Science.gov

Sample records for determining acceptable thermal

  1. Monte Carlo determination of Phoswich Array acceptance

    SciTech Connect

    Costales, J.B.; E859 Collaboration

    1992-07-01

    The purpose of this memo is to describe the means by which the acceptance of the E859 Phoswich Array is determined. By acceptance, two things are meant: first, the geometrical acceptance (the angular size of the modules); second, the detection acceptance (the probability that a particle of a given 4-momentum initially in the detector line-of-sight is detected as such). In particular, this memo will concentrate on those particles for which the energy of the particle can be sufficiently measured; that is to say, protons, deuterons and tritons. In principle, the phoswich array can measure the low end of the pion energy spectrum, but with a poor resolution. The detection acceptance of pions and baryon clusters heavier than tritons will be neglected in this memo.

  2. Evaluation and certification of heater assemblies developed for thermal vacuum acceptance testing

    NASA Technical Reports Server (NTRS)

    Allen, J. E.

    1986-01-01

    Preparation of Rockwell International's Thermal Vacuum Chamber for acceptance testing of a mass produced satellite required the development of unique quartz lamp and hot wire heater assemblies. Testing performed on the basic elements of these heaters is described, as is the final testing done to certify that the heater assemblies meet the thermal requirements for acceptance testing. The methods and procedures of thermal mapping used during the development and final certification of these heater assemblies are presented. The absence of a definitive standard for determining flux distribution and heating boundaries for heaters of this type required the development of a test plan incorporating several thermal mapping techniques. These techniques include the development of heat flux using a multiple calorimeter array for both vacuum and ambient test conditions, and a photographic method for detecting heating boundaries. The test plan and thermal mapping techniques are discussed.

  3. Determining Performance Acceptability of Electrochemical Oxygen Sensors

    NASA Technical Reports Server (NTRS)

    Gonzales, Daniel

    2012-01-01

    A method has been developed to screen commercial electrochemical oxygen sensors to reduce the failure rate. There are three aspects to the method: First, the sensitivity over time (several days) can be measured and the rate of change of the sensitivity can be used to predict sensor failure. Second, an improvement to this method would be to store the sensors in an oxygen-free (e.g., nitrogen) environment and intermittently measure the sensitivity over time (several days) to accomplish the same result while preserving the sensor lifetime by limiting consumption of the electrode. Third, the second time derivative of the sensor response over time can be used to determine the point in time at which the sensors are sufficiently stable for use.

  4. Determinants of debit cards acceptance: An empirical investigation

    NASA Astrophysics Data System (ADS)

    Ismail, Shafinar; Bakri, Mohamed Hariri; Zulkepli, Jafri; Adnan, Azimah; Azizi, Amsyar

    2014-12-01

    These days, most of the Malaysians realize that the consumption of debit card will help them to reduce the household debt. Thus, it is important to analyse the acceptance of debit cards for further enhancement and expanding its market share in Malaysia. In addition, there is lacked of research being conducted on the determinants affecting the acceptance of debit cards among Malaysians. Thus, the study aimed to investigate the factors affecting the acceptance of debit cards. This study focuses on payment methods, consumer attitude, and safety of debit card in acceptance of debit cards. Questionnaires were distributed to the 300 respondents. The sampling procedure adopted was stratified random sampling. The data obtained were analysed using SPSS 20.0 which involves scale reliability, descriptive and regression analysis. The result indicates that payment methods, consumer attitude and safety are the determinants of debit cards acceptance. Safety is the best predictor as most of the customers are confidents to use debit cards because of the security being developed around these debit card transactions. The analyses presented in this study can be used by policymakers and managers as a guide to promote banking products and services. The findings achieved in this study will be of interest for practitioners and academics concerned with developments of the Malaysian banking industry.

  5. Determinants of debit cards acceptance: An empirical investigation

    SciTech Connect

    Ismail, Shafinar; Adnan, Azimah; Azizi, Amsyar; Bakri, Mohamed Hariri; Zulkepli, Jafri

    2014-12-04

    These days, most of the Malaysians realize that the consumption of debit card will help them to reduce the household debt. Thus, it is important to analyse the acceptance of debit cards for further enhancement and expanding its market share in Malaysia. In addition, there is lacked of research being conducted on the determinants affecting the acceptance of debit cards among Malaysians. Thus, the study aimed to investigate the factors affecting the acceptance of debit cards. This study focuses on payment methods, consumer attitude, and safety of debit card in acceptance of debit cards. Questionnaires were distributed to the 300 respondents. The sampling procedure adopted was stratified random sampling. The data obtained were analysed using SPSS 20.0 which involves scale reliability, descriptive and regression analysis. The result indicates that payment methods, consumer attitude and safety are the determinants of debit cards acceptance. Safety is the best predictor as most of the customers are confidents to use debit cards because of the security being developed around these debit card transactions. The analyses presented in this study can be used by policymakers and managers as a guide to promote banking products and services. The findings achieved in this study will be of interest for practitioners and academics concerned with developments of the Malaysian banking industry.

  6. The indicator performance estimate approach to determining acceptable wilderness conditions

    NASA Astrophysics Data System (ADS)

    Hollenhorst, Steven; Gardner, Lisa

    1994-11-01

    Using data from a study conducted in the Cranberry Wilderness Area of West Virginia, United States, this paper describes how a modified importance—performance approach can be used to prioritize wilderness indicators and determine how much change from the pristine is acceptable. The approach uses two key types of information: (1) indicator importance, or visitor opinion as to which wilderness indicators have the greatest influence on their experience, and (2) management performance, or the extent to which actual indicator conditions exceed or are within visitor expectations. Performance was represented by calculating indicator performance estimates (IPEs), as defined by standardized differences between actual conditions and visitor preferences for each indicator. The results for each indicator are then presented graphically on a four-quadrant matrix for objective interpretation. Each quadrant represents a management response: keep up the good work, concentrate here, low priority, or possible overkill. The technique allows managers to more systematically and effectively utilize information routinely collected during the limits of acceptable change wilderness planning process.

  7. Porosity determination of thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Van Roode, Mark; Beardsley, Brad

    1988-01-01

    Coating porosity is believed to be a critical factor for the thermal conductivity of thermal barrier coatings (TBCs). A number of different techniques have been used to determine the porosities of thermal barrier coatings for diesel applications as part of a NASA/DOE sponsored study. A comparison is made between methods based on water immersion, optical microscopy, eddy current thickness measurements, and Archimedes principle for TBC porosity determination.

  8. Determinants of Taste Preference and Acceptability: Quality vs. Hedonics

    PubMed Central

    Loney, Gregory C.; Blonde, Ginger D.; Eckel, Lisa A.; Spector, Alan C.

    2012-01-01

    Several methods exist for reliably determining the motivational valence of a taste stimulus in animals, but few to determine its perceptual quality independent of its apparent affective properties. Individual differences in taste preference and acceptability could result from variance in the perceptual qualities of the stimulus leading to different hedonic evaluations. Alternatively, taste perception might be identical across subjects whereas processing of the sensory signals in reward circuits could differ. Utilizing an operant-based taste cue discrimination/generalization task involving a gustometer, we trained male Long-Evans rats to report the degree to which a test stimulus resembled the taste quality of either sucrose or quinine irrespective of its intensity. The rats, grouped by a characteristic bimodal phenotypic difference in their preference for sucralose, treated this artificial sweetener as qualitatively different with the sucralose-preferring rats finding the stimulus much more perceptually similar to sucrose, relative to sucralose-avoiding rats. Although the possibility that stimulus palatability may have served as a discriminative cue cannot entirely be ruled out, the profile of results suggested otherwise. Subsequent brief-access licking tests revealed that affective licking responses of the same sucralose-avoiding and -preferring rats differed across concentration in a manner roughly similar to that found in the stimulus generalization task. Thus, the perceived taste quality of sucralose alone may be sufficient to drive the observed behavioral avoidance of the compound. By virtue of its potential ability to dissociate the sensory and motivational consequences of a given experimental manipulation on taste-related behavior, this approach could be interpretively valuable. PMID:22815522

  9. Effect of addition of thermally modified cowpea protein on sensory acceptability and textural properties of wheat bread and sponge cake.

    PubMed

    Campbell, Lydia; Euston, Stephen R; Ahmed, Mohamed A

    2016-03-01

    This paper investigates the sensory acceptability and textural properties of leavened wheat bread and sponge cake fortified with cow protein isolates that had been denatured and glycated by thermal treatment. Defatted cowpea flour was prepared from cow pea beans and the protein isolate was prepared (CPI) and thermally denatured (DCPI). To prepare glycated cowpea protein isolate (GCPI) the cowpea flour slurry was heat treated before isolation of the protein. CPI was more susceptible to thermal denaturation than GCPI as determined by turbidity and sulphydryl groups resulting in greater loss of solubility. This is attributed to the higher glycation degree and higher carbohydrate content of GCPI as demonstrated by glycoprotein staining of SDS PAGE gels. Water absorption of bread dough was significantly enhanced by DCPI and to a larger extent GCPI compared to the control, resulting in softer texture. CPI resulted in significantly increased crumb hardness in baked bread than the control whereas DCPI or GCPI resulted in significantly softer crumb. Bread fortified with 4% DCPI or GCPI was similar to control as regards sensory and textural properties whereas 4% CPI was significantly different, limiting its inclusion level to 2%. There was a trend for higher sensory acceptability scores for GCPI containing bread compared DCPI. Whole egg was replaced by 20% by GCPI (3.5%) in sponge cake without affecting the sensory acceptability, whereas CPI and DCPI supplemented cakes were significantly different than the control.

  10. Determinants of Mobile Learning Acceptance: An Empirical Investigation in Higher Education

    ERIC Educational Resources Information Center

    Akour, Hassan

    2010-01-01

    Scope and method of study: The purpose of this study was to investigate the determinants of mobile learning acceptance in higher education. Mobile learning is a rapidly growing method of learning that utilizes mobile devices to deliver content. Acceptance of mobile learning theory was derived from technology acceptance theories. The study…

  11. Determination of thermal/dynamic characteristics of lava flow from surface thermal measurements

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, Alik; Melnik, Oleg; Korotkii, Alexander; Tsepelev, Igor; Kovtunov, Dmitry

    2016-04-01

    Rapid development of ground based thermal cameras, drones and satellite data allows getting repeated thermal images of the surface of the lava flow. Available instrumentation allows getting a large amount of data during a single lava flow eruption. These data require development of appropriate quantitative techniques to link subsurface dynamics with observations. We present a new approach to assimilation of thermal measurements at lava's surface to the bottom of the lava flow to determine lava's thermal and dynamic characteristics. Mathematically this problem is reduced to solving an inverse boundary problem. Namely, using known conditions at one part of the model boundary we determine the missing condition at the remaining part of the boundary. Using an adjoint method we develop a numerical approach to the mathematical problem based on the determination of the missing boundary condition and lava flow characteristics. Numerical results show that in the case of smooth input data lava temperature and velocity can be determined with a high accuracy. A noise imposed on the smooth input data results in a less accurate solution, but still acceptable below some noise level. The proposed approach to assimilate measured data brings an opportunity to estimate thermal budget of the lava flow.

  12. 41 CFR 101-27.506 - Determination of acceptability for credit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-INVENTORY MANAGEMENT 27.5-Return of GSA Stock Items § 101-27.506 Determination of acceptability for credit... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Determination of acceptability for credit. 101-27.506 Section 101-27.506 Public Contracts and Property Management...

  13. Determining the drivers' acceptance of EFTCD in highway work zones.

    PubMed

    Bai, Yong; Li, Yingfeng

    2011-05-01

    Traffic safety is a major concern in the temporary one-lane, two-way highway work zones due to the increasing of construction and maintenance operations. To prevent rear-end crashes and to mitigate the severity of these crashes caused by the inattentive driving, the utilization of the Emergency Flasher Traffic Control Device (EFTCD) was under consideration by government agencies, in addition to existing temporary traffic control devices installed in the one-lane, two-way highway work zones. The EFTCD was a newly proposed traffic warning device implemented through the use of vehicles' hazard warning flashers. The primary objective of the research project was to investigate the drivers' acceptance of the proposed EFTCD by measuring the mean speed changes of vehicles with and without EFTCD and by evaluating the drivers' opinions of the EFTCD using the survey method. Field experimental results revealed that the EFTCD effectively reduced the mean vehicle speeds in the upstream of two work zones. A slow speed is more likely to reduce the severity of a crash in work zones. In addition, survey results indicated that 60% of the drivers thought the EFTCD signified a need for speed reduction and 82% of drivers recommended the implementation of the EFTCD in one-lane, two-way work zones. These results provide the necessary scientific justifications for the government agencies to decide if the EFTCD should be implemented in the one-lane, two-way highway work zones to prevent rear-end crashes and to mitigate the severity of these crashes.

  14. Determination of Thermal Properties of Composting Bulking Materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal properties of compost bulking materials affect temperature and biodegradation during the composting process. Well determined thermal properties of compost feedstocks will therefore contribute to practical thermodynamic approaches. Thermal conductivity, thermal diffusivity, and volumetric hea...

  15. Of Acceptable Risk: Science and the Determination of Safety.

    ERIC Educational Resources Information Center

    Lowrance, William W.

    This book looks at the problems of determination of safety and the underlying concept of safety itself. It is believed that if certain pervasive themes are properly appreciated, the whole field of safety will be better understood. The first chapter of the book sketches the general nature of safety decisions, defining safety as a measure of the…

  16. Determinants Of Acceptability Of Radiographic Images For Archival Digital Storage

    NASA Astrophysics Data System (ADS)

    Markivee, C. R.; Nalesnik, W. J.; Chiang, M. C.; Tio, J. R.; Hall, E. L.

    1983-05-01

    The parameter, quality of radiographic film exposure, was evaluated by computer and 15 human observers for the purpose of determining the feasibility of automatic computer eval-uation of radiographs prior to archival storage. Histograms of digitized knee radiographs were parameterized according to the Pearson technique and the computer was used to grade exposure quality relative to a set of training radiographs evaluated by the readers. There was a significant variation in the assessment of film exposure quality among the different observers. The computer scored 73% for the AP films and 53% for the laterals relative to the general consensus. The discrepancies were explained in terms of differences in anatomy and radiographic technique. The significance of this work is that it demonstrates that a computer can grade films according to a predetermined standard set by the radiologist.

  17. 41 CFR 102-75.1150 - What happens to the gift if GSA determines it to be acceptable?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... if GSA determines it to be acceptable? 102-75.1150 Section 102-75.1150 Public Contracts and Property...-75.1150 What happens to the gift if GSA determines it to be acceptable? When GSA determines that the gift is acceptable and can be accepted and used in the form in which it was offered, GSA must...

  18. Determinants of Intention to Use eLearning Based on the Technology Acceptance Model

    ERIC Educational Resources Information Center

    Punnoose, Alfie Chacko

    2012-01-01

    The purpose of this study was to find some of the predominant factors that determine the intention of students to use eLearning in the future. Since eLearning is not just a technology acceptance decision but also involves cognition, this study extended its search beyond the normal technology acceptance variables into variables that could affect…

  19. Determination of the thermal stability of perfluoroalkylethers

    NASA Technical Reports Server (NTRS)

    Helmick, Larry S.; Jones, William R., Jr.

    1990-01-01

    The thermal decomposition temperatures of several commercial and custom synthesized perfluoroalkylether fluids were determined with a computerized tensimeter. In general, the decomposition temperatures of the commercial fluids were all similar and significantly higher than those for custom synthesized fluids. Correlation of the decomposition temperatures with the molecular structures of the primary components of the commercial fluids revealed that the stability of the fluids is not affected by intrinsic factors such as carbon chain length, branching, or cumulated difluoroformal groups. Instead, correlation with extrinsic factors revealed that the stability may be limited by the presence of small quantities of thermally unstable material and/or chlorine-containing material arising from the use of chlorine-containing solvents during synthesis. Finally, correlation of decomposition temperatures with molecular weights for Demnum and Krytox fluids supports a chain cleavage reaction mechanism for Demnum fluids and an unzipping reaction mechanism for Krytox fluids.

  20. Method of determining the thermal deformations of astronomical mirrors

    NASA Technical Reports Server (NTRS)

    Khablo-Grossvald, Y. G.

    1986-01-01

    Procedures are given for calculating thermal fields and associated thermal deformations in astronomical mirrors. A technique is described for thermal strain simulation when complex thermal fields develop in astronomical mirrors. Thermal strains in pyroceramic, quartz and pyrex mirrors can be effectively determined at temperatures ranging from -70 to 150 C by this technique.

  1. Acceptance Performance Test Guideline for Utility Scale Parabolic Trough and Other CSP Solar Thermal Systems: Preprint

    SciTech Connect

    Mehos, M. S.; Wagner, M. J.; Kearney, D. W.

    2011-08-01

    Prior to commercial operation, large solar systems in utility-size power plants need to pass a performance acceptance test conducted by the engineering, procurement, and construction (EPC) contractor or owners. In lieu of the present absence of ASME or other international test codes developed for this purpose, the National Renewable Energy Laboratory has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. Progress on interim guidelines was presented at SolarPACES 2010. Significant additions and modifications were made to the guidelines since that time, resulting in a final report published by NREL in April 2011. This paper summarizes those changes, which emphasize criteria for assuring thermal equilibrium and steady state conditions within the solar field.

  2. Determining heat tolerance in finishing pigs using thermal imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat production from modern pigs has been determined to be significantly higher than previously defined in the standards. This increase in heat production changes the thermal needs of growing swine. A study was designed to evaluate thermal images to determine the thermal status of swine. Thermal ...

  3. 32 CFR 644.543 - Determination of acceptable offers after advertising.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... experienced real estate employee who need not be a real estate appraiser. This determination may be in the... (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Sale Procedure § 644.543 Determination of acceptable... not required where real property components: (1) Are to be offered on a competitive sale basis...

  4. 32 CFR 644.543 - Determination of acceptable offers after advertising.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... experienced real estate employee who need not be a real estate appraiser. This determination may be in the... (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Sale Procedure § 644.543 Determination of acceptable... not required where real property components: (1) Are to be offered on a competitive sale basis...

  5. 32 CFR 644.543 - Determination of acceptable offers after advertising.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... experienced real estate employee who need not be a real estate appraiser. This determination may be in the... (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Sale Procedure § 644.543 Determination of acceptable... not required where real property components: (1) Are to be offered on a competitive sale basis...

  6. 32 CFR 644.543 - Determination of acceptable offers after advertising.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... experienced real estate employee who need not be a real estate appraiser. This determination may be in the... (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Sale Procedure § 644.543 Determination of acceptable... not required where real property components: (1) Are to be offered on a competitive sale basis...

  7. Experimental methods of determining thermal properties of granite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of thermal properties of granite using the block method is discussed and compared with other methods. Problems that limit the accuracy of contact method in determining thermal properties of porous media are evaluated. Thermal properties of granite is determined in the laboratory with a...

  8. Socio-psychological determinants of public acceptance of technologies: A review

    PubMed Central

    Gupta, Nidhi; Fischer, Arnout R.H.; Frewer, Lynn J.

    2012-01-01

    Historically, many technologies have been associated with societal controversies, leading to public rejection of their use. It is therefore important to understand the psychological determinants of societal acceptance of emerging technologies. Socio-psychological determinants of public acceptance of 10 (controversial) technologies are reviewed. The results indicate that there has been an increased interest in and focus on public acceptance of technologies in academia. Risk, trust, perceived benefit, knowledge, individual differences and attitude were found to have been a focus of research in 60% of articles. The results of correspondence analysis suggest that some determinants have been used more extensively in association with some technologies compared to others. As the published research has predominantly been conducted in North America and Europe, research across different cultural contexts internationally is required if globally relevant conclusions are to be reached. Implications for future research are discussed. PMID:23832558

  9. Determinants of human papillomavirus vaccine acceptability in Latin America and the Caribbean.

    PubMed

    Winkler, Jennifer L; Wittet, Scott; Bartolini, Rosario M; Creed-Kanashiro, Hilary M; Lazcano-Ponce, Eduardo; Lewis-Bell, Karen; Lewis, Merle J; Penny, Mary E

    2008-08-19

    Prophylactic human papillomavirus (HPV) vaccines provide promise as a key component of future cervical cancer prevention programs in the Latin America and the Caribbean region. The successful introduction and acceptance of these vaccines will depend on a range of factors including awareness of cervical cancer as a problem, affordability of the vaccine, political will, competition with other vaccines, feasibility of vaccine delivery and acceptability of the vaccine among the range of groups who will influence uptake. While existing data about acceptability from Latin America and the Caribbean is scarce, it is clear that health policymakers, providers and the general public lack knowledge about HPV and cervical cancer. Furthermore, they would value more local epidemiologic data related to cervical cancer. Price is currently a major barrier to vaccine acceptability and a priority for advocacy. More research is required in Latin America and the Caribbean to determine what messages and strategies will work in these communities.

  10. 18 CFR Appendix A to Part 2 - Guidance for Determining the Acceptable Construction Area for Replacements

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Guidance for Determining the Acceptable Construction Area for Replacements A Appendix A to Part 2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL...

  11. 18 CFR Appendix A to Part 2 - Guidance for Determining the Acceptable Construction Area for Replacements

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Guidance for Determining the Acceptable Construction Area for Replacements A Appendix A to Part 2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL...

  12. 18 CFR Appendix A to Part 2 - Guidance for Determining the Acceptable Construction Area for Replacements

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Guidance for Determining the Acceptable Construction Area for Replacements A Appendix A to Part 2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL...

  13. 18 CFR Appendix A to Part 2 - Guidance for Determining the Acceptable Construction Area for Replacements

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Guidance for Determining the Acceptable Construction Area for Replacements A Appendix A to Part 2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL...

  14. 50 CFR 600.1006 - Accepting a request for, and determinations about conducting, a subsidized program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Accepting a request for, and determinations about conducting, a subsidized program. 600.1006 Section 600.1006 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Fishing...

  15. 50 CFR 600.1004 - Accepting a request for, and determinations about initiating, a financed program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Accepting a request for, and determinations about initiating, a financed program. 600.1004 Section 600.1004 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Fishing...

  16. Determinants of Acceptance and Subsequent Uptake of the HPV Vaccine in a Cohort in Eldoret, Kenya

    PubMed Central

    Vermandere, Heleen; Naanyu, Violet; Mabeya, Hillary; Vanden Broeck, Davy; Michielsen, Kristien; Degomme, Olivier

    2014-01-01

    The development of Human Papillomavirus (HPV) vaccines provides new opportunities in the fight against cervical cancer. Many acceptability studies have revealed high interest in these vaccines, but acceptance is only a precursor of behavior, and many factors, at personal, community and provider level, may inhibit the translation of willingness to vaccinate into actual uptake. Through a longitudinal study in Eldoret, Kenya, HPV vaccine acceptability was measured before a vaccination program (n = 287) and vaccine uptake, as reported by mothers, once the program was finished (n = 256). In between baseline and follow-up, a pilot HPV vaccination program was implemented via the GARDASIL Access Program, in which parents could have their daughter vaccinated for free at the referral hospital. The program was promoted at schools: Health staff informed teachers who were then asked to inform students and parents. Even though baseline acceptance was very high (88.1%), only 31.1% of the women reported at follow-up that their daughter had been vaccinated. The vaccine was declined by 17.7%, while another 51.2% had wanted the vaccination but were obstructed by practical barriers. Being well-informed about the program and baseline awareness of cervical cancer were independently associated with vaccine uptake, while baseline acceptance was correlated in bivariate analysis. Side effects were of great concern, even among those whose daughter was vaccinated. Possible partner disapproval lowered acceptance at baseline, and women indeed reported at follow-up that they had encountered his opposition. In Kenya, women prove to be very willing to have their daughter vaccinated against cervical cancer. However, in this study, uptake was more determined by program awareness than by HPV vaccine acceptance. School-based vaccination might improve coverage since it reduces operational problems for parents. In addition, future HPV vaccination campaigns should address concerns about side

  17. Analytical methodology for determination of helicopter IFR precision approach requirements. [pilot workload and acceptance level

    NASA Technical Reports Server (NTRS)

    Phatak, A. V.

    1980-01-01

    A systematic analytical approach to the determination of helicopter IFR precision approach requirements is formulated. The approach is based upon the hypothesis that pilot acceptance level or opinion rating of a given system is inversely related to the degree of pilot involvement in the control task. A nonlinear simulation of the helicopter approach to landing task incorporating appropriate models for UH-1H aircraft, the environmental disturbances and the human pilot was developed as a tool for evaluating the pilot acceptance hypothesis. The simulated pilot model is generic in nature and includes analytical representation of the human information acquisition, processing, and control strategies. Simulation analyses in the flight director mode indicate that the pilot model used is reasonable. Results of the simulation are used to identify candidate pilot workload metrics and to test the well known performance-work-load relationship. A pilot acceptance analytical methodology is formulated as a basis for further investigation, development and validation.

  18. Determination of an acceptable assimilable organic carbon (AOC) level for biological stability in water distribution systems with minimized chlorine residual.

    PubMed

    Ohkouchi, Yumiko; Ly, Bich Thuy; Ishikawa, Suguru; Kawano, Yoshihiro; Itoh, Sadahiko

    2013-02-01

    There is considerable interest in minimizing the chlorine residual in Japan because of increasing complaints about a chlorinous odor in drinking water. However, minimizing the chlorine residual causes the microbiological water quality to deteriorate, and stricter control of biodegradable organics in finished water is thus needed to maintain biological stability during water distribution. In this investigation, an acceptable level of assimilable organic carbon (AOC) for biologically stable water with minimized chlorine residual was determined based on the relationship between AOC, the chlorine residual, and bacterial regrowth. In order to prepare water samples containing lower AOC, the fractions of AOC and biodegradable organic matter (BOM) in tap water samples were reduced by converting into biomass after thermal hydrolysis of BOM at alkaline conditions. The batch-mode incubations at different conditions of AOC and chlorine residual were carried out at 20 °C, and the presence or absence of bacterial regrowth was determined. The determined curve for biologically stable water indicated that the acceptable AOC was 10.9 μg C/L at a minimized chlorine residual (0.05 mg Cl(2)/L). This result indicated that AOC removal during current water treatment processes in Japan should be significantly enhanced prior to minimization of the chlorine residual in water distribution.

  19. Intention to Accept Pertussis Vaccination for Cocooning: A Qualitative Study of the Determinants

    PubMed Central

    Hautvast, Jeannine L. A.; van der Velden, Koos; Hulscher, Marlies E. J. L.

    2016-01-01

    Context Several countries have reported a resurgence of pertussis in the last decades. This puts infants (especially <6 months) at risk of severe complications, because they are too young to be fully protected by vaccination. The global pertussis initiative has proposed pertussis vaccination of young infants’ close contacts, in order to reduce pertussis transmission and the burden of the disease on infants. Our aim is to explore the perceived determinants (barriers and facilitators) of intention to accept vaccination among the possible target groups of pertussis vaccination for cocooning. Consideration of these determinants is necessary to optimise the uptake of the vaccination. Methods We conducted 13 focus groups and six individual semi-structured interviews with members of possible target groups for pertussis cocooning (i.e. parents, maternity assistants, midwives, and paediatric nurses) in the Netherlands. Here, both maternal pertussis vaccination as well as pertussis cocooning has not been implemented. The topic list was based on a literature review and a barrier framework. All interviews were transcribed verbatim and two researchers performed thematic content analysis. Findings The participants’ risk perception, outcome expectations, general vaccination beliefs, moral norms, opinion of others, perceived autonomy, anticipated regret, decisional uncertainty, and perceived organisational barriers were all factors that influenced the intention to accept pertussis vaccination for cocooning. Discussion This study has identified nine perceived determinants that influence the intention to accept pertussis cocooning vaccination. We add the following determinants to the literature: perceived cost-effectiveness (as a concept of outcome expectations), justice (as a concept of moral norms), anticipated regret, and decisional uncertainty. We recommend considering these determinants in vaccination programmes for pertussis cocooning vaccination. Experience, information

  20. 45 CFR 2544.130 - How will the Corporation determine whether to solicit or accept a donation?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... solicit or accept a donation? 2544.130 Section 2544.130 Public Welfare Regulations Relating to Public... DONATIONS § 2544.130 How will the Corporation determine whether to solicit or accept a donation? (a) The Corporation will solicit and accept a donation only for the purpose of furthering the mission and goals of...

  1. Determining the Thermal Properties of Space Lubricants

    NASA Technical Reports Server (NTRS)

    Maldonado, Christina M.

    2004-01-01

    Many mechanisms used in spacecrafts, such as satellites or the space shuttle, employ ball bearings or gears that need to be lubricated. Normally this is not a problem, but in outer space the regular lubricants that are used on Earth will not function properly. Regular lubricants will quickly vaporize in the near vacuum of space. A unique liquid called a perfluoropolyalkylether (PFPE) has an extremely low vapor pressure, around l0(exp -10) torr at 20 C, and has been used in numerous satellites and is currently used in the space shuttle. Many people refer to the PFPEs as "liquid Teflon". PFPE lubricants however, have a number of problems with them. Lubricants need many soluble additives, especially boundary and anti-wear additives, in them to function properly. All the regular known boundary additives are insoluble in PFPEs and so PFPEs lubricate poorly under highly loaded conditions leading to many malfunctioning ball bearings and gears. JAXA, the Japanese Space Agency, is designing and building a centrifuge rotor to be installed in the International Space Station. The centrifuge rotor is part of a biology lab module. They have selected a PFPE lubricant to lubricate the rotor s ball bearings and NASA bearing experts feel this is not a wise choice. An assessment of the centrifuge rotor design is being conducted by NASA and part of the assessment entails knowing the physical and thermal properties of the PFPE lubricant. One important property, the thermal diffusivity, is not known. An experimental apparatus was set up in order to measure the thermal diffusivity of the PFPE. The apparatus consists of a constant temperature heat source, cylindrical Pyrex glassware, a thermal couple and digital thermometer. The apparatus was tested and calibrated using water since the thermal diffusivity of water is known.

  2. Psychophysically determining the maximum acceptable weight of lift for polypropylene laminated bags

    PubMed Central

    CHEN, Yi-Lang; HO, Ting-Kuang

    2016-01-01

    The objective of this study was to psychophysically determine the maximum acceptable weight of lift (MAWL) for polypropylene (PP) laminated bags. Twelve men were requested to decide their MAWLs under various task combinations involving 3 lifting ranges, 3 lifting frequencies, and 2 hand conditions. The results revealed that the MAWL was significantly affected by the frequency and range variables (all p<.001), whereas the hand condition did not influence the MAWL. The participants exhibited relatively low MAWL values compared with subjects in previous studies, especially in infrequent lifts. The results of multiple stepwise regression revealed that certain anthropometric data (e.g., chest circumference, wrist circumference, and acromial height) accounted for the percentage of variance for the determined MAWLs, ranging from 56.2% to 83.4%. These data can be obtained simply and quickly, and are considered the superior predictors for MAWL determination when handling PP laminated bags. PMID:27181917

  3. Variety in snack servings as determinant for acceptance in school children.

    PubMed

    Bergamaschi, Valentina; Olsen, Annemarie; Laureati, Monica; Zangenberg, Sabine; Pagliarini, Ella; Bredie, Wender L P

    2016-01-01

    Variety within a meal is known to increase intake. However, intake of certain food items (e.g. vegetables) in children is consistently below recommendations, and increasing the consumption of such food would lead to health benefits. This study investigated how different levels of food variety influence children's acceptance. A total of 132 children, aged from 9 to 11 years, were exposed to vegetables, fruits and nut snacks during mid-morning break at school. Two different sets of stimuli were used in a within subject design: Classical Variety (CV), i.e. serving of different foods and Perceived Variety (PV), i.e. serving of the same food in different shapes. For each set, three levels of variety in the servings were tested: low, medium, and high. Intake and liking were determined for each serving set. ANOVA results showed that intake of CV set decreased according to the level of variety, whereas results of PV set only showed an increase of liking with increasing levels of variety. Adding more variations of products appeared to be less successful on consumption despite changing the liking of the products, may be because consumption is more affected by acceptability and familiarity for the stimuli than by variety.

  4. Evidence contrary to the accepted Diels-Alder mechanism in the thermal modification of vegetable oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A transesterified oleochemical product has been made using two routes. Soybean oil was thermally polymerized anaerobically at 330 deg C. and the material was then transesterified using base catalyst and methanol. Alternatively, a similar product can be obtained by heating methyl linoleate to the sam...

  5. Applying infrared measurements in a measuring system for determining thermal parameters of thermal insulation materials

    NASA Astrophysics Data System (ADS)

    Chudzik, S.

    2017-03-01

    The paper presents results of research on an innovative method for determining thermal parameters of thermal insulating materials. The method is based on harmonic thermal excitations. Temperature measurements at selected points of a specimen under test are performed by means of semiconductor infrared sensors. The study also employs a 3D model of thermal diffusion. To obtain a solution of the coefficient inverse problem a method based on an artificial neural network is presented. The heat transfer coefficient on the specimen surface is estimated on the basis of a reference specimen. The validity of the adopted model of heat diffusion and the usefulness of the method proposed are verified experimentally.

  6. Determination of thermal properties of composting bulking materials.

    PubMed

    Ahn, H K; Sauer, T J; Richard, T L; Glanville, T D

    2009-09-01

    Thermal properties of compost bulking materials affect temperature and biodegradation during the composting process. Well determined thermal properties of compost feedstocks will therefore contribute to practical thermodynamic approaches. Thermal conductivity, thermal diffusivity, and volumetric heat capacity of 12 compost bulking materials were determined in this study. Thermal properties were determined at varying bulk densities (1, 1.3, 1.7, 2.5, and 5 times uncompacted bulk density), particle sizes (ground and bulk), and water contents (0, 20, 50, 80% of water holding capacity and saturated condition). For the water content at 80% of water holding capacity, saw dust, soil compost blend, beef manure, and turkey litter showed the highest thermal conductivity (K) and volumetric heat capacity (C) (K: 0.12-0.81 W/m degrees C and C: 1.36-4.08 MJ/m(3) degrees C). Silage showed medium values at the same water content (K: 0.09-0.47 W/m degrees C and C: 0.93-3.09 MJ/m(3) degrees C). Wheat straw, oat straw, soybean straw, cornstalks, alfalfa hay, and wood shavings produced the lowest K and C values (K: 0.03-0.30 W/m degrees C and C: 0.26-3.45 MJ/m(3) degrees C). Thermal conductivity and volumetric heat capacity showed a linear relationship with moisture content and bulk density, while thermal diffusivity showed a nonlinear relationship. Since the water, air, and solid materials have their own specific thermal property values, thermal properties of compost bulking materials vary with the rate of those three components by changing water content, bulk density, and particle size. The degree of saturation was used to represent the interaction between volumes of water, air, and solids under the various combinations of moisture content, bulk density, and particle size. The first order regression models developed in this paper represent the relationship between degree of saturation and volumetric heat capacity (r=0.95-0.99) and thermal conductivity (r=0.84-0.99) well. Improved

  7. Experimental determination of thermal properties of alluvial soil

    NASA Astrophysics Data System (ADS)

    Kulkarni, N. G.; Bhandarkar, U. V.; Puranik, B. P.; Rao, A. B.

    2016-12-01

    In the present work, thermal conductivity and specific heat of a particular type of alluvial soil used in brick making in a certain region of India (Karad, Maharashtra State) are experimentally determined for later use in the estimation of ground heat loss in clamp type kilns. These properties are determined simultaneously using the steady-state and the transient temperature data measured in the setup constructed for this purpose. Additionally, physical properties of the soil are experimentally determined for use with six models for the prediction of the thermal conductivity of soil. The predictions from the models are compared with the experimental data. A separate data fitting exercise revealed a small temperature dependence of the soil thermal conductivity on the soil mean temperature.

  8. Gender Differences in the Determinants of the Willingness to Accept an International Assignment

    ERIC Educational Resources Information Center

    van der Velde, Mandy E. G.; Bossink, Carin J. H.; Jansen, Paul G. W.

    2005-01-01

    Multinational organisations experience difficulties in finding managers willing to accept international assignments. This study has therefore focused on factors that can predict males' and females' willingness to accept international assignments, or to follow their partners on international assignments. Hypotheses were formulated based on the…

  9. Determination of the Thermal Noise Limit of Graphene Biotransistors.

    PubMed

    Crosser, Michael S; Brown, Morgan A; McEuen, Paul L; Minot, Ethan D

    2015-08-12

    To determine the thermal noise limit of graphene biotransistors, we have measured the complex impedance between the basal plane of single-layer graphene and an aqueous electrolyte. The impedance is dominated by an imaginary component but has a finite real component. Invoking the fluctuation-dissipation theorem, we determine the power spectral density of thermally driven voltage fluctuations at the graphene/electrolyte interface. The fluctuations have 1/f(p) dependence, with p = 0.75-0.85, and the magnitude of fluctuations scales inversely with area. Our results explain noise spectra previously measured in liquid-gated suspended graphene devices and provide realistic targets for future device performance.

  10. Research to Support the Determination of Spacecraft Maximum Acceptable Concentrations of Potential Atmospheric Contaminants

    NASA Technical Reports Server (NTRS)

    Orr, John L.

    1997-01-01

    In many ways, the typical approach to the handling of bibliographic material for generating review articles and similar manuscripts has changed little since the use of xerographic reproduction has become widespread. The basic approach is to collect reprints of the relevant material and place it in folders or stacks based on its dominant content. As the amount of information available increases with the passage of time, the viability of this mechanical approach to bibliographic management decreases. The personal computer revolution has changed the way we deal with many familiar tasks. For example, word processing on personal computers has supplanted the typewriter for many applications. Similarly, spreadsheets have not only replaced many routine uses of calculators but have also made possible new applications because the cost of calculation is extremely low. Objective The objective of this research was to use personal computer bibliographic software technology to support the determination of spacecraft maximum acceptable concentration (SMAC) values. Specific Aims The specific aims were to produce draft SMAC documents for hydrogen sulfide and tetrachloroethylene taking maximum advantage of the bibliographic software.

  11. Determination of thermal diffusivities of cylindrical bodies being cooled

    SciTech Connect

    Dincer, I.

    1996-09-01

    This paper deals with the development of an analytical model for determining the thermal diffusivities of the individual solid cylindrical bodies subjected to cooling is presented. Applications of this model were made using the experimental center temperature data obtained from the cylindrical products (e.g., cucumber and grape) during air cooling at the flow velocity of 2 m/s. As an experimental result, the thermal diffusivities of products were found to be 1.45{times}10{sup {minus}7} m{sup 2}/s for cucumber and 1.68{times}10{sup {minus}7} m{sup 2}/s for grape. It can be concluded that the present model is capable of determining the thermal diffusivities of cylindrical bodies during cooling in a simple and effective form.

  12. Use of thermal lensing for the determination of pyrogens

    NASA Astrophysics Data System (ADS)

    Orlova, N. V.; Proskurnin, M. A.; Samburova, V. A.; Dryagleva, I. D.; Brusnichkin, A. V.

    2003-01-01

    The conditions of spectrophotometric determination of lipopolysaccharides (LPS) by methylene blue dye were proposed. The limit of detection of LPS is 100 ng/ml. The conditions of spectrophotometric determination of LPS with Stains-all were proposed, the limit of detection of LPS is 500 ng/ml. The optimization of spectrophotometric determination of LPS by the reaction of 2-keto-3-deoxyoctonic acid with thiobarbituric acid in the presence of periodate and metaarsenite was made, the limit of detection is 800 ng/ml. The limit of detection by thermal lensing is 70 ng/ml. The thermal-lens method was successfully used for LPS determination in the endotoxin standard from E. coli.

  13. Probing the physical determinants of thermal expansion of folded proteins.

    PubMed

    Dellarole, Mariano; Kobayashi, Kei; Rouget, Jean-Baptiste; Caro, José Alfredo; Roche, Julien; Islam, Mohammad M; Garcia-Moreno E, Bertrand; Kuroda, Yutaka; Royer, Catherine A

    2013-10-24

    The magnitude and sign of the volume change upon protein unfolding are strongly dependent on temperature. This temperature dependence reflects differences in the thermal expansivity of the folded and unfolded states. The factors that determine protein molar expansivities and the large differences in thermal expansivity for proteins of similar molar volume are not well understood. Model compound studies have suggested that a major contribution is made by differences in the molar volume of water molecules as they transfer from the protein surface to the bulk upon heating. The expansion of internal solvent-excluded voids upon heating is another possible contributing factor. Here, the contribution from hydration density to the molar thermal expansivity of a protein was examined by comparing bovine pancreatic trypsin inhibitor and variants with alanine substitutions at or near the protein-water interface. Variants of two of these proteins with an additional mutation that unfolded them under native conditions were also examined. A modest decrease in thermal expansivity was observed in both the folded and unfolded states for the alanine variants compared with the parent protein, revealing that large changes can be made to the external polarity of a protein without causing large ensuing changes in thermal expansivity. This modest effect is not surprising, given the small molar volume of the alanine residue. Contributions of the expansion of the internal void volume were probed by measuring the thermal expansion for cavity-containing variants of a highly stable form of staphylococcal nuclease. Significantly larger (2-3-fold) molar expansivities were found for these cavity-containing proteins relative to the reference protein. Taken together, these results suggest that a key determinant of the thermal expansivities of folded proteins lies in the expansion of internal solvent-excluded voids.

  14. Development of acceptance criteria for batches of silane primer for external tank thermal protection system bonding applications

    NASA Technical Reports Server (NTRS)

    Mikes, F.

    1984-01-01

    Silane primers for use as thermal protection on external tanks were subjected to various analytic techniques to determine the most effective testing method for silane lot evaluation. The analytic methods included high performance liquid chromatography, gas chromatography, thermogravimetry (TGA), and fourier transform infrared spectroscopy (FTIR). It is suggested that FTIR be used as the method for silane lot evaluation. Chromatograms, TGA profiles, bar graphs showing IR absorbances, and FTIR spectra are presented.

  15. An active thermal control surfaces experiment. [spacecraft temperature determination

    NASA Technical Reports Server (NTRS)

    Wilkes, D. R.; Brown, M. J.

    1979-01-01

    An active flight experiment is described that has the objectives to determine the effects of the low earth natural environment and the Shuttle induced environment on selected thermal control and optical surfaces. The optical and thermal properties of test samples will be measured in-situ using an integrating sphere reflectrometer and using calorimetric methods. This experiment has been selected for the Long Duration Exposure Facility (LDEF) flight which will be carried to orbit by the NASA Space Shuttle. The LDEF will remain in orbit to be picked up by a later Shuttle mission and returned for postflight evaluation.

  16. Thermal threshold determination in alcoholic polyneuropathy: an improvement of diagnosis.

    PubMed

    Hilz, M J; Zimmermann, P; Claus, D; Neundörfer, B

    1995-05-01

    Reports on the incidence of alcoholic polyneuropathies are variable depending on diagnostic tools. In this study, 50 chronic alcoholics with positive MALT (Munich Alcoholism Test) and greater than seven years history of excessive alcohol abuse were examined neurologically. Tibial and peroneal motor and sural nerve conduction velocities (NCV) were studied. Warm and cold perception was evaluated in the area behind the internal malleolus using a Somedic-Thermotest. Thresholds were determined by the method of limits. The effect of a slow, medium and fast temperature change rate on thermal perception was tested. Thirty-eight patients (76%) showed signs of neuropathy. Thermal perception was more often abnormal (62%) than NCV (42%) and clinical examination (56%). A medium temperature change rate of 2.0-2.5 degrees C/s was the most sensitive index of small fiber neuropathy. Thermal threshold measurement proved to be a reliable, sensitive and easy to perform method that should become standard in the examination of polyneuropathies.

  17. 18 CFR Appendix A to Part 2 - Guidance for Determining the Acceptable Construction Area for Auxiliary and Replacement Facilities

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Guidance for Determining the Acceptable Construction Area for Auxiliary and Replacement Facilities A Appendix A to Part 2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY...

  18. 41 CFR 102-80.125 - Who has the responsibility for determining the acceptability of each equivalent level of safety...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... responsibility for determining the acceptability of each equivalent level of safety analysis? 102-80.125 Section... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Accident and Fire Prevention Equivalent Level of Safety Analysis § 102-80.125 Who has the responsibility...

  19. Thermal conductivity determination of cometary and asteroid material analogues

    NASA Astrophysics Data System (ADS)

    Banaszkiewicz, M.; Seweryn, K.; Wawrzaszek, R.

    Measurements of physical properties of surface and subsurface layers of planetary bodies often provide important information about the structure of the medium and processes that occur there Thermal properties of cometary nuclues subsurface material are crucial in determining the heat and gas transport Similarly asteroid s regolith is a buffering zone in heat transfer from to surface to from interior of a body There are space experiments planned to perform temperature and thermal conductivity measurements on a comet ROSETTA and one can easily foresee such measurements carried out by future robotic missions on Mars planetary satellites and asteroids In the paper we present the results of measurements carried out with a new type of thermal sensors The elementary cylindrical sensor is made of platinum wire resistance thermometer and isotan wire heating element that can operate independently By choosing these materials the problems of temperature measurement calibration and constant heating power are resolved We confront the results of measurements made for a number of sensors combined into a long cylinder in delrin basalt ice-dust mixture comet analogue and regolith-like material with models and show that agreement is very good Therefore we can recommend both the sensors and the method of data interpretation for the thermal conductivity determination as very useful tools in future space missions and in laboratory experiments on cometary and asteroid material analogues

  20. Determination of effective thermal expansion coefficients of unidirectional fibrous nanocomposites

    NASA Astrophysics Data System (ADS)

    Dai, Ming; Schiavone, Peter; Gao, Cun-Fa

    2016-10-01

    We present an efficient numerical scheme (based on complex variable techniques) to calculate the effective thermal expansion coefficients of a composite containing unidirectional periodic fibers. Moreover, the mechanical behavior of the fibers incorporates interface effects allowing the ensuing analytical model of the composite to accommodate deformations at the nanoscale. The resulting `nanocomposite' is subjected to a uniform temperature variation which leads to periodic deformations within the plane perpendicular to the fibers and uniform deformations along the direction of the fibers. These deformation fields are determined by analyzing a representative unit cell of the composite subsequently leading to the corresponding effective thermal expansion coefficients. Numerical results are illustrated via several physical examples. We find that the influence of interface effects on the effective thermal expansion coefficients (in particular that corresponding to the transverse direction in the plane perpendicular to the fibers) decays rapidly as the fibers become harder. In addition, by comparing the results obtained here with those from effective medium theories, we show that the latter may induce significant errors in the determination of the effective transverse thermal expansion coefficient when the fibers are much softer than the matrix and the fiber volume fraction is relatively high.

  1. Determinants of Parental Acceptance of the H1N1 Vaccine.

    PubMed

    Hilyard, Karen M; Quinn, Sandra Crouse; Kim, Kevin H; Musa, Don; Freimuth, Vicki S

    2014-06-01

    Although designated as a high-risk group during the 2009-2010 H1N1 pandemic, only about 40% of U.S. children received the vaccine, a relatively low percentage compared with high-risk groups in seasonal influenza, such as the elderly, whose vaccine rates typically top 70%. To better understand parental decision making and predictors of acceptance of the H1N1 vaccine, we examined data from a representative national sample of parents (n = 684), using the health belief model as a framework. The most important predictors of vaccine acceptance were "cues to action" at multiple levels, from intrapersonal to mass communication, including the influence of friends, family, the media, and modeling by the Obama family; costs and benefits and self-efficacy were also significant predictors of vaccine acceptance. Higher perceived levels of H1N1 risk were not associated with vaccine uptake. Results suggest that traditional measures of perceived risk may not account for the cost-benefit analysis inherent in vaccine decision making, and that messages designed to emphasize disease risk may be ineffective. The authors recommend emphasizing cues to action that support norming and modeling of vaccine acceptance.

  2. Investigating the Determinants and Age and Gender Differences in the Acceptance of Mobile Learning

    ERIC Educational Resources Information Center

    Wang, Yi-Shun; Wu, Ming-Cheng; Wang, Hsiu-Yuan

    2009-01-01

    With the proliferation of mobile computing technology, mobile learning (m-learning) will play a vital role in the rapidly growing electronic learning market. M-learning is the delivery of learning to students anytime and anywhere through the use of wireless Internet and mobile devices. However, acceptance of m-learning by individuals is critical…

  3. Determinants of Social Networking Software Acceptance: A Multi-Theoretical Approach

    ERIC Educational Resources Information Center

    Shittu, Ahmed Tajudeen; Madarsha, Kamal Basha; AbduRahman, Nik Suryani Nik; Ahmad, Tunku Badariah Tunku

    2013-01-01

    Understanding reasons why students use social media has become a major preoccupation of researchers in recent time due to the rate of its adoption among the present generation of students. Some of the few study on social media phenomenon employed a single theory as a framework in order to understand the factors that influence the acceptance of it…

  4. Oxidative stability, thermal stability and acceptability of coconut oil flavored with essential oils from black pepper and ginger.

    PubMed

    Chandran, Janu; Nayana, N; Roshini, N; Nisha, P

    2017-01-01

    The present study investigates the oxidative and thermal stability of flavoured oils developed by incorporating essential oils from black pepper and ginger to coconut oil (CNO) at concentrations of 0.1 and 1.0% (CNOP-0.1, CNOP-1, CNOG-0.1, CNOG-1). The stability of oils were assessed in terms of free fatty acids, peroxide, p-anisidine, conjugated diene and triene values and compared with CNO without any additives and a positive control with synthetic antioxidant TBHQ (CNOT). It was found that the stability of CNOP-1 and CNOG-1 were comparable with CNOT at both study conditions. The possibility of flavoured oil as a table top salad oil was explored by incorporating the same in vegetable salad and was found more acceptable than the control, on sensory evaluation. The synergetic effect of essential oil as a flavour enhancer and a powerful natural antioxidant that can slow down the oxidation of fats was established in the study.

  5. Psychosocial determinants of physicians' acceptance of recommendations by antibiotic computerised decision support systems: A mixed methods study.

    PubMed

    Chow, Angela; Lye, David C B; Arah, Onyebuchi A

    2015-03-01

    Antibiotic computerised decision support systems (CDSSs) were developed to facilitate optimal prescribing, but acceptance of their recommendations has remained low. We aimed to evaluate physicians' perceptions and attitudes toward antibiotic CDSSs and determine psychosocial factors associated with acceptance of CDSS recommendations for empirical therapy. A mixed methods study was conducted in an adult tertiary-care hospital in Singapore, with its in-house antibiotic CDSS that integrates antimicrobial stewardship with electronic prescribing. Focus group discussions were conducted among purposively sampled physicians and data were analysed using the framework approach. Emerging themes were included in the questionnaire with newly developed scales for the subsequent cross-sectional survey involving all physicians. Principal components analysis was performed to derive the latent factor structure that was later applied in multivariate analyses. Physicians expressed confidence in the credibility of CDSS recommendations. Junior physicians accepted CDSS recommendations most of the time, whilst senior physicians acknowledged overriding recommendations in complex patients with multiple infections or allergies. Willingness to consult the CDSS for common and complex infections (OR=1.68, 95% CI 1.16-2.44) and preference for personal or team decision (OR=0.61, 95% CI 0.43-0.85) were associated with acceptance of CDSS recommendations. Cronbach's α for scales measuring physicians' attitudes and perceptions towards acceptance of CDSS recommendations ranged from 0.64 to 0.88. Physicians' willingness to consult an antibiotic CDSS determined acceptance of its recommendations. Physicians would choose to exercise their own or clinical team's decision over CDSS recommendations in complex patient situations when the antibiotic prescribing needs were not met.

  6. Method for determining thermal conductivity and thermal capacity per unit volume of earth in situ

    DOEpatents

    Poppendiek, Heinz F.

    1982-01-01

    A method for determining the thermal conductivity of the earth in situ is based upon a cylindrical probe (10) having a thermopile (16) for measuring the temperature gradient between sets of thermocouple junctions (18 and 20) of the probe after it has been positioned in a borehole and has reached thermal equilibrium with its surroundings, and having means (14) for heating one set of thermocouple junctions (20) of the probe at a constant rate while the temperature gradient of the probe is recorded as a rise in temperature over several hours (more than about 3 hours). A fluid annulus thermally couples the probe to the surrounding earth. The recorded temperature curves are related to the earth's thermal conductivity, k.sub..infin., and to the thermal capacity per unit volume, (.gamma.c.sub.p).sub..infin., by comparison with calculated curves using estimates of k.sub..infin. and (.gamma.c.sub.p).sub..infin. in an equation which relates these parameters to a rise in the earth's temperature for a known and constant heating rate.

  7. Experimental determination of satellite bolted joints thermal resistance

    NASA Technical Reports Server (NTRS)

    Mantelli, Marcia Barbosa Henriques; Basto, Jose Edson

    1990-01-01

    The thermal resistance was experimentally determined of the bolted joints of the first Brazilian satellite (SCD 01). These joints, used to connect the satellite structural panels, are reproduced in an experimental apparatus, keeping, as much as possible, the actual dimensions and materials. A controlled amount of heat is forced to pass through the joint and the difference of temperature between the panels is measured. The tests are conducted in a vacuum chamber with liquid nitrogen cooled walls, that simulates the space environment. Experimental procedures are used to avoid much heat losses, which are carefully calculated. Important observations about the behavior of the joint thermal resistance with the variation of the mean temperature are made.

  8. Determination of the thermal stability of perfluoropolyalkyl ethers by tensimetry

    NASA Technical Reports Server (NTRS)

    Helmick, Larry A.; Jones, William R., Jr.

    1992-01-01

    The thermal decomposition temperatures of several perfluoropolyalkyl ether fluids were determined with a computerized tensimeter. In general, the decomposition temperatures of the commercial fluids were all similar and significantly higher than those for noncommercial fluids. Correlation of the decomposition temperatures with the molecular structures of the primary components of the commercial fluids revealed that the stability of the fluids was not affected by carbon chain length, branching, or adjacent difluoroformal groups. Instead, stability was limited by the presence of small quantities of thermally unstable material and/or chlorine-containing material arising from the use of chlorine containing solvents during synthesis. Finally, correlation of decomposition temperatures with molecular weights for two fluids supports a chain cleavage reaction mechanism for one and an unzipping reaction mechanism for the other.

  9. What determines the acceptability of genetically modified food that can improve human nutrition?

    PubMed

    Purchase, Iain F H

    2005-09-01

    It has been predicted that by 2025 there will be an annual shortfall of cereals for feeding the human population of 68.5 million tones. One possible solution is the use of genetically modified (GM) crops, which are already grown extensively (59 million ha of GM crops were planted in 2002) in the USA, South America, Africa and China. Nevertheless, there is considerable disagreement about the advisability of using such crops, particularly in Europe. Obviously, the safety of the food derived from the GM crops is a primary consideration. Safety assessment relies on establishing that the food is substantially equivalent to its non-GM counterpart and specific testing for allergenicity of proteins and toxicity of metabolites and the whole food. There appears to be international agreement on the principles of safety assessment. Safety to the environment is equally important, but will not be covered in this presentation. The public's perception of the risk of new technology is critical to its acceptance. Perception of risk, in turn, depends on the credibility of the source of the information and trust in the regulatory process. In many countries, the public appears to have lost its trust in the scientists and government dealing with GM food, making the acceptability of GM crops uncertain. Of equal importance are the socio-economic factors that impinge on the viability of GM produce. These include intellectual property protection, trade liberalization (through subsidy and tariff barriers in developed countries) and the intensity of bio safety regulations. The socio-economic interests of developed and developing countries may diverge and may even be contradictory in any one country. Acceptance of GM crops will thus depend on detailed issues surrounding particular crops and economies.

  10. What determines the acceptability of genetically modified food that can improve human nutrition?

    SciTech Connect

    Purchase, Iain F.H. . E-mail: ifhp@chadzombe.u-net.com

    2005-09-01

    It has been predicted that by 2025 there will be an annual shortfall of cereals for feeding the human population of 68.5 million tonnes. One possible solution is the use of genetically modified (GM) crops, which are already grown extensively (59 million ha of GM crops were planted in 2002) in the USA, South America, Africa and China. Nevertheless, there is considerable disagreement about the advisability of using such crops, particularly in Europe. Obviously, the safety of the food derived from the GM crops is a primary consideration. Safety assessment relies on establishing that the food is substantially equivalent to its non-GM counterpart and specific testing for allergenicity of proteins and toxicity of metabolites and the whole food. There appears to be international agreement on the principles of safety assessment. Safety to the environment is equally important, but will not be covered in this presentation. The public's perception of the risk of new technology is critical to its acceptance. Perception of risk, in turn, depends on the credibility of the source of the information and trust in the regulatory process. In many countries, the public appears to have lost its trust in the scientists and government dealing with GM food, making the acceptability of GM crops uncertain. Of equal importance are the socio-economic factors that impinge on the viability of GM produce. These include intellectual property protection, trade liberalisation (through subsidy and tariff barriers in developed countries) and the intensity of bio safety regulations. The socio-economic interests of developed and developing countries may diverge and may even be contradictory in any one country. Acceptance of GM crops will thus depend on detailed issues surrounding particular crops and economies.

  11. [Evaluation of consumer's acceptance of a peach palm snack (Bactris gasipaes) and determination of its potential as a functional food].

    PubMed

    López-Calvo, Rebeca; Pérez, Ana M; Ivankovich Guillén, Carmen; Calderón Villaplana, Sandra; Pineda Castro, Maria Lourdes

    2015-03-01

    The aim of this study was to evaluate consumers' acceptance of a peach palm snack and to determine its potential as a functional food by chemical characterization. An assessment was conducted with 100 consumers to determine the acceptance of different snack formulations and the results were subjected to cluster analysis. This analysis revealed two groups. Group 2 included people that consume snacks and peach palm frequently and showed the highest grades for the snack evaluated characteristics. All the consumers in group 2 and approximately 85% of the consumers in group 1 indicated that they would buy the product suggesting that there is a niche market for the developed peach palm snack. Also, a qualitative evaluation, using mini focus groups, of the two most widely accepted formulas of the snack (chosen according to previously described study) was performed. The sessions considered the opinion of middle class professionals and housewives. It was determined that the combination of tara gum and carboxymethylcellulose (CMC) allows a positive synergistic effect on the sensory characteristics of the snack, highlighting natural peach flavor and improving crunchiness. In a dry basis, the snack contains per 100 g: 9 ± 4 g of fat, 14.0 ± 0.3 g of dietary fiber, 15500 ± 32 µg of carotenoids and has an antioxidant capacity of 4700 ± 8 µmol TE, which demonstrates its potential as a functional food.

  12. Determination of the thermal, oxidative and photochemical degradation rates of scintillator liquid by fluorescence EEM spectroscopy.

    PubMed

    Andrews, N L P; Fan, J Z; Forward, R L; Chen, M C; Loock, H-P

    2016-12-21

    The thermal, oxidative and photochemical stability of the scintillator liquid proposed for the SNO+ experiment has been tested experimentally using accelerated aging methods. The stability of the scintillator constituents was determined through fluorescence excitation emission matrix (EEM) spectroscopy and absorption spectroscopy, using parallel factor analysis (PARAFAC) as an multivariate analysis tool. By exposing the scintillator liquid to a well-known photon flux at 365 nm and by measuring the decay rate of the fluorescence shifters and the formation rate of their photochemical degradation products, we can place an upper limit on the acceptable photon flux as 1.38 ± 0.09 × 10(-11) photon mol L(-1). Similarly, the oxidative stability of the scintillator liquid was determined by exposure to air at several elevated temperatures. Through measurement of the corresponding activation energy it was determined that the average oxygen concentration would have to be kept below 4.3-7.1 ppbw (headspace partial pressure below 24 ppmv). On the other hand, the thermal stability of the scintillator cocktail in the absence of light and oxygen was remarkable and poses no concern to the SNO+ experiment.

  13. Determination of Viral Capsid Elastic Properties from Equilibrium Thermal Fluctuations

    NASA Astrophysics Data System (ADS)

    May, Eric R.; Brooks, Charles L., III

    2011-05-01

    We apply two-dimensional elasticity theory to viral capsids to develop a framework for calculating elastic properties of viruses from equilibrium thermal fluctuations of the capsid surface in molecular dynamics and elastic network model trajectories. We show that the magnitudes of the long wavelength modes of motion available in a simulation with all atomic degrees of freedom are recapitulated by an elastic network model. For the mode spectra to match, the elastic network model must be scaled appropriately by a factor which can be determined from an icosahedrally constrained all-atom simulation. With this method we calculate the two-dimensional Young’s modulus Y, bending modulus κ, and Föppl-von Kármán number γ, for the T=1 mutant of the Sesbania mosaic virus. The values determined are in the range of previous theoretical estimates.

