specific degradation models and is based on the relatively modest fractional contribution DOE HLW makes to the repository radionuclide and hazardous metals inventory. The existing analysis models, with appropriate data modifications, are used to evaluate geochemical interactions and material transport through the repository. This methodology would support early screening of proposed waste forms through simplified evaluation of disposal performance, and would provide preliminary guidance for repository license amendment in the future.

  10. PERMEABLE REACTIVE BARRIER PERFORMANCE MONITORING: LONG-TERM TRENDS IN GEOCHEMICAL PARAMETERS AT TWO SITES

    EPA Science Inventory

    A major goal of research on the long-term performance of subsurface reactive barriers is to identify standard ground water monitoring parameters that may be useful indicators of declining performance or impending system failure. Results are presented from ground water monitoring ...

  11. PERMEABLE REACTIVE BARRIER PERFORMANCE MONITORING: LONG-TERM TRENDS IN GEOCHEMICAL PARAMETERS AT TWO SITES

    EPA Science Inventory

    A major goal of research on the long-term performance of subsurface reactive barriers is to identify standard ground-water monitoring parameters that may be useful indicators of declining performance or impending system failure. Results are presented from studies conducted over ...

  12. Effect of Process Parameters on Dynamic Mechanical Performance of FDM PC/ABS Printed Parts Through Design of Experiment

    NASA Astrophysics Data System (ADS)

    Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal; Nikzad, Mostafa; Azadmanjiri, Jalal

    2016-07-01

    In fused deposition modeling (FDM) additive manufacturing process, it is often difficult to determine the actual levels of process parameters in order to achieve the best dynamic mechanical properties of FDM manufactured part. This is mainly due to the large number of FDM parameters and a high degree of interaction between the parameters affecting such properties. This requires a large number of experiments to be determined. This paper presents a study on the influence of six FDM process parameters (layer thickness, air gap, raster angle, build orientation, road width, and number of contours) on the dynamic mechanical properties of the FDM manufactured parts using the fraction factorial design. The most influential parameters were statistically obtained through the analysis of variance (ANOVA) technique, and the results indicate that the layer thickness, the air gap, and the number of contours have the largest impact on dynamic mechanical properties. The optimal parameters for maximum dynamic mechanical properties were found to be layer thickness of 0.3302 mm, air gap of 0.00 mm, raster angle of 0.0°, build orientation of 0.0°, road width of 0.4572 mm, and 10 contours. Finally, a confirmation experiment was performed using optimized levels of process parameters, which showed good fit with the estimated values.

  13. Effect of Process Parameters on Dynamic Mechanical Performance of FDM PC/ABS Printed Parts Through Design of Experiment

    NASA Astrophysics Data System (ADS)

    Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal; Nikzad, Mostafa; Azadmanjiri, Jalal

    2016-06-01

    In fused deposition modeling (FDM) additive manufacturing process, it is often difficult to determine the actual levels of process parameters in order to achieve the best dynamic mechanical properties of FDM manufactured part. This is mainly due to the large number of FDM parameters and a high degree of interaction between the parameters affecting such properties. This requires a large number of experiments to be determined. This paper presents a study on the influence of six FDM process parameters (layer thickness, air gap, raster angle, build orientation, road width, and number of contours) on the dynamic mechanical properties of the FDM manufactured parts using the fraction factorial design. The most influential parameters were statistically obtained through the analysis of variance (ANOVA) technique, and the results indicate that the layer thickness, the air gap, and the number of contours have the largest impact on dynamic mechanical properties. The optimal parameters for maximum dynamic mechanical properties were found to be layer thickness of 0.3302 mm, air gap of 0.00 mm, raster angle of 0.0°, build orientation of 0.0°, road width of 0.4572 mm, and 10 contours. Finally, a confirmation experiment was performed using optimized levels of process parameters, which showed good fit with the estimated values.

  14. Effects of addition of different carbon materials on the electrochemical performance of nickel hydroxide electrode

    NASA Astrophysics Data System (ADS)

    Sierczynska, Agnieszka; Lota, Katarzyna; Lota, Grzegorz

    Nickel hydroxide is used as an active material in positive electrodes of rechargeable alkaline batteries. The capacity of nickel-metal hydride (Ni-MH) batteries depends on the specific capacity of the positive electrode and utilization of the active material because of the Ni(OH) 2/NiOOH electrode capacity limitation. The practical capacity of the positive nickel electrode depends on the efficiency of the conductive network connecting the Ni(OH) 2 particle with the current collector. As β-Ni(OH) 2 is a kind of semiconductor, the additives are necessary to improve the conductivity between the active material and the current collector. In this study the effect of adding different carbon materials (flake graphite, multi-walled carbon nanotubes (MWNT)) on the electrochemical performance of pasted nickel-foam electrode was established. A method of production of MWNT special type of catalysts had an influence on the performance of the nickel electrodes. The electrochemical tests showed that the electrode with added MWNT (110-170 nm diameter) exhibited better electrochemical properties in the chargeability, specific discharge capacity, active material utilization, discharge voltage and cycling stability. The nickel electrodes with MWNT addition (110-170 nm diameter) have exhibited a specific capacity close to 280 mAh g -1 of Ni(OH) 2, and the degree of active material utilization was ∼96%.

  15. Animal performance and carcass characteristics from confined lambs fed on concentrate feed and additives.

    PubMed

    Prado, Tayrone F; França, Aldi F S; Meirinhos, Maria Lúcia G; Peron, Hugo J M C; Ferreira, Reginaldo N; Oliveira, Leonardo G; Corrêa, Daniel S

    2015-01-01

    The number of sheep flocks in Brazil is increasing. It is known that lambs must be slaughtered when young for producing quality meat. The current study evaluated the inclusion of protected methionine, protected lysine, lysophospholipid and amylolytic enzymes in a diet to lambs and their effects on weight gain and quantitative carcass traits at slaughtering. Eighty non-castrated male crossbred Dorper x Santa Inês lambs, 20.57 ± 4.33 kg live weight, were used. The feedlot lasted 64 days and 60 animals were slaughtered. There were no differences for live weight, daily feed intake, feed conversion and average daily weight gain at the first 28 days of feedlot. From the 28th day lysophospholipid treatment presented the highest live weight. Lysophospholipid and amylolytic enzyme presented the best performance in average daily gain, followed by protected methionine, control and protected lysine. Lysophospholipid treatment presented higher daily feed intake rates than protected lysine and protected methionine. Feed conversion was lower for amylolytic enzyme and higher for control. No changing in carcass traits was reported due to additives. Better performance may be achieved with feedlot lambs fed on diets with the addition of amylolytic enzyme and lysophospholipid at the finishing phase. PMID:26536854

  16. [Simultaneous determination of six food additives in meat products by high performance liquid chromatography].

    PubMed

    Li, Xiuqin; Zhang, Qinghe; Yang, Zong

    2010-12-01

    A novel method was proposed for the simultaneous separation and determination of six food additives, benzoic acid, sorbic acid, saccharin sodium, acesulfame potassium, ponceau 4R and allura red AC, by high performance liquid chromatography (HPLC). After optimized the separation conditions of HPLC, the separation can be completed within 18 min by using a ZORBAX Eclipse Plus C18 column (150 mm x 4.6 mm, 5 microm) with 20 mmol/L ammonium acetate (pH 6.9) and methanol as the mobile phases. The gradient elution was performed by 8% methanol (0-2 min), 8%-50% methanol (2-3 min), 50% methanol (3-9 min), 50%-8% methanol (9-12 min) and 8% methanol (12-18 min). The detection wavelength was set at 235 nm. This method has been successfully applied to the analysis of meat products and the average recoveries ranged from 80.7% to 94.4% at high and low spiked levels. The relative standard deviations (RSDs, n=3) were between 2.0% and 7.1%. The method is simple, rapid, accurate and suitable for the simultaneous determination of the six food additives in meat products. PMID:21438379

  17. Performance enhancement with powdered activated carbon (PAC) addition in a membrane bioreactor (MBR) treating distillery effluent.

    PubMed

    Satyawali, Yamini; Balakrishnan, Malini

    2009-10-15

    This work investigated the effect of powdered activated carbon (PAC) addition on the operation of a membrane bioreactor (MBR) treating sugarcane molasses based distillery wastewater (spentwash). The 8L reactor was equipped with a submerged 30 microm nylon mesh filter with 0.05 m(2) filtration area. Detailed characterization of the commercial wood charcoal based PAC was performed before using it in the MBR. The MBR was operated over 200 days at organic loading rates (OLRs) varying from 4.2 to 6.9 kg m(-3)d(-1). PAC addition controlled the reactor foaming during start up and enhanced the critical flux by around 23%; it also prolonged the duration between filter cleaning. Operation at higher loading rates was possible and for a given OLR, the chemical oxygen demand (COD) removal was higher with PAC addition. However, biodegradation in the reactor was limited and the high molecular weight compounds were not affected by PAC supplementation. The functional groups on PAC appear to interact with the polysaccharide portion of the sludge, which may reduce its propensity to interact with the nylon mesh. PMID:19467782

  18. Bioreactor Performance Parameters for an Industrially-Promising Methanotroph Methylomicrobium buryatense 5GB1

    DOE PAGESBeta

    Gilman, Alexey; Laurens, Lieve M.; Puri, Aaron W.; Chu, Frances; Pienkos, Philip T.; Lidstrom, Mary E.

    2015-11-16

    Methane is a feedstock of interest for the future, both from natural gas and from renewable biogas sources. Methanotrophic bacteria have the potential to enable commercial methane bioconversion to value-added products such as fuels and chemicals. A strain of interest for such applications is Methylomicrobium buryatense 5GB1, due to its robust growth characteristics. But, to take advantage of the potential of this methanotroph, it is important to generate comprehensive bioreactor-based datasets for different growth conditions to compare bioprocess parameters. The datasets of growth parameters, gas utilization rates, and products (total biomass, extracted fatty acids, glycogen, excreted acids) were obtained formore » cultures of M. buryatense 5GB1 grown in continuous culture under methane limitation and O2 limitation conditions. Additionally, experiments were performed involving unrestricted batch growth conditions with both methane and methanol as substrate. All four growth conditions show significant differences. The most notable changes are the high glycogen content and high formate excretion for cells grown on methanol (batch), and high O2:CH4 utilization ratio for cells grown under methane limitation. The results presented here represent the most comprehensive published bioreactor datasets for a gamma-proteobacterial methanotroph. This information shows that metabolism by M. buryatense 5GB1 differs significantly for each of the four conditions tested. O2 limitation resulted in the lowest relative O2 demand and fed-batch growth on methane the highest. Future studies are needed to understand the metabolic basis of these differences. However, these results suggest that both batch and continuous culture conditions have specific advantages, depending on the product of interest.« less

  19. Bioreactor Performance Parameters for an Industrially-Promising Methanotroph Methylomicrobium buryatense 5GB1

    SciTech Connect

    Gilman, Alexey; Laurens, Lieve M.; Puri, Aaron W.; Chu, Frances; Pienkos, Philip T.; Lidstrom, Mary E.

    2015-11-16

    Methane is a feedstock of interest for the future, both from natural gas and from renewable biogas sources. Methanotrophic bacteria have the potential to enable commercial methane bioconversion to value-added products such as fuels and chemicals. A strain of interest for such applications is Methylomicrobium buryatense 5GB1, due to its robust growth characteristics. But, to take advantage of the potential of this methanotroph, it is important to generate comprehensive bioreactor-based datasets for different growth conditions to compare bioprocess parameters. The datasets of growth parameters, gas utilization rates, and products (total biomass, extracted fatty acids, glycogen, excreted acids) were obtained for cultures of M. buryatense 5GB1 grown in continuous culture under methane limitation and O2 limitation conditions. Additionally, experiments were performed involving unrestricted batch growth conditions with both methane and methanol as substrate. All four growth conditions show significant differences. The most notable changes are the high glycogen content and high formate excretion for cells grown on methanol (batch), and high O2:CH4 utilization ratio for cells grown under methane limitation. The results presented here represent the most comprehensive published bioreactor datasets for a gamma-proteobacterial methanotroph. This information shows that metabolism by M. buryatense 5GB1 differs significantly for each of the four conditions tested. O2 limitation resulted in the lowest relative O2 demand and fed-batch growth on methane the highest. Future studies are needed to understand the metabolic basis of these differences. However, these results suggest that both batch and continuous culture conditions have specific advantages, depending on the product of interest.

  20. Impact of parameter fluctuations on RF stability performance of DG tunnel FET

    NASA Astrophysics Data System (ADS)

    Sivasankaran, K.; Mallick, P. S.

    2015-08-01

    This paper presents the impact of parameter fluctuation due to process variation on radio frequency (RF) stability performance of double gate tunnel FET (DG TFET). The influence of parameter fluctuation due to process variation leads to DG TFET performance degradation. The RF figures of merit (FoM) such as cut-off frequency (ft), maximum oscillation frequency (fmax) along with stability factor for different silicon body thickness, gate oxide thickness and gate contact alignment are obtained from extracted device parameters through numerical simulation. The impact of parameter fluctuation of silicon body thickness, gate oxide thickness and gate contact alignment was found significant and the result provides design guidelines of DG TFET for RF applications.

  1. Parameters and pitfalls to consider in the conduct of food additive research, Carrageenan as a case study.

    PubMed

    Weiner, Myra L

    2016-01-01

    This paper provides guidance on the conduct of new in vivo and in vitro studies on high molecular weight food additives, with carrageenan, the widely used food additive, as a case study. It is important to understand the physical/chemical properties and to verify the identity/purity, molecular weight and homogeneity/stability of the additive in the vehicle for oral delivery. The strong binding of CGN to protein in rodent chow or infant formula results in no gastrointestinal tract exposure to free CGN. It is recommended that doses of high Mw non-caloric, non-nutritive additives not exceed 5% by weight of total solid diet to avoid potential nutritional effects. Addition of some high Mw additives at high concentrations to liquid nutritional supplements increases viscosity and may affect palatability, caloric intake and body weight gain. In in vitro studies, the use of well-characterized, relevant cell types and the appropriate composition of the culture media are necessary for proper conduct and interpretation. CGN is bound to media protein and not freely accessible to cells in vitro. Interpretation of new studies on food additives should consider the interaction of food additives with the vehicle components and the appropriateness of the animal or cell model and dose-response. PMID:26615870

  2. Additive benefits of external focus and enhanced performance expectancy for motor learning.

    PubMed

    Pascua, Luigi A M; Wulf, Gabriele; Lewthwaite, Rebecca

    2015-01-01

    The authors examined the individual and combined influences of 2 factors that have been shown to benefit motor learning: an external focus of attention and enhanced performance expectancies. Another purpose of this study was to gain further insight into the mechanisms underlying these variables. In a factorial design, participants learning a novel motor skill (i.e., throwing with the non-dominant arm) were or were not given external focus instructions, and were or were not provided bogus positive social-comparative feedback to enhance their expectancies. This resulted in 4 groups: external focus, enhanced expectancy, external focus/enhanced expectancy and control. External focus instructions and enhanced expectancies had additive benefits for learning: the external focus/enhanced expectancy group demonstrated the greatest throwing accuracy on both retention and transfer tests, while the accuracy scores of the external focus and enhanced expectancy groups were lower, but higher than those of the control group. Furthermore, self-efficacy was increased by both external focus and enhanced expectancy, and predicted retention and transfer performance. Positive affect was heightened in the enhanced expectancy and external focus/enhanced expectancy groups after practice and predicted transfer performance. The findings suggest that the learning benefits of an external focus and enhanced expectancies mediate learning through partially different mechanisms. PMID:24875153

  3. Evaluation of the Performance of Smoothing Functions in Generalized Additive Models for Spatial Variation in Disease

    PubMed Central

    Siangphoe, Umaporn; Wheeler, David C.

    2015-01-01

    Generalized additive models (GAMs) with bivariate smoothing functions have been applied to estimate spatial variation in risk for many types of cancers. Only a handful of studies have evaluated the performance of smoothing functions applied in GAMs with regard to different geographical areas of elevated risk and different risk levels. This study evaluates the ability of different smoothing functions to detect overall spatial variation of risk and elevated risk in diverse geographical areas at various risk levels using a simulation study. We created five scenarios with different true risk area shapes (circle, triangle, linear) in a square study region. We applied four different smoothing functions in the GAMs, including two types of thin plate regression splines (TPRS) and two versions of locally weighted scatterplot smoothing (loess). We tested the null hypothesis of constant risk and detected areas of elevated risk using analysis of deviance with permutation methods and assessed the performance of the smoothing methods based on the spatial detection rate, sensitivity, accuracy, precision, power, and false-positive rate. The results showed that all methods had a higher sensitivity and a consistently moderate-to-high accuracy rate when the true disease risk was higher. The models generally performed better in detecting elevated risk areas than detecting overall spatial variation. One of the loess methods had the highest precision in detecting overall spatial variation across scenarios and outperformed the other methods in detecting a linear elevated risk area. The TPRS methods outperformed loess in detecting elevated risk in two circular areas. PMID:25983545

  4. Electrode performance parameters for a radioisotope-powered AMTEC for space power applications

    NASA Technical Reports Server (NTRS)

    Underwood, M. L.; O'Connor, D.; Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Bankston, C. P.

    1992-01-01

    The alkali metal thermoelastic converter (AMTEC) is a device for the direct conversion of heat to electricity. Recently a design of an AMTEC using a radioisotope heat source was described, but the optimum condenser temperature was hotter than the temperatures used in the laboratory to develop the electrode performance model. Now laboratory experiments have confirmed the dependence of two model parameters over a broader range of condenser and electrode temperatures for two candidate electrode compositions. One parameter, the electrochemical exchange current density at the reaction interface, is independent of the condenser temperature, and depends only upon the collision rate of sodium at the reaction zone. The second parameter, a morphological parameter, which measures the mass transport resistance through the electrode, is independent of condenser and electrode temperatures for molybdenum electrodes. For rhodium-tungsten electrodes, however, this parameter increases for decreasing electrode temperature, indicating an activated mass transport mechanism such as surface diffusion.

  5. Laser-shocked energetic materials with metal additives: evaluation of detonation performance

    NASA Astrophysics Data System (ADS)

    Gottfried, Jennifer; Bukowski, Eric

    A focused, nanosecond-pulsed laser with sufficient energy to exceed the breakdown threshold of a material generates a laser-induced plasma with high peak temperatures, pressures, and shock velocities. Depending on the laser parameters and material properties, nanograms to micrograms of material is ablated, atomized, ionized and excited in the laser-induced plasma. The subsequent shock wave expansion into the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The estimated detonation velocities using LASEM agree well with published experimental values. A comparison of the measured shock velocities for various energetic materials including RDX, DNTF, and LLM-172 doped with Al or B to the detonation velocities predicted by CHEETAH for inert or active metal participation demonstrates that LASEM has potential for predicting the early time participation of metal additives in detonation events. The LASEM results show that reducing the amount of hydrogen present in B formulations increases the resulting detonation velocities

  6. Investigations of non-linear polymers as high performance lubricant additives

    SciTech Connect

    Robinson, Joshua W.; Bhattacharya, Priyanka; Qu, Jun; Bays, J. Timothy; Cosimbescu, Lelia

    2015-03-22

    Off-the-shelf available engine oils contain an assortment of additives that increase the performance of base oils and maximize the overall efficiency of the machine. With ever increasing requirements for fuel efficiency, the demand for novel materials that outperform older generations is also on the rise. One approach towards increasing overall efficiency is to reduce internal friction and wear in an engine. From an additive approach, this is typically achieved by altering the bulk oil’s viscosity at high temperatures via polymers. In general, the hydrodynamic volume of polymers increase (expand) at elevated temperatures and decrease (contract/deflate) with declining temperatures and this effect is enhanced be carefully designing specific structures and architectures. The natural thinning tendency of base oil with increasing temperatures is in part mitigated by the expansion of the macromolecules added, and the overall effect is decreasing the viscosity losses at high temperatures. Traditional polymer architectures vary from linear to dendritic, where linear polymers of the same chemical composition and molecular weight to its dendritic counterpart will undergo a more significant free volume change in solution with regards to temperature changes. This advantage has been exploited in the literature towards the production of viscosity modifiers. However, one major disadvantage of linear polymers is degradation due to mechanical shear forces and high temperatures causing a shorter additive lifetime. Dendrimers on the other hand are known to demonstrate superior robustness to shear degradation when compared to their respective linear counterparts. An additional advantage of the dendritic architecture is the ability to tailor the peripheral end-groups towards influencing polymer-solvent and/or polymer-surface interactions. Comb-burst hyperbranched polymers are a hybrid of the aforementioned architectures and provide several compromises between the traditional

  7. Additive Manufacturing and High-Performance Computing: a Disruptive Latent Technology

    NASA Astrophysics Data System (ADS)

    Goodwin, Bruce

    2015-03-01

    This presentation will discuss the relationship between recent advances in Additive Manufacturing (AM) technology, High-Performance Computing (HPC) simulation and design capabilities, and related advances in Uncertainty Quantification (UQ), and then examines their impacts upon national and international security. The presentation surveys how AM accelerates the fabrication process, while HPC combined with UQ provides a fast track for the engineering design cycle. The combination of AM and HPC/UQ almost eliminates the engineering design and prototype iterative cycle, thereby dramatically reducing cost of production and time-to-market. These methods thereby present significant benefits for US national interests, both civilian and military, in an age of austerity. Finally, considering cyber security issues and the advent of the ``cloud,'' these disruptive, currently latent technologies may well enable proliferation and so challenge both nuclear and non-nuclear aspects of international security.

  8. Bifunctional hairy silica nanoparticles as high-performance additives for lubricant

    PubMed Central

    Sui, Tianyi; Song, Baoyu; Wen, Yu-ho; Zhang, Feng

    2016-01-01

    Bifunctional hairy silica nanoparticles (BHSNs), which are silica nanoparticles covered with alkyl and amino organic chains, were prepared as high-performance additives for lubricants. Compared with hairy silica nanoparticles covered by a single type of organic chain, binary hairy silica nanoparticles exhibit the advantages of both types of organic chains, which exhibit excellent compatibility with lubricants and adsorbability to metal surfaces. Nanoparticles with different ratios of amino and alkyl ligands were investigated. In comparison to an untreated lubricant, BHSNs reduce the friction coefficient and wear scar diameter by 40% and 60%, respectively. The wear mechanism of BHSNs was investigated, and the protective and filling effect of the nanoparticles improved because of collaboration of amino and alkyl ligands. PMID:26936117

  9. Bifunctional hairy silica nanoparticles as high-performance additives for lubricant.

    PubMed

    Sui, Tianyi; Song, Baoyu; Wen, Yu-Ho; Zhang, Feng

    2016-01-01

    Bifunctional hairy silica nanoparticles (BHSNs), which are silica nanoparticles covered with alkyl and amino organic chains, were prepared as high-performance additives for lubricants. Compared with hairy silica nanoparticles covered by a single type of organic chain, binary hairy silica nanoparticles exhibit the advantages of both types of organic chains, which exhibit excellent compatibility with lubricants and adsorbability to metal surfaces. Nanoparticles with different ratios of amino and alkyl ligands were investigated. In comparison to an untreated lubricant, BHSNs reduce the friction coefficient and wear scar diameter by 40% and 60%, respectively. The wear mechanism of BHSNs was investigated, and the protective and filling effect of the nanoparticles improved because of collaboration of amino and alkyl ligands. PMID:26936117

  10. Bifunctional hairy silica nanoparticles as high-performance additives for lubricant

    NASA Astrophysics Data System (ADS)

    Sui, Tianyi; Song, Baoyu; Wen, Yu-Ho; Zhang, Feng

    2016-03-01

    Bifunctional hairy silica nanoparticles (BHSNs), which are silica nanoparticles covered with alkyl and amino organic chains, were prepared as high-performance additives for lubricants. Compared with hairy silica nanoparticles covered by a single type of organic chain, binary hairy silica nanoparticles exhibit the advantages of both types of organic chains, which exhibit excellent compatibility with lubricants and adsorbability to metal surfaces. Nanoparticles with different ratios of amino and alkyl ligands were investigated. In comparison to an untreated lubricant, BHSNs reduce the friction coefficient and wear scar diameter by 40% and 60%, respectively. The wear mechanism of BHSNs was investigated, and the protective and filling effect of the nanoparticles improved because of collaboration of amino and alkyl ligands.

  11. Using performance parameters, metrified performance objectives, and quality management assessments to improve the effectiveness of research organizations

    SciTech Connect

    Bodnarczuk, M

    1995-04-01

    This paper begins by raising the issue of whether the theoretical model of customer-suppliers-products-services usefully describes the activities of laboratory life, using a case study from Fermilab. After describing scientific activities as work, not volunteerism, I present a model that has four performance parameters that can be used to evaluate DOE-funded research laboratories: (1) Do they have a well-defined management system? (2) Are they doing good science? (3) Are they managing their resources effectively? (4) Are they responsive to their customers? From these four parameters I describe how to metrify performance objectives, then use them to evaluate research organizations. I describe these performance objectives within the context of views I have published elsewhere, and according to Stephen R. Covey`s metaphor of production/production capability (P/PC) balance in his book The 7 Habits of Highly Effective People.

  12. Effect of cleaning agents and additives on Protein A ligand degradation and chromatography performance.

    PubMed

    Yang, Lihua; Harding, Jason D; Ivanov, Alexander V; Ramasubramanyan, Natarajan; Dong, Diane D

    2015-03-13

    Protein A chromatography, employing the recombinant Protein A ligand, is widely used as a capture step for antibody and Fc-fusion proteins manufacture. Protein A ligands in these matrices are susceptible to degradation/loss when exposed to cleaning agents such as sodium hydroxide, resulting in loss of capacity on reuse. In this study, MabSelect Protein A ligand and MabSelect SuRe Protein A ligand were chosen to evaluate the impact of alkaline cleaning solutions on the ligands and the packed columns. The Protein A ligands alone and the Protein A columns were incubated or cycled in different concentrations of sodium hydroxide solutions with and without additives, respectively. Ligand integrity (degradation) and ligand function (binding affinity) were studied using SDS-PAGE and customized Biacore technology, surface plasma resonance (SPR) and were successfully correlated with column performance measurement in terms of static binding capacity (SBC), dynamic binding capacity (DBC) and recovery as a function of exposure to cleaning agents with and without additives. The findings and the methodology presented in this study are not only able to determine appropriate cleaning conditions for Protein A chromatography, but also provided tools to enable systematic and rapid study of the cleaning solutions and conditions. PMID:25680549

  13. Effect of Hf and Y Alloy Additions on Aluminide Coating Performance

    SciTech Connect

    Pint, Bruce A; Haynes, James A; Besmann, Theodore M

    2010-01-01

    Iron- and Ni-base alloys, with and without Hf or Hf and Y alloy additions, were aluminized by chemical vapor deposition to study the potential for minor alloy additions to improve oxidation resistance of coated alloys. Compared to uncoated specimens, the coated specimens showed improved cyclic oxidation resistance at 1100 and 1150 C. However, alumina scale spallation was observed at relatively short times and, particularly for the Ni-base alloy X, the aluminized lab-cast alloy with Hf tended to have poor coating performance compared to the commercial alloy without Hf. Internal oxidation of Hf at 1150 C and rapid Al depletion in the relatively thin aluminide coatings contributed to the observed detrimental Hf effect. For the Ni-base alloys, the increased scale spallation could be attributed to much higher S contents (10-50 ppma) in the laboratory-cast alloys. Oxide scale spallation from the coating surface was minimized when Hf and Y were added to a casting and the [Y]/[S] content ratio was {approx}1.

  14. The impact of layer thickness on the performance of additively manufactured lapping tools

    NASA Astrophysics Data System (ADS)

    Williams, Wesley B.

    2015-10-01

    Lower cost additive manufacturing (AM) machines which have emerged in recent years are capable of producing tools, jigs, and fixtures that are useful in optical fabrication. In particular, AM tooling has been shown to be useful in lapping glass workpieces. Various AM machines are distinguished by the processes, materials, build times, and build resolution they provide. This research investigates the impact of varied build resolution (specifically layer resolution) on the lapping performance of tools built using the stereolithographic assembly (SLA) process in 50 μm and 100 μm layer thicknesses with a methacrylate photopolymer resin on a high resolution desktop printer. As with previous work, the lapping tools were shown to remove workpiece material during the lapping process, but the tools themselves also experienced significant wear on the order of 2-3 times the mass loss of the glass workpieces. The tool wear rates for the 100 μm and 50 μm layer tools were comparable, but the 50 μm layer tool was 74% more effective at removing material from the glass workpiece, which is attributed to some abrasive particles being trapped in the coarser surface of the 100 um layer tooling and not being available to interact with the glass workpiece. Considering the tool wear, these additively manufactured tools are most appropriate for prototype tooling where the low cost (<$45) and quick turnaround make them attractive when compared to a machined tool.

  15. [Simultaneous determination of various food additives by high performance liquid chromatography].

    PubMed

    Chen, Q C; Yu, W L; Wang, J

    2001-03-01

    A novel method is proposed for the simultaneous separation and determination of eight food additives, acesulfame potassium (AK), aspartame (ASP), benzoic acid (BA), caffeine (CA), saccharin sodium (SA), sorbic acid (SOR), theobromine (TB) and theophylline (TP) by reversed-phase high performance liquid chromatography. The separation was achieved within 23 min by using an Alltech Econosphere C18 column with 10 mmol/L NaH2PO4(pH 4.00)-acetonitrile (90:10, V/V) as mobile phase. The qualification and quantitation were accomplished by using a photodiode array detector. The detection limits (S/N = 3) for all analytes were below mg/L level. Under the experimental conditions, other common food additives and organic acids such as cyclamate, citric acid, malic acid, tartaric acid and ascorbic acid, did not interfere with the determination. The method has been successfully applied to the analysis of various foods as well as pharmaceutical preparation, and the average recoveries for real samples ranged from 78.5% to 107.2%. PMID:12541649

  16. Regional Assessment of the Parameter-Dependent Performance of CAM4 in Simulating Tropical Clouds

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Xie, S.; Covey, C. C.; Lucas, D. D.; Gleckler, P. J.; Klein, S. A.; Tannahill, J.; Doutriaux, C.; Klein, R.

    2012-12-01

    Representation of clouds remains among the largest uncertainties in climate models and thus climate projections. Clouds vary significantly over different climate regimes and are controlled by different dynamics and physics. Using the cloud simulator output from perturbed-parameter ensemble climate runs with prescribed monthly sea surface temperature, this study examines the performance of the Community Atmosphere Model version 4 (CAM4) in simulating clouds over different tropical regions. Perturbing 28 selected parameters shows that model performance is quite sensitive to parameter values in different cloud regimes. Carefully adjusting these parameters could lead to a better simulation of clouds over many regions compared with the default model. Latin hypercube runs that pseudo-randomly sample the 28 parameters simultaneously have much wider spread and more spatial variations than the runs with parameters varied One-At-a-Time (OAT), suggesting the importance of non-linearities and interactions among parameters associated with different physical processes. The perturbed parameters have a relatively large impact on the mean bias compared to the pattern error. This study is supported by the LLNL Institutional Science and Technology Office under the Uncertainty Quantification Strategic Initiative Laboratory-Directed Research and Development Project 10-SI-013. This work is also supported by the Regional and Global Climate Modeling Program and Earth System Modeling program of the Office of Science at the U. S. Department of Energy. This work was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  17. Enhancing the performance of polymer solar cells using CuPc nanocrystals as additives

    NASA Astrophysics Data System (ADS)

    Zhang, Yajie; Wei, Zhixiang

    2015-05-01

    There is an increasing interest in the use of different nanoparticles as additives in polymer solar cells for enhancing the light absorption of active layers as well as their power conversion efficiency (PCE). In this paper, we report a PCE enhancement by simply adding copper phthalocyanine (CuPc) nanocrystals into photovoltaic devices based on a poly(3-hexylthiophene) (P3HT): fullerene system. Two kinds of device structure were studied: the first one is a CuPc nanocrystal suspension spin coated on the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-coated substrate; the second one is the CuPc nanocrystal suspension added into the active layer solutions. It is proved that incorporating organic semiconductor nanocrystals into the active layer can help trap light and enhance the crystallinity of the active layers, thus improving the device performance. This strategy might be generally compatible with a broad range of organic photovoltaic materials and offers an effective approach to enhance the device performance.

  18. Enhancing the performance of polymer solar cells using CuPc nanocrystals as additives.

    PubMed

    Zhang, Yajie; Wei, Zhixiang

    2015-05-22

    There is an increasing interest in the use of different nanoparticles as additives in polymer solar cells for enhancing the light absorption of active layers as well as their power conversion efficiency (PCE). In this paper, we report a PCE enhancement by simply adding copper phthalocyanine (CuPc) nanocrystals into photovoltaic devices based on a poly(3-hexylthiophene) (P3HT): fullerene system. Two kinds of device structure were studied: the first one is a CuPc nanocrystal suspension spin coated on the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-coated substrate; the second one is the CuPc nanocrystal suspension added into the active layer solutions. It is proved that incorporating organic semiconductor nanocrystals into the active layer can help trap light and enhance the crystallinity of the active layers, thus improving the device performance. This strategy might be generally compatible with a broad range of organic photovoltaic materials and offers an effective approach to enhance the device performance. PMID:25912794

  19. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    DOE PAGESBeta

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. Thismore » symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.« less

  20. Effects of Si Addition and Heating Ar on the Electromigration Performance of Al-Alloy Interconnects

    NASA Astrophysics Data System (ADS)

    Lee, Dok Won; Lee, Byung-Zu; Jeong, Jong Yeul; Park, Hyun; Shim, Kyu Cheol; Kim, Jong Seok; Park, Young Bae; Woo, Sun-Woong; Lee, Jeong-gun

    2002-02-01

    The electromigration (EM) performance of Ti/Al-alloy multilayered metallization with one-step sputtered Al-alloy has been studied. The Al-alloys investigated included Al-1.0%Si-0.5%Cu and Al-0.5%Cu, and the Al-alloy films were prepared with and without heating Ar. The package-level EM test results indicate that the EM resistance of the Al-Si-Cu stack is nearly identical to that of the Al-Cu stack. Si addition was found to degrade the microstructure of the Al-alloy film, while it had the retarding effect on the Ti/Al reaction, which suggests that there exists a trade-off between the film microstructure and the formation of TiAl3 intermetallic compound. The EM performance of the one-step sputtered Al-alloy stack was enhanced by the use of heating Ar during the deposition of Al-alloy film, which has been attributed to the improved microstructure of the Al-alloy film by the use of heating Ar.

  1. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    SciTech Connect

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. This symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.

  2. Separating response-execution bias from decision bias: arguments for an additional parameter in Ratcliff's diffusion model.

    PubMed

    Voss, Andreas; Voss, Jochen; Klauer, Karl Christoph

    2010-11-01

    Diffusion model data analysis permits the disentangling of different processes underlying the effects of experimental manipulations. Estimates can be provided for the speed of information accumulation, for the amount of information used to draw conclusions, and for a decision bias. One parameter describes the duration of non-decisional processes including the duration of motor-response execution. In the default diffusion model, it is implicitly assumed that both responses are executed with the same speed. In some applications of the diffusion model, this assumption will be violated. This will lead to biased parameter estimates. Consequently, we suggest accounting explicitly for differences in the speed of response execution for both responses. Results from a simulation study illustrate that parameter estimates from the default model are biased if the speed of response execution differs between responses. A second simulation study shows that large trial numbers (N>1,000) are needed to detect whether differences in response-execution times are based on different execution times. PMID:20030967

  3. Effects of Learning Parameters on Learning Procedure and Performance of a BPNN.

    PubMed

    MacBeth, Colin; Dai, Hengchang

    1997-11-01

    We examined the effects of changing learning parameters on the learning procedure and performance of back-propagation neural networks used to pick seismic arrivals. The results show that such change mainly affects the speed of convergence of the learning procedures, and does not affect the BPNN structure and its overall performance. A relationship between the learning parameters and iteration number is obtained. This relationship may be used as a guide to check the convergence of the learning procedure and the BPNN performance. We also use a weight map of BPNN structure to analyze its interior and performance. Two BPNNs used to pick seismic arrivals from three-component and single-component seismograms have similar weight patterns and operate in a similar way, although they have different structures and trained by different training dataset. PMID:12662490

  4. An evaluation of some pertinent parameters that influence the dosimetric performance of synthetic diamond detectors

    NASA Astrophysics Data System (ADS)

    Ade, N.; Nam, T. L.; Mhlanga, S. H.

    2013-05-01

    Although the near-tissue equivalence of diamond allows the direct measurement of dose for clinical applications without the need for energy-corrections, it is often cited that diamond detectors require pre-irradiation, a procedure necessary to stabilize the response or sensitivity of a diamond detector before dose measurements. In addition it has been pointed out that the relative dose measured with a diamond detector requires dose rate dependence correction and that the angular dependence of a detector could be due to its mechanical design or to the intrinsic angular sensitivity of the detection process. While the cause of instability of response has not been meticulously investigated, the issue of dose rate dependence correction is uncertain as some studies ignored it but reported good results. The aims of this study were therefore to investigate, in particular (1) the major cause of the unstable response of diamond detectors requiring pre-irradiation; (2) the influence of dose rate dependence correction in relative dose measurements; and (3) the angular dependence of the diamond detectors. The study was conducted with low-energy X-rays and electron therapy beams on HPHT and CVD synthesized diamonds. Ionization chambers were used for comparative measurements. Through systematic investigations, the major cause of the unstable response of diamond detectors requiring the recommended pre-irradiation step was isolated and attributed to the presence and effects of ambient light. The variation in detector's response between measurements in light and dark conditions could be as high as 63% for a CVD diamond. Dose rate dependence parameters (Δ values) of 0.950 and 1.035 were found for the HPHT and CVD diamond detectors, respectively. Without corrections based on dose rate dependence, the relative differences between depth-doses measured with the diamond detectors and a Markus chamber for exposures to 7 and 14 MeV electron beams were within 2.5%. A dose rate dependence

  5. Computer simulation for prediction of performance and thermodynamic parameters of high energy materials.

    PubMed

    Muthurajan, H; Sivabalan, R; Talawar, M B; Asthana, S N

    2004-08-01

    A new code viz., Linear Output Thermodynamic User-friendly Software for Energetic Systems (LOTUSES) developed during this work predicts the theoretical performance parameters such as density, detonation factor, velocity of detonation, detonation pressure and thermodynamic properties such as heat of detonation, heat of explosion, volume of explosion gaseous products. The same code also assists in the prediction of possible explosive decomposition products after explosion and power index. The developed code has been validated by calculating the parameters of standard explosives such as TNT, PETN, RDX, and HMX. Theoretically predicated parameters are accurate to the order of +/-5% deviation. To the best of our knowledge, no such code is reported in literature which can predict a wide range of characteristics of known/unknown explosives with minimum input parameters. The code can be used to obtain thermochemical and performance parameters of high energy materials (HEMs) with reasonable accuracy. The code has been developed in Visual Basic having enhanced windows environment, and thereby advantages over the conventional codes, written in Fortran. The theoretically predicted HEMs performance can be directly printed as well as stored in text (.txt) or HTML (.htm) or Microsoft Word (.doc) or Adobe Acrobat (.pdf) format in the hard disk. The output can also be copied into the Random Access Memory as clipboard text which can be imported/pasted in other software as in the case of other codes. PMID:15225927

  6. Performance impact of parameter tuning on the CCSDS-123 lossless multi- and hyperspectral image compression standard

    NASA Astrophysics Data System (ADS)

    Augé, Estanislau; Sánchez, Jose Enrique; Kiely, Aaron; Blanes, Ian; Serra-Sagristà, Joan

    2013-01-01

    Multi-spectral and hyperspectral image data payloads have large size and may be challenging to download from remote sensors. To alleviate this problem, such images can be effectively compressed using specially designed algorithms. The new CCSDS-123 standard has been developed to address onboard lossless coding of multi-spectral and hyperspectral images. The standard is based on the fast lossless algorithm, which is composed of a causal context-based prediction stage and an entropy-coding stage that utilizes Golomb power-of-two codes. Several parts of each of these two stages have adjustable parameters. CCSDS-123 provides satisfactory performance for a wide set of imagery acquired by various sensors; but end-users of a CCSDS-123 implementation may require assistance to select a suitable combination of parameters for a specific application scenario. To assist end-users, this paper investigates the performance of CCSDS-123 under different parameter combinations and addresses the selection of an adequate combination given a specific sensor. Experimental results suggest that prediction parameters have a greater impact on the compression performance than entropy-coding parameters.

  7. An Approach for Improving Prediction in River System Models Using Bayesian Probabilities of Parameter Performance

    NASA Astrophysics Data System (ADS)

    Kim, S. S. H.; Hughes, J. D.; Chen, J.; Dutta, D.; Vaze, J.

    2014-12-01

    Achieving predictive success is a major challenge in hydrological modelling. Predictive metrics indicate whether models and parameters are appropriate for impact assessment, design, planning and management, forecasting and underpinning policy. It is often found that very different parameter sets and model structures are equally acceptable system representations (commonly described as equifinality). Furthermore, parameters that produce the best goodness of fit during a calibration period may often yield poor results outside of that period. A calibration method is presented that uses a recursive Bayesian filter to estimate the probability of consistent performance of parameter sets in different sub-periods. The result is a probability distribution for each specified performance interval. This generic method utilises more information within time-series data than what is typically used for calibrations, and could be adopted for different types of time-series modelling applications. Where conventional calibration methods implicitly identify the best performing parameterisations on average, the new method looks at the consistency of performance during sub-periods. The proposed calibration method, therefore, can be used to avoid heavy weighting toward rare periods of good agreement. The method is trialled in a conceptual river system model called the Australian Water Resources Assessments River (AWRA-R) model in the Murray-Darling Basin, Australia. The new method is tested via cross-validation and results are compared to a traditional split-sample calibration/validation to evaluate the new technique's ability to predict daily streamflow. The results showed that the new calibration method could produce parameterisations that performed better in validation periods than optimum calibration parameter sets. The method shows ability to improve on predictive performance and provide more realistic flux terms compared to traditional split-sample calibration methods.

  8. The player and the bowed string: coordination of bowing parameters in violin and viola performance.

    PubMed

    Schoonderwaldt, E

    2009-11-01

    An experiment was conducted with four violin and viola players, measuring their bowing performance using an optical motion capture system and sensors on the bow. The measurements allowed for a detailed analysis of the use and coordination of the main bowing parameters bow velocity, bow force, and bow-bridge distance. An analysis of bowing strategies in detache playing of notes of three durations (0.2, 2, and 4 s) at three dynamic levels (pp, mf, and f) on all four strings is presented, focusing on the "steady" part of the notes. The results revealed clear trends in the coordinated variations of the bowing parameters depending on the constraints of the task, reflecting a common behavior as well as individual strategies. Furthermore, there were clear indications that the players adapted the bowing parameters to the physical properties of the string and the instrument, respecting the limits of the playable control parameter space. PMID:19894847

  9. Impact of various operating modes on performance and emission parameters of small heat source

    NASA Astrophysics Data System (ADS)

    Vician, Peter; Holubčík, Michal; Palacka, Matej; Jandačka, Jozef

    2016-06-01

    Thesis deals with the measurement of performance and emission parameters of small heat source for combustion of biomass in each of its operating modes. As the heat source was used pellet boiler with an output of 18 kW. The work includes design of experimental device for measuring the impact of changes in air supply and method for controlling the power and emission parameters of heat sources for combustion of woody biomass. The work describes the main factors that affect the combustion process and analyze the measurements of emissions at the heat source. The results of experiment demonstrate the values of performance and emissions parameters for the different operating modes of the boiler, which serve as a decisive factor in choosing the appropriate mode.

  10. Important Physiological Parameters and Physical Activity Data for Evaluating Exposure Modeling Performance: a Synthesis

    EPA Science Inventory

    The purpose of this report is to develop a database of physiological parameters needed for understanding and evaluating performance of the APEX and SHEDS exposure/intake dose rate model used by the Environmental Protection Agency (EPA) as part of its regulatory activities. The A...

  11. Performance, blood parameters and meat yield in broiler chickens supplemented with Mexican oregano oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the inclusion of Mexican oregano oil (MOO) Lippia berlandieri Schauer in broiler diets during grow-out on performance, blood parameters, and meat yield. One hundred and sixty-two one-day-old broilers, randomly divided into three equal groups (treatments): CON =...

  12. Relationship between residual feed intake, performance, and carcass parameters of pasture finished cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2009 and 2010, Angus-crossbred steers (n = 39) were used to evaluate the relationship between residual feed intake (RFI), pasture-finishing performance and carcass parameters. During RFI determinations prior to pasture finishing initiation in mid-April, animals were fed an alfalfa hay cube diet....

  13. Cefaclor pharmacokinetic parameters: serum concentrations determined by a new high-performance liquid chromatographic technique.

    PubMed

    Rotschafer, J C; Crossley, K B; Lesar, T S; Zaske, D; Miller, K

    1982-01-01

    Pharmacokinetic parameters of cefaclor were studied in eight patients after an oral dose of 250 mg. Serum samples were obtained before and on 19 occasions after oral administration. Cefaclor serum concentrations were determined by a new high-performance liquid chromatographic technique. PMID:7081972

  14. Design of measurement system for low illuminance CCD's key performance parameters

    NASA Astrophysics Data System (ADS)

    Shao, Xiao-peng; Du, Juan; Wang, Yang

    2013-08-01

    As an important photovoltaic detector in the night vision imaging systems, some main performance parameters decide the properties of the low illuminance CCDs greatly including noise, quantum effects, dynamic range and dark current, and it is necessary to design a measurement system to measure the performance parameters of the low illuminance CCD. This article designs a set of low illuminance CCD chips' performance parameter measurement system, which is consisted of five parts including adjustable monochromatic light source, integrating sphere-darkroom, Dewar control chamber, main control circuit and the master computer software for automatic measurement. By persistent demonstration, the performance parameters measurement system which is focused on the low illuminance CCD proposed in this paper has the advantages of compact, good compatibility, theoretical measurement precision and fully automated measurement etc.The appropriate equipment and instruments are selected in this measurement system. And the connections of each subsystem are designed independently, which guarantees the tightness of the total system, eliminate the effects of stray light at the same time and improves the measurement accuracy of the system. Besides, this measurement system solves the generation of monochromatic light, and the measurement of low illuminance CCDs at a low temperature.

  15. Investigation of the relative significance of individual environmental parameters to sonar performance prediction uncertainty

    NASA Astrophysics Data System (ADS)

    Wang, Ding; Xu, Wen; Schmidt, Henrik

    2002-11-01

    A large part of sonar performance prediction uncertainty is associated with the uncertain ocean acoustic environment. Optimal in situ measurement strategy, i.e. adaptively capturing the most critical uncertain environmental parameters within operational constrains can minimize the sonar performance prediction uncertainty. Understanding the relative significance of individual environmental parameters to sonar performance prediction uncertainty is fundamental to the heuristics to determine the most critical environmental parameters. Based on this understanding, the optimal parametrization of ocean acoustic environments can be defined, which will significantly simplify the adaptively sampling pattern. As an example, the matched-field processing is used to localize an unknown sound source position in a realistic ocean environment. Typical shallow water environmental models are used with some of the properties being stochastic variables. The ratio of the main lobe peak to the maximum side lobe peak of the ambiguity function and the main lobe peak displacement due to mismatch are chosen as performance metrics, respectively, in two different scenarios. The relative significance of some environmental parameters such as sediment thickness, weights of empirical orthogonal functions (EOFs) has been computed. Some preliminary results are discussed.

  16. New electrolytes and electrolyte additives to improve the low temperature performance of lithium-ion batteries

    SciTech Connect

    Yang, Xiao-Qing

    2008-08-31

    In this program, two different approaches were undertaken to improve the role of electrolyte at low temperature performance - through the improvement in (i) ionic conductivity and (ii) interfacial behavior. Several different types of electrolytes were prepared to examine the feasibil.ity of using these new electrolytes in rechargeable lithium-ion cells in the temperature range of +40°C to -40°C. The feasibility studies include (a) conductivity measurements of the electrolytes, (b) impedance measurements of lithium-ion cells using the screened electrolytes with di.fferent electrochemical history such as [(i) fresh cells prior to formation cycles, (ii) after first charge, and (iii) after first discharge], (c) electrical performance of the cells at room temperatures, and (d) charge discharge behavior at various low temperatures. Among the different types of electrolytes investigated in Phase I and Phase II of this SBIR project, carbonate-based LiPF6 electrolytes with the proposed additives and the low viscous ester as a third component to the carbonate-based LiPF6 electrolytes show promising results at low temperatures. The latter electrolytes deliver over 80% of room temperature capacity at -20{degrees}C when the lithium-ion cells containing these electrolytes were charged at -20 °C. Also, there was no lithium plating when the lithium­-ion cells using C-C composite anode and LiPF{sub 6} in EC/EMC/MP electrolyte were charged at -20{degrees}C at C/5 rate. The studies of ionic conductivity and AC impedance of these new electrolytes, as well as the charge discharge characteristics of lithium-ion cells using these new electrolytes at various low temperatures provide new findings: The reduced capacity and power capability, as well as the problem of lithium plating at low temperatures charging of lithium-ion cells are primarily due to slow the lithium-ion intercalation/de-intercalation kinetics in the carbon structure.

  17. Spatiotemporal and Kinematic Parameters Relating to Oriented Gait and Turn Performance in Patients with Chronic Stroke

    PubMed Central

    Bonnyaud, Céline; Pradon, Didier; Vuillerme, Nicolas; Bensmail, Djamel; Roche, Nicolas

    2015-01-01

    Background The timed up and go test (TUG) is a functional test which is increasingly used to evaluate patients with stroke. The outcome measured is usually global TUG performance-time. Assessment of spatiotemporal and kinematic parameters during the Oriented gait and Turn sub-tasks of the TUG would provide a better understanding of the mechanisms underlying patients’ performance and therefore may help to guide rehabilitation. The aim of this study was thus to determine the spatiotemporal and kinematic parameters which were most related to the walking and turning sub-tasks of TUG performance in stroke patients. Methods 29 stroke patients carried out the TUG test which was recorded using an optoelectronic system in two conditions: spontaneous and standardized condition (standardized foot position and instructed to turn towards the paretic side). They also underwent a clinical assessment. Stepwise regression was used to determine the parameters most related to Oriented gait and Turn sub-tasks. Relationships between explanatory parameters of Oriented gait and Turn performance and clinical scales were evaluated using Spearman correlations. Results Step length and cadence explained 82% to 95% of the variance for the walking sub-tasks in both conditions. Percentage single support phase and contralateral swing phase (depending on the condition) respectively explained 27% and 56% of the variance during the turning sub-task in the spontaneous and standardized conditions. Discussion and Conclusion Step length, cadence, percentage of paretic single support phase and non-paretic swing phase, as well as dynamic stability were the main parameters related to TUG performance and they should be targeted in rehabilitation. PMID:26091555

  18. The effects of additive gases (Ar, N2, H2, Cl2, O2) on HCl plasma parameters and composition

    NASA Astrophysics Data System (ADS)

    Efremov, A.; Yudina, A.; Davlyatshina, A.; Murin, D.; Svetsov, V.

    2013-01-01

    The direct current (dc) glow discharge plasma parameters and active species kinetics in HCl-X (X = Ar, N2, H2, Cl2, O2) mixtures were studied using both plasma diagnostics Langmuir probes and modeling. The 0-dimensional self-consistent steady-state model included the simultaneous solution of Boltzmann kinetic equation, the equations of chemical kinetics for neutral and charge particles, plasma conductivity equation and the quasi-neutrality conditions for volume densities of charged particles as well as for their fluxes to the reactor walls. The data on the steady-state electron energy distribution function, electron gas characteristics (mean energy, drift rate and transport coefficients), volume-averaged densities of plasma active species and their fluxed to the reactor walls were obtained as functions of gas mixing ratios and gas pressure at fixed discharge current.

  19. High-performance lubricant additives based on modified graphene oxide by ionic liquids.

    PubMed

    Fan, Xiaoqiang; Wang, Liping

    2015-08-15

    Graphene oxide (GO) is a layered material bearing a variety of oxygen-containing functional groups on its basal planes and edges, which allow it as a substrate to conduct a variety of chemical transformations. Here modified graphene oxide (MGO) was prepared using alkyl imidazolium ionic liquids (ILs) (1-butyl-3-methylimidazolium tetrafluoroborate (LB104), 1-butyl-3-methyl imidazolium hexafluorophosphate (LP104) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide (LF106)) via epoxide ring-opening reaction, cation-π stacking or van der Waals interactions, with LB104 modified graphene (MG) exfoliated from graphite rod by a moderate electrochemical method as a comparison. The stability and tribological properties of MGO and MG as multialkylated cyclopentanes (MACs) additives were investigated in detail. The results show that GO is converted into graphene through the chemical modification using ILs, and MGO with good dispersion and stability in MACs significantly improves the tribological performance (friction and wear were reduced about 27% and 74% with pure MACs as a comparison, respectively). The excellent tribological properties are attributed to the formation of an ILs-containing graphene-rich tribofilm on the sliding surfaces, which as the third body can prevent the sliding surfaces from straight asperity contact and improve friction reducing and anti-wear behaviors. PMID:25935280

  20. Key parameters of the swimming start and their relationship to start performance.

    PubMed

    Tor, Elaine; Pease, David L; Ball, Kevin A

    2015-01-01

    The swimming start is typically broken into three sub-phases; on-block, flight, and underwater phases. While overall start performance is highly important to elite swimming, the contribution of each phase and important technical components within each phase, particularly with the new kick-start technique, has not been established. The aim of this study was to identify technical factors associated with overall start performance, with a particular focus on the underwater phase. A number of parameters were calculated from 52 starts performed by elite freestyle and butterfly swimmers. These parameters were split into above-water and underwater groupings, before factor analysis was used to reduce parameter numbers for multiple regression. For the above-water phases, 81% of variance in start performance was accounted for by take-off horizontal velocity. For the underwater water phase, 96% of variance was accounted for with time underwater in descent, time underwater in ascent and time to 10 m. Therefore, developing greater take-off horizontal velocity and focussing on the underwater phase by finding the ideal trajectory will lead to improved start performance. PMID:25555171

  1. Objective evaluation of two deworming regimens in young Thoroughbreds using parasitological and performance parameters.

