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Sample records for determining acceptable thermal

  1. 5 CFR 531.409 - Acceptable level of competence determinations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Acceptable level of competence... REGULATIONS PAY UNDER THE GENERAL SCHEDULE Within-Grade Increases § 531.409 Acceptable level of competence... delegated shall determine which employees are performing at an acceptable level of competence. (b) Basis...

  2. 5 CFR 531.409 - Acceptable level of competence determinations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Acceptable level of competence... REGULATIONS PAY UNDER THE GENERAL SCHEDULE Within-Grade Increases § 531.409 Acceptable level of competence... delegated shall determine which employees are performing at an acceptable level of competence. (b) Basis...

  3. 5 CFR 531.409 - Acceptable level of competence determinations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Acceptable level of competence... REGULATIONS PAY UNDER THE GENERAL SCHEDULE Within-Grade Increases § 531.409 Acceptable level of competence... delegated shall determine which employees are performing at an acceptable level of competence. (b) Basis...

  4. 5 CFR 531.409 - Acceptable level of competence determinations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Acceptable level of competence... REGULATIONS PAY UNDER THE GENERAL SCHEDULE Within-Grade Increases § 531.409 Acceptable level of competence... delegated shall determine which employees are performing at an acceptable level of competence. (b) Basis...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Pulsed electric fields versus thermal treatment: equivalent processes to obtain equally acceptable citrus juices.

    PubMed

    Sentandreu, E; Carbonell, L; Rodrigo, D; Carbonell, J V

    2006-08-01

    Pulsed electric field treatment has been claimed to produce more acceptable chilled citrus juices than those obtained by conventional thermal treatment. The pectin methylesterase activity and the acceptability of nine juices obtained from Clementine mandarins, Valencia oranges, and Ortanique fruits (hybrid of mandarin and orange), untreated, pasteurized (85 degrees C for 10 s), and treated by pulsed electric fields (25 kV/cm for 330 micros), were evaluated. The treatments, selected to reach a similar level of pectin methylesterase inactivation, produced juices that did not differ in acceptability from each other for the three varieties and in all cases were less acceptable than the untreated juice. PMID:16924935

  10. 5 CFR 531.409 - Acceptable level of competence determinations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS PAY UNDER THE GENERAL SCHEDULE Within-Grade Increases § 531.409 Acceptable level of competence... competence in his or her current position, and the employee has not been given a performance rating in any... acceptable level of competence, the within-grade increase will be granted retroactively to the beginning...

  11. Determinants of taste preference and acceptability: quality versus hedonics.

    PubMed

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

    2012-07-18

    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, but the processing of the sensory signals in reward circuits could differ. Using 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 regardless of its intensity. The rats, grouped by a characteristic bimodal phenotypic difference in their preference for sucralose, treated this artificial sweetener as qualitatively different-compared to sucralose-avoiding rats, the sucralose-preferring rats found the stimulus much more perceptually similar to sucrose. Although the possibility that stimulus palatability may have served as a discriminative cue cannot entirely be ruled out, the profile of results suggests 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 approximately 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

  12. 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

  13. 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.

  14. 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. PMID:26471676

  15. 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. PMID:21376864

  16. 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.

  17. 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…

  18. Geoscience Laser Altimeter System (GLAS) Instrument: Flight Loop Heat Pipe (LHP) Acceptance Thermal Vacuum Test

    NASA Technical Reports Server (NTRS)

    Baker, Charles; Butler, Dan; Ku, Jentung; Grob, Eric; Swanson, Ted; Nikitkin, Michael; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Two loop heat pipes (LHPs) are to be used for tight thermal control of the Geoscience Laser Altimeter System (GLAS) instrument, planned for flight in late 2001. The LHPs are charged with Propylene as a working fluid. One LHP will be used to transport 110 W from a laser to a radiator, the other will transport 160 W from electronic boxes to a separate radiator. The application includes a large amount of thermal mass in each LHP system and low initial startup powers. The initial design had some non-ideal flight design compromises, resulted in a less than ideal charge level for this design concept with a symmetrical secondary wick. This less than ideal charge was identified as the source of inadequate performance of the flight LHPs during the flight thermal vacuum test in October of 2000. We modified the compensation chamber design, re-built and charged the LHPs for a final LHP acceptance thermal vacuum test. This test performed March of 2001 was 100% successful. This is the last testing to be performed on the LHPs prior to instrument thermal vacuum test. This sensitivity to charge level was shown through varying the charge on a Development Model Loop Heat Pipe (DM LHP) and evaluating performance at various fill levels. At lower fills similar to the original charge in the flight units, the same poor performance was observed. When the flight units were re-designed and filled to the levels similar to the initial successful DM LHP test, the flight units also successfully fulfilled all requirements. This final flight Acceptance test assessed performance with respect to startup, low power operation, conductance, and control heater power, and steady state control. The results of the testing showed that both LHPs operated within specification. Startup on one of the LHPs was better than the other LHP because of the starter heater placement and a difference in evaporator design. These differences resulted in a variation in the achieved superheat prior to startup. The LHP with

  19. 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...

  20. 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...

  1. Acceptance of Disability: Determinants of Overcoming Social Frustration

    PubMed Central

    Morozova, Elena Valeryevna; Shmeleva, Svetlana Vasilyevna; Sorokoumova, Elena Aleksandrovna; Nikishina, Vera Borisovna; Abdalina, Larisa Vasilyevna

    2015-01-01

    The article is devoted to the subjective reaction of patients at different stages of disabling disease, in the context of the formation of a specific cognitive-emotional and motivational model of “internal picture of disability”, depending on the severity of social frustration as the most important deconditioning factor. We wanted to identify psychological determinant of the specificity of adaptive activity of the patient to the situation disabling disease, depending on the level of increase social frustration. Nature of adaptation to the disabling disease depending on the level of increase social frustration expressed by: 1) decrease in self-esteem of patient self-efficacy with an increase in subjective experience of disability; 2) the growing tension of personal protective mechanisms; 3) reductions coping competence, which, depending on the rise of frustration, becomes effective instead of the rational-intelligent, more maladaptive emotional. PMID:25948469

  2. 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...

  3. 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…

  4. Novel method of thermal-inertia determination

    NASA Astrophysics Data System (ADS)

    MacLennan, E.; Emery, J.

    2014-07-01

    Spacecraft missions have shown how asteroids can be covered by a regolith ranging from fine-grained to large cobbles and boulders. Regolith properties for many objects can give information on processes altering the surfaces of these bodies, yet only a few have been imaged in sufficient detail to directly investigate their regoliths. For objects not visited by spacecraft, thermal inertia can be used to infer the physical properties of the regolith [1]. In general, surfaces of bare rock have a higher thermal inertia, whereas the presence of small regolith grains yields a lower thermal inertia. Thermal inertia is a quantity indicative of how resistive a material is to changes in temperature. An insulating layer of fine-grained material will cause large diurnal changes in temperature, whereas a ''bare rock'' surface causes temperatures to be longitudinally isothermal. Thermal inertia is thus also important for understanding the radiative forces acting to alter the dynamical properties of airless bodies (e.g. Yarkovsky and YORP; [2]). Traditional methods of thermal inertia determination require knowledge of the spin axis as input for thermophysical models (TPMs). TPMs invoke the heat diffusion equation in order to calculate surface temperatures for a rotating asteroid [3]. Asteroid spin axes provide the boundary condition needed to calculate the incident solar energy across the surface. Since spin axes for only small fraction of the total asteroid population are known [4], application of the traditional method is limited. Here, we assess the effectiveness of a method that does not require previous knowledge of an object's spin axis. This method uses multi-epoch observations of asteroid thermal emission at different viewing geometries. Many such observations of objects were made in 2010 by the WISE mission during its all sky survey [5]. As a result, object flux data for a warmer "afternoon" and cooler ''morning'' side are gathered at two wavelengths (12 & 22 μ m). This

  5. Human papilloma virus vaccine: determinants of acceptability by mothers for adolescents in Nigeria.

    PubMed

    Ezeanochie, Michael C; Olagbuji, Biodun N

    2014-09-01

    Vaccination of adolescent females against Human Papilloma Virus (HPV), the causative agent for cervical cancer has recently become available. As minors, parental acceptance of the vaccines for adolescent daughters requires exploration. This was a cross-sectional survey of 201 mothers attending the gynaecology clinic in a University Teaching Hospital in Nigeria on acceptability of the HPV vaccines and its determinants. Although 70% accepted vaccination of their daughters, 30% were unwilling and the commonest reason for unwillingness was that it may encourage sexual promiscuity (62.3%). Mothers with poor knowledge of STI were significantly more unwilling to accept HPV vaccines compared to those with average or good knowledge (p = 0.002). Furthermore, perception of susceptibility to HPV infection by daughters was significantly associated with acceptance of the vaccines (p = 0.0001). Increased advocacy and public enlightenment on cervical cancer control and the role of HPV vaccines in its prevention is still necessary especially in developing countries. PMID:25508051

  6. Human papilloma virus vaccine: determinants of acceptability by mothers for adolescents in Nigeria.

    PubMed

    Ezeanochie, Michael C; Olagbuji, Biodun N

    2014-09-01

    Vaccination of adolescent females against Human Papilloma Virus (HPV), the causative agent for cervical cancer has recently become available. As minors, parental acceptance of the vaccines for adolescent daughters requires exploration. This was a cross-sectional survey of 201 mothers attending the gynaecology clinic in a University Teaching Hospital in Nigeria on acceptability of the HPV vaccines and its determinants. Although 70% accepted vaccination of their daughters, 30% were unwilling and the commonest reason for unwillingness was that it may encourage sexual promiscuity (62.3%). Mothers with poor knowledge of STI were significantly more unwilling to accept HPV vaccines compared to those with average or good knowledge (p = 0.002). Furthermore, perception of susceptibility to HPV infection by daughters was significantly associated with acceptance of the vaccines (p = 0.0001). Increased advocacy and public enlightenment on cervical cancer control and the role of HPV vaccines in its prevention is still necessary especially in developing countries. PMID:25438520

  7. 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.

  8. 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.

  9. 32 CFR 644.543 - Determination of acceptable offers after advertising.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Sale Procedure § 644.543 Determination of acceptable... experienced real estate employee who need not be a real estate appraiser. This determination may be in the... responsible bidder. (2) Conforms to the Invitation for Bids. (3) Equals or exceeds the appraised fair...

  10. 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

    ... Determining the Acceptable Construction Area for Replacements A Appendix A to Part 2 Conservation of Power and... Construction Area for Replacements These guidelines shall be followed to determine what area may be used to... physical evidence in the area. Areas obviously not cleared during the original construction, as...

  11. 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 ...

  12. 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

  13. 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...

  14. Thermal parameters determination of battery cells by local heat flux measurements

    NASA Astrophysics Data System (ADS)

    Murashko, K. A.; Mityakov, A. V.; Pyrhönen, J.; Mityakov, V. Y.; Sapozhnikov, S. S.

    2014-12-01

    A new approach to define of the thermal parameters, such as heat capacity and through-plane thermal conductivity, of pouch-type cells is introduced. Application of local heat flux measurement with a gradient heat flux sensor (GHFS) allows determination of the cell thermal parameters in different surface points of the cell. The suggested method is not cell destructive as it does not require deep discharge of the cell or application of any charge/discharge cycles during the measurements of the thermal parameters of the cell. The complete procedure is demonstrated on a high-power lithium-ion (Li-ion) pouch cell, and it is verified on a sample with well-known thermal parameters. A comparison of the experimental results with conventional thermal characterization methods shows an acceptably low error. The dependence of the cell thermal parameters on the state of charge (SoC) and measurement points on the surface was studied by the proposed measurement approach.

  15. 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... temporary and permanent rights-of-way and associated work space that was used to construct the...

  16. 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... temporary and permanent rights-of-way and associated work space that was used to construct the...

  17. 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

  18. Determinants of acceptance and subsequent uptake of the HPV vaccine in a cohort in Eldoret, Kenya.

    PubMed

    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

  19. 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.

  20. 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

  1. Determinants of telemedicine acceptance in selected public hospitals in Malaysia: clinical perspective.

    PubMed

    Zailani, Suhaiza; Gilani, Mina Sayyah; Nikbin, Davoud; Iranmanesh, Mohammad

    2014-09-01

    The purpose of this study is to explore the determinants of telemedicine acceptance in selected public hospitals in Malaysia and to investigate the effect of health culture on the relationship between these determinants and telemedicine acceptance. Data were gathered by means of a survey of physicians and nurses as the main group of users of telemedicine technology from hospitals that are currently using telemedicine technology. The results indicated that government policies, top management support, perception of usefulness and computer self-efficiency have a positive and significant impact on telemedicine acceptance by public hospitals in Malaysia. The results also confirmed the moderating role of health culture on the relationship between government policies as well as perceived usefulness on telemedicine acceptance by Malaysian hospitals. The results are useful for decision-makers as well as managers to recognize the potential role of telemedicine and assist in the process of implementation, adoption and utilization, and, therefore, spread the usage of telemedicine technology in more hospitals in the country. PMID:25038891

  2. 45 CFR 2544.130 - How will the Corporation determine whether to solicit or accept a donation?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  3. 45 CFR 2544.130 - How will the Corporation determine whether to solicit or accept a donation?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  4. 45 CFR 2544.130 - How will the Corporation determine whether to solicit or accept a donation?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

  5. Social and individual determinants of adolescents' acceptance of novel healthy and cool snack products.

    PubMed

    Nørgaard, Maria Kümpel; Sørensen, Bjarne Taulo; Grunert, Klaus G

    2014-12-01

    Four new, healthy snack products, consisting of fruit, vegetables, bread, dip and topping, were tested with 600 Danish adolescents aged 9-16. Participants could view, handle, and test the products in a school setting. Acceptance was measured by overall buying intention, as well as buying intention contingent on specific substitutes and on the social situation. Price consciousness, health consciousness, snack neophobia, peer influence, social activities and word-of-mouth were measured as potential determinants of acceptance of the novel products. An exploratory analysis in TETRAD suggested that the measured constructs form three layers, with overall buying intention as the terminal causal effect, health consciousness, word of mouth, snack neophobia and peer influence as endogenous determinants, and social activities and the contingent buying intentions as mediators. Estimation of the causal relationships was conducted in LISREL. Findings show a predominance of social factors as determinants of novel snack acceptance, whereas health consciousness had only a weak and indirect effect on buying intentions and the effect of snack neophobia was partly mediated by social factors. PMID:25173064

  6. Effective thermal conductivity determination for low-density insulating materials

    NASA Technical Reports Server (NTRS)

    Williams, S. D.; Curry, D. M.

    1978-01-01

    That nonlinear least squares can be used to determine effective thermal conductivity was demonstrated, and a method for assessing the relative error associated with these predicted values was provided. The differences between dynamic and static determination of effective thermal conductivity of low-density materials that transfer heat by a combination of conduction, convection, and radiation were discussed.

  7. Pathway analysis approach for determining acceptable levels of contamination of radionuclides in soil

    SciTech Connect

    Till, J.E.; Moore, R.E.