  14. Determinations of TSD facility acceptability under the CERCLA Off-Site Rule

    SciTech Connect

    1997-06-01

    On September 22, 1993, the US Environmental Protection Agency (EPA) published the ``Off-Site Rule`` to implement section 121(d)(3) of the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). CERCLA {section}121(d)(3) requires that wastes generated as a result of remediation activities taken under CERCLA authority and transferred off-site be managed only at facilities that comply with the Resource Conservation and Recovery Act. In 1994, the DOE`s Office of Environmental Policy and Assistance (OEPA), RCRA/CERCLA Division (EH-413) published a CERCLA Information Brief titled ``The Off-Site Rule`` which describes the content of the Off-Site Rule and clarifies some of its implications for DOE remedial actions under CERCLA. Additionally, EH-413 published the Guide on Selecting Compliant Off-Site Hazardous Waste Treatment, Storage and Disposal Facilities which provides a regulatory roadmap for accomplishing off-site transfers of environmental restoration and process hazardous waste at DOE facilities in a manner compliant with the Off-Site Rule and other relevant Federal regulations. Those guidance documents concentrate primarily on DOE`s perspective as a hazardous waste generator. The purpose of this Information Brief is to address the implications of the Off-Site Rule for DOE-owned hazardous waste treatment, storage or disposal facilities that accept CERCLA remediation wastes from off-site locations.

  15. Guidance for Determining the Acceptability of Environmental Fate Studies Conducted with Foreign Soils

    EPA Pesticide Factsheets

    International and U.S. soil taxonomical classification systems, distribution of soil orders in the United States, specific criteria to help scientists determine when foreign soils are representative of U.S. soils at intended pesticide use sites.

  16. Effect of cycle time and duty cycle on psychophysically determined acceptable levels in a highly repetitive task.

    PubMed

    Moore, Anne; Wells, Richard

    2005-06-10

    Psychophysical methodology has been used to develop guidelines for lifting and more recently similar methods have been applied to repetitive upper limb movements. While a range of cycle times are usually used, there is often no control for duty cycle. The purpose of this paper is to present psychophysically determined acceptable torques for a common upper limb task, with both cycle time and duty cycle conditions set by the researcher. Eight female participants, sitting at adjustable workstations, performed a simulated in-line screw running task. A computer-controlled torque motor applied a torque every 3, 6, 12 or 20 s with a duty cycle of 25, 50 or 83%. The participants worked with one set of conditions each day and self-selected the highest torque that they felt was acceptable without developing undue pain and discomfort. Duty cycle was found to significantly affect the amount of torque selected. With duty cycle controlled, cycle time was no longer found to have any significant effect on selected torque. Acceptable torques for 25, 50 and 83% duty cycles were 1.09, 0.9 and 0.73 Nm. Discomfort and stiffness were concentrated on the back of the hand and on the thumb web. These findings suggest that increased perception of discomfort with increased frequency (decreased cycle time) may be related to decreased rest/recovery time for muscles.

  17. Determinant of Mobile Devices Acceptance for Learning among Students in Developing Country

    ERIC Educational Resources Information Center

    Tajudeen, Shittu Ahmed; Basha, Madarsha Kamal; Michael, Fakomogbon O.; Mukthar, Alhaji Liman

    2013-01-01

    This study was conducted to understand the determinant of mobile devices for learning among students in the developing world. A sample of 247 undergraduate students from Malaysia and Nigeria were involved in the study. An adapted but modified survey instrument was used to gather the data of the study. The variable of the study are perceived…

  18. Determination of thermal dispersivity using a borehole heat exchanger

    NASA Astrophysics Data System (ADS)

    Wagner, V.; Bayer, P.; Bisch, G.; Braun, J.; Klaas, N.; Blum, P.

    2012-04-01

    Shallow geothermal energy is a popular option for the heating and air-conditioning of buildings, because it is a regenerative energy and modern heat-pump-based low-enthalpy geothermal systems are often economically advantageous to alternative technologies. Geothermal systems extract heat from the ground, or inject waste heat. This may cause temperature anomalies in the subsurface, and when shallow aquifers exist, these anomalies can be observed in the groundwater. To ensure an efficiently operating, and in the long-run, sustainable, geothermal system, a precise knowledge of the evolving temperature anomaly is desirable. When planning a system, among the subsurface heat transport processes, advection due to flowing groundwater is not often considered. Accordingly, the role of thermal dispersion is rarely inspected. To determine the thermal dispersion influencing the temperature plume around a borehole heat extractor (BHE), a geothermal lab experiment is performed in an artificial aquifer. The size of the aquifer is 9 m × 6 m × 4.5 m, it is heterogeneous and composed of five different sand layers. In the lab, a specific hydraulic gradient is imposed. A BHE is installed in this aquifer, and the exact size and temporal evolution of the induced temperature anomaly is measured by a monitoring network of over 100 temperature sensors. Based on the known hydraulic and thermal properties of the different sand layers, a high-resolution finite element model is built, which simulates the transient conditions during the experiment. This model contains a fully discretized BHE, with an integrated heat carrier fluid flow inside the U-pipes, located inside the BHE. Therefore, the model is able to consider the coupled processes between the temperature development of the heat carrier fluid and the heat propagation in the subsurface. Except the longitudinal and transversal dispersivity, all material properties and boundary conditions are known, thus the dispersivities can be

  19. Psycho-vibratory evaluation of timber floors - Towards the determination of design indicators of vibration acceptability and vibration annoyance

    NASA Astrophysics Data System (ADS)

    Negreira, J.; Trollé, A.; Jarnerö, K.; Sjökvist, L.-G.; Bard, D.

    2015-03-01

    In timber housing constructions, vibrations can be a nuisance for inhabitants. Notably, the vibrational response of wooden floor systems is an issue in need of being dealt with more adequately in the designing of such buildings. Studies addressing human response to vibrations are needed in order to be able to better estimate what level of vibrations in dwellings can be seen as acceptable. In the present study, measurements on five different wooden floors were performed in a laboratory environment at two locations in Sweden (SP in Växjö and LU in Lund). Acceleration measurements were carried out while a person either was walking on a particular floor or was seated in a chair placed there as the test leader was walking on the floor. These participants filled out a questionnaire regarding their perception and experiencing of the vibrations in question. Independently of the subjective tests, several static and dynamic characteristics of the floors were determined through measurements. The ultimate aim was to develop indicators of human response to floor vibrations, specifically those regarding vibration acceptability and vibration annoyance, their being drawn based on relationships between the questionnaire responses obtained and the parameter values determined on the basis of the measurements carried out. To that end, use was made of multilevel regression. Although the sample of floors tested was small, certain clear trends could be noted. The first eigenfrequency (calculated in accordance with Eurocode 5) and Hu and Chui's criterion (calculated from measured quantities) proved to be the best indicators of vibration annoyance, and the Maximum Transient Vibration Value (computed on the basis of the accelerations experienced by the test subjects) to be the best indicator of vibration acceptability.

  20. Psychological Determinants of Consumer Acceptance of Personalised Nutrition in 9 European Countries

    PubMed Central

    Poínhos, Rui; van der Lans, Ivo A.; Rankin, Audrey; Fischer, Arnout R. H.; Bunting, Brendan; Kuznesof, Sharron; Stewart-Knox, Barbara; Frewer, Lynn J.

    2014-01-01

    Objective To develop a model of the psychological factors which predict people’s intention to adopt personalised nutrition. Potential determinants of adoption included perceived risk and benefit, perceived self-efficacy, internal locus of control and health commitment. Methods A questionnaire, developed from exploratory study data and the existing theoretical literature, and including validated psychological scales was administered to N = 9381 participants from 9 European countries (Germany, Greece, Ireland, Poland, Portugal, Spain, the Netherlands, the UK, and Norway). Results Structural equation modelling indicated that the greater participants’ perceived benefits to be associated with personalised nutrition, the more positive their attitudes were towards personalised nutrition, and the greater their intention to adopt it. Higher levels of nutrition self-efficacy were related to more positive attitudes towards, and a greater expressed intention to adopt, personalised nutrition. Other constructs positively impacting attitudes towards personalised nutrition included more positive perceptions of the efficacy of regulatory control to protect consumers (e.g. in relation to personal data protection), higher self-reported internal health locus of control, and health commitment. Although higher perceived risk had a negative relationship with attitude and an inverse relationship with perceived benefit, its effects on attitude and intention to adopt personalised nutrition was less influential than perceived benefit. The model was stable across the different European countries, suggesting that psychological factors determining adoption of personalised nutrition have generic applicability across different European countries. Conclusion The results suggest that transparent provision of information about potential benefits, and protection of consumers’ personal data is important for adoption, delivery of public health benefits, and commercialisation of personalised

  1. Nuclear Weapon Yield Determination through Nano Indentation of Thermally Degraded Automobile Paint

    DTIC Science & Technology

    2011-03-01

    NUCLEAR WEAPON YIELD DETERMINATION THROUGH NANO INDENTATION OF THERMALLY DEGRADED AUTOMOBILE PAINT THESIS Michael Joseph Richards...NUCLEAR WEAPON YIELD DETERMINATION THROUGH NANO INDENATION OF THERMALLY DEGRADED AUTOMOBILE PAINT THESIS Presented to the Faculty Department...that has the potential to overcome these limitations relies on the change in automobile paint caused by the thermal pulse of the weapon. This work

  2. Numerical Determination of Critical Conditions for Thermal Ignition

    NASA Technical Reports Server (NTRS)

    Luo, W.; Wake, G. C.; Hawk, C. W.; Litchford, R. J.

    2008-01-01

    The determination of ignition or thermal explosion in an oxidizing porous body of material, as described by a dimensionless reaction-diffusion equation of the form .tu = .2u + .e-1/u over the bounded region O, is critically reexamined from a modern perspective using numerical methodologies. First, the classic stationary model is revisited to establish the proper reference frame for the steady-state solution space, and it is demonstrated how the resulting nonlinear two-point boundary value problem can be reexpressed as an initial value problem for a system of first-order differential equations, which may be readily solved using standard algorithms. Then, the numerical procedure is implemented and thoroughly validated against previous computational results based on sophisticated path-following techniques. Next, the transient nonstationary model is attacked, and the full nonlinear form of the reaction-diffusion equation, including a generalized convective boundary condition, is discretized and expressed as a system of linear algebraic equations. The numerical methodology is implemented as a computer algorithm, and validation computations are carried out as a prelude to a broad-ranging evaluation of the assembly problem and identification of the watershed critical initial temperature conditions for thermal ignition. This numerical methodology is then used as the basis for studying the relationship between the shape of the critical initial temperature distribution and the corresponding spatial moments of its energy content integral and an attempt to forge a fundamental conjecture governing this relation. Finally, the effects of dynamic boundary conditions on the classic storage problem are investigated and the groundwork is laid for the development of an approximate solution methodology based on adaptation of the standard stationary model.

  3. A Study to Develop a Scale for Determining the Social Acceptance Levels of Special-Needs Students, Participating in Inclusion Practices

    ERIC Educational Resources Information Center

    Arslan, Erdinc; Sahbaz, Umit

    2012-01-01

    The aim of this study is to develop a scale of social acceptance for determining the social acceptance levels of special-needs students, participating in inclusion practices. The target population of the research is 8th grade students of all primary schools in the provincial center of Burdur in the 2008 to 2009 academic year and the target study…

  4. A Flight Investigation to Determine the Lateral Oscillatory Damping Acceptable for an Airplane in the Landing Approach

    NASA Technical Reports Server (NTRS)

    McNeill, Walter E.; Vomaske, Richard F.

    1959-01-01

    An F-86E airplane, in which servo actuation of the ailerons and rudder provides artificial variation of the important lateral and directional aerodynamic stability parameters, has been flown by test pilots of the NASA, U.S. Air Force, and one aircraft manufacturer to determine satisfactory and acceptable levels of lateral oscillatory damping in the landing approach. In addition to normal operational use, particular consideration was given to the emergency condition of failure of stability-augmentation equipment. In this study, the pilots' opinions of the airplane dynamic stability and control characteristics in smooth and simulated rough air have been recorded according to a numerical rating scale. The results are presented in the form of boundaries in terms of cycles to damp to half amplitude, 1/C(sub 1/2), or time to damp to half amplitude, 1/T(1/2) and bank-to-sideslip ratio, and are discussed in relation to existing flying-qualities criteria. Though the present results, which were obtained at 170 knots indicated airspeed and 10,000-feet altitude, indicated that increased damping is required with increased bank-to-sideslip ratio (as found in previous work), consideration of the dampers-failed condition indicated a great reduction in the minimum acceptable damping. At moderate values of bank-to-sideslip ratio, effects of lateral-oscillation period on pilot-opinion variation with damping appeared to be taken into account by use of the parameter 1/T(sub 1/2).

  5. Method And Apparatus For Determining Health Of Thermal Barrier Coatings

    DOEpatents

    Srivastava, Alok Mani; Setlur, Anant Achyut; Comanzo, Holly Ann; Devitt, John William; Ruud, James Anthony; Brewer, Luke Nathaniel

    2005-09-13

    A method for determining past-service conditions and/or remaining useful life of a component of a combustion engine and/or a thermal barrier coating ("TBC") of the component comprises providing a photoluminescent ("PL") material in the TBC, directing an exciting radiation at the TBC, measuring the intensity of a characteristic peak in the emission spectrum of the PL material, and correlating the intensity of the characteristic peak or another quantity derived therefrom to an amount of a new phase that has been formed as a result of the exposure of the component to extreme temperatures. An apparatus for carrying out the method comprises a radiation source that provides the exciting radiation to the TBC, a radiation detector for detecting radiation emitted by the PL material, and means for relating a characteristic of the emission spectrum of the PL material to the amount of the new phase in the TBC, thereby inferring the past-service conditions or the remaining useful life of the component.

  6. Thermal Effusivity Determination of Metallic Films of Nanometric Thickness by the Electrical Micropulse Method

    NASA Astrophysics Data System (ADS)

    Lugo, J. M.; Oliva, A. I.

    2017-02-01

    The thermal effusivity of gold, aluminum, and copper thin films of nanometric thickness (20 nm to 200 nm) was investigated in terms of the films' thickness. The metallic thin films were deposited onto glass substrates by thermal evaporation, and the thermal effusivity was estimated by using experimental parameters such as the specific heat, thermal conductivity, and thermal diffusivity values obtained at room conditions. The specific heat, thermal conductivity, and thermal diffusivity values of the metallic thin films are determined with a methodology based on the behavior of the thermal profiles of the films when electrical pulses of few microseconds are applied at room conditions. For all the investigated materials, the thermal effusivity decreases with decreased thickness. The thermal effusivity values estimated by the presented methodology are consistent with other reported values obtained under vacuum conditions and more elaborated methodologies.

  7. The determinants of thermal comfort in cool water.

    PubMed

    Guéritée, J; House, J R; Redortier, B; Tipton, M J

    2015-10-01

    Water-based activities may result in the loss of thermal comfort (TC). We hypothesized that in cooling water, the hands and feet would be responsible. Supine immersions were conducted in up to five clothing conditions (exposing various regions), as well as investigations to determine if a "reference" skin temperature (Tsk) distribution in thermoneutral air would help interpret our findings. After 10 min in 34.5 °C water, the temperature was decreased to 19.5 °C over 20 min; eight resting or exercising volunteers reported when they no longer felt comfortable and which region was responsible. TC, rectal temperature, and Tsk were measured. Rather than the extremities, the lower back and chest caused the loss of overall TC. At this point, mean (SD) chest Tsk was 3.3 (1.7) °C lower than the reference temperature (P = 0.005), and 3.8 (1.5) °C lower for the back (P = 0.002). Finger Tsk was 3.1 (2.7) °C higher than the reference temperature (P = 0.037). In cool and cooling water, hands and feet, already adapted to colder air temperatures, will not cause discomfort. Contrarily, more discomfort may arise from the chest and lower back, as these regions cool by more than normal. Thus, Tsk distribution in thermoneutral air may help understand variations in TC responses across the body.

  8. Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady-state Laser Heat-flux Approach

    NASA Technical Reports Server (NTRS)

    Zhu, Dong-Ming; Miller, Robert A.

    2004-01-01

    The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.

  9. Determining Effective Thermal Conductivity of Fabrics by Using Fractal Method

    NASA Astrophysics Data System (ADS)

    Zhu, Fanglong; Li, Kejing

    2010-03-01

    In this article, a fractal effective thermal conductivity model for woven fabrics with multiple layers is developed. Structural models of yarn and plain woven fabric are derived based on the fractal characteristics of macro-pores (gap or channel) between the yarns and micro-pores inside the yarns. The fractal effective thermal conductivity model can be expressed as a function of the pore structure (fractal dimension) and architectural parameters of the woven fabric. Good agreement is found between the fractal model and the thermal conductivity measurements in the general porosity ranges. It is expected that the model will be helpful in the evaluation of thermal comfort for woven fabric in the whole range of porosity.

  10. Spatially resolved determination of thermal conductivity by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Stoib, B.; Filser, S.; Stötzel, J.; Greppmair, A.; Petermann, N.; Wiggers, H.; Schierning, G.; Stutzmann, M.; Brandt, M. S.

    2014-12-01

    We review the Raman shift method as a non-destructive optical tool to investigate the thermal conductivity and demonstrate the possibility to map this quantity with a micrometer resolution by studying thin film and bulk materials for thermoelectric applications. In this method, a focused laser beam both thermally excites a sample and undergoes Raman scattering at the excitation spot. The temperature dependence of the phonon energies measured is used as a local thermometer. We discuss that the temperature measured is an effective one and describe how the thermal conductivity is deduced from single temperature measurements to full temperature maps, with the help of analytical or numerical treatments of heat diffusion. We validate the method and its analysis on three- and two-dimensional single crystalline samples before applying it to more complex Si-based materials. A suspended thin mesoporous film of phosphorus-doped laser-sintered S{{i}78}G{{e}22} nanoparticles is investigated to extract the in-plane thermal conductivity from the effective temperatures, measured as a function of the distance to the heat sink. Using an iterative multigrid Gauss-Seidel algorithm the experimental data can be modelled yielding a thermal conductivity of 0.1 W/m K after normalizing by the porosity. As a second application we map the surface of a phosphorus-doped three-dimensional bulk-nanocrystalline Si sample which exhibits anisotropic and oxygen-rich precipitates. Thermal conductivities as low as 11 W/m K are found in the regions of the precipitates, significantly lower than the 17 W/m K in the surrounding matrix. The present work serves as a basis to more routinely use the Raman shift method as a versatile tool for thermal conductivity investigations, both for samples with high and low thermal conductivity and in a variety of geometries.

  11. Development of acceptance criteria for batches of silane primer for external tank thermal protection system bonding applications

    NASA Technical Reports Server (NTRS)

    Mikes, F.

    1985-01-01

    Fourier transform infrared spectroscopy is currently the best technique for observing hydrolytic changes in DC 1200 silane the primers caused by moisture in the atmosphere. To further prove that FTIR can be used as a criterion test for acceptance of silane primer lots, intensities of the FTIR OH- band are being compared with primer adhesive bond strength using a mechanical test suggested by NASA. Results of tests for shear strength and Oh-absorption are tabulated and compared with FTIR absorption intensities in the OH-region.

  12. Configuration of the thermal landscape determines thermoregulatory performance of ectotherms.

    PubMed

    Sears, Michael W; Angilletta, Michael J; Schuler, Matthew S; Borchert, Jason; Dilliplane, Katherine F; Stegman, Monica; Rusch, Travis W; Mitchell, William A

    2016-09-20

    Although most organisms thermoregulate behaviorally, biologists still cannot easily predict whether mobile animals will thermoregulate in natural environments. Current models fail because they ignore how the spatial distribution of thermal resources constrains thermoregulatory performance over space and time. To overcome this limitation, we modeled the spatially explicit movements of animals constrained by access to thermal resources. Our models predict that ectotherms thermoregulate more accurately when thermal resources are dispersed throughout space than when these resources are clumped. This prediction was supported by thermoregulatory behaviors of lizards in outdoor arenas with known distributions of environmental temperatures. Further, simulations showed how the spatial structure of the landscape qualitatively affects responses of animals to climate. Biologists will need spatially explicit models to predict impacts of climate change on local scales.

  13. Configuration of the thermal landscape determines thermoregulatory performance of ectotherms

    PubMed Central

    Sears, Michael W.; Angilletta, Michael J.; Schuler, Matthew S.; Borchert, Jason; Dilliplane, Katherine F.; Stegman, Monica; Rusch, Travis W.; Mitchell, William A.

    2016-01-01

    Although most organisms thermoregulate behaviorally, biologists still cannot easily predict whether mobile animals will thermoregulate in natural environments. Current models fail because they ignore how the spatial distribution of thermal resources constrains thermoregulatory performance over space and time. To overcome this limitation, we modeled the spatially explicit movements of animals constrained by access to thermal resources. Our models predict that ectotherms thermoregulate more accurately when thermal resources are dispersed throughout space than when these resources are clumped. This prediction was supported by thermoregulatory behaviors of lizards in outdoor arenas with known distributions of environmental temperatures. Further, simulations showed how the spatial structure of the landscape qualitatively affects responses of animals to climate. Biologists will need spatially explicit models to predict impacts of climate change on local scales. PMID:27601639

  14. Starch transitions of different gluten free flour doughs determined by dynamic thermal mechanical analysis and differential scanning calorimetry.

    PubMed

    Moreira, R; Chenlo, F; Arufe, S

    2015-01-01

    Gluten-free flour doughs (three from different maize varieties and one from chestnut fruit) processed at the same consistency level (1.10 ± 0.07 N m) with different water absorption were used to determine the starch transitions by means of two different experimental techniques, differential scanning calorimetry (DSC) and dynamic thermal mechanical analysis (DMTA). The ranges of temperatures of gelatinization (G), amylopectin melting (M1), amylose-lipid complexes melting (M2) and amylose melting (M3) for all tested flour doughs were determined by both experimental techniques with acceptable agreement between them. The starch transitions in DMTA were determined by means of the elastic modulus (G, M1 and M2) or damping factor (G, M3) evolution with temperature. The temperatures and enthalpies of the transitions depended on water content, the nature and characteristics (mainly damaged starch) of the starch and the presence of other compounds (mainly lipid and sugars) in the flour doughs.

  15. Method to determine thermal profiles of nanoscale circuitry

    DOEpatents

    Zettl, Alexander K; Begtrup, Gavi E

    2013-04-30

    A platform that can measure the thermal profiles of devices with nanoscale resolution has been developed. The system measures the local temperature by using an array of nanoscale thermometers. This process can be observed in real time using a high resolution imagining technique such as electron microscopy. The platform can operate at extremely high temperatures.

  16. Thermal Loss Determination for a Small Internal Combustion Engine

    DTIC Science & Technology

    2014-03-27

    Combustion Engines . . . . . . . . . . . . . . . . . 4 2.1.1 Engine Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.2 Ignition Types...Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.1 Otto Cycle ...Figure Page 2.1 Pressure-Volume diagram of ideal four-stroke Otto cycle [12] . . . . . . . . . . 9 2.2 Ideal Otto thermal efficiency for range of

  17. Utility of thermal remote sensing for determining evapotranspiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land surface temperature (LST) from thermal remote sensing is a surface boundary condition that is strongly linked to the partitioning of the available energy between latent (evapotranspiration) and sensible heat flux. Numerous modeling approaches have been developed ranging in level of complexity ...

  18. Thermal Applications as a Determiner of Joint Flexibility.

    ERIC Educational Resources Information Center

    Grobaker, Mark Randolph; Stull, G. Alan

    This study investigates the relative effects of thermal applications of varying temperatures on the flexibility of specified joints. Subjects were 14 male college students ranging in age from 17 to 22 years with no previous joint injury or orthopedic disability. Each subject became familiar with the experimental design and was asked not to engage…

  19. Scanning thermal probe microscope method for the determination of thermal diffusivity of nanocomposite thin films

    NASA Astrophysics Data System (ADS)

    Varandani, Deepak; Agarwal, Khushboo; Brugger, Juergen; Mehta, Bodh Raj

    2016-08-01

    A commercial scanning thermal microscope has been upgraded to facilitate its use in estimating the radial thermal diffusivity of thin films close to room temperature. The modified setup includes a microcontroller driven microhotplate coupled with a Bluetooth module for wireless control. The microcontroller board (Arduino Leonardo) is used to generate a bias of suitable voltage amplitude and pulse duration which is applied across the microhotplate contact pads. A corresponding heat pulse from the Pt heating element (1 mm2) embedded within the microhotplate is delivered to the lower surface of the thin film (25 mm2) deposited over it. The large difference in the dimensions of the heating source and the thin film surface causes heat to flow radially outwards on the top surface of the latter. The decay of this radial heat wave as it flows outwards is recorded by the scanning thermal microscope in terms of temperature-time (T-t) profiles at varying positions around the central heating zone. A fitting procedure is suggested to extract the thermal diffusivity value from the array of T-t profiles. The efficacy of the above setup has been established by evaluating the thermal diffusivities of Bi2Te3 and Bi2Te3:Si thin film samples. Further, with only minor alterations in design the capabilities of the above setup can be extended to estimate the axial thermal diffusivity and specific heat of thin films, as a function of temperature.

  20. Scanning thermal probe microscope method for the determination of thermal diffusivity of nanocomposite thin films.

    PubMed

    Varandani, Deepak; Agarwal, Khushboo; Brugger, Juergen; Mehta, Bodh Raj

    2016-08-01

    A commercial scanning thermal microscope has been upgraded to facilitate its use in estimating the radial thermal diffusivity of thin films close to room temperature. The modified setup includes a microcontroller driven microhotplate coupled with a Bluetooth module for wireless control. The microcontroller board (Arduino Leonardo) is used to generate a bias of suitable voltage amplitude and pulse duration which is applied across the microhotplate contact pads. A corresponding heat pulse from the Pt heating element (1 mm(2)) embedded within the microhotplate is delivered to the lower surface of the thin film (25 mm(2)) deposited over it. The large difference in the dimensions of the heating source and the thin film surface causes heat to flow radially outwards on the top surface of the latter. The decay of this radial heat wave as it flows outwards is recorded by the scanning thermal microscope in terms of temperature-time (T-t) profiles at varying positions around the central heating zone. A fitting procedure is suggested to extract the thermal diffusivity value from the array of T-t profiles. The efficacy of the above setup has been established by evaluating the thermal diffusivities of Bi2Te3 and Bi2Te3:Si thin film samples. Further, with only minor alterations in design the capabilities of the above setup can be extended to estimate the axial thermal diffusivity and specific heat of thin films, as a function of temperature.

  1. Thermal Conductivity Change Kinetics of Ceramic Thermal Barrier Coatings Determined by the Steady-State Laser Heat Flux Technique

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    2000-01-01

    A steady-state laser heat flux technique has been developed at the NASA Glenn Research Center at Lewis Field to obtain critical thermal conductivity data of ceramic thermal barrier coatings under the temperature and thermal gradients that are realistically expected to be encountered in advanced engine systems. In this study, thermal conductivity change kinetics of a plasma-sprayed, 254-mm-thick ZrO2-8 wt % Y2O3 ceramic coating were obtained at high temperatures. During the testing, the temperature gradients across the coating system were carefully measured by the surface and back pyrometers and an embedded miniature thermocouple in the substrate. The actual heat flux passing through the coating system was determined from the metal substrate temperature drop (measured by the embedded miniature thermocouple and the back pyrometer) combined with one-dimensional heat transfer models.

  2. A water framework directive (WFD) compliant determination of eologically acceptable flows in alpine rivers - a river type specific approach

    NASA Astrophysics Data System (ADS)

    Jäger, Paul; Zitek, Andreas

    2010-05-01

    Currently the EU-Water Framework Directive (WFD) represents the driving force behind the assessment for rehabilitation and conservation of aquatic resources throughout Europe. Hydropower production, often considered as "green energy", in the past has put significant pressures on river systems like fragmentation by weirs, impoundment, hydropeaking and water abstraction. Due to the limited availability of data for determining ecologically acceptable flow for rivers at water abstraction sites, a special monitoring program was conducted in the federal state of Salzburg in Austria from 2006 to 2009. Water abstraction sites at 19 hydropower plants, mostly within the trout region of the River Salzach catchment, were assessed in detail with regard to the effect of water abstraction on fish and macrozoobenthos. Based on a detailed assessment of the specific local hydro-morphological and biological situations, the validity of natural low flow criteria (Absolute Minimum Flow - AMF, the lowest daily average flow ever measured and Mean Annual Daily Low Flow - MADLF) as starting points for the determination of an ecologically acceptable flow was tested. It was assessed, if a good ecological status in accordance with the EU-WFD can be maintained at natural AMF. Additionally it was tested, if important habitat parameters describing connectivity, river type specific flow variability and river type specific habitats are maintained at this discharge. Habitat modelling was applied in some situations. Hydraulic results showed that at AMF the highest flow velocity classes were lost in most situations. When AMF was significantly undercut, flow velocities between 0,0 - 0,4 m/s became dominant, describing the loss of the river type specific flow character, leading to a loss of river type specific flow variability and habitats and increased sedimentation of fines. Furthermore limits for parameters describing connectivity for fish like maximum depth at the pessimum profile and minimum flow

  3. Determination of photochemical reaction rates using thermal lens spectrometry

    NASA Astrophysics Data System (ADS)

    Astrath, N. G. C.; Astrath, F. B. G.; Shen, J.; Zhou, J.; Michaelian, K. H.; Fairbridge, C.; Malacarne, L. C.; Pedreira, P. R. B.; Baesso, M. L.

    2010-03-01

    Considering the time dependence of the absorption coefficient due to the photo-induced chemical reaction (PCR) and species diffusion, we calculate the temperature rise in the thermal lens (TL) effect and the TL signal at the detector plane. This theoretical approach removes the restriction that the PCR time constant is much greater than the characteristic TL time constant, which was assumed in a previously published model. Aqueous Cr(VI)-diphenylcarbazide solution is investigated, and quantitative experimental results for the thermal, optical and PCR properties of the sample are obtained. The relative difference between the parameters extracted from the same experimental data of the Cr(VI) solution using the previous and present models is found to be less than 5%, showing the present model can be used to study the PCR. Moreover the present model is more general than the previous one.

  4. Procedure to Determine Thermal Characteristics and Groundwater Influence in Heterogeneous Subsoil by an Enhanced Thermal Response Test and Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Aranzabal, Nordin; Martos, Julio; Montero, Álvaro; Monreal, Llúcia; Soret, Jesús; Torres, José; García-Olcina, Raimundo

    2016-04-01

    Ground thermal conductivity and borehole thermal resistance are indispensable parameters for the optimal design of subsoil thermal processes and energy storage characterization. The standard method to determine these parameters is the Thermal Response Test (TRT) which results are evaluated by models considering the ground being homogeneous and isotropic. This method obtains an effective ground thermal conductivity which represents an average of the thermal conductivity along the different layers crossed by perforation. In order to obtain a ground thermal conductivity profile as a function of depth two additional key factors are required, first, a new significant data set: a temperature profile along the borehole; and second, a new analysis procedure to extract ground heterogeneity from the recorded data. This research work presents the results of an analysis procedure, complementing the standard TRT analysis, which allows to estimate the thermal conductivity profile from a temperature profile measured along the borehole during a TRT. In the analysis procedure, a 3D Finite Element Model (FEM) is used to fit simulation results with experimental data, by a set of iterative simulations. This methodology is applied to a data set obtained throughout a TRT of 1kW heat power injection in a 30m depth Borehole Heat Exchange (BHE) facility. A highly conductive layer have been detected and located at 25 m depth. In addition, a novel automated device to obtain temperature profiles along geothermal pipes with or without fluid flow is presented. This sensor system is intended to improve the standard TRT and it allows the collection of depth depending thermal characteristics of the subsoil geological structure. Currently, some studies are being conducted in double U-pipe borehole installations in order to improve previously introduced analysis procedure. From a numerical model simulation that takes into account advective effects is pretended to estimate underground water velocity

  5. Sociocultural Determinants of Anticipated Vaccine Acceptance for Acute Watery Diarrhea in Early Childhood in Katanga Province, Democratic Republic of Congo

    PubMed Central

    Merten, Sonja; Schaetti, Christian; Manianga, Cele; Lapika, Bruno; Hutubessy, Raymond; Chaignat, Claire-Lise; Weiss, Mitchell

    2013-01-01

    Rotavirus and oral cholera vaccines have the potential to reduce diarrhea-related child mortality in low-income settings and are recommended by the World Health Organization. Uptake of vaccination depends on community support, and is based on local priorities. This study investigates local perceptions of acute watery diarrhea in childhood and anticipated vaccine acceptance in two sites in the Democratic Republic of Congo. In 2010, 360 randomly selected non-affected adults were interviewed by using a semi-structured questionnaire. Witchcraft and breastfeeding were perceived as potential cause of acute watery diarrhea by 51% and 48% of respondents. Despite misperceptions, anticipated vaccine acceptance at no cost was 99%. The strongest predictor of anticipated vaccine acceptance if costs were assumed was the educational level of the respondents. Results suggest that the introduction of vaccines is a local priority and local (mis)perceptions of illness do not compromise vaccine acceptability if the vaccine is affordable. PMID:23878187

  6. Simultaneous determination of thermal conductivity, thermal diffusivity and specific heat in sI methane hydrate

    USGS Publications Warehouse

    Waite, W.F.; Stern, L.A.; Kirby, S.H.; Winters, W.J.; Mason, D.H.

    2007-01-01

    Thermal conductivity, thermal diffusivity and specific heat of sI methane hydrate were measured as functions of temperature and pressure using a needle probe technique. The temperature dependence was measured between −20°C and 17°C at 31.5 MPa. The pressure dependence was measured between 31.5 and 102 MPa at 14.4°C. Only weak temperature and pressure dependencies were observed. Methane hydrate thermal conductivity differs from that of water by less than 10 per cent, too little to provide a sensitive measure of hydrate content in water-saturated systems. Thermal diffusivity of methane hydrate is more than twice that of water, however, and its specific heat is about half that of water. Thus, when drilling into or through hydrate-rich sediment, heat from the borehole can raise the formation temperature more than 20 per cent faster than if the formation's pore space contains only water. Thermal properties of methane hydrate should be considered in safety and economic assessments of hydrate-bearing sediment.

  7. Development of acceptance criteria for batches of silane primer for external tank thermal protection system bonding applications

    NASA Technical Reports Server (NTRS)

    Mikes, F.

    1985-01-01

    Concluding tests for the thermogravimetric and FTIR analyses of DC 1200 silane primers are discussed as well as methods for HPLC and GC analyses and for determining titanium and silicon by atomic absorption spectroscopy. Tables summarizes results obtained for residue, ash, titanium, silicone, Si/Ti ratio, OH-absorption, the lap-shear test, and the GC headspace for alcohols.

  8. Determination of cytotoxic thermal dose during HIFU ablation

    NASA Astrophysics Data System (ADS)

    Nandlall, Sacha D.; Bazán-Peregrino, Miriam; Mo, Steven; Coussios, Constantin-C.

    2012-10-01

    Thermal dose has been proposed for various hyperthermic cancer treatment modalities as a measure of heat-induced cell and tissue damage. However, many of the models that are currently used for calculating thermal dose have not been validated or suitably adapted for the elevated temperatures and rates of heating encountered during ablation by High-Intensity Focused Ultrasound (HIFU). This work quantifies the performance of the widely employed Cumulative Equivalent Minutes at 43°C (CEM43) thermal dose metric under HIFU-relevant heating. A total of 36 agar phantoms were embedded with different human cancer cell lines (PC3, 22RV1, or ZR75.1) as well as calcein AM and propidium iodide assays. The phantoms were cast in sterile molds with internal dimensions of 7 cm × 7 cm × 2 mm. Using a water bath, 12 of the phantoms were treated with mild hyperthermia (43-46°C for up to 60 minutes), while another 12 were subjected to HIFU-relevant temperature profiles (60-80°C peak temperature, 2-3°C/s peak heating rate). In each of the remaining 12 phantoms, 8 HIFU exposures were carried out in a 37°C water tank (1.067 MHz, 95% duty cycle, 3-6 MPa peak rarefaction pressure, 2-20 s exposure duration). Cavitation emissions were monitored passively with a detector transducer that was confocally and co-axially aligned with the HIFU source. Cell death was quantified by measuring the locally averaged fluorescence intensity of the assays relative to unheated and severely heat-shocked phantoms. The results show that the CEM43 dose required to achieve the same level of heat-induced cell death varies considerably across cell lines, and that inertial cavitation can cause significant mechanical damage at ablation-relevant intensities even when no significant thermal dose is delivered (CEM43 < 5 s). These findings demonstrate the need for improved models of cell death at ablation-relevant temperatures.

  9. Determining the thermal noise floor of graphene biosensors

    NASA Astrophysics Data System (ADS)

    Crosser, Michael; Brown, Morgan; Minot, Ethan

    2015-03-01

    The use of graphene field-effect transistors (GFETs) as biosensors in aqueous environments is fundamentally limited by voltage noise. In many GFET devices, noise is dominated by the fluctuating occupancy of charge traps in the substrate. Fabrication techniques have been found to reduce this substrate effect, but thermally-driven charge transfer across the graphene liquid interface has yet to be quantified and addressed. In this report we present the first characterization of this noise source. We show that the power spectral density of this noise scales inversely with frequency and inversely with interface area. Our results are in quantitative agreement with recent measurements of voltage noise in clean, suspended graphene. This work is supported by NSF Award Number 1450967.

  10. Temperature determines toxicity: bisphenol A reduces thermal tolerance in fish.

    PubMed

    Little, Alexander G; Seebacher, Frank

    2015-02-01

    Bisphenol A (BPA) is a ubiquitous pollutant around the globe, but whether environmental concentrations have toxic effects remains controversial. BPA interferes with a number of nuclear receptor pathways, including several that mediate animal responses to environmental input. Because thermal acclimation is regulated by these pathways in fish, we hypothesized that the toxicity of BPA would change with ambient temperature. We exposed zebrafish (Danio rerio) to ecologically relevant and artificially high concentrations of BPA at two acclimation temperatures, and tested physiological responses at two test temperatures that corresponded to acclimation temperatures. We found ecologically relevant concentrations of BPA (20 μg l(-1)) impair swimming performance, heart rate, muscle and cardiac SERCA activity and gene expression. We show many of these responses are temperature-specific and non-monotonic. Our results suggest that BPA pollution can compound the effects of climate change, and that its effects are more dynamic than toxicological assessments currently account for.

  11. Thermally denatured state determines refolding in lipase: mutational analysis.

    PubMed

    Ahmad, Shoeb; Rao, Nalam Madhusudhana

    2009-06-01

    Irreversibility of thermally denatured proteins due to aggregation limits thermodynamic characterization of proteins and also confounds the identification of thermostable mutants in protein populations. Identification of mutations that prevent the aggregation of unfolded proteins provides insights into folding pathways. In a lipase from Bacillus subtilis, evolved by directed evolution procedures, the irreversibility due to temperature-mediated aggregation was completely prevented by a single mutation, M137P. Though the parent and the mutants unfold completely on heating, mutants having substitutions M137P, along with M134E and S163P, completely or partially prevent the formation of aggregation-prone intermediate(s) at 75 degrees C. The three mutants show only a marginal increase in free energy of unfolding (DeltaG(H(2)O)), however, the profiles of the residual activity with temperature shows remarkable shift to higher temperature compared to parent. The intermediate(s) were characterized by enhanced binding of bis-ANS, a probe to titrate surface hydrophobicity, aggregation profiles and by estimation of soluble protein. Inclusion of salt in the refolding conditions prevents the reversibility of mutant having charge substitution, while the reversibility of mutant with the introduction of proline was unaffected, indicating the role of charge mediated interaction in M134E in preventing aggregation. Partial prevention of thermal aggregation in wild-type lipase with single substitution, M137P, incorporated by site-directed mutagenesis, suggests that the affect of M137P is independent of the intrinsic thermostability of lipase. Various effects of the mutations suggest their role is in prevention of the formation of aggregation prone intermediate(s). These mutations, describe yet another strategy to enhance the thermotolerance of proteins, where their influence is observed only on the denatured ensemble.

  12. Improved petrographic-coded model and its evaluation to determine a thermal conductivity log

    NASA Astrophysics Data System (ADS)

    Gegenhuber, Nina; Kienler, Markus

    2017-01-01

    Thermal conductivity is one of the crucial properties for thermal modelling as well as tunnelling or geological modelling. Available data are mainly from laboratory measurements. Therefore, additional ways, such as correlations with other properties to derive the petrophysical parameter, will be an advantage. The research presented here continues and improves the petrographic-coded model concept with an increased set of data, including a variety of lithologies, and, furthermore, the correlations, including the electrical resistivity. Input parameters are no longer taken from the literature, but are derived directly from measurements. In addition, the results are compared with other published approaches. Results show good correlations with measured data. The comparison with the multi-linear regression method shows acceptable outcome, in contrast to a geometric-mean method, where data scatter. In summary, it can be said that the improved model delivers for both correlation (compressional wave velocity and electrical resistivity with thermal conductivity) positive results.

  13. 40 CFR Appendix Xiv to Part 86 - Determination of Acceptable Durability Test Schedule for Light-Duty Vehicles and Light Light-Duty...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Determination of Acceptable Durability Test Schedule for Light-Duty Vehicles and Light Light-Duty Trucks Certifying to the Provisions of Part... Light-Duty Vehicles and Light Light-Duty Trucks Certifying to the Provisions of Part 86, Subpart R...

  14. A Study to Determine the Acceptance and Effectiveness of an Experimental Mobile Unit Which Serves Milford, Beaver, Delta, and Fillmore in Southern Utah.

    ERIC Educational Resources Information Center

    Widmer, Grant W.

    The study determined the acceptance by high school students of a mobile-classroom approach to the teaching of electronics. Also investigated was the effectiveness of this teaching method with high school students in the southern Utah communities of Milford, Beaver, Delta, and Fillmore during the 1968-69 school year. As ascertained by the attitude…

  15. The Experimental Determination of Thermal Neutron Flux in the Radiochemistry Curriculum

    ERIC Educational Resources Information Center

    Grant, Patrick M.

    1977-01-01

    Describes an experiment for determining the thermal neutron flux of the light-water nuclear reactor at the University of California, Irvine. The difficulty of the activity can be varied to match the student's level of proficiency. (SL)

  16. Thermal Properties of Porcine Tissues Determined by Modified Photoacoustic Piezoelectric Technique

    NASA Astrophysics Data System (ADS)

    Zhao, Binxing; Wang, Yafei; Gao, Chunming; Liu, Ting; Sun, Qiming

    2013-09-01

    Using the modified photoacoustic piezoelectric (PAPE) technique, the influence of the piezoelectric transducer on the vibrations of the sample is taken into account. The modified PAPE technique is employed to determine the average thermal diffusivities of the porcine tissues, which include fresh and dry skin, fat, and muscle. The values of the thermal diffusivities of all measured porcine tissues determined by the modified PAPE technique are smaller than those of the conventional ones, especially for the dry skin and fresh fat samples. The thermal diffusivity of the fresh skin sample is the biggest, and the dry samples of different tissues have similar thermal properties with each other. These results show that the modified PAPE technique can provide thermal characterization of the porcine tissues more effectively.

  17. Learning with Interactive Whiteboards: Determining the Factors on Promoting Interactive Whiteboards to Students by Technology Acceptance Model

    ERIC Educational Resources Information Center

    Kilic, Eylem; Güler, Çetin; Çelik, H. Eray; Tatli, Cemal

    2015-01-01

    Purpose: The purpose of this study is to investigate the factors which might affect the intention to use interactive whiteboards (IWBs) by university students, using Technology Acceptance Model by the structural equation modeling approach. The following hypothesis guided the current study: H1. There is a positive relationship between IWB…

  18. Thermal stability of ladderane lipids as determined by hydrous pyrolysis

    USGS Publications Warehouse

    Jaeschke, A.; Lewan, M.D.; Hopmans, E.C.; Schouten, S.; Sinninghe, Damste J.S.

    2008-01-01

    Anaerobic ammonium oxidation (anammox) has been recognized as a major process resulting in loss of fixed inorganic nitrogen in the marine environment. Ladderane lipids, membrane lipids unique to anammox bacteria, have been used as markers for the detection of anammox in marine settings. However, the fate of ladderane lipids after sediment burial and maturation is unknown. In this study, anammox bacterial cell material was artificially matured by hydrous pyrolysis at constant temperatures ranging from 120 to 365 ??C for 72 h to study the stability of ladderane lipids during progressive dia- and catagenesis. HPLC-MS/MS analysis revealed that structural alterations of ladderane lipids already occurred at 120 ??C. At temperatures >140 ??C, ladderane lipids were absent and only more thermally stable products could be detected, i.e., ladderane derivatives in which some of the cyclobutane rings were opened. These diagenetic products of ladderane lipids were still detectable up to temperatures of 260 ??C using GC-MS. Thus, ladderane lipids are unlikely to occur in ancient sediments and sedimentary rocks, but specific diagenetic products of ladderane lipids will likely be present in sediments and sedimentary rocks of relatively low maturity (i.e., C31 hopane 22S/(22S + 22R) ratio 0.5). ?? 2008 Elsevier Ltd.

  19. Using the heat flow plate method for determining thermal conductivity of building materials

    NASA Astrophysics Data System (ADS)

    Flori, M.; Puţan, V.; Vîlceanu, L.

    2017-01-01

    The heat flow plate method is used to determine thermal conductivity of a building material sample made of Rohacell (insulating foam). Experimental technique consists in placing the sample with a reference material on top (polystyrene sample) in a calorimetric chamber and heating from underside. Considering that the heat flux which passes through the two layers is constant and knowing thermal conductivity of the reference material, the sample thermal conductivity is determined. The temperature difference between the two opposite sample’s sides is recorded only when the steady state is achieved (constant heat flux).

  20. On-Line, Self-Learning, Predictive Tool for Determining Payload Thermal Response

    NASA Technical Reports Server (NTRS)

    Jen, Chian-Li; Tilwick, Leon

    2000-01-01

    This paper will present the results of a joint ManTech / Goddard R&D effort, currently under way, to develop and test a computer based, on-line, predictive simulation model for use by facility operators to predict the thermal response of a payload during thermal vacuum testing. Thermal response was identified as an area that could benefit from the algorithms developed by Dr. Jeri for complex computer simulations. Most thermal vacuum test setups are unique since no two payloads have the same thermal properties. This requires that the operators depend on their past experiences to conduct the test which requires time for them to learn how the payload responds while at the same time limiting any risk of exceeding hot or cold temperature limits. The predictive tool being developed is intended to be used with the new Thermal Vacuum Data System (TVDS) developed at Goddard for the Thermal Vacuum Test Operations group. This model can learn the thermal response of the payload by reading a few data points from the TVDS, accepting the payload's current temperature as the initial condition for prediction. The model can then be used as a predictive tool to estimate the future payload temperatures according to a predetermined shroud temperature profile. If the error of prediction is too big, the model can be asked to re-learn the new situation on-line in real-time and give a new prediction. Based on some preliminary tests, we feel this predictive model can forecast the payload temperature of the entire test cycle within 5 degrees Celsius after it has learned 3 times during the beginning of the test. The tool will allow the operator to play "what-if' experiments to decide what is his best shroud temperature set-point control strategy. This tool will save money by minimizing guess work and optimizing transitions as well as making the testing process safer and easier to conduct.

  1. Determination of physical properties of fibrous thermal insulation

    NASA Astrophysics Data System (ADS)

    Tilioua, A.; Libessart, L.; Joulin, A.; Lassue, S.; Monod, B.; Jeandel, G.

    2012-10-01

    The objective of this study is to characterize both experimentally and theoretically, conductive and radiative heat transfer within polyester batting. This material is derived from recycled bottles (PET) with fibres of constant diameters. Two other mineral and plant fibrous insulation materials, (glass wool and hemp wool) are also characterized for comparative purposes. To determine the overall thermophysical properties of the tested materials, heat flux measurement are carried out using a device developed in house. The radiative properties of the material are determined by an inverse method based on measurements of transmittance and reflectance using a FTIR spectrometer and by solving the equation of radiative heat transfer. These measures are compared to results of numerical simulations.

  2. LATERAL HEAT FLOW INFRARED THERMOGRAPHY FOR THICKNESS INDEPENDENT DETERMINATION OF THERMAL DIFFUSIVITY IN CFRP

    SciTech Connect

    Tralshawala, Nilesh; Howard, Don; Knight, Bryon; Plotnikov, Yuri; Ringermacher, Harry

    2008-02-28

    In conventional infrared thermography, determination of thermal diffusivity requires thickness information. Recently GE has been experimenting with the use of lateral heat flow to determine thermal diffusivity without thickness information. This work builds on previous work at NASA Langley and Wayne State University but we incorporate thermal time of flight (tof) analysis rather than curve fitting to obtain quantitative information. We have developed appropriate theoretical models and a tof based data analysis framework to experimentally determine all components of thermal diffusivity from the time-temperature measurements. Initial validation was carried out using finite difference simulations. Experimental validation was done using anisotropic carbon fiber reinforced polymer (CFRP) composites. We found that in the CFRP samples used, the in-plane component of diffusivity is about eight times larger than the through-thickness component.

  3. Advanced Failure Determination Measurement Techniques Used in Thermal Fatigue Life Testing of Electronic Packaging

    NASA Technical Reports Server (NTRS)

    Wallace, A. P.; Cornford, S. L.; Gross, M. A.

    1996-01-01

    Thermal fatigue life testing of various electronic packaging technologies is being performed by the Reliability Technology Group at the Jet Propulsion Laboratory. These testing efforts are in progress to improve uderstanding of the reliability issues associated with low volume packaging technologies for space applications and to develop qualification and acceptance approaches for these technologies. The work described here outlines the electrical failure detection techniques used during testing by documenting the circuits and components used to make these measurements, the sensitivity of the measurements, and the applicability of each specific measurement.

  4. Determination of the optical and the thermal properties of an absorbing medium by using infrared thermometry

    NASA Astrophysics Data System (ADS)

    Yang, Seung-Jin; Baek, Jun-Hyeok; Kim, Seung-Eun; Kwon, Min-Ki; Park, Jong-Rak; Yeom, Dong-Il; Kim, Ji-Sun; Baek, Jin-Young; Kim, Hyung-Sik; Jun, Jae-Hoon; Chung, Soon-Cheol

    2016-12-01

    Spatiotemporal changes in the surface temperature of an absorbing medium irradiated by using 532-nm laser pulses were measured using an infrared camera. Relevant numerical simulations of the heat transfer equation were performed. The simulations showed that the maximum temperature increase was linearly proportional to the absorption coefficient with no dependence on the thermal conductivity and that the decay time constant depended on both the absorption coefficient and the thermal conductivity. The absorption coefficient and the thermal conductivity of the medium were determined by fitting the simulated results for the maximum temperature increase and decay time constant to the measured results.

  5. Electropyroelectric technique: A methodology free of fitting procedures for thermal effusivity determination in liquids.

    PubMed

    Ivanov, R; Marin, E; Villa, J; Gonzalez, E; Rodríguez, C I; Olvera, J E

    2015-06-01

    This paper describes an alternative methodology to determine the thermal effusivity of a liquid sample using the recently proposed electropyroelectric technique, without fitting the experimental data with a theoretical model and without having to know the pyroelectric sensor related parameters, as in most previous reported approaches. The method is not absolute, because a reference liquid with known thermal properties is needed. Experiments have been performed that demonstrate the high reliability and accuracy of the method with measurement uncertainties smaller than 3%.

  6. A psychophysical study to determine maximum acceptable efforts for a thumb abduction task with high duty cycles.

    PubMed

    Sonne, Michael W; Potvin, Jim R

    2015-01-01

    Potvin (2012, 'Predicting Maximum Acceptable Efforts for Repetitive Tasks: An Equation Based on Duty Cycle', Human Factors: The Journal of the Human Factors and Ergonomics Society, 54 (2), 175-188) developed an equation using psychophysical data to estimate maximum acceptable efforts (MAEs) as a function of duty cycle (DC). However, only ∼6% of the data featured DCs ≥ 0.50. The purpose of this study was to evaluate the MAE equation in the high DC range. We tested a repetitive thumb adduction task with DCs of 0.50, 0.70 and 0.90, at frequencies of both 2 and 6 per minute (n = 6 conditions). Participants were trained for 2 hours and tested for 1 hour on each condition. The MAE decreased with increasing DC, and MAEs at 2/min were higher than those at 6/min. When these current six means were added to the original psychophysical studies, the root-mean squared difference of the MAE equation decreased from 7.23% to 7.05% maximum voluntary contraction. The values from our study are also consistent with those demonstrating physiological evidence of fatigue during both continuous isotonic and high DC tasks.

  7. Determination of long-lived fission products and actinides in Savannah River site HLW sludge and glass for waste acceptance

    SciTech Connect

    Bibler, N.E.; Boyce, W.T.; Coleman, C.J.

    1997-10-01

    Savannah River Site (SRS) is currently immobilizing the radioactive, caustic, high-level waste sludge in Tank 51 into a borosilicate glass for disposal in a geologic repository. A requirement for repository acceptance is that SRS report the concentrations of certain fission product and actinide radionuclides in the glass. This paper presents measurements of many of these concentrations in both Tank 51 sludge and the final glass. The radionuclides were measured by inductively coupled plasma - mass spectrometry and {alpha}, {beta}, and {gamma} counting methods. Examples of the radionuclides are Sr-90, Cs-137, U-238, Pu-239, and Cm-244. Concentrations in the glass are 3.1 times lower due to dilution of the sludge with a nonradioactive glass forming frit in the vitrification process. Results also indicated that in both the sludge and glass the relative concentrations of the long lived fission products insoluble in caustic area in proportion to their yields from the fission of U-235 in the SRS reactors. This allowed the calculation of a fission yield scaling factor. This factor in addition to the sludge dilution factor can be used to estimate concentrations of waste acceptance radionuclides that cannot be measured in the glass.

  8. A combined diffusion and thermal modeling approach to determine peak temperatures of thermal metamorphism experienced by meteorites

    NASA Astrophysics Data System (ADS)

    Schwinger, Sabrina; Dohmen, Ralf; Schertl, Hans-Peter

    2016-10-01

    Carbonaceous chondrites are affected to different degrees by thermal and aqueous metamorphism on their parent bodies. However, the degree of alteration has been categorized mainly by relative scales and achieving quantitative information about metamorphic temperature by conventional mineral thermometry is problematic for low petrologic types. We have developed a general approach to estimate the metamorphic peak temperature experienced by type 3 chondrites from diffusion zoning in minerals, and have applied this approach to olivine in type I and type II chondrules of CO3 chondrites. To obtain metamorphic temperatures from diffusion zoning, we have combined diffusion modeling with thermal modeling of the meteorite parent body. The integrated diffusion coefficient over time (Γ) was identified as a useful parameter to quantify the extent of chemical change by diffusion occurring in a mineral during a given thermal history. Knowing the temperature dependence of the diffusion coefficient, Γ values can be calculated for each thermal history and be compared to the Γ values obtained from diffusion modeling. For thermal histories realistic for the parent body, Γ depends primarily on the metamorphic peak temperature, so that Γ values determined from diffusion profiles in meteorite minerals can be directly related to the metamorphic peak temperature. This general approach is relatively insensitive to uncertainties in the input parameters for the thermal model. We found that chemical zoning in type I and type II chondrule olivine of the CO chondrites Kainsaz and Lancé was largely influenced by solid state diffusion, which is evident from the observed correlation of zoning anisotropy with the crystallographic orientation. Chemical zoning in type II chondrule olivine is mainly igneous for CO chondrites of petrologic types up to at least 3.2 (Kainsaz) and was influenced only minor by diffusion during parent body metamorphism. Fe-Mg zoning in type II chondrule olivine and

  9. Comparative analysis of methods for determination of the thermal characteristics of filled polymer composites

    NASA Astrophysics Data System (ADS)

    Bochkareva, S. A.; Grishaeva, N. Yu.; Lyukshin, P. A.; Lyukshin, B. A.; Panin, S. V.; Reutov, Yu. A.; Matolygina, N. Yu.

    2016-11-01

    The thermal conductivity of a number of dispersely filled polymer materials has been determined on the basis of a heat problem solution. The temperature distribution in a heterogeneous media has been defined with the use of finite element method for the model that takes into account the location, geometry and properties of inclusions and/or pores. The results for the composites based on various polymer matrices have been obtained. For the studied methods for determination of effective characteristics of filled polymer composites, it was shown that the values of effective thermal conductivity both qualitatively and quantitatively agree with experimental data.

  10. Determining the cation exchange capacity of montmorillonite by simultaneous thermal analysis method

    NASA Astrophysics Data System (ADS)

    Boeva, N. M.; Bocharnikova, Yu. I.; Belousov, P. E.; Zhigarev, V. V.

    2016-08-01

    A way of determining the cation exchange capacity of montmorillonite by simultaneous thermal analysis is developed using as an example the bentonites of the 10th Khutor deposit (Republic of Khakassia) and the Vodopadnyi area (Sakhalin Island). A correlation is established between the cation exchange capacity of smectite and its weight loss upon heating in the range of dehydration; the enthalpy of dehydration of montmorillonite; and the weight loss and the enthalpy of thermal dissociation of ethylene glycol contained in the interlayer space of the mineral's crystal structure. These data open up new possibilities for determining the cation exchange capacity of montmorillonite, the most important technological indicator of the natural clay nanomineral.

  11. The application of thermal methods for determining chemical composition of carbonaceous aerosols: a review.

    PubMed

    Chow, Judith C; Yu, Jian Zhen; Watson, John G; Ho, Steven Sai Hang; Bohannan, Theresa L; Hays, Michael D; Fung, Kochy K

    2007-09-01

    Thermal methods of various forms have been used to quantify carbonaceous materials. Thermal/optical carbon analysis provides measurements of organic and elemental carbon concentrations as well as fractions evolving at specific temperatures in ambient and source aerosols. Detection of thermally desorbed organic compounds with thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) identifies and quantifies over 100 individual organic compounds in particulate matter (PM) samples. The resulting mass spectra contain information that is consistent among, but different between, source emissions even in the absence of association with specific organic compounds. TD-GC/MS is a demonstrated alternative to solvent extraction for many organic compounds and can be applied to samples from existing networks. It is amenable to field-deployable instruments capable of measuring organic aerosol composition in near real-time. In this review, thermal stability of organic compounds is related to chemical structures, providing a basis for understanding thermochemical properties of carbonaceous aerosols. Recent advances in thermal methods applied to determine aerosol chemical compositions are summarized and their potential for uncovering aerosol chemistry are evaluated. Current limitations and future research needs of the thermal methods are included.

  12. Molecular simulations and lattice dynamics determination of Stillinger-Weber GaN thermal conductivity

    SciTech Connect

    Liang, Zhi; Jain, Ankit; McGaughey, Alan J. H.; Keblinski, Pawel

    2015-09-28

    The bulk thermal conductivity of Stillinger-Weber (SW) wurtzite GaN in the [0001] direction at a temperature of 300 K is calculated using equilibrium molecular dynamics (EMD), non-equilibrium MD (NEMD), and lattice dynamics (LD) methods. While the NEMD method predicts a thermal conductivity of 166 ± 11 W/m·K, both the EMD and LD methods predict thermal conductivities that are an order of magnitude greater. We attribute the discrepancy to significant contributions to thermal conductivity from long-mean free path phonons. We propose that the Grüneisen parameter for low-frequency phonons is a good predictor of the severity of the size effects in NEMD thermal conductivity prediction. For weakly anharmonic crystals characterized by small Grüneisen parameters, accurate determination of thermal conductivity by NEMD is computationally impractical. The simulation results also indicate the GaN SW potential, which was originally developed for studying the atomic-level structure of dislocations, is not suitable for prediction of its thermal conductivity.