    PubMed

    Bellaw, Jennifer L; Pagan, Joe; Cadell, Steve; Phethean, Eileen; Donecker, John M; Nielsen, Martin K

    2016-05-15

    Parasitic helminths of equids are capable of causing ill-thrift, clinical disease, and death. Although young horses are the most susceptible to parasitic disease and are the most intensively treated cohort, deworming regimens are rarely evaluated within this age group. This study objectively evaluated the impact of deworming regimen on fecal egg counts (FECs), growth rates, and body-condition scores in young Thoroughbreds. Forty-eight Thoroughbred foals from three central Kentucky farms were randomly allocated to two treatment groups: an interval dose program receiving bi-monthly rotations of pyrantel pamoate and ivermectin and a daily deworming group receiving daily rations of pyrantel tartrate feed additive throughout the study, oxibendazole at two months of age, and moxidectin treatments at 9.5 and 16.5 months of age. Pre- and post-treatment eggs per gram of feces (EPGs) of Parascaris spp. and strongyle family parasites, gel/paste dewormer efficacies, and monthly weights and body condition scores were collected. Ascarid and strongyle FECs were not significantly different between groups but were significantly influenced by horse age with strongyle counts continually increasing and ascarid counts peaking at 4.5 months of age. Reduced strongyle efficacies of ivermectin and moxidectin were observed on two farms with consistently low pyrantel pamoate efficacies on all three farms. Ivermectin also exhibited reduced ascarid efficacy. Average daily gain did not differ significantly between groups and was only significantly influenced by age, mirroring average daily gain reference data for Kentucky Thoroughbreds born in 2013. Body condition scores also did not differ between groups, remaining in the optimal range (5-6) for the duration of the study. Management practices resulting in growth rates matching the reference data and in optimal body condition scores compensate for the negative impacts of parasitism even in cases of reduced drug efficacy. Performance parameters

  2. Parameter Plane Synthesis and Performance Investigation of a Three-Phase Three-Level Bidirectional Rectifier

    NASA Astrophysics Data System (ADS)

    Bhat, Abdul Hamid; Langer, Nitin

    2014-12-01

    In this paper, parameter plane synthesis of a three-phase neutral-point clamped bidirectional rectifier has been performed. The converter involves one outer-loop PI voltage controller and two inner-loop PI current controllers for the closed-loop control. D-partition technique has been employed for the precise design of the voltage controller. An experimental prototype of the converter has been developed, and the experimental investigation of the converter performance in closed loop has been carried out. DSP DS1104 of dSPACE has been used for real-time implementation of the designed controller. The converter gives a very good performance in steady state and dynamic state (for rectification as well as inversion modes of operation) using the designed controller parameters.

  3. Use of Additives to Improve Performance of Methyl Butyrate-Based Lithium-Ion Electrolytes

    NASA Technical Reports Server (NTRS)

    Smart, Marshall C.; Bugga, Ratnakumar V.

    2011-01-01

    This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range. To this end, a number of electrolyte formulations have been developed that incorporate the use of electrolyte additives to improve the high-temperature resilience, low-temperature power capability, and life characteristics of methyl butyrate-based electrolyte solutions. These electrolyte additives include mono-fluoroethylene carbonate (FEC), lithium oxalate, vinylene carbonate (VC), and lithium bis(oxalato)borate (LiBOB), which have been shown to result in improved high-temperature resilience of all carbonate-based electrolytes. Improved performance has been demonstrated of Li-ion cells with methyl butyrate-based electrolytes, including 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %); 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 4% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + lithium oxalate; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% VC; and 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 0.10M LiBOB. These electrolytes have been shown to improve performance in MCMB-LiNiCoO2 and graphite-LiNi1/3Co1/3Mn1/3O2 experimental Li-ion cells. A number of LiPF6-based mixed carbonate electrolyte formulations have been developed that contain ester co-solvents, which have been optimized for operation at low temperature, while still providing reasonable performance at high temperature. For example, a number of ester co-solvents were investigated, including methyl propionate (MP), ethyl propionate (EP), methyl butyrate (MB), ethyl butyrate (EB), propyl butyrate (PB), and butyl butyrate (BB) in multi-component electrolytes of the following composition: 1.0M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (20:60:20 v/v %) [where X = ester co-solvent]. ["Optimized Car bon ate and Ester-Based Li-Ion Electrolytes", NASA Tech Briefs, Vol. 32, No. 4 (April 2008), p. 56.] Focusing upon improved rate

  4. Mechanical Performance and Parameter Sensitivity Analysis of 3D Braided Composites Joints

    PubMed Central

    Wu, Yue; Nan, Bo; Chen, Liang

    2014-01-01

    3D braided composite joints are the important components in CFRP truss, which have significant influence on the reliability and lightweight of structures. To investigate the mechanical performance of 3D braided composite joints, a numerical method based on the microscopic mechanics is put forward, the modeling technologies, including the material constants selection, element type, grid size, and the boundary conditions, are discussed in detail. Secondly, a method for determination of ultimate bearing capacity is established, which can consider the strength failure. Finally, the effect of load parameters, geometric parameters, and process parameters on the ultimate bearing capacity of joints is analyzed by the global sensitivity analysis method. The results show that the main pipe diameter thickness ratio γ, the main pipe diameter D, and the braided angle α are sensitive to the ultimate bearing capacity N. PMID:25121121

  5. Mechanical performance and parameter sensitivity analysis of 3D braided composites joints.

    PubMed

    Wu, Yue; Nan, Bo; Chen, Liang

    2014-01-01

    3D braided composite joints are the important components in CFRP truss, which have significant influence on the reliability and lightweight of structures. To investigate the mechanical performance of 3D braided composite joints, a numerical method based on the microscopic mechanics is put forward, the modeling technologies, including the material constants selection, element type, grid size, and the boundary conditions, are discussed in detail. Secondly, a method for determination of ultimate bearing capacity is established, which can consider the strength failure. Finally, the effect of load parameters, geometric parameters, and process parameters on the ultimate bearing capacity of joints is analyzed by the global sensitivity analysis method. The results show that the main pipe diameter thickness ratio γ, the main pipe diameter D, and the braided angle α are sensitive to the ultimate bearing capacity N. PMID:25121121

  6. Analysis report for WIPP colloid model constraints and performance assessment parameters

    SciTech Connect

    Mariner, Paul E.; Sassani, David Carl

    2014-03-01

    An analysis of the Waste Isolation Pilot Plant (WIPP) colloid model constraints and parameter values was performed. The focus of this work was primarily on intrinsic colloids, mineral fragment colloids, and humic substance colloids, with a lesser focus on microbial colloids. Comments by the US Environmental Protection Agency (EPA) concerning intrinsic Th(IV) colloids and Mg-Cl-OH mineral fragment colloids were addressed in detail, assumptions and data used to constrain colloid model calculations were evaluated, and inconsistencies between data and model parameter values were identified. This work resulted in a list of specific conclusions regarding model integrity, model conservatism, and opportunities for improvement related to each of the four colloid types included in the WIPP performance assessment.

  7. Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

    NASA Astrophysics Data System (ADS)

    Saikia, Partha; Saikia, Bipul Kumar; Bhuyan, Heman

    2016-04-01

    We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te), electron density (ne), ion density (ni), degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

  8. Effects of variation of environmental parameters on the performance of Resistive Plate Chamber detectors

    NASA Astrophysics Data System (ADS)

    Meghna, K. K.; Biswas, S.; Jash, A.; Chattopadhyay, S.; Saha, S.

    2016-04-01

    Performance of single gap Resistive Plate Chamber (RPC) detectors is investigated under variation of environmental parameters, such as temperature and relative humidity. Operational characteristics of the RPCs depend on both the environmental temperature and the relative humidity. Sensitivity to such dependence is found to be more on temperature rather than the relative humidity. Qualitative interpretation of some of the results obtained is given based on the known properties of the electrode materials and gases used in the detectors.

  9. Does a boar's season of birth determine semen parameters and reproductive performance?

    PubMed

    Knecht, D; Środoń, S; Duziński, K

    2014-04-01

    This article studies the effect of a boar's birth season and breed on semen parameters and its further reproductive performance. Research material consisted of 72 boars from three breeds (24 Polish Large White PLW, 24 Polish Landrace PL, 24 Duroc × Pietrain D × P). During the whole period of the study, selected semen parameters were analysed: semen volume, spermatozoa concentration, total number of spermatozoa, total number of motile spermatozoa, number of insemination doses and also reproductive indicators: farrowing rate, total born litter size, total number of piglets born live and still, and average piglet weight. Boars born in the winter and summer months demonstrated the highest spermatozoa concentrations (383.25 and 392.37 × 10(6)/ml), total number of spermatozoa (91.75 and 93.21 × 10(9)), total number of motile spermatozoa (76.10 and 77.99 × 10(9)) and number of insemination doses (24.53 and 24.89; p ≤ 0.01). Statistically lower values for these parameters were observed for boars born in the spring and especially in autumn (p ≤ 0.01). The significant impact of birth season on farrowing rate (p ≤ 0.05) and average piglet weight (p ≤ 0.05) was confirmed for PLW boars. For the PL breed, only the total number of piglets born live was proven to be significantly affected (p ≤ 0.05). No impact of birth season was shown on semen quality or reproductive performance for D × P boars. In our study, we showed that the birth season of a boar had a more impact on the level of semen parameters, and less on the reproductive performance indicators. The results indicated that both the quality of semen and reproductive performance varied in terms of the study factors, as well as between individual breeds of boars involved in the experiment. PMID:24237255

  10. An information-measuring system for evaluating performance parameters of lighting devices

    NASA Astrophysics Data System (ADS)

    Abulkhanov, Stanislav R.; Kharitonov, Sergey I.

    2016-04-01

    We propose the design of an information-measuring system for evaluating performance parameters of lighting devices. The system comprises four basic components: a software-hardware complex for designing lighting devices, an emulator of natural and technogeneous effects on an optical surface, an optical surface condition analyzer, and a lighting-device laboratory test unit. With this system, the duration of optical device certification tests can be reduced by several orders of magnitude when compared to full-scale tests.

  11. Static internal performance of single-expansion-ramp nozzles with various combinations of internal geometric parameters

    NASA Technical Reports Server (NTRS)

    Re, R. J.; Leavitt, L. D.

    1984-01-01

    The effects of five geometric design parameters on the internal performance of single-expansion-ramp nozzles were investigated at nozzle pressure ratios up to 10 in the static-test facility of the Langley 16-Foot Transonic Tunnel. The geometric variables on the expansion-ramp surface of the upper flap consisted of ramp chordal angle, ramp length, and initial ramp angle. On the lower flap, the geometric variables consisted of flap angle and flap length. Both internal performance and static-pressure distributions on the centerlines of the upper and lower flaps were obtained for all 43 nozzle configurations tested.

  12. Polysulfide and bio-based EP additive performance in vegetable vs. paraffinic base oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twist compression test (TCT) and 4-ball extreme pressure (EP) methods were used to investigate commercial polysulfide (PS) and bio-based polyester (PE) EP additives in paraffinic (150N) and refined soybean (SOY) base oils of similar viscosity. Binary blends of EP additive and base oil were investiga...

  13. Parameters affecting resin-anchored cable bolt performance: Results of in situ evaluations

    SciTech Connect

    Zelanko, J.C.; Mucho, T.P.; Compton, C.S.; Long, L.E.; Bailey, P.E.

    1995-11-01

    Cable bolt support techniques, including hardware and anchorage systems, continue to evolve to meet US mining requirements. For cable support systems to be successfully implemented into new ground control areas, the mechanics of this support and the potential range of performance need to be better understood. To contribute to this understanding, a series of 36 pull tests were performed on 10 ft long cable bolts using various combinations of hole diameters, resin formulations, anchor types, and with and without resin dams. These test provided insight as to the influence of these four parameters on cable system performance. Performance was assessed in terms of support capacity (maximum load attained in a pull test), system stiffness (assessed from two intervals of load-deformation), and from the general load-deformation response. Three characteristic load-deformation responses were observed. An Analysis of Variance identified a number of main effects and interactions of significance to support capacity and stiffness. The factorial experiment performed in this study provides insight to the effects of several design parameters associated with resin-anchored cable bolts.

  14. Improving the environmental and performance characteristics of vehicles by introducing the surfactant additive into gasoline.

    PubMed

    Magaril, Elena; Magaril, Romen

    2016-09-01

    The operation of modern vehicles requires the introduction of package of fuel additives to ensure the required level of operating characteristics, some of which cannot be achieved by current oil refining methods. The use of additives allows flexibility of impact on the properties of the fuel at minimal cost, increasing the efficiency and environmental safety of vehicles. Among the wide assortment of additives available on the world market, many are surfactants. It has been shown that the introduction of some surfactants into gasoline concurrently reduces losses from gasoline evaporation, improves the mixture formation during injection of gasoline into the engine and improves detergent and anticorrosive properties. The surfactant gasoline additive that provides significant improvement in the quality of gasoline used and environmental and operating characteristics of vehicles has been developed and thoroughly investigated. The results of studies confirming the efficiency of the gasoline additive application are herein presented. PMID:27206755

  15. Effects of different additives on the performance of spray dryer system during incineration process.

    PubMed

    Wey, M Y; Peng, C Y; Wu, H Y; Chiang, B C; Liu, Z S

    2002-06-01

    The spray dryer system was conventionally employed to remove the SOx, NOx, and HCl in the flue gas. However, the removal efficiency of acid gas in the practical incineration flue gas, which contains dust, heavy metals, and acid gas itself, was seldom mentioned in the literature. The alkaline sorbents possess large specific surface that was a main factor on the adsorption of heavy metals and acid gas. Therefore, the primary objective of this study was focused on the effect of different additives on the removal efficiency of acid gas and heavy metals (Cr, Cd and Pb). The mass and element size distribution of heavy metals in fly ash under different additives were also investigated. The results indicated that the removal efficiency of HCl in the spray dryer system was higher than 97.8%. The effects of additives on the removal efficiency of HCl, however, were undistinguished. In the desulfurization process, the highest removal efficiency was 71.3% when the additive of amorphous SiO2 was added in the spray dryer system. The removal efficiency was 66.0% with the additive of CaCl2 and 63.1% without any additives, respectively. It was also found that the spray dryer system could decrease the concentration of metal in fly ash but increase the amount of fly ash. In addition, amorphous SiO2 in the alkaline sorbent tended to increase the adsorption of heavy metal on reactant, because it could enhance the dispersion of alkaline sorbent. PMID:12118621

  16. The effect of alkaline additives on the performance of surfactant systems designed to recover light oils

    SciTech Connect

    French, T.R.; Josephson, C.B.; Evans, D.B.

    1991-02-01

    Surfactant flooding is flexible because of the ability to optimize formulations for a wide range of reservoir conditions and crude oil types. The objective for this work was to determine if the addition of alkaline additives will allow the design of surfactant formulations that are effective for the recovery of crude oil, while, at the same time, maintaining the surfactant concentration at a much lower level than has previously been used for micellar flooding. Specifically, the focus of the work was on light, midcontinent crudes that typically have very low acid contents. These oils are typical of much of the midcontinent resource. The positive effect of alkaline additives on the phase behavior of the surfactant formulations and acidic crude oils is well known. The extension to nonacidic and slightly acidic oils is not obvious. Three crude oils, a variety of commercial surfactants, and several alkaline additives were tested. The oils had acid numbers that ranged from 0.13, which is quite low, to less than 0.01 mg KOH/g of oil. Alkaline additives were found to be very effective in recovering Delaware-Childers (OK) oil at elevated temperatures, but much less effective at reservoir temperatures. Alkaline additives were very effective with Teapot Dome (WY) oil. With Teapot Dome oil, surfactant/alkali systems produced ultralow IFT values and recovered 60% of the residual oil that remained after waterflooding. The effect of alkaline additives on recovering Hepler (KS) oil was minimal. The results of this work indicate that alkaline additives do have merit for use in surfactant flooding of low acid crude oils; however, no universal statement about applicability can be made. Each oil behaves differently, with this treatment, and the effect of alkaline additives must be determined (at reservoir conditions) for each oil. 23 refs., 13 figs., 3 tabs.

  17. Dependence of the source performance on plasma parameters at the BATMAN test facility

    SciTech Connect

    Wimmer, C.; Fantz, U.

    2015-04-08

    The investigation of the dependence of the source performance (high j{sub H{sup −}}, low j{sub e}) for optimum Cs conditions on the plasma parameters at the BATMAN (Bavarian Test MAchine for Negative hydrogen ions) test facility is desirable in order to find key parameters for the operation of the source as well as to deepen the physical understanding. The most relevant source physics takes place in the extended boundary layer, which is the plasma layer with a thickness of several cm in front of the plasma grid: the production of H{sup −}, its transport through the plasma and its extraction, inevitably accompanied by the co-extraction of electrons. Hence, a link of the source performance with the plasma parameters in the extended boundary layer is expected. In order to characterize electron and negative hydrogen ion fluxes in the extended boundary layer, Cavity Ring-Down Spectroscopy and Langmuir probes have been applied for the measurement of the H{sup −} density and the determination of the plasma density, the plasma potential and the electron temperature, respectively. The plasma potential is of particular importance as it determines the sheath potential profile at the plasma grid: depending on the plasma grid bias relative to the plasma potential, a transition in the plasma sheath from an electron repelling to an electron attracting sheath takes place, influencing strongly the electron fraction of the bias current and thus the amount of co-extracted electrons. Dependencies of the source performance on the determined plasma parameters are presented for the comparison of two source pressures (0.6 Pa, 0.45 Pa) in hydrogen operation. The higher source pressure of 0.6 Pa is a standard point of operation at BATMAN with external magnets, whereas the lower pressure of 0.45 Pa is closer to the ITER requirements (p ≤ 0.3 Pa)

  18. Effects of Khaya senegalensis leaves on performance, carcass traits, hemtological and biochemical parameters in rabbits

    PubMed Central

    Abdel-Wareth, A. A. A.; Hammad, Seddik; Ahmed, Hassan

    2014-01-01

    One of the challenges facing farmers today is to ensure adequate integration of natural resources into animal feeds. The aim of the present study is to evaluate the effects of Khaya senegalensis (KS) leaves on the performance of growing male rabbits, carcass traits and biochemical as well as hematological parameters. Thirty New Zealand White male growing rabbits were randomly divided into 3 groups (10 rabbits per group). Group I (control) received standard rabbit diet. Rabbits in group II and group III were fed standard rabbit diet supplemented with 35 % and 65 % KS leaves, respectively. All rabbits were fed daily for 25 days. The performance parameters and carcass criteria, including daily body weight gain, final body weight, and the percentage of dressing, were increased in rabbits fed 35 % KS when compared to the control group. Kidney and liver weight ratios increased significantly in group II but dropped in group III. Furthermore, liver enzymes - alanine aminotransferase and aspartate transaminase and kidney function parameters - urea, and creatinine - increased in both group II (significant P<0.05) and in group III (significant P<0.01) when compared to the control group. Moreover, KS leaves induced a significant increase (P<0.05) in the total white blood cell count, the percentage of granulocytes and the platelet count; whereas, the percentage of lymphocytes, red blood cell count, hemoglobin content, mean corpuscular hemoglobin, mean corpuscular volume and mean corpuscular hemoglobin concentration were not statistically significantly changed. This study demonstrates that the performance parameters and carcass traits are improved by the replacement of rabbit's diet with KS leaves. However, KS leaves may adversely affect liver and kidney function in a dose-dependent manner. Therefore, further studies are required to elucidate the maximum tolerable and toxic, as well as lethal doses, and to isolate the pharmacologically active components from KS leaves. PMID

  19. Effects of post-exercise recovery interventions on physiological, psychological, and performance parameters.

    PubMed

    Cortis, C; Tessitore, A; D'Artibale, E; Meeusen, R; Capranica, L

    2010-05-01

    At present, there is no consensus on the effectiveness of post-exercise recovery interventions on subsequent daily performances. The purpose of this study was to compare the effectiveness of 20 min low-intensity water exercises, supine electrostimulation, and passive (sitting rest) recovery modalities on physiological (oxygen consumption, blood lactate concentration, and percentage of hemoglobin saturation in the muscles), psychological (subjective ratings of perceived exertion, muscle pain, and feeling of recovery), and performance (countermovement, bouncing jumping) parameters. During three experimental sessions, 8 men (age: 21.9+/-1.3 yrs; height: 175.8+/-10.7 cm; body mass: 71.2+/-9.8 kg; VO(2max): 57.9+/-5.1 ml x kg x min(-1)) performed a morning and an afternoon submaximal running test. The recovery interventions were randomly administered after the first morning tests. Activity and dietary intake were replicated on each occasion. ANOVA for repeated measures (p<0.05) showed no difference between the morning and afternoon physiological (ratios: range 0.90-1.18) and performance parameters (ratios: range 0.80-1.24), demonstrating that post-exercise recovery interventions do not provide significant beneficial effects over a limited time period. Conversely, subjects perceived water exercises (60%) and electrostimulation (40%) as the most effective interventions, indicating that these recovery strategies might improve the subjective feelings of wellbeing of the individual. PMID:20180177

  20. [Effects of long term mental arithmetic on physiological parameters, subjective indices and task performances].

    PubMed

    Yamada, Shimpei; Miyake, Shinji

    2007-03-01

    This study examined the effects of long term mental arithmetic on physiological parameters, subjective indices and task performances to investigate the psychophysiological changes induced by mental tasks. Fifteen male university students performed six successive trials of a ten-minute mental arithmetic task. They took a five-minute resting period before and after the tasks. CFF (Critical Flicker Fusion frequency) and subjective fatigue scores using a visual analog scale, POMS (Profiles of Mood States) and SFF (Subjective Feelings of Fatigue) were obtained after each task and resting period. The voices of participants who were instructed to speak five Japanese vowels ('a', 'i', 'u', 'e', 'o') were recorded after each block to investigate a chaotic property of vocal signals that is reported to be changed by fatigue. Subjective workload ratings were also obtained by the NASA-TLX (National Aeronautics and Space Administration-Task Load Index) after the task. Physiological signals of ECG (Electrocardiogram), PTG (Photoelectric Plethysmogram), SCL (Skin Conductance Level), TBV (Tissue Blood Volume) and Respiration were recorded for all experimental blocks. The number of answers, correct rates and average levels of task difficulty for each ten-minute task were used as task performance indices. In this experiment, the task performance did not decrease, whereas subjective fatigue increased. Activation of the sympathetic nervous system was suggested by physiological parameters. PMID:17380727

  1. Additional Evidence on the Relationship between Class Size and Student Performance

    ERIC Educational Resources Information Center

    Arias, J. J.; Walker, Douglas M.

    2004-01-01

    Much of the economic education literature suggests that the principles of economics class size does not significantly affect student performance. However, study methods have varied in terms of the aggregation level (student or class), the measure of performance (TUCE or course letter grade), and the class size measure (e.g., students who completed…

  2. Sensitivity of storage field performance to geologic and cavern design parameters in salt domes.

    SciTech Connect

    Ehgartner, Brian L.; Park, Byoung Yoon; Herrick, Courtney Grant

    2010-06-01

    A sensitivity study was performed utilizing a three dimensional finite element model to assess allowable cavern field sizes in strategic petroleum reserve salt domes. A potential exists for tensile fracturing and dilatancy damage to salt that can compromise the integrity of a cavern field in situations where high extraction ratios exist. The effects of salt creep rate, depth of salt dome top, dome size, caprock thickness, elastic moduli of caprock and surrounding rock, lateral stress ratio of surrounding rock, cavern size, depth of cavern, and number of caverns are examined numerically. As a result, a correlation table between the parameters and the impact on the performance of a storage field was established. In general, slower salt creep rates, deeper depth of salt dome top, larger elastic moduli of caprock and surrounding rock, and a smaller radius of cavern are better for structural performance of the salt dome.

  3. Sensitivity of storage field performance to geologic and cavern design parameters in salt domes.

    SciTech Connect

    Ehgartner, Brian L.; Park, Byoung Yoon

    2009-03-01

    A sensitivity study was performed utilizing a three dimensional finite element model to assess allowable cavern field sizes for strategic petroleum reserve salt domes. A potential exists for tensile fracturing and dilatancy damage to salt that can compromise the integrity of a cavern field in situations where high extraction ratios exist. The effects of salt creep rate, depth of salt dome top, dome size, caprock thickness, elastic moduli of caprock and surrounding rock, lateral stress ratio of surrounding rock, cavern size, depth of cavern, and number of caverns are examined numerically. As a result, a correlation table between the parameters and the impact on the performance of storage field was established. In general, slower salt creep rates, deeper depth of salt dome top, larger elastic moduli of caprock and surrounding rock, and a smaller radius of cavern are better for structural performance of the salt dome.

  4. PERFORMANCE ENHANCEMENT OF COMPRESSION MOLDED KENAF FIBER REINFORCED VINYL ESTER COMPOSITES THROUGH RESIN ADDITIVE

    SciTech Connect

    Fifield, Leonard S.; Simmons, Kevin L.; Laddha, Sachin; Kafentzis, Tyler A.

    2010-05-17

    Plant-based bio-fiber has the potential to achieve weight and cost savings over glass fiber in automotive polymer composites if moisture stability and fiber-resin compatibility issues can be solved. This paper describes the compression molding of 50vol% 2 inch random nonwoven mat kenaf fiber vinyl ester composites with and without chemical resin additives intended to improve moisture stability and resin compatibility. The 2wt% addition of n-undecanoyl chloride or 10-undecenoyl chloride to the styrene-based resin prior to molding of the kenaf composites was observed to decrease the 24hr, 25oC moisture uptake of the molded panels by more than 50%. The tensile stiffness and flexural stiffness of the soaked panels containing these additives were seen to increase by more than 30% and 70%, respectively, relative to panels made with no additives. While ‘dry’ panel (50% relative humidity at 25oC) strengths did not significantly change in the presence of the additives, tensile strength was observed to increase by more than 40% and flexural strength more than doubled for the soaked panels.

  5. Detonation of highly dilute porous explosives; II: Influence of inert additives on the structure of the front, the parameters, and the reaction time

    SciTech Connect

    Shvedov, K.K.; Aniskin, A.I.; Dremin, A.N.; Il'in, A.N.

    1982-06-01

    For the detonation of porous explosives with inert additives, as for the detonation of individual porous explosives, the basic postulates and conclusions of the modern gasdynamic theory of detonation are valid. The influence of solid, refractory inert additives on the decomposition mechanism of porous explosives depends on the individual properties of the explosives and mainly on the dispersity of the additives. With the elimination of pronounced heating of the additives in mixtures with TNT, a certain positive influence on the appearance of decomposition sources and the total reaction time is observed. In cases with hexogen, no such influence is observed, which is evidently the result of physical inhomogeneity of the porous structure of the charge and the sufficiently high detonation pressures of the mixtures. The basic influence of inert additives on the critical diameter, front structure, detonation parameters, and reaction time of porous explosives is exerted through processes of energy absorption in the reaction region and factors leading to energy losses may lead to ambiguity of the detonation conditions in a system with specified chemical potential energy. The state of the additive in the reaction region must be taken into account for reliable theoretical description of the detonation conditions of porous explosives with a large content of inert additives.

  6. Atmospheric parameters, spectral indexes and their relation to CPV spectral performance

    NASA Astrophysics Data System (ADS)

    Núñez, Rubén; Antón, Ignacio; Askins, Steve; Sala, Gabriel

    2014-09-01

    Air Mass and atmosphere components (basically aerosol (AOD) and precipitable water (PW)) define the absorption of the sunlight that arrive to Earth. Radiative models such as SMARTS or MODTRAN use these parameters to generate an equivalent spectrum. However, complex and expensive instruments (as AERONET network devices) are needed to obtain AOD and PW. On the other hand, the use of isotype cells is a convenient way to characterize spectrally a place for CPV considering that they provide the photocurrent of the different internal subcells individually. Crossing data from AERONET station and a Tri-band Spectroheliometer, a model that correlates Spectral Mismatch Ratios and atmospheric parameters is proposed. Considering the amount of stations of AERONET network, this model may be used to estimate the spectral influence on energy performance of CPV systems close to all the stations worldwide.

  7. Atmospheric parameters, spectral indexes and their relation to CPV spectral performance

    SciTech Connect

    Núñez, Rubén Antón, Ignacio Askins, Steve Sala, Gabriel

    2014-09-26

    Air Mass and atmosphere components (basically aerosol (AOD) and precipitable water (PW)) define the absorption of the sunlight that arrive to Earth. Radiative models such as SMARTS or MODTRAN use these parameters to generate an equivalent spectrum. However, complex and expensive instruments (as AERONET network devices) are needed to obtain AOD and PW. On the other hand, the use of isotype cells is a convenient way to characterize spectrally a place for CPV considering that they provide the photocurrent of the different internal subcells individually. Crossing data from AERONET station and a Tri-band Spectroheliometer, a model that correlates Spectral Mismatch Ratios and atmospheric parameters is proposed. Considering the amount of stations of AERONET network, this model may be used to estimate the spectral influence on energy performance of CPV systems close to all the stations worldwide.

  8. Aerodynamic Parameters of High Performance Aircraft Estimated from Wind Tunnel and Flight Test Data

    NASA Technical Reports Server (NTRS)

    Klein, Vladislav; Murphy, Patrick C.

    1999-01-01

    A concept of system identification applied to high performance aircraft is introduced followed by a discussion on the identification methodology. Special emphasis is given to model postulation using time invariant and time dependent aerodynamic parameters, model structure determination and parameter estimation using ordinary least squares and mixed estimation methods. At the same time problems of data collinearity detection and its assessment are discussed. These parts of methodology are demonstrated in examples using flight data of the X-29A and X-31A aircraft. In the third example wind tunnel oscillatory data of the F-16XL model are used. A strong dependence of these data on frequency led to the development of models with unsteady aerodynamic terms in the form of indicial functions. The paper is completed by concluding remarks.

  9. Aerodynamic Parameters of High Performance Aircraft Estimated from Wind Tunnel and Flight Test Data

    NASA Technical Reports Server (NTRS)

    Klein, Vladislav; Murphy, Patrick C.

    1998-01-01

    A concept of system identification applied to high performance aircraft is introduced followed by a discussion on the identification methodology. Special emphasis is given to model postulation using time invariant and time dependent aerodynamic parameters, model structure determination and parameter estimation using ordinary least squares an mixed estimation methods, At the same time problems of data collinearity detection and its assessment are discussed. These parts of methodology are demonstrated in examples using flight data of the X-29A and X-31A aircraft. In the third example wind tunnel oscillatory data of the F-16XL model are used. A strong dependence of these data on frequency led to the development of models with unsteady aerodynamic terms in the form of indicial functions. The paper is completed by concluding remarks.

  10. METHODS FOR IMPROVEMENT OF TRICKLING FILTER PLANT PERFORMANCE. PART II. CHEMICAL ADDITION

    EPA Science Inventory

    An experimental program to explore potential methods for removing phosphorus and generally enhancing trickling filter plant performance was conducted at the Mason Farm Wastewater Treatment Plant, Chapel Hill, North Carolina. Preliminary investigations included jar testing with se...

  11. Antiwear performance and mechanism of an oil-miscible ionic liquid as a lubricant additive.

    PubMed

    Qu, Jun; Bansal, Dinesh G; Yu, Bo; Howe, Jane Y; Luo, Huimin; Dai, Sheng; Li, Huaqing; Blau, Peter J; Bunting, Bruce G; Mordukhovich, Gregory; Smolenski, Donald J

    2012-02-01

    An ionic liquid (IL) trihexyltetradecylphosphonium bis(2-ethylhexyl) phosphate has been investigated as a potential antiwear lubricant additive. Unlike most other ILs that have very low solubility in nonpolar fluids, this IL is fully miscible with various hydrocarbon oils. In addition, it is thermally stable up to 347 °C, showed no corrosive attack to cast iron in an ambient environment, and has excellent wettability on solid surfaces (e.g., contact angle on cast iron <8°). Most importantly, this phosphonium-based IL has demonstrated effective antiscuffing and antiwear characteristics when blended with lubricating oils. For example, a 5 wt % addition into a synthetic base oil eliminated the scuffing failure experienced in neat oil and, as a result, reduced the friction coefficient by 60% and the wear rate by 3 orders of magnitude. A synergistic effect on wear protection was observed with the current antiwear additive when added into a fully formulated engine oil. Nanostructure examination and composition analysis revealed a tribo-boundary film and subsurface plastic deformation zone for the metallic surface lubricated by the IL-containing lubricants. This protective boundary film is believed to be responsible for the IL's antiscuffing and antiwear functionality. PMID:22248297

  12. Improved Irradiation Performance of Uranium-Molybdenum/Aluminum Dispersion Fuel by Silicon Addition in Aluminum

    SciTech Connect

    Yeon Soo Kim; G. L. Hofman; A. B. Robinson; D. M. Wachs

    2013-10-01

    Uranium-molybdenum fuel particle dispersion in aluminum is a form of fuel under development for conversion of high-power research and test reactors from highly enriched to low-enriched uranium in the U.S. Global Threat Reduction Initiative program (also known as the Reduced Enrichment for Research and Test Reactors program). Extensive irradiation tests have been conducted to find a solution for problems caused by interaction layer growth and pore formation between U-Mo and Al. Adding a small amount of Si (up to [approximately]5 wt%) in the Al matrix was one of the proposed remedies. The effect of silicon addition in the Al matrix was examined using irradiation test results by comparing side-by-side samples with different Si additions. Interaction layer growth was progressively reduced with increasing Si addition to the matrix Al, up to 4.8 wt%. The Si addition also appeared to delay pore formation and growth between the U-Mo and Al.

  13. Influence of geometrical parameters on performance of plasma synthetic jet actuator

    NASA Astrophysics Data System (ADS)

    Zong, Hao-hua; Wu, Yun; Jia, Min; Song, Hui-min; Liang, Hua; Li, Ying-hong; Zhang, Zhi-bo

    2016-01-01

    Plasma synthetic jet actuator (PSJA) has shown wide and promising application prospects in a high speed flow control field, due to its rapid response, high exhaust velocity, and non-moving components. In this paper, the total pressure profile of a plasma synthetic jet (PSJ) is measured and a new method is developed to evaluate the pulsed thrust of the PSJA. The influence of geometrical parameters including the electrode distance, the orifice diameter, and the throat length on PSJA performance is analyzed based on the pulsed thrust, the discharge characteristics, and the schlieren images. When varying the electrode distance, the dominant factor determining the jet intensity is the heating volume instead of the discharge energy. For the arc discharge, the electrode distance should be extended to increase both the jet velocity and the jet duration time. The design of the orifice diameter should be based on the controlled flow field. A large orifice diameter produces a strong perturbation with short time duration, while a small orifice diameter induces a lasting jet with low mass flux. In order to obtain better high frequency performance, the throat length should be shortened on the condition that the structural strength of the PSJA is maintained, while there is almost no influence of the throat length on the single cycle performance of the PSJA. Once the discharge energy is fixed, the pulsed thrust remains almost unchanged with different orifice diameters and throat lengths. These three geometrical parameters are independent to some extent and can be optimized separately.

  14. Comparison of Monte Carlo simulated and measured performance parameters of miniPET scanner

    NASA Astrophysics Data System (ADS)

    Kis, S. A.; Emri, M.; Opposits, G.; Bükki, T.; Valastyán, I.; Hegyesi, Gy.; Imrek, J.; Kalinka, G.; Molnár, J.; Novák, D.; Végh, J.; Kerek, A.; Trón, L.; Balkay, L.

    2007-02-01

    In vivo imaging of small laboratory animals is a valuable tool in the development of new drugs. For this purpose, miniPET, an easy to scale modular small animal PET camera has been developed at our institutes. The system has four modules, which makes it possible to rotate the whole detector system around the axis of the field of view. Data collection and image reconstruction are performed using a data acquisition (DAQ) module with Ethernet communication facility and a computer cluster of commercial PCs. Performance tests were carried out to determine system parameters, such as energy resolution, sensitivity and noise equivalent count rate. A modified GEANT4-based GATE Monte Carlo software package was used to simulate PET data analogous to those of the performance measurements. GATE was run on a Linux cluster of 10 processors (64 bit, Xeon with 3.0 GHz) and controlled by a SUN grid engine. The application of this special computer cluster reduced the time necessary for the simulations by an order of magnitude. The simulated energy spectra, maximum rate of true coincidences and sensitivity of the camera were in good agreement with the measured parameters.

  15. Photovoltaic performance parameters at the nanoscale from in situ I-V curve measurements

    NASA Astrophysics Data System (ADS)

    Naseem, Sadia; Tennyson, Elizabeth; Leite, Marina

    Monocrystalline photovoltaic (PV) devices exhibit higher efficiencies than polycrystalline devices, but the high manufacturing costs associated with single crystal solar cells pose a hindrance to their wide implementation. Polycrystalline CuInxGa(1 - x)Se2 (CIGS) material with high optical absorbance and low cost/Watt, is a promising alternative. Yet, the efficiency of this low-cost technology is still substantially lower than the theoretical values estimated by the Shockley-Queisser limit. This is likely due to microstructural non-uniformities, which cannot be accessed by macroscopic light I-V measurements. Therefore, we spatially resolve the electrical response of these devices by `local' I-Vs. For that, we utilize a 100x objective as a local excitation source and LabVIEW to map the PV performance with sub-micronscale resolution through extrapolation of key parameters from pixel by pixel I-V curves. Extraction of performance parameters such as short-circuit current, opencircuit voltage fill factor, and maximum power point can provide useful information regarding optimal microstructural characteristics. This information is not only valuable for CIGS-based devices, but also will be an essential tool for maximizing performance across all PV technologies.

  16. Effect of angular stability and other locking parameters on the mechanical performance of intramedullary nails.

    PubMed

    Hoffmann, Stefanie; Gerber, Claus; von Oldenburg, Geert; Kessler, Manuel; Stephan, Daniel; Augat, Peter

    2015-04-01

    To extend the indications of intramedullary nails for distal or proximal fractures, nails with angle stable locking options have been developed. Studies on the mechanical efficacy of these systems have been inconsistent likely due to confounding variables such as number, geometry, or orientation of the screws, as well as differences in the loading mode. Therefore, the aim of this study was to quantify the effect of angular stability on the mechanical performance of intramedullary nails. The results could then be compared with the effects of various locking screw parameters and loading modes. A generic model was developed consisting of artificial bone material and titanium intramedullary nail that provided the option to systematically modify the locking screw configuration. Using a base configuration, the following parameters were varied: number of screws, distance and orientation between screws, blocking of screws, and simulation of freehand locking. Tension/compression, torsional, and bending loads were applied. Stiffness and clearance around the zero loading point were determined. Angular stability had no effect on stiffness but completely blocked axial clearance (p=0.003). Simulation of freehand locking reduced clearance for all loading modes by at least 70% (p<0.003). The greatest increases in torsional and bending stiffness were obtained by increasing the number of locking screws (up to 80%, p<0.001) and by increasing the distance between them (up to 70%, p<0.001). In conclusion, our results demonstrate that the mechanical performance of IM nailing can be affected by various locking parameters of which angular stability is only one. While angular stability clearly reduces clearance of the screw within the nail, mechanical stiffness depends more on the number of screws and their relative distance. Thus, optimal mechanical performance in IM nailing could potentially be obtained by combining angular stability with optimal arrangement of locking screws. PMID

  17. Determining probability distributions of parameter performances for time-series model calibration: A river system trial

    NASA Astrophysics Data System (ADS)

    Kim, Shaun Sang Ho; Hughes, Justin Douglas; Chen, Jie; Dutta, Dushmanta; Vaze, Jai

    2015-11-01

    A calibration method is presented that uses a sub-period resampling method to estimate probability distributions of performance for different parameter sets. Where conventional calibration methods implicitly identify the best performing parameterisations on average, the new method looks at the consistency of performance during sub-periods. The method is implemented with the conceptual river reach algorithms within the Australian Water Resources Assessments River (AWRA-R) model in the Murray-Darling Basin, Australia. The new method is tested for 192 reaches in a cross-validation scheme and results are compared to a traditional split-sample calibration-validation implementation. This is done to evaluate the new technique's ability to predict daily streamflow outside the calibration period. The new calibration method produced parameterisations that performed better in validation periods than optimum calibration parameter sets for 103 reaches and produced the same parameterisations for 35 reaches. The method showed a statistically significant improvement to predictive performance and potentially provides more rational flux terms over traditional split-sample calibration methods. Particular strengths of the proposed calibration method is that it avoids extra weighting towards rare periods of good agreement and also prevents compensating biases through time. The method can be used as a diagnostic tool to evaluate stochasticity of modelled systems and used to determine suitable model structures of different time-series models. Although the method is demonstrated using a hydrological model, the method is not limited to the field of hydrology and could be adopted for many different time-series modelling applications.

  18. Analysis of the performance parameters of lead/acid batteries in photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Sauer, D. U.; Bächler, M.; Bopp, G.; Höhe, W.; Mittermeier, J.; Sprau, P.; Willer, B.; Wollny, M.

    A systematic effort is made to define analysis and performance parameters for lead/acid batteries in photovoltaic (PV) systems. In this paper, results from the data analysis are presented, showing typical current and voltage profiles and time series of state-of-charge. Four major classes of battery operating conditions in PV systems and another four classes of temperature conditions are identified. Typical results from all classes are shown as examples. These results should help system engineers to choose the right control strategies and the battery industry to choose and develop appropriate batteries for PV applications especially for Central Europe, where most of the systems under investigation are located.

  19. Effect of additives on the tensile performance and protein solubility of industrial oilseed residual based plastics.

    PubMed

    Newson, William R; Kuktaite, Ramune; Hedenqvist, Mikael S; Gällstedt, Mikael; Johansson, Eva

    2014-07-16

    Ten chemical additives were selected from the literature for their proposed modifying activity in protein-protein interactions. These consisted of acids, bases, reducing agents, and denaturants and were added to residual deoiled meals of Crambe abyssinica (crambe) and Brassica carinata (carinata) to modify the properties of plastics produced through hot compression molding at 130 °C. The films produced were examined for tensile properties, protein solubility, molecular weight distribution, and water absorption. Of the additives tested, NaOH had the greatest positive effect on tensile properties, with increases of 105% in maximum stress and 200% in strain at maximum stress for crambe and a 70% increase in strain at maximum stress for carinata. Stiffness was not increased by any of the applied additives. Changes in tensile strength and elongation for crambe and elongation for carinata were related to changes in protein solubility. Increased pH was the most successful in improving the protein aggregation and mechanical properties within the complex chemistry of residual oilseed meals. PMID:24971658

  20. EFFECT OF STARCH ADDITION ON THE PERFORMANCE AND SLUDGE CHARACTERIZATION OF UASB PROCESS TREATING METHANOLIC WASTEWATER

    NASA Astrophysics Data System (ADS)

    Yan, Feng; Kobayashi, Takuro; Takahashi, Shintaro; Li, Yu-You; Omura, Tatsuo

    A mesophilic(35℃) UASB reactor treating synthetic wastewater containing methanol with addition of starch was continuously operated for over 430 days by changing the organic loading rate from 2.5 to 120kg-COD/m3.d. The microbial community structure of the granules was analyzed with the molecular tools and its metabolic characteristics were evaluated using specific methanogenic activity tests. The process was successfully operated with over 98% soluble COD removal efficiency at VLR 30kg-COD/m3.d for approximately 300 days, and granulation satisfactory proceeded. The results of cloning and fluorescence in situ hybridization analysis suggest that groups related the genus Methanomethylovorans and the genus Methanosaeta were predominant in the reactor although only the genus Methanomethylovorans was predominant in the reactor treating methanolic wastewater in the previous study. Abundance of the granules over 0.5 mm in diameter in the reactor treating methanolic wastewater with addition of starch was 3 times larger than that in the reactor treating methanolic wastewater. Specific methanogenic activity tests in this study indicate that the methanol-methane pathway and the methanol-H2/CO2-methane pathway were predominant, and however, there was a certain level of activity for acetate-methane pathway unlike the reactor treating methanolic wastewater. These results suggest addition of starch might be responsible for diversifying the microbial community and encouraging the granulation.

  1. Effects of moclobemide and mianserin on highway driving, psychometric performance and subjective parameters, relative to placebo.

    PubMed

    Ramaekers, J G; Swijgman, H F; O'Hanlon, J F

    1992-01-01

    The acute and sub-chronic effects of moclobemide and mianserin on driving and psychometric performance were compared to those of placebo in a double-blind, cross-over study involving 17 healthy volunteers. Mianserin, moclobemide and placebo were administered for 8 days. Subjects' performance was measured on days 1 and 8 of each treatment series; subjective sleep parameters, mood, and possible side-effects were recorded each treatment day on questionnaires or visual analog scales. Mianserin affected most of the performance measures, while moclobemide affected none; mianserin also impaired driving and tracking performance and decreased CFF. Whilst receiving mianserin, subjects reported depressed levels of alertness, calmness, and contentment; the quality of their sleep was unaffected, but its duration increased, together with feelings of drowsiness and fatigue during the day. No statistical interactions between the factors Drugs and (Treatment) Days were found, indicating that little pharmacological tolerance developed over time during mianserin treatment. Mianserin's sedative properties are held responsible for all performance and subjective effects of the drug. It is concluded that moclobemide 200 mg b.i.d. has no important sedative properties. PMID:1546144

  2. A Methodology for Evaluating Technical Performance Parameter Design Margins to Control Earth and Space Science Instrument Cost

    NASA Astrophysics Data System (ADS)

    Jones-Selden, Felicia L.

    Costs of aerospace missions have increased over the last twenty years, placing the future of the space program in jeopardy. A potential source for such growth can be attributed to the complex multidisciplinary and challenging nature of earth and space science instrument development. Design margins are additional resources carried in technical performance parameters to mitigate uncertainties throughout the product lifecycle. Margins are traditionally derived and allocated based upon historical experience intrinsic to organizations, as opposed to quantitative methods, jeopardizing the development of low-cost space-based instruments. This dissertation utilizes a methodology to evaluate the interrelationships between pre-launch and actual launch margins for the key technical performance parameters of mass, power, and data-rate to identify the extent to which excessive or insufficient margins are used in the design of space-based instruments in an effort to control instrument cost growth. The research examined 62 space-based instruments from the National Aeronautics and Space Administration, Federally Funded Research and Development Centers, and universities. Statistical analysis consisting of paired t-tests and multiple linear regression were utilized to determine the degree to which space-based instruments are over or under designed by the use of excessive or insufficient design margins and to determine the effect of design margins for the technical performance parameters of mass, power, and data-rate on the percentage instrument cost growth from the preliminary design phase to launch. Findings confirm, that in the implementation of space-based instruments, design margins are allocated to technical performance parameters above suggested government/industry standards, impacting the development of low-cost space-based instruments. The findings provide senior leadership, systems engineers, project managers, and resource managers with the ability to determine where

  3. Inferring model structural deficits by analyzing temporal dynamics of model performance and parameter sensitivity

    NASA Astrophysics Data System (ADS)

    Reusser, D. E.; Zehe, E.

    2011-07-01

    In this paper we investigate the use of hydrological models as learning tools to help improve our understanding of the hydrological functioning of a catchment. With the model as a hypothetical conceptualization of how dominant hydrological processes contribute to catchment-scale response, we investigate three questions: (1) During which periods does the model (not) reproduce observed quantities and dynamics? (2) What is the nature of the error during times of bad model performance? (3) Which model components are responsible for this error? To investigate these questions, we combine a method for detecting repeating patterns of typical differences between model and observations (time series of grouped errors, TIGER) with a method for identifying the active model components during each simulation time step based on parameter sensitivity (temporal dynamics of parameter sensitivities, TEDPAS). The approach generates a time series of occurrence of dominant error types and time series of parameter sensitivities. A synoptic discussion of these time series highlights deficiencies in the assumptions about the functioning of the catchment. The approach is demonstrated for the Weisseritz headwater catchment in the eastern Ore Mountains. Our results indicate that the WaSiM-ETH complex grid-based model is not a sufficient working hypothesis for the functioning of the Weisseritz catchment and point toward future steps that can help improve our understanding of the catchment.

  4. Effect of additives on the performance and morphology of sulfonated copoly (phthalazinone biphenyl ether sulfone) composite nanofiltration membranes☆

    NASA Astrophysics Data System (ADS)

    Guan, Shanshan; Zhang, Shouhai; Liu, Peng; Zhang, Guozhen; Jian, Xigao

    2014-03-01

    Sulfonated copoly (phthalazinone biphenyl ether sulfone) (SPPBES) composite nanofiltration membranes were fabricated by adding low molecular weight additives into SPPBES coating solutions during a dip coating process. Three selected additives: glycol, glycerol and hydroquinone were used in this work. The effect of additives on the membrane performance was studied and discussed in terms of rejection and permeation flux. Among all the composite membranes, the membrane prepared with glycol as an additive achieved the highest Na2SO4 rejection, and the membrane fabricated with glycerol as an additive exhibited the highest flux. The salts rejection of SPPBES composite membranes increased in the following order MgCl2 < NaCl ≤ MgSO4 < Na2SO4. The morphologies of the SPPBES composite membranes were characterized by SEM, it was found that the membrane prepared with hydroquinone showed a rough membrane surface. Composite membrane fabricated with glycol or glycerol as the additive showed very good chemical stability.

  5. Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project

    SciTech Connect

    Not Available

    1992-12-29

    This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.

  6. Simulation of Thematic Mapper performance as a function of sensor scanning parameters

    NASA Technical Reports Server (NTRS)

    Johnson, R. H.; Shah, N. J.; Schmidt, N. F.

    1975-01-01

    The investigation and results of the Thematic Mapper Instrument Performance Study are described. The Thematic Mapper is the advanced multispectral scanner initially planned for the Earth Observation Satellite and now planned for LANDSAT D. The use of existing digital airborne scanner data obtained with the Modular Multispectral Scanner (M2S) at Bendix provided an opportunity to simulate the effects of variation of design parameters of the Thematic Mapper. Analysis and processing of this data on the Bendix Multispectral Data Analysis System were used to empirically determine categorization performance on data generated with variations of the sampling period and scan overlap parameters of the Thematic Mapper. The Bendix M2S data, with a 2.5 milliradian instantaneous field of view and a spatial resolution (pixel size) of 10-m from 13,000 ft altitude, allowed a direct simulation of Thematic Mapper data with a 30-m resolution. The flight data chosen were obtained on 30 June 1973 over agricultural test sites in Indiana.

  7. Performance verification and system parameter identification of spacecraft tape recorder control servo

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, A. K.

    1979-01-01

    Design adequacy of the lead-lag compensator of the frequency loop, accuracy checking of the analytical expression for the electrical motor transfer function, and performance evaluation of the speed control servo of the digital tape recorder used on-board the 1976 Viking Mars Orbiters and Voyager 1977 Jupiter-Saturn flyby spacecraft are analyzed. The transfer functions of the most important parts of a simplified frequency loop used for test simulation are described and ten simulation cases are reported. The first four of these cases illustrate the method of selecting the most suitable transfer function for the hysteresis synchronous motor, while the rest verify and determine the servo performance parameters and alternative servo compensation schemes. It is concluded that the linear methods provide a starting point for the final verification/refinement of servo design by nonlinear time response simulation and that the variation of the parameters of the static/dynamic Coulomb friction is as expected in a long-life space mission environment.

  8. The role of interior watershed processes in improving parameter estimation and performance of watershed models.

    PubMed

    Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

    2014-09-01

    Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation. PMID:25603246

  9. Numerical modeling of heat-transfer and the influence of process parameters on tailoring the grain morphology of IN718 in electron beam additive manufacturing

    DOE PAGESBeta

    Raghavan, Narendran; Dehoff, Ryan; Pannala, Sreekanth; Simunovic, Srdjan; Kirka, Michael; Turner, John; Carlson, Neil; Babu, Sudarsanam S.

    2016-04-26

    The fabrication of 3-D parts from CAD models by additive manufacturing (AM) is a disruptive technology that is transforming the metal manufacturing industry. The correlation between solidification microstructure and mechanical properties has been well understood in the casting and welding processes over the years. This paper focuses on extending these principles to additive manufacturing to understand the transient phenomena of repeated melting and solidification during electron beam powder melting process to achieve site-specific microstructure control within a fabricated component. In this paper, we have developed a novel melt scan strategy for electron beam melting of nickel-base superalloy (Inconel 718) andmore » also analyzed 3-D heat transfer conditions using a parallel numerical solidification code (Truchas) developed at Los Alamos National Laboratory. The spatial and temporal variations of temperature gradient (G) and growth velocity (R) at the liquid-solid interface of the melt pool were calculated as a function of electron beam parameters. By manipulating the relative number of voxels that lie in the columnar or equiaxed region, the crystallographic texture of the components can be controlled to an extent. The analysis of the parameters provided optimum processing conditions that will result in columnar to equiaxed transition (CET) during the solidification. Furthermore, the results from the numerical simulations were validated by experimental processing and characterization thereby proving the potential of additive manufacturing process to achieve site-specific crystallographic texture control within a fabricated component.« less

  10. Performance analysis for time-frequency MUSIC algorithm in presence of both additive noise and array calibration errors

    NASA Astrophysics Data System (ADS)

    Khodja, Mohamed; Belouchrani, Adel; Abed-Meraim, Karim

    2012-12-01

    This article deals with the application of Spatial Time-Frequency Distribution (STFD) to the direction finding problem using the Multiple Signal Classification (MUSIC)algorithm. A comparative performance analysis is performed for the method under consideration with respect to that using data covariance matrix when the received array signals are subject to calibration errors in a non-stationary environment. An unified analytical expression of the Direction Of Arrival (DOA) error estimation is derived for both methods. Numerical results show the effect of the parameters intervening in the derived expression on the algorithm performance. It is particularly observed that for low Signal to Noise Ratio (SNR) and high Signal to sensor Perturbation Ratio (SPR) the STFD method gives better performance, while for high SNR and for the same SPR both methods give similar performance.

  11. Assessment of the aerobic preparation and bottom ash addition as pretreatment steps before landfilling: impact on methanogenesis kinetics and leachate parameters.