    1988-09-01

    A methodology for determining acceptable levels for decontamination of soil containing radionuclides at waste sites is described. This methodology calculates the annual radiation dose that an individual receives while living on property that has been decommissioned and decontaminated. Pathways of exposure include direct radiation from ground surfaces, ingestion of contaminated food, inhalation of resuspended radionuclides and drinking contaminated water. Results calculated using this methodology were compared with U.S. Department of Energy (DOE) guidelines for a southeastern U.S. site. There is good agreement between the two methods provided similar assumptions are used.

  8. 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.

  9. Thermal diffusivity of seasonal snow determined from temperature profiles

    NASA Astrophysics Data System (ADS)

    Oldroyd, H. J.; Higgins, C. W.; Huwald, H.; Selker, J. S.; Parlange, M. B.

    2013-05-01

    Thermal diffusivity of snow is an important thermodynamic property associated with key hydrological phenomena such as snow melt and heat and water vapor exchange with the atmosphere. Direct determination of snow thermal diffusivity requires coupled point measurements of thermal conductivity and density, which continually change due to snow metamorphism. Traditional methods for determining these two quantities are generally limited by temporal resolution. In this study we present a method to determine the thermal diffusivity of snow with high temporal resolution using snow temperature profile measurements. High resolution (between 2.5 and 10 cm at 1 min) temperature measurements from the seasonal snow pack at the Plaine-Morte glacier in Switzerland are used as initial conditions and Neumann (heat flux) boundary conditions to numerically solve the one-dimensional heat equation and iteratively optimize for thermal diffusivity. The implementation of Neumann boundary conditions and a t-test, ensuring statistical significance between solutions of varied thermal diffusivity, are important to help constrain thermal diffusivity such that spurious high and low values as seen with Dirichlet (temperature) boundary conditions are reduced. The results show that time resolved thermal diffusivity can be determined from temperature measurements of seasonal snow and support density-based empirical parameterizations for thermal conductivity.

  10. Structural features determining thermal adaptation of esterases.

    PubMed

    Kovacic, Filip; Mandrysch, Agathe; Poojari, Chetan; Strodel, Birgit; Jaeger, Karl-Erich

    2016-02-01

    The adaptation of microorganisms to extreme living temperatures requires the evolution of enzymes with a high catalytic efficiency under these conditions. Such extremophilic enzymes represent valuable tools to study the relationship between protein stability, dynamics and function. Nevertheless, the multiple effects of temperature on the structure and function of enzymes are still poorly understood at the molecular level. Our analysis of four homologous esterases isolated from bacteria living at temperatures ranging from 10°C to 70°C suggested an adaptation route for the modulation of protein thermal properties through the optimization of local flexibility at the protein surface. While the biochemical properties of the recombinant esterases are conserved, their thermal properties have evolved to resemble those of the respective bacterial habitats. Molecular dynamics simulations at temperatures around the optimal temperatures for enzyme catalysis revealed temperature-dependent flexibility of four surface-exposed loops. While the flexibility of some loops increased with raising the temperature and decreased with lowering the temperature, as expected for those loops contributing to the protein stability, other loops showed an increment of flexibility upon lowering and raising the temperature. Preserved flexibility in these regions seems to be important for proper enzyme function. The structural differences of these four loops, distant from the active site, are substantially larger than for the overall protein structure, indicating that amino acid exchanges within these loops occurred more frequently thereby allowing the bacteria to tune atomic interactions for different temperature requirements without interfering with the overall enzyme function. PMID:26647400

  11. Biological and chemical tests of contaminated soils to determine bioavailability and environmentally acceptable endpoints (EAE)

    SciTech Connect

    Montgomery, C.R.; Menzie, C.A.; Pauwells, S.J.

    1995-12-31

    The understanding of the concept of bioavailability of soil contaminants to receptors and its use in supporting the development of EAE is growing but still incomplete. Nonetheless, there is increased awareness of the importance of such data to determine acceptable cleanup levels and achieve timely site closures. This presentation discusses a framework for biological and chemical testing of contaminated soils developed as part of a Gas Research Institute (GRI) project entitled ``Environmentally Acceptable Endpoints in Soil Using a Risk Based Approach to Contaminated Site Management Based on Bioavailability of Chemicals in Soil.`` The presentation reviews the GRI program, and summarizes the findings of the biological and chemical testing section published in the GRI report. The three primary components of the presentation are: (1) defining the concept of bioavailability within the existing risk assessment paradigm, (2) assessing the usefulness of the existing tests to measure bioavailability and test frameworks used to interpret these measurements, and (3) suggesting how a small selection of relevant tests could be incorporated into a flexible testing scheme for soils to address this issue.

  12. DECOM: A pathway analysis approach for determining acceptable levels of contamination of radionuclides in soil

    SciTech Connect

    Till, J.E.; Moore, R.E.

    1986-02-28

    The purpose of this report is to describe a method for determining acceptable levels for decontamination of soil containing radionuclides at waste sites located on the Savannah River Plant. This task was achieved through development of a computer program called ''DECOM.'' The DECOM code is written in BASIC, runs on an IBM microcomputer (AT, XT, or compatible), is interactive, and calculates the annual radiation dose that an individual receives while living on property that has been decommissioned and decontaminated. User selected pathways of exposure include direct radiation from ground surface, ingestion of contaminated food, inhalation of resuspended radionuclides, and drinking contaminated water. The program requires a minimum of knowledge in radiological assessment. Although default values have been provided for most parameters, the methodology requires the user to define an acceptable effective dose equivalent that the resident can receive. Other input data required to run the code include the concentration of radionuclides in soil and some site specific parameters relating to the characteristics of the area. 37 refs., 2 figs., 4 tabs.

  13. Coupled inverse and forward modelling to assess the range of acceptable thermal histories, a case study from SE Brazil

    NASA Astrophysics Data System (ADS)

    Cogné, N.; Gallagher, K.; Cobbold, P. R.

    2012-04-01

    We performed a new thermochronological study (fission track analysis and (U-Th)/He dating on apatite) in SE Brazil and integrate those data with inverse and forward modelling via QTQt software (Gallagher, 2012) to obtain thermal histories. The inversion results were used to characterize the general thermal histories and the associated uncertainties. For most of the samples we had a first phase of cooling during Late Cretaceous or Early Tertiary with subsequent reheating followed by Neogene cooling. The inverse modelling does not provide a unique solution and the associated uncertainties can be quite significant. Moreover the Tertiary parts of thermal histories were usually near the accepted resolution of the thermochronometric methods (~50-40°C). Therefore we performed deterministic forward modelling within the range of uncertainties to assess which solution is the most consistent with the data and independent geological information. These results are always conditional on the assumed kinetics for fission track annealing and diffusion of He, so we do not test the validity of that aspect. However, we can look at the range of predictions for the different forward models tested. This apporach implies that the reheating is required only for the samples around onshore Tertiary basins. For other samples we cannot conclude but geological information are against this hypothesis. However the Neogene cooling is required for all the samples.The combination of forward and inverse modelling allows us to better constrain the thermal histories for each sample in exploring the range of uncertainties and to reconcile a range of possible thermal histories with independent geological information. It also provides new information on the contrasting thermal evolution between different regions of the onshore SE Brazilian margin. Gallagher, K. 2012, Transdimensional Inverse thermal history modeling for quantitative thermochronology, Journal of Geophysical Research, in press.

  14. 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...

  15. A technique for determining thermal parameters using measured temperatures

    SciTech Connect

    Dincer, I.; Dost, S.

    1995-12-31

    This paper presents a simple but accurate technique for determining thermal parameters during direct cooling of solid objects, in terms of the cooling coefficient, lag factor, thermal diffusivity, and heat transfer coefficient. Solid objects are assumed to be cooled in a fluid medium. In the modeling the objects are approximated to infinite slabs, infinite cylinders or spherical bodies. A one-dimensional unsteady-state heat transfer analysis is carried out under three different conditions: Bi < 0.01, 0.1 < Bi < 100, and Bi > 100. A technique is then developed for determining the thermal parameters during cooling of such objects. The developed technique is illustrated by examples using actual temperature measurements taken from the studies presented previously. Results show that the technique presented here is capable of determining the thermal parameters during such a cooling process accurately.

  16. 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.

  17. 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.

    2016-02-01

    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.

  18. The meaning of air quality and flue gas emission standards for public acceptance of new thermal power plants.

    PubMed

    Barbalić, N; Marijan, G; Marić, M

    2000-06-01

    For the time being only 30-40% of the electric energy supply in Croatia comes from burning fossil fuel. New capacities of 800-1400 MW for the next decade will have to rely on the exclusive use of fossil fuels in thermal power plants (TPP). Public opinion will probably have a decisive influence on the issuing of construction permissions. The potential adverse effects on air seem to be the main argument against construction of TPPs. The priority is therefore to unambiguously state what air quality is warranted in the influenced area for the whole operation period of a TPP. It is important that the public should understand the real meaning of current air quality standards and emission limits. The only known way to do it today is through comparison with the corresponding standards and limits accepted worldwide. This paper discusses some important aspects of such comparison. PMID:11103526

  19. 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. PMID:26176844

  20. 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.

  1. Determination of thermal diffusion coefficient of nanofluid: Fullerene-toluene

    NASA Astrophysics Data System (ADS)

    Martin, Alain; Bou-Ali, M. Mounir

    2011-05-01

    Thermodiffusion coefficient at fullerene mass concentrations of 0.05%, 0.1%, 0.15%, and 0.2% was established for pure fullerene (C 60) diluted in toluene solutions. For this, the thermogravitational technique has been used in planar configuration with 4 extraction points. The determination of the concentration distribution along the column in steady state is determined by the method of analysis based on density measurements. In order to determine the thermal diffusion coefficient all thermophysical properties such as density, viscosity, thermal expansion coefficient and mass expansion coefficients were determined. All these studies coincide with the importance of the knowledge of the thermophysics and transport properties of the nanofluids to develop new applications and to optimize the existing ones.

  2. 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.

  3. 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. PMID:23646824

  4. 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.

  5. 76 FR 61269 - Protection of Stratospheric Ozone: acceptability Determination 26 for Significant New...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... SNAP rulemaking published in the Federal Register on March 18, 1994 (59 FR 13044). Notices and... 18, 1994, 59 FR 13044; August 26, 1994, 59 FR 44240; January 13, 1995, 60 FR 3318; September 5, 1996, 61 FR 47012; December 20, 2002, 67 FR 77927). Today's decision finds R- 507A acceptable as...

  6. 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…

  7. 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…

  8. Determination of Thermal-Diffusivity Dependence on Temperature of Transparent Samples by Thermal Wave Method

    NASA Astrophysics Data System (ADS)

    Kaźmierczak-Bałata, Anna; Bodzenta, Jerzy; Trefon-Radziejewska, Dominika

    2010-01-01

    The use of a typical measuring cryostat with a standard temperature controller was proposed for investigation of the temperature dependence of the thermal diffusivity of transparent samples. The basic idea is to use the cryostat heater to control the mean sample temperature and to generate the thermal wave in it, simultaneously. Because of the relatively high thermal inertia of the system, the measurements are carried out at frequencies not exceeding 50 mHz. The periodic temperature disturbance in the sample was detected optically by the use of the mirage effect. The proposed method was used for determination of the thermal diffusivity of yttrium aluminum garnet single crystals in a temperature range from 20 °C to 200 °C.

  9. Determination of BWR Spent Nuclear Fuel Assembly Effective Thermal Conductivity

    SciTech Connect

    Matthew D. Hinds

    2001-10-17

    The purpose of this calculation is to provide an effective thermal conductivity for use in predicting peak cladding temperatures in boiling water reactor (BWR) fuel assemblies with 7x7,8x8, and 9x9 rod arrays. The first objective of this calculation is to describe the development and application of a finite element representation that predicts peak spent nuclear fuel temperatures for BWR assemblies. The second objective is to use the discrete representation to develop a basis for determining an effective thermal conductivity (described later) for a BWR assembly with srneared/homogeneous properties and to investigate the thermal behavior of a spent fuel assembly. The scope of this calculation is limited to a steady-state two-dimensional representation of the waste package interior region. This calculation is subject to procedure AP-3.124, Calculations (Ref. 27) and guided by the applicable technical work plan (Ref. 14). While these evaluations were originally developed for the thermal analysis of conceptual waste package designs emplaced in the potential repository at Yucca Mountain, the methodology applies to storage and transportation thermal analyses as well. Note that the waste package sketch in Attachment V depicts a preliminary design, and should not be interpreted otherwise.

  10. Rapid Determination of the Thermal Nociceptive Threshold in Diabetic Rats

    PubMed Central

    Alshahrani, Saeed; Fernandez-Conti, Filipe; Araujo, Amanda; DiFulvio, Mauricio

    2012-01-01

    Painful diabetic neuropathy (PDN) is characterized by hyperalgesia i.e., increased sensitivity to noxious stimulus, and allodynia i.e., hypersensitivity to normally innocuous stimuli1. Hyperalgesia and allodynia have been studied in many different rodent models of diabetes mellitus2. However, as stated by Bölcskei et al, determination of "pain" in animal models is challenging due to its subjective nature3. Moreover, the traditional methods used to determine behavioral responses to noxious thermal stimuli usually lack reproducibility and pharmacological sensitivity3. For instance, by using the hot-plate method of Ankier4, flinch, withdrawal and/or licking of either hind- and/or fore-paws is quantified as reflex latencies at constant high thermal stimuli (52-55 °C). However, animals that are hyperalgesic to thermal stimulus do not reproducibly show differences in reflex latencies using those supra-threshold temperatures3,5. As the recently described method of Bölcskei et al.6, the procedures described here allows for the rapid, sensitive and reproducible determination of thermal nociceptive thresholds (TNTs) in mice and rats. The method uses slowly increasing thermal stimulus applied mostly to the skin of mouse/rat plantar surface. The method is particularly sensitive to study anti-nociception during hyperalgesic states such as PDN. The procedures described bellow are based on the ones published in detail by Almási et al5 and Bölcskei et al3. The procedures described here have been approved the Laboratory Animal Care and Use Committee (LACUC), Wright State University. PMID:22643870

  11. Soil thermal resistivity and thermal stability measuring instrument. Volume 1. Determination of soil thermal stability and other soil thermal properties. Final report

    SciTech Connect

    Boggs, S.A.; Radhakrishna, H.S.

    1981-11-01

    Numerous considerations influence the thermal design of an underground power cable, including the soil thermal resistivity, thermal diffusivity and thermal stability. Each of these properties is a function of soil moisture which is, in turn, a function of past weather, soil composition, and biological burden. The Neher-McGrath formalism has been widely used for thermal cable design. However, this formalism assumes knowledge of soil thermal properties (resistivity and diffusivity). For design purposes, these parameters should be treated statistically, since weather varies greatly from year-to-year. As well, soil thermal property surveys are normally required along the route to assess the thermal quality of the native soil. This project is intended to fill the gap between the need to carry out thermal design and the use of the Neher-McGrath formalism which is normally employed. This goal has been addressed through: (1) development of instrumentation and methods of measuring soil thermal properties in situ and in the laboratory; (2) recommendation of methods for conducting soil surveys along a proposed cable route and of assessing the thermal quality of soils; and (3) development of a computerized method to treat soil thermal design parameters on a statistical basis using computerized weather records as supplied by the US Environmental Data Service. This volume discussed methods for determining the thermal properties of soils. The use of the methods and instrumentation developed as a result of this contract should permit less conservative thermal design thereby improving the economics of underground transmission. As well, these techniques and instrumentation facilitate weather-dependent prediction of cable ampacity for installed cables, monitoring of backfill thermal stability, and many other new practices.