  13. Is Socio-Economic Status a Determinant of HIV-Related Stigma Attitudes in Zimbabwe? Findings from Project Accept

    PubMed Central

    Singh, Basant; Chingono, Alfred; Sibanda, E.; Machingura, Ian

    2016-01-01

    HIV related stigma and discrimination is a known barrier for HIV prevention and care. We aimed to assess the relationship between socio-economic status (SES) and HIV related stigma in Zimbabwe. This paper uses data from Project Accept, which examined the impact of community-based voluntary counseling and testing intervention on HIV incidence and stigma. Total of 2522 eligible participants responded to a psychometric assessment tool, which assessed HIV related stigma and discrimination attitudes on 4 point Likert scale. The tool measured three components of HIV-related stigma: shame, blame and social isolation, perceived discrimination, and equity. Participants’ ownership of basic assets was used to assess the socio-economic status. Shame, blame and social isolation component of HIV related stigma was found to be significantly associated with medium [odds ratio (OR)=1.73, P<0.01] and low SES (OR=1.97, P<0.01), indicating more stigmatizing attitudes by participants belonging to medium and low SES in comparison to high SES. For HIV related stigma and discrimination programs to be effective, they should take into account the socio-economic context of target population. PMID:28299151

  14. Is Socio-Economic Status a Determinant of HIV-Related Stigma Attitudes in Zimbabwe? Findings from Project Accept.

    PubMed

    Mateveke, Kudzanai; Singh, Basant; Chingono, Alfred; Sibanda, E; Machingura, Ian

    2016-08-17

    HIV related stigma and discrimination is a known barrier for HIV prevention and care. We aimed to assess the relationship between socio-economic status (SES) and HIV related stigma in Zimbabwe. This paper uses data from Project Accept, which examined the impact of community-based voluntary counseling and testing intervention on HIV incidence and stigma. Total of 2522 eligible participants responded to a psychometric assessment tool, which assessed HIV related stigma and discrimination attitudes on 4 point Likert scale. The tool measured three components of HIV-related stigma: shame, blame and social isolation, perceived discrimination, and equity. Participants' ownership of basic assets was used to assess the socio-economic status. Shame, blame and social isolation component of HIV related stigma was found to be significantly associated with medium [odds ratio (OR)=1.73, P<0.01] and low SES (OR=1.97, P<0.01), indicating more stigmatizing attitudes by participants belonging to medium and low SES in comparison to high SES. For HIV related stigma and discrimination programs to be effective, they should take into account the socio-economic context of target population.

  15. The direct determination of HgS by thermal desorption coupled with atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Coufalík, Pavel; Zvěřina, Ondřej; Komárek, Josef

    2016-04-01

    This research was aimed at the direct determination of HgS in environmental samples by means of thermal desorption coupled with atomic absorption spectrometry. Operating parameters of the apparatus used for thermal desorption (including a prototype desorption unit) are described in this work, as well as the procedure for measuring mercury release curves together with an evaluation of the analytical signal including two methods of peak integration. The results of thermal desorption were compared with HgS contents obtained by sequential extraction. The limits of quantification of the proposed method for the selective determination of the black and red forms of HgS were 4 μg kg- 1 and 5 μg kg- 1, respectively. The limit of quantification of red HgS in soils was 35 μg kg- 1. The developed analytical procedure was applied to soil and sediment samples from historical mining areas.

  16. Composite tube and plate manufacturing repeatability as determined by precision measurements of thermal strain

    NASA Astrophysics Data System (ADS)

    Riddle, Lenn A.; Tucker, James R.; Bluth, A. Marcel

    2013-09-01

    Composite materials often carry the reputation of demonstrating high variability in critical material properties. The JWST telescope metering structure is fabricated of several thousand separate composite piece parts. The stringent dimensional stability requirements on the metering structure require the critical thermal strain response of every composite piece be verified either at the billet or piece part level. JWST is a unique composite space structure in that it has required the manufacturing of several hundred composite billets that cover many lots of prepreg and many years of fabrication. The flight billet thermal expansion acceptance criteria limits the coefficient of thermal expansion (CTE) to a tolerance ranging between +/-0.014 ppm/K to +/-0.04 ppm/K around a prescribed nominal when measured from 293 K down to 40 K. The different tolerance values represent different material forms including flat plates and different tube cross-section dimensions. A precision measurement facility was developed that could measure at the required accuracy and at a pace that supported the composite part fabrication rate. The test method and facility is discussed and the results of a statistical process analysis of the flight composite billets are surveyed.

  17. Computer program determines thermal environment and temperature history of lunar orbiting space vehicles

    NASA Technical Reports Server (NTRS)

    Head, D. E.; Mitchell, K. L.

    1967-01-01

    Program computes the thermal environment of a spacecraft in a lunar orbit. The quantities determined include the incident flux /solar and lunar emitted radiation/, total radiation absorbed by a surface, and the resulting surface temperature as a function of time and orbital position.

  18. Influence Pulse Duration Methodical Error of Determination of Thermal Translucent Materials Laser Flash Method

    NASA Astrophysics Data System (ADS)

    Katz, Mark M.; Katz, Ilija M.

    2016-02-01

    The analysis of errors in the determination of thermal diffusivity of a typical semiconductor material - Germany, due to radiative energy transfer in the heated layer of material, under conditions consistent with the implementation of the method under the influence of the laser pulse on the surface of the collimated laser pulse of finite duration.

  19. Acoustical determination of the parameters governing thermal dissipation in porous media.

    PubMed

    Olny, Xavier; Panneton, Raymond

    2008-02-01

    In this paper, the question of the acoustical determination of macroscopic thermal parameters used to describe heat exchanges in rigid open-cell porous media subjected to acoustical excitations is addressed. The proposed method is based on the measurement of the dynamic bulk modulus of the material, and analytical inverse solutions derived from different semiphenomenological models governing the thermal dissipation of acoustic waves in the material. Three models are considered: (1) Champoux-Allard model [J. Appl. Phys. 20, 1975-1979 (1991)] requiring knowledge of the porosity and thermal characteristic length, (2) Lafarge et al. model [J. Acoust. Soc. Am. 102, 1995-2006 (1997)] using the same parameters and the thermal permeability, and (3) Wilson model [J. Acoust. Soc. Am. 94, 1136-1145 (1993)] that requires two adjusted parameters. Except for the porosity that is obtained from direct measurement, all the other thermal parameters are derived from the analytical inversion of the models. The method is applied to three porous materials-a foam, a glass wool, and a rock wool-with very different thermal properties. It is shown that the method can be used to assess the validity of the descriptive models for a given material.

  20. Bench-scale experimental determination of the thermal diffusivity of crushed tuff

    SciTech Connect

    Ryder, E.E.; Finley, R.E.; George, J.T.; Ho, C.K.; Longenbaugh, R.S.; Connolly, J.R.

    1996-06-01

    A bench-scale experiment was designed and constructed to determine the effective thermal diffusivity of crushed tuff. Crushed tuff particles ranging from 12.5 mm to 37.5 mm (0.5 in. to 1.5 in.) were used to fill a cylindrical volume of 1.58 m{sup 3} at an effective porosity of 0.48. Two iterations of the experiment were completed; the first spanning approximately 502 hours and the second 237 hours. Temperatures near the axial heater reached 700 degrees C, with a significant volume of the test bed exceeding 100 degrees C. Three post-test analysis techniques were used to estimate the thermal diffusivity of the crushed tuff. The first approach used nonlinear parameter estimation linked to a one dimensional radial conduction model to estimate thermal diffusivity from the first 6 hours of test data. The second method used the multiphase TOUGH2 code in conjunction with the first 20 hours of test data not only to estimate the crushed tuffs thermal diffusivity, but also to explore convective behavior within the test bed. Finally, the nonlinear conduction code COYOTE-II was used to determine thermal properties based on 111 hours of cool-down data. The post-test thermal diffusivity estimates of 5.0 x 10-7 m{sup 2}/s to 6.6 x 10-7 m{sup 2}/s were converted to effective thermal conductivities and compared to estimates obtained from published porosity-based relationships. No obvious match between the experimental data and published relationships was found to exist; however, additional data for other particle sizes and porosities are needed.

  1. High accuracy determination of the thermal properties of supported 2D materials.

    PubMed

    Judek, Jarosław; Gertych, Arkadiusz P; Świniarski, Michał; Łapińska, Anna; Dużyńska, Anna; Zdrojek, Mariusz

    2015-07-16

    We present a novel approach for the simultaneous determination of the thermal conductivity κ and the total interface conductance g of supported 2D materials by the enhanced opto-thermal method. We harness the property of the Gaussian laser beam that acts as a heat source, whose size can easily and precisely be controlled. The experimental data for multi-layer graphene and MoS2 flakes are supplemented using numerical simulations of the heat distribution in the Si/SiO2/2D material system. The procedure of κ and g extraction is tested in a statistical approach, demonstrating the high accuracy and repeatability of our method.

  2. High accuracy determination of the thermal properties of supported 2D materials

    NASA Astrophysics Data System (ADS)

    Judek, Jarosław; Gertych, Arkadiusz P.; Świniarski, Michał; Łapińska, Anna; Dużyńska, Anna; Zdrojek, Mariusz

    2015-07-01

    We present a novel approach for the simultaneous determination of the thermal conductivity κ and the total interface conductance g of supported 2D materials by the enhanced opto-thermal method. We harness the property of the Gaussian laser beam that acts as a heat source, whose size can easily and precisely be controlled. The experimental data for multi-layer graphene and MoS2 flakes are supplemented using numerical simulations of the heat distribution in the Si/SiO2/2D material system. The procedure of κ and g extraction is tested in a statistical approach, demonstrating the high accuracy and repeatability of our method.

  3. Determining the energy distribution of traps in insulating thin films using the thermally stimulated current technique

    NASA Astrophysics Data System (ADS)

    Miller, S. L.; Fleetwood, D. M.; McWhorter, P. J.

    1992-08-01

    We have developed a simple method to analyze and predict the thermally stimulated current (TSC) of charged insulating thin films experiencing arbitrary time-dependent thermal environments and high electric fields. The method allows greater flexibility in experimental conditions than previous work, and includes the effect of field-induced barrier lowering on the trap energy scale. Trap distributions for irradiated metal-SiO2-Si capacitors were accurately determined from TSC measurements spanning a factor of 50 in heating rate, providing an improved estimate of trapped-hole energies in SiO2 (peak ~1.8 eV).

  4. Method and apparatus for determining the content and distribution of a thermal neutron absorbing material in an object

    DOEpatents

    Crane, Thomas W.

    1986-01-01

    The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

  5. Method and apparatus for determining the content and distribution of a thermal neutron absorbing material in an object

    DOEpatents

    Crane, T.W.

    1983-12-21

    The disclosure is directed to an apparatus and method for determining the content and distribution of a thermal neutron absorbing material within an object. Neutrons having an energy higher than thermal neutrons are generated and thermalized. The thermal neutrons are detected and counted. The object is placed between the neutron generator and the neutron detector. The reduction in the neutron flux corresponds to the amount of thermal neutron absorbing material in the object. The object is advanced past the neutron generator and neutron detector to obtain neutron flux data for each segment of the object. The object may comprise a space reactor heat pipe and the thermal neutron absorbing material may comprise lithium.

  6. A Heuristic Approach to the Determination of the Effective Thermal Conductivity Coefficients of Biperiodic Composite Media

    NASA Astrophysics Data System (ADS)

    Yankovskii, A. P.

    2016-11-01

    A heuristic approach to determining the effective thermal conductivity coefficients of unidirectionally reinforced biperiodic composite media is suggested allowing one to substantially refine the calculated values of the effective coefficients of transverse thermal conductivity of the indicated compositions by using the simplest partitioning of a periodicity cell into thin layers (subelements) with subsequent application of the simplest formulas of averaging by simple and inverse mixture rules. A comparison of the calculated values of these coefficients with familiar experimental data is made. The good agreement of the prediction with experiment allows an assumption that the method developed can be used for practical calculations of the thermophysical characteristics of fibrous media with biperiodic structure. At the present time the accuracy of more complex structural models of the thermal conductivity of unidirectionally reinforced composites lacks a strict experimental justification.

  7. [Determination of trace rare earth in fossil of dinosaurian egg by laser thermal lens spectrometry].

    PubMed

    Yan, H; Zheng, Y; Yan, S

    1997-10-01

    Determination of trace rare earth in fossil of dinosaurian egg by LTLS (Laser thermal lens spectrometry) is presented in this paper. The trace rare earth in fossil of dinosaurian egg was separated and concentrated with ion exchange method. The measure conditions and effect factors are discussedian. The LTLS was applied to the determination of trace rare earth in fossil of dinosaurian egg with satisfactory results. It provides the reference data for the studies on the fossil of dinosaurian egg and an analytical method for the determination of rare earth in geochemical sample.

  8. 7 CFR 3300.13 - Determination of the efficiency of the thermal appliances as installed in the insulated body.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Determination of the efficiency of the thermal appliances as installed in the insulated body. In determining the efficiency of a thermal appliance with respect to maintaining a prescribed temperature inside the body, the... appliances as installed in the insulated body. 3300.13 Section 3300.13 Agriculture Regulations of...

  9. 7 CFR 3300.13 - Determination of the efficiency of the thermal appliances as installed in the insulated body.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Determination of the efficiency of the thermal appliances as installed in the insulated body. In determining the efficiency of a thermal appliance with respect to maintaining a prescribed temperature inside the body, the... appliances as installed in the insulated body. 3300.13 Section 3300.13 Agriculture Regulations of...

  10. 7 CFR 3300.13 - Determination of the efficiency of the thermal appliances as installed in the insulated body.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... appliances as installed in the insulated body. 3300.13 Section 3300.13 Agriculture Regulations of the... Determination of the efficiency of the thermal appliances as installed in the insulated body. In determining the efficiency of a thermal appliance with respect to maintaining a prescribed temperature inside the body,...

  11. 7 CFR 3300.13 - Determination of the efficiency of the thermal appliances as installed in the insulated body.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... appliances as installed in the insulated body. 3300.13 Section 3300.13 Agriculture Regulations of the... Determination of the efficiency of the thermal appliances as installed in the insulated body. In determining the efficiency of a thermal appliance with respect to maintaining a prescribed temperature inside the body,...

  12. Determination of Thermal Neutron Capture Cross-Sections at Budapest PGAA Facility

    SciTech Connect

    Revay, Zsolt; Belgya, Tamas; Firestone, Richard B.

    2007-10-26

    Prompt gamma activation analysis (PGAA) is a powerful nuclear analytical technique to determine the elemental and isotopic composition of materials. The PGAA facility at Budapest, Hungary is one of the leading laboratories of the world, determining spectroscopic data for chemical analysis to be used in other laboratories. These partial gamma-ray production cross-sections and k{sub 0} values, being proportional to the analytical sensitivities of the chemical elements, can be transformed into thermal neutron capture cross-sections, i.e. the probabilities of the (n,{gamma}) reactions, which are of broader interest in different fields of nuclear physics. Some preliminary results on thermal neutron capture cross-sections are presented.

  13. Reconstruction of the welding thermal cycle and determination of residual stresses from isotherm traces

    NASA Astrophysics Data System (ADS)

    Goldstein, R. V.; Kozintsev, V. M.; Kurov, D. A.; Popov, A. L.; Chelyubeev, D. A.

    2013-01-01

    The earlier method for reconstructing the welding thermal cycle from the dislocation of the temper colors and the cold weld joint boundaries was applied in the case of contact flash welding of rod samples. The possibility of using this method to determine the key parameters of the welding processes such as the approach speed of the welded rods, the temperature at the weld center at the beginning of cooling, and the time in which the characteristic temperature isotherm moves to the largest distance from the weld center, which allow one to reconstruct the temperature distribution curve near the weld at any time after the heating termination, was shown. The reconstructed thermal cycle was used to determine the residual stresses in the weld and in the heat-affected zone.

  14. Accuracy of the correlation method of the thermal neutron absorption cross-section determination for rocks

    NASA Astrophysics Data System (ADS)

    Krynicka, Ewa

    1995-08-01

    The influence of various random errors on the accuracy of thermal neutron absorption cross-sections determined by a correlation method is discussed. It is considered either as an absolute accuracy, when all experimental errors arc taken into account, or as an experimental assay accuracy, when the reference moderator parameters are assumed as the invariant data fixed for all experiments. The estimated accuracy is compared with the accuracy of results obtained for the same rock sample by Czubek's measurement method.

  15. Methods of testing to determine the thermal performance of solar collectors

    NASA Astrophysics Data System (ADS)

    This Standard has been prepared by a committee drawn primarily from the membership of ASHRAE. The Committee's objective was to formulate a test procedure whereby solar energy collectors can be tested both indoors and outdoors, to rate the collectors in accordance with their thermal performance, and to determine their time constant and the variation of their efficiency with changes in the angle of incidence between the Sun's direct rays and the normal to the collector aperture.

  16. Photoacoustic determination of thermal and electron transport properties of single crystal NiO

    NASA Astrophysics Data System (ADS)

    Nikolic, P. M.; Lukovic, D.; Savic, S.; Vasiljevic Radovic, D.; Radulovic, K.; Vujatovic, S.; Lukic, L.; Nikolic, M. V.; Bojicic, A.; Djuric, S.

    2005-06-01

    Thermal and electron transport properties of single crystal NiO were determined using the photoacoustic technique. NiO single crystals were prepared using the Verneuil method and were easily cleaved parallel to the (100) plane. All samples were of the p type. Atomic force microscopy images of cleaved NiO samples were made enabling a view of steps along the (001) direction and terraces, which were between 20 nm and 100 nm thick.

  17. A sensor to perform in-situ thermal conductivity determination of cometary and asteroid material

    NASA Astrophysics Data System (ADS)

    Banaszkiewicz, M.; Seweryn, K.; Wawrzaszek, R.

    Measurements of the physical properties of surface and subsurface layers of planetary bodies often provide important information about the structure of the medium and processes that occur there. Thermal properties of the subsurface material of cometary nuclei are crucial in determining the heat and gas transport. Similarly, asteroids' regolith is a buffering zone for the process of heat transfer from the surface to the interior of a body and vice versa. There are space experiments planned to perform temperature and thermal conductivity measurements on a comet (ROSETTA) and one can easily foresee such measurements carried out by future robotic missions on Mars, planetary satellites and asteroids. In this paper we present the results of measurements carried out with a new type of thermal sensors. The elementary cylindrical sensor is made of platinum wire (resistance thermometer) and isotan wire (heating element) that can operate independently. Their advantage is that they use very well known and calibrated materials for temperature sensors (platinum) and for heaters (isotan). By choosing these materials the problems of temperature measurement, calibration and constant heating power are resolved. We interpret the results of measurements made for a number of sensors combined into a long cylinder in teflon, delrin, ice-dust mixture (comet analogue) and regolith-like material in terms of numerical models and show that the obtained values of thermal conductivity are in agreement with what one could expect. Therefore, we can recommend both the sensors and the method of data interpretation for the thermal conductivity determination as very useful tools for future space missions and in laboratory experiments on cometary and asteroid material analogues.

  18. A multicentre study to determine the efficacy and patient acceptability of the Paxman Scalp Cooler to prevent hair loss in patients receiving chemotherapy.

    PubMed

    Massey, Carolyn S

    2004-06-01

    Alopecia is a distressing and common side-effect of chemotherapy, especially anthracycline- and taxane-containing regimen. A series of studies and reviews have considered scalp cooling as a means of reducing this side-effect without a definitive result. The aim of the study was to determine the efficacy and patient acceptability of scalp cooling using the Paxman Scalp Cooler. This was an open, non-randomised, observational study conducted at eight sites involving 94 patients. Alopecia was assessed using the World Health Organisation (WHO) grading system. Patient acceptability was assessed by questionnaire. Results were compiled by Scalp Cooling Assessment Groups using data from eight centres in the UK collected between 1997 and 2000. Use of the Paxman Scalp Cooler was adjudged a success for 89% of all patients using the WHO grading system for alopecia and for 87% of patients being specifically administered the commonly used 5-fluorouracil, epirubicin and cyclophosphamide (FEC) regimen. When asked about degrees of comfort during the scalp-cooling process, 85% of patients described it as very comfortable, reasonably comfortable or comfortable, with only 15% of patients reporting a description of uncomfortable or very uncomfortable. Scalp cooling using the Paxman Scalp Cooler was found to be an effective technique with minimal side-effects for patients treated with commonly prescribed alopecia-inducing chemotherapy drugs.

  19. A New Method for Determining Material Thermal Properties at Static High Pressures

    NASA Astrophysics Data System (ADS)

    Carney, J. R.; Ladouceur, H. D.; Russell, T. P.; Pangilinan, G. I.

    2004-07-01

    The response of materials under shock loading is strongly dependent on the mechanical and thermal properties of materials at high pressures. Despite the availability of several methods that quantify mechanical properties of materials at high pressures and loading rates, only a few existing techniques can measure heat capacity or thermal conductivity at high pressures. A new method is proposed to determine the thermal transport properties of materials in gem anvil cells (GAC). The test material and a ruby sphere were enclosed in a GAC and brought to pressure. The ruby was heated at a constant rate by a pulse of light whose intensity had a square wave temporal profile. Time-resolved ruby fluorescence spectra were recorded with a spectrometer and a streak camera. The temperature profile of the ruby during both the heating and cooling (following removal of the laser light) periods was sensitively dependent on the thermal transport properties of the surrounding material. A pressure-dependent set of results is presented for sodium chloride (NaCl) and Teflon, utilizing this new technique. The data is compared to simulations using previously published data.

  20. Determination of the thermal properties of leaves by non-invasive contact‑free laser probing.

    PubMed

    Buyel, J F; Gruchow, H M; Tödter, N; Wehner, M

    2016-01-10

    The thermal properties of materials provide valuable data for quality monitoring and the rational design of process steps where heating is required. Here we report a rapid, simple and reliable technique that determines the most important thermal properties of leaves, i.e. the specific heat capacity (cp) and thermal conductivity (λ). Such data are useful when leaves are heated during processing, e.g. for the precipitation of host cell proteins during the extraction of high-value products such as recombinant proteins produced by molecular farming. The cp of tobacco (Nicotiana tabacum) and Nicotiana benthamiana leaves was determined by infrared measurement of the temperature increase caused by a near-infrared laser pulse of defined length and intensity. We used the sample temperature profiles to calculate λ based on exponential fits of the temperature decline, taking convective heat transfer and thermal radiation into account. We found that the average cp was 3661 ± 323 J kg(-1) K(-1) (n=19) for tobacco and 2253 ± 285 J kg(-1) K(-1) (n=25) for N. benthamiana, whereas the average λ was 0.49 ± 0.13 (n=19) for tobacco and 0.41 ± 0.20 (n=25) Jm(-1) s(-1)K(-1) for N. benthamiana. These values are similar to those established for other plant species by photothermal imaging and other methods. The cp and λ values of leaves can be determined easily using our non-invasive method, which is therefore suitable for the in-line or at-line monitoring of plants, e.g. during the highly regulated production of biopharmaceutical proteins.

  1. Determination of the Thermal Decomposition Products of Terephthalic Acid by Using Curie-Point Pyrolyzer

    NASA Astrophysics Data System (ADS)

    Begüm Elmas Kimyonok, A.; Ulutürk, Mehmet

    2016-04-01

    The thermal decomposition behavior of terephthalic acid (TA) was investigated by thermogravimetry/differential thermal analysis (TG/DTA) and Curie-point pyrolysis. TG/DTA analysis showed that TA is sublimed at 276°C prior to decomposition. Pyrolysis studies were carried out at various temperatures ranging from 160 to 764°C. Decomposition products were analyzed and their structures were determined by gas chromatography-mass spectrometry (GC-MS). A total of 11 degradation products were identified at 764°C, whereas no peak was observed below 445°C. Benzene, benzoic acid, and 1,1‧-biphenyl were identified as the major decomposition products, and other degradation products such as toluene, benzophenone, diphenylmethane, styrene, benzaldehyde, phenol, 9H-fluorene, and 9-phenyl 9H-fluorene were also detected. A pyrolysis mechanism was proposed based on the findings.

  2. Fluorescence quantum yield of Yb3+-doped tellurite glasses determined by thermal lens spectroscopy

    NASA Astrophysics Data System (ADS)

    Lima, S. M.; Souza, A. K. R.; Langaro, A. P.; Silva, J. R.; Costa, F. B.; Moraes, J. C. S.; Figueiredo, M. S.; Santos, F. A.; Baesso, M. L.; Nunes, L. A. O.; Andrade, L. H. C.

    2017-01-01

    In this work, the combination of three different thermal lens spectroscopic methodologies was used to better determine the fluorescence quantum yield and to observe the concentration quenching in Yb3+-doped binary tellurite glasses (in mol%, 80TeO2 - 20Li2O and 80TeO2 - 20WO3). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (TLS). These characterizations enabled investigation of the radiative and nonradiative processes involved in the ytterbium doped systems. High fluorescence quantum yield was obtained for low Yb3+ doping (>90%), and in both glasses the Yb3+ presented concentration quenching mainly caused by impurities, host-ion interaction and OH- vibrations. The observations suggested that there is a possibility of doping the glasses with higher Yb concentration (>1.6 × 1021 ions/cm3) with low reduction of the quantum yield.

  3. Determination of the thermal neutron flux in a fast neutron beam by use of a boron-coated ionization chamber.

    PubMed

    Lüdemann, L; Matzen, T; Matzke, M; Schmidt, R; Scobel, W

    1995-11-01

    The thermal neutron distribution in slow and fast neutron beams is usually determined using the foil activation method. In this work a small magnesium walled ionization chamber, in which the inner surface of the wall has been coated with 10B to increase the sensitivity for thermal neutrons, is used to estimate the thermal neutron component of the beam. After calibration and determination of the directional response in a thermal neutron beam a comparison with foil activation at different depths in water was performed to investigate the reliability of the ionization measurements. The chamber was used in a computer controlled water phantom to measure the depth and lateral distribution of the thermal neutron dose. With this arrangement two-dimensional scans of the thermal neutrons could be performed quickly and with high accuracy.

  4. Determination of Thermal Conductivity of Reconsolidated Crushed Salt to 200°C

    NASA Astrophysics Data System (ADS)

    Urquhart, A.; Bauer, S. J.; Hansen, F. D.

    2012-12-01

    Thermal, mechanical, and fluid transport properties of reconsolidating granular salt are important for design, analysis and performance assessment of potential salt repositories for heat-generating nuclear waste. Properties such as thermal conductivity (λ) and permeability (k) are functions of porosity. To inform salt repository evaluations, where salt creep at elevated pressures and temperatures will reduce the porosity of salt enclosures, we have undertaken an experimental program to determine λ of reconsolidated granular salt as a function of porosity, with the secondary intent of quantifying temperature dependence over a range of temperatures from 100-200°C. Mine-run salt from the Waste Isolation Pilot Program (WIPP) was first dried at 100°C until weight loss ceased. The disaggregated salt was compacted at room temperature by quasistatic die compression into samples with porosities ranging from 40% (unconsolidated) to 5%. Thermal conductivity was also measured on intact domal salt, WIPP bedded salt, and commercially available salt licks in order to determine λ in salt with porosity as low as 1-8%. For every sample, measurements were made at 100, 125, 150, 175, and 200°C using a guarded heat flow meter. Thermal conductivity was found to decrease by a factor of about 4-5 for the porosity range studied. The λ versus porosity relationship is well represented by a simple mixture model. A temperature dependence is also observed, the effect of which increases at lower porosities. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Simultaneous Determination of Thermal Conductivity and Thermal Diffusivity of Food and Agricultural Materials Using a Transient Plane-Source Method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal conductivity and thermal diffusivity are two important physical properties essential for designing any food engineering processes. Recently a new transient plane-source method was developed to measure a variety of materials, but its application in foods has not been documented. Therefore, ...

  6. Thermal conductivity profile determination in proton-irradiated ZrC by spatial and frequency scanning thermal wave methods

    SciTech Connect

    Jensen, C.; Chirtoc, M.; Horny, N.; Antoniow, J. S.; Pron, H.; Ban, H.

    2013-10-07

    Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the best resolution finding a very uniform thermal conductivity envelope in the damaged region measuring ∼52 ± 2 μm deep. Frequency-based scanning PTR provides quantification of the thermal parameters of the sample using the SThM measured profile to provide validation of a heating model. Measured irradiated and virgin thermal conductivities are found to be 11.9 ± 0.5 W m{sup −1} K{sup −1} and 26.7 ±1 W m{sup −1} K{sup −1}, respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10{sup −6} m{sup 2} K W{sup −1}. The measured thermal conductivity values compare well with the thermal conductivity extracted from the SThM calibrated signal and the spatially scanned PTR. Combined spatial and frequency scanning techniques are shown to provide a valuable, complementary combination for thermal property characterization of proton-irradiated ZrC. Such methodology could be useful for other studies of ion-irradiated materials.

  7. Analysis of the possibility of determining the internal structure of composite material by estimating its thermal diffusivity

    NASA Astrophysics Data System (ADS)

    Kosowska-Golachowska, Monika; Gajewski, Władysław; Musiał, Tomasz

    2014-09-01

    In this study, a new laser flash system was proposed for the determination of the thermal conductivity of brown coal, hard coal and anthracite. The main objective of the investigation was to determine the effect of coal rank, composition, physical structure and temperature on thermal conductivity. The solid fuels tested were medium conductors of heat whose determined thermal conductivities were in the range of 0.09 to 0.23W/(mK) at room temperature. The thermal conductivity of the solid fuels tested typically increased with the rank of coal and the measurement temperature. The results of this study show that the physical structure of solid fuels and temperature have a dominant effect on the fuels' thermal conductivity.

  8. Acceptance speech.

    PubMed

    Yusuf, C K

    1994-01-01

    I am proud and honored to accept this award on behalf of the Government of Bangladesh, and the millions of Bangladeshi children saved by oral rehydration solution. The Government of Bangladesh is grateful for this recognition of its commitment to international health and population research and cost-effective health care for all. The Government of Bangladesh has already made remarkable strides forward in the health and population sector, and this was recognized in UNICEF's 1993 "State of the World's Children". The national contraceptive prevalence rate, at 40%, is higher than that of many developed countries. It is appropriate that Bangladesh, where ORS was discovered, has the largest ORS production capacity in the world. It was remarkable that after the devastating cyclone in 1991, the country was able to produce enough ORS to meet the needs and remain self-sufficient. Similarly, Bangladesh has one of the most effective, flexible and efficient control of diarrheal disease and epidemic response program in the world. Through the country, doctors have been trained in diarrheal disease management, and stores of ORS are maintained ready for any outbreak. Despite grim predictions after the 1991 cyclone and the 1993 floods, relatively few people died from diarrheal disease. This is indicative of the strength of the national program. I want to take this opportunity to acknowledge the contribution of ICDDR, B and the important role it plays in supporting the Government's efforts in the health and population sector. The partnership between the Government of Bangladesh and ICDDR, B has already borne great fruit, and I hope and believe that it will continue to do so for many years in the future. Thank you.

  9. A unified approach to combine temperature estimation and elastography for thermal lesion determination in focused ultrasound thermal therapy

    NASA Astrophysics Data System (ADS)

    Liu, Hao-Li; Li, Meng-Lin; Tsui, Po-Hsiang; Lin, Ming-Shi; Huang, Sheng-Min; Bai, Jing

    2011-01-01

    Sonogram-based temperature estimation and elastography have both shown promise as methods of monitoring focused ultrasound (FUS) treatments to induce thermal ablation in tissue. However, each method has important limitations. Temperature estimates based on echo delays become invalid when the relationship between sound speed and temperature is nonlinear, and are further complicated by thermal expansion and other changes in tissue. Elastography can track thermal lesion formation over a wider range of elasticity, but with low specificity and high noise. Furthermore, this method is poor at small lesion detection. This study proposes integrating the two estimates to improve the quality of monitoring FUS-induced thermal lesions. Our unified computational kernel is tested on three types of phantoms. Experiments with type I and type II phantoms were conducted to calibrate the thermal mapping and elastography methods, respectively. The optimal settings were then used in experiments with the type III phantom, which contains ex vivo swine liver tissue. Three different spatial-peak temporal-average intensities (Ispta; 35, 133 and 240 W cm-2) were delivered with a sonication time of 60 s. The new procedure can closely monitor heating while identifying the dimensions of the thermal lesion, and is significantly better at the latter task than either approach alone. This work may help improve the current clinical practice, which employs sonograms to guide the FUS-induced thermal ablation procedure.

  10. A unified approach to combine temperature estimation and elastography for thermal lesion determination in focused ultrasound thermal therapy.

    PubMed

    Liu, Hao-Li; Li, Meng-Lin; Tsui, Po-Hsiang; Lin, Ming-Shi; Huang, Sheng-Min; Bai, Jing

    2011-01-07

    Sonogram-based temperature estimation and elastography have both shown promise as methods of monitoring focused ultrasound (FUS) treatments to induce thermal ablation in tissue. However, each method has important limitations. Temperature estimates based on echo delays become invalid when the relationship between sound speed and temperature is nonlinear, and are further complicated by thermal expansion and other changes in tissue. Elastography can track thermal lesion formation over a wider range of elasticity, but with low specificity and high noise. Furthermore, this method is poor at small lesion detection. This study proposes integrating the two estimates to improve the quality of monitoring FUS-induced thermal lesions. Our unified computational kernel is tested on three types of phantoms. Experiments with type I and type II phantoms were conducted to calibrate the thermal mapping and elastography methods, respectively. The optimal settings were then used in experiments with the type III phantom, which contains ex vivo swine liver tissue. Three different spatial-peak temporal-average intensities (I(spta); 35, 133 and 240 W cm(-2)) were delivered with a sonication time of 60 s. The new procedure can closely monitor heating while identifying the dimensions of the thermal lesion, and is significantly better at the latter task than either approach alone. This work may help improve the current clinical practice, which employs sonograms to guide the FUS-induced thermal ablation procedure.

  11. Determination of femtogram quantities of protactinium in geologic samples by thermal ionization mass spectrometry

    SciTech Connect

    Pickett, D.A.; Murrell, M.T.; Williams, R.W. )

    1994-04-01

    We describe a procedure for measurement of [sup 231]Pa in geologic samples by isotope dilution thermal ionization mass spectrometry, using [sup 233]Pa as a spike isotope, which provides marked improvements in precision and sample size relative to established decay counting techniques. This method allows determination of as little as a few tens of femtograms of [sup 231]Pa (approximately 10[sup 3] atoms) with a conservative estimated uncertainty of [+-]1% (95% confidence level). Applications of [sup 231]Pa-[sup 235]U systematics to uranium-series geochemistry and geochronology should be greatly enhanced by this approach. 31 refs., 4 figs., 1 tab.

  12. Experimental determination of in situ utilization of lunar regolith for thermal energy storage

    NASA Astrophysics Data System (ADS)

    Richter, Scott W.

    A Lunar Thermal Energy from Regolith (LUTHER) experiment has been designed and fabricated at the NASA Lewis Research Center to determine the feasibility of using lunar soil as thermal energy storage media. The experimental apparatus includes an alumina ceramic canister which contains simulated lunar regolith, a heater, nine heat shields, a heat transfer cold jacket, and 19 type-B platinum rhodium thermocouples. The simulated lunar regolith is a basalt that closely resembles the lunar basalt returned to earth by the Apollo missions. The experiment will test the effects of vacuum, particle size, and density on the thermophysical properties of the regolith, which include melt temperature, specific heat thermal conductivity, and latent heat of storage. Two separate tests, using two different heaters, will be performed to study the effect of heating the system using radiative and conductive heat transfer. A finite differencing SINDA model was developed at NASA Lewis Research Center to predict the performance of the LUTHER experiment. The code will predict the effects of vacuum, particle size, and density has on the heat transfer to the simulated regolith.

  13. Experimental determination of in situ utilization of lunar regolith for thermal energy storage

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1992-01-01

    A Lunar Thermal Energy from Regolith (LUTHER) experiment has been designed and fabricated at the NASA Lewis Research Center to determine the feasibility of using lunar soil as thermal energy storage media. The experimental apparatus includes an alumina ceramic canister which contains simulated lunar regolith, a heater, nine heat shields, a heat transfer cold jacket, and 19 type-B platinum rhodium thermocouples. The simulated lunar regolith is a basalt that closely resembles the lunar basalt returned to earth by the Apollo missions. The experiment will test the effects of vacuum, particle size, and density on the thermophysical properties of the regolith, which include melt temperature, specific heat thermal conductivity, and latent heat of storage. Two separate tests, using two different heaters, will be performed to study the effect of heating the system using radiative and conductive heat transfer. A finite differencing SINDA model was developed at NASA Lewis Research Center to predict the performance of the LUTHER experiment. The code will predict the effects of vacuum, particle size, and density has on the heat transfer to the simulated regolith.

  14. Response of DWPF thermal flowmeters to composition change: Effect on 02 determination in Salt Process Cell

    SciTech Connect

    Jacobs, R.A.

    1992-02-03

    Thermal flowmeters (more accurately described as hot wire anamometers) have been installed in the Salt Process Cell (SPC) at the Savannah River Site to measure in-cell process flows. However, upon investigating the effect of composition on thermal flow meters, it was concluded that determining a priori correction factors is a very complicated process requiring fairly precise knowledge of the vapor composition and the meter characteristics. It is recommended that DWPF estimate air enleakage using a test procedure similar to one being developed in the Precipitate Hydrolysis Experimental Facility (PHEF) which circumvents the correction problem by in situ calibration, and develop a profile which characterizes air inleakaqe as a function of [Delta]P to be used in conjunction with the inleakage test procedure. The recommended test procedure has some distinct advantages over the simple material balance approach. More detailed information on the characteristics of thermal flow meters the recommended air inleakage test procedure, and the inleakage profile are discussed in this report.

  15. Response of DWPF thermal flowmeters to composition change: Effect on 02 determination in Salt Process Cell

    SciTech Connect

    Jacobs, R.A.

    1992-02-03

    Thermal flowmeters (more accurately described as hot wire anamometers) have been installed in the Salt Process Cell (SPC) at the Savannah River Site to measure in-cell process flows. However, upon investigating the effect of composition on thermal flow meters, it was concluded that determining a priori correction factors is a very complicated process requiring fairly precise knowledge of the vapor composition and the meter characteristics. It is recommended that DWPF estimate air enleakage using a test procedure similar to one being developed in the Precipitate Hydrolysis Experimental Facility (PHEF) which circumvents the correction problem by in situ calibration, and develop a profile which characterizes air inleakaqe as a function of {Delta}P to be used in conjunction with the inleakage test procedure. The recommended test procedure has some distinct advantages over the simple material balance approach. More detailed information on the characteristics of thermal flow meters the recommended air inleakage test procedure, and the inleakage profile are discussed in this report.

  16. Method for collecting naturally occurring airborne bacterial spores for determining their thermal resistance.

    PubMed

    Puleo, J R; Favero, M S; Oxborrow, G S; Herring, C M

    1975-11-01

    The ability to determine the thermal resistance of naturally occurring airborne bacterial spores associated with spacecraft and their assembly areas has been hindered by lack of an effective collecting system. Efforts to collect and concentrate spores with air samplers or from air filters have not been successful. A fallout method was developed for this purpose and tested. Sterile Teflon ribbons (7.6 by 183 cm) were exposed in pertinent spacecraft assembly areas and subsequently treated with dry heat. Thermal inactivation experiments were conducted at 125 and 113 C. Heating intervals ranged from 1 to 12 h at 125 C and 6, 12, 18, and 24 h at 113 C. Eight hours was the longest heating time yielding survivors at 125 C, whereas survivors were recovered at all of the heating intervals at 113 C. D125C values were calculated using the fractional-replicate-unit-negative technique of Pflug and Schmidt (1968) and ranged from 25 to 126 min. This variation indicated that the most probable number of survivors at each heating interval did not fall on a straight line passing through the initial spore population. However, the most-probable-number values taken alone formed a straight line suggesting logarithmic thermal destruction of a subpopulation of spores with a D125C value of 6.3 h.

  17. Determination of Non-Thermal Velocity Distributions from SERTS Linewidth Observations

    NASA Technical Reports Server (NTRS)

    Coyner, Aaron J.; Davila, Joseph M.

    2011-01-01

    Non-thermal velocities obtained from the measurement of coronal Extreme Ultraviolet (EUV) linewidths have been consistently observed in solar EUV spectral observations and have been theorized to result fro m many plausible scenarios including wave motions, turbulence, or magnetic reconnection. Constraining these velocities can provide a physical limit for the available energy resulting from unresolved motions in the corona. We statistically determine a series of non-thermal velocity distributions from linewidth measurements of 390 emission lines from a wide array of elements and ionization states observed during the Solar Extreme Ultraviolet Research Telescope and Spectrograph 1991-1997 flights covering the spectral range 174-418 A and a temperature range from 80,000 K to 12.6 MK. This sample includes 248 lines from active regions, 101 lines from quiet-Sun regions, and 41 lines were observed from plasma off the solar limb. We find a strongly peaked distribution corresponding to a non-thermal velocity of 19-22 km/s in all three of the quiet-Sun, active region, and off-limb distributions. For the possibility of Alfven wave resonance heating, we find thai velocities in the core of these distributions do not provide sufficient energy, given typical densities and magnetic field strengths for the coronal plasma, to overcome the estimated coronal energy losses required to maintain the corona at the typical temperatures working as the sole mechanism. We find that at perfect efficiency 50%-60% of the needed energy flux can be produced from the non-thermal velocities measured.

  18. Accepting space radiation risks.

    PubMed

    Schimmerling, Walter

    2010-08-01

    The human exploration of space inevitably involves exposure to radiation. Associated with this exposure are multiple risks, i.e., probabilities that certain aspects of an astronaut's health or performance will be degraded. The management of these risks requires that such probabilities be accurately predicted, that the actual exposures be verified, and that comprehensive records be maintained. Implicit in these actions is the fact that, at some point, a decision has been made to accept a certain level of risk. This paper examines ethical and practical considerations involved in arriving at a determination that risks are acceptable, roles that the parties involved may play, and obligations arising out of reliance on the informed consent paradigm seen as the basis for ethical radiation risk acceptance in space.

  19. Methods of testing to determine the thermal performance of unglazed flat-plate liquid-type solar collectors. (ASHRAE standard)

    SciTech Connect

    1989-01-28

    The purpose of this standard is to provide test methods for determining the thermal performance of unglazed flat-plate liquid-type solar energy collector modules which heat a liquid for low temperature applications.

  20. Determination of thermal equilibrium in a sealed cell based on optical depth

    NASA Astrophysics Data System (ADS)

    Zou, Sheng; Zhang, Hong; Chen, Xi-yuan; Shan, Guang-cun; Quan, Wei

    2017-01-01

    An effective method based on optical depth (OD) is presented to measure thermal equilibrium in a cell. First, the principle of determining the temperature distribution in the cell by using the OD is demonstrated. Subsequently, relevant experiments are carried out. Original experimental results showed that some gradients of OD distributions in the cell at different wavelengths and variations of the OD increased slowly along the direction of motion of the beam at a fixed wavelength. At a wavelength of 766.6839 nm, which is about 7 GHz blue shifted with respect to the potassium resonance, the average value of the OD was about 0.764 and the maximal and the minimum inhomogeneity biases among all location points were about 6.07% and 0.56%, respectively. As for the corresponding wavelengths of 766.67785 nm and 766.73004 nm, some deviations from previous results, which were caused by different absorptions of the alkali-metal atoms at different frequencies of the laser beam, were observed. The nonuniform OD values along the direction of motion of the beam reflected an inhomogeneous distribution of the temperature in the cell, which may have been caused by layout of the oven. When the layout of the oven was modified, comparative experiments comparable to these with the previous layout of the oven demonstrated that the uniformity of the temperature distribution in the cell was improved and that thermal equilibrium time was shorter by about 10 minutes. This method played an important role in determining the thermal equilibrium time in the cell.

  1. Determining picogram quantities of U in human urine by thermal ionization mass spectrometry

    SciTech Connect

    Kelly, W.R.; Fassett, J.D.; Hotes, S.A.

    1987-03-01

    The U concentration in Standard Reference Material 2670 (Toxic Metals in Freeze-Dried Urine) and the urine of two preschool-age children were determined by measuring the chemically separated U by isotope dilution thermal ionization mass spectrometry using ion counting detection. This procedure can detect about 1% of the U atoms loaded into the mass spectrometer and has a total chemical blank of about 5 pg U. The U concentration in SRM 2670 was found to be 113 +/- 2 pg /sup 238/U/ml (1 s). At this concentration, a 1-ml sample is sufficient for a determination with a total uncertainty of less than 5%. The U concentrations in the two children were 3.1 +/- 0.9 and 3.6 +/- 0.9 pg /sup 238/U/g. These values suggest that the U concentration in urine of unexposed persons may be at this low level or lower.

  2. Determination of the thermal stability of perfluoroalkylethers by tensimetry: Instrumentation and Procedure

    NASA Technical Reports Server (NTRS)

    Helmick, Larry S.; Jones, William R., Jr.

    1989-01-01

    A computerized tensimeter and experimental procedure for determination of the thermal decomposition temperature (T sub d) of perfluoro alkylethers were developed and tested. Both the apparatus and the procedure are described in detail. Results of testing with bis(2-ethylhexyl) phthalate and trimethylolpropane triheptanoate demonstrate that the reciprocal of the decomposition temperature is a linear function of the logarithm of the gas volume/heated liquid volume ratio. The T sub d obtained for each compound at a gas volume/heated liquid volume ration of one was similar to the value previously reported using an isoteniscope technique. Results of testing with a polymer of hexafluoropropylene oxide demonstrate that this instrument and procedure can be used to determine the T sub d of perfluoroalkylethers.

  3. The measurement of thermal neutron flux depression for determining the concentration of boron in blood.

    PubMed

    Brooke, S L; Green, S; Charles, M W; Beddoe, A H

    2001-03-01

    Boron neutron capture therapy (BNCT) is a form of targeted radiotherapy that relies on the uptake of the capture element boron by the volume to be treated. The treatment procedure requires the measurement of boron in the patient's blood. The investigation of a simple and inexpensive method for determining the concentration of the capture element 10B in blood is described here. This method, neutron flux depression measurement, involves the determination of the flux depression of thermal neutrons as they pass through a boron-containing sample. It is shown via Monte Carlo calculations and experimental verification that, for a maximum count rate of 1 x 10(4) counts/s measured by the detector, a 10 ppm 10B sample of volume 20 ml can be measured with a statistical precision of 10% in 32 +/- 2 min. For a source activity of less than 1.11 x 10(11) Bq and a maximum count rate of less than 1 x 10(4) counts/s, a 10 ppm 10B sample of volume 20 ml can be measured with a statistical precision of 10% in 58 +/- 3 min. It has also been shown that this technique can be applied to the measurement of the concentration of any element with a high thermal neutron cross section such as 157Gd.

  4. Application of vacuum stability test to determine thermal decomposition kinetics of nitramines bonded by polyurethane matrix

    NASA Astrophysics Data System (ADS)

    Elbeih, Ahmed; Abd-Elghany, Mohamed; Elshenawy, Tamer

    2017-03-01

    Vacuum stability test (VST) is mainly used to study compatibility and stability of energetic materials. In this work, VST has been investigated to study thermal decomposition kinetics of four cyclic nitramines, 1,3,5-trinitro-1,3,5-triazinane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX), cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole (BCHMX), 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-HNIW, CL-20), bonded by polyurethane matrix based on hydroxyl terminated polybutadiene (HTPB). Model fitting and model free (isoconversional) methods have been applied to determine the decomposition kinetics from VST results. For comparison, the decomposition kinetics were determined isothermally by ignition delay technique and non-isothermally by Advanced Kinetics and Technology Solution (AKTS) software. The activation energies for thermolysis obtained by isoconversional method based on VST technique of RDX/HTPB, HMX/HTPB, BCHMX/HTPB and CL20/HTPB were 157.1, 203.1, 190.0 and 176.8 kJ mol-1 respectively. Model fitting method proved that the mechanism of thermal decomposition of BCHMX/HTPB is controlled by the nucleation model while all the other studied PBXs are controlled by the diffusion models. A linear relationship between the ignition temperatures and the activation energies was observed. BCHMX/HTPB is interesting new PBX in the research stage.

  5. Experimental determination of in situ utilization of lunar regolith for thermal energy storage

    NASA Astrophysics Data System (ADS)

    Richter, Scott W.

    1993-01-01

    A Lunar Thermal Energy from Regolith (LUTHER) experiment has been designed and fabricated at the NASA Lewis Research Center to determine the feasibility of using lunar soil as thermal energy storage media. The experimental apparatus includes an alumina ceramic canister (25.4 cm diameter by 45.7 cm length) which contains simulated lunar regolith, a heater (either radiative or conductive), 9 heat shields, a heat transfer cold jacket, and 19 type B platinum rhodium thermocouples. The simulated lunar regolith is a basalt, mined and processed by the University of Minnesota, that closely resembles the lunar basalt returned to earth by the Apollo missions. The experiment will test the effects of vacuum, particle size, and density on the thermophysical properties of the regolith. The properties include melt temperature (range), specific heat, thermal conductivity, and latent heat of storage. Two separate tests, using two different heaters, will be performed to study the effect of heating the system using radiative and conductive heat transfer. The physical characteristics of the melt pattern, material compatibility of the molten regolith, and the volatile gas emission will be investigated by heating a portion of the lunar regolith to its melting temperature (1435 K) in a 10(exp -4) pascal vacuum chamber, equipped with a gas spectrum analyzer. A finite differencing SINDA model was developed at NASA Lewis Research Center to predict the performance of the LUTHER experiment. The analytical results of the code will be compared with the experimental data generated by the LUTHER experiment. The code will predict the effects of vacuum, particle size, and density has on the heat transfer to the simulated regolith.

  6. Experimental Determination of in Situ Utilization of Lunar Regolith for Thermal Energy Storage

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1993-01-01

    A Lunar Thermal Energy from Regolith (LUTHER) experiment has been designed and fabricated at the NASA Lewis Research Center to determine the feasibility of using lunar soil as thermal energy storage media. The experimental apparatus includes an alumina ceramic canister (25.4 cm diameter by 45.7 cm length) which contains simulated lunar regolith, a heater (either radiative or conductive), 9 heat shields, a heat transfer cold jacket, and 19 type B platinum rhodium thermocouples. The simulated lunar regolith is a basalt, mined and processed by the University of Minnesota, that closely resembles the lunar basalt returned to earth by the Apollo missions. The experiment will test the effects of vacuum, particle size, and density on the thermophysical properties of the regolith. The properties include melt temperature (range), specific heat, thermal conductivity, and latent heat of storage. Two separate tests, using two different heaters, will be performed to study the effect of heating the system using radiative and conductive heat transfer. The physical characteristics of the melt pattern, material compatibility of the molten regolith, and the volatile gas emission will be investigated by heating a portion of the lunar regolith to its melting temperature (1435 K) in a 10(exp -4) pascal vacuum chamber, equipped with a gas spectrum analyzer. A finite differencing SINDA model was developed at NASA Lewis Research Center to predict the performance of the LUTHER experiment. The analytical results of the code will be compared with the experimental data generated by the LUTHER experiment. The code will predict the effects of vacuum, particle size, and density has on the heat transfer to the simulated regolith.

  7. Determination of the Thermal Offset of the Eppley Precision Spectral Pyranometer

    NASA Technical Reports Server (NTRS)

    Haeffelin, Martial; Kato, Seiji; Smith, Amie M.; Rutledge, C. Ken; Charlock, Thomas P.; Mahan, J. Robert

    2001-01-01

    Eppley's precision spectral pyranometer (PSP) is used in networks around the world to measure downwelling diffuse and global solar irradiance at the surface of the Earth. In recent years several studies have shown significant discrepancy between irradiances measured by pyranometers and those computed by atmospheric radiative transfer models. Pyranometer measurements have been questioned because observed diffuse irradiances sometimes are below theoretical minimum values for a pure molecular atmosphere, and at night the instruments often produce nonzero signals ranging between + 5 and - 10 W/sq m. We install thermistor sondes in the body of a PSP as well as on its inner dome to monitor the temperature gradients within the instrument, and we operate a pyrgeometer (PIR) instrument side by side with the PSP. We derive a relationship between the PSP output and thermal radiative exchange by the dome and the detector and a relationship between the PSP output and the PIR thermopile output (net-IR). We determine the true PSP offset by quickly capping the instrument at set time intervals. For a ventilated and shaded PSP, the thermal offset can reach - 15 W/sq m under clear skies, whereas it remains close to zero for low overcast clouds. We estimate the PSP thermal offset by two methods: (1) using the PSP temperatures and (2) using the PIR net-IR signal. The offset computed from the PSP temperatures yields a reliable estimate of the true offset (+/- 1 W/sq m). The offset computed from net-IR is consistent with the true offset at night and under overcast skies but predicts only part of the true range under clear skies.

  8. Clothing resultant thermal insulation determined on a movable thermal manikin. Part I: effects of wind and body movement on total insulation

    NASA Astrophysics Data System (ADS)

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Shi, Wen; Zhang, Chengjiao

    2015-10-01

    In this serial study, 486 thermal manikin tests were carried out to examine the effects of air velocity and walking speed on both total and local clothing thermal insulations. Seventeen clothing ensembles with different layers (i.e., one, two, or three layers) were selected for the study. Three different wind speeds (0.15, 1.55, 4.0 m/s) and three levels of walking speed (0, 0.75, 1.2 m/s) were chosen. Thus, there are totally nine different testing conditions. The clothing total insulation and local clothing insulation at different body parts under those nine conditions were determined. In part I, empirical equations for estimating total resultant clothing insulation as a function of the static thermal insulation, relative air velocity, and walking speed were developed. In part II, the local thermal insulation of various garments was analyzed and correction equations on local resultant insulation for each body part were developed. This study provides critical database for potential applications in thermal comfort study, modeling of human thermal strain, and functional clothing design and engineering.

  9. Clothing resultant thermal insulation determined on a movable thermal manikin. Part I: effects of wind and body movement on total insulation.

    PubMed

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Shi, Wen; Zhang, Chengjiao

    2015-10-01

    In this serial study, 486 thermal manikin tests were carried out to examine the effects of air velocity and walking speed on both total and local clothing thermal insulations. Seventeen clothing ensembles with different layers (i.e., one, two, or three layers) were selected for the study. Three different wind speeds (0.15, 1.55, 4.0 m/s) and three levels of walking speed (0, 0.75, 1.2 m/s) were chosen. Thus, there are totally nine different testing conditions. The clothing total insulation and local clothing insulation at different body parts under those nine conditions were determined. In part I, empirical equations for estimating total resultant clothing insulation as a function of the static thermal insulation, relative air velocity, and walking speed were developed. In part II, the local thermal insulation of various garments was analyzed and correction equations on local resultant insulation for each body part were developed. This study provides critical database for potential applications in thermal comfort study, modeling of human thermal strain, and functional clothing design and engineering.

  10. LC method for determination of prasugrel and mass spectrometry detection for thermal and alkaline degradation products.

    PubMed

    Rigobello, C; Barden, A T; Steppe, M

    2015-08-01

    A stability-indicating RP-LC method for the determination of prasugrel in tablets was developed and validated. Stress testing of prasugrel was carried out in accordance with ICH guidelines, where the drug was submitted to acidic and basic hydrolysis, oxidative, thermal and photolytic conditions. Prasugrel was unstable under all the conditions and the degradations products were analyzed by HPLC-UV. Furthermore, two main degradation products found under alkaline and thermal conditions were investigated by LC-MS. Based on the fragmentation patterns, two products resulted from hydrolysis of the acetate ester moiety of prasugrel were observed. Due the chemical equilibrium, tautomerism occurs between the ketone and alcohol functions justifying the similar molecular weight and fragment pattern obtained in degradation products analysis. Successful separation was achieved on a RP-18 octadecyl silane column using acetonitrile and triethylamine 0.5% mixture (50:50, v/v) as the mobile phase at 25 degrees C. The flow rate was 1.0 mL/min and the detector wavelength was 263 nm. The method proposed in this work was successfully applied to quality control of prasugrel and contribute to stability assessment of pharmaceutical products containing this drug.

  11. A New Method to Determine the Thermal Properties of Soil Formations from In Situ Field Tests

    SciTech Connect

    Shonder, J.A.

    2000-05-02

    local regulations; water is heated and pumped through the U-tube (using a field generator to power the equipment, or line voltage where available); and the inlet and outlet water temperatures are measured as a function of time. Data on inlet and outlet temperature, power input to the heater and pump, and water flow rate are collected at regular intervals--typically 1 to 15 min--for the duration of the experiment, which may be as long as 60 h. Two common methods for determining soil thermal properties from such measurements are the line source method and the cylinder source method. Both are based on long-term approximate solutions to the classical heat conduction problem of an infinitely long heat source in an infinite homogeneous medium. Although there are some differences in the way the two methods are implemented, the only difference between the two models is whether the heat source is considered to be a line or a cylinder. In both methods, power input to the water loop is assumed to be constant. The simplicity of these methods makes them attractive, but they also have some disadvantages. First of all, because the line source and cylinder source approximations are inaccurate for early time behavior, some of the initial data from the field test must be discarded. The amount of data discarded can affect the property measurement. Also, both methods assume that the heat transfer to the ground loop is constant. In practice, heat input to the loop may vary significantly over the course of a field test due to rough operation of the generator or short-term sags and swells in power line voltage. Presumably, this variation affects the accuracy of the thermal property measurement, but error analysis is rarely performed. This report presents a new method for determining thermal properties from short-term in situ tests using a parameter estimation technique. Because it is based on numerical solutions to the heat conduction equation, the new method is not affected by short

  12. Determination of the Optimal Fourier Number on the Dynamic Thermal Transmission

    NASA Astrophysics Data System (ADS)

    Bruzgevičius, P.; Burlingis, A.; Norvaišienė, R.

    2016-12-01

    This article represents the result of experimental research on transient heat transfer in a multilayered (heterogeneous) wall. Our non-steady thermal transmission simulation is based on a finite-difference calculation method. The value of a Fourier number shows the similarity of thermal variation in conditional layers of an enclosure. Most scientists recommend using no more than a value of 0.5 for the Fourier number when performing calculations on dynamic (transient) heat transfer. The value of the Fourier number is determined in order to acquire reliable calculation results with optimal accuracy. To compare the results of simulation with experimental research, a transient heat transfer calculation spreadsheet was created. Our research has shown that a Fourier number of around 0.5 or even 0.32 is not sufficient ({≈ }17 % of oscillation amplitude) for calculations of transient heat transfer in a multilayered wall. The least distorted calculation results were obtained when the multilayered enclosure was divided into conditional layers with almost equal Fourier number values and when the value of the Fourier number was around 1/6, i.e., approximately 0.17. Statistical deviation analysis using the Statistical Analysis System was applied to assess the accuracy of the spreadsheet calculation and was developed on the basis of our established methodology. The mean and median absolute error as well as their confidence intervals has been estimated by the two methods with optimal accuracy ({F}_{oMDF}= 0.177 and F_{oEPS}= 0.1633 values).

  13. A method for determining structural properties of RCC thermal protection material. [Reinforced Carbon-Carbon

    NASA Technical Reports Server (NTRS)

    Wakefield, R. M.; Fowler, K. R.

    1978-01-01

    A method was developed for evaluation and prediction of effects of oxidation of the graphitic substrate on structural properties of Reinforced Carbon-Carbon (RCC) thermal protection material. Test specimens of RCC material were exposed to successive periods of convective heating in a plasma-jet facility to simulate the chemical reactions of Shuttle atmospheric entry. After each period of testing, the test specimen mass loss and performance in a nondestructive flexure test were determined. A computational model of the RCC specimen was developed for the NASA Structural Analysis (NASTRAN) program and validated by comparison of calculated and experimental results of flexure tests. The elastic moduli and ultimate loads in tension and compression were then computed for various levels of substrate oxidation.

  14. Determination of Flaw Size and Depth From Temporal Evolution of Thermal Response

    NASA Technical Reports Server (NTRS)

    Winfree, William P.; Zalameda, Joseph N.; Cramer, Elliott; Howell, Patricia A.

    2015-01-01

    Simple methods for reducing the pulsed thermographic responses of flaws have tended to be based on either the spatial or temporal response. This independent assessment limits the accuracy of characterization. A variational approach is presented for reducing the thermographic data to produce an estimated size for a flaw that incorporates both the temporal and spatial response to improve the characterization. The size and depth are determined from both the temporal and spatial thermal response of the exterior surface above a flaw and constraints on the length of the contour surrounding the delamination. Examples of the application of the technique to simulation and experimental data acquired are presented to investigate the limitations of the technique.

  15. Determination of temperature-dependent heat conductivity and thermal diffusivity of waste glass melter feed

    SciTech Connect

    Pokorny, Richard; Rice, Jarrett A.; Schweiger, Michael J.; Hrma, Pavel R.

    2013-06-01

    The cold cap is a layer of reacting glass batch floating on the surface of melt in an all-electric continuous glass melter. The heat needed for the conversion of the melter feed to molten glass must be transferred to and through the cold cap. Since the heat flux into the cold cap determines the rate of melting, the heat conductivity is a key property of the reacting feed. We designed an experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples that monitors the evolution of the temperature field while the crucible is heated at a constant rate. Then we used two methods to calculate the heat conductivity and thermal diffusivity of the reacting feed: the approximation of the temperature field by polynomial functions and the finite-volume method coupled with least-squares analysis. Up to 680°C, the heat conductivity of the reacting melter feed was represented by a linear function of temperature.