    PubMed

    Mansour, Alicia A; Motte, Antoine; Pallier, Virginie; Feuillade-Cathalifaud, Geneviève; Ponthieux, Arnaud

    2012-10-01

    This work focuses on assessing the impact of two types of waste pretreatment: addition of bottom ashes and aerobic pretreatment on both the onset and kinetics of methanogenesis and the evolution of different parameters in the leachate. It also studies the correlation between methane production and the different parameters measured in the leachate produced. A total of six 68-L pilots were thus used with fresh municipal solid waste (MSW) shredded to a 40-mm size. After 14 months of landfilling, the control has produced less than 10 NLkg(-1)DM, which corresponds to around 7% of its biochemical methane potential (BMP). Nevertheless, on one hand for aerobically pretreated waste, the lag phase before the onset of methanogenesis is significantly reduced to 0.9 month compared to more than 1 year for the control. In addition to that, on average 110 NLkg(-1)DM (90% of the BMP) is produced within around 6.5 months. On the other hand, the waste with added bottom ash shows a slight improvement of the lag phase over the control for one of the duplicate: 6.1 months of lag phase. At this stage, on average of 26 NLkg(-1)DM waste are detected (22% of the BMP) no final conclusion concerning the impact of bottom ashes could be made. The data obtained for the leachate parameters agrees with the observations on methane production. Statistical correlation study shows that the two components of the corrected PCA interpret 76% of the variability of the data: SUVA (specific UV absorbance at 254 nm) and HPI(*) (% of hydrophilic compounds) are identified as interesting parameters for following up the biodegradation in landfill conditions. PMID:22640801

  12. Additive Manufacturing Thermal Performance Testing of Single Channel GRCop-84 SLM Components

    NASA Technical Reports Server (NTRS)

    Garcia, Chance P.; Cross, Matthew

    2014-01-01

    The surface finish found on components manufactured by sinter laser manufacturing (SLM) is rougher (0.013 - 0.0006 inches) than parts made using traditional fabrication methods. Internal features and passages built into SLM components do not readily allow for roughness reduction processes. Alternatively, engineering literature suggests that the roughness of a surface can enhance thermal performance within a pressure drop regime. To further investigate the thermal performance of SLM fabricated pieces, several GRCop-84 SLM single channel components were tested using a thermal conduction rig at MSFC. A 20 kW power source running at 25% duty cycle and 25% power level applied heat to each component while varying water flow rates between 2.1 - 6.2 gallons/min (GPM) at a supply pressure of 550 to 700 psi. Each test was allowed to reach quasi-steady state conditions where pressure, temperature, and thermal imaging data were recorded. Presented in this work are the heat transfer responses compared to a traditional machined OHFC Copper test section. An analytical thermal model was constructed to anchor theoretical models with the empirical data.

  13. Study of PET Detector Performance with Varying SiPM Parameters and Readout Schemes

    PubMed Central

    Li, Xiaoli; Lockhart, Cate; Lewellen, Tom K.; Miyaoka, Robert S.

    2012-01-01

    The spatial resolution performance characteristics of a monolithic crystal PET detector utilizing a sensor on the entrance surface (SES) design is reported. To facilitate this design, we propose to utilize a 2D silicon photomultiplier (SiPM) array device. Using a multi-step simulation process, we investigated the performance of a monolithic crystal PET detector with different data readout schemes and different SiPM parameters. The detector simulated was a 49.2mm by 49.2mm by 15mm LYSO crystal readout by a 12 by 12 array of 3.8mm by 3.8mm SiPM elements. A statistics based positioning (SBP) method was used for event positioning and depth of interaction (DOI) decoding. Although individual channel readout provided better spatial resolution, row-column summing is proposed to reduce the number of readout channels. The SiPM parameters investigated include photon detection efficiency (PDE) and gain variability between different channels; PDE and gain instability; and dark count noise. Of the variables investigated, the PDE shift of -3.2±0.7% and gain shift of -4±0.9% between detector testing and detector calibration had the most obvious impact on the detector performance, since it not only degraded the spatial resolution but also led to bias in positioning, especially at the edges of the crystal. The dark count noise also had an impact on the intrinsic spatial resolution. No data normalization is required for PDE variability of up to 12% FWHM and gain variability of up to 15% FWHM between SiPM channels. Based upon these results, a row-column summing readout scheme without data normalization will be used. Further, we plan to cool our detectors below room temperature to reduce dark count noise and to actively control the temperature of the SiPMs to reduce drifts in PDE and gain. PMID:22685348

  14. Study of PET Detector Performance with Varying SiPM Parameters and Readout Schemes.

    PubMed

    Li, Xiaoli; Lockhart, Cate; Lewellen, Tom K; Miyaoka, Robert S

    2011-01-01

    The spatial resolution performance characteristics of a monolithic crystal PET detector utilizing a sensor on the entrance surface (SES) design is reported. To facilitate this design, we propose to utilize a 2D silicon photomultiplier (SiPM) array device. Using a multi-step simulation process, we investigated the performance of a monolithic crystal PET detector with different data readout schemes and different SiPM parameters. The detector simulated was a 49.2mm by 49.2mm by 15mm LYSO crystal readout by a 12 by 12 array of 3.8mm by 3.8mm SiPM elements. A statistics based positioning (SBP) method was used for event positioning and depth of interaction (DOI) decoding. Although individual channel readout provided better spatial resolution, row-column summing is proposed to reduce the number of readout channels. The SiPM parameters investigated include photon detection efficiency (PDE) and gain variability between different channels; PDE and gain instability; and dark count noise. Of the variables investigated, the PDE shift of -3.2±0.7% and gain shift of -4±0.9% between detector testing and detector calibration had the most obvious impact on the detector performance, since it not only degraded the spatial resolution but also led to bias in positioning, especially at the edges of the crystal. The dark count noise also had an impact on the intrinsic spatial resolution. No data normalization is required for PDE variability of up to 12% FWHM and gain variability of up to 15% FWHM between SiPM channels. Based upon these results, a row-column summing readout scheme without data normalization will be used. Further, we plan to cool our detectors below room temperature to reduce dark count noise and to actively control the temperature of the SiPMs to reduce drifts in PDE and gain. PMID:22685348

  15. Effects of anode fabrication parameters on the performance and redox behavior of solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Timurkutluk, Bora; Mat, Mahmut D.

    2014-07-01

    Anode supported solid oxide fuel cells (SOFCs) having various anode support porosities and electrolyte thicknesses are developed and their effects on the cell performance and redox behavior of the cell are investigated experimentally. An yttria stabilized zirconia based anode supported membrane electrode group (MEG) is developed with the tape casting, co-sintering and screen printing methodologies. For comparison, various anode supported cells with different electrolyte thickness and anode support porosities are also fabricated. An experimental setup is devised for the performance measurement of the cells before and after redox cycling. The mechanical performance of the cell before and after redox cycling is also measured via three point bending tests. Experimental results reveal that the porosity of the anode support and the thickness of the electrolyte should be carefully decided by considering not only the cell performances but also the redox stability. In addition, after single redox cycle the decrease in the mechanical properties of the cell is found to be around 50% while the same cell shows only around 10% electrochemical performance loss.

  16. Experimental parameters affecting the Morris water maze performance of a mouse model of Down syndrome.

    PubMed

    Stasko, Melissa R; Costa, Alberto C S

    2004-09-23

    The Ts65Dn mouse is the most studied and genetically the most complete animal model of Down syndrome (DS) available. These mice display many DS-like features, including performance deficits in different behavioral tasks, motor dysfunction, and age-dependent loss of cholinergic markers in the basal forebrain. At present, the only robust data demonstrating a behavioral deficit potentially associated with learning and memory in Ts65Dn mice less than 6 months old have come from studies that used some variation of the Morris water maze task. However, the specific features of the water maze deficits seen in these animals are still poorly defined. This study is an initial attempt to bridge this knowledge gap. We investigated three major factors potentially influencing the performance of Ts65Dn mice in the water maze: (1) order in which the test is executed; (2) age of the animals; and (3) levels of aversiveness associated with the test. Measurements of plasma corticosterone levels and core body temperature after swimming were also carried out in additional subsets of mice. Overall, we found that the behavioral phenotype of Ts65Dn mice was milder than previously described in the literature. Additionally, Ts65Dn mice were significantly more responsive to potential stressors and more prone to swim-induced hypothermia than euploid control animals. More studies are needed to tease out further the potential effects of confounding factors on the performance of Ts65Dn mice. PMID:15302106

  17. Impact of an additional chronic BDNF reduction on learning performance in an Alzheimer mouse model

    PubMed Central

    Psotta, Laura; Rockahr, Carolin; Gruss, Michael; Kirches, Elmar; Braun, Katharina; Lessmann, Volkmar; Bock, Jörg; Endres, Thomas

    2015-01-01

    There is increasing evidence that brain-derived neurotrophic factor (BDNF) plays a crucial role in Alzheimer’s disease (AD) pathology. A number of studies demonstrated that AD patients exhibit reduced BDNF levels in the brain and the blood serum, and in addition, several animal-based studies indicated a potential protective effect of BDNF against Aβ-induced neurotoxicity. In order to further investigate the role of BDNF in the etiology of AD, we created a novel mouse model by crossing a well-established AD mouse model (APP/PS1) with a mouse exhibiting a chronic BDNF deficiency (BDNF+/−). This new triple transgenic mouse model enabled us to further analyze the role of BDNF in AD in vivo. We reasoned that in case BDNF has a protective effect against AD pathology, an AD-like phenotype in our new mouse model should occur earlier and/or in more severity than in the APP/PS1-mice. Indeed, the behavioral analysis revealed that the APP/PS1-BDNF+/−-mice show an earlier onset of learning impairments in a two-way active avoidance task in comparison to APP/PS1- and BDNF+/−-mice. However in the Morris water maze (MWM) test, we could not observe an overall aggrevated impairment in spatial learning and also short-term memory in an object recognition task remained intact in all tested mouse lines. In addition to the behavioral experiments, we analyzed the amyloid plaque pathology in the APP/PS1 and APP/PS1-BDNF+/−-mice and observed a comparable plaque density in the two genotypes. Moreover, our results revealed a higher plaque density in prefrontal cortical compared to hippocampal brain regions. Our data reveal that higher cognitive tasks requiring the recruitment of cortical networks appear to be more severely affected in our new mouse model than learning tasks requiring mainly sub-cortical networks. Furthermore, our observations of an accelerated impairment in active avoidance learning in APP/PS1-BDNF+/−-mice further supports the hypothesis that BDNF deficiency

  18. Effect of a mineral additive on the electrical performances of the positive plate of lead acid battery

    NASA Astrophysics Data System (ADS)

    Foudia, M.; Matrakova, M.; Zerroual, L.

    2015-04-01

    The objective of this work is to improve the performance of the positive electrode of lead-acid battery. The use of the additive in the positive paste is to increase the capacity and cycle life of the positive active material. Mineral porous additives, dispersed uniformly in the PAM, may act as acid reservoirs and favor the ionic diffusion. The results show that the addition of mineral additive in the paste before oxidation influences the composition and the crystal size of the PAM after oxidation. We observe a remarkable improvement of the discharge capacity of the PAM for an amount of additive ranging between 1 and 5%. Nano-sized particles of PbO2 with amorphous character are obtained. XRD, TG and DSC, SEM, and galvanostatic discharge were used as techniques of investigation.

  19. Improved performance of U-Mo dispersion fuel by Si addition in Al matrix.

    SciTech Connect

    Kim, Y S; Hofman, G L

    2011-06-01

    The purpose of this report is to collect in one publication and fit together work fragments presented in many conferences in the multi-year time span starting 2002 to the present dealing with the problem of large pore formation in U-Mo/Al dispersion fuel plates first observed in 2002. Hence, this report summarizes the excerpts from papers and reports on how we interpreted the relevant results from out-of-pile and in-pile tests and how this problem was dealt with. This report also provides a refined view to explain in detail and in a quantitative manner the underlying mechanism of the role of silicon in improving the irradiation performance of U-Mo/Al.

  20. Influence of antimicrobial feed additives on broiler commensal posthatch gut microbiota development and performance.

    PubMed

    Torok, Valeria A; Allison, Gwen E; Percy, Nigel J; Ophel-Keller, Kathy; Hughes, Robert J

    2011-05-01

    The effects of avilamycin, zinc bacitracin, and flavophospholipol on broiler gut microbial community colonization and bird performance in the first 17 days posthatch were investigated. Significant differences in gut microbiota associated with gut section, dietary treatment, and age were identified by terminal restriction fragment length polymorphism (T-RFLP), although no performance-related differences between dietary treatments were detected. Similar age-related shifts in the gut microbiota were identified regardless of diet but varied between the ilea and ceca. Interbird variabilities in ileal bacterial communities were reduced (3 to 7 days posthatch) in chicks fed with feed containing antimicrobial agents. Avilamycin and flavophospholipol had the most consistent effect on gut microbial communities. Operational taxonomic units (OTU) linked to changes in gut microbiota in birds on antimicrobial-supplemented diets were characterized and identified. Some OTUs could be identified to the species level; however, the majority could be only tentatively classified to the genus, family, order, or domain level. OTUs 140 to 146 (Lachnospiraceae), OTU 186/188 (Lactobacillus johnsonii), OTU 220 (Lachnospiraceae), OTUs 284 to 288 (unclassified bacterial spp. or Ruminococcaceae), OTU 296/298 (unclassified bacterium or Clostridiales), and OTU 480/482 (Oxalobacteraceae) were less prevalent in the guts of chicks fed antimicrobial-supplemented diets. OTU 178/180 (Lactobacillus crispatus), OTU 152 (Lactobacillus reuteri or unclassified Clostridiales), OTU 198/200 (Subdoligranulum spp.), and OTU 490/492 (unclassified bacterium or Enterobacteriaceae) were less prevalent in the gut of chicks raised on the antimicrobial-free diet. The identification of key bacterial species influenced by antimicrobial-supplemented feed immediately posthatch may assist in the formulation of diets that facilitate beneficial gut microbial colonization and, hence, the development of alternatives to current

  1. Rational nanoconjugation improves biocatalytic performance of enzymes: aldol addition catalyzed by immobilized rhamnulose-1-phosphate aldolase.

    PubMed

    Ardao, Inés; Comenge, Joan; Benaiges, M Dolors; Álvaro, Gregorio; Puntes, Víctor F

    2012-04-17

    Gold nanoparticles (AuNPs) are attractive materials for the immobilization of enzymes due to several advantages such as high enzyme loading, absence of internal diffusion limitations, and Brownian motion in solution, compared to the conventional immobilization onto porous macroscopic supports. The affinity of AuNPs to different groups present at the protein surface enables direct enzyme binding to the nanoparticle without the need of any coupling agent. Enzyme activity and stability appear to be improved when the biocatalyst is immobilized onto AuNPs. Rhamnulose-1-phosphate aldolase (RhuA) was selected as model enzyme for the immobilization onto AuNPs. The enzyme loading was characterized by four different techniques: surface plasmon resonance (SPR) shift and intensity, dynamic light scattering (DLS), and transmission electron microscopy (TEM). AuNPs-RhuA complexes were further applied as biocatalyst of the aldol addition reaction between dihydroxyacetone phosphate (DHAP) and (S)-Cbz-alaninal during two reaction cycles. In these conditions, an improved reaction yield and selectivity, together with a fourfold activity enhancement were observed, as compared to soluble RhuA. PMID:22428999

  2. Performance of seedlings of a shade-tolerant tropical tree species after moderate addition of N and P

    NASA Astrophysics Data System (ADS)

    Cárate Tandalla, Daisy; Leuschner, Christoph; Homeier, Jürgen

    2015-12-01

    Nitrogen deposition to tropical forests is predicted to increase in future in many regions due to agricultural intensification. We conducted a seedling transplantation experiment in a tropical premontane forest in Ecuador with a locally abundant late-successional tree species (Pouteria torta, Sapotaceae) aimed at detecting species-specific responses to moderate N and P addition and to understand how increasing nutrient availability will affect regeneration. From locally collected seeds, 320 seedlings were produced and transplanted to the plots of the Ecuadorian Nutrient Manipulation Experiment (NUMEX) with three treatments (moderate N addition: 50 kg N ha-1 yr-1, moderate P addition: 10 kg P ha-1 yr-1 and combined N and P addition) and a control (80 plants per treatment). After 12 months, mortality, relative growth rate, leaf nutrient content and leaf herbivory rate were measured. N and NP addition significantly increased the mortality rate (70 % vs. 54 % in the control). However, N and P addition also increased the diameter growth rate of the surviving seedlings. N and P addition did not alter foliar nutrient concentrations and leaf N:P ratio, but N addition decreased the leaf C:N ratio and increased SLA. P addition (but not N addition) resulted in higher leaf area loss to herbivore consumption and also shifted carbon allocation to root growth. This fertilization experiment with a common rainforest tree species conducted in old-growth forest shows that already moderate doses of added N and P are affecting seedling performance which most likely will have consequences for the competitive strength in the understory and the recruitment success of P. torta. Simultaneous increases in growth, herbivory and mortality rates make it difficult to assess the species' overall performance and predict how a future increase in nutrient deposition will alter the abundance of this species in the Andean tropical montane forests.

  3. Influence of Electrical Resistivity and Machining Parameters on Electrical Discharge Machining Performance of Engineering Ceramics

    PubMed Central

    Ji, Renjie; Liu, Yonghong; Diao, Ruiqiang; Xu, Chenchen; Li, Xiaopeng; Cai, Baoping; Zhang, Yanzhen

    2014-01-01

    Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM) is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR). The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical discharge

  4. Influence of probiotic supplementation on blood parameters and growth performance in broiler chickens

    PubMed Central

    Alkhalf, A.; Alhaj, M.; Al-homidan, I.

    2010-01-01

    Effects of commercial probiotic (Bactocell®) on growth performance and blood parameters were evaluated. A total of 800 one day-old Ross broiler chicks were raised over 42 days. Chicks were wing-banded, weighed individually and randomly allocated into four equally major groups each having two replicates. Chicks of group 1 (control group) were fed the starter and finisher diets that did not supplemented with probiotic. The chicks of groups 2, 3, and 4 were fed the control starter and finisher diets supplemented with 1.6 g, 1 g and 0.8 g of probiotic per kg feed, respectively. Weekly body weight, feed consumption and feed conversion were measured. Blood parameters at 1, 4 and 6 weeks of age including packed cell volume (PCV), haemoglobin (Hb), total protein, albumin, total lipid and cholesterol were determined. All birds were kept under similar environmental, managerial and hygienic conditions. The results of the current study revealed that there was no significant change for Hb and PCV concentrations among different groups at all studied times. Also, total protein, lipids and albumin concentrations were not affected by probiotic supplementation. Chicken fed a diet containing various levels of probiotic showed a significant decrease (p ⩽ 0.05) in cholesterol concentration compared to control group. Probiotic supplementation significantly increased the body weight and daily weight gain of broiler chicks at late ages (3–6 weeks). Also, the birds fed on probiotic levels 1 and 0.8 g/kg diet exhibited higher body weight among chicken groups at 6 weeks of age. Improved feed conversion was noticed in birds fed a diet supplemented with probiotic. There was no significant difference in mortality rate among groups. We concluded that use of selected commercial probiotic resulted in improved performance parameters and reduced serum cholesterol in broiler chickens. Moreover, supplementation of the probiotic to broilers in the levels of 1 and 0.8 g/kg diet was found

  5. Influence of electrical resistivity and machining parameters on electrical discharge machining performance of engineering ceramics.

    PubMed

    Ji, Renjie; Liu, Yonghong; Diao, Ruiqiang; Xu, Chenchen; Li, Xiaopeng; Cai, Baoping; Zhang, Yanzhen

    2014-01-01

    Engineering ceramics have been widely used in modern industry for their excellent physical and mechanical properties, and they are difficult to machine owing to their high hardness and brittleness. Electrical discharge machining (EDM) is the appropriate process for machining engineering ceramics provided they are electrically conducting. However, the electrical resistivity of the popular engineering ceramics is higher, and there has been no research on the relationship between the EDM parameters and the electrical resistivity of the engineering ceramics. This paper investigates the effects of the electrical resistivity and EDM parameters such as tool polarity, pulse interval, and electrode material, on the ZnO/Al2O3 ceramic's EDM performance, in terms of the material removal rate (MRR), electrode wear ratio (EWR), and surface roughness (SR). The results show that the electrical resistivity and the EDM parameters have the great influence on the EDM performance. The ZnO/Al2O3 ceramic with the electrical resistivity up to 3410 Ω·cm can be effectively machined by EDM with the copper electrode, the negative tool polarity, and the shorter pulse interval. Under most machining conditions, the MRR increases, and the SR decreases with the decrease of electrical resistivity. Moreover, the tool polarity, and pulse interval affect the EWR, respectively, and the electrical resistivity and electrode material have a combined effect on the EWR. Furthermore, the EDM performance of ZnO/Al2O3 ceramic with the electrical resistivity higher than 687 Ω·cm is obviously different from that with the electrical resistivity lower than 687 Ω·cm, when the electrode material changes. The microstructure character analysis of the machined ZnO/Al2O3 ceramic surface shows that the ZnO/Al2O3 ceramic is removed by melting, evaporation and thermal spalling, and the material from the working fluid and the graphite electrode can transfer to the workpiece surface during electrical discharge

  6. Addition of meloxicam to the treatment of clinical mastitis improves subsequent reproductive performance.

    PubMed

    McDougall, S; Abbeloos, E; Piepers, S; Rao, A S; Astiz, S; van Werven, T; Statham, J; Pérez-Villalobos, N

    2016-03-01

    A blinded, negative controlled, randomized intervention study was undertaken to test the hypothesis that addition of meloxicam, a nonsteroidal anti-inflammatory drug, to antimicrobial treatment of mild to moderate clinical mastitis would improve fertility and reduce the risk of removal from the herd. Cows (n=509) from 61 herds in 8 regions (sites) in 6 European countries were enrolled. Following herd-owner diagnosis of mild to moderate clinical mastitis within the first 120 d of lactation in a single gland, the rectal temperature, milk appearance, and California Mastitis Test score were assessed. Cows were randomly assigned within each site to be treated either with meloxicam or a placebo (control). All cows were additionally treated with 1 to 4 intramammary infusions of cephalexin and kanamycin at 24-h intervals. Prior to treatment and at 14 and 21 d posttreatment, milk samples were collected for bacteriology and somatic cell count. Cows were bred by artificial insemination and pregnancy status was subsequently defined. General estimating equations were used to determine the effect of treatment (meloxicam versus control) on bacteriological cure, somatic cell count, the probability of being inseminated by 21 d after the voluntary waiting period, the probability of conception to first artificial insemination, the number of artificial insemination/conception, the probability of pregnancy by 120 or 200 d postcalving, and the risk of removal by 300 d after treatment. Cox's proportional hazards models were used to test the effect of treatment on the calving to first insemination and calving to conception intervals. Groups did not differ in terms of age, clot score, California Mastitis Test score, rectal temperature, number of antimicrobial treatments given or bacteria present at the time of enrollment, but cows treated with meloxicam had greater days in milk at enrollment. Cows treated with meloxicam had a higher bacteriological cure proportion than those treated with

  7. Impact of spatial and temporal aggregation of input parameters on the assessment of irrigation scheme performance

    NASA Astrophysics Data System (ADS)

    Lorite, I. J.; Mateos, L.; Fereres, E.

    2005-01-01

    SummaryThe simulations of dynamic, spatially distributed non-linear models are impacted by the degree of spatial and temporal aggregation of their input parameters and variables. This paper deals with the impact of these aggregations on the assessment of irrigation scheme performance by simulating water use and crop yield. The analysis was carried out on a 7000 ha irrigation scheme located in Southern Spain. Four irrigation seasons differing in rainfall patterns were simulated (from 1996/1997 to 1999/2000) with the actual soil parameters and with hypothetical soil parameters representing wider ranges of soil variability. Three spatial aggregation levels were considered: (I) individual parcels (about 800), (II) command areas (83) and (III) the whole irrigation scheme. Equally, five temporal aggregation levels were defined: daily, weekly, monthly, quarterly and annually. The results showed little impact of spatial aggregation in the predictions of irrigation requirements and of crop yield for the scheme. The impact of aggregation was greater in rainy years, for deep-rooted crops (sunflower) and in scenarios with heterogeneous soils. The highest impact on irrigation requirement estimations was in the scenario of most heterogeneous soil and in 1999/2000, a year with frequent rainfall during the irrigation season: difference of 7% between aggregation levels I and III was found. Equally, it was found that temporal aggregation had only significant impact on irrigation requirements predictions for time steps longer than 4 months. In general, simulated annual irrigation requirements decreased as the time step increased. The impact was greater in rainy years (specially with abundant and concentrated rain events) and in crops which cycles coincide in part with the rainy season (garlic, winter cereals and olive). It is concluded that in this case, average, representative values for the main inputs of the model (crop, soil properties and sowing dates) can generate results

  8. Effects crude protein levels on female Nile tilapia (Oreochromis niloticus) reproductive performance parameters.

    PubMed

    de Oliveira, Marinez Moraes; Ribeiro, Tainá; Orlando, Tamira Maria; de Oliveira, Dênio Garcia Silva; Drumond, Mariana Martins; de Freitas, Rilke Tadeu Fonseca; Rosa, Priscila Vieira

    2014-11-10

    The goal of the present work was to study the reproductive performance of Nile Tilapia (Oreochromis niloticus) female broodstock fed diets containing different levels of crude protein (CP). Two hundred and forty Nile tilapia (O. niloticus) were used at an average age of 30 months, with 180 females and 60 males. The broodstock were lodged separately in masonry tanks with continuous water flow. The females were stocked in thirty tanks with dimensions of 8 m(3) in a completely randomized design consisting of five treatments and six replications. The treatments consisted of five diets with different levels of CP (32, 34, 36, 38 and 40%) and with digestible energy per gram of protein of 9.5 kg of feed. The crude protein (CP) levels positively influenced (p<0.05) reproductive parameters (female relative and absolute fecundity, egg diameter, fasting larvae survival capacity), the somatic indexes (gonadosomatic (GSI), hepatosomatic (HIS), viscerosomatic (VSI)), total plasma protein, albumin and triglycerides. There were no significant differences (p>0.05) observed with regard to spawning weight and female weight. The reproductive parameters studied in the present research indicate that diets formulated with 38% CP with digestible energy per gram of CP of 9.5 were the best diets for tilapia females during the reproductive period. PMID:25201770

  9. Seasonal variation of selected performance parameters in épée fencers.

    PubMed Central

    Koutedakis, Y; Ridgeon, A; Sharp, N C; Boreham, C

    1993-01-01

    In this study, anthropometric measurements were carried out on seven British international male épée fencers, using a maximal treadmill running test, a 20-s Wingate-type test, and isokinetic dynamometry. Testing was conducted on two occasions, 5 to 6 months apart, during mid-off-season (preparation) and mid-in-season (competition) periods. Maximal oxygen intake (VO2max) and maximal respiratory exchange ratio (Rmax) were among the parameters obtained from the treadmill test, while peak and mean anaerobic power outputs were measured during a 20-s maximal effort. Knee extensor and flexor muscle forces from both dominant (leading) and non-dominant (trailing) legs were assessed at 1.04, 3.14 and 4.19 rad sec-1. Statistical analyses revealed lower mean VO2max (P < 0.05) and mean Rmax values (P < 0.02) at the in-season assessments compared with off-season. In-season testing also demonstrated significantly lower peak torques for both dominant and non-dominant knee extensors compared with off-season assessments at all velocities (P < 0.05 to P < 0.004). Furthermore, in-season peak torque for the non-dominant leg flexors was lower (P < 0.03) at 4.19 rad sec-1 than off-season. We conclude that current training practices may account for the observed seasonal variations in performance related physiological parameters in fencers. PMID:8242273

  10. The performance of a prototype device designed to evaluate general quality parameters of X-ray equipment

    NASA Astrophysics Data System (ADS)

    Murata, C. H.; Fernandes, D. C.; Lavínia, N. C.; Caldas, L. V. E.; Pires, S. R.; Medeiros, R. B.

    2014-02-01

    The performance of radiological equipment can be assessed using non-invasive methods and portable instruments that can analyze an X-ray beam with just one exposure. These instruments use either an ionization chamber or a state solid detector (SSD) to evaluate X-ray beam parameters. In Brazil, no such instruments are currently being manufactured; consequently, these instruments come at a higher cost to users due to importation taxes. Additionally, quality control tests are time consuming and impose a high workload on the X-ray tubes when evaluating their performance parameters. The assessment of some parameters, such as the half-value layer (HVL), requires several exposures; however, this can be reduced by using a SSD that requires only a single exposure. One such SSD uses photodiodes designed for high X-ray sensitivity without the use of scintillation crystals. This sensitivity allows one electron-hole pair to be created per 3.63 eV of incident energy, resulting in extremely high and stable quantum efficiencies. These silicon photodiodes operate by absorbing photons and generating a flow of current that is proportional to the incident power. The aim of this study was to show the response of the solid sensor PIN RD100A detector in a multifunctional X-ray analysis system that is designed to evaluate the average peak voltage (kVp), exposure time, and HVL of radiological equipment. For this purpose, a prototype board that uses four SSDs was developed to measure kVp, exposure time, and HVL using a single exposure. The reproducibility and accuracy of the results were compared to that of different X-ray beam analysis instruments. The kVp reproducibility and accuracy results were 2% and 3%, respectively; the exposure time reproducibility and accuracy results were 2% and 1%, respectively; and the HVL accuracy was ±2%. The prototype's methodology was able to calculate these parameters with appropriate reproducibility and accuracy. Therefore, the prototype can be considered

  11. Effects of parameters on the performance of amorphous IGZO thin films prepared by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Niu, Jian-wen; Ma, Rui-xin; Wang, Yuan-yuan; Li, Shi-na; Cheng, Shi-yao; Liu, Zi-lin

    2014-09-01

    Amorphous indium-gallium-zinc oxide (IGZO) transparent conductive thin films are prepared on glass substrates by radio frequency (RF) magnetron sputtering. The effects of seven factors, which are substrate temperature, sputtering atmosphere, working pressure, sputtering power, annealing temperature, negative bias voltage and sputtering time, on Hall mobility, transmittance and surface roughness are studied through orthogonal experiments. The results show that the effects of working pressure, substrate temperature and sputtering atmosphere on performance of films are the most prominent. According to the experimental results and discussion, relatively reasonable process parameters are obtained, which are working pressure of 0.35 Pa, substrate temperature of 200 °C, sputtering atmosphere of Ar, sputtering power of 125 W, sputtering time of 30 min, negative bias voltage of 0 V and annealing temperature of 300 °C.

  12. Critical parameters and TCLP performance of the RFP microwave solidification system

    SciTech Connect

    Sprenger, G.S.

    1993-01-01

    Two series of experiments were conducted at Rocky Flats Plant (RFP) to identify the critical operating parameters for microwave solidification and to evaluate the performance of the product against the EPA's Toxicity Characteristic Leach Procedure (TCLP). A surrogate hydroxide coprecipitation sludge spiked with heavy metals was used in the study. The RFP process uses microwave energy to heat and melt the waste into a vitreous final form that is suitable for land disposal. The results of the study indicate that waste loading and borax content in the glass forming frit are critical in the treatment of hydroxide sludge. Also, the product will easily satisfy EPA's limitations for land disposal. These results are very encouraging and support RFP's commitment to the use of microwave technology for treatment of various mixed waste streams at the facility.

  13. Analytical ballistic theory of carbon nanotube transistors: Experimental validation, device physics, parameter extraction, and performance projection

    NASA Astrophysics Data System (ADS)

    Akinwande, Deji; Liang, Jiale; Chong, Soogine; Nishi, Yoshio; Wong, H.-S. Philip

    2008-12-01

    We developed a fully analytical ballistic theory of carbon nanotube field effect transistors enabled by the development of an analytical surface potential capturing the temperature dependence and gate and quantum capacitance electrostatics. The analytical ballistic theory is compared to the experimental results of a ballistic transistor with good agreement. The validated analytical theory enables intuitive circuit design, provides techniques for parameter extraction of the bandgap and surface potential, and elucidates on the device physics of drain optical phonon scattering and its role in reducing the linear conductance and intrinsic gain of the transistor. Furthermore, a threshold voltage definition is proposed reflecting the bandgap-diameter dependence. Projections for key analog and digital performances are discussed.

  14. Effect of emitter parameter variation on the performance of heteroepitaxial indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, R. K.; Flood, D. J.

    1990-01-01

    Metalorganic chemical-vapor-deposited heteroepitaxial indium phosphide (InP) solar cell experimental results were simulated by using a PC-1D computer model. The effect of emitter parameter variation on the performance of n(+)/p/p(+) heteroepitaxial InP/GaAs solar cell was presented. The thinner and lighter doped emitters were observed to offer higher cell efficiencies. The influence of emitter thickness and minority carrier diffusion length on the cell efficiency with respect to dislocation density was studied. Heteroepitaxial cells with efficiencies similar to present day homojunction InP efficiencies (greaater than 16 percent AM0) were shown to be attainable if a dislocation density lower than 10(exp 6)/sq cm could be achieved. A realistic optimized design study yielded InP solar cells of over 22 percent AM0 efficiency at 25 C.

  15. Effect of emitter parameter variation on the performance of heteroepitaxial indium phosphide solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Metallorganic chemical-vapor-deposited heteroepitaxial indium phosphide (InP) solar cell experimental results were simulated by using a PC-1D computer model. The effect of emitter parameter variation on the performance of n(+)/p/p(+) heteroepitaxial InP/GaAs solar cell was presented. The thinner and lighter doped emitters were observed to offer higher cell efficiencies. The influence of emitter thickness and minority carrier diffusion length on the cell efficiency with respect to dislocation density was studied. Heteroepitaxial cells with efficiencies similar to present day homojunction InP efficiencies (greater than 16 percent AMO) were shown to be attainable if a dislocation density lower than 10(exp 6)/sq cm could be achieved. A realistic optimized design study yielded InP solar cells of over 22 percent AMO efficiency at 25 C.

  16. High performance flexible double-sided micro-supercapacitors with an organic gel electrolyte containing a redox-active additive.

    PubMed

    Kim, Doyeon; Lee, Geumbee; Kim, Daeil; Yun, Junyeong; Lee, Sang-Soo; Ha, Jeong Sook

    2016-08-25

    In this study, we report the fabrication of a high performance flexible micro-supercapacitor (MSC) with an organic gel electrolyte containing a redox-active additive, referred to as poly(methyl methacrylate)-propylene carbonate-lithium perchlorate-hydroquinone (PMMA-PC-LiClO4-HQ). Hexagonal MSCs fabricated on thin polyethylene terephthalate (PET) films had interdigitated electrodes made of spray-coated multi-walled carbon nanotubes (MWNTs) on Au. The addition of HQ as a redox-active additive enhanced not only the specific capacitance but also the energy density of the MSCs dramatically, which is approximately 35 times higher than that of MSCs without the HQ additive. In addition, both areal capacitance and areal energy density could be doubled by fabrication of double-sided MSCs, where two MSCs are connected in parallel. The double-sided MSCs exhibited stable electrochemical performance during repeated deformation by bending. By dry-transferring the double-sided MSCs based on PMMA-PC-LiClO4-HQ on a deformable polymer substrate, we fabricated a stretchable MSC array, which also retained its electrochemical performance during a uniaxial strain of 40%. Furthermore, a wearable energy storage bracelet made of such an MSC array could operate a μ-LED on the wrist. PMID:27511060

  17. 46 CFR 160.151-17 - Additional requirements for design and performance of SOLAS A and SOLAS B inflatable liferafts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Additional requirements for design and performance of SOLAS A and SOLAS B inflatable liferafts. 160.151-17 Section 160.151-17 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Inflatable Liferafts...

  18. Nontargeted Screening Method for Illegal Additives Based on Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometry.

    PubMed

    Fu, Yanqing; Zhou, Zhihui; Kong, Hongwei; Lu, Xin; Zhao, Xinjie; Chen, Yihui; Chen, Jia; Wu, Zeming; Xu, Zhiliang; Zhao, Chunxia; Xu, Guowang

    2016-09-01

    Identification of illegal additives in complex matrixes is important in the food safety field. In this study a nontargeted screening strategy was developed to find illegal additives based on ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). First, an analytical method for possible illegal additives in complex matrixes was established including fast sample pretreatment, accurate UHPLC separation, and HRMS detection. Second, efficient data processing and differential analysis workflow were suggested and applied to find potential risk compounds. Third, structure elucidation of risk compounds was performed by (1) searching online databases [Metlin and the Human Metabolome Database (HMDB)] and an in-house database which was established at the above-defined conditions of UHPLC-HRMS analysis and contains information on retention time, mass spectra (MS), and tandem mass spectra (MS/MS) of 475 illegal additives, (2) analyzing fragment ions, and (3) referring to fragmentation rules. Fish was taken as an example to show the usefulness of the nontargeted screening strategy, and six additives were found in suspected fish samples. Quantitative analysis was further carried out to determine the contents of these compounds. The satisfactory application of this strategy in fish samples means that it can also be used in the screening of illegal additives in other kinds of food samples. PMID:27480407

  19. Performance of AA5052 alloy anode in alkaline ethylene glycol electrolyte with dicarboxylic acids additives for aluminium-air batteries

    NASA Astrophysics Data System (ADS)

    Wang, DaPeng; Zhang, DaQuan; Lee, KangYong; Gao, LiXin

    2015-11-01

    Dicarboxylic acid compounds, i.e. succinic acid (SUA), adipic acid (ADA) and sebacic acid (SEA), are used as electrolyte additives in the alkaline ethylene glycol solution for AA5052 aluminium-air batteries. It shows that the addition of dicarboxylic acids lowers the hydrogen gas evolution rate of commercial AA5052 aluminium alloy anode. AA5052 aluminium alloy has wide potential window for electrochemical activity and better discharge performance in alkaline ethylene glycol solution containing dicarboxylic acid additives. ADA has the best inhibition effect for the self-corrosion of AA5052 anode among the three dicarboxylic acid additives. Fourier transform infrared spectroscopy (FT-IR) reveals that dicarboxylic acids and aluminium ions can form coordination complexes. Quantum chemical calculations shows that ADA has a smaller energy gap (ΔE, the energy difference between the lowest unoccupied orbital and the highest occupied orbital), indicating that ADA has the strongest interaction with aluminium ions.

  20. The effect of porous support composition and operating parameters on the performance of supported liquid membranes

    SciTech Connect

    Takigawa, D.Y.

    1991-02-01

    Factors, such as porous support composition and operating parameters, that influence the performance of supported liquid membranes (SLMs) were investigated. SLMs of varying porous support compositions and structures were studied for the transport of metal ions. A microporous polybenzimidazole support was synthesized and prepared in the form of an SLM. This SLM containing the selective extractant di-(2-ethylhexyl)phosphoric acid was evaluated for the transport of copper and neodymium. Dramatically improved performance over that of commercially available membranes was found in tests for removing the metal ions from solution. Metal ion transport reaches near completion in less than 3 hours, whereas Celgard-polypropylene and Nuclepore-polycarbonate reaches only 50% completion even after 15 hours. The transport driving force for acidic extractants is a pH gradient between the feed and strip solutions. Polybenzimidazole, an acid- and radiation-resistant polymer, has two protonatable tertiary nitrogens per repeat unit that may help sustain the pH driving force. Another factor may be the ability of the polybenzimidazole to hydrogen bond with the extractant. Transport through the flat-sheet SLMs were tested using a unique cell design. Countercurrent flow of the feed and strip solutions was established through machined channels in half-cell faceplates that are in a spiral, mirror-image pattern with respect to each other, with the flat-sheet SLM interposed between the two channeled solutions. 7 refs., 14 figs.

  1. Evolution of match performance parameters for various playing positions in the English Premier League.

    PubMed

    Bush, Michael; Barnes, Chris; Archer, David T; Hogg, Bob; Bradley, Paul S

    2015-02-01

    This study aimed to investigate position-specific evolution of physical and technical performance parameters in the English Premier League (EPL). Match performance observations (n=14700) were collected using a multiple-camera computerized tracking system across seven seasons (2006-07 to 2012-13). Data were analyzed relative to five playing positions: central defenders (n=3792), full backs (n=3420), central midfielders (n=3200), wide midfielders (n=2136) and attackers (n=2152). High-intensity running distance increased in the final season versus the first season in all playing positions (p<.05, ES: 0.9-1.3) with full backs displaying the greatest increase (∼36% higher in 2012-13). Similar trends were observed for sprint distance with full backs demonstrating the most pronounced increase across the seven seasons (36-63%, p<.001, ES: 0.8-1.3). Central players (central defenders and midfielders) illustrated the most pronounced increases in total passes and pass success rate (p<.05, ES: 0.7-0.9) whilst wide players (full backs and wide midfielders) demonstrated only small-moderate increases in total passes and pass success rate (p<.05, ES: 0.6-0.8). The data demonstrates that evolving tactics in the EPL have impacted on the physical demands of wide players and the technical requirements of central players. These findings could be used for talent identification or position-specific physical and technical training. PMID:25461429

  2. Influence of dimension parameters of the gravity heat pipe on the thermal performance

    NASA Astrophysics Data System (ADS)

    Kosa, Ľuboš; Nemec, Patrik; Jobb, Marián; Malcho, Milan

    2016-06-01

    Currently the problem with the increasing number of electronic devices is a problem with the outlet Joule heating. Joule heating, also known as ohmic heating and resistive heating, is the process by which the passage of an electric current through a conductor releases heat. Perfect dustproof cooling of electronic components ensures longer life of the equipment. One of more alternatives of heat transfer without the using of mechanical equipment is the use of the heat pipe. Heat pipes are easy to manufacture and maintenance of low input investment cost. The advantage of using the heat pipe is its use in hermetic closed electronic device which is separated exchange of air between the device and the environment. This experiment deals with the influence of changes in the working tube diameter and changing the working fluid on performance parameters. Changing the working fluid and the tube diameter changes the thermal performance of the heat pipe. The result of this paper is finding the optimal diameter with ideal working substance for the greatest heat transfer for 1cm2 sectional area tube.

  3. Effects of egg storage on hatchability, chick quality, performance and immunocompetence parameters of broiler chickens.

    PubMed

    Goliomytis, Michael; Tsipouzian, Theofania; Hager-Theodorides, Ariadne L

    2015-09-01

    Pre-incubation egg storage is a necessity for the poultry industry. This study evaluated the effects of pre-incubation storage length of broiler eggs on hatchability, 1-day-old chick quality, subsequent performance, and immunocompetence. To this end, a total of 360 hatching eggs were stored for 4, 12, or 16 d prior to incubation. Hatchability and chick quality were assessed at hatch, and growth performance and immunocompetence parameters were assessed during a 35 d rearing period. Hatchability of set and fertile eggs, and embryonic mortality, were not affected by egg storage. On the contrary, 1-day-old chick BW and length were linearly negatively correlated with egg storage length (P-linear<0.05). Nevertheless, BW corrected for egg weight prior to setting was unaffected, and corrected chick length was positively affected by storage length. One-day-old chick Tona score, navel quality, and post-hatch growth performance (BW at 7 and 35 d, cumulative feed intake, and feed conversion ratio at 35 d) were unaffected by egg storage (P, P-linear>0.05). Lymphoid organ weights at 2 and 35 d, the titre of maternal anti-NDV antibodies, most of the thymocyte subpopulations defined by CD3, CD4, and CD8 cell surface expression in the thymus of 2-d-old chicks, cellular responses to the PHA skin test, humoral responses to primary SRBC, and NDV immunizations were also not influenced by length of storage (P, P-linear>0.05). On the contrary, the length of egg storage was found to negatively influence the abundance of CD3+CD4-CD8- thymocytes that represent the majority of γδ-T cells in the thymus of 2-day-old chicks, as well as the humoral response to booster NDV immunization of the birds. In brief, pre-incubation storage of broiler hatching eggs for up to 16 d did not affect most developmental and growth parameters investigated, except for BW and length at hatch. Egg storage was found to suppress some aspects of the immunocompetence of the birds, particularly aspects of acquired

  4. The evolution of physical and technical performance parameters in the English Premier League.

    PubMed

    Barnes, C; Archer, D T; Hogg, B; Bush, M; Bradley, P S

    2014-12-01

    This study examined the evolution of physical and technical soccer performance across a 7-season period in the English Premier League. Match performance observations (n=14 700) were analysed for emergent trends. Total distance covered during a match was ~2% lower in 2006-07 compared to 2012-13. Across 7 seasons, high-intensity running distance and actions increased by ~30% (890±299 vs. 1 151±337 m, p<0.001; ES: 0.82) and ~50% (118±36 vs. 176±46, p<0.001; ES: 1.41), respectively. Sprint distance and number of sprints increased by ~35% (232±114 vs. 350±139 m, p<0.001; ES: 0.93) and ~85% (31±14 vs. 57±20, p<0.001; ES: 1.46), respectively. Mean sprint distance was shorter in 2012-13 compared to 2006-07 (5.9±0.8 vs. 6.9±1.3 m, p<0.001; ES: 0.91), with the proportion of explosive sprints increasing (34±11 vs. 47±9%, p<0.001; ES: 1.31). Players performed more passes (35±17 vs. 25±13, p<0.001; ES: 0.66) and successful passes (83±10% vs. 76±13%, p<0.001; ES: 0.60) in 2012-13 compared to 2006-07. Whereas the number of short and medium passes increased across time (p<0.001; ES>0.6), the number of long passes varied little (p<0.001; ES: 0.11). This data demonstrates evolution of physical and technical parameters in the English Premier League, and could be used to aid talent identification, training and conditioning preparation. PMID:25009969

  5. Influence of tall oil biodiesel with Mg and Mo based fuel additives on diesel engine performance and emission.

    PubMed

    Keskin, Ali; Gürü, Metin; Altiparmak, Duran

    2008-09-01

    The purpose of this study is to investigate influences of tall oil biodiesel with Mg and Mo based fuel additives on diesel engine performance and emission. Tall oil resinic acids were reacted with MgO and MoO(2) stoichiometrically for the production of metal-based fuel additives (combustion catalysts). The metal-based additives were added into tall oil biodiesel (B60) at the rate of 4 micromol/l, 8 micromol/l and 12 micromol/l for preparing test fuels. In general, both of the metal-based additives improved flash point, pour point and viscosity of the biodiesel fuel, depending on the rate of additives. A single cylinder DI diesel engine was used in the tests. Engine performance values did not change significantly with biodiesel fuels, but exhaust emission profile was improved. CO emissions and smoke opacity decreased by 56.42% and by 30.43%, respectively. In general, low NO(x) and CO(2) emissions were measured with the biodiesel fuels. PMID:18164614

  6. SIGNIFICANCE OF SIZE REDUCTION IN SOLID WASTE MANAGEMENT. VOLUME 3. EFFECTS OF MACHINE PARAMETERS ON SHREDDER PERFORMANCE

    EPA Science Inventory

    Hammermill shredders for size reduction of refuse were examined at three sites to determine the influence of key machine parameters on their performance. Internal machine configuration and single-versus two stage size reduction were studied. Key parameters that were investigated ...

  7. A Discussion of Oxygen Recovery Definitions and Key Performance Parameters for Closed-Loop Atmosphere Revitalization Life Support Technology Development

    NASA Technical Reports Server (NTRS)

    Abney, Morgan B.; Perry, Jay L.

    2016-01-01

    Over the last 55 years, NASA has evolved life support for crewed space exploration vehicles from simple resupply during Project Mercury to the complex and highly integrated system of systems aboard the International Space Station. As NASA targets exploration destinations farther from low Earth orbit and mission durations of 500 to 1000 days, life support systems must evolve to meet new requirements. In addition to having more robust, reliable, and maintainable hardware, limiting resupply becomes critical for managing mission logistics and cost. Supplying a crew with the basics of food, water, and oxygen become more challenging as the destination ventures further from Earth. Aboard ISS the Atmosphere Revitalization Subsystem (ARS) supplies the crew's oxygen demand by electrolyzing water. This approach makes water a primary logistics commodity that must be managed carefully. Chemical reduction of metabolic carbon dioxide (CO2) provides a method of recycling oxygen thereby reducing the net ARS water demand and therefore minimizing logistics needs. Multiple methods have been proposed to achieve this recovery and have been reported in the literature. However, depending on the architecture and the technology approach, "oxygen recovery" can be defined in various ways. This discontinuity makes it difficult to compare technologies directly. In an effort to clarify community discussions of Oxygen Recovery, we propose specific definitions and describe the methodology used to arrive at those definitions. Additionally, we discuss key performance parameters for Oxygen Recovery technology development including challenges with comparisons to state-of-the-art.

  8. Effects of processed parameters on the magnetic performance of a powder magnetic core

    NASA Astrophysics Data System (ADS)

    Xie, Ding-Zhou; Lin, Kuan-Hong; Lin, Shun-Tian

    2014-03-01

    The goal of this study is to develop a high magnetic flux density and low iron loss powder magnetic core with insulated layer coating on pure iron powders of varying sizes. After processing the phosphate treatment, the insulated layer Zn3(PO4)2 was coated onto the iron powder surface. It not only maintained the magnetic flux density of pure iron, but also enhanced the electrical resistivity of the magnetic core by reducing eddy current loss, which allowed a wider frequency range. In addition, the annealing treatment after the compression process raised the magnetic flux density of the magnetic core; however, an annealing temperature above 200 °C caused the binder to decompose, resulting in decreased electrical resistivity. Experimental results indicate that the best magnetic performances were achieved with a powder magnetic core of fine and coarse iron powder proportion of 2:1, phosphate treatment of 90 s, and an annealing temperature of 200 °C.

  9. Effect of oestrogenic compounds on performance and biochemical parameters of chickens in Egypt.

    PubMed

    Badr, Mohamed O T; Hashem, Mohamed A; Gado, Nissreen N

    2009-01-01

    Comparative studies of the effects of Nordette and LutoFolone on 15-day-old chickens were performed to determine their effects on growth performance, biochemical parameters and on hormonal residues in the liver and muscle. Sixty chickens were equally divided into three groups, with 20 chickens per group. Group 1 served as the control group. Groups 2 and 3 were treated daily with Nordette (1 mg/kg body weight) mixed in the ration and LutoFolone (0.5 mg/kg body weight) administered orally through a bent stainless steel feeding tube, respectively, for 30 days (from the 15th to the 45th day of age). The treated groups were left for a further period of 15 days without treatment. Blood samples were collected at 45 and 60 days of age and used for biochemical studies, while liver and muscles were excised from each chicken and used to prepare tissue homogenates for an estimation of hormonal residues (oestrogen and progesterone). Both drugs caused a gain in body weight. They also significantly increased (p<0.01) several serum variables, including alanine aminotransferase (ALT) (410% and 300%), aspartate aminotransferase (AST) (277.69% and 261.90%), cholesterol (16.91% and 17.19%), creatine kinase (CK) (72.47% and 27.46%), creatinine (62.22% and 42.22%) and uric acid (85.43% and 70.86%), and reduced total proteins (54.38% and 51.28%), albumin (60.38% and 52.08%) and globulin levels (50.22% and 49.36%) for Groups 2 and 3 respectively at 30 days post administration, in comparison with the control birds. Moreover, this study exhibited a significant increase in the levels of oestrogen residues in the liver (26.17% and 70.99%) and muscle (17.50% and 43.41%) for Groups 2 and 3, respectively. This indicated that the oestrogen level was much higher in the liver than in muscle in comparison to that of the controls. However, some of these findings showed insignificant changes 15 days after ceasing the administration of hormones. Data on the biochemical parameters and residue levels

  10. Parameters influencing the aerosol capture performance of the Submerged-Bed Scrubber

    SciTech Connect

    Ruecker, C.M.; Scott, P.A.

    1987-04-01

    The Submerged-Bed Scrubber (SBS) is a novel air cleaning device that has been investigated by Pacific Northwest Laboratory (PNL) for scrubbing off gases from liquid-fed ceramic melters used to vitrify high-level waste (HLW). The concept for the SBS was originally conceived at Hanford for emergency venting of a reactor containment building. The SBS was adapted for use as a quenching scrubber at PNL because it can cool the hot melter off gas as well as remove over 90% of the airborne particles, thus meeting the minimum particulate decontamination factor (DF) of 10 required of a primary scrubber. The experiments in this study showed that the submicron aerosol DF for the SBS can exceed 100 under certain conditions. A conventional device, the ejector-venturi scrubber (EVS), has been previously used in this application. The EVS also adequately cools the hot gases from the melter while exhibiting aerosol removal DFs in the range of 5 to 30. In addition to achieving higher DFs than the EVS, however, the SBS has the advantage of being a passive system, better suited to the remote environment of an HLW processing system. The objective of this study was to characterize the performance of the SBS and to improve the aerosol capture efficiency by modifying the operating procedure or the design. A partial factorial experimental matrix was completed to determine the main effects of aerosol solubility, inlet off-gas temperature, inlet off-gas flow rate, steam-to-air ratio, bed diameter and packing diameter on the particulate removal efficiency of the SBS. Several additional experiments were conducted to measure the influence of the inlet aerosol concentration and scrubbing-water concentration on aerosol-removal performance. 33 refs., 17 figs., 14 tabs.

  11. Influence of operating parameters on the performance of magnetic seeding flocculation.

    PubMed

    Chen, Yiqing; Luo, Man; Cai, Wangfeng

    2016-02-01

    In the present study, magnetic seeding flocculation was applied to remove copper (200 mg/L) and turbidity (180 mg/L) from simulated microetch copper waste. Fe3O4 particles (40 to 1600 mesh) were used as magnetic seeds. Poly-aluminum chloride (PAC) and anionic polyacrylamide (PAM) were added as coagulant and flocculant, respectively. The effect of operating factors, such as the dosages of the coagulant and flocculant, initial pH of the wastewater, and dosage and size of the magnetic seeds, on copper and turbidity removal was systematically investigated. In addition, settling speed, floc-size distribution, and volume of sludge were measured with and without the addition of magnetic seeds to compare the efficiency of magnetic seeding to that of traditional flocculation. The results indicated that the highest settling speed, the largest floc size, and the smallest volume of sludge were obtained simultaneously when the dosage and size of magnetic seeds were 2.0 g/L and 300–400 mesh, respectively. High removal efficiencies of 98.53 and 94.72 % for copper and turbidity, respectively, were also achieved under this condition; values that are 4.11 and 0.61 % higher, respectively, than those found in traditional flocculation. The high performance might be attributed to efficient collision of particles and slightly moderate vortex centrifugal force of inertia among the magnetic seeds, which could produce larger magnetic flocs with lower moisture. PMID:26467253

  12. Effects of Supplemental Glutamine on Growth Performance, Plasma Parameters and LPS-induced Immune Response of Weaned Barrows after Castration

    PubMed Central

    Hsu, C. B.; Lee, J. W.; Huang, H. J.; Wang, C. H.; Lee, T. T.; Yen, H. T.; Yu, B.