  12. 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. PMID:15982686

  13. 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.

  14. Determining the primary drivers of liking to predict consumers' acceptance of fresh nectarines and peaches.

    PubMed

    Delgado, Claudia; Crisosto, Gayle M; Heymann, Hildegarde; Crisosto, Carlos H

    2013-04-01

    A generic descriptive analysis using 11 judges provided 16 sensory attributes that described the aroma, flavor, and texture characteristics of 7 nectarine and peach cultivars selected for their predominant sensory attributes. Simultaneously, the "in-store" acceptability of these cultivars was evaluated by 120 consumers from northern California. The relationships among instrumental measurements (flesh firmness, ripe soluble solids concentration (RSSC), and ripe titratable acidity (RTA), sensory panel descriptors, and consumer hedonic responses were studied. In these cultivars, RSSC was the only instrumental measurement significantly related to overall liking. Cultivars with medium acidity and/or flavor/aroma were liked "very much," and consumer willingness to pay more was correlated with overall liking without regard to cultivar. Cluster analysis revealed 3 segments that were associated with ethnicity and consumer preferences within each segment. Sweetness was the main driver of liking for 2 consumer clusters; however, for the 3rd cluster, the perception of fruit aromas described as grassy/green fruit and pit aromas were the main drivers of liking. There was a high correlation between instrumental measurements and their sensory perception; however, the sensory attribute measurements explained cultivar characteristics better than instrumental measurements alone. Sweetness correlated positively with overall liking and consumer acceptance. PMID:23464630

  15. [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. PMID:26320306

  16. Temperature measurement by thermal strain imaging with diagnostic power ultrasound, with potential for thermal index determination.

    PubMed

    Liang, Hai-Dong; Zhou, Li-Xia; Wells, Peter N T; Halliwell, Michael

    2009-05-01

    Over the years, there has been a substantial increase in acoustic exposure in diagnostic ultrasound as new imaging modalities with higher intensities and frame rates have been introduced; and more electronic components have been packed into the probe head, so that there is a tendency for it to become hotter. With respect to potential thermal effects, including those which may be hazardous occurring during ultrasound scanning, there is a correspondingly growing need for in vivo techniques to guide the operator as to the actual temperature rise occurring in the examined tissues. Therefore, an in vivo temperature estimator would be of considerable practical value. The commonly-used method of tissue thermal index (TI) measurement with a hydrophone in water could underestimate the actual value of TI (in one report by as much as 2.9 times). To obtain meaningful results, it is necessary to map the temperature elevation in 2-D (or 3-D) space. We present methodology, results and validation of a 2-D spatial and temporal thermal strain ultrasound temperature estimation technique in phantoms, and its apparently novel application in tracking the evolution of heat deposition at diagnostic exposure levels. The same ultrasound probe is used for both transmission and reception. The displacement and thermal strain estimation methods are similar to those used in high-intensity focused ultrasound thermal monitoring. The use of radiofrequency signals permits the application of cross correlation as a similarity measurement for tracking feature displacement. The displacement is used to calculate the thermal strain directly related to the temperature rise. Good agreement was observed between the temperature rise and the ultrasound power and scan duration. Thermal strain up to 1.4% was observed during 4000-s scan. Based on the results obtained for the temperature range studied in this work, the technique demonstrates potential for applicability in phantom (and possibly in vivo tissue

  17. 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.

  18. 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.

  19. Determination of thermal properties of commercial Ni-MH cells

    NASA Technical Reports Server (NTRS)

    Darcy, Eric C.

    1994-01-01

    The test objectives were to evaluate the electrical and thermal performance of commercial Ni-MH cells, evaluate the effectiveness of commercial charge control circuits, assess the abuse tolerance of these cells, and correlate performance and abuse tolerances to cell design via disassembly. Design objectives were to determine which cell designs are most suitable for scale-up and to guide the design of future shuttle and space station based battery chargers. Results, displayed in viewgraph format, include: reflex charging with ICS circuit resulted in premature charge termination; Ni-MH cells appear very tolerant to overcharge at low rates; Enstore's charger is more electrically and thermally efficient at high rates; and Ni-MH cycles much more efficiently than Ni-Cd with the delta-V/delta-t termination.

  20. 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.

  1. Determination of Thermal State of Charge in Solar Heat Receivers

    NASA Technical Reports Server (NTRS)

    Glakpe, E. K.; Cannon, J. N.; Hall, C. A., III; Grimmett, I. W.

    1996-01-01

    The research project at Howard University seeks to develop analytical and numerical capabilities to study heat transfer and fluid flow characteristics, and the prediction of the performance of solar heat receivers for space applications. Specifically, the study seeks to elucidate the effects of internal and external thermal radiation, geometrical and applicable dimensionless parameters on the overall heat transfer in space solar heat receivers. Over the last year, a procedure for the characterization of the state-of-charge (SOC) in solar heat receivers for space applications has been developed. By identifying the various factors that affect the SOC, a dimensional analysis is performed resulting in a number of dimensionless groups of parameters. Although not accomplished during the first phase of the research, data generated from a thermal simulation program can be used to determine values of the dimensionless parameters and the state-of-charge and thereby obtain a correlation for the SOC. The simulation program selected for the purpose is HOTTube, a thermal numerical computer code based on a transient time-explicit, axisymmetric model of the total solar heat receiver. Simulation results obtained with the computer program are presented the minimum and maximum insolation orbits. In the absence of any validation of the code with experimental data, results from HOTTube appear reasonable qualitatively in representing the physical situations modeled.

  2. Interactions among thermal parameters determine offspring sex under temperature-dependent sex determination

    PubMed Central

    Warner, Daniel A.; Shine, Richard

    2011-01-01

    In many animals, temperatures experienced by developing embryos determine offspring sex (e.g. temperature-dependent sex determination, TSD), but most studies focus strictly on the effects of mean temperature, with little emphasis on the importance of thermal fluctuations. In the jacky dragon (Amphibolurus muricatus), an Australian lizard with TSD, data from nests in the field demonstrate that offspring sex ratios are predictable from thermal fluctuations but not from mean nest temperatures. To clarify this paradox, we incubated eggs in a factorial experiment with two levels of mean temperature and three levels of diel fluctuation. We show that offspring sex is determined by an interaction between these critical thermal parameters. Intriguingly, because these two thermal descriptors shift in opposing directions throughout the incubation season, this interactive effect inhibits seasonal shifts in sex ratio. Hence, our results suggest that TSD can yield offspring sex ratios that resemble those produced under genotypic sex-determining systems. These findings raise important considerations for understanding the diversity of TSD reaction norms, for designing experiments that evaluate the evolutionary significance of TSD, and for predicting sex ratios under past and future climate change scenarios. PMID:20685704

  3. 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.

  4. Determination of Fe(II) by Optimized Thermal Lens Microscope

    NASA Astrophysics Data System (ADS)

    Cabrera, Humberto; Korte, Dorota; Franko, Mladen

    2015-09-01

    A simple and accurate method for the determination of Fe(II) species in liquid solutions was developed. The measurement principle was realized by the photothermal effect and performed by the use of a thermal lens microscope (TLM) in its optimized, mode-mismatched configuration with a counter-propagating probe beam (PB) and an excitation beam (EB). Additionally, due to the combination of the collimated PB and tightly focused EB measurement, the detection limit was significantly decreased. Our preliminary results demonstrated that a TLM enables the detection of iron ions at the levels of \\upmu g{\\cdot }{L}^{-1}, which makes this technique an alternative to traditional spectroscopic methods as a promising detector for the ultrasensitive determination of different compounds in liquid solutions.

  5. 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.

  6. 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…

  7. 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.

  8. Stress determination in thermally grown alumina scales using ruby luminescence

    SciTech Connect

    Renusch, D.; Veal, B.W.; Koshelev, I.; Natesan, K.; Grimsditch; Hou, P.Y.

    1996-06-01

    By exploiting the strain dependence of the ruby luminescence line, we have measured the strain in alumina scales thermally grown on Fe-Cr- Al alloys. Results are compared and found to be reasonably consistent with strains determined using x rays. Oxidation studies were carried out on alloys Fe - 5Cr - 28Al and Fe - 18Cr - 10Al (at.%). Significantly different levels of strain buildup were observed in scales on these alloys. Results on similar alloys containing a ``reactive element`` (Zr or Hf) in dilute quantity are also presented. Scales on alloys containing a reactive element (RE) can support significantly higher strains than scales on RE-free alloys. With the luminescence technique, strain relief associated with spallation thresholds is readily observed.

  9. A thermal approach to waveform-independent energy determination

    NASA Astrophysics Data System (ADS)

    Möhring, Tobias; Spiegel, Thomas; Funck, Torsten

    2014-08-01

    In this paper, a new device for power and rms value measurement is presented. Unlike the commercially available measurement equipment, this device is not limited to special waveforms. As a reaction to the increasing use of energy harvesters, which gather energy from the ambience to power low-power electronics, it is necessary to develop new measurement equipment that is not limited to sinusoidal signals (harvesters generally deliver nonsinusoidal signals). Therefore, a new device is presented based on an isothermal operating mode of a planar multijunction thermal converter (PMJTC). Unlike previous PMJTCs, this one is equipped with an additional gold heater and is operated by a regulating circuit, which is electrically isolated from the input. The output signal of the regulator is recorded and analyzed to determine the power and rms value of the input signal.

  10. 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

  11. 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…

  12. Determination of thermal stability of oils by pyrolytic gas chromatography

    SciTech Connect

    Kudryavtseva, N.A.; Mikhailov, I.A.; Nikonorov, E.M.; Rakova, L.A.

    1984-03-01

    This article demonstrates how pyrolytic gas chromatography (PGC) offers a means for unambiguous differentiation of the decomposition products from the accompanying products of oil vaporization. The proposed method based on PGC uses a furnace-type pyrolyzer connected to an LKhM-7A chromatograph. The common peak of propane with propylene was selected as a characteristic peak to indicate the oil decomposition temperature. Propane and propylene, along with lighter hydrocarbons, are always present in the decomposition products. A volume graph method is used to determine the temperature of vaporization or decomposition of the substance, based on plotting a curve for the relationship between the heating temperature and the relative volume (or pressure) of the test sample. The decomposition temperatures determined by the PGC method agree with the values report by foreign manufacturers (deviation no greater than 2/sup 0/C). The accuracy of calculation of the thermal stability of the hydrocarbon oils by the PGC method was 5-10/sup 0/C as a result of deficiencies in the heating device in the pyrolytic unit. Includes a table.

  13. Thermal perception thresholds: influence of determination paradigm and reference temperature.

    PubMed

    Hilz, M J; Glorius, S; Berić, A

    1995-04-01

    The use of different paradigms and initial skin and thermode reference temperatures in quantitative thermal testing does not allow strict comparison of results generated from different laboratories. We tested (a) whether the reproducibility of the method of limits is higher for measurement of isolated warm and cold thresholds (WT, CT) as compared to difference limen (DL) thresholds, i.e. values derived from alternating warm and cold stimulation, and (b) whether WT-, CT- and DL-thresholds depend on the value of baseline skin and thermode temperatures. In 20 healthy volunteers WT-, CT-, and DL-thresholds were determined at the volar wrist using a Somedic-Thermotest. In condition A the baseline thermode temperature was set at 30 degrees C, and in conditions B and C at 35 degrees C; in condition C the tested skin area was also warmed to 35 degrees C prior to the test. The randomized tests were repeated within 1-8 days. WT-, CT-, and DL-values were reproducible, but DL-values were more widely spread than WT and CT. CT variability was lowest in condition A, and WT variability in condition C. We conclude that DL determination should be abandoned, since CT and WT better differentiate normal from abnormal thresholds than the coarse DL-values. We recommend the use of the lower baseline thermode temperature (30 degrees C) and elimination of warming of the tested skin area prior to the test. PMID:7608727

  14. 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.

  15. 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).

  16. Mass and thermal diffusivity algorithms: reduced algorithms for mass and thermal diffusivity determinations.

    PubMed

    Banish, R Michael; Albert, Lyle B J; Pourpoint, Timothee L; Alexander, J Iwan D; Sekerka, Robert F

    2002-10-01

    Mass and thermal diffusivity measurements conducted on Earth are prone to contamination by uncontrollable convective contributions to the overall transport. Previous studies of mass and thermal diffusivities conducted on spacecraft have demonstration the gain in precision, and lower absolute values, resulting from the reduced convective transport possible in a low-gravity environment. We have developed and extensively tested real-time techniques for diffusivity measurements, where several measurements may be obtained on a single sample. This is particularly advantageous for low gravity research were there is limited experiment time. The mass diffusivity methodology uses a cylindrical sample geometry. A radiotracer, initially located at one end of the host is used as the diffusant. The sample is positioned in a concentric isothermal radiation shield with collimation bores located at defined positions along its axis. The intensity of the radiation emitted through the collimators is measured versus time with solid-state detectors and associated energy discrimination electronics. For the mathematical algorithm that we use, only a single pair of collimation bores and detectors are necessary for single temperature measurements. However, by employing a second, offset, pair of collimation holes and radiation detectors, diffusivities can be determined at several temperatures per sample. For thermal diffusivity measurements a disk geometry is used. A heat pulse is applied in the center of the sample and the temperature response of the sample is measured at several locations. Thus, several values of the diffusivity are measured versus time. The exact analytic solution to a heat pulse in the disk geometry leads to a unique heated area and measurement locations. Knowledge of the starting time and duration of he heating pulse is not used in the data evaluation. Thus, this methodology represents an experimentally simpler and more robust scheme. PMID:12446321

  17. 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.

  18. Computer-aided methods of determining thyristor thermal transients

    SciTech Connect

    Lu, E.; Bronner, G.

    1988-08-01

    An accurate tracing of the thyristor thermal response is investigated. This paper offers several alternatives for thermal modeling and analysis by using an electrical circuit analog: topological method, convolution integral method, etc. These methods are adaptable to numerical solutions and well suited to the use of the digital computer. The thermal analysis of thyristors was performed for the 1000 MVA converter system at the Princeton Plasma Physics Laboratory. Transient thermal impedance curves for individual thyristors in a given cooling arrangement were known from measurements and from manufacturer's data. The analysis pertains to almost any loading case, and the results are obtained in a numerical or a graphical format. 6 refs., 9 figs.

  19. 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.

  20. Determination of the sensitivity of thermoluminescent detectors to thermal neutrons

    SciTech Connect

    Zhilov, Y.N.; Erkin, V.G.; Kuchomov, V.A.; Lebedev, O.V.; Tyurin, G.A.

    1985-10-01

    The authors show how the considerable difference in sensitivity to thermal neutrons of the TLD-6-05 and TLD-7-05 detectors allows them to be used jointly for the separate recording of thermal neutrons and -radiation in mixed fields. For detectors with the natural content of lithium isotopes, the sensitivity to thermal neutrons is an order of magnitude lower than for the TLD-6-05, which corresponds to the ratio of the Li-6 concentrations in these detectors. These detectors may be found useful in individual neutron dosimeters of the albedo type for monitoring the radiation safety of personnel.