  16. Rapid determination of drugs and semivolatile organics by direct thermal desorption ion trap mass spectrometry

    SciTech Connect

    Wise, M.B.; Ilgner, R.H.; Buchanan, M.V.; Guerin, M.R.

    1991-01-01

    Direct thermal desorption of analytes into an ion trap mass spectrometer (ITMS) is being investigated as a technique for the rapid screening of a wide variety of samples for target semivolatile organic compounds. This includes the direct detection of drugs in physiological fluids, semivolatile organic pollutants in water and waste samples, and air pollutants collected on sorbent cartridges. In order to minimize the analysis time, chromatographic separation is not performed on the sample prior to introduction into the ITMS. Instead, selective chemical ionization and tandem mass spectrometry (MS/MS) are used achieve the specificity required for the target analytes. Detection limits are typically 10--50 ppb using a 1 uL aliquot of a liquid sample without preconcentration. Sample turn-around time is 2 to 5 minutes and 3 to 5 target analytes can be quantitatively determined simultaneously. 6 figs.

  17. Age determination of ballpoint pen ink by thermal desorption and gas chromatography-mass spectrometry.

    PubMed

    Bügler, Jürgen H; Buchner, Hans; Dallmayer, Anton

    2008-07-01

    Two main approaches can be used for determining the age of an ink: indirect dating and direct dating. Indirect dating is based on the chemical analysis of an ink followed by comparison with known samples in a reference collection. The collection should contain information about the inks including the market introduction dates. This approach may allow for an anachronism to be detected. The second concept is based on measuring ink components that change with age. The analysis of solvents in ballpoint inks may be a useful parameter for determining the age of ink on paper. In a previous study, the authors demonstrated that thermal desorption of ink directly from paper, followed by chemical analysis using gas chromatography-mass spectrometry (GC-MS), is a promising procedure for characterizing ink-binder resins and solvents. Preliminary tests showed that monitoring the evaporation of ink solvent from ink on paper is not a suitable method for ink dating. Thermal analysis of ink on paper in two steps revealed that fresh ink releases a relative amount of solvent at a certain low temperature in a defined period of time, which decreases as the ink ages. As a consequence, this relative amount of solvent released at a certain low temperature, and its decrease with time, can be used to estimate ink age. This age-dependent parameter was studied in 85 different inks ranging in age from 1 week to 1.5 years. It was found that some inks showed a significant decrease of this parameter up to an age of several months, and that the aging process can be monitored within this period. For other inks, however, the age-dependent parameter decreases relatively fast, e.g., within a few days, to a constant level, which can be too fast for casework. Based on these results, a general procedure for assessing the age of ballpoint pen inks on paper was developed.

  18. To determine the end point of wet granulation by measuring powder energies and thermal properties.

    PubMed

    Dave, Rutesh H; Wu, Stephen H; Contractor, Labdhi D

    2012-04-01

    Wet granulation has been widely used in pharmaceutical industry as a tablet manufacturing process. However, end-point determination of wet granulation process has always remained a challenge. Many traditional methods are available for end-point determination, yet accuracy and reproducibility still remain a challenge. Microcrystalline cellulose, widely used as an excipient in pharmaceutical industry, was granulated using water. Wet mass was passed through sieve # 12 and dried till constant percentage loss on drying was obtained and dried granules were obtained. Wet and dried granules collected were subjected to basic flow energy, specific energy, bulk density, pressure drop, differential scanning calorimetry and effusivity measurements. Analysis of data revealed various stages of granule growth from initial seed formation by adding 200-400 g of water, granule growth was observed by adding 600-800 g of water and over wetting was observed at 1155 g of water. In this work, we have justified our work to properly identify and utilize this technique for practical purpose to correctly identify the end-point determination of microcrystalline cellulose and explain various principles underlying energies associated with powder and thermal measurements.

  19. Approaches to acceptable risk

    SciTech Connect

    Whipple, C.

    1997-04-30

    Several alternative approaches to address the question {open_quotes}How safe is safe enough?{close_quotes} are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made.

  20. A Novel Method to Determine the Thermal Conductivity of Interfacial Layers Surrounding the Nanoparticles of a Nanofluid

    PubMed Central

    Pal, Rajinder

    2014-01-01

    Nanofluids are becoming increasingly popular as heat transfer fluids in a variety of industrial applications, due to their enhanced heat transfer characteristics. The thermal conductivity of nanofluids is usually found to be much larger than that predicted from the classical models, such as the Maxwell model. The key mechanism of enhancement of thermal conductivity of dilute nanofluids is the solvation of nanoparticles with a layer of matrix liquid. As of now, little is known quantitatively about the thermal conductivity of the interfacial layers surrounding the nanoparticles. In this article, a novel method is presented to determine the thermal conductivity of the interfacial layers of the nanoparticles. The proposed method allows the estimation of the thermal conductivity of interfacial layers based on the combined measurements of the intrinsic viscosity and intrinsic thermal conductivity of a bulk nanofluid. From the measured intrinsic viscosity of the nanofluid, the thickness of the interfacial layer is estimated. Using the known interfacial layer thickness along with the measured intrinsic thermal conductivity of the nanofluid, the thermal conductivity of the interfacial layer is estimated. The proposed method is validated by simulation and experimental results.

  1. Determining the Thermal Conductivity of Nanocrystalline Bismuth Telluride Thin Films Using the Differential 3 ω Method While Accounting for Thermal Contact Resistance

    NASA Astrophysics Data System (ADS)

    Kudo, S.; Hagino, H.; Tanaka, S.; Miyazaki, K.; Takashiri, M.

    2015-06-01

    We have estimated the thermal conductivity of nanocrystalline bismuth telluride thin films using the differential 3 ω method, taking into account the thermal contact resistance (TCR) between the substrate and thin-film layers. The thin films were prepared on alumina substrates by radio-frequency (RF) magnetron sputtering at temperature of 200°C. Film thickness varied between 0.8 μm and 3.1 μm. The structural properties of the films were analyzed using x-ray diffraction analysis. Their electrical conductivity, Seebeck coefficient, and power factor were evaluated. For measurement of thermal properties by the differential 3 ω method, SiO2 thin films were deposited onto the samples, to act as insulating layers. Thin aluminum wire was then patterned onto the SiO2 layer. The observed variations in temperature amplitude as a function of film thickness indicated that the TCR contribution was very small and could therefore be neglected when estimating the thermal conductivity of the thin films. The thermal conductivity of the nanocrystalline bismuth telluride thin films with thickness of 0.8 μm and 2.1 μm were determined to be 0.55 W/(m K) and 0.48 W/(m K), respectively.

  2. Microfluidic Flow Injection Analysis with Thermal Lens Microscopic Detection for Determination of NGAL

    NASA Astrophysics Data System (ADS)

    Radovanović, Tatjana; Liu, Mingqiang; Likar, Polona; Klemenc, Matjaž; Franko, Mladen

    2015-06-01

    A combined microfluidic flow injection analysis-thermal lens microscopy (FIA-TLM) system was applied for determination of neutrophil gelatinase-associated lipocalin (NGAL)—a biomarker of acute kidney injury. NGAL was determined following a commercial ELISA assay and transfer of the resulting solution into the FIA-TLM system with a 100 m deep microchannel. At an excitation power of 100 mW, the FIA-TLM provided about seven times lower limits of detection (1.5 pg as compared to a conventional ELISA test, and a sample throughput of six samples per minute, which compares favorably with sample throughput of the microtiter plate reader, which reads 96 wells in about 30 min. Comparison of results for NGAL in plasma samples from healthy individuals and for NGAL dynamics in patients undergoing coronary angiography measured with transmission mode spectrometry on a microtiter plate reader and with FIA-TLM showed good agreement. In addition to improved LOD, the high sensitivity of FIA-TLM offers possibilities of a further reduction of the total reaction time of the NGAL ELISA test by sacrificing some of the sensitivity while reducing the duration of individual incubation steps.

  3. Rapid determination of the chemical oxygen demand of water using a thermal biosensor.

    PubMed

    Yao, Na; Wang, Jinqi; Zhou, Yikai

    2014-06-06

    In this paper we describe a thermal biosensor with a flow injection analysis system for the determination of the chemical oxygen demand (COD) of water samples. Glucose solutions of different concentrations and actual water samples were tested, and their COD values were determined by measuring the heat generated when the samples passed through a column containing periodic acid. The biosensor exhibited a large linear range (5 to 3000 mg/L) and a low detection limit (1.84 mg/L). It could tolerate the presence of chloride ions in concentrations of 0.015 M without requiring a masking agent. The sensor was successfully used for detecting the COD values of actual samples. The COD values of water samples from various sources were correlated with those obtained by the standard dichromate method; the linear regression coefficient was found to be 0.996. The sensor is environmentally friendly, economical, and highly stable, and exhibits good reproducibility and accuracy. In addition, its response time is short, and there is no danger of hazardous emissions or external contamination. Finally, the samples to be tested do not have to be pretreated. These results suggest that the biosensor is suitable for the continuous monitoring of the COD values of actual wastewater samples.

  4. Thermal Inertia Determination of C-type Asteroid Ryugu from in-situ Surface Brightness Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Hamm, Maximilian; Grott, Matthias; Knollenberg, Jörg; Kührt, Ekkehard; Pelivan, Ivanka

    2016-10-01

    The Japanese Hayabusa-2 mission is a sample-return mission currently on its way to the C-type asteroid Ryugu. Hayabusa-2 carries the small lander MASCOT (Mobile Asteroid Surface Scout), whose scientific payload includes the infrared radiometer MARA. The primary science goal of MARA is to determine Ryugu's surface brightness temperatures at the landing site for a full asteroid rotation, which will be measured using a long-pass filter, an 8 to 12 µm bandpass, as well as four narrow bandpasses centered at wavelengths between 5 and 15 µm. From these measurements, surface thermal inertia will be derived, but because MARA performs single pixel measurements, heterogeneity in the field of view cannot be resolved. Yet, the surface will likely exhibit different surface textures, and thermal inertia in the field of view could vary from 600 (small rocks) to 50 Jm-2s-0.5K-1 (fine regolith grains). Sub-pixel heterogeneity is a common problem when interpreting radiometer data, since the associated ambiguities cannot be resolved without additional information on surface texture. For MARA, this information will be provided by the MASCOT camera, and in the present paper we have investigated to what extent different thermal inertias can be retrieved from MARA data. To test the applied approach, we generated synthetic MARA data using a thermal model of Ryugu, assuming different thermal inertias for sections of the field of view. We find that sub-pixel heterogeneity systematically deforms the diurnal temperature curve so that it is not possible to fit the data using a single thermal inertia value. However, including the area fractions of the different surface sections enables us to reconstruct the different thermal inertias to within 10% assuming appropriate measurement noise. The presented approach will increase robustness of the Ryugu thermal inertia determination and results will serve as a ground truth for the global measurements performed by the thermal infrared mapper (TIR) on

  5. Determination of 30 elements in coal and fly ash by thermal and epithermal neutron-activation analysis

    USGS Publications Warehouse

    Rowe, J.J.; Steinnes, E.

    1977-01-01

    Thirty elements are determined in coal and fly ash by instrumental neutron-activation analysis using both thermal and epithermal irradiation. Gamma-ray spectra were recorded 7 and 20 days after the irradiations. The procedure is applicable to the routine analysis of coals and fly ash. Epithermal irradiation was found preferable for the determination of Ni, Zn, As, Se, Br, Rb, Sr, Mo, Sb, Cs, Ba, Sm, Tb, Hf, Ta, W, Th and U, whereas thermal irradiation was best for Sc, Cr, Fe, Co, La, Ce, Nd, Eu, Yb and Lu. Results for SRM 1632 (coal) and SRM 1633 (fly ash) agree with those of other investigators. ?? 1977.

  6. Determination and validation of an aquatic Maximum Acceptable Concentration-Environmental Quality Standard (MAC-EQS) value for the agricultural fungicide azoxystrobin.

    PubMed

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo; Gante, Cristiano; Loureiro, João; Lopes, Isabel

    2017-02-01

    The main goal of the present study was to determine and validate an aquatic Maximum Acceptable Concentration-Environmental Quality Standard (MAC-EQS) value for the agricultural fungicide azoxystrobin (AZX). Assessment factors were applied to short-term toxicity data using the lowest EC50 and after the Species Sensitivity Distribution (SSD) method. Both ways of EQS generation were applied to a freshwater toxicity dataset for AZX based on available data, and to marine toxicity datasets for AZX and Ortiva(®) (a commercial formulation of AZX) obtained by the present study. A high interspecific variability in AZX sensitivity was observed in all datasets, being the copepoda Eudiaptomus graciloides (LC50,48h = 38 μg L(-1)) and the gastropod Gibbula umbilicalis (LC50,96h = 13 μg L(-1)) the most sensitive freshwater and marine species, respectively. MAC-EQS values derived using the lowest EC50 (≤0.38 μg L(-1)) were more protective than those derived using the SSD method (≤3.2 μg L(-1)). After comparing the MAC-EQS values estimated in the present study to the smallest AA-EQS available, which protect against the occurrence of prolonged exposure of AZX, the MAC-EQS values derived using the lowest EC50 were considered overprotective and a MAC-EQS of 1.8 μg L(-1) was validated and recommended for AZX for the water column. This value was derived from marine toxicity data, which highlights the importance of testing marine organisms. Moreover, Ortiva affects the most sensitive marine species to a greater extent than AZX, and marine species are more sensitive than freshwater species to AZX. A risk characterization ratio higher than one allowed to conclude that AZX might pose a high risk to the aquatic environment. Also, in a wider conclusion, before new pesticides are approved, we suggest to improve the Tier 1 prospective Ecological Risk Assessment by increasing the number of short-term data, and apply the SSD approach, in order to ensure the safety of

  7. Determination Of Thermal And Mechanical Properties Of Packaging Materials For The Use In FEM-Simulations

    NASA Astrophysics Data System (ADS)

    Roellig, Mike; Boehme, Bjoern; Meier, Karsten; Metasch, René

    2011-09-01

    Conventional and future electronic packages merge several different materials. Polymers, metals, solders, dielectrics, glasses, silicon, composites come together and show strong mechanical and material interaction. These interfacial effects increase if the miniaturization and diversification keep on rising as it is proposed. Many efforts have to be done to assure the system reliability of new electronic packages. The Finite Element Simulation has the ability to support the development process of new packages. The application of the FEM-analysis requires the knowledge about the precise mechanical and thermal behaviour of the materials. The paper presents different measurement methods to determine accurate mechanical material properties of moulding compound polymers, underfillers, solder mask, and wafer photo resist and solder joints. The temperature dependency is essential to be respected. The polymer materials moulding compound as well as solder mask were characterized by Dynamic Mechanical Analysis under humidity influences to determine mechanical properties as function of moisture and temperature. Further experiments on polymer were conducted to extract the cure kinetics by Differential Scanning Calorimetry and to determine Bulk Modulus by Pressure-Volume-Temperature experiments (PVT). Altogether, these material properties need to be modeled in a comprehensive way fitting to each other. The common practice of just compiling data from different sources has been found to fail yielding in reliable and accurate results. The conditions under which the data were determined may cause mismatches between them and cause inconsistencies within the model. If a convergent solution was obtained at all, much simulation time would be needed as many iterations with small time steps were needed. In order to avoid this, the paper reports an approach of characterizing the temperature and time dependent mechanical material properties in one comprehensive scheme. The solder

  8. Thermal desorption-gas chromatography for the determination of emission of volatile organic compounds from furnishing materials.

    PubMed

    Igielska, B; Wiglusz, R; Jarnuszkiewicz, I

    1995-01-01

    In order to determine volatile organic compounds (VOC) released from the building and furnishing materials gas chromatography with air samples enrichment on Tenax TA and thermal desorption was used. The results obtained were compared with the results of air samples enrichment on active carbon with carbon disulfide extraction. To the thermal desorption the home made device, a similar to device developed at Research Triangle Institute (USA), was used. The both methods of the air samples enrichment with thermal desorption or carbon disulfide extraction showed that the emission of the volatile organic compounds from the PVC floor covering is very low within the range from 0.01 to 0.03 mg/m2.h. Thermal desorption technique allows to detect a larger number of compounds in trace levels.

  9. Determination of the effect of particle thermal conductivity on thermophoretic force

    NASA Astrophysics Data System (ADS)

    Bosworth, Ryan W.; Ketsdever, Andrew D.

    2016-11-01

    The contribution of vane thermal conductivity on the Crookes radiometer is experimentally investigated with four vane materials. This work examines increasing the force production of a radiometer vane for applications such as near-space propulsion by increasing the vane's perimeter while decreasing the total surface area of the vane by means of machined holes in the vanes. Experimental results are given for four vane thermal conductivities. These results indicate that force production is improved for vanes with relatively low thermal conductivity.

  10. Use of thermal inertia determined by HCMM to predict nocturnal cold prone areas in Florida

    NASA Technical Reports Server (NTRS)

    Allen, L. H., Jr. (Principal Investigator); Chen, E.; Martsolf, J. D.; Jones, P. H.

    1981-01-01

    The HCMM transparency scenes for the available winter of 1978-1979 were evaluated; scenes were identified on processed magnetic tapes; other remote sensing information was identified; and a soil heat flux model with variable-depth thermal profile was developed. The Image 100 system was used to compare HCMM and GOES transparent images of surface thermal patterns. Excellent correspondence of patterns was found, with HCMM giving the greater resolution. One image shows details of thermal patterns in Florida that are attributable to difference in near surface water contents. The wide range of surface temperatures attributable to surface thermal inertia that exist in the relatively flat Florida topography is demonstrated.

  11. Methods to determine stratification efficiency of thermal energy storage processes - Review and theoretical comparison

    SciTech Connect

    Haller, Michel Y.; Streicher, Wolfgang; Andersen, Elsa; Furbo, Simon

    2009-10-15

    This paper reviews different methods that have been proposed to characterize thermal stratification in energy storages from a theoretical point of view. Specifically, this paper focuses on the methods that can be used to determine the ability of a storage to promote and maintain stratification during charging, storing and discharging, and represent this ability with a single numerical value in terms of a stratification efficiency for a given experiment or under given boundary conditions. Existing methods for calculating stratification efficiencies have been applied to hypothetical storage processes of charging, discharging and storing, and compared with the rate of entropy production caused by mixing calculated for the same experiments. The results depict that only one of the applied methods is in qualitative agreement with the rate of entropy production, however, none of the applied methods is in agreement with the rate of entropy production and also able to distinguish between the entropy production caused by mixing and the entropy changes due to heat losses. (author)

  12. Rapid determination of nicotine in urine by direct thermal desorption ion trap mass spectrometry

    SciTech Connect

    Wise, M.B.; Ilgner, R.H.; Guerin, M.R.

    1990-01-01

    The measurement of nicotine and cotinine in physiological fluids (urine, blood serum, and saliva) is widely used as a means of assessing human exposure to environmental tobacco smoke (ETS). Although numerous analytical methods exist for these measurements, they generally involve extensive sample preparation which increases cost and decreases sample throughput. We report the use of thermal desorption directly into an ion trap mass spectrometer (ITMS) for the rapid determination of nicotine and cotinine in urine. A 1{mu}L aliquot of urine is injected into a specially designed inlet and flash vaporized directly into an ITMS through an open-split capillary restrictor interface. Isobutane chemical ionization is used to generate (M+H){sup +} ions of the analytes and collision induced dissociation is used to generate characteristic fragment ions which are used to confirm their identity. Quantification is achieved by integrating the ion current for the characteristic ions and comparing with an external working curve. Detection limits are approximately 50 pg per analyte and the sample turnaround time is approximately 3 minutes without the need for extensive sample preparation. 12 refs., 5 figs.

  13. Condensation of water vapor: Experimental determination of mass and thermal accommodation coefficients

    NASA Astrophysics Data System (ADS)

    Winkler, P. M.; Vrtala, A.; Rudolf, R.; Wagner, P. E.; Riipinen, I.; Vesala, T.; Lehtinen, K. E. J.; Viisanen, Y.; Kulmala, M.

    2006-10-01

    Experimental determinations of mass and thermal accommodation coefficients αm and αt for condensation of water vapor in air have been conducted covering a temperature range from about 250 to 290 K. For the first time, both coefficients have been determined directly and simultaneously. To this end, growth of water droplets in air has been observed at different total gas pressures ranging from about 1000 down to 100 hPa. Monodispersed seed particles have been used as condensation nuclei. After addition of water vapor with well-defined partial vapor pressure, supersaturation was achieved by adiabatic expansion in an expansion chamber. Most experiments reported in the present paper were performed at vapor saturation ratios ranging from 1.30 to 1.50. Monodispersed Ag particles with a diameter of 9 nm have been used as condensation nuclei, and for humidification a diffusion humidifier was applied. One experiment was performed at the saturation ratio of 1.02, which resembles conditions observed in the Earth's lower atmosphere. In this experiment, monodispersed DEHS particles with a diameter of 80 nm were used as condensation nuclei, and water vapor was generated by quantitative evaporation of a liquid jet. Droplet growth was monitored using the CAMS method. For determination of the accommodation coefficients, experimental droplet growth curves were compared to corresponding theoretical curves. Quantitative comparison was performed by varying the respective accommodation coefficient and the starting time of droplet growth in a two-parameter best fit procedure. Considering the uncertainty with respect to the starting time of droplet growth and the uncertainties of the experimental water vapor supersaturation, corresponding maximum errors have been determined. From the results obtained it can be stated that αt is larger than 0.85 over the whole considered temperature range. For 250-270 K, values of αm below 0.8 are excluded, and for higher temperatures up to 290 K we can

  14. Determination of elemental carbon in lake sediments using a thermal-optical transmittance (TOT) method

    NASA Astrophysics Data System (ADS)

    Khan, A. J.; Swami, Kamal; Ahmed, Tanveer; Bari, A.; Shareef, Akhtar; Husain, Liaquat

    2009-12-01

    An improved chemical oxidation pretreatment method has been developed for the determination of elemental carbon (EC) [also known as black carbon (BC) or soot] in lake sediments, using a thermal-optical transmittance (TOT) carbon analyzer. The method employs six steps: (1) removal of carbonates by treatment with HCl; (2) removal of silicates by treatment with HF + HCl; (3) removal of any remaining carbonates by treatment with HCl; (4) removal of humic acids by treatment with NaOH; and (5) oxidation of kerogens by K 2Cr 2O 7 + H 2SO 4. A critical step of zinc chloride treatment was added; this apparently changes EC's morphology and enhances retention on quartz fiber filter, resulting in several-fold increased chemical yield. EC was determined using the TOT method with modified combustion timings. Carbon black (acetylene) and four NIST standard reference materials (SRMs) were used for quality control, and to assess the precision of the analysis. The EC recoveries from 18 carbon black samples varied from 90 to 111%, with a mean value of 99 ± 6%. The high EC recoveries confirmed the validity of the method. Char reference materials (i.e. chestnut wood and grass char) were used to determine potential contribution to EC in our measurements. The char references containing about 700 mg total organic carbon (OC) contributed ˜1.5% EC. The measured EC values from four NIST standards were 17.0 ± 0.6, 24.2 ± 3.2, 5.6, and 1.9 ± 0.1 mg g dw-1 for SRM-1648, SRM-1649a, SRM-1941b and SRM-8704, respectively. These values in SRMs were in agreement (<±4%) with the previously reported values. The method was applied to determine the EC in sediment cores from an urban lake and a remote mountain lake in the Northeastern United States. The EC concentrations in two lakes mimic the model EC emissions from the industrial revolution in United States.

  15. Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

    DOE PAGES

    Mei, A. B.; Hellman, O.; Schlepuetz, C. M.; ...

    2015-11-03

    Synchrotron reflection x-ray thermal diffuse scattering (TDS) measurements, rather than previously reported transmission TDS, are carried out at room temperature and analyzed using a formalism based upon second-order interatomic force constants and long-range Coulomb interactions to obtain quantitative determinations of MgO phonon dispersion relations (h) over bar omega(j) (q), phonon densities of states g((h) over bar omega), and isochoric temperature-dependent vibrational heat capacities cv (T). We use MgO as a model system for investigating reflection TDS due to its harmonic behavior as well as its mechanical and dynamic stability. Resulting phonon dispersion relations and densities of states are found tomore » be in good agreement with independent reports from inelastic neutron and x-ray scattering experiments. Temperature-dependent isochoric heat capacities cv (T), computed within the harmonic approximation from (h) over bar omega(j) (q) values, increase with temperature from 0.4 x 10-4 eV/atom K at 100 K to 1.4 x 10-4 eV/atom K at 200 K and 1.9 x 10-4 eV/atom K at 300 K, in excellent agreement with isobaric heat capacity values cp (T) between 4 and 300 K. We anticipate that the experimental approach developed here will be valuable for determining vibrational properties of heteroepitaxial thin films since the use of grazing-incidence (θ ≲ θc where θc is the density-dependent critical angle) allows selective tuning of x-ray penetration depths to ≲ 10 nm.« less

  16. Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

    NASA Astrophysics Data System (ADS)

    Mei, A. B.; Hellman, O.; Schlepütz, C. M.; Rockett, A.; Chiang, T.-C.; Hultman, L.; Petrov, I.; Greene, J. E.

    2015-11-01

    Synchrotron reflection x-ray thermal diffuse scattering (TDS) measurements, rather than previously reported transmission TDS, are carried out at room temperature and analyzed using a formalism based upon second-order interatomic force constants and long-range Coulomb interactions to obtain quantitative determinations of MgO phonon dispersion relations ℏ ωj (q), phonon densities of states g (ℏ ω ), and isochoric temperature-dependent vibrational heat capacities cv(T ) . We use MgO as a model system for investigating reflection TDS due to its harmonic behavior as well as its mechanical and dynamic stability. Resulting phonon dispersion relations and densities of states are found to be in good agreement with independent reports from inelastic neutron and x-ray scattering experiments. Temperature-dependent isochoric heat capacities cv(T ) , computed within the harmonic approximation from ℏ ωj (q) values, increase with temperature from 0.4 ×10-4eV /atom K at 100 K to 1.4 ×10-4eV /atom K at 200 K and 1.9 ×10-4eV /atom K at 300 K, in excellent agreement with isobaric heat capacity values cp(T ) between 4 and 300 K. We anticipate that the experimental approach developed here will be valuable for determining vibrational properties of heteroepitaxial thin films since the use of grazing-incidence (θ ≲θc , where θc is the density-dependent critical angle) allows selective tuning of x-ray penetration depths to ≲10 nm .

  17. Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

    SciTech Connect

    Mei, A. B.; Hellman, O.; Schlepuetz, C. M.; Rockett, A.; Chiang, T. -C.; Hultman, L.; Petrov, I.; Greene, J. E.

    2015-11-03

    Synchrotron reflection x-ray thermal diffuse scattering (TDS) measurements, rather than previously reported transmission TDS, are carried out at room temperature and analyzed using a formalism based upon second-order interatomic force constants and long-range Coulomb interactions to obtain quantitative determinations of MgO phonon dispersion relations (h) over bar omega(j) (q), phonon densities of states g((h) over bar omega), and isochoric temperature-dependent vibrational heat capacities cv (T). We use MgO as a model system for investigating reflection TDS due to its harmonic behavior as well as its mechanical and dynamic stability. Resulting phonon dispersion relations and densities of states are found to be in good agreement with independent reports from inelastic neutron and x-ray scattering experiments. Temperature-dependent isochoric heat capacities cv (T), computed within the harmonic approximation from (h) over bar omega(j) (q) values, increase with temperature from 0.4 x 10-4 eV/atom K at 100 K to 1.4 x 10-4 eV/atom K at 200 K and 1.9 x 10-4 eV/atom K at 300 K, in excellent agreement with isobaric heat capacity values cp (T) between 4 and 300 K. We anticipate that the experimental approach developed here will be valuable for determining vibrational properties of heteroepitaxial thin films since the use of grazing-incidence (θ ≲ θc where θc is the density-dependent critical angle) allows selective tuning of x-ray penetration depths to ≲ 10 nm.

  18. Reflectance and Thermal Infrared Spectroscopy of Mars: Relationship Between ISM and TES for Compositional Determinations

    NASA Technical Reports Server (NTRS)

    Boyce, Joseph (Technical Monitor); Mustard, John

    2004-01-01

    Reflectance spectroscopy has demonstrated that high albedo surfaces on Mars contain heavily altered materials with some component of hematite, poorly crystalline ferric oxides, and an undefined silicate matrix. The spectral properties of many low albedo regions indicate crystalline basalts containing both low and high calcium pyroxene, a mineralogy consistent with the basaltic SNC meteorites. The Thermal Emission Spectrometer (TES) experiment on the Mars Geochemical Surveyor has acquired critical new data relevant to surface composition and mineralogy, but in a wavelength region that is complementary to reflectance spectroscopy. The essence of the completed research was to analyze TES data in the context of reflectance data obtained by the French ISM imaging spectrometer experiment in 1989. This approach increased our understanding of the complementary nature of these wavelength regions for mineralogic determinations using actual observations of the martian surface. The research effort focused on three regions of scientific importance: Syrtis Major-Isidis Basin, Oxia Palus-Arabia, and Valles Marineris. In each region distinct spatial variations related to reflectance, and in derived mineralogic information and interpreted compositional units were analyzed. In addition, specific science questions related to the composition of volcanics and crustal evolution, soil compositions and pedogenic processes, and the relationship between pristine lithologies and weathering provided an overall science-driven framework for the work. The detailed work plan involved colocation of TES and ISM data, extraction of reflectance and emissivity spectra from areas of known reflectance variability, and quantitative analysis using factor analysis and statistical techniques to determine the degree of correspondence between these different wavelength regions. Identified coherent variations in TES spectroscopy were assessed against known atmospheric effects to validate that the variations

  19. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Thermal Properties of Organic Hydrocarbons

    ERIC Educational Resources Information Center

    D'Amelia, Ronald; Franks, Thomas; Nirode, William F.

    2007-01-01

    In first-year general chemistry undergraduate courses, thermodynamics and thermal properties such as melting points and changes in enthalpy ([Delta]H) and entropy ([Delta]S) of phase changes are frequently discussed. Typically, classical calorimetric methods of analysis are used to determine [Delta]H of reactions. Differential scanning calorimetry…

  20. A Rapid Laser Probing Method Facilitates the Non-invasive and Contact-free Determination of Leaf Thermal Properties.

    PubMed

    Buyel, Johannes F; Gruchow, Hannah M; Wehner, Martin

    2017-01-07

    Plants can produce valuable substances such as secondary metabolites and recombinant proteins. The purification of the latter from plant biomass can be streamlined by heat treatment (blanching). A blanching apparatus can be designed more precisely if the thermal properties of the leaves are known in detail, i.e., the specific heat capacity and thermal conductivity. The measurement of these properties is time consuming and labor intensive, and usually requires invasive methods that contact the sample directly. This can reduce the product yield and may be incompatible with containment requirements, e.g., in the context of good manufacturing practice. To address these issues, a non-invasive, contact-free method was developed that determines the specific heat capacity and thermal conductivity of an intact plant leaf in about one minute. The method involves the application of a short laser pulse of defined length and intensity to a small area of the leaf sample, causing a temperature increase that is measured using a near infrared sensor. The temperature increase is combined with known leaf properties (thickness and density) to determine the specific heat capacity. The thermal conductivity is then calculated based on the profile of the subsequent temperature decline, taking thermal radiation and convective heat transfer into account. The associated calculations and critical aspects of sample handling are discussed.

  1. Determination of thermal stability of specific biomarker lipids of the freshwater fern Azolla through hydrous pyrolysis

    NASA Astrophysics Data System (ADS)

    Sap, Merel; Speelman, Eveline N.; Lewan, Michael D.; Sinninghe Damsté, Jaap S.; Reichart, Gert-Jan

    2010-05-01

    Enormous blooms of the free-floating freshwater fern Azolla occurred within the Arctic Basin during an extended period of ~1.2 Ma during the middle Eocene (Brinkhuis et al. 2006; Speelman et al., GB, 2009). The sustained growth of Azolla, currently ranking among the fastest growing plants on Earth, in a major anoxic basin may have substantially contributed to decreasing atmospheric CO2 levels by burial of Azolla-derived organic matter. Speelman et al. (OG, 2009) reported biomarkers for Azolla (1,w20 C32 - C36 diols, structurally related C29 ω20,ω21 diols, C29 1,20,21 triols, C29 dihydroxy fatty acids as well as a series of wax esters containing these mono- and dihydroxy lipids), which can be used to reconstruct palaeo-environmental conditions. Here we assess the thermal stability of these compounds, to extend their biomarker potential. We specifically focused on the thermal stability of the Azolla biomarkers using hydrous pyrolysis in order to determine which burial conditions allow reconstruction of past occurrences of Azolla. In addition, hydrous pyrolysis was also performed on samples from the Eocene Arctic Ocean (ACEX core), to test if and how the biomarkers change under higher temperatures and pressures in situ. During hydrous pyrolysis, the biomass was heated under high pressure at temperatures ranging between 220 and 365°C for 72 hours. Four experiments were also run using different durations to explore the kinetics of biomarker degradation at specific temperatures. First results indicate that the Azolla specific diols are still present at 220°C, while the corresponding wax esters are already absent. At 300°C all Azolla specific biomarkers are destroyed. More specific determination of the different biomarkers' stability and kinetics would potentially allow the reconstruction of the temperature and pressure history of Azolla deposits. Literature: • Brinkhuis, H., Schouten, S., Collinson, M. E., Sluijs, A., Sinninghe Damste, J. S., Dickens, G. R., Huber

  2. ANALYSIS OF TWO SMALL MAGELLANIC CLOUD H II REGIONS CONSIDERING THERMAL INHOMOGENEITIES: IMPLICATIONS FOR THE DETERMINATIONS OF EXTRAGALACTIC CHEMICAL ABUNDANCES

    SciTech Connect

    Pena-Guerrero, Maria A.; Peimbert, Antonio; Peimbert, Manuel; Ruiz, Maria Teresa E-mail: antonio@astroscu.unam.mx E-mail: mtruiz@das.uchile.cl

    2012-02-20

    We present long-slit spectrophotometry considering the presence of thermal inhomogeneities (t{sup 2}) of two H II regions in the Small Magellanic Cloud (SMC): NGC 456 and NGC 460. Physical conditions and chemical abundances were determined for three positions in NGC 456 and one position in NGC 460, first under the assumption of uniform temperature and then allowing for the possibility of thermal inhomogeneities. We determined t{sup 2} values based on three different methods: (1) by comparing the temperature derived using oxygen forbidden lines with the temperature derived using helium recombination lines (RLs), (2) by comparing the abundances derived from oxygen forbidden lines with those derived from oxygen RLs, and (3) by comparing the abundances derived from ultraviolet carbon forbidden lines with those derived from optical carbon RLs. The first two methods averaged t{sup 2} = 0.067 {+-} 0.013 for NGC 456 and t{sup 2} = 0.036 {+-} 0.027 for NGC 460. These values of t{sup 2} imply that when gaseous abundances are determined with collisionally excited lines they are underestimated by a factor of nearly two. From these objects and others in the literature, we find that in order to account for thermal inhomogeneities and dust depletion, the O/H ratio in low-metallicity H II regions should be corrected by 0.25-0.45 dex depending on the thermal structure of the nebula or by 0.35 dex if such information is not available.

  3. Strontium diffusion kinetics in amphiboles and significance to thermal history determinations

    NASA Astrophysics Data System (ADS)

    Brabander, D. J.; Giletti, B. J.

    1995-06-01

    Strontium tracer-diffusion coefficients have been determined in hornblende and tremolite single crystals using experiments conducted at a confining pressure of 200 MPa at temperatures ranging from 700 to 960°C. A quasi-hydrothermal experimental technique was devised to avoid solution-precipitation effects. Depth profile analyses were made with an ion microprobe. The Arrhenius relation for diffusion parallel to the c-crystallographic direction in the Gore Mountain hornblende over this temperature interval has an activation energy ( Q) = 260 (±12) kJ/mol and a pre-exponential factor ( D0) = 4.9( +18.-1.3) × 10 -8 m 2/ s. At 800°C, transport rates parallel to the c-axis measured in the two tremolite samples (AMNH #30563 and Barrie Township, Ontario) are 3.2 × 10 -21 m 2/s and 2.0 × 10 -21 M 2/s, respectively. These values are factors of 3 and 5 slower than those observed for the hornblende sample at the same temperature. Transport rates parallel and perpendicular to the c-axis are the same within the estimated uncertainty for all three compositions. Experiments that differed in ƒ O2 by a factor of 6 × 10 7 [MnOMn 3O 4 (MNO) and magnetite-wüstite (MW)] for the hornblende gave the same strontium diffusion rates within a factor of two. Crystals with cleavage faces, or polished with alumina or diamond, gave the same D values, provided the crystals were annealed prior to the diffusion experiment. Using a combination of closed-system RbSr systematics and strontium diffusion kinetics it is now possible to determine the thermal histories of hornblende-bearing igneous and metamorphic rocks. Since the diffusion rates for strontium in amphiboles are relatively slow, hornblende will be more retentive of Sr than of other species for which transport rates are known (Ar, O, H) and will be a useful tool to record higher temperature portions of cooling paths.

  4. Thermal boundary resistance in Si/Ge interfaces determined by approach-to-equilibrium simulations

    NASA Astrophysics Data System (ADS)

    Puligheddu, Marcello; Hahn, Konstanze; Melis, Claudio; Colombo, Luciano

    2015-03-01

    Nanostructured materials hold great promises as efficient thermoelectrics. In such materials, the propagation of phonons is hindered by the internal interfaces (grain boundaries), leading to a reduced overall thermal conductivity and, therefore, to a larger figure of merit. Any further improvement in this field does, however, require a better fundamental understanding of the specific interface effects on thermal transport. In the present work we use approach-to-equilibrium molecular dynamics simulations (AEMD) to investigate the interfacial thermal resistance (ITR) of Si/Ge interfaces, occurring in very promising nanostructured SiGe alloys. We discuss how ITR depends on the thickness of the interface layer, as well as on its composition. Furthermore, the effect of the heat flux direction has been investigated at ambient temperature showing lower ITR for thermal transport from Si to Ge than vice versa. This feature is discussed in connection to possible rectification effects. Present address: The Institute for Molecular Engineering, University of Chicago.

  5. Thermophysical Properties of Te-based II-VI Semiconductors: Reduced Algorithms for Thermal Diffusivity Determination

    NASA Technical Reports Server (NTRS)

    Banish, R. Michael; Brantschen, Segolene; Pourpoint, Timothee L.; Wessling, Francis; Sekerka, Robert F.

    2003-01-01

    This paper presents methodologies for measuring the thermal diffusivity using the difference between temperatures measured at two, essentially independent, locations. A heat pulse is applied for an arbitrary time to one region of the sample; either the inner core or the outer wall. Temperature changes are then monitored versus time. The thermal diffusivity is calculated from the temperature difference versus time. No initial conditions are used directly in the final results.

  6. Field mapping for heat capacity mapping determinations: Ground support for airborne thermal surveys

    NASA Technical Reports Server (NTRS)

    Lyon, R. J. P.

    1976-01-01

    Thermal models independently derived by Watson, Outcalt, and Rosema were compared using similar input data and found to yield very different results. Each model has a varying degree of sensitivity to any specified parameter. Data collected at Pisgah Crater-Lavic Lake was re-examined to indicate serious discrepancy in results for thermal inertia from Jet Lab Propulsion Laboratory calculations, when made using the same orginal data sets.

  7. Through-thickness determination of phase composition and residual stresses in thermall barrier coatings using high- energy x-rays.

    SciTech Connect

    Weyant, , C. M.; Almer, J. D.; Faber, K. T.; Stony Brook Univ.

    2009-01-01

    High-energy X-rays were used to determine the local phase composition and residual stresses through the thickness of as-sprayed and heat-treated plasma-sprayed thermal barrier coatings consisting of a NiCoCrAlY bond coat and an yttria-stabilized zirconia (YSZ) topcoat produced with through-thickness segmentation cracks. The as-sprayed residual stresses reflected the combined influence of quenching stresses from the plasma spray process, thermal expansion mismatch between the topcoat, bond coat and substrate, and stress relief from the segmentation cracks. Heat treatments led to the formation of a thermally grown oxide (TGO) which was in compression in the plane, as well as relief of quenching stresses and development of a stress gradient in the YSZ topcoat. The high-energy X-ray technique used in this study revealed the effects that TGO and segmentation cracks have on the in-plane stress state of the entire coating.

  8. Self-acceptance: a factor in the adoption process.

    PubMed

    DiGiulio, J F

    1988-01-01

    This study determined that high self-acceptance of adoptive parents influenced high parental acceptance of their adopted children. A case is made for emphasizing self-acceptance in adoption procedures.

  9. On the determination of the thermal comfort conditions of a metropolitan city underground railway.

    PubMed

    Katavoutas, George; Assimakopoulos, Margarita N; Asimakopoulos, Dimosthenis N

    2016-10-01

    Although the indoor thermal comfort concept has received increasing research attention, the vast majority of published work has been focused on the building environment, such as offices, residential and non-residential buildings. The present study aims to investigate the thermal comfort conditions in the unique and complex underground railway environment. Field measurements of air temperature, air humidity, air velocity, globe temperature and the number of passengers were conducted in the modern underground railway of Athens, Greece. Environmental monitoring was performed in the interior of two types of trains (air-conditioned and forced air ventilation cabins) and on selected platforms during the summer period. The thermal comfort was estimated using the PMV (predicted mean vote) and the PPD (predicted percentage dissatisfied) scales. The results reveal that the recommended thermal comfort requirements, although at relatively low percentages are met only in air-conditioned cabins. It is found that only 33% of the PPD values in air-conditioned cabins can be classified in the less restrictive comfort class C, as proposed by ISO-7730. The thermal environment is "slightly warm" in air-conditioned cabins and "warm" in forced air ventilation cabins. In addition, differences of the thermal comfort conditions on the platforms are shown to be associated with the depth and the design characteristics of the stations. The average PMV at the station with small depth is 0.9 scale points higher than that of the station with great depth. The number of passengers who are waiting at the platforms during daytime reveals a U-shaped pattern for a deep level station and an inverted course of PMV for a small depth station. Further, preliminary observations are made on the distribution of air velocity on the platforms and on the impact of air velocity on the thermal comfort conditions.

  10. Determination of biogenic amines by high-performance liquid chromatography (HPLC-DAD) in probiotic cow's and goat's fermented milks and acceptance

    PubMed Central

    Costa, Marion P; Balthazar, Celso F; Rodrigues, Bruna L; Lazaro, Cesar A; Silva, Adriana C O; Cruz, Adriano G; Conte Junior, Carlos A

    2015-01-01

    This study evaluated the presence of biogenic amines in fermented cow's and goat's milks containing probiotic bacteria, during the first 10 days of chilled storage (4 ± 2°C), when the probiotic strains are most viable. The overall acceptance of both fermented milks, produced using the same starter culture and probiotics, was tested. In both products, the initially high levels of tyramine (560 mg kg−1 means for both fermented milks), the predominant biogenic amine, increased during the storage period, which may be considered this amine as a quality index for fermented milks. The other principal biogenic amines (putrescine, cadaverine, histamine, and spermidine) were produced on days 1–5 of storage, and thereafter decreased. At the end of the 10th day, these amines, respectively, showed values of fermented cow's milk 20.26, 29.09, 17.97, and 82.07 mg kg−1; and values of fermented goat's milk 22.92, 29.09, 34.85, and 53.85 mg kg−1, in fermented cow's and goat's milk. Fermented cow's milk was well accepted compared to fermented goat's milk. The results suggested that the content of biogenic amines may be a criterion for selecting lactic acid bacteria used to produce fermented milks. PMID:25987991

  11. Use of thermal inertia determined by HCMM to predict nocturnal cold prone areas in Florida

    NASA Technical Reports Server (NTRS)

    Allen, L. H., Jr. (Principal Investigator)

    1983-01-01

    Pairs of HCMM day-night thermal infrared (IR) data were selected during the 1978-79 winter to examine patterns of surface temperature and thermal inertia (TI) of peninsular Florida. The GOES and NOAA-6 thermal IR, as well as National Climatic Center temperatures and rainfall, were also used. The HCMM apparent thermal inertia (ATI) images closely corresponded to the general soil map of Florida, based on soil drainage classes. Areas with low ATI overlay well-drained soils, such as deep sands and drained organic soils, whereas with high ATI overlay areas with wetlands and bodies of water. The HCMM ATI images also corresponded well with GOES-detected winter nocturnal cold-prone areas. Use of HCMM data with Carlson's energy balance model showed both high moisture availability (MA) and high thermal inertia (TI) of wetland-type surfaces and low MA and low TI of upland, well-drained soils. Since soil areas with low TI develop higher temperatures during the day, then antecedent patterns of highest maximum daytime surface temperature can also be used to predict nocturnal cold-prone areas in Florida.

  12. Using thermal balance model to determine optimal reactor volume and insulation material needed in a laboratory-scale composting reactor.

    PubMed

    Wang, Yongjiang; Pang, Li; Liu, Xinyu; Wang, Yuansheng; Zhou, Kexun; Luo, Fei

    2016-04-01

    A comprehensive model of thermal balance and degradation kinetics was developed to determine the optimal reactor volume and insulation material. Biological heat production and five channels of heat loss were considered in the thermal balance model for a representative reactor. Degradation kinetics was developed to make the model applicable to different types of substrates. Simulation of the model showed that the internal energy accumulation of compost was the significant heat loss channel, following by heat loss through reactor wall, and latent heat of water evaporation. Lower proportion of heat loss occurred through the reactor wall when the reactor volume was larger. Insulating materials with low densities and low conductive coefficients were more desirable for building small reactor systems. Model developed could be used to determine the optimal reactor volume and insulation material needed before the fabrication of a lab-scale composting system.

  13. Temperature dependence of viscosity and density of viscous liquids determined from thermal noise spectra of uncalibrated atomic force microscope cantilevers.

    PubMed

    McLoughlin, Neal; Lee, Stephen L; Hähner, Georg

    2007-08-01

    We demonstrate that the thermal response of uncalibrated atomic force microscope cantilevers can be used to extract the density and the viscosity of viscous liquids with good accuracy. Temperature dependent thermal noise spectra were measured in water/poly(ethylene glycol) mixtures. Empirical parameters characteristic of the resonance behavior of the system were extracted from data recorded for one of the solutions at room temperature. These parameters were then employed to determine both viscosity and density values of the solutions simultaneously at different temperatures. In addition, activation energies for viscous flow were determined from the viscosity values obtained. The method presented is both fast and reliable and has the potential to be applied in connection with microfluidic systems, making macroscopic amounts of liquid and separate measurements with a viscometer and a densimeter redundant.

  14. Determination of the succinonitrile-benzene and succinonitrile-cyclohexanol phase diagrams by thermal and UV spectroscopic analysis

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Frazier, D. O.; Facemire, B.

    1984-01-01

    Equilibrium temperature-composition diagrams were determined for the two organic systems, succinonitrile-benzene and succinonitrile-cyclohexanol. Measurements were made using the common thermal analysis methods and UV spectrophotometry. Succinonitrile-benzene monotectic was chosen for its low affinity for water and because UV analysis would be simplified. Succinonitrile-cyclohexanol was chosen because both components are transparent models for metallic solidification, as opposed to the other known succinonitrile-based monotectics.

  15. Experimental and Theoretical Determination of the Thermomechanical Response of Inelastic Structural Materials to High Energy Thermal Inputs

    DTIC Science & Technology

    1988-12-01

    CLASSIFICATION AUTHORITY 3 . DISTRIBUTION /AVAILABILITY OF REPORT __________________________________ A~PrOyed tOr publIc release, 2o. DECLASSIFICATION...DETERMINATION OF THE THERMOMECHANICAL RESPONSE OF INELASTIC STRUCTURAL MATERIALS TO HIGH ENERGY THERMAL INPUTS 3 Semi-Annual Technical Report Submitted by...D.H. Allen Aerospace Engineering Department and M.S. Pilant Mathematics Department 5Texas A&M University College Station, Texas 77843U 3 to the Air

  16. Offer/Acceptance Ratio.

    ERIC Educational Resources Information Center

    Collins, Mimi

    1997-01-01

    Explores how human resource professionals, with above average offer/acceptance ratios, streamline their recruitment efforts. Profiles company strategies with internships, internal promotion, cooperative education programs, and how to get candidates to accept offers. Also discusses how to use the offer/acceptance ratio as a measure of program…

  17. Liquid temperature determination in a seasonal heat storage at joint operation with a solar collector and thermal energy consumer

    SciTech Connect

    Sivoraksha, V.E.; Zolotko, K.E.; Markov, V.L.; Petrov, B.E.; Lyagushyn, S.F.

    1998-07-01

    Usual solar thermal systems include a solar collector providing solar power conversion into the thermal form and a heat storage accumulating thermal energy, the great capacity of storage systems allows heating and hot water supply during the cold season. The joint operation of the solar collector and a seasonal heat storage has a cyclic mode day by day. The following operation scheme is analyzed in the paper: in night liquid (water) does not circulate; after sunrise the solar collector is warmed up and after its temperature reaching the temperature of water in the thermal energy storage TTS circulation is switched on and thermal power is transferred to the heat storage; after midday water temperature in the solar collector decreases and circulation stops when it becomes equal to the heat storage temperature. TTS increase results in the reduction of the duration of the joint operation of the solar collector and the energy storage and in the decrease of the heat power input. A functional connection between the daily input of power from the solar collector and an average temperature in the heat storage is of importance for technological calculations. The moments of the beginning and end of circulation and daily heat input from the solar collector are determined under the assumption of the sinusoidal law of solar radiation coming in the day-time. Then the heat balance equation is solved for the whole power system with taking into account power consumption and heat losses. The polynomial approximation for the dependence of heat input upon heat carrier temperature permits obtaining an analytical solution for the seasonal behavior of the liquid temperature in the thermal energy storage. The obtained dependence of TTS upon time allows calculation of this parameter with admissible accuracy at the stage of the project development proceeding from the performance of the solar collector and heat storage and from the averaged meteorological data.

  18. First-Principles Determination of Ultralow Thermal Conductivity of monolayer WSe2

    PubMed Central

    Zhou, Wu-Xing; Chen, Ke-Qiu

    2015-01-01

    By using first-principles calculations combined with the phonon Boltzmann transport equation, we systematically investigate the phonon transport of monolayer WSe2. Compared with other 2D materials, the monolayer WSe2 is found to have an ultralow thermal conductivity due to the ultralow Debye frequency and heavy atom mass. The room temperature thermal conductivity for a typical sample size of 1 μm is 3.935  W/m K, which is one order of magnitude lower than that of MoS2. And the room temperature thermal conductivity can be further decreased by about 95% in 10 nm sized samples. Moreover, we also find the ZA phonons have the dominant contribution to the thermal conductivity, and the relative contribution is almost 80% at room temperature, which is remarkably higher than that for monolayer MoS2. This is because the ZA phonons have longer lifetime than that of LA and TA phonons in monolayer WSe2. PMID:26464052

  19. Infrared-based NDE methods for determining thermal properties and defects in ceramic composites

    SciTech Connect

    Ahuja, S.; Ellingson, W.A.; Steckenrider, J.S.; Koch, S.

    1996-08-01

    Continuous-fiber ceramic matrix composites are currently being developed for various high temperature applications, including use in advanced heat engines. In the material classes of interest for such applications, i.e., silicon carbide (SiC)-fiber-reinforced SiC (SiC{sub (f)}/SiC), SiC-fiber-reinforced silicon nitride (SiC{sub (f)}/Si{sub 3}N{sub 4}), Al{sub 2}O{sub 3 (f)}/Al{sub 2}O{sub 3}, etc., the condition of the interface between the fibers and matrix is critical to the mechanical and thermal behavior of each component. A nondestructive evaluation method developed at Argonne National Laboratory uses infrared thermal imaging to provide ``single-shot`` full-field measurement of the distribution of thermal diffusivity in large components. By applying digital filtering, interpolation, and least-squares-estimation techniques for noise reduction, the authors have achieved acquisition and analysis times of minutes or less with submillimeter spatial resolution. The system has been used to examine the effects of thermal shock, oxidation treatment, density, and variations in fiber coatings in a full array of test specimens.

  20. Determination of the thermal and physical properties of black tattoo ink using compound analysis.

    PubMed

    Humphries, Alexander; Lister, Tom S; Wright, Philip A; Hughes, Michael P

    2013-07-01

    Despite the widespread use of laser therapy in the removal of tattoos, comparatively little is known about its mechanism of action. There is a need for an improved understanding of the composition and thermal properties of the tattoo ink in order that simulations of laser therapy may be better informed and treatment parameters optimised. Scanning electron microscopy and time-of-flight secondary ion mass spectrometry identified that the relative proportions of the constituent compounds of the ink likely to exist in vivo are the following: carbon black pigment (89 %), carvacrol (5 %), eugenol (2 %), hexenol (3 %) and propylene glycol (1 %). Chemical compound property tables identify that changes in phase of these compounds lead to a considerable reduction in the density and thermal conductivity of the ink and an increase in its specific heat as temperature increases. These temperature-dependent values of density, thermal conductivity and specific heat are substantially different to the constant values, derived from water or graphite at a fixed temperature, which have been applied in the simulations of laser therapy as previously described in the literature. Accordingly, the thermal properties of black tattoo ink described in this study provide valuable information that may be used to improve simulations of tattoo laser therapy.

  1. Noninvasive determination of burn depth in children by digital infrared thermal imaging

    NASA Astrophysics Data System (ADS)

    Medina-Preciado, Jose David; Kolosovas-Machuca, Eleazar Samuel; Velez-Gomez, Ezequiel; Miranda-Altamirano, Ariel; González, Francisco Javier

    2013-06-01

    Digital infrared thermal imaging is used to assess noninvasively the severity of burn wounds in 13 pediatric patients. A delta-T (ΔT) parameter obtained by subtracting the temperature of a healthy contralateral region from the temperature of the burn wound is compared with the burn depth measured histopathologically. Thermal imaging results show that superficial dermal burns (IIa) show increased temperature compared with their contralateral healthy region, while deep dermal burns (IIb) show a lower temperature than their contralateral healthy region. This difference in temperature is statistically significant (p<0.0001) and provides a way of distinguishing deep dermal from superficial dermal burns. These results show that digital infrared thermal imaging could be used as a noninvasive procedure to assess burn wounds. An additional advantage of using thermal imaging, which can image a large skin surface area, is that it can be used to identify regions with different burn depths and estimate the size of the grafts needed for deep dermal burns.

  2. Destructive materials thermal characteristics determination with application for spacecraft structures testing

    NASA Astrophysics Data System (ADS)

    Alifanov, O. M.; Budnik, S. A.; Nenarokomov, A. V.; Netelev, A. V.; Titov, D. M.

    2013-04-01

    In many practical situations it is impossible to measure directly thermal and thermokinetic properties of analyzed composite materials. The only way that can often be used to overcome these difficulties is indirect measurements. This type of measurements is usually formulated as the solution of inverse heat transfer problems. Such problems are ill-posed in mathematical sense and their main feature shows itself in the solution instabilities. That is why special regularizing methods are needed to solve them. The general method of iterative regularization is concerned with application to the estimation of materials properties. The objective of this paper is to estimate thermal and thermokinetic properties of advanced materials using the approach based on inverse methods. An experimental-computational system is presented for investigating the thermal and kinetics properties of composite materials by methods of inverse heat transfer problems and which is developed at the Thermal Laboratory of Department Space Systems Engineering, of Moscow Aviation Institute (MAI). The system is aimed at investigating the materials in conditions of unsteady contact and/or radiation heating over a wide range of temperature changes and heating rates in a vacuum, air and inert gas medium.

  3. Effects of thermal maturation on steroid hydrocarbons as determined by hydrous pyrolysis of Phosphoria Retort Shale

    NASA Astrophysics Data System (ADS)

    Lewan, M. D.; Bjorøy, M.; Dolcater, D. L.

    1986-09-01

    Hydrous pyrolysis experiments on the Phosphoria Retort Shale generate bitumen extracts and expelled oils that have steroid hydrocarbons with m/z 217-, 231-, and 253-mass Chromatographic distributions that are similar to those of bitumens and crude oils in the natural system. These experiments agree with the natural observations that diasteroid hydrocarbons increase relative to their regular counterparts with increasing thermal stress, while their C 27 through C 29 proportionality shows a slight enrichment in C 27. Relative concentrations of 20S to 20R configurations of 24-ethyl-14α,17α-cholestane show the expected increase with increasing thermal stress into the early part of the primary oil generation stage, but thereafter decrease with increasing thermal stress. If this reversal is found in high maturity sections of the natural system, the utility of this transformation as a maturity index will be limited. Triaromatic- to monoaromatic-steroid hydrocarbon concentrations increase with increasing thermal stress as observed in the natural system. Preferred migration of monoaromatic steroid hydrocarbons from bitumen extracts to expelled oils places considerable doubt on currently employed kinetic models for this aromatization reaction. As in the natural system, the experiments show relative concentrations of low-molecular weight- to high-molecular weight-triaromatic steroid hydrocarbons to increase with increasing thermal stress. Assuming a first-order reaction rate, the apparent activation energy and pre-exponential factor for this apparent side-chain cleavage reaction are 175.59 kJ mol -1 and 2.82 × 10 13hr-1, respectively. These kinetic parameters are geologically reasonable and are similar to those for the overall generation of expelled oil.

  4. Development and application of a thermal desorption-based method for the determination of nicotine in inddor environments

    SciTech Connect

    Jenkins, R.A.; Thompson, C.V.; Higgins, C.E.

    1988-01-01

    A personal monitoring system for the determination of exposure to nicotine has been developed. The system consists of a sampling cartidge packed with 200 mg of Tenax GC/sup R/ and a small, constant flow, personal sampling pump. After sampling, the cartridges are analyzed by triethylamine-assisted thermal desorption gas chromatography with nitrogen-selective detection. Collection and desorption efficiencies for the cartridges have been determined. The system has been applied in a variety of work sites, and in 36 restaurants, where measured concentrations of nicotine ranged from 0.5 to 37.2 ..mu..gm/sup /minus/3/. 25 refs., 2 figs., 4 tabs.

  5. 41 CFR 304-6.9 - Does acceptance by OGE of the Standard Form (SF) 326 constitute a determination by OGE that the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or a concurrence by OGE in the agency's conflict of interest analysis? 304-6.9 Section 304-6.9 Public Contracts and... (SF) 326 constitute a determination by OGE that the data submitted is adequate or a concurrence by...

  6. 41 CFR 304-6.9 - Does acceptance by OGE of the Standard Form (SF) 326 constitute a determination by OGE that the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of the Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or a concurrence by OGE in the agency's conflict of interest analysis? 304-6.9 Section 304-6.9 Public... Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or...

  7. 41 CFR 304-6.9 - Does acceptance by OGE of the Standard Form (SF) 326 constitute a determination by OGE that the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of the Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or a concurrence by OGE in the agency's conflict of interest analysis? 304-6.9 Section 304-6.9 Public... Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or...

  8. 41 CFR 304-6.9 - Does acceptance by OGE of the Standard Form (SF) 326 constitute a determination by OGE that the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of the Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or a concurrence by OGE in the agency's conflict of interest analysis? 304-6.9 Section 304-6.9 Public... Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or...

  9. 41 CFR 304-6.9 - Does acceptance by OGE of the Standard Form (SF) 326 constitute a determination by OGE that the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of the Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or a concurrence by OGE in the agency's conflict of interest analysis? 304-6.9 Section 304-6.9 Public... Standard Form (SF) 326 constitute a determination by OGE that the data submitted is adequate or...

  10. Determination of second-order elastic constants of cyclotetramethylene tetranitramine (β-HMX) using impulsive stimulated thermal scattering

    NASA Astrophysics Data System (ADS)

    Sun, B.; Winey, J. M.; Gupta, Y. M.; Hooks, D. E.

    2009-09-01

    The second-order elastic constants for cyclotetramethylene tetranitramine (β-HMX) single crystals were determined using the impulsive stimulated thermal scattering (ISTS) method. Despite the low symmetry of these crystals, the complete set of 13 elastic constants were determined accurately from acoustic velocity measurements using samples cut parallel to three different crystal planes. Our acoustic velocities are consistent with the limited sound speed data available from ultrasonic measurements. However, significant differences are observed between the elastic constants determined from our experiments and those obtained previously using Brillouin scattering. Our results demonstrate the usefulness and efficiency of the ISTS method for determining the full set of elastic constants of low-symmetry molecular crystals, including energetic crystals.