    2012-01-01

    Two experiments were conducted to investigate the effects of supplemental glutamine on growth performance, plasma parameters and LPS-induced immune response of weaned barrows after castration. In experiment 1, forty-eight weaned male piglets were used and fed maize and soybean meal diets supplemented with 0 (Control) or 2% L-Gln (Gln+) for 25 days. The results indicated that the Gln+ group tended to increase average daily gain compared to control in stages of days 7 to 14 and 0 to 25. The Gln+ had significantly better feed efficiency than the control group did during days 14 to 25 and 0 to 25. The plasma blood urea nitrogen and alkaline phosphatase contents of Gln+ group were higher than those of the control group on day 14 post-weaning. In experiment 2, sixteen weaned male piglets were injected with E. coli K88+ lipopolysaccharide (LPS) on day 14 post-weaning. The results showed that the Gln+ group had lower concentrations of plasma adrenocorticotrophic hormone and cortisol than the control group on day 14 pre-LPS challenge. In addition, Gln+ group had higher plasma IgG concentration than the control group for pre- or post-LPS challenged on day 14 post-weaning. In summary, dietary supplementation of Gln was able to alleviate the stressful condition and inflammation associated with castration in weaned barrows, and to improve their immunity and growth performance in the early starter stage. PMID:25049613

  13. Enhanced performance of a submerged membrane bioreactor with powdered activated carbon addition for municipal secondary effluent treatment.

    PubMed

    Lin, Hongjun; Wang, Fangyuan; Ding, Linxian; Hong, Huachang; Chen, Jianrong; Lu, Xiaofeng

    2011-09-15

    The aim of this study was to investigate the feasibility of PAC-MBR process treating municipal secondary effluent. Two laboratory-scale submerged MBRs (SMBR) with and without PAC addition were continuously operated in parallel for secondary effluent treatment. Approximately 63%TOC, 95% NH(4)(+)-N and 98% turbidity in secondary effluent were removed by the PAC-MBR process. Most organics in the secondary effluent were found to be low molecular weight (MW) substances, which could be retained in the reactor and then removed to some extent by using PAC-MBR process. Parallel experiments showed that the addition of PAC significantly increased organic removal and responsible for the largest fraction of organic removal. Membrane fouling analysis showed the enhanced membrane performance in terms of sustainable operational time and filtration resistances by PAC addition. Based on these results, the PAC-MBR process was considered as an attractive option for the reduction of pollutants in secondary effluent. PMID:21794980

  14. Improving the performance of an aerobic membrane bioreactor (MBR) treating pharmaceutical wastewater with powdered activated carbon (PAC) addition.

    PubMed

    Kaya, Yasemin; Bacaksiz, A Murat; Golebatmaz, Ugur; Vergili, Ilda; Gönder, Z Beril; Yilmaz, Gulsum

    2016-04-01

    In this study, the effects of organic loading rate (OLR) and the addition of powdered activated carbon (PAC) on the performance and membrane fouling of MBR were conducted to treat real pharmaceutical process wastewater. Over 145 days of operation, the MBR system was operated at OLRs ranging from 1 to 2 kg COD m(-3) day(-1) without sludge wasting. The addition of PAC provided an improvement in the flux, despite an increase in the OLR:PAC ratio. The results demonstrated that the hybrid PAC-MBR system maintained a reduced amount of membrane fouling and steadily increased the removal performance of etodolac. PAC addition reduced the deposition of extracellular polymeric substance and organic matter on the membrane surface and resulted an increase in COD removal even at higher OLRs with low PAC addition. Membrane fouling mechanisms were investigated using combined adsorption fouling models. Modified fouling index values and normalized mass transfer coefficient values indicated that predominant fouling mechanism was cake adsorption. PMID:26846538

  15. Effects of Flux Precoating and Process Parameter on Welding Performance of Inconel 718 Alloy TIG Welds

    NASA Astrophysics Data System (ADS)

    Lin, Hsuan-Liang; Wu, Tong-Min; Cheng, Ching-Min

    2014-01-01

    The purpose of this study is to investigate the effect of activating flux on the depth-to-width ratio (DWR) and hot cracking susceptibility of Inconel 718 alloy tungsten inert gas (TIG) welds. The Taguchi method is employed to investigate the welding parameters that affect the DWR of weld bead and to achieve optimal conditions in the TIG welds that are coated with activating flux in TIG (A-TIG) process. There are eight single-component fluxes used in the initial experiment to evaluate the penetration capability of A-TIG welds. The experimental results show that the Inconel 718 alloy welds precoated with 50% SiO2 and 50% MoO3 flux were provided with better welding performance such as DWR and hot cracking susceptibility. The experimental procedure of TIG welding process using mixed-component flux and optimal conditions not only produces a significant increase in DWR of weld bead, but also decreases the hot cracking susceptibility of Inconel 718 alloy welds.

  16. Assessment of impact of acoustic and nonacoustic parameters on performance and well-being

    NASA Astrophysics Data System (ADS)

    Mellert, Volker; Weber, Reinhard; Nocke, Christian

    2001-05-01

    It is of interest to estimate the influence of the environment in a specific work place area on the performance and well-being of people. Investigations have been carried out for the cabin environment of an airplane and for class rooms. Acoustics is only one issue of a variety of environmental factors, therefore the combined impact of temperature, humidity, air quality, lighting, vibration, etc. on human perception is the subject of psychophysical research. Methods for the objective assessment of subjective impressions have been developed for applications in acoustics for a long time, e.g., for concert hall acoustics, noise evaluation, and sound design. The methodology relies on questionnaires, measurement of acoustic parameters, ear-related signal processing and analysis, and on correlation of the physical input with subjective output. Methodology and results are presented from measurements of noise and vibration, temperature and humidity in aircraft simulators, and of reverberation, coloring, and lighting in a primary school, and of the environmental perception. [The work includes research with M. Klatte, A. Schick from the Psychology Department of Oldenburg University, and M. Meis from Hoerzentrum Oldenburg GmbH and with the European Project HEACE (for partners see www.heace.org).

  17. Fiber heart valve prosthesis: influence of the fabric construction parameters on the valve fatigue performances.

    PubMed

    Vaesken, Antoine; Heim, Frederic; Chakfe, Nabil

    2014-12-01

    Transcatheter aortic valve replacement (TAVR) has become today a largely considered alternative technique to surgical valve replacement in patients who are not operable or patients with high risk for open chest surgery. However, the biological valve tissue used in the devices implanted clinically appears to be fragile material when folded for low diameter catheter insertion purpose and released in calcified environment with irregular geometry. Textile polyester material is characterized by outstanding folding and strength properties combined with proven biocompatibility. It could thereof be considered to replace biological valve leaflets in the TAVR procedure. The textile construction parameters must however be tuned to obtain a material compatible with the valve requested durability. In that context, one issue to be addressed is the friction effect that occurs between filaments and between yarns within a fabric under flexure loading. This phenomenon could be critical for the resistance of the material on the long term. The purpose of the present work is to assess the fatigue performances of textile valve prototypes made from different fabric constructions (monofilament, multifilament, calendered mutifilament) under accelerated cyclic loading. The goal is to identify, which construction is the best suited to long term fatigue stress. Results show that calendered multifilament and monofilament fabric constructions undergo strong ruptures already from 40 Mio cycles, while non calendered multifilament appears more durable. The rupture patterns observed point out that durability is directly related to the flexure stiffness level of the fibrous elements in the construction. PMID:25201184

  18. Superposition-additive approach in the description of thermodynamic parameters of formation and clusterization of substituted alkanes at the air/water interface.

    PubMed

    Vysotsky, Yu B; Belyaeva, E A; Fomina, E S; Vasylyev, A O; Vollhardt, D; Fainerman, V B; Aksenenko, E V; Miller, R

    2012-12-01

    The superposition-additive approach developed previously was shown to be applicable for the calculations of the thermodynamic parameters of formation and atomization of conjugate systems, their dipole polarizability, molecular diamagnetic susceptibility, π-electronic ring currents, etc. In the present work, the applicability of this approach for the calculation of the thermodynamic parameters of formation and clusterization at the water/air interface of alkanes, fatty alcohols, thioalcohols, amines, nitriles, fatty acids (C(n)H(2n+1)X, X is the functional group) and cis-unsaturated carboxylic acids (C(n)H(2n-1)COOH) is studied. Using the proposed approach the thermodynamic quantities determined agree well with the available data, either calculated using the semiempirical (PM3) quantum chemical method, or obtained in experiments. In particular, for enthalpy and Gibbs' energy of the formation of substituted alkane monomers from the elementary substances, and their absolute entropy, the standard deviations of the values calculated according to the superposition-additive scheme with the mutual superimposition domain C(n-2)H(2n-4) (n is the number of carbon atoms in the alkyl chain) from the results of PM3 calculations for alkanes, alcohols, thioalcohols, amines, fatty acids, nitriles and cis-unsaturated carboxylic acids are respectively: 0.05, 0.004, 2.87, 0.02, 0.01, 0.77, and 0.01 kJ/mol for enthalpy; 2.32, 5.26, 4.49, 0.53, 1.22, 1.02, 5.30 J/(molK) for absolute entropy; 0.69, 1.56, 3.82, 0.15, 0.37, 0.69, 1.58 kJ/mol for Gibbs' energy, whereas the deviations from the experimental data are: 0.52, 5.75, 1.40, 1.00, 4.86 kJ/mol; 0.52, 0.63, 1.40, 6.11, 2.21 J/(molK); 2.52, 5.76, 1.58, 1.78, 4.86 kJ/mol, respectively (for nitriles and cis-unsaturated carboxylic acids experimental data are not available). The proposed approach provides also quite accurate estimates of enthalpy, entropy and Gibbs' energy of boiling and melting, critical temperatures and standard heat

  19. Investigation of Cross-Linked and Additive Containing Polymer Materials for Membranes with Improved Performance in Pervaporation and Gas Separation

    PubMed Central

    Hunger, Katharina; Schmeling, Nadine; Jeazet, Harold B. Tanh; Janiak, Christoph; Staudt, Claudia; Kleinermanns, Karl

    2012-01-01

    Pervaporation and gas separation performances of polymer membranes can be improved by crosslinking or addition of metal-organic frameworks (MOFs). Crosslinked copolyimide membranes show higher plasticization resistance and no significant loss in selectivity compared to non-crosslinked membranes when exposed to mixtures of CO2/CH4 or toluene/cyclohexane. Covalently crosslinked membranes reveal better separation performances than ionically crosslinked systems. Covalent interlacing with 3-hydroxypropyldimethylmaleimide as photocrosslinker can be investigated in situ in solution as well as in films, using transient UV/Vis and FTIR spectroscopy. The photocrosslinking yield can be determined from the FTIR-spectra. It is restricted by the stiffness of the copolyimide backbone, which inhibits the photoreaction due to spatial separation of the crosslinker side chains. Mixed-matrix membranes (MMMs) with MOFs as additives (fillers) have increased permeabilities and often also selectivities compared to the pure polymer. Incorporation of MOFs into polysulfone and Matrimid® polymers for MMMs gives defect-free membranes with performances similar to the best polymer membranes for gas mixtures, such as O2/N2 H2/CH4, CO2/CH4, H2/CO2, CH4/N2 and CO2/N2 (preferentially permeating gas is named first). The MOF porosity, its particle size and content in the MMM are factors to influence the permeability and the separation performance of the membranes. PMID:24958427

  20. Effect on supplementation of Spirulina maxima enriched with Cu on production performance, metabolical and physiological parameters in fattening pigs.

    PubMed

    Saeid, A; Chojnacka, K; Korczyński, M; Korniewicz, D; Dobrzański, Z

    2013-01-01

    In this paper, the effect of addition of the biomass of Spirulina maxima enriched with copper (Sm-Cu) to the animal feed is discussed. The biomass was cultivated in the photobioreactor with the capacity of 10 m(3). After the biosorption process, the enriched biomass was investigated as the source of valuable nutrients. The feeding experiment was conducted for 87 days. The study was performed in individual rearing pens, with controlled microclimate, feed and water were available semi-ad libitum. Piglets (24) were divided into two groups (control and experimental). The experimental group was fed with addition of the biomass of Sm-Cu instead of inorganic salts. There were no statistically significant differences between the average daily and periodic weight gain, daily and periodic feed collection, as well as feed conversion ratio. There were no statistically significant differences between the amount of N excreted in faeces and urine, when considering the retention of N, both in relation to the consumed N, and relative N digested which was at a similar level. In the experimental group in comparison to the control group, the lower low-density lipoprotein cholesterol by 17.05 % (P < 0.05) and total cholesterol by 9.43 % (P < 0.05) were observed. Additionally, the increase of parameter a* of 13 % (P < 0.05) and the reduction of the natural leakage by 34 % (P < 0.05) were found. PMID:24027355

  1. Enhanced performance of Li|LiFePO4 cells using CsPF6 as an electrolyte additive

    NASA Astrophysics Data System (ADS)

    Xiao, Liang; Chen, Xilin; Cao, Ruiguo; Qian, Jiangfeng; Xiang, Hongfa; Zheng, Jianming; Zhang, Ji-Guang; Xu, Wu

    2015-10-01

    The practical application of lithium (Li) metal anode in rechargeable Li batteries is hindered by both the growth of Li dendrites and the low Coulombic efficiency (CE) during repeated charge/discharge cycles. Recently, we have discovered that CsPF6 as an electrolyte additive can significantly suppress Li dendrite growth and lead to highly compacted and well aligned Li nanorod structures during Li deposition on copper substrates. In this paper, the effect of CsPF6 additive on the performance of rechargeable Li metal batteries with lithium iron phosphate (LFP) cathode is further studied. Li|LFP coin cells with CsPF6 additive in electrolytes show well protected Li anode surface, decreased resistance, enhanced rate capability and extended cycling stability. In Li|LFP cells, the electrolyte with CsPF6 additive shows excellent long-term cycling stability (at least 500 cycles) at a charge current density of 0.5 mA cm-2 without internal short circuit. At high charge current densities, the effect of CsPF6 additive becomes less significant. Future work needs to be done to protect Li metal anode, especially at high charge current densities and for long cycle life.

  2. Enhanced Performance of Li|LiFePO4 Cells Using CsPF6 as an Electrolyte Additive

    SciTech Connect

    Xiao, Liang; Chen, Xilin; Cao, Ruiguo; Qian, Jiangfeng; Xiang, Hongfa; Zheng, Jianming; Zhang, Jiguang; Xu, Wu

    2015-10-20

    The practical application of lithium (Li) metal anode in rechargeable Li batteries is hindered by both the growth of Li dendrites and the low Coulombic efficiency (CE) during repeated charge/discharge cycles. Recently, we have discovered that CsPF6 as an electrolyte additive can significantly suppress Li dendrite growth and lead to highly compacted and well aligned Li nanorod structure during Li deposition on copper substrates. In this paper, the effect of CsPF6 additive on the performance of rechargeable Li metal batteries with lithium iron phosphate (LFP) cathode was further studied. Li|LFP coin cells with CsPF6 additive in electrolytes show well protected Li anode surface, decreased resistance, enhanced rate capability and extended cycling stability. In Li|LFP cells, the electrolyte with CsPF6 additive shows excellent long-term cycling stability (at least 500 cycles) at a charge current density of 0.5 mA cm-2 without internal short circuit. At high charge current densities, the effect of CsPF6 additive becomes less significant. Future work needs to be done to protect Li metal anode, especially at high charge current densities and for long cycle life.

  3. Study on Antiwear and Repairing Performances about Mass of Nano-copper Lubricating Additives to 45 Steel

    NASA Astrophysics Data System (ADS)

    Wang, X. L.; Yin, Y. L.; Zhang, G. N.; Wang, W. Y.; Zhao, K. K.

    Nano-copper usually serve for lubricating additives in tribology field. The antiwear and reducing friction performances both basic lubrication oil and basic lubrication oil with nano-copper in different mass were tested by friction wear test machine. The morphologies and the main elements of worn surfaces were analyzed by SEM. The results indicated that nano-copper could improve tribology performances of basic lubrication oil. Comparing with base lubrication oil, the mass is 0.15% of nano-copper, the friction coefficient and the worn trace width can be reduced 34% and 32% respectively. Nano-copper can form self-repairing film in lubrication oil which availably separates the friction materials in friction process. Therefore, nano-copper has wonderful antiwear, reducing friction and self-repairing performances. And the function mechanism of Cu nanoparticles is studied in the paper.

  4. Effects of non-antibiotic feed additives on performance, tibial dyschondroplasia incidence and tibia characteristics of broilers fed low-calcium diets.

    PubMed

    Houshmand, M; Azhar, K; Zulkifli, I; Bejo, M H; Meimandipour, A; Kamyab, A

    2011-06-01

    This experiment was conducted to investigate and compare the efficacy of different feed additives on performance, tibial dyschondroplasia (TD) incidence and tibia characteristics of male broilers fed low-calcium diets. A completely randomized design, with six treatments and five replicates of five chicks per each was used. Experimental treatments were: (i) Basal diet containing recommended level of calcium (0.9%) as control treatment (Ctrl), (ii) low-calcium (0.67%) diet without any additive (LC), (iii) low-calcium diet + probiotic (2 g/kg diet), (iv) low-calcium diet + prebiotic (2 g/kg diet), (v) low-calcium diet + synbiotic [mix of probiotic and prebiotic (each 2 g/kg diet)], (vi) low-calcium diet + organic acid (1.5 g/kg diet). Birds were reared in an open-sided house system under natural tropical condition until 21 days of age. Feeding with low-calcium diet negatively influenced broiler performance (body weight, body weight gain and feed conversion ratio) and tibia characteristics, whereas dietary inclusion of all feed additives had beneficial effects on above-mentioned parameters and helped the birds to overcome problems related to low-calcium diets. Different treatments had no effect on TD incidence. PMID:21156001

  5. Combining normobaric hypoxia with short-term resistance training has no additive beneficial effect on muscular performance and body composition.

    PubMed

    Ho, Jen-Yu; Kuo, Tai-Yu; Liu, Kuan-Lin; Dong, Xiang-Yi; Tung, Kang

    2014-04-01

    The aim of this study was to determine the effects of short-term resistance training combined with systemic hypoxia on muscular performance and body composition. Eighteen resistance-untrained men (21.3 ± 2.0 years, 172.7 ± 5.5 cm, 67.3 ± 9.7 kg) were matched and assigned to 2 experimental groups: performing 6 weeks of squat exercise training under normobaric hypoxia (H, FiO2 = 15%) or normoxia (N). In both groups, subjects performed 3 weekly sessions (a total of 18 sessions) of 3 sets of back squat at 10-repetition maximum with 2 minutes of rest between sets. Dynamic, isometric, and isokinetic leg strength and body composition were measured under normoxia before and after resistance training. Squat 1 repetition maximum (1RM) improved significantly (p ≤ 0.05) after resistance training in both H and N groups (88.9 ± 16.9 to 109.4 ± 17.0 kg and 90.0 ± 12.2 to 105.6 ± 13.3 kg, respectively). However, there were no changes in maximal isometric and isokinetic leg strength, lean body mass, and fat mass after the resistance training in both groups. In addition, no significant differences were observed between H and N groups in squat 1RM, maximal isometric and isokinetic leg strength, and body composition. The major findings of this study suggest that short-term resistance training performed under normobaric hypoxia has no additive beneficial effect on muscular performance and body composition. In practical terms, our data suggest that the use of systemic hypoxia during short-term resistance training is not a viable method to further enhance muscular performance and body composition in previously resistance-untrained men. PMID:24149753

  6. Improvement on the storage performance of LiMn2O4 with the mixed additives of ethanolamine and heptamethyldisilazane

    NASA Astrophysics Data System (ADS)

    Wu, Xianwen; Li, Xinhai; Wang, Zhixing; Guo, Huajun; Yue, Peng; Zhang, Yunhe

    2013-03-01

    The commercial LiMn2O4 are added into the LiPF6-based electrolyte without or with the mixed additives of ethanolamine and heptamethyldisilazane to be exposed in air at 60 °C for 2-6 h, and the effect of different electrolytes on the storage behavior of LiMn2O4 materials and LiMn2O4/Li cells at elevated temperature is investigated comparatively for the first time by FTIR, SEM, TEM, XRD and charge-discharge measurements. The results show that the electrochemical performances of LiMn2O4 exposed in the LiPF6-based electrolyte become worse gradually with the storage time increasing. However, when the mixture of ethanolamine and heptamethyldisilazane as electrolyte additives is added into the LiPF6-based electrolyte, it can stabilize the original morphology and spinel structure of LiMn2O4 greatly and improve the storage performance of the material and LiMn2O4/Li cells effectively. As the commercial LiMn2O4 is exposed in the LiPF6-based electrolyte with additives for 4 h at 60 °C, the initial discharge capacity of 97.7 mA h g-1 at 0.1 C and the capacity retention of 89.14% at 1 C rate after 150 cycles are much better than that LiMn2O4 exposed in the LiPF6-based electrolyte under the same conditions. Furthermore, the LiMn2O4/Li cells using the LiPF6-based electrolyte with additives exhibit higher initial discharge capacity before storage and higher capacity retention after storage at 60 °C for a week compared to the cells without additives in the LiPF6-based electrolyte.

  7. Application of a Constant Gain Extended Kalman Filter for In-Flight Estimation of Aircraft Engine Performance Parameters

    NASA Technical Reports Server (NTRS)

    Kobayashi, Takahisa; Simon, Donald L.; Litt, Jonathan S.

    2005-01-01

    An approach based on the Constant Gain Extended Kalman Filter (CGEKF) technique is investigated for the in-flight estimation of non-measurable performance parameters of aircraft engines. Performance parameters, such as thrust and stall margins, provide crucial information for operating an aircraft engine in a safe and efficient manner, but they cannot be directly measured during flight. A technique to accurately estimate these parameters is, therefore, essential for further enhancement of engine operation. In this paper, a CGEKF is developed by combining an on-board engine model and a single Kalman gain matrix. In order to make the on-board engine model adaptive to the real engine s performance variations due to degradation or anomalies, the CGEKF is designed with the ability to adjust its performance through the adjustment of artificial parameters called tuning parameters. With this design approach, the CGEKF can maintain accurate estimation performance when it is applied to aircraft engines at offnominal conditions. The performance of the CGEKF is evaluated in a simulation environment using numerous component degradation and fault scenarios at multiple operating conditions.

  8. Performing forward-viewing endoscopy at time of pancreaticobiliary EUS and ERCP may detect additional upper gastrointestinal lesions

    PubMed Central

    Thomas, Ashby; Vamadevan, Arunan S; Slattery, Eoin; Sejpal, Divyesh V; Trindade, Arvind J

    2016-01-01

    Background and study aims: It is unknown whether significant incidental upper gastrointestinal lesions are missed when using non-forward-viewing endoscopes without completing a forward-viewing exam in linear endoscopic ultrasound (EUS) or endoscopic retrograde cholangiopancreatography (ERCP) exams. We evaluated whether significant upper GI lesions are missed during EUS and ERCP when upper endoscopy is not performed routinely with a gastroscope. Patients and methods: A retrospective analysis was performed in which an EGD with a forward-viewing gastroscope was performed after using a non-forward-viewing endoscope (linear echoendoscope, duodenoscope, or both) during a single procedure. Upper gastrointestinal tract findings were recorded separately for each procedure. Significant lesions found with a forward-viewing gastroscope were defined as findings that led to a change in the patient’s medication regimen, additional endoscopic surveillance/interventions, or the need for other imaging studies. Results: A total of 168 patients were evaluated. In 83 patients, a linear echoendoscope was used, in 52 patients a duodenoscope was used, and in 33 patients both devices were used. Clinically significant additional lesions diagnosed with a gastroscope but missed by a non-forward-viewing endoscope were found in 30 /168 patients (18 %). EGD after linear EUS resulted in additional lesion findings in 17 /83 patients (20.5 %, χ2 = 13.385, P = 0.00025). EGD after use of a duodenoscope resulted in additional lesions findings in 10 /52 patients (19.2 %, χ2 = 9.987, P = 0.00157). EGD after the use of both a linear echoendoscope and a duodenoscope resulted in additional lesions findings in 3/33 patients (9 %, χ2 = 3.219, P = 0.07). Conclusion: Non forward-viewing endoscopes miss a significant amount of incidental upper gastrointestinal lesions during pancreaticobiliary endoscopy. Performing an EGD with a gastroscope at the time of linear EUS or

  9. [Turkey fattening under extensive rearing conditions--selected parameters concerning health, performance and behavior].

    PubMed

    Bergmann, Shana; Platz, Siegfried; Heyn, Elke; Schweizer, Claudia; Strassmeier, Petra; Erhard, Michael

    2009-01-01

    Within two consecutive studies (study I and study II), each involving a summer (su) and a winter mast (wi), 36 male turkeys per B.U.T. Big 6 (BUT) and Kelly Bronze (KB) origin were set on two seperated areas in free range and fatted over a period of 20 (winter mast in study II) and 22 weeks respectively. Aim of both studies was to analyze the effects of extensive rearing conditions on these two turkey origins concerning health, performance and behavior and whether seasonal climatic differences had any additional influence. Besides the aim in study II was to detect how intensely environmental enrichment (plateau and perches) was accepted by the turkeys and if co-housing of BUT and KB turkeys was possible. The occurence of skin lesions in the breast area (breast blisters and/or breast buttons) was significantly influenced by season (su > wi) and origin (BUT > KB). Malposition of the hind extremities was found significantly more often in the BUT origin, whereas the X-leg position was the most common observed leg abnormality. The mortality rate remained beneath 6% during three of the four fattening periods. Due to their genetical determination, the BUT constantly gained higher weights than the KB (wi > su).The intensity of acceptance of the structural elements was influenced by season (su > wi), forage (ecological > commercial) and time of day (night > day).The results of the studies lead to the conclusion that turkeys of the BUT origin can certainly be fattened under extensive rearing conditions alongside the KB origin, while providing good performance. PMID:19681401

  10. Effects of graded levels of montmorillonite on performance, hematological parameters and bone mineralization in weaned pigs.

    PubMed

    Duan, Q W; Li, J T; Gong, L M; Wu, H; Zhang, L Y

    2013-11-01

    The aim of this study was to investigate the effects of graded levels of montmorillonite, a constituent of clay, on performance, hematological parameters and bone mineralization in weaned pigs. One hundred and twenty, 35-d-old crossbred pigs (Duroc×Large White×Landrace, 10.50±1.20 kg) were used in a 28-d experiment and fed either an unsupplemented corn-soybean meal basal diet or similar diets supplemented with 0.5, 1.0, 2.5 or 5.0% montmorillonite added at the expense of wheat bran. Each treatment was replicated six times with four pigs (two barrows and two gilts) per replicate. Feed intake declined (linear and quadratic effect, p< 0.01) with increasing level of montmorillonite while feed conversion was improved (linear and quadratic effect, p<0.01). Daily gain was unaffected by dietary treatment. Plasma myeloperoxidase declined linearly (p = 0.03) with increasing dietary level of montmorillonite. Plasma malondialdehyde and nitric oxide levels were quadratically affected (p<0.01) by montmorillonite with increases observed for pigs fed the 0.5 and 1.0% levels which then declined for pigs fed the 2.5 and 5.0% treatments. In bone, the content of potassium, sodium, copper, iron, manganese and magnesium were decreased (linear and quadratic effect, p<0.01) in response to an increase of dietary montmorillonite. These results suggest that dietary inclusion of montmorillonite at levels as high as 5.0% does not result in overt toxicity but could induce potential oxidative damage and reduce bone mineralization in pigs. PMID:25049749

  11. Effects of Graded Levels of Montmorillonite on Performance, Hematological Parameters and Bone Mineralization in Weaned Pigs

    PubMed Central

    Duan, Q. W.; Li, J. T.; Gong, L. M.; Wu, H.; Zhang, L. Y.

    2013-01-01

    The aim of this study was to investigate the effects of graded levels of montmorillonite, a constituent of clay, on performance, hematological parameters and bone mineralization in weaned pigs. One hundred and twenty, 35-d-old crossbred pigs (Duroc×Large White×Landrace, 10.50±1.20 kg) were used in a 28-d experiment and fed either an unsupplemented corn-soybean meal basal diet or similar diets supplemented with 0.5, 1.0, 2.5 or 5.0% montmorillonite added at the expense of wheat bran. Each treatment was replicated six times with four pigs (two barrows and two gilts) per replicate. Feed intake declined (linear and quadratic effect, p< 0.01) with increasing level of montmorillonite while feed conversion was improved (linear and quadratic effect, p<0.01). Daily gain was unaffected by dietary treatment. Plasma myeloperoxidase declined linearly (p = 0.03) with increasing dietary level of montmorillonite. Plasma malondialdehyde and nitric oxide levels were quadratically affected (p<0.01) by montmorillonite with increases observed for pigs fed the 0.5 and 1.0% levels which then declined for pigs fed the 2.5 and 5.0% treatments. In bone, the content of potassium, sodium, copper, iron, manganese and magnesium were decreased (linear and quadratic effect, p<0.01) in response to an increase of dietary montmorillonite. These results suggest that dietary inclusion of montmorillonite at levels as high as 5.0% does not result in overt toxicity but could induce potential oxidative damage and reduce bone mineralization in pigs. PMID:25049749

  12. Effects of Dietary Energy Levels on the Physiological Parameters and Reproductive Performance of Gestating Gilts

    PubMed Central

    Jin, S. S.; Jung, S. W.; Jang, J. C.; Chung, W. L.; Jeong, J. H.; Kim, Y. Y.

    2016-01-01

    This experiment was conducted to investigate the effects of dietary energy levels on the physiological parameters and reproductive performance of gestating first parity sows. A total of 52 F1 gilts (Yorkshire×Landrace) were allocated to 4 dietary treatments using a completely randomized design. Each treatment contained diets with 3,100, 3,200, 3,300, or 3,400 kcal of metabolizable energy (ME)/kg, and the daily energy intake of the gestating gilts in each treatment were 6,200, 6,400, 6,600, and 6,800 kcal of ME, respectively. During gestation, the body weight (p = 0.04) and weight gain (p = 0.01) of gilts linearly increased with increasing dietary energy levels. Backfat thickness was not affected at d110 of gestation by dietary treatments, but increased linearly (p = 0.05) from breeding to d 110 of gestation. There were no significant differences on the litter size or litter birth weight. During lactation, the voluntary feed intake of sows tended to decrease when the dietary energy levels increased (p = 0.08). No difference was observed in backfat thickness of the sows within treatments; increasing energy levels linearly decreased the body weight of sows (p<0.05) at d 21 of lactation and body weight gain during lactation (p<0.01). No significant differences were observed in the chemical compositions of colostrum and milk. Therefore, these results indicated that high-energy diets influenced the bodyweight and backfat thickness of sows during gestation and lactation. NRC (2012) suggested that the energy requirement of the gestation gilt should be between 6,678 and 7,932 kcal of ME/d. Similarly, our results suggested that 3,100 kcal of ME/kg is not enough to maintain the reproductive performance for gilts during gestation with 2 kg feed daily. Gilts in the treatment 3,400 kcal of ME/kg have a higher weaning number of piglets, but bodyweight and backfat loss were higher than other treatments during lactation. But bodyweight and backfat loss were higher than other

  13. Serological examination of fattening pigs reveals associations between Ascaris suum, lung pathogens and technical performance parameters.

    PubMed

    Vlaminck, Johnny; Düsseldorf, Simon; Heres, Lourens; Geldhof, Peter

    2015-06-15

    Diagnosing the presence of the highly prevalent and economically important pig parasite Ascaris suum on fattening farms has so far been challenging. Currently, only the number of livers affected at slaughter is routinely used to measure parasite exposure. However, recently, a new serological test was developed based on the detection of antibodies to the A. suum haemoglobin molecule. The test showed to be highly sensitive for the detection of exposure to A. suum in fattening pigs. In this study we first compared the performance of A. suum serology versus the percentage of affected livers at slaughter, subsequently we investigated potential associations between A. suum infection levels and exposure to important lung pathogens and finally we identified correlations between serological data and technical performance parameters (TPIs) from 20 Belgian and 20 German pig fattening farms. In both Belgian and German farms, a significant relationship was detected between elevated average Ascaris serology and percentages of affected livers (ρ=0.63 and ρ=0.75, respectively). On the Belgian farms, both Ascaris serology and the percentage of affected livers were negatively correlated with average daily gain (ADG) (ρ=-0.69 and ρ=-0.56, respectively). Using the German dataset, only a borderline negative association was detected between the percentage of affected livers and the ADG (ρ=-0.44, P=0.053). In contrast, only in the German farms, correlations between the percentage of affected lungs at slaughter and elevated presence of A. suum and several other airway pathogens were detected. To conclude, this study indicates that serological screening for A. suum on fattening farms is an attractive new diagnostic tool that can be used to indicate the presence of roundworm infection by measuring infection intensity. Furthermore the results of this study also add weight to the evidence that both roundworm infections as well as herd exposure to airway pathogens have a significant

  14. Effects of Dietary Energy Levels on the Physiological Parameters and Reproductive Performance of Gestating Gilts.

    PubMed

    Jin, S S; Jung, S W; Jang, J C; Chung, W L; Jeong, J H; Kim, Y Y

    2016-07-01

    This experiment was conducted to investigate the effects of dietary energy levels on the physiological parameters and reproductive performance of gestating first parity sows. A total of 52 F1 gilts (Yorkshire×Landrace) were allocated to 4 dietary treatments using a completely randomized design. Each treatment contained diets with 3,100, 3,200, 3,300, or 3,400 kcal of metabolizable energy (ME)/kg, and the daily energy intake of the gestating gilts in each treatment were 6,200, 6,400, 6,600, and 6,800 kcal of ME, respectively. During gestation, the body weight (p = 0.04) and weight gain (p = 0.01) of gilts linearly increased with increasing dietary energy levels. Backfat thickness was not affected at d110 of gestation by dietary treatments, but increased linearly (p = 0.05) from breeding to d 110 of gestation. There were no significant differences on the litter size or litter birth weight. During lactation, the voluntary feed intake of sows tended to decrease when the dietary energy levels increased (p = 0.08). No difference was observed in backfat thickness of the sows within treatments; increasing energy levels linearly decreased the body weight of sows (p<0.05) at d 21 of lactation and body weight gain during lactation (p<0.01). No significant differences were observed in the chemical compositions of colostrum and milk. Therefore, these results indicated that high-energy diets influenced the bodyweight and backfat thickness of sows during gestation and lactation. NRC (2012) suggested that the energy requirement of the gestation gilt should be between 6,678 and 7,932 kcal of ME/d. Similarly, our results suggested that 3,100 kcal of ME/kg is not enough to maintain the reproductive performance for gilts during gestation with 2 kg feed daily. Gilts in the treatment 3,400 kcal of ME/kg have a higher weaning number of piglets, but bodyweight and backfat loss were higher than other treatments during lactation. But bodyweight and backfat loss were higher than other

  15. Enhanced CO2 adsorptive performance of PEI/SBA-15 adsorbent using phosphate ester based surfactants as additives.

    PubMed

    Cheng, Dandan; Liu, Yue; Wang, Haiqiang; Weng, Xiaole; Wu, Zhongbiao

    2015-12-01

    In this study, a series of polyetherimide/SBA-15: 2-D hexagonal P6mm, Santa Barbara USA (PEI/SBA-15) adsorbents modified by phosphoric ester based surfactants (including tri(2-ethylhexyl) phosphate (TEP), bis(2-ethylhexyl) phosphate (BEP) and trimethyl phosphonoacetate (TMPA)) were prepared for CO2 adsorption. Experimental results indicated that the addition of TEP and BEP had positive effects on CO2 adsorption capacity over PEI/SBA-15. In particular, the CO2 adsorption amount could be improved by around 20% for 45PEI-5TEP/SBA-15 compared to the additive-free adsorbent. This could be attributed to the decrease of CO2 diffusion resistance in the PEI bulk network due to the interactions between TEP and loaded PEI molecules, which was further confirmed by adsorption kinetics results. In addition, it was also found that the cyclic performance of the TEP-modified adsorbent was better than the surfactant-free one. This could be due to two main reasons, based on the results of in situ DRIFT and TG-DSC tests. First and more importantly, adsorbed CO2 species could be desorbed more rapidly over TEP-modified adsorbent during the thermal desorption process. Furthermore, the enhanced thermal stability after TEP addition ensured lower degradation of amine groups during adsorption/desorption cycles. PMID:26702962

  16. Banana as adjunct in beer production: applicability and performance of fermentative parameters.

    PubMed

    Carvalho, Giovani B M; Silva, Daniel P; Bento, Camila V; Vicente, António A; Teixeira, José A; Felipe, Maria das Graças A; Almeida E Silva, João B

    2009-05-01

    Traditionally, the raw materials for beer production are barley, hops, water, and yeast, but most brewers use also different adjuncts. During the alcoholic fermentation, the contribution of aroma compounds from other ingredients to the final beer flavor depends on the wort composition, on the yeast strain, and mainly on the process conditions. In this context, banana can also be a raw material favorable to alcoholic fermentation being rich in carbohydrates and minerals and providing low acidity. In this work, the objective was to evaluate the performance of wort adjusted with banana juice in different concentrations. For this, static fermentations were conducted at 15 degrees C at pilot scale (140 L of medium). The addition of banana that changed the concentration of all-malt wort from 10 degrees P to 12 and 15 degrees P were evaluated ( degrees P is the weight of the extract or the sugar equivalent in 100 g solution, at 20 degrees C). The results showed an increase in ethanol production, with approximately 0.4 g/g ethanol yield and 0.6 g/L h volumetric productivity after 84 h of processing when concentrated wort was used. Thus, it was concluded that banana can be used as an adjunct in brewing methods, helping in the development of new products as well as in obtaining concentrated worts. PMID:19089653

  17. Effect of kaolin addition on the performance of controlled low-strength material using industrial waste incineration bottom ash.

    PubMed

    Naganathan, Sivakumar; Razak, Hashim Abdul; Hamid, Siti Nadzriah Abdul

    2010-09-01

    Incineration of industrial waste produces large quantities of bottom ash which are normally sent to secured landfill, but is not a sustainable solution. Use of bottom ash in engineering applications will contribute to sustainability and generate revenue. One way of using the industrial waste incineration bottom ash is in controlled low-strength material (CLSM). Use of bottom ash in CLSM has problems related to bleeding and excessive strength development and so an additive has to be used to control bleeding and strength development. The main objective of this research is to study the effect of kaolin addition on the performance of CLSM made using industrial waste incineration bottom ash. CLSM mixes were made with bottom ash, cement, and refined kaolin. Various tests were performed on the CLSM in fresh and hardened states including compressive strength, water absorption, California bearing ratio (CBR) and the tests for concentration of leachable substances on the bleed and leachate. The compressive strength of CLSM tested ranged from 0.11 to 9.86 MPa. CBR values ranged from 6 to 46, and water absorption values from 12 to 36%. It was shown that the addition of kaolin delayed the initial setting time of CLSM mixtures, reduced bleeding, lowered the compressive strength, and increased the values of water absorption, sorption, and initial surface absorption. The CLSM tested did not have corrosivity. It was shown that the hardened CLSM was non hazardous, and the addition of kaolin increased the concentration of heavy metals and salts in the bleed and leachate. PMID:20852000

  18. Kinetic analysis of HO{sub 2} addition to ethylene, propene, and isobutene, and thermochemical parameters of alkyl hydroperoxides and hydroperoxide alkyl radicals

    SciTech Connect

    Chen, C.J.; Bozzelli, J.W.

    2000-06-01

    Thermochemical kinetic analysis for the reactions of HO{sub 2} radical addition to the primary, secondary, and tertiary carbon-carbon double bonds of ethylene, propene, and isobutene are studied using canonical transition state theory (TST). Thermochemical properties of reactants, alkyl hydroperoxides (ROOH), hydroperoxy alkyl radicals (R-OOH), and transition states (TSs) are determined by ab initio and density functional calculations. Enthalpies of formation ({Delta}H{sub f 298}{degree}) of product radicals (R-OOH) are determined using isodesmic reactions with group balance at MP4(full)6-31G(d,p)/MP2(full)/6-31G(d), MP2(full)/6-31G(d), complete basis set model chemistry (CBS-q with MP2(full)/6-31g(d) and B3LYP/6-31g(d) optimized geometries), and density functional (B3LYP/6-31g(d) and B3LYP/6-311+g(3df,2p)//B3LYP/6-31g(d)) calculations. {Delta}H{sub f 298}{degree} of TSs are obtained from the {Delta}H{sub f 298}{degree} of reactants plus energy differences between reactants and TSs. Entropies (S{sub 298}{degree}) and heat capacities (Cp(T) 300 {le} T/K {le} 1,500) contributions from vibrational, translational, and external rotational are calculated using the rigid-rotor-harmonic-oscillator approximation based on geometric parameters and vibrational frequencies obtained at MP2(full)/6-31G(d) and B3LYP/6-31G(d) levels of theory. Selected potential barriers of internal rotations for hydroperoxy alkyl radicals and TSs are calculated at MP2(full)/6-31G(d) and CBS-Q//MP2(full)/6-31G(d) levels. Contributions from hindered rotors of S{sub 298}{degree} and Cp(T) are calculated by the method of Pitzer and Gwinn and by summation over the energy levels obtained by direct diagonalization of the Hamiltonian matrix of hindered internal rotations when the potential barriers of internal rotations are available. calculated rate constants obtained at CBS-q/MP2(full)/6-31G(d) and CBS-q//B3LYP/6-31G(d) levels of theory show similar trends with experimental data: HO{sub 2} radical

  19. Effect of supplementation of phytogenic feed additives (powdered vs. encapsulated) on performance and nutrient digestibility in broiler chickens.

    PubMed

    Hafeez, A; Männer, K; Schieder, C; Zentek, J

    2016-03-01

    Inclusion of phytogenic feed additives (PFA) in feed may enhance performance of broilers. Levels of essential oils in powdered form (characterized by menthol and anethole) at 150 mg/kg (P-150) and matrix-encapsulated form (characterized by carvacrol, thymol, and limonene) at 100 mg/kg (ME-100) were supplemented in diet to investigate their effect on performance (trial 1) and apparent ileal digestibility (AID) of nutrients (trial 2) in broilers. A total of 480 1-day-old broilers (Cobb 500) were used in trial 1 and 120 broilers in trial 2. Broilers were distributed in 24 pens with 8 pens per treatment (trial 1) and 6 pens with 2 pens per treatment (trial 2), with 20 birds per pen. Feed and water were offered ad libitum throughout the experimental periods in both trials. In trial 1, body weight of birds at d 42 and overall body weight gain from d 1 to d 42, was higher in treatment ME-100 than birds in control treatment (P = 0.023 and P = 0.024, respectively). Feed efficiency during finisher phase was improved in treatment ME-100 relatively to control and P-150 treatments (P = 0.035). At d 21 in trial 2, the apparent ileal digestibility of crude protein was higher in ME-100 treatment in comparison with control and P-150 treatments (P < 0.001). Apparent ileal absorption (AIA) of phosphorus was higher in ME-100 treatment than control treatment (P = 0.028). AID of cysteine was higher in both phytogenic additive supplemented treatments in comparison with control treatment (P = 0.001). In conclusion, inclusion of a powdered phytogenic additive characterized by menthol and anethole at 150 mg/kg had no effect but only a tendency towards improved performance and AIA of phosphorus, whereas essential oils addition in encapsulated form characterized by caravacol, thymol, and limonene at 100 mg/kg improved performance as well as apparent ileal digestibility of nutrients in broilers, possibly due to improved secretion of digestive enzymes. PMID:26706360

  20. Additive Manufacturing of Single-Crystal Superalloy CMSX-4 Through Scanning Laser Epitaxy: Computational Modeling, Experimental Process Development, and Process Parameter Optimization

    NASA Astrophysics Data System (ADS)

    Basak, Amrita; Acharya, Ranadip; Das, Suman

    2016-06-01

    This paper focuses on additive manufacturing (AM) of single-crystal (SX) nickel-based superalloy CMSX-4 through scanning laser epitaxy (SLE). SLE, a powder bed fusion-based AM process was explored for the purpose of producing crack-free, dense deposits of CMSX-4 on top of similar chemistry investment-cast substrates. Optical microscopy and scanning electron microscopy (SEM) investigations revealed the presence of dendritic microstructures that consisted of fine γ' precipitates within the γ matrix in the deposit region. Computational fluid dynamics (CFD)-based process modeling, statistical design of experiments (DoE), and microstructural characterization techniques were combined to produce metallurgically bonded single-crystal deposits of more than 500 μm height in a single pass along the entire length of the substrate. A customized quantitative metallography based image analysis technique was employed for automatic extraction of various deposit quality metrics from the digital cross-sectional micrographs. The processing parameters were varied, and optimal processing windows were identified to obtain good quality deposits. The results reported here represent one of the few successes obtained in producing single-crystal epitaxial deposits through a powder bed fusion-based metal AM process and thus demonstrate the potential of SLE to repair and manufacture single-crystal hot section components of gas turbine systems from nickel-based superalloy powders.

  1. Additive Manufacturing of Single-Crystal Superalloy CMSX-4 Through Scanning Laser Epitaxy: Computational Modeling, Experimental Process Development, and Process Parameter Optimization

    NASA Astrophysics Data System (ADS)

    Basak, Amrita; Acharya, Ranadip; Das, Suman

    2016-08-01

    This paper focuses on additive manufacturing (AM) of single-crystal (SX) nickel-based superalloy CMSX-4 through scanning laser epitaxy (SLE). SLE, a powder bed fusion-based AM process was explored for the purpose of producing crack-free, dense deposits of CMSX-4 on top of similar chemistry investment-cast substrates. Optical microscopy and scanning electron microscopy (SEM) investigations revealed the presence of dendritic microstructures that consisted of fine γ' precipitates within the γ matrix in the deposit region. Computational fluid dynamics (CFD)-based process modeling, statistical design of experiments (DoE), and microstructural characterization techniques were combined to produce metallurgically bonded single-crystal deposits of more than 500 μm height in a single pass along the entire length of the substrate. A customized quantitative metallography based image analysis technique was employed for automatic extraction of various deposit quality metrics from the digital cross-sectional micrographs. The processing parameters were varied, and optimal processing windows were identified to obtain good quality deposits. The results reported here represent one of the few successes obtained in producing single-crystal epitaxial deposits through a powder bed fusion-based metal AM process and thus demonstrate the potential of SLE to repair and manufacture single-crystal hot section components of gas turbine systems from nickel-based superalloy powders.

  2. Fusarium and Aspergillus mycotoxins effects on dairy cow health, performance and the efficacy of Anti-Mycotoxin Additive.

    PubMed

    Jovaišienė, J; Bakutis, B; Baliukonienė, V; Gerulis, G

    2016-01-01

    One hundred two samples of feeds made in Lithuania, which included maize silage, grass-legume silage, hay and ensiled crimped maize were investigated during 2008-2012 for contamination with some mycotoxins. The highest concentrations of mycotoxins determined were those of deoxynivalenol (DON)--471.0 μg/kg and aflatoxin B1 (AFB1)--21.2 μg/kg in ryegrass silage from bales, and zearalenone (ZEA)--625.0 μg/kg in maize silage from trenches. The present study has been carried out based on these data because animal feeds contaminated with mycotoxins can cause reduced productivity of dairy cows and health disorders in the long term. The aim of this study was to investigate the long-term exposure of toxic effects of a diet naturally contaminated with low concentrations of mycotoxins on milk composition and biochemical, hematological, immunological parameters of dairy cows and to determine the anti-mycotoxin effect of Mycofix Plus 3.E. Twenty eight clinically healthy, medium productive Lithuanian Red cows were selected. ZEA was a major contaminant found in the corn silage at concentration levels of up to 1000.0 μg/kg of dry matter. DON was the second major found in the hay at concentration levels of up to 600.0 μg/kg of dry matter. The highest concentration AFB1- 10.0 μg/kg was determined in ground barley. The Anti-Mycotoxin Additive (AMA) Mycofix Plus 3.E was given individually to 14 cows at a concentration of 40.0 g daily for 9 weeks. The present results indicate that feeds naturally contaminated with low concentration of mycotoxins produced by Fusarium spp. and Aspergillus spp. in a diet of dairy cows can have a negative influence on somatic cell count, blood parameters and immunity. The addition of an Anti-Mycotoxin Additive (Mycofix Plus 3.E) to diet of dairy cows can prevent many of these effects. PMID:27096791

  3. The Effects of Various Conductive Additive and Polymeric Binder Contents on the Performance of a Lithium-ion Composite

    SciTech Connect

    Stevenson, Cynthia; Liu, G.; Zheng, H.; Kim, S.; Deng, Y.; Minor, A.M.; Song, X.; Battaglia, V.S.

    2008-08-07

    Fundamental electrochemical methods, cell performance tests, and physical characterization tests such as electron microscopy were used to study the effects of levels of the inert materials (acetylene black (AB), a nano-conductive additive, and polyvinylidene difluoride (PVDF), a polymer binder) on the power performance of lithium-ion composite cathodes. The electronic conductivity of the AB/PVDF composites at different compositions was measured with a four-point probe direct current method. The electronic conductivity was found to increase rapidly and plateau at a AB:PVDF ratio 0.2:1 (by weight), with 0.8:1 being the highest conductivity composition. AB:PVDF compositions along the plateau of 0.2:1, 0.4:1, 0.6:1 and 0.8:1 were investigated. Electrodes of each of those compositions were fabricated with different fractions of AB/PVDF to active material. It was found that at the 0.8:1 AB:PVDF, the rate performance improved with increases in the AB/PVDF loading, whereas at the 0.2:1 AB:PVDF, the rate performance improved with decreases in the AB/PVDF loading. The impedance of electrodes made with 0.6:1 AB:PVDF was low and relatively invariant.

  4. Automatic Detection of Laryngeal Pathology on Sustained Vowels Using Short-Term Cepstral Parameters: Analysis of Performance and Theoretical Justification

    NASA Astrophysics Data System (ADS)

    Fraile, Rubén; Godino-Llorente, Juan Ignacio; Sáenz-Lechón, Nicolás; Osma-Ruiz, Víctor; Gómez-Vilda, Pedro

    The majority of speech signal analysis procedures for automatic detection of laryngeal pathologies mainly rely on parameters extracted from time-domain processing. Moreover, calculation of these parameters often requires prior pitch period estimation; therefore, their validity heavily depends on the robustness of pitch detection. Within this paper, an alternative approach based on cepstral - domain processing is presented which has the advantage of not requiring pitch estimation, thus providing a gain in both simplicity and robustness. While the proposed scheme is similar to solutions based on Mel-frequency cepstral parameters, already present in literature, it has an easier physical interpretation while achieving similar performance standards.

  5. The influence of the regularization parameter and the first estimate on the performance of tikhonov regularized non-linear image restoration algorithms

    PubMed

    Van Kempen GM; Van Vliet LJ

    2000-04-01

    This paper reports studies on the influence of the regularization parameter and the first estimate on the performance of iterative image restoration algorithms. We discuss regularization parameter estimation methods that have been developed for the linear Tikhonov-Miller filter to restore images distorted by additive Gaussian noise. We have performed experiments on synthetic data to show that these methods can be used to determine the regularization parameter of non-linear iterative image restoration algorithms, which we use to restore images contaminated by Poisson noise. We conclude that the generalized cross-validation method is an efficient method to determine a value of the regularization parameter close to the optimal value. We have also derived a method to estimate the regularization parameter of a Tikhonov regularized version of the Richardson-Lucy algorithm. These iterative image restoration algorithms need a first estimate to start their iteration. An obvious and frequently used choice for the first estimate is the acquired image. However, the restoration algorithm could be sensitive to the noise present in this image, which may hamper the convergence of the algorithm. We have therefore compared various choices of first estimates and tested the convergence of various iterative restoration algorithms. We found that most algorithms converged for most choices, but that smoothed first estimates resulted in a faster convergence. PMID:10781209

  6. Estimating Parameters for the PVsyst Version 6 Photovoltaic Module Performance Model

    SciTech Connect

    Hansen, Clifford

    2015-10-01

    We present an algorithm to determine parameters for the photovoltaic module perf ormance model encoded in the software package PVsyst(TM) version 6. Our method operates on current - voltage (I - V) measured over a range of irradiance and temperature conditions. We describe the method and illustrate its steps using data for a 36 cell crystalli ne silicon module. We qualitatively compare our method with one other technique for estimating parameters for the PVsyst(TM) version 6 model .

  7. Analyzing the performance of fluorescence parameters in the monitoring of leaf nitrogen content of paddy rice.

    PubMed

    Yang, Jian; Gong, Wei; Shi, Shuo; Du, Lin; Sun, Jia; Song, Shalei; Chen, Biwu; Zhang, Zhenbing

    2016-01-01

    Leaf nitrogen content (LNC) is a significant factor which can be utilized to monitor the status of paddy rice and it requires a reliable approach for fast and precise quantification. This investigation aims to quantitatively analyze the correlation between fluorescence parameters and LNC based on laser-induced fluorescence (LIF) technology. The fluorescence parameters exhibited a consistent positive linear correlation with LNC in different growing years (2014 and 2015) and different rice cultivars. The R(2) of the models varied from 0.6978 to 0.9045. Support vector machine (SVM) was then utilized to verify the feasibility of the fluorescence parameters for monitoring LNC. Comparison of the fluorescence parameters indicated that F740 is the most sensitive (the R(2) of linear regression analysis of the between predicted and measured values changed from 0.8475 to 0.9226, and REs ranged from 3.52% to 4.83%) to the changes in LNC among all fluorescence parameters. Experimental results demonstrated that fluorescence parameters based on LIF technology combined with SVM is a potential method for realizing real-time, non-destructive monitoring of paddy rice LNC, which can provide guidance for the decision-making of farmers in their N fertilization strategies. PMID:27350029

  8. Analyzing the performance of fluorescence parameters in the monitoring of leaf nitrogen content of paddy rice

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Gong, Wei; Shi, Shuo; Du, Lin; Sun, Jia; Song, Shalei; Chen, Biwu; Zhang, Zhenbing

    2016-06-01

    Leaf nitrogen content (LNC) is a significant factor which can be utilized to monitor the status of paddy rice and it requires a reliable approach for fast and precise quantification. This investigation aims to quantitatively analyze the correlation between fluorescence parameters and LNC based on laser-induced fluorescence (LIF) technology. The fluorescence parameters exhibited a consistent positive linear correlation with LNC in different growing years (2014 and 2015) and different rice cultivars. The R2 of the models varied from 0.6978 to 0.9045. Support vector machine (SVM) was then utilized to verify the feasibility of the fluorescence parameters for monitoring LNC. Comparison of the fluorescence parameters indicated that F740 is the most sensitive (the R2 of linear regression analysis of the between predicted and measured values changed from 0.8475 to 0.9226, and REs ranged from 3.52% to 4.83%) to the changes in LNC among all fluorescence parameters. Experimental results demonstrated that fluorescence parameters based on LIF technology combined with SVM is a potential method for realizing real-time, non-destructive monitoring of paddy rice LNC, which can provide guidance for the decision-making of farmers in their N fertilization strategies.