  1. Spectrophotometric method for the determination, validation, spectroscopic and thermal analysis of diphenhydramine in pharmaceutical preparation

    NASA Astrophysics Data System (ADS)

    Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

    2010-09-01

    A sensitive, simple and rapid spectrophotometric method was developed for the determination of diphenhydramine in pharmaceutical preparation. The method was based on the charge-transfer complex of the drug, as n-electron donor, with 2,3-dichloro-5,6-dicyano- p-benzoquinone (DDQ), as π-acceptor. The formation of this complex was also confirmed by UV-vis, FTIR and 1H NMR spectra techniques and thermal analysis. The proposed method was validated according to the ICH guidelines with respect to linearity, limit of detection, limit of quantification, accuracy, precision, recovery and robustness. The linearity range for concentrations of diphenhydramine was found to be 12.5-150 μg/mL with acceptable correlation coefficients. The detection and quantification limits were found to be 2.09 and 6.27 μg/mL, respectively. The proposed and references methods were applied to the determination of drug in syrup. This preparation were also analyzed with an reference method and statistical comparison by t- and F-tests revealed that there was no significant difference between the results of the two methods with respect to mean values and standard deviations at the 95% confidence level.

  2. Spectrophotometric method for the determination, validation, spectroscopic and thermal analysis of diphenhydramine in pharmaceutical preparation.

    PubMed

    Ulu, Sevgi Tatar; Elmali, Fikriye Tuncel

    2010-09-15

    A sensitive, simple and rapid spectrophotometric method was developed for the determination of diphenhydramine in pharmaceutical preparation. The method was based on the charge-transfer complex of the drug, as n-electron donor, with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), as pi-acceptor. The formation of this complex was also confirmed by UV-vis, FTIR and (1)H NMR spectra techniques and thermal analysis. The proposed method was validated according to the ICH guidelines with respect to linearity, limit of detection, limit of quantification, accuracy, precision, recovery and robustness. The linearity range for concentrations of diphenhydramine was found to be 12.5-150 microg/mL with acceptable correlation coefficients. The detection and quantification limits were found to be 2.09 and 6.27 microg/mL, respectively. The proposed and references methods were applied to the determination of drug in syrup. This preparation were also analyzed with an reference method and statistical comparison by t- and F-tests revealed that there was no significant difference between the results of the two methods with respect to mean values and standard deviations at the 95% confidence level. PMID:20621611

  3. 45 CFR 2544.130 - How will the Corporation determine whether to solicit or accept a donation?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE SOLICITATION AND ACCEPTANCE OF... business relationship, financial interest, litigation, or other factors that may indicate such a...

  4. 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

    ... Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE SOLICITATION AND ACCEPTANCE OF... business relationship, financial interest, litigation, or other factors that may indicate such a...

  5. Experimental Determination of Thermal Conductivity of Low-Density Ice

    NASA Technical Reports Server (NTRS)

    Coles, Willard D.

    1954-01-01

    The thermal conductivity of low-density ice has been computed from data obtained in an experimental investigation of the heat transfer and mass transfer by sublimation for an iced surface on a flat plate in a high-velocity tangential air stream. The results are compared with data from several sources on the thermal conductivity of packed snow and solid glaze ice. The results show good agreement with the equations for the thermal conductivity of packed snow as a function of snow density. The agreement of the curves for packed snow near the solid ice regime with the values of thermal conductivity, of ice indicates that the curves are applicable over the entire-ice-density range.

  6. 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.

  7. Computer code for determination of thermally perfect gas properties

    NASA Technical Reports Server (NTRS)

    Witte, David W.; Tatum, Kenneth E.

    1994-01-01

    A set of one-dimensional compressible flow relations for a thermally perfect, calorically imperfect gas is derived for the specific heat c(sub p), expressed as a polynomial function of temperature, and developed into the thermally perfect gas (TPG) computer code. The code produces tables of compressible flow properties similar to those of NACA Rep. 1135. Unlike the tables of NACA Rep. 1135 which are valid only in the calorically perfect temperature regime, the TPG code results are also valid in the thermally perfect calorically imperfect temperature regime which considerably extends the range of temperature application. Accuracy of the TPG code in the calorically perfect temperature regime is verified by comparisons with the tables of NACA Rep. 1135. In the thermally perfect, calorically imperfect temperature regime, the TPG code is validated by comparisons with results obtained from the method of NACA Rep. 1135 for calculating the thermally perfect calorically imperfect compressible flow properties. The temperature limits for application of the TPG code are also examined. The advantage of the TPG code is its applicability to any type of gas (monatomic, diatomic, triatomic, or polyatomic) or any specified mixture thereof, whereas the method of NACA Rep. 1135 is restricted to only diatomic gases.

  8. Determining in-situ thermal conductivity of coarse textured materials through numerical analysis of thermal

    NASA Astrophysics Data System (ADS)

    Saito, H.; Hamamoto, S.; Moldrup, P.; Komatsu, T.

    2013-12-01

    Ground source heat pump (GSHP) systems use ground or groundwater as a heat/cooling source, typically by circulating anti-freezing solution inside a vertically installed closed-loop tube known as a U-tube to transfer heat to/from the ground. Since GSHP systems are based on renewable energy and can achieve much higher coefficient of performance (COP) than conventional air source heat pump systems, use of GSHP systems has been rapidly increasing worldwide. However, environmental impacts by GSHP systems including thermal effects on subsurface physical-chemical and microbiological properties have not been fully investigated. To rigorously assess GSHP impact on the subsurface environment, ground thermal properties including thermal conductivity and heat capacity need to be accurately characterized. Ground thermal properties were investigated at two experimental sites at Tokyo University of Agriculture and Technology (TAT) and Saitama University (SA), both located in the Kanto area of Japan. Thermal properties were evaluated both by thermal probe measurements on boring core samples and by performing in-situ Thermal Response Tests (TRT) in 50-80 m deep U-tubes. At both TAT and SU sites, heat-pulse probe measurements gave unrealistic low thermal conductivities for coarse textured materials (dominated by particles > 75 micrometers). Such underestimation can be partly due to poor contact between probe and porous material and partly to markedly decreasing sample water content during drilling, carrying, and storing sandy/gravelly samples. A more reliable approach for estimating in-situ thermal conductivity of coarse textured materials is therefore needed, and may be based on the commonly used TRT test. However, analyses of TRT data is typically based on Kelvin's line source model and provides an average (effective) thermal property for the whole soil profile around the U-tube but not for each geological layer. The main objective of this study was therefore to develop a method

  9. 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

  10. Determination of Thermal Spray Coating Property with Curvature Measurements

    NASA Astrophysics Data System (ADS)

    Dwivedi, Gopal; Nakamura, Toshio; Sampath, Sanjay

    2013-12-01

    Real-time curvature measurement of a coating-substrate system during deposition has facilitated the monitoring of coating stresses and provided additional insights into thermal spray deposition mechanisms. However, the non-equilibrium state of coating formation along with harsh spray booth environment introduces complexity not only in data interpretation but also in the coating properties estimation. In this paper, a new procedure is proposed to estimate the elastic modulus of thermal sprayed ceramic coatings using in situ curvature and temperature measurements. In order to correlate the measurable parameters to coating elastic modulus, a systematic study is conducted to develop a suitable methodology. First, various finite element model analyses are carried out to formulate suitable relations between the measurements and elastic modulus. Subsequently, experiments are conducted to validate the procedure to estimate coating moduli. The results are compared with more accurate measurements obtained from post-deposition characterization technique under low temperature thermal cycles. The comparison suggests that the moduli estimated using the proposed procedure are in good agreements with those obtained from the post-deposition technique. Further, the nonlinear response of coatings are evaluated from the estimated moduli during deposition and cool down, which offer additional information on the characteristics of thermal spray coatings.

  11. 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.

  12. 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…

  13. Sociocultural determinants of anticipated vaccine acceptance for acute watery diarrhea in early childhood in Katanga Province, Democratic Republic of Congo.

    PubMed

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

    2013-09-01

    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

  14. 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

  15. Placebo use in pain management: the role of medical context, treatment efficacy, and deception in determining placebo acceptability

    PubMed Central

    Kisaalita, Nkaku; Staud, Roland; Hurley, Robert; Robinson, Michael

    2014-01-01

    Placebo effects can act as powerful pain relievers. While the ethics of therapeutic placebo use is highly controversial, recent evidence suggests that medical providers frequently utilize placebo treatments, and patients may be open to these interventions under certain contexts. This investigation used a patient-centered approach to answer essential questions about placebo treatment acceptability. People with chronic musculoskeletal pain completed a placebo survey where they: 1) rated their knowledge of placebo and its efficacy for alleviating pain; 2) evaluated the acceptability of a placebo analgesic interventions across several unique medical contexts; and 3) responded to six different patient-physician treatment scenarios to assess the role of deception and placebo effectiveness on mood and provider trust. Results showed that participants had limited knowledge of placebo and it’s efficacy for alleviating pain. Placebo acceptability was highly dependent on the context of the intervention, as placebo treatments were considered acceptable when used as complementary/adjunct treatments and when no other established treatments were available. Also, an analgesic placebo response mitigated the negative consequences of deception by improving provider trust and decreasing negative mood. These findings suggest that patients may be rather pragmatic in their appraisals of placebo treatment acceptability and may consider a variety of treatments/contexts as permissible for managing their pain. This is the first study of its kind to quantify perceptions of placebo analgesia knowledge and efficacy among individuals with chronic pain, and to assess the role of different medical contexts in treatment acceptability. PMID:25267208

  16. 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. PMID:27587146

  17. 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.

  18. Silver nanoparticle assisted urine sugar determination using thermal lens spectroscopy

    NASA Astrophysics Data System (ADS)

    Thomas, Lincy; John, Jisha; George, Nibu A.; Kurian, Achamma

    2014-11-01

    Nanotechnology plays a vital role in the development of biosensors by enhancing their sensitivity and performance. In this paper, we report a novel urine sugar sensing method that makes use of the unique properties of silver-nanofluids in combination with the laser induced photothermal lens technique. The thermal lens signal decreases with increase in sugar levels in urine samples, which may be attributed to the enhanced interaction of glucose and conduction electrons of silver-nanoparticles, thereby changing the surface plasmon energy.

  19. Determines the Thermal and Optical Properties of Fenestration Systems

    Energy Science and Technology Software Center (ESTSC)

    1995-01-27

    WINDOW4.1 computes the thermal properties of windows and other fenestration elements used in typical residential and commercial buildings. Manufactures, specifiers, architects, consumers, and the energy code specialists all need to know these properties (U-values, Solar Heat Gain Coefficients, optical properties). The use of this program to calculate these properties is typically much more cost effective than laboratory test procedures. Properties of complete window systems are based on libraries (or user input) component data.

  20. 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.

  1. 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.

  2. Quantitative scanning thermal microscopy based on determination of thermal probe dynamic resistance.

    PubMed

    Bodzenta, J; Juszczyk, J; Chirtoc, M

    2013-09-01

    Resistive thermal probes used in scanning thermal microscopy provide high spatial resolution of measurement accompanied with high sensitivity to temperature changes. At the same time their sensitivity to variations of thermal conductivity of a sample is relatively low. In typical dc operation mode the static resistance of the thermal probe is measured. It is shown both analytically and experimentally that the sensitivity of measurement can be improved by a factor of three by measuring the dynamic resistance of a dc biased probe superimposed with small ac current. The dynamic resistance can be treated as a complex value. Its amplitude represents the slope of the static voltage-current U-I characteristic for a given I while its phase describes the delay between the measured ac voltage and applied ac current component in the probe. The phase signal also reveals dependence on the sample thermal conductivity. Signal changes are relatively small but very repeatable. In contrast, the difference between dynamic and static resistance has higher sensitivity (the same maximum value as that of the 2nd and 3rd harmonics), and also much higher amplitude than higher harmonics. The proposed dc + ac excitation scheme combines the benefits of dc excitation (mechanical stability of probe-sample contact, average temperature control) with those of ac excitation (base-line stability, rejection of ambient temperature influence, high sensitivity, lock-in signal processing), when the experimental conditions prohibit large ac excitation. PMID:24089831

  3. 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.

  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. 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.

  6. 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…

  7. Development of a consensus standard for determining thermal performance of high-concentration-ratio solar collectors

    NASA Astrophysics Data System (ADS)

    Blackmon, J. B.; Linskens, M. C.; Reed, K. A.

    1982-12-01

    Consensus standard test method, for determining the thermal performance of concentrating solar collectors is described. The method applies to outdoor testing of one or two axis concentrating collectors with heat fluids for use in thermal systems and whose design is such that the effects of diffuse sky irradiance is negligible. The procedures determine the optical response of the collector for various angles of incidence of solar radiation, and the thermal performance of the collector at various operating temperatures for the condition of maximum optical response. The method requires quasi steady state conditions, measurement of enviromental parameters, and determination of the fluidmass flow rate specific heat product and temperature difference of the heat transfer fluid between the inlet and outlet of the collector. These quantities determine the rate of heat gain for the solar irradiance condition encountered. Thermal performance is determined as the rate of heat gain of the collector relative to the solar power incident on the plane of the collector aperture.

  8. 40 CFR Appendix Xv to Part 86 - Procedure for Determining an Acceptable Exhaust Regeneration Durability-Data Test Schedule for...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... freedom. 6. If (Aprop)1/2 ≥ tp / ts × (Bstd)1/2 the proposed plan is acceptable. Table I to Appendix XV... Periodically Regenerating Trap Oxidizer Systems Certifying to the Provisions of Part 86, Subpart R XV Appendix XV to Part 86 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

  9. 40 CFR Appendix Xv to Part 86 - Procedure for Determining an Acceptable Exhaust Regeneration Durability-Data Test Schedule for...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... freedom. 6. If (Aprop)1/2 ≥ tp / ts × (Bstd)1/2 the proposed plan is acceptable. Table I to Appendix XV... Periodically Regenerating Trap Oxidizer Systems Certifying to the Provisions of Part 86, Subpart R XV Appendix XV to Part 86 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR...

  10. 41 CFR 102-80.125 - Who has the responsibility for determining the acceptability of each equivalent level of safety...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (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 for... acceptability must include a review of the fire protection engineer's qualifications, the appropriateness of...

  11. 41 CFR 102-80.125 - Who has the responsibility for determining the acceptability of each equivalent level of safety...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (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 for... acceptability must include a review of the fire protection engineer's qualifications, the appropriateness of...

  12. 41 CFR 102-80.125 - Who has the responsibility for determining the acceptability of each equivalent level of safety...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (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 for... acceptability must include a review of the fire protection engineer's qualifications, the appropriateness of...

  13. 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…

  14. 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. PMID:25514059

  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. Determination of the Thermal and Non-Thermal Emissions in the X-Ray Spectrum of Kepler's Supernova Remnant.

    NASA Astrophysics Data System (ADS)

    Decourchelle, Anne

    The XTE/PCA instrument, with its large efficiency and wide energy range, offers an unique opportunity to observe the high energy X-ray emission of Kepler's supernova remnant. Previous observations in the 0.1-10 keV range (EINSTEIN, EXOSAT, GINGA, ROSAT and ASCA) have favored non-equilibrium ionization reverse shock models. A very high temperature (24 keV) is predicted in the shocked interstellar medium by these models. Observation of this high energy component will put strong constraints on the SN type and SNR evolution. The other major objective is to seek for an X-ray synchrotron emission in addition to the thermally produced X-rays. The observational goal for XTE PCA is thus to determine both these thermal and non-thermal contributions in the Kepler's high energy spectrum.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Lateral Heat Flow Infrared Thermography for Thickness Independent Determination of Thermal Diffusivity in CFRP

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    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.

  2. Atmospheric effects on the remote determination of thermal inertia on Mars

    NASA Astrophysics Data System (ADS)

    Haberle, R. M.; Jakosky, B. M.

    1991-04-01

    Measurements of the IR brightness temperature at the Martian surface at many different times of day are presently compared with temperatures predicted by thermal models which allow sunlight to reach the surface unattenuated, in order to determine the thermal inertia of the uppermost 1-10 cm of the Martian surface. The consequences of the assumptions made are assessed in view of results from a different thermal model which invokes radiation-transfer through a dusty CO2 atmosphere, as well as sensible heat-exchange with the surface. Smaller thermal inertias imply smaller particle sizes; the results obtained suggest that low thermal-inertia regions consist of 5-micron, rather than 50-micron, particle sizes.

  3. Atmospheric effects on the remote determination of thermal inertia on Mars

    NASA Technical Reports Server (NTRS)

    Haberle, Robert M.; Jakosky, Bruce M.

    1991-01-01

    Measurements of the IR brightness temperature at the Martian surface at many different times of day are presently compared with temperatures predicted by thermal models which allow sunlight to reach the surface unattenuated, in order to determine the thermal inertia of the uppermost 1-10 cm of the Martian surface. The consequences of the assumptions made are assessed in view of results from a different thermal model which invokes radiation-transfer through a dusty CO2 atmosphere, as well as sensible heat-exchange with the surface. Smaller thermal inertias imply smaller particle sizes; the results obtained suggest that low thermal-inertia regions consist of 5-micron, rather than 50-micron, particle sizes.

  4. Simultaneous determination of temperature-dependent thermal conductivity and volumetric heat capacity by an inverse technique

    SciTech Connect

    Woodbury, K.A.; Boohaker, C.G.

    1996-12-31

    Determination of thermal properties by inverse methods often involves limited thermal excitation of a relatively small sample. If these thermal properties are to be found as functions of temperature, then this procedure must be replicated at several artificially elevated temperatures. For some types of materials (for example, those bearing moisture) this approach is impractical. In this paper, a procedure is developed for determining thermal properties (conductivity k and volumetric heat capacity C {equivalent_to} {rho}c{sub p}) as functions of temperature from a single experiment. This procedure is targeted for determination of k(T) and C(T) for sand molds used in castings. An inverse method based on a Gauss linearization is used to estimate these functions. The experiment used to determine these properties consists of heating a one-dimensional specimen of the material from one end. The variation of thermal properties with temperature is assumed to be a piecewise linear function, with values of properties to be determined at prescribed temperatures. A numerical experiment is used to demonstrate the technique.

  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%. PMID:26133860

  6. Impacts of small-scale variability on the determination of bulk thermal diffusivity in snowpacks

    NASA Astrophysics Data System (ADS)

    Oldroyd, H. J.; Higgins, C. W.; Huwald, H.; Selker, J. S.; Parlange, M. B.

    2012-04-01

    Thermal diffusivity of snow is an important physical property associated with key hydrological phenomena such as snowmelt and heat and water vapor exchange with the atmosphere. These phenomena have broad implications in studies of climate and heat and water budgets on many scales. Furthermore, sub grid scale phenomena may enhance these heat and mass exchanges in the snow pack due to its porous nature. We hypothesize that the heat transfer effects of these small-scale variabilities may be seen as an increased bulk thermal diffusivity of the snow. Direct measurements of snow thermal diffusivity require coupled measurements of thermal conductivity and density, which are nonstationary due to snow metamorphism. Furthermore, thermal conductivity measurements are typically obtained with specialized heating probes or plates and snow density measurements require digging snow pits. Therefore, direct measurements are difficult to obtain with high enough temporal resolution such that direct comparisons with atmospheric conditions can be made. This study uses highly resolved temperature measurements from the Plaine Morte glacier in Switzerland as initial and boundary conditions to numerically solve the 1D heat equation and iteratively optimize for thermal diffusivity. The method uses flux boundary conditions to constrain thermal diffusivity such that spuriously high values in thermal diffusivity are eliminated. Additionally, a t-test ensuring statistical significance between solutions of varied thermal diffusivity results in further constraints on thermal diffusivity that eliminate spuriously low values. The results show that time resolved thermal diffusivity can be determined from easily implemented and inexpensive temperature measurements of seasonal snow with good agreement to widely used parameterizations based on snow density. This high time resolution further affords the ability to explore possible turbulence-induced enhancements to heat and mass transfer in the snow.

  7. Thermal power output determination of 2 MW heat source by using of thermocouples

    NASA Astrophysics Data System (ADS)

    Holubcik, Michal; Vician, Peter; Palacka, Matej

    2016-06-01

    Experiment is an operation or procedure carried out under controlled conditions in order to discover an unknown effect or law, to test or establish a hypothesis, or to illustrate a known law. The most important part of the experiment is to evaluate the measured values. Measurement accuracy depends on a number of factors. Deviations of instruments cannot eliminate or influence if it is neglect the possibility of using more precise measuring equipment. Another way for the most accurate results can be calibration. Calibration allows achieve measurement values with relatively high accuracy using less precision instruments. The paper deals about the problematic of thermal power measurement accuracy. Thermal power was measured on heat source with nominal thermal power 2 MW by using direct calorimetric method. There were used ultrasonic flow meter and type K thermocouples. Type K thermocouples are not very suitable for these applications because of their low precision. The paper presents the possibility of using calibrated thermocouples for the thermal power measurement with acceptable accuracy.

  8. Determination of Elastic Properties and Characterization of Thermal Barrier Coatings using Resonant Ultrasound Spectroscopy

    SciTech Connect

    Shyam, Amit; Lara-Curzio, Edgar

    2009-01-01

    Mechanical properties of plasma sprayed ceramic coatings are extremely important to engine design. However, the determination of these properties is often difficult because of the unique and complicated microstructure of the coatings. In this presentation the determination of the elastic constants of plasma sprayed Yttria stabilized Zirconia thermal barrier coatings using resonant ultrasound spectroscopy will be described along with an analysis that enables the determination of the elastic constants as a function of temperature and coating direction. In this work, results on the following issues will be discussed: 1) the elastic anisotropy of thermal barrier coatings, which is associated with coating failure modes; 2) sintering effects on coating compliance comparing with thermal behavior, which is important to coating performance on engineering structures, such as turbine engines; 3) coating elastic modulus at high temperatures close to the service condition, which provides insights of coating mechanical behavior in both fundamental and practical studies.

  9. Time Resolved Thermal Diffusivity of Seasonal Snow Determined from Inexpensive, Easily-Implemented Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Oldroyd, H. J.; Higgins, C. W.; Huwald, H.; Selker, J. S.; Parlange, M. B.

    2011-12-01

    Thermal diffusivity of snow is an important physical property associated with key hydrological phenomena such as snow melt and heat and water vapor exchange with the atmosphere. These phenomena have broad implications in studies of climate and heat and water budgets on many scales. However, direct measurements of snow thermal diffusivity require coupled point measurements of thermal conductivity and density, which are nonstationary due to snow metamorphism. Furthermore, thermal conductivity measurements are typically obtained with specialized heating probes or plates and snow density measurements require digging snow pits. Therefore, direct measurements are difficult to obtain with high enough temporal resolution such that direct comparisons with atmospheric conditions can be made. This study uses highly resolved (7.5 to 10 cm for depth and 1min for time) temperature measurements from the Plaine Morte glacier in Switzerland as initial and boundary conditions to numerically solve the 1D heat equation and iteratively optimize for thermal diffusivity. The method uses flux boundary conditions to constrain thermal diffusivity such that spuriously high values in thermal diffusivity are eliminated. Additionally, a t-test ensuring statistical significance between solutions of varied thermal diffusivity result in further constraints on thermal diffusivity that eliminate spuriously low values. The results show that time resolved (1 minute) thermal diffusivity can be determined from easily implemented and inexpensive temperature measurements of seasonal snow with good agreement to widely used parameterizations based on snow density. This high time resolution further affords the ability to explore possible turbulence-induced enhancements to heat and mass transfer in the snow.

  10. Electron-accepting potential of solvents determines photolysis rates of polycyclic aromatic hydrocarbons: experimental and density functional theory study.

    PubMed

    Shao, Jianping; Chen, Jingwen; Xie, Qing; Wang, Ying; Li, Xuehua; Hao, Ce

    2010-07-15

    Photochemical behaviour of polycyclic aromatic hydrocarbons (PAHs) is strongly dependent on the physical and chemical nature of the media in/on which they exist. To understand the media effects, the photolysis of phenanthrene (PHE) and benzo[a]pyrene (BaP) in several solvents was investigated. Distinct photolysis rate constants for PHE and BaP in the different solvents were observed. Some theoretical parameters reflecting the solvent properties were computed and employed to explain the solvent effects. Acetone competitively absorbed light with PHE and BaP, and the excited acetone molecules played different roles for the photodegradation of PHE and BaP. The photolysis rate constants of PHE and BaP in hexane, isopropanol, ethanol, methanol, acetonitrile and dichloromethane were observed to correlate with the electron-accepting potential of the solvent molecules. Absolute electronegativity of the solvents linearly correlated with the photolytic activity (log k) of the PAHs significantly. The results are important for better understanding the photodegradation mechanism of PAHs in different media. PMID:20303660

  11. 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.

  12. Determination of Creep Behavior of Thermal Barrier Coatings Under Laser Imposed High Thermal and Stress Gradient Conditions

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    1999-01-01

    A laser sintering/creep technique has been established to determine the creep behavior of thermal barrier coatings under steady-state high heat flux conditions. For a plasma sprayed zirconia-8 wt. % yttria coating, a significant primary creep strain and a low apparent creep activation energy were observed. Possible creep mechanisms involved include stress induced mechanical sliding and temperature and stress enhanced cation diffusion through the splat and grain boundaries. The elastic modulus evolution, stress response, and total accumulated creep strain variation across the ceramic coating are simulated using a finite difference approach. The modeled creep response is consistent with experimental observations.

  13. 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. PMID:17849294

  14. 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.

  15. Determinants of accepting non-invasive ventilation treatment in motor neurone disease: a quantitative analysis at point of need

    PubMed Central

    Cousins, Rosanna; Ando, Hikari; Thornton, Everard; Chakrabarti, Biswajit; Angus, Robert; Young, Carolyn

    2013-01-01

    Objectives: Motor neurone disease (MND) progressively damages the nervous system causing wasting to muscles, including those used for breathing. There is robust evidence that non-invasive ventilation (NIV) relieves respiratory symptoms and improves quality of life in MND. Nevertheless, about a third of those who would benefit from NIV decline the treatment. The purpose of the study was to understand this phenomenon. Design: A cross-sectional quantitative analysis. Methods: Data including age, sex, MND symptomatology, general physical and mental health and psychological measures were collected from 27 patients and their family caregivers at the point of being offered ventilatory support based on physiological markers. Results: Quantitative analyses indicated no difference in patient characteristics or symptomatology between those who tolerated (n = 17) and those who declined (n = 10) NIV treatment. A comparison of family caregivers found no differences in physical or mental health or in caregiving distress, emphasising that this was high in both groups; however, family caregivers supporting NIV treatment were significantly more resilient, less neurotic and less anxious than family caregivers who did not. Regression analyses, forcing MND symptoms to enter the equation first, found caregiver resilience:commitment the strongest predictor of uptake of NIV treatment adding 22% to the 56% explained variance. Conclusion: Patients who tolerated NIV treatment had family caregivers who cope through finding meaning and purpose in their situation. Psychological support and proactive involvement for family caregivers in the management of the illness situation is indicated if acceptance of NIV treatment is to be maximised in MND. PMID:25264500

  16. Determination of Thermal Contact Conductance of Metal Tabs for Battery Ultrasonic Welding Process

    SciTech Connect

    Chen, Jian; Zhang, Wei; Yu, Zhenzhen; Feng, Zhili

    2012-01-01

    A new experimental apparatus and data analysis algorithm were used to determine the thermal contact conductance between 0.2-mm-thick pure aluminum battery tabs as a function of contact pressure from 3.6 to 14.4 MPa. Specimens were sandwiched between one optically transparent and one infrared (IR) transparent glass windows, and heated up from one side by an intense short pulse of flash light. The temperature transient on the other side was measured by an IR camera. In order to determine the thermal contact conductance, two experiment configurations having different number of Al specimen layers were used. Numerical heat conduction simulations showed that the thermal contact conductance strongly depended on the ratio of the maximum temperature rise between the two configurations. Moreover, this ratio was not sensitive to the uncertainties of other thermal properties. Through the simulation results, a simple correlation between the gap conductance and the ratio was established. Therefore, once the ratio of the temperature rise between two configurations was experimentally measured, the thermal contact conductance could be readily determined from the correlation. The new method was fast and robust. Most importantly, the data analysis algorithm improved the measurement accuracy by considerably reducing the uncertainties associated with the thermophysical properties of materials and measurement system.

  17. 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.

  18. 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.

  19. Releasing-addition method for the flame-photometric determination of calcium in thermal waters

    USGS Publications Warehouse

    Rowe, J.J.

    1963-01-01

    Study of the interferences of silica and sulfate in the flame-photometric determination of calcium in thermal waters has led to the development of a method requiring no prior chemical separations. The interference effects of silica, sulfate, potassium, sodium, aluminum, and phosphate are overcome by an addition technique coupled with the use of magnesium as a releasing agent. ?? 1963.

  20. 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.

  1. 40 CFR Appendix Xv to Part 86 - Procedure for Determining an Acceptable Exhaust Regeneration Durability-Data Test Schedule for...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 5,000, 25,000, 50,000, 75,000, and 100,000 miles will be designated as the standard (std) test... = [∑(Xs)2 − ((∑Xs)2 / Ns))std Where: Xs = Individual mileages at which the vehicle will be tested. Ns... to table I and determine tp at (Np − 2)prop degrees of freedom and ts at (Ns − 2)std degrees...

  2. 40 CFR Appendix Xv to Part 86 - Procedure for Determining an Acceptable Exhaust Regeneration Durability-Data Test Schedule for...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 5,000, 25,000, 50,000, 75,000, and 100,000 miles will be designated as the standard (std) test... = [∑(Xs)2 − ((∑Xs)2 / Ns))std Where: Xs = Individual mileages at which the vehicle will be tested. Ns... to table I and determine tp at (Np − 2)prop degrees of freedom and ts at (Ns − 2)std degrees...

  3. 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

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Determination of the efficiency of the thermal 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...

  4. 7 CFR 3300.13 - Determination of the efficiency of the thermal appliances as installed in the insulated body.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Determination of the efficiency of the thermal 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...

  5. 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

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Determination of the efficiency of the thermal 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...

  6. 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

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Determination of the efficiency of the thermal 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...

  7. 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. PMID:18247886

  8. Determination of the effective thermal diffusivity of nanofluids by the double hot-wire technique

    NASA Astrophysics Data System (ADS)

    Murshed, S. M. S.; Leong, K. C.; Yang, C.

    2006-12-01

    This paper introduces a new transient double hot-wire technique for the direct measurement of the thermal diffusivity of nanofluids. A correlation to be used with the double hot-wire technique to calculate the effective thermal diffusivity of nanofluids is also developed. Several types of nanofluids were prepared by suspending different volume percentages (1-5%) of titanium dioxide (TiO2), aluminium oxide (Al2O3) and aluminium (Al) nanoparticles in ethylene glycol and engine oil. The thermal diffusivities of these nanofluids determined directly by this technique were found to increase substantially with the increased volume fraction of nanoparticles in base fluids. Based on the calibration results obtained for the base fluids, ethylene glycol and engine oil, the measurement error is estimated to be within 1.2%. The measured thermal diffusivities of nanofluids were found to be significantly higher than those calculated from the thermal diffusivity expression (i.e. αeff = keff/(ρ cp)eff) by using the effective thermal conductivities and volumetric specific heats obtained from the conventional hot-wire method and from the volume fraction mixture rule, respectively.

  9. 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.

  10. ASME PTC 46 -- Acceptance test code for overall plant performance

    SciTech Connect

    Friedman, J.R.; Yost, J.G.

    1999-11-01

    ASME published PTC 46 in 1996 after five years of development. PTC 46 is the first industry standard providing explicit procedures for conducting acceptance tests to determine the overall thermal performance and output of power generating units. It is applicable to any heat cycle power generating unit. This survey paper provides an overview of PTC 46 and discusses how PTC 46 can be used for acceptance testing of new combined cycle and fossil steam power generating units. Several technical papers have been previously presented that provide more detailed information and discussion on the use of PTC 46 in acceptance testing.

  11. Evaluation of Glass Capillary Tube and TDT Disk Methods for Determining Thermal Inactivation Kinetics of Salmonella in Liquid Whole Egg

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA liquid egg pasteurization standards are based on the thermal inactivation of Salmonella. Glass capillary tubes have been traditionally used to determine thermal death times of microorganisms in liquid foods. A new thermal-death-time (TDT) disk is a reportedly simpler means for evaluating ...

  12. 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.

  13. 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.

  14. Noncontact technique for determining the thermal diffusivity coefficient on acoustically levitated liquid drops

    NASA Astrophysics Data System (ADS)

    Ohsaka, K.; Rednikov, A.; Sadhal, S. S.

    2003-02-01

    We present a technique that can be used to determine the thermal diffusivity coefficient of undercooled liquids, which exist at temperatures below their freezing points. The technique involves levitation of a small amount of liquid in a flattened drop shape using an acoustic levitator and heating it with a laser beam. The heated drop is then subjected to natural cooling by heat loss from the surface. Due to acoustic streaming, the heat loss mainly occurs through the equator section of the drop. The measured cooling rate in combination with a radial heat conduction model allows us to calculate the thermal diffusivity coefficient of the drop. We demonstrate the feasibility of the technique using glycerin drops as a model liquid. The technique is well suited if the thermal diffusivity coefficient of the liquid in the normal state (i.e., above the freezing point) is known or can be measured by conventional techniques.

  15. Determination of thermal accommodation coefficients from heat transfer measurements between parallel plates.

    SciTech Connect

    Gallis, Michail A.; Castaneda, Jaime N.; Rader, Daniel John; Torczynski, John Robert; Trott, Wayne Merle

    2010-10-01

    Thermal accommodation coefficients have been derived for a variety of gas-surface combinations using an experimental apparatus developed to measure the pressure dependence of the conductive heat flux between parallel plates at unequal temperature separated by a gas-filled gap. The heat flux is inferred from temperature-difference measurements across the plates in a configuration where the plate temperatures are set with two carefully controlled thermal baths. Temperature-controlled shrouds provide for environmental isolation of the opposing test plates. Since the measured temperature differences in these experiments are very small (typically 0.3 C or less over the entire pressure range), high-precision thermistors are used to acquire the requisite temperature data. High-precision components have also been utilized on the other control and measurement subsystems in this apparatus, including system pressure, gas flow rate, plate alignment, and plate positions. The apparatus also includes the capability for in situ plasma cleaning of the installed test plates. Measured heat-flux results are used in a formula based on Direct Simulation Monte Carlo (DSMC) code calculations to determine the thermal accommodation coefficients. Thermal accommodation coefficients have been determined for three different gases (argon, nitrogen, helium) in contact with various surfaces. Materials include metals and alloys such as aluminum, gold, platinum, and 304 stainless steel. A number of materials important to fabrication of Micro Electro Mechanical Systems (MEMS) devices have also been examined. For most surfaces, coefficient values are near 0.95, 0.85, and 0.45 for argon, nitrogen, and helium, respectively. Only slight differences in accommodation as a function of surface roughness have been seen. Surface contamination appears to have a more significant effect: argon plasma treatment has been observed to reduce thermal accommodation by as much as 0.10 for helium. Mixtures of argon and

  16. A high temperature thermal diffusivity determination procedure for solids and liquids

    NASA Technical Reports Server (NTRS)

    Bayazitoglu, Yildiz; Suryanarayana, P. V. R.; Sathuvalli, Udaya B.

    1990-01-01

    A new method for measuring the thermal diffusivity of materials at high temperatures is presented. The method is applicable to solids on Earth, and to liquids in the reduced gravity environment of space. It is especially suited to levitated liquid metals at elevated temperatures where thermal diffusivity data is not available. The method is applied in two parts, such that lumped analysis is valid in the first part, and Fourier's law of conduction is valid in the second. In both parts, the spherical specimen is assumed to have been heated to a desired temperature and cooled. An inverse conduction problem is then formulated and solved using Laplace transformation techniques. Using this solution, sample sizes, and experimentally obtained surface temperature history, the thermal diffusivity is determined by minimizing a function that satisifies the heat balance at the surface. Minimization is performed using a modified quasilinearization algorithm. Accuracy is very sensitive to error in the temperature data and increases with better curve fits to the temperature data. An error analysis is also performed, and the effect of errors in the various parameters on the evaluated thermal diffusivity is determined. An experimental study for solids on Earth is suggested, before development for implementation in space.

  17. Determination of the pK of an Indicator by Thermal Lens Spectroscopy: A Laser Experiment for Instrumental Analysis Laboratory.

    ERIC Educational Resources Information Center

    Erskine, Steven R.; Bobbitt, Donald R.

    1989-01-01

    Gives upper level chemistry students a better understanding of the application of lasers in the field of spectroscopy. Provides three experiments to demonstrate the thermal lens effect: determination of beam profile, cell position optimization, and pKa determination. (MVL)

  18. 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.

  19. Metallurgical characterization and determination of residual stresses of coatings formed by thermal spraying

    NASA Astrophysics Data System (ADS)

    Laribi, M.; Mesrati, N.; Vannes, A. B.; Treheux, D.

    2003-06-01

    This work presents an experimental determination of residual stresses in 35CrMo4 (Euronorm) low alloyed steel substrates with thermally sprayed coatings. Two different materials were separately deposited. The first one consisted of a blend of two superalloys: Cr-Ni steel and Cr-Mn steel, designated 55E and 65E, respectively. The second material was molybdenum. In a first part, basic characteristics of the deposited layers (metallographic analysis, hardness, and adhesion) are presented. In a second part, the determination of the residual stresses, in both substrate and thermal sprayed layers is performed using an extensometric method in combination with a simultaneous progressive electrolytic polishing. The influence of a nickel-aluminum (80:20%) bond-coat and/or a post-annealing at 850 °C in air for 1 h is studied.

  20. Thermal diffusivity coefficient of glycerin determined on an acoustically levitated drop.

    PubMed

    Ohsaka, K; Rednikov, A; Sadhal, S S

    2002-10-01

    We present a technique that can be used to determine the thermal diffusivity coefficient of undercooled liquids that exist at temperatures below their freezing points. The technique involves levitation of a small amount of liquid in the shape of a flattened drop using an acoustic levitator and heating it with a CO2 laser. The heated drop is then allowed to cool naturally by heat loss from the surface. Due to acoustic streaming, heat loss is highly non-uniform and appears to mainly occur at the drop circumference (equatorial region). This fact allows us to relate the heat loss rate with a heat transfer model to determine the thermal diffusion coefficient. We demonstrate the feasibility of the technique using glycerin drops as a model liquid. PMID:12446319

  1. 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

    ... 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...

  2. Determination of nitrate in atmospheric particulate matter by thermal decomposition and chemiluminescence

    SciTech Connect

    Spicer, C.W.; Joseph, D.W.; Schumacher, P.M.

    1985-10-01

    A thermal decomposition/chemiluminescence method is presented for determining nitrate in atmospheric particular matter. Nitrate in the sample is thermally decomposed to NO/sub x/, which is then determined with a commercial chemiluminescence NO/sub x/ monitor. The nitrate in a filter sample can be determined directly by heating a segment of the filter in a furnace or after extraction of the filter by flash heating the aqueous extract in a sample loop. In either case, the sample is decomposed in a nitrogen atmosphere to avoid interference from ammonium. The NO/sub x/ peak from nitrate decomposition can be quantified by integrating the chemiluminescence signal or by integrating the gas sample in a Tedlar bag prior to the chemiluminescence measurement. The technique is straightforward, fast, and sensitive, and interferences in atmospheric samples are negligible. A comparison of the thermal decomposition/chemiluminescence method with ion chromatography using filter samples collected in ambient air showed good agreement over a wide range of concentrations. 26 references.

  3. Determination of physical properties of the Asteroid (41) Daphne from interferometric observations in the thermal infrared

    NASA Astrophysics Data System (ADS)

    Matter, Alexis; Delbo, Marco; Ligori, Sebastiano; Crouzet, Nicolas; Tanga, Paolo

    2011-09-01

    We describe interferometric observations of the Asteroid (41) Daphne in the thermal infrared obtained with the Mid-Infrared Interferometric Instrument (MIDI) and the Auxiliary Telescopes (ATs) of the European Southern Observatory (ESO) Very Large Telescope Interferometer (VLTI). We derived the size and the surface thermal properties of (41) Daphne by means of a thermophysical model (TPM), which is used for the interpretation of interferometric data for the first time. From our TPM analysis, we derived a volume equivalent diameter for (41) Daphne of 189 km, using a non-convex 3-D shape model derived from optical lightcurves and adaptive optics images (B. Carry, private communication). On the other hand, when using the convex shape of Kaasalainen et al. (Kaasalainen, M., Mottola, S., Fulchignoni, M. [2002]. Icarus 159, 369-395) in our TPM analysis, the resulting volume equivalent diameter of (41) Daphne is between 194 and 209 km, depending on the surface roughness. The shape of the asteroid is used as an a priori information in our TPM analysis. No attempt is made to adjust the shape to the data. Only the size of the asteroid and its thermal parameters such as, albedo, thermal inertia and roughness are adjusted to the data. We estimated our model systematic uncertainty to be of 4% and of 7% on the determination of the asteroid volume equivalent diameter depending on whether the non-convex or the convex shape is used, respectively. In terms of thermal properties, we derived a value of the surface thermal inertia smaller than 50 J m -2 s -0.5 K -1 and preferably in the range between 0 and ˜30 J m -2 s -0.5 K -1. Our TPM analysis also shows that Daphne has a moderate macroscopic surface roughness.

  4. Determination of water content by capillary gas chromatography coupled with thermal conductivity detection.

    PubMed

    Lodi, A; Bellini, M S; Clavel, A; Pijnenburg, N

    2011-11-01

    This article presents some experience obtained by applying capillary gas chromatography coupled with thermal conductivity detection (GC/TCD) to the determination of water in substances for pharmaceutical use. This technique represents a useful, orthogonal tool complementary to water determination methods based on volumetric or coulometric titration. It can also represent an alternative technique when such titrations are not applicable. This article presents the preliminary results obtained in a number of case studies where a GC/TCD procedure was applied in comparison with pharmacopoeial methods to substances with different water contents. PMID:22225767

  5. 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. PMID:26608794

  6. Determining thermal diffusivity and defect attributes in ceramic matrix composites by infrared imaging

    NASA Astrophysics Data System (ADS)

    Ahuja, Sanjay; Ellingson, William A.; Stuckey, J. B.; Koehl, E. R.

    1996-03-01

    Ceramic matrix composites are being developed for numerous high temperature applications, including rotors and combustors for advanced turbine engines, heat exchanger and hot-gas filters for coal gasification plants. Among the materials of interest are silicon-carbide-fiber- reinforced-silicon-carbide (SiC(f)/SiC), silicon-carbide-fiber-reinforced-silicon-nitride (SiC(f)/Si3N4), aluminum-oxide-reinforced-alumina (Al2O3(f)/Al2O3, etc. In the manufacturing of these ceramic composites, the conditions of the fiber/matrix interface are critical to the mechanical and thermal behavior of the component. Defects such as delaminations and non-uniform porosity can directly affect the performance. A nondestructive evaluation (NDE) method, developed at Argonne National Laboratory has proved beneficial in analyzing as-processed conditions and defect detection created during manufacturing. This NDE method uses infrared thermal imaging for full-field quantitative measurement of the distribution of thermal diffusivity in large components. Intensity transform algorithms have been used for contrast enhancement of the output image. Nonuniformity correction and automatic gain control are used to dynamically optimize video contrast and brightness, providing additional resolution in the acquired images. Digital filtering, interpolation, and least-squares-estimation techniques have been incorporated for noise reduction and data acquisition. The Argonne NDE system has been utilized to determine thermal shock damage, density variations, and variations in fiber coating in a full array of test specimens.

  7. 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. PMID:12345479

  8. Acceptance speech.

    PubMed

    Carpenter, M

    1994-01-01

    In Bangladesh, the assistant administrator of USAID gave an acceptance speech at an awards ceremony on the occasion of the 25th anniversary of oral rehydration solution (ORS). The ceremony celebrated the key role of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) in the discovery of ORS. Its research activities over the last 25 years have brought ORS to every village in the world, preventing more than a million deaths each year. ORS is the most important medical advance of the 20th century. It is affordable and client-oriented, a true appropriate technology. USAID has provided more than US$ 40 million to ICDDR,B for diarrheal disease and measles research, urban and rural applied family planning and maternal and child health research, and vaccine development. ICDDR,B began as the relatively small Cholera Research Laboratory and has grown into an acclaimed international center for health, family planning, and population research. It leads the world in diarrheal disease research. ICDDR,B is the leading center for applied health research in South Asia. It trains public health specialists from around the world. The government of Bangladesh and the international donor community have actively joined in support of ICDDR,B. The government applies the results of ICDDR,B research to its programs to improve the health and well-being of Bangladeshis. ICDDR,B now also studies acute respiratory diseases and measles. Population and health comprise 1 of USAID's 4 strategic priorities, the others being economic growth, environment, and democracy, USAID promotes people's participation in these 4 areas and in the design and implementation of development projects. USAID is committed to the use and improvement of ORS and to complementary strategies that further reduce diarrhea-related deaths. Continued collaboration with a strong user perspective and integrated services will lead to sustainable development. PMID:12345470

  9. Development of a Test Technique to Determine the Thermal Conductivity of Large Refractory Ceramic Test Specimens

    SciTech Connect

    Hemrick, James Gordon; Dinwiddie, Ralph Barton; Loveland, Erick R; Prigmore, Andre L

    2012-01-01

    A method has been developed to utilize the High Intensity Infrared lamp located at Oak Ridge National Laboratory for the measurement of thermal conductivity of bulk refractory materials at elevated temperatures. The applicability of standardized test methods to determine the thermal conductivity of refractory materials at elevated temperatures is limited to small sample sizes (laser flash) or older test methods (hot wire, guarded hot plate), which have their own inherent problems. A new method, based on the principle of the laser flash method, but capable of evaluating test specimens on the order of 200 x 250 x 50 mm has been developed. Tests have been performed to validate the method and preliminary results are presented in this paper.

  10. Why do the Abundances of Ions Generated by MALDI Look Thermally Determined?

    NASA Astrophysics Data System (ADS)

    Bae, Yong Jin; Choe, Joong Chul; Moon, Jeong Hee; Kim, Myung Soo

    2013-11-01

    In a previous study ( J. Mass Spectrom. 48, 299-305, 2013), we observed that the abundance of each ion in a matrix-assisted laser desorption ionization (MALDI) spectrum looked thermally determined. To find out the explanation for the phenomenon, we estimated the ionization efficiency and the reaction quotient (QA) for the autoprotolysis of matrix, M + M → [M + H]+ + [M - H]-, from the temperature-controlled laser desorption ionization spectra of α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB). We also evaluated the equilibrium constants (KA) for the autoprotolysis at various temperatures by quantum chemical calculation. Primary ion formation via various thermal models followed by autoprotolysis-recombination was compatible with the observations. The upper limit of the effective temperature of the plume where autoprotolysis-recombination occurs was estimated by equating QA with the calculated equilibrium constant. [Figure not available: see fulltext.

  11. Novel methodology to determine thermal conductivity of thermoelectric materials and comparison with device performance

    NASA Astrophysics Data System (ADS)

    Maddux, Jay R.; Taylor, Patrick J.

    2012-06-01

    Accuracy of thermal conductivity measurements is an ongoing area of controversy in thermoelectric materials development. In this work, we demonstrate a novel steady-state method for characterizing thermal conductivity of bulk materials and devices under isothermal and near-isothermal conditions. The isothermal condition is achieved by exactly balancing Peltier heat flow against an externally imposed heat flow in the material. Under steady-state, isothermal conditions, heat flow in the material can be determined with high accuracy because external parasitic heat flows become negligible. We compare our results with conventional measurement techniques and also with measured thermoelectric device performance. Agreement between predicted and measured thermoelectric cooler performance is within 2%. Results for thermoelectric power generators will also be discussed.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26179785

  13. 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.

  14. Determination of thermal inactivation kinetics of hepatitis A virus in blue mussel (Mytilus edulis) homogenate.

    PubMed

    Bozkurt, Hayriye; D'Souza, Doris H; Davidson, P Michael

    2014-05-01

    Hepatitis A virus (HAV) is a food-borne enteric virus responsible for outbreaks of hepatitis associated with shellfish consumption. The objectives of this study were to determine the thermal inactivation behavior of HAV in blue mussels, to compare the first-order and Weibull models to describe the data, to calculate Arrhenius activation energy for each model, and to evaluate model efficiency by using selected statistical criteria. The times required to reduce the population by 1 log cycle (D-values) calculated from the first-order model (50 to 72°C) ranged from 1.07 to 54.17 min for HAV. Using the Weibull model, the times required to destroy 1 log unit (tD = 1) of HAV at the same temperatures were 1.57 to 37.91 min. At 72°C, the treatment times required to achieve a 6-log reduction were 7.49 min for the first-order model and 8.47 min for the Weibull model. The z-values (changes in temperature required for a 90% change in the log D-values) calculated for HAV were 15.88 ± 3.97°C (R(2), 0.94) with the Weibull model and 12.97 ± 0.59°C (R(2), 0.93) with the first-order model. The calculated activation energies for the first-order model and the Weibull model were 165 and 153 kJ/mol, respectively. The results revealed that the Weibull model was more appropriate for representing the thermal inactivation behavior of HAV in blue mussels. Correct understanding of the thermal inactivation behavior of HAV could allow precise determination of the thermal process conditions to prevent food-borne viral outbreaks associated with the consumption of contaminated mussels. PMID:24632250

  15. 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, ...

  16. Application of Photothermal Techniques in the Determination of the Water-Vapor Diffusion Coefficient and Thermal Effusivity of Hydrogels

    NASA Astrophysics Data System (ADS)

    Raymundo-Ortiz, A. I.; Ramos-Ramirez, E. G.; Cruz-Orea, A.; Salazar-Montoya, J. A.

    2013-09-01

    The main objective of this work is to determine the effect of different sodium alginate concentrations in hydrogels on their water-vapor diffusion coefficient (WVDC) and thermal effusivity (. These physical parameters were measured by photoacoustic and pyroelectric techniques, respectively. The results indicate that the higher values for the WVDC are presented at a concentration of 2 % sodium alginate. At lower concentrations of sodium alginate, the sample thermal effusivity increases, with a value close to the water thermal effusivity.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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-1 K-1 and 26.7 ±1 W m-1 K-1, respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10-6 m2 K W-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.

  18. 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.

  19. 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.

  20. 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

    2011-01-01

    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 (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. PMID:21149945

  1. 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.

  2. Determination of core design thermal safety limits for a two-loop pressurized water reactor

    SciTech Connect

    Kostadinov, V.

    1996-04-01

    Results are given of independent research of core thermal design limits for the Nuklearna Elektrarna Krsko (NEK) nuclear power plant; procedures for two-loop pressurized water reactor plant core design safety limit calculation are used. Emphasis is placed on researching the vessel exit boiling and the hot-channel exit quality limits and their impact on the maximum available design safety operating range and thermal operating margin of the NEK reactor core. For this purpose, the LIMITS computer code is developed. Based on the modified, well-tried COBRA-IV-I computer code, the departure of nuclear boiling ratio core safety limits are calculated. The original results complement well those of the NEK Final Safety Analysis Report. The procedures and the methods for determining the reactor core design thermal limits are successfully proven despite the unavailability of proprietary data, different models, and computer codes. In addition to the acquired capability of in-house independent checking of the vendor`s results, the bases are set for further independent analyses of the limiting safety system settings for the NEK core.

  3. 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.

  4. Determination of the coefficient of thermal expansion with embedded long-gauge fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Feng, Xin; Sun, Changsen; Zhang, Xiaotan; Ansari, Farhad

    2010-06-01

    A novel methodology for the determination of the coefficient of thermal expansion (CTE) is proposed by using long-gauge fiber optic sensors. Current approaches either neglect the shear-lag effects or do not compensate for the thermo-optic effects in optical fibers leading to precision errors. The embedded long-gauge sensor measures not only the thermo-optic effect due to temperature fluctuations, but also the strain-optic effect created by thermal stresses. However, it is difficult to directly separate these two effects in the measurements. Given that only the strain-optic effect correlates to the CTE of a host material, it is necessary to compensate for the thermo-optic effect. An additional error is attributed to the fact that the shear-lag effect is ignored, i.e. assumption is made that the strain distribution in the optical fiber is the same as that in the host material. This study reports on the development of a methodology for the computation of the coefficient of thermal expansion in structural materials using long-gauge fiber optic sensors. The proposed formulations account for both the shear-lag and thermo-optic effects.

  5. DETERMINATION OF NON-THERMAL VELOCITY DISTRIBUTIONS FROM SERTS LINEWIDTH OBSERVATIONS

    SciTech Connect

    Coyner, Aaron J.; Davila, Joseph M.

    2011-12-01

    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 from 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{sup -1} in all three of the quiet-Sun, active region, and off-limb distributions. For the possibility of Alfven wave resonance heating, we find that 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.

  6. Sensitivity of the interpretation of the experimental ion thermal diffusivity to the determination of the ion conductive heat flux

    SciTech Connect

    Stacey, W. M.

    2014-04-15

    A moments equation formalism for the interpretation of the experimental ion thermal diffusivity from experimental data is used to determine the radial ion thermal conduction flux that must be used to interpret the measured data. It is shown that the total ion energy flux must be corrected for thermal and rotational energy convection, for the work done by the flowing plasma against the pressure and viscosity, and for ion orbit loss of particles and energy, and expressions are presented for these corrections. Each of these factors is shown to have a significant effect on the interpreted ion thermal diffusivity in a representative DIII-D [J. Luxon, Nucl. Fusion 42, 614 (2002)] discharge.

  7. 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.

  8. Determination of the thermal stability of fluids by tensimetry - Instrumentation and procedure

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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 perfluoro alkylethers.

  9. Determination of absorption coefficient based on laser beam thermal blooming in gas-filled tube.

    PubMed

    Hafizi, B; Peñano, J; Fischer, R; DiComo, G; Ting, A

    2014-08-01

    Thermal blooming of a laser beam propagating in a gas-filled tube is investigated both analytically and experimentally. A self-consistent formulation taking into account heating of the gas and the resultant laser beam spreading (including diffraction) is presented. The heat equation is used to determine the temperature variation while the paraxial wave equation is solved in the eikonal approximation to determine the temporal and spatial variation of the Gaussian laser spot radius, Gouy phase (longitudinal phase delay), and wavefront curvature. The analysis is benchmarked against a thermal blooming experiment in the literature using a CO₂ laser beam propagating in a tube filled with air and propane. New experimental results are presented in which a CW fiber laser (1 μm) propagates in a tube filled with nitrogen and water vapor. By matching laboratory and theoretical results, the absorption coefficient of water vapor is found to agree with calculations using MODTRAN (the MODerate-resolution atmospheric TRANsmission molecular absorption database) and HITRAN (the HIgh-resolution atmospheric TRANsmission molecular absorption database). PMID:25090334

  10. Determination of enzyme thermal parameters for rational enzyme engineering and environmental/evolutionary studies.

    PubMed

    Lee, Charles K; Monk, Colin R; Daniel, Roy M

    2013-01-01

    Of the two independent processes by which enzymes lose activity with increasing temperature, irreversible thermal inactivation and rapid reversible equilibration with an inactive form, the latter is only describable by the Equilibrium Model. Any investigation of the effect of temperature upon enzymes, a mandatory step in rational enzyme engineering and study of enzyme temperature adaptation, thus requires determining the enzymes' thermodynamic parameters as defined by the Equilibrium Model. The necessary data for this procedure can be collected by carrying out multiple isothermal enzyme assays at 3-5°C intervals over a suitable temperature range. If the collected data meet requirements for V max determination (i.e., if the enzyme kinetics are "ideal"), then the enzyme's Equilibrium Model parameters (ΔH eq, T eq, ΔG (‡) cat, and ΔG (‡) inact) can be determined using a freely available iterative model-fitting software package designed for this purpose.Although "ideal" enzyme reactions are required for determination of all four Equilibrium Model parameters, ΔH eq, T eq, and ΔG (‡) cat can be determined from initial (zero-time) rates for most nonideal enzyme reactions, with substrate saturation being the only requirement. PMID:23504427

  11. RAPID COMMUNICATION: Simultaneous determination of anisotropic thermal conductivities of liquid crystals by means of a photothermal self-diffracting technique

    NASA Astrophysics Data System (ADS)

    Ono, Hiroshi; Shibata, Kazuaki

    2000-11-01

    Anisotropic thermal conductivities of liquid crystals were simultaneously determined by means of a photothermal self-diffracting technique. A single-mode laser beam with Gaussian profile excited refractive index distribution due to the photothermal effect in homogeneously-aligned liquid-crystal films. The refractive index distribution, which is affected by thermal conductivities of liquid crystals, transformed the incident Gaussian beam. The laser beam was self-diffracted and thermal conductivities of liquid crystals were determined by characterizing the beam profile by both Kirchhoff's diffraction theory and heat conduction analysis.

  12. Acceptance dependence of fluctuation measures near the QCD critical point

    NASA Astrophysics Data System (ADS)

    Ling, Bo; Stephanov, Mikhail A.

    2016-03-01

    We argue that a crucial determinant of the acceptance dependence of fluctuation measures in heavy-ion collisions is the range of correlations in the momentum space, e.g., in rapidity, Δ ycorr . The value of Δ ycorr˜1 for critical thermal fluctuations is determined by the thermal rapidity spread of the particles at freeze-out, and has little to do with position space correlations, even near the critical point where the spatial correlation length ξ becomes as large as 2-3 fm (this is in contrast to the magnitudes of the cumulants, which are sensitive to ξ ). When the acceptance window is large, Δ y ≫Δ ycorr , the cumulants of a given particle multiplicity, κk, scale linearly with Δ y , or mean multiplicity in acceptance, , and cumulant ratios are acceptance independent. In the opposite regime, Δ y ≪Δ ycorr , the factorial cumulants, κ̂k, scale as (Δy ) k, or k. We demonstrate this general behavior quantitatively in a model for critical point fluctuations, which also shows that the dependence on transverse momentum acceptance is very significant. We conclude that the extension of rapidity coverage as proposed by the STAR Collaboration should significantly increase the magnitude of the critical point fluctuation signatures.

  13. 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.

  14. 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.

  15. 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.

  16. Simplified estimation method for the determination of the thermal effusivity and thermal conductivity using a low cost hot strip

    NASA Astrophysics Data System (ADS)

    Jannot, Yves; Meukam, Pierre

    2004-09-01

    This paper presents the study of a hot strip made of thin rectangular electrical resistance with a thermocouple placed on its centre. The purpose was to simultaneously estimate thermal effusivity and conductivity in a limited time (t2 < 180 s) using a low cost probe. Heat transfer has been modelled with the quadrupole formalism to simulate the evolution of the temperature at the centre of a hot strip set between two samples of material to be characterized when a heat flux step is applied. Simulation is used to fix the optimal dimensions of a hot strip that behaves as a hot plate (1D transfer) during a minimal time t1 (>20 s) and that has higher sensitivity to the thermal conductivity between t1 and t2 (2D transfer). The thermal effusivity is estimated between 0 and t1 by minimization of the quadratic errors between the experimental curve and the curve calculated by the classical hot plate model. The thermal conductivity is estimated between t1 and t2 but using the complete 2D model. To validate the model and the estimation process, experimental tests were realized on three materials with low diffusivities (a < 2 × 10-7 m2 s-1) and having typical area of 6 cm × 4 cm and typical thickness of 1.5 cm.

  17. Thermal resistance of Salmonella enteritidis and Escherichia coli K12 in liquid egg determined by thermal-death-time disks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A thermal-death-time (TDT) disk was designed to evaluate microbiological inactivation kinetics by heat. A first order inactivation kinetic model is described by the D value as the hold time at a specific temperature that causes 90% reduction in microbial viability and the z value as the increase in ...

  18. 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.

  19. 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. PMID:25597033

  20. Drought stress determination of crops by means of ground based thermal remote sensing

    NASA Astrophysics Data System (ADS)

    Weihs, P.; Linke, R.; Richter, K.; Eitzinger, J.; Berger, L.; Besnard, T.

    2009-04-01

    Drought stress is known to have a restricting effect on plant growth and thus inevitably decreases crop yield. In the presence of drought stress, occurring whenever the evaporative demand of the atmosphere can no longer be met by the water uptake of the plant, transpiration rates of the leaves are reduced leading to higher leaf-temperatures. Remote Sensing in the thermal infrared region has been proved to be useful for acquiring information about canopy temperature and thus crop condition. Consequently, the adequate interpretation of these observations provides an instrument for irrigation scheduling, needed to avoid the negative effects of yield losses and to support a sustainable use of water in agriculture. In this study, thermal measurements by means of CIR-5 were routinely performed during the growth period from May to July 2006, on an irrigated and a rainfed wheat (Triticum aestivum L. (cv. Xenos)) plot at the study test site ‘Augarten', Vienna. Physiological measurements, such as leaf water potential and relative water content, were performed on the youngest fully expanded leaf at the three developmental stages. Additionally, spectral measurements with a portable field spectrometer were performed and meteorological data including net radiation and shortwave global radiation were continuously recorded. The objective of the present study was to assess the potential of crop water stress indices (CWSI, WDI) to determine the level of drought stress and thus irrigation needs. The results of the analyses will be presented and discussed, also in terms of a potential application in irrigation management systems.

  1. 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

  2. Ionic liquid based in situ solvent formation microextraction coupled to thermal desorption for chlorophenols determination in waters by gas chromatography/mass spectrometry.

    PubMed

    Galán-Cano, Francisco; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel

    2012-03-16

    A simple and efficient method for the determination of ten chlorophenols (including mono, di, tri, tetra and pentachlorophenols) in water samples is presented. The analytical method is based on a previous derivatization of the target compounds with acetic anhydride, being the derivatized compounds finally isolated/preconcentrated by an in situ solvent formation microextraction. Later on the extractant (an ionic liquid) containing the analytes is recovered by centrifugation and thermally desorbed. The analytes are finally separated and determined by gas chromatography/mass spectrometry. The main variables involved in the extraction and thermal desorption steps have been studied in depth. Once evaluated, the analytical method has been characterized in terms of linearity, sensitivity, precision and accuracy. The limits of detection were in the range from 60 ng L(-1) (4-chlorophenol) to 440 ng L(-1) (pentachlorophenol) while the precision, expressed as relative standard deviation, was in the interval from 4.5% (2,6-dichlorophenol) to 9.9% (3-chlorophenol). In addition, acceptable recovery values were obtained in samples of different nature, including river, tap and reservoir water samples. PMID:22307153

  3. Mesoscopic Nonlinear Elastic Modulus of Thermal Barrier Coatings Determined by Cylindrical Punch Indentation

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Zhu, Dong-Ming; Miller, Robert A.

    2000-01-01

    Cylindrical punch indentations are performed to determine the effective modulus of a plasma-sprayed ZrO2-8Wt%Y2O3 thermal barrier coating (TBC) as a function of coating depth. Cylindrical punch indentations offer significant advantages over pointed (Vickers, Berkovich, or Knoop) indentations for materials that do not exhibit linear elastic behavior. Cyclic loading with a cylindrical punch clearly shows the TBCs to exhibit nonlinear elastic behavior with significant hysteresis that is related to the compaction and internal sliding within the plasma-spray splat microstructure. In addition, the effect of a high heat flux laser treatment was shown to produce a gradient both in the effective TBC modulus and degree of loading/unloading hysteresis with depth.

  4. 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.

  5. 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. PMID:18503526

  6. Rapid Determination of the Chemical Oxygen Demand of Water Using a Thermal Biosensor

    PubMed Central

    Yao, Na; Wang, Jinqi; Zhou, Yikai

    2014-01-01

    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. PMID:24915178

  7. 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.

  8. Determining Experimental Parameters for Thermal-Mechanical Forming Simulation considering Martensite Formation in Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Schmid, Philipp; Liewald, Mathias

    2011-08-01

    The forming behavior of metastable austenitic stainless steel is mainly dominated by the temperature-dependent TRIP effect (transformation induced plasticity). Of course, the high dependency of material properties on the temperature level during forming means the temperature must be considered during the FE analysis. The strain-induced formation of α'-martensite from austenite can be represented by using finite element programs utilizing suitable models such as the Haensel-model. This paper discusses the determination of parameters for a completely thermal-mechanical forming simulation in LS-DYNA based on the material model of Haensel. The measurement of the martensite evolution in non-isothermal tensile tests was performed with metastable austenitic stainless steel EN 1.4301 at different rolling directions between 0° and 90 °. This allows an estimation of the influence of the rolling direction to the martensite formation. Of specific importance is the accuracy of the martensite content measured by magnetic induction methods (Feritscope). The observation of different factors, such as stress dependence of the magnetisation, blank thickness and numerous calibration curves discloses a substantial important influence on the parameter determination for the material models. The parameters obtained for use of Haensel model and temperature-dependent friction coefficients are used to simulate forming process of a real component and to validate its implementation in the commercial code LS-DYNA.

  9. Physical and thermal properties of human teeth determined by photomechanical, photothermal images to rapidly diagnose

    NASA Astrophysics Data System (ADS)

    Elsharkawy, Yasser H.

    2009-02-01

    This paper details the current techniques for the detection of caries using non-invasive techniques, A promising option is tooth trans-illumination which is based on an increase of light scattering or light absorption in the affected tissue region. In this study trans-illumination applied to detect microscopic caries lesions was investigated using premolar teeth containing affected caries lesions. One line coincides with a carious absorption line, while the other is used as a reference. By this referencing the system is auto-calibrated continuously. Normal and carious human teeth were applied for the determination of NIR absorption by using a micro-spectrophotometer. Relative NIR absorption value for normal tooth and for carious one distributed in different quantity relating to the tooth structure, whereas the value showed much higher in enamel than in dentine. This paper suggests a way to use a commercially available system, which has the capability to carious detection. It is based on photomechanical and photothermal monitoring of teeth response. This technique is based on irradiation of the teeth with a short pulse Nd:YAG laser (1064 μm, 12 ns) and monitoring the laser-induced local thermal effects. This is realized with thermal imagers that locate the heated teeth absorbing zones. The photothermal (PT) image represents a two-dimensional depth-integrated temperature distribution in the irradiated volume and correlates with the conventional optical absorption coefficients. In addition to a description as to how each of the modalities function, consideration is given to recent advances and changes in the relevant technologies, and a comparison of relative benefits and shortfalls of the systems.

  10. Triple sorbent thermal desorption/gas chromatography/mass spectrometry determination of vapor phase organic contaminants

    SciTech Connect

    Ma, C.Y.; Skeen, J.T.; Dindal, A.B.; Higgins, C.E.; Jenkins, R.A.

    1994-05-01

    A thermal desorption/ps chromatography/mass spectrometry (TD/GC/MS) has been evaluated for the determination of volatile organic compounds (VOCS) in vapor phase samples using Carbosieve S-III/Carbotrap/Carotrap C triple sorbent traps (TST) similar to those available from a commercial source. The analysis was carried out with a Hewlett-Packard 5985A or 5995 GC/MS system with a modified injector to adapt an inhouse manufactured short-path desorber for transferring desorbate directly onto a cryofocusing loop for subsequent GC/MS analysis. Vapor phase standards generated from twenty six compounds were used for method validation, including alkanes, alkyl alcohols, alkyl ketones, and alkyl nitrites, a group of representative compounds that have previously been identified in a target airborne matrix. The method was validated based on the satisfactory results in terms of reproducibility, recovery rate, stability, and linearity. A relative, standard deviation of 0.55 to 24.3 % was obtained for the entire TD process (generation of gas phase standards, spiking the standards on and desorbing from TST) over a concentration range of 20 to 500 ng/trap. Linear correlation coefficients for the calibration curves as determined ranged from 0.81 to 0.99 and limits of detection ranged from 3 to 76 ng. For a majority of standards, recoveries of greater than 90% were observed. For three selected standards spiked on TSTS, minimal loss (10 to 22%) was observed after storing the spiked in, a 4{degree}C refrigerator for 29 days. The only chromatographable artifact observed was a 5% conversion of isopropanol to acetone. The validated method been successfully applied, to the determination of VOCs collected from various emission sources in a diversified concentration range.

  11. Determining majors fluid-flow zones in a geothermal sandstone reservoir from thermal conductivity and temperature logs

    NASA Astrophysics Data System (ADS)

    Haffen, S.; Géraud, Y.; Diraison, M.; Dezayes, C.

    2012-04-01

    A method, based on thermal gradient analysis, is presented for locating hot fluid flow in a rock formation. The method involves determining the thermal gradient from thermal conductivity measurements on core samples and also from borehole temperature logs run in the same borehole. With a heat flow density calculation and thermal conductivity measurements, one can apply Fourier's law to calculate the thermal gradient in a rock system where the heat transfer is assumed to be controlled only by conduction. The thermal gradient calculated from a measured temperature log profile takes into account both the conductive and the convective or advective part due to fluid circulation. On the one hand, if the thermal gradient deduced from temperature logs indicates similar values to the thermal gradient calculated with Fourier's law, the heat transfer is assumed to be controlled solely by conduction in the rock formation and thus involves no relative hot or cold fluid circulation. If, on the other hand, the thermal gradient deduced from the temperature logs indicates higher or lower values than that calculated with Fourier's law, then respectively hot or cold fluid flow could be suspected. We applied this method to borehole EPS1 (Soultz-sous-Forêts, Upper Rhine Graben) for which temperature logs and core samples from the Buntsandstein are available. Variations between the two determined thermal gradient curves revealed three main hot fluid flow levels alternating with non-flow zones in the sandstone formation. The pattern was then compared against the fracture distribution, and also against sedimentological analyses determined from the borehole cores, in order to determine the driving components of the fluid flows. The flow zones in the Buntsandstein are controlled on the one hand by a macroscopic network with two major fault zones providing a flow path for the deep heat source and on the other hand by a matrix network formed during sedimentary or diagenetic processes within

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    DOE PAGESBeta

    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 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

  18. 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 .

  19. 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

  20. Determination of trace iron in zirconium by isotope dilution-thermal ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Elliot, N. L.; Campbell, M. A.; Green, L. W.

    1995-08-01

    An isotope dilution-thermal ionization mass spectrometry method for the determination of parts-per-million levels of iron in zirconium is required for precise, accurate analyses in studies of the effects of iron on the irradiation deformation of nuclear alloys. A two-stage purification procedure was developed to avoid the signal suppression and interference caused by the zirconium matrix. After sample dissolution and spiking with 54Fe, the bulk of the zirconium is removed by ion exchange chromatography, and the eluted Fe(III) is further purified by micro-solvent extraction into tributyl phosphate-impregnated resin beads. The iron is back-extracted, submicrogram amounts are loaded onto previously outgassed zone-refined Re filaments, and 54/56 ratios are measured at 1170°C. A silica gel/boric acid ionization enhancer is used to obtain stable Fe+ currents as strong as 2 × 10-14. A from nanogram loadings of pure iron. The procedural blank of 20 ± 6 ng is sufficiently low to allow determination of ppm levels of iron in 0.1 g zirconium samples. The analyses of solution standards showed agreement within 2% between measured and expected values, and a good fit, r2 = 0.99997, to a linear regression. The analyses of metal standards exhibited a similar good fit to a linear regression of measured against expected values, and showed good agreement with other methods. The method meets the requirements for zirconium metallurgical studies, and may be extended to other applications.

  1. 24 CFR 3282.355 - Submission acceptance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Submission acceptance. 3282.355... § 3282.355 Submission acceptance. (a) A party whose submission is determined by the Department to be adequate shall be granted provisional acceptance until December 15, 1976, or for a six month period...

  2. 24 CFR 3282.355 - Submission acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Submission acceptance. 3282.355... § 3282.355 Submission acceptance. (a) A party whose submission is determined by the Department to be adequate shall be granted provisional acceptance until December 15, 1976, or for a six month period...

  3. Determination of the thermal expansion and thermo-optic coefficients of a bacteriorhodopsin film

    NASA Astrophysics Data System (ADS)

    Wang Song, Q.; Zhang, Chunping; Ku, Chin-Yu; Huang, Ming-Chieh; Gross, Richard B.; Birge, Robert R.

    1995-02-01

    The linear expansion and thermo-optic coefficients of a bacteriorhodopsin film were measured by using an interferometric method. The experimental results confirm the previous suspicions that the large refractive nonlinearity which occurs at high illumination intensities arises form a thermal effect. The results also suggest a possible way to increase the usable thermal nonlinearity by four times.

  4. 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…

  5. Photothermal determination of thermal diffusivity and polymerization depth profiles of polymerized dental resins

    NASA Astrophysics Data System (ADS)

    Martínez-Torres, P.; Mandelis, A.; Alvarado-Gil, J. J.

    2009-12-01

    The degree and depth of curing due to photopolymerization in a commercial dental resin have been studied using photothermal radiometry. The sample consisted of a thick layer of resin on which a thin metallic gold layer was deposited, thus guaranteeing full opacity. Purely thermal-wave inverse problem techniques without the interference of optical profiles were used. Thermal depth profiles were obtained by heating the gold coating with a modulated laser beam and by performing a frequency scan. Prior to each frequency scan, photopolymerization was induced using a high power blue light emitted diode (LED). Due to the highly light dispersive nature of dental resins, the polymerization process depends strongly on optical absorption of the blue light, thereby inducing a depth dependent thermal diffusivity profile in the sample. A robust depth profilometric method for reconstructing the thermal diffusivity depth dependence on degree and depth of polymerization has been developed. The thermal diffusivity depth profile was linked to the polymerization kinetics.

  6. 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

  7. Contributions of the Complementarity Determining Regions to the Thermal Stability of a Single-Domain Antibody

    PubMed Central

    Zabetakis, Dan; Anderson, George P.; Bayya, Nikhil; Goldman, Ellen R.

    2013-01-01

    Single domain antibodies (sdAbs) are the recombinantly-expressed variable domain from camelid (or shark) heavy chain only antibodies and provide rugged recognition elements. Many sdAbs possess excellent affinity and specificity; most refold and are able to bind antigen after thermal denaturation. The sdAb A3, specific for the toxin Staphylococcal enterotoxin B (SEB), shows both sub-nanomolar affinity for its cognate antigen (0.14 nM) and an unusually high melting point of 85°C. Understanding the source of sdAb A3’s high melting temperature could provide a route for engineering improved melting temperatures into other sdAbs. The goal of this work was to determine how much of sdAb A3’s stability is derived from its complementarity determining regions (CDRs) versus its framework. Towards answering this question we constructed a series of CDR swap mutants in which the CDRs from unrelated sdAbs were integrated into A3’s framework and where A3’s CDRs were integrated into the framework of the other sdAbs. All three CDRs from A3 were moved to the frameworks of sdAb D1 (a ricin binder that melts at 50°C) and the anti-ricin sdAb C8 (melting point of 60°C). Similarly, the CDRs from sdAb D1 and sdAb C8 were moved to the sdAb A3 framework. In addition individual CDRs of sdAb A3 and sdAb D1 were swapped. Melting temperature and binding ability were assessed for each of the CDR-exchange mutants. This work showed that CDR2 plays a critical role in sdAb A3’s binding and stability. Overall, results from the CDR swaps indicate CDR interactions play a major role in the protein stability. PMID:24143255

  8. 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.

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

    PubMed

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

    2015-05-01

    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

  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