Science.gov

Sample records for aged material evaluations

  1. In-service irradiated and aged material evaluations

    SciTech Connect

    Haggag, F.M.; Nanstad, R.K.; Alexander, D.J.

    1995-10-01

    The objective of this task is to provide a direct assessment of actual material properties in irradiated components of nuclear reactors, including the effects of irradiation and aging. Four activities are currently in progress: (1) establishing a machining capability for contaminated or activated materials by completing procurement and installation of a computer-based milling machine in a hot cell; (2) machining and testing specimens from cladding materials removed from the Gundremmingen reactor to establish their fracture properties; (3) preparing an interpretive report on the effects of neutron irradiation on cladding; and (4) continuing the evaluation of long-term aging of austenitic structural stainless steel weld metal by metallurgically examining and testing specimens aged at 288 and 343{degrees}C and reporting the results, as well as by continuing the aging of the stainless steel cladding toward a total time of 50,000 h.

  2. Evaluation of Ultrasonic and Thermal Nondestructive Evaluation for the Characterization of Aging Degradation in Braided Composite Materials

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.

    2010-01-01

    This paper examines the ability of traditional nondestructive evaluation (NDE) techniques to measure the degradation of braided polymer composite materials subjected to thermal-humidity cycling to simulate aging. A series of braided composite coupons were examined using immersion ultrasonic and pulsed thermography techniques in the as received condition. These same specimens were then examined following extended thermal-humidity cycling. Results of this examination did not show a significant change in the resulting (NDE) signals.

  3. Fireset materials aging study

    SciTech Connect

    Smith, H.M.; Arnold, C.; Bailey, M.E.

    1982-07-01

    A thermally-accelerated aging study of 10 selected organic materials used in a fireset has been conducted. The study included both quantitative and qualitative gas analyses as well as the measurement of physical properties before and after accelerated aging. The test plan involved single material aging, as well as pairs and larger groups to look for synergistic interactions. The material types tested were epoxies, polyurethanes, polysulfides, silicones, phenolics, polyolefins, and diallyl phthalates. Only two of the materials tested showed evidence of degradation as a result of aging.

  4. Quantitative evaluation of material degradation of thermally aged duplex stainless steels using chemical immersion test

    NASA Astrophysics Data System (ADS)

    Yi, Y. S.; Shoji, T.

    1996-12-01

    In order to develop a non-destructive evaluation technique for detection of thermal aging embrittlement of duplex stainless steels, corrosion tests on unaged and aged specimens of cast duplex stainless steels were performed in 5 wt% HCl solution. After the immersion test, the dissolution rate of specimens was obtained by a dissolved depth measurement with an AFM. In the measurements of dissolved depths, a replica technique was used for easier handling and also for a possible field application of the AFM analysis method. Changes in corrosion properties by aging measured in terms of the dissolved depth after the immersion were compared with the changes in mechanical properties by aging embrittlement. The changes in corrosion properties of unaged and aged specimen were analyzed in relation to the microstructural change by thermal aging. Based upon insights on the immersion test results and the comparison of the changes in corrosion properties and mechanical properties, a possible non-destructive detection and evaluation technique for thermal aging embrittlement by spinodal decomposition is proposed.

  5. Material property evaluations of bimetallic welds, stainless steel saw fusion lines, and materials affected by dynamic strain aging

    SciTech Connect

    Rudland, D.; Scott, P.; Marschall, C.; Wilkowski, G.

    1997-04-01

    Pipe fracture analyses can often reasonably predict the behavior of flawed piping. However, there are material applications with uncertainties in fracture behavior. This paper summarizes work on three such cases. First, the fracture behavior of bimetallic welds are discussed. The purpose of the study was to determine if current fracture analyses can predict the response of pipe with flaws in bimetallic welds. The weld joined sections of A516 Grade 70 carbon steel to F316 stainless steel. The crack was along the carbon steel base metal to Inconel 182 weld metal fusion line. Material properties from tensile and C(T) specimens were used to predict large pipe response. The major conclusion from the work is that fracture behavior of the weld could be evaluated with reasonable accuracy using properties of the carbon steel pipe and conventional J-estimation analyses. However, results may not be generally true for all bimetallic welds. Second, the toughness of austenitic steel submerged-arc weld (SAW) fusion lines is discussed. During large-scale pipe tests with flaws in the center of the SAW, the crack tended to grow into the fusion line. The fracture toughness of the base metal, the SAW, and the fusion line were determined and compared. The major conclusion reached is that although the fusion line had a higher initiation toughness than the weld metal, the fusion-line J-R curve reached a steady-state value while the SAW J-R curve increased. Last, carbon steel fracture experiments containing circumferential flaws with periods of unstable crack jumps during steady ductile tearing are discussed. These instabilities are believed to be due to dynamic strain aging (DSA). The paper discusses DSA, a screening criteria developed to predict DSA, and the ability of the current J-based methodologies to assess the effect of these crack instabilities. The effect of loading rate on the strength and toughness of several different carbon steel pipes at LWR temperatures is also discussed.

  6. Space aging of solid rocket materials

    NASA Technical Reports Server (NTRS)

    Lester, Dean M.; Jones, Leon L.; Smalley, R. B., Jr.; Ord, R. Neil

    1991-01-01

    Solid rocket propellant and rocket motor components were aged in a vented container on the interior of the LDEF. The results of aging IPSM-II/PAM-DII space motor components are presented. Ballistic and mechanical properties of the space aged main propellant, igniter propellant, and ignition system were compared with similar data from preflight and ground aged samples. Mechanical properties of the composite materials and bonded joints used in the motor case, insulation, liner, nozzle, exit cone, and skirt were similarly evaluated. The space aging results are compared to data collected in a ground based vacuum aging program on similar components.

  7. Experimental Techniques for Evaluating the Effects of Aging on Impact and High Strain Rate Properties of Triaxial Braided Composite Materials

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Roberts, Gary D.; Ruggeri, Charles R.; Gilat, Amos; Matrka, Thomas

    2010-01-01

    An experimental program is underway to measure the impact and high strain rate properties of triaxial braided composite materials and to quantify any degradation in properties as a result of thermal and hygroscopic aging typically encountered during service. Impact tests are being conducted on flat panels using a projectile designed to induce high rate deformation similar to that experienced in a jet engine fan case during a fan blade-out event. The tests are being conducted on as-fabricated panels and panels subjected to various numbers of aging cycles. High strain rate properties are being measured using a unique Hopkinson bar apparatus that has a larger diameter than conventional Hopkinson bars. This larger diameter is needed to measure representative material properties because of the large unit cell size of the materials examined in this work. In this paper the experimental techniques used for impact and high strain rate testing are described and some preliminary results are presented for both as-fabricated and aged composites.

  8. Space aging of solid rocket materials

    NASA Technical Reports Server (NTRS)

    Lester, Dean M.; Jones, Leon L.; Smalley, R. B., Jr.; Ord, R. Neil

    1992-01-01

    Solid rocket propellant and rocket motor components were aged in a vented container on the interior of the LDEF. This paper will present the results of aging the Improved Performance Space Motor-II/Payload Assist Module-Delta II (IPSM-II/PAM-DII) space motor components. Ballistic and mechanical properties of the space aged main propellant, igniter propellant, and ignition system were compared with similar data from preflight and ground aged samples. Mechanical properties of the composite materials and bonded joints used in the motor case, insulation, liner, nozzle, exit cone, and skirt were similarly evaluated. The space aging results will be compared to data collected in a ground based vacuum aging program on similar components. The operation of the vacuum actuated venting valve and pressure actuated resealing of the container will also be addressed. The materials tested showed no significant changes due to space aging. These results indicate that properly designed solid rocket motors can be expected to perform reliably after extended periods of exposure to a space environment.

  9. Accelerated Aging of Polymer Composite Bridge Materials

    SciTech Connect

    J. G. Rodriguez; L. G. Blackwood; L. L. Torres; N. M. Carlson; T. S. Yoder

    1999-03-01

    Accelerated aging research on samples of composite material and candidate ultraviolet (UV) protective coatings is determining the effects of six environmental factors on material durability. Candidate fastener materials are being evaluated to determine corrosion rates and crevice corrosion effects at load-bearing joints. This work supports field testing of a 30-ft long, 18-ft wide polymer matrix composite (PMC) bridge at the Idaho National Engineering and Environmental Laboratory (INEEL). Durability results and sensor data from tests with live loads provide information required for determining the cost/benefit measures to use in life-cycle planning, determining a maintenance strategy, establishing applicable inspection techniques, and establishing guidelines, standards, and acceptance criteria for PMC bridges for use in the transportation infrastructure.

  10. School Age Child Care Staff Training Evaluation.

    ERIC Educational Resources Information Center

    Gore, Jane S.; And Others

    A formative and summative evaluation was made of eight school-age child care (SACC) training workshops conducted in 1989-90 for 190 participants in upstate New York. (The focus of the SACC workshops was to "train the trainers," as well as to provide trainees with quality materials and instruction for future training with their staff members.) All…

  11. ALPHA SPECTROMETRIC EVALUATION OF SRM-995 AS A POTENTIAL URANIUM/THORIUM DOUBLE TRACER SYSTEM FOR AGE-DATING URANIUM MATERIALS

    SciTech Connect

    Beals, D.

    2011-12-06

    Uranium-233 (t{sub 1/2} {approx} 1.59E5 years) is an artificial, fissile isotope of uranium that has significant importance in nuclear forensics. The isotope provides a unique signature in determining the origin and provenance of uranium-bearing materials and is valuable as a mass spectrometric tracer. Alpha spectrometry was employed in the critical evaluation of a {sup 233}U standard reference material (SRM-995) as a dual tracer system based on the in-growth of {sup 229}Th (t{sub 1/2} {approx} 7.34E3 years) for {approx}35 years following radiochemical purification. Preliminary investigations focused on the isotopic analysis of standards and unmodified fractions of SRM-995; all samples were separated and purified using a multi-column anion-exchange scheme. The {sup 229}Th/{sup 233}U atom ratio for SRM-995 was found to be 1.598E-4 ({+-} 4.50%) using recovery-corrected radiochemical methods. Using the Bateman equations and relevant half-lives, this ratio reflects a material that was purified {approx} 36.8 years prior to this analysis. The calculated age is discussed in contrast with both the date of certification and the recorded date of last purification.

  12. Skylab parasol material evaluation

    NASA Technical Reports Server (NTRS)

    Jacobs, S.

    1975-01-01

    Results of experimental work to evaluate the degradation rate of a parasol that was used as a means of alleviating thermal problems encountered soon after the launch of the Skylab 1 space vehicle are presented. Material selection criteria are discussed; the material chosen is described, and results of tests performed after environmental exposure at five facilities are given. The facilities used for exposure to ultraviolet radiation/thermal-vacuum environments and the equipment used for testing physical properties before and after exposure are described. Comparisons of ground test and flight test data are included.

  13. Kevlar 49/Epoxy COPV Aging Evaluation

    NASA Technical Reports Server (NTRS)

    Sutter, James K.; Salem, Jonathan L.; Thesken, John C.; Russell, Richard W.; Littell, Justin; Ruggeri, Charles; Leifeste, Mark R.

    2008-01-01

    NASA initiated an effort to determine if the aging of Kevlar 49/Epoxy composite overwrapped pressure vessels (COPV) affected their performance. This study briefly reviews the history and certification of composite pressure vessels employed on NASA Orbiters. Tests to evaluate overwrap tensile strength changes compared 30 year old samples from Orbiter vessels to new Kevlar/Epoxy pressure vessel materials. Other tests include transverse compression and thermal analyses (glass transition and moduli). Results from these tests do not indicate a noticeable effect due to aging of the overwrap materials.

  14. [Research on the aging of all-ceramics restoration materials].

    PubMed

    Zhang, Dongjiao; Chen, Xinmin

    2011-10-01

    All-ceramic crowns and bridges have been widely used for dental restorations owing to their excellent functionality, aesthetics and biocompatibility. However, the premature clinical failure of all-ceramic crowns and bridges may easily occur when they are subjected to the complex environment of oral cavity. In the oral environment, all-ceramic materials are prone to aging. Aging can lead all-ceramic materials to change color, to lower bending strength, and to reduce anti-fracture toughness. There are many factors affecting the aging of the all-ceramic materials, for example, the grain size, the type of stabilizer, the residual stress and the water environment. In order to analyze the aging behavior, to optimize the design of all-ceramic crowns and bridges, and to evaluate the reliability and durability, we review in this paper recent research progress of aging behavior for all-ceramics restoration materials. PMID:22097281

  15. A preliminary mechanical property and stress corrosion evaluation of VIM-VAR work strengthened and direct aged Inconel 718 bar material

    NASA Technical Reports Server (NTRS)

    Montano, J. W.

    1987-01-01

    This report presents a preliminary mechanical property and stress corrosion evaluation of double melted (vacuum induction melted (VIM), and vacuum arc remelted (VAR)), solution treated, work strengthened and direct aged Inconel 718 alloy bar (5.50 in. (13.97 cm) diameter). Two sets of tensile specimens, one direct single aged and the other direct double aged, were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 200 ksi (1378.96 MPa) and 168 ksi (1158.33 MPa), respectively, were realized at ambient temperature, for the direct double aged specimen. No failures occurred in the single or double edged longitudinal and transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test showed no mechanical property degradation.

  16. The Material Convoy After Age 50

    PubMed Central

    2014-01-01

    Objectives. Possessions constitute a dynamic “material convoy” that accumulates across adulthood to furnish role enactments and the development of the self. Following a familiar life course arc, older people should hypothetically release the possessions that equipped the daily lives that they no longer have. Method. We use new survey data on possession divestment from the 2010 Health and Retirement Study to assess activity on behalf of the material convoy after age 50. Results. After age 50, people are progressively less likely to divest themselves of belongings. After age 70, about 30% of persons say that they have done nothing in the past year to clean out, give away, or donate things, and over 80% have sold nothing. We tested whether divestments diminish with age because they do not seem necessary or because of health limitations, but the age pattern is robust, suggesting retention of the material convoy in later life. Discussion. Further research on this age pattern might consider housing, the construction of the self, and social networks as explanations for retention. Inertia toward the material convoy maintains the availability and comfort of things, but it may also lead to a predicament wherein the collection becomes a worry for self and others. PMID:24518148

  17. Evaluating Multiethnic Materials.

    ERIC Educational Resources Information Center

    Garcia, Jesus

    The problem of identifying good ethnic studies materials is a result of the large amount of materials produced in the 1960s and of the currently renewed interest in ethnic studies. Four types of materials are available to elementary classroom teachers: ethnic information, single-ethnic approaches, minority or European-ethnic approaches, and…

  18. A research project to develop and evaluate a technical education component on materials technology for orientation to space-age technology

    NASA Technical Reports Server (NTRS)

    Jacobs, J. A.

    1976-01-01

    A project was initiated to develop, implement, and evaluate a prototype component for self-pacing, individualized instruction on basic materials science. Results of this project indicate that systematically developed, self-paced instruction provides an effective means for orienting nontraditional college students and secondary students, especially minorities, to both engineering technology and basic materials science. In addition, students using such a system gain greater chances for mastering subject matter than with conventional modes of instruction.

  19. Narayanaswamy's 1971 aging theory and material time.

    PubMed

    Dyre, Jeppe C

    2015-09-21

    The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy's phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the "unique-triangles property" according to which any three points on the system's path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)]. PMID:26395719

  20. Narayanaswamy's 1971 aging theory and material time

    NASA Astrophysics Data System (ADS)

    Dyre, Jeppe C.

    2015-09-01

    The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy's phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the "unique-triangles property" according to which any three points on the system's path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)].

  1. Creep and aging in jammed granular materials

    NASA Astrophysics Data System (ADS)

    Srivastava, Ishan; Fisher, Timothy

    Granular materials flow (or unjam) when stressed above the Coulomb yield stress, but a slow creep is observed when the applied stresses are low. In this work, using a recently introduced enthalpy-based variable-cell simulation method, we will present results on the creep and slow aging dynamics in granular systems comprised of soft particles of varying shape that are hydrostatically jammed and subjected to an external stress. We observe a two-stage creep with an initial fast exponential evolution followed by a slow logarithmic evolution over long time scales. We correlate the slow creeping dynamics with micromechanical evolution at the grain scale, such as increasing dynamical heterogeneity and force-chain rearrangements. Results will also be presented on the effect of grain shape (faceted vs. spherical) on the creep and aging dynamics. Finally, a continuum granular fluidity model is developed to rationalize these observations.

  2. Teaching and Learning About Aging. Evaluation Report.

    ERIC Educational Resources Information Center

    Peters, Eileen

    This evaluation study determined the extent to which teachers and students involved with the Teaching and Learning About Aging (TLA) project experienced cognitive growth and attitudinal change. The major purpose of the TLA project was to help students understand aging and related issues and to foster more positive attitudes toward aging and older…

  3. Spectral Age Dating of Volcanic Materials

    NASA Astrophysics Data System (ADS)

    Pearson, N.; Calvin, W. M.

    2015-12-01

    As part of the HyspIRI preparatory airborne campaign, high spectral resolution data of the Mono-Inyo craters had been collected. The Mono-Inyo Craters are a chain of geologically young craters that have been erupted over the past 40,000 years. We show a spectral variation in the 2.21μm absorption band depth (commonly associated with the Si-OH stretch) between craters of different ages. To explain this we propose the devitrification of the surface of the volcanic materials creating a weathering rind that thickens with age. A definite linear correlation between age and band depth is shown for craters less than 5,000 years old and potential logarithmic correlation for older craters. To help test this, hand samples from the craters were collected from several of the volcanic craters and the weathering rind thickness measured using a scanning electron microprobe. This correlation combined with a HyspIRI like dataset could be used to define volcanic hazards in large or remote regions, such as the Aleutian Island Arc or Kamchatka Peninsula.

  4. Material compatibility and thermal aging of thermoelectric materials.

    SciTech Connect

    Gardea, Andrew D.; Nishimoto, Ryan; Yang, Nancy Y. C.; Morales, Alfredo Martin; Whalen, Scott A.; Chames, Jeffrey M.; Clift, W. Miles

    2009-09-01

    In order to design a thermoelectric (TE) module suitable for long-term elevated temperature use, the Department 8651 has conducted parametric experiments to study material compatibility and thermal aging of TE materials. In addition, a comprehensive material characterization has been preformed to examine thermal stability of P- and N-based alloys and their interaction with interconnect diffusion barrier(s) and solder. At present, we have completed the 7-days aging experiments for 36 tiles, from ambient to 250 C. The thermal behavior of P- and N-based alloys and their thermal interaction with both Ni and Co diffusion barriers and Au-Sn solder were examined. The preliminary results show the microstructure, texture, alloy composition, and hardness of P-(Bi,Sb){sub 2}Te{sub 3} and N-Bi{sub 2}(Te,Se){sub 3} alloys are thermally stable up to 7 days annealing at 250 C. However, metallurgical reactions between the Ni-phosphor barriers and P-type base alloy were evident at temperatures {ge} 175 C. At 250 C, the depth (or distance) of the metallurgical reaction and/or Ni diffusion into P-(Bi,Sb){sub 2}Te{sub 3} is approximately 10-15 {micro}m. This thermal instability makes the Ni-phosphor barrier unsuitable for use at temperatures {ge} 175 C. The Co barrier appeared to be thermally stable and compatible with P(Bi,Sb){sub 2}Te{sub 3} at all annealing temperatures, with the exception of a minor Co diffusion into Au-Sn solder at {ge} 175 C. The effects of Co diffusion on long-term system reliability and/or the thermal stability of the Co barrier are yet to be determined. Te evaporation and its subsequent reaction with Au-Sn solder and Ni and Co barriers on the ends of the tiles at temperatures {ge} 175 C were evident. The Te loss and its effect on the long-term required stoichiometry of P-(Bi, Sb){sub 2}Te{sub 3} are yet to be understood. The aging experiments of 90 days and 180 days are ongoing and scheduled to be completed in 30 days and 150 days, respectively. Material

  5. Evaluation of Alkaline Cleaner Materials

    NASA Technical Reports Server (NTRS)

    Partz, Earl

    1998-01-01

    Alkaline cleaners used to process aluminum substrates have contained chromium as the corrosion inhibitor. Chromium is a hazardous substance whose use and control are described by environmental laws. Replacement materials that have the characteristics of chromated alkaline cleaners need to be found that address both the cleaning requirements and environmental impacts. This report will review environmentally friendly candidates evaluated as non-chromium alkaline cleaner replacements and methods used to compare those candidates one versus another. The report will also list characteristics used to select candidates based on their declared contents. It will also describe and evaluate methods used to discriminate among the large number of prospective candidates.

  6. DWPF MATERIALS EVALUATION SUMMARY REPORT

    SciTech Connect

    Gee, T.; Chandler, G.; Daugherty, W.; Imrich, K.; Jankins, C.

    1996-09-12

    To better ensure the reliability of the Defense Waste Processing Facility (DWPF) remote canyon process equipment, a materials evaluation program was performed as part of the overall startup test program. Specific test programs included FA-04 ('Process Vessels Erosion/Corrosion Studies') and FA-05 (melter inspection). At the conclusion of field testing, Test Results Reports were issued to cover the various test phases. While these reports completed the startup test requirements, DWPF-Engineering agreed to compile a more detailed report which would include essentially all of the materials testing programs performed at DWPF. The scope of the materials evaouation programs included selected equipment from the Salt Process Cell (SPC), Chemical Process Cell (CPC), Melt Cell, Canister Decon Cell (CDC), and supporting facilities. The program consisted of performing pre-service baseline inspections (work completed in 1992) and follow-up inspections after completion of the DWPF cold chemical runs. Process equipment inspected included: process vessels, pumps, agitators, coils, jumpers, and melter top head components. Various NDE (non-destructive examination) techniques were used during the inspection program, including: ultrasonic testing (UT), visual (direct or video probe), radiography, penetrant testing (PT), and dimensional analyses. Finally, coupon racks were placed in selected tanks in 1992 for subsequent removal and corrosion evaluation after chemical runs.

  7. Images of Aging in Selected Religious Education Curriculum Materials.

    ERIC Educational Resources Information Center

    Cram, Ronald H.

    Images of aging that appear in popular child/teen curricular materials used in church-related contexts were examined to determine how older adults are portrayed in words and pictures in these materials and what images of aging emerge. Materials from the following sources, randomly selected from those that had been checked out of the Ecumenical…

  8. Computational Age Dating of Special Nuclear Materials

    SciTech Connect

    None, None

    2012-06-30

    This slide-show presented an overview of the Constrained Progressive Reversal (CPR) method for computing decays, age dating, and spoof detecting. The CPR method is: Capable of temporal profiling a SNM sample; Precise (compared with known decay code, such a ORIGEN); Easy (for computer implementation and analysis). We have illustrated with real SNM data using CPR for age dating and spoof detection. If SNM is pure, may use CPR to derive its age. If SNM is mixed, CPR will indicate that it is mixed or spoofed.

  9. Aging management of major LWR components with nondestructive evaluation

    SciTech Connect

    Shah, V.N.; MacDonald, P.E.; Akers, D.W.; Sellers, C.; Murty, K.L.; Miraglia, P.Q.; Mathew, M.D.; Haggag, F.M.

    1997-12-31

    Nondestructive evaluation of material damage can contribute to continued safe, reliable, and economical operation of nuclear power plants through their current and renewed license period. The aging mechanisms active in the major light water reactor components are radiation embrittlement, thermal aging, stress corrosion cracking, flow-accelerated corrosion, and fatigue, which reduce fracture toughness, structural strength, or fatigue resistance of the components and challenge structural integrity of the pressure boundary. This paper reviews four nondestructive evaluation methods with the potential for in situ assessment of damage caused by these mechanisms: stress-strain microprobe for determining mechanical properties of reactor pressure vessel and cast stainless materials, magnetic methods for estimating thermal aging damage in cast stainless steel, positron annihilation measurements for estimating early fatigue damage in reactor coolant system piping, and ultrasonic guided wave technique for detecting cracks and wall thinning in tubes and pipes and corrosion damage to embedded portion of metal containments.

  10. The Empirical Evaluation of Language Teaching Materials.

    ERIC Educational Resources Information Center

    Ellis, Rod

    1997-01-01

    Distinguishes two types of materials evaluation: a predictive evaluation designed to make a decision regarding what materials to use, and a retrospective evaluation to examine materials already used. Describes a procedure for conducting task evaluations, suggesting that they constitute a kind of action research that can contribute to reflective…

  11. Age as a Determinant of Interpersonal Evaluations.

    ERIC Educational Resources Information Center

    Scheier, Michael F.; Schulz, Richard

    This study focuses on the impact of age on interpersonal evaluation of persons, particularly the elderly as individuals and not as a group. Using a 75-year-old target and a 23-year-old target, the experimenter predicted and found support for the idea that personal information contained in a transcript would evoke sympathy, and thereby lead…

  12. A mechanical property and stress corrosion evaluation of VIM-ESR-VAR work strengthened and direct double aged Inconel 718 bar material

    NASA Technical Reports Server (NTRS)

    Montano, J. W.

    1986-01-01

    Presented are the mechanical properties and the stress corrosion resistance of triple melted vacuum induction melted (VIM), electro-slag remelted (ESR), and vacuum arc remelted (VAR), solution treated, work strengthened and direct double aged Inconel 718 alloy bars 4.00 in. (10.16) and 5.75 in. (14.60 cm) diameter. Tensile, charpy v-notched impact, and compact tension specimens were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 220 ksi (1516.85 MPa) and 200 ksi (1378.00 MPa) respectively, were realized at ambient temperature. Additional charpy impact and compact tension tests were performed at -100 F (-73 C). Longitudinal charpy impact strength equalled or exceeded 12.0 ft-lbs (16.3 Joules) at ambient and at -100 F(-73 C) while longitudinal compact (LC) tension fracture toughness strength remained above 79 ksi (86.80 MPa) at ambient and at -100 F(-73 C) temperatures. No failures occurred in the longitudinal or transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test indicated no mechanical property degradation.

  13. A mechanical property and stress corrosion evaluation of VIM-ESR-VAR work strengthened and direct double aged Inconel 718 bar material

    NASA Astrophysics Data System (ADS)

    Montano, J. W.

    1986-09-01

    Presented are the mechanical properties and the stress corrosion resistance of triple melted vacuum induction melted (VIM), electro-slag remelted (ESR), and vacuum arc remelted (VAR), solution treated, work strengthened and direct double aged Inconel 718 alloy bars 4.00 in. (10.16) and 5.75 in. (14.60 cm) diameter. Tensile, charpy v-notched impact, and compact tension specimens were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 220 ksi (1516.85 MPa) and 200 ksi (1378.00 MPa) respectively, were realized at ambient temperature. Additional charpy impact and compact tension tests were performed at -100 F (-73 C). Longitudinal charpy impact strength equalled or exceeded 12.0 ft-lbs (16.3 Joules) at ambient and at -100 F(-73 C) while longitudinal compact (LC) tension fracture toughness strength remained above 79 ksi (86.80 MPa) at ambient and at -100 F(-73 C) temperatures. No failures occurred in the longitudinal or transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test indicated no mechanical property degradation.

  14. Nanomodification of Cementitious Materials: Fresh State and Early Age

    NASA Astrophysics Data System (ADS)

    Kawashima, Shiho

    Concrete is heterogeneous at all length scales and its microstructure evolves continuously over decades. Through the use of nanoparticles, it is possible to alter the microstructure of cementitious materials from within the first microsecond to control its rheological and eventual mechanical properties. The continued development of this technology hinges on adopting a materials science approach to achieve proper processing and measurement techniques, both of which are investigated in this study. Novel rheological methods are implemented to evaluate the fresh-state properties of cement pastes modified with nano-sized attapulgite clays. Previous studies have demonstrated that clays can reduce the lateral pressure exerted on formwork by self-consolidating concrete (SCC). It is hypothesized that this is tied to the influence of clays on two rheological properties of SCC: material cohesion and structural rebuilding. Therefore the effect of clays on adhesive properties is measured by the tack test and rate of rebuilding is evaluated by measuring relaxation time during creep. In addition, due to the complexity of cement rheology, i.e. simultaneous thixotropic rebuilding and hydration, the results are supplemented with a measure of the viscoelastic properties obtained through oscillatory shear rheometry. It is found that clays significantly increase cohesion and accelerate structural recovery of cement pastes. The results also indicate that the tack test is a suitable method for measuring the adhesive properties and structural evolution of cementitious materials in the fresh state. The potential of calcium carbonate (CaCO3) nanoparticles in improving the early-age properties of fly ash-cement pastes is investigated. The focus is on dispersing the CaCO3 nanoparticles to enhance their effect and limit the addition level necessary. The selected approach involves sonication in an aqueous medium and use of surfactant. Degree of dispersion and stability are quantitatively

  15. Space shuttle nonmetallic materials age life prediction

    NASA Technical Reports Server (NTRS)

    Mendenhall, G. D.; Hassell, J. A.; Nathan, R. A.