  9. Analyzing the performance of fluorescence parameters in the monitoring of leaf nitrogen content of paddy rice

    PubMed Central

    Yang, Jian; Gong, Wei; Shi, Shuo; Du, Lin; Sun, Jia; Song, Shalei; Chen, Biwu; Zhang, Zhenbing

    2016-01-01

    Leaf nitrogen content (LNC) is a significant factor which can be utilized to monitor the status of paddy rice and it requires a reliable approach for fast and precise quantification. This investigation aims to quantitatively analyze the correlation between fluorescence parameters and LNC based on laser-induced fluorescence (LIF) technology. The fluorescence parameters exhibited a consistent positive linear correlation with LNC in different growing years (2014 and 2015) and different rice cultivars. The R2 of the models varied from 0.6978 to 0.9045. Support vector machine (SVM) was then utilized to verify the feasibility of the fluorescence parameters for monitoring LNC. Comparison of the fluorescence parameters indicated that F740 is the most sensitive (the R2 of linear regression analysis of the between predicted and measured values changed from 0.8475 to 0.9226, and REs ranged from 3.52% to 4.83%) to the changes in LNC among all fluorescence parameters. Experimental results demonstrated that fluorescence parameters based on LIF technology combined with SVM is a potential method for realizing real-time, non-destructive monitoring of paddy rice LNC, which can provide guidance for the decision-making of farmers in their N fertilization strategies. PMID:27350029

  10. Enantiomeric separation of dansyl amino acids using macrocyclic antibiotics as chiral mobile phase additives by narrow-bore high-performance liquid chromatography.

    PubMed

    Sharp, V Scott; Letts, Maureen N; Risley, Donald S; Rose, John P

    2004-03-01

    Seven macrocyclic antibiotics were evaluated as chiral selectors for the enantiomeric separation of 11 dansyl amino acids using narrow-bore high-performance liquid chromatography (HPLC). The macrocyclic antibiotics were incorporated as mobile phase additives to determine the enantioselective effects on the chiral analytes. The resolution and capacity factor (k') of each analyte were assessed while varying the structure of macrocyclic antibiotic and the mobile phase buffer pH. The selectivity of the chiral selectors was measured as a function of changes in these parameters. All 11 dansyl amino acids were separated by at least one of the chiral selectors. Three-dimensional computer modeling of the more effective chiral selectors illustrated the importance of macrocyclic antibiotic structure concerning stereospecific analyte interaction. PMID:14770411

  11. Effect of quarry dust addition on the performance of controlled low-strength material made from industrial waste incineration bottom ash

    NASA Astrophysics Data System (ADS)

    Sivakumar, Naganathan; Hashim, Abdul Razak; Nadzriah, Abdul Hamid Siti

    2012-06-01

    The performance of industrial waste incineration bottom ash in controlled low-strength material (CLSM) was investigated in this paper, as the quarry dust was added. CLSM mixtures were made from the industrial waste incineration bottom ash, quarry dust, and cement. Tests for fresh density, bleeding, compressive strength, shear strength, hydraulic conductivity, and excavatability were carried out. The compressive strength ranges from 60 kPa to 6790 kPa, the friction angle varies from 5° to 19°, and the cohesion is from 4 to 604 kPa. Most of the mixtures are found to be non-excavatable. It is indicated that the quarry dust addition increases the compressive strength and shear parameters, decreases bleeding, and increases the removability modulus.

  12. Graphene oxide as a high-performance fluid-loss-control additive in water-based drilling fluids.

    PubMed

    Kosynkin, Dmitry V; Ceriotti, Gabriel; Wilson, Kurt C; Lomeda, Jay R; Scorsone, Jason T; Patel, Arvind D; Friedheim, James E; Tour, James M

    2012-01-01

    Graphene oxide (GO) performs well as a filtration additive in water-based drilling fluids at concentrations as low as 0.2 % (w/w) by carbon content. Standard American Petroleum Institute (API) filtration tests were conducted on pH-adjusted, aqueous dispersions of GO and xanthan gum. It was found that a combination of large-flake GO and powdered GO in a 3:1 ratio performed best in the API tests, allowing an average fluid loss of 6.1 mL over 30 min and leaving a filter cake ~20 μm thick. In comparison, a standard suspension (~12 g/L) of clays and polymers used in the oil industry gave an average fluid loss of 7.2 mL and a filter cake ~280 μm thick. Scanning electron microscopy imaging revealed the extreme pliability of well-exfoliated GO, as the pressure due to filtration crumpled single GO sheets, forcing them to slide through pores with diameters much smaller than the flake's flattened size. GO solutions also exhibited greater shear thinning and higher temperature stability compared to clay-based fluid-loss additives, demonstrating potential for high-temperature well applications. PMID:22136134

  13. Linking process, structure, property, and performance for metal-based additive manufacturing: computational approaches with experimental support

    NASA Astrophysics Data System (ADS)

    Smith, Jacob; Xiong, Wei; Yan, Wentao; Lin, Stephen; Cheng, Puikei; Kafka, Orion L.; Wagner, Gregory J.; Cao, Jian; Liu, Wing Kam

    2016-04-01

    Additive manufacturing (AM) methods for rapid prototyping of 3D materials (3D printing) have become increasingly popular with a particular recent emphasis on those methods used for metallic materials. These processes typically involve an accumulation of cyclic phase changes. The widespread interest in these methods is largely stimulated by their unique ability to create components of considerable complexity. However, modeling such processes is exceedingly difficult due to the highly localized and drastic material evolution that often occurs over the course of the manufacture time of each component. Final product characterization and validation are currently driven primarily by experimental means as a result of the lack of robust modeling procedures. In the present work, the authors discuss primary detrimental hurdles that have plagued effective modeling of AM methods for metallic materials while also providing logical speculation into preferable research directions for overcoming these hurdles. The primary focus of this work encompasses the specific areas of high-performance computing, multiscale modeling, materials characterization, process modeling, experimentation, and validation for final product performance of additively manufactured metallic components.

  14. Detection and characterisation of frauds in bovine meat in natura by non-meat ingredient additions using data fusion of chemical parameters and ATR-FTIR spectroscopy.

    PubMed

    Nunes, Karen M; Andrade, Marcus Vinícius O; Santos Filho, Antônio M P; Lasmar, Marcelo C; Sena, Marcelo M

    2016-08-15

    Concerns about meat authenticity are increasing recently, due to great fraud scandals. This paper analysed real samples (43 adulterated and 12 controls) originated from criminal networks dismantled by the Brazilian Police. This fraud consisted of injecting solutions of non-meat ingredients (NaCl, phosphates, carrageenan, maltodextrin) in bovine meat, aiming to increase its water holding capacity. Five physico-chemical variables were determined, protein, ash, chloride, sodium, phosphate. Additionally, infrared spectra were recorded. Supervised classification PLS-DA models were built with each data set individually, but the best model was obtained with data fusion, correctly detecting 91% of the adulterated samples. From this model, a variable selection based on the highest VIPscores was performed and a new data fusion model was built with only one chemical variable, providing slightly lower predictions, but a good cost/performance ratio. Finally, some of the selected infrared bands were specifically associated to the presence of adulterants NaCl, tripolyphosphate and carrageenan. PMID:27006208

  15. On the performance of low pressure die-cast Al-Cu based automotive alloys: Role of additives

    NASA Astrophysics Data System (ADS)

    Zaki, Gergis Adel

    The present study focuses on the effect of alloying elements, namely, strontium (Sr), titanium (Ti), zirconium (Zr), scandium (Sc) and silver(Ag) individually or in combination, on the performance of a newly developed Al-2%Cu based alloy. A total of thirteen alloy compositions were used in the study. Tensile test bar castings were prepared employing the low pressure die casting (LPDC) technique. The test bars were solution heat treated at 495°C for 8 hours, followed by quenching in warm water, and then subjected to different isochronal aging treatments using an aging time of 5 hours and aging temperatures of 155°C, 180°C, 200°C, 240°C and 300°C. Tensile testing of as-cast and heat-treated test bars was carried out at room temperature using a strain rate of 4 x 10-4s-1. Five test bars were used per alloy composition/condition. Hardness measurements were also carried out on these alloys using a Brinell hardness tester. The microstructures of selected samples were examined using optical microscopy and electron probe microanalysis (EPMA). The results showed that adding Ti in the amount of 0.15 wt% in the form of Al-5%Ti-1%B master alloy is sufficient to refine the grains in the cast structure in the presence of 200 ppm Sr (0.02 wt%). Addition of Zr and Sc did not contribute further to the grain refining effect. The main role of addition of these two elements appeared in the formation of complex compounds with Al and Ti. Their presence resulted in extending the aging temperature range before the onset of softening. Mathematical analysis of the hardness and tensile data was carried out using the Minitab statistical software program. It was determined that the alloy containing (0.5wt% Zr + 0.15wt% Ti) is the most effective in maximizing the alloy tensile strength over the range of aging temperatures, from 155°C to 300°C. Addition of Ag is beneficial at high aging temperatures, in the range of 240°C-300°C. However, it is less effective compared to the (Zr + Ti

  16. Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters. [Instrument Meteorological Conditions

    NASA Technical Reports Server (NTRS)

    Karmali, M. S.; Phatak, A. V.; Bull, J. S.; Peach, L. L.; Demko, P. S.

    1984-01-01

    The present investigation is concerned with a sensitivity analysis of the Decelerated Steep Approach and Landing (DSAL) maneuver to on-board and ground-based navigation system parameters. The Instrument Meteorological Conditions (IMC) DSAL maneuver involves decelerating to zero range rate while tracking the localizer and glideslope. The considered study investigated the performance of the navigation systems using Constant Deceleration Profile (CDP) guidance and a six degrees glideslope trajectory. A closed-loop computer simulation of the UH1H helicopter DSAL system was developed for the sensitivity analysis. Conclusions on system performance parameter sensitivity are discussed.

  17. Study on Performance Parameters of the Plasma Source for a Short-Conduction-Time Plasma Opening Switch

    NASA Astrophysics Data System (ADS)

    Luo, Weixi; Zeng, Zhengzhong; Wang, Liangping; Lei, Tianshi; Hu, Yixiang; Huang, Tao; Sun, Tieping

    2012-12-01

    Plasma source performance parameters, including plasma ejection density and velocity, greatly affect the operation of a short-conduction-time plasma opening switch (POS). In this paper, the plasma source used in the POS of Qiangguang I generator is chosen as the study object. At first the POS working process is analyzed. The result shows that the opening performance of the POS can be improved by increasing the plasma ejection velocity and decreasing the plasma density. The influence of the cable plasma gun structure and number on the plasma ejection parameters is experimentally investigated with two charge collectors. Finally a semi-empirical model is proposed to describe the experimental phenomenon.

  18. TGLF Recalibration for ITER Standard Case Parameters FY2015: Theory and Simulation Performance Target Final Report

    SciTech Connect

    Candy, J.

    2015-12-01

    This work was motivated by the observation, as early as 2008, that GYRO simulations of some ITER operating scenarios exhibited nonlinear zonal-flow generation large enough to effectively quench turbulence inside r /a ~ 0.5. This observation of flow-dominated, low-transport states persisted even as more accurate and comprehensive predictions of ITER profiles were made using the state-of-the-art TGLF transport model. This core stabilization is in stark contrast to GYRO-TGLF comparisons for modern-day tokamaks, for which GYRO and TGLF are typically in very close agreement. So, we began to suspect that TGLF needed to be generalized to include the effect of zonal-flow stabilization in order to be more accurate for the conditions of reactor simulations. While the precise cause of the GYRO-TGLF discrepancy for ITER parameters was not known, it was speculated that closeness to threshold in the absence of driven rotation, as well as electromagnetic stabilization, created conditions more sensitive the self-generated zonal-flow stabilization than in modern tokamaks. Need for nonlinear zonal-flow stabilization: To explore the inclusion of a zonal-flow stabilization mechanism in TGLF, we started with a nominal ITER profile predicted by TGLF, and then performed linear and nonlinear GYRO simulations to characterize the behavior at and slightly above the nominal temperature gradients for finite levels of energy transport. Then, we ran TGLF on these cases to see where the discrepancies were largest. The predicted ITER profiles were indeed near to the TGLF threshold over most of the plasma core in the hybrid discharge studied (weak magnetic shear, q > 1). Scanning temperature gradients above the TGLF power balance values also showed that TGLF overpredicted the electron energy transport in the low-collisionality ITER plasma. At first (in Q3), a model of only the zonal-flow stabilization (Dimits shift) was attempted. Although we were able to construct an ad hoc model of the zonal

  19. Incremental Diagnostic Performance of Combined Parameters in the Detection of Severe Coronary Artery Disease Using Exercise Gated Myocardial Perfusion Imaging

    PubMed Central

    Liu, Chia-Ju; Wu, Yen-Wen; Ko, Kuan-Yin; Chen, Yi-Chieh; Cheng, Mei-Fang; Yen, Ruoh-Fang; Tzen, Kai-Yuan

    2015-01-01

    Purpose Myocardial perfusion imaging (MPI) using gated single-photon emission tomography (gSPECT) may underestimate the severity of coronary artery disease (CAD). This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD. Methods A total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI) were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS); sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR) were calculated. Treadmill parameters, including ST depression (STD) at the 1st and 3rd minutes of recovery stage (1’STD and 3’STD), maximal STD corrected by heart rate increment (ST/HR), heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio), systolic and mean blood pressure ratios (SBP ratio and MAP ratio) during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC) analysis and logistic regression for detection of left main (≥ 50%) or 3-vessel disease (all ≥ 70% luminal stenosis) on invasive angiography. Results Among various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS) and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm), respectively. By univariate logistic regression, all parameters except 1’HRR, 3’HRR, SBP and MAP ratios increased the odds ratio of severe CAD

  20. Nutritional and productive performance of dairy cows fed corn silage or sugarcane silage with or without additives.

    PubMed

    de Andrade, Felipe Leite; Rodrigues, João Paulo Pacheco; Detmann, Edenio; Valadares Filho, Sebastião de Campos; Castro, Marcelo Messias Duarte; Trece, Aline Souza; Silva, Tadeu Eder; Fischer, Vivian; Weiss, Kirsten; Marcondes, Marcos Inácio

    2016-04-01

    The objective of this study was to compare the intake, digestibility, and performance of dairy cows fed corn silage, fresh sugarcane, and sugarcane ensiled in three different forms. Twenty-five Holstein cows at 114 ± 12.6 days in milk (DIM) were used. A randomized block design was adopted, using an arrangement of repeated measures over time. The following treatments were tested: corn silage (CS); fresh sugarcane (FS); sugarcane silage without additives (SCS); sugarcane silage enriched with calcium oxide at 5 g/kg of forage (SCSc); and sugarcane silage enriched with Lactobacillus buchneri at 5 × 10(4) cfu/kg of forage (SCSb). The roughage to concentrate ratio was 60:40 for the CS diet and 40:60 for the sugarcane-based diets. The dry matter intake (DMI) as a function of body weight had a downward trend for the cows fed sugarcane silage, compared with those fed FS. The sugarcane silages had higher digestibilities of dry matter (DM), organic matter (OM), and neutral detergent fiber (NDFap), compared with FS. The use of L. buchneri or calcium oxide improved the diet's digestibility. The use of FS, sugarcane silage, or sugarcane silage with additives had no effects on milk and fat-corrected milk yield, compared to corn silage. Cows fed FS presented lower milk total solids content and had a downward trend for milk fat, compared with cows fed sugarcane-silage diets. Cows fed sugarcane silages produced milk with higher casein stability in the alcohol test than cows fed fresh-sugarcane diet. Sugarcane silage, with or without additives, did not reduce the intake of dairy cows, and the use of additives improved the fiber's digestibility. PMID:26898688

  1. Use of MiniColumns for linear isotherm parameter estimation and prediction of benchtop column performance.

    PubMed

    Keller, William R; Evans, Steven T; Ferreira, Gisela; Robbins, David; Cramer, Steven M

    2015-10-30

    In this paper, a comparison between experimental chromatography data and column simulations is carried out to determine the efficacy of using miniaturized chromatography columns (MiniColumns) for both column modeling parameter estimation and process development. Normalization of the data with respect to column volumes along with appropriate translations to account for system differences is shown to result in comparability of the experimental data for the MiniColumn and benchtop systems. A parameter estimation protocol is then employed to determine the linear steric mass-action (SMA) isotherm and lumped mass transport parameters for two cation exchange resins. The models are then validated and simulations using different parameter sets from the MiniColumn and benchtop systems are shown to result in similar predicted chromatography profiles and calculated retention volumes. The parameters generated from the MiniColumn system are demonstrated to be well suited for predicting experimental data from the benchtop system. These simulation results, the ability to operate MiniColumns in parallel, and the significantly lower material requirements per experiment support an industry trend toward increased usage of miniaturized chromatography columns as a scale-down model for process development. PMID:26422303

  2. The effect of exercise training with an additional inspiratory load on inspiratory muscle fatigue and time-trial performance.

    PubMed

    McEntire, Serina J; Smith, Joshua R; Ferguson, Christine S; Brown, Kelly R; Kurti, Stephanie P; Harms, Craig A

    2016-08-01

    The purpose was to determine the effect of moderate-intensity exercise training (ET) on inspiratory muscle fatigue (IMF) and if an additional inspiratory load during ET (ET+IL) would further improve inspiratory muscle strength, IMF, and time-trial performance. 15 subjects were randomly divided to ET (n=8) and ET+IL groups (n=7). All subjects completed six weeks of exercise training three days/week at ∼70%V̇O2peak for 30min. The ET+IL group breathed through an inspiratory muscle trainer (15% PImax) during exercise. 5-mile, and 30-min time-trials were performed pre-training, weeks three and six. Inspiratory muscle strength increased (p<0.05) for both groups to a similar (p>0.05) extent. ET and ET+IL groups improved (p<0.05) 5-mile time-trial performance (∼10% and ∼18%) and the ET+IL group was significantly faster than ET at week 6. ET and ET+IL groups experienced less (p<0.05) IMF compared to pre-training following the 5-mile time-trial. In conclusion, these data suggest ET leads to less IMF, ET+IL improves inspiratory muscle strength and IMF, but not different than ET alone. PMID:27195511

  3. BASELINE PARAMETER UPDATE FOR HUMAN HEALTH INPUT AND TRANSFER FACTORS FOR RADIOLOGICAL PERFORMANCE ASSESSMENTS AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Coffield, T; Patricia Lee, P

    2007-01-31

    The purpose of this report is to update parameters utilized in Human Health Exposure calculations and Bioaccumulation Transfer Factors utilized at SRS for Performance Assessment modeling. The reason for the update is to utilize more recent information issued, validate information currently used and correct minor inconsistencies between modeling efforts performed in SRS contiguous areas of the heavy industrialized central site usage areas called the General Separations Area (GSA). SRS parameters utilized were compared to a number of other DOE facilities and generic national/global references to establish relevance of the parameters selected and/or verify the regional differences of the southeast USA. The parameters selected were specifically chosen to be expected values along with identifying a range for these values versus the overly conservative specification of parameters for estimating an annual dose to the maximum exposed individual (MEI). The end uses are to establish a standardized source for these parameters that is up to date with existing data and maintain it via review of any future issued national references to evaluate the need for changes as new information is released. These reviews are to be added to this document by revision.

  4. Effects of a combination of feed additives on methane production, diet digestibility, and animal performance in lactating dairy cows.

    PubMed

    van Zijderveld, S M; Fonken, B; Dijkstra, J; Gerrits, W J J; Perdok, H B; Fokkink, W; Newbold, J R

    2011-03-01

    Two experiments were conducted to assess the effects of a mixture of dietary additives on enteric methane production, rumen fermentation, diet digestibility, energy balance, and animal performance in lactating dairy cows. Identical diets were fed in both experiments. The mixture of feed additives investigated contained lauric acid, myristic acid, linseed oil, and calcium fumarate. These additives were included at 0.4, 1.2, 1.5, and 0.7% of dietary dry matter, respectively (treatment ADD). Experimental fat sources were exchanged for a rumen inert source of fat in the control diet (treatment CON) to maintain isolipidic rations. Cows (experiment 1, n=20; experiment 2, n=12) were fed restricted amounts of feed to avoid confounding effects of dry matter intake on methane production. In experiment 1, methane production and energy balance were studied using open-circuit indirect calorimetry. In experiment 2, 10 rumen-fistulated animals were used to measure rumen fermentation characteristics. In both experiments animal performance was monitored. The inclusion of dietary additives decreased methane emissions (g/d) by 10%. Milk yield and milk fat content tended to be lower for ADD in experiment 1. In experiment 2, milk production was not affected by ADD, but milk fat content was lower. Fat- and protein-corrected milk was lower for ADD in both experiments. Milk urea nitrogen content was lowered by ADD in experiment 1 and tended to be lower in experiment 2. Apparent total tract digestibility of fat, but not that of starch or neutral detergent fiber, was higher for ADD. Energy retention did not differ between treatments. The decrease in methane production (g/d) was not evident when methane emission was expressed per kilogram of milk produced. Feeding ADD resulted in increases of C12:0 and C14:0 and the intermediates of linseed oil biohydrogenation in milk in both experiments. In experiment 2, ADD-fed cows tended to have a decreased number of protozoa in rumen fluid when

  5. Influence of control parameters on the joint tracking performance of a coaxial weld vision system

    NASA Technical Reports Server (NTRS)

    Gangl, K. J.; Weeks, J. L.

    1985-01-01

    The first phase of a series of evaluations of a vision-based welding control sensor for the Space Shuttle Main Engine Robotic Welding System is described. The robotic welding system is presently under development at the Marshall Space Flight Center. This evaluation determines the standard control response parameters necessary for proper trajectory of the welding torch along the joint.

  6. Small Ruminant Performance and Carcass Parameters when Finished on Pasture With and Without Whole Cottonseed Supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The meat goat industry is growing rapidly in the U.S., particularly on small farms. Weight gain and carcass parameters were determined for traditional lambs (Suffolk, SX), hair sheep lambs (Katahdin, KA), and Boer x Kiko meat goats (GX) finished on a mixed pasture of orchardgrass (Dactylis glomerat...

  7. Effects of constant-current/constant-voltage charge parameters on lead-acid traction cell performance

    SciTech Connect

    Deluca, W.H.; Biwer, R.L.; Yao, N.P.

    1981-01-01

    A factor described for the application of battery systems for electric vehicle propulsion is the methodology of charging. It was quantitatively determined that both the total charge cycle time and the maximum charging rate (constant-current level) are limited by battery charge acceptance. The test system and procedures are outlined, acquired battery parameter data presented, and conclusions discussed.

  8. Performance of DFT+U method for prediction of structural and thermodynamic parameters of monazite-type ceramics.

    PubMed

    Blanca Romero, Ariadna; Kowalski, Piotr M; Beridze, George; Schlenz, Hartmut; Bosbach, Dirk

    2014-07-01

    We performed a density functional theory (DFT) study of the monazite-type ceramics using DFT+U method, where the Hubbard U parameters are derived ab initio, with the main goal in testing the predictive power of this computational method for modeling of f-electron materials that are of interest in nuclear waste management. We show that DFT+U approach with PBEsol as the exchange-correlation functional significantly improves description of structures and thermodynamic parameters of lanthanide-bearing oxides and monazites over commonly used standard DFT (PBE) approach. We found that it is essential to use the Hubbard U parameter derived for a given element and a given structure to reproduce the structural parameters of the measured materials. We obtained exceptionally good description of the structural parameters with U parameter derived using the linear response approach of Cococcioni and de Gironcoli (Phys. Rev. B 2005, 71, 035105). This shows that affordable methods, such as DFT+U with a clever choice of exchange-correlation functional and the Hubbard U parameter can lead to a good description of f-electron materials. PMID:24760757

  9. Tribological Performance of NiAl Self-lubricating Matrix Composite with Addition of Graphene at Different Loads

    NASA Astrophysics Data System (ADS)

    Xiao, Yecheng; Shi, Xiaoliang; Zhai, Wenzheng; Yao, Jie; Xu, Zengshi; Chen, Long; Zhu, Qingshuai

    2015-08-01

    This research was carried out on the beneficial effect of graphene additive in self-lubricating composites for use at different loads of tribological application. The dry friction and wear behaviors of NiAl self-lubricating matrix composite with graphene (NSMG) were investigated at different loads at room temperature. Finite element method served as aided method to analyze the stress condition of contact pair, which would provide another perspective to comprehend the relationship between tribological behaviors and different degrees of load-induced deformation. In the load range of 2-16 N, the results indicated that NSMG showed excellent tribological performance at load of 16 N due to the formation of anti-friction tribo-film on the worn surface. Moreover, suitable load would lead to the contact situation transfer from multi-point contact to area contact, which could contribute to the beneficial effect on friction behavior of NSMG.

  10. Study on the performance of polycarboxylate-based superplasticizers synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization

    NASA Astrophysics Data System (ADS)

    Yu, Binbin; Zeng, Zhong; Ren, Qinyu; Chen, Yang; Liang, Mei; Zou, Huawei

    2016-09-01

    A series of block type polycarboxylate-based superplasticizers (PCs) with different molecular architectures were synthesized with macromonomer butenyl alkylene polyoxyethylene-polyoxypropylene ether (BAPP) and acrylic acid (AA) by reversible addition-fragmentation chain transfer (RAFT) polymerization. Fourier-Transformed Infrared (FTIR) Spectroscopy and dynamic light scattering (DLS) were applied to investigate the PCs' molecular structure. The dispersion capacity of the PCs in cement were also measured, and the results showed that the polycarboxylic dispersing agents prepared by this method were suitable for portlant cement. It was found that the PCs could affect the hydration process, which was performed through retarding the generation of ettringite in the hydrated product. Our studies with X-ray diffraction (XRD), scanning electron microscopy (SEM) and compressive strength measurement of hydrated production were all supporting this conclusion.

  11. Evaluation of the thermal performance of fire fighter protective clothing with the addition of phase change material

    NASA Astrophysics Data System (ADS)

    McCarthy, Lee K.

    Fire fighters rely on fire fighter protective clothing (FFPC) to provide adequate protection in the various hazardous environments they may encounter during operations. FFPC has seen significant advancement in technology over the past few decades. The addition of phase change material (PCM) to FFPC is a new technology with potential to enhance the thermal protection provided by the FFPC. To explore this technology, data from bench-scale experiments involving FFPC with PCMs are compared with a theoretical finite difference heat transfer model. The results demonstrate an effective method to mathematically model the heat transfer and provide insight into the effectiveness of improving the thermal protection of FFPC. The experiments confirm that the latent heat absorbed during the phase change reduces temperatures that might be experienced at the fire fighter's skin surface, advancing the high temperature performance of FFPC.

  12. Speciation of arsenic animal feed additives by microbore high-performance liquid chromatography with inductively coupled plasma mass spectrometry.

    PubMed

    Pergantis, S A; Heithmar, E M; Hinners, T A

    1997-10-01

    Phenylarsonic compounds have been used as poultry and swine feed additives for the purpose of growth promotion and disease prevention. Owing to the lack of suitable analytical methods, however, knowledge of their metabolism, environmental fate and impact remains incomplete. In order to compensate for this, analytical procedures were developed that allow the speciation of arsenic animal feed additives by using microbore high-performance liquid chromatography (microHPLC) coupled on-line with ICP-MS. More specifically, reversed-phase (RP) chromatographic methods were optimised to achieve the separation of various phenylarsonic acids from each other and from the more toxic inorganic arsenic compounds. This mode of chromatography, however, exhibits limitations, especially in the presence of naturally occurring organoarsenic compounds. The application of RP ion-pairing chromatography eliminates such shortcomings by minimising the co-elution of arsenic species. In general, the microHPLC-ICP-MS methods developed in this study provide high selectivity, extremely good sensitivity, low limits of detection (low-ppb or sub-pg amounts of As), require small sample volumes (< 1 microliter), minimise waste and operate most efficiently under low mobile-phase flow rates (15-40 microliters min-1), which are compatible for use with other types of mass spectrometers, e.g., electrospray. Reference materials containing naturally occurring arsenic compounds were spiked with phenylarsonic compounds and then analysed by using the procedures developed in this study. PMID:9463956

  13. Performance of supercritical CO{sub 2} Brayton cycle with additive gases at varying critical points for SFR application

    SciTech Connect

    Jeong, W. S.; Jeong, Y. H.

    2012-07-01

    The supercritical carbon dioxide Brayton cycle (S-CO{sub 2} cycle) has received attention as alternative to the energy conversion system for a Sodium-cooled Fast Reactor (SFR). The high cycle efficiency of S-CO{sub 2} cycle is attributed to significantly reduced compressor work. This is because the compressor operates like a pump in the vicinity of CO{sub 2} critical point. To make use of this feature, the minimum cycle operating range of S-CO{sub 2} cycle, which is the main compressor inlet condition, should be located close to the critical point of CO{sub 2}. This translated into that the critical point of CO{sub 2} is the limitation of the lowest cycle condition of S-CO{sub 2} cycles. To increase the flexibility and broaden the applicability of the cycle, changing the critical point of CO{sub 2} by mixing additive gases could be adopted. An increase in the efficiency of the S-CO{sub 2} cycle could be achieved by decreasing critical point of CO{sub 2}. In addition, increasing critical point of CO{sub 2} could be utilized to obtain improved cycle performances at ascending heat sink temperature of hot arid areas. Due to the rapid fluctuations of thermo-physical properties of gas mixtures near the critical point, an in-house cycle analysis code coupled to NIST property database was developed. Several gases were selected as potential additives through the screening process for thermal stability and chemical interaction with sodium. By using the developed cycle code, optimized cycles of each gas mixture were compared with the reference case of S-CO{sub 2} cycle. For decreased critical temperatures, CO{sub 2}-Xe and CO{sub 2}-Kr showed an increase in the total cycle efficiency. At increasing critical temperatures, the performance of CO{sub 2}-H{sub 2}S and CO{sub 2}-cyclohexane is superior to S-CO{sub 2}cycle when the compressor inlet temperature is above the critical temperature of CO{sub 2}. (authors)

  14. The Effects of Ultrasonic Vibration Parameters on Machining Performance in Turning of Mild Steels

    NASA Astrophysics Data System (ADS)

    Celaya, A.; Campa, F. J.; López de Lacalle, L. N.; Marina, D.

    2011-01-01

    The present work presents the results obtained when an ultrasonic vibration is applied to tool on the turning of mild steels. Currently high-end materials, usually present low machinability so it is necessary to employ new machining technologies. Ultrasonic assisted turning (UAT) is presented as an effective process for machining these difficult-to-cut materials. In order to achieve a better understanding of the process, a complete study of the influence of the vibration parameters is presented when machining mild steels. Several parameter of UAT were monitored, including surface roughness, tool wear, chip formation by a high-speed imaging camera, and tool temperature by means of an infrared camera: surface roughness and tool temperature decrease and an tool life increase as compared to conventional turning (CT).

  15. Performance of D-Parameters in Isolating Meteor Showers from the Sporadic Background

    NASA Technical Reports Server (NTRS)

    Moorhead, Althea

    2016-01-01

    It is often necessary to draw a division between meteor showers and the sporadic meteor complex in order to study these components of the meteoroid environment. Meteor showers persist for less than a season and are composed of members with a greater-than-average degree of orbital similarity. The level of orbital similarity is often quantified using so-called D-parameters; a D-parameter cutoff may be employed to define or extract a shower. Depending on the study, this cutoff value may be chosen based on the size of the data-set, the percentage of sporadic meteors within the data-set, or the inclination of the shower in question. We argue that the cutoff value should also reject the strength of the shower compared to the local sporadic background. We therefore present a method for determining, on a per-shower basis, the D-parameter cutoff that limits the false-positive rate to an acceptable percentage. If the false-positive rate exceeds this percentage regardless of cutoff value, we deem the shower to be undetectable in our data. We apply this method to optical meteor observations from the NASA All-Sky and Southern Ontario Meteor Networks and present the detectable meteor showers and their characteristics.

  16. The effect of spin coating parameters on the performance of PTB7/PC71BM polymer solar cells

    NASA Astrophysics Data System (ADS)

    Li, Jie; Li, Shu-guang; Zheng, Yi-fan; Yu, Jun-Sheng

    2014-09-01

    We fabricated the inverted polymer solar cells (PSCs) with a structure of ITO/ZnO/PTB7:PC71BM/MoO3/Ag, and investigate the influence of spin coating on the device performance in this article. Through modifying the spin coating parameters, the high PSC performance could be obtained with VOC=0.769 (V), JSC=11.6 (mA/cm2), FF=58.8 % and PCE=5.26 %, respectively. The improvement of device performance was attributed to the enhanced absorption of active layer in the wavelength from 550 nm to 700 nm and the increased phase separation of PTB7:PC71BM.

  17. Sensitivity Analysis of Wind Plant Performance to Key Turbine Design Parameters: A Systems Engineering Approach; Preprint

    SciTech Connect

    Dykes, K.; Ning, A.; King, R.; Graf, P.; Scott, G.; Veers, P.

    2014-02-01

    This paper introduces the development of a new software framework for research, design, and development of wind energy systems which is meant to 1) represent a full wind plant including all physical and nonphysical assets and associated costs up to the point of grid interconnection, 2) allow use of interchangeable models of varying fidelity for different aspects of the system, and 3) support system level multidisciplinary analyses and optimizations. This paper describes the design of the overall software capability and applies it to a global sensitivity analysis of wind turbine and plant performance and cost. The analysis was performed using three different model configurations involving different levels of fidelity, which illustrate how increasing fidelity can preserve important system interactions that build up to overall system performance and cost. Analyses were performed for a reference wind plant based on the National Renewable Energy Laboratory's 5-MW reference turbine at a mid-Atlantic offshore location within the United States.

  18. Study of parameters affecting the performance of solar desiccant cooling systems

    NASA Astrophysics Data System (ADS)

    Pesaran, A. A.; Hoo, E. A.

    1993-01-01

    The performance of a solar desiccant cooling system depends on the performance of its components, particularly the desiccant dehumidifier and solar collectors. The desiccant dehumidifier performance is affected by the properties of the desiccant, particularly the shape of the isotherm and the regeneration temperature. The performance of a solar collector, as one would expect, depends on its operating temperature, which is very close to the desiccant regeneration temperature. The purpose of this study was to identify the desiccant isotherm shape (characterized by separation factor) that would result in the optimum performance - based on thermal coefficient of performance and cooling capacity - of a desiccant cooling cycle operating in ventilation mode. Different regeneration temperatures ranging from 65 to 160 C were investigated to identify the corresponding optimum isotherm shape at each. Thermal COP dictates the required area of the solar collectors, and the cooling capacity is an indication of the size and cost of the cooling equipment. Staged and no-staged regeneration methods were studied.

  19. Addition of crude glycerin to pig diets: sow and litter performance, and metabolic and feed intake regulating hormones.

    PubMed

    Hernández, F; Orengo, J; Villodre, C; Martínez, S; López, M J; Madrid, J

    2016-06-01

    The continued growth in biofuel production has led to a search for alternative value-added applications of its main by-product, crude glycerin. The surplus glycerin production and a higher cost of feedstuffs have increased the emphasis on evaluating its nutritive value for animal feeding. The aim of this research was to evaluate the effect of the dietary addition of crude glycerin on sow and litter performance, and to determine the serum concentrations of hormones related to energy metabolism and feed intake in sows during gestation and lactation. A total of 63 sows were assigned randomly to one of three dietary treatments, containing 0, 3 or 6% crude glycerin (G0, G3 and G6, respectively) added to a barley-soybean meal-based diet. During gestation, none of the dietary treatments had an effect on performance, while during lactation, glycerin-fed sows consumed less feed than those fed the control diet (3.8 v. 4.2kg DM/day; P=0.007). Although lactating sows fed the G3 diet had a higher BW loss than those fed the control diet (���20.6 v. ���8.7 kg; P=0.002), this difference was not reflected in litter performance. In gestation, the inclusion of glycerin did not affect blood concentrations of insulin or cortisol. However, pregnant sows fed diets supplemented with glycerin showed lower concentrations of acyl-ghrelin and higher concentrations of leptin (���55 and +68%, respectively; P<0.001). In lactating sows, there were no differences between dietary treatments for any of the hormones measured. Pre-prandial acyl-ghrelin concentrations were positively correlated with cortisol concentrations during gestation (r=0.81; P=0.001) and lactation (r=0.61; P=0.015). In conclusion, the inclusion of up to 6% crude glycerin did not affect the performance of sows during the gestation period; however it had a negative effect on the feed intake and weight loss of lactating sows. Moreover, further research is needed to elucidate the potential relationship between

  20. Key Performance Parameter Driven Technology Goals for Electric Machines and Power Systems

    NASA Technical Reports Server (NTRS)

    Bowman, Cheryl; Jansen, Ralph; Brown, Gerald; Duffy, Kirsten; Trudell, Jeffrey

    2015-01-01

    Transitioning aviation to low carbon propulsion is one of the crucial strategic research thrust and is a driver in the search for alternative propulsion system for advanced aircraft configurations. This work requires multidisciplinary skills coming from multiple entities. The feasibility of scaling up various electric drive system technologies to meet the requirements of a large commercial transport is discussed in terms of key parameters. Functional requirements are identified that impact the power system design. A breakeven analysis is presented to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  1. Defining the Performance Parameters of a Rapid Screening Tool for FMR1 CGG-Repeat Expansions Based on Direct Triplet-Primed PCR and Melt Curve Analysis.

    PubMed

    Rajan-Babu, Indhu-Shree; Lian, Mulias; Tran, Anh H; Dang, Truong T; Le, Huong T-M; Thanh, Minh N; Lee, Caroline G; Chong, Samuel S

    2016-09-01

    Population-based screening for CGG-repeat expansions in the fragile X mental retardation 1 (FMR1) gene that cause fragile X syndrome can now be performed more cost-effectively and simply by combining direct triplet-primed PCR (dTP-PCR) with melting curve analysis (MCA). We have now performed a detailed technical validation to define the operational parameters for achieving robust and reliable performance of the FMR1 dTP-PCR MCA assay. We compared the assay's performance on 2 real-time PCR platforms and determined its analytic sensitivity and specificity. We also assessed the assay's performance on DNA isolated from different sources, the effect of differences in CGG-repeat length and AGG-interruption pattern on melt peak temperature (Tm), and the effect of common substances found in DNA solutions on Tms. The assay performed well in distinguishing normal from expansion-carrying samples. The assay had detection sensitivity down to 1 ng and an analytical specificity beyond 150 ng. In addition to peripheral blood DNA, analysis could also be performed on DNA from saliva, buccal swabs, and dried blood spots. Salt increased Tms, glycogen contamination had minimal effect, whereas AGG interruptions lowered Tms. The FMR1 dTP-PCR MCA screening assay is highly sensitive and specific, performs well using DNA from different sources, and is robust and reproducible when reagent concentrations are maintained across all tested samples. PMID:27375073

  2. The Symbiotic Performance of Chickpea Rhizobia Can Be Improved by Additional Copies of the clpB Chaperone Gene.

    PubMed

    Paço, Ana; Brígido, Clarisse; Alexandre, Ana; Mateos, Pedro F; Oliveira, Solange

    2016-01-01

    The ClpB chaperone is known to be involved in bacterial stress response. Moreover, recent studies suggest that this protein has also a role in the chickpea-rhizobia symbiosis. In order to improve both stress tolerance and symbiotic performance of a chickpea microsymbiont, the Mesorhizobium mediterraneum UPM-Ca36T strain was genetically transformed with pPHU231 containing an extra-copy of the clpB gene. To investigate if the clpB-transformed strain displays an improved stress tolerance, bacterial growth was evaluated under heat and acid stress conditions. In addition, the effect of the extra-copies of the clpB gene in the symbiotic performance was evaluated using plant growth assays (hydroponic and pot trials). The clpB-transformed strain is more tolerant to heat shock than the strain transformed with pPHU231, supporting the involvement of ClpB in rhizobia heat shock tolerance. Both plant growth assays showed that ClpB has an important role in chickpea-rhizobia symbiosis. The nodulation kinetics analysis showed a higher rate of nodule appearance with the clpB-transformed strain. This strain also induced a greater number of nodules and, more notably, its symbiotic effectiveness increased ~60% at pH5 and 83% at pH7, compared to the wild-type strain. Furthermore, a higher frequency of root hair curling was also observed in plants inoculated with the clpB-transformed strain, compared to the wild-type strain. The superior root hair curling induction, nodulation ability and symbiotic effectiveness of the clpB-transformed strain may be explained by an increased expression of symbiosis genes. Indeed, higher transcript levels of the nodulation genes nodA and nodC (~3 folds) were detected in the clpB-transformed strain. The improvement of rhizobia by addition of extra-copies of the clpB gene may be a promising strategy to obtain strains with enhanced stress tolerance and symbiotic effectiveness, thus contributing to their success as crop inoculants, particularly under

  3. Beneficial effects of training at the anaerobic threshold in addition to pharmacotherapy on weight loss, body composition, and exercise performance in women with obesity

    PubMed Central

    Ozcelik, Oguz; Ozkan, Yusuf; Algul, Sermin; Colak, Ramis

    2015-01-01

    Objective The aim of this study was to determine and compare the effects of weight loss achieved through orlistat therapy alone or a combination of orlistat and an aerobic exercise training program on aerobic fitness and body composition in obese females. Methods Twenty-eight obese patients were randomly assigned to receive 12-week treatment with hypocaloric diet–orlistat or diet–orlistat–exercise. Each participant performed an incremental ramp exercise test every 4 weeks to measure aerobic fitness. Fourteen participants performed continuous exercise (approximately 45 minutes per session) at a work rate corresponding to the anaerobic threshold three times per week. Results A decrease in the fat mass to body weight ratio of 3.8% (P=0.006) was observed at the end of the 12 weeks in the orlistat group, while a decrease of 9.5% (P=0.001) was seen in the orlistat–exercise group. Maximal exercise capacity increased by 46.5% in the orlistat–exercise group and by 19.5% in the orlistat group. Conclusion While orlistat therapy resulted in an improvement in body composition and aerobic fitness at the end of the 12-week period, its combination with exercise training provided improvements in the same parameters within the first 4 weeks of the study. These additional beneficial effects of combining aerobic exercise with orlistat therapy are important with regards to obesity-associated risk factors. PMID:26203232

  4. Effects of L-proline on the Growth Performance, and Blood Parameters in Weaned Lipopolysaccharide (LPS)-challenged Pigs

    PubMed Central

    Kang, Ping; Zhang, Lili; Hou, Yongqing; Ding, Binying; Yi, Dan; Wang, Lei; Zhu, Huiling; Liu, Yulan; Yin, Yulong; Wu, Guoyao

    2014-01-01

    This trail was conducted to study the effect of L-proline on the growth performance, and blood parameter in the weaned lipopolysaccharide (LPS)-challenged pigs. Thirty six pigs (9.13±0.85 kg) were assigned randomly to dietary treatments in a 2×3 factorial arrangement in a 20-d growth assay. Factors were intraperitoneal injection with saline or LPS, and three dietary L-proline supplement levels (0%, 0.5%, or 1.0%). On d 10, blood samples were collected at 3 h after LPS (100 μg LPS/kg body weight [BW]) or saline injection. On d 20 of the trial, all pigs were orally administrated D-xylose (0.1 g/kg BW) at 2 h, and blood samples were collected at 3 h after LPS or saline injection. As a result, dietary supplementation with 0.5% proline had a tendency to increase average daily gain (ADG) in piglets during d 10 to 20 (p = 0.088). Without LPS challenge, dietary supplementation with 1.0% proline had no effect on growth hormone (GH) concentrations on d 10 (p>0.05), but decreased it after LPS challenge (p<0.05). There was LPS challenge×proline interaction for GH concentrations on d 10 (p<0.05). Dietary supplementation with 1.0% proline decreased glucagon concentration on d 10 after LPS challenge (p<0.05). In addition, dietary supplementation with proline increased superoxide dismutase (SOD) activity significantly on d 10 and 20 (p<0.05), and 1.0% proline increased heat shock proteins-70 concentration on d 10 (p<0.05). Moreover, proline supplementation increased diamine oxidase (DAO) concentrations after LPS challenge (p<0.05). There was LPS challenge×proline interaction for DAO (p<0.05). Furthermore, dietary supplementation with 1.0% proline increased the D-xylose level when no LPS challenge (p<0.05). These results indicate that proline supplementation could improve growth performance, increase SOD activities, and has a positive effect on the gastrointestinal tract digestibility in early weaned pigs. PMID:25083109

  5. Enhancing the Performance of the Rechargeable Iron Electrode in Alkaline Batteries with Bismuth Oxide and Iron Sulfide Additives

    SciTech Connect

    Manohar, AK; Yang, CG; Malkhandi, S; Prakash, GKS; Narayanan, SR

    2013-09-07

    Iron-based alkaline rechargeable batteries have the potential of meeting the needs of large-scale electrical energy storage because of their low-cost, robustness and eco-friendliness. However, the widespread commercial deployment of iron-based batteries has been limited by the low charging efficiency and the poor discharge rate capability of the iron electrode. In this study, we have demonstrated iron electrodes containing bismuth oxide and iron sulfide with a charging efficiency of 92% and capable of being discharged at the 3C rate. Such a high value of charging efficiency combined with the ability to discharge at high rates is being reported for the first time. The bismuth oxide additive led to the in situ formation of elemental bismuth and a consequent increase in the overpotential for the hydrogen evolution reaction leading to an increase in the charging efficiency. We observed that the sulfide ions added to the electrolyte and iron sulfide added to the electrode mitigated-electrode passivation and allowed for continuous discharge at high rates. At the 3C discharge rate, a utilization of 0.2 Ah/g was achieved. The performance level of the rechargeable iron electrode demonstrated here is attractive for designing economically-viable large-scale energy storage systems based on alkaline nickel-iron and iron-air batteries. (C) 2013 The Electrochemical Society. All rights reserved.

  6. Tribological performance of Mg/Al/Ce layered double hydroxides nanoparticles and intercalated products as lubricant additives

    NASA Astrophysics Data System (ADS)

    Li, Shuo; Qin, Haojing; Zuo, Ranfang; Bai, Zhimin

    2015-10-01

    Mg/Al/Ce ternary layered double hydroxides (LDHs) were synthesized via coprecipitation and intercalated by succinic acid and lauric acid through ion exchange method respectively. The LDHs products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared (FT-IR). Tribological properties of LDHs as lubricant additives were evaluated by four-ball friction and air compressor test. The results indicated that Mg/Al/Ce LDHs were prepared successfully with Ce/Al molar ratio of 0.05 and crystallization temperature of 140 °C. The interlayer spacing of LDHs precursor was expanded by succinic acid and lauric acid to 8.838 and 17.519 Å respectively. All the three LDHs products can reduce friction and wear of engine lubricating oil in the tests. LDHs intercalated with lauric acid showed best tribological performance among them which was attributed to sliding each other between laminates, good dispersibility in oil medium and a protective tribofilm formed on the worn surface.

  7. Spatial interpolation of monthly climate data for Finland: comparing the performance of kriging and generalized additive models

    NASA Astrophysics Data System (ADS)

    Aalto, Juha; Pirinen, Pentti; Heikkinen, Juha; Venäläinen, Ari

    2013-04-01

    The Finnish Meteorological Institute has calculated statistics for the new reference period of 1981-2010. During this project, the grid size has been reduced from 10 to 1 km, the evaluation of the interpolation has been improved, and comparisons between different methods has been performed. The climate variables of interest were monthly mean temperature and mean precipitation, for which the spatial variability was explained using auxiliary information: mean elevation, sea percentage, and lake percentage. We compared three methods for spatial prediction: kriging with external drift (KED), generalized additive models (GAM), and GAM combined with residual kriging (GK). Every interpolation file now has attached statistical key figures describing the bias and the normality of the prediction error. According to the cross-validation results, GAM was the best method for predicting mean temperatures, with only very small differences relative to the other methods. For mean precipitation, KED produced the most accurate predictions, followed by GK. In both cases, there was notable seasonal variation in the statistical skill scores. For the new reference period and future interpolations, KED was chosen as the primary method due to its robustness and accuracy.

  8. Comparing species decisions in a dichotomous choice task: adjusting task parameters improves performance in monkeys.

    PubMed

    Prétôt, Laurent; Bshary, Redouan; Brosnan, Sarah F

    2016-07-01

    In comparative psychology, both similarities and differences among species are studied to better understand the evolution of their behavior. To do so, we first test species in tasks using similar procedures, but if differences are found, it is important to determine their underlying cause(s) (e.g., are they due to ecology, cognitive ability, an artifact of the study, and/or some other factor?). In our previous work, primates performed unexpectedly poorly on an apparently simple two-choice discrimination task based on the natural behavior of cleaner fish, while the fish did quite well. In this task, if the subjects first chose one of the options (ephemeral) they received both food items, but if they chose the other (permanent) option first, the ephemeral option disappeared. Here, we test several proposed explanations for primates' relatively poorer performance. In Study 1, we used a computerized paradigm that differed from the previous test by removing interaction with human experimenters, which may be distracting, and providing a more standardized testing environment. In Study 2, we adapted the computerized paradigm from Study 1 to be more relevant to primate ecology. Monkeys' overall performance in these adapted tasks matched the performance of the fish in the original study, showing that with the appropriate modifications they can solve the task. We discuss these results in light of comparative research, which requires balancing procedural similarity with considerations of how the details of the task or the context may influence how different species perceive and solve tasks differently. PMID:27086302

  9. Attentional Focus and Control Parameter: Effect on Throwing Pattern and Performance

    ERIC Educational Resources Information Center

    Southard, Dan

    2011-01-01

    In two separate experiments, this study examined changes in motor pattern and performance accuracy when low-level throwers focused on internal variables, external variables, and/or velocity of throw. In Experiment 1 the task goal was to improve the throwing pattern. In Experiment 2 the task goal was to throw as accurately as possible at a target.…

  10. Effects of repeated oral corticosterone administration on performance and stress parameters of laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of repeated stress during rearing on performance and physiology of laying hens was studied using a corticosterone (Cort) model. 240 Hisex laying hens were reared in environmentally controlled battery cages. At 7, 11, and 15 wk of age they were exposed for 1 wk to the following treatments...

  11. Confocal Microscopy and Flow Cytometry System Performance: Assessment of QA Parameters that affect data Quanitification

    EPA Science Inventory

    Flow and image cytometers can provide useful quantitative fluorescence data. We have devised QA tests to be used on both a flow cytometer and a confocal microscope to assure that the data is accurate, reproducible and precise. Flow Cytometry: We have provided two simple perform...

  12. The role of interior watershed processes in improving parameter estimation and performance of watershed models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the l...

  13. Linear-Parameter-Varying Antiwindup Compensation for Enhanced Flight Control Performance

    NASA Technical Reports Server (NTRS)

    Lu, Bei; Wu, Fen; Kim, Sung Wan

    2005-01-01

    Actuator saturation is one of the major issues of flight control in the high angle-of-attack region. This paper presents a saturation control scheme for linear parameter varyjing (LPV) systems from an antiwindup control perspective. The proposed control approach is advantageous from the implementation standpoint because it can be thought of as an augmented control algorithm to the existing control system. Moreover, the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality (LMI) optimization problem and can be solved efficiently. We have applied te LPV antiwindup controller to an F-16 longitudinal autopilot control system design and compared it with the thrust vectoring control scheme. The nonlinear simulations show that an LPV antiwindup controller improves flight quality and offers advantages over thrust vectoring in a high angle-of-attack region.

  14. Estimation of aerosol optical depth and additional atmospheric parameters for the calculation of apparent reflectance from radiance measured by the Airborne Visible/Infrared Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Conel, James E.; Roberts, Dar A.

    1993-01-01

    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) measures spatial images of the total upwelling spectral radiance from 400 to 2500 nm through 10 nm spectral channels. Quantitative research and application objectives for surface investigations require inversion of the measured radiance of surface reflectance or surface leaving radiance. To calculate apparent surface reflectance, estimates of atmospheric water vapor abundance, cirrus cloud effects, surface pressure elevation, and aerosol optical depth are required. Algorithms for the estimation of these atmospheric parameters from the AVIRIS data themselves are described. From these atmospheric parameters we show an example of the calculation of apparent surface reflectance from the AVIRIS-measured radiance using a radiative transfer code.

  15. Comparative performance between human and automated face recognition systems, using CCTV imagery, different compression levels and scene parameters

    NASA Astrophysics Data System (ADS)

    Tsifouti, A.; Triantaphillidou, S.; Larabi, M.-C.; Bilissi, E.; Psarrou, A.

    2015-01-01

    In this investigation we identify relationships between human and automated face recognition systems with respect to compression. Further, we identify the most influential scene parameters on the performance of each recognition system. The work includes testing of the systems with compressed Closed-Circuit Television (CCTV) footage, consisting of quantified scene (footage) parameters. Parameters describe the content of scenes concerning camera to subject distance, facial angle, scene brightness, and spatio-temporal busyness. These parameters have been previously shown to affect the human visibility of useful facial information, but not much work has been carried out to assess the influence they have on automated recognition systems. In this investigation, the methodology previously employed in the human investigation is adopted, to assess performance of three different automated systems: Principal Component Analysis, Linear Discriminant Analysis, and Kernel Fisher Analysis. Results show that the automated systems are more tolerant to compression than humans. In automated systems, mixed brightness scenes were the most affected and low brightness scenes were the least affected by compression. In contrast for humans, low brightness scenes were the most affected and medium brightness scenes the least affected. Findings have the potential to broaden the methods used for testing imaging systems for security applications.

  16. Parameter-Based Performance Analysis of Object-Based Image Analysis Using Aerial and Quikbird-2 Images

    NASA Astrophysics Data System (ADS)

    Kavzoglu, T.; Yildiz, M.

    2014-09-01

    Opening new possibilities for research, very high resolution (VHR) imagery acquired by recent commercial satellites and aerial systems requires advanced approaches and techniques that can handle large volume of data with high local variance. Delineation of land use/cover information from VHR images is a hot research topic in remote sensing. In recent years, object-based image analysis (OBIA) has become a popular solution for image analysis tasks as it considers shape, texture and content information associated with the image objects. The most important stage of OBIA is the image segmentation process applied prior to classification. Determination of optimal segmentation parameters is of crucial importance for the performance of the selected classifier. In this study, effectiveness and applicability of the segmentation method in relation to its parameters was analysed using two VHR images, an aerial photo and a Quickbird-2 image. Multi-resolution segmentation technique was employed with its optimal parameters of scale, shape and compactness that were defined after an extensive trail process on the data sets. Nearest neighbour classifier was applied on the segmented images, and then the accuracy assessment was applied. Results show that segmentation parameters have a direct effect on the classification accuracy, and low values of scale-shape combinations produce the highest classification accuracies. Also, compactness parameter was found to be having minimal effect on the construction of image objects, hence it can be set to a constant value in image classification.

  17. Discriminating performance parameters for 50 amp-hour and 60 amp-hour nickel-cadmium plates and battery cells

    NASA Technical Reports Server (NTRS)

    Toft, Mark R.

    1994-01-01

    This is a follow-up of studies of the NASA standard 50 AH cell presented at the NASA battery workshop each of the last two years. This is a dynamic study. Data trends continue to be developed and analyzed for their utility in judging NiCd performance. The trends and parameters presented here may bear relevance to many designs of conventional NiCd batteries, not just the 50 AH and 60 AH sizes.

  18. Effect of new rules on the correlation between situation parameters and performance in beach volleyball.

    PubMed

    Grgantov, Zoran; Katić, Ratko; Marelić, Nenad

    2005-12-01

    The aim of the study was to assess the effect of basic technical-tactical elements, i.e. specific motor abilities, on performance in beach volleyball, with special reference to differences between the old and new official rules. Analysis of variance for 6 variables of technical-tactical elements between the winning and defeated teams included a sample of 129 sets played according to the old official rules (1995 and 1996) and 74 sets played according to the new official rules (2003). This was followed by regression analysis between these technical-tactical elements as predictors and a variable, i.e. score difference at which the team won or lost the game, as a criterion. Results of the analysis of variance between the winning and defeated teams showed highest differences in the performance of attack-hit, followed by counterattack-hit and blocking in both game types. However, difference in the performance of serve reception, serve, and field defense between the winning and defeated teams decreased significantly with the use of new rules as compared with the old ones. Results of regression analysis indicated the sets played according to the new rules relative to old ones to increase the predominant impact of technical-tactical elements in the above-net actions, especially attack-hit and block, on the final result in beach volleyball. PMID:16417188

  19. Elucidating the Performance Limitations of Lithium-ion Batteries due to Species and Charge Transport through Five Characteristic Parameters

    PubMed Central

    Jiang, Fangming; Peng, Peng

    2016-01-01

    Underutilization due to performance limitations imposed by species and charge transports is one of the key issues that persist with various lithium-ion batteries. To elucidate the relevant mechanisms, two groups of characteristic parameters were proposed. The first group contains three characteristic time parameters, namely: (1) te, which characterizes the Li-ion transport rate in the electrolyte phase, (2) ts, characterizing the lithium diffusion rate in the solid active materials, and (3) tc, describing the local Li-ion depletion rate in electrolyte phase at the electrolyte/electrode interface due to electrochemical reactions. The second group contains two electric resistance parameters: Re and Rs, which represent respectively, the equivalent ionic transport resistance and the effective electronic transport resistance in the electrode. Electrochemical modeling and simulations to the discharge process of LiCoO2 cells reveal that: (1) if te, ts and tc are on the same order of magnitude, the species transports may not cause any performance limitations to the battery; (2) the underlying mechanisms of performance limitations due to thick electrode, high-rate operation, and large-sized active material particles as well as effects of charge transports are revealed. The findings may be used as quantitative guidelines in the development and design of more advanced Li-ion batteries. PMID:27599870

  20. Elucidating the Performance Limitations of Lithium-ion Batteries due to Species and Charge Transport through Five Characteristic Parameters.

    PubMed

    Jiang, Fangming; Peng, Peng

    2016-01-01

    Underutilization due to performance limitations imposed by species and charge transports is one of the key issues that persist with various lithium-ion batteries. To elucidate the relevant mechanisms, two groups of characteristic parameters were proposed. The first group contains three characteristic time parameters, namely: (1) te, which characterizes the Li-ion transport rate in the electrolyte phase, (2) ts, characterizing the lithium diffusion rate in the solid active materials, and (3) tc, describing the local Li-ion depletion rate in electrolyte phase at the electrolyte/electrode interface due to electrochemical reactions. The second group contains two electric resistance parameters: Re and Rs, which represent respectively, the equivalent ionic transport resistance and the effective electronic transport resistance in the electrode. Electrochemical modeling and simulations to the discharge process of LiCoO2 cells reveal that: (1) if te, ts and tc are on the same order of magnitude, the species transports may not cause any performance limitations to the battery; (2) the underlying mechanisms of performance limitations due to thick electrode, high-rate operation, and large-sized active material particles as well as effects of charge transports are revealed. The findings may be used as quantitative guidelines in the development and design of more advanced Li-ion batteries. PMID:27599870

  1. Responses of hematological parameters and aerobic performance of elite men and women swimmers during a 14-week training program.

    PubMed

    Santhiago, Vanessa; da Silva, Adelino S R; Papoti, Marcelo; Gobatto, Claudio A

    2009-07-01

    The main purpose of the present investigation was to verify the responses of hematological parameters in men and women competitive swimmers during a 14-week training program. Twenty-three Olympic and international athletes were evaluated 4 times during the experiment: at the beginning of the endurance training phase (T1), at the end of the endurance training phase (T2), at the end of the quality phases (T3), and at the end of the taper period (T4). On the first day at 8:00 AM, each swimmer had a blood sample taken for the determination of hematological parameters. At 3:00 PM, the athletes had their aerobic performance measured by anaerobic threshold. On the second day at 8:00 AM, the swimmers had their aerobic performance measured by critical velocity. Hematocrit and mean corpuscular volume diminished (p < or = 0.05) from T1 to T2 (men: 5.8 and 7.2%; women: 11.6 and 6.8%), and increased (p < or = 0.05) from T2 to T3 (men: 7.2 and 6.0%; women: 7.4 and 5.2%). These results were related to the plasma volume changes of the athletes. However, these alterations do not seem to affect the swimmers' aerobic performance. For practical applications, time-trial performance is better than aerobic performance (i.e., anaerobic threshold and critical velocity) for monitoring training adaptations. PMID:19528852

  2. One-and-Two-Dimensional Simulations of Liner Performance at Atlas Parameters

    SciTech Connect

    Keinigs, R.K.; Atchison, W.L.; Faehl, R.J.; Mclenithan, K.D.; Trainor, R.J.

    1998-10-18

    The authors report results of one-and-two-dimensional MHD simulations of an imploding heavy liner in Z-pinch geometry. The driving current has a pulse shape and peak current characteristic of the Atlas pulsed-power facility being constructed at Los Alamos National Laboratory. One-dimensional simulations of heavy composite liners driven by 30 MA currents can achieve velocities on the order of 14 km/sec. Used to impact a tungsten target, the liner produces shock pressures of approximately fourteen megabars. The first 2-D simulations of imploding liners driven at Atlas current parameters are also described. These simulations have focused on the interaction of the liner with the glide planes, and the effect of realistic surface perturbations on the dynamics of the pinch. It is found that the former interaction does not seriously affect the inner liner surface. Results from the second problem indicate that a surface perturbation having amplitude as small as 0.2 {micro}m can have a significant effect on the implosion dynamics.

  3. High Pressure Size Exclusion Chromatography (HPSEC) of humic substances: molecular sizes, analytical parameters, and column performance

    PubMed

    Conte; Piccolo

    1999-02-01

    High Pressure Size Exclusion chromatography (HPSEC) is increasingly used to evaluate molecular sizes of humic substances from different sources. Asymmetry factors (As), number of theoretical plates (N), coefficient of distribution (k(d)), and column resolution (Rs) were determined for two different HPSEC columns (TSK G3000SW and Biosep S2000) and polysaccharides of known molecular weights were used as standards. Calibration curves were equivalent for both columns whereas analytical parameters revealed that the TSK column was only slightly more efficient in separating polysaccharide standards. Mw and Mn values for humic substances differed according to the molecular weight range of each column but relative standard deviation never exceeded 5% for both columns. Variations between columns were attributed to intrinsic humic properties such as the stability of conformational structures. These results suggested that humic substances in solutions are loosely-bound association of small molecules that may be consistently dispersed by diffusion through size-exclusion pores. HPSEC is confirmed to represent a highly precise method to evaluate the relative molecular-size distribution of dissolved humic substances. PMID:10901671

  4. Influence of process parameters to composite interface organization and performance of liquid/solid bimetal

    NASA Astrophysics Data System (ADS)

    Rong, S. F.; Zhu, Y. C.; Wu, Y. H.; Yang, P. H.; Duan, X. L.; Zhou, H. T.

    2015-12-01

    The liquid-solid composite technique was used to prepare the high carbon high chromium steel (HCHCS) and low alloy steel (LCS) bimetal composite materials by means of insert casting method. The influence of some process parameters such as liquid-solid ratio, preheat temperature, pouring temperature on the interface microstructure and mechanical properties were studied. Interface microstructure and element distribution were analyzed. The results show that the interface microstructure becomes better, and bonding area becomes thicker with the increase of the volume of liquid to solid ratio, preheating temperature and pouring temperature. When the liquid-solid ratio is 8:1, the preheating temperature is 300 °C and the pouring temperature is 1565 °C, a good metallurgical bonding area without any hole can be obtained with the interface combination of diffusion and fusion. The composite interface structure was composed of a core material diffusion layer, a cooling solidification layer, a direction growth layer and some cell particles. The elements of C, Cr and Mn diffuse from the HCHCS side to the alloy steel side. The microhardness increased in the gradient from the LCS side to the HCHCS. The microhardness of the interface is significantly higher than that of LCS.

  5. Impact of parameter fluctuations on the performance of ethanol precipitation in production of Re Du Ning Injections, based on HPLC fingerprints and principal component analysis.

    PubMed

    Sun, Li-Qiong; Wang, Shu-Yao; Li, Yan-Jing; Wang, Yong-Xiang; Wang, Zhen-Zhong; Huang, Wen-Zhe; Wang, Yue-Sheng; Bi, Yu-An; Ding, Gang; Xiao, Wei

    2016-01-01

    The present study was designed to determine the relationships between the performance of ethanol precipitation and seven process parameters in the ethanol precipitation process of Re Du Ning Injections, including concentrate density, concentrate temperature, ethanol content, flow rate and stir rate in the addition of ethanol, precipitation time, and precipitation temperature. Under the experimental and simulated production conditions, a series of precipitated resultants were prepared by changing these variables one by one, and then examined by HPLC fingerprint analyses. Different from the traditional evaluation model based on single or a few constituents, the fingerprint data of every parameter fluctuation test was processed with Principal Component Analysis (PCA) to comprehensively assess the performance of ethanol precipitation. Our results showed that concentrate density, ethanol content, and precipitation time were the most important parameters that influence the recovery of active compounds in precipitation resultants. The present study would provide some reference for pharmaceutical scientists engaged in research on pharmaceutical process optimization and help pharmaceutical enterprises adapt a scientific and reasonable cost-effective approach to ensure the batch-to-batch quality consistency of the final products. PMID:26850350

  6. Applying probabilistic well-performance parameters to assessments of shale-gas resources

    USGS Publications Warehouse

    Charpentier, Ronald R.; Cook, Troy

    2010-01-01

    In assessing continuous oil and gas resources, such as shale gas, it is important to describe not only the ultimately producible volumes, but also the expected well performance. This description is critical to any cost analysis or production scheduling. A probabilistic approach facilitates (1) the inclusion of variability in well performance within a continuous accumulation, and (2) the use of data from developed accumulations as analogs for the assessment of undeveloped accumulations. In assessing continuous oil and gas resources of the United States, the U.S. Geological Survey analyzed production data from many shale-gas accumulations. Analyses of four of these accumulations (the Barnett, Woodford, Fayetteville, and Haynesville shales) are presented here as examples of the variability of well performance. For example, the distribution of initial monthly production rates for Barnett vertical wells shows a noticeable change with time, first increasing because of improved completion practices, then decreasing from a combination of decreased reservoir pressure (in infill wells) and drilling in less productive areas. Within a partially developed accumulation, historical production data from that accumulation can be used to estimate production characteristics of undrilled areas. An understanding of the probabilistic relations between variables, such as between initial production and decline rates, can improve estimates of ultimate production. Time trends or spatial trends in production data can be clarified by plots and maps. The data can also be divided into subsets depending on well-drilling or well-completion techniques, such as vertical in relation to horizontal wells. For hypothetical or lightly developed accumulations, one can either make comparisons to a specific well-developed accumulation or to the entire range of available developed accumulations. Comparison of the distributions of initial monthly production rates of the four shale-gas accumulations that were

  7. Effects of additional repeated sprint training during preseason on performance, heart rate variability, and stress symptoms in futsal players: a randomized controlled trial.

    PubMed

    Soares-Caldeira, Lúcio F; de Souza, Eberton A; de Freitas, Victor H; de Moraes, Solange M F; Leicht, Anthony S; Nakamura, Fábio Y

    2014-10-01

    The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heart rate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ≤ 0.05). The HRV parameters improved significantly within both groups (p ≤ 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heart rate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players. PMID:24662230

  8. Effects of various dietary lipid additives on lamb performance, carcass characteristics, adipose tissue fatty acid composition, and wool characteristics.

    PubMed

    Meale, S J; Chaves, A V; He, M L; Guan, L L; McAllister, T A

    2015-06-01

    Tasco (Ascophyllum nodosum; TA) was compared to canola (CO), flax (FO), and safflower oils (SO) for effects on performance, carcass characteristics, and fatty acid profiles of adipose tissue in skirt muscle (SM), subcutaneous and perirenal adipose tissues, and wool production and quality characteristics of Canadian Arcott lambs. Fifty-six lambs were randomly assigned to dietary treatments (n = 14 per treatment). Diets consisted of a pelleted, barley-based finishing diet containing either TA, CO, FO, or SO (2% of dietary DM). Feed deliveries and orts were recorded daily. Lambs were weighed weekly and slaughtered once they reached ≥ 45 kg BW. Carcass characteristics, rumen pH, and liver weights were determined at slaughter. Wool yield was determined on mid-side patches of 100 cm2 shorn at d 0 and on the day before slaughter (d 105 or 140). Dye-bands were used to determine wool growth, micrometer and staple length. Adipose tissues and SM samples were taken at slaughter and analyzed for FA profiles. No effects were observed on intake, growth, or carcass characteristics. A greater (P = 0.02) staple strength of lambs fed CO was the only effect observed in wool. Flax oil increased total n-3 and decreased the n-6/n-3 ratio in tissue FA profiles (P < 0.001) in comparison to other diets. Tasco increased (P ≤ 0.001) SFA/PUFA in all tissues, whereas concentrations of CLA c-9, t-11 were greatest with SO in all tissues (P ≤ 0.02), compared to other diets. These results suggest Tasco supplementation did not improve the n-3/n-6 or SFA/PUFA ratios of lamb adipose tissues compared to other dietary lipid additives. PMID:26115297

  9. Changes in Respiratory Parameters and Fin-Swimming Performance Following a 16-Week Training Period with Intermittent Breath Holding

    PubMed Central

    Stavrou, Vasileios; Toubekis, Argyris G.; Karetsi, Eleni

    2015-01-01

    The purpose of this study was to examine the effects of training with intermittent breath holding (IBH) on respiratory parameters, arterial oxygen saturation (SpO2) and performance. Twenty-eight fin-swimming athletes were randomly divided into two groups and followed the same training for 16 weeks. About 40% of the distance of each session was performed with self-selected breathing frequency (SBF group) or IBH (IBH group). Performance time of 50 and 400 m at maximum intensity was recorded and forced expired volume in 1 s (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF) and SpO2 were measured before and after the 50 m test at baseline and post-training. Post-training, the respiratory parameters were increased in the IBH but remained unchanged in the SBF group (FEV1: 17 ±15% vs. −1 ±11%; FVC: 22 ±13% vs. 1 ±10%; PEF: 9 ±14% vs. −4 ±15%; p<0.05). Pre compared to post-training SpO2 was unchanged at baseline and decreased post-training following the 50 m test in both groups (p<0.05). The reduction was higher in the IBH compared to the SBF group (p<0.05). Performance in the 50 and 400 m tests improved in both groups, however, the improvement was greater in the IBH compared to the SBF group in both 50 and 400 m tests (p<0.05). The use of IBH is likely to enhance the load on the respiratory muscles, thus, contributing to improvement of the respiratory parameters. Decreased SpO2 after IBH is likely due to adaptation to hypoventilation. IBH favours performance improvement at 50 and 400 m fin-swimming. PMID:26839609

  10. Changes in Respiratory Parameters and Fin-Swimming Performance Following a 16-Week Training Period with Intermittent Breath Holding.

    PubMed

    Stavrou, Vasileios; Toubekis, Argyris G; Karetsi, Eleni

    2015-12-22

    The purpose of this study was to examine the effects of training with intermittent breath holding (IBH) on respiratory parameters, arterial oxygen saturation (SpO2) and performance. Twenty-eight fin-swimming athletes were randomly divided into two groups and followed the same training for 16 weeks. About 40% of the distance of each session was performed with self-selected breathing frequency (SBF group) or IBH (IBH group). Performance time of 50 and 400 m at maximum intensity was recorded and forced expired volume in 1 s (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF) and SpO2 were measured before and after the 50 m test at baseline and post-training. Post-training, the respiratory parameters were increased in the IBH but remained unchanged in the SBF group (FEV1: 17 ±15% vs. -1 ±11%; FVC: 22 ±13% vs. 1 ±10%; PEF: 9 ±14% vs. -4 ±15%; p<0.05). Pre compared to post-training SpO2 was unchanged at baseline and decreased post-training following the 50 m test in both groups (p<0.05). The reduction was higher in the IBH compared to the SBF group (p<0.05). Performance in the 50 and 400 m tests improved in both groups, however, the improvement was greater in the IBH compared to the SBF group in both 50 and 400 m tests (p<0.05). The use of IBH is likely to enhance the load on the respiratory muscles, thus, contributing to improvement of the respiratory parameters. Decreased SpO2 after IBH is likely due to adaptation to hypoventilation. IBH favours performance improvement at 50 and 400 m fin-swimming. PMID:26839609

  11. Thioether profragrances: parameters influencing the performance of precursor-based fragrance delivery in functional perfumery.

    PubMed

    Maddalena, Umberto; Trachsel, Alain; Fankhauser, Peter; Berthier, Damien L; Benczédi, Daniel; Wang, Wei; Xi, Xiujuan; Shen, Youqing; Herrmann, Andreas

    2014-11-01

    A series of thioether profragrances was prepared by reaction of different sulfanylalkanoates with δ-damascone and tested for their release efficiencies in a fabric-softener and an all-purpose cleaner application. Dynamic headspace analysis on dry cotton and on a ceramic plate revealed that the performance of the different precursors depended on the structure, but also on the particular conditions encountered in different applications. Moreover, profragrances derived from other α,β-unsaturated fragrance aldehydes and ketones were synthesized analogously and evaluated using the same test protocol. Thioethers were found to be suitable precursors to release the corresponding fragrances, but neither the quantity of profragrance deposited from an aqueous environment onto the target surface, nor the amount of fragrance released after deposition could be linearly correlated to the hydrophilicity or hydrophobicity of the compounds. Different sets of compounds were found to be the best performers for different types of applications. Only one of the compounds evaluated in the present work, namely the thiolactic acid derivative of δ-damascone, efficiently released the corresponding fragrance in both of the tested applications. Profragrance development for functional perfumery thus remains a partially empirical endeavour. More knowledge (and control) of the various application conditions are required for an efficient profragrance design. PMID:25408319

  12. Effects of structural parameters on flow boiling performance of reentrant porous microchannels

    NASA Astrophysics Data System (ADS)

    Deng, Daxiang; Tang, Yong; Shao, Haoran; Zeng, Jian; Zhou, Wei; Liang, Dejie

    2014-06-01

    Flow boiling within advanced microchannel heat sinks provides an efficient and attractive method for the cooling of microelectronics chips. In this study, a series of porous microchannels with Ω-shaped reentrant configurations were developed for application in heat sink cooling. The reentrant porous microchannels were fabricated by using a solid-state sintering method under the replication of specially designed sintering modules. Micro wire electrical discharge machining was utilized to process the graphite-based sintering modules. Two types of commonly used copper powder in heat transfer devices, i.e., spherical and irregular powder, with three fractions of particle sizes respectively, were utilized to construct the porous microchannel heat sinks. The effects of powder type and size on the flow boiling performance of reentrant porous microchannels, i.e., two-phase heat transfer, pressure drop and flow instabilities, were examined under boiling deionized water conditions. The test results show that enhanced two-phase heat transfer was achieved with the increase of particle size for the reentrant porous microchannels with spherical powder, while the reversed trend existed for the counterparts with irregular powder. The reentrant porous microchannels with irregular powder of the smallest particle size presented the best heat transfer performance and lowest pressure drop.

  13. The effect of modifying response and performance feedback parameters on the CNV in humans

    NASA Technical Reports Server (NTRS)

    Otto, D. A.; Leifer, L. J.

    1972-01-01

    The effect on the CNV of sustained and delayed motor response with the dominant and nondominant hand in the presence and absence of visual performance feedback, was studied in 15 male adults. Monopolar scalp recordings were obtained at Fz, Cz, Pz, and bilaterally over the motor hand area. Results indicated that the magnitude of the CNV was greater in the delayed than sustained response task, greater in the presence than absence of feedback, and greater over the motor hand area contralateral to movement. Frontal CNV habituated in the sustained, but not the delayed response task, suggested that frontal negative variations in the former case signify an orienting response to novelty or uncertainty. The absence of habituation in the delay condition was interpreted in terms of the motor inhibitory function of frontal association cortex. Performance feedback appeared to enhance CNV indirectly by increasing the motivation of subjects. A multiprocess conception of CNV was proposed in which vortex-negative slow potentials reflect a multiplicity of psychophysiological processes occurring at a variety of cortical and subcortical locations in the brain preparatory to a motor or mental action.

  14. Performance & stability analysis of a three lobe journal bearing with varying parameters: Experiments and analysis

    NASA Astrophysics Data System (ADS)

    Biswas, Nabarun; Chakraborti, Prasun; Saha, Ankuran; Biswas, Srijit

    2016-07-01

    3-lobe Hydrodynamic oil journal bearings are widely used in heavy industries as a part of different rotating machinery due to their high level of performances. 3-lobe hydrodynamic oil journal bearing allows the transmission of large amounts of loads at a mean speed of rotation. In this present work, an attempt has been made to investigate the pressure domain and subsequent effects in a 3 lobe journal bearing under different static loads in a stable operating speed. Analytical calculations were carried out with codes generated using Matlab software. Experiments were performed in Journal Bearing test rig incorporating 3-lobe under different loads with stable operating speed of 1000 RPM. It has been observed that an increase in load resulted rise in pressure profile, maximum pressure angle and temperature. A further attempt has been made to see the effect of eccentricity ratio and dynamic viscosity considering no change in the RPM. It has also been observed that dynamic viscosity has a significant effect on the stable operating speed. With the reduction in static load, the stability of operating speed attained at higher values.

  15. Long-term Short Implants Performance: Systematic Review and Meta-Analysis of the Essential Assessment Parameters.

    PubMed

    Gonçalves, Thais Marques Simek Vega; Bortolini, Sergio; Martinolli, Matteo; Alfenas, Bruna Fernandes Moreira; Peruzzo, Daiane Cristina; Natali, Alfredo; Berzaghi, Andrea; Garcia, Renata Cunha Matheus Rodrigues

    2015-01-01

    Lack of standard criteria in the outcome assessment makes it difficult to draw conclusions on the clinical performance of short implants and, under these circumstances, determine the reasons for implant failure. This study evaluated, through a systematic review of the literature and meta-analysis, the essential parameters required to assess the long-term clinical performance of short and extra-short implants. Electronic databases (Pubmed-MEDLINE, Cochrane Library Database, Embase, and Lilacs) were searched by two independent reviewers, without language limitation, to identify eligible papers. References from the selected articles were also reviewed. The review included clinical trials involving short dental implants placed in humans, published between January 2000 and March 2014, which described the parameters applied for outcome's measurements and provided data on survival rates. Thirteen methodologically acceptable studies were selected and 24 parameters were identified. The most frequent parameters assessed were the marginal bone loss and the cumulative implant survival rate, followed by implant failure rate and biological complications such as bleeding on probing and probing pocket depths. Only cumulative implant survival rate data allows meta-analysis revealing a positive effect size (from 0.052 (fixed) to 0.042 (random)), which means that short implant appears to be a successful treatment option. Mechanical complications and crown-to-implant (C/I) ratio measurement were also commonly described, however, considering the available evidence; no strong conclusions could be drawn since different methods were used to assess each parameter. By means of this literature review, a standard evaluation scheme is proposed, being helpful to regiment further investigations and comparisons on future studies. PMID:26312967

  16. The effect of porous support composition and operating parameters on the performance of supported liquid membranes

    SciTech Connect

    Takigawa, D.Y. )

    1992-03-01

    Supported liquid membranes (SLMs) of varying porous support compositions and structures were studied for the transport of metal ions. A microporous polybenzimidazole support was synthesized and prepared in the form of an SLM. This SLM, containing the selective extractant di-(2-ethylhexyl) phosphoric acid, was evaluated for the transport of copper and neodymium. Metal ion transport reaches near completion in less than 3 h, whereas Celgard-polypropylene and Nucleopore-polycarbonate reaches only 50% completion even after 15 h. The transport driving force for acidic extractants is a pH gradient between the feed and strip solutions. Polybenzimidazole, an acid-and radiation-resistant polymer, has two protonatable tertiary nitrogens per repeat unit that may help sustain the pH driving force. Another factor may be the ability of the polybenzimidazole to hydrogen bond with the extractant. Transport through the flat-sheet SLMs was tested by using a unique cell design. Countercurrent flow of the feed and strip solutions was established through machined channels in half-cell face plates that are in a spiral, mirror-image pattern with respect to each other, with the flat-sheet SLM interposed between the two channeled solutions. Advantages comprised in the design of the two clamped half-cells (tangential entry, zero primary pressure, zero pressure differential, controlled flow regimes, no sharp turns, and channeled flow) give operating parameters that will not physically dislodge the liquid membrane from the porous support; consequently, the lifetime of the support is increased. Permeability coefficients remained unchanged after a month of daily use versus 20 to 100% declines for membranes in other cell configurations.

  17. Asymmetric Conjugate Addition of Benzofuran-2-ones to Alkyl 2-Phthalimidoacrylates: Modeling Structure-Stereoselectivity Relationships with Steric and Electronic Parameters.

    PubMed

    Yang, Chen; Zhang, En-Ge; Li, Xin; Cheng, Jin-Pei

    2016-05-23

    A highly predictive model to correlate the steric and electronic parameters of tertiary amine thiourea catalysts with the stereoselectivity of Michael reactions of 3-substituted benzofuranones and alkyl 2-phthalimidoacrylates is described. As predicted, new 3,5-bis(trifluoromethyl)benzyl- and methyl-substituted tertiary amine thioureas turned out to be highly suitable catalysts for this reaction and enabled the synthesis of enantioenriched α-amino acid derivatives with 1,3-nonadjacent stereogenic centers. PMID:27080558

  18. Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America; additional conifers, hardwoods, and monocots

    USGS Publications Warehouse

    Thompson, Robert S.; Anderson, Katherine H.; Bartlein, Patrick J.; Smith, Sharon A.

    2000-01-01

    This volume explores the continental-scale relations between climate and the geographic ranges of woody plant species in North America. A 25-km equal-area grid of modern climatic and bioclimatic parameters for North America was constructed from instrumental weather records. The geographic distributions of selected tree and shrub species were digitized, and the presence or absence of each species was determined for each cell on the 25-km grid, thus providing a basis for comparing climatic data and species' distribution.

  19. The Ma_Miss instrument performance, II: Band parameters of rocks powders spectra by Martian VNIR spectrometer

    NASA Astrophysics Data System (ADS)

    De Angelis, Simone; De Sanctis, Maria Cristina; Ammannito, Eleonora; Carli, Cristian; Di Iorio, Tatiana; Altieri, Francesca

    2015-11-01

    The Ma_Miss instrument (Mars Multispectral Imager for Subsurface Studies, Coradini et al. (2001)) is a Visible and Near Infrared miniaturized spectrometer that will observe the Martian subsurface in the 0.4-2.2 μm spectral range. The instrument will be entirely hosted within the Drill of the ExoMars-2018 Pasteur Rover: it will allow analyzing the borehole wall excavated by the Drill, at different depths, down to 2 m. The aim will be to investigate and characterize the mineralogy and stratigraphy of the shallow Martian subsurface. A series of spectroscopic measurements have been performed in order to characterize the spectral performances of the laboratory model of the instrument (breadboard). A set of six samples have been analyzed. Each sample (four volcanic rocks, a micritic limestone and a calcite) has been reduced in particulate form, ground, sieved and divided into nine different grain sizes in the range d<0.02÷0.8 mm. Spectroscopic measurements have been performed on all samples using two distinct experimental setup: (a) the Ma_Miss breadboard, and (b) the Spectro-Goniometer setup, both in use in the laboratory at INAF - IAPS. In a previous paper spectral parameters such as the continuum slope and the reflectance level of the spectra have been discussed (De Angelis et al., 2014). In this work we focus our discussion on absorption band parameters (position, depth, area, band slope and asymmetry). We analyzed/investigated the absorption features at 1 μm for the volcanic samples and at 1.4, 1.9 and 2.2 μm for the two carbonate samples. Band parameters have been retrieved from spectra measured with both experimental setup and then compared. The comparison shows that band parameters are mutually consistent: band centers (for carbonate samples) are similar within few percent, and band depth and area values (for carbonates) show consistent trends vs. grain size (decreasing towards coarser grains) for most of samples.

  20. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  1. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  2. Effect of powdered activated carbon (PAC) on MBR performance and effluent trihalomethane formation: At the initial stage of PAC addition.

    PubMed

    Gao, Yue; Ma, Defang; Yue, Qinyan; Gao, Baoyu; Huang, Xia

    2016-09-01

    In this study, the MBR was used to treat municipal wastewater for reuse. Effects of powdered activated carbon (PAC) addition on MBR system in terms of effluent water quality, trihalomethane (THM) formation and membrane organic fouling tendency of MBR sludge supernatant at the initial stage of PAC addition were investigated. Effects of chlorine dose and contact time on THM formation and speciation were also studied. PAC addition enhanced the removal of organic matters, especially aromatic components, which improved the UV254 removal rate from 34% to 83%. PAC addition greatly reduced the membrane organic fouling tendency of MBR sludge supernatant. PAC addition reduced the MBR effluent trihalomethane formation potential (THMFP) from 351.29 to 241.95μg/L, while increased THM formation reactivity by 42%. PAC addition enhanced the formation of higher toxic bromine-containing THMs. High chlorine dose and contact time resulted in higher THM formation but lower proportion of bromine-containing THMs. PMID:27318162

  3. Effects of selected feed additives on the performance of laying hens given a diet rich in maize dried distiller's grains with solubles (DDGS).

    PubMed

    Świątkiewicz, S; Arczewska-Włosek, A; Krawczyk, J; Puchała, M; Józefiak, D

    2013-01-01

    1. A total of 192 ISA Brown hens were given diets containing a high concentration of maize dried distiller's grains with solubles (DDGS) and the effect of selected feed additives on laying performance and egg quality was determined. 2. Birds were allocated to 8 treatment groups with 12 replicates (cages) of two hens and were given, from week 26 to 55, iso-caloric and iso-nitrogenous experimental diets with or without a high concentration of DDGS (200 g/kg). The diet containing DDGS was not supplemented or supplemented with enzymes (xylanase and phytase), sodium butyrate, probiotic bacteria (Lactobacillus salivarius) and a mixture of herbal extracts (Taraxaci siccum, Urticae siccum and Salviae siccum), inulin or chitosan. 3. The inclusion of DDGS in the diet had no effect on number of eggs produced, total egg mass, mean egg weight, feed intake or feed conversion ratio. Egg and eggshell quality parameters were also unaffected by dietary DDGS. The yolk colour score (points in Roche scale) was significantly increased by DDGS inclusion. DDGS in the diet caused some changes in the yolk lipid profile that were rather unfavourable from a dietary perspective (an increase of cholesterol content, and PUFA n-6/PUFA n-3 ratio). 4. During the experimental period (26-55 weeks of age) supplementation of the diet containing a high concentration of DDGS with enzymes, inulin as well as chitosan, increased number of eggs produced and daily egg mass. In older hens (50 weeks of age) inulin positively affected eggshell quality parameters, i.e. shell percentage, thickness and density. Diet supplementation with herb extracts, inulin or chitosan, decreased the content of cholesterol in yolks. 5. The results of this study suggest that DDGS may be incorporated up to a concentration of 200 g/kg in the diet of laying hens without any negative effects on egg performance. Moreover, supplementation of xylanase and phytase, as well as inulin and chitosan, can positively affect the performance of

  4. Effect of feeding organic and inorganic sources of additional zinc on growth performance and zinc balance in nursery pigs.

    PubMed

    Case, C L; Carlson, M S

    2002-07-01

    Three experiments were conducted to evaluate the effect of feeding pharmacological concentrations of zinc (Zn), from organic and inorganic sources, on growth performance, plasma and tissue Zn accumulation, and Zn excretion of nursery pigs. Blood from all pigs was collected for plasma Zn determination on d 14 in Exp. 1, d 7 and 28 in Exp. 2, and d 15 in Exp. 3. In Exp. 1, 2, and 3, 90, 100, and 15 crossbred (GenetiPorc USA, LLC, Morris, MN) pigs were weaned at 24+/-0.5, 18, and 17 d of age (6.45, 5.47, and 5.3 kg avg initial BW), respectively, and allotted to dietary treatment based on initial weight, sex, and litter. A Phase 1 nursery diet was fed as crumbles from d 0 to 14 in Exp. 1, 2, and 3, and a Phase 2 nursery diet was fed as pellets from d 15 to 28 in Exp. 1 and 2. The Phase 1 and Phase 2 basal diets were supplemented with 100 ppm Zn as ZnSO4. Both dietary phases contained the same five dietary treatments: 150 ppm additional Zn as zinc oxide (ZnO), 500 ppm added Zn as ZnO, 500 ppm added Zn as a Zn-amino acid complex (Availa-Zn 100), 500 ppm added Zn as a Zn-polysaccharide complex (SQM-Zn), and 3,000 ppm added Zn as ZnO. Overall in Exp. 1, pigs fed 500 ppm added Zn as SQM-Zn or 3,000 ppm added Zn as ZnO had greater ADG (P < 0.05) than pigs fed 150 ppm, 500 ppm added Zn as ZnO, or 500 ppm added Zn as Availa-Zn 100 (0.44 and 0.46 kg/d vs 0.35, 0.38, and 0.33 kg/d respectively). Overall in Exp. 2, pigs fed 3,000 ppm added Zn as ZnO had greater (P < 0.05) ADG and ADFI than pigs fed any other dietary treatment. On d 14 of Exp. 1 and d 28 of Exp. 2, pigs fed 3,000 ppm added Zn as ZnO had higher (P < 0.05) plasma Zn concentrations than pigs on any other treatment. In Exp. 3, fecal, urinary, and liver Zn concentrations were greatest (P < 0.05) in pigs fed 3,000 ppm added Zn as ZnO. On d 10 to 15 of Exp. 3, pigs fed 3,000 ppm added Zn as ZnO had the most negative Zn balance (P < 0.05) compared with pigs fed the other four dietary Zn treatments. In conclusion, feeding

  5. Quantifying the performance of in vivo portal dosimetry in detecting four types of treatment parameter variations

    SciTech Connect

    Bojechko, C.; Ford, E. C.

    2015-12-15

    Purpose: To quantify the ability of electronic portal imaging device (EPID) dosimetry used during treatment (in vivo) in detecting variations that can occur in the course of patient treatment. Methods: Images of transmitted radiation from in vivo EPID measurements were converted to a 2D planar dose at isocenter and compared to the treatment planning dose using a prototype software system. Using the treatment planning system (TPS), four different types of variability were modeled: overall dose scaling, shifting the positions of the multileaf collimator (MLC) leaves, shifting of the patient position, and changes in the patient body contour. The gamma pass rate was calculated for the modified and unmodified plans and used to construct a receiver operator characteristic (ROC) curve to assess the detectability of the different parameter variations. The detectability is given by the area under the ROC curve (AUC). The TPS was also used to calculate the impact of the variations on the target dose–volume histogram. Results: Nine intensity modulation radiation therapy plans were measured for four different anatomical sites consisting of 70 separate fields. Results show that in vivo EPID dosimetry was most sensitive to variations in the machine output, AUC = 0.70 − 0.94, changes in patient body habitus, AUC = 0.67 − 0.88, and systematic shifts in the MLC bank positions, AUC = 0.59 − 0.82. These deviations are expected to have a relatively small clinical impact [planning target volume (PTV) D{sub 99} change <7%]. Larger variations have even higher detectability. Displacements in the patient’s position and random variations in MLC leaf positions were not readily detectable, AUC < 0.64. The D{sub 99} of the PTV changed by up to 57% for the patient position shifts considered here. Conclusions: In vivo EPID dosimetry is able to detect relatively small variations in overall dose, systematic shifts of the MLC’s, and changes in the patient habitus. Shifts in the

  6. Rabbit dietary supplementation with pale purple coneflower. 1. Effects on the reproductive performance and immune parameters of does.

    PubMed

    Dabbou, S; Rotolo, L; Kovitvadhi, A; Bergagna, S; Dezzutto, D; Barbero, R; Rubiolo, P; Schiavone, A; De Marco, M; Helal, A N; Zoccarato, I; Gasco, L

    2016-07-01

    Echinacea pallida (EPAL), also known as pale purple coneflower, is a herbaceous flowering plant with immune-enhancement and antioxidative properties. The effect of EPAL on the reproductive performance, serum biochemistry and haematological parameters of rabbit does has been studied here. A total of 100, 21-week-old Grimaud rabbit does, were randomly assigned to two groups. One group was fed a basal diet supplemented with 3 g EPAL/kg diet (Echinacea group, E), while the other was fed the basal diet without the supplementation (control group, C). The reproductive performance of the does was not affected by the treatment (P>0.05). The haematological parameters of pregnant rabbits showed that there was no interaction between gestation day and treatment. The EPAL supplementation induced a reduction (-47.3%) in the basophil cell rate (0.55% and 0.29%, for the control and treatment groups, respectively; P=0.049). The gestation day significantly affected most of the haematological parameters (P<0.05). The white blood cell counts declined progressively after day 14. The mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red cell distribution width, mean platelet volume and eosinophils increased steadily throughout the study, and reached a maximum value on day 28. The red blood cells, haemoglobin, haematocrit, mean corpuscular volume and neutrophils increased slightly up to day 14, and then subsequently decreased progressively until day 28. The lymphocytes and platelet distribution width decreased until day 14, and then increased to a maximum value on day 28. No significant effect of gestation day or treatment was observed on the blood serum chemistry. As far as the immune parameters are concerned, no significant differences were observed between groups, while a significant effect of gestation day was observed for lysozymes (6.02 v. 7.99 v. 1.91; for 0, 14 and 28 days, respectively; P=0.014). In conclusion, a lack of effect of EPAL has been observed

  7. Exploring medical diagnostic performance using interactive, multi-parameter sourced receiver operating characteristic scatter plots.

    PubMed

    Moore, Hyatt E; Andlauer, Olivier; Simon, Noah; Mignot, Emmanuel

    2014-04-01

    Determining diagnostic criteria for specific disorders is often a tedious task that involves determining optimal diagnostic thresholds for symptoms and biomarkers using receiver-operating characteristic (ROC) statistics. To help this endeavor, we developed softROC, a user-friendly graphic-based tool that lets users visually explore possible ROC tradeoffs. The software requires MATLAB installation and an Excel file containing threshold symptoms/biological measures, with corresponding gold standard diagnoses for a set of patients. The software scans the input file for diagnostic and symptom/biomarkers columns, and populates the graphical-user-interface (GUI). Users select symptoms/biomarkers of interest using Boolean algebra as potential inputs to create diagnostic criteria outputs. The software evaluates subtests across the user-established range of cut-points and compares them to a gold standard in order to generate ROC and quality ROC scatter plots. These plots can be examined interactively to find optimal cut-points of interest for a given application (e.g. sensitivity versus specificity needs). Split-set validation can also be used to set up criteria and validate these in independent samples. Bootstrapping is used to produce confidence intervals. Additional statistics and measures are provided, such as the area under the ROC curve (AUC). As a testing set, softROC is used to investigate nocturnal polysomnogram measures as diagnostic features for narcolepsy. All measures can be outputted to a text file for offline analysis. The softROC toolbox, with clinical training data and tutorial instruction manual, is provided as supplementary material and can be obtained online at http://www.stanford.edu/~hyatt4/software/softroc or from the open source repository at http://www.github.com/informaton/softroc. PMID:24561350

  8. Performance and emission parameters of single cylinder diesel engine using castor oil bio-diesel blended fuels

    NASA Astrophysics Data System (ADS)

    Rahimi, A.; Ghobadian, B.; Najafi, G.; Jaliliantabar, F.; Mamat, R.

    2015-12-01

    The purpose of this study is to investigate the performance and emission parameters of a CI single cylinder diesel engine operating on biodiesel-diesel blends (B0, B5, B10, B15 and E20: 20% biodiesel and 80% diesel by volume). A reactor was designed, fabricated and evaluated for biodiesel production. The results showed that increasing the biodiesel content in the blend fuel will increase the performance parameters and decrease the emission parameters. Maximum power was detected for B0 at 2650 rpm and maximum torque was belonged to B20 at 1600 rpm. The experimental results revealed that using biodiesel-diesel blended fuels increased the power and torque output of the engine. For biodiesel blends it was found that the specific fuel consumption (sfc) was decreased. B10 had the minimum amount for sfc. The concentration of CO2 and HC emissions in the exhaust pipe were measured and found to be decreased when biodiesel blends were introduced. This was due to the high oxygen percentage in the biodiesel compared to the net diesel fuel. In contrast, the concentration of CO and NOx was found to be increased when biodiesel is introduced.

  9. Business-objective-directed, constraint-based multivariate optimization of high-performance liquid chromatography operational parameters.

    PubMed

    Chester, T L

    2003-10-24

    The goal of a separation can be defined in terms of business needs. One goal often used is to provide the required separation in minimum time, but many other goals are also possible. These include maximizing resolution within an analysis-time limit, or minimizing the overall cost. The remaining requirements of the separation can be applied as constraints in the optimization of the goal. We will present a flexible, business-objective-based approach for optimizing the operational parameters of high performance liquid chromatography (HPLC) methods. After selecting the stationary phase and the mobile-phase components, several isocratic experiments are required to build a retention model. Multivariate optimization is performed, within the model, to find the best combination of the parameters being varied so that the result satisfies the goal to the fullest extent possible within the constraints. Interdependencies of parameters can be revealed by plotting the loci of optimal variable values or the function being optimized against a constraint. We demonstrate the concepts with a model separation originally requiring a 54 min analysis time. Multivariate optimization reduces the predicted analysis time to as short as 8 min, depending on the goals and constraints specified. PMID:14601838

  10. Stair Descending Exercise Using a Novel Automatic Escalator: Effects on Muscle Performance and Health-Related Parameters

    PubMed Central

    Paschalis, Vassilis; Theodorou, Anastasios A.; Panayiotou, George; Kyparos, Antonios; Patikas, Dimitrios; Grivas, Gerasimos V.; Nikolaidis, Michalis G.; Vrabas, Ioannis S.

    2013-01-01

    A novel automatic escalator was designed, constructed and used in the present investigation. The aim of the present investigation was to compare the effect of two repeated sessions of stair descending versus stair ascending exercise on muscle performance and health-related parameters in young healthy men. Twenty males participated and were randomly divided into two equal-sized groups: a stair descending group (muscle-damaging group) and a stair ascending group (non-muscle-damaging group). Each group performed two sessions of stair descending or stair ascending exercise on the automatic escalator while a three week period was elapsed between the two exercise sessions. Indices of muscle function, insulin sensitivity, blood lipid profile and redox status were assessed before and immediately after, as well as at day 2 and day 4 after both exercise sessions. It was found that the first bout of stair descending exercise caused muscle damage, induced insulin resistance and oxidative stress as well as affected positively blood lipid profile. However, after the second bout of stair descending exercise the alterations in all parameters were diminished or abolished. On the other hand, the stair ascending exercise induced only minor effects on muscle function and health-related parameters after both exercise bouts. The results of the present investigation indicate that stair descending exercise seems to be a promising way of exercise that can provoke positive effects on blood lipid profile and antioxidant status. PMID:23437093

  11. Impact on the Spatial Resolution Performance of a Monolithic Crystal PET Detector Due to Different Sensor Parameters.

    PubMed

    Li, Xiaoli; Lockhart, Cate; Lewellen, Tom K; Miyaoka, Robert S

    2009-10-24

    The performance characteristics of a monolithic crystal PET detector utilizing a novel sensor on the entrance surface (SES) design is reported. To facilitate this design, we propose to utilize a 2D silicon photomultiplier (SiPM) array device. SiPMs are a form of Geiger-Muller mode avalanche photodiodes (GMAPD) that can provide signal gain similar to a photomultiplier tube (PMT). Since these devices are still under active development, their performance parameters are changing. Using a multi-step simulation process, we investigated how different SiPM parameters affect the performance of a monolithic crystal PET detector. These parameters include gain variability between different channels; gain instability; and dark count noise. The detector simulated was a 49.6 mm by 49.6 mm by 15 mm LYSO crystal detector readout by a 16 by 16 array of 2.8 mm by 2.8 mm SiPM elements. To reduce the number of signal channels that need to be collected, the detector utilizes row-column summing. A statistics based positioning method is used for event positioning and depth of interaction (DOI) decoding. Of the variables investigated, the dark count noise had the largest impact on the intrinsic spatial resolution. Gain differences of 5-10% between detector calibration and detector testing had a modest impact on the intrinsic spatial resolution performance and led to a slight bias in positioning. There was no measurable difference with a gain variability of up to 25% between the individual SiPM channels. Based upon these results we are planning to cool our detectors below room temperature to reduce dark count noise and to actively control the temperature of the SiPMs to reduce drifts in gain over time. PMID:20806058

  12. Performance analysis of short-range NLOS UV communication system using Monte Carlo simulation based on measured channel parameters.

    PubMed

    Luo, Pengfei; Zhang, Min; Han, Dahai; Li, Qing

    2012-10-01

    The research presented in this paper is a performance study of short-range NLOS ultraviolet (UV) communication system, using a Monte-Carlo-based system-level model, in which the channel parameters, such as the path loss and the background noise are experimentally measured using an outdoor UV communication test-bed. Various transceiver geometry and background noise condition are considered. Furthermore, 4 modulation schemes are compared, which provides an insight into the performance prediction and the system trade-offs among the path loss, the optical power, the distance, the link geometry, the bit rate and the bit error rate. Finally, advices are given on UV system design and performance improvement. PMID:23188312

  13. Influence of fiber parameters on the performance of a SCM_QPSK transmission system

    NASA Astrophysics Data System (ADS)

    Togneri, Arnaldo P.; Segatto, Marcelo E. V.; Pontes, Maria José; Giraldi, Maria Thereza M. R.; Costa, J. C. W. A.

    2006-04-01

    The performance of a Subcarrier Multiplexing (SCM) optical fibre system using QPSK modulation is analysed in this paper. Our results will show that it is possible to increase the system bandwidth by controlling the input optical power. Various fibre dispersion values and subcarrier channel spacing are used in order to check the bandwidth increase proportional to the optical power. The transmission bandwidth was studied in terms of fibre dispersion and input optical power. The frequency response was measured and computed. Limitations imposed by nonlinear distortions mainly due to interplay between dispersion and self-phase modulation are verified as well. The analysis to the SCM_QPSK transmission system such as the subcarrier channel spacing, signal input power, available frequency bandwidth under the fibre specifications and system conditions operation will be explored in a specific application. It means applying this technique after setting the requirements necessary to the operation of an optical ground-wire (OPGW) already installed system. The results showed an increase of the transmission bandwidth as the optical power increases. For QPSK modulation, power penalties smaller than 1 dB were obtained only for channel spacing higher than 1.2 multiplied by the symbol rate. Experimental measurements obtained in the literature were used to validate our results. Eye opening and received eye diagrams will be evaluated in order to have a simpler receiver layout and make the entire system more reliable, since it will become more robust to error disturbance, maintenance is easier and system upgrades will be facilitated.

  14. Assessing seal performance and parameter sensitivity with a full-shaft model

    SciTech Connect

    Reeves, M.; Fryar, D.G.; Statham, W.H.; Knowles, M.K.

    1998-05-01

    The Waste Isolation Pilot Plant (WIPP) is a planned geologic repository for permanent disposal of transuranic waste generated by US government defense programs. Located near Carlsbad in southeastern New Mexico, the facility`s disposal regions are mined from the bedded salt of the Salado Formation at a depth of approximately 652 m. Four shafts service the operational needs of the facility for air intake, exhaust, waste handling and salt handling. These shafts range in diameter from 3.5 to 6.1 m and extend from the ground surface to the repository. During repository closure, following an operational life of approximately 50 years, these shafts will be sealed in accordance with an acceptable design. Under contract to the US Department of Energy (DOE), the Repository Isolation Systems Department (RISD) of Sandia National Laboratories has developed a design for the WIPP shaft sealing system. This design has been reviewed by the US Environmental Protection Agency (EPA) as part of the 1996 WIPP Compliance Certification Application (CCA). An effective shaft sealing system for the WIPP will limit liquid and gas flows, and permanently prevent the migration of radiological or other hazardous constituents through the sealed shafts from repository to accessible environment. Because of these performance objectives, a significant effort has been directed toward evaluation of the seal design. Whereas RISD (1996) provides a comprehensive discussion, this paper focuses on only one aspect of the evaluation effort, namely a full shaft, fluid flow model.

  15. The Sensitivity of Precooled Air-Breathing Engine Performance to Heat Exchanger Design Parameters

    NASA Astrophysics Data System (ADS)

    Webber, H.; Bond, A.; Hempsell, M.

    The issues relevant to propulsion design for Single Stage To Orbit (SSTO) vehicles are considered. In particular two air- breathing engine concepts involving precooling are compared; SABRE (Synergetic Air-Breathing and Rocket Engine) as designed for the Skylon SSTO launch vehicle, and a LACE (Liquid Air Cycle Engine) considered in the 1960's by the Americans for an early generation spaceplane. It is shown that through entropy minimisation the SABRE has made substantial gains in performance over the traditional LACE precooled engine concept, and has shown itself as the basis of a viable means of realising a SSTO vehicle. Further, it is demonstrated that the precooler is a major source of thermodynamic irreversibility within the engine cycle and that further reduction in entropy can be realised by increasing the heat transfer coefficient on the air side of the precooler. If this were to be achieved, it would improve the payload mass delivered to orbit by the Skylon launch vehicle by between 5 and 10%.

  16. Installation methods to perform subsea tie-in of pipelines: Sensitivity analysis versus design parameters

    SciTech Connect

    Radicioni, A.; Corbetta, G.; D`Aloisio, G.; Bjoerset, A.

    1995-12-31

    The development of a subsea field requires among other things a definition of the methods for pipeline, flow-lines and umbilicals laying and tie-in. The selection of a particular method is the result of a detailed analysis where advantages and drawbacks are highlighted arid weighted versus global costs and reliability. During the conceptual study for the assessment of possible different solutions, engineering tools can be used as a time saving solution for the selection of the best installation method. Different installation methods to perform tie-in have been analyzed and simplified mathematical models have been used to better understand the behavior of the pipeline during its installation. The following methods were considered: first-end pull-in, second-end pull-in, deflect-to-connect. This paper summarizes the results achieved and describes the design tools prepared during the development of the subject sensitivity analysis; such tools can be used as a helpful basis for the selection or design of a tie-in system.

  17. Influence of Feedback Parameters on Performance of a Vibrotactile Balance Prosthesis

    PubMed Central

    Goodworth, Adam D.; Wall, Conrad; Peterka, Robert J.

    2009-01-01

    We investigated the influence of feedback conditions on the effectiveness of a balance prosthesis. The balance prosthesis used an array of 12 tactile vibrators (tactors) placed on the anterior and posterior surfaces of the torso to provide body orientation feedback related to several different combinations of angular position and velocity of body sway in the sagittal plane. Control tests were performed with no tactor activation. Body sway was evoked in subjects with normal sensory function by rotating the support surface upon which subjects stood with eyes closed. Body sway was analyzed by computing root-mean-square sway measures and by a frequency-response function analysis that characterized the amplitude (gain) and timing (phase) of body sway over a frequency range of 0.017 to 2.2 Hz. Root-mean-square sway measures showed a reduction of surface stimulus evoked body sway for most vibrotactile feedback settings compared to control conditions. However, frequency-response function analysis showed that the sway reduction was due primarily to a reduction in sway below about 0.5 Hz, whereas there was actually an enhancement of sway above 0.6 Hz. Finally, we created a postural model that accounted for the experimental results and gave insight into how vibrotactile information was incorporated into the postural control system. PMID:19497820

  18. Determination of Polymer Additives-Antioxidants, Ultraviolet Stabilizers, Plasticizers and Photoinitiators in Plastic Food Package by Accelerated Solvent Extraction Coupled with High-Performance Liquid Chromatography.

    PubMed

    Li, Bo; Wang, Zhi-Wei; Lin, Qin-Bao; Hu, Chang-Ying; Su, Qi-Zhi; Wu, Yu-Mei

    2015-07-01

    An analytical method for the quantitative determination of 4 antioxidants, 9 ultraviolet (UV) stabilizers, 12 phthalate plasticizers and 2 photoinitiators in plastic food package using accelerated solvent extraction (ASE) coupled with high-performance liquid chromatography-photodiode array detector (HPLC-PDA) has been developed. Parameters affecting the efficiency in the process such as extraction and chromatographic conditions were studied in order to determine operating conditions. The analytical method of ASE-HPLC showed good linearity with good correlation coefficients (R ≥ 0.9833). The limits of detection and quantification were between 0.03 and 0.30 µg mL(-1) and between 0.10 and 1.00 µg mL(-1) for 27 analytes. Average spiked recoveries for most analytes in samples were >70.4% at 10, 20 and 40 µg g(-1) spiked levels, except UV-9 and Irganox 1010 (58.6 and 64.0% spiked at 10 µg g(-1), respectively), the relative standard deviations were in the range from 0.4 to 15.4%. The methodology has been proposed for the analysis of 27 polymer additives in plastic food package. PMID:25472804

  19. Additive effects of growth promoting technologies on performance of grazing steers and economics of the wheat pasture enterprise.

    PubMed

    Beck, P; Hess, T; Hubbell, D; Hufstedler, G D; Fieser, B; Caldwell, J

    2014-03-01

    This research was designed to evaluate the effect of monensin (Elanco Animal Health, Greenfield, IN) supplementation via mineral or pressed protein block with or without a growth-promoting implant on performance of steers grazing wheat pasture in Arkansas over 2 yr. Preconditioned steers (n = 360, BW = 238 ± 5.1 kg) grazed 15 1.6-ha wheat pastures in the fall (n = 60 steers each fall, stocking rate of 2.5 steers/ha) or 30 0.8-ha wheat pastures in the spring (n = 120 steers each spring, stocking rate of 5 steers/ha). Steers in each pasture were given free-choice access to nonmedicated mineral (CNTRL; MoorMan's WeatherMaster Range Minerals A 646AAA; ADM Alliance Nutrition, Inc., Quincy, IL), or were supplemented with monensin (Elanco Animal Health, Greenfield, IN) via mineral containing 1.78 g monensin/kg (RMIN; MoorMan's Grower Mineral RU-1620 590AR; ADM Alliance Nutrition, Inc.), or pressed protein block containing 0.33 g monensin/kg (RBLCK; MoorMan's Mintrate Blonde Block RU; ADM Alliance Nutrition, Inc.). Additionally, one-half of the steers in each pasture were implanted (IMPL) with 40 mg trenbolone acetate and 8 mg estradiol (Component TE-G with Tylan; Elanco Animal Health). There was no interaction (P ≥ 0.71) between supplement treatment and growth-promoting implants, and ADG for RMIN and RBLCK were increased (P < 0.01) over CNTRL by 0.07 to 0.09 kg/d, respectively. Implanting steers with Component TE-G increased (P < 0.01) ADG by 0.14 kg/d. The combination of these growth-promoting technologies are a cost-effective means of increasing beef production by 22% without increasing level of supplementation or pasture acreage. Utilizing ionophores and implants together for wheat pasture stocker cattle decreased cost of gain by 26%. Utilizing both IMPL and monensin increased net return by $30 to $54/steer for RMIN or $18 to $43/steer for RBLCK compared with UNIMPL CNTRL at Low and High values of BW gain, respectively. PMID:24492552

  20. Effect of hot temperatures on the hematological parameters, health and performance of calves

    NASA Astrophysics Data System (ADS)

    Broucek, Jan; Kisac, Peter; Uhrincat, Michael

    2009-03-01

    The objective of this paper was to evaluate the effects of high temperatures on calves. The hypothesis that the red and white blood cells, health, and performance of calves would be influenced by the temperature period at birth and gender was tested. Sixty-three Holstein calves were used. They were reared in individual hutches from the second day of life to weaning at the age of 8 weeks. All calves were allotted to treatment groups according to the temperature period at birth: moderate temperature period 1 (MT1), high temperature period (HT), moderate temperature period 2 (MT2). The same conditions of nutrition were ensured. We recorded 62 summer days and 14 tropical days during HT. Sixty-six days with a value above 72.0 of the temperature-humidity index (THI) and 26 with values greater than 78.0 were found. No significant differences were found in red blood cells with the exception of hemoglobin between MT1 and MT2 ( p = 0.031) during the 8th week. Significant differences were observed among treatment groups in the percentage of eosinophiles during the 6th week ( p = 0.044). The HT calves had the least body weight from the first week to weaning ( p = 0.053) and the highest water consumption ( p = 0.042). The results emphasize the ability of dairy calves to maintain homeostasis during prolonged periods of heat stress. The exposure to high temperatures resulted only in a significant decrease of starter concentrate consumption and reduced growth.

  1. Effects of liquid aluminum chloride additions to poultry litter on broiler performance, ammonia emissions, soluble phosphorus, total volatile Fatty acids, and nitrogen contents of litter.

    PubMed

    Choi, I H; Moore, P A

    2008-10-01

    Recent studies have shown that the use of aluminum sulfate [alum, Al2(SO4)3.14H2O] and aluminum chloride (AlCl3) additions to animal manures are more effective than other chemicals in reducing ammonia (NH3) emissions and P solubility. Although the use of Al2(SO4)3.14H2O has been intensively used in the poultry industry for many years, no research has been conducted to evaluate the effect of liquid AlCl3 on these parameters. The objectives of this study were to determine the effects of applying liquid AlCl3 to poultry litter on 1) broiler performance, 2) NH3 fluxes, and 3) litter chemical characteristics, including soluble reactive P, total volatile fatty acids, and N content. Eight hundred broiler chicks were placed into 16 floor pens (50 birds/pen) in a single house for 6 wk. Liquid AlCl3 treatments were sprayed on the litter surface at rates of 100, 200, and 300 g of liquid AlCl3/kg of litter; un-treated litter served as controls. At the 2 lower rates, liquid AlCl3 treatments tended to improve weight gain and feed intake but had no effect on feed conversion or mortality, whereas the higher rate (300 g/kg of litter) had a negative effect on intake. Application of 100, 200, and 300 g of liquid AlCl3 reduced NH3 fluxes by 63, 76, and 76% during the 6-wk period, respectively, compared with the controls. Liquid AlCl3 additions reduced litter soluble reactive P contents by 24, 30, and 36%, respectively, at the low, medium, and high rates. Total volatile fatty acid contents (odor precursors) in litter were reduced by 20, 50, and 51%, respectively, with 100, 200, and 300 g of liquid AlCl3/kg of litter. Liquid AlCl3 additions increased total N, inorganic N, and plant available N contents in litter. These results indicate that liquid AlCl3 additions at the lower rates can provide significant positive environmental benefits to broiler operations. PMID:18809856

  2. Assessing the performance of community-available global MHD models using key system parameters and empirical relationships

    NASA Astrophysics Data System (ADS)

    Gordeev, E.; Sergeev, V.; Honkonen, I.; Kuznetsova, M.; Rastätter, L.; Palmroth, M.; Janhunen, P.; Tóth, G.; Lyon, J.; Wiltberger, M.

    2015-12-01

    Global magnetohydrodynamic (MHD) modeling is a powerful tool in space weather research and predictions. There are several advanced and still developing global MHD (GMHD) models that are publicly available via Community Coordinated Modeling Center's (CCMC) Run on Request system, which allows the users to simulate the magnetospheric response to different solar wind conditions including extraordinary events, like geomagnetic storms. Systematic validation of GMHD models against observations still continues to be a challenge, as well as comparative benchmarking of different models against each other. In this paper we describe and test a new approach in which (i) a set of critical large-scale system parameters is explored/tested, which are produced by (ii) specially designed set of computer runs to simulate realistic statistical distributions of critical solar wind parameters and are compared to (iii) observation-based empirical relationships for these parameters. Being tested in approximately similar conditions (similar inputs, comparable grid resolution, etc.), the four models publicly available at the CCMC predict rather well the absolute values and variations of those key parameters (magnetospheric size, magnetic field, and pressure) which are directly related to the large-scale magnetospheric equilibrium in the outer magnetosphere, for which the MHD is supposed to be a valid approach. At the same time, the models have systematic differences in other parameters, being especially different in predicting the global convection rate, total field-aligned current, and magnetic flux loading into the magnetotail after the north-south interplanetary magnetic field turning. According to validation results, none of the models emerges as an absolute leader. The new approach suggested for the evaluation of the models performance against reality may be used by model users while planning their investigations, as well as by model developers and those interesting to quantitatively

  3. A Weibull statistics-based lignocellulose saccharification model and a built-in parameter accurately predict lignocellulose hydrolysis performance.

    PubMed

    Wang, Mingyu; Han, Lijuan; Liu, Shasha; Zhao, Xuebing; Yang, Jinghua; Loh, Soh Kheang; Sun, Xiaomin; Zhang, Chenxi; Fang, Xu

    2015-09-01

    Renewable energy from lignocellulosic biomass has been deemed an alternative to depleting fossil fuels. In order to improve this technology, we aim to develop robust mathematical models for the enzymatic lignocellulose degradation process. By analyzing 96 groups of previously published and newly obtained lignocellulose saccharification results and fitting them to Weibull distribution, we discovered Weibull statistics can accurately predict lignocellulose saccharification data, regardless of the type of substrates, enzymes and saccharification conditions. A mathematical model for enzymatic lignocellulose degradation was subsequently constructed based on Weibull statistics. Further analysis of the mathematical structure of the model and experimental saccharification data showed the significance of the two parameters in this model. In particular, the λ value, defined the characteristic time, represents the overall performance of the saccharification system. This suggestion was further supported by statistical analysis of experimental saccharification data and analysis of the glucose production levels when λ and n values change. In conclusion, the constructed Weibull statistics-based model can accurately predict lignocellulose hydrolysis behavior and we can use the λ parameter to assess the overall performance of enzymatic lignocellulose degradation. Advantages and potential applications of the model and the λ value in saccharification performance assessment were discussed. PMID:26121186

  4. Multilayer insulation (MLI) in the Superconducting Super Collider: A practical engineering approach to physical parameters governing MLI thermal performance

    SciTech Connect

    Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.

    1989-03-01

    Multilayer insulation (MLI) is employed in cryogenic devices to control the heat load of those devices. The physics defining the thermal performance of an MLI system is extremely complex due to the thermal dynamics of numerous interdependent parameters which in themselves contribute differently depending on whether boundary conditions are transient or steady-state. The Multilayer Insulation system for the Superconducting Super Collider (SSC) consists of full cryostat length assemblies of aluminized polyester film, fabricated in the form of blankets, and installed as blankets to the 4.5K cold mass, and the 20K and 80K thermal radiation shields. Approximately 40,000 blankets will be required in the 10,000 cryogenic devices comprising the SSC accelerator. Each blanket will be nearly 56 feet long by 6 feet wide and will consist of as many as 32 reflective and 31 spacer layers of material. Discussed are MLI material choices, and the physical parameters which contribute to the operational performance of MLI systems. Disclosed is a method for fabricating MLI blankets by employing a large diameter winding mandrel having a circumference sufficient for the required blanket length. The blanket fabrication method assures consistency in mass produced MLI blankets by providing positive control of the dimensional parameters which contribute to the MLI blanket thermal performance. The fabrication method can be used to mass produce prefabricated MLI blankets that by virtue of the product have inherent features of dimensional stability, three-dimensional uniformity, controlled layer density, layer-to-layer registration, interlayer cleanliness, and interlayer material to accommodate thermal contraction differences. 9 refs., 4 figs., 2 tabs.

  5. Static internal performance of convergent single-expansion-ramp nozzles with various combinations of internal geometric parameters

    NASA Technical Reports Server (NTRS)

    Bare, E. Ann; Capone, Francis J.

    1989-01-01

    An investigation was conducted in the Static Test Facility of the Langley 16-Foot Transonic Tunnel to determine the effects of five geometric design parameters on the internal performance of convergent single expansion ramp nozzles. The effects of ramp chordal angle, initial ramp angle, flap angle, flap length, and ramp length were determined. All nozzles tested has a nominally constant throat area and aspect ratio. Static pressure distributions along the centerlines of the ramp and flap were also obtained for each configuration. Nozzle pressure ratio was varied up to 10.0 for all configurations.

  6. Assessment of a phytogenic feed additive (Digestarom P.E.P. MGE) on growth performance, processing yield, fillet composition, and survival of channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of feed additives to improve production has been identified as an important area for development in aquaculture. A study was conducted to investigate the effects of a phytogenic feed additive (Digestarom® P.E.P. MGE) on growth performance, processing yield, fillet composition, and survival ...

  7. Optimizing the external optical cavity parameters for performance improvement of a fiber grating Fabry-Perot laser

    NASA Astrophysics Data System (ADS)

    Hisham, Hisham Kadhum; Abas, Ahmad Fauzi; Amouzad Mahdiraji, Ghafour; Mahdi, Mohd Adzir; Mahamd Adikan, Faisal Rafiq

    2015-04-01

    The effects of the external optical cavity parameters (external optical cavity length ( L ext), amplitude coupling ( C o) and anti-reflection coating (ARC) reflectivity coefficients) on the noise and modulation spectra of a fiber grating Fabry-Perot laser are numerically analyzed for designing a laser that operates in strong feedback regime (Regime V). Fiber Bragg grating (FBG) is used as a wavelength selective element to control the properties of the laser output by controlling the external optical feedback (OFB) level. The study is performed by modifying a set of rate equations that are solved by considering the effects of external OFB and ambient temperature ( T) variations. We proposed a model to calculate the temperature dependence (TD) of laser characteristics according to the TD of laser parameters. An accurate analytical expression for the TD of threshold carrier density ( N th,fe) has been derived. The TD of N th,fe was calculated according to the TD of laser cavity parameters instead of using well-known empirical Pankove relationship via the use of characteristics temperature ( T o) and current ( I o). Results show that the optimum external fiber length ( L ext) is 3.1 cm. Also, it is shown that ARC with reflectivity value of 1 × 10-2 is sufficient for the laser to operate at low noise, good modulation response, and low fabrication complexity.

  8. Influence of Input Parameters on the Performance of an Artificial Neural Network Used to Detect Structural Damage

    NASA Astrophysics Data System (ADS)

    Villalba, Jesus Daniel; Gomez, Ivan Dario; Laier, Jose Elias

    2010-09-01

    Structural damage detection is a very important research topic and, currently, there are not specific tools to solve it. A promising tool that can be used is the artificial neural network, ANN, which can deal with hard problems. This paper uses a back propagation ANN with Bayesian regularization training to locate and quantify damage in truss structures. The input parameters corresponded to natural frequencies combined with shape modes, modal flexibilities or modal strain energies. The ANN was trained by considering only simple damage scenarios, random multiple damage scenarios or a combination of them. The results are shown in terms of the percentage of cases in which the ANN trained achieves a determined performance in assessing both the damage extension and the presence of damaged elements. The best performance for the ANN is obtained by using modal strain energies and multiple damage scenarios.

  9. Particle-in-cell based parameter study of 12-cavity, 12-cathode rising-sun relativistic magnetrons for improved performance

    NASA Astrophysics Data System (ADS)

    Majzoobi, A.; Joshi, R. P.; Neuber, A. A.; Dickens, J. C.

    2015-10-01

    Particle-in-cell simulations are performed to analyze the efficiency, output power and leakage currents in a 12-Cavity, 12-Cathode rising-sun magnetron with diffraction output (MDO). The central goal is to conduct a parameter study of a rising-sun magnetron that comprehensively incorporates performance enhancing features such as transparent cathodes, axial extraction, the use of endcaps, and cathode extensions. Our optimum results demonstrate peak output power of about 2.1 GW, with efficiencies of ˜70% and low leakage currents at a magnetic field of 0.45 Tesla, a 400 kV bias with a single endcap, for a range of cathode extensions between 3 and 6 centimeters.

  10. Particle-in-cell based parameter study of 12-cavity, 12-cathode rising-sun relativistic magnetrons for improved performance

    SciTech Connect

    Majzoobi, A.; Joshi, R. P. Neuber, A. A.; Dickens, J. C.

    2015-10-15

    Particle-in-cell simulations are performed to analyze the efficiency, output power and leakage currents in a 12-Cavity, 12-Cathode rising-sun magnetron with diffraction output (MDO). The central goal is to conduct a parameter study of a rising-sun magnetron that comprehensively incorporates performance enhancing features such as transparent cathodes, axial extraction, the use of endcaps, and cathode extensions. Our optimum results demonstrate peak output power of about 2.1 GW, with efficiencies of ∼70% and low leakage currents at a magnetic field of 0.45 Tesla, a 400 kV bias with a single endcap, for a range of cathode extensions between 3 and 6 centimeters.

  11. Use of Vitamin D3 and Its Metabolites in Broiler Chicken Feed on Performance, Bone Parameters and Meat Quality

    PubMed Central

    Garcia, Ana Flávia Quiles Marques; Murakami, Alice Eiko; Duarte, Cristiane Regina do Amaral; Rojas, Iván Camilo Ospina; Picoli, Karla Paola; Puzotti, Maíra Mangili

    2013-01-01

    The objective of this experiment was to assess the use of different vitamin D metabolites in the feed of broiler chickens and the effects of the metabolites on performance, bone parameters and meat quality. A total of 952 one-day-old male broiler chicks were distributed in a completely randomised design, with four treatments, seven replicates and 34 birds per experimental unit. The treatments consisted of four different sources of vitamin D included in the diet, D3, 25(OH)D3, 1,25(OH)2D3, and 1α(OH)D3, providing 2000 and 1600 IU of vitamin D in the starter (1 to 21 d) and growth phases (22 to 42 d), respectively. Mean weight, feed:gain and weight gain throughout the rearing period were less in animals fed 1α(OH)D3 when compared with the other treatments (p<0.05). No significant differences were noted among the treatments (p>0.05) for various bone parameters. Meat colour differed among the treatments (p>0.05). All of the metabolites used in the diets, with the exception of 1α(OH)D3, can be used for broiler chickens without problems for performance and bone quality, however, some aspects of meat quality were affected. PMID:25049804

  12. Interactions between minimum run time, modifier concentration, and efficiency parameters in a high performance liquid chromatography separation.

    PubMed

    Chester, T L; Stalcup, A M

    2011-01-14

    We modeled and studied the separation of uracil, nicotinamide, resorcinol, theobromine, theophylline, and caffeine on four C-18 columns of different lengths packed with the same stationary phase using water/methanol mobile phase at one temperature. Predictions of retention times and peak widths were compared with experimental results and were found to be sufficiently accurate for performing optimization calculations. With limits set on the required resolution and on maximum values for pressure and flow rate, calculations were performed for numerous virtual column lengths seeking the smallest possible analysis time for each length while allowing methanol concentration and flow rate to vary as required to minimize run time. Predictions were experimentally verified for the column lengths actually available. These calculations revealed the dependence of best-possible analysis time on column length, modifier concentration, flow rate, and pressure for the real system that was modeled, and provided insight into parameter interactions with respect to analysis times meeting the needs and limits specified. We show that when these parameters are considered in concert, rather than individually, conventional guidelines regarding setting their values may not always lead to the optimum. PMID:21130461

  13. An improved cognitive model of the Iowa and Soochow Gambling Tasks with regard to model fitting performance and tests of parameter consistency

    PubMed Central

    Dai, Junyi; Kerestes, Rebecca; Upton, Daniel J.; Busemeyer, Jerome R.; Stout, Julie C.

    2015-01-01

    The Iowa Gambling Task (IGT) and the Soochow Gambling Task (SGT) are two experience-based risky decision-making tasks for examining decision-making deficits in clinical populations. Several cognitive models, including the expectancy-valence learning (EVL) model and the prospect valence learning (PVL) model, have been developed to disentangle the motivational, cognitive, and response processes underlying the explicit choices in these tasks. The purpose of the current study was to develop an improved model that can fit empirical data better than the EVL and PVL models and, in addition, produce more consistent parameter estimates across the IGT and SGT. Twenty-six opiate users (mean age 34.23; SD 8.79) and 27 control participants (mean age 35; SD 10.44) completed both tasks. Eighteen cognitive models varying in evaluation, updating, and choice rules were fit to individual data and their performances were compared to that of a statistical baseline model to find a best fitting model. The results showed that the model combining the prospect utility function treating gains and losses separately, the decay-reinforcement updating rule, and the trial-independent choice rule performed the best in both tasks. Furthermore, the winning model produced more consistent individual parameter estimates across the two tasks than any of the other models. PMID:25814963

  14. Effect of commercial feed additives in nursery and finisher pig diets containing DDGS on nutrient digestibility and growth performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ten commercially available feed additives were selected based on their potential to affect energy and fiber digestion, or their ability to modulate gastrointestinal bacterial ecology. A total of 192 nursery pigs (11.9 kg initial BW) and 96 finishing pigs (98.4 kg initial BW) were allotted to individ...

  15. Anti-Wear Performance and Mechanism of an Oil-Miscible Ionic Liquid as a Lubricant Additive

    SciTech Connect

    Qu, Jun; Bansal, Dinesh G; Yu, Bo; Howe, Jane Y; Luo, Huimin; Dai, Sheng; Li, Huaqing; Blau, Peter Julian; Bunting, Bruce G; Mordukhovich, Gregory; Smolenski, Donald

    2012-01-01

    An ionic liquid (IL) trihexyltetradecylphosphonium bis(2-ethylhexyl) phosphate has been investigated as a potential anti-wear lubricant additive. Unlike most other ILs that have very low solubility in non-polar fluids, this IL is fully miscible with various hydrocarbon oils. In addition, it is thermally stable up to 347 oC, showed no corrosive attack to cast iron in ambient environment, and has excellent wettability on solid surfaces (e.g., contact angle on cast iron <8o). Most importantly, this phosphonium-based IL has demonstrated effective anti-scuffing and anti-wear characteristics when blended with lubricating oils. For example, a 5 wt.% addition into a synthetic base oil eliminated the scuffing failure experienced by the neat oil and, as a result, reduced the friction coefficient by 60% and the wear rate by three orders of magnitude. A synergistic effect on wear protection was observed with the current anti-wear additive when added into a fully-formulated engine oil. Nanostructure examination and composition analysis revealed a tribo-boundary film and subsurface plastic deformation zone for the metallic surface lubricated by the IL-containing lubricants. This protective boundary film is believed to be responsible for the IL s anti-scuffing and anti-wear functionality.

  16. Improving the long-term cycling performance of lithium-ion batteries at elevated temperature with electrolyte additives

    NASA Astrophysics Data System (ADS)

    Xia, Jian; Ma, Lin; Dahn, J. R.

    2015-08-01

    The effects of vinylene carbonate-based and prop-1-ene-1,3-sultone-based electrolyte additives on the cycling behavior of Li[Ni1/3Mn1/3Co1/3]O2/graphite pouch type cells at elevated temperature have been systematically studied. Capacity fade during cycling, charge-transfer resistance before and after cycling as well as gas evolution during formation and also during cycling were examined and compared. For vinylene carbonate-based additive blends, only 3% vinylene carbonate, 2% vinylene carbonate + 1% 1,3,2-dioxathiolane-2,2-dioxide + 1% tris(trimethylsilyl) phosphite or 2% vinylene carbonate + 1% methylene methyl disulfonate + 1% tris(trimethylsilyl) phosphite showed less capacity fade than 2% vinylene carbonate alone. Cells with all of these vinylene carbonate-based electrolyte additive blends lost more than 20% of their initial capacity after ∼1000 cycles at 55 °C and all the vinylene carbonate-based cells swelled more than 10% of their initial volume during this test. Cells containing all prop-1-ene-1,3-sultone-based additive blends generally produced much less gas than the vinylene carbonate-based blends. Many cells containing prop-1-ene-1,3-sultone-based additive blends lost less than 20% of their initial capacity after 1000 cycles. Moreover, the impedance of these prop-1-ene-1,3-sultone-based electrolytes decreased after long-term cycling. These results suggest that prop-1-ene-1,3-sultone-based electrolytes are more useful than vinylene carbonate-based electrolytes at high temperatures in Li[Ni1/3Mn1/3Co1/3]O2/graphite cells.

  17. Technical Approach for Determining Key Parameters Needed for Modeling the Performance of Cast Stone for the Integrated Disposal Facility Performance Assessment

    SciTech Connect

    Yabusaki, Steven B.; Serne, R. Jeffrey; Rockhold, Mark L.; Wang, Guohui; Westsik, Joseph H.

    2015-03-30

    the critical link between the short-term understanding from laboratory and field tests, and the prediction of repository performance over repository time frames and scales. One common recommendation is that experiments be designed to permit the appropriate scaling in the models. There is a large contrast in the physical and chemical properties between the Cast Stone waste package and the IDF backfill and surrounding sediments. Cast Stone exhibits low permeability, high tortuosity, low carbonate, high pH, and low Eh whereas the backfill and native sediments have high permeability, low tortuosity, high carbonate, circumneutral pH, and high Eh. These contrasts have important implications for flow, transport, and reactions across the Cast Stone – backfill interface. Over time with transport across the interface and subsequent reactions, the sharp geochemical contrast will blur and there will be a range of spatially-distributed conditions. In general, COC mobility and transport will be sensitive to these geochemical variations, which also include physical changes in porosity and permeability from mineral reactions. Therefore, PA modeling must address processes, properties, and conditions that alter the physical and chemical controls on COC transport in the cementitious waste forms over time. Section 2 of this document reviews past Hanford PAs and SRS Saltstone PAs, which to date have mostly relied on the lumped parameter COC release conceptual models for TSPA predictions, and provides some details on the chosen values for the lumped parameters. Section 3 provides more details on the hierarchical modeling strategy and processes and mechanisms that control COC release. Section 4 summarizes and lists the key parameters for which numerical values are needed to perform PAs. Section 5 provides brief summaries of the methods used to measure the needed parameters and references to get more details.

  18. Genetic parameters of growth, feed intake, feed conversion and carcass composition of dual-purpose bulls in performance testing.

    PubMed

    Jensen, J; Mao, I L; Andersen, B B; Madsen, P

    1991-03-01

    Genetic parameters for growth, total energy intake, feed conversion ratio, average daily energy intake and carcass composition were estimated in an experiment with 650 bull calves from 31 half-sib groups of Holstein Friesian or Brown Swiss sires. All traits analyzed had an amount of additive genetic variance that allows for considerable response to selection. No interaction between genotype (sire group) and proportion of roughage in the diet was found. Daily gain was strongly correlated negatively with feed conversion ratio but positively correlated with daily energy intake. Results indicate that genetic selection for either daily gain or average daily energy intake would decrease carcass fatness at a constant slaughter weight. However, the environmental correlation between daily energy intake and carcass fatness was positive. PMID:2061263

  19. [Simultaneous rapid determination of eight food additives in foods by reversed-phase high performance liquid chromatography].

    PubMed

    Zhang, X Y

    2000-11-01

    A simple and rapid method for the determination of eight food additives by RP-HPLC is described. They were saccharin, aspartame, benzoic acid, sorbic acid, vanillin, caffeine, carmine and sunset yellow. The experiments were carried on Shim-pack CLC-ODS (150 mm x 6.0 mm i.d.) with methanol-20 mmol/L NH4Ac (44:56, V/V; pH 7.0) as the eluent at a flow rate of 1.0 mL/min. The UV detection wavelength was fixed at 220 nm. The food samples, after precipitation of the impurities with Carrez reagent, were injected directly into the HPLC system. The average recoveries of all the eight additives were between 91.9%-108.5%, and the RSDs were lower than 4% (n = 5). The analysis of a single sample required only 8 min. This method has been successfully applied to the routine analysis of these additives in foods. PMID:12541745

  20. Performance Analysis of a New Coded TH-CDMA Scheme in Dispersive Infrared Channel with Additive Gaussian Noise

    NASA Astrophysics Data System (ADS)

    Hamdi, Mazda; Kenari, Masoumeh Nasiri

    2013-06-01

    We consider a time-hopping based multiple access scheme introduced in [1] for communication over dispersive infrared links, and evaluate its performance for correlator and matched filter receivers. In the investigated time-hopping code division multiple access (TH-CDMA) method, the transmitter benefits a low rate convolutional encoder. In this method, the bit interval is divided into Nc chips and the output of the encoder along with a PN sequence assigned to the user determines the position of the chip in which the optical pulse is transmitted. We evaluate the multiple access performance of the system for correlation receiver considering background noise which is modeled as White Gaussian noise due to its large intensity. For the correlation receiver, the results show that for a fixed processing gain, at high transmit power, where the multiple access interference has the dominant effect, the performance improves by the coding gain. But at low transmit power, in which the increase of coding gain leads to the decrease of the chip time, and consequently, to more corruption due to the channel dispersion, there exists an optimum value for the coding gain. However, for the matched filter, the performance always improves by the coding gain. The results show that the matched filter receiver outperforms the correlation receiver in the considered cases. Our results show that, for the same bandwidth and bit rate, the proposed system excels other multiple access techniques, like conventional CDMA and time hopping scheme.

  1. Relative performance of soft contact lenses having lathe-cut posterior surfaces with and without additional polishing.

    PubMed

    O'Brien, C; Charman, W N

    2006-05-01

    After a preliminary investigation of the effects of tool feed rate and spindle speed on the surface roughness of unhydrated, lathe-cut polymacon surfaces, a laboratory and clinical comparison was made between lenses with identical parameters except that the lathe-cut posterior surface was left unpolished in the "test" lenses and was polished in the "control" lenses. The lenses had moulded anterior surfaces. Laboratory comparisons included surface roughness, lens power and its uniformity across the surface. Double-blind clinical trials over 4-hour (27 subjects) and 1-month (10 subjects) periods, involved one eye of each subject wearing a "test" lens and the other, a "control" lens. No clinically significant differences were found between the results for the test and control lenses. It is concluded that today's lathing technology makes a final polishing stage unnecessary. PMID:16701199

  2. Improved electrochemical performances of binder-free CoMoO4 nanoplate arrays@Ni foam electrode using redox additive electrolyte

    NASA Astrophysics Data System (ADS)

    Veerasubramani, Ganesh Kumar; Krishnamoorthy, Karthikeyan; Kim, Sang Jae

    2016-02-01

    Herein, we are successfully prepared cobalt molybdate (CoMoO4) grown on nickel foam as a binder free electrode by hydrothermal approach for supercapacitors and improved their electrochemical performances using potassium ferricyanide (K3Fe(CN)6) as redox additive. The formation of CoMoO4 on Ni foam with high crystallinity is confirmed using XRD, Raman, and XPS measurements. The nanoplate arrays (NPAs) of CoMoO4 are uniformly grown on Ni foam which is confirmed by FE-SEM analysis. The prepared binder-free CoMoO4 NPAs achieved maximum areal capacity of 227 μAh cm-2 with KOH electrolyte at 2.5 mA cm-2. This achieved areal capacity is further improved about three times using the addition of K3Fe(CN)6 as redox additive. The increased electrochemical performances of CoMoO4 NPAs on Ni foam electrode via redox additive are discussed in detail and the mechanism has been explored. Moreover, the assembled CoMoO4 NPAs on Ni foam//activated carbon asymmetric supercapacitor device with an extended operating voltage window of 1.5 V exhibits an excellent performances such as high energy density and cyclic stability. The overall performances of binder-free CoMoO4 NPAs on Ni foam with redox additives suggesting their potential use as positive electrode material for high performance supercapacitors.

  3. Does skip metastasis or other lymph node parameters have additional effects on survival of patients undergoing radical cystectomy for bladder cancer?

    PubMed Central

    Baltaci, Sumer; Aslan, Guven; Can, Cavit; Cal, Cag; Elhan, Atilla; Turkeri, Levent; Mungan, Aydin

    2015-01-01

    Purpose To investigate the effects of lymph node metastasis, skip metastasis, and other factors related to lymph node status on survival in patients who underwent radical cystectomy (RC) and extended lymph node dissection (eLND). Materials and Methods RC and eLND were performed in 85 patients with a diagnosis of bladder cancer. Disease-free survival (DFS) and overall survival (OS) were determined by using a Cox proportional hazards model that included the number of excised lymph nodes, the presence of pathological lymph node metastasis, the anatomical level of positive nodes, the number of positive lymph nodes, lymph node density, and the presence of skip metastasis. Results The mean number of lymph nodes removed per patient was 29.4±9.3. Lymph node positivity was detected in 85 patients (34.1%). The mean follow-up duration was 44.9±27.4 months (2-93 months). Five-year estimated OS and DFS for the 85 patients were 62.6% and 57%, respectively. Three of 29 lymph node-positive patients (10.3%) had skip metastasis. Only lymph node positivity had a significant effect on 5-year OS and DFS (p<0.001). No difference in OS and DFS was found between the three patients with skip metastasis and other lymph node-positive patients. Other factors related to lymph node status had no significant effect on 5-year OS and DFS. Conclusions No factors related to lymph node status predict DFS and OS, except for lymph node positivity. OS and DFS were comparable between patients with skip metastasis and other lymph node-positive patients. PMID:25964836

  4. Enhanced photovoltaic performance of Cu-based metal-organic frameworks sensitized solar cell by addition of carbon nanotubes

    PubMed Central

    Lee, Deok Yeon; Shin, Chan Yong; Yoon, Seog Joon; Lee, Haw Young; Lee, Wonjoo; Shrestha, Nabeen K.; Lee, Joong Kee; Han, Sung-Hwan

    2014-01-01

    In the present work, TiO2 nanoparticle and multi-walled carbon nanotubes composite powder is prepared hydrothermally. After doctor blading the paste from composite powder, the resulted composite film is sensitized with Cu-based metal-organic frameworks using a layer-by-layer deposition technique and the film is characterized using FE-SEM, EDX, XRD, UV/Visible spectrophotometry and photoluminescence spectroscopy. The influence of the carbon nanotubes in photovoltaic performance is studied by constructing a Grätzel cell with I3−/I− redox couple containing electrolyte. The results demonstrate that the introduction of carbon nanotubes accelerates the electron transfer, and thereby enhances the photovoltaic performance of the cell with a nearly 60% increment in power conversion efficiency. PMID:24488110

  5. Enhanced photovoltaic performance of Cu-based metal-organic frameworks sensitized solar cell by addition of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Lee, Deok Yeon; Shin, Chan Yong; Yoon, Seog Joon; Lee, Haw Young; Lee, Wonjoo; Shrestha, Nabeen K.; Lee, Joong Kee; Han, Sung-Hwan

    2014-02-01

    In the present work, TiO2 nanoparticle and multi-walled carbon nanotubes composite powder is prepared hydrothermally. After doctor blading the paste from composite powder, the resulted composite film is sensitized with Cu-based metal-organic frameworks using a layer-by-layer deposition technique and the film is characterized using FE-SEM, EDX, XRD, UV/Visible spectrophotometry and photoluminescence spectroscopy. The influence of the carbon nanotubes in photovoltaic performance is studied by constructing a Grätzel cell with I3-/I- redox couple containing electrolyte. The results demonstrate that the introduction of carbon nanotubes accelerates the electron transfer, and thereby enhances the photovoltaic performance of the cell with a nearly 60% increment in power conversion efficiency.

  6. Global performance parameters for different pneumatic bioreactors operating with water and glycerol solution: experimental data and CFD simulation.

    PubMed

    Rodriguez, G Y; Valverde-Ramírez, M; Mendes, C E; Béttega, R; Badino, A C

    2015-11-01

    Global variables play a key role in evaluation of the performance of pneumatic bioreactors and provide criteria to assist in system selection and design. The purpose of this work was to use experimental data and computational fluid dynamics (CFD) simulations to determine the global performance parameters gas holdup ([Formula: see text]) and volumetric oxygen transfer coefficient (k L a), and conduct an analysis of liquid circulation velocity, for three different geometries of pneumatic bioreactors: bubble column, concentric-tube airlift, and split tube airlift. All the systems had 5 L working volumes and two Newtonian fluids of different viscosities were used in the experiments: distilled water and 10 cP glycerol solution. Considering the high oxygen demand in certain types of aerobic fermentations, the assays were carried out at high flow rates. In the present study, the performances of three pneumatic bioreactors with different geometries and operating with two different Newtonian fluids were compared. A new CFD modeling procedure was implemented, and the simulation results were compared with the experimental data. The findings indicated that the concentric-tube airlift design was the best choice in terms of both gas holdup and volumetric oxygen transfer coefficient. The CFD results for gas holdup were consistent with the experimental data, and indicated that k L a was strongly influenced by bubble diameter and shape. PMID:26227509

  7. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  8. Influences of porous structurization and Pt addition on the improvement of photocatalytic performance of WO3 particles.

    PubMed

    Arutanti, Osi; Nandiyanto, Asep Bayu Dani; Ogi, Takashi; Kim, Tae Oh; Okuyama, Kikuo

    2015-02-11

    Tungsten trioxide (WO3) displays excellent performance in solar-related material applications. However, this material is rare and expensive. Therefore, developing efficient materials using smaller amounts of WO3 is inevitable. In this study, we investigated how to create high photocatalytic performance of WO3 particles containing platinum (Pt, as a co-catalyst) and homogeneously spherical macropores (as a medium to enable access of large molecules and light penetration into the remote internal regions of the catalyst). The present particles were prepared by spray drying of a precursor solution containing WO3 nanoparticles, Pt solution, and polystyrene (PS) spheres (as a colloidal template). Photocatalytic studies showed that changes in particle morphology (from dense with smooth surfaces, to dense with rough surfaces, to porous structures) and added Pt effectively improved the photocatalytic performance over WO3 nanoparticles. Our results showed that the best precursor (prepared using a PS/WO3 mass ratio of 0.32 and containing Pt co-catalyst) provided WO3 particles with a photocatalytic rate of more than 5 times that of pure 10 nm WO3 nanoparticles. Moreover, the catalyst can be effectively recycled without an apparent decrease in its photocatalytic activity. The experimental results were also supported by a proposal mechanism of the photocatalytic reaction phenomenon. PMID:25608579

  9. Stimulus modality and working memory performance in Greek children with reading disabilities: additional evidence for the pictorial superiority hypothesis.

    PubMed

    Constantinidou, Fofi; Evripidou, Christiana

    2012-01-01

    This study investigated the effects of stimulus presentation modality on working memory performance in children with reading disabilities (RD) and in typically developing children (TDC), all native speakers of Greek. It was hypothesized that the visual presentation of common objects would result in improved learning and recall performance as compared to the auditory presentation of stimuli. Twenty children, ages 10-12, diagnosed with RD were matched to 20 TDC age peers. The experimental tasks implemented a multitrial verbal learning paradigm incorporating three modalities: auditory, visual, and auditory plus visual. Significant group differences were noted on language, verbal and nonverbal memory, and measures of executive abilities. A mixed-model MANOVA indicated that children with RD had a slower learning curve and recalled fewer words than TDC across experimental modalities. Both groups of participants benefited from the visual presentation of objects; however, children with RD showed the greatest gains during this condition. In conclusion, working memory for common verbal items is impaired in children with RD; however, performance can be facilitated, and learning efficiency maximized, when information is presented visually. The results provide further evidence for the pictorial superiority hypothesis and the theory that pictorial presentation of verbal stimuli is adequate for dual coding. PMID:21942734

  10. Double jeopardy! The additive consequences of negative affect on performance-monitoring decrements following traumatic brain injury.

    PubMed

    Larson, Michael J; Kaufman, David A S; Kellison, Ida L; Schmalfuss, Ilona M; Perlstein, William M

    2009-07-01

    Survivors of severe traumatic brain injury (TBI) are at increased risk for emotional sequelae. The current study utilized the error-related negativity (ERN) and posterror positivity (Pe) components of the event-related potential (ERP) to test the hypothesis that negative affect disproportionately impairs performance-monitoring following severe TBI. High-density ERPs were acquired while 20 survivors of severe TBI and 20 demographically matched controls performed a single-trial Stroop task. Response-locked ERPs were separately averaged for correct and error trials. Negative affect was measured as the single latent factor of measures of depression and anxiety. Groups did not differ on overall level of negative affect. Control and TBI participants did not differ on error rates as a function of negative affect, but differed in response times. ERP results revealed disproportionately smaller ERN amplitudes in participants with TBI relative to controls as a function of negative affect. Pe amplitude did not differ between groups. Negative affect inversely correlated with ERN amplitude in TBI but not control participants. Overall, results support a "double jeopardy" hypothesis of disproportionate impairments in performance monitoring when negative affect is overlaid on severe TBI. PMID:19586208

  11. Optimizing the performance of a reactor by reducing the retention time and addition of glycerin for anaerobically digesting manure

    PubMed Central

    Timmerman, Maikel; Schuman, Els; van Eekert, Miriam; van Riel, Johan

    2015-01-01

    Anaerobic digestion of manure is a widely accepted technology for energy production. However, only a minimal portion of the manure production in the EU is anaerobically digested and occurs predominantly in codigestion plants. There is substantial potential for biogas plants that primarily operate on manure (>90%); however, the methane yields of manure are less compared to coproducts, which is one of the reasons for manure-based biogas plants often being economically non-viable. Therefore, it is essential to begin increasing the efficiency of these biogas plants. This study investigated the effect of decreasing retention time and introducing a moderate amount of glycerin on the biogas production as methods to improve efficiency. An experiment has been conducted with two different manure types in four biogas reactors. The results of the study demonstrated that, first, it was possible to decrease the retention time to 10–15 days; however, the effect on biogas production varied per manure type. Secondly, the biogas production almost triples at a retention time of 15.6 days with an addition of 4% glycerin. The relative production-enhancing effect of glycerin did not vary significantly with both manure types. However, the absolute production-enhancing effect of glycerin differed per manure type since the biogas production per gram VS differed per manure type. Thirdly, the positive effect of the glycerin input declines with shorter retention times. Therefore, the effect of glycerin addition depends on the manure type and retention time. PMID:25401272

  12. Lead acid battery performance and cycle life increased through addition of discrete carbon nanotubes to both electrodes

    NASA Astrophysics Data System (ADS)

    Sugumaran, Nanjan; Everill, Paul; Swogger, Steven W.; Dubey, D. P.

    2015-04-01

    Contemporary applications are changing the failure mechanisms of lead acid batteries. Sulfation at the negative electrode, acid stratification, and dendrite formation now precede positive electrode failures such as grid corrosion and active material shedding. To attenuate these failures, carbon has been explored as a negative electrode additive to increase charge acceptance, eliminate sulfation, and extend cycle life. Frequently, however, carbon incorporation decreases paste density and hinders manufacturability. Discrete carbon nanotubes (dCNT), also known as Molecular Rebar®, are lead acid battery additives which can be stably incorporated into either electrode to increase charge acceptance and cycle life with no change to paste density and without impeding the manufacturing process. Here, full-scale automotive batteries containing dCNT in the negative electrode or both negative and positive electrodes are compared to control batteries. dCNT batteries show little change to Reserve Capacity, improved Cold Cranking, increased charge acceptance, and enhanced overall system efficiency. Life cycle tests show >60% increases when dCNT are incorporated into the negative electrode (HRPSoC/SBA) and up to 500% when incorporated into both electrodes (SBA), with water loss per cycle reduced >20%. Failure modes of cycled batteries are discussed and a hypothesis of dCNT action is introduced: the dCNT/Had Overcharge Reaction Mechanism.

  13. Evaluating Gaia performances on eclipsing binaries. IV. Orbits and stellar parameters for SV Cam, BS Dra and HP Dra

    NASA Astrophysics Data System (ADS)

    Milone, E. F.; Munari, U.; Marrese, P. M.; Williams, M. D.; Zwitter, T.; Kallrath, J.; Tomov, T.

    2005-10-01

    This is the fourth in a series of papers that aim both to provide reasonable orbits for a number of eclipsing binaries and to evaluate the expected performance of Gaia of these objects and the accuracy that is achievable in the determination of such fundamental stellar parameters as mass and radius. In this paper, we attempt to derive the orbits and physical parameters for three eclipsing binaries in the mid-F to mid-G spectral range. As for previous papers, only the H_P, V_T, BT photometry from the Hipparcos/Tycho mission and ground-based radial velocities from spectroscopy in the region 8480-8740 Å are used in the analyses. These data sets simulate the photometric and spectroscopic data that are expected to be obtained by Gaia, the approved ESA Cornerstone mission to be launched in 2011. The systems targeted in this paper are SV Cam, BS Dra and HP Dra. SV Cam and BS Dra have been studied previously, allowing comparisons of the derived parameters with those from full scale and devoted ground-based investigations. HP Dra has no published orbital solution. SV Cam has a β Lyrae type light curve and the others have Algol-like light curves. SV Cam has the complication of light curve anomalies, usually attributed to spots; BS Dra has non-solar metallicity, and HP Dra appears to have a small eccentricity and a sizeable time derivative in the argument of the periastron. Thus all three provide interesting and different test cases.

  14. Influence of the acquisition parameters on the performance of laser-thermography for crack detection in metallic components

    NASA Astrophysics Data System (ADS)

    Myrach, Philipp; Ziegler, Mathias; Maierhofer, Christiane; Kreutzbruck, Marc

    2014-02-01

    We present a systematic study on the performance of laser-thermography for the detection of surface cracks in metallic components. Scanning a metallic surface with laser causes local heating that is mapped simultaneously by an IR-camera and allows identifying cracks with sub-μm openings. The detectability, however, depends on a number of acquisition parameters (e.g. scanning speed, laser power, IR-camera resolution) that typically relate on each other. Most importantly, the detection-sensitivity of surface breaking cracks is given by a particular combination for the acquisition parameter values. As a result, this sensitivity is adaptable within wide ranges allowing the detection of cracks with openings ranging from 200 to 0.1 μm at testing speeds of 100 to 0.05 cm2/s. By examining artificial as well as fatigue cracks, we demonstrate that the method can be even applied to shiny surfaces with no need of pretreatments, which makes it an entirely contactless, remote and automatable NDT technique. A comparison with magnetic particle testing shows that laser-thermography has the potential to become a strong competitor to conventional surface inspection methods in the future.

  15. Probiotic level effects on growth performance, carcass traits, blood parameters, cecal microbiota, and immune response of broilers.

    PubMed

    Pourakbari, Mohammadreza; Seidavi, Alireza; Asadpour, Leila; Martínez, Andrés

    2016-05-31

    Probiotic effects on growth performance, carcass traits, blood parameters, cecal microbiota, and immune response of broilers were studied. Two hundred one-day-old male chickens were allocated to one of five treatments (four replicates of 10 birds per treatment): control, and the same control diet supplemented with 0.005%, 0.01%, 0.015% and 0.02% probiotics. Probiotics in feed at 0.01% or higher levels of supplementation improved body weight gain (+12%) and feed conversion rate (-5%) compared with the control. There were no effects on carcass traits, but the relative weights of drumsticks and wings showed increasing and decreasing linear responses, respectively, to probiotic supplementation level. Blood plasma glucose and albumin contents linearly increased (from 167.1 to 200.5 mg dl-1, and from 1.70 to 3.25 g dl-1) with increasing probiotic supplementation. Triglycerides and cholesterol contents were lower in probiotic supplemented treatments (average contents 71.3 and 125.3 mg dl-1 vs. 92.6 and 149.9 mg dl-1 in the control). Probiotics decreased cecal Escherichia coli counts, but had no effects on immunity related organs or immune response. The linear trends, either positive or negative, observed in many of the parameters studied, suggest that more studies are needed to establish the optimal concentration of probiotics in broiler feed. PMID:27254451

  16. Performance Parameters Analysis of an XD3P Peugeot Engine Using Artificial Neural Networks (ANN) Concept in MATLAB

    NASA Astrophysics Data System (ADS)

    Rangaswamy, T.; Vidhyashankar, S.; Madhusudan, M.; Bharath Shekar, H. R.

    2015-04-01

    The current trends of engineering follow the basic rule of innovation in mechanical engineering aspects. For the engineers to be efficient, problem solving aspects need to be viewed in a multidimensional perspective. One such methodology implemented is the fusion of technologies from other disciplines in order to solve the problems. This paper mainly deals with the application of Neural Networks in order to analyze the performance parameters of an XD3P Peugeot engine (used in Ministry of Defence). The basic propaganda of the work is divided into two main working stages. In the former stage, experimentation of an IC engine is carried out in order to obtain the primary data. In the latter stage the primary database formed is used to design and implement a predictive neural network in order to analyze the output parameters variation with respect to each other. A mathematical governing equation for the neural network is obtained. The obtained polynomial equation describes the characteristic behavior of the built neural network system. Finally, a comparative study of the results is carried out.

  17. Nondestructive quantification of leakage at the tooth-composite interface and its correlation with material performance parameters.

    PubMed

    Sun, Jirun; Fang, Rui; Lin, Nancy; Eidelman, Naomi; Lin-Gibson, Sheng

    2009-09-01

    Current methods to determine debonding/leakage at the tooth-composite interface are qualitative or semi-quantitative. Our previous work introduced a 3D imaging technique to determine and visualize leakage and its distribution at the interface of cavity wall and composite restoration in model cavities. In this study, an automated program was developed to quantify leakage in terms of area and volume. 3D leakage distribution obtained via the image analysis program was shown to have excellent agreement with leakage visualized by dye penetration. The relationship between leakage and various material performance parameters including processability, shrinkage, stress, and shrinkage strain-rate was determined using a series of experimental composites containing different filler contents. Results indicate that the magnitude of leakage correlated well with polymerization stress, confirming the validity of the common approach utilizing polymerization stress to predict bonding durability. 3D imaging and image analysis provide insight to help understand the relations between leakage and material properties. PMID:19515419

  18. Effects of dietary supplementation of meat-type quail breeders with guanidinoacetic acid on their reproductive parameters and progeny performance.

    PubMed

    Murakami, A E; Rodrigueiro, R J B; Santos, T C; Ospina-Rojas, I C; Rademacher, M

    2014-09-01

    This study was conducted to assess the effect of dietary supplementation of meat-type quail breeders with guanidinoacetic acid (GAA) on their reproductive parameters and progeny performance. Two hundred forty meat-type quails at 25 wk of age were distributed in a completely randomized design with 5 treatments and 8 replicates of 6 birds each. The treatments consisted of 5 dietary levels of GAA (0.00, 0.06, 0.12, 0.18, and 0.24%). The progenies from quail breeders were housed according to breeder treatments and fed a conventional diet based on corn and soybean meal without GAA supplementation. Dietary GAA levels did not affect (P > 0.05) the productivity of meat-type quail breeders, although the concentration of guanidinic compounds (creatine, GAA, and creatinine) in the eggs from the breeders increased linearly (P < 0.05) according to the increase in dietary GAA levels. The number of spermatozoa present in the vitelline membrane was not affected (P > 0.05) by the treatments, but there was a quadratic effect (P < 0.05) of the levels of GAA on fertility, embryonic mortality, and egg hatchability, with the best results estimated at 0.13, 0.15, and 0.14% GAA, respectively. The creatine levels of the pectoral muscle in newborn quails showed a quadratic effect (P ≤ 0.07), and the dietary GAA level of 0.11% was estimated to maximize the muscular creatine level in the progeny. There was a quadratic effect (P < 0.05) of GAA levels on weight gain and feed conversion of progeny at 35 d of age with an optimization point of 0.14% GAA for these variables. Dietary GAA supplementation of meat-type quail breeders increases the availability of creatine in eggs and muscle of progeny, which results in better reproductive parameters and better postnatal progeny performance. PMID:24974392

  19. Effects of Dietary Electrolyte Balance on Growth Performance, Nitrogen Metabolism and Some Blood Biochemical Parameters of Growing Rabbits

    PubMed Central

    Li, J. W.; Wang, X. P.; Wang, C. Y.; Zhu, Y. L.; Li, F. C.

    2013-01-01

    The effects of different dietary electrolyte balance (DEB) on growth performance, nitrogen (N) metabolism and some blood biochemical parameters were investigated in 2 to 3 months old growing rabbits. A total of 150 growing rabbits of 2 months age were randomly divided into five groups according to average body weight, with 30 rabbits in each group. The DEB levels of the five experimental diets were −154, −3.16, +201, +347, and +500 meq/kg of dry matter (DM), respectively. There was a 7-d adaptation period and a 23-d experimental period. The results showed that the DEB levels had a quadratic affect on the average daily feed intake (ADFI) (p<0.001). The greatest ADFI was achieved when the DEB level was +201 meq/kg DM. Fecal N (FN) content linearly decreased (0.047), while digestible N (DN), retained N (RN), efficiency of intake N converted into digestible N (DN/IN) and the efficiency of intake N converted into retained N (RN/IN) linearly increased with the DEB increase (0.020, 0.004, 0.021, and 0.049, respectively). Serum phosphorus (P) ion content linearly increased with the DEB increase (p = 0.036). The DEB had a quadratic relationship with serum anion gap (AG) (p = 0.002) and serum parathyroid hormone (PTH) content (p = 0.016). The DEB levels quadratically affected base excess (BE) in the plasma (p<0.001). In conclusion, the DEB unaffected growth performance but affected feed intake, N metabolism and some blood biochemical parameters of growing rabbits. PMID:25049763

  20. Effect of the addition of β-mannanase on the performance, metabolizable energy, amino acid digestibility coefficients, and immune functions of broilers fed different nutritional levels.

    PubMed

    Ferreira, H C; Hannas, M I; Albino, L F T; Rostagno, H S; Neme, R; Faria, B D; Xavier, M L; Rennó, L N

    2016-08-01

    Three experiments were conducted to evaluate the effect of β-mannanase BM: supplementation on the performance, metabolizable energy, amino acid digestibility, and immune function of broilers. A total of 1,600 broilers were randomly distributed in a 4 × 2 factorial arrangement (4 nutritional levels × 0 or 500 g/ton BM), with 10 replicates and 20 broilers per pen. The same design was used in the energy and digestibility experiments with 8 and 6 replicates, respectively, and 6 broilers per pen. The nutritional levels : NL : were formulated to meet the nutritional requirements of broilers : NL1 : ; reductions of 100 kcal metabolizable energy : NL2 : ; 3% of the total amino acids (NL3); and 100 kcal metabolizable energy and 3% total amino acids (NL4) from NL1. The serum immunoglobulin (Ig) concentration was determined in two broilers per pen, and these broilers were slaughtered to determine the relative weight of spleen, thymus, and bursa of Fabricius. Throughout the experiment, the lower nutritional levels reduced (P < 0.05) body weight gain : BWG : and increased (P < 0.05) feed conversion : FCR : for the NL4 treatment. The BM increased (P < 0.05) the BWG values and improved (P < 0.05) the FCR of the broilers. The apparent metabolizable energy corrected for nitrogen balance (AMEn) values were reduced (P < 0.05) for NL2 and NL3. The BM increased (P < 0.05) the AMEn values and reduced (P < 0.05) the excreted nitrogen. NL3 and NL4 reduced (P < 0.05) the true ileal digestibility coefficients (TIDc) of the amino acids cystine and glycine, and BM increased (P < 0.05) the TIDc for all amino acids. The addition of BM reduced (P < 0.05) the relative weights of the spleen and bursa. NL2 increased (P < 0.05) the Ig values, whereas BM reduced (P < 0.05) the serum IgA, IgG, and IgM values of the broilers. This study indicates that using suboptimal nutrient levels leads to losses in production parameters, whereas BM-supplemented diets were effective in improving performance

  1. Effect of the addition of β-mannanase on the performance, metabolizable energy, amino acid digestibility coefficients, and immune functions of broilers fed different nutritional levels

    PubMed Central

    Ferreira, H. C.; Hannas, M. I.; Albino, L. F. T.; Rostagno, H. S.; Neme, R.; Faria, B. D.; Xavier, M. L.; Rennó, L. N.

    2016-01-01

    Three experiments were conducted to evaluate the effect of β-mannanase (BM) supplementation on the performance, metabolizable energy, amino acid digestibility, and immune function of broilers. A total of 1,600 broilers were randomly distributed in a 4 × 2 factorial arrangement (4 nutritional levels × 0 or 500 g/ton BM), with 10 replicates and 20 broilers per pen. The same design was used in the energy and digestibility experiments with 8 and 6 replicates, respectively, and 6 broilers per pen. The nutritional levels (NL) were formulated to meet the nutritional requirements of broilers (NL1); reductions of 100 kcal metabolizable energy (NL2); 3% of the total amino acids (NL3); and 100 kcal metabolizable energy and 3% total amino acids (NL4) from NL1. The serum immunoglobulin (Ig) concentration was determined in two broilers per pen, and these broilers were slaughtered to determine the relative weight of spleen, thymus, and bursa of Fabricius. Throughout the experiment, the lower nutritional levels reduced (P < 0.05) body weight gain (BWG) and increased (P < 0.05) feed conversion (FCR) for the NL4 treatment. The BM increased (P < 0.05) the BWG values and improved (P < 0.05) the FCR of the broilers. The apparent metabolizable energy corrected for nitrogen balance (AMEn) values were reduced (P < 0.05) for NL2 and NL3. The BM increased (P < 0.05) the AMEn values and reduced (P < 0.05) the excreted nitrogen. NL3 and NL4 reduced (P < 0.05) the true ileal digestibility coefficients (TIDc) of the amino acids cystine and glycine, and BM increased (P < 0.05) the TIDc for all amino acids. The addition of BM reduced (P < 0.05) the relative weights of the spleen and bursa. NL2 increased (P < 0.05) the Ig values, whereas BM reduced (P < 0.05) the serum IgA, IgG, and IgM values of the broilers. This study indicates that using suboptimal nutrient levels leads to losses in production parameters, whereas BM-supplemented diets were effective in improving performance, energy

  2. Comparison of capillary zone electrophoresis with high-performance liquid chromatography for the determination of additives in foodstuffs.

    PubMed

    Jimidar, M; Hamoir, T P; Foriers, A; Massart, D L

    1993-04-23

    A capillary zone electrophoretic (CZE) method was developed to determine caffeine, aspartame and benzoic acid in diet cola soft drinks and in artificial sweetening powders. The effects of pH, ionic strength, organic solvents and different buffers were investigated to select the optimum conditions. These consisted of a sodium phosphate buffer at pH 11 and ionic strength 0.025. The running voltage was set at 15 kV and the injection was performed hydrostatically for 30 s. The CZE method was then compared with a previously developed high-performance liquid chromatographic (HPLC) method in terms of repeatability, reproducibility, accuracy, linearity, sensitivity and separation efficiency. Both methods gave good repeatability. The relative standard deviations for reproducibility were significantly higher in CZE than in HPLC. The main reason for this is probably the condition of the wall of the capillary, which was difficult to keep constant between the days of analysis. The separation efficiency of CZE was 65-110 times higher than that of HPLC; on the other hand, 10-20 times lower detection limits were obtained in HPLC. Both methods were linear, but the linear ranges were different owing to the lower detection limit of HPLC. In CZE, the effect of the matrix was higher. PMID:8491835

  3. A temperature compensation procedure for performance improvement of mass-produced MEMS gyroscopes based on direct parameter measurement

    NASA Astrophysics Data System (ADS)

    Straube, Timothy Milton

    Micro Electro Mechanical Systems gyroscopes are an enabling technology for many rate sensing applications that require low cost, mass and volume, including the class of spacecraft known as nano- or pico-satellites. The weakness of these types of gyroscopes to date has been limited performance capabilities, especially over a varying temperature range. This thesis presents a methodology for correcting the gyroscope output signal for variations over temperature based on measurements of specific internal gyro parameters, namely, drive and sense axis resonant frequency, and off-axis electrostatic forcing function. The thesis presents the development of the full analytical equations of motion for a translating type MEMS gyro. The equations are simplified, numerically validated, and decomposed for gyro scale factor and bias expressions. Employing gyroscope parameters obtained from open literature sources as a function of temperature, a reference model of gyro scale factor and bias voltage as a function of temperature is developed. The research also includes the empirical testing of two types of gyro, and ten total individual devices, including eight ADXRS150 automotive grade gyroscopes from Analog Devices. Device outputs at temperatures from -35°C to +75°C and across a range of rotation rate were measured and processed to calculate individual gyro scale factor and bias. Data from all gyros were analyzed using a principal component methodology to extract the dominant structures in the gyro behavior. The final correction model is individualized for each gyro using ambient scale factor and bias data from that gyro. This model is used to compensate the individual raw gyro output taken during testing. Compositing the compensated output from all gyro provides a final rate estimate, which can be compared against the known testing inputs. The results demonstrate considerable improvement over manufacturer-provided scale factor and bias correction values. With the linkage between

  4. The use of oxytocin in liquid semen doses to reduce seasonal fluctuations in the reproductive performance of sows and improve litter parameters--a 2-year study.

    PubMed

    Duziński, Kamil; Knecht, Damian; Srodoń, Sebastian

    2014-04-01

    both, P ≤ 0.01). The greatest daily gains were observed in the winter season (P ≤ 0.05) in favor of oxytocin. On the basis of the presented results, it should be noted that the use of oxytocin into insemination doses improves the farrowing rate and other parameters of the reproductive performance of sows. In the absence of negative effects, year-round insemination with oxytocin addition into seminal doses is recommended, which effectively improves the production performance and reduces the problem of seasonality in reproduction. PMID:24503107

  5. Notable improvement of capacitive performance of highly nanoporous carbon materials simply by a redox additive electrolyte of p-nitroaniline

    NASA Astrophysics Data System (ADS)

    Zhu, Yan Qi; Zhang, Lei; Chen, Xiang Ying; Xiao, Zheng Hui; Zhang, Zhong Jie

    2015-12-01

    Highly nanoporous carbon materials have been produced by a synchronous carbonization/graphitization process, using magnesium citrate serves as the carbon source and nickel nitrate as graphitization catalyst. The carbonization temperature plays a crucial role in determining the porosity and graphitization. The lower temperature favors for the formation of larger porosity, whilst higher temperature for better crystallinity. Resultantly, a high BET surface area of 2587.13 m2 g-1 and large total pore volume of 4.64 cm3 g-1 appear, the case of C-800 sample, thereby resulting in a large specific capacitance of 305.3 F g-1 at 1 A g-1 from the contribution of electric double layer capacitances. More importantly, we demonstrate a novel redox active additive of p-nitroaniline (PNA) into the 6 mol L-1 KOH electrolyte to largely improve the capacitance by the quick self-discharge redox reaction of H+/e-. The C-800-2 sample with the PNA concentration of 2 mmol delivers largely improved capacitance of 502.1 F g-1 at 1 A g-1, which is almost 1.65 fold increase. Apparently, the present PNA is commercially available, and highly effective for elevating the specific capacitance and might be implemented for the wide supercapacitor application.

  6. Effect of dietary vitamin C addition on performance, plasma vitamin C and hematic iron status in weanling pigs.

    PubMed

    Yen, J T; Pond, W G

    1981-11-01

    Each of 64 pigs weaned between 4 and 5 weeks of age was fed ad libitum one of four diets: (1) a basal 18% crude protein, corn-soybean meal-oats-dried whey starter diet or (2,3,4) the basal diet supplemented with 330, 660 or 990 ppm L-ascorbic acid (vitamin C). The pigs were kept in groups of four and housed in an environmentally regulated nursery with a raised, expanded metal floor. The room temperature was maintained at 21 C and floor allowance was .54 m2/pig. After 28 days, dietary vitamin C supplementation had improved daily weight gain and daily feed intake of pigs without altering gain to feed ratio. Plasma vitamin C concentration decreased during the 4 weeks period after weaning in pigs not fed supplemental vitamin C but not in those fed supplemental vitamin C. Plasma Fe was reduced at day 28 in pigs given supplemental vitamin C. Simple correlation indicated a positive (P less than .05) relationship between plasma vitamin C concentration and weight gain and a negative (P less than .05) relationship between plasma vitamin C and plasma Fe concentration. Results obtained suggest that, under the experimental conditions, young pigs weaned between 4 and 5 weeks of age require dietary vitamin C supplementation for maximum weight gain and that the benefit of vitamin C addition may be related to Fe metabolism. PMID:7319970

  7. Effect of the addition CNTs on performance of CaP/chitosan/coating deposited on magnesium alloy by electrophoretic deposition.

    PubMed

    Zhang, Jie; Wen, Zhaohui; Zhao, Meng; Li, Guozhong; Dai, Changsong

    2016-01-01

    CaP/chitosan/carbon nanotubes (CNTs) coating on AZ91D magnesium alloy was prepared via electrophoretic deposition (EPD) followed by conversion in a phosphate buffer solution (PBS). The bonding between the layer and the substrate was studied by an automatic scratch instrument. The phase compositions and microstructures of the composite coatings were determined by using X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscope (SEM). The element concentration and gentamicin concentration were respectively determined by inductively coupled plasma optical emission spectrometer (ICP-OES) test and ultraviolet spectrophotometer (UV). The cell counting kit (CCK) assay was used to evaluate the cytotoxicity of samples to SaOS-2 cells. The results showed that a few CNTs with their original tubular morphology could be found in the CaP/chitosan coating and they were beneficial for the crystal growth of phosphate and improvement of the coating bonding when the addition amount of CNTs in 500 ml of electrophoretic solution was from 0.05 g to 0.125 g. The loading amount of gentamicin increased and the releasing speed of gentamicin decreased after CNTs was added into the CaP/chitosan coating for immersion loading and EPD loading. The cell viability of Mg based CaP/chitosan/CNTs was higher than that of Mg based CaP/chitosan from 16 days to 90 days. PMID:26478396

  8. Productive performance, egg quality, blood constituents, immune functions, and antioxidant parameters in laying hens fed diets with different levels of Yucca schidigera extract.

    PubMed

    Alagawany, Mahmoud; Abd El-Hack, Mohamed E; El-Kholy, Mohamed S

    2016-04-01

    This study evaluated the effect of Yucca schidigera extract on productive performance, egg quality, blood metabolites, immune function, and antioxidant parameters in laying hens. A total of 96 36-week-old hens were allocated into four groups, the control diet or the diet supplemented with 50, 100, or 150 mg/kg of yucca extract, from 36 to 52 weeks of age. Hens were divided into four equal groups replicated six times with four hens per replicate. As a result of this study, there were no linearly or quadratically differences in body weight change (BWC), feed consumption (FC), feed conversion ratio (FCR), and egg weight (EW) due to yucca treatments at different ages, except FCR and EW that were improved with yucca supplementation during 36-40 weeks of age. Supplemental dietary yucca up to 100 mg/kg diet led to significant improvement in egg number (EN) and egg mass (EM). Egg qualities were not linearly or quadratically affected by yucca treatments except shell thickness was quadratically (P < 0.001) increased with increasing yucca level up to 100 mg/kg diet. Dietary supplementation of yucca exhibited a positive impact on albumin and immunoglobulin G (IgG). Comparing to the control group, yucca addition to laying hen diets resulted in a significant linear (P < 0.001) and quadratic (P = 0. 010) decrease in blood ammonia-N and urea-N, respectively. The activity of superoxide dismutase (SOD) and reduced glutathione (GSH) level in serum were quadratically improved in yucca groups. The malondialdehyde (MDA) concentration was decreased with yucca addition in comparison with the control group. In conclusion, yucca supplemented up to 100 mg/kg diet can be used as effective feed additive to improve productive performance, blood profile, and antioxidant enzyme activities in laying hens. PMID:26662788

  9. Repository environmental parameters and models/methodologies relevant to assessing the performance of high-level waste packages in basalt, tuff, and salt

    SciTech Connect

    Claiborne, H.C.; Croff, A.G.; Griess, J.C.; Smith, F.J.

    1987-09-01

    This document provides specifications for models/methodologies that could be employed in determining postclosure repository environmental parameters relevant to the performance of high-level waste packages for the Basalt Waste Isolation Project (BWIP) at Richland, Washington, the tuff at Yucca Mountain by the Nevada Test Site, and the bedded salt in Deaf Smith County, Texas. Guidance is provided on the identify of the relevant repository environmental parameters; the models/methodologies employed to determine the parameters, and the input data base for the models/methodologies. Supporting studies included are an analysis of potential waste package failure modes leading to identification of the relevant repository environmental parameters, an evaluation of the credible range of the repository environmental parameters, and a summary of the review of existing models/methodologies currently employed in determining repository environmental parameters relevant to waste package performance. 327 refs., 26 figs., 19 tabs.

  10. Ionic liquids as mobile phase additives for the high-performance liquid chromatographic analysis of fluoroquinolone antibiotics in water samples.

    PubMed

    Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel Angel

    2008-12-01

    In this work, four ionic liquids differing in the length of the alkyl chain on the imidazolium cation and one ionic liquid containing tetraethylammonium, all with the same counterion, (i.e. 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIm-BF(4)), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF(4)), 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIm-BF(4)), 1-methyl-3-octylimidazolium tetrafluoroborate (MOIm-BF(4)), and tetraethylammonium tetrafluroborate (Et(4)N-BF(4))) were tested as mobile phase additives for HPLC separation of a group of seven basic fluoroquinolone (FQ) antibiotics for human and veterinary use (i.e. fleroxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, and difloxacin) using a conventional reversed-phase Nova-Pak C(18) column. Fluorescence detection was used. Among the ionic liquids selected, use of BMIm-BF(4) enabled effective separation of these compounds with relatively low analysis time (14 min). The best separation was achieved by isocratic elution at 1 mL min(-1) with 5 mmol L(-1) BMIm-BF(4) and 10 mmol L(-1) ammonium acetate at pH 3.0 with 13% (v/v) acetonitrile. Limits of detection (LODs) for fluorescence detection were in the range 0.5-11 microg L(-1). The method was tested by analyzing several water samples after the optimization of a suitable solid-phase extraction (SPE) procedure using Oasis HLB cartridges. Mean recovery values were above 84% for all analytes with LODs in the range 1-29 ng L(-1). PMID:18854988

  11. Small Addition of Boron in Palladium Catalyst, Big Improvement in Fuel Cell's Performance: What May Interfacial Spectroelectrochemistry Tell?

    PubMed

    Jiang, Kun; Chang, Jinfa; Wang, Han; Brimaud, Sylvain; Xing, Wei; Behm, R Jürgen; Cai, Wen-Bin

    2016-03-23

    Direct formic acid fuel cell (DFAFC) with Pd-based catalyst anode is a promising energy converter to power portable devices. However, its commercialization is entangled with insufficient activity and poor stability of existing anode catalysts. Here we initially report that a DFAFC using facilely synthesized Pd-B/C with ca. 6 at. % B doping as the anode catalyst yields a maximum output power density of 316 mW cm(-2) at 30 °C, twice that with a same DFAFC using otherwise the state-of-the-art Pd/C. More strikingly, at a constant voltage of 0.3 V, the output power of the former cell is ca. 9 times as high as that of the latter after 4.5 h of continuous operation. In situ attenuated total reflection infrared spectroscopy is applied to probe comparatively the interfacial behaviors at Pd-B/C and Pd/C in conditions mimicking those for the DFAFC anode operation, revealing that the significantly improved cell performance correlates well with a substantially lowered CO accumulation at B-doped Pd surfaces. PMID:26938473

  12. Understanding the role of dip-coating process parameters in the mechanical performance of polymer-coated bioglass robocast scaffolds.

    PubMed

    Motealleh, Azadeh; Eqtesadi, Siamak; Perera, Fidel Hugo; Pajares, Antonia; Guiberteau, Fernando; Miranda, Pedro

    2016-12-01

    The effect of different dip-coating variables-solvent, deposition temperature and polymer concentration-on the mechanical performance of polycaprolactone-coated 45S5 bioglass robocast scaffolds is systematically analyzed in this work. The reproducible geometry of the scaffolds produced by this additive manufacturing technique makes them an optimal model system and facilitates the analysis. The results suggest that the mechanical performance of the hybrid scaffolds is improved monotonically with polymer concentration, but this concentration cannot be increased indefinitely if the macroporosity interconnectivity, and thus the scaffold׳s capacity to promote tissue ingrowth, are to be preserved. An optimal concentration, and therefore viscosity (~1-4Pas in the present case), exists for any given set of process variables (scaffold geometry and material, polymer, solvent and process temperature) that yields coatings with optimal reinforcement and minimal reduction of scaffold functionality. Solvent and process temperature do not directly affect the strengthening provided by the polymeric coating. However they can determine the maximum concentration at the critical viscosity, and thereby the maximum achievable mechanical performance of the resulting hybrid scaffold. PMID:27522314

  13. Visual and Optical Performances of Multifocal Intraocular Lenses with Three Different Near Additions: 6-Month Follow-Up

    PubMed Central

    Wang, Mengmeng; Corpuz, Christine Carole C; Fujiwara, Megumi; Tomita, Minoru

    2015-01-01

    Purpose : To compare the visual and optical outcomes of four multifocal intraocular lenses (IOLs) with three different near additions of +3.00 diopters (D), +3.75 D and +4.00 D. Methods : In this prospective study, 133 eyes of 88 patients were implanted with one of the following IOLs: AcrySof® ReSTOR® SN6AD1 (+3.00 D) for Group A, AcrivaUD Reviol BB MF 613 or BB MFM 611 (+3.75 D) for Group B, and AcrySof® ReSTOR® SN6AD3 (+4.00 D) for Group C. The visual acuity, refraction, intraocular pressure, tomography and corneal endothelial cell density (ECD) were compared between the three groups preoperatively and at 6 month postoperatively. Defocus curve, contrast sensitivity and higher order aberrations (HOAs) at 6 month postoperative visit were measured and compared. Results : There were no statistically significant differences in distance visual acuity, refraction, intraocular pressure or ECD among the three groups after 6 months (P > 0.05). The photopic contrast sensitivity in Group C was statistically better than in Group A (P < 0.05). The scotopic ocular aberration in Group B was statistically greater compared to that in Group A (P < 0.05). The highest near-visual peaks were -0.06 logMAR at a -2.50 D (40 cm) in Group A, -0.07 logMAR at -3.00D (33 cm) in Group B, and -0.06 logMAR at -3.50 D (29 cm) in Group C. Statistically significant differences in near and intermediate visual acuities were observed among the three groups at -2.00 D (50 cm), -2.50 D (40 cm), -3.50 D (29 cm) and -4.00 D (25 cm) (P < 0.01). Conclusion : AcrySof® ReSTOR® SN6AD1 IOLs (+3.00 D) and SN6AD3 (+4.00 D) IOLs provided the best intermediate and near vision, respectively. Both intermediate and near vision were comparatively better in the eyes with AcrivaUD Reviol BB MFM 611 IOLs or BB MF 613 IOLs (+3.75 D). PMID:25674189

  14. Effect of dietary supplementation of fructooligosaccharide (FOS) on growth performance, survival, lactobacillus bacterial population and hemato-immunological parameters of stellate sturgeon (Acipenser stellatus) juvenile.

    PubMed

    Akrami, Reza; Iri, Yousef; Rostami, Hosseinali Khoshbavar; Razeghi Mansour, Majid

    2013-10-01

    The dietary supplementation of fructooligosaccharide (FOS) in stellate sturgeon juvenile, Acipenser stellatus (with mean initial body weight of 30.16 ± 0.14 g) was evaluated for the effect on growth, autochthonous intestinal microbiata and hemato-immunological parameters for 11 weeks. FOS was added at a level of 0, 1% and 2% to the commercial pellet diet (BioMar). At the end of the experiment, growth parameters, survival rate, lactobacillus bacterial population, hematological and immunological parameters were determined. The fish fed on 1% FOS significantly showed higher final weight, WG%, SGR and PER and lower FCR compared to those of the control group (P < 0.05). Survival rate did not significantly differ between the treatments (P > 0.05). However, FOS administration resulted in lower survival. The serum lysozyme activity was significantly affected by dietary 1% FOS (P < 0.05), while respiratory burst activity was not significantly affected by dietary treatments (P > 0.05). In fish fed on the diet with 1% FOS showed a significant increase of total heterotrophic autochthonous bacterial and presumptive LAB levels (P < 0.05) compared with those fed on the diets supplemented with prebiotics. In addition to increase in WBC, RBC, MCV, hematocrit, hemoglobin and lymphocyte levels were observed in this group. These results indicated that dietary supplementation of FOS at a dose of 1% improved growth performance, beneficial intestinal microbiata and stimulate immune response of stellate sturgeon juvenile. PMID:23973846

  15. The Additive Effects of Values Clarification Training to an Online Goal-Setting Procedure on Measures of Student Retention and Performance

    ERIC Educational Resources Information Center

    Chase, Jared A.

    2010-01-01

    The purpose of this study was to provide individuals with online tutorials to help participants generate strategies to achieve their academic goals and clarify their academic values to assess the additive effects of values clarification training to an online goal-setting training procedure on (1) measures of academic performance and (2) student…

  16. Application of Taguchi technique coupled with grey relational analysis for multiple performance characteristics optimization of EDM parameters on ST 42 steel

    NASA Astrophysics Data System (ADS)

    Prayogo, Galang Sandy; Lusi, Nuraini

    2016-04-01

    The optimization technique of machining parameters considering multiple performance characteristics of non conventional machining EDM process using Taguchi method combined with grey relational analysis (GRA) is presented in this study. ST 42 steel was chosen as material work piece and graphite as electrode during this experiment. Performance characteristics such as material removal rate and overcut are selected to evaluated the effect of machining parameters. Current, pulse on time, pulse off time and discharging time/ Z down were selected as machining parameters. The experiments was conducted by varying that machining parameters in three different levels. Based on the Taguchi quality design concept, a L27 orthogonal array table was chosen for the experiments. By using the combination of GRA and Taguchi, the optimization of complicated multiple performance characteristics was transformed into the optimization of a single response performance index. Optimal levels of machining parameters were identified by using Grey Relational Analysis method. The statistical application of analysis of variance was used to determine the relatively significant machining parameters. The result of confirmation test indicted that the determined optimal combination of machining parameters effectively improve the performance characteristics of the machining EDM process on ST 42 steel.

  17. Chemometric approach to open validation protocols: Prediction of validation parameters in multi-residue ultra-high performance liquid chromatography-tandem mass spectrometry methods.

    PubMed

    Alladio, Eugenio; Pirro, Valentina; Salomone, Alberto; Vincenti, Marco; Leardi, Riccardo

    2015-06-01

    The recent technological advancements of liquid chromatography-tandem mass spectrometry allow the simultaneous determination of tens, or even hundreds, of target analytes. In such cases, the traditional approach to quantitative method validation presents three major drawbacks: (i) it is extremely laborious, repetitive and rigid; (ii) it does not allow to introduce new target analytes without starting the validation from its very beginning and (iii) it is performed on spiked blank matrices, whose very nature is significantly modified by the addition of a large number of spiking substances, especially at high concentration. In the present study, several predictive chemometric models were developed from closed sets of analytes in order to estimate validation parameters on molecules of the same class, but not included in the original training set. Retention time, matrix effect, recovery, detection and quantification limits were predicted with partial least squares regression method. In particular, iterative stepwise elimination, iterative predictors weighting and genetic algorithms approaches were utilized and compared to achieve effective variables selection. These procedures were applied to data reported in our previously validated ultra-high performance liquid chromatography-tandem mass spectrometry multi-residue method for the determination of pharmaceutical and illicit drugs in oral fluid samples in accordance with national and international guidelines. Then, the partial least squares model was successfully tested on naloxone and lormetazepam, in order to introduce these new compounds in the oral fluid validated method, which adopts reverse-phase chromatography. Retention time, matrix effect, recovery, limit of detection and limit of quantification parameters for naloxone and lormetazepam were predicted by the model and then positively compared with their corresponding experimental values. The whole study represents a proof-of-concept of chemometrics potential to

  18. Physical effects of mechanical design parameters on photon sensitivity and spatial resolution performance of a breast-dedicated PET system

    PubMed Central

    Spanoudaki, V. C.; Lau, F. W. Y.; Vandenbroucke, A.; Levin, C. S.

    2010-01-01

    Purpose: This study aims to address design considerations of a high resolution, high sensitivity positron emission tomography scanner dedicated to breast imaging. Methods: The methodology uses a detailed Monte Carlo model of the system structures to obtain a quantitative evaluation of several performance parameters. Special focus was given to the effect of dense mechanical structures designed to provide mechanical robustness and thermal regulation to the minuscule and temperature sensitive detectors. Results: For the energies of interest around the photopeak (450–700 keV energy window), the simulation results predict a 6.5% reduction in the single photon detection efficiency and a 12.5% reduction in the coincidence photon detection efficiency in the case that the mechanical structures are interspersed between the detectors. However for lower energies, a substantial increase in the number of detected events (approximately 14% and 7% for singles at a 100–200 keV energy window and coincidences at a lower energy threshold of 100 keV, respectively) was observed with the presence of these structures due to backscatter. The number of photon events that involve multiple interactions in various crystal elements is also affected by the presence of the structures. For photon events involving multiple interactions among various crystal elements, the coincidence photon sensitivity is reduced by as much as 20% for a point source at the center of the field of view. There is no observable effect on the intrinsic and the reconstructed spatial resolution and spatial resolution uniformity. Conclusions: Mechanical structures can have a considerable effect on system sensitivity, especially for systems processing multi-interaction photon events. This effect, however, does not impact the spatial resolution. Various mechanical structure designs are currently under evaluation in order to achieve optimum trade-off between temperature stability, accurate detector positioning, and minimum

  19. Effects of lycopene supplementation in both maternal and offspring diets on growth performance, antioxidant capacity and biochemical parameters in chicks.

    PubMed

    Sun, B; Chen, C; Wang, W; Ma, J; Xie, Q; Gao, Y; Chen, F; Zhang, X; Bi, Y

    2015-02-01

    This study investigated the effects of different supplementation ways of lycopene during pre-hatch (from the diet of hens) and post-hatch (from the diet of progeny) on production performance, antioxidant capacity and biochemical parameters in chicks. In total, 360 hens were fed diets supplemented with 0 (control group) or 40 mg lycopene/kg diet. From 28 to 34 days after the start of supplementation (30 weeks old), 650 qualified eggs were collected to artificial incubation. In this trial, 2 × 2 factorial designs were used. Male chicks hatched from hens fed with 0 or 40 mg lycopene/kg diet were fed a diet containing either 0 or 40 mg lycopene/kg diet. The results showed that, relative to control, in ovo-deposited lycopene significantly increased chick birth body weight, improved liver total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px) and glutathione to oxidized glutathione ratio (GSH: GSSG), and significantly declined liver malondialdehyde (MDA) level and increased liver lycopene content during 0-14 days after hatching. On days 14 after hatching, dietary lycopene in diet began to take over gradually. Both supplementation ways of lycopene increased immune organ index, serum high-density lipoprotein (HDL) cholesterol, villus length and villus/crypt in duodenum, jejunum and ileum. Data in this study suggested lycopene supplementation could improve antioxidant capacity and immune function, and regulate lipid metabolism in chicks. PMID:24773606

  20. Multi-objective optimization of combustion, performance and emission parameters in a jatropha biodiesel engine using Non-dominated sorting genetic algorithm-II

    NASA Astrophysics Data System (ADS)

    Dhingra, Sunil; Bhushan, Gian; Dubey, Kashyap Kumar

    2014-03-01

    The present work studies and identifies the different variables that affect the output parameters involved in a single cylinder direct injection compression ignition (CI) engine using jatropha biodiesel. Response surface methodology based on Central composite design (CCD) is used to design the experiments. Mathematical models are developed for combustion parameters (Brake specific fuel consumption (BSFC) and peak cylinder pressure (Pmax)), performance parameter brake thermal efficiency (BTE) and emission parameters (CO, NO x , unburnt HC and smoke) using regression techniques. These regression equations are further utilized for simultaneous optimization of combustion (BSFC, Pmax), performance (BTE) and emission (CO, NO x , HC, smoke) parameters. As the objective is to maximize BTE and minimize BSFC, Pmax, CO, NO x , HC, smoke, a multiobjective optimization problem is formulated. Nondominated sorting genetic algorithm-II is used in predicting the Pareto optimal sets of solution. Experiments are performed at suitable optimal solutions for predicting the combustion, performance and emission parameters to check the adequacy of the proposed model. The Pareto optimal sets of solution can be used as guidelines for the end users to select optimal combination of engine output and emission parameters depending upon their own requirements.

  1. Microbial ecology and performance of ammonia oxidizing bacteria (AOB) in biological processes treating petrochemical wastewater with high strength of ammonia: effect of Na(2)CO(3) addition.

    PubMed

    Whang, L M; Yang, K H; Yang, Y F; Han, Y L; Chen, Y J; Cheng, S S

    2009-01-01

    This study evaluated nitrification performance and microbial ecology of AOB in a full-scale biological process, powder activated carbon treatment (PACT), and a pilot-scale biological process, moving bed biofilm reactor (MBBR), treating wastewater collected from a petrochemical industry park. The petrochemical influent wastewater characteristics showed a relative low carbon to nitrogen ratio around 1 with average COD and ammonia concentrations of 310 mg/L and 325 mg-N/L, respectively. The average nitrification efficiency of the full-scale PACT process was around 11% during this study. For the pilot-scale MBBR, the average nitrification efficiency was 24% during the Run I operation mode, which provided a slightly better performance in nitrification than that of the PACT process. During the Run II operation, the pH control mode was switched from addition of NaOH to Na(2)CO(3), leading to a significant improvement in nitrification efficiency of 51%. In addition to a dramatic change in nitrification performance, the microbial ecology of AOB, monitored with the terminal restriction fragment length polymorphism (T-RFLP) molecular methodology, was found to be different between Runs I and II. The amoA-based TRFLP results indicated that Nitrosomonas europaea lineage was the dominant AOB population during Run I operation, while Nitrosospira-like AOB was dominant during Run II operation. To confirm the effects of Na(2)CO(3) addition on the nitrification performance and AOB microbial ecology observed in the MBBR process, batch experiments were conducted. The results suggest that addition of Na(2)CO(3) as a pH control strategy can improve nitrification performance and also influence AOB microbial ecology as well. Although the exact mechanisms are not clear at this time, the results showing the effects of adding different buffering chemicals such as NaOH or Na(2)CO(3) on AOB populations have never been demonstrated until this study. PMID:19182331

  2. Relationship of efficiency indices with performance, heart rate, oxygen consumption, blood parameters, and estimated heat production in Nellore steers.

    PubMed

    Chaves, A S; Nascimento, M L; Tullio, R R; Rosa, A N; Alencar, M M; Lanna, D P

    2015-10-01

    The objective of this study was to examine the relationship of efficiency indices with performance, heart rate, oxygen consumption, blood parameters, and estimated heat production (EHP) in Nellore steers. Eighteen steers were individually lot-fed diets of 2.7 Mcal ME/kg DM for 84 d. Estimated heat production was determined using oxygen pulse (OP) methodology, in which heart rate (HR) was monitored for 4 consecutive days. Oxygen pulse was obtained by simultaneously measuring HR and oxygen consumption during a 10- to 15-min period. Efficiency traits studied were feed efficiency (G:F) and residual feed intake (RFI) obtained by regression of DMI in relation to ADG and midtest metabolic BW (RFI). Alternatively, RFI was also obtained based on equations reported by the NRC's to estimate individual requirement and DMI (RFI calculated by the NRC [1996] equation [RFI]). The slope of the regression equation and its significance was used to evaluate the effect of efficiency indices (RFI, RFI, or G:F) on the traits studied. A mixed model was used considering RFI, RFI, or G:F and pen type as fixed effects and initial age as a covariate. For HR and EHP variables, day was included as a random effect. There was no relationship between efficiency indices and back fat depth measured by ultrasound or daily HR and EHP ( > 0.05). Because G:F is obtained in relation to BW, the slope of G:F was positive and significant ( < 0.05). Regardless of the method used, efficient steers had lower DMI ( < 0.05). The initial LM area was indirectly related to RFI and RFI ( < 0.05); however, the final muscle area was related to only RFI. Oxygen consumption per beat was not related to G:F; however, it was lower for RFI- and RFI-efficient steers, and consequently, oxygen volume (mL·min·kg) and OP (μL O·beat·kg) were also lower ( < 0.05). Blood parameters were not related to RFI and RFI ( > 0.05); however, G:F-efficient steers showed lower hematocrit and hemoglobin concentrations ( < 0

  3. Dietary supplementation with glutamine and γ-aminobutyric acid improves growth performance and serum parameters in 22- to 35-day-old broilers exposed to hot environment.

    PubMed

    Hu, H; Bai, X; Shah, A A; Wen, A Y; Hua, J L; Che, C Y; He, S J; Jiang, J P; Cai, Z H; Dai, S F

    2016-04-01

    This study was designed using 360 21-day-old chicks to determine the influences of diet supplementation with glutamine (5 g/kg), γ-aminobutyric acid (GABA, 100 mg/kg) or their combinations on performance and serum parameters exposed to cycling high temperatures. From 22 to 35 days, the experimental groups (2 × 2) were subjected to circular heat stress by exposing them to 30-34 °C cycling, while the positive control group was exposed to 23 °C constant. The blood of broilers was collected to detect serum parameters on days 28 and 35. Compared with the positive control group, the cycling high temperature decreased (p < 0.05) the feed consumption, weight gain and serum total protein (TP), glucose, thyroxine (T4), insulin, alkaline phosphatase (ALP), glutamine, GABA and glutamate levels, while increased (p < 0.05) the serum triglyceride (TG), corticosterone (CS), glucagon (GN), creatine kinase (CK), glutamic oxaloacetic transaminase (GOT), nitric oxide synthase (NOS), glutamate pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) levels during 22-35 days. However, dietary glutamine (5 g/kg) increased (p < 0.05) the feed consumption, weight gain and serum levels of glutamine, TP, insulin and ALP, but decreased (p < 0.05) the serum TG, CK, GOT, NOS and GPT levels. Diet supplemented with GABA also increased (p < 0.05) weight gain and the serum levels of TP, T4, ALP, GABA and glutamine. In addition, the significant interactions (p < 0.05) between glutamine and GABA were found in the feed consumption, weight gain and the serum ALP, CK, LDH, GABA, T3 and T4 levels of heat-stressed chickens. This research indicated that dietary glutamine and GABA improved the antistress ability in performance and serum parameters of broilers under hot environment. PMID:25980810

  4. Performance analysis of precoding-based asymmetrically clipped optical orthogonal frequency division multiplexing wireless system in additive white Gaussian noise and indoor multipath channel

    NASA Astrophysics Data System (ADS)

    Ranjha, Bilal; Zhou, Zhou; Kavehrad, Mohsen

    2014-08-01

    We have compared the bit error rate (BER) performance of precoding-based asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) and pulse amplitude modulated discrete multitone (PAM-DMT) optical wireless (OW) systems in additive white Gaussian noise (AWGN) and indoor multipath frequency selective channel. Simulation and analytical results show that precoding schemes such as discrete Fourier transform, discrete cosine transform, and Zadoff-Chu sequences do not affect the performance of the OW systems in the AWGN channel while they do reduce the peak-to-average power ratio (PAPR) of the OFDM output signal. However, in a multipath indoor channel, using zero forcing frequency domain equalization precoding-based systems give better BER performance than their conventional counterparts. With additional clipping to further reduce the PAPR, precoding-based systems also show better BER performance compared to nonprecoded systems when clipped relative to the peak of nonprecoded systems. Therefore, precoding-based ACO-OFDM and PAM-DMT systems offer better BER performance, zero signaling overhead, and low PAPR compared to conventional systems.

  5. Effect of solution additives on the performance of PMAN carbon anodes in 1M LiPF{sub 6}/EC-DMC solutions

    SciTech Connect

    Guidotti, R.A.; Johnson, B.J.

    1996-12-31

    A study was undertaken to examine the use of a number of solution additives in 1M LiPF{sub 6}/ethylene carbonate (EC)-dimethyl carbonate (DMC) solutions to improve the performance of carbon anodes derived from polymethylacrylonitrile (PMAN)-divinylbenzene (DVB) copolymers. The study goals were to improve the cycle life and reduce the formation of the passivation layer during the first reduction, thereby minimizing the irreversible-capacity losses. Additives studied were 12-crown-4 (12-Cr-4) ether, decalin, and dilithium phthalocyanine (Li{sub 2}Pc). The carbon performance was characterized by galvanostatic cycling, cyclic voltammetry, and complex-impedance spectroscopy. Limited success was obtained with 12-Cr-4 ether at 0.25 M and decalin at 1 v/o. Poor results were noted with Li{sub 2}Pc at 0.025 M and 0.5 M.

  6. Growth performance and physiological parameters of conventional and specified pathogen-free rats fed autoclaved diets with different protein sources.

    PubMed

    Barszcz, M; Paradziej-Łukowicz, J; Taciak, M; Tuśnio, A; Staśkiewicz, Ł; Muszyńska-Furas, B; Lewandowska, A; Pastuszewska, B; Skomiał, J

    2015-12-01

    The effects of feeding autoclaved commercial SSNIFF (SN) diet and diets containing soya bean (S) and casein (C) to growing conventional (CON) and specified pathogen-free (SPF) rats were determined. Diets S, C and SN, autoclaved at 121 °C during 20 min (T1), at 134 °C during 10 min (T2) and non-autoclaved (T0), were fed during four weeks, each to 8 CON males and 8 females of mean initial body weight 56 g, kept individually. Diets S, C and SN, autoclaved at T1, were fed during two months, each to 20 SPF males and 20 females of mean initial body weight 58 g, kept in group of 5 animals per cage. In CON rats, autoclaving did not affect feed intake and weight gain, decreased thyroid and stomach weight, increased caecal tissue and digesta weight, and concentrations of isobutyric, isovaleric and valeric acid in caecal digesta. Among biochemical blood parameters, autoclaving decreased only total protein concentration and aspartate aminotransferase activity. Feeding C diet resulted in lower feed intake and weight gain in CON and SPF males. Diet affected organ weights and the greatest differences were found in rats on SN diet for weights of stomach, caecum and female reproductive organs. Diet affected concentration of all short-chain fatty acids, pH and weight of caecal digesta, the most important being the greatest butyric acid concentration on SN diet and isoacids on C diet. It is concluded that autoclaving of both soya-containing and soya-free diets does not affect negatively animal performance and physiology. PMID:25475549

  7. The electrochemical performance improvement of LiMn2O4/Zn based on zinc foil as the current collector and thiourea as an electrolyte additive

    NASA Astrophysics Data System (ADS)

    Wu, Xianwen; Li, Yehua; Li, Chuanchang; He, Zhangxing; Xiang, Yanhong; Xiong, Lizhi; Chen, Doris; Yu, Yan; Sun, Kate; He, Zeqiang; Chen, Pu

    2015-12-01

    The polished commercial zinc foil as the current collector and thiourea (TU) as the electrolyte additive are studied systematically to improve the performance of LiMn2O4/Zn aqueous battery. The results show that the coulombic efficiency and the cycling performance are significantly improved by using the polished zinc foil as the anode current collector. Moreover, the TU addition increases the cycling performance of LiMn2O4/Zn battery and decreases the float charge current density of the battery at room as well as high temperature. X-ray diffraction (XRD) and scanning electron microscopy (SEM) tests confirm that there is nearly no effect of TU in the electrolyte on the crystal structure of LiMn2O4 electrode. However, the addition of TU has an indirect effect on the morphology. Cyclic voltammetry (CV) and deposition-dissolution measurement demonstrate that TU is stable on the cathode electrode and it is able to adsorb to the surface of the zinc anode current collector. As such, the deposition-dissolution efficiency and energy efficiency are improved, which also can be attributed to faster deposition-dissolution and smaller self-discharge process of zinc.

  8. Analysis of Geologic Parameters on the Performance of CO2-Plume Geothermal (CPG) Systems in a Multi-Layered Reservoirs

    NASA Astrophysics Data System (ADS)

    Garapati, N.; Randolph, J.; Saar, M. O.

    2013-12-01

    -Burman experiments resulting in 16 simulations for the seven parameters investigated. The reservoir is divided into 3-, 4-, or 5- layer systems with log-normal permeability distributions. We consider 10 sets of values for each case resulting in a total of 16x3x10 =480 simulations.We analyze the performance of the system to maximize the amount of heat energy extracted, minimize reservoir temperature depletion and maximize the CO2concentration in the produced fluid. Achieving the latter objective reduces power system problems as Welch and Boyle (GRC Trans. 2009) found that CO2 concentration should be >94% in the systems they investigated.

  9. The Evaluation of the Effect of Processing Parameters on Adhesion Performance of Polyether based TPU over mold on to Polycarbonate Substrate

    NASA Astrophysics Data System (ADS)

    Patankar, Mukund Purushottam

    The overmolding process involves the use of two separate materials to form one cohesive component. The final product is a single piece, made out of polymers with very different mechanical properties that must be safe and permanently bonded together throughout its useful life. The first shot is generally a hard plastic and is referred to as a substrate the second material is generally a soft thermoplastic elostomer (TPE) and referred as overmold. The rigid substrate is used for structural purposes, and the softer materials are expected to take care of the user comfort. Overmolding can add immeasurable value to product design by enhancing the comforts for user, ergonomics, and ease of use. It finds applications in household appliances, hand tools, automotive interiors, hand held computers and medical devices. The most common problems with overmolding are insufficient chemical or mechanical bonding of the polymers, incomplete filling of one or more components, and flashing of overmold. This paper deals with adhesion issues and describes the study performed to evaluate the effect of processing parameters on adhesion performance of Polyether based TPU over mold on to Polycarbonate Substrate. The study established the effect of various processing parameters on the adhesion of overmold to substrate. In addition effect of various surface roughness of substrate on adhesion was also determined. Study also describes the criteria used to design specimen and the specimen tool was build. The specimens were molded using design of experiments. The specimens were tested using Inston universal testing machine by establishing the test procedure and test set up to yield consistent results. The force at which constant peel occurred, called peel force was determined for all experiments. The study concludes that melt temperature is the most dominating factor and the specimen molded with lower melt temperature results in good bond. Light roughness on the substrate surface further enhances

  10. Effect of PEG additive on anode microstructure and cell performance of anode-supported MT-SOFCs fabricated by phase inversion method

    NASA Astrophysics Data System (ADS)

    Ren, Cong; Liu, Tong; Maturavongsadit, Panita; Luckanagul, Jittima Amie; Chen, Fanglin

    2015-04-01

    Anode-supported micro-tubular solid oxide fuel cells (MT-SOFCs) have been fabricated by phase inversion method. For the anode support preparation, N-methyl-2-pyrrolidone (NMP), polyethersulfone (PESf) and poly ethylene glycol (PEG) were applied as solvent, polymer binder and additive, respectively. The effect of molecular weight and amount of PEG additive on the thermodynamics of the casting solutions was characterized by measuring the coagulation value. Viscosity of the casting slurries was also measured and the influence of PEG additive on viscosity was studied and discussed. The presence of PEG in the casting slurry can significantly influence the final anode support microstructure. Based on the microstructure result and the measured gas permeation value, two anode supports were selected for cell fabrication. For cell with the anode support fabricated using slurry with PEG additive, a maximum cell power density of 704 mW cm-2 is obtained at 750 °C with humidified hydrogen as fuel and ambient air as oxidant; cell fabricated without any PEG additive shows the peak cell power density of 331 mW cm-2. The relationship between anode microstructure and cell performance was discussed.

  11. Food additives

    MedlinePlus

    Food additives are substances that become part of a food product when they are added during the processing or making of that food. "Direct" food additives are often added during processing to: Add nutrients ...

  12. Fatigue performance of laser additive manufactured Ti-6Al-4V in very high cycle fatigue (VHCF) regime up to 109 cycles

    NASA Astrophysics Data System (ADS)

    Wycisk, Eric; Siddique, Shafaqat; Herzog, Dirk; Walther, Frank; Emmelmann, Claus

    2015-12-01

    Additive manufacturing technologies are in the process of establishing themselves as an alternative production technology to conventional manufacturing such as casting or milling. Especially laser additive manufacturing (LAM) enables the production of metallic parts with mechanical properties comparable to conventionally manufactured components. Due to the high geometrical freedom in LAM the technology enables the production of ultra-light weight designs and therefore gains increasing importance in aircraft and space industry. The high quality standards of these industries demand predictability of material properties for static and dynamic load cases. However, fatigue properties especially in the very high cycle fatigue regime until 109 cycles have not been sufficiently determined yet. Therefore this paper presents an analysis of fatigue properties of laser additive manufactured Ti-6Al-4V under cyclic tension-tension until 107 cycles and tension-compression load until 109 cycles. For the analysis of laser additive manufactured titanium alloy Ti-6Al-4V Woehler fatigue tests under tension-tension and tension-compression were carried out in the high cycle and very high cycle fatigue regime. Specimens in stress-relieved as well as hot-isostatic-pressed conditions were analyzed regarding crack initiation site, mean stress sensitivity and overall fatigue performance. The determined fatigue properties show values in the range of conventionally manufactured Ti-6Al-4V with particularly good performance for hot-isostatic-pressed additive-manufactured material. For all conditions the results show no conventional fatigue limit but a constant increase in fatigue life with decreasing loads. No effects of test frequency on life span could be determined. However, independently of testing principle, a shift of crack initiation from surface to internal initiation could be observed with increasing cycles to failure.

  13. The link between a negative high resolution resist contrast/developer performance and the Flory-Huggins parameter estimated from the Hansen solubility sphere

    SciTech Connect

    StCaire, Lorri; Olynick, Deirdre L.; Chao, Weilun L.; Lewis, Mark D.; Lu, Haoren; Dhuey, Scott D.; Liddle, J. Alexander

    2008-07-01

    We have implemented a technique to identify candidate polymer solvents for spinning, developing, and rinsing for a high resolution, negative electron beam resist hexa-methyl acetoxy calix(6)arene to elicit the optimum pattern development performance. Using the three dimensional Hansen solubility parameters for over 40 solvents, we have constructed a Hansen solubility sphere. From this sphere, we have estimated the Flory Huggins interaction parameter for solvents with hexa-methyl acetoxy calix(6)arene and found a correlation between resist development contrast and the Flory-Huggins parameter. This provides new insights into the development behavior of resist materials which are necessary for obtaining the ultimate lithographic resolution.

  14. Adjusting the specificity of an engine map based on the sensitivity of an engine control parameter relative to a performance variable

    DOEpatents

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2014-10-28

    Methods and systems for engine control optimization are provided. A first and a second operating condition of a vehicle engine are detected. An initial value is identified for a first and a second engine control parameter corresponding to a combination of the detected operating conditions according to a first and a second engine map look-up table. The initial values for the engine control parameters are adjusted based on a detected engine performance variable to cause the engine performance variable to approach a target value. A first and a second sensitivity of the engine performance variable are determined in response to changes in the engine control parameters. The first engine map look-up table is adjusted when the first sensitivity is greater than a threshold, and the second engine map look-up table is adjusted when the second sensitivity is greater than a threshold.

  15. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  16. Measured effects of retrofits -- a refrigerant oil additive and a condenser spray device -- on the cooling performance of a heat pump

    SciTech Connect

    Levins, W.P.; Sand, J.R.; Baxter, V.D.; Linkous, R.L.

    1996-05-01

    A 15-year old, 3-ton single package air-to-air heat pump was tested in laboratory environmental chambers simulating indoor and outdoor conditions. After documenting initial performance, the unit was retrofitted with a prototype condenser water-spray device and retested. Results at standard ARI cooling rating conditions (95 F outdoor dry bulb and 80/67 F indoor dry bulb/wet bulb temperatures) showed the capacity increased by about 7%, and the electric power demand dropped by about 8%, resulting in a steady-state EER increase of 17%. Suction and discharge pressures were reduced by 7 and 37 psi, respectively. A refrigerant oil additive formulated to enhance refrigerant-side heat transfer was added at a dose of one ounce per ton of rated capacity, and the unit was tested for several days at the same 95 F outdoor conditions and showed essentially no increase in capacity, and a slight 3% increase in steady-state EER. Adding more additive lowered the EER slightly. Suction and discharge pressures were essentially unchanged. The short-term testing showed that the condenser-spray device was effective in increasing the cooling capacity and lowering the electrical demand on an old and relatively inefficient heat pump, but the refrigerant additive had little effect on the cooling performance of the unit. Sprayer issues to be resolved include the effect of a sprayer on a new, high-efficiency air conditioner/heat pump, reliable long-term operation, and economics.

  17. Effect of non-solvent additives on the morphology, pore structure, and direct contact membrane distillation performance of PVDF-CTFE hydrophobic membranes.

    PubMed

    Zheng, Libing; Wu, Zhenjun; Zhang, Yong; Wei, Yuansong; Wang, Jun

    2016-07-01

    Four common types of additives for polymer membrane preparation including organic macromolecule and micromolecule additives, inorganic salts and acids, and the strong non-solvent H2O were used to prepare poly (vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) hydrophobic flat-sheet membranes. Membrane properties including morphology, porosity, hydrophobicity, pore size and pore distribution were investigated, and the permeability was evaluated via direct contact membrane distillation (DCMD) of 3.5g/L NaCl solution in a DCMD configuration. Both inorganic and organic micromolecule additives were found to slightly influence membrane hydrophobicity. Polyethylene glycol (PEG), organic acids, LiCl, MgCl2, and LiCl/H2O mixtures were proved to be effective additives to PVDF-CTFE membranes due to their pore-controlling effects and the capacity to improve the properties and performance of the resultant membranes. The occurrence of a pre-gelation process showed that when organic and inorganic micromolecules were added to PVDF-CTFE solution, the resultant membranes presented a high interconnectivity structure. The membrane prepared with dibutyl phthalate (DBP) showed a nonporous surface and symmetrical cross-section. When H2O and LiCl/H2O mixtures were also used as additives, they were beneficial for solid-liquid demixing, especially when LiCl/H2O mixed additives were used. The membrane prepared with 5% LiCl+2% H2O achieved a flux of 24.53kg/(m(2)·hr) with 99.98% salt rejection. This study is expected to offer a reference not only for PVDF-CTFE membrane preparation but also for other polymer membranes. PMID:27372116

  18. Investigation on the effect of different levels of dried sweet orange (Citrus sinensis) pulp on performance, carcass characteristics and physiological and biochemical parameters in broiler chicken

    PubMed Central

    Abbasi, Hossein; Seidavi, Alireza; Liu, Wuyi; Asadpour, Leila

    2014-01-01

    Utilization of agricultural by-products in animal nutrition is a matter of great concern. Dried sweet orange (Citrus sinensis) pulp (DCSP) is a potential source of valuable nutrients and natural antioxidants for poultry feed. In the experiment, a feeding trial was conducted in order to investigate the effect of different levels of dried orange residues in diet on broiler growth performance, carcass characteristics, blood metabolites, humoral immunity, and cecum microbial population. A total of 200 one day experimental broiler chicks were distributed into a completely randomized design (CRD) which included 5 dietary treatments with 4 replicates per each treatment and 10 birds fed in each replicate. The experimental treatments consist of a control group (without additive), 0.5%, 1.0%, 1.5%, and 2% of DCSP (residue) in diet. Weight gain, feed intake and feed conversion ratio (FCR) were measured. Blood parameters and carcass traits were measured in the postnatal 35th day. The highest level of dried orange residues in treatment 5 (T5) had significantly increased the feed intake and body weight of broilers in groups and overall during the rearing period (P > 0.05). Different levels of dried orange residues had no significant effect on chicken FCR. Using of dried orange residues significantly decreased the liver and abdominal fat of broilers (P < 0.05). T5 has also significantly lower level of triglyceride than the control (T1) and treatment 2 (T2) (P < 0.05). In conclusion, the use of dried orange residues improved some performance (e.g. feed intake and body weight gain), decreased liver and abdominal fat and also serum triglyceride level in broiler chicken. PMID:25737644

  19. Investigation on the effect of different levels of dried sweet orange (Citrus sinensis) pulp on performance, carcass characteristics and physiological and biochemical parameters in broiler chicken.

    PubMed

    Abbasi, Hossein; Seidavi, Alireza; Liu, Wuyi; Asadpour, Leila

    2015-03-01

    Utilization of agricultural by-products in animal nutrition is a matter of great concern. Dried sweet orange (Citrus sinensis) pulp (DCSP) is a potential source of valuable nutrients and natural antioxidants for poultry feed. In the experiment, a feeding trial was conducted in order to investigate the effect of different levels of dried orange residues in diet on broiler growth performance, carcass characteristics, blood metabolites, humoral immunity, and cecum microbial population. A total of 200 one day experimental broiler chicks were distributed into a completely randomized design (CRD) which included 5 dietary treatments with 4 replicates per each treatment and 10 birds fed in each replicate. The experimental treatments consist of a control group (without additive), 0.5%, 1.0%, 1.5%, and 2% of DCSP (residue) in diet. Weight gain, feed intake and feed conversion ratio (FCR) were measured. Blood parameters and carcass traits were measured in the postnatal 35th day. The highest level of dried orange residues in treatment 5 (T5) had significantly increased the feed intake and body weight of broilers in groups and overall during the rearing period (P > 0.05). Different levels of dried orange residues had no significant effect on chicken FCR. Using of dried orange residues significantly decreased the liver and abdominal fat of broilers (P < 0.05). T5 has also significantly lower level of triglyceride than the control (T1) and treatment 2 (T2) (P < 0.05). In conclusion, the use of dried orange residues improved some performance (e.g. feed intake and body weight gain), decreased liver and abdominal fat and also serum triglyceride level in broiler chicken. PMID:25737644

  20. Methods for Quantifying the Uncertainties of LSIT Test Parameters, Test Results, and Full-Scale Mixing Performance Using Models Developed from Scaled Test Data

    SciTech Connect

    Piepel, Gregory F.; Cooley, Scott K.; Kuhn, William L.; Rector, David R.; Heredia-Langner, Alejandro

    2015-05-01

    This report discusses the statistical methods for quantifying uncertainties in 1) test responses and other parameters in the Large Scale Integrated Testing (LSIT), and 2) estimates of coefficients and predictions of mixing performance from models that relate test responses to test parameters. Testing at a larger scale has been committed to by Bechtel National, Inc. and the U.S. Department of Energy (DOE) to “address uncertainties and increase confidence in the projected, full-scale mixing performance and operations” in the Waste Treatment and Immobilization Plant (WTP).