  11. First principles determination of ultra-high thermal conductivity fo Boron Arsenide: A competitor for diamond?

    NASA Astrophysics Data System (ADS)

    Lindsay, Lucas; Broido, David; Reinecke, Tom; Lindsay Collaboration

    2014-03-01

    We have calculated the thermal conductivities (k) of cubic III-V boron compounds using a predictive first principles approach. Boron Arsenide (BAs) is found to have a remarkable room temperature k over 2000Wm-1K-1; this is comparable to those in diamond and graphite, which are the highest bulk values known. We trace this behavior in BAs to an interplay of certain basic vibrational properties that lie outside of the conventional guidelines in searching for high k materials. We also find that cubic BN and BSb will have high k with isotopic purification. This work provides new insight into the nature of thermal transport at a quantitative level and predicts a new ultra-high k material of potential interest for passive cooling applications. This work was supported by ONR, DARPA, DOE-BES and NSF.

  12. What Determines the Presence of a Thermal Inversion in Hot Jupiters?

    NASA Astrophysics Data System (ADS)

    Beatty, Thomas G.; Madhusudhan, Nikku; Pogge, Richard W.; Tsiaras, Angelos; Gaudi, B. Scott; Chung, Sun Mi

    2017-01-01

    Stratospheric temperature inversions in the atmospheres of giant exoplanets, once expected to be fairly common in hot Jupiters, have proven to be extremely elusive. Even though many planets have day side temperatures above the TiO/VO condensation point, TiO/VO-driven thermal inversions seem to be rare. Recent observations, however, have given some of the first clear detections of thermal inversions in two very hot giant exoplanets' atmospheres. We report on observations of two additional systems in the same temperature range, which again suggest that the presence of an inversion is not solely driven by atmospheric temperature. Our hypothesis for why this is so would explain the lack of an inversion in our two targets, as well as in cooler hot Jupiters, and would support some theoretical predictions for the processes governing TiO/VO inversions.

  13. Determination of the strain rate dependent thermal softening behavior of thermoplastic materials for crash simulations

    NASA Astrophysics Data System (ADS)

    Hopmann, Christian; Klein, Jan; Schöngart, Maximilian

    2016-03-01

    Thermoplastic materials are increasingly used as a light weight replacement for metal, especially in automotive applications. Typical examples are frontends and bumpers. The loads on these structures are very often impulsive, for example in a crash situation. A high rate of loading causes a high strain rate in the material which has a major impact on the mechanical behavior of thermoplastic materials. The stiffness as well as the rigidity of polymers increases to higher strain rates. The increase of the mechanical properties is superimposed at higher rates of loading by another effect which works reducing on stiffness and rigidity, the increase of temperature caused by plastic deformation. The mechanical behavior of thermoplastic materials is influenced by temperature opposing to strain rate. The stiffness and rigidity are decreased to higher values of temperature. The effect of thermal softening on thermoplastic materials is investigated at IKV. For this purpose high-speed tensile tests are performed on a blend, consisting of Polybutylenterephthalate (PBT) and Polycarbonate (PC). In preliminary investigations the effects of strain rate on the thermomechanical behavior of thermoplastic materials was studied by different authors. Tensile impact as well as split Hopkinson pressure bar (SHPB) tests were conducted in combination with high-speed temperature measurement, though, the authors struggled especially with temperature measurement. This paper presents an approach which uses high-speed strain measurement to transpire the link between strain, strain rate and thermal softening as well as the interdependency between strain hardening and thermal softening. The results show a superimposition of strain hardening and thermal softening, which is consistent to preliminary investigations. The advantage of the presented research is that the results can be used to calibrate damage and material models to perform mechanical simulations using Finite Element Analysis.

  14. Determination of thermal contact conductance in vacuum-bagged thermoplastic prepreg stacks using infrared thermography

    NASA Astrophysics Data System (ADS)

    Baumard, Théo; De Almeida, Olivier; Menary, Gary; Le Maoult, Yannick; Schmidt, Fabrice; Bikard, Jérôme

    2016-10-01

    The infrared heating of a vacuum-bagged, thermoplastic prepreg stack of glass/PA66 was studied to investigate the influence of vacuum level on thermal contact resistance between plies. A higher vacuum level was shown experimentally to decrease the transverse heat transfer efficiency, indicating that considering only the effect of heat conduction at the plies interfaces is not sufficient to predict the temperature distribution. An inverse analysis was used to retrieve the contact resistance coefficients as a function of vacuum pressure.

  15. Absolute thermal neutron fluence determination by thin film of natural uranium

    NASA Astrophysics Data System (ADS)

    Bigazzi, G.; Hadler N., J. C.; Iunes, P. J.; Oddone, M.; Paulo, S. R.; Zúñiga G., A.

    1995-01-01

    An absolute monitor of thermal neutron fluence based on the 235U induced fission was developed. This monitor is constituted by a solid state nuclear track detector juxtaposed to a natural uranium film with a negligible self-absorption to fission fragments. In order to perform the calibration of the films, the alpha-activity was measured by using nuclear emulsions. The preparation, calibration and employment procedures of this monitor are presented.

  16. Uncertainty in determining thermal performance of liquid-heating flat-plate solar collectors

    NASA Astrophysics Data System (ADS)

    Streed, E. R.; Waksman, D.

    1981-05-01

    Thermal performance measurements of eight types of liquid-heating flat-plate solar collectors were conducted with two to four collectors of each type at four outdoor test sites. Tests were performed in accordance with the procedure prescribed by ASHRAE Standard 93-77. Statistical analysis of data sets for each collector type within test sites and between test sites was done using ASTM recommended methods to evaluate test method measurement uncertainty.

  17. Thermal expansion in UO2 determined by high-energy X-ray diffraction

    DOE PAGES

    Guthrie, M.; Benmore, C. J.; Skinner, L. B.; ...

    2016-06-24

    In this study, we present crystallographic analyses of high-energy X-ray diffraction data on polycrystalline UO2 up to the melting temperature. The Rietveld refinements of our X-ray data are in agreement with previous measurements, but are systematically located around the upper bound of their uncertainty, indicating a slightly steeper trend of thermal expansion compared to established values. This observation is consistent with recent first principles calculations.

  18. Effect of additives on jet fuel thermal stability determined using the gravimetric JFTOT

    SciTech Connect

    Pande, S.G.; Hardy, D.R.

    1996-10-01

    In an effort to address the need for improving the thermal stabilities of jet fuels, various additives are being examined. These include the antioxidant, BHT; a metal deactivator, MDA (N,N{prime}-Disalicylidene-1,2-propane diamine); a combination of BHT and MDA; and two dispersant/detergent additives, viz., a Betz and Mobil additive. In general, the additives were screened in three test fuels, viz., a refinery sampling blend (RSB), a JP-8, and a Jet A. Additive effectiveness on aging a fuel in the presence of 400 ppb copper was examined in the RSB fuel. Based on the studies conducted, the most effective additives were the MDA/BHT combination, the Betz, and the Mobil additive (when tested). For example, these additives significantly lowered the total thermal deposits formed for the copper-doped aged fuel. For the remaining two test fuels, differentiation in effectiveness among the additives screened was considerably less. These results, which are likely due to the test fuels being relatively thermally stable, focus on the necessity of using less stable fuels to better differentiate additive effectiveness.

  19. Virtual method for the determination of an optimum thermal design of hot stamping tools

    NASA Astrophysics Data System (ADS)

    Weiß, W.; Koplenig, M.; Alb, M.; Graf, J.

    2016-11-01

    This work presents a new virtual method for the optimised thermal design of hot stamping tools. It provides optimal positions of the tool's tempering ducts with respect to the average working temperature and its homogeneous distribution on the surface of a tool. It consists of a specific procedure for hot stamping tool design and a software framework in order to interconnect three domains: (I) a parametrised CAD tool model, (II) a linear thermal solver using a fast boundary element method and (III) an optimisation algorithm. This enables the automated set-up, simulation and optimisation of a duct topology. The boundary conditions for the simulations are derived from a reduced model of the thermal loading of the tool. The virtual method proposed is demonstrated on simplified tool segment geometries. The results are transferred to complex tool designs used in industry. For a selected use case, the number of ducts could be reduced by 50% through the application of the proposed method. These results are validated virtually based on an existing design. Hence, the new virtual method contributes to a CAE-driven tool design and a more efficient tool manufacturing.

  20. Transcriptional Response to Acute Thermal Exposure in Juvenile Chinook Salmon Determined by RNAseq

    PubMed Central

    Tomalty, Katharine M. H.; Meek, Mariah H.; Stephens, Molly R.; Rincón, Gonzalo; Fangue, Nann A.; May, Bernie P.; Baerwald, Melinda R.

    2015-01-01

    Thermal exposure is a serious and growing challenge facing fish species worldwide. Chinook salmon (Oncorhynchus tshawytscha) living in the southern portion of their native range are particularly likely to encounter warmer water due to a confluence of factors. River alterations have increased the likelihood that juveniles will be exposed to warm water temperatures during their freshwater life stage, which can negatively impact survival, growth, and development and pose a threat to dwindling salmon populations. To better understand how acute thermal exposure affects the biology of salmon, we performed a transcriptional analysis of gill tissue from Chinook salmon juveniles reared at 12° and exposed acutely to water temperatures ranging from ideal to potentially lethal (12° to 25°). Reverse-transcribed RNA libraries were sequenced on the Illumina HiSeq2000 platform and a de novo reference transcriptome was created. Differentially expressed transcripts were annotated using Blast2GO and relevant gene clusters were identified. In addition to a high degree of downregulation of a wide range of genes, we found upregulation of genes involved in protein folding/rescue, protein degradation, cell death, oxidative stress, metabolism, inflammation/immunity, transcription/translation, ion transport, cell cycle/growth, cell signaling, cellular trafficking, and structure/cytoskeleton. These results demonstrate the complex multi-modal cellular response to thermal stress in juvenile salmon. PMID:25911227

  1. A multi-thermogram-based Bayesian model for the determination of the thermal diffusivity of a material

    NASA Astrophysics Data System (ADS)

    Allard, Alexandre; Fischer, Nicolas; Ebrard, Géraldine; Hay, Bruno; Harris, Peter; Wright, Louise; Rochais, Denis; Mattout, Jeremie

    2016-02-01

    The determination of thermal diffusivity is at the heart of modern materials characterisation. The evaluation of the associated uncertainty is difficult because the determination is performed in an indirect way, in the sense that the thermal diffusivity cannot be measured directly. The well-known GUM uncertainty framework does not provide a reliable evaluation of measurement uncertainty for such inverse problems, because in that framework the underlying measurement model is supposed to be a direct relationship between the measurand (the quantity intended to be measured) and the input quantities on which the measurand depends. This paper is concerned with the development of a Bayesian approach to evaluate the measurement uncertainty associated with thermal diffusivity. A Bayesian model is first developed for a single thermogram and is then extended to the case of several thermograms obtained under repeatability and reproducibility conditions. This multi-thermogram based model is able to take into consideration a large set of influencing quantities that occur during the measurements and yields a more reliable uncertainty evaluation than the one obtained from a single thermogram. Different aspects of the Bayesian model are discussed, including the sensitivity to the choice of the prior distribution, the Metropolis-Hastings algorithm used for the inference and the convergence of the Markov chains.

  2. Thermal desorption-gas chromatography-mass spectrometry method to determine phthalate and organophosphate esters from air samples.

    PubMed

    Aragón, M; Borrull, F; Marcé, R M

    2013-08-16

    A method based on thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) has been developed to determine four organophosphate esters, seven phthalate esters, and bis(2-ethylhexyl) adipate in the gas phase from harbour and urban air samples. The method involves the sampling of 1.5L of air in a Tenax TA sorbent tube followed by thermal desorption (using a Tenax TA cryogenic trap) coupled to gas chromatography-mass spectrometry. The repeatability of the method expressed as %RSD (n=3) is less than 15% and the MQLs are between 0.007μgm(-3) (DMP, TBP, BBP, TPP and DnOP) and 6.7μgm(-3) (DEHP). The method was successfully applied in two areas (urban and harbour) testing two and three points in each one, respectively. Some of these compounds were found in both urban and harbour samples. Di-(2-ethylhexyl)phthalate was the most abundant compound found in both areas at concentration levels between 6.7μgm(-3) and 136.4μgm(-3). This study demonstrates that thermal desorption is an efficient method for the determination of these semi-volatile compounds in the gas phase fraction of air samples.

  3. A method for determination of heat storage capacity of the mold materials using a differential thermal analysis

    NASA Astrophysics Data System (ADS)

    Ol'khovik, E.

    2016-04-01

    The article proposes a method for determining of the heat storage capacity of the mould materials. Modern materials for mouldsare made using a variety of technologies, and the manufacturers of binders and additives ensure thermal properties of certain materials only when using a certain recipe. In practice, for management of the casting solidification process (creation of the volume or directed mode) it is favorable to apply various technological methods, including modification of one of the important properties of the casting mould, which is heat storage capacity. A rather simple technique based on the application of the differential thermal analysis was developed for its experimental definition. The obtained data showed a possibility of industrial application of the method.

  4. A Positive View of Peer Acceptance in Aggressive Youth: Risk for Future Peer Acceptance.

    ERIC Educational Resources Information Center

    Hughes, Jan N.; Cavell, Timothy A.; Prasad-Gaur, Archna

    2001-01-01

    Uses longitudinal data to determine whether a positive view of perceived peer acceptance is a risk factor for continued aggression and social rejection for aggressive children. Results indicate that perceived peer acceptance did not predict aggression. However, children who reported higher levels of perceived peer acceptance received lower actual…

  5. What determines a species' geographical range? Thermal biology and latitudinal range size relationships in European diving beetles (Coleoptera: Dytiscidae).

    PubMed

    Calosi, Piero; Bilton, David T; Spicer, John I; Votier, Stephen C; Atfield, Andrew

    2010-01-01

    1. The geographical range sizes of individual species vary considerably in extent, although the factors underlying this variation remain poorly understood, and could include a number of ecological and evolutionary processes. A favoured explanation for range size variation is that this result from differences in fundamental niche breadths, suggesting a key role for physiology in determining range size, although to date empirical tests of these ideas remain limited. 2. Here we explore relationships between thermal physiology and biogeography, whilst controlling for possible differences in dispersal ability and phylogenetic relatedness, across 14 ecologically similar congeners which differ in geographical range extent; European diving beetles of the genus Deronectes Sharp (Coleoptera, Dytiscidae). Absolute upper and lower temperature tolerance and acclimatory abilities are determined for populations of each species, following acclimation in the laboratory. 3. Absolute thermal tolerance range is the best predictor of both species' latitudinal range extent and position, differences in dispersal ability (based on wing size) apparently being less important in this group. In addition, species' northern and southern range limits are related to their tolerance of low and high temperatures respectively. In all cases, absolute temperature tolerances, rather than acclimatory abilities are the best predictors of range parameters, whilst the use of independent contrasts suggested that species' thermal acclimation abilities may also relate to biogeography, although increased acclimatory ability does not appear to be associated with increased range size. 4. Our study is the first to provide empirical support for a relationship between thermal physiology and range size variation in widespread and restricted species, conducted using the same experimental design, within a phylogenetically and ecologically controlled framework.

  6. Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

    PubMed

    Iftikar, Fathima I; MacDonald, Julia R; Baker, Daniel W; Renshaw, Gillian M C; Hickey, Anthony J R

    2014-07-01

    For many aquatic species, the upper thermal limit (Tmax) and the heart failure temperature (THF) are only a few degrees away from the species' current environmental temperatures. While the mechanisms mediating temperature-induced heart failure (HF) remain unresolved, energy flow and/or oxygen supply disruptions to cardiac mitochondria may be impacted by heat stress. Recent work using a New Zealand wrasse (Notolabrus celidotus) found that ATP synthesis capacity of cardiac mitochondria collapses prior to T(HF). However, whether this effect is limited to one species from one thermal habitat remains unknown. The present study confirmed that cardiac mitochondrial dysfunction contributes to heat stress-induced HF in two additional wrasses that occupy cold temperate (Notolabrus fucicola) and tropical (Thalassoma lunare) habitats. With exposure to heat stress, T. lunare had the least scope to maintain heart function with increasing temperature. Heat-exposed fish of all species showed elevated plasma succinate, and the heart mitochondria from the cold temperate N. fucicola showed decreased phosphorylation efficiencies (depressed respiratory control ratio, RCR), cytochrome c oxidase (CCO) flux and electron transport system (ETS) flux. In situ assays conducted across a range of temperatures using naive tissues showed depressed complex II (CII) and CCO capacity, limited ETS reserve capacities and lowered efficiencies of pyruvate uptake in T. lunare and N. celidotus. Notably, alterations of mitochondrial function were detectable at saturating oxygen levels, indicating that cardiac mitochondrial insufficiency can occur prior to HF without oxygen limitation. Our data support the view that species distribution may be related to the thermal limits of mitochondrial stability and function, which will be important as oceans continue to warm.

  7. Testing to determine the vacuum-ultraviolet degradation rate of thermal control coatings

    NASA Technical Reports Server (NTRS)

    Gilligan, J. E.

    1972-01-01

    Samples of S-13G that had been exposed to the salt air environment of Cape Kennedy, Florida were irradiated with simulated solar ultraviolet radiation after various cleaning treatments. In both of the the tests conducted two of the salt air exposed samples were not cleaned, two were lightly cleaned with water and detergent (i.e. rinsed), and two were vigorously scrubbed. Several other white thermal control coatings were also irradiated. The solar absorptance values of these coatings before and as a result of the ultraviolet irradiation are reported for exposure levels up to approximately 2000 ESH.

  8. X-ray crystal analysis method of determining the anisotropy of thermal expansion of petroleum cokes

    SciTech Connect

    Vakhitov, R.R.; Biktimirova, T.G.; Novoselov, V.F.

    1985-06-01

    This paper presents a simple and sensitive method to evaluate indirectly the anisotropy of the CTE of cokes. It is based on the change of intensity of the reflection from the plane with changing temperature. At high temperatures the mean amplitudes of the thermal oscillations of the atoms are consderable, the nature of the oscillations is anharmonic. In consequence of this, the atoms are displaced relative to their mean positions, and the x-ray beams scattered by them do not coincide in phase. The new characteristic is correlated with the structure of the cokes, and it makes it possible to classify them for further industrial application.

  9. Drying characteristics and heat requirement of coconut endocarp determined by simultaneous thermal analyzer

    NASA Astrophysics Data System (ADS)

    Zhang, Yufeng; Duan, Kejun; Song, Fei; Chen, Weijun; Zhao, Songlin

    2016-09-01

    Drying characteristics and heat requirement of coconut endocarp at 40, 50 and 60 °C were investigated by a simultaneous thermal analyzer (TG-DSC). Results showed that Page model was the suitable model to describe and estimate the drying characteristics of coconut endocarp with a relatively higher R 2 value and lower χ2 value. Effective moisture diffusivity ( D eff) ranged from 9.90 × 10-9 to 1.10 × 10-8 m2/s. Activation energies were 4.70 kJ/mol and heat requirements ranged from 59.3 to 55.9 kJ/kg.

  10. LIMS user acceptance testing.

    PubMed

    Klein, Corbett S

    2003-01-01

    Laboratory Information Management Systems (LIMS) play a key role in the pharmaceutical industry. Thorough and accurate validation of such systems is critical and is a regulatory requirement. LIMS user acceptance testing is one aspect of this testing and enables the user to make a decision to accept or reject implementation of the system. This paper discusses key elements in facilitating the development and execution of a LIMS User Acceptance Test Plan (UATP).

  11. Thermal summation model and instar determination of all developmental stages of necrophagous beetle, Sciodrepoides watsoni (Spence) (Coleoptera: Leiodidae: Cholevinae)

    PubMed Central

    2016-01-01

    Necrophagous beetles are underrepresented in forensic entomology studies despite their undeniable utility for the field. In the present article, information is presented regarding the developmental biology and instar determination of Sciodrepoides watsoni (Spence, 1813), a very common species occurring across the Holarctic region. Wild collected beetles were kept in climate chambers at constant temperature (12, 15, 18, 21 and 28 °C) and their development was regularly documented. Parameters of thermal summation models and standard errors were calculated for each developmental stage. These models may be used for an estimation of post-mortem interval in legal investigations after further validation on local populations of S. watsoni. An additional methodology is introduced for future studies of size-based characteristics, addressing instar identification bias. The methodology provided estimations (mean, standard error and standard deviation) of S. watsoni larval head capsule width for preliminary larval instar determination. The methodology may be used with other morphological features to improve instar determination accuracy. PMID:27123379

  12. On Maximum FODO Acceptance

    SciTech Connect

    Batygin, Yuri Konstantinovich

    2014-12-24

    This note illustrates maximum acceptance of FODO quadrupole focusing channel. Acceptance is the largest Floquet ellipse of a matched beam: A = $\\frac{a^2}{β}$$_{max}$ where a is the aperture of the channel and βmax is the largest value of beta-function in the channel. If aperture of the channel is restricted by a circle of radius a, the s-s acceptance is available for particles oscillating at median plane, y=0. Particles outside median plane will occupy smaller phase space area. In x-y plane, cross section of the accepted beam has a shape of ellipse with truncated boundaries.

  13. Acceptability of GM foods among Pakistani consumers.

    PubMed

    Ali, Akhter; Rahut, Dil Bahadur; Imtiaz, Muhammad

    2016-04-02

    In Pakistan majority of the consumers do not have information about genetically modified (GM) foods. In developing countries particularly in Pakistan few studies have focused on consumers' acceptability about GM foods. Using comprehensive primary dataset collected from 320 consumers in 2013 from Pakistan, this study analyzes the determinants of consumers' acceptability of GM foods. The data was analyzed by employing the bivariate probit model and censored least absolute deviation (CLAD) models. The empirical results indicated that urban consumers are more aware of GM foods compared to rural consumers. The acceptance of GM foods was more among females' consumers as compared to male consumers. In addition, the older consumers were more willing to accept GM food compared to young consumers. The acceptability of GM foods was also higher among wealthier households. Low price is the key factor leading to the acceptability of GM foods. The acceptability of the GM foods also reduces the risks among Pakistani consumers.

  14. A method to determine stratification efficiency of thermal energy storage processes independently from storage heat losses

    SciTech Connect

    Haller, Michel Y.; Streicher, Wolfgang; Bales, Chris

    2010-06-15

    A new method for the calculation of a stratification efficiency of thermal energy storages based on the second law of thermodynamics is presented. The biasing influence of heat losses is studied theoretically and experimentally. Theoretically, it does not make a difference if the stratification efficiency is calculated based on entropy balances or based on exergy balances. In practice, however, exergy balances are less affected by measurement uncertainties, whereas entropy balances can not be recommended if measurement uncertainties are not corrected in a way that the energy balance of the storage process is in agreement with the first law of thermodynamics. A comparison of the stratification efficiencies obtained from experimental results of charging, standby, and discharging processes gives meaningful insights into the different mixing behaviors of a storage tank that is charged and discharged directly, and a tank-in-tank system whose outer tank is charged and the inner tank is discharged thereafter. The new method has a great potential for the comparison of the stratification efficiencies of thermal energy storages and storage components such as stratifying devices. (author)

  15. Determination of the interfacial tension by thermal grooving and zero creep in coaxial wires -- Theory

    SciTech Connect

    Genin, F.Y. )

    1994-11-01

    Thermal grooving (TG) and zero creep (ZC) theory has been extensively discussed since the original experiments by Udin et al. on thin metallic wires of copper, silver and gold. Corrections to the theory were added later by Udin and very recently by Josell. While the initial TG studies of foils can yield precious information on the ratio between the grain boundary (GB) tension and the surface energy, ZC experiments on such planar systems are more difficult to analyze because a given microstructure (usually a rectangular or hexagonal array of columnar grains), which is almost impossible to control, and a constitutive law relating stress and strain rate have to be assumed. In comparison to other interfaces, the measurement of interphase boundary energy has been neglected. The role of interfacial energy in the nucleation and growth of second phase precipitates, in the adhesion between materials, as in metal-ceramic composite structures or multilayered films, emphasizes the crucial need for reliable measurements. Here, a model based on the thermal grooving and zero creep theory is developed to allow absolute measurements of the interfacial energy between two materials in the shape of bamboo coaxial wires.

  16. Resource allocation between reproductive phases: the importance of thermal conditions in determining the cost of incubation.

    PubMed Central

    Reid, J M; Monaghan, P; Ruxton, G D

    2000-01-01

    Changes in the resources allocated to particular stages of reproduction are expected to influence allocation to, and performance in, subsequent reproductive stages. Experimental manipulation of individual investment patterns provides important evidence that such physiological trade-offs occur, and can highlight the key environmental variables that influence reproductive costs. By temporarily altering the thermal properties of starling nests, we reduced the energetic demand of first-clutch incubation, and examined the effect of this manipulation on performance during the same and the subsequent reproductive attempts. Compared with controls, starlings investing less in incubation were more successful in fledging young, and were more likely to hatch all their eggs if a subsequent reproductive attempt was made. Our results show that incubation demands can limit reproductive success, and that resources saved during incubation can be reallocated to later stages of the same reproductive attempt and to future reproductive attempts. This study also shows that small changes in thermal environment can affect breeding success by altering the energetic demands imposed on incubating parents, independently of the effect of temperature on other environmental variables such as food supply. PMID:10670950

  17. Determination of rock type on Mercury and the moon through remote sensing in the thermal infrared

    NASA Technical Reports Server (NTRS)

    Tyler, Ann L.; Kozlowski, Richard W. H.; Lebofsky, Larry A.

    1988-01-01

    Thermal infrared emission spectra of the moon and Mercury have been obtained using the Si:As photoconductor and circular variable filter at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii. Lunar spectra from 7.2 to 12.2 microns for two different locations in the south polar highlands have Christiansen frequency peaks at 8.1 microns and 7.9 microns, respectively. This indicates different compositions at the two locations; mafic in the first case, more felsic in the second. Emission spectra from Mercury are not as spatially localized,; however, the longitude of maximum contribution to the spectrum can be calculated from thermal models of the earth-facing disk. Results for areas centered at two longitudes have been obtained. Two locations in the intercrater plains were observed. At 40-deg longitude (very near the crater Homer), a peak at 7.9 microns indicates mafic igneous rock type. Spectra emanating from 46-deg longitude have peaks at 7.8 microns, indicating a region borderline between mafic and intermediate composition.

  18. CEQATR Thermal Test Overview

    NASA Technical Reports Server (NTRS)

    Balusek, Alan R.

    2009-01-01

    A thermal test overview of the Constellation Environmental Qualification and Acceptance Test Requirement (CEQATR) is presented. The contents include: 1) CEQATR Thermal Test Overview; 2) CxP Environments; 3) CEQATR Table 1.2-1; 4) Levels of Assembly; 5) Definitions for Levels of Assembly; 6) Hardware Applicability; 7) CEQATR Thermal-Related Definitions; 8) Requirements for unit-level thermal testing; 9) Requirements for major assembly level thermal testing; 10) General thermal testing requirements; 11) General thermal cycle, thermal vacuum profiles; 12) Test tolerances; 13) Vacuum vs Ambient; 14) Thermal Gradient; 15) Sequence of Testing; 16) Alternative Strategies; 17) Protoflight; 18) Halt/Hass; 19) Humidity; and 20) Tailoring.

  19. Pt/graphene-CNTs nanocomposite based electrochemical sensors for the determination of endocrine disruptor bisphenol A in thermal printing papers.

    PubMed

    Zheng, Zhixiang; Du, Yongling; Wang, Zaihua; Feng, Qingliang; Wang, Chunming

    2013-01-21

    A facile and green method was developed to synthesize the graphene-carbon nanotubes (Gr-CNTs) nanocomposite with a sandwich lamination structure. Pt nanoparticles were loaded on the as-synthesized Gr-CNTs nanocomposite to prepare an electrochemical sensor for determining bisphenol A (BPA) in thermal printing paper. The electrochemical behavior of BPA on the Pt/Gr-CNTs nanocomposite was investigated by cyclic voltammetry (CV) and chronocoulometry (CC). The direct determination of BPA was accomplished by using differential pulse voltammetry (DPV) under optimized conditions. The oxidation peak current was proportional to the BPA concentration in the range from 6.0 × 10(-8) to 1.0 × 10(-5) M and 1.0 × 10(-5) to 8.0 × 10(-5) M with a correlation coefficient of 0.987 and 0.998, respectively. The detection limit was 4.2 × 10(-8) M (S/N = 3). The fabricated electrode showed good reproducibility, stability and selectivity. The proposed method was successfully applied to determine BPA in thermal printing papers samples and the results were satisfactory.

  20. Development of a thermal desorption-gas chromatography-mass spectrometry method for determining personal care products in air.

    PubMed

    Ramírez, Noelia; Marcé, Rosa Maria; Borrull, Francesc

    2010-06-25

    This study describes the development of a new analytical method for determining 14 personal care products (PCPs) - nine synthetic musks, four parabens and one insect repellent - in air samples. The method is based on active sampling on sorbent tubes and thermal desorption-gas chromatography-mass spectrometry analysis, and is rapid, sensitive and drastically reduces the risk of sample contamination. Three kinds of tubes and traps were tested, those filled with Tenax TA being the most suitable for this study. Method validation showed good repeatability and reproducibility, low detection limits (between 0.03 ng m(-3) for DPMI and 12.5 ng m(-3) for propyl paraben) and good linearity for all compounds. Stability during storage indicated that samples must be kept refrigerated at 4 degrees C and analysed within 1 week of collection. The applicability of the technique to real samples was tested in different indoor and outdoor atmospheres. The total PCP values for indoor air ranged from 135 ng m(-3) in a pharmacy to 2838 ng m(-3) in a hairdresser's, whereas the values for outdoor air ranged from 14 ng m(-3) for a suburban environment to 26 ng m(-3) for an urban environment. In general, the most abundant synthetic musks were galaxolide (5.9-1256 ng m(-3)), musk xylene (1.6-766 ng m(-3)) and tonalide (1.1-138 ng m(-3)). Methyl and ethyl paraben (2.4-313 ng m(-3) and 1.8-117 ng m(-3), respectively) were the most abundant parabens. Although thermal desorption methods have been widely used for determining volatile organic compounds, they are rarely used with semi-volatile compounds. This study thus demonstrates that the thermal desorption method performs well with semi-volatile compounds and, for the first time, that it can be used for determining PCPs.

  1. Determination of Natural 14C Abundances in Dissolved Organic Carbon in Organic-Rich Marine Sediment Porewaters by Thermal Sulfate Reduction

    NASA Astrophysics Data System (ADS)

    Johnson, L.; Komada, T.

    2010-12-01

    The abundances of natural 14C in dissolved organic carbon (DOC) in the marine environment hold clues regarding the processes that influence the biogeochemical cycling of this large carbon reservoir. At present, UV irradiation is the widely accepted method for oxidizing seawater DOC for determination of their 14C abundances. This technique yields precise and accurate values with low blanks, but it requires a dedicated vacuum line, and hence can be difficult to implement. As an alternative technique that can be conducted on a standard preparatory vacuum line, we modified and tested a thermal sulfate reduction method that was previously developed to determine δ13C values of marine DOC (Fry B. et al., 1996. Analysis of marine DOC using a dry combustion method. Mar. Chem., 54: 191-201.) to determine the 14C abundances of DOC in marine sediment porewaters. In this method, the sample is dried in a 100 ml round-bottom Pyrex flask in the presence of excess oxidant (K2SO4) and acid (H3PO4), and combusted at 550 deg.C. The combustion products are cryogenically processed to collect and quantify CO2 using standard procedures. Materials we have oxidized to date range from 6-24 ml in volume, and 95-1500 μgC in size. The oxidation efficiency of this method was tested by processing known amounts of reagent-grade dextrose and sucrose (as examples of labile organic matter), tannic acid and humic acid (as examples of complex natural organic matter), and porewater DOC extracted from organic-rich nearshore sediments. The carbon yields for all of these materials averaged 99±4% (n=18). The 14C abundances of standard materials IAEA C-6 and IAEA C-5 processed by this method using >1mgC aliquots were within error of certified values. The size and the isotopic value of the blank were determined by a standard dilution technique using IAEA C-6 and IAEA C-5 that ranged in size from 150 to 1500 μgC (n=4 and 2, respectively). This yielded a blank size of 6.7±0.7 μgC, and a blank isotopic

  2. Apparatus for determining past-service conditions and remaining life of thermal barrier coatings and components having such coatings

    DOEpatents

    Srivastava, Alok Mani; Setlur, Anant Achyut; Comanzo, Holly Ann; Devitt, John William; Ruud, James Anthony; Brewer, Luke Nathaniel

    2004-05-04

    An apparatus for determining past-service conditions and/or remaining useful life of a component of a combustion engine and/or a thermal barrier coating ("TBC") of the component comprises a radiation source that provides the exciting radiation to the TBC to excite a photoluminescent ("PL") material contained therein, a radiation detector for detecting radiation emitted by the PL material, and means for relating a characteristic of an emission spectrum of the PL material to the amount of a crystalline phase in the TBC, thereby inferring the past-service conditions or the remaining useful life of the component or the TBC.

  3. Thermal desorption-gas chromatography for the determination of benzene, aniline, nitrobenzene and chlorobenzene in workplace air.

    PubMed

    Patil, S F; Lonkar, S T

    1992-05-29

    Sampling on Tenax TA of different mesh sizes followed by thermal desorption and gas chromatography was evaluated as a simple method for the determination of benzene, aniline, nitrobenzene and chlorobenzene in the workplace air. An alternative sampling technique in place of pump sampling was developed. Quantitative recoveries were obtained in the mass range 0.04-10 micrograms. It was found that air humidity had no effect on recovery. The charged tubes can be stored at room temperature for 5 days with no change in recovery. The particle size of Tenax TA has no significant effect on adsorption and desorption.

  4. Thermal decomposition of HO2NO2 (peroxynitric acid, PNA): rate coefficient and determination of the enthalpy of formation.

    PubMed

    Gierczak, Tomasz; Jiménez, Elena; Riffault, Veronique; Burkholder, James B; Ravishankara, A R

    2005-02-03

    Rate coefficients for the gas-phase thermal decomposition of HO(2)NO(2) (peroxynitric acid, PNA) are reported at temperatures between 331 and 350 K at total pressures of 25 and 50 Torr of N(2). Rate coefficients were determined by measuring the steady-state OH concentration in a mixture of known concentrations of HO(2)NO(2) and NO. The measured thermal decomposition rate coefficients k(-)(1)(T,P) are used in combination with previously published rate coefficient data for the HO(2)NO(2) formation reaction to yield a standard enthalpy for reaction 1 of Delta(r)H degrees (298K) = -24.0 +/- 0.5 kcal mol(-1) (uncertainties are 2sigma values and include estimated systematic errors). A HO(2)NO(2) standard heat of formation, Delta(f)H degrees (298K)(HO(2)NO(2)), of -12.6 +/- 1.0 kcal mol(-1) was calculated from this value. Some of the previously reported data on the thermal decomposition of HO(2)NO(2) have been reanalyzed and shown to be in good agreement with our reported value.

  5. Determination of thermal process schedule for emulsion type buffalo meat block in retort pouch.

    PubMed

    Devadason, I Prince; Anjaneyulu, A S R; Mendirtta, S K; Murthy, T R K

    2014-11-01

    The process temperature for buffalo met blocks processed in retort pouches calculated based on the heat resistance of Clostridium sporogenes PA 3679 in Phosphate buffer saline (PBS- Ph 7.0) as reference medium and in buffalo meat block (pH 6.28) was in the range of 110-121°C. The D values and Z values calculated for C.sporogenes PA 3679 confirmed that the suspension was best suited for conducting thermal resistance studies. The experiment for indirect confirmation of microbial safety of the products involving inoculating the buffalo meat emulsion filled in pouches with C.sporogenes PA 3679 and processed at Fo 12.13 min showed no growth of microorganisms.

  6. Experimental determination of thermal profiles during laser spike annealing with quantitative comparison to 3-dimensional simulations

    SciTech Connect

    Iyengar, Krishna; Jung, Byungki; Willemann, Michael; Thompson, Michael O.; Clancy, Paulette

    2012-05-21

    Thin film platinum resistors were used to directly measure temperature profiles during laser spike annealing (LSA) with high spatial and temporal resolution. Observed resistance changes were calibrated to absolute temperatures using the melting points of the substrate silicon and thin gold films. Both the time-dependent temperature experienced by the sample during passage of the focussed laser beam and profiles across the spatially dependent laser intensity were obtained with sub-millisecond time resolution and 50 {mu}m spatial resolution. Full 3-dimensional simulations incorporating both optical and thermal variations of material parameters were compared with these results. Accounting properly for the specific material parameters, good agreement between experiments and simulations was achieved. Future temperature measurements in complex environments will permit critical evaluation of LSA simulations methodologies.

  7. Determination of Acreage Thermal Protection Foam Loss From Ice and Foam Impacts

    NASA Technical Reports Server (NTRS)

    Carney, Kelly S.; Lawrence, Charles

    2015-01-01

    A parametric study was conducted to establish Thermal Protection System (TPS) loss from foam and ice impact conditions similar to what might occur on the Space Launch System. This study was based upon the large amount of testing and analysis that was conducted with both ice and foam debris impacts on TPS acreage foam for the Space Shuttle Project External Tank. Test verified material models and modeling techniques that resulted from Space Shuttle related testing were utilized for this parametric study. Parameters varied include projectile mass, impact velocity and impact angle (5 degree and 10 degree impacts). The amount of TPS acreage foam loss as a result of the various impact conditions is presented.

  8. Determination of thermoelastic material properties by differential heterodyne detection of impulsive stimulated thermal scattering

    PubMed Central

    Verstraeten, B.; Sermeus, J.; Salenbien, R.; Fivez, J.; Shkerdin, G.; Glorieux, C.

    2015-01-01

    The underlying working principle of detecting impulsive stimulated scattering signals in a differential configuration of heterodyne diffraction detection is unraveled by involving optical scattering theory. The feasibility of the method for the thermoelastic characterization of coating-substrate systems is demonstrated on the basis of simulated data containing typical levels of noise. Besides the classical analysis of the photoacoustic part of the signals, which involves fitting surface acoustic wave dispersion curves, the photothermal part of the signals is analyzed by introducing thermal wave dispersion curves to represent and interpret their grating wavelength dependence. The intrinsic possibilities and limitations of both inverse problems are quantified by making use of least and most squares analysis. PMID:26236643

  9. Automated determinations of selenium in thermal power plant wastewater by sequential hydride generation and chemiluminescence detection.

    PubMed

    Ezoe, Kentaro; Ohyama, Seiichi; Hashem, Md Abul; Ohira, Shin-Ichi; Toda, Kei

    2016-02-01

    After the Fukushima disaster, power generation from nuclear power plants in Japan was completely stopped and old coal-based power plants were re-commissioned to compensate for the decrease in power generation capacity. Although coal is a relatively inexpensive fuel for power generation, it contains high levels (mgkg(-1)) of selenium, which could contaminate the wastewater from thermal power plants. In this work, an automated selenium monitoring system was developed based on sequential hydride generation and chemiluminescence detection. This method could be applied to control of wastewater contamination. In this method, selenium is vaporized as H2Se, which reacts with ozone to produce chemiluminescence. However, interference from arsenic is of concern because the ozone-induced chemiluminescence intensity of H2Se is much lower than that of AsH3. This problem was successfully addressed by vaporizing arsenic and selenium individually in a sequential procedure using a syringe pump equipped with an eight-port selection valve and hot and cold reactors. Oxidative decomposition of organoselenium compounds and pre-reduction of the selenium were performed in the hot reactor, and vapor generation of arsenic and selenium were performed separately in the cold reactor. Sample transfers between the reactors were carried out by a pneumatic air operation by switching with three-way solenoid valves. The detection limit for selenium was 0.008 mg L(-1) and calibration curve was linear up to 1.0 mg L(-1), which provided suitable performance for controlling selenium in wastewater to around the allowable limit (0.1 mg L(-1)). This system consumes few chemicals and is stable for more than a month without any maintenance. Wastewater samples from thermal power plants were collected, and data obtained by the proposed method were compared with those from batchwise water treatment followed by hydride generation-atomic fluorescence spectrometry.

  10. Sonic boom acceptability studies

    NASA Technical Reports Server (NTRS)

    Shepherd, Kevin P.; Sullivan, Brenda M.; Leatherwood, Jack D.; Mccurdy, David A.

    1992-01-01

    The determination of the magnitude of sonic boom exposure which would be acceptable to the general population requires, as a starting point, a method to assess and compare individual sonic booms. There is no consensus within the scientific and regulatory communities regarding an appropriate sonic boom assessment metric. Loudness, being a fundamental and well-understood attribute of human hearing was chosen as a means of comparing sonic booms of differing shapes and amplitudes. The figure illustrates the basic steps which yield a calculated value of loudness. Based upon the aircraft configuration and its operating conditions, the sonic boom pressure signature which reaches the ground is calculated. This pressure-time history is transformed to the frequency domain and converted into a one-third octave band spectrum. The essence of the loudness method is to account for the frequency response and integration characteristics of the auditory system. The result of the calculation procedure is a numerical description (perceived level, dB) which represents the loudness of the sonic boom waveform.

  11. Determination of auroral heat fluxes and thermal ion outflows using a numerical ionospheric model and incoherent-scatter radar data

    SciTech Connect

    Min, Q.L.; Watkins, B.J.

    1995-01-01

    A comprehensive one-dimensional model of the polar ionosphere has been used in conjunction with incoherent-scatter radar data from Sondrestrom, Greenland, to determine downward heat fluxes and thermal ion outflows at very high latitudes. For periods of very quiet geomagnetic activity the model closely simulates the observed time-dependent behavior of the electron density, ion and electron temperatures. To obtain this similarity between model and data, the upper boundary conditions of the model, namely downward heat flux, and magnetic field-aligned ion flows, are continually adjusted with time to provide a best fit with data. The heat fluxes and ion flows are determined indirectly from this fitting procedure. The technique has been applied to a 10-hour daytime data set for February 12, 1990, to search for enhanced downward heat fluxes and outward thermal ion fluxes associated with dayside auroral oval. Variations of heat flux ranged from about 2 x 10{sup 9} to 2 x 10{sup 10} eVcm{sup {minus}2}s{sup {minus}1}, and vertical outward fluxes of ionization ranged from about zero to 8 x 10{sup 8} cm{sup {minus}2}s{sup {minus}1}. For both quantities the peak values occurred when the radar site was located under the dayside auroral oval. It is suggested that these marked upward thermal ion flows in the dayside auroral ionosphere may be associated with energetic O{sup +} ion outflows that have been observed at high altitudes with spacecraft. 12 refs., 6 figs.

  12. Gas temperature determination in an argon non-thermal plasma at atmospheric pressure from broadenings of atomic emission lines

    NASA Astrophysics Data System (ADS)

    Yubero, C.; Rodero, A.; Dimitrijevic, M. S.; Gamero, A.; García, M. C.

    2017-03-01

    In this work a new spectroscopic method, allowing gas temperature determination in argon non-thermal plasmas sustained at atmospheric pressure, is presented. The method is based on the measurements of selected pairs of argon atomic lines (Ar I 603.2 nm/Ar I 549.6 nm, Ar I 603.2 nm/Ar I 522.1 nm, Ar I 549.6 nm/Ar I 522.1 nm). For gas temperature determination using the proposed method, there is no need of knowing the electron density, neither making assumptions on the degree of thermodynamic equilibrium existing in the plasma. The values of the temperatures obtained using this method, have been compared with the rotational temperatures derived from the OH ro-vibrational bands, using both, the well-known Boltzmann-plot technique and the best fitting to simulated ro-vibrational bands. A very good agreement has been found.

  13. Prediction of the determinants of thermal stability by linear discriminant analysis: the case of the glutamate dehydrogenase protein family.

    PubMed

    Pavesi, Angelo

    2014-09-21

    Little is known about the determinants of thermal stability in individual protein families. Most of the knowledge on thermostability comes, in fact, from comparative analyses between large, and heterogeneous, sets of thermo- and mesophilic proteins. Here, we present a multivariate statistical approach aimed to detect signature sequences for thermostability in a single protein family. It was applied to the glutamate dehydrogenase (GDH) family, which is a good model for investigating this peculiar process. The structure of GDH consists of six subunits, each of them organized into two domains. Formation of ion-pair networks on the surface of the protein subunits, or increase in the inter-subunit hydrophobic interactions, have been suggested as important factors for explaining stability at high temperatures. However, identification of the amino acid changes that are involved in this process still remains elusive. Our approach consisted of a linear discriminant analysis on a set of GDH sequences from Archaea and Bacteria (33 thermo- and 36 mesophilic GDHs). It led to detection of 3 amino acid clusters as the putative determinants of thermal stability. They were localized at the subunit interface or in close proximity to the binding site of the NAD(P)(+) coenzyme. Analysis within the clusters led to prediction of 8 critical amino acid sites. This approach could have a wide utility, in the ligth of the notion that each protein family seems to adopt its own strategy for achieving thermostability.

  14. Phase transitions in PbZr(x)Hf(1-x)O3 determined by thermal analysis and impedance spectroscopy.

    PubMed

    de la Rubia, Miguel Angel; Alonso, Roberto Emilio; López-Garcia, Alberto R; de Frutos, Jose

    2009-09-01

    The objective of this study is to determine the influence of partial substitutions of Zr by Hf in the perovskitetype crystalline structure of PbZrO(3). Different samples over the whole composition range (0 < or = x < or = 1) in the PbZr(x)Hf(1-x)O(3) family have been prepared. Phase transitions have been determined by thermal analysis (DSC) and complex impedance (IS) spectroscopy over a wide temperature range. As a consequence of the cation replacement, the changes that take place in the different phase transitions temperatures are reported. By both techniques, thermal analysis and electrical characterization, it is shown that for all compositions prepared there are 2 phase transitions in a temperature range between 160 and 230 degrees C. With these results and the previously known crystalline structure of pure PbZrO(3) and PbHfO(3) perovskites, the phase diagram of the PbZr(x)Hf(1-x) O(3) family is presented for the first time.

  15. Determination of airborne isocyanates generated during the thermal degradation of car paint in body repair shops.

    PubMed

    Boutin, Michel; Dufresne, André; Ostiguy, Claude; Lesage, Jacques

    2006-06-01

    Polyurethanes are widely used in car paint formulations. During thermal degradation, such polymeric systems can generate powerful asthmatic sensitizing agents named isocyanates. In body repair shops, the thermal degradation of car paint can occur during abrasive processes that generate enough heat to involve release of isocyanates in air. An environmental monitoring study was performed in two body repair training schools and in a body repair shop to evaluate the workers' exposure to isocyanates during cutting, grinding and orbital sanding operations. For sampling, cassettes containing two 1-(2-methoxyphenyl)piperazine (MOPIP)-coated glass fiber filters (MFs) ( approximately 5 mg of MOPIP per filter) and bubblers containing 15 ml of MOPIP solution in toluene (1.0 mg ml(-1)) backed at the outlet with cassettes containing two MFs were used. Tandem mass spectrometry was used to analyze the MOPIP derivatives of isocyanic acid (HNCO), all the linear aliphatic isocyanates ranging from methyl isocyanate (Me-i) to hexyl isocyanate, all the alkenyl isocyanates ranging from propylene isocyanate to hexylene isocyanate, 1,6-hexamethylene diisocyanate (HDI), trans- and cis-isophorone diisocyanate (IPDI), 2,4- and 2,6-toluene diisocyanate (TDI), 2,4'-; 2,2'- and 4,4'-methylenediphenyl diisocyanate (MDI), phenyl isocyanate (Ph-i) and p-toluene isocyanate (p-Tol-i). The instrumental detection limits (LOD) were in the 0.13-0.75 microg of NCO per m(3) range for 15 l air samples converted into 3 ml liquid samples. The isocyanate concentrations detected in the workers' breathing zone were in the 1.07-9.80 microg of NCO per m(3) range for cutting, 0.63-3.62 microg of NCO per m(3) range for grinding and 0-1.29 microg of NCO per m(3) range for sanding. However, a rapid decrease of the isocyanate concentration was observed while moving away from the emission source. Among the isocyanates detected the most abundant were the monomers (MDI, HDI, TDI and IPDI) and Me-i.

  16. A simplified UV spectrometric method for determination of peroxide value in thermally oxidized canola oil.

    PubMed

    Talpur, M Younis; Sherazi, S T H; Mahesar, S A; Bhutto, Aijaz A

    2010-03-15

    The aim of present study was to develop a simple method on UV spectrometer for the determination of peroxide value (PV) of the frying oil. The basis of the PV determination was the stoichiometric reaction of triphenylphosphine (TPP) with the hydroperoxides present in frying oil to produce triphenylphosphine oxide (TPPO), which exhibits a readily measurable absorption band at 240 nm by ultraviolet region. The PV ranged between 0.15 and 11.66 meq. of active oxygen per kilogram of oil as the canola oil was heated from 0 to 12h in the fryer at 180 degrees C. The proposed method was correlated with official AOCS titration method and best correlation coefficient (R(2)=0.99525) was achieved, proving that there is no significant difference in the results. Therefore, developed method could serve as an alternative to the titration method, for the determination of PV in frying oils.

  17. Thermally determining flow and/or heat load distribution in parallel paths

    SciTech Connect

    Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

    2016-12-13

    A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

  18. Determination of refraction nonlinear index, for effect thermal, of solutions with nanoparticles of gold

    NASA Astrophysics Data System (ADS)

    Olivares-Vargas, A.; Trejo-Durán, M.; Alvarado-Méndez, E.; Cornejo-Monroy, D.; Mata-Chávez, R. I.; Estudillo-Ayala, J. M.; Castaño-Meneses, V.

    2013-09-01

    Research of nonlinear optical properties of materials for manufacturing opto-electronic devices, had a great growth in the last years. The solutions with nanoparticle metals present nonlinear optical properties. In this work we present the results of characterizing, analyzing and determining the magnitude and sign of the nonlinear refractive index, using the z-scan technique in solutions with nanoparticles of gold, lipoic acid and sodium chloride. We used a continuous Argon laser at 514 nm with variable power, an 18 cms lens, and a chopper. We determined the nonlinear refractive index in the order of 10-9. These materials have potential applications mainly as optical limiters.

  19. Thermally insensitive determination of the linewidth broadening factor in nanostructured semiconductor lasers using optical injection locking

    PubMed Central

    Wang, Cheng; Schires, Kevin; Osiński, Marek; Poole, Philip J.; Grillot, Frédéric

    2016-01-01

    In semiconductor lasers, current injection not only provides the optical gain, but also induces variation of the refractive index, as governed by the Kramers-Krönig relation. The linear coupling between the changes of the effective refractive index and the modal gain is described by the linewidth broadening factor, which is responsible for many static and dynamic features of semiconductor lasers. Intensive efforts have been made to characterize this factor in the past three decades. In this paper, we propose a simple, flexible technique for measuring the linewidth broadening factor of semiconductor lasers. It relies on the stable optical injection locking of semiconductor lasers, and the linewidth broadening factor is extracted from the residual side-modes, which are supported by the amplified spontaneous emission. This new technique has great advantages of insensitivity to thermal effects, the bias current, and the choice of injection-locked mode. In addition, it does not require the explicit knowledge of optical injection conditions, including the injection strength and the frequency detuning. The standard deviation of the measurements is less than 15%. PMID:27302301

  20. Thermally insensitive determination of the linewidth broadening factor in nanostructured semiconductor lasers using optical injection locking.

    PubMed

    Wang, Cheng; Schires, Kevin; Osiński, Marek; Poole, Philip J; Grillot, Frédéric

    2016-06-15

    In semiconductor lasers, current injection not only provides the optical gain, but also induces variation of the refractive index, as governed by the Kramers-Krönig relation. The linear coupling between the changes of the effective refractive index and the modal gain is described by the linewidth broadening factor, which is responsible for many static and dynamic features of semiconductor lasers. Intensive efforts have been made to characterize this factor in the past three decades. In this paper, we propose a simple, flexible technique for measuring the linewidth broadening factor of semiconductor lasers. It relies on the stable optical injection locking of semiconductor lasers, and the linewidth broadening factor is extracted from the residual side-modes, which are supported by the amplified spontaneous emission. This new technique has great advantages of insensitivity to thermal effects, the bias current, and the choice of injection-locked mode. In addition, it does not require the explicit knowledge of optical injection conditions, including the injection strength and the frequency detuning. The standard deviation of the measurements is less than 15%.

  1. A Simple Temperature Gradient Apparatus To Determine Thermal Preference in "Daphnia."

    ERIC Educational Resources Information Center

    Fenske, Christiane; McCauley, Robert

    2002-01-01

    Explores the dominant factor controlling the distribution of Daphnia. Describes components of a temperature gradient apparatus that can be assembled from materials readily obtainable in the laboratory and hardware stores. Investigates whether the mean depth of Daphnia is determined by temperature. (KHR)

  2. Physical characteristics of a lava flow determined from thermal measurements at the lava's surface

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, A. T.; Kovtunov, D. A.; Korotkii, A. I.; Melnik, O. E.; Tsepelev, I. A.

    2016-04-01

    We consider the problem about determination of characteristics of a lava flow from the physical parameters measured on its surface. The problem is formulated as an inverse boundary problem for the model simulating the dynamics of a viscous heat-conducting incompressible inhomogeneous fluid, where, on the basis of additional data at one part of the model boundary, the missing conditions at another part of the boundary have to be determined, and then the characteristics of fluid in the entire model domain have to be reconstructed. The considered problem is ill-posed. We develop a numerical approach to the solution of the problem in the case of a steady-state flow. Assuming that the temperature and the heat flow are known at the upper surface of the lava, we determine the flow characteristics inside the lava. We compute model examples and show that the lava temperature and flow velocity can be determined with a high precision when the initial data are smooth or slightly noisy.

  3. Determinants of thermal balance in the Hawaiian giant rosette plant, Argyroxiphium sandwicense.

    PubMed

    Melcher, P J; Goldstein, G; Meinzer, F C; Minyard, B; Giambelluca, T W; Loope, L L

    1994-08-01

    The effects of leaf pubescence and rosette geometry on thermal balance were studied in a subspecies of a Hawaiian giant rosette plant, Argyroxiphium sandwicense. This species, a member of the silversword alliance, grows above 2000 m elevation in the alpine zone of two Hawaiian volcanoes. Its highly pubescent leaves are very reflective (absorptance in the 400-700 nm waveband=0.44). Temperature of the expanded leaves was very similar to, or even lower than, air temperature during clear days, which was somewhat surprising given that solar radiation at the high elevation sites where this species grows can exceed 1100 W m(-2). However, the temperature of the apical bud, which is located in the center of the parabolic rosette, was usually 25°C higher than air temperature at midday. Experimental manipulations in the field indicated that incoming solar radiation being focussed towards the center of the rosette resulted in higher temperatures of the apical bud. Attenuation of wind speed inside the rosette, which increased the thickness of the boundary layer surrounding the apical bud, also contributed to higher temperatures. The heating effect on the apical bud of the large parabolic rosette, which apparently enhances the rates of physiological processes in the developing leaves, may exclude the species from lower elevations by producing lethal tissue temperatures. Model simulations of apical bud temperatures at different elevations and laboratory estimates of the temperature threshold for permanent heat injury predicted that the lower altitude limit should be approximately 1900 m, which is reasonably close to the lower limit of distribution of A. sandwicense on Haleakala volcano.

  4. Could behaviour and not physiological thermal tolerance determine winter survival of aphids in cereal fields?

    PubMed

    Alford, Lucy; Andrade, Thiago Oliveira; Georges, Romain; Burel, Françoise; van Baaren, Joan

    2014-01-01

    Traits of physiological thermotolerance are commonly measured in the laboratory as predictors of the field success of ectotherms at unfavourable temperatures (e.g. during harsh winters, heatwaves, or under conditions of predicted global warming). Due to being more complicated to measure, behavioural thermoregulation is less commonly studied, although both physiology and behaviour interact to explain the survival of ectotherms. The aphids Metopolophium dirhodum, Rhopalosiphum padi and Sitobion avenae are commercially important pests of temperate cereal crops. Although coexisting, these species markedly differ in winter success, with R. padi being the most abundant species during cold winters, followed by S. avenae and lastly M. dirhodum. To better understand the thermal physiology and behavioural factors contributing to differential winter success, the lethal temperature (physiological thermotolerance) and the behaviour of aphids in a declining temperature regime (behavioural thermotolerance) of these three species were investigated. Physiological thermotolerance significantly differed between the three species, with R. padi consistently the least cold tolerant and S. avenae the most cold tolerant. However, although the least cold tolerant of the study species, significantly more R. padi remained attached to the host plant at extreme sub-zero temperatures than S. avenae and M. dirhodum. Given the success of anholocyclic R. padi in harsh winters compared to its anholocyclic counterparts, this study illustrates that behavioural differences could be more important than physiological thermotolerance in explaining resistance to extreme temperatures. Furthermore it highlights that there is a danger to studying physiological thermotolerance in isolation when ascertaining risks of ectotherm invasions, the establishment potential of exotic species in glasshouses, or predicting species impacts under climate change scenarios.

  5. Newbery Medal Acceptance.

    ERIC Educational Resources Information Center

    Freedman, Russell

    1988-01-01

    Presents the Newbery Medal acceptance speech of Russell Freedman, writer of children's nonfiction. Discusses the place of nonfiction in the world of children's literature, the evolution of children's biographies, and the author's work on "Lincoln." (ARH)

  6. A radiative thermal analysis method for phase-change determination of strictly controlled refractory alloys

    SciTech Connect

    Antoni-Zdziobek, A.; Durand, F.; Pina, V.; Herve, P.

    1997-04-01

    Radiative measurements using an InSb detector ({lambda} = 5.15 {micro}m) coupled to a photomultiplier ({lambda} = 0.36 {micro}m) were performed during melting and subsequent cooling on samples (pure Fe, Ni, Ti, and Ti-Al alloys and Nb-Ti-Al alloys) in an inductive cold crucible. The UV signal can be used to estimate the temperature, whereas the IR signal is subjected to a significant change related to the phase transformation. It is demonstrated that the transformation temperatures measured by this technique are closer to the thermodynamic values than those determined by the two-color pyrometer.

  7. Evolution of elastic and thermal properties during TMOS-gel formation determined by ringing bottle acoustic resonance spectroscopy, impulsive stimulated scattering, photopyroelectric spectroscopy and the hot ball method

    NASA Astrophysics Data System (ADS)

    Xu, Xiaodong; Agustin Flores Cuautle, Jose Jesus; Kouyate, Mansour; Bernardus Roozen, Nicolaas; Goossens, Jozefien; Menon, Preethy; Kuriakose Malayil, Maju; Salenbien, Robbe; Nair Rajesh, Ravindran; Glorieux, Christ; Griesmar, Pascal; Martinez, Loïc; Serfaty, Stéphane

    2016-03-01

    The evolution of the elastic and thermal properties of a tetramethylorthosilicate (TMOS)-based gel that exhibits an extraordinary ringing effect when enclosed in a bottle is investigated during the sol-gel transition. The results demonstrate the feasibility of three proposed experimental methods for monitoring of gels during their formation. The shear stiffening evolution during gelation is monitored by ringing bottle, resonant acoustic spectroscopy and by an ultrasonic technique using piezo electric excitation and detection. The evolution of the longitudinal modulus and the thermal diffusivity of the gel during stiffening are simultaneously determined by a combined photoacoustic and photothermal method based on heterodyne diffraction detection of impulsive stimulated scattering by, respectively, a propagating acoustic wave grating and a decaying thermal expansion grating that were both thermo elastically generated using a pulsed laser. Also, the feasibility of an inverse photopyroelectric method and a hot ball technique to monitor the thermal transport efficiency and thermal impedance of a forming gel by tracking the thermal conductivity, the thermal diffusivity, and the thermal effusivity is demonstrated. The network polymerization and stiffening during the sol-gel transition in TMOS-gel corresponds with substantial changes in the shear acoustic velocity and in all thermal properties, while the longitudinal acoustic velocity is only weakly affected.

  8. Cd in planktonic and benthic foraminiferal shells determined by thermal ionization mass spectrometry

    SciTech Connect

    Rickaby, R.E.M.; Greaves, M.J.; Elderfield, H.

    2000-04-01

    A highly sensitive method for Cd determination in foraminiferal shells by isotope-dilution TIMS has been developed and applied to (1) a more detailed reconstruction of seawater Cd depth profiles for the North Atlantic in the Holocene and at the Last Glacial Maximum (LGM); (2) the analysis of Cd/Ca in individual benthic foraminifera shells; and (3) determination of Cd/Ca in Holocene and glacial planktonic foraminifera. Although Ca has a high first ionization potential, through chemical separation of Cd from the Ca and optimization of the loading technique, it is possible to analyze routine sized samples (10 benthics) with a reproducibility in Cd/Ca of {+-}0.0025 {micro}mol/mol between replicate picks from a single sample. The blank of the method is 1.1 pg, permitting analysis of individual benthics and of planktonic foraminifera. The seawater Cd reconstruction for the LGM is consistent with previous work, but also suggests that depths >2,500 m were ventilated by a northern source of nutrient depleted deep water on the western side of the Mid Atlantic Ridge. Individual benthic Cd/Ca ratios show interspecimen variability which is averaged in routine analysis of multiple specimens. Planktonic Cd/Ca from N. Atlantic cores shows interspecific differences between Globigerina bulloides and Neogloboquadrina pachyderma and Holocene-LGM contrasts which offers potential for use of planktonic Cd/Ca as a palaeochemical tracer.

  9. Anisotropic Mechanical Properties of Plasma-Sprayed Thermal Barrier Coatings at High Temperature Determined by Ultrasonic Method

    NASA Astrophysics Data System (ADS)

    Wei, Qin; Zhu, Jianguo; Chen, Wei

    2016-02-01

    The mechanical properties of plasma-sprayed thermal barrier coatings (TBC) are of great scientific and technological significance for the design and fabrication of TBC systems. The ultrasonic method combined with a sing-around method for mechanical properties measurement of TBC is deduced and the elastic modulus can be determined in the spray, or longitudinal, direction, and the transverse direction. Tested specimens of plasma-sprayed TBC are detached from the substrate and treated with thermal exposure at 1400 °C. The elastic moduli along the longitudinal and transverse directions of the TBCs are measured by different types of ultrasonic waves combined with a sing-around method, while the Poisson's ratio is also obtained simultaneously. The experimental results indicate that the magnitude of longitudinal elastic modulus is larger than that of the transverse one, and thus the plasma-sprayed TBC has an anisotropic mechanical property. Moreover, the elastic moduli along both longitudinal and transverse directions change with high-temperature exposure time, which consists of a rapid increasing stage followed by a slow decreasing stage. In addition, the magnitude of Poisson's ratio increases slightly from 0.05 to 0.2 with the high-temperature exposure time. Generally, the microstructures in the plasma-sprayed coatings and their evolution in a high-temperature environment are the main causes of the varying anisotropic mechanical properties.

  10. Preparation, Structure Determination and Thermal Transformation of a New Lithium Zinc Phosphate, δ 1-LiZnPO 4

    NASA Astrophysics Data System (ADS)

    Jensen, Torben R.; Norby, Poul; Stein, Paul C.; Bell, Anthony M. T.

    1995-06-01

    A new lithium zinc orthophosphate, δI-LiZnPO4, was synthesized from aqueous solution. Information from powder diffraction, using synchrotron radiation, and 31P MAS NMR spectroscopy allowed determination of the structure. The structure is orthorhombic (a = 10.0193(1), b = 4.9657(1), c = 6.6746(1) Å space group Pna21 , No. 33, Z = 4. The structure may be seen as built from corner-sharing ZnO4- and PO4- tetrahedra forming a cristobalite-type framework structure. The lithium ions are 4-coordinated and situated in the 6-ring channels. The thermal transformations were investigated by thermogravimetric measurements (TG), differential thermal analysis (DTA), and high-temperature powder diffraction (HT-PXD). A transformation at ∼575°C is clearly visible on the Guinier Simon film (HT-PXD). This transformation is characterized by some disappearing lines in the powder pattern. The high-temperature polymorph of δI-LiZnPO4 is named δII-LiZnPO4. Phase transformations at ∼730 and δ1003°C are observed by HT-PXD and DTA, respectively. These observations are designated to the transformation to β-LiZnPO4 and from β- to γ-LiZnPO4.

  11. Cloud point extraction and gas chromatography with direct microvial insert thermal desorption for the determination of haloanisoles in alcoholic beverages.

    PubMed

    Cacho, J I; Campillo, N; Viñas, P; Hernández-Córdoba, M

    2016-11-01

    A sensitive analytical procedure for the determination of four haloanisoles (2,4,6 trichloroanisole, 2,4,6-tribromoanisole, 2,3,4,6-tetrachloroanisole and pentachloroanisole) related with cork taint defects in wines, in different types of alcoholic beverages has been developed. The analytes were extracted from the matrix samples by cloud point extraction (CPE) using Triton X-114 heated to 75°C, and the surfactant rich phase was separated by centrifugation. By means of direct microvial insert thermal desorption, 20µL of the CPE obtained extract was submitted to gas chromatography-mass spectrometry (GC-MS) analysis. The parameters affecting the CPE and microvial insert thermal desorption were optimized. Quantification was carried by matrix-matched calibration using an internal standard. Detection limits ranged between 12.9 and 20.8ngL(-1), depending on the compound, for beer and wine samples, whereas for whiskies values in the 46.3-48ngL(-1) range were obtained, since these samples were diluted for analysis. Recoveries for alcoholic beverages were in the 89-111% range, depending on the analyte and the sample.

  12. Determination of the effective thermal diffusivity in a porous bed containing rice grains: effects of moisture content and temperature

    NASA Astrophysics Data System (ADS)

    Dotto, G. L.; Pinto, L. A. A.; Moreira, M. F. P.

    2016-04-01

    The effective thermal diffusivity ( α ef ) of a porous bed containing rice grains was determined under different experimental conditions. The α ef values were estimated by the Log method. The effects of rice moisture content (2, 12 and 22 % w.b.) and temperature (15, 35, 55 and 75 °C) on the α ef values were investigated. Finally, an empirical model was proposed to represent the effective thermal diffusivity as a function of the moisture content ( X) and temperature ( T). The results revealed that the increase in the rice moisture content and temperature caused an increase in α ef values, which ranged from 0.91 × 10-7 to 3.23 × 10-7 m2 s-1. In the studied range, the dependence of α ef with the rice moisture content and temperature can be represented as: α ef (m2s-1) = (0.63 + 5.63 × 10-2 X + 1.51 × 10-2 T + 1.17 × 10-4 XT) × 10-7. The proposed empirical model was suitable to predict the α ef values with mean absolute percentage deviation of 3.8 % and is a tool for future modeling purposes.

  13. Optimum comfort limits determination through the characteristics of asymmetric thermal radiation in a heated floor space, "ondol".

    PubMed

    Yoon, Y J; Park, S D; Sohn, J Y

    1992-09-01

    This study was undertaken to evaluate the effects of the asymmetric radiation on thermal comfort, and to suggest the optimum comfort limits in a radiant heating space. The index of V.R.T. (Vector Radiant Temperature) was used to describe the environmental quality of the heated floor space. Optimum comfort limits of this space were suggested through both theoretical and empirical studies. It is recommended to use not only man's sensation of the ambient air but also that of the floor surface for the determination of the optimum comfort limits on the heated floor space such as an "Ondol" in Korea. In the present study the optimum comfort limits were suggested in terms of the V.R.T. The optimum limits obtained were as follows: the vector radiant temperature 11.0 approximately 15.0 K.

  14. On the significance of including the thermal motion of ions in determining the ion distribution behind a satellite

    NASA Technical Reports Server (NTRS)

    Samir, U.; Widjaja, D.

    1981-01-01

    A comparative investigation concerning the spatial distribution of ions in the wake of small bodies was conducted using the theoretical wake models of Call (1969) and Parker (1976). Results for bodies with radius/ambient Debye length ratios of 2 and 5, with an electron temperature equal to the ambient electron temperature, and for the ionic Mach numbers S = 2, 4, 6, 8 are presented. Since the main physical difference between the models is in the consideration of the thermal motion of ions (Parker) versus ignoring this component (Call), a comparison between the models yields the quantitative significance of this component in determining the distribution of ions in the wake of artificial satellites. The application of this result to future experiments to be conducted on board the Spacelab and for any other large space platform in the area of space plasma physics is mentioned.

  15. Strength Training for Adolescents with cerebral palsy (STAR): study protocol of a randomised controlled trial to determine the feasibility, acceptability and efficacy of resistance training for adolescents with cerebral palsy

    PubMed Central

    Ryan, Jennifer M; Theis, Nicola; Kilbride, Cherry; Baltzopoulos, Vasilios; Waugh, Charlie; Shortland, Adam; Lavelle, Grace; Noorkoiv, Marika; Levin, Wendy; Korff, Thomas

    2016-01-01

    Introduction Gait is inefficient in children with cerebral palsy, particularly as they transition to adolescence. Gait inefficiency may be associated with declines in gross motor function and participation among adolescents with cerebral palsy. Resistance training may improve gait efficiency through a number of biomechanical and neural mechanisms. The aim of the Strength Training for Adolescents with cerebral palsy (STAR) trial is to evaluate the effect of resistance training on gait efficiency, activity and participation in adolescents with cerebral palsy. We also aim to determine the biomechanical and neural adaptations that occur following resistance training and evaluate the feasibility and acceptability of such an intervention for adolescents with cerebral palsy. Methods and analysis 60 adolescents (Gross Motor Function Classification System level I–III) will be randomised to a 10-week resistance training group or a usual care control group according to a computer-generated random schedule. The primary outcome is gait efficiency. Secondary outcomes are habitual physical activity, participation, muscle–tendon mechanics and gross motor function. General linear models will be used to evaluate differences in continuous data between the resistance training and usual care groups at 10 and 22 weeks, respectively. A process evaluation will be conducted alongside the intervention. Fidelity of the resistance training programme to trial protocol will be quantified by observations of exercise sessions. Semistructured interviews will be conducted with participants and physiotherapists following the resistance training programme to determine feasibility and acceptability of the programme. Ethics and dissemination This trial has ethical approval from Brunel University London's Department of Clinical Sciences' Research Ethics Committee and the National Research Ethics Service (NRES) Committee London—Surrey Borders. The results of the trial will be submitted for

  16. Laser-heating thermal modulation voltammetric determination of phosphate ion using a graphite-reinforced carbon electrode.

    PubMed

    Shariar, Shovon Mohammad; Suga, Mizuki; Nishikawa, Yumiko; Hinoue, Teruo

    2009-04-01

    Thermal modulation (TM) voltammetry was successfully applied to the determination of phosphate ion in natural water, by using a He-Cd dual laser as a heating source and a graphite-reinforced carbon (GRC) electrode. A heteropoly ion, i.e., 12-molybdophosphate ion ([PMo(VI)(12)O(40)](3-)), was formed through a reaction between a phosphate ion and molybdate ions in an acidic solution, and its electroreduction was examined in a flow electrolytic cell by TM voltammetry. Measured TM voltammograms showed two peaks corresponding to two successive two-electron reductions of the 12-molybdophosphate ion, and the peak intensities were proportional to the concentration of the phosphate ion. Because of the strong adsorption of 12-molybdophosphate ion onto the GRC electrode, a detection limit as low as 0.8 nmol dm(-3) (S/N = 3) was achieved. The determination of phosphate ion in real samples (river water) was carried out by spectrophotometry (the molybdenum-blue method) and TM voltammetry, and the determination values obtained by both methods were in a good agreement with each other. These results prove the possibility of TM voltammetry as an electroanalytical method.

  17. Determination of microplastic polyethylene (PE) and polypropylene (PP) in environmental samples using thermal analysis (TGA-DSC).

    PubMed

    Majewsky, Marius; Bitter, Hajo; Eiche, Elisabeth; Horn, Harald

    2016-10-15

    Microplastics are increasingly detected in the environment and the consequences on water resources and ecosystems are not clear to date. The present study provides a cost-effective and straightforward method to determine the mass concentrations of polymer types using thermal analysis. Characteristic endothermic phase transition temperatures were determined for seven plastic polymer types using TGA-DSC. Based on that, extracts from wastewater samples were analyzed. Results showed that among the studied polymers, only PE and PP could be clearly identified, while the phase transition signals of the other polymers largely overlap each other. Subsequently, calibration curves were run for PE and PP for qualitative measurements. 240 and 1540mg/m(3) of solid material (12µm to 1mm) was extracted from two wastewater effluent samples of a municipal WWTP of which 34% (81mg/m(3)) and 17% (257mg/m(3)) could be assigned to PE, while PP was not detected in any of the samples. The presented application of TGA-DSC provides a complementary or alternative method to FT-IR analyses for the determination of PE and PP in environmental samples.

  18. Thermal and Physical Property Determinations for Ionsiv IE-911 Crystalline Silicotitanate and Savannah River Site Waste Simulant Solutions

    SciTech Connect

    Bostick, D.T.; Steele, W.V.

    1999-08-01

    This document describes physical and thermophysical property determinations that were made in order to resolve questions associated with the decontamination of Savannah River Site (SRS) waste streams using ion exchange on crystalline silicotitanate (CST). The research will aid in the understanding of potential issues associated with cooling of feed streams within SRS waste treatment processes. Toward this end, the thermophysical properties of engineered CST, manufactured under the trade name, Ionsive{reg_sign} IE-911 by UOP, Mobile, AL, were determined. The heating profiles of CST samples from several manufacturers' production runs were observed using differential scanning calorimetric (DSC) measurements. DSC data were obtained over the region of 10 to 215 C to check for the possibility of a phase transition or any other enthalpic event in that temperature region. Finally, the heat capacity, thermal conductivity, density, viscosity, and salting-out point were determined for SRS waste simulants designated as Average, High NO{sub 3}{sup {minus}} and High OH{sup {minus}} simulants.

  19. Determination of sensible heat flux over sparse canopy using thermal infrared data

    USGS Publications Warehouse

    Kustas, W.P.; Choudhury, B.J.; Moran, M.S.; Reginato, R. J.; Jackson, R. D.; Gay, L.W.; Weaver, H.L.

    1989-01-01

    Surface temperatures, Ts, were estimated for a natural vegetative surface in Owens Valley, California, with infrared thermometric observations collected from an aircraft. The region is quite arid and is composed primarily of bushes (???30%) and bare soil (???70%). Application of the bulk transfer equation for the estimation of sensible heat, H, gave unsatisfactory values when compared to Bowen ratio and eddy correlation methods over a particular site. This was attributed to the inability with existing data to properly evaluate the resistance to heat transfer, rah. To obtain appropriate rah-values the added resistance to heat transfer, kB-1, was allowed to vary although there is both theoretical and experimental evidence that kB-1 for vegetative surfaces can be treated as constant. The present data indicate that for partial canopy cover under arid conditions kB-1 may be a function of Ts measured radiometrically. The equation determining kB-1 was simplified and tested over another arid site with good results; however, this had a limited data set (i.e., 6 data points). The dimensionless kB-1 equation is simplified for use over full canopy cover and is shown to give satisfactory estimates of H over a fully-grown wheat crop. ?? 1989.

  20. Determination of bilirubin by thermal lens spectrometry and studies of its transport into hepatic cells

    NASA Astrophysics Data System (ADS)

    Margon, A.; Terdoslavich, M.; Cocolo, A.; Decorti, G.; Passamonti, S.; Franko, M.

    2005-06-01

    The liver is responsible for clearance of bilirubin, the end product of heme catabolism, from the bloodstream. The main aim of our investigation was to determine the role of the carrier protein bilitranslocase in bilirubin uptake into the liver. Our experiments consisted of exposing cell cultures to bilirubin solutions under different conditions and measuring the uptake of bilirubin into the cells. However, since bilirubin is only slightly soluble in aqueous solution (< 70 nM at pH 7.4), we had to use bilirubin concentrations that are far below the limit of detection of the commonly used techniques (e.g. LOD for HPLC with UV-Vis detection \\cong 10 μM). TLS showed up to be a suitable technique for investigation of bilirubin uptake with an LOD of 2 nM. Under basal conditions, bilirubin uptake did not occur. However, increase of cytosolic NADH due to catabolism of specific substrates (e.g. lactate or ethanol) seemed to trigger bilirubin uptake. Furthermore, bilirubin uptake was completely inhibited by addition of specific anti-bilitranslocase antibodies. We can thus infer that, under these conditions, bilitranslocase is the main bilirubin transporter.

  1. Determinants of bovine thermal response to heat and solar radiation exposures in a field environment

    NASA Astrophysics Data System (ADS)

    Scharf, Brad; Leonard, Michael J.; Weaber, Robert L.; Mader, Terry L.; Hahn, G. Leroy; Spiers, Donald E.

    2011-07-01

    Continuous exposure of cattle to summer heat in the absence of shade results in significant hyperthermia and impairs growth and general health. Reliable predictors of heat strain are needed to identify this condition. A 12-day study was conducted during a moderate summer heat period using 12 Angus x Simmental ( Bos taurus) steers (533 ± 12 kg average body weight) to identify animal and ambient determinations of core body temperature ( T core) and respiration rate (RR) responses to heat stress. Steers were provided standard diet and water ad libitum, and implanted intraperitoneally with telemetric transmitters to monitor T core hourly. Visual count of flank movement at 0800 and 1500 hours was used for RR. Dataloggers recorded air temperature ( T a), and black globe temperatures ( T bg) hourly to assess radiant heat load. Analysis was across four periods and 2 consecutive days averaged within each period. Average T a and T bg increased progressively from 21.7 to 30.3°C and 25.3 to 34.0°C, respectively, from the first to fourth periods. A model utilizing a quadratic function of T a explained the most variation in T core ( R 2 = 0.56). A delay in response from 1 to 3 h did not significantly improve R 2 for this relationship. Measurements at 0800 and 1500 hours alone are sufficient to predict heat strain. Daily minimum core body temperature and initial 2-h rise in T a were predictors of maximum core temperature and RR. Further studies using continuous monitoring are needed to expand prediction of heat stress impact under different conditions.

  2. Thermal Stabilization Blend Plan

    SciTech Connect

    RISENMAY, H.R.

    2000-05-02

    This Blend Plan documents the feed material items that are stored in 2736-2 vaults, the 2736-ZB 638 cage, the 192C vault, and the 225 vault that will be processed through the thermal stabilization furnaces. The purpose of thermal stabilization is to heat the material to 1000 degrees Celsius to drive off all water and leave the plutonium and/or uranium as oxides. The stabilized material will be sampled to determine the Loss On Ignition (LOI) or percent water. The stabilized material must meet water content or LOI of less than 0.5% to be acceptable for storage under DOE-STD-3013-99 specifications. Out of specification material will be recycled through the furnaces until the water or LOI limits are met.

  3. Experimental determination of single-crystal halite thermal conductivity, diffusivity and specific heat from -75°C to 300°C

    SciTech Connect

    Urquhart, Alexander; Bauer, Stephen

    2015-05-19

    The thermal properties of halite have broad practical importance, from design and long-term modeling of nuclear waste repositories to analysis and performance assessment of underground natural gas, petroleum and air storage facilities. Using a computer-controlled transient plane source method, single-crystal halite thermal conductivity, thermal diffusivity and specific heat were measured from -75°C to 300°C. These measurements reproduce historical high-temperature experiments and extend the lower temperature extreme into cryogenic conditions. Measurements were taken in 25-degree increments from -75°C to 300°C. Over this temperature range, thermal conductivity decreases by a factor of 3.7, from 9.975 to 2.699 W/mK , and thermal diffusivity decreases by a factor of 3.6, from 5.032 to 1.396 mm²/s. Specific heat does not appear to be temperature dependent, remaining near 2.0 MJ/m³K at all temperatures. This work is intended to develop and expand the existing dataset of halite thermal properties, which are of particular value in defining the parameters of salt storage thermophysical models. The work was motivated by a need for thermal conductivity values in a mixture theory model used to determine bulk thermal conductivity of reconsolidating crushed salt.

  4. Experimental determination of single-crystal halite thermal conductivity, diffusivity and specific heat from -75°C to 300°C

    DOE PAGES

    Urquhart, Alexander; Bauer, Stephen

    2015-05-19

    The thermal properties of halite have broad practical importance, from design and long-term modeling of nuclear waste repositories to analysis and performance assessment of underground natural gas, petroleum and air storage facilities. Using a computer-controlled transient plane source method, single-crystal halite thermal conductivity, thermal diffusivity and specific heat were measured from -75°C to 300°C. These measurements reproduce historical high-temperature experiments and extend the lower temperature extreme into cryogenic conditions. Measurements were taken in 25-degree increments from -75°C to 300°C. Over this temperature range, thermal conductivity decreases by a factor of 3.7, from 9.975 to 2.699 W/mK , and thermal diffusivitymore » decreases by a factor of 3.6, from 5.032 to 1.396 mm²/s. Specific heat does not appear to be temperature dependent, remaining near 2.0 MJ/m³K at all temperatures. This work is intended to develop and expand the existing dataset of halite thermal properties, which are of particular value in defining the parameters of salt storage thermophysical models. The work was motivated by a need for thermal conductivity values in a mixture theory model used to determine bulk thermal conductivity of reconsolidating crushed salt.« less

  5. Stir bar sorptive extraction for the determination of pyrethroids in water samples A comparison between thermal desorption in a dedicated thermal desorber, in a split/splitless inlet and by liquid desorption.

    PubMed

    Van Hoeck, Els; David, Frank; Sandra, Pat

    2007-07-20

    Stir bar sorptive extraction (SBSE) was applied to the enrichment of pyrethroids in water samples. Analysis was done by retention time-locked GC/MS in selected ion-monitoring (SIM) mode using trans-permethrin-d(6) as internal standard. Thermal desorption (TD) was performed in a classical split/splitless inlet equipped with a flip-top sealing system and in a dedicated thermal desorption unit. These two thermal desorption methods were compared to liquid desorption with ethyl acetate. Sensitivity was the highest for thermal desorption in the dedicated system and the lowest for liquid desorption even at injection volumes of 10 microL. The SBSE-TD-GC/MS method is able to determine pyrethroids at ultra-trace level (<1 ng/L) with RSD% smaller than 15 (n=6).

  6. The Use of the Airborne Thermal/Visible Land Application Sensor (ATLAS) to Determine the Thermal Response Numbers for Urban Areas

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey C.; Rickman, Doug; Quattroch, Dale; Estes. Maury

    2007-01-01

    Although satellite data are very useful for analysis of the urban heat island effect at a coarse scale, they do not lend themselves to developing a better understanding of which surfaces across the city contribute or drive the development of the urban heat island effect. Analysis of thermal energy responses for specific or discrete surfaces typical of the urban landscape (e.g., asphalt, building rooftops, vegetation) requires measurements at a very fine spatial scale (i.e., < 15m) to adequately resolve these surfaces and their attendant thermal energy regimes. Additionally, very fine scale spatial resolution thermal infrared data, such as that obtained from aircraft, are very useful for demonstrating to planning officials, policy makers, and the general populace the benefits of the urban forest. These benefits include mitigating the urban heat island effect, making cities more aesthetically pleasing and more habitable environments, and aid in overall cooling of the community. High spatial resolution thermal data are required to quantify how artificial surfaces within the city contribute to an increase in urban heating and the benefit of cool surfaces (e.g., surface coatings that reflect much of the incoming solar radiation as opposed to absorbing it thereby lowering urban temperatures). The TRN (thermal response number)(Luvall and Holbo 1989) is a technique using aircraft remotely sensed surface temperatures to quantify the thermal response of urban surfaces. The TRN was used to quantify the thermal response of various urban surface types ranging from completely vegetated surfaces to asphalt and concrete parking lots for several cities in the United States.

  7. Determination of volatile N-nitrosamines in irradiated fermented sausage by gas chromatography coupled to a thermal energy analyzer.

    PubMed

    Byun, Myung-Woo; Ahn, Hyun-Joo; Kim, Jae-Hyun; Lee, Ju-Woon; Yook, Hong-Sun; Han, Sang-Bae

    2004-10-29

    Volatile N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) in irradiated pepperoni and salami sausages were determined using a gas chromatography coupled to a thermal energy analyzer (GC-TEA). These fermented sausages with aerobic or vacuum packaging were irradiated at 0, 5, 10, and 20 kGy, and then stored for 4 weeks at 4 degrees C. Both NDMA and NPYR in the fermented sausage were significantly reduced by irradiation. The vacuum packaging showed significantly lower (P < 0.05) N-nitrosamine levels than that of the aerobic ones. After storage, the contents of NDMA and NPYR in the irradiated sausage were lower than those of the non-irradiated control. Results indicated that a high dose of irradiation (>10 kGy) was needed to reduce the carcinogenic N-nitrosamines in the fermented sausage during storage and the GC-TEA analysis was effective in determining the N-nitrosamines in irradiated meats even at low trace levels.

  8. Clothing resultant thermal insulation determined on a movable thermal manikin. Part II: effects of wind and body movement on local insulation

    NASA Astrophysics Data System (ADS)

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Zhang, Chengjiao; Shi, Wen

    2015-10-01

    Part II of this two-part series study was focused on examining the effects of wind and body movement on local clothing thermal insulation. Seventeen clothing ensembles with different layers (i.e., 1, 2, or 3 layers) were selected for this study. Local thermal insulation with different air velocities (0.15, 1.55, and 4.0 m/s) and walking speeds (0, 0.75, and 1.17 m/s) were investigated on a thermal manikin. Empirical equations for estimating local resultant clothing insulation as a function of local insulation, air velocity, and walking speed were developed. The results showed that the effects of wind and body movement on local resultant thermal resistance are complex and differ distinctively among different body parts. In general, the reductions of local insulation with wind at the chest, abdomen, and pelvis were greater than those at the lower leg and back, and the changes at the body extremity such as the forearm, thigh, and lower leg were higher than such immobile body parts as the chest and back. In addition, the wind effect interacted with the walking effect. This study may have important applications in human local thermal comfort modeling and functional clothing design.

  9. Clothing resultant thermal insulation determined on a movable thermal manikin. Part II: effects of wind and body movement on local insulation.

    PubMed

    Lu, Yehu; Wang, Faming; Wan, Xianfu; Song, Guowen; Zhang, Chengjiao; Shi, Wen

    2015-10-01

    Part II of this two-part series study was focused on examining the effects of wind and body movement on local clothing thermal insulation. Seventeen clothing ensembles with different layers (i.e., 1, 2, or 3 layers) were selected for this study. Local thermal insulation with different air velocities (0.15, 1.55, and 4.0 m/s) and walking speeds (0, 0.75, and 1.17 m/s) were investigated on a thermal manikin. Empirical equations for estimating local resultant clothing insulation as a function of local insulation, air velocity, and walking speed were developed. The results showed that the effects of wind and body movement on local resultant thermal resistance are complex and differ distinctively among different body parts. In general, the reductions of local insulation with wind at the chest, abdomen, and pelvis were greater than those at the lower leg and back, and the changes at the body extremity such as the forearm, thigh, and lower leg were higher than such immobile body parts as the chest and back. In addition, the wind effect interacted with the walking effect. This study may have important applications in human local thermal comfort modeling and functional clothing design.

  10. Why was Relativity Accepted?

    NASA Astrophysics Data System (ADS)

    Brush, S. G.

    Historians of science have published many studies of the reception of Einstein's special and general theories of relativity. Based on a review of these studies, and my own research on the role of the light-bending prediction in the reception of general relativity, I discuss the role of three kinds of reasons for accepting relativity (1) empirical predictions and explanations; (2) social-psychological factors; and (3) aesthetic-mathematical factors. According to the historical studies, acceptance was a three-stage process. First, a few leading scientists adopted the special theory for aesthetic-mathematical reasons. In the second stage, their enthusiastic advocacy persuaded other scientists to work on the theory and apply it to problems currently of interest in atomic physics. The special theory was accepted by many German physicists by 1910 and had begun to attract some interest in other countries. In the third stage, the confirmation of Einstein's light-bending prediction attracted much public attention and forced all physicists to take the general theory of relativity seriously. In addition to light-bending, the explanation of the advance of Mercury's perihelion was considered strong evidence by theoretical physicists. The American astronomers who conducted successful tests of general relativity became defenders of the theory. There is little evidence that relativity was `socially constructed' but its initial acceptance was facilitated by the prestige and resources of its advocates.

  11. UGV acceptance testing

    NASA Astrophysics Data System (ADS)

    Kramer, Jeffrey A.; Murphy, Robin R.

    2006-05-01

    With over 100 models of unmanned vehicles now available for military and civilian safety, security or rescue applications, it is important to for agencies to establish acceptance testing. However, there appears to be no general guidelines for what constitutes a reasonable acceptance test. This paper describes i) a preliminary method for acceptance testing by a customer of the mechanical and electrical components of an unmanned ground vehicle system, ii) how it has been applied to a man-packable micro-robot, and iii) discusses the value of testing both to ensure that the customer has a workable system and to improve design. The test method automated the operation of the robot to repeatedly exercise all aspects and combinations of components on the robot for 6 hours. The acceptance testing process uncovered many failures consistent with those shown to occur in the field, showing that testing by the user does predict failures. The process also demonstrated that the testing by the manufacturer can provide important design data that can be used to identify, diagnose, and prevent long-term problems. Also, the structured testing environment showed that sensor systems can be used to predict errors and changes in performance, as well as uncovering unmodeled behavior in subsystems.

  12. Thermal history of type 3 chondrites from the Antarctic meteorite collection determined by Raman spectroscopy of their polyaromatic carbonaceous matter

    NASA Astrophysics Data System (ADS)

    Bonal, Lydie; Quirico, Eric; Flandinet, Laurène; Montagnac, Gilles

    2016-09-01

    This paper is focused on the characterization of the thermal history of 151 CV, CO and unequilibrated ordinary chondrites (UOCs) from the NASA Antarctic meteorite collection, using an approach based on the structure of the included polyaromatic carbonaceous matter determined by Raman spectroscopy. 114 out of these 151 chondrites provided Raman spectra of carbonaceous matter and allowing to assign a petrologic type, which mostly reflects the peak temperature experienced by the rock on the parent body. A thorough review of literature shows however that it is not possible to deduce a peak temperature because accurate calibration is not available. Twenty-three new weakly metamorphosed chondrites have been identified: MIL 07671 (CV3.1); DOM 08006 (CO3.0); DOM 03238, MIL 05024, MIL 05104, MIL 07193 (CO3.1); TIL 82408, LAR 06279 (LL3.05-3.1); EET 90628 (L3.0); GRO 06054, QUE 97008 (L3.05), ALHA 77176, EET 90066, LAR 04380, MET 96515, MIL 05050 (L3.1); ALHA 78133, EET 87735, EET 90909, LEW 87208, PRE 95401 (L3.05-3.1); MCY 05218 (H3.05-3.1) and MET 00506 (H3.1). This study confirms that the width of the D band (FWHMD) and the ratio of the peak intensity of the D and G bands (ID/IG) are the most adapted tracers of the extent of thermal metamorphism in type 3 chondrites. It also unambiguously shows, thanks to the large number of samples, that the width of the G band (FWHMG) does not correlate with the maturity of polyaromatic carbonaceous matter. This parameter is nevertheless very valuable because it shows that Raman spectra of CV chondrites preserve memory of either the metamorphic conditions (possibly oxidation controlled by aqueous alteration) or the nature of the organic precursor. Oxidation memory is our preferred interpretation, however an extensive petrologic characterization of this CV series is required to get firm conclusions. Pre-graphitic carbonaceous matter is reported in seven chondrites and is even the only carbonaceous material detected in the chondrites

  13. Relationship of roughness of building stones on the effective thermal conductivity determined by transient hot-wire method

    NASA Astrophysics Data System (ADS)

    Benoit, Merckx; Jean-Didier, Mertz; Patrick, Dudoignon; David, Giovannacci; Jean-Philippe, Garnier

    2013-04-01

    Alteration of inorganic materials in monuments is mainly related to relative humidity change in the porous network. Characterization of water content is a complex issue, specially in case of non-intrusive measurement. An innovative method is developed to quantify the water content using a direct calculation of the thermal conductivity. In order to validate the non-intrusive application to heritage stone, a control of the influence of the rock-sensor interface is required. The study was carried out on five sedimentary french rocks : three limestones (lithographic, oolithic and micritic), a sandstone of Fontainebleau and the so-called Tuffeau limestone. The textural properties are characterized by optical and electronical microscopy, X-ray diffraction, and mercury intrusion porosimetry. The transient hot-wire method is useful to obtain a quick value of effective conductivity of material. Initially used in liquids and gas, It's now more and more used for solid materials. The calculation of one effective thermal conductivity is formulated by the slope of recorded DT/ln(t) diagrams. In case of continuous and homogeneous media, only one slope can be measured. For heterogeneous solids a typical curve present two slopes : the first one measured in the short time acquisitions (<1s) mainly depends on the contact between the wire and grains and thus micro texture of the material. The second one, measured for longer time acquisitions, characterizes the mean effective thermal conductivity of the material. In the case of surface measurement, the first part of curve is relevant from the texture and roughness of the material. Roughness properties are determined by an interferometer system on different polished surfaces of the materials. For all studied stones, the arithmetic average roughness (Sa) is ranged between 44 µm and 1 µm, respectively for the coarse-grained limestone (Bretigny) and the finest one (Migné). According to the relative error of the apparatus (10%), the

  14. Consumer acceptance of ginseng food products.

    PubMed

    Chung, Hee Sook; Lee, Young-Chul; Rhee, Young Kyung; Lee, Soo-Yeun

    2011-01-01

    Ginseng has been utilized less in food products than in dietary supplements in the United States. Sensory acceptance of ginseng food products by U.S. consumers has not been reported. The objectives of this study were to: (1) determine the sensory acceptance of commercial ginseng food products and (2) assess influence of the addition of sweeteners to ginseng tea and ginseng extract to chocolate on consumer acceptance. Total of 126 consumers participated in 3 sessions for (1) 7 commercial red ginseng food products, (2) 10 ginseng teas varying in levels of sugar or honey, and (3) 10 ginseng milk or dark chocolates varying in levels of ginseng extract. Ginseng candy with vitamin C and ginseng crunchy white chocolate were the most highly accepted, while sliced ginseng root product was the least accepted among the seven commercial products. Sensory acceptance increased in proportion to the content of sugar and honey in ginseng tea, whereas acceptance decreased with increasing content of ginseng extract in milk and dark chocolates. Findings demonstrate that ginseng food product types with which consumers have been already familiar, such as candy and chocolate, will have potential for success in the U.S. market. Chocolate could be suggested as a food matrix into which ginseng can be incorporated, as containing more bioactive compounds than ginseng tea at a similar acceptance level. Future research may include a descriptive analysis with ginseng-based products to identify the key drivers of liking and disliking for successful new product development.

  15. Technology Acceptance in an Academic Context: Faculty Acceptance of Online Education

    ERIC Educational Resources Information Center

    Gibson, Shanan G.; Harris, Michael L.; Colaric, Susan M.

    2008-01-01

    The authors surveyed faculty from a college of business and a college of education regarding their attitudes toward online education. Results of the survey were examined to determine the degree to which the technology acceptance model was able to adequately explain faculty acceptance of online education. Results indicate that perceived usefulness…

  16. Consumer Acceptance of Dry Dog Food Variations

    PubMed Central

    Donfrancesco, Brizio Di; Koppel, Kadri; Swaney-Stueve, Marianne; Chambers, Edgar

    2014-01-01

    Simple Summary The objectives of this study were to compare the acceptance of different dry dog food products by consumers, determine consumer clusters for acceptance, and identify the characteristics of dog food that drive consumer acceptance. Pet owners evaluated dry dog food samples available in the US market. The results indicated that appearance of the sample, especially the color, influenced pet owner’s overall liking more than the aroma of the product. Abstract The objectives of this study were to compare the acceptance of different dry dog food products by consumers, determine consumer clusters for acceptance, and identify the characteristics of dog food that drive consumer acceptance. Eight dry dog food samples available in the US market were evaluated by pet owners. In this study, consumers evaluated overall liking, aroma, and appearance liking of the products. Consumers were also asked to predict their purchase intent, their dog’s liking, and cost of the samples. The results indicated that appearance of the sample, especially the color, influenced pet owner’s overall liking more than the aroma of the product. Overall liking clusters were not related to income, age, gender, or education, indicating that general consumer demographics do not appear to play a main role in individual consumer acceptance of dog food products. PMID:26480043

  17. Management applications for thermal IR imagery of lake processes

    NASA Technical Reports Server (NTRS)

    Whipple, J. M.; Haynes, R. B.

    1971-01-01

    A thermal infrared scanning program was conducted in the Lake Ontario Basin region in an effort to determine: (1) limonologic data that could be collected by remote sensing techniques, and (2) local interest in and routine use of such data in water management programs. Difficulties encountered in the development of an infrared survey program in New York suggest that some of the major obstacles to acceptance of remotely sensed data for routine use are factors of psychology rather than technology. Also, terminology used should suit the measurement technique in order to encourage acceptance of the surface thermal data obtained.

  18. Acceptability of human risk.

    PubMed

    Kasperson, R E

    1983-10-01

    This paper has three objectives: to explore the nature of the problem implicit in the term "risk acceptability," to examine the possible contributions of scientific information to risk standard-setting, and to argue that societal response is best guided by considerations of process rather than formal methods of analysis. Most technological risks are not accepted but are imposed. There is also little reason to expect consensus among individuals on their tolerance of risk. Moreover, debates about risk levels are often at base debates over the adequacy of the institutions which manage the risks. Scientific information can contribute three broad types of analyses to risk-setting deliberations: contextual analysis, equity assessment, and public preference analysis. More effective risk-setting decisions will involve attention to the process used, particularly in regard to the requirements of procedural justice and democratic responsibility.

  19. Acceptability of human risk.

    PubMed Central

    Kasperson, R E

    1983-01-01

    This paper has three objectives: to explore the nature of the problem implicit in the term "risk acceptability," to examine the possible contributions of scientific information to risk standard-setting, and to argue that societal response is best guided by considerations of process rather than formal methods of analysis. Most technological risks are not accepted but are imposed. There is also little reason to expect consensus among individuals on their tolerance of risk. Moreover, debates about risk levels are often at base debates over the adequacy of the institutions which manage the risks. Scientific information can contribute three broad types of analyses to risk-setting deliberations: contextual analysis, equity assessment, and public preference analysis. More effective risk-setting decisions will involve attention to the process used, particularly in regard to the requirements of procedural justice and democratic responsibility. PMID:6418541

  20. Acceptance Test Plan.

    DTIC Science & Technology

    2014-09-26

    7 RD-Ai507 154 CCEPTANCE TEST PLN(U) WESTINGHOUSE DEFENSE ND i/i ELECTRO ICS CENTER BALTIMORE MD DEVELOPMENT AND OPERATIONS DIY D C KRRiJS 28 JUN...Ln ACCEPTANCE TEST PLAN FOR SPECIAL RELIABILITY TESTS FOR BROADBAND MICROWAVE AMPLIFIER PANEL David C. Kraus, Reliability Engineer WESTINGHOUSE ...ORGANIZATION b. OFFICE SYMBOL 7g& NAME OF MONITORING ORGANIZATION tIf appdeg ble) WESTINGHOUSE ELECTRIC CORP. - NAVAL RESEARCH LABORATORY e. AOORES$ (Ci7t

  1. Accuracy of Young's Modulus of Thermal Barrier Coating Layer Determined by Bending Resonance of a Multilayered Specimen

    NASA Astrophysics Data System (ADS)

    Waki, Hiroyuki; Takizawa, Kensuke; Kato, Masahiko; Takahashi, Satoru

    2016-04-01

    The Young's modulus of individual layer in thermal barrier coating (TBC) system is an important mechanical property because it allows determining the parameters of materials mechanics in the TBC system. In this study, we investigated the accuracy of the evaluation method for the Young's modulus of a TBC layer according to the first bending resonance of a multilayered specimen comprising a substrate, bond coating, and TBC. First, we derived a closed-form solution for the Young's modulus of the TBC layer using the equation of motion for the bending vibration of a composite beam. The solution for the three-layered model provided the Young's modulus of the TBC layer according to the measured resonance frequency and the known values for the dimensions, mass, and Young's moduli of all the other layers. Next, we analyzed the sensitivity of these input errors to the evaluated Young's modulus and revealed the important inputs for accurate evaluation. Finally, we experimentally confirmed that the Young's modulus of the TBC layer was obtained accurately by the developed method.

  2. Determination of unsaturation grade and trans isomers generated during thermal oxidation of edible oils and fats by FTIR

    NASA Astrophysics Data System (ADS)

    Moya Moreno, M. C. M.; Mendoza Olivares, D.; Amézquita López, F. J.; Gimeno Adelantado, J. V.; Bosch Reig, F.

    1999-05-01

    The oxidative deterioration of culinary oils and fats during episodes of heating associated with normal usage (80°C-300°C, 20-40 min) was monitored by FTIR spectroscopy. The thermal oxidation of polyunsaturated fatty acids during heating was studied by the determination of unsaturation percentage and trans isomers at various temperatures and heating times. Oils frequently used in food frying such as olive oil, sunflower oil, corn oil and seeds oil (sunflower, safflower and canola seed), and lard were studied. The Absorbance Correction Method is proposed to correct the spectral interference and allows the analytic use of signal which would not be initially valid for quantitative analysis. The results show that there is a decrease in unsaturation and an increase in trans isomers starting at 150°C and becomes more pronounced at temperatures around 250°C. This variation in unsaturation grade and conformation provides evidence of the transformation of essential polyunsaturated fatty acids and subsequent decrease in the oils' nutritional value.

  3. Determination of sulphur in liquids obtained by thermal cracking of waste polymers and commercial fuels with different analytical methods.

    PubMed

    Miskolczi, N; Bartha, L; Antal, F; Dudas, Cs

    2005-06-15

    Low sulphur concentration in hydrocarbon products as fuels or lubricants is an important requirement for the high quality standards of refineries. A non-polarised energy dispersive X-ray fluorescence spectroscopy (EDXRFS) and sample combustion technique (ASTM D6428-99) was compared. A new application of energy dispersive X-ray spectrometry as analytical method for the determination of sulphur in fuels and fuel-like fractions was investigated. Low sulphur containing fuels and hydrocarbon mixtures obtained by thermal cracking of waste polymers were measured and the influence of C/H ratio on accuracy was studied. The concentration of sulphur in samples was measured with calibration graphs of different hydrocarbon matrices (commercial gasoline, diesel oil and white oil were used). Good correlation was observed between the different methods, but the correlation was depending on the characteristics of the matrices. Detection limits of 1.0ppm, 1.1ppm and 0.9ppm were obtained for S in gasoline, diesel oil and white oil, respectively.

  4. Age and Acceptance of Euthanasia.

    ERIC Educational Resources Information Center

    Ward, Russell A.

    1980-01-01

    Study explores relationship between age (and sex and race) and acceptance of euthanasia. Women and non-Whites were less accepting because of religiosity. Among older people less acceptance was attributable to their lesser education and greater religiosity. Results suggest that quality of life in old age affects acceptability of euthanasia. (Author)

  5. Determination of Scattering and Absorption Coefficients for Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Spuckler, Charles M.; Markham, James R.

    2009-01-01

    The temperature dependence of the scattering and absorption coefficients for a set of freestanding plasma-sprayed 8 wt% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) was determined at temperatures up to 1360 C in a wavelength range from 1.2 micrometers up to the 8YSZ absorption edge. The scattering and absorption coefficients were determined by fitting the directional-hemispherical reflectance and transmittance values calculated by a four-flux Kubelka Munk method to the experimentally measured hemispherical-directional reflectance and transmittance values obtained for five 8YSZ thicknesses. The scattering coefficient exhibited a continuous decrease with increasing wavelength and showed no significant temperature dependence. The scattering is primarily attributed to the relatively temperature-insensitive refractive index mismatch between the 8YSZ and its internal voids. The absorption coefficient was very low (less than 1 per centimeter) at wavelengths between 2 micrometers and the absorption edge and showed a definite temperature dependence that consisted of a shift of the absorption edge to shorter wavelengths and an increase in the weak absorption below the absorption edge with increasing temperature. The shift in the absorption edge with temperature is attributed to strongly temperature-dependent multiphonon absorption. While TBC hemispherical transmittance beyond the absorption edge can be predicted by a simple exponential decrease with thickness, below the absorption edge, typical TBC thicknesses are well below the thickness range where a simple exponential decrease in hemispherical transmittance with TBC thickness is expected. [Correction added after online publication August 11, 2009: "edge to a shorter wavelengths" has been updated as edge to shorter wavelengths."

  6. 24 CFR 7.34 - Acceptability.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., Color Religion, Sex, National Origin, Age, Disability or Reprisal Complaints § 7.34 Acceptability. (a...), the Department shall notify the Complainant in writing of its determination, the rationale for that determination and that those claims will not be investigated, and shall place a copy of the notice in...

  7. 12 CFR 412.7 - Conditions for acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... SOURCE FOR TRAVEL EXPENSES § 412.7 Conditions for acceptance. (a) Eximbank may accept payment for employee travel from a non-Federal source when a written authorization to accept payment is issued in advance of the travel following a determination by the employee's supervisor (except in the case of...

  8. In-situ determination of macroscopic thermal neutron absorption cross-section of borehole model materials using the integrated flux method

    NASA Astrophysics Data System (ADS)

    Menn, Scott A.; Hall, Hugh E.

    1995-02-01

    The integrated thermal neutron flux method of determining the macroscopic thermal neutron absorption cross-section of samples consisting of approx. 400 kg of unconsolidated geologic material, saturated with fresh water, to be used in borehole models is reported. One advantage of this method is that bulk cross-section determinations are made relative to a single standard, with fresh (distilled) water being used as the standard in this work. The values of matrix Σ determined for unconsolidated sand, limestone, and dolomite for the particular samples measured fall within the range of previously reported measurements of similar type samples. The method was checked using 50,000 ppm NaCl for which a value of 39.1 ± 0.5 c.u. was determined.

  9. Application of Effective Media Theory for Determination of Thermal Properties of Hollow Bricks as a Function of Moisture Content

    NASA Astrophysics Data System (ADS)

    Pavlík, Zbyšek; Fiala, Lukáš; Vejmelková, Eva; Černý, Robert

    2013-05-01

    The effective thermal conductivity and effective specific heat capacity of hollow brick blocks are investigated as a function of moisture content. While the effective specific heat capacity as a heat storage parameter is calculated using the linear theory of mixtures, the effective thermal conductivity as a heat transport parameter is analyzed using the effective media theory. At first, the effective thermal conductivity of the dry hollow brick block is calculated using a combination of properties of the brick body and air cavities, and verified using experimental data. Then, the effective thermal conductivity of the brick body is analyzed as a function of moisture content both theoretically and experimentally, and appropriate homogenization formulas are identified. Finally, the effective thermal conductivity of the whole hollow bricks is expressed as a function of moisture content from the dry state to water saturation.

  10. Determination of off-flavor compounds, 2-methylisoborneol and geosmin, in salmon fillets using stir bar sorptive extraction–thermal desorption coupled with gas chromatography–mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A sensitive and solvent-less method for the determination of musty and earthy off-flavor compounds, 2-methylisoborneol (MIB) and geosmin (GSM), in salmon tissue was developed using stir bar sorptive extraction -thermal desorption coupled with gas chromatography -mass spectrometry (SBSE -TD -GCMS). M...

  11. POLYCYCLIC AROMATIC HYDROCARBON (PAH) SIZE DISTRIBUTIONS IN AEROSOLS FROM APPLIANCES OF RESIDENTIAL WOOD COMBUSTION AS DETERMINED BY DIRECT THERMAL DESORPTION - GC/MS

    EPA Science Inventory

    The paper describesd a direct thermal desorption (TDS) approach to determine the PAH composition (MW = 202-302 amu) in size-segregated aerosols from residential wood combustion (RWC). Six combustion tests are performed with two highly available wood fuel varieties, Douglas-fir (P...

  12. High acceptance recoil polarimeter

    SciTech Connect

    The HARP Collaboration

    1992-12-05

    In order to detect neutrons and protons in the 50 to 600 MeV energy range and measure their polarization, an efficient, low-noise, self-calibrating device is being designed. This detector, known as the High Acceptance Recoil Polarimeter (HARP), is based on the recoil principle of proton detection from np[r arrow]n[prime]p[prime] or pp[r arrow]p[prime]p[prime] scattering (detected particles are underlined) which intrinsically yields polarization information on the incoming particle. HARP will be commissioned to carry out experiments in 1994.

  13. Baby-Crying Acceptance

    NASA Astrophysics Data System (ADS)

    Martins, Tiago; de Magalhães, Sérgio Tenreiro

    The baby's crying is his most important mean of communication. The crying monitoring performed by devices that have been developed doesn't ensure the complete safety of the child. It is necessary to join, to these technological resources, means of communicating the results to the responsible, which would involve the digital processing of information available from crying. The survey carried out, enabled to understand the level of adoption, in the continental territory of Portugal, of a technology that will be able to do such a digital processing. It was used the TAM as the theoretical referential. The statistical analysis showed that there is a good probability of acceptance of such a system.

  14. Soil water content determination with cosmic-ray neutron sensor: Correcting aboveground hydrogen effects with thermal/fast neutron ratio

    NASA Astrophysics Data System (ADS)

    Tian, Zhengchao; Li, Zizhong; Liu, Gang; Li, Baoguo; Ren, Tusheng

    2016-09-01

    The cosmic-ray neutron sensor (CRNS), which estimates field scale soil water content, bridges the gap between point measurement and remote sensing. The accuracy of CRNS measurements, however, is affected by additional hydrogen pools (e.g., vegetation, snow, and rainfall interception). The objectives of this study are to: (i) evaluate the accuracy of CRNS estimates in a farmland system using depth and horizontal weighted point measurements, (ii) introduce a novel method for estimating the amounts of hydrogen from biomass and snow cover in CRNS data, and (iii) propose a simple approach for correcting the influences of aboveground hydrogen pool (expressed as aboveground water equivalent, AWE) on CRNS measurements. A field experiment was conducted in northeast China to compare soil water content results from CRNS to in-situ data with time domain reflectometry (TDR) and neutron probe (NP) in the 0-40 cm soil layers. The biomass water equivalent (BWE) and snow water equivalent (SWE) were observed to have separate linear relationships with the thermal/fast neutron ratio, and the dynamics of BWE and SWE were estimated correctly in the crop seasons and snow-covered seasons, respectively. A simple approach, which considered the AWE, AWE at calibration, and the effective measurement depth of CRNS, was introduced to correct the errors caused by BWE and SWE. After correction, the correlation coefficients between soil water contents determined by CRNS and TDR were 0.79 and 0.77 during the 2014 and 2015 crop seasons, respectively, and CRNS measurements had RMSEs of 0.028, 0.030, and 0.039 m3 m-3 in the 2014 and 2015 crop seasons and the snow-covered seasons, respectively. The experimental results also indicated that the accuracies of CRNS estimated BWE and SWE were affected by the distributions of aboveground hydrogen pools, which were related to the height of the CRNS device above ground surface.

  15. Combining climatic and geo-hydrological preconditions as a method to determine world potential for aquifer thermal energy storage.

    PubMed

    Bloemendal, Martin; Olsthoorn, Theo; van de Ven, Frans

    2015-12-15

    A heat pump combined with Aquifer Thermal Energy Storage (ATES) is proven technology to economically and sustainably provide space heating and cooling. The two most important preconditions for the applicability of ATES are favorable climatic conditions and the availability of a suitable aquifer. This paper shows how these two preconditions can be combined to identify where in the world ATES potential is present, or will become present as a consequence of climate change. Countries and regions are identified where regulation and stimulation measures may increase application of ATES technologies and thus help reduce CO2-emissions. Two types of data determine ATES suitability, and their combination with a 3rd identifies potential hot-spots in the world: 1) geo-hydrological conditions, 2) current and projected climate classification and 3) urbanization. Our method combines the data into an ATES-suitability score as explained in this paper. On the one hand the results confirm the suitability for ATES where it is already applied and on the other they identify places where the technology is or will become suitable. About 15% of urban population lived in areas with high potential for ATES at the start of the 21st century, but this figure will decrease to about 5% during the 21st century as a consequence of expected climate change. Around 50% of urban population currently lives in areas of medium ATES suitability, a percentage that will remain constant. Demand for ATES is likely to exceed available subsurface space in a significant part of the urban areas.

  16. Determination of formal kinetic constants of thermal decomposition of aqueous hydrogen peroxide solution in a mixture of magnetic powder, based on experimental thermogram, obtained in adiabatic conditions

    NASA Astrophysics Data System (ADS)

    Zaripov, Jamshed; Borisov, Boris; Bondarchuk, Sergey

    2014-08-01

    Process of thermal decomposition of hydrogen peroxide aqueous solution with the addition of magnetic powder in the form of toner for printers and lanthanum manganite were considered. Obtained resulting from an experiment in the Dewar container conducted thermogram analyzed using mass balance equations and heat. Formal kinetic parameters determined, and conclude that the magnetic powder in the mixture does not have catalytic properties. The described technique is recommended as a rapid analysis of the kinetics of the various reactions to substances having predefined thermal and thermodynamic properties.

  17. How the local geometry of the Cu-binding site determines the thermal stability of blue copper proteins.

    PubMed

    Chaboy, Jesús; Díaz-Moreno, Sofía; Díaz-Moreno, I; De la Rosa, Miguel A; Díaz-Quintana, Antonio

    2011-01-28

    Identifying the factors that govern the thermal resistance of cupredoxins is essential for understanding their folding and stability, and for improving our ability to design highly stable enzymes with potential biotechnological applications. Here, we show that the thermal unfolding of plastocyanins from two cyanobacteria--the mesophilic Synechocystis and the thermophilic Phormidium--is closely related to the short-range structure around the copper center. Cu K-edge X-ray absorption spectroscopy shows that the bond length between Cu and the S atom from the cysteine ligand is a key structural factor that correlates with the thermal stability of the cupredoxins in both oxidized and reduced states. These findings were confirmed by an additional study of a site-directed mutant of Phormidium plastocyanin showing a reverse effect of the redox state on the thermal stability of the protein.

  18. The folding state of the lumenal loop determines the thermal stability of light-harvesting chlorophyll a/b protein.

    PubMed

    Mick, Vera; Geister, Sonja; Paulsen, Harald

    2004-11-23

    The major light-harvesting protein of photosystem II (LHCIIb) is the most abundant chlorophyll-binding protein in the thylakoid membrane. It contains three membrane-spanning alpha helices; the first and third one closely interact with each other to form a super helix, and all three helices bind most of the pigment cofactors. The protein loop domains connecting the alpha helices also play an important role in stabilizing the LHCIIb structure. Single amino acid exchanges in either loop were found to be sufficient to significantly destabilize the complex assembled in vitro [Heinemann, B., and Paulsen, H. (1999) Biochemistry 38, 14088-14093. Mick, V., Eggert, K., Heinemann, B., Geister, S., and Paulsen, H (2004) Biochemistry 43, 5467-5473]. This work presents an analysis of such point mutations in the lumenal loop with regard to the extent and nature of their effect on LHCIIb stability to obtain detailed information on the contribution of this loop to stabilizing the complex. Most of the mutant proteins yielded pigment-protein complexes if their reconstitution and/or isolation was performed under mild conditions; however, the yields were significantly different. Several mutations in the vicinity of W97 in the N-proximal section of the loop gave low reconstitution yields even under very mild conditions. This confirms our earlier notion that W97 may be of particular relevance in stabilizing LHCIIb. The same amino acid exchanges accelerated thermal complex dissociation in the absence of lithium dodecyl sulfate (LDS) and raised the accessibility of the lumenal loop to protease; both effects were well correlated with the reduction in reconstitution yields. We conclude that a detachment of the lumenal loop is a possible first step in the dissociation of LHCIIb. Dramatically reduced complex yields in the presence but not in the absence of LDS were observed for some but not all mutants, particularly those near the C-proximal end of the loop. We conclude that complex

  19. Comparison of six algorithms to determine the soil thermal diffusivity at a site in the Loess Plateau of China

    NASA Astrophysics Data System (ADS)

    Gao, Z.; Wang, L.; Horton, R.

    2009-03-01

    Soil thermal diffusivity is a crucial physical parameter that affects soil temperature. Six prevalent algorithms to calculate soil thermal diffusivity are inter-compared by using soil temperature data collected at the depths of 0.05 m and 0.10 m at a bare site in the China Loess Plateau from DOY 201 through DOY 207 in 2005. Five of the six algorithms (i.e., Amplitude, Phase, Arctangent, Logarithm, and Harmonic or HM algorithms) are developed from the traditional one-dimensional heat conduction equation. The other algorithm is based on the one-dimensional heat conduction-convection equation which considers the vertical heterogeneity of thermal diffusivity in soil and couples thermal conduction and convection processes (hereinafter referred to as the Conduction-convection algorithm). To assess these six algorithms, we (1) calculate the soil thermal diffusivities by using each of the algorithms, (2) use the soil thermal diffusivities to predict soil temperature at the 0.10 m depth, and (3) compare the estimated soil temperature against direct measurements. Results show that (1) HM algorithm gives the most reliable estimates among the traditional five algorithms; and (2) generally, the Conduction-convection algorithm provides the second best estimates. Among all of the algorithms, the HM algorithm has the best description of the upper boundary temperature with time, but it only includes conduction heat transfer in the soil. Compared to the HM algorithm, the Conduction-convection algorithm has a less accurate description of the upper boundary temperature, but by accounting for the vertical gradient of soil diffusivity and the water flux density it includes more physics in the soil heat transfer process. The Conduction-convection algorithm has potential application within land surface models, but future effort should be made to combine the HM and Conduction-convection algorithms in order to make use of the advantages of each.

  20. Thermal stress analysis in permanent mold processing determining mold life and utilizing a combined thermomechanical finite element model

    SciTech Connect

    Fackeldey, M.; Guan, J.; Helling, V.; Sahm, P.R.

    1995-12-31

    Permanent mold casting offers various advantages, but its process control requires high technical skill, especially when cast iron is utilized. Thermal stresses resulting from non-uniform cooling and hindering of shrinkage frequently cause cracks, which can lead to a destruction of the permanent mold. In this paper an in-house 3-dimensional finite element model is presented, which allows an easy and comfortable analysis of the origin of thermal and residual stresses. By varying single parameters, i.e. the initial temperature as well as the mold geometry, the process may be evaluated. This leads to an optimization of the process and allows an assessment of the mold life.

  1. Experimental determination of gamma-ray discrimination in pillar-structured thermal neutron detectors under high gamma-ray flux

    SciTech Connect

    Shao, Qinghui; Conway, Adam M.; Voss, Lars F.; Radev, Radoslav P.; Nikolić, Rebecca J.; Dar, Mushtaq A.; Cheung, Chin L.

    2015-08-04

    Silicon pillar structures filled with a neutron converter material (10B) are designed to have high thermal neutron detection efficiency with specific dimensions of 50 μm pillar height, 2 μm pillar diameter and 2 μm spacing between adjacent pillars. In this paper, we have demonstrated such a detector has a high neutron-to-gamma discrimination of 106 with a high thermal neutron detection efficiency of 39% when exposed to a high gamma-ray field of 109 photons/cm2s.

  2. Treatment Acceptability among Mexican American Parents

    ERIC Educational Resources Information Center

    Borrego, Joaquin, Jr.; Ibanez, Elizabeth S.; Spendlove, Stuart J.; Pemberton, Joy R.

    2007-01-01

    There is a void in the literature with regard to Hispanic parents' views about common interventions for children with behavior problems. The purpose of this study was to examine the treatment acceptability of child management techniques in a Mexican American sample. Parents' acculturation was also examined to determine if it would account for…

  3. Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures, Part 1: Method assessment. Final report

    SciTech Connect

    Kauffman, R.

    1993-04-01

    This report presents results of a literature search performed to identify analytical techniques suitable for accelerated screening of chemical and thermal stabilities of different refrigerant/lubricant combinations. Search focused on three areas: Chemical stability data of HFC-134a and other non-chlorine containing refrigerant candidates; chemical stability data of CFC-12, HCFC-22, and other chlorine containing refrigerants; and accelerated thermal analytical techniques. Literature was catalogued and an abstract was written for each journal article or technical report. Several thermal analytical techniques were identified as candidates for development into accelerated screening tests. They are easy to operate, are common to most laboratories, and are expected to produce refrigerant/lubricant stability evaluations which agree with the current stability test ANSI/ASHRAE (American National Standards Institute/American Society of Heating, Refrigerating, and Air-Conditioning Engineers) Standard 97-1989, ``Sealed Glass Tube Method to Test the Chemical Stability of Material for Use Within Refrigerant Systems.`` Initial results of one accelerated thermal analytical candidate, DTA, are presented for CFC-12/mineral oil and HCFC-22/mineral oil combinations. Also described is research which will be performed in Part II to optimize the selected candidate.

  4. Influence of the Duration of Thermal Action on the Errors in Determining the Thermophysical Characteristics of Ceramic Materials by a Laser Pulse Method

    NASA Astrophysics Data System (ADS)

    Kuznetsov, G. V.; Kats, M. D.

    2016-05-01

    An analysis of the errors involved in determining the thermophysical characteristics of a special-purpose ceramic material — zirconium carbide — is made. It is shown that the errors of determining the heat capacity and thermal diffusivity of the indicated material under conditions corresponding to the implementation of the laser pulse method vary nonmonotonically depending on the pulse duration. The possibility of attaining minimum values of methodical errors by appropriately selecting the thickness of a sample and of the time of its heating is shown.

  5. Determination of Thermal Expansion Coefficients and Locating the Temperature-Induced Phase Transition in Methylammonium Lead Perovskites Using X-ray Diffraction.

    PubMed

    Jacobsson, T Jesper; Schwan, L Josef; Ottosson, Mikael; Hagfeldt, Anders; Edvinsson, Tomas

    2015-11-16

    Lead halogen perovskites, and particularly methylammonium lead iodine, CH3NH3PbI3, have recently attracted considerable interest as alternative solar cell materials, and record solar cell efficiencies have now surpassed 20%. Concerns have, however, been raised about the thermal stability of methylammonium lead iodine, and a phase transformation from a tetragonal to a cubic phase has been reported at elevated temperature. Here, this phase transition has been investigated in detail using temperature-dependent X-ray diffraction measurements. The phase transformation is pinpointed to 54 °C, which is well within the normal operating range of a typical solar cell. The cell parameters were extracted as a function of the temperature, from which the thermal expansion coefficient was calculated. The latter was found to be rather high (αv = 1.57 × 10(-4) K(-1)) for both the tetragonal and cubic phases. This is 6 times higher than the thermal expansion coefficient for soda lime glass and CIGS and 11 times larger than that of CdTe. This could potentially be of importance for the mechanical stability of perovskite solar cells in the temperature cycling experienced under normal day-night operation. The experimental knowledge of the thermal expansion coefficients and precise determination of the cell parameters can potentially also be valuable while conducting density functional theory simulations on these systems in order to deliver more accurate band structure calculations.

  6. Acceptance Equipment System Data Acquisition and Processing Utility

    SciTech Connect

    Fakhro, Rowan

    2015-02-01

    My internship at Sandia National Laboratories took place in the Department of Sensors and Embedded Systems, which is tasked with, among many things, the non-destructive testing of thermal batteries. The Acceptance Equipment System (AES) is a flexible rack system designed to electrically test thermal batteries individually for internal defects before they are stored in the battery stock pile. Aside from individual testing, data acquired by the AES is used for many things including trending and catching outliers within the tolerance levels of a particular battery type, allowing for the development of more refined acceptance requirements and testing procedures.

  7. Study Task for Determining the Effects of Boost-Phase Environments on Densified Propellants Thermal Conditions for Expendable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Haberbusch, Mark S.; Meyer, Michael L. (Technical Monitor)

    2002-01-01

    A thermodynamic study has been conducted that investigated the effects of the boost-phase environment on densified propellant thermal conditions for expendable launch vehicles. Two thermodynamic models were developed and utilized to bound the expected thermodynamic conditions inside the cryogenic liquid hydrogen and oxygen propellant tanks of an Atlas IIAS/Centaur launch vehicle during the initial phases of flight. The ideal isentropic compression model was developed to predict minimum pressurant gas requirements. The thermal equilibrium model was developed to predict the maximum pressurant gas requirements. The models were modified to simulate the required flight tank pressure profiles through ramp pressurization, liquid expulsion, and tank venting. The transient parameters investigated were: liquid temperature, liquid level, and pressurant gas consumption. Several mission scenarios were analyzed using the thermodynamic models, and the results indicate that flying an Atlas IIAS launch vehicle with densified propellants is feasible and beneficial but may require some minor changes to the vehicle.

  8. Soil water content and evaporation determined by thermal parameters obtained from ground-based and remote measurements

    NASA Technical Reports Server (NTRS)

    Reginato, R. J.; Idso, S. B.; Jackson, R. D.; Vedder, J. F.; Blanchard, M. B.; Goettelman, R.

    1976-01-01

    Soil water contents from both smooth and rough bare soil were estimated from remotely sensed surface soil and air temperatures. An inverse relationship between two thermal parameters and gravimetric soil water content was found for Avondale loam when its water content was between air-dry and field capacity. These parameters, daily maximum minus minimum surface soil temperature and daily maximum soil minus air temperature, appear to describe the relationship reasonably well. These two parameters also describe relative soil water evaporation (actual/potential). Surface soil temperatures showed good agreement among three measurement techniques: in situ thermocouples, a ground-based infrared radiation thermometer, and the thermal infrared band of an airborne multispectral scanner.

  9. Ground-Atmosphere Interactions at Gale: Determination of the Surface Energy Budget, Thermal Inertia and Water Sorption on the Regolith

    NASA Astrophysics Data System (ADS)

    Martinez, German; Renno, Nilton; Fischer, Erik; Borlina, Caue; Hallet, Bernard; De la Torre Juarez, Manuel; Vasavada, Aswhin; Gomez-Elvira, Javier

    2014-05-01

    The analysis of the Surface Energy Budget (SEB) yields insights into the local climate and the soil-atmosphere interactions, while the analysis of the thermal inertia of the shallow subsurface augments surface observations, providing information about the local geology. The Mars Global Surveyor Thermal Emission Spectrometer and the Mars Odyssey Thermal Emission Imaging System have measured near subsurface thermal inertia from orbit at scales of ~104 m2 to ~10 km2. Here we report analysis of the thermal inertia at a few locations at Gale Crater at scales of 100 m2. The thermal inertia is calculated by solving the heat conduction equation in the soil using hourly measurements by the Rover Environmental Station (REMS) ground temperature sensor as an upper boundary condition. Three Sols representative of different environmental conditions and soil properties, namely, Sol 82 at Rocknest (RCK), Sol 112 at Point Lake (PL) and Sol 139 at Yellowknife Bay (YKB) are analyzed in detail. The largest thermal inertia (I) value is found at YKB, I = 445 J m-2 K-1 s-1/2 or 445 tiu (thermal inertia unit), followed by PL with I= 300 tiu and RCK withI = 280 tiu [1]. These values are consistent with the type of terrain imaged by MastCam and with previous satellite estimates at Gale Crater [2,3]. The SEB is calculated by using all REMS data products as well as dust opacity values derived from MastCam measurements, whereas previously, the SEB has been calculated using numerical models only [4]. At each location and during the daytime, the SEB is dominated by the downwelling shortwave (SW) solar radiation (~450-500 W/m2) and the upwelling longwave (LW) radiation emitted by the surface (~300-400 W/m2). The sum of these two terms accounts for at least 70% of the net surface heating rate between 0900 and 1400 local solar time. At nighttime, the SEB is dominated by the upwelling LW radiation emitted by the surface (~50-100 W/m2) and the downwelling LW radiation from the atmosphere (~50 W/m2

  10. Frequency-dependent hydrodynamic inductance and the determination of the thermal and quantum noise of a superfluid gyroscope

    SciTech Connect

    Chui, Talso; Penanen, Konstantin

    2005-04-01

    We reexamine mass flow in a superfluid gyroscope containing a superfluid Josephson weak link. We introduce a frequency-dependent hydrodynamic inductance to account for an oscillatory flow of the normal fluid component in the sensing loop. With this hydrodynamic inductance, we derive the thermal phase noise, and hence the thermal rotational noise of the gyroscope. We examine the thermodynamic stability of the system based on an analysis of the free energy. We derive a quantum phase noise, which is analogous to the zero-point motion of a simple harmonic oscillator. The configuration of the studied gyroscope is analogous to a conventional superconducting RF SQUID. We show that the gyroscope has very low intrinsic noise (1.9x10{sup -13} rad s{sup -1}/{radical}(Hz)), and it can potentially be applied to study general relativity, Earth science, and to improve global positioning systems (GPS)

  11. Thermal expansion in UO2 determined by high-energy X-ray diffraction

    SciTech Connect

    Guthrie, M.; Benmore, C. J.; Skinner, L. B.; Alderman, O. L. G.; Weber, J. K. R.; Parise, J. B.; Williamson, M.

    2016-06-24

    In this study, we present crystallographic analyses of high-energy X-ray diffraction data on polycrystalline UO2 up to the melting temperature. The Rietveld refinements of our X-ray data are in agreement with previous measurements, but are systematically located around the upper bound of their uncertainty, indicating a slightly steeper trend of thermal expansion compared to established values. This observation is consistent with recent first principles calculations.

  12. The promise of acceptance as an NGO security management approach.

    PubMed

    Fast, Larissa; Freeman, Faith; O'Neill, Michael; Rowley, Elizabeth

    2015-04-01

    This paper explores three questions related to acceptance as a security management approach. Acceptance draws upon relationships with community members, authorities, belligerents and other stakeholders to provide consent for the presence and activities of a non-governmental organisation (NGO), thereby reducing threats from these actors. Little is documented about how NGOs gain and maintain acceptance, how they assess and monitor the presence and degree of acceptance, or how they determine whether acceptance is effective in a particular context. Based on field research conducted in April 2011 in Kenya, South Sudan and Uganda, we address each of these three issues and argue that acceptance must be actively sought as both a programme and a security management strategy. In the paper we delineate elements common to all three contexts as well as missed opportunities, which identify areas that NGOs can and should address as part of an acceptance approach.

  13. To prepare and characterize microcrystalline cellulose granules using water and isopropyl alcohol as granulating agents and determine its end-point by thermal and rheological tools.

    PubMed

    Chaudhari, Smruti P; Dave, Rutesh H

    2015-05-01

    Microcrystalline cellulose (MCC-102) is one of the most commonly used excipient in the pharmaceutical industry. For this research purpose, authors have developed a different technique to determine the end point for MCC-102 using water and isopropyl alcohol 70% (IPA) as granulating agent. Wet and dry granules obtained were characterized for their flow properties using the powder rheometer and thermal analysis. Powder rheometer was used to measure basic flowability energy (BFE), specific energy (SE), percentage compressibility, permeability and aeration. Thermal analysis includes effusivity and differential scanning calorimetry (DSC) measurements. BFE and SE results showed water granules requires high energy as compared to IPA granules. Permeability and compressibility results suggest IPA forms more porous granules and have better compressibility as compared to water granules. Hardness data reveals interesting phenomena in which as the amount of water increases, hardness decreases and vice-versa for IPA. Optimal granules were obtained in the range of 45-55% w/w. DSC data supported the formation of optimal granules. Empirical measurements like angle of repose did not reveal any significant differences between powder flow among various granules. In this paper, with the help of thermal effusivity and powder rheology we were able to differentiate between various powder flows and determine the optimal range for granule formation.

  14. Physiologic correlates to background noise acceptance

    NASA Astrophysics Data System (ADS)

    Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

    2001-05-01

    Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

  15. Acceptance of tinnitus: validation of the tinnitus acceptance questionnaire.

    PubMed

    Weise, Cornelia; Kleinstäuber, Maria; Hesser, Hugo; Westin, Vendela Zetterqvist; Andersson, Gerhard

    2013-01-01

    The concept of acceptance has recently received growing attention within tinnitus research due to the fact that tinnitus acceptance is one of the major targets of psychotherapeutic treatments. Accordingly, acceptance-based treatments will most likely be increasingly offered to tinnitus patients and assessments of acceptance-related behaviours will thus be needed. The current study investigated the factorial structure of the Tinnitus Acceptance Questionnaire (TAQ) and the role of tinnitus acceptance as mediating link between sound perception (i.e. subjective loudness of tinnitus) and tinnitus distress. In total, 424 patients with chronic tinnitus completed the TAQ and validated measures of tinnitus distress, anxiety, and depression online. Confirmatory factor analysis provided support to a good fit of the data to the hypothesised bifactor model (root-mean-square-error of approximation = .065; Comparative Fit Index = .974; Tucker-Lewis Index = .958; standardised root mean square residual = .032). In addition, mediation analysis, using a non-parametric joint coefficient approach, revealed that tinnitus-specific acceptance partially mediated the relation between subjective tinnitus loudness and tinnitus distress (path ab = 5.96; 95% CI: 4.49, 7.69). In a multiple mediator model, tinnitus acceptance had a significantly stronger indirect effect than anxiety. The results confirm the factorial structure of the TAQ and suggest the importance of a general acceptance factor that contributes important unique variance beyond that of the first-order factors activity engagement and tinnitus suppression. Tinnitus acceptance as measured with the TAQ is proposed to be a key construct in tinnitus research and should be further implemented into treatment concepts to reduce tinnitus distress.

  16. Thermal diffusivity of periderm from tomatoes of different maturity stages as determined by the concept of the frequency-domain open photoacoustic cell

    NASA Astrophysics Data System (ADS)

    Velasco, Daniel Soares; Baesso, Mauro Luciano; Medina, Antonio Neto; Bicanic, Dane Danijel; Koehorst, Rob; van der Hooft, Justin Johan Jozias; Bento, Antonio Carlos

    2011-02-01

    The frequency-domain open photoacoustic cell (OPC) approach was used to determine room temperature thermal diffusivity of skins (pericarps) from the raw tomatoes (Lycopersicon esculetum Mill.) characterized by the three different stages of ripeness (from immature-green to a mature-red). Periodically interrupted 532 nm laser radiation was used to heat the dry tomato skins, typically 10 mm in diameter and up to 68 μm thick; the modulating frequency f varied from 8 to 150 Hz. Initially, a combined OPC-model that takes into account both, the thermoelastic bending and the effect of thermal diffusion (TD), has been applied. Preliminary results showed that until at least 40 Hz, the effect of TD dominates; above this value the combined model fits the experimental data only poorly. For this reason a less complex OPC-TD approach was applied to all investigated skins instead, which predicts an exponential decrease for the amplitude of measured photoacoustic signal S with increasing f. For a specimen that is simultaneously opaque and thermally thick, S depends on f as S˜exp(-b f1/2) where b is a fitting parameter. The S versus f plot enables one to deduce the numerical value for b which, on its turn allows for the assessment of skin's thermal diffusivity α. Thermal diffusivities obtained for the immature green, orange, and red skins (periderms) are 9.9×10-8 m2 s-1, 7.2×10-8 m2 s-1, and 4.6×10-8 m2 s-1, respectively; the uncertainty was typically 5% of the measured value.

  17. Determination of metformin in mouse, rat, dog and human plasma samples by laser diode thermal desorption/atmospheric pressure chemical ionization tandem mass spectrometry.

    PubMed

    Swales, John G; Gallagher, Richard; Peter, Raimund M

    2010-11-02

    A simple, rapid and robust high-throughput assay for the quantitative analysis of metformin in plasma from different species using laser diode thermal desorption interfaced with atmospheric chemical pressure ionization tandem mass spectrometry (LDTD-APCI-MSMS) was developed for use in a pharmaceutical discovery environment. In order to minimize sample preparation a generic protein precipitation method was used to extract metformin from the plasma. Laser diode thermal desorption is a relatively new sample introduction method, the optimization of the instrumental parameters are presented. The method was successfully applied to spiked mouse, rat, dog and human plasma samples and was subsequently used to determine the oral pharmacokinetics of metformin after dosing to male rats in order to support drug discovery projects. The deviations for intra-assay accuracy and precision across the four species were less than 30% at all calibration and quality control levels.

  18. Effect of silver nano particles on the fluorescence quantum yield of Rhodamine 6G determined using dual beam thermal lens method.

    PubMed

    Santhi, A; Umadevi, M; Ramakrishnan, V; Radhakrishnan, P; Nampoori, V P N

    2004-04-01

    Nano structured noble metals have very important applications in diverse fields as photovoltaics, catalysis, electronic and magnetic devices, etc. Here, we report the application of dual beam thermal lens technique for the determination of the effect of silver sol on the absolute fluorescence quantum yield (FQY) of the laser dye rhodamine 6G. A 532 nm radiation from a diode pumped solid state laser was used as the excitation source. It has been observed that the presence of silver sol decreases the fluorescence quantum efficiency. This is expected to have a very important consequence in enhancing Raman scattering which is an important spectrochemical tool that provides information on molecular structures. We have also observed that the presence of silver sol can enhance the thermal lens signal which makes the detection of the signal easier at any concentration.

  19. Meteorological determinants of spider ballooning: the roles of thermals vs. the vertical windspeed gradient in becoming airborne.

    PubMed

    Greenstone, M H

    1990-09-01

    Spiders disperse by ballooning, a form of aeronautic behavior which they initiate by launching themselves into thermals. An attempt was made to define meteorological variables related to production and maintenance of thermals and use them as predictors of the number of aeronauts. Ballooning spiders were collected throughout a full growing season at an agricultural site and a native tall grass prairie 25 km distant, and numbers of ballooners were regressed against variables derived from meteorological data taken at locations near each site. The variables were the proportions of cloud cover and of possible sunshine, differences between maximum and minimum daily temperature (DT), wind speed, and a modification of the aeronautic index of Vugts and van Wingerden (1976). Ballooner numbers and meteorological variables used in the regressions were all weekly means. Significant one-step models were derived for both sites, but the addition of a second variable did not significantly increase the proportion of variation explained in either model. The modified aeronautic index explained 23% of the variation in ballooner numbers at the prairie site, while the proportion of possible sunshine explained 82% of the variation at the agricultural site. However the signs of the partial regression coefficients were contrary to expected. This may be due to the masking of short term meteorological and behavioral events by the averaging of meteorological variables and aeronaut numbers over a week. Alternatively it may indicate that the source of updrafts used by aeronauts may not always be thermals, but may sometimes be the vertical gradient in windspeed, a model which is consistent with the contrary signs of the regression coefficients.

  20. Cone penetrometer acceptance test report

    SciTech Connect

    Boechler, G.N.

    1996-09-19

    This Acceptance Test Report (ATR) documents the results of acceptance test procedure WHC-SD-WM-ATR-151. Included in this report is a summary of the tests, the results and issues, the signature and sign- off ATP pages, and a summarized table of the specification vs. ATP section that satisfied the specification.

  1. Space thermal control development

    NASA Technical Reports Server (NTRS)

    Hoover, M. J.; Grodzka, P. G.; Oneill, M. J.

    1971-01-01

    The results of experimental investigations on a number of various phase change materials (PCMs) and PCMs in combination with metals and other materials are reported. The evaluations include the following PCM system performance characteristics: PCM and PCM/filler thermal diffusivities, the effects of long-term thermal cycling, PCM-container compatibility, and catalyst effectiveness and stability. Three PCMs demonstrated performance acceptable enough to be considered for use in prototype aluminum thermal control devices. These three PCMs are lithium nitrate trihydrate with zinc hydroxy nitrate catalyst, acetamide, and myristic acid. Of the fillers tested, aluminum honeycomb filler was found to offer the most increase in system thermal diffusivity.

  2. Determination of the thermal conductivity of opalinus clay via simulations of experiments performed at the Mont Terri underground laboratory

    NASA Astrophysics Data System (ADS)

    Mügler, C.; Filippi, M.; Montarnal, Ph.; Martinez, J.-M.; Wileveau, Y.

    2006-02-01

    Storage in deep geological formations is a potential solution for the management of high-level radioactive wastes. In this context, different types of rocks such as argillite are extensively studied. In the Mont Terri underground laboratory (Switzerland), several experiments have been performed in order to characterize the properties of the opalinus clay. One of these experiments, called HE-C, has consisted in measuring in situ the time evolution of the rock temperature submitted to a heating source. Experimental measurements have shown that the thermal behaviour of the clay was not homogeneous around the borehole where the heater was installed. Furthermore, 3D direct numerical simulations of this experiment performed with the code Cast3M have proved that it was necessary to introduce a new parameter α to model the amount of electric power lost in cables and by air convection inside the metallic tube containing the heater. A numerical simulation-optimization technique has been used to estimate the thermal longitudinal and transverse conductivities ( λ// and λ⊥) of the host rock. It consists in minimizing an objective function that is the sum of the squared differences between measured and calculated temperatures. But this method induced a lot of Cast3M simulations. In order to drastically reduce the CPU time, we used a neural network approximation built from a sample training of 1100 Cast3M simulations. It allowed us to calculate the objective function for 500 000 different values of the triplet ( λ//, λ⊥, α). Finally, we obtained the following values for the thermal conductivities on one side of the borehole, λ// = 1.84 ± 0.04 W m - 1 K - 1 and λ⊥ = 0.55 ± 0.03 W m - 1 K - 1 ; on the other side, λ// = 1.90 ± 0.07 W m - 1 K - 1 and λ⊥ = 1.07 ± 0.09 W m - 1 K - 1 . The estimated thermal conductivities λ⊥ perpendicular to the bedding plane are quite different. It is perhaps caused by the presence of an intensive fractured zone on one side of

  3. Emperical Tests of Acceptance Sampling Plans

    NASA Technical Reports Server (NTRS)

    White, K. Preston, Jr.; Johnson, Kenneth L.

    2012-01-01

    Acceptance sampling is a quality control procedure applied as an alternative to 100% inspection. A random sample of items is drawn from a lot to determine the fraction of items which have a required quality characteristic. Both the number of items to be inspected and the criterion for determining conformance of the lot to the requirement are given by an appropriate sampling plan with specified risks of Type I and Type II sampling errors. In this paper, we present the results of empirical tests of the accuracy of selected sampling plans reported in the literature. These plans are for measureable quality characteristics which are known have either binomial, exponential, normal, gamma, Weibull, inverse Gaussian, or Poisson distributions. In the main, results support the accepted wisdom that variables acceptance plans are superior to attributes (binomial) acceptance plans, in the sense that these provide comparable protection against risks at reduced sampling cost. For the Gaussian and Weibull plans, however, there are ranges of the shape parameters for which the required sample sizes are in fact larger than the corresponding attributes plans, dramatically so for instances of large skew. Tests further confirm that the published inverse-Gaussian (IG) plan is flawed, as reported by White and Johnson (2011).

  4. Experimental and numerical determination of temperature gradients for a single tube alkali metal thermal-to-electric converter cell

    NASA Technical Reports Server (NTRS)

    Wright, S.

    2001-01-01

    This paper presents the results from the experimental and numerical determination of shell temperature gradients for a single tube AMTEC cell evaluated under simulated deep space operating conditions.

  5. Theoretical determination of anisotropic thermal conductivity for crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

    NASA Astrophysics Data System (ADS)

    Kroonblawd, Matthew; Sewell, Thomas

    2013-06-01

    Bond stretching and three-center angle bending potentials have been developed to extend an existing rigid-bond TATB molecular dynamics (MD) force field (FF) for simulations requiring fully flexible molecules. The FF potentials were fit to experimental vibrational spectra and electronic structure predictions of vibrational normal modes and frequencies using a combination of zero Kelvin eigenmode analysis for the isolated molecule and finite-temperature power spectra for the isolated molecule and bulk crystal. Crystal structures computed using the revised FF are in good agreement with results from other computational models and experimental data. A non-equilibrium MD method was used to obtain the room temperature, atmospheric pressure thermal conductivity along three directions in a well-defined, non-orthogonal basis. The thermal conductivity was found to be significantly anisotropic with values of 1.13 +/- 0.07, 1.07 +/- 0.07 and 0.65 +/- 0.03 W m-1 K-1 for directions nominally parallel to the a, b, and c crystal directions, respectively. The U.S. Air Force Office of Scientific Research supported this research.

  6. Short loop length and high thermal stability determine genomic instability induced by G-quadruplex-forming minisatellites

    PubMed Central

    Piazza, Aurèle; Adrian, Michael; Samazan, Frédéric; Heddi, Brahim; Hamon, Florian; Serero, Alexandre; Lopes, Judith; Teulade-Fichou, Marie-Paule; Phan, Anh Tuân; Nicolas, Alain

    2015-01-01

    G-quadruplexes (G4) are polymorphic four-stranded structures formed by certain G-rich nucleic acids, with various biological roles. However, structural features dictating their formation and/or functionin vivo are unknown. InS. cerevisiae, the pathological persistency of G4 within the CEB1 minisatellite induces its rearrangement during leading-strand replication. We now show that several other G4-forming sequences remain stable. Extensive mutagenesis of the CEB25 minisatellite motif reveals that only variants with very short (≤ 4 nt) G4 loops preferentially containing pyrimidine bases trigger genomic instability. Parallel biophysical analyses demonstrate that shortening loop length does not change the monomorphic G4 structure of CEB25 variants but drastically increases its thermal stability, in correlation with thein vivo instability. Finally, bioinformatics analyses reveal that the threat for genomic stability posed by G4 bearing short pyrimidine loops is conserved inC. elegans and humans. This work provides a framework explanation for the heterogeneous instability behavior of G4-forming sequencesin vivo, highlights the importance of structure thermal stability, and questions the prevailing assumption that G4 structures with short or longer loops are as likely to formin vivo. PMID:25956747

  7. Thermal-stress modeling of an optical microphone at high temperature.

    SciTech Connect

    Barnard, Casey Anderson

    2010-08-01

    To help determine the capability range of a MEMS optical microphone design in harsh conditions computer simulations were carried out. Thermal stress modeling was performed up to temperatures of 1000 C. Particular concern was over stress and strain profiles due to the coefficient of thermal expansion mismatch between the polysilicon device and alumina packaging. Preliminary results with simplified models indicate acceptable levels of deformation within the device.

  8. Consumer Acceptance of a Polyphenolic Coffee Beverage.

    PubMed

    Nguyen, Thuy; Kuchera, Meredith; Smoot, Katie; Diako, Charles; Vixie, Beata; Ross, Carolyn F

    2016-10-05

    The objective of this study was to determine if Chardonnay grape seed pomace (GSP), a waste stream of wine production, could be used as a functional ingredient in brewed coffee. Two consumer panels were conducted to assess the acceptance of coffee at coffee replacement (w/w) values of 0% (control), 6.25%, 12.50%, 18.75%, or 25% GSP. The 1st consumer panel (n = 80) assessed the coffee samples served "black." The 2nd panel (n = 67) assessed the coffee samples with adjustment (that is, sweeteners, milk, and cream) options available. Consumer sensory evaluation involved evaluating the 5 treatments individually for acceptance of appearance, aroma, taste/flavor, and overall acceptance using a 9-point hedonic scale. A check-all-that-apply questionnaire surveyed the sensory attributes describing aroma, appearance, and taste/flavor of the samples. Oxygen radical absorbance capacity was used to measure the effects of antioxidant levels in GSP coffee samples. Results showed that GSP could be added at 6.25% replacement without significantly affecting the overall consumer acceptance of coffee compared to the control (0% GSP). Above 6.25% GSP supplementation, the coffee beverage was described as more tan, milky, watery/dilute, and mild, and was generally less accepted by the consumers. GSP also increased the antioxidant capacity of the coffee compared to the control (0% GSP), with no significant differences among replacement values. Therefore, 6.25% GSP replacement is recommended for creating coffee beverages acceptable to consumers. Further in vivo investigation may substantiate the free-radical scavenging capacity of GSP coffee and its potential health benefits.

  9. Validation of a solvent-free sampler for the determination of low molecular weight aliphatic isocyanates under thermal degradation conditions.

    PubMed

    Boutin, M; Lesage, J; Ostiguy, C; Pauluhn, J

    2005-09-01

    During the thermal degradation of 1,6-hexamethylenediiso- cyanate-based (HDI) car paint, the eight most abundant isocyanates generated are isocyanic acid, methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, and 1,6-hexamethylenediisocyanate. For the first time, a method using solvent-free samplers is proposed and validated for the simultaneous sampling of all these isocyanates. The sampling efficiency during thermal degradation of car paint can be affected by the formation of dust and aerosols and by the emission of many chemicals, such as isocyanic acid, anhydrides, amines, and alcohols that consume the reagent or interfere in the derivatization procedure. Sampling was performed using cassettes containing two 1-(2-methoxyphenyl)piperazine (MOPIP)-coated glass fiber filters (MFs) (approximately 4.9 mg per filter) and compared with bubblers containing 15 mL of MOPIP solution in toluene (1.0 mg/mL(-1)) and with bubblers backed with MFs. A DIN 53436 laboratory scale furnace was used to generate the isocyanates under thermal degradation conditions. For an aliphatic isocyanate concentration of approximately 42 microg(NCO) m(-3), no significant difference in sampling efficiency was observed between the three techniques studied, thus confirming the sampling efficiency of the MFs. The samples were analyzed using high-performance liquid chromatography coupled with electrospray/tandem mass spectrometry. Quantification was performed in daughter mode monitoring (MOPIP+H)(+) fragments. For concentrations between 0.013 microg(NCO) mL(-1) and 0.52 microg(NCO) mL(-1) for the monoisocyanates, and between 0.026 microg(NCO) mL(-1) and 1.04 microg(NCO) mL(-1) for the HDI, the correlation coefficients were in the 0.9974-0.9996 range (n = 18). Analytical reproducibility and precision were better than 95.4% and 94.9%, respectively, for all the isocyanates. The instrumental detection limits, defined as three times the standard

  10. 40 CFR 240.200 - Solid wastes accepted.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Solid wastes accepted. 240.200 Section 240.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.200...

  11. 40 CFR 240.200 - Solid wastes accepted.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Solid wastes accepted. 240.200 Section 240.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.200...

  12. 40 CFR 240.200 - Solid wastes accepted.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Solid wastes accepted. 240.200 Section 240.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.200...

  13. 40 CFR 240.200 - Solid wastes accepted.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Solid wastes accepted. 240.200 Section 240.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.200...

  14. Payload test philosophy. [JPL views on qualification/acceptance testing

    NASA Technical Reports Server (NTRS)

    Gindorf, T.

    1979-01-01

    The general philosophy of how JPL views payload qualification/acceptance testing for programs that are done either in-house or by contractors is described. Particular attention is given to mission risk classifications, preliminary critical design reviews, environmental design requirements, the thermal and dynamics development tests, and the flight spacecraft system test.

  15. 42 CFR 411.379 - When CMS accepts a request.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false When CMS accepts a request. 411.379 Section 411.379... Physicians and Entities Furnishing Designated Health Services § 411.379 When CMS accepts a request. (a) Upon receiving a request for an advisory opinion, CMS promptly makes an initial determination of whether...

  16. 42 CFR 411.379 - When CMS accepts a request.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false When CMS accepts a request. 411.379 Section 411.379... Physicians and Entities Furnishing Designated Health Services § 411.379 When CMS accepts a request. (a) Upon receiving a request for an advisory opinion, CMS promptly makes an initial determination of whether...

  17. 42 CFR 411.379 - When CMS accepts a request.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false When CMS accepts a request. 411.379 Section 411.379... Physicians and Entities Furnishing Designated Health Services § 411.379 When CMS accepts a request. (a) Upon receiving a request for an advisory opinion, CMS promptly makes an initial determination of whether...

  18. 42 CFR 411.379 - When CMS accepts a request.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false When CMS accepts a request. 411.379 Section 411.379... Physicians and Entities Furnishing Designated Health Services § 411.379 When CMS accepts a request. (a) Upon receiving a request for an advisory opinion, CMS promptly makes an initial determination of whether...

  19. 42 CFR 411.379 - When CMS accepts a request.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false When CMS accepts a request. 411.379 Section 411.379... Physicians and Entities Furnishing Designated Health Services § 411.379 When CMS accepts a request. (a) Upon receiving a request for an advisory opinion, CMS promptly makes an initial determination of whether...

  20. Overcoming Denial through the Group: A Test of Acceptance Theory.

    ERIC Educational Resources Information Center

    Rugel, Robert P.; Barry, Denise

    1990-01-01

    Found participants (N=28) in alcohol treatment groups showed decreases in denial of drinking problems and decreases in psychopathology following 12 weeks of group counseling. Determined greater self-acceptance was associated with experiencing acceptance by group and with greater decreases in denial; decreases in denial and psychopathology were…

  1. Assessing the Acceptance of a Blended Learning University Course

    ERIC Educational Resources Information Center

    Tselios, Nikolaos; Daskalakis, Stelios; Papadopoulou, Maria

    2011-01-01

    Usefulness and ease of use proved to be key determinants of the acceptance and usage of e-learning. On the contrary, little is known about students' perceptions in a blended learning setting. In this paper, the Technology Acceptance Model (TAM) was utilised, in order to investigate Greek university students' attitudes toward blended learning. The…

  2. Extending the Technology Acceptance Model: Policy Acceptance Model (PAM)

    NASA Astrophysics Data System (ADS)

    Pierce, Tamra

    There has been extensive research on how new ideas and technologies are accepted in society. This has resulted in the creation of many models that are used to discover and assess the contributing factors. The Technology Acceptance Model (TAM) is one that is a widely accepted model. This model examines people's acceptance of new technologies based on variables that directly correlate to how the end user views the product. This paper introduces the Policy Acceptance Model (PAM), an expansion of TAM, which is designed for the analysis and evaluation of acceptance of new policy implementation. PAM includes the traditional constructs of TAM and adds the variables of age, ethnicity, and family. The model is demonstrated using a survey of people's attitude toward the upcoming healthcare reform in the United States (US) from 72 survey respondents. The aim is that the theory behind this model can be used as a framework that will be applicable to studies looking at the introduction of any new or modified policies.

  3. Determination of Cd and Zn by isotope dilution-thermal ionisation mass spectrometry using a sequential analysis procedure.

    PubMed

    Ayoub, Ahmed S; McGaw, Brian A; Midwood, Andrew J

    2002-05-16

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) was used to examine the certified Cd and Zn content of 4 Certified Reference Materials (CRMs); 2 soils: GBW07401 and GBW07405, 1 plant CRM060 and an animal tissue SRM1566a. The CRMs were chosen to be of contrasting origin and Cd:Zn content. Three digestion procedures were compared: (i) an open tube aqua regia procedure (ii) microwave digestion using Teflon bombs and (iii) hydrofluoric acid (HF) digestion using PTFE bombs. The Cd and Zn levels obtained using ID-TIMS all fell within the published certified range for the CRMs. This was the case regardless of the digestion procedure used, although HF digestion tended to yield marginally higher levels than the other procedures and in one instance, Cd in GBW07401, was significantly different (P<0.05) from the certified range. A filament loading procedure was developed, to allow sequential analysis of Cd and Zn on the same single filament during thermal ionisation mass spectrometry analysis. The sequential analysis technique was evaluated to ensure that Zn did not fractionate during Cd analysis and there was no inter-element interference. No marked difference in the precision and accuracy of the isotope ratio measurements were obtained from sequential element analyses on the same filament when compared to individual element analyses for a range of standard solutions or for sample digests. The most efficient procedure in terms of costs and productivity for future work of this kind would be a combination of microwave digestion and sequential analysis of Cd and Zn on the same filament.

  4. A simple method for determining the coagulation threshold temperature of transparent tissue-mimicking thermal therapy gel phantoms: Validated by magnetic resonance imaging thermometry

    PubMed Central

    Brodin, N. Patrik; Partanen, Ari; Asp, Patrik; Branch, Craig A.; Guha, Chandan; Tomé, Wolfgang A.

    2016-01-01

    Purpose: Tissue-mimicking thermal therapy phantoms that coagulate at specific temperatures are valuable tools for developing and evaluating treatment strategies related to thermal therapy. Here, the authors propose a simple and efficient method for determining the coagulation threshold temperature of transparent thermal therapy gel phantoms. Methods: The authors used a previously published gel phantom recipe with 2% (w/v) of bovine serum albumin as the temperature-sensitive protein. Using the programmable heating settings of a polymerase chain reaction (PCR) machine, the authors heated 50 μl gel samples to various temperatures for 3 min and then imaged them using the BioRad Gel Doc system to determine the coagulation temperature using an opacity quantification method. The estimated coagulation temperatures were then validated for gel phantoms prepared with different pH levels using high-intensity focused ultrasound (HIFU) heating and magnetic resonance imaging (MRI) thermometry methods on a clinical MR-HIFU system. Results: The PCR heating method produced consistent and reproducible coagulation of gel samples in precise correlation with the set incubation temperatures. The resulting coagulation threshold temperatures for gel phantoms of varying pH levels were found to be 44.1 ± 0.1, 53.4 ± 0.9, and 60.3 ± 0.9 °C for pH levels of 4.25, 4.50, and 4.75, respectively. This corresponded well with the coagulation threshold temperatures determined by MR-thermometry, with coagulation defined as a 95% decrease in T2 relaxation time, which were estimated at 53.6 ± 1.9 and 62.9 ± 2.4 °C for a pH of 4.50 and 4.75, respectively. Conclusions: The opacity quantification method provides a fast and reproducible estimate of the coagulation threshold temperature of transparent temperature-sensitive gel phantoms. The temperatures determined using this method were well within the range of temperatures estimated using MR-thermometry. Due to the specific heating capabilities

  5. Thermal and physical property determination for IONSIV/256 IE-911 crystalline silicotitanate and Savannah River Site waste simulant solutions

    SciTech Connect

    1999-12-08

    This document describes physical and thermophysical property determinations that were made in order to resolve questions associated with the decontamination of Savannah River Site waste streams using ion exchange on crystalline silicotitanate.

  6. Thermal Remote Anemometer Device

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Heath, D. Michele; Winfree, William P.; Miller, William E.; Welch, Christopher S.

    1988-01-01

    Thermal Remote Anemometer Device developed for remote, noncontacting, passive measurement of thermal properties of sample. Model heated locally by scanning laser beam and cooled by wind in tunnel. Thermal image of model analyzed to deduce pattern of airflow around model. For materials applications, system used for evaluation of thin films and determination of thermal diffusivity and adhesive-layer contact. For medical applications, measures perfusion through skin to characterize blood flow and used to determine viabilities of grafts and to characterize tissues.

  7. Market Acceptance of Smart Growth

    EPA Pesticide Factsheets

    This report finds that smart growth developments enjoy market acceptance because of stability in prices over time. Housing resales in smart growth developments often have greater appreciation than their conventional suburban counterparts.

  8. L-286 Acceptance Test Record

    SciTech Connect

    HARMON, B.C.

    2000-01-14

    This document provides a detailed account of how the acceptance testing was conducted for Project L-286, ''200E Area Sanitary Water Plant Effluent Stream Reduction''. The testing of the L-286 instrumentation system was conducted under the direct supervision

  9. Determination of clothing evaporative resistance on a sweating thermal manikin in an isothermal condition: heat loss method or mass loss method?

    PubMed

    Wang, Faming; Gao, Chuansi; Kuklane, Kalev; Holmér, Ingvar

    2011-08-01

    This paper addresses selection between two calculation options, i.e heat loss option and mass loss option, for thermal manikin measurements on clothing evaporative resistance conducted in an isothermal condition (T(manikin) = T(a) = T(r)). Five vocational clothing ensembles with a thermal insulation range of 1.05-2.58 clo were selected and measured on a sweating thermal manikin 'Tore'. The reasons why the isothermal heat loss method generates a higher evaporative resistance than that of the mass loss method were thoroughly investigated. In addition, an indirect approach was applied to determine the amount of evaporative heat energy taken from the environment. It was found that clothing evaporative resistance values by the heat loss option were 11.2-37.1% greater than those based on the mass loss option. The percentage of evaporative heat loss taken from the environment (H(e,env)) for all test scenarios ranged from 10.9 to 23.8%. The real evaporative cooling efficiency ranged from 0.762 to 0.891, respectively. Furthermore, it is evident that the evaporative heat loss difference introduced by those two options was equal to the heat energy taken from the environment. In order to eliminate the combined effects of dry heat transfer, condensation, and heat pipe on clothing evaporative resistance, it is suggested that manikin measurements on the determination of clothing evaporative resistance should be performed in an isothermal condition. Moreover, the mass loss method should be applied to calculate clothing evaporative resistance. The isothermal heat loss method would appear to overestimate heat stress and thus should be corrected before use.

  10. Dynamic thermal environment and thermal comfort.

    PubMed

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research.

  11. Acceptance of sugar reduction in flavored yogurt.

    PubMed

    Chollet, M; Gille, D; Schmid, A; Walther, B; Piccinali, P

    2013-09-01

    To investigate what level of sugar reduction is accepted in flavored yogurt, we conducted a hedonic test focusing on the degree of liking of the products and on optimal sweetness and aroma levels. For both flavorings (strawberry and coffee), consumers preferred yogurt containing 10% added sugar. However, yogurt containing 7% added sugar was also acceptable. On the just-about-right scale, yogurt containing 10% sugar was more often described as too sweet compared with yogurt containing 7% sugar. On the other hand, the sweetness and aroma intensity for yogurt containing 5% sugar was judged as too low. A second test was conducted to determine the effect of flavoring concentration on the acceptance of yogurt containing 7% sugar. Yogurts containing the highest concentrations of flavoring (11% strawberry, 0.75% coffee) were less appreciated. Additionally, the largest percentage of consumers perceived these yogurts as "not sweet enough." These results indicate that consumers would accept flavored yogurts with 7% added sugar instead of 10%, but 5% sugar would be too low. Additionally, an increase in flavor concentration is undesirable for yogurt containing 7% added sugar.

  12. Development of a method for the determination of naphthalene and phenanthrene in workplace air using diffusive sampling and thermal desorption GC-MS analysis.

    PubMed

    Lindahl, Roger; Claesson, Anna-Sara; Khan, Muhammad Akhtar; Levin, Jan-Olof

    2011-07-01

    Diffusive sampling methods have been validated for the determination of naphthalene and phenanthrene in workplace air. The diffusive sampler tested was the Perkin Elmer ATD tube, and the analysis was performed with thermal desorption, gas chromatography, and mass spectrometric detection. The sampling methods were validated in controlled test atmospheres, mainly according to the protocol proposed in the European standard EN 838. For the determination of naphthalene, the diffusive sampling rate was 0.41 ml min(-1) with a coefficient of variation (CV) of 19%. The mean sampling rate for phenanthrene was 0.49 ml min(-1) with a CV of 21%. Field tests confirmed the naphthalene results but could not be used to confirm the phenanthrene results. The method is not recommended for phenanthrene sampling unless the method has been tested in the specific environment and the results confirm the laboratory tests.

  13. Determination of trichloroanisole and trichlorophenol in wineries' ambient air by passive sampling and thermal desorption-gas chromatography coupled to tandem mass spectrometry.

    PubMed

    Camino-Sánchez, F J; Bermúdez-Peinado, R; Zafra-Gómez, A; Ruíz-García, J; Vílchez-Quero, J L

    2015-02-06

    The present paper describes the calibration of selected passive samplers used in the quantitation of trichlorophenol and trichloroanisole in wineries' ambient air, by calculating the corresponding sampling rates. The method is based on passive sampling with sorbent tubes and involves thermal desorption-gas chromatography-triple quadrupole mass spectrometry analysis. Three commercially available sorbents were tested using sampling cartridges with a radial design instead of axial ones. The best results were found for Tenax TA™. Sampling rates (R-values) for the selected sorbents were determined. Passive sampling was also used for accurately determining the amount of compounds present in the air. Adequate correlation coefficients between the mass of the target analytes and exposure time were obtained. The proposed validated method is a useful tool for the early detection of trichloroanisole and its precursor trichlorophenol in wineries' ambient air while avoiding contamination of wine or winery facilities.

  14. User Acceptance of YouTube for Procedural Learning: An Extension of the Technology Acceptance Model

    ERIC Educational Resources Information Center

    Lee, Doo Young; Lehto, Mark R.

    2013-01-01

    The present study was framed using the Technology Acceptance Model (TAM) to identify determinants affecting behavioral intention to use YouTube. Most importantly, this research emphasizes the motives for using YouTube, which is notable given its extrinsic task goal of being used for procedural learning tasks. Our conceptual framework included two…

  15. Determination of bisphenol A in thermal printing papers treated by alkaline aqueous solution using the combination of single-drop microextraction and HPLC.

    PubMed

    Gao, Leihong; Zou, Jing; Liu, Haihong; Zeng, Jingbin; Wang, Yiru; Chen, Xi

    2013-04-01

    A method for the quantitative determination of bisphenol A in thermal printing paper was developed and validated. Bisphenol A was extracted from the paper samples using 2% NaOH solution, then the extracted analyte was enriched using single-drop microextraction followed by HPLC analysis. Several parameters relating to the single-drop microextraction efficiency including extraction solvent, extraction temperature and time, stirring rate, and pH of donor phase were studied and optimized. Spiked recovery of bisphenol A at 20 and 5 mg/g was found to be 95.8 and 108%, and the method detection limit and method quantification limit was 0.03 and 0.01 mg/g, respectively. Under the optimized conditions, the proposed method was applied to the determination of bisphenol A in seven types of thermal printing paper samples, and the concentration of bisphenol A was found in the range of 0.53-20.9 mg/g. The considerably minimum usage of organic solvents (5 μL 1-octanol) and high enrichment factor (189-197) in the sample preparation are the two highlighted advantages in comparison with previously published works.

  16. Determination of aniline and related mono-aromatic amines in indoor air in selected Canadian residences by a modified thermal desorption GC/MS method.

    PubMed

    Zhu, Jiping; Aikawa, Bio

    2004-04-01

    A modified thermal desorption method to determine low levels of aniline and other related mono-aromatic amines (MAAs) in residential air is described. The method was successfully applied to the determination of levels of these chemicals in residential air from 69 selected homes in two Canadian regions. Instrument detection limits of between 0.02 and 0.06 ng per thermal desorption tube were achieved for aniline and other MAAs. In the absence of environmental tobacco smoke (ETS) the mean concentrations of aniline in both indoor air and outdoor air were similar, at about 0.01 microgram/m3 after correction with field blanks. There was however a statistically significant difference in aniline concentrations between field blanks and indoor or outdoor air samples. No significant difference of aniline levels in the two study regions was observed. A clear link between aniline concentrations in indoor air and smoking activities inside homes was evident. Analysis of cigarette leaves indicated that aniline was most likely formed due to combustion during smoking. Shoe polishing was identified as another source of aniline in indoor air.

  17. Somatotopic arrangement of thermal sensory regions in the healthy human spinal cord determined by means of spinal cord functional MRI.

    PubMed

    Stroman, Patrick W; Bosma, Rachael L; Tsyben, Anastasia

    2012-09-01

    Previous functional MRI studies of normal sensory function in the human spinal cord, including right-to-left symmetry of activity, have been influenced by order effects between repeated studies. In this study, we apply thermal sensory stimulation to four dermatomes within each functional MRI time-series acquisition. Each of the four dermatomes receives a unique stimulation paradigm, such that the four paradigms form a linearly independent set, enabling detection of each individual stimulus response. Functional MRI data are shown spanning the cervical spinal cord and brainstem in 10 healthy volunteers. Results of general linear model analysis demonstrate consistent patterns of activity within the spinal cord segments corresponding to each dermatome, and a high degree of symmetry between right-side and left-side stimulation. Connectivity analyses also demonstrate consistent areas of activity and connectivity between spinal cord and brainstem regions corresponding to known anatomy. However, right-side and left-side responses are not at precisely the same rostral-caudal positions, but are offset by several millimeters, with left-side responses consistently more caudal than right-side responses. The results confirm that distinct responses to multiple interleaved sensory stimuli can be distinguished, enabling studies of sensory responses within the spinal cord without the confounding effects of comparing sequential studies.

  18. Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area

    SciTech Connect

    Pruess, K.; Doughty, C.

    2010-01-15

    Single-well injection-withdrawal (SWIW) tracer tests involve injection of traced fluid and subsequent tracer recovery from the same well, usually with some quiescent time between the injection and withdrawal periods. SWIW are insensitive to variations in advective processes that arise from formation heterogeneities, because upon withdrawal, fluid parcels tend to retrace the paths taken during injection. However, SWIW are sensitive to diffusive processes, such as diffusive exchange of conservative or reactive solutes between fractures and rock matrix. This paper focuses on SWIW tests in which temperature itself is used as a tracer. Numerical simulations demonstrate the sensitivity of temperature returns to fracture-matrix interaction. We consider thermal SWIW response to the two primary reservoir improvements targeted with stimulation, (1) making additional fractures accessible to injected fluids, and (2) increasing the aperture and permeability of pre-existing fractures. It is found that temperature returns in SWIW tests are insensitive to (2), while providing a strong signal of more rapid temperature recovery during the withdrawal phase for (1).

  19. Using Variable Temperature Powder X-Ray Diffraction to Determine the Thermal Expansion Coefficient of Solid MgO

    ERIC Educational Resources Information Center

    Corsepius, Nicholas C.; DeVore, Thomas C.; Reisner, Barbara A.; Warnaar, Deborah L.

    2007-01-01

    A laboratory exercise was developed by using variable temperature powder X-ray diffraction (XRD) to determine [alpha] for MgO (periclase)and was tested in the Applied Physical Chemistry and Materials Characterization Laboratories at James Madison University. The experiment which was originally designed to provide undergraduate students with a…

  20. A Statistical Approach for Determining Subsurface Thermal Structure from Sea Surface Temperature in the Northeast Pacific Ocean.

    DTIC Science & Technology

    1983-06-01

    due to the thick cloud cove: over ths area; therefcze, this ffethod of sea sur face -’em;)sratur=e determi-nation was not used as was desired (Tabata...s computec alcng wit--h a strong linear r-eresin t eaton culdter uda toam.eTereo e bottoma- tredsin heqregiona catlde usdiag tm Terieo r abottom point

  1. Thermal comfort of various building layouts with a proposed discomfort index range for tropical climate.

    PubMed

    Md Din, Mohd Fadhil; Lee, Yee Yong; Ponraj, Mohanadoss; Ossen, Dilshan Remaz; Iwao, Kenzo; Chelliapan, Shreeshivadasan

    2014-04-01

    Recent years have seen issues related to thermal comfort gaining more momentum in tropical countries. The thermal adaptation and thermal comfort index play a significant role in evaluating the outdoor thermal comfort. In this study, the aim is to capture the thermal sensation of respondents at outdoor environment through questionnaire survey and to determine the discomfort index (DI) to measure the thermal discomfort level. The results indicated that most respondents had thermally accepted the existing environment conditions although they felt slightly warm and hot. A strong correlation between thermal sensation and measured DI was also identified. As a result, a new discomfort index range had been proposed in association with local climate and thermal sensation of occupants to evaluate thermal comfort. The results had proved that the respondents can adapt to a wider range of thermal conditions.Validation of the questionnaire data at Putrajaya was done to prove that the thermal sensation in both Putrajaya and UTM was almost similar since they are located in the same tropical climate region. Hence, a quantitative field study on building layouts was done to facilitate the outdoor human discomfort level based on newly proposed discomfort index range. The results showed that slightly shaded building layouts of type- A and B exhibited higher temperature and discomfort index. The resultant adaptive thermal comfort theory was incorporated into the field studies as well. Finally, the study also showed that the DI values were highly dependent on ambient temperature and relative humidity but had fewer effects for solar radiation intensity.

  2. Thermal Neutron Capture Cross Section of {sup 22}Ne

    SciTech Connect

    Belgya, T.; Uberseder, E.; Petrich, D.; Kaeppeler, F.

    2009-01-28

    The radiative thermal neutron capture cross section of the astrophysically important {sup 22}Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched {sup 22}Ne and CH{sub 4} were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7{+-}0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

  3. Optimizing Thermal-Optical Analysis for Atmospheric Black Carbon (BC): Determining the Beer-Lambert Mass Without a Fixed Mass Absorption Coefficient for BC

    NASA Astrophysics Data System (ADS)

    Conny, J. M.; Norris, G.

    2007-12-01

    In thermal-optical transmission analysis (TOT), laser light passing through a particle-laden filter is monitored while carbonaceous material is removed in several heating steps and measured by flame ionization detection. In a helium atmosphere, the laser signal is attenuated by the pyrolysis of organic carbon (OC). Later, while carbon is removed in an oxidizing atmosphere, the laser signal returns to its value prior to pyrolysis (split point), whereupon the amount of carbon equivalent to the native BC is measured. Since pyrolyzed OC may actually evolve beyond the split point, the specific absorption cross sections of pyrolyzed OC and native BC must be equivalent. Moreover, OC pyrolysis must be sufficient so that unpyrolyzed OC is not measured as BC beyond the split point. Using response surfaces models of the apparent specific absorption cross sections for pyrolyzed OC and what the instrument measures as native BC, we determined the thermal conditions for establishing the equivalence of the apparent cross sections while insuring sufficient pyrolysis of OC. In this way, we have optimized TOT for BC mass based on the Beer-Lambert Law but without the need for an absolute mass absorption coefficient (or an absolute attenuation coefficient) for BC. Optimal thermal conditions for the equivalence of the cross sections were indicated by the intersection of the response surfaces. Concurrently, optimal conditions for sufficient pyrolysis of OC were indicated by a plateau in the response surface for the BC cross section. Modeling was based on extensive analyses of PM2.5 samples collected from Atlanta, Los Angeles, and Seattle. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

  4. Validation and acceptance of synthetic infrared imagery

    NASA Astrophysics Data System (ADS)

    Smith, Moira I.; Bernhardt, Mark; Angell, Christopher R.; Hickman, Duncan; Whitehead, Philip; Patel, Dilip

    2004-08-01

    This paper describes the use of an image query database (IQ-DB) tool as a means of implementing a validation strategy for synthetic long-wave infrared images of sea clutter. Specifically it was required to determine the validity of the synthetic imagery for use in developing and testing automatic target detection algorithms. The strategy adopted for exploiting synthetic imagery is outlined and the key issues of validation and acceptance are discussed in detail. A wide range of image metrics has been developed to achieve pre-defined validation criteria. A number of these metrics, which include post processing algorithms, are presented. Furthermore, the IQ-DB provides a robust mechanism for configuration management and control of the large volume of data used. The implementation of the IQ-DB is reviewed in terms of its cardinal point specification and its central role in synthetic imagery validation and EOSS progressive acceptance.

  5. Selected contribution: ambient temperature for experiments in rats: a new method for determining the zone of thermal neutrality.

    PubMed

    Romanovsky, Andrej A; Ivanov, Andrei I; Shimansky, Yury P

    2002-06-01

    There is a misbelief that the same animal has the same thermoneutral zone (TNZ) in different experimental setups. In reality, TNZ strongly depends on the physical environment and varies widely across setups. Current methods for determining TNZ require elaborate equipment and can be applied only to a limited set of experimental conditions. A new, broadly applicable approach that rapidly determines whether given conditions are neutral for a given animal is needed. Consistent with the definition of TNZ [the range of ambient temperature (T(a)) at which body core temperature (T(c)) regulation is achieved only by control of sensible heat loss], we propose three criteria of thermoneutrality: 1) the presence of high-magnitude fluctuations in skin temperature (T(sk)) of body parts serving as specialized heat exchangers with the environment (e.g., rat tail), 2) the closeness of T(sk) to the median of its operational range, and 3) a strong negative correlation between T(sk) and T(c). Thermocouple thermometry and liquid crystal thermography were performed in five rat strains at 13 T(a). Under the conditions tested (no bedding or filter tops, no group thermoregulation), the T(a) range of 29.5-30.5 degrees C satisfied all three TNZ criteria in Wistar, BDIX, Long-Evans, and Zucker lean rats; Zucker fatty rats had a slightly lower TNZ (28.0-29.0 degrees C). Skin thermometry or thermography is a definition-based, simple, and inexpensive technique to determine whether experimental or housing conditions are neutral, subneutral, or supraneutral for a given animal.

  6. Parametric Studies Of Failure Mechanisms In Thermal Barrier Coatings During Thermal Cycling Using FEM

    NASA Astrophysics Data System (ADS)

    Srivathsa, B.; Das, D. K.

    2015-12-01

    Thermal barrier coatings (TBCs) are widely used on different hot components of gas turbine engines such as blades and vanes. Although, several mechanisms for the failure of the TBCs have been suggested, it is largely accepted that the durability of these coatings is primarily determined by the residual stresses that are developed during the thermal cycling. In the present study, the residual stress build-up in an electron beam physical vapour deposition (EB-PVD) based TBCs on a coupon during thermal cycling has been studied by varying three parameters such as the cooling rate, TBC thickness and substrate thickness. A two-dimensional thermomechanical generalized plane strain finite element simulations have been performed for thousand cycles. It was observed that these variations change the stress profile significantly and the stress severity factor increases non-linearly. Overall, the predictions of the model agree with reported experimental results and help in predicting the failure mechanisms.

  7. Thermal neutron diffraction determination of the magnetic structure of EuCu{sub 2}Ge{sub 2}

    SciTech Connect

    Rowan-Weetaluktuk, W. N.; Ryan, D. H.; Lemoine, P.; Cadogan, J. M.

    2014-05-07

    The magnetic structure of EuCu{sub 2}Ge{sub 2} has been determined by flat-plate neutron powder diffraction. Two magnetic phases are present in the neutron diffraction pattern at 3.5 K. They have the same moment, within error, and a common transition temperature. Both {sup 151}Eu and {sup 153}Eu Mössbauer spectroscopy show that the two magnetic phases belong to the same crystallographic phase. Both phases can be modelled by planar helimagnetic structures: one with a propagation vector of [0.654(1), 0, 0], the other with a propagation vector of [0.410(1), 0.225(1), 0].

  8. From requirements to acceptance tests

    NASA Technical Reports Server (NTRS)

    Baize, Lionel; Pasquier, Helene

    1993-01-01

    From user requirements definition to accepted software system, the software project management wants to be sure that the system will meet the requirements. For the development of a telecommunication satellites Control Centre, C.N.E.S. has used new rules to make the use of tracing matrix easier. From Requirements to Acceptance Tests, each item of a document must have an identifier. A unique matrix traces the system and allows the tracking of the consequences of a change in the requirements. A tool has been developed, to import documents into a relational data base. Each record of the data base corresponds to an item of a document, the access key is the item identifier. Tracing matrix is also processed, providing automatically links between the different documents. It enables the reading on the same screen of traced items. For example one can read simultaneously the User Requirements items, the corresponding Software Requirements items and the Acceptance Tests.

  9. Defining acceptable conditions in wilderness

    NASA Astrophysics Data System (ADS)

    Roggenbuck, J. W.; Williams, D. R.; Watson, A. E.

    1993-03-01

    The limits of acceptable change (LAC) planning framework recognizes that forest managers must decide what indicators of wilderness conditions best represent resource naturalness and high-quality visitor experiences and how much change from the pristine is acceptable for each indicator. Visitor opinions on the aspects of the wilderness that have great impact on their experience can provide valuable input to selection of indicators. Cohutta, Georgia; Caney Creek, Arkansas; Upland Island, Texas; and Rattlesnake, Montana, wilderness visitors have high shared agreement that littering and damage to trees in campsites, noise, and seeing wildlife are very important influences on wilderness experiences. Camping within sight or sound of other people influences experience quality more than do encounters on the trails. Visitors’ standards of acceptable conditions within wilderness vary considerably, suggesting a potential need to manage different zones within wilderness for different clientele groups and experiences. Standards across wildernesses, however, are remarkably similar.

  10. Determination of short chain chlorinated paraffins in water by stir bar sorptive extraction-thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry.

    PubMed

    Tölgyessy, P; Nagyová, S; Sládkovičová, M

    2017-03-08

    A simple, robust, sensitive and environment friendly method for the determination of short chain chlorinated paraffins (SCCPs) in water using stir bar sorptive extraction (SBSE) coupled to thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry (TD-GC-QqQ-MS/MS) was developed. SBSE was performed using 100mL of water sample, 20mL of methanol as a modifier, and a commercial sorptive stir bar (with 10mm×0.5mm PDMS layer) during extraction period of 16h. After extraction, the sorptive stir bar was thermally desorbed and online analysed by GC-MS/MS. Method performance was evaluated for MilliQ and surface water spiked samples. For both types of matrices, a linear dynamic range of 0.5-3.0μgL(-1) with correlation coefficients >0.999 and relative standard deviations (RSDs) of the relative response factors (RRFs) <12% was established. The limits of quantification (LOQs) of 0.06 and 0.08μgL(-1), and the precision (repeatability) of 6.4 and 7.7% (RSDs) were achieved for MilliQ and surface water, respectively. The method also showed good robustness, recovery and accuracy. The obtained performance characteristics indicate that the method is suitable for screening and monitoring and compliance checking with environmental quality standards (EQS, set by the EU) for SCCPs in surface waters.

  11. Structural and energetic determinants of thermal stability and hierarchical unfolding pathways of hyperthermophilic proteins, Sac7d and Sso7d.

    PubMed

    Priyakumar, U Deva; Ramakrishna, S; Nagarjuna, K R; Reddy, S Karunakar

    2010-02-04

    Identification of the structural and energetic determinants responsible for enhancing the stability of proteins is crucial. Hyperthermophilic proteins are naturally occurring proteins that exhibit high thermal stability and are good candidates for the investigation and understanding of structure-stability relationships. Sac7d from Sulfolobus acidocaldarius and Sso7d from Sulfolobus solfactaricus are two homologous hyperthermophilic proteins that were shown to be quite stable at high temperatures. Molecular dynamics simulations at the nanosecond time scale at different temperatures were performed to examine the factors affecting their stability. The three-dimensional structures of these proteins were observed to be similar to the experimental structure at 300 and 360 K but were found to undergo denaturation at 500 K. Both proteins exhibit similar unfolding pathways that correlates well with the calculated intermolecular interaction energies. The differential dynamic behaviors of these molecules at different temperatures were examined. Structural and energetic analysis of the contributions of salt bridges indicates a stabilizing effect at higher temperatures. However, the lifetimes of the salt bridges were found to be quite short, and several new salt bridges formed at 500 K supporting previous studies that the desolvation penalty due to the formation of salt bridges decreases at elevated temperatures. Hydrophobic interactions, which decrease with increase in temperature, were also found to be crucial in the stability of these proteins. Overall, the study shows that a balance among the salt bridge interactions, hydrophobic interactions, and solvent properties is primarily responsible for the high thermal stability of this class of proteins.

  12. Experimental determination of blast-wave pressure loading, thermal radiation protection, and electrical transmission loss for parabolic antenna models in simulated nuclear blast environments

    SciTech Connect

    George, J.H.

    1991-01-01

    A twelve-inch-diameter parabolic antenna model instrumented with eleven differential pressure sensors was tested at the Ballistics Research Laboratory, Aberdeen Proving Ground, Maryland. Transient pressure loading was determined for 37 different antenna model angular positions with respect to the direction of the blast wave at a peak overpressure of 3.0 pounds per square inch; limited data at 4.5 and 6.0 pounds per square inch were also investigated. The first millisecond of shock-wave interaction with the antenna features the most prominent fully reversed triangular pressure pulse. A blast function, F, was developed that accurately approximates the transient behavior of the blast wave resultant force and moment loading on the antenna model. The resultant blast force on the antenna model is minimized when the axis of the paraboloid of the model is rotated 82{degree} with respect to the direction of the blast wave. Four different thermal protective coatings were tested to evaluate the effects of coating color and thickness. Transmission-loss measurements were completed on eight different quartz-polyimide antenna models coated with Caapcoat and Ocean 477 thermal protective coatings.

  13. 78 FR 53483 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... COMMISSION Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 3 AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and..., tests, and analyses have been successfully completed, and that the specified acceptance criteria are...

  14. 78 FR 53484 - Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 4

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... COMMISSION Inspections, Tests, Analyses, and Acceptance Criteria; Vogtle Electric Generating Plant, Unit 4 AGENCY: Nuclear Regulatory Commission. ACTION: Determination of inspections, tests, analyses, and..., tests, and analyses have been successfully completed, and that the specified acceptance criteria are...

  15. Modeling thermal influence on animal growth and sex determination in reptiles: being closer to the target gives new views.

    PubMed

    Girondot, M; Ben Hassine, S; Sellos, C; Godfrey, M; Guillon, J-M

    2010-01-01

    Many species of oviparous reptiles, including crocodilians, a majority of turtles, some lizards and the 2 closely related species of Sphenodon have been shown to display temperature-dependent sex determination (TSD). Whereas it has been demonstrated very early that TSD also occurs in natural conditions, the relationship between a time series of changing temperatures and sex ratio remains a challenging problem for reptiles. We describe how a physiological model of embryo growth, gonadal development and aromatase activity can produce outputs that mimic well TSD. We provide an enhancement of a previously published model taking into account direct effect of temperature on aromatase activity. The comparison between the original model and the new one suggests that aromatase expression is controlled by a repressor factor expressed at masculinizing temperatures rather than its enhancement at feminizing temperatures.

  16. Thermal-maturity limit for primary thermogenic-gas generation from humic coals as determined by hydrous pyrolysis

    USGS Publications Warehouse

    Lewan, Michael; Kotarba, M.J.

    2014-01-01

    Hydrous-pyrolysis experiments at 360°C (680°F) for 72 h were conducted on 53 humic coals representing ranks from lignite through anthracite to determine the upper maturity limit for hydrocarbon-gas generation from their kerogen and associated bitumen (i.e., primary gas generation). These experimental conditions are below those needed for oil cracking to ensure that generated gas was not derived from the decomposition of expelled oil generated from some of the coals (i.e., secondary gas generation). Experimental results showed that generation of hydrocarbon gas ends before a vitrinite reflectance of 2.0%. This reflectance is equivalent to Rock-Eval maximum-yield temperature and hydrogen indices (HIs) of 555°C (1031°F) and 35 mg/g total organic carbon (TOC), respectively. At these maturity levels, essentially no soluble bitumen is present in the coals before or after hydrous pyrolysis. The equivalent kerogen atomic H/C ratio is 0.50 at the primary gas-generation limit and indicates that no alkyl moieties are remaining to source hydrocarbon gases. The convergence of atomic H/C ratios of type-II and -I kerogen to this same value at a reflectance of indicates that the primary gas-generation limits for humic coal and type-III kerogen also apply to oil-prone kerogen. Although gas generation from source rocks does not exceed vitrinite reflectance values greater than , trapped hydrocarbon gases can remain stable at higher reflectance values. Distinguishing trapped gas from generated gas in hydrous-pyrolysis experiments is readily determined by of the hydrocarbon gases when a -depleted water is used in the experiments. Water serves as a source of hydrogen in hydrous pyrolysis and, as a result, the use of -depleted water is reflected in the generated gases but not pre-existing trapped gases.

  17. Determination of true temperature of opaque matter based on its thermal radiation spectrum: Using relative emissivity and the Wien displacement law

    NASA Astrophysics Data System (ADS)

    Rusin, S. P.

    2015-11-01

    Two methods for determining of the true (thermodynamic) temperature via thermal radiation spectrum of an opaque heated object are presented. The first method is based on the relative emissivity. It is shown that in many cases, the range of the true temperature values may be narrowed down using the “convex-concave” criterion. As shown, that any relative spectral emissivity dependence can be approximated by the same parametric model. The second method is based on the use of the Wien displacement law for real materials. This method is effective when the radiation of the object close to the gray-body radiation in the region of the spectral emission maximum. It is shown that these two methods complement each other.

  18. Further Conceptualization of Treatment Acceptability

    ERIC Educational Resources Information Center

    Carter, Stacy L.

    2008-01-01

    A review and extension of previous conceptualizations of treatment acceptability is provided in light of progress within the area of behavior treatment development and implementation. Factors including legislation, advances in research, and service delivery models are examined as to their relationship with a comprehensive conceptualization of…

  19. Acceptance and Commitment Therapy: Introduction

    ERIC Educational Resources Information Center

    Twohig, Michael P.

    2012-01-01

    This is the introductory article to a special series in Cognitive and Behavioral Practice on Acceptance and Commitment Therapy (ACT). Instead of each article herein reviewing the basics of ACT, this article contains that review. This article provides a description of where ACT fits within the larger category of cognitive behavior therapy (CBT):…

  20. Nitrogen trailer acceptance test report

    SciTech Connect

    Kostelnik, A.J.

    1996-02-12

    This Acceptance Test Report documents compliance with the requirements of specification WHC-S-0249. The equipment was tested according to WHC-SD-WM-ATP-108 Rev.0. The equipment being tested is a portable contained nitrogen supply. The test was conducted at Norco`s facility.

  1. Imaginary Companions and Peer Acceptance

    ERIC Educational Resources Information Center

    Gleason, Tracy R.

    2004-01-01

    Early research on imaginary companions suggests that children who create them do so to compensate for poor social relationships. Consequently, the peer acceptance of children with imaginary companions was compared to that of their peers. Sociometrics were conducted on 88 preschool-aged children; 11 had invisible companions, 16 had personified…

  2. Euthanasia Acceptance: An Attitudinal Inquiry.

    ERIC Educational Resources Information Center

    Klopfer, Fredrick J.; Price, William F.

    The study presented was conducted to examine potential relationships between attitudes regarding the dying process, including acceptance of euthanasia, and other attitudinal or demographic attributes. The data of the survey was comprised of responses given by 331 respondents to a door-to-door interview. Results are discussed in terms of preferred…

  3. Helping Our Children Accept Themselves.

    ERIC Educational Resources Information Center

    Gamble, Mae

    1984-01-01

    Parents of a child with muscular dystrophy recount their reactions to learning of the diagnosis, their gradual acceptance, and their son's resistance, which was gradually lessened when he was provided with more information and treated more normally as a member of the family. (CL)

  4. MOF-5 metal-organic framework as sorbent for in-field sampling and preconcentration in combination with thermal desorption GC/MS for determination of atmospheric formaldehyde.

    PubMed

    Gu, Zhi-Yuan; Wang, Gen; Yan, Xiu-Ping

    2010-02-15

    Metal-organic frameworks (MOFs) are one kind of highly porous crystalline materials, which are constructed by metal-containing inorganic nodes and organic linkers. With large surface area and high thermal stability, MOFs have great potential as sorbents for the preconcentration of trace analytes. However, such application of MOFs to the analysis of real samples has not been reported before. Here we report the utilization of MOF-5 as sorbent for in-field sampling and preconcentration of atmospheric formaldehyde before thermal desorption (TD) GC/MS (TD-GC/MS) determination without the need for any chemical derivatization. MOF-5 gave a 53 and 73 times better concentration effect than Tenax TA (organic polymers) and Carbograph 1TD (graphitized carbon black), respectively, for TD-GC/MS determination of formaldehyde. MOF-5 showed good performance for in-field sampling and preconcentration of formaldehyde from air samples with a relative humidity less than 45%. The collected formaldehyde on MOF-5 sorbent was stable for at least 72 h at room temperature before TD-GC/MS analysis. One tube packed with 300 mg of MOF-5 lasted 200 cycles of adsorption/TD without significant loss of collection efficiency. The breakthrough volume of such a tube was 1.2 L of 28.35 mg m(-3) formaldehyde at a sampling flow rate of 100 mL min(-1). The use of MOF-5 for in-field sampling and preconcentration in combination with TD-GC/MS for the determination of formaldehyde offered a linear range covering 3 orders of magnitude, and a detection limit of 0.6 microg m(-3). The precision for six replicate cycles of in-field sampling and preconcentration for TD-GC/MS determination using one 300 mg MOF-5 packed tube ranged from 2.8% to 5.3%. The tube-to-tube reproducibility of three MOF-5 tubes prepared in parallel was 7.7%. The developed method was applied to analysis of local indoor and outdoor air samples for formaldehyde and validated by the standard method TO-11A of the United States Environmental

  5. A new NMR approach for structure determination of thermally unstable biflavanones and application to phytochemicals from Garcinia buchananii.

    PubMed

    Stark, Timo D; Lösch, Sofie; Salger, Mathias; Balemba, Onesmo B; Wakamatsu, Junichiro; Frank, Oliver; Hofmann, Thomas

    2015-10-01

    Previous activity-guided phytochemical studies on Garcinia buchananii stem bark, which is traditionally used in Africa to treat various gastrointestinal and metabolic illnesses, revealed xanthones, polyisoprenylated benzophenones, flavanone-C-glycosides, biflavonoids, and/or biflavanones as bioactive key molecules. Unequivocal structure elucidation of biflavonoids and biflavanones by means of NMR spectroscopy is often complicated by the hindered rotation of the monomers around the C-C axis (atropisomerism), resulting in a high spectral complexity. In order to facilitate an unrestricted rotation, NMR spectra are usually recorded at elevated temperatures, commonly over 80 °C, which effects in a single set of resonance signals. However, under these conditions, one of the target compounds of this investigation, (2R,3S,2″R,3″R)-manniflavanone (1), undergoes degradation. Therefore, we demonstrated in the present study that the 1,1-ADEQUATE could be successfully used as a powerful alternative approach to confirm the C-C connectivities in 1, avoiding detrimental conditions. However, a moderate increase in temperature up to 50 °C was sufficient to deliver sharp signals in the proton NMR experiment of (2R,3S,2″R,3″R)-isomanniflavanone (2) and (2″R,3″R)-preussianone (3). In addition, two new compounds could be isolated, namely (2R,3S,2″R,3″R)-GB-2 7″-O-β-D-glucopyranoside (4) and (2R,3S,2″R,3″R)-manniflavanone-7″-O-β-D-glucopyranoside (5), and whose structures were elucidated by spectroscopic analysis including 1D and 2D NMR and mass spectrometry methods. The absolute configurations were determined by a combination of NMR and electronic circular dichroism (ECD) spectroscopy. The aforementioned compounds exhibited high anti-oxidative capacity in the H2O2 scavenging, hydrophilic Trolox equivalent antioxidant capacity (H-TEAC) and hydrophilic oxygen radical absorbance capacity (H-ORAC) assays.

  6. Acceptance Probability (P a) Analysis for Process Validation Lifecycle Stages.

    PubMed

    Alsmeyer, Daniel; Pazhayattil, Ajay; Chen, Shu; Munaretto, Francesco; Hye, Maksuda; Sanghvi, Pradeep

    2016-04-01

    This paper introduces an innovative statistical approach towards understanding how variation impacts the acceptance criteria of quality attributes. Because of more complex stage-wise acceptance criteria, traditional process capability measures are inadequate for general application in the pharmaceutical industry. The probability of acceptance concept provides a clear measure, derived from specific acceptance criteria for each quality attribute. In line with the 2011 FDA Guidance, this approach systematically evaluates data and scientifically establishes evidence that a process is capable of consistently delivering quality product. The probability of acceptance provides a direct and readily understandable indication of product risk. As with traditional capability indices, the acceptance probability approach assumes that underlying data distributions are normal. The computational solutions for dosage uniformity and dissolution acceptance criteria are readily applicable. For dosage uniformity, the expected AV range may be determined using the s lo and s hi values along with the worst case estimates of the mean. This approach permits a risk-based assessment of future batch performance of the critical quality attributes. The concept is also readily applicable to sterile/non sterile liquid dose products. Quality attributes such as deliverable volume and assay per spray have stage-wise acceptance that can be converted into an acceptance probability. Accepted statistical guidelines indicate processes with C pk > 1.33 as performing well within statistical control and those with C pk < 1.0 as "incapable" (1). A C pk > 1.33 is associated with a centered process that will statistically produce less than 63 defective units per million. This is equivalent to an acceptance probability of >99.99%.

  7. Aspects of audit. 4: Acceptability of audit.

    PubMed

    Shaw, C D

    1980-06-14

    Whether or not audit is accepted in Britain will be determined principally by how it is controlled, how much it costs, and how effective it is. The objectives of audit have been defined as education, planning, evaluation, research, and anticipatory diplomacy--that is, starting internal audit before external audit is imposed on the medical profession. Published reports suggest that in Britain internal audit would be more effective andless expensive than the complex professional standards review organisation devised by the Federal Government in the United States.

  8. Experiments and Simulations of the Use of Time-Correlated Thermal Neutron Counting to Determine the Multiplication of an Assembly of Highly Enriched Uranium

    SciTech Connect

    David L. Chichester; Mathew T. Kinlaw; Scott M. Watson; Jeffrey M. Kalter; Eric C. Miller; William A. Noonan

    2014-11-01

    A series of experiments and numerical simulations using thermal-neutron time-correlated measurements has been performed to determine the neutron multiplication, M, of assemblies of highly enriched uranium available at Idaho National Laboratory. The experiments used up to 14.4 kg of highly-enriched uranium, including bare assemblies and assemblies reflected with high-density polyethylene, carbon steel, and tungsten. A small 252Cf source was used to initiate fission chains within the assembly. Both the experiments and the simulations used 6-channel and 8-channel detector systems, each consisting of 3He proportional counters moderated with polyethylene; data was recorded in list mode for analysis. 'True' multiplication values for each assembly were empirically derived using basic neutron production and loss values determined through simulation. A total of one-hundred and sixteen separate measurements were performed using fifty-seven unique measurement scenarios, the multiplication varied from 1.75 to 10.90. This paper presents the results of these comparisons and discusses differences among the various cases.

  9. Optimization of a Dynamic Headspace-Thermal Desorption-Gas Chromatography/Mass Spectrometry procedure for the determination of furfurals in vinegars.

    PubMed

    Manzini, Simona; Durante, Caterina; Baschieri, Carlo; Cocchi, Marina; Sighinolfi, Simona; Totaro, Sara; Marchetti, Andrea

    2011-08-15

    The use of a Dynamic Headspace System (DHS) device combined with a Thermal Desorption Unit (TDU) interfaced to a Gas Chromatography/Mass Spectrometry (GC/MS) system is proposed for the determination of furfurals in oenological products. An experimental design protocol has been employed for the optimization of the instrumental settings concerning DHS and TDU extraction and desorption steps. It has been possible to individuate the following optimized conditions: incubation temperature 40°C, purge volume 800 mL, dry volume 1500 mL, TDU hold time 5 min and incubation time 10 min. The performance of two different SPE sorbents, namely Tenax TA and Tenax GR used for the furfurals trapping, was investigated too. The developed DHS sampling procedure showed good reproducibility values with a RSD% lower than 10% for all the monitored species. The optimized experimental settings have been used to determine furfurals in several vinegar samples obtained by traditional procedure starting from cooked grape musts, i.e. in Aceto Balsamico Tradizionale di Modena (ABTM). In fact, the control of these species is extremely important for quality and safety issues.

  10. Determination of parabens in house dust by pressurised hot water extraction followed by stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Ramírez, Noelia; Marcé, Rosa Maria; Borrull, Francesc

    2011-09-16

    This study describes the development of a new method for determining p-hydroxybenzoic esters (parabens) in house dust. This optimised method was based on the pressurised hot water extraction (PHWE) of house dust, followed by the acetylation of the extracted parabens, stir bar sorptive extraction (SBSE) with a polydimethylsiloxane stir bar, and finally analysis using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The combination of SBSE and PHWE allows the analytes to be preconcentrated and extracted from the aqueous extract in a single step with minimal manipulation of the sample. Furthermore the in situ acetylation of parabens prior to SBSE improved their extraction efficiency and their GC-MS signal. The method showed recoveries of between 40 and 80%, good linearity, repeatability and reproducibility (<10% RSD, at 100 ng g(-1), n=5), low limits of detection (from 1.0 ng g(-1) for propyl paraben to 2.1 ng g(-1) for methyl paraben) and quantification (from 3.3 ng g(-1) for propyl paraben to 8.5 ng g(-1) for methyl paraben). The proposed method was applied to the analysis of house dust samples. All the target parabens were found in the samples. Methyl and propyl parabens were the most abundant, with concentrations up to 2440 ng g(-1) and 910 ng g(-1), respectively. The high levels of parabens found in the samples confirm the importance of determining organic contaminants in indoor environments.

  11. Validated spectrophotometric method for the determination, spectroscopic characterization and thermal structural analysis of duloxetine with 1,2-naphthoquinone-4-sulphonate

    NASA Astrophysics Data System (ADS)

    Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

    2012-03-01

    A novel, selective, sensitive and simple spectrophotometric method was developed and validated for the determination of the antidepressant duloxetine hydrochloride in pharmaceutical preparation. The method was based on the reaction of duloxetine hydrochloride with 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline media to yield orange colored product. The formation of this complex was also confirmed by UV-visible, FTIR, 1H NMR, Mass spectra techniques and thermal analysis. This method was validated for various parameters according to ICH guidelines. Beer's law is obeyed in a range of 5.0-60 μg/mL at the maximum absorption wavelength of 480 nm. The detection limit is 0.99 μg/mL and the recovery rate is in a range of 98.10-99.57%. The proposed methods was validated and applied to the determination of duloxetine hydrochloride in pharmaceutical preparation. The results were statistically analyzed and compared to those of a reference UV spectrophotometric method.

  12. Rift flank uplift and thermal evolution of an intracratonic rift basin (eastern Canada) determined by combined apatite and zircon (U-Th)/He thermochronology

    NASA Astrophysics Data System (ADS)

    Hardie, Rebecca; Schneider, David; Metcalf, James; Flowers, Rebecca

    2015-04-01

    As a significant portion of the world's oil reserves are retrieved from rift systems, a better understanding of the timing of thermal evolution and burial history of these systems will increase the potential for the discovery of hydrocarbon-bearing rifts. The Ottawa Embayment of the St. Lawrence Platform of eastern Canada is a reactivated intracratonic rift basin related to the opening of the Iapetus Ocean at ca. 620-570 Ma, followed by the formation of the well-developed continental passive margin. Siliciclastic sediments derived from the adjacent uplifted Neoproterozoic Grenville basement provide the basin fill material. Apatite and zircon (U-Th)/He thermochronology allows for low-temperature analysis across the exposed crystalline rift flank into the synrift sedimentary sequence to resolve the unroofing, burial and subsidence history of the region. Samples were collected along a ~250 km NE-SW transect, oblique to the axis of the rift, from Mont-Tremblant, Québec (~900 m) to the central axis of the Paleozoic rift in the Southern Ontario Lowlands (~300 m). Targets included Neoproterozoic metamorphic rocks of the Grenville Province along the rift flank and basinal Cambro-Ordovician Potsdam Group. Samples from the rift flank yield zircon ages from ca. 650 Ma to ca. 560 Ma and apatite ages from ca. 290 Ma to ca. 190 Ma, with a weak positive correlation between age and grain size. Zircon ages demonstrate a strong negative correlation with radiation damage: as eU increases, age decreases. By incorporating (U-Th)/He ages with regional constraints in the thermal modelling program HeFTy, viable temperature time paths for the region can be determined. Through inverse and forward modeling, preliminary rift flank (U-Th)/He ages correspond to post-Grenville cooling with <4 km of post-Carboniferous burial. The data define slow and long episodes of syn- to post-rift cooling with rates between 0.4 and 0.1 °C/Ma. (U-Th)/He dating of samples along the full-length of the transect

  13. Determination of thermally induced trans-fatty acids in soybean oil by attenuated total reflectance fourier transform infrared spectroscopy and gas chromatography analysis.

    PubMed

    Li, An; Ha, Yiming; Wang, Feng; Li, Weiming; Li, Qingpeng

    2012-10-24

    The intake of edible oil containing trans-fatty acids has deleterious effects mainly on the cardiovascular system. Thermal processes such as refining and frying cause the formation of trans-fatty acids in edible oil. This study was conducted to investigate the possible formation of trans-fatty acids because of the heat treatment of soybean oil. The types of trans-fatty acids in heated soybean oil are determined by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry methods. The effects of the heating temperature on the trans-fatty acids in soybean oil were evaluated using gas chromatography flame ionization detection analysis. Results show that heat treatment at 240 °C causes the formation of trans-fatty acids in soybean oil and the amount of trans-fatty acids increases with heating time. The only peak observed at 966 cm(-1) of the samples indicates the formation of nonconjugated trans isomers in the heated soybean oil. The major types of trans-fatty acids formed were trans-polyunsaturated fatty acids. Significant increases (P < 0.05) in the amounts of two trans-linoleic acids (C18:2-9c,12t and C18:2-9t,12c) and four trans-linolenic acids (C18:3-9c,12c,15t, C18:3-9t,12c,15c, and C18:3-9t,12t,15c/C18:3-9t,12c,15t) in soybean oil heated to temperatures exceeding 200 °C were compared with those of the control sample. The heating temperature and duration should be considered to reduce the formation of trans-fatty acids during thermal treatment.

  14. Application of a superoxide (O(2)(-)) thermal source (SOTS-1) for the determination and calibration of O(2)(-) fluxes in seawater.

    PubMed

    Heller, M I; Croot, P L

    2010-05-14

    Superoxide (O(2)(-)) is an important short lived transient reactive oxygen species (ROS) in seawater. The main source of O(2)(-) in the ocean is believed to be through photochemical reactions though biological processes may also be important. Sink terms for O(2)(-) include redox reactions with bioactive trace metals, including Cu and Fe, and to a lesser extent dissolved organic matter (DOM). Information on the source fluxes, sinks and concentration of superoxide in the open ocean are crucial to improving our understanding of the biogeochemical cycling of redox active species. As O(2)(-) is a highly reactive transient species present at low concentrations it is not a trivial task to make accurate and precise measurements in seawater. In this study we developed the appropriate numerical analysis tools and investigated a number of superoxide sources and methods for the purposes of calibrating O(2)(-) concentrations and/or fluxes specifically in seawater. We found the superoxide thermal source bis(4-carboxybenzyl)hyponitrite (SOTS)-1 easy to employ as a reliable source of O(2)(-) which could be successfully applied in seawater. The thermal decomposition of SOTS-1 in seawater was evaluated over a range of seawater temperatures using both a flux based detection scheme developed using two spectrophotometric methods: (i) 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and (ii) ferricytochrome c (FC), or a concentration based detection scheme using a chemiluminescence flow injection method based on the Cypridina luciferin analog 2-methyl-6-(p-methoxyphenyl)3-7-dihydroimidazol[1,2-alpha]pyrazin-3-one (MCLA) as reagent. Our results suggest SOTS-1 is the best available O(2)(-) source for determining concentrations and fluxes, all detection systems tested have their pros and cons and the choice of which to use depends more on the duration and type of experiment that is required.

  15. Determination of dithiocarbamate pesticides in occupational hygiene sampling devices using the isooctane method and comparison with an automatic thermal desorption (ATD) method.

    PubMed

    Coldwell, Matthew R; Pengelly, Ian; Rimmer, Duncan A

    2003-01-10

    Two new methods for the determination of dithiocarbamate pesticides in occupational hygiene sampling devices are described. Dithiocarbamate spiked occupational hygiene sampling devices, consisting of glass fibre (GF/A) filters, cotton pads, cotton gloves and disposable overalls, were reduced under acidic conditions and the CS2 evolved as a decomposition product was extracted into isooctane. The isooctane was then analysed using gas chromatography with mass spectrometry, for CS2, which provided a quantitative result for dithiocarbamates. Recoveries obtained were generally within a 70-110% range and reproducibilities better than 15% RSD were typically achieved. The method has been successfully applied to samples collected during occupational exposure surveys. A second method employing automatic thermal desorption-gas chromatography-mass spectrometry (ATD-GC-MS) has also been developed and applied to the direct analysis of GF/A (airborne) samples. The method relies on the thermal degradation of dithiocarbamates to release CS2, which is used to quantify the analytes. Thiram spiked GF/A filters gave an average recovery of 107% with an RSD of 4%. The performance of the two analytical methods were directly compared by analysing sub-portions of GF/A filters collected during a survey to evaluate occupational exposures to thiram during seed treatment operations. Both methods performed well for the analysis of airborne (GF/A) samples and produced results in good agreement. ATD-GC-MS is the preferred method for studies involving GF/A (airborne) samples only. Because of the wider applicability of the isooctane method for other sampling devices, it is the preferred choice when carrying out surveys which require a dermal as well as respirable exposure assessment.

  16. Determination of diffusion parameters of thermal neutrons for non-moderator media by a pulsed method and a time independent method

    NASA Astrophysics Data System (ADS)

    Boufraqech, A.

    1991-02-01

    Two methods for determining the diffusion parameters of thermal neutrons for non-moderator and non-multiplicator media have been developed. The first one, which is a pulsed method, is based on thermal neutrons relaxation coefficients measurement in a moderator, with and without the medium of interest that plays the role of reflector. For the experimental results interpretation using the diffusion theory, a corrective factor which takes into account the neutron cooling by diffusion has been introduced. Its dependence on the empirically obtained relaxation coefficients is in a good agreement with the calculations made in P3L2 approximation. The difference between linear extrapolation lengths of the moderator and the reflector has been taken into account, by developing the scalar fluxes in Bessel function series which automatically satisfy the boundary conditions at the extrapolated surfaces of the two media. The obtained results for iron are in a good agreement with those in the literature. The second method is time independent, based on the 'flux albedo' measurements interpretation (concept introduced by Amaldi and Fermi) by P3 approximation in the one group transport theory. The independent sources are introduced in the Marshak boundary conditions. An angular albedo matrix has been used to deal with multiple reflections and to take into account the distortion of the current vector when entering a medium, after being reflected by this latter. The results obtained by this method are slightly different from those given in the literature. The analysis of the possible sources causing this discrepancy, particulary the radial distribution of flux in cylindrical geometry and the flux depression at medium-black body interface, has shown that the origin of this discrepancy is the neutron heating by diffusion.

  17. Acceptability of reactors in space

    SciTech Connect

    Buden, D.

    1981-01-01

    Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it does not appear that reactors add measurably to the risk associated with the Space Transportation System.

  18. Acceptability of reactors in space

    SciTech Connect

    Buden, D.

    1981-04-01

    Reactors are the key to our future expansion into space. However, there has been some confusion in the public as to whether they are a safe and acceptable technology for use in space. The answer to these questions is explored. The US position is that when reactors are the preferred technical choice, that they can be used safely. In fact, it dies not appear that reactors add measurably to the risk associated with the Space Transportation System.

  19. Outdoor thermal comfort in public space in warm-humid Guayaquil, Ecuador

    NASA Astrophysics Data System (ADS)

    Johansson, Erik; Yahia, Moohammed Wasim; Arroyo, Ivette; Bengs, Christer

    2017-03-01

    The thermal environment outdoors affects human comfort and health. Mental and physical performance is reduced at high levels of air temperature being a problem especially in tropical climates. This paper deals with human comfort in the warm-humid city of Guayaquil, Ecuador. The main aim was to examine the influence of urban micrometeorological conditions on people's subjective thermal perception and to compare it with two thermal comfort indices: the physiologically equivalent temperature (PET) and the standard effective temperature (SET*). The outdoor thermal comfort was assessed through micrometeorological measurements of air temperature, humidity, mean radiant temperature and wind speed together with a questionnaire survey consisting of 544 interviews conducted in five public places of the city during both the dry and rainy seasons. The neutral and preferred values as well as the upper comfort limits of PET and SET* were determined. For both indices, the neutral values and upper thermal comfort limits were lower during the rainy season, whereas the preferred values were higher during the rainy season. Regardless of season, the neutral values of PET and SET* are above the theoretical neutral value of each index. The results show that local people accept thermal conditions which are above acceptable comfort limits in temperate climates and that the subjective thermal perception varies within a wide range. It is clear, however, that the majority of the people in Guayaquil experience the outdoor thermal environment during daytime as too warm, and therefore, it is important to promote an urban design which creates shade and ventilation.

  20. Outdoor thermal comfort in public space in warm-humid Guayaquil, Ecuador.

    PubMed

    Johansson, Erik; Yahia, Moohammed Wasim; Arroyo, Ivette; Bengs, Christer

    2017-03-10

    The thermal environment outdoors affects human comfort and health. Mental and physical performance is reduced at high levels of air temperature being a problem especially in tropical climates. This paper deals with human comfort in the warm-humid city of Guayaquil, Ecuador. The main aim was to examine the influence of urban micrometeorological conditions on people's subjective thermal perception and to compare it with two thermal comfort indices: the physiologically equivalent temperature (PET) and the standard effective temperature (SET*). The outdoor thermal comfort was assessed through micrometeorological measurements of air temperature, humidity, mean radiant temperature and wind speed together with a questionnaire survey consisting of 544 interviews conducted in five public places of the city during both the dry and rainy seasons. The neutral and preferred values as well as the upper comfort limits of PET and SET* were determined. For both indices, the neutral values and upper thermal comfort limits were lower during the rainy season, whereas the preferred values were higher during the rainy season. Regardless of season, the neutral values of PET and SET* are above the theoretical neutral value of each index. The results show that local people accept thermal conditions which are above acceptable comfort limits in temperate climates and that the subjective thermal perception varies within a wide range. It is clear, however, that the majority of the people in Guayaquil experience the outdoor thermal environment during daytime as too warm, and therefore, it is important to promote an urban design which creates shade and ventilation.

  1. Grammaticality, Acceptability, and Probability: A Probabilistic View of Linguistic Knowledge.

    PubMed

    Lau, Jey Han; Clark, Alexander; Lappin, Shalom

    2016-10-12

    The question of whether humans represent grammatical knowledge as a binary condition on membership in a set of well-formed sentences, or as a probabilistic property has been the subject of debate among linguists, psychologists, and cognitive scientists for many decades. Acceptability judgments present a serious problem for both classical binary and probabilistic theories of grammaticality. These judgements are gradient in nature, and so cannot be directly accommodated in a binary formal grammar. However, it is also not possible to simply reduce acceptability to probability. The acceptability of a sentence is not the same as the likelihood of its occurrence, which is, in part, determined by factors like sentence length and lexical frequency. In this paper, we present the results of a set of large-scale experiments using crowd-sourced acceptability judgments that demonstrate gradience to be a pervasive feature in acceptability judgments. We then show how one can predict acceptability judgments on the basis of probability by augmenting probabilistic language models with an acceptability measure. This is a function that normalizes probability values to eliminate the confounding factors of length and lexical frequency. We describe a sequence of modeling experiments with unsupervised language models drawn from state-of-the-art machine learning methods in natural language processing. Several of these models achieve very encouraging levels of accuracy in the acceptability prediction task, as measured by the correlation between the acceptability measure scores and mean human acceptability values. We consider the relevance of these results to the debate on the nature of grammatical competence, and we argue that they support the view that linguistic knowledge can be intrinsically probabilistic.

  2. 20 CFR 655.143 - Notice of acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... § 655.143 Notice of acceptance. (a) Notification timeline. When the CO determines the Application for... subpart, the CO will notify the employer within 7 calendar days of the CO's receipt of the Application for... system and direct the SWA to circulate a copy of the job order to other such States the CO determines...

  3. 12 CFR 150.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accept it? 150.200 Section 150.200 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE... Account § 150.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  4. 12 CFR 550.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accept it? 550.200 Section 550.200 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE... § 550.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  5. 12 CFR 150.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... accept it? 150.200 Section 150.200 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE... Account § 150.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  6. 12 CFR 550.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... accept it? 550.200 Section 550.200 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE... § 550.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  7. 12 CFR 550.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... accept it? 550.200 Section 550.200 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE... § 550.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  8. 12 CFR 550.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... accept it? 550.200 Section 550.200 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE... § 550.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  9. 12 CFR 150.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... accept it? 150.200 Section 150.200 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE... Account § 150.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  10. 12 CFR 550.200 - Must I review a prospective account before I accept it?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accept it? 550.200 Section 550.200 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE... § 550.200 Must I review a prospective account before I accept it? Before accepting a prospective fiduciary account, you must review it to determine whether you can properly administer the account....

  11. 49 CFR 232.505 - Pre-revenue service acceptance testing plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... acceptance tests; (3) Correct any safety deficiencies identified by FRA in the design of the equipment or in... measure or determine the success or failure of the tests. If acceptance is to be based on extrapolation of... 49 Transportation 4 2010-10-01 2010-10-01 false Pre-revenue service acceptance testing plan....

  12. 49 CFR 232.505 - Pre-revenue service acceptance testing plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... acceptance tests; (3) Correct any safety deficiencies identified by FRA in the design of the equipment or in... measure or determine the success or failure of the tests. If acceptance is to be based on extrapolation of... 49 Transportation 4 2011-10-01 2011-10-01 false Pre-revenue service acceptance testing plan....

  13. Information and Communications Technology Acceptance among Malaysian Adolescents in Urban Poverty

    ERIC Educational Resources Information Center

    Halili, Siti Hajar; Sulaiman, Hamidah; Razak, Rafiza Abdul

    2017-01-01

    This study was conducted to identify the information communication and technology (ICT) usage among adolescents in urban poverty and their acceptance of using ICT in teaching and learning (T&L) process. The Technology Acceptance Model was used in determining the acceptance of ICT by focusing on factors such as perceived ease of use and…

  14. Necessity of Eigenstate Thermalization

    NASA Astrophysics Data System (ADS)

    De Palma, Giacomo; Serafini, Alessio; Giovannetti, Vittorio; Cramer, Marcus

    2015-11-01

    Under the eigenstate thermalization hypothesis (ETH), quantum-quenched systems equilibrate towards canonical, thermal ensembles. While at first glance the ETH might seem a very strong hypothesis, we show that it is indeed not only sufficient but also necessary for thermalization. More specifically, we consider systems coupled to baths with well-defined macroscopic temperature and show that whenever all product states thermalize then the ETH must hold. Our result definitively settles the question of determining whether a quantum system has a thermal behavior, reducing it to checking whether its Hamiltonian satisfies the ETH.

  15. Axelrod model: accepting or discussing

    NASA Astrophysics Data System (ADS)

    Dybiec, Bartlomiej; Mitarai, Namiko; Sneppen, Kim

    2012-10-01

    Agents building social systems are characterized by complex states, and interactions among individuals can align their opinions. The Axelrod model describes how local interactions can result in emergence of cultural domains. We propose two variants of the Axelrod model where local consensus is reached either by listening and accepting one of neighbors' opinion or two agents discuss their opinion and achieve an agreement with mixed opinions. We show that the local agreement rule affects the character of the transition between the single culture and the multiculture regimes.

  16. Development of a method for the determination of UV filters in water samples using stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Rodil, Rosario; Moeder, Monika

    2008-02-01

    Stir bar sorptive extraction (SBSE) in combination with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was applied for the determination of 9 UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 20 mL of water sample at pH 2 (10% MeOH) and stirred at 1000 rpm for 180 min. Then, the stir bar was subjected to TD-GC-MS. The desorption conditions (desorption temperature and desorption time) and SBSE parameters (ionic strength, pH, presence of organic solvent and time) were optimised using a full factorial design and a Box-Behnken design, respectively. The method shows good linearity (correlation coefficients >0.994) and reproducibility (RSD<16%). The extraction efficiencies were above 63% for all the compounds. Detection limits were between 0.2 and 63 ng/L. The developed method offers the ability to detect several UV filters at ultra-low concentration levels with only 20 mL of sample volume. The effectiveness of the method was tested by analysing real samples such as lake water, river water and treated wastewater. The application of the method allowed reporting the levels of UV filters in environmental water samples.

  17. How to determine the thermal electron density and the magnetic field strength from the Cluster/Whisper observations around the Earth

    NASA Astrophysics Data System (ADS)

    Trotignon, J. G.; Décréau, P. M. E.; Rauch, J. L.; Randriamboarison, O.; Krasnoselskikh, V.; Canu, P.; Alleyne, H.; Yearby, K.; Le Guirriec, E.; Séran, H. C.; Sené, F. X.; Martin, Ph.; Lévêque, M.; Fergeau, P.

    2001-10-01

    The Wave Experiment Consortium, WEC, is a highly integrated package of five instruments used to study the plasma environment around the Earth. One of these instruments, the Waves of HIgh frequency and Sounder for Probing of Electron density by Relaxation, Whisper, aims at the thermal electron density evaluation and natural wave monitoring in the 4-83 kHz frequency range. In its active working mode, which is our primarily concern here, the Whisper instrument transmits a short wave train at a swept frequency and receives echoes after a delay. Incidentally, it behaves like a classical ground-based ionosonde. Natural modes of oscillations may thus be excited in the surrounding medium. This means that with suitable interpretations, the Whisper sounding technique becomes a powerful tool for plasma diagnosis. By taking into account the characteristic frequencies of the magnetoplasmas encountered by the Cluster spacecraft, it is indeed possible to reliably and accurately determine the electron density and, to a lesser degree, the magnetic field strength from the Whisper electric field measurements. Due to the predominantly electrostatic nature of the waves that are excited, observations of resonances may also lead to information on the electron velocity distribution functions. The existence of a hot population may indeed be revealed and the hot to cold density ratio can be estimated.

  18. The gas chromatographic determination of volatile fatty acids in wastewater samples: evaluation of experimental biases in direct injection method against thermal desorption method.

    PubMed

    Ullah, Md Ahsan; Kim, Ki-Hyun; Szulejko, Jan E; Cho, Jinwoo

    2014-04-11

    The production of short-chained volatile fatty acids (VFAs) by the anaerobic bacterial digestion of sewage (wastewater) affords an excellent opportunity to alternative greener viable bio-energy fuels (i.e., microbial fuel cell). VFAs in wastewater (sewage) samples are commonly quantified through direct injection (DI) into a gas chromatograph with a flame ionization detector (GC-FID). In this study, the reliability of VFA analysis by the DI-GC method has been examined against a thermal desorption (TD-GC) method. The results indicate that the VFA concentrations determined from an aliquot from each wastewater sample by the DI-GC method were generally underestimated, e.g., reductions of 7% (acetic acid) to 93.4% (hexanoic acid) relative to the TD-GC method. The observed differences between the two methods suggest the possibly important role of the matrix effect to give rise to the negative biases in DI-GC analysis. To further explore this possibility, an ancillary experiment was performed to examine bias patterns of three DI-GC approaches. For instance, the results of the standard addition (SA) method confirm the definite role of matrix effect when analyzing wastewater samples by DI-GC. More importantly, their biases tend to increase systematically with increasing molecular weight and decreasing VFA concentrations. As such, the use of DI-GC method, if applied for the analysis of samples with a complicated matrix, needs a thorough validation to improve the reliability in data acquisition.

  19. Simultaneous determination of parabens and synthetic musks in water by stir-bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Ramírez, Noelia; Borrull, Francesc; Marcé, Rosa Maria

    2012-02-01

    This study focuses on a method for simultaneously determining personal care products in a wide range of polarities in different water matrices. The method is based on stir-bar sorptive extraction followed by thermal desorption-gas chromatography-mass spectrometry. Prior to extraction, the parabens were acetylated to improve their affinity for the polydimethylsiloxane phase of the stir bar. The method showed good linearity, repeatability and reproducibility between days for all compounds and limits of detection at low ng/L levels (between 0.02 and 0.3 ng/L). The proposed method is also environmentally friendly, because it does not use organic solvents, and reduces the risk of external pollution, due to the minimal manipulation of the sample required. The method developed was successfully applied for the analysis of personal care products in different kinds of water matrices: influents and effluents of urban and industrial wastewater treatment plants, effluents of a reverse osmosis treatment plant and river waters. The influents of urban treatment plants generally showed the highest values for synthetic musks, with concentrations of up to 2219 ng/L of galaxolide, whereas the highest concentrations of parabens were detected in the industrial treatment plants influents.

  20. Determination of off-flavor compounds, 2-methylisoborneol and geosmin, in salmon fillets using stir bar sorptive extraction-thermal desorption coupled with gas chromatography-mass spectrometry.

    PubMed

    Ruan, E D; Aalhus, J L; Summerfelt, S T; Davidson, J; Swift, B; Juárez, M

    2013-12-20

    A sensitive and solvent-less method for the determination of musty and earthy off-flavor compounds, 2-methylisoborneol (MIB) and geosmin (GSM), in salmon tissue was developed using stir bar sorptive extraction-thermal desorption coupled with gas chromatography-mass spectrometry (SBSE-TD-GCMS). MIB and GSM were solid phase extracted using polydimethylsiloxane (PDMS) coated stir bars, analyzed by gas chromatography, and detected in full scan mode of mass selective detector (MSD). Using this method, the calibration curves of MIB and GSM were linear in the range of 0.3-100ng/L, with a correlation coefficient above 0.999 and RSDs less than 4% (n=4). The limit of detection (LOD, S/N=3, n=6) and limit of quantification (LOQ, S/N=10, n=6) of MIB and GSM were both ∼0.3 and 1ng/L, respectively. The recoveries of MIB and GSM were 22% and 29% by spike in 30ng/L standard compounds, 23% and 30% by spike-in 100ng/L standard compounds in salmon tissue samples with good precision (<8% of RSDs, n=6), respectively. The recoveries of MIB and GSM were better than reported methodologies using SPME fibres (<10%) in fish tissue samples. This method was successfully applied to monitor and characterize depurated salmon fillet samples (0, 3, 6 and 10 days).

  1. Thermally stable ionic liquid-based sol-gel coating for ultrasonic extraction-solid-phase microextraction-gas chromatography determination of phthalate esters in agricultural plastic films.

    PubMed

    Zhou, Xin; Shao, Xiao; Shu, Jian-jun; Liu, Ming-ming; Liu, Han-lan; Feng, Xiong-han; Liu, Fan

    2012-01-30

    A novel sol-gel-coated ionic liquid-based ([AMIM][N(SO(2)CF(3))(2)]-OH-TSO) fiber was successfully applied for the determination of phthalate esters (PAEs) in agricultural plastic films by ultrasonic extraction (UE) combined with solid phase microextraction-gas chromatography (SPME-GC) due to its high thermal stability, specific selectivity and extraction efficiency. The extractant for UE and the adsorption time for SPME were optimized to achieve higher extraction efficiency. The desorption temperature and time were also optimized to avoid the carryover effect of previous extraction, and ultimately improve the precision and accuracy of the method. The [AMIM][N(SO(2)CF(3))(2)]-OH-TSO fiber showed comparable, or even higher response to most of the investigated PAEs than the commercial PDMS, PDMS-DVB and PA fibers. The carryover problem, often encountered when using commercial fibers, had been eliminated when desorption was performed at 360°C for 8 min. The proposed SPME-GC method showed good linearity over three to four orders of magnitude, and low limits of detection ranged from 0.003 to 0.063 μg L(-1). The relative standard deviation values obtained were below 10%, and the recoveries were in the ranges of 90.2-111.4%. Some of the PAEs studied were detected at very high concentration in these agricultural plastic film samples, resulting in a potential risk of crop damage, environmental contamination and human health exposure.

  2. Determination of volatile organic compounds in urban and industrial air from Tarragona by thermal desorption and gas chromatography-mass spectrometry.

    PubMed

    Ras-Mallorquí, Maria Rosa; Marcé-Recasens, Rosa Maria; Borrull-Ballarín, Francesc

    2007-05-15

    This study describes the optimisation of an analytical method to determine 54 volatile organic compounds (VOCs) in air samples by active collection on multisorbent tubes, followed by thermal desorption and gas chromatography-mass spectrometry. Two multisorbent beds, Carbograph 1/Carboxen 1000 and Tenax/Carbograph 1TD, were tested. The latter gave better results, mainly in terms of the peaks that appeared in blank chromatograms. Temperatures, times and flow desorption were optimised. Recoveries were higher than 98.9%, except methylene dichloride, for which the recovery was 74.9%. The method's detection limits were between 0.01 and 1.25mugm(-3) for a volume sample of 1200ml, and the repeatability on analysis of 100ng of VOCs, expressed as relative standard deviation for n=3, was lower than 4% for all compounds. Urban and industrial air samples from the Tarragona region were analysed. Benzene, toluene, ethylbenzene and xylenes (BTEX) were found to be the most abundant VOCs in urban air. Total VOCs in urban samples ranged between 18 and 307mugm(-3). Methylene chloride, 1,4-dichlorobenzene, chloroform and styrene were the most abundant VOCs in industrial samples, and total VOCs ranged between 19 and 85mugm(-3).

  3. Process management using component thermal-hydraulic function classes

    DOEpatents

    Morman, James A.; Wei, Thomas Y. C.; Reifman, Jaques

    1999-01-01

    A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced.

  4. Process management using component thermal-hydraulic function classes

    DOEpatents

    Morman, J.A.; Wei, T.Y.C.; Reifman, J.

    1999-07-27

    A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced. 5 figs.

  5. Progress in thermal comfort research over the last twenty years.

    PubMed

    de Dear, R J; Akimoto, T; Arens, E A; Brager, G; Candido, C; Cheong, K W D; Li, B; Nishihara, N; Sekhar, S C; Tanabe, S; Toftum, J; Zhang, H; Zhu, Y

    2013-12-01

    Climate change and the urgency of decarbonizing the built environment are driving technological innovation in the way we deliver thermal comfort to occupants. These changes, in turn, seem to be setting the directions for contemporary thermal comfort research. This article presents a literature review of major changes, developments, and trends in the field of thermal comfort research over the last 20 years. One of the main paradigm shift was the fundamental conceptual reorientation that has taken place in thermal comfort thinking over the last 20 years; a shift away from the physically based determinism of Fanger's comfort model toward the mainstream and acceptance of the adaptive comfort model. Another noticeable shift has been from the undesirable toward the desirable qualities of air movement. Additionally, sophisticated models covering the physics and physiology of the human body were developed, driven by the continuous challenge to model thermal comfort at the same anatomical resolution and to combine these localized signals into a coherent, global thermal perception. Finally, the demand for ever increasing building energy efficiency is pushing technological innovation in the way we deliver comfortable indoor environments. These trends, in turn, continue setting the directions for contemporary thermal comfort research for the next decades.

  6. The Acceptability Limit in Food Shelf Life Studies.

    PubMed

    Manzocco, Lara

    2016-07-26

    Despite its apparently intuitive nature, the acceptability limit is probably the most difficult parameter to be defined when developing a shelf life test. Although it dramatically affects the final shelf life value, it is surprising that discussion on its nature has been largely neglected in the literature and only rare indications about the possible methodologies for its determination are available in the literature. This is due to the fact that the definition of this parameter is a consumer- and market-oriented issue, requiring a rational evaluation of the potential negative consequences of food unacceptability in the actual market scenario. This paper critically analyzes the features of the acceptability limit and the role of the decision maker. The methodologies supporting the choice of the acceptability limit as well as acceptability limit values proposed in the literature to calculate shelf life of different foods are reviewed.

  7. Sexual Education In Malaysia: Accepted Or Rejected?

    PubMed Central

    Mohd Mutalip, Siti Syairah; Mohamed, Ruzianisra

    2012-01-01

    Background: Introduction to sexual education in schools was suggested by the Malaysian government as one of the effort taken in the aim to reduce the sexual-related social problems among Malaysian teenagers nowadays. This study was proposed in the aim to determine the rate of acceptance among adolescents on the implementation of sexual education in schools. Methods: This study was conducted using questionnaires distributed to 152 pre-degree students in Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Kampus Puncak Alam, Selangor, Malaysia. Obtained data were statistically analyzed. Results: Almost half (49.3%) of the respondents agreed that sexual education might help to overcome the social illness among school teenagers. Besides, a large number (77.6%) of respondents also agreed that this module should be incorporated with other core subjects compare to the feedback received on the implementation of this module on its own (28.9%). Conclusion: These results have provided some insight towards the perception of sexual education among the teenagers. Since most of the respondents agreed with this idea, so it might be a sign that the implementation of sexual education is almost accepted by the adolescents. PMID:23113207

  8. Site acceptance test, W-030 MICON system

    SciTech Connect

    Hill, L.F., Westinghouse Hanford

    1996-06-10

    Monitoring and control of the W-030 ventilation upgrade is provided by a distributed control system (DCS) furnished by MICON Corporation. After shipment to the Hanford Site, the site acceptance test (SAT) for this system was conducted in a laboratory environment over a six month period, involving four distinct phases and numerous hardware and software modifications required to correct test exceptions. The final results is a system which is not fully compliant with procurement specifications but is determined to meet minimum Project W-030 safety and functional requirements. A negotiated settlement was reached with the supplier to establish a `path forward` for system implementation. This report documents the `as-run` status of the SAT. The SAT was completed in August of 1995. It was later followed by comprehensive acceptance testing of the W-030 control-logic configuration software; results are documented in WHC-SD-W030-ATR-011. Further testing is reported as part of process system startup operational testing, performed after the MICON installation.

  9. Determination of a wide range of volatile organic compounds in ambient air using multisorbent adsorption/thermal desorption and gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Pankow, J.F.; Luo, W.; Isabelle, L.M.; Bender, D.A.; Baker, R.J.

    1998-01-01

    Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The eight most volatile compounds were determined using a 1.5-L air sample and a sample cartridge containing 50 mg of Carbotrap B and 280 mg of Carboxen 1000; the remaining 79 compounds were determined using a 5-L air sample and a cartridge containing 180 mg of Carbotrap B and 70 mg of Carboxen 1000. Analysis and detection were by gas chromatography/mass spectrometry. The minimum detectable level (MDL) concentration values ranged from 0.01 parts per billion by volume (ppbv) for chlorobenzene to 0.4 ppbv for bromomethane; most of the MDL values were in the range 0.02-0.06 ppbv. No breakthrough was detected with the prescribed sample volumes. Analyte stability on the cartridges was very good. Excellent recoveries were obtained with independent check standards. Travel spike recoveries ranged from 90 to 110% for 72 of the 87 compounds. The recoveries were less than 70% for bromomethane and chloroethene and for a few compounds such as methyl acetate that are subject to losses by hydrolysis; the lowest travel spike recovery was obtained for bromomethane (62%). Blank values for all compounds were either below detection or very low. Ambient atmospheric sampling was conducted in New Jersey from April to December, 1997. Three sites characterized by low, moderate, and high densities of urbanization/traffic were sampled. The median detected concentrations of the compounds were either similar at all three sites (as with the chlorofluorocarbon compounds) or increased with the density of urbanization/traffic (as with dichloromethane, MTBE, benzene, and toluene). For toluene, the median detected

  10. Quantum Thermal Transistor.

    PubMed

    Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

    2016-05-20

    We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

  11. Quantum Thermal Transistor

    NASA Astrophysics Data System (ADS)

    Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

    2016-05-01

    We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

  12. Studying Student Teachers' Acceptance of Role Responsibility.

    ERIC Educational Resources Information Center

    Davis, Michael D.; Davis, Concetta M.

    1980-01-01

    There is variance in the way in which student teachers accept responsibility for the teaching act. This study explains why some variables may affect student teachers' acceptance of role responsibilities. (CM)

  13. [Subjective well-being and self acceptance].

    PubMed

    Makino, Y; Tagami, F

    1998-06-01

    The purpose of the present study was to examine the relationship between subjective well-being and self acceptance, and to design a happiness self-writing program to increase self acceptance and subjective well-being of adolescents. In study 1, we examined the relationship between social interaction and self acceptance. In study 2, we created a happiness self-writing program in cognitive behavioral approach, and examined whether the program promoted self acceptance and subjective well-being. Results indicated that acceptance of self-openness, an aspect of self acceptance, was related to subjective well-being. The happiness self-writing program increased subjective well-being, but it was not found to have increased self acceptance. It was discussed why the program could promote subjective well-being, but not self acceptance.

  14. HYDROGEN ATOM THERMAL PARAMETERS.

    PubMed

    JENSEN, L H; SUNDARALINGAM, M

    1964-09-11

    Isotropic hydrogen atom thermal parameters for N,N'- hexamethylenebispropionamide have been determined. They show a definite trend and vary from approximately the same as the mean thermal parameters for atoms other than hydrogen near the center of the molecule to appreciably greater for atoms near the end. The indicated trend for this compound, along with other results, provides the basis for a possible explanation of the anomolous values that have been obtained for hydrogen atom thermal parameters.

  15. Method validation for control determination of mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry.

    PubMed

    Torres, Daiane Placido; Martins-Teixeira, Maristela Braga; Cadore, Solange; Queiroz, Helena Müller

    2015-01-01

    A method for the determination of total mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) has been validated following international foodstuff protocols in order to fulfill the Brazilian National Residue Control Plan. The experimental parameters have been previously studied and optimized according to specific legislation on validation and inorganic contaminants in foodstuff. Linearity, sensitivity, specificity, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness as well as accuracy of the method have been evaluated. Linearity of response was satisfactory for the two range concentrations available on the TDA AAS equipment, between approximately 25.0 and 200.0 μg kg(-1) (square regression) and 250.0 and 2000.0 μg kg(-1) (linear regression) of mercury. The residues for both ranges were homoscedastic and independent, with normal distribution. Correlation coefficients obtained for these ranges were higher than 0.995. Limits of quantification (LOQ) and of detection of the method (LDM), based on signal standard deviation (SD) for a low-in-mercury sample, were 3.0 and 1.0 μg kg(-1), respectively. Repeatability of the method was better than 4%. Within-laboratory reproducibility achieved a relative SD better than 6%. Robustness of the current method was evaluated and pointed sample mass as a significant factor. Accuracy (assessed as the analyte recovery) was calculated on basis of the repeatability, and ranged from 89% to 99%. The obtained results showed the suitability of the present method for direct mercury measurement in fresh fish and shrimp samples and the importance of monitoring the analysis conditions for food control purposes. Additionally, the competence of this method was recognized by accreditation under the standard ISO/IEC 17025.

  16. The NA49 large acceptance hadron detector

    NASA Astrophysics Data System (ADS)

    Afanasiev, S.; Alber, T.; Appelshäuser, H.; Bächler, J.; Barna, D.; Barnby, L. S.; Bartke, J.; Barton, R. A.; Betev, L.; Bialkowska, H.; Bieser, F.; Billmeier, A.; Blyth, C. O.; Bock, R.; Bormann, C.; Bracinik, J.; Brady, F. P.; Brockmann, R.; Brun, R.; Buncic, P.; Caines, H. L.; Cebra, D.; Cooper, G. E.; Cramer, J. G.; Csato, P.; Cyprian, M.; Dunn, J.; Eckardt, V.; Eckhardt, F.; Empl, T.; Eschke, J.; Ferguson, M. I.; Fessler, H.; Fischer, H. G.; Flierl, D.; Fodor, Z.; Frankenfeld, U.; Foka, P.; Freund, P.; Friese, V.; Ftacnik, J.; Fuchs, M.; Gabler, F.; Gal, J.; Ganz, R.; Gaździcki, M.; Gładysz, E.; Grebieszkow, J.; Günther, J.; Harris, J. W.; Hegyi, S.; Henkel, T.; Hill, L. A.; Hlinka, V.; Huang, I.; Hümmler, H.; Igo, G.; Irmscher, D.; Ivanov, M.; Janik, R.; Jacobs, P.; Jones, P. G.; Kadija, K.; Kolesnikov, V. I.; Kowalski, M.; Lasiuk, B.; Lévai, P.; Liebicher, K.; Lynen, U.; Malakhov, A. I.; Margetis, S.; Markert, C.; Marks, C.; Mayes, B.; Melkumov, G. L.; Mock, A.; Molnár, J.; Nelson, J. M.; Oldenburg, M.; Odyniec, G.; Palla, G.; Panagiotou, A. D.; Pestov, Y.; Petridis, A.; Pikna, M.; Pimpl, W.; Pinsky, L.; Piper, A.; Porter, R. J.; Poskanzer, A. M.; Poziombka, S.; Prindle, D. J.; Pühlhofer, F.; Rauch, W.; Reid, J. G.; Renfordt, R.; Retyk, W.; Ritter, H. G.; Röhrich, D.; Roland, C.; Roland, G.; Rudolph, H.; Rybicki, A.; Sammer, T.; Sandoval, A.; Sann, H.; Schäfer, E.; Schmidt, R.; Schmischke, D.; Schmitz, N.; Schönfelder, S.; Semenov, A. Yu.; Seyboth, J.; Seyboth, P.; Seyerlein, J.; Sikler, F.; Sitar, B.; Skrzypczak, E.; Squier, G. T. A.; Stelzer, H.; Stock, R.; Strmen, P.; Ströbele, H.; Struck, C.; Susa, T.; Szarka, I.; Szentpetery, I.; Szymański, P.; Sziklai, J.; Toy, M.; Trainor, T. A.; Trentalange, S.; Ullrich, T.; Vassiliou, M.; Veres, G.; Vesztergombi, G.; Vranic, D.; Wang, F. Q.; Weerasundara, D. D.; Wenig, S.; Whitten, C.; Wieman, H.; Wienold, T.; Wood, L.; Yates, T. A.; Zimanyi, J.; Zhu, X.-Z.; Zybert, R.

    1999-07-01

    The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large-volume TPCs for tracking and particle identification via d E/d x. TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions.

  17. 48 CFR 2911.103 - Market acceptance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Market acceptance. 2911... DESCRIBING AGENCY NEEDS Selecting And Developing Requirements Documents 2911.103 Market acceptance. The... offered have either achieved commercial market acceptance or been satisfactorily supplied to an...

  18. 48 CFR 11.103 - Market acceptance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Market acceptance. 11.103... DESCRIBING AGENCY NEEDS Selecting and Developing Requirements Documents 11.103 Market acceptance. (a) Section... either— (i) Achieved commercial market acceptance; or (ii) Been satisfactorily supplied to an...

  19. Older Adults' Acceptance of Information Technology

    ERIC Educational Resources Information Center

    Wang, Lin; Rau, Pei-Luen Patrick; Salvendy, Gavriel

    2011-01-01

    This study investigated variables contributing to older adults' information technology acceptance through a survey, which was used to find factors explaining and predicting older adults' information technology acceptance behaviors. Four factors, including needs satisfaction, perceived usability, support availability, and public acceptance, were…

  20. 46 CFR 28.73 - Accepted organizations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Accepted organizations. 28.73 Section 28.73 Shipping... INDUSTRY VESSELS General Provisions § 28.73 Accepted organizations. An organization desiring to be designated by the Commandant as an accepted organization must request such designation in writing. As...