    1975-01-01

    The chemiluminescence from samples of polybutadiene, Viton, Teflon, Silicone, PL 731 Adhesive, and SP 296 Boron-Epoxy composite was measured at temperatures from 25 to 150 C. Excellent correlations were obtained between chemiluminescence and temperature. These correlations serve to validate accelerated aging tests (at elevated temperatures) designed to predict service life at lower temperatures. In most cases, smooth or linear correlations were obtained between chemiluminescence and physical properties of purified polymer gums, including the tensile strength, viscosity, and loss tangent. The latter is a complex function of certain polymer properties. Data were obtained with far greater ease by the chemiluminescence technique than by the conventional methods of study. The chemiluminescence from the Teflon (Halon) samples was discovered to arise from trace amounts of impurities, which were undetectable by conventional, destructive analysis of the sample.

  16. Constitutive equations of ageing polymeric materials

    NASA Technical Reports Server (NTRS)

    Peng, S. T. J.

    1985-01-01

    The constitutive equation for the relaxation behavior of time-dependent, chemically unstable materials developed by Valanis and Peng (1983), which used the irreversible thermodynamics of internal variables in Eyring's absolute reaction theory and yielded a theoretical expression for the effect of chemical crosslink density on the relaxation rate, is presently applied to the creep behavior of a network polymer which is undergoing a scission process. In particular, two equations are derived which may for the first time show the relations between mechanical models and internal variables in the creep expressions, using a three-element model with a Maxwell element.

  17. Evaluation of aging degradation of structural components

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1992-03-01

    Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

  18. Evaluation of aging degradation of structural components

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1992-03-01

    Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center_dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

  19. Quality evaluation of aged concrete by ultrasound

    NASA Astrophysics Data System (ADS)

    Tavossi, H. M.; Tittmann, Bernhard R.; Cohen-Tenoudji, Frederic

    1999-02-01

    The velocity, attenuation and scattering of ultrasonic waves measured in concrete, mortar and cement structures can be used to evaluate their quality with weathering and aging. In this investigation the hardening of concrete mixture with time is monitored by ultrasonic waves under different conditions of temperature and water to cement ratio. The measured ultrasonic parameters can then be utilized to determine the final quality of the completely cured concrete structure from initial measurement. The quality of a concrete structure is determined by its resistance to compression and its rigidity, which should be within the acceptable values required by the design specifications. The internal and external flaws that could lower its strength can also be detected by ultrasonic technique. Aging process of concrete by weathering can be simulated in the laboratory by subjecting the concrete to extremes of cold and hot cycles in the range of temperatures normally encountered in summer and winter. In this research ultrasonic sensors in low frequency range of 40 to 100 kHz are used to monitor the quality of concrete. Ultrasonic pulses transmitted through the concrete sample are recorded for analysis in time and frequency domains. ULtrasonic waves penetration in concrete of the order of few feet has been achieved in laboratory. Data analyses on ultrasonic signal velocity, spectral content, phase and attenuation, can be utilized to evaluate, in situ, the quality and mechanical strength of concrete.

  20. Evaluation of Locally Produced Materials

    ERIC Educational Resources Information Center

    Gale, Fred

    1976-01-01

    Describes conditions important to the assessment process in the development of instructional materials. Out of these conditions several questions were suggested as key check points in the assessment model. (Author/RK)

  1. Electrostatic Evaluation: SCAPE Suit Materials

    NASA Technical Reports Server (NTRS)

    Buhler, Charles; Calle, Carlos

    2005-01-01

    The surface resistivity tests are performed per the requirements of the ESD Association Standard Test Method ESD STM11.11*. These measurements are taken using a PRS-801 resistance system with an Electro Tech System (ETS) PRF-911 concentric ring resistance probe. The tests require a five pound weight on top of cylindrical electrodes and were conducted at both ambient and low humidity conditions. In order for materials to "pass" resistivity tests the surface of the materials must either be conductive or statically dissipative otherwise the materials "fail" ESD. Volume resistivity tests are also conducted to measure conductivity through the material as opposed to conductivity along the surface. These tests are conducted using the same PRS-801 resistance system with the Electro Tech System PRF-911 concentric ring resistance probe but are performed in accordance with ESD Association Standard Test Method ESD STM11.l2**.

  2. Evaluation of optical materials samples

    NASA Astrophysics Data System (ADS)

    1988-07-01

    The primary objective of order subcontract was to prepare AGT and UGT test specimens, provide characterization data and provide damage assessments on tech base laser mirror materials being developed on other government contracts. The properties to be determined included flexural strength, Young's modulus, Poisson's ratio, fracture toughness (KIc), coefficient of thermal expansion, thermal diffusivity, hardness, and specific heat. In some cases Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), energy dispersive X-ray analysis (EDAX), and Auger spectroscopy (AES) were to be performed to determine chemical composition and crystal structure and damage mechanisms. In addition if materials problems occurred, that could not be anticipated in advance, studies were to be initiated to aid the SDI optical materials efforts as required.

  3. LIGA microsystems aging : evaluation and mitigation.

    SciTech Connect

    Cadden, Charles H.; Yang, Nancy Y. C.; San Marchi, Christopher W.

    2003-12-01

    The deployment of LIGA structures in DP applications requires a thorough understanding of potential long term physical and chemical changes that may occur during service. While these components are generally fabricated from simple metallic systems such as copper, nickel and nickel alloys, the electroplating process used to form them creates microstructural features which differ from those found in conventional (e.g. ingot metallurgy) processing of such materials. Physical changes in non-equilibrium microstructures may occur due to long term exposure to temperatures sufficient to permit atomic and vacancy mobility. Chemical changes, particularly at the surfaces of LIGA parts, may occur in the presence of gaseous chemical species (e.g. water vapor, HE off-gassing compounds) and contact with other metallic structures. In this study, we have characterized the baseline microstructure of several nickel-based materials that are used to fabricate LIGA structures. Solute content and distribution was found to have a major effect on the electroplated microstructures. Microstructural features were correlated to measurements of hardness and tensile strength. Dormancy testing was conducted on one of the baseline compositions, nickel-sulfamate. Groups of specimens were exposed to controlled thermal cycles; subsequent examinations compared properties of 'aged' specimens to the baseline conditions. Results of our testing indicate that exposure to ambient temperatures (-54 C to 71 C) do not result in microstructural changes that might be expected to significantly effect mechanical performance. Additionally, no localized changes in surface appearance were found as a result of contact between electroplated parts.

  4. Developing and Evaluating Patient Education Materials.

    ERIC Educational Resources Information Center

    Monsivais, Diane; Reynolds, Audree

    2003-01-01

    Discusses the rationale for nurse involvement in the development of patient education materials. Presents guidelines for evaluating existing material, including print and web resources, for credibility and readability. Makes recommendations for rewriting material at an easier-to-read level. (SK)

  5. Aging mechanisms in amorphous phase-change materials

    NASA Astrophysics Data System (ADS)

    Raty, Jean Yves; Zhang, Wei; Luckas, Jennifer; Chen, Chao; Mazzarello, Riccardo; Bichara, Christophe; Wuttig, Matthias

    2015-06-01

    Aging is a ubiquitous phenomenon in glasses. In the case of phase-change materials, it leads to a drift in the electrical resistance, which hinders the development of ultrahigh density storage devices. Here we elucidate the aging process in amorphous GeTe, a prototypical phase-change material, by advanced numerical simulations, photothermal deflection spectroscopy and impedance spectroscopy experiments. We show that aging is accompanied by a progressive change of the local chemical order towards the crystalline one. Yet, the glass evolves towards a covalent amorphous network with increasing Peierls distortion, whose structural and electronic properties drift away from those of the resonantly bonded crystal. This behaviour sets phase-change materials apart from conventional glass-forming systems, which display the same local structure and bonding in both phases.

  6. Heliostat materials development and evaluation

    NASA Astrophysics Data System (ADS)

    1980-05-01

    Both UV stabilized poly (ethylene terephthalate) (PET) polyvinylidiene fluoride films were produced, characterized, and tested to establish a data base of predicting life cycles and upgrading the cost/performance ratio of heliostat enclosures. Laminated aluminized PET, protected and unprotected by a thin layer of resin was studied as suitable reflector material. Procedures and results of weathering tests are presented. Methods for bonding plastic films, specularly optimized film reflectors, and the mechanism of a weathering degradation are discussed. Data on the flammability of plastic films are included.

  7. Narayanaswamy’s 1971 aging theory and material time

    SciTech Connect

    Dyre, Jeppe C.

    2015-09-21

    The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy’s phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the “unique-triangles property” according to which any three points on the system’s path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)].

  8. International Law in a Global Age. Student Materials.

    ERIC Educational Resources Information Center

    Croddy, Marshall; Maxey, Phyllis

    This global approach to teaching high school students about international law uses existing curriculum materials from a variety of social studies disciplines to present five major perspectives. Perspective I "Global Links," focuses on the meaning of citizenship in a global age and the interconnectedness between individuals and the international…

  9. Aging characteristics of short glass fiber reinforced ZA-27 alloy composite materials

    NASA Astrophysics Data System (ADS)

    Sharma, S. C.; Girish, B. M.; Satish, B. M.; Kamath, R.

    1998-12-01

    Aging characteristics of short glass fiber reinforced ZA-27 alloy composite materials have been evaluated in the present study. The liquid metallurgy technique was used to fabricate the composites, in which preheated short glass fibers were introduced into the ZA-27 alloy melt above its liquidus temperature. The aging temperature employed was 125 °C for 6, 12,18, and 24 h. The aged alloy (no fibers) reached the peak hardness after 18 h, while the composites (regardless of filler content) reached the same hardness in 12 h. It is hypothesized that the aging treatment of a composite improves the strength of the interface between the short fibers and the matrix. This is confirmed by the tensile fractograph analysis, which indicates that at a given aging temperature, the composites aged for 18 h exhibit short fibers that remain attached to the metal matrix, while those aged for 6 h undergo debonding.

  10. Reinterpreting Evaluation Classics in the Modern Age.

    ERIC Educational Resources Information Center

    Adams, Joan Duncan

    2001-01-01

    Analyzes features of impact evaluation models by Kirkpatrick, Grotelueschen, Cervero, Robinson and Robinson, and Jackson. Incorporates features into the Behaviorally Based Impact Evaluation Model, designed for evaluating continuing professional education outcomes in corporate settings. Contains 23 references. (SK)

  11. Aging behavior of polymeric solar absorber materials: Aging on the component level

    SciTech Connect

    Kahlen, S.; Wallner, G.M.; Lang, R.W.; Meir, M.; Rekstad, J.

    2010-03-15

    Within this study, the aging behavior of a PPE + PS absorber material was investigated on the absorber component level. To indicate aging, characteristic mechanical values were determined by indentation tests of specimens taken from components and exposed to laboratory aging (140 C in air, 80 C in water) and service near outdoor aging conditions (stagnation in northern climate). In addition to the mechanical tests, the unaged and aged specimens were also characterized thermo-analytically via differential scanning calorimetry (DSC). The results indicate that reductions in both characteristic mechanical values of the indentation tests, i.e., load of the first transition and ultimate indentation, reflect at least some physical aging although chemical aging may also be of importance based on previous analytical investigations of laboratory aged polymer films. While laboratory aging in air at 140 C and service exposure at a test facility in Oslo (N) under stagnation conditions led to a significant reduction in the mechanical indentation resistance, no influence of laboratory aging in water at 80 C on the mechanical behavior of the absorber sheet was found. Depending on the ultimate failure criterion applied (reduction of characteristic mechanical values to 80% and 50%, respectively), the technical service life found for hot air laboratory and stagnation service conditions was found to be less than 51 and 159 h, respectively. As these durations are significantly below the estimated stagnation conditions accumulated in the desired operation lifetime for such a collector, the PPE + PS type investigated does not seem to be a proper material candidate for solar thermal absorbers. Finally, based on the results obtained, a relation between laboratory aging time in air at 140 C and cumulated irradiation energy during exposure on the test facility in Oslo was established. (author)

  12. Thermal Protection Materials: Development, Characterization and Evaluation

    NASA Technical Reports Server (NTRS)

    Johnson, Silvia M.

    2012-01-01

    Thermal protection materials and systems (TPS) are used to protect space vehicles from the heat experienced during entry into an atmosphere. The application for these materials is very specialized as are the materials. They must have specific properties to withstand conditions during specific entries. There is no one-size-fits-all TPS as the conditions experienced by a material are very dependent upon the atmosphere, the entry speed, the size and shape of the vehicle, and the location on the vehicle. However, all TPS must be reliable and efficient to ensure mission safety, that is to protect the vehicle while ensuring that payload is maximized. Types of TPS will be reviewed in relation to types of missions and applications. Both reusable and ablative materials will be discussed. Approaches to characterizing and evaluating these materials will be presented. The role of heritage versus new materials will be described.

  13. Physical properties of three maxillofacial materials as a function of accelerated aging.

    PubMed

    Dootz, E R; Koran, A; Craig, R G

    1994-04-01

    This study compares the tensile strength, elongation, Shore-A hardness, and tear resistance of three silicone maxillofacial materials before and after aging to provide comparative data for evaluation of new or experimental elastomers. The materials evaluated were MDX-4-4210, Factor II (A-2186), and Cosmesil. Tests were conducted 24 hours after specimen preparation and were repeated after aging for 900 hours in a Weather-Ometer device. Five samples were made for each material under all test conditions. After testing, mean values were calculated for all materials under all test conditions and were compared by two-way analysis of variance and Tukey intervals at p < or = 0.05. PMID:8196002

  14. Composite Overwrapped Pressure Vessels (COPV) Materials Aging Issues

    NASA Technical Reports Server (NTRS)

    2010-01-01

    This slide presentation reviews some of the issues concerning the aging of the materials in a Composite Overwrapped Pressure Vessels (COPV). The basic composition of the COPV is a Boss, a composite overwrap, and a metallic liner. The lifetime of a COPV is affected by the age of the overwrap, the cyclic fatigue of the metallic liner, and stress rupture life, a sudden and catastrophic failure of the overwrap while holding at a stress level below the ultimate strength for an extended time. There is information about the coupon tests that were performed, and a test on a flight COPV.

  15. Evaluation of Speakers at CME: Cosmecon 2006, An International Conference on Ageing and Anti-ageing

    PubMed Central

    Vijayashankar MR

    2008-01-01

    Aim: To determine what constitutes effective or ineffective lecturing in dermatological conferences and also the utility of a scientific programme for the dermatologists. Methods and Materials: Evaluation forms were circulated to delegates attending the Cosmecon conference on ageing and anti-ageing, held in July 2006 at Bangalore. Feedback from the delegates in the form of completed evaluation forms of individual speakers and each session of the 3-day conference Cosmecon (including the live workshop on aesthetic and surgical procedures) were studied. Comments were analysed with the help of a biostatistician to determine the positive and negative responses. Results: On day 1 of the conference, workshop included 14 procedures by different specialists and on the second and third days of the conference, there were a total of 10 sessions, with five on each day. Evaluation forms were handed out to 440 delegates on day 1 and 600 delegates on days 2 and 3. Fifty-five speakers were evaluated by an average 56 delegates out of 440 delegates on day 1 and 600 delegates on the second and third days. The delegate response to completing the evaluation form was poor. Only about 25% of the delegates completed the feedback forms. However, the feedback did give some insight to the scientific programme, on both positive and negative aspects. Most delegates stated that they benefited from the presentations. The main negative response was lack of opportunity to ask questions after a lecture. The main positive comment was that the time keeping in the conference was very good. Conclusion: The response of the delegates in providing feedback was poor. Efforts have to be made to educate and encourage delegates to complete the feedback forms. Systematic review of the speakers would provide information to design future CME programmes effectively and to incorporate improvements for effective lecturing and to avoid ineffective lectures. The CME evaluation can also help the organizers to provide

  16. Investigation of Hygro-Thermal Aging on Carbon/Epoxy Materials for Jet Engine Fan Sections

    NASA Technical Reports Server (NTRS)

    Kohlman, Lee W.; Roberts, Gary D.; Miller, Sandi G.; Pereira, J. Michael

    2011-01-01

    This poster summarizes 2 years of aging on E862 epoxy and E862 epoxy with triaxial braided T700s carbon fiber composite. Several test methods were used to characterize chemical, physical, and mechanical properties of both the resin and composite materials. The aging cycle that was used included varying temperature and humidity exposure. The goal was to evaluate the environmental effects on a potential jet engine fan section material. Some changes were noted in the resin which resulted in increased brittleness, though this did not significantly affect the tensile and impact test results. A potential decrease in compression strength requires additional investigation.

  17. Age-Related Differences in Evaluating Developmental Stability

    ERIC Educational Resources Information Center

    Mustafic, Maida; Freund, Alexandra M.

    2013-01-01

    Two studies examined the hypothesis that the evaluation of developmental stability changes across adulthood. Results of Study 1 ("N" = 119) supported the expectation that older adults ("M"[subscript age] = 65.29 years)--compared to younger ("M"[subscript age] = 23.38 years) and middle-aged adults…

  18. Radiocarbon dating of marine material: mollusc versus foraminifera ages

    NASA Astrophysics Data System (ADS)

    Callard, L.; Long, A. J.; Plets, R. M.; Cooper, A.; Belknap, D. F.; Edwards, R.; Jackson, D.; Kelley, J. T.; Long, D.; Milne, G. A.; Monteys, X.; Quinn, R.

    2013-12-01

    A key challenge in reconstructing Quaternary environmental change from marine archives is developing a robust chronology. During the last ~50k a-1, radiocarbon dating is the mainstay for many studies. Often investigators are restricted in the material that is available for dating, with studies relying on AMS dating of either mono-specific or mixed assemblages of foraminifera. In some instances, marine molluscs (broken or whole, articulated or disarticulated) may also be present and can provide an alternative or complementary dating target. Previous radiocarbon dating of paired foraminiferal and marine molluscan samples from the Kattegat (Denmark) revealed significant age offsets between these materials, inferred to reflect greater reworking of foraminifera compared to the marine molluscs (Heier-Nielsen et al., 1995). Here we present the results of a comparable study from the Irish Sea Basin, which forms part of a wider investigation into the evidence for the Late Glacial sea-level minima at offshore sites from around Britain and Ireland. We have collected and AMS 14C-dated twelve paired samples of foraminifera and marine shells. The results shows a systematic age offset with the monospecific foraminifera samples consistently giving older ages than their shell counterparts. This offset increases with sample age, reaching a maximum offset of 3000 years in the oldest sample (~ 13 ka cal a BP). These results are consistent with the observations of Heier-Nielsen et al. (1995), and we hypothesize that foraminifera may be more susceptible to reworking from older deposits because of their lower effective density than the shell samples. However, foraminifera size and shape may also be contributing factors. These findings are potentially significant for studies that develop chronologies based on radiocarbon dating of foraminifera alone, since the resulting dates may over-estimate sample age by several thousand years. We conclude by outlining an experimental design that seeks

  19. An evaluation of candidate oxidation resistant materials

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon; Banks, Bruce; Mirtich, Michael; Difilippo, Frank; Hotes, Deborah; Labed, Richard; Dever, Terese; Kussmaul, Michael

    1987-01-01

    Ground based testing of materials considered for Kapton solar array blanket protection, graphite epoxy structural member protection, and high temperature radiators was performed in an RF plasma asher. Ashing rates for Kapton were correlated with rates measured on STS-8 to determine the exposure time equivalent to one year in low Earth orbit (LEO) at a constant density space station orbital flux. Protective coatings on Kapton from Tekmat, Andus Corporation, and LeRC were evaluated in the plasma asher and mass loss rates per unit area were measured for each sample. All samples evaluated provided some protection to the underlying surface but ion beam sputter deposited samples of SiO2 and SiO2 with 8% polytetrafluoroethylene (PTFE) showed no evidence of degradation after 47 hours of exposure. Mica paint was evaluated as a protective coating for graphite epoxy structural members. Mica appears to be resistant to attack by atomic oxygen but only offers some limited protection as a paint because the paint vehicles evaluated to date were not resistant to atomic oxygen. Four materials were selected for evaluation as candidate radiator materials: stainless steel, copper, niobium-1% zirconium, and titanium-6% aluminum-4% vanadium. These materials were surface textured by various means to improve their emittance. Emittances as high as 0.93 at 2.5 microns for stainless steel and 0.89 at 2.5 microns for Nb-1 Zr were obtained from surface texturing. There were no significant changes in emittance after asher exposure.

  20. Evaluating Materials About Africa for Children.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    Choosing texts, media, and literature about Africa is a difficult task for school librarians who have not studied Africa in detail; however it is possible to evaluate the available materials on the basis of several important criteria. These include the authority of the author, the dates of preparation and publication, and the accuracy of…

  1. ASC Supercomputers Predict Effects of Aging on Materials

    SciTech Connect

    Kubota, A; Reisman, D B; Wolfer, W G

    2005-08-25

    In an extensive molecular dynamics (MD) study of shock compression of aluminum containing such microscopic defects as found in aged plutonium, LLNL scientists have demonstrated that ASC supercomputers live up to their promise as powerful tools to predict aging phenomena in the nuclear stockpile. Although these MD investigations are carried out on material samples containing only about 10 to 40 million atoms, and being not much bigger than a virus particle, they have shown that reliable materials properties and relationships between them can be extracted for density, temperature, pressure, and dynamic strength. This was proven by comparing their predictions with experimental data of the Hugoniot, with dynamic strength inferred from gas-gun experiments, and with the temperatures behind the shock front as calculated with hydro-codes. The effects of microscopic helium bubbles and of radiation-induced dislocation loops and voids on the equation of state were also determined and found to be small and in agreement with earlier theoretical predictions and recent diamond-anvil-cell experiments. However, these microscopic defects play an essential role in correctly predicting the dynamic strength for these nano-crystalline samples. These simulations also prove that the physics involved in shock compression experiments remains the same for macroscopic specimens used in gas-gun experiments down to micrometer samples to be employed in future NIF experiments. Furthermore, a practical way was discovered to reduce plastic instabilities in NIF target materials by introducing finely dispersed defects.

  2. Evaluation of dental age in protein energy malnutrition children

    PubMed Central

    Kumar, Vinod; Patil, Kavitha; Munoli, Karishma

    2015-01-01

    Background: Knowledge of dental age is very essential for a dental practitioner in planning treatment and it is a supplementary source of information for Pediatrician, Orthopedician and Endocrinologist. There are few studies in the literature about the comparison of dental with chronological age in protein energy malnutrition children (PEM). Accordingly, the aim of this study was to evaluate and compare dental age and chronological age in PEM children. Aims and Objective: To determine and compare dental age and chronological age in PEM children. Methods: A total of 100 PEM children within the age range of 6–12 years were selected. Chronological age was recorded using date of birth. Dental age was assessed by Demirjian's method using orthopantomogram. Comparison of two ages was done using the unpaired Student's t-test and Pearson's correlation coefficient. Results: Dental age was retarded compared to chronological age, and the difference was statistically significant (P < 0.001). The correlations between two ages were positive in both sexes. Conclusion: Dental age was delayed in our sample of 100 PEM children. Dental age can be considered as variable for diagnosing growth retardation in PEM children. Further studies are required to support our findings. PMID:26538919

  3. Application of Raman Spectroscopy for Nondestructive Evaluation of Composite Materials

    NASA Technical Reports Server (NTRS)

    Washer, Glenn A.; Brooks, Thomas M. B.; Saulsberry, Regor

    2007-01-01

    This paper will present an overview of efforts to investigate the application of Raman spectroscopy for the characterization of Kevlar materials. Raman spectroscopy is a laser technique that is sensitive to molecular interactions in materials such as Kevlar, graphite and carbon used in composite materials. The overall goal of this research reported here is to evaluate Raman spectroscopy as a potential nondestructive evaluation (NDE) tool for the detection of stress rupture in Kevlar composite over-wrapped pressure vessels (COPVs). Characterization of the Raman spectra of Kevlar yarn and strands will be presented and compared with analytical models provided in the literature. Results of testing to investigate the effects of creep and high-temperature aging on the Raman spectra will be presented.

  4. The rules of implicit evaluation by race, religion, and age.

    PubMed

    Axt, Jordan R; Ebersole, Charles R; Nosek, Brian A

    2014-09-01

    The social world is stratified. Social hierarchies are known but often disavowed as anachronisms or unjust. Nonetheless, hierarchies may persist in social memory. In three studies (total N > 200,000), we found evidence of social hierarchies in implicit evaluation by race, religion, and age. Participants implicitly evaluated their own racial group most positively and the remaining racial groups in accordance with the following hierarchy: Whites > Asians > Blacks > Hispanics. Similarly, participants implicitly evaluated their own religion most positively and the remaining religions in accordance with the following hierarchy: Christianity > Judaism > Hinduism or Buddhism > Islam. In a final study, participants of all ages implicitly evaluated age groups following this rule: children > young adults > middle-age adults > older adults. These results suggest that the rules of social evaluation are pervasively embedded in culture and mind. PMID:25079218

  5. Characterization and damage evaluation of advanced materials

    NASA Astrophysics Data System (ADS)

    Mitrovic, Milan

    Mechanical characterization of advanced materials, namely magnetostrictive and graphite/epoxy composite materials, is studied in this dissertation, with an emphasis on damage evaluation of composite materials. Consequently, the work in this dissertation is divided into two parts, with the first part focusing on characterization of the magneto-elastic response of magnetostrictlve materials, while the second part of this dissertation describes methods for evaluating the fatigue damage in composite materials. The objective of the first part of this dissertation is to evaluate a nonlinear constitutive relation which more closely depict the magneto-elastic response of magnetostrictive materials. Correlation between experimental and theoretical values indicate that the model adequately predicts the nonlinear strain/field relations in specific regimes, and that the currently employed linear approaches are inappropriate for modeling the response of this material in a structure. The objective of the second part of this dissertation is to unravel the complexities associated with damage events associated with polymeric composite materials. The intent is to characterize and understand the influence of impact and fatigue induced damage on the residual thermo-mechanical properties and compressive strength of composite systems. The influence of fatigue generated matrix cracking and micro-delaminations on thermal expansion coefficient (TEC) and compressive strength is investigated for woven graphite/epoxy composite system. Experimental results indicate that a strong correlation exists between TEC and compressive strength measurements, indicating that TEC measurements can be used as a damage metric for this material systems. The influence of delaminations on the natural frequencies and mode shapes of a composite laminate is also investigated. Based on the changes of these parameters as a function of damage, a methodology for determining the size and location of damage is suggested

  6. Electrochemical migration technique to accelerate ageing of cementitious materials

    NASA Astrophysics Data System (ADS)

    Babaahmadi, A.; Tang, L.; Abbas, Z.

    2013-07-01

    Durability assessment of concrete structures for constructions in nuclear waste repositories requires long term service life predictions. As deposition of low and intermediate level radioactive waste (LILW) takes up to 100 000 years, it is necessary to analyze the service life of cementitious materials in this time perspective. Using acceleration methods producing aged specimens would decrease the need of extrapolating short term data sets. Laboratory methods are therefore, needed for accelerating the ageing process without making any influencing distortion in the properties of the materials. This paper presents an electro-chemical migration method to increase the rate of calcium leaching from cementitious specimens. This method is developed based on the fact that major long term deterioration process of hardened cement paste in concrete structures for deposition of LILW is due to slow diffusion of calcium ions. In this method the cementitious specimen is placed in an electrochemical cell as a porous path way through which ions can migrate at a rate far higher than diffusion process. The electrical field is applied to the cell in a way to accelerate the ion migration without making destructions in the specimen's micro and macroscopic properties. The anolyte and catholyte solutions are designed favoring dissolution of calcium hydroxide and compensating for the leached calcium ions with another ion like lithium.

  7. Characterization and Evaluation of Aged Chromium Nickel Niobium Stainless Steels

    NASA Astrophysics Data System (ADS)

    Dewar, Matthew

    20Cr-32Ni-1Nb stainless steel alloys are commonly used in hydrogen reformer manifolds for transporting hot hydrogen by-products at 750-950°C. After long periods of exposure, embrittling secondary carbides and intermetallic phases can precipitate at the grain boundaries which can drastically reduce the ductility, and the repair weldability of the alloy. The intermetallic silicide, G-phase, is commonly observed in 20Cr-32Ni-1Nb stainless steels, and is prone to liquation cracking during welding operations. G-phase is deleterious to the material, where a high degree of G-phase coarsening will render the material unweldable. The present work will investigate various methods in mitigating G-phase precipitation. Variations in casting methods, wall thickness, homogenization treatments, and alloy chemistry will be examined by evaluating their microstructure after periodically aging the samples. Thermodynamic equilibrium modeling using computational thermodynamic tools will be used to optimize the 20Cr-32Ni-1Nb chemistry following ASTM specifications.

  8. Materials Compatibility and Aging for Flux and Cleaner Combinations.

    SciTech Connect

    Archuleta, Kim; Piatt, Rochelle

    2015-01-01

    A materials study of high reliability electronics cleaning is presented here. In Phase 1, mixed type substrates underwent a condensed contaminants application to view a worst- case scenario for unremoved flux with cleaning agent residue for parts in a silicone oil filled environment. In Phase 2, fluxes applied to copper coupons and to printed wiring boards underwent gentle cleaning then accelerated aging in air at 65% humidity and 30 O C. Both sets were aged for 4 weeks. Contaminants were no-clean (ORL0), water soluble (ORH1 liquid and ORH0 paste), and rosin (RMA; ROL0) fluxes. Defluxing agents were water, solvents, and engineered aqueous defluxers. In the first phase, coupons had flux applied and heated, then were placed in vials of oil with a small amount of cleaning agent and additional coupons. In the second phase, pairs of copper coupons and PWB were hand soldered by application of each flux, using tin-lead solder in a strip across the coupon or a set of test components on the PWB. One of each pair was cleaned in each cleaning agent, the first with a typical clean, and the second with a brief clean. Ionic contamination residue was measured before accelerated aging. After aging, substrates were removed and a visual record of coupon damage made, from which a subjective rank was applied for comparison between the various flux and defluxer combinations; more corrosion equated to higher rank. The ORH1 water soluble flux resulted in the highest ranking in both phases, the RMA flux the least. For the first phase, in which flux and defluxer remained on coupons, the aqueous defluxers led to worse corrosion. The vapor phase cleaning agents resulted in the highest ranking in the second phase, in which there was no physical cleaning. Further study of cleaning and rinsing parameters will be required.

  9. Characterization of Finnish Building materials under salt frost artificial ageing

    NASA Astrophysics Data System (ADS)

    Luodes, Nike M.; Torppa, Akseli; Pirinen, Heikki; Bellopede, Rossana; Marini, Paola

    2016-04-01

    Under a national project co financed by the Confederation of Finnish Construction Industries RT (CFCI), the Finnish Natural Stone Association and the Geological Survey of Finland (GTK), and thanks to the cooperation with the Polytechnic of Turin a comprehensive number of Finnish natural stones has been tested according to SFS EN standards for national CE marking and according to non standardized methods for research purposes. The aim was to evaluate the effects of combined salt and frost weathering caused by de-icing salts and to research a possible correlation between laboratory's accelerated decay and site weathering. The materials tested (60 stones in total) are mainly silicate rocks showing good resistance to the weathering. Results have been affected in some cases by uncertainties connected to the variation of material quality. Some materials have been from new quarries and variation of their properties has been higher than the effects of artificial weathering. Material sampled from crop presented higher weathering level and the additional artificial weathering has induced small variations. Results have shown that material weathering has been better represented by variation of flexural strength compared to uniaxial compressive strength. The most probable reason has been that small changes of planarity and perpendicularity had greater effects on the compressive strength than variations by weathering. Fifteen representative typologies of natural stones have been tested with non standardized methodologies to study the changes of the material and finding a possible correlation with methods used on site. Schmidt rebound test and Ultra Pulse Velocity (UPV) have been used on site to assess the durability of stone on construction. Materials tested in laboratory have shown less variation between rebounds compared to site tests, this can be because of a more controlled environment and saw cut surface instead of rocky or chiselled ones. Laboratory tests showed an average

  10. The difficult issue of age assessment on pedo-pornographic material.

    PubMed

    Cattaneo, Cristina; Ritz-Timme, Stefanie; Gabriel, Peter; Gibelli, Daniele; Giudici, Elena; Poppa, Pasquale; Nohrden, Doerte; Assmann, Sabine; Schmitt, Roland; Grandi, Marco

    2009-01-10

    The issue of juvenile pornography has seen an increase in the past few years of the number of expert opinions requested to forensic pathologists, paediatricians and other various experts within the forensic and medical fields concerning the age of represented individuals. Regardless of the entity of the problem, no actual method exists which can allow us to give an objective and scientific answer, particularly in the postpubertal stage. Using parameters related to sexual maturation can be very dangerous. Nonetheless some experts still insist with similar types of "expertises". This study aims at verifying the ability of different experts in assessing age of postpubertal individuals represented in pornographic material. Results underline the difficulties and major uncertainties of age evaluation by visual observation of photographic material particularly when the subjects have reached the sexual maturation stage - and therefore in verifying whether the individual is above or below 18 years of age (an important age limit for most European countries as far as this type of crime is concerned). Furthermore the study stresses the need both to search for an alternate approach and to apply extreme caution in judicial evaluation. PMID:19019589

  11. Evaluation Of Potting Materials For Use In Extreme Cold

    NASA Technical Reports Server (NTRS)

    Acosta, Ernesto

    1992-01-01

    Tests help identify noncracking combinations of materials. Aid evaluation of potting materials for copper coils used at low temperatures to measure magnetic fields. Also determine effects of distribution of microballoons, voids, and porosity. Materials also evaluated for ease of use.

  12. Aging evaluation of class 1E batteries: Seismic testing

    SciTech Connect

    Edson, J.L. )

    1990-08-01

    This report presents the results of a seismic testing program on naturally aged class 1E batteries obtained from a nuclear plant. The testing program is a Phase 2 activity resulting from a Phase 1 aging evaluation of class 1E batteries in safety systems of nuclear power plants, performed previously as a part of the US Nuclear Regulatory Commission's Nuclear Plant Aging Research Program and reported in NUREG/CR-4457. The primary purpose of the program was to evaluate the seismic ruggedness of naturally aged batteries to determine if aged batteries could have adequate electrical capacity, as determined by tests recommended by IEEE Standards, and yet have inadequate seismic ruggedness to provide needed electrical power during and after a safe shutdown earthquake (SSE) event. A secondary purpose of the program was to evaluate selected advanced surveillance methods to determine if they were likely to be more sensitive to the aging degradation that reduces seismic ruggedness. The program used twelve batteries naturally aged to about 14 years of age in a nuclear facility and tested them at four different seismic levels representative of the levels of possible earthquakes specified for nuclear plants in the United States. Seismic testing of the batteries did not cause any loss of electrical capacity. 19 refs., 29 figs., 7 tabs.

  13. Evaluation of nonaqueous processes for nuclear materials

    SciTech Connect

    Musgrave, B.C.; Grens, J.Z.; Knighton, J.B.; Coops, M.S.

    1983-12-01

    A working group was assigned the task of evaluating the status of nonaqueous processes for nuclear materials and the prospects for successful deployment of these technologies in the future. In the initial evaluation, the study was narrowed to the pyrochemical/pyrometallurgical processes closely related to the processes used for purification of plutonium and its conversion to metal. The status of the chemistry and process hardware were reviewed and the development needs in both chemistry and process equipment technology were evaluated. Finally, the requirements were established for successful deployment of this technology. The status of the technology was evaluated along three lines: (1) first the current applications were examined for completeness, (2) an attempt was made to construct closed-cycle flow sheets for several proposed applications, (3) and finally the status of technical development and future development needs for general applications were reviewed. By using these three evaluations, three different perspectives were constructed that together present a clear picture of how complete the technical development of these processes are.

  14. Colour measurements of surfaces to evaluate the restoration materials

    NASA Astrophysics Data System (ADS)

    Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

    2011-06-01

    In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (▵E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

  15. Evaluation of a Community-Based Aging Intervention Program

    ERIC Educational Resources Information Center

    Hsu, Hui-Chuan; Wang, Chun-Hou; Chen, Yi-Chun; Chang, Ming-Chen; Wang, Jean

    2010-01-01

    This study evaluated the outcome and process of a community-based aging intervention program for the elderly in Taiwan. The program included education on nutrition and dietary behavior and on physical activities. Outcome and process evaluations were conducted. The program may have had some effects on decreasing some dietary behavioral problems and…

  16. Thermography evaluation of metal bonding materials

    NASA Astrophysics Data System (ADS)

    Safai, Morteza

    The thermographic technique used for the nondestructive evaluation of bondline integrity in metal and silicone rubber bonded material is described. An AGEMA model 880 IR thermographic scanner combined with a 20-deg lens was used to detect the IR radiation from the test panel. A video tape recorder was used to record the live temperature distribution at 25 picture frames per second. A personal computer with an AGEMA TIC-8000 digital image processor was used to record and plot the temperature vs time. The technique was found to be capable of detecting subsurface disbonds as small as 0.0625 sq in. in 0.187-in.-thick thermal protection system bonded materials. The thermography technique meets all the requirements of other approved NDT techniques, and it works well with complex structures and is noncontaminating, noncontact, real-time, and portable.

  17. Thermography evaluation of metal bonding materials

    NASA Astrophysics Data System (ADS)

    Safai, Morteza

    1992-04-01

    The thermographic technique used for the nondestructive evaluation of bondline integrity in metal and silicone rubber bonded material is described. An AGEMA model 880 IR thermographic scanner combined with a 20-deg lens was used to detect the IR radiation from the test panel. A video tape recorder was used to record the live temperature distribution at 25 picture frames per second. A personal computer with an AGEMA TIC-8000 digital image processor was used to record and plot the temperature vs time. The technique was found to be capable of detecting subsurface disbonds as small as 0.0625 sq in. in 0.187-in.-thick thermal protection system bonded materials. The thermography technique meets all the requirements of other approved NDT techniques, and it works well with complex structures and is noncontaminating, noncontact, real-time, and portable.

  18. Commercial off-the-Shelf (COTS) Refractory Material Evaluation

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Kolody, Mark R.; Curran, Jerome P.; Back, Teddy; Hintze, Paul E.; Parlier, Christopher R.; Sampson, Jeffrey W.; Perusich, Stephen; Bucherl, Cori

    2009-01-01

    Fondu Fyre (FF) is currently the only refractory material qualified for use in the flame trench at KSC's Shuttle Launch Pads 39A and 39B. However, the material is not used as it was qualified and has undergone increasingly frequent and severe degradation due to the launch blasts. This degradation is costly as well as dangerous for launch infrastructure, crew and vehicle. FF is applied at the pad via the gunnite process, where wetted refractory material is sprayed onto a steel grid mounted on a support structure. The water content in this process can be manually adjusted by operators, causing distinct visual and physical discrepancies among repair areas. Since the application process is unlikely to change for new refractory materials, it is important to understand the effects of water content on commercial off-the-shelf (COTS) refractory materials. The purpose of this study was to evaluate the performance of the FF with respect to various water contents as well as heat treatments, to simulate aging and exposure to the blast. Initial results indicated that different water contents and heat treatments result in distinct differences in crushing strength, apparent porosity and bulk density. However, water content became an insignificant factor in both crush strength and porosity when FF was cured to at least 1500 deg. Additionally, inspection of the material's surface microstructure by scanning electron microscopy indicated distinguishable characteristics for different heat treatment levels. Results from this study will help guide future studies on the development and identification of new refractory materials.

  19. Evaluation of powder metallurgy superalloy disk materials

    NASA Technical Reports Server (NTRS)

    Evans, D. J.

    1975-01-01

    A program was conducted to develop nickel-base superalloy disk material using prealloyed powder metallurgy techniques. The program included fabrication of test specimens and subscale turbine disks from four different prealloyed powders (NASA-TRW-VIA, AF2-1DA, Mar-M-432 and MERL 80). Based on evaluation of these specimens and disks, two alloys (AF2-1DA and Mar-M-432) were selected for scale-up evaluation. Using fabricating experience gained in the subscale turbine disk effort, test specimens and full scale turbine disks were formed from the selected alloys. These specimens and disks were then subjected to a rigorous test program to evaluate their physical properties and determine their suitability for use in advanced performance turbine engines. A major objective of the program was to develop processes which would yield alloy properties that would be repeatable in producing jet engine disks from the same powder metallurgy alloys. The feasibility of manufacturing full scale gas turbine engine disks by thermomechanical processing of pre-alloyed metal powders was demonstrated. AF2-1DA was shown to possess tensile and creep-rupture properties in excess of those of Astroloy, one of the highest temperature capability disk alloys now in production. It was determined that metallographic evaluation after post-HIP elevated temperature exposure should be used to verify the effectiveness of consolidation of hot isostatically pressed billets.

  20. The Effects of Aging on Clinical Vestibular Evaluations

    PubMed Central

    Maheu, Maxime; Houde, Marie-Soleil; Landry, Simon P.; Champoux, François

    2015-01-01

    Balance disorders are common issues for aging populations due to the effects of normal aging on peripheral vestibular structures. These changes affect the results of vestibular function evaluations and make the interpretation of these results more difficult. The objective of this article is to review the current state of knowledge of clinically relevant vestibular measures. We will first focus on otolith function assessment methods cervical-VEMP (cVEMP) and ocular-VEMP (oVEMP), then the caloric and video-head impulse test (vHIT) methods for semicircular canals assessment. cVEMP and oVEMP are useful methods, though research on the effects of age for some parameters are still inconclusive. vHIT results are largely independent of age as compared to caloric stimulation and should therefore be preferred for the evaluation of the semicircular canals function. PMID:26441824

  1. Performance testing of aged hydrogen getters against criteria for interim safe storage of plutonium bearing materials.

    SciTech Connect

    Shepodd, Timothy J.; Nissen, April; Buffleben, George M.

    2006-01-01

    Hydrogen getters were tested for use in storage of plutonium-bearing materials in accordance with DOE's Criteria for Interim Safe Storage of Plutonium Bearing Materials. The hydrogen getter HITOP was aged for 3 months at 70 C and tested under both recombination and hydrogenation conditions at 20 and 70 C; partially saturated and irradiated aged getter samples were also tested. The recombination reaction was found to be very fast and well above the required rate of 45 std. cc H2h. The gettering reaction, which is planned as the backup reaction in this deployment, is slower and may not meet the requirements alone. Pressure drop measurements and {sup 1}H NMR analyses support these conclusions. Although the experimental conditions do not exactly replicate the deployment conditions, the results of our conservative experiments are clear: the aged getter shows sufficient reactivity to maintain hydrogen concentrations below the flammability limit, between the minimum and maximum deployment temperatures, for three months. The flammability risk is further reduced by the removal of oxygen through the recombination reaction. Neither radiation exposure nor thermal aging sufficiently degrades the getter to be a concern. Future testing to evaluate performance for longer aging periods is in progress.

  2. Survey and evaluation of aging risk assessment methods and applications

    SciTech Connect

    Sanzo, D.L.; Kvam, P.; Apostolakis, G.; Wu, J.; Milici, T.; Ghoniem, N.; Guarro, S.

    1993-11-01

    The Nuclear Regulatory Commission (NRC) initiated the nuclear power plant aging research (NPAR) program about 6 years ago to gather information about nuclear power plant aging. Since then, this program has collected a significant amount of information, largely qualitative, on plant aging and its potential effects on plant safety. However, this body of knowledge has not yet been integrated into formalisms that can be used effectively and systematically to assess plant risk resulting from aging, although models for assessing the effect of increasing failure rates on core damage frequency have been proposed. The purpose of this review is to survey the work conducted to address the aging of systems, structures, and components (SSCs) of nuclear power plants (NPPs), as well as the associated data bases. The review takes a critical look at the need to revise probabilistic risk assessment (PRAs) so that they will include the contribution to risk from plant aging, the adequacy of existing methods for evaluating this contribution, and the adequacy of the data that have been used in these evaluation methods. A preliminary framework is identified for integrating the aging of SSCs into the PRA, including the identification of needed data for such an integration.

  3. Evaluation of Instructional Materials. Position Paper No. 1.

    ERIC Educational Resources Information Center

    Ward, Ted

    The position paper on the evaluation of instructional materials by the Michigan State University Regional Instructional Materials Center for Handicapped Children and Youth (IMC HCY) examines the professional and ethical dilemmas of evaluation and presents evaluation policies of the center. Evaluated by a roster of field evaluators throughout the…

  4. Materials evaluation for a transuranic processing facility

    SciTech Connect

    Barker, S.A., Schwenk, E.B. ); Divine, J.R. )

    1990-11-01

    The Westinghouse Hanford Company, with the assistance of the Pacific Northwest Laboratory, is developing a transuranium extraction process for preheating double-shell tank wastes at the Hanford Site to reduce the volume of transuranic waste being sent to a repository. The bench- scale transuranium extraction process development is reaching a stage where a pilot plant design has begun for the construction of a facility in the existing B Plant. Because of the potential corrosivity of neutralized cladding removal waste process streams, existing embedded piping alloys in B Plant are being evaluated and new'' alloys are being selected for the full-scale plant screening corrosion tests. Once the waste is acidified with HNO{sub 3}, some of the process streams that are high in F{sup {minus}} and low in Al and zr can produce corrosion rates exceeding 30,000 mil/yr in austenitic alloys. Initial results results are reported concerning the applicability of existing plant materials to withstand expected process solutions and conditions to help determine the feasibility of locating the plant at the selected facility. In addition, process changes are presented that should make the process solutions less corrosive to the existing materials. Experimental work confirms that Hastelloy B is unsatisfactory for the expected process solutions; type 304L, 347 and 309S stainless steels are satisfactory for service at room temperature and 60{degrees}C, if process stream complexing is performed. Inconel 625 was satisfactory for all solutions. 17 refs., 5 figs., 8 tabs.

  5. Synthesis and evaluation of energetic materials

    NASA Astrophysics Data System (ADS)

    Santhosh, G.

    Over the years new generations of propellants and explosives are being developed. High performance and pollution prevention issues have become the subject of interest in recent years. Desired properties of these materials are a halogen-free, nitrogen and oxygen rich molecular composition with high density and a positive heat of formation. The dinitramide anion is a new oxy anion of nitrogen and forms salts with variety of metal, organic and inorganic cations. Particular interest is in ammonium dinitramide (ADN, NH4N(NO 2)2) which is a potentially useful energetic oxidizer. ADN is considered as one of the most promising substitutes for ammonium perchlorate (AP, NH4ClO4) in currently used composite propellants. It is unique among energetic materials in that it has no carbon or chlorine; its combustion products are not detrimental to the atmosphere. Unquestionable advantage of ADN over AP is the significant improvement in the performance of solid rocket motors by 5-15%. The present thesis is centered on the experimental results along with discussion of some of the most pertinent aspects related to the synthesis and characterization of few dinitramide salts. The chemistry, mechanism and kinetics of the formation of dinitramide salts by nitration of deactivated amines are investigated. The evaluation of the thermal and spectral properties along with the adsorption and thermal decomposition characteristics of the dinitramide salts are also explored in this thesis.

  6. 46 CFR 30.30-3 - Evaluation materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Evaluation materials. 30.30-3 Section 30.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim Procedures for Evaluating Vessel Personnel Licensing and Certification Programs of Foreign Countries § 30.30-3 Evaluation materials. The materials to be submitted...

  7. 46 CFR 30.30-3 - Evaluation materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Evaluation materials. 30.30-3 Section 30.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim Procedures for Evaluating Vessel Personnel Licensing and Certification Programs of Foreign Countries § 30.30-3 Evaluation materials. The materials to be submitted...

  8. 46 CFR 30.30-3 - Evaluation materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Evaluation materials. 30.30-3 Section 30.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim Procedures for Evaluating Vessel Personnel Licensing and Certification Programs of Foreign Countries § 30.30-3 Evaluation materials. The materials to be submitted...

  9. 46 CFR 30.30-3 - Evaluation materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Evaluation materials. 30.30-3 Section 30.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim Procedures for Evaluating Vessel Personnel Licensing and Certification Programs of Foreign Countries § 30.30-3 Evaluation materials. The materials to be submitted...

  10. 46 CFR 30.30-5 - Submission of evaluation materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Submission of evaluation materials. 30.30-5 Section 30.30-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim...-5 Submission of evaluation materials. (a) The evaluation materials listed in § 30.30-3 should...

  11. 46 CFR 30.30-5 - Submission of evaluation materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Submission of evaluation materials. 30.30-5 Section 30.30-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim...-5 Submission of evaluation materials. (a) The evaluation materials listed in § 30.30-3 should...

  12. 46 CFR 30.30-5 - Submission of evaluation materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Submission of evaluation materials. 30.30-5 Section 30.30-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim...-5 Submission of evaluation materials. (a) The evaluation materials listed in § 30.30-3 should...

  13. Effect of aging on tear strength and cytotoxicity of soft denture lining materials; in vitro

    PubMed Central

    Landayan, Jordi Izzard Andaya; Manaloto, Adrian Carlos Francisco; Shin, Sang-Wan

    2014-01-01

    PURPOSE The aim of this in vitro study was to evaluate the effect of aging on the tear strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for tear strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). RESULTS Before thermocycling, Sofreliner Tough M (10.36 ± 1.00 N) had the highest tear strength value while Coe-Comfort™ (0.46 ± 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 ± 1.66 N) presented the highest value and Coe-Comfort™ (0.42 ± 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort™, Coe-Soft™, and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. CONCLUSION This in vitro study revealed that aging can affect both the tear strength and cytotoxicity of soft denture materials depending on the composition. PMID:24843396

  14. Evaluation of NRC maintenance team inspection reports for managing aging

    SciTech Connect

    Fresco, A.; Gunther, W.

    1991-01-01

    A nuclear power plant's maintenance program is the principal vehicle through which age-related degradation is managed. Over the past two years, the NRC (Nuclear Regulatory Commission) has evaluated the maintenance program of every nuclear power plant in the U.S. The reports issued on these in-depth team inspections have been reviewed to ascertain the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear power plant systems, structures, and components. Selected results of this review are presented in this paper, including examples of inspection and monitoring techniques successfully used by utilities to detect degradation due to aging. Attributes of plant maintenance programs where the NRC inspectors felt that improvement was needed to properly address the aging issue are also discussed. 6 refs., 1 tab.

  15. METHODOLOGY FOR EXAMINING SYSTEM AGING DUE TO INTERACTIONS BETWEEN CHEMICALLY INCOMPATIBLE MATERIALS

    SciTech Connect

    J. DENINGER; J. TANSKI

    1999-04-01

    We start with a stored and unused population of fielded engineered units that are composed of chemically incompatible materials. The units age primarily through heterogeneous chemical reactions between the materials resulting in possible degradation in performance. The engineered units are unused in storage, but may be called into actual service at any time. We sample several units from the population per year and perform a number of non-destructive evaluation (NDE) techniques, such as radiography, low-frequency vibration analysis, and ultrasonic imaging on the selected units. From those units, some are selected for destructive testing (D-test) involving disassembly and testing of internal parts and components. Chemical analyses, mechanical properties measurements and other tests are performed. All of the above steps provide information that is used in the system simulation mathematical model. The system simulation model incorporates chemical reactions and gas-solid transport processes, along with changes in both the surface and bulk properties of the solids. Model results are used to suggest improvements in NDE analyses of the units and improvements in component and material analyses. Model results give trending indications of individual component and overall system changes over time, plus some understanding of the mechanisms involved which allow science-based predictions of the aged state of the units in future times. The NDE, D-test, and model results can also be used to assess statistically the reliability and performance of the overall aging population of units.

  16. A Research Project to Develop and Evaluate a Technical Education Component on Materials Technology for Orientation to Space-Age Technology, Covering the Period July 1, 1974 - January 31, 1976. Final Technical Report.

    ERIC Educational Resources Information Center

    Jacobs, James A.

    This developmental applied research project aims to provide an effective means of orienting non-traditional students, especially minorities and females, to engineering technology, and particularly to basic materials science. The instructional system adopted involves self-paced, individualized instruction, breaking the technical education component…

  17. Working with Aging and Aged Developmentally Disabled Persons: Training Materials for Caregivers. Instructor's Manual, Volume I.

    ERIC Educational Resources Information Center

    Dickerson, Martha Ufford; Thurman, Eunice M.

    This instructor's manual, developed to assist the training instructor of a program entitled "The Aging and Aged Developmentally Disabled," provides information to enhance the skills of inservice and preservice caregivers and other professionals who work with the aging developmentally disabled. The objectives of the two training units,…

  18. Evaluation of aging of cast stainless steel components

    SciTech Connect

    Chung, H.M.

    1991-02-01

    Cast stainless steel is used extensively in nuclear reactors for primary-pressure-boundary components such as primary coolant pipes, elbows, valves, pumps, and safe ends. These components are, however, susceptible to thermal aging embrittlement in light water reactors because of the segregation of Cr atoms from Fe and Ni by spinodal decomposition in ferrite and the precipitation of Cr-rich carbides on ferrite/austenite boundaries. A recent advance in understanding the aging kinetics is presented. Aging kinetics are strongly influenced by the synergistic effects of other metallurgical reactions that occur in parallel with spinodal decomposition, i.e., clustering of Ni, Mo, and Si solute atoms and the nucleation and growth of G-phase precipitates in the ferrite phase. A number of methods are outlined for estimating aging embrittlement under end-of-life of life-extension conditions, depending on several factors such as degree of permissible conservatism, availability of component archive material, and methods of estimating and verifying the activation energy of aging. 33 refs., 6 figs., 3 tabs.

  19. Effect of shelf aging on O-ring materials

    NASA Technical Reports Server (NTRS)

    Wood, T. E.; Stone, W. P.

    1978-01-01

    Commercial O-rings made from 13 different rubber compounds were tested for physical properties after 7 and 12 years of shelf aging. No gross changes were observed in tensile strength, elongation, or compression deflection characteristics.

  20. Evaluation of Obesity in School-Age Children.

    PubMed

    Dobashi, Kazushige

    2016-01-01

    To prevent obesity in middle age, early precautions and interventions are required during childhood. Therefore, it is very important to accurately evaluate the degree of overweight in children. Body mass index (BMI) is widely used worldwide in adults, but not in children. Because standard BMI, which is calculated using the average height and weight for age, changes widely during growth, a constant cut-off point cannot be set for children. An international unified method defining childhood obesity has not been established. In many countries, BMI-for-age percentile (BMI%) value or Z (standard deviation) score is used, whereas in Japan, the percentage of overweight (POW), which is the modified weight-for-height method, is used. We compared BMI% values with POW values obtained using the anthropometric data of elementary and junior high school students based on the Japanese school survey conducted in 2000 and found that the values for the degree of overweight were significantly different between the two methods. It became clear that tall students were easily defined as being overweight, whereas short students tended to be evaluated as being underweight when using BMI%. POW method seemed to be more appropriate than BMI% for school-age children. Abdominal obesity, excess visceral adipose tissue (VAT), is highly associated with obesity-related complications. Waist circumference (WC) is now accepted as an appropriate guide to VAT accumulation. The cut-off value of WC defining excess VAT is 80 cm at the umbilical level in Japanese school-age children. It is not easy to decide the obesity criteria and optimum WC in school-age children. Childhood obesity should be discussed more internationally. PMID:26510873

  1. [Expert evaluation by forensic psychiatrists of aged delinquents].

    PubMed

    Lemańczyk, W; Kordacka, M

    1989-01-01

    In the period from 1970 till 1987 forensic psychiatric certification of 1333 delinquents war made in Regional Psychiatric Hospital in Cibórz. Forty experts (3%) regarded subjects aged 60 years or more. The most common crimes were those against life and health--62.5%; predominantly homicides, assaults and assaults on public functioning, as well as arson--10%. Among male delinquents 68% were under the influence of alcohol at the time of crime of arson and assaults. Other common crime were establish in 15%. Only 1 patient was accused of sexual child abuse (2.5%). Women made 20% of offenders; one half of them committed the crime against life and health, mainly menace. Mental disturbances were found in 90% of patients. Dementia was diagnosed in 20%, organic personality disorder in 30%, and pseudoneurotic syndrome in 15%. Delusional syndrome was diagnosed in 15% while 5% of patients had long history of psychiatric disorders. 35% of expertise were made during single psychiatric interview. It is our opinion that a single examination of aged delinquent does not allow the correct evaluation of the influence of complex relations between possible mental disturbances, somatic illness, drugs (often various pathology and polytherapy) and alcohol, on delinquent's soundness of mind. Taking into consideration the widespread of above mentioned disturbances in the aged population we think that every person in the age above 60 suspected of crime should undergo psychiatric evaluation and hospital observation. PMID:2631130

  2. 46 CFR 30.30-3 - Evaluation materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Evaluation materials. 30.30-3 Section 30.30-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Interim Procedures for... materials. The materials to be submitted for evaluation must include the English text of the following:...

  3. Mechanical evaluation of a soft cast material.

    PubMed

    Zmurko, M G; Belkoff, S M; Herzenberg, J E

    1997-08-01

    In this study, the structural and material properties of a new semi-rigid material, Scotchcast SoftCast (SCS), were compared to the properties of two rigid materials, plaster of paris (POP) and Scotchcast Plus (SCP). Cylinders and flat beams made from 4, 6, 8, and 10 layers of each casting material were tested in three-point bending and diametrical compression. Initial stiffness and yield force values of SCS casts were significantly lower than for casts of SCP and POP made of the same number of layers. Casts made from SCS may be indicated for non-rigid applications, but not where rigid immobilization is required. PMID:9263288

  4. LEVERAGING AGING MATERIALS DATA TO SUPPORT EXTENSION OF TRANSPORTATION SHIPPING PACKAGES SERVICE LIFE

    SciTech Connect

    Dunn, K.; Bellamy, S.; Daugherty, W.; Sindelar, R.; Skidmore, E.

    2013-08-18

    Nuclear material inventories are increasingly being transferred to interim storage locations where they may reside for extended periods of time. Use of a shipping package to store nuclear materials after the transfer has become more common for a variety of reasons. Shipping packages are robust and have a qualified pedigree for performance in normal operation and accident conditions but are only certified over an approved transportation window. The continued use of shipping packages to contain nuclear material during interim storage will result in reduced overall costs and reduced exposure to workers. However, the shipping package materials of construction must maintain integrity as specified by the safety basis of the storage facility throughout the storage period, which is typically well beyond the certified transportation window. In many ways, the certification processes required for interim storage of nuclear materials in shipping packages is similar to life extension programs required for dry cask storage systems for commercial nuclear fuels. The storage of spent nuclear fuel in dry cask storage systems is federally-regulated, and over 1500 individual dry casks have been in successful service up to 20 years in the US. The uncertainty in final disposition will likely require extended storage of this fuel well beyond initial license periods and perhaps multiple re-licenses may be needed. Thus, both the shipping packages and the dry cask storage systems require materials integrity assessments and assurance of continued satisfactory materials performance over times not considered in the original evaluation processes. Test programs for the shipping packages have been established to obtain aging data on materials of construction to demonstrate continued system integrity. The collective data may be coupled with similar data for the dry cask storage systems and used to support extending the service life of shipping packages in both transportation and storage.

  5. Non-Destructive Evaluation of Materials via Ultraviolet Spectroscopy

    NASA Technical Reports Server (NTRS)

    Pugel, Betsy

    2008-01-01

    A document discusses the use of ultraviolet spectroscopy and imaging for the non-destructive evaluation of the degree of cure, aging, and other properties of resin-based composite materials. This method can be used in air, and is portable for field use. This method operates in reflectance, absorbance, and luminescence modes. The ultraviolet source is used to illuminate a composite surface of interest. In reflectance mode, the reflected response is acquired via the imaging system or via the spectrometer. The spectra are analyzed for organic compounds (conjugated organics) and inorganic compounds (semiconducting band-edge states; luminescing defect states such as silicates, used as adhesives for composite aerospace applications; and metal oxides commonly used as thermal coating paints on a wide range of spacecraft). The spectra are compared with a database for variation in conjugation, substitution, or length of molecule (in the case of organics) or band edge position (in the case of inorganics). This approach is useful in the understanding of material quality. It lacks the precision in defining the exact chemical structure that is found in other materials analysis techniques, but it is advantageous over methods such as nuclear magnetic resonance, infrared spectroscopy, and chromatography in that it can be used in the field to assess significant changes in chemical structure that may be linked to concerns associated with weaknesses or variations in structural integrity, without disassembly of or destruction to the structure of interest.

  6. Assessment of Cable Aging Equipment, Status of Acquired Materials, and Experimental Matrix at the Pacific Northwest National Laboratory

    SciTech Connect

    Fifield, Leonard S.; Westman, Matthew P.; Zwoster, Andy; Schwenzer, Birgit

    2015-03-30

    The need for increased understanding of the aging and degradation behavior for polymer components of nuclear power plant electrical cables is described in this report. The highest priority materials for study and the resources available at PNNL for these studies are also described. The anticipated outcomes of the PNNL work described are : improved understanding of appropriate accelerated aging conditions, improved knowledge of correlation between observable aging indicators and cable condition in support of advanced non-destructive evaluation methods, and practical knowledge of condition-based cable lifetime prediction.

  7. AGING MANAGEMENT USING PROACTIVE MANAGEMENT OF MATERIALS DEGRADATION

    SciTech Connect

    Doctor, S. R.; Bond, L. J.; Cumblidge, S. E.; Bruemmer, S. M.; Taylor, W. B.; Carpenter, C. E.; Hull, A. B.; Malik, S. N.

    2010-02-22

    The U.S. Nuclear Regulatory Commission (NRC) has undertaken a program to lay the technical foundations for defining proactive actions to manage degradation of materials in light water reactors. The current focus is existing plants; however, if applied to new construction, there is potential to better monitor and manage plants throughout their life cycle. This paper discusses the NRC's Proactive Management of Materials Degradation program and its application to nuclear power plant structures, systems, and components.

  8. Aging Management using Proactive Management of Materials Degradation

    SciTech Connect

    Doctor, Steven R.; Bond, Leonard J.; Cumblidge, Stephen E.; Bruemmer, Stephen M.; Taylor, W Boyd; Carpenter, C. E.; Hull, Amy B.; Malik, Shah

    2010-10-01

    The U.S. Nuclear Regulatory Commission (NRC) has undertaken a program to lay the technical foundations for defining proactive actions to manage degradation of materials in light water reactors (LWRs). The current focus is existing plants; however, if applied to new construction, there is potential to better monitor and manage plants throughout their life cycle. This paper discusses the NRC’s Proactive Management of Materials Degradation (PMMD) program and its application to nuclear power plant structures, systems, and components (SSC).

  9. Aging Management Using Proactive Management of Materials Degradation

    NASA Astrophysics Data System (ADS)

    Doctor, S. R.; Bond, L. J.; Cumblidge, S. E.; Bruemmer, S. M.; Taylor, W. B.; Carpenter, C. E.; Hull, A. B.; Malik, S. N.

    2010-02-01

    The U.S. Nuclear Regulatory Commission (NRC) has undertaken a program to lay the technical foundations for defining proactive actions to manage degradation of materials in light water reactors. The current focus is existing plants; however, if applied to new construction, there is potential to better monitor and manage plants throughout their life cycle. This paper discusses the NRC's Proactive Management of Materials Degradation program and its application to nuclear power plant structures, systems, and components.

  10. Explosive materials equivalency, test methods and evaluation

    NASA Technical Reports Server (NTRS)

    Koger, D. M.; Mcintyre, F. L.

    1980-01-01

    Attention is given to concepts of explosive equivalency of energetic materials based on specific airblast parameters. A description is provided of a wide bandwidth high accuracy instrumentation system which has been used extensively in obtaining pressure time profiles of energetic materials. The object of the considered test method is to determine the maximum output from the detonation of explosive materials in terms of airblast overpressure and positive impulse. The measured pressure and impulse values are compared with known characteristics of hemispherical TNT data to determine the equivalency of the test material in relation to TNT. An investigation shows that meaningful comparisons between various explosives and a standard reference material such as TNT should be based upon the same parameters. The tests should be conducted under the same conditions.

  11. Aging rat vestibular ganglion: I. Quantitative light microscopic evaluation.

    PubMed

    Alidina, A; Lyon, M J

    1990-01-01

    This study was undertaken to quantify age-related changes in the rat vestibular ganglion. Cell number, diameter, and proximal-distal distribution based on size were evaluated. Serial 5-microns plastic sections of the vestibular ganglion from 15 female Wistar rats were examined. Rats were divided into three age groups: young (Y, 3 to 5 months, n = 5), old (0, 24 to 26 months, n = 3), and very old (VO, 28 to 31 months, n = 7). Quantitative analysis indicated no significant differences (P less than .05) in the estimated number of ganglion cells (mean: Y = 1,690, 0 = 2,257, VO = 1,678), ganglion cell profile diameters (mean: Y = 22.5 microns, n = 2,886; O = 23.7 microns, n = 2,313; VO = 22.8 microns, n = 4,061), or proximal-distal localization (proximal: 22.3 microns, 24.4 microns, 22.7 microns; middle: 22.6 microns, 23.1 microns, 22.4 microns; distal: 23.3 microns, 23.4 microns, 23.7 microns; Y, O, and VO, respectively). When pooled, the old animals tended to have slightly larger cell profiles than the other groups. We noted a dramatic age-related increase of aging pigment within the ganglion cell profiles, making the old and very old animals easily distinguishable from the young. In most of the cell profiles, the aging pigment was more or less uniformly distributed throughout the cytoplasm. However, in some, aging pigment was accumulated at one pole of the cell profile. While no typical degenerating cellular profiles were found in any of the sections, several of the ganglion cell profiles from the old animals revealed dense cytoplasm, possibly indicating an early stage of degeneration. PMID:2382785

  12. Evaluations of mosquito age grading techniques based on morphological changes.

    PubMed

    Hugo, L E; Quick-Miles, S; Kay, B H; Ryan, P A

    2008-05-01

    Evaluations were made of the accuracy and practicality of mosquito age grading methods based on changes to mosquito morphology; including the Detinova ovarian tracheation, midgut meconium, Polovodova ovariole dilatation, ovarian injection, and daily growth line methods. Laboratory maintained Aedes vigilax (Skuse) and Culex annulirostris (Skuse) females of known chronological and physiological ages were used for these assessments. Application of the Detinova technique to laboratory reared Ae. vigilax females in a blinded trial enabled the successful identification of nulliparous and parous females in 83.7-89.8% of specimens. The success rate for identifying nulliparous females increased to 87.8-98.0% when observations of ovarian tracheation were combined with observations of the presence of midgut meconium. However, application of the Polovodova method only enabled 57.5% of nulliparous, 1-parous, 2-parous, and 3-parous Ae. vigilax females to be correctly classified, and ovarian injections were found to be unfeasible. Poor correlation was observed between the number of growth lines per phragma and the calendar age of laboratory reared Ae. vigilax females. In summary, morphological age grading methods that offer simple two-category predictions (ovarian tracheation and midgut meconium methods) were found to provide high-accuracy classifications, whereas methods that offer the separation of multiple age categories (ovariolar dilatation and growth line methods) were found to be extremely difficult and of low accuracy. The usefulness of the morphology-based methods is discussed in view of the availability of new mosquito age grading techniques based on cuticular hydrocarbon and gene transcription changes. PMID:18533427

  13. An Evaluation of the Oxygen Compatibility of Composite Materials

    NASA Technical Reports Server (NTRS)

    Richardson, Erin H.; Hall, Joylene

    2003-01-01

    Three tests are described which evaluate the oxygen compatibility characteristics of multiple composite materials: 1) Mechanical Impact Bruceton 'Up and Down' Method; 2) Promoted Combustion; 3) Electrostatic Discharge.

  14. Materialism across the life span: An age-period-cohort analysis.

    PubMed

    Jaspers, Esther D T; Pieters, Rik G M

    2016-09-01

    This research examined the development of materialism across the life span. Two initial studies revealed that (a) lay beliefs were that materialism declines with age and (b) previous research findings also implied a modest, negative relationship between age and materialism. Yet, previous research has considered age only as a linear control variable, thereby precluding the possibility of more intricate relationships between age and materialism. Moreover, prior studies have relied on cross-sectional data and thus confound age and cohort effects. To improve on this, the main study used longitudinal data from 8 waves spanning 9 years of over 4,200 individuals (16 to 90 years) to examine age effects on materialism while controlling for cohort and period effects. Using a multivariate multilevel latent growth model, it found that materialism followed a curvilinear trajectory across the life span, with the lowest levels at middle age and higher levels before and after that. Thus, in contrast to lay beliefs, materialism increased in older age. Moreover, age effects on materialism differed markedly between 3 core themes of materialism: acquisition centrality, possession-defined success, and acquisition as the pursuit of happiness. In particular, acquisition centrality and possession-defined success were higher at younger and older age. Independent of these age effects, older birth cohorts were oriented more toward possession-defined success, whereas younger birth cohorts were oriented more toward acquisition centrality. The economic downturn since 2008 led to a decrease in acquisition as the pursuit of happiness and in desires for personal growth, but to an increase in desires for achievement. (PsycINFO Database Record PMID:27560768

  15. Nondestructive evaluation of composite materials - A design philosophy

    NASA Technical Reports Server (NTRS)

    Duke, J. C., Jr.; Henneke, E. G., II; Stinchcomb, W. W.; Reifsnider, K. L.

    1984-01-01

    Efficient and reliable structural design utilizing fiber reinforced composite materials may only be accomplished if the materials used may be nondestructively evaluated. There are two major reasons for this requirement: (1) composite materials are formed at the time the structure is fabricated and (2) at practical strain levels damage, changes in the condition of the material, that influence the structure's mechanical performance is present. The fundamental basis of such a nondestructive evaluation capability is presented. A discussion of means of assessing nondestructively the material condition as well as a damage mechanics theory that interprets the material condition in terms of its influence on the mechanical response, stiffness, strength and life is provided.

  16. Aging-related tau astrogliopathy (ARTAG): harmonized evaluation strategy.

    PubMed

    Kovacs, Gabor G; Ferrer, Isidro; Grinberg, Lea T; Alafuzoff, Irina; Attems, Johannes; Budka, Herbert; Cairns, Nigel J; Crary, John F; Duyckaerts, Charles; Ghetti, Bernardino; Halliday, Glenda M; Ironside, James W; Love, Seth; Mackenzie, Ian R; Munoz, David G; Murray, Melissa E; Nelson, Peter T; Takahashi, Hitoshi; Trojanowski, John Q; Ansorge, Olaf; Arzberger, Thomas; Baborie, Atik; Beach, Thomas G; Bieniek, Kevin F; Bigio, Eileen H; Bodi, Istvan; Dugger, Brittany N; Feany, Mel; Gelpi, Ellen; Gentleman, Stephen M; Giaccone, Giorgio; Hatanpaa, Kimmo J; Heale, Richard; Hof, Patrick R; Hofer, Monika; Hortobágyi, Tibor; Jellinger, Kurt; Jicha, Gregory A; Ince, Paul; Kofler, Julia; Kövari, Enikö; Kril, Jillian J; Mann, David M; Matej, Radoslav; McKee, Ann C; McLean, Catriona; Milenkovic, Ivan; Montine, Thomas J; Murayama, Shigeo; Lee, Edward B; Rahimi, Jasmin; Rodriguez, Roberta D; Rozemüller, Annemieke; Schneider, Julie A; Schultz, Christian; Seeley, William; Seilhean, Danielle; Smith, Colin; Tagliavini, Fabrizio; Takao, Masaki; Thal, Dietmar Rudolf; Toledo, Jon B; Tolnay, Markus; Troncoso, Juan C; Vinters, Harry V; Weis, Serge; Wharton, Stephen B; White, Charles L; Wisniewski, Thomas; Woulfe, John M; Yamada, Masahito; Dickson, Dennis W

    2016-01-01

    Pathological accumulation of abnormally phosphorylated tau protein in astrocytes is a frequent, but poorly characterized feature of the aging brain. Its etiology is uncertain, but its presence is sufficiently ubiquitous to merit further characterization and classification, which may stimulate clinicopathological studies and research into its pathobiology. This paper aims to harmonize evaluation and nomenclature of aging-related tau astrogliopathy (ARTAG), a term that refers to a morphological spectrum of astroglial pathology detected by tau immunohistochemistry, especially with phosphorylation-dependent and 4R isoform-specific antibodies. ARTAG occurs mainly, but not exclusively, in individuals over 60 years of age. Tau-immunoreactive astrocytes in ARTAG include thorn-shaped astrocytes at the glia limitans and in white matter, as well as solitary or clustered astrocytes with perinuclear cytoplasmic tau immunoreactivity that extends into the astroglial processes as fine fibrillar or granular immunopositivity, typically in gray matter. Various forms of ARTAG may coexist in the same brain and might reflect different pathogenic processes. Based on morphology and anatomical distribution, ARTAG can be distinguished from primary tauopathies, but may be concurrent with primary tauopathies or other disorders. We recommend four steps for evaluation of ARTAG: (1) identification of five types based on the location of either morphologies of tau astrogliopathy: subpial, subependymal, perivascular, white matter, gray matter; (2) documentation of the regional involvement: medial temporal lobe, lobar (frontal, parietal, occipital, lateral temporal), subcortical, brainstem; (3) documentation of the severity of tau astrogliopathy; and (4) description of subregional involvement. Some types of ARTAG may underlie neurological symptoms; however, the clinical significance of ARTAG is currently uncertain and awaits further studies. The goal of this proposal is to raise awareness of

  17. Aging behavior of polymeric solar absorber materials - Part 1: Engineering plastics

    SciTech Connect

    Kahlen, S.; Wallner, G.M.; Lang, R.W.

    2010-09-15

    In this series of two papers, various polymeric materials are investigated as to their potential applicability as absorber materials for solar thermal collectors. The focus of the investigation is to study the aging behavior of these materials under maximum operating conditions (80 C in water up to 16,000 h) and stagnation conditions (140 C in air up to 500 h) typical for northern climate. The materials supplied or produced as polymer films were first characterized in the unaged state and then for different states of aging by differential scanning calorimetry (DSC), by size exclusion chromatography (SEC) and by mechanical tensile tests. Physical aging phenomena were studied by DSC, SEC analysis provided information on chemical degradation of the materials. In addition, physical and chemical aging were both analyzed via the small and large strain mechanical behavior. While the present Part 1 of this paper series deals with the aging behavior of engineering plastics, including two amorphous polymers (a polyphenylene ether polystyrene blend (PPE + PS) and polycarbonate (PC)) and two semi-crystalline polymers (two types of polyamide 12 (PA12)), the aging behavior of so-called ''commodity'' plastics (PE and PP) is the subject of Part 2. Comparing the two aging conditions, the amorphous materials (PPE + PS and PC) turned out to be more prone to physical and chemical aging at 140 C in air. In contrast, the semi-crystalline PA12 materials were more strongly affected by exposure to water at 80 C, although to different degrees, depending on the modification. (author)

  18. An evaluation of sex-age-kill (SAK) model performance

    USGS Publications Warehouse

    Millspaugh, Joshua J.; Skalski, John R.; Townsend, Richard L.; Diefenbach, Duane R.; Boyce, Mark S.; Hansen, Lonnie P.; Kammermeyer, Kent

    2009-01-01

    The sex-age-kill (SAK) model is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable age distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable age distribution and λ > 1, the SAK model underestimated abundance. Conversely, when λ < 1, the SAK overestimated abundance. When changes to male harvest were introduced, SAK estimates were opposite the true population trend. In contrast, SAK estimates were robust to changes in female harvest rates. Stochastic effects caused SAK estimates to fluctuate about their equilibrium abundance, but the effect dampened as the size of the surveyed population increased. When we considered both stochastic effects and sampling error at a deer management unit scale the resultant abundance estimates were within ±121.9% of the true population level 95% of the time. These combined results demonstrate extreme sensitivity to model violations and scale of analysis. Without changes to model formulation, the SAK model will be biased when λ ≠ 1. Furthermore, any factor that alters the male harvest rate, such as changes to regulations or changes in hunter attitudes, will bias population estimates. Sex-age-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative models, such as statistical age-at-harvest models, which require similar data types, might allow for more robust, broad-scale demographic assessments.

  19. To Evaluate the Relationship between Mandibular Canine Calcification Stages and Skeletal Age

    PubMed Central

    Rana, Vivek; Rehani, Usha

    2012-01-01

    ABSTRACT Aim: The purpose of this study was to assess skeletal age and establish relationship between mandibular canine calcification and skeletal age. Materials and methods: The study included 147 females aged 10 to 13 years. The subjects were divided into three groups: Group I—comprising of 10 to 11 years old female; Group II—comprising of 11 to 12 years old female; Group III—12 to 13 years female. OPG and hand and wrist radiographs of left side for each subject were taken with prior consent of their parents. The calcification status of canine was evaluated from orthopantomograms according to scores given in Demirjian’s method. The stages of ossification of various carpal bones were evaluated using radiographic atlas of Greulich-Pyle and skeletal age was calculated. Results: Data collected was statistically analyzed. Conclusion: The results drawn from this study showed that a strong correlation was observed for canine calcification stage F for 10 to 11 years and for stage G in 11 to 12 years and 12 to 13 years respectively. How to cite this article: Malik P, Rana V, Rehani U. To Evaluate the Relationship between Mandibular Canine Calcification Stages and Skeletal Age. Int J Clin Pediatr Dent 2012;5(1): 14-19. PMID:25206128

  20. A microcalorimeter used to detect changes in aged energetic materials

    SciTech Connect

    Wiedenheft, C.J.; Rodenburg, W.W.; Shockey, G.C.

    1987-01-01

    To ensure the quality of chemical explosives, analytical tests are performed on the materials. One of the most fundamental measurements is that of heat released during an exothermic reaction. Because only small amounts, less than 20 mg, of explosive material can be removed from most weapons, special techniques and instruments must be used to measure a heat output of a few tens of calories. The calorimeter described in this report consists of a sample side and a reference side placed in a constant temperature bath. The calorimeter and sample are heated by passing the current from a bank of capacitors through a heating wire. In order to measure the temperature change, the resistance of Ni wire is measured. The unit was calibrated and found to be accurate for reactions with greater than 5 calories of heat output. (JDH)

  1. Environmental Effects on ISS Materials Aging (1998 to 2008)

    NASA Technical Reports Server (NTRS)

    Alred, John; Dasgupta, Rajib; Koontz, Steve; Soares, Carlos; Golden, John

    2009-01-01

    The performance of ISS spacecraft materials and systems on prolonged exposure to the low- Earth orbit (LEO) space flight are reported in this paper. In-flight data, flight crew observations, and the results of ground-based test and analysis directly supporting programmatic and operational decision-making are described. The space flight environments definitions (both natural and induced) used for ISS design, material selection, and verification testing are shown, in most cases, to be more severe than the actual flight environment accounting, in part, for the outstanding performance of ISS as a long mission duration spacecraft. No significant ISS material or system failures have been attributed to spacecraft-environments interactions. Nonetheless, ISS materials and systems performance data is contributing to our understanding of spacecraft material interactions with the spaceflight environment so as to reduce cost and risk for future spaceflight projects and programs. Orbital inclination (51.6 deg) and altitude (nominally near 360 km) determine the set of natural environment factors affecting the functional life of materials and systems on ISS. ISS operates in an electrically conducting environment (the F2 region of Earth s ionosphere) with well-defined fluxes of atomic oxygen, other charged and neutral ionospheric plasma species, solar UV, VUV, and x-ray radiation as well as galactic cosmic rays, trapped radiation, and solar cosmic rays. The LEO micrometeoroid and orbital debris environment is an especially important determinant of spacecraft design and operations. The magnitude of several environmental factors varies dramatically with latitude and longitude as ISS orbits the Earth. The high latitude orbital environment also exposes ISS to higher fluences of trapped energetic electrons, auroral electrons, solar cosmic rays, and galactic cosmic rays than would be the case in lower inclination orbits, largely as a result of the overall shape and magnitude of the

  2. 20 CFR 416.924b - Age as a factor of evaluation in the sequential evaluation process for children.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Evaluation of Disability § 416.924b Age as a factor of evaluation in the sequential...

  3. 20 CFR 416.924b - Age as a factor of evaluation in the sequential evaluation process for children.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Evaluation of Disability § 416.924b Age as a factor of evaluation in the sequential...

  4. Photochemical aging of light-absorbing secondary organic aerosol material.

    PubMed

    Sareen, Neha; Moussa, Samar G; McNeill, V Faye

    2013-04-11

    Dark reactions of methylglyoxal with NH4(+) in aqueous aerosols yield light-absorbing and surface-active products that can influence the physical properties of the particles. Little is known about how the product mixture and its optical properties will change due to photolysis as well as oxidative aging by O3 and OH in the atmosphere. Here, we report the results of kinetics and product studies of the photochemical aging of aerosols formed by atomizing aqueous solutions of methylglyoxal and ammonium sulfate. Experiments were performed using aerosol flow tube reactors coupled with an aerosol chemical ionization mass spectrometer (Aerosol-CIMS) for monitoring gas- and particle-phase compositions. Particles were also impacted onto quartz windows in order to assess changes in their UV-visible absorption upon oxidation. Photooxidation of the aerosols leads to the formation of small, volatile organic acids including formic acid, acetic acid, and glyoxylic acid. The atmospheric lifetime of these species during the daytime is predicted to be on the order of minutes, with photolysis being an important mechanism of degradation. The lifetime with respect to O3 oxidation was observed to be on the order of hours. O3 oxidation also leads to a net increase in light absorption by the particles due to the formation of additional carbonyl compounds. Our results are consistent with field observations of high brown carbon absorption in the early morning. PMID:23506538

  5. Weightless Environment Training Facility (WETF) materials coating evaluation, volume 2

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This volume consists of Appendices A and B to the report on the Weightless Environment Training Facility Materials Coating Evaluation project. The project selected 10 coating systems to be evaluated in six separate exposure environments, and subject to three tests for physical properties. Appendix A holds the coating system, surface preparation, and application data. Appendix B holds the coating material infrared spectra.

  6. A Sourcebook for the Evaluation of Instructional Materials and Media.

    ERIC Educational Resources Information Center

    Armstrong, Jenny R., Ed.

    Described is a generalized model for the evaluation of instructional materials and media designed to be usable by the Instructional Materials Centers/Regional Media Centers/Regional Resource Centers Network. The model is described as a guide to the inclusion of the critical elements in an evaluation problem situation. Discussed are a system for…

  7. Evaluation of advanced materials. Final report

    SciTech Connect

    Wright, I.G.; Clauer, A.H.; Shetty, D.K.; Tucker, T.R.; Stropki, J.T.

    1982-11-18

    Cemented tungsten carbides with a binder level in the range of 5 to 6 percent exhibited the best resistance to erosion for this class of materials. Other practical cermet meterials were diamond - Si/SiC, Al/sub 2/O/sub 3/-B/sub 4/C-Cr, and B/sub 4/C-Co. SiAlON exhibited erosion resistance equivalent to the best WC-cermet. The only coating system to show promise of improved erosion resistance was CVD TiB/sub 2/ on cemented TiB/sub 2/-Ni. Cracking and/or spalling of a TiC coating and a proprietary TMT coating occurred in the standard slurry erosion test. Ranking of cemented tungsten carbide materials in the laboratory erosion test was the same as that found in service in the Wilsonville pilot plant. Specimens from the Fort Lewis pilot plant which performed well in service exhibited low erosion in the laboratory test. A substitute slurry, was found to be 2 to 4 times more erosive than the coal-derived slurry 8 wt% solids. Ranking of materials in the substitute slurry was nearly identical to that in the coal-derived slurry. Three modes of erosion were: ductile cutting; elastic-plastic indentation and fracture; and intergranular fracture. Erosion of a given material was closely related to its microstructure. In the substitute slurry, the angle-dependence of erosion of two forms of SiC, hot-pressed and sintered, were similar, but the sintered material eroded slower. Laser fusing of preplaced powder mixtures can produce cermet-like structures with potential for erosive and sliding wear resistance. TiC particles in Stellite 6 matrix proved less prone to cracking than WC particles in the same matrix. 74 figures, 14 tables.

  8. Evaluation of Skin Ageing Through Wrinkle Analysis in Capacitive Images

    NASA Astrophysics Data System (ADS)

    Bevilacqua, Alessandro; Gherardi, Alessandro; Guerrieri, Roberto

    Quantitative evaluation of the changes in skin topographic structures are of great importance in the dermocosmetic field to assess subjects response to medical or cosmetic treatments. Although many devices and methods are known to measure these changes, they are not suitable for a routine approach and most of them are invasive. Moreover, it has always been difficult to give a measure of the skin health status as well as of the human aging process by simply analyzing the skin surface appearance. This work describes how a portable capacitive device could be utilized to achieve measurements of skin ageing in vivo and routinely. The capacitive images give a high resolution representation of the skin micro-relief, both in terms of skin surface tissue and wrinkles. In a previous work we dealt with the former; here we have addressed the latter. The algorithm we have developed allowed us to extract two original features from wrinkles: the first is based on photometric properties while the second has been achieved through the multiresolution analysis of the wavelet transform. Accurate experiments accomplished on 87 subjects show how the features we conceived are related to skin ageing.

  9. Design and evaluation of lost circulation materials for severe environments

    SciTech Connect

    Loeppke, G.E.; Glowka, D.A.; Wright, E.K.

    1988-01-01

    An independent analysis of lost circulation materials for geothermal applications has been completed using unique laboratory tools developed for the purpose. Test results of commercial materials as well as mathematical models for evaluating their performance are presented. Physical attributes that govern the performance of lost circulation materials are identified and correlated with test results. 9 refs., 27 figs., 4 tabs.

  10. Quantitative nondestructive evaluation of materials and structures

    NASA Technical Reports Server (NTRS)

    Smith, Barry T.

    1991-01-01

    An experimental investigation was undertaken to quantify damage tolerance and resistance in composite materials impacted using the drop-weight method. Tests were conducted on laminates of several different carbon-fiber composite systems, such as epoxies, modified epoxies, and amorphous and semicrystalline thermoplastics. Impacted composite specimens were examined using destructive and non-destructive techniques to establish the characteristic damage states. Specifically, optical microscopy, ultrasonic, and scanning electron microscopy techniques were used to identify impact induced damage mechanisms. Damage propagation during post impact compression was also studied.

  11. Evaluation of oxidative behavior of polyolefin geosynthetics utilizing accelerated aging tests based on temperature and pressure

    NASA Astrophysics Data System (ADS)

    Li, Mengjia

    Polyolefin geosynthetics are susceptible to oxidation, which eventually leads to the reduction in their engineering properties. In the application of polyolefin geosynthetics, a major issue is an estimate of the materials durability (i.e. service lifetime) under various aging conditions. Antioxidant packages are added to the polyolefin products to extend the induction time, during which antioxidants are gradually depleted and polymer oxidation reactions are prevented. In this PhD study, an improved laboratory accelerating aging method under elevated and high pressure environments was applied to evaluate the combined effect of temperature and pressure on the depletion of the antioxidants and the oxidation of polymers. Four types of commercial polyolefn geosynthetic materials selected for aging tests included HDPE geogrid, polypropylene woven and nonwoven geotextiles. A total of 33 different temperature/pressure aging conditions were used, with the incubation duration up to 24 months. The applied oven temperature ranged from 35°C to 105°C and the partial oxygen pressure ranged from 0.005 MPa to 6.3 MPa. Using the Oxidative Induction Time (OIT) test, the antioxidant depletion, which is correlated to the decrease of the OIT value, was found to follow apparent first-order decay. The OIT data also showed that, the antioxidant depletion rate increased with temperature according to the Arrhenius equation, while under constant temperatures, the rate increased exponentially with the partial pressure of oxygen. A modified Arrhenius model was developed to fit the antioxidant depletion rate as a function of temperature and pressure and to predict the antioxidant lifetime under various field conditions. This study has developed new temperature/pressure incubation aging test method with lifetime prediction models. Using this new technique, the antioxidant lifetime prediction results are close to regular temperature aging data while the aging duration can be reduced considerably

  12. Application of Ultrasonic Guided Waves for Evaluating Aging Wire Insulation

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.; Madaras, Eric I.

    2005-01-01

    Aging wiring has become a critical issue to the aerospace and aircraft industries due to Shuttle and aircraft incidents. The problem is that over time the insulation on wire becomes brittle and cracks. This exposes the underlying conductive wire to the potential for short circuits and fire. Popular methods of monitoring aging wire problems focuses on applying electrical sensing techniques that are sensitive to the conductor's condition, but not very sensitive to the wire insulation's condition. Measurement of wire insulation stiffness and ultrasonic properties by ultrasonic guided waves is being examined. Experimental measurements showed that the lowest order extensional mode could be sensitive to stiffness changes in the wire insulation. To test this theory conventional wire samples were heat damaged in an oven, in a range of heating conditions. The samples were 12, 16, and 20 gauge and the heat damage introduced material changes in the wire insulation that made the originally flexible insulation brittle and darker in color. Results showed that extensional mode phase velocity increased for the samples that were exposed to heat for longer duration.

  13. Age effects on load-dependent brain activations in working memory for novel material

    PubMed Central

    Holtzer, Roee; Rakitin, Brian, C.; Steffener, Jason; Flynn, Joe; Kumar, Arjun; Stern, Yaakov

    2009-01-01

    Three competing models of cognitive aging (neural compensation, capacity limitations, neural inefficiency) were examined in relation to working memory for novel non-verbal material. To accomplish this goal young (n=25) and old (n=25) participants performed a delayed item recognition (DIR) task while being scanned with bold fMRI. The stimuli in the DIR task consisted of computer-generated closed-curve shapes with each shape presented only once in the testing conditions of each participant. This ensured that both the novelty and appearance of the shapes maximized visual demands and limited the extent of phonologic processing. Behaviorally, as expected, the old participants were slower and less accurate compared to the young participants. Spatial patterns of brain activation that corresponded to load-dependent (stimulus set size ranged from 1 to 3) fMRI signal during the three phases of the DIR task (memory set presentation, retention delay, probe presentation) were evaluated in both age groups. Support for neural compensation and capacity limitation was evident in retention delay and the probe phase, respectively. Data were inconsistent with the neural inefficiency model. The process specific support for the theories we examined is consistent with a large corpus of research showing that the substrates underlying the encoding, retention and probe phases are different. That is, cognitive aging theories can be specific to the neural networks/regions underlying the different phases of working memory. Delineating how these theories work in concert can increase knowledge of age-related effects on working memory. PMID:18983833

  14. Understanding and controlling low-temperature aging of nanocrystalline materials.

    SciTech Connect

    Battaile, Corbett Chandler; Boyce, Brad Lee; Brons, Justin G.; Foiles, Stephen Martin; Hattar, Khalid Mikhiel; Holm, Elizabeth Ann; Padilla, Henry A.,; Sharon, John Anthony; Thompson, Gregory B.

    2013-10-01

    Nanocrystalline copper lms were created by both repetitive high-energy pulsed power, to produce material without internal nanotwins; and pulsed laser deposition, to produce nan- otwins. Samples of these lms were indented at ambient (298K) and cryogenic temperatures by immersion in liquid nitrogen (77K) and helium (4K). The indented samples were sectioned through the indented regions and imaged in a scanning electron microscope. Extensive grain growth was observed in the lms that contained nanotwins and were indented cryogenically. The lms that either lacked twins, or were indented under ambient conditions, were found to exhibit no substantial grain growth by visual inspection. Precession transmission elec- tron microscopy was used to con rm these ndings quantitatively, and show that 3 and 7 boundaries proliferate during grain growth, implying that these interface types play a key role in governing the extensive grain growth observed here. Molecular dynamics sim- ulations of the motion of individual grain boundaries demonstrate that speci c classes of boundaries - notably 3 and 7 - exhibit anti- or a-thermal migration, meaning that their mobilities either increase or do not change signi cantly with decreasing temperature. An in-situ cryogenic indentation capability was developed and implemented in a transmission electron microscope. Preliminary results do not show extensive cryogenic grain growth in indented copper lms. This discrepancy could arise from the signi cant di erences in con g- uration and loading of the specimen between the two approaches, and further research and development of this capability is needed.

  15. Investigation of Aging Processes of Ti-6Al-4 V Powder Material in Laser Melting

    NASA Astrophysics Data System (ADS)

    Seyda, V.; Kaufmann, N.; Emmelmann, C.

    Laser melting of titanium material, e.g. Ti-6Al-4 V, offers great potential in manufacturing automotive components, lightweight structures and medical implants. In order to achieve required mechanical properties of laser melted components quality of powder materials is essential. Unmelted powder is recycled and reused in a subsequent process. Due to repeated recycling it is suggested that powder material changes. In this paper aging processes of Ti-6Al-4 V powder are studied. It was observed that powder particles coarsen and flowability increases. Comparing examined powder characteristics to bulk material properties it was noticed that there are significant effects of aged powder on laser melted components.

  16. Evaluation of materials and design modifications for aircraft brakes

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  17. Aging behavior of polymeric solar absorber materials - Part 2: Commodity plastics

    SciTech Connect

    Kahlen, S.; Wallner, G.M.; Lang, R.W.

    2010-09-15

    In this series of two papers, various polymeric materials are investigated as to their potential applicability as absorber materials for solar thermal collectors. While Part 1 of this paper series deals with the aging behavior of engineering plastics, including two amorphous polymers (PPE + PS) and (PC) and two semi-crystalline polymers (two types of PA12), the present Part 2 treats the aging behavior of semi-crystalline so-called ''commodity'' plastics (two types of crosslinked polyethylene (PE-X) and two types of polypropylene (PP)). As in Part 1, the focus of the investigation is to study the aging behavior of these materials under maximum operating conditions (80 C in water up to 16,000 h) and stagnation conditions (140 C in air up to 500 h) typical for northern climate. The materials supplied or produced as polymer films were first characterized in the unaged state and then for different states of aging by differential scanning calorimetry (DSC), by size exclusion chromatography (SEC) and by mechanical tensile tests. DSC was applied primarily to obtain information on physical aging phenomena, whereas SEC analysis was used to characterize chemical degradation of the materials. In addition, physical and chemical aging were both analyzed via the small and large strain mechanical behavior. Comparing the two aging conditions in hot air and hot water, a rather stable mechanical performance profile was found for both PP types over the investigated aging time, which was interpreted in terms of competing physical and chemical aging mechanisms. Analogously such competing mechanisms were also inferred for one of the PE-X materials, while the other exhibited substantial degradation in terms of strain-to-break values for both aging conditions. In principle, both PP and PE-X are promising candidates for black absorber applications in northern climates if proper measures against overheating are taken and when adequately modified. (author)

  18. Method and Apparatus for Non-Destructive Evaluation of Materials

    NASA Technical Reports Server (NTRS)

    Goldfine, Neil J. (Inventor); Washabaugh, Andrew P. (Inventor); Lyons, Robert (Inventor); Thomas, Zachary (Inventor); Jablonski, David A. (Inventor); Martin, Christopher (Inventor)

    2015-01-01

    Methods and apparatus for characterizing composite materials for manufacturing quality assurance (QA), periodic inspection during the useful life, or for forensic analysis/material testing. System are provided that relate eddy-current sensor responses to the fiber layup of a composite structure, the presence of impact damage on a composite structure with or without a metal liner, volumetric stress within the composite, fiber tow density, and other NDE inspection requirements. Also provided are systems that determine electromagnetic material properties and material dimensions of composite materials from capacitive sensor inspection measurements. These properties are related to the presence of buried defects in non-conductive composite materials, moisture ingress, aging of the material due to service or environmental/thermal exposure, or changes in manufacturing quality.

  19. Evaluation of the bond strength between aged composite cores and luting agent

    PubMed Central

    2015-01-01

    PURPOSE The aim of this study was to evaluate effect of different surface treatment methods on the bond strength between aged composite-resin core and luting agent. MATERIALS AND METHODS Seventy-five resin composites and also seventy-five zirconia ceramic discs were prepared. 60 composite samples were exposed to thermal aging (10,000 cycles, 5 to 55℃) and different surface treatment. All specimens were separated into 5 groups (n=15): 1) Intact specimens 2) Thermal aging-air polishing 3) Thermal aging- Er:YAG laser irradiation 4) Thermal aging- acid etching 5) Thermal-aging. All specimens were bonded to the zirconia discs with resin cement and fixed to universal testing machine and bond strength testing loaded to failure with a crosshead speed of 0.5 mm/min. The fractured surface was classified as adhesive failure, cohesive failure and adhesive-cohesive failure. The bond strength data was statistically compared by the Kruskal-Wallis method complemented by the Bonferroni correction Mann-Whitney U test. The probability level for statistical significance was set at α=.05. RESULTS Thermal aging and different surface treatment methods have significant effect on the bond strength between composite-resin cores and luting-agent (P<.05). The mean baseline bond strength values ranged between 7.07 ± 2.11 and 26.05 ± 6.53 N. The highest bond strength of 26.05 ± 6.53 N was obtained with Group 3. Group 5 showed the lowest value of bond strength. CONCLUSION Appropriate surface treatment method should be applied to aged composite resin cores or aged-composites restorations should be replaced for the optimal bond strength and the clinical success. PMID:25932308

  20. Durability evaluation techniques and modeling for highway materials

    SciTech Connect

    Biswas, M.; Muchane, G.K.

    1995-06-01

    For satisfactory long-term performance of highway facilities, the authors are concerned about durability of materials, in addition to their initial strength. Besides conventional materials, such as Portland cement concrete and asphalt concrete, their interests include high-performance materials such as polymer concrete and polymer modified concrete. Degradation of materials may occur over time due to exposure to a number of aggravating conditions and environments. For investigation of durability, the aggravating exposures that the authors have considered include repeated loading, freeze-thaw cycling. Methods of evaluation of performance of materials include application of vibration spectral techniques for evaluating of material stiffness and damage. Materials are modeled to characterize their performance under repeated loads and other aggravating exposures.

  1. Tribological evaluation and analysis of coating materials

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1992-01-01

    A physical characterization of coating materials by analytical techniques such as XPS, AES, ellipsometry, and nuclear reaction analysis can contribute to the understanding of adhesion and friction of the coatings and can partially predict the tribological properties of the coatings. This two-part paper describes the tribological properties and physical characteristics of (1) diamondlike carbon (DLC) films and (2) silicon nitride (SiN(x)) films. Emphasis is to relate plasma deposition conditions to the film chemistry and composition and to the adhesion and friction of the films. With the DLC films, the higher the plasma deposition power, the less the hydrogen concentration and the greater the film density and the hardness. The friction behavior of DLC films deposited at higher deposition powers (200 to 300 W) is similar to that of bulk diamond. Even in a vacuum, the DLC films effectively lubricate ceramic surfaces (Si3N4) at temperatures to 500 C. With SiN(x) films, the silicon to nitrogen ratios and the amount of amorphous silicon depend on deposition frequency. The presence of rich amorphous silicon in the high-frequency plasma-deposited SiN(x) films increases their adhesion and friction above 500 C in vacuum.

  2. Evaluation criteria for commercially oriented materials processing in space proposals

    NASA Technical Reports Server (NTRS)

    Moore, W. F.; Mcdowell, J. R.

    1979-01-01

    An approach and criteria for evaluating NASA funded experiments and demonstrations which have commercial potential were developed. Methods for insuring quick initial screening of commercial proposals are presented. Recommendations are given for modifying the current evaluation approach. New criteria for evaluating commercially orientated materials processing in space (MPS) proposals are introduced. The process for selection of qualified individuals to evaluate the phases of this approach and criteria is considered and guidelines are set for its implementation.

  3. Sensory evaluation of a novel vegetable in school age children.

    PubMed

    Coulthard, Helen; Palfreyman, Zoe; Morizet, David

    2016-05-01

    A behavioural sensory task was undertaken to further understanding into whether children's sensory evaluation of a new vegetable is associated with tasting and food neophobia scores. A sample of ninety-five children, aged 7-11 years, was recruited from a primary school in inner city Birmingham, UK. They were asked to rate the sight, smell and feel of a familiar vegetable (carrot) and an unfamiliar vegetable (celeriac) in a randomised order to control for order effects. They were then asked to try the each vegetable, and rate its taste. It was found that children rated the sensory characteristics of the familiar vegetable more positively than the novel vegetable across all sensory domains (p < 0.05). Refusing to try the novel vegetable was associated with food neophobia scores and olfactory ratings. The ratings of the taste of the novel vegetable were associated with olfactory and tactile ratings. In addition there was a clear developmental shift in the sample with younger children being more likely to rate the novel vegetable as 'looking strange' and older children rating the novel vegetable as 'smelling strange'. This research strengthens the idea that sensory information is important in children deciding to try, and their hedonic evaluation of the taste of a new vegetable. PMID:26809143

  4. Ultrasonic and radiographic evaluation of advanced aerospace materials: Ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    Two conventional nondestructive evaluation techniques were used to evaluate advanced ceramic composite materials. It was shown that neither ultrasonic C-scan nor radiographic imaging can individually provide sufficient data for an accurate nondestructive evaluation. Both ultrasonic C-scan and conventional radiographic imaging are required for preliminary evaluation of these complex systems. The material variations that were identified by these two techniques are porosity, delaminations, bond quality between laminae, fiber alignment, fiber registration, fiber parallelism, and processing density flaws. The degree of bonding between fiber and matrix cannot be determined by either of these methods. An alternative ultrasonic technique, angular power spectrum scanning (APSS) is recommended for quantification of this interfacial bond.

  5. Evaluation of Eco-Efficiency and Performance of Retrofit Materials

    NASA Astrophysics Data System (ADS)

    Gopinath, Smitha; Rama Chandra Murthy, A.; Iyer, Nagesh R.; Kokila, S.

    2015-12-01

    In this work three materials namely Fiber Reinforced Polymer (FRP), ferrocement and Textile Reinforced Concrete (TRC) have been evaluated towards their performance efficiency and eco-effectiveness for sustainable retrofitting applications. Investigations have been carried out for flexural strengthening of RC beams with FRP, ferrocement and TRC. It is observed that in the case of FRP, it is not possible to tailor the material according to design requirements and most of the time strengthened structure becomes over stiff. Eco-effectiveness of these retrofitting materials has been evaluated by computing the embodied energy. It is observed that the amount of CO2 emitted by TRC is less compared to other retrofit materials. Further, the performance point of retrofitted RC frames has been evaluated and damage index has been calculated to find out the effective retrofit material. It is concluded that, if RC frame is retrofitted with FRP and TRC, it undergoes less damage compared to ferrocement.

  6. Concepts and techniques for ultrasonic evaluation of material mechanical properties

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    The ultrasonic nondestructive evaluation techniques discussed in the present paper indicate potentials for material characterization and property prediction. Stress wave interaction and material transfer function concepts are examined as a basis for explaining correlations between material mechanical behavior and ultrasonically measured quantities. It is observed that the effect and criticality of any discrete flaw, such as crack, inclusion, or any other stress raiser, is definable only in terms of its material microstructural environment. This underscores the importance of ultrasonic techniques capable of characterizing the stress wave energy transfer properties of a material.

  7. Acceleration factors for oxidative aging of polymeric materials by oxygen detection.

    SciTech Connect

    Assink, Roger Alan; Celina, Mathias Christopher; Skutnik, Julie Michelle

    2005-01-01

    Three methods that were used to measure the chemical changes associated with oxidative degradation of polymeric materials are presented. The first method is based on the nuclear activation of {sup 18}O in an elastomer that was thermally aged in an {sup 18}O{sub 2} atmosphere. Second, the alcohol groups in a thermally aged elastomer were derivatized with trifluoroacetic anhydride and their concentration measured via {sup 19}F NMR spectroscopy. Finally, a respirometer was used to directly measure the oxidative rates of a polyurethane foam as a function of aging temperature. The measurement of the oxidation rates enabled acceleration factors for oxidative degradation of these materials to be calculated.

  8. Evaluation and clinical significance of the stomach age model for evaluating aging of the stomach-a multicenter study in China

    PubMed Central

    2014-01-01

    Background A higher prevalence of chronic atrophic gastritis (CAG) occurs in younger adults in Asia. We used Stomach Age to examine the different mechanisms of CAG between younger adults and elderly individuals, and established a simple model of cancer risk that can be applied to CAG surveillance. Methods Stomach Age was determined by FISH examination of telomere length in stomach biopsies. Δψm was also determined by flow cytometry. Sixty volunteers were used to confirm the linear relationship between telomere length and age while 120 subjects were used to build a mathematical model by a multivariate analysis. Overall, 146 subjects were used to evaluate the validity of the model, and 1,007 subjects were used to evaluate the relationship between prognosis and Δage (calculated from the mathematical model). ROC curves were used to evaluate the relationship between prognosis and Δage and to determine the cut-off point for Δage. Results We established that a tight linear relationship between the telomere length and the age. The telomere length was obvious different between patients with and without CAG even in the same age. Δψm decreased in individuals whose Stomach Age was greater than real age, especially in younger adults. A mathematical model of Stomach Age (real age + Δage) was successfully constructed which was easy to apply in clinical work. A higher Δage was correlated with a worse outcome. The criterion of Δage >3.11 should be considered as the cut-off to select the subgroup of patients who require endoscopic surveillance. Conclusion Variation in Stomach Age between individuals of the same biological age was confirmed. Attention should be paid to those with a greater Stomach Age, especially in younger adults. The Δage in the Simple Model can be used as a criterion to select CAG patients for gastric cancer surveillance. PMID:25057261

  9. Study on the Aging Behaviors of Rubber Materials in Tension and Compression Loads

    NASA Astrophysics Data System (ADS)

    Jiang, Can; Wang, Hongyu; Ma, Xiaobing

    Rubber materials are widely used in aviation, aerospace, shipbuilding, automobile and other military field. However, rubber materials are easy to aging, which largely restricts its using life. In working environment, due to the combined effect of heat and oxygen, vulcanized rubber will undergo degradation and crosslinking reaction which will cause elasticity decease and permanent deformation, so mostly rubber products are used under stress state. Due to the asymmetric structure and asymmetric stress distribution, mechanical stress may cause serious damage to molecular structure; therefore, this paper is aimed to analyze the aging behavior of rubber materials under tensile and compressive loadings, through analyzing experiment data, and adopting Gauss function to describe stress relaxation coefficient, to build an aging equation containing compression ratio parameter and aging time.

  10. Material evaluation program, high-temperature nitriding environment

    NASA Technical Reports Server (NTRS)

    Marcy, R. D.

    1973-01-01

    Results of a program conducted to evaluate materials for construction of a space shuttle hydrazine monopropellant gas generator are presented. The program was designed to select those materials that maintain the properties of strength and ductility after exposure to an 1800 F nitriding environment for 1000 hours.

  11. A Procedure to Evaluate Cognitive Requirements of Beginning Reading Materials.

    ERIC Educational Resources Information Center

    Williams, Connie K.

    Designed to assess the cognitive requirement expected or implied in beginning reading materials and in their instructional suggestions and to determine whether these materials are appropriate to the cognitive development of the children who will use them, this instrument is for use by evaluators with the first reader in a basal series. It directs…

  12. Evaluating Course Design Principles for Multimedia Learning Materials

    ERIC Educational Resources Information Center

    Scott, Bernard; Cong, Chunyu

    2010-01-01

    Purpose: This paper aims to report on evaluation studies of principles of course design for interactive multimedia learning materials. Design/methodology/approach: At the Defence Academy of the UK, Cranfield University has worked with military colleagues to produce multimedia learning materials for courses on "Military Knowledge". The courses are…

  13. Identification and Assessment of Material Models for Age-Related Degradation of Structures and Passive Components in Nuclear Power Plants

    SciTech Connect

    Nie,J.; Braverman, J.; Hofmayer, C.; Kim, M. K.; Choi, I-K.

    2009-04-27

    When performing seismic safety assessments of nuclear power plants (NPPs), the potential effects of age-related degradation on structures, systems, and components (SSCs) should be considered. To address the issue of aging degradation, the Korea Atomic Energy Research Institute (KAERI) has embarked on a five-year research project to develop a realistic seismic risk evaluation system which will include the consideration of aging of structures and components in NPPs. Three specific areas that are included in the KAERI research project, related to seismic probabilistic risk assessment (PRA), are probabilistic seismic hazard analysis, seismic fragility analysis including the effects of aging, and a plant seismic risk analysis. To support the development of seismic capability evaluation technology for degraded structures and components, KAERI entered into a collaboration agreement with Brookhaven National Laboratory (BNL) in 2007. The collaborative research effort is intended to continue over a five year period with the goal of developing seismic fragility analysis methods that consider the potential effects of age-related degradation of SSCs, and using these results as input to seismic PRAs. In the Year 1 scope of work BNL collected and reviewed degradation occurrences in US NPPs and identified important aging characteristics needed for the seismic capability evaluations that will be performed in the subsequent evaluations in the years that follow. This information is presented in the Annual Report for the Year 1 Task, identified as BNL Report-81741-2008 and also designated as KAERI/RR-2931/2008. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, the report provides a description of U.S. current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. This report

  14. Absolute age of lunar regolith material from the Sea of Fertility

    NASA Technical Reports Server (NTRS)

    Vinogradov, A. P.; Artemov, Y. M.

    1974-01-01

    By averaging the absolute age of lunar regolith materials from the Sea of Fertility for the fine regolith fraction from the core zone V, an age of 4.65 10 to the 9th power + 0.4 10 to the 9th power years was obtained, employing as the primordial Sr-87/Sr-86 ratio 0.69884 (ADOR). Also close to this age value is the age estimate based on the Pb-207/Pb-206 ratio. Using the value 0.69898 (BABI) as a primordial Sr-87/Sr-86 ratio reduces the calculated age of the fine regolith fraction to 4.25 X 10 to the 9th power years. The fine fraction of lunar regolith from the Sea of Fertility is also characterized by a minimum addition of radiogenic Sr-87, a minimum Rb/Sr ratio, and a maximum K/Rb ratio compared with analogous lunar material from other points.

  15. A micro-continuum-mechanical material model for failure of rubber-like materials: Application to ageing-induced fracturing

    NASA Astrophysics Data System (ADS)

    Dal, Hüsnü; Kaliske, Michael

    2009-08-01

    Rubbery polymers are subjected to severe environmental conditions under service. As a consequence of various ageing mechanisms, the outer surface of rubber components hardens in time and cracking occurs as a result of combined mechanical and chemical processes. Conventional phenomenological hyperelastic constitutive models do not account for material softening. Consequently, the stored energy and stresses tend to infinity as stretch increases. In this contribution, a network alteration for the ageing mechanism of rubber-like materials is introduced along with a micromolecular description of material failure. The proposed micro-continuum material model is based on a serial construction of a Langevin-type spring representing the energy storage owing to conformational changes induced by deformation, to a bond potential representing the energy stored in the polymer chain due to the interatomic displacement. For the representation of the micro-macro transition, the non-affine kinematics of the micro-sphere model is used. The Morse potential is utilized for the interatomic bond, which describes the energetic contribution to rubber-like materials and governs the failure of the polymer chain in terms of bond rupture. A novel numerical scheme for the FE implementation of the proposed model is demonstrated. The hardening phenomenon as a result of diffusion limited oxidation of rubber is explained by the principle of mass conservation which dictates simultaneous modulus hardening along with decrease in ultimate stretch observed in aged rubbery polymers.

  16. Influence of the humidity on leakage current under accelerated aging of polymer insulating materials

    SciTech Connect

    Otsubo, M.; Shimono, Y.; Hikami, T.; Honda, C.

    1996-12-31

    This paper describes the experimental results of accelerated aging tests conducted on three different types of polymer materials. Salt fog chamber tests were used to study the surface degradation modes for all materials. The work presented here was performed using a newly constructed fog chamber system that was able to control both chamber humidity and UV radiation. The changes in the surface morphology, material structure and leakage current were examined to study the influence of environmental humidity.

  17. Standards for Evaluations of Educational Programs, Projects, and Materials.

    ERIC Educational Resources Information Center

    Stufflebeam, Daniel L.

    Thirty specific standards developed as guiding principles to maintain the utility, feasibility, propriety and accuracy of evaluations in educational programs, projects and materials are presented. Utility Standards include Audience Identification, Evaluator Credibility, Information Scope and Selection, Valuational Interpretation, Report Clarity,…

  18. Evaluation of Composite Materials for Use on Launch Complexes

    NASA Technical Reports Server (NTRS)

    Finchum, A.; Welch, Peter J.

    1989-01-01

    Commercially available composite structural shapes were evaluated for use. These composites, fiberglass-reinforced polyester and vinylester resin materials are being used extensively in the fabrication and construction of low maintenance, corrosion resistant structures. The evaluation found that in many applications these composite materials can be successfully used at the space center. These composite materials should not be used where they will be exposed to the hot exhaust plume/cloud of the launch vehicle during the liftoff, and caution should be taken in their use in areas where electrostatic discharge and hypergolic propellant compatibility are primary concerns.

  19. Benefit evaluation of space processing of biological materials

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A rational analytical basis for the evaluation of potential benefits of space processing of biological materials is described. A preliminary evaluation of three candidate space processed biological materials was accomplished. Materials investigated were human lymphocytes, urokinase, and Beta cells. Separation of lymphocyte groups was considered in order to improve the matching of donors and recipients for kidney transplantation, while urokinase was examined in regard to treatment of thromboembolic diseases. Separation of Beta cells was studied since it could provide a highly effective means for the treatment of juvenile-onset diabetes.

  20. Evaluation of ceramic filter material, selection for application

    SciTech Connect

    Alvin, M.A.; Tressler, R.E.; Lippert, T.E.; Diaz, E.S.

    1993-09-01

    Field testing in several of the Westinghouse Advanced Particulate Filtration (APF) systems has indicated that the oxide-based materials are more susceptible to thermal shock which results from system transients (i.e., combustion of char or reducing gases; system startup/turbine transients). The current clay bonded silicon carbide filter materials have a higher thermal shock resistance, but appear to be more susceptible to high temperature creep, as well as to changes that occur within the binder phase(s). Strength has frequently been used to assess what effects advanced coal fired process systems have on the stability and projected life of the various porous ceramic filter materials (Tables 1 and 2). Based on the numerous phase changes that occur, and the influence of pulse cleaning on the thermal fatigue characteristics of both the alumina/mullite and clay bonded silicon carbide filter materials, alternate material properties as thermal conductivity, thermal coefficient of expansion, elastic modulus, fracture toughness, and emissivity as a function of thermal/chemical aging are now being considered as critical factors for projecting filter durability and operating life. Table 3 provides a summary of the as-manufactured material properties for the alumina/mullite and clay bonded silicon carbide filter materials which have been used in the Westinghouse`s APF systems. Effort is currently being directed to determine how these properties change during thermal aging of the filters in various subpilot and pilot plant systems.

  1. Aging commuter aeroplanes: Fatigue evaluation and control methods

    NASA Technical Reports Server (NTRS)

    Emmerson, A. J.

    1992-01-01

    The loss of reliability in aircraft is caused by two broad classes of problems. There are those problems which are self evident and hazardous rather than catastrophic. These are the problem areas where characteristically there have been multiple overhauls, repairs, and replacements, and where aging really means the results of repair ineffectiveness that accumulates. The other class of the problem is the insidious and potentially catastrophic class. It includes the progressive deterioration of items that are not maintained, and often cannot be maintained because the deterioration cannot be seen. It includes the loss of physical properties in adhesives and other organic compounds, corrosion, and the response of repeated loads. Dealt with here is a currently unnecessarily troublesome aspect of that response. Although we must remain concerned about those types of aircraft which have been certified under a design standard or operational rule which embodies the elementary fail-safe concept and which have not been subjected to a subsequent structural audit, the focus here is on types of aircraft for which fatigue and damage tolerance evaluation was not required as a condition of certification.

  2. Instrumental evaluation of anti-aging effects of cosmetic formulations containing palmitoyl peptides, Silybum marianum seed oil, vitamin E and other functional ingredients on aged human skin

    PubMed Central

    Hahn, Hyung Jin; Jung, Ho Jung; Schrammek-Drusios, Med Christine; Lee, Sung Nae; Kim, Ji-Hyun; Kwon, Seung Bin; An, In-Sook; An, Sungkwan; Ahn, Kyu Joong

    2016-01-01

    Anti-aging cosmetics are widely used for improving signs of aged skin such as skin wrinkles, decreased elasticity, low dermal density and yellow skin tone. The present study evaluated the effects of cosmetic formulations, eye cream and facial cream, containing palmitoyl peptides, Silybum marianum (S. marianum) seed oil, vitamin E and other functional ingredients on the improvement of facial wrinkles, elasticity, dermal density and skin tone after 4 weeks period of application on aged human skin. Healthy volunteers (n=20) with aged skin were recruited to apply the test materials facially twice per day for 4 weeks. Skin wrinkles, elasticity, dermal density and skin tone were measured instrumentally for assessing the improvement of skin aging. All the measurements were conducted prior to the application of test materials and at 2 and 4 weeks of treatment. Crow's feet wrinkles were decreased 5.97% after 2 weeks of test material application and 14.07% after 4 weeks of application in comparison of pre-application. Skin elasticity was increased 6.81% after 2 weeks and 8.79% after 4 weeks. Dermal density was increased 16.74% after 2 weeks and 27.63% after 4 weeks. With the L* value indicating skin brightness and the a* value indicating erythema (redness), the results showed that brightness was increased 1.70% after 2 weeks and 2.14% after 4 weeks, and erythema was decreased 10.45% after 2 weeks and 22.39% after 4 weeks. Hence, the test materials appear to exert some degree of anti-aging effects on aged human skin. There were no abnormal skin responses from the participants during the trial period. We conclude that the facial and eye cream containing palmitoyl peptides and S. marianum seed oil, vitamin E and other ingredients have effects on the improvement of facial wrinkles, elasticity, dermal density and skin tone. PMID:27446338

  3. 230Th-234U Model-Ages of Some Uranium Standard Reference Materials

    SciTech Connect

    Williams, R W; Gaffney, A M; Kristo, M J; Hutcheon, I D

    2009-05-28

    The 'age' of a sample of uranium is an important aspect of a nuclear forensic investigation and of the attribution of the material to its source. To the extent that the sample obeys the standard rules of radiochronometry, then the production ages of even very recent material can be determined using the {sup 230}Th-{sup 234}U chronometer. These standard rules may be summarized as (a) the daughter/parent ratio at time=zero must be known, and (b) there has been no daughter/parent fractionation since production. For most samples of uranium, the 'ages' determined using this chronometer are semantically 'model-ages' because (a) some assumption of the initial {sup 230}Th content in the sample is required and (b) closed-system behavior is assumed. The uranium standard reference materials originally prepared and distributed by the former US National Bureau of Standards and now distributed by New Brunswick Laboratory as certified reference materials (NBS SRM = NBL CRM) are good candidates for samples where both rules are met. The U isotopic standards have known purification and production dates, and closed-system behavior in the solid form (U{sub 3}O{sub 8}) may be assumed with confidence. We present here {sup 230}Th-{sup 234}U model-ages for several of these standards, determined by isotope dilution mass spectrometry using a multicollector ICP-MS, and compare these ages with their known production history.

  4. Economic evaluation of closure cap barrier materials study

    SciTech Connect

    Serrato, M.G.; Bhutani, J.S.; Mead, S.M.

    1993-09-01

    Volume II of the Economic Evaluation of the Closure Cap Barrier Materials, Revision I contains detailed cost estimates for closure cap barrier materials. The cost estimates incorporate the life cycle costs for a generic hazardous waste seepage basin closure cap under the RCRA Post Closure Period of thirty years. The economic evaluation assessed six barrier material categories. Each of these categories consists of several composite cover system configurations, which were used to develop individual cost estimates. The information contained in this report is not intended to be used as a cost estimating manual. This information provides the decision makers with the ability to screen barrier materials, cover system configurations, and identify cost-effective materials for further consideration.

  5. Metallurgical evaluation of factors influencing the ductility of aged T-111

    NASA Technical Reports Server (NTRS)

    Gold, R. E.

    1972-01-01

    The metallurgical factors influencing the ductility of T-111 (Ta-8W-2Hf) alloy following long-time exposures of GTA welds and tubing in the temperature range 982 C (1800 F) through 1316 C (2400 F) were evaluated by means of scanning and transmission electron microscopy, Auger electron emission spectroscopy, and optical metallographic procedures. No classical aging response occurs in the alloy over the temperature range studied. The ductility impairment implied by previous investigations is not the result of microstructural response of the alloy to thermal exposures. Intergranular failure in the GTA sheet welds appears the result of random contamination by silicon, potassium, and/or fluorine at the grain boundaries of the fusion zones. Exposure to lithium at high temperatures had no adverse effects on the ductility of T-111 tubing. These materials were, however, sensitive to post-age handling and testing procedures.

  6. Job Characteristics, Core Self-Evaluations, and Job Satisfaction: What's Age Got to Do with It?

    ERIC Educational Resources Information Center

    Besen, Elyssa; Matz-Costa, Christina; Brown, Melissa; Smyer, Michael A.; Pitt-Catsouphes, Martha

    2013-01-01

    There is a well-established relationship between age and job satisfaction. To date, there is little research about how many well-known predictors of job satisfaction, specifically job characteristics and core self-evaluations, may vary with age. Using a multi-worksite sample of 1,873 employed adults aged 17 to 81, this study evaluated the extent…

  7. AGING PERFORMANCE OF VITON GLT O-RINGS IN RADIOACTIVE MATERIAL PACKAGES

    SciTech Connect

    Skidmore, E; Kerry Dunn, K; Elizabeth Hoffman, E; Elise Fox, E; Kathryn Counts, K

    2007-05-07

    Radioactive material packages used for transportation of plutonium-bearing materials often contain multiple O-ring seals for containment. Packages such as the Model 9975 are also being used for interim storage of Pu-bearing materials at the Savannah River Site (SRS). One of the seal materials used in such packages is Viton{reg_sign} GLT fluoroelastomer. The aging behavior of containment vessel O-rings based on Viton{reg_sign} GLT at long-term containment term storage conditions is being characterized to assess its performance in such applications. This paper summarizes the program and test results to date.

  8. The aging of wire chambers filled with dimethyl ether: wire and construction materials and freon impurities

    NASA Astrophysics Data System (ADS)

    Jibaly, Mohammed; Majewski, Stan; Chrusch, Peter; Wojcik, Randolph; Sauli, Fabio; Gaudaen, Jan

    1989-11-01

    This is a complete summary of our study of the aging of different types of wire chambers, with a variety of construction materials and wires, filled with dimethyl ether (DME) of varying degrees of purity. The resistive Nicotin and Stablohm wires were corroded by DME, producing fast aging. The moderately resistive stainless steel wires were able to withstand extended irradiation (up to 1 C/cm) in high-purity DME without any apparent damage; and gold-plated tungsten and molybdenum wires exhibited a comparable behavior. Many construction materials were tested and recommendations are thus reached as to what kinds of materials are safe in building DME-operated wire chambers. Among many different Freon and hydrocarbon impurities detected in DME by means of gas chromatography (GC), Freon-11 was found to be mostly responsible for the aging, even with noncorrosive stainless steel or gold-plated wires. The availability and feasibility of obtaining Freon-free DME is reported as well.

  9. Objective evaluation of insert material for diabetic and athletic footwear.

    PubMed

    Brodsky, J W; Kourosh, S; Stills, M; Mooney, V

    1988-12-01

    Five of the most commonly used materials for shoe inserts (soft Plastazote, medium Pelite, PPT, Spenco, and Sorbothane) were objectively evaluated in the laboratory to characterize their behavior in the following three specific functions that correspond to clinical use: (1) the effect on the materials of repeated compression. (2) the effect of a combination of repetitive shear and compression. (3) the force-distribution (force-attenuation) properties of these materials, both when new and after repeated compression. The last function represents a model for relief of pressure beneath plantar bony prominences, a topic of special concern for the insensitive foot. All materials were effective in reducing transmitted force over the simulated bony prominence with a rank order of effectiveness. Other factors considered were: amount and rate of permanent deformation offset by considerations of enhanced moldability when comparing the neoprene and urethane materials with the polyethylene foams. The ideal insert represents a combination of material to achieve both durability and moldability. PMID:3229697

  10. Material Aging and Degradation Detection and Remaining Life Assessment for Plant Life Management

    SciTech Connect

    Ramuhalli, Pradeep; Henager, Charles H.; Griffin, Jeffrey W.; Meyer, Ryan M.; Coble, Jamie B.; Pitman, Stan G.; Bond, Leonard J.

    2012-12-31

    One of the major factors that may impact long term operations is structural material degradation, Detecting materials degradation, estimating the remaining useful life (RUL) of the component, and determining approaches to mitigating the degradation are important from the perspective of long term operations. In this study, multiple nondestructive measurement and monitoring methods were evaluated for their ability to assess the material degradation state. Metrics quantifying the level of damage from these measurements were defined, and evaluated for their ability to provide estimates of remaining life of the component. An example of estimating the RUL from nondestructive measurements of material degradation condition is provided.

  11. Evaluation and Validation of Organic Materials for Advanced Stirling Convertors (ASCs): Overview

    NASA Technical Reports Server (NTRS)

    Shin, Euy-Sik Eugene

    2015-01-01

    Various organic materials are used as essential parts in Stirling Convertors for their unique properties and functionalities such as bonding, potting, sealing, thread locking, insulation, and lubrication. More efficient Advanced Stirling Convertors (ASC) are being developed for future space applications especially with a long mission cycle, sometimes up to 17 years, such as deep space exploration or lunar surface power or Mars rovers, and others. Thus, performance, durability, and reliability of those organics should be critically evaluated in every possible material-process-fabrication-service environment relations based on their mission specifications. In general, thermal stability, radiation hardness, outgassing, and material compatibility of the selected organics have been systematically evaluated while their process and fabrication conditions and procedures were being optimized. Service environment-simulated long term aging tests up to 4 years were performed as a function of temperature for durability assessment of the most critical organic material systems.

  12. Low earth orbital atomic oxygen simulation for materials durability evaluation

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Rutledge, Sharon K.

    1989-01-01

    The erosion yields of numerous materials have been evaluated in low earth orbital space tests. There appears to be three classes of materials: materials of high erosion yield which include most of the hydrocarbon organic materials; materials which either do not react with atomic oxygen or form self-protecting oxides which allow the underlying material to appear durable to atomic oxygen, and materials with low but nonnegligeable erosion yields, such as fluoropolymers. A NASA atomic oxygen effects test program has been established to utilize collective data from a multitude of simulation facilities to promote an understanding of mechanism and erosion yield dependencies. Atomic oxygen protective coatings for Kapton polymide solar array blankets, fiberglass-epoxy composite mast structures, and solar dynamic power system concentrator surfaces have been identified and evaluated under atomic oxygen exposure in RF plasma asher laboratory tests. The control of defect density in protective coatings appears to be the key to the assurance of long-term protection of oxidizable materials in low earth orbit.

  13. Materials and Nondestructive Evaluation Laboratoriers: User Test Planning Guide

    NASA Technical Reports Server (NTRS)

    Schaschl, Leslie

    2011-01-01

    The Materials and Nondestructive Evaluation Laboratory process, milestones and inputs are unknowns to first-time users. The Materials and Nondestructive Evaluation Laboratory Planning Guide aids in establishing expectations for both NASA and non- NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware developers. It is intended to assist their project engineering personnel in materials analysis planning and execution. Material covered includes a roadmap of the analysis process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, products, and inputs necessary to define scope of analysis, cost, and schedule are included as an appendix to the guide.

  14. Recyclability Evaluation Method Considering Material Combination and Degradation

    NASA Astrophysics Data System (ADS)

    Oyasato, Naohiko; Kobayashi, Hideki

    A new method of recyclability evaluation is proposed. The recyclability of a product is given by summing up recyclability of all units to which the product is manually disassembled. The recyclability of a unit is calculated if all names and amounts of materials of which the unit is composed are known. The recyclability of a disassembled unit consisting of multiple materials is judged on the grounds of removability of impurities, miscibility and marketability of polymer blends. Recyclability of a long-lifetime product can be estimated from recyclability of units, which are modeled as probabilistically distributed degradation of materials. The proposed method is applied to recyclability evaluation for a refrigerator with several scenarios of disassembly levels. The practical disassembly scenarios limit the maximum recyclability rate of the product. Therefore, recyclability rates calculated based on the proposed method are considerably lower than those of the recyclable materials of which the product consisted.

  15. Methodology for Evaluating Raw Material Changes to RSRM Elastomeric Insulation Materials

    NASA Technical Reports Server (NTRS)

    Mildenhall, Scott D.; McCool, Alex (Technical Monitor)

    2001-01-01

    The Reusable Solid Rocket Motor (RSRM) uses asbestos and silicon dioxide filled acrylonitrile butadiene rubber (AS-NBR) as the primary internal insulation to protect the case from heat. During the course of the RSRM Program, several changes have been made to the raw materials and processing of the AS-NBR elastomeric insulation material. These changes have been primarily caused by raw materials becoming obsolete. In addition, some process changes have been implemented that were deemed necessary to improve the quality and consistency of the AS-NBR insulation material. Each change has been evaluated using unique test efforts customized to determine the potential impacts of the specific raw material or process change. Following the evaluations, the various raw material and process changes were successfully implemented with no detectable effect on the performance of the AS-NBR insulation. This paper will discuss some of the raw material and process changes evaluated, the methodology used in designing the unique test plans, and the general evaluation results. A summary of the change history of RSRM AS-NBR internal insulation is also presented.

  16. Evaluation of Generalized Performance across Materials When Using Video Technology by Students with Autism Spectrum Disorder and Moderate Intellectual Disability

    ERIC Educational Resources Information Center

    Mechling, Linda C.; Ayres, Kevin M.; Foster, Ashley L.; Bryant, Kathryn J.

    2015-01-01

    The purpose of this study was to evaluate the ability of four high school-aged students with a diagnosis of autism spectrum disorder and moderate intellectual disability to generalize performance of skills when using materials different from those presented through video models. An adapted alternating treatments design was used to evaluate student…

  17. 20 CFR 416.924b - Age as a factor of evaluation in the sequential evaluation process for children.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... chronological age. When we evaluate the development or linear growth of a child born prematurely, we may use a... infants. We generally use chronological age (that is, a child's age based on birth date) when we decide... children until the child's prematurity is no longer a relevant factor; generally no later than...

  18. 20 CFR 416.924b - Age as a factor of evaluation in the sequential evaluation process for children.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... chronological age. When we evaluate the development or linear growth of a child born prematurely, we may use a... infants. We generally use chronological age (that is, a child's age based on birth date) when we decide... children until the child's prematurity is no longer a relevant factor; generally no later than...

  19. 20 CFR 416.924b - Age as a factor of evaluation in the sequential evaluation process for children.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... chronological age. When we evaluate the development or linear growth of a child born prematurely, we may use a... infants. We generally use chronological age (that is, a child's age based on birth date) when we decide... children until the child's prematurity is no longer a relevant factor; generally no later than...

  20. Weightless Environment Training Facility (WETF) materials coating evaluation, volume 1

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Weightless Environment Training Facility Material Coating Evaluation project has included preparing, coating, testing, and evaluating 800 test panels of three differing substrates. Ten selected coating systems were evaluated in six separate exposure environments and subject to three tests for physical properties. Substrate materials were identified, the manner of surface preparation described, and exposure environments defined. Exposure environments included immersion exposure, cyclic exposure, and field exposure. Cyclic exposures, specifically QUV-Weatherometer and the KTA Envirotest were found to be the most agressive of the environments included in the study when all three evaluation criteria are considered. This was found to result primarily from chalking of the coatings under ultraviolet (UV) light exposure. Volumes 2 and 3 hold the 5 appendices to this report.

  1. An Evaluation of Techroll Seal Flexible Joint Material

    NASA Technical Reports Server (NTRS)

    Hall, W. B.

    1983-01-01

    This study evaluated the materials utilized in the flexible joint for possible failure modes. Studies undertaken included effect of temperature on the strength of the system, effect of fatigue on the strength of the system, thermogravimetric analysis, thermochemical analysis, differential scanning calorimeter analysis, dynamic mechanical analysis, and peel test. These studies indicate that if the joint failed due to a materials deficiency, the most likely mode was excessive temperature in the joint. In addition, the joint material is susceptible to fatigue damage which could have been a contributing factor.

  2. Weightless Environment Training Facility (WETF) materials coating evaluation, volume 3

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This volume consists of Appendices C, D, E, and F to the report on the Weightless Environment Training Facility Materials Coating Evaluation project. The project selected 10 coating systems to be evaluated in six separate exposure environments, and subject to three tests for physical properties. Appendix C is the photographic appendix of the test panels. Appendix D details methods and procedures. Appendix E lists application equipment costs. Appendix F is a compilation of the solicitation of the candidate coating systems.

  3. Environmental Evaluation of Building Materials of 5 Slovak Buildings

    NASA Astrophysics Data System (ADS)

    Porhincak, Milan; Estokova, Adriana

    2013-11-01

    Building activity has recently led to the deterioration of environment and has become unsustainable. Several strategies have been introduced in order to minimize consumption of energy and resulting CO2 emissions having their origin in the operational phase. But also other stages of Life Cycle should are important to identify the overall environmental impact of construction sector. In this paper 5 similar Slovak buildings (family houses) were analyzed in terms of environmental performance of building materials used for their structures. Evaluation included the weight of used materials, embodied energy and embodied CO2 and SO2 emissions. Analysis has proven that the selection of building materials is an important factor which influences the environmental profile. Findings of the case study indicated that materials like concrete, ceramic or thermal insulation materials based on polystyrene and mineral wool are ones with the most negative environmental impact.

  4. Evaluation of heat- and blast-protection materials

    NASA Technical Reports Server (NTRS)

    Morrison, J. D.; Lockhart, B. J.

    1971-01-01

    A program was initiated at the Kennedy Space Center in December 1967 and conducted through December 1969 to evaluate the performance of heat- and blast-protection materials for ground support equipment used during the Apollo/Saturn launches. Materials believed to be generally suitable for heat and blast protection were subjected to launch-exposure tests. Tests were made during the Apollo/Saturn 502, 503, and 505 launches. Tests were also made in a local laboratory, as an alternative to the restrictive requirements of launch-exposure tests, to determine the effects of torch-flame exposure on ablative materials. Five materials were found to be satisfactory in all major test categories. It was determined that torch-flame tests can probably be utilized as an acceptable substitute for the booster-engine-exhaust exposure tests for basic screening of candidate materials.

  5. Age, Sex and Socioeconomic Background as Factors in Preschool Children's Preference for Play Materials.

    ERIC Educational Resources Information Center

    Bogdanoff, Ruth F.; Peebles, Linda M.

    A total of 103 preschool children of lower and middle socioeconomic status families were observed in three preschool programs during 15 standardized free play periods for the purpose of investigating preschool children's preferences for different types of traditionally used play materials. The influence of age, sex, and socioeconomic status (SES)…

  6. Disseminating the Positively Aging[R] Teaching Materials: Results of a Controlled Trial

    ERIC Educational Resources Information Center

    Lichtenstein, Michael J.; Pruski, Linda A.; Marshall, Carolyn E.; Blalock, Cheryl L.; Liu, Yan; Plaetke, Rosemarie

    2005-01-01

    This study tested the effectiveness of 2 dissemination methods for the Positively Aging teaching materials. In San Antonio, Texas, 4 middle schools participated in a 3-year controlled trial of dissemination via distance electronic support alone (control) compared to distance electronic support plus in-school support from study staff…

  7. Long-term thermal aging of 2 graphite-polyimide composite materials

    NASA Technical Reports Server (NTRS)

    Nelson, J. B.

    1984-01-01

    Two graphite/polyimide composite materials were aged in circulating air ovens at temperatures 204 C, 232 C, 260 C, and 288 C for various times up to 25000 hours. The composites were: (1) Celanese Celion 6000 graphite fiber and PMR-15 polyimide resin (Celion/PMR-15) and (2) Celion 6000 graphite fiber and LARC-160 polyimide resin (Celion/LARC-160). Three unidirectional specimen geometries were studied: short beam shear (SBS) specimens, flexure specimens, and 153 mm square panels. The interior regions of the square panels exhibited only minor property degradation. The individually aged SBS and flexure specimens exhibited large reductions in strengths after aging. Both laminate materials cracked and degraded preferentially at the specimen edge perpendicular to the fibers.

  8. Evaluation of docket files for terminated source material licenses

    SciTech Connect

    Holoway, C.F.; Lantz, P.M.; Dickson, H.W.

    1980-01-01

    Terminated source material licenses from docket files of the Nuclear Regulatory Commission (NRC) have been evaluated with respect to the potential for residual radiological health problems. Some 8,275 source material docket files were sent from the Federal Repository for NRC to Oak Ridge National Laboratory for evaluation. An NRC printed inventory of terminated source material licenses was sent separately and input to a computer file for ready access. The files were inventoried and a methodology was developed for evaluation of these files. The methodology included development of a combined analysis/computer input form. Pertinent data were abstracted from each file, placed on this form, and entered into a separate private-access computer file. At the same time, analysts using screening criteria made a preliminary categorization of the files. All files categorized initially as potential radiological health problems were reviewed in depth to arrive at a final categorization. Criteria for judgment included quantities of source material (uranium and/or thorium) going to and leaving the site in question during the operational lifetime of the site, disposition of source material not leaving the site, types of operations carried on at the site during the licensed period, and the physicochemical forms of products and wastes involved. In the final analysis, 193 dockets were identified as having potential for residual radiological health problems.

  9. Evaluation of SRM flex bearing materials and processes

    NASA Technical Reports Server (NTRS)

    Wood, T. E.

    1980-01-01

    Tensile, peel, and shear testing was performed on combinations of primers, adhesives, tycements and rubber compounds cured at various times and temperatures. The materials used in the fabrication of the solid rocket motor flex bearing as well as in other systems were evaluated. A compatibility study between adhesives and tycements was initiated. The flex bearing mold design was reviewed by our tooling experts.

  10. The evaluation of two radiographic methods for age determination of children in an Indian population.

    PubMed

    Rai, B

    2008-12-01

    The aim of the present study was to evaluate the applicability of the methods proposed by Nolla and Nicodemo for estimation of dental age and its correction with chronological age. Orthopantograms of 413 patients, aged 6-16 year (70-195 months) were selected to estimate the correlation between dental and chronological age. With both the Nolla and Nicodemo methods, the estimated age was lower than compared to chronological age except for the Nolla method in girls. There were significant correlations between chronological and estimated dental age (by Nolla and Nicodemo methods) in both genders. PMID:22717786

  11. Safety of Disposable Diaper Materials: Extensive Evaluations Validate Use.

    PubMed

    Dey, Swatee; Helmes, C Tucker; White, Jeffrey C; Zhou, Shaoying

    2014-06-24

    Disposable diapers are primarily composed of polymers, such as cellulose, polypropylene, polyester, and polyethylene, which are biologically inert and not bioavailable. They are used in clothes, fabrics, personal hygiene products, and other materials that are commonly in contact with the skin. Each component used throughout the production process must undergo rigorous safety evaluations and assessments and are proven to be well tolerated and safe for their intended uses. No materials are incorporated into a diaper until their safety is confirmed through robust assessments, and additional factors are integrated into the process to compensate for the uncertainty associated with extrapolating toxicity data. After a thorough assessment of the materials and final product, extensive skin compatibility evaluations are conducted as appropriate. This rigorous safety process provides reassurance that consumers can rely on the safety of these diapers. PMID:24961774

  12. Materials Development and Evaluation of Selective Laser Sintering Manufacturing Applications

    SciTech Connect

    Smith, Peter F.; Mitchell, Russell R.

    1997-01-15

    This report summarizes the FY96 accomplishments for CRADA No. LA95C10254, "Materials Development and Evaluation of Laser Sintering Manufacturing Applications". To research the potential for processing additional materials using DTM Corporations Selective Laser Sintering rapid prototyping technology and evaluate the capability for rapid manufacturing applications, the following materials were processed experimentally using the Sinterstation 2000 platform; Linear Low Density Polyethylene thermoplastic; Polypropylene thermoplastic; Polysulfone thermoplastic; Polymethylpentene (TPX) thermoplastic; Carbon microsphere filled nylon 11; "APO-BMI" Apocure bismaleimide thermoset polyimide glass m.icrosphere filled and carbon microsphere filled formulations; and 900-24 physical properties mock for plastic bonded TATB high explosive These materials have been successfully processed to a "proof of concept" level or better (with the exception of No. 7). While none of these materials have been introduced as a standard product as of this date, the potential to do so is viable. Present status of materials processing efforts is presented in Section A 2.0. Some recent efforts in manufacturing applications is discussed in Section A 4.0.

  13. Separator Materials Used in Secondary Alkaline Batteries Characterized and Evaluated

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Nickel-cadmium (Ni/Cd) and nickel-hydrogen (Ni/H2) secondary alkaline batteries are vital to aerospace applications. Battery performance and cycle life are significantly affected by the type of separators used in those batteries. A team from NASA Lewis Research Center's Electrochemical Technology Branch developed standardized testing procedures to characterize and evaluate new and existing separator materials to improve performance and cycle life of secondary alkaline batteries. Battery separators must function as good electronic insulators and as efficient electrolyte reservoirs. At present, new types of organic and inorganic separator materials are being developed for Ni/Cd and Ni/H2 batteries. The separator material previously used in the NASA standard Ni/Cd was Pellon 2505, a 100-percent nylon-6 polymer that must be treated with zinc chloride (ZnCl2) to bond the fibers. Because of stricter Environmental Protection Agency regulation of ZnCl2 emissions, the battery community has been searching for new separators to replace Pellon 2505. As of today, two candidate separator materials have been identified; however, neither of the two materials have performed as well as Pellon 2505. The separator test procedures that were devised at Lewis are being implemented to expedite the search for new battery separators. The new test procedures, which are being carried out in the Separator Laboratory at Lewis, have been designed to guarantee accurate evaluations of the properties that are critical for sustaining proper battery operation. These properties include physical and chemical stability, chemical purity, gas permeability, electrolyte retention and distribution, uniformity, porosity, and area resistivity. A manual containing a detailed description of 12 separator test procedures has been drafted and will be used by the battery community to evaluate candidate separator materials for specific applications. These standardized procedures will allow for consistent, uniform

  14. Characterization of aging in organic materials on atomic-, meso- and macro-length scales by {sup 13}C NMR spectroscopy

    SciTech Connect

    Assink, R.A.; Jamison, G.M.; Alam, T.M.; Gillen, K.T.

    1997-10-01

    A fundamental understanding of aging in an organic material requires that one understand how aging affects the chemical structure of a material, and how these chemical changes are related to the material`s macroscopic properties. This level of understanding is usually achieved by examining the material on a variety of length scales ranging from atomic to meso-scale to macroscopic. The authors are developing and applying several {sup 13}C nuclear magnetic resonance (NMR) spectroscopy experiments to characterize the aging process of organic materials over a broad range of length scales. Examples of studies which range from atomic to macroscopic will be presented.

  15. Evaluation of bone remodeling in regard to the age of scaphoid non-unions

    PubMed Central

    Rein, Susanne; Hanisch, Uwe; Schaller, Hans-Eberhard; Zwipp, Hans; Rammelt, Stefan; Weindel, Stefan

    2016-01-01

    AIM: To analyse bone remodeling in regard to the age of scaphoid non-unions (SNU) with immunohistochemistry. METHODS: Thirty-six patients with symptomatic SNU underwent surgery with resection of the pseudarthrosis. The resected material was evaluated histologically after staining with hematoxylin-eosin (HE), tartrate resistant acid phosphatase (TRAP), CD 68, osteocalcin (OC) and osteopontin (OP). Histological examination was performed in a blinded fashion. RESULTS: The number of multinuclear osteoclasts in the TRAP-staining correlated with the age of the SNU and was significantly higher in younger SNU (P = 0.034; r = 0.75). A higher number of OP-immunoreactive osteoblasts significantly correlated with a higher number of OC-immunoreactive osteoblasts (P = 0.001; r = 0.55). Furthermore, a greater number of OP-immunoreactive osteoblasts correlated significantly with a higher number of OP-immunoreactive multinuclear osteoclasts (P = 0.008; r = 0.43). SNU older than 6 mo showed a significant decrease of the number of fibroblasts (P = 0.04). Smoking and the age of the patients had no influence on bone remodeling in SNU. CONCLUSION: Multinuclear osteoclasts showed a significant decrease in relation to the age of SNU. However, most of the immunhistochemical findings of bone remodeling do not correlate with the age of the SNU. This indicates a permanent imbalance of bone formation and resorption as indicated by a concurrent increase in both osteoblast and osteoclast numbers. A clear histological differentiation into phases of bone remodeling in SNU is not possible. PMID:27458552

  16. THIRD STATUS REPORT: TESTING OF AGED SOFTWOOD FIBERBOARD MATERIAL FOR THE 9975 SHIPPING PACKAGE

    SciTech Connect

    Daugherty, W.

    2011-12-13

    Samples have been prepared from a 9975 lower fiberboard subassembly fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. There is no clear trend thus far to indicate one material ages in a manner significantly different from the other material. Some softwood fiberboard properties degrade faster in some environments, while cane fiberboard degrades faster with regards to other properties and environments. Given the limited aging time accumulated to date in the elevated humidity environments, it is recommended that aging and testing of softwood fiberboard continue for another year. Post-conditioning data have been measured on samples from a single softwood fiberboard assembly, and baseline data are also available from a limited number of vendor-provided samples. This provides minimal information on the possible sample-to-sample variation exhibited by softwood fiberboard. Data to date are generally consistent with the range seen in cane fiberboard, but some portions of the data trends are skewed toward the lower end of that range. Further understanding of the variability of softwood fiberboard properties will require testing of additional material.

  17. 20 CFR 408.413 - How do we evaluate the evidence of age you give us?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false How do we evaluate the evidence of age you give us? 408.413 Section 408.413 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Evidence Requirements Age § 408.413 How do we evaluate the...

  18. 20 CFR 408.413 - How do we evaluate the evidence of age you give us?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false How do we evaluate the evidence of age you give us? 408.413 Section 408.413 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Evidence Requirements Age § 408.413 How do we evaluate the...

  19. 20 CFR 408.413 - How do we evaluate the evidence of age you give us?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false How do we evaluate the evidence of age you give us? 408.413 Section 408.413 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Evidence Requirements Age § 408.413 How do we evaluate the...

  20. 20 CFR 408.413 - How do we evaluate the evidence of age you give us?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false How do we evaluate the evidence of age you give us? 408.413 Section 408.413 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Evidence Requirements Age § 408.413 How do we evaluate the...

  1. 20 CFR 408.413 - How do we evaluate the evidence of age you give us?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How do we evaluate the evidence of age you give us? 408.413 Section 408.413 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Evidence Requirements Age § 408.413 How do we evaluate the...

  2. Ageing of organic electrical insulating materials due to radiation—III. Dielectric properties of a cycloaliphatic epoxy resin: Effect of irradiation environmental conditions and dose rate

    NASA Astrophysics Data System (ADS)

    Spadaro, G.; Calderaro, E.; Schifani, R.; Rizzo, G.

    The effect of dose rate under different environmental conditions on a cycloaliphatic epoxy resin is considered. In particular dielectric measurements were performed. The dose rate is an interesting parameter on evaluating the behaviour of insulating materials in real operating conditions by means of accelerated ageing laboratory tests.

  3. Potential techniques for non-destructive evaluation of cable materials

    NASA Astrophysics Data System (ADS)

    Gillen, Kenneth T.; Clough, Roger L.; Mattson, Bengt; Stenberg, Bengt; Oestman, Erik

    This paper describes the connection between mechanical degradation of common cable materials, in radiation and elevated temperature environments, and density increases caused by the oxidation which leads to this degradation. Two techniques based on density changes are suggested as potential non-destructive evaluation (NDE) procedures which may be applicable to monitoring the mechanical condition of cable materials in power plant environments. The first technique is direct measurement of density changes, via a density gradient column, using small shavings removed from the surface of cable jackets at selected locations. The second technique is computed X-ray tomography, utilizing a portable scanning device.

  4. Gas turbine materials evaluation program utilizing coal derived gaseous fuel

    NASA Astrophysics Data System (ADS)

    Williams, M. L.; Yates, C. C.; Manning, G. B.; Peterson, R. R.

    1981-03-01

    A gas turbine materials evaluation test facility under the sponsorship of the U.S. Department of Energy is described. The objective of the mobile test facility is to obtain dynamic and static test data on the erosion/corrosion characteristics of materials exposed to the hot products of the combustion of coal-derived fuels. The engine being utilized for the tests is the WR 24-7 aircraft turbojet unit reconfigurated to burn coke oven gas. Approximately 100 hours of engine operating time have been logged to date.

  5. Post STS-134 Evaluation of Main Flame Deflector Witness Materials

    NASA Technical Reports Server (NTRS)

    Long, Victoria

    2011-01-01

    NASA and USA design engineers submitted witness materials from the solid rocket booster (SRB) main flame deflector for evaluation after the launch of STS-134. The following items were submitted for analysis: 1018 steel witness rods 304 stainless steel caps, tungsten pistons, and A-286 piston sleeves. All of the items were photographed in order to document their condition after the launch of STS-134. All of the items were dimensionally measured in order to determine the amount of material lost during launch. Microstructural changes were observed in the 1018 witness rod metallographic samples due to the heat of the launch

  6. Post STS-135 Evaluation of Main Flame Deflector Witness Materials

    NASA Technical Reports Server (NTRS)

    Long, Victoria

    2011-01-01

    NASA and USA design engineers submitted witness materials from the solid rocket booster (SRB) main flame deflector for evaluation after the launch of STS-135. The following items were submitted for analysis: HY-80 steel witnes rods, 304 sta inles steel caps, and tungsten pistons. All of the items were photographed in order to document their condition after the launch of STS-135. The submitted samples were dimensionally measured in order to determine the amount of material lost during launch. Microstructural changes were observed in the HY-80 witness rod metallographic samples due to the heat of the launch.

  7. Evaluating and treating school-aged children who stutter.

    PubMed

    Yaruss, J Scott

    2010-11-01

    School-based speech-language pathologists are often called upon to treat children who stutter, though many clinicians have reported that they feel uncomfortable working with this population. Fortunately, there is much that speech-language pathologists can do to help children who stutter speak more easily and minimize the adverse impact of stuttering in both academic and social settings. The purpose of this article is to provide clinicians with a guide to some of the key issues they should consider when working with school-aged children who stutter. The goal is to encourage clinicians to develop a better understanding of how stuttering can affect school-aged children, how the adverse effects of the disorder can be documented so children can be qualified for treatment, and, ultimately, how the negative consequences of stuttering can be minimized through a comprehensive approach to treatment. PMID:21080298

  8. Evaluation of dredged material proposed for ocean disposal from MOTBY

    SciTech Connect

    Barrows, E.S.; Mayhew, H.L.; Word, J.Q.

    1996-09-01

    The National Park Service, US Department of the Interior requested U.S. Army Corps of Engineers/New York District (USACE-NYD) to evaluate sediments around the Military Ocean Terminal (MOTBY) in Bayonne, New Jersey for unconfined ocean disposal at the Mud Dump Site. Sediment samples were collected from MOTBY. Tests and analyses were conducted on MOTBY sediment core samples. The evaluation of proposed dredged material from MOTBY included grain size and total organic carbon (TOC) analyses and one acute toxicity test with the amphipod Ampelisca abdita. In addition to this benthic toxicity test, a bioaccumulation test (28-day exposure) was conducted.

  9. Sixth Status Report: Testing of Aged Softwood Fiberboard Material for the 9975 Shipping Package

    SciTech Connect

    Daugherty, W.

    2015-03-31

    Samples have been prepared from several 9975 lower fiberboard subassemblies fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. Some softwood fiberboard properties tend to degrade faster in some environments, while some cane fiberboard properties degrade faster in the two most aggressive environments. As a result, it is premature to assume both materials will age at the same rates, and the preliminary aging models developed for cane fiberboard might not apply to softwood fiberboard. However, it is expected that both cane and softwood fiberboard assemblies will perform satisfactorily in conforming packages stored in a typical KAC storage environment for up to 15 years. Samples from an additional 3 softwood fiberboard assemblies have begun aging during the past year to provide information on the variability of softwood fiberboard behavior. Aging and testing of softwood fiberboard will continue and additional data will be collected to support development of an aging model specific to softwood fiberboard.

  10. Decreases in bone blood flow and bone material properties in aging Fischer-344 rats

    NASA Technical Reports Server (NTRS)

    Bloomfield, Susan A.; Hogan, Harry A.; Delp, Michael D.

    2002-01-01

    The purpose of this study was to quantify precisely aging-induced changes in skeletal perfusion and bone mechanical properties in a small rodent model. Blood flow was measured in conscious juvenile (2 months old), adult (6 months old), and aged (24 months old) male Fischer-344 rats using radiolabeled microspheres. There were no significant differences in bone perfusion rate or vascular resistance between juvenile and adult rats. However, blood flow was lower in aged versus adult rats in the forelimb bones, scapulas, and femurs. To test for functional effects of this decline in blood flow, bone mineral density and mechanical properties were measured in rats from these two age groups. Bone mineral density and cross-sectional moment of inertia in femoral and tibial shafts and the femoral neck were significantly larger in the aged versus adult rats, resulting in increased (+14%-53%) breaking strength and stiffness. However, intrinsic material properties at midshaft of the long bones were 12% to 25% lower in the aged rats. Although these data are consistent with a potential link between decreased perfusion and focal alterations in bone remodeling activity related to clinically relevant bone loss, additional studies are required to establish the mechanisms for this putative relationship.

  11. Modifications of the Response of Materials to Shock Loading by Age Hardening

    NASA Astrophysics Data System (ADS)

    Millett, Jeremy C. F.

    2015-10-01

    The shock response of two age-hardened alloys, aluminum 6061 and copper-2 wt pct beryllium (CuBe), has been investigated in terms of their microstructual state; either solution treated or age hardened. While age hardening induces large increases in strength at quasi-static strain rates, age hardening does not produce the same magnitude of strength increase during shock loading. Examination of the shocked microstructures (of 6061) indicates that the presence of a fine distribution of precipitates throughout the microstructure hinders the motion and generation of dislocations and hence reduces the strain-rate sensitivity of the aged material, thus allowing the properties of the solution-treated state to approach those of the aged. It has also been observed that the shear strength of solution-treated CuBe is near identical to that of pure copper. It is suggested that this is the result of two competing processes; large lattice strains as beryllium substitutes onto the copper lattice inducing a high degree of solution strengthening acting against a reduction in shear strength caused by twinning in the alloy.

  12. Evaluation of hardness and wear resistance of interim restorative materials

    PubMed Central

    Savabi, Omid; Nejatidanesh, Farahnaz; Fathi, Mohamad Hossein; Navabi, Amir Arsalan; Savabi, Ghazal

    2013-01-01

    Background: The interim restorative materials should have certain mechanical properties to withstand in oral cavity. The aim of this study was to evaluate the hardness and wear resistance of interim restorative materials. Materials and Methods: Fifteen identical rectangular shape specimens with dimensions of 2 mm × 10 mm × 30 mm were made from 7 interim materials (TempSpan, Protemp 3 Garant, Revotek, Unifast LC, Tempron, Duralay, and Acropars). The Vickers hardness and abrasive wear of specimens were tested in dry conditions and after 1 week storage in artificial saliva. The depth of wear was measured using surface roughness inspection device. Data were subjected to Kruskal–Wallis and Mann–Whitney tests. The Pearson correlation coefficient was used to determine the relationship between hardness and wear (α =0.05). Results: TempSpan had the highest hardness. The wear resistance of TempSpan (in dry condition) and Revotek (after conditioning in artificial saliva) was significantly higher (P < 0.05). There was no statistically significant correlation between degree of wear and hardness of the materials (P = 0.281, r = −0.31). Conclusion: Hardness and wear resistance of interim resins are material related rather than category specified. PMID:23946734

  13. New Technique for Evaluating Adhesion Properties between Soft Materials

    NASA Astrophysics Data System (ADS)

    Sato, Takaya; Goto, Motoaki; Nakano, Ken; Suzuki, Atsushi

    2005-11-01

    A new, simple apparatus for measuring the surface adhesion properties of soft materials was designed, where the adhesion force of a point contact between soft materials and the total energy required to separate the contact can be measured using the springs of phosphor-bronze thin plates with strain gauges. The adhesion between swollen hydrogels was studied here by this simple technique in air at room temperature. The gels used in the present preliminary experiments were poly(sodium acrylate) hydrogels physically cross-linked by aluminum ions. The adhesion force and the separation energy showed a power-law increase with separation velocity. The apparatus was applied to evaluate the adhesion properties of seven anti-inflammatory analgesic cataplasms on the market. It was found that the easiness to separate (rank of adhesion force and the separation energy) was consistent with the results of those obtained by organoleptic evaluations.

  14. Dielectric Spectroscopy Analysis of Aged EVOH films with Application to Deterioration of Food Packaging Materials

    NASA Astrophysics Data System (ADS)

    Hoeller, Timothy

    2007-06-01

    Samples of EVOH films from compositions of 29 - 44 mol% ethylene content were exposed to thermal aging with and without light exposure. The results of Dielectric Spectroscopy on select samples showed Cole-Cole plots of skewed dielectric constant indicating multiple distributions of dipole relaxation times. The onset for decreases in dielectric response occurs earlier in samples exposed to elevated temperature under light exposure. Lower permittivity is exhibited in samples of higher ethylene content. Results from heat exposed samples are presented. Colorimetric analysis indicates only a slight film yellowing in one case. Raman spectroscopy on untreated films discerns changes in the C-C-O stretch associated with the alcohol. The effects of aging on microstructure may cause hindrance of molecular motion from moisture desorption. Slight material degradation occurs from film hardening presumably due to crosslinking. An electrical circuit model of the conduction processes associated with the EVOH films is presented. Dielectric analysis shows promise for monitoring material changes related to deterioration. We are also using these methods to understand Fluorescence Imaging which has been recently released for paper and plastic materials analysis. Future work may include refinement of these techniques for identification of changes in material properties correlated to packaging material barrier resistance.

  15. Physical property comparison of 11 soft denture lining materials as a function of accelerated aging.

    PubMed

    Dootz, E R; Koran, A; Craig, R G

    1993-01-01

    Soft denture-lining materials are an important treatment option for patients who have chronic soreness associated with dental prostheses. Three distinctly different types of materials are generally used. These are plasticized polymers or copolymers, silicones, or polyphosphazene fluoroelastomer. The acceptance of these materials by patients and dentists is variable. The objective of this study is to compare the tensile strength, percent elongation, hardness, tear strength, and tear energy of eight plasticized polymers or copolymers, two silicones, and one polyphosphazene fluoroelastomer. Tests were run at 24 hours after specimen preparation and repeated after 900 hours of accelerated aging in a Weather-Ometer device. The data indicated a wide range of physical properties for soft denture-lining materials and showed that accelerated aging dramatically affected the physical and mechanical properties of many of the elastomers. No soft denture liner proved to be superior to all others. The data obtained should provide clinicians with useful information for selecting soft denture lining materials for patients. PMID:8455156

  16. Nondestructive evaluation of critical composite material structural elements

    NASA Astrophysics Data System (ADS)

    Duke, John C., Jr.; Lesko, John J.; Weyers, R.

    1996-11-01

    A small span bridge that has suffered corrosive deterioration of a number of the steel structural members is in the process of being rehabilitated with glass and carbon fiber reinforced, pultruded polymer structural beams. As part of a comprehensive research program to develop methods for modeling long term durability of the composite material, nondestructive evaluation if being used to provide a preliminary assessment of the initial condition of the beams as well as to monitor the deterioration of the beams during service.

  17. Non-destructive evaluation of composite materials using ultrasound

    NASA Technical Reports Server (NTRS)

    Miller, J. G.

    1984-01-01

    Investigation of the nondestructive evaluation of advanced composite-laminates is summarized. Indices derived from the measurement of fundamental acoustic parameters are used in order to quantitatively estimate the local material properties of the laminate. The following sections describe ongoing studies of phase insensitive attenuation measurements, and discuss several phenomena which influences the previously reported technique of polar backscatter. A simple and effective programmable gate circuit designed for use in estimating attenuation from backscatter is described.

  18. Evaluating candidate lost circulation materials for geothermal drilling

    SciTech Connect

    Loeppke, G.

    1986-01-01

    Sandia National Laboratories' Geothermal Technology Development Division is working to advance the state of the art of lost circulation prevention and control. For this purpose, a large-scale lost Circulation Test Facility was designed and built. This paper addresses the evaluation of candidate lost circulation materisl using this facility and also using the recommended practice of API RP 131. Test results from these facilities are compared and discussed for the materials tested.

  19. A simple-rapid method to separate uranium, thorium, and protactinium for U-series age-dating of materials.

    PubMed

    Knight, Andrew W; Eitrheim, Eric S; Nelson, Andrew W; Nelson, Steven; Schultz, Michael K

    2014-08-01

    Uranium-series dating techniques require the isolation of radionuclides in high yields and in fractions free of impurities. Within this context, we describe a novel-rapid method for the separation and purification of U, Th, and Pa. The method takes advantage of differences in the chemistry of U, Th, and Pa, utilizing a commercially-available extraction chromatographic resin (TEVA) and standard reagents. The elution behavior of U, Th, and Pa were optimized using liquid scintillation counting techniques and fractional purity was evaluated by alpha-spectrometry. The overall method was further assessed by isotope dilution alpha-spectrometry for the preliminary age determination of an ancient carbonate sample obtained from the Lake Bonneville site in western Utah (United States). Preliminary evaluations of the method produced elemental purity of greater than 99.99% and radiochemical recoveries exceeding 90% for U and Th and 85% for Pa. Excellent purity and yields (76% for U, 96% for Th and 55% for Pa) were also obtained for the analysis of the carbonate samples and the preliminary Pa and Th ages of about 39,000 years before present are consistent with (14)C-derived age of the material. PMID:24681438

  20. Development and evaluation of die and container materials

    NASA Technical Reports Server (NTRS)

    Wills, R. R.; Niesz, D. E.

    1979-01-01

    X = 0.75 Beta prime Sialon (a silicon aluminum oxynitride) and Sibeon (silicon beryllium oxynitride) are promising die materials. In sessile drop tests in contact with molten silicon, beryllium contamination was less than ppm and aluminum contamination 50 ppm. A shaping die of the Sialon material was successfully fabricated. Dry milling studies for the preparation of Si3N4-Al2O3-ALN mixtures were performed with butanol, acetic anhydride, oleic acid, and triethanolamine milling aids. Optimum mixing was achieved with 0.15 percent triethanolamine using a milling time of 8 hours. Preliminary evaluation of Sibeon materials indicates that they are more resistent to molten silicon attack than Sialon. Silicon contamination from the beryllium was less than aluminum contamination even though the aluminum impurity level in the Sibeon was only 450 to 1300 ppm. Work designed to produce an aluminum-free Sibeon is described.

  1. A new tribological test for candidate brush seal materials evaluation

    SciTech Connect

    Fellenstein, J.A.; DellaCorte, C.

    1994-10-01

    A new tribological test for candidate brush seal materials evaluation has been developed. The sliding contact between the brush seal wires and their mating counterface journal is simulated by testing a small tuft of wire against the outside diameter of a high speed rotating shaft. The test configuration is similar to a standard block on ring geometry. The new tester provides the capability to measure both the friction and wear of candidate wire and counterface materials under controlled loading conditions in the gram to kilogram range. A wide test condition latitude of speeds (1 to 27 m/s), temperatures (25 to 700C), and loads (0.5 to 10 N) enables the simulation of many of the important tribological parameters found in turbine engine brush seals. This paper describes the new test rig and specimen configuration and presents initial data for candidate seal materials comparing tuft test results and wear surface morphology to field tested seal components.

  2. A New Tribological Test for Candidate Brush Seal Materials Evaluation

    NASA Technical Reports Server (NTRS)

    Fellenstein, James A.; Dellacorte, Christopher

    1994-01-01

    A new tribological test for candidate brush seal materials evaluation has been developed. The sliding contact between the brush seal wires and their mating counterface journal is simulated by testing a small tuft of wire against the outside diameter of a high speed rotating shaft. The test configuration is similar to a standard block on ring geometry. The new tester provides the capability to measure both the friction and wear of candidate wire and counterface materials under controlled loading conditions in the gram to kilogram range. A wide test condition latitude of speeds (1 to 27 m/s), temperatures (25 to 700 C), and loads (0.5 to 10 N) enables the simulation of many of the important tribological parameters found in turbine engine brush seals. This paper describes the new test rig and specimen configuration and presents initial data for candidate seal materials comparing tuft test results and wear surface morphology to field tested seal components.

  3. Age- and Race-Related Differences in Human Scleral Material Properties

    PubMed Central

    Grytz, Rafael; Fazio, Massimo A.; Libertiaux, Vincent; Bruno, Luigi; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2014-01-01

    Purpose. We tested the hypothesis that there are age- and race-related differences in posterior scleral material properties, using eyes from human donors of European (20–90 years old, n = 40 eyes) and African (23–74 years old, n = 22 eyes) descent. Methods. Inflation tests on posterior scleral shells were performed while full-field, three-dimensional displacements were recorded using laser speckle interferometry. Scleral material properties were fit to each eye using a microstructure-based constitutive formulation that incorporates the collagen fibril crimp and the local anisotropic collagen architecture. The effects of age and race were estimated using Generalized Estimating Equations, while accounting for intradonor correlations. Results. The shear modulus significantly increased (P = 0.038) and collagen fibril crimp angle significantly decreased with age (P = 0.002). Donors of African descent exhibited a significantly higher shear modulus (P = 0.019) and showed evidence of a smaller collagen fibril crimp angle (P = 0.057) compared to donors of European descent. The in-plane strains in the peripapillary sclera were significantly lower with age (P < 0.015) and African ancestry (P < 0.015). Conclusions. The age- and race-related differences in scleral material properties result in a loss of scleral compliance due to a higher shear stiffness and a lower level of stretch at which the collagen fibrils uncrimp. The loss of compliance should lead to larger high frequency IOP fluctuations and changes in the optic nerve head (ONH) biomechanical response in the elderly and in persons of African ancestry, and may contribute to the higher susceptibility to glaucoma in these at-risk populations. PMID:25389203

  4. On the Use of Accelerated Aging Methods for Screening High Temperature Polymeric Composite Materials

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Grayson, Michael A.

    1999-01-01

    A rational approach to the problem of accelerated testing of high temperature polymeric composites is discussed. The methods provided are considered tools useful in the screening of new materials systems for long-term application to extreme environments that include elevated temperature, moisture, oxygen, and mechanical load. The need for reproducible mechanisms, indicator properties, and real-time data are outlined as well as the methodologies for specific aging mechanisms.

  5. Friction, mechanical and ageing properties of surface modified materials for space debris capture

    NASA Astrophysics Data System (ADS)

    Ferraris, S.; Perero, S.; Gautier di Confiengo, G.; Chiesa, A.; Messidoro, A.; Ferraris, M.

    2016-03-01

    Space debris removal is a challenging problem for a clean and safe space environment. The present paper focuses on a novel concept of capture mechanism in the framework of technologies, strategies and concepts known as "tentacles with belts" method. Within this framework two different strategies (based on inorganic or organic materials) have been developed in order to improve the capture efficiency of the belts. The mechanical, tribological and ageing characterization of modified belt fabrics for space application is reported and discussed.

  6. FOURTH STATUS REPORT: TESTING OF AGED SOFTWOOD FIBERBOARD MATERIAL FOR THE 9975 SHIPPING PACKAGE

    SciTech Connect

    Daugherty, W.

    2013-03-05

    Samples have been prepared from a 9975 lower fiberboard subassembly fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. Some softwood fiberboard properties tend to degrade faster in elevated humidity environments, while some cane fiberboard properties degrade faster in the hotter dry environments. As a result, it is premature to assume both materials will age at the same rates, and the preliminary aging models developed for cane fiberboard might not apply to softwood fiberboard. However, it is expected that both cane and softwood fiberboard assemblies will perform satisfactorily in conforming packages stored in a typical KAMS environment for up to 15 years. Aging and testing of softwood fiberboard will continue and additional data will be collected. Post-conditioning data have been measured on samples from a single softwood fiberboard assembly, and baseline data are also available from a limited number of vendor-provided samples. This provides minimal information on the possible sample-to-sample variation exhibited by softwood fiberboard. Data to date are generally consistent with the range seen in cane fiberboard, but some portions of the data trends are skewed toward the lower end of that range. Further understanding of the variability of softwood fiberboard properties will require testing of additional material.

  7. FIFTH STATUS REPORT: TESTING OF AGED SOFTWOOD FIBERBOARD MATERIAL FOR THE 9975 SHIPPING PACKAGE

    SciTech Connect

    Daugherty, W.; Skidmore, E.; Dunn, K.

    2014-04-15

    Samples have been prepared from a 9975 lower fiberboard subassembly fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. Some softwood fiberboard properties tend to degrade faster in elevated humidity environments, while some cane fiberboard properties degrade faster in the hotter dry environments. As a result, it is premature to assume both materials will age at the same rates, and the preliminary aging models developed for cane fiberboard might not apply to softwood fiberboard. However, it is expected that both cane and softwood fiberboard assemblies will perform satisfactorily in conforming packages stored in a typical KAC storage environment for up to 15 years. Aging and testing of softwood fiberboard will continue and additional data will be collected. Additional samples will be added to each aging environment, to support development of an aging model specific to softwood fiberboard. Post-conditioning data have been measured on samples from a single softwood fiberboard assembly, and baseline data are also available from a limited number of vendor-provided samples. This provides minimal information on the possible sample-to-sample variation exhibited by softwood fiberboard. Data to date are generally consistent with the range seen in cane fiberboard, but some portions of the data trends are skewed toward the lower end of that range. Two additional softwood fiberboard source packages have been obtained and will begin to provide data on the range of variability of this material.

  8. Subretinal Hyper-Reflective Material in the Comparison of Age-related Macular Degeneration Treatments Trials

    PubMed Central

    Willoughby, Alex S.; Ying, Gui-shuang; Toth, Cynthia A.; Maguire, Maureen G.; Burns, Russell E.; Grunwald, Juan E.; Daniel, Ebenezer; Jaffe, Glenn J.

    2015-01-01

    Objective To evaluate the association of subretinal hyper-reflective material (SHRM) with visual acuity (VA), geographic atrophy (GA) and scar in the Comparison of Age related Macular Degeneration Treatments Trials (CATT) Design Prospective cohort study within a randomized clinical trial. Participants The 1185 participants in CATT. Methods Participants were randomly assigned to ranibizumab or bevacizumab treatment monthly or as-needed. Masked readers graded scar and GA on fundus photography and fluorescein angiography images, SHRM on time domain (TD) and spectral domain (SD) optical coherence tomography (OCT) throughout 104 weeks. Measurements of SHRM height and width in the fovea, within the center 1mm2, or outside the center 1mm2 were obtained on SD-OCT images at 56 (n=76) and 104 (n=66) weeks. VA was measured by certified examiners. Main Outcome Measures SHRM presence, location and size, and associations with VA, scar, and GA. Results Among all CATT participants, the percentage with SHRM at enrollment was 77%, decreasing to 68% at 4 weeks after treatment and 54% at 104 weeks. At 104 weeks, scar was present more often in eyes with persistent SHRM than eyes with SHRM that resolved (64% vs. 31%; p<0.0001). Among eyes with detailed evaluation of SHRM at weeks 56 (n=76) and 104 (n=66), mean [SE] VA letter score was 73.5 [2.8], 73.1 [3.4], 65.3 [3.5], and 63.9 [3.7] when SHRM was absent, present outside the central 1mm2, present within the central 1mm2 but not the foveal center, or present at the foveal center (p=0.02). SHRM was present at the foveal center in 43 (30%), within the central 1mm2 in 21 (15%) and outside the central 1mm2 in 19 (13%). When SHRM was present, the median maximum height in microns under the fovea, within the central 1 mm2 including the fovea and anywhere within the scan was 86; 120; and 122, respectively. VA was decreased with greater SHRM height and width (p<0.05). Conclusions SHRM is common in eyes with NVAMD and often persists after anti

  9. Research Approach for Aging and Evaluating Diesel Exhaust catalysts

    SciTech Connect

    Wayne, Scott

    2000-08-20

    To determine the impact of diesel fuel sulfur levels on emissions control devices that could lower emissions of oxides of nitrogen (NOX) and particulate matter (PM) from on-highway trucks and buses in the 2002-2004 model years. West Virginia University is evaluating: - Diesel Oxidation Catalysts - Lean NOX Catalysts

  10. 40Ar/39Ar age of material returned from asteroid 25143 Itokawa

    NASA Astrophysics Data System (ADS)

    Park, Jisun; Turrin, Brent D.; Herzog, Gregory F.; Lindsay, Fara N.; Delaney, Jeremy S.; Swisher, Carl C.; Uesugi, Masayuki; Karouji, Yuzuru; Yada, Toru; Abe, Masanao; Okada, Tatsuaki; Ishibashi, Yukihiro

    2015-11-01

    The Hayabusa mission to asteroid 25143, Itokawa, brought back 2000 small particles, which most closely resemble material found in LL4-6 chondrites. We report an 40Ar/39Ar age of 1.3 ± 0.3 Ga for a sample of Itokawa consisting of three grains with a total mass of ~2 μg. This age is lower than the >4.0 Ga ages measured for 75% of LL chondrites but close to one for Y-790964 and its pairs. The flat 40Ar/39Ar release spectrum of the sample suggests complete degassing 1.3 Ga ago. Recent solar heating in Itokawa's current orbit does not appear likely to have reset that age. Solar or impact heating 1.3 Ga ago could have done so. If impact heating was responsible, then the 1.3 Ga age sets an upper bound on the time at which the Itokawa rubble pile was assembled and suggests that rubble pile creation was an ongoing process in the inner solar system for at least the first 3 billion years of solar system history.

  11. Aging gauge

    DOEpatents

    Betts, Robert E.; Crawford, John F.

    1989-04-04

    An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment). Because of the relationship of doubling reaction rates for increases of 10.degree. C., equivalency of item used in accelerated aging evaluation can be obtained by referring to a calibration curve depicting storage temperature on the abscissa scale and multiplier on the ordinate scale.

  12. Aging gauge

    DOEpatents

    Betts, Robert E.; Crawford, John F.

    1989-01-01

    An aging gauge comprising a container having a fixed or a variable sized t opening with a cap which can be opened to control the sublimation rate of a thermally sublimational material contained within the container. In use, the aging gauge is stored with an item to determine total heat the item is subjected to and also the maximum temperature to which the item has been exposed. The aging gauge container contains a thermally sublimational material such as naphthalene or similar material which has a low sublimation rate over the temperature range from about 70.degree. F. to about 160.degree. F. The aging products determined by analyses of a like item aged along with the aging gauge for which the sublimation amount is determined is employed to establish a calibration curve for future aging evaluation. The aging gauge is provided with a means for determining the maximum temperature exposure (i.e., a thermally indicating material which gives an irreversible color change, Thermocolor pigment). Because of the relationship of doubling reaction rates for increases of 10.degree. C., equivalency of item used in accelerated aging evaluation can be obtained by referring to a calibration curve depicting storage temperature on the abscissa scale and multiplier on the ordinate scale.

  13. Gender bias in the evaluation of new age music.

    PubMed

    Colley, Ann; North, Adrian; Hargreaves, David J

    2003-04-01

    Eminent composers in Western European art music continue to be predominantly male and eminence in contemporary pop music is similarly male dominated. One contributing factor may be the continuing under-valuation of women's music. Possible anti-female bias in a contemporary genre was investigated using the Goldberg paradigm to elicit judgments of New Age compositions. Since stronger stereotyping effects occur when information provided about individuals is sparse, fictitious male and female composers were presented either by name only or by name with a brief biography. Evidence for anti-female bias was found in the name-only condition and was stronger when liking for the music was controlled. Other findings were the tendency for females to give higher ratings, and the association of gender differences in liking of the music with ratings of quality in the name-only condition. These results are relevant to the design of formal assessment procedures for musical composition. PMID:12778980

  14. Evaluating the Reliability of Three Different Dental Age Estimation Methods in Visakhapatnam Children

    PubMed Central

    Vabbalareddy, Raja Sekhar; V Vanga, Narasimha Rao

    2014-01-01

    ABSTRACT% Dental age is important for treatment planning in the specialities of pedodontics and orthodontics. Although, Demirjian's method was considered standard for dental age estimation, it may not be reliable for all population. Aim: The goal of the study was to evaluate the reliability of Demir-jian's, Haavikko's and Willems method of dental age estimation methods in Visakhapatnam (Andhra Pradesh, India) children. Study design: One hundred and two children of 6 to 14 years old who underwent panaromic digital radiography for routine diagnostic purposes were included. Dental age was calculated using Demirjian's, Haavikko's and Willems methods and compared with chronologic age for each patient. Results: Dental age showed a significant overestimation by Demirjian's method with a mean difference of 0.55 year and underestimation by Haavikko's and Willems methods with a mean difference of 1.95 and 0.20 year respectively when compared with chronologic age. The mean difference between dental age and chronologic age was not significant in Willems method which shows a close relation between dental and chronologic ages. Conclusion: The dental age estimation by Willems method is found to be more accurate than Demirjian's and Haavikko's methods in Visakhapatnam children. How to cite this article: Patnana AK, Vabbalareddy RS, Vanga NRV. Evaluating the Reliability of Three Different Dental Age Estimation Methods in Visakhapatnam Children. Int J Clin Pediatr Dent 2014;7(3):186-191. PMID:25709299

  15. STATUS REPORT FOR AGING STUDIES OF EPDM O-RING MATERIAL FOR THE H1616 SHIPPING PACKAGE

    SciTech Connect

    Stefek, T.; Daugherty, W.; Skidmore, E.

    2012-08-31

    This is an interim status report for tasks carried out per Task Technical Plan SRNL-STI-2011-00506. A series of tasks/experiments are being performed at the Savannah River National Laboratory to monitor the aging performance of ethylene propylene diene monomer (EPDM) Orings used in the H1616 shipping package. The data will support the technical basis to extend the annual maintenance of the EPDM O-rings in the H1616 shipping package and to predict the life of the seals at bounding service conditions. Current expectations are that the O-rings will maintain a seal at bounding normal temperatures in service (152 F) for at least 12 months. The baseline aging data review suggests that the EPDM O-rings are likely to retain significant mechanical properties and sealing force at bounding service temperatures to provide a service life of at least 2 years. At lower, more realistic temperatures, longer service life is likely. Parallel compression stress relaxation and vessel leak test efforts are in progress to further validate this assessment and quantify a more realistic service life prediction. The H1616 shipping package O-rings were evaluated for baseline property data as part of this test program. This was done to provide a basis for comparison of changes in material properties and performance parameters as a function of aging. This initial characterization was limited to physical and mechanical properties, namely hardness, thickness and tensile strength. These properties appear to be consistent with O-ring specifications. Three H1616-1 Containment Vessels were placed in test conditions and are aging at temperatures ranging from 160 to 300 F. The vessels were Helium leak-tested initially and have been tested at periodic intervals after cooling to room temperature to determine if they meet the criterion of leaktightness defined in ANSI standard N14.5-97 (< 1E-07 std cc air/sec at room temperature). To date, no leak test failures have occurred. The cumulative time at

  16. Availability of Nitrogen in Poultry litter: Influence of Bedding Material and Litter Age

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field experiments were conducted to evaluate the influence of bedding material on the availability of N in poultry to crop production. Experiments included two corn grain trials in which litter sources were applied at a rate of 125 lbs N acre-1 and inorganic fertilizer was applied at 0, 50, 100, 1...

  17. Emotional expressions preferentially elicit implicit evaluations of faces also varying in race or age.

    PubMed

    Craig, Belinda M; Lipp, Ottmar V; Mallan, Kimberley M

    2014-10-01

    Both facial cues of group membership (race, age, and sex) and emotional expressions can elicit implicit evaluations to guide subsequent social behavior. There is, however, little research addressing whether group membership cues or emotional expressions are more influential in the formation of implicit evaluations of faces when both cues are simultaneously present. The current study aimed to determine this. Emotional expressions but not race or age cues elicited implicit evaluations in a series of affective priming tasks with emotional Caucasian and African faces (Experiments 1 and 2) and young and old faces (Experiment 3). Spontaneous evaluations of group membership cues of race and age only occurred when those cues were task relevant, suggesting the preferential influence of emotional expressions in the formation of implicit evaluations of others when cues of race or age are not salient. Implications for implicit prejudice, face perception, and person construal are discussed. PMID:25046242

  18. Effect of material aging on parachute pack life: a synopsis of Sandia National Laboratories studies

    SciTech Connect

    Auerbach, I.; Mead, J.W.; Mead, K.E.; Ericksen, R.H.; Burns, F.B.; Renschler, C.L.

    1984-01-01

    A systematic study of the effects of environmental factors on nylon 66 and Kevlar 29 strength degradation in parachute components is being conducted at Sandia National Laboratories. It includes: (1) accelerated aging studies in air, inert environments, humidity, ozone, and smog; (2) a 25-year surveillance program of parachutes in a variety of natural climatic environments; (3) moisture absorption as a function of humidity; (4) effects of surface coatings normally applied to parachutes; and (5) development of nondestructive evaluation techniques which can be used to map mechanical properties over the entire parachute surface. The accelerated aging and moisture absorption studies show that air, humidity, and smog contribute to degradation. Chemiluminescence, gas chromatographic pyrograms, and uv spectroscopy show promise as nondestructive evaluation techniques.

  19. Ultrasound velocity test to decay evaluation on decorative stone after different artificial ageing treatments

    NASA Astrophysics Data System (ADS)

    Fioretti, Giovanna; Andriani, Gioacchino Francesco

    2016-04-01

    Ultrasound propagation velocity depends on several physical properties, for instance density, porosity and textural discontinuities within stones. These properties are strongly influenced by state of conservation of materials and their modification can be considered decay markers; therefore, ultrasound velocity measurement represents a non-destructive technique to evaluate the decay underway on employed stone. In this study, samples of the Avorio variety, an Apulian limestones, were processed to artificial ageing treatments, in particular thermal shocks, extreme thermal exposure at high temperatures between 200 and 600°C, and cycles of immersion of rock samples into saline solution alternating with drying phases in muffle furnace. Effects of induced deterioration were examined by comparing p-wave ultrasound velocity values, visual appearance and mass loss with water absorption values and capillarity test results. This research suggests first that the ultrasound velocity test can be considered a valuable non-invasive technique to assess the state of decay of decorative and building stones. Furthermore, in order to simulate dangerous and extreme environmental conditions and study their influence on the stone decay patterns, new considerations and suggestions about ageing test and procedures were proposed.

  20. Criteria for clinical translucency evaluation of direct esthetic restorative materials.

    PubMed

    Lee, Yong-Keun

    2016-08-01

    The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (ΔCR) of 0.07 could be transformed into ΔTP value of 2. Translucency differences between direct and indirect resin composites were perceivable (ΔTP > 2). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials. PMID:27508156

  1. Criteria for clinical translucency evaluation of direct esthetic restorative materials

    PubMed Central

    2016-01-01

    The purpose of this review was to suggest practical criteria for the clinical translucency evaluation of direct esthetic restorative materials, and to review the translucency with these criteria. For the evaluation of reported translucency values, measuring instrument and method, specimen thickness, background color, and illumination should be scrutinized. Translucency parameter (TP) of 15 to 19 could be regarded as the translucency of 1 mm thick human enamel. Visual perceptibility threshold for translucency difference in contrast ratio (ΔCR) of 0.07 could be transformed into ΔTP value of 2. Translucency differences between direct and indirect resin composites were perceivable (ΔTP > 2). Universal and corresponding flowable resin composites did not show perceivable translucency differences in most products. Translucency differed significantly by the product within each shade group, and by the shade group within each product. Translucency of human enamel and perceptibility threshold for translucency difference may be used as criteria for the clinical evaluation of translucency of esthetic restorative materials. PMID:27508156

  2. Age-Related Changes to the Neural Correlates of Social Evaluation

    PubMed Central

    Cassidy, Brittany S.; Shih, Joanne Y.; Gutchess, Angela H.

    2012-01-01

    Recent work suggests the existence of a specialized neural system underlying social processing that may be relatively spared with age, unlike pervasive aging-related decline occurring in many cognitive domains. We investigated how neural mechanisms underlying social evaluation are engaged with age, and how age-related changes to socioemotional goals affect recruitment of regions within this network. In a functional MRI study, fifteen young and fifteen older adults formed behavior-based impressions of individuals. They also responded to a prompt that was interpersonally meaningful, social but interpersonally irrelevant, or non-social. Both age groups engaged regions implicated in mentalizing and impression formation when making social relative to non-social evaluations, including dorsal and ventral medial prefrontal cortices, precuneus, and temporoparietal junction. Older adults had increased activation over young in right temporal pole when making social relative to non-social evaluations, suggesting reliance on past experiences when evaluating others. Young had greater activation than old in posterior cingulate gyrus when making interpersonally irrelevant, compared to interpersonally meaningful, evaluations, potentially reflecting enhanced valuation of this information. The findings demonstrate the age-related preservation of the neural correlates underlying social evaluation, and suggest that functioning in these regions might be mediated by age-related changes in socioemotional goals. PMID:22439896

  3. Systematic evaluation of neutron shielding effects for materials

    SciTech Connect

    Ueki, K.; Ohashi, A.; Nariyama, N.; Nagayama, S.; Fujita, T.; Hattori, K.; Anayama, Y.

    1996-11-01

    Three types of experiments with a {sup 252}Cf neutron source are proposed to evaluate systematically the neutron shielding effects of a material. The type 1 experiment deals with each shielding material alone, the type 2 experiment combines a shielding material and a structural material, and the type 3 experiment constructs the optimization with the materials used in the type 2 experiment. In the stainless steel (SS) + polyethylene shielding system, because of the location of the SS slabs at the source side, the tenth layer of the polyethylene becomes approximately one-half the value as when the polyethylene is employed alone. This is the enhancement effect of the SS. In the type 3 experiment, the total thickness of the SS + polyethylene shielding system is 40 cm, and the total thicknesses of the SS and the polyethylene slabs are fixed at 25 and 15 cm thick, respectively. The minimum total dose-equivalent rate (neutron + secondary gamma rays) is observed when the polyethylene slabs are located at a 20-cm depth from the source side, with an arrangement of 20-cm-thick SS + 15-cm-thick polyethylene + 5-cm-thick and SS, and with a ratio of the maximum to the minimum dose-equivalent rate of 2.5. The shielding optimization can be constructed by combining the materials having different shielding characteristics. The experimental results of the three types of experiments are reproduced fairly well by using the continuous-energy Monte Carlo code MCNP 4A with a next-event surface crossing estimator.

  4. The Development and Evaluation of Physical Science Curriculum Materials Designed to Improve the Attitudes of the Secondary School Slow Learner.

    ERIC Educational Resources Information Center

    Milson, James Lee

    The purpose of this study was to develop and evaluate physical science curriculum materials suitable for secondary school age slow learners. A unit on measuring heat and temperature was developed, using guidelines based on a study of the characteristics of students of below-average intelligence (I.Q. between 75 to 90) and reading ability at or…

  5. Evaluation of new stratospheric age tracers and SF6

    NASA Astrophysics Data System (ADS)

    Laube, J. C.; Gallacher, E.; Oram, D.; Boenisch, H.; Engel, A.; Fraser, P. J.; Röckmann, T.; Sturges, W. T.

    2015-12-01

    Sulphur hexafluoride (SF6) is a very long-lived, potent greenhouse gas. Its abundances continue to increase in the atmosphere. Due to its inert behaviour it has also been extensively used as a tracer of transport in the ocean, the troposphere and the stratosphere. We here combine long-term tropospheric records obtained from the Cape Grim Baseline station, Tasmania, with stratospheric data from high-altitude aircraft and balloon campaigns. We then assess the novel use of several alternative transport tracers (e.g. C2F6, C3F8 and HFC-23) in the stratosphere. The results indicate good suitability for some of these gases in terms of their inertness, tropospheric growth rates and measurement precisions. In addition we and compare the derived mean ages to those obtained from SF6 and find indications for the possibility of the existence of a stratospheric SF6 sink. The latter finding would also imply that the total atmospheric lifetime of SF6 is substantially shorter than previously believed, with further implications for its use as a transport tracer in the stratosphere.

  6. An evaluation of agreement between pectoral spines and otoliths for estimating ages of catfishes

    USGS Publications Warehouse

    Olive, J.A.; Schramm, Harold, Jr.; Gerard, Patrick D.; Irwin, E.

    2011-01-01

    Otoliths have been shown to provide more accurate ages than pectoral spine sections for several catfish populations; but sampling otoliths requires euthanizing the specimen, whereas spines can be sampled non-lethally. To evaluate whether, and under what conditions, spines provide the same or similar age estimates as otoliths, we examined data sets of individual fish aged from pectoral spines and otoliths for six blue catfish Ictalurus furcatus populations (n=420), 14 channel catfish Ictalurus punctatus populations (n=997), and 10 flathead catfish Pylodictus olivaris populations (n=947) from lotic and lentic waters throughout the central and eastern U.S. Logistic regression determined that agreement between ages estimated from otoliths and spines was consistently related to age, but inconsistently related to growth rate. When modeled at mean growth rate, we found at least 80% probability of no difference in spine- and otolith-assigned ages up to ages 4 and 5 for blue and channel catfish, respectively. For flathead catfish, an 80% probability of agreement between spine- and otolith-assigned ages did not occur at any age due to high incidence of differences in assigned ages even for age-1 fish. Logistic regression models predicted at least 80% probability that spine and otolith ages differed by ≤1 year up to ages 13, 16, and 9 for blue, channel, and flathead catfish, respectively. Age-bias assessment found mean spine-assigned age differed by less than 1 year from otolith-assigned age up to ages 19, 9, and 17 for blue catfish, channel catfish, and flathead catfish, respectively. These results can be used to help guide decisions about which structure is most appropriate for estimating catfish ages for particular populations and management objectives.

  7. Age related differences in mechanical demands imposed on the lower back by manual material handling tasks.

    PubMed

    Shojaei, Iman; Vazirian, Milad; Croft, Emily; Nussbaum, Maury A; Bazrgari, Babak

    2016-04-11

    The prevalence of low back pain (LBP) increases with age, yet the underlying mechanism(s) responsible for this remains unclear. To explore the role of biomechanical factors, we investigated age-related differences in lower-back biomechanics during sagittally-symmetric simulated manual material handling tasks. For each task, trunk kinematics and mechanical demand on the lower back were examined, from among 60 participants within five equal-sized and gender-balanced age groups spanning from 20 to 70 years old. The tasks involved lowering a 4.5kg load from an upright standing posture to both knee height and a fixed height and then lifting the load back to the initial upright posture. During these tasks, segmental body kinematics and ground reaction forces were collected using wireless inertial measurement units and a force platform. Overall, older participants completed the tasks with larger pelvic rotation and smaller lumbar flexion. Such adopted trunk kinematics resulted in larger peak shearing demand at the lower back in older vs. younger participants. These results suggest that older individuals may be at a higher risk for developing lower back pain when completing similar manual material handling tasks, consistent with epidemiological evidence for higher risks of occupational low back pain among this cohort. PMID:26556714

  8. Evaluation Of Shielding Efficacy Of A Ferrite Containing Ceramic Material

    SciTech Connect

    Verst, C.

    2015-10-12

    The shielding evaluation of the ferrite based Mitsuishi ceramic material has produced for several radiation sources and possible shielding sizes comparative dose attenuation measurements and simulated projections. High resolution gamma spectroscopy provided uncollided and scattered photon spectra at three energies, confirming theoretical estimates of the ceramic’s mass attenuation coefficient, μ/ρ. High level irradiation experiments were performed using Co-60, Cs-137, and Cf-252 sources to measure penetrating dose rates through steel, lead, concrete, and the provided ceramic slabs. The results were used to validate the radiation transport code MCNP6 which was then used to generate dose rate attenuation curves as a function of shielding material, thickness, and mass for photons and neutrons ranging in energy from 200 keV to 2 MeV.

  9. Quantitative Ultrasonic Evaluation of Mechanical Properties of Engineering Materials

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1978-01-01

    Progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength of engineering materials is reviewed. A dormant concept in nondestructive evaluation (NDE) is invoked. The availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions is discussed. It was shown that ultrasonic methods yield measurements of elastic moduli, microstructure, hardness, fracture toughness, tensile strength, yield strength, and shear strength for a wide range of materials (including many types of metals, ceramics, and fiber composites). It was also indicated that although most of these methods were shown feasible in laboratory studies, more work is needed before they can be used on actual parts in processing, assembly, inspection, and maintenance lines.

  10. Using ABAQUS Scripting Interface for Materials Evaluation and Life Prediction

    NASA Technical Reports Server (NTRS)

    Powers, Lynn M.; Arnold, Steven M.; Baranski, Andrzej

    2006-01-01

    An ABAQUS script has been written to aid in the evaluation of the mechanical behavior of viscoplastic materials. The purposes of the script are to: handle complex load histories; control load/displacement with alternate stopping criteria; predict failure and life; and verify constitutive models. Material models from the ABAQUS library may be used or the UMAT routine may specify mechanical behavior. User subroutines implemented include: UMAT for the constitutive model; UEXTERNALDB for file manipulation; DISP for boundary conditions; and URDFIL for results processing. Examples presented include load, strain and displacement control tests on a single element model. The tests are creep with a life limiting strain criterion, strain control with a stress limiting cycle and a complex interrupted cyclic relaxation test. The techniques implemented in this paper enable complex load conditions to be solved efficiently with ABAQUS.

  11. Hot piston ring/cylinder liner materials - Selection and evaluation

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.

    1988-01-01

    A materials testing program to determine whether automotive Stirling engine efficiency can be improved by locating 'hot piston rings' near the top of the pistons is described. Candidate materials were screened theoretically and experimentally by friction and wear tests. Based on the test results, a cobalt-based alloy, Stellite 6B, was chosen for the piston rings and PS200, which consists of a metal-bonded chromium carbide matrix with dispersed solid lubricants, was chosen as the cylinder coating. Tests of a modified engine and a baseline engine showed that the hot ring did reduce specific fuel consumption by up to 7 percent for some operating conditions and averaged about three percent for all conditions evaluated. Related applications of high-temperature coatings for shaft seals and as backup lubricants for gas bearings are also described.

  12. Post STS-133 Evaluation of Main Flame Deflector Witness Materials

    NASA Technical Reports Server (NTRS)

    Long, Victoria

    2011-01-01

    NASA and USA Structures engineers submitted main flame deflector witness materials for evaluation after the launch of STS-133. The following items were submitted for analysis: HY-80 steel witness rods, 304 stainless steel caps, tungsten pistons, 17-4 precipitation hardened (PH) stainless steel and A-286 piston sleeves, Medtherm Corporation calorimeters, and Nanmac Corporation thermocouples. All of the items were photographed in order to document their condition after the launch of STS-133, and before they were reinstalled at the launch pad for future launches. The HY -80 witness rods, 304 stainless steel caps, and the piston sleeves were dimensionally measured in order to determine the amount of material lost during launch. Microstructural changes were observed in the HY-80 witness rod and 304 stainless steel cap metallographic samples due to the heat of the launch.

  13. Aging of nuclear station diesel generators: Evaluation of operating and expert experience: Phase 1, Study

    SciTech Connect

    Hoopingarner, K.R.; Vause, J.W.; Dingee, D.A.; Nesbitt, J.F.

    1987-08-01

    Pacific Northwest Laboratory evaluated operational and expert experience pertaining to the aging degradation of diesel generators in nuclear service. The research, sponsored by the US Nuclear Regulatory Commission (NRC), identified and characterized the contribution of aging to emergency diesel generator failures. This report, Volume I, reviews diesel-generator experience to identify the systems and components most subject to aging degradation and isolates the major causes of failure that may affect future operational readiness. Evaluations show that as plants age, the percent of aging-related failures increases and failure modes change. A compilation is presented of recommended corrective actions for the failures identified. This study also includes a review of current, relevant industry programs, research, and standards. Volume II reports the results of an industry-wide workshop held on May 28 and 29, 1986 to discuss the technical issues associated with aging of nuclear service emergency diesel generators.

  14. Aging.

    PubMed

    Park, Dong Choon; Yeo, Seung Geun

    2013-09-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  15. Aging

    PubMed Central

    Park, Dong Choon

    2013-01-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  16. Investigating the Use of Ultrasound for Evaluating Aging Wiring Insulation

    NASA Technical Reports Server (NTRS)

    Madaras, Eric I.; Anastasi, Robert F.

    2001-01-01

    This paper reviews our initial efforts to investigate the use of ultrasound to evaluate wire insulation. Our initial model was a solid conductor with heat shrink tubing applied. In this model, various wave modes were identified. Subsequently, several aviation classes of wires (MIL-W- 81381, MIL-W-22759/34, and MIL-W-22759/87) were measured. The wires represented polyimide and ethylene-tetraflouroethylene insulations, and combinations of polyimide and flouropolymer plastics. Wire gages of 12, 16, and 20 AWG sizes were measured. Finally, samples of these wires were subjected to high temperatures for short periods of time to cause the insulation to degrade. Subsequent measurements indicated easily detectable changes.

  17. Material Evaluation Test Series 07, 08A, and 09A

    SciTech Connect

    Zalk, D; Ingram, C; Simmons, L; Arganbright, R; Koester, C; Lyle, J

    2006-04-11

    This research effort examines the post-detonation environmental, safety, health and operational aspects of experimental explosive tests with mercury. Specific experimental information is necessary for the evaluation of post-detonation by-products in comparison with those potentially resulting from mercury-bearing material accumulation in biomass accumulation areas, such as landfills, from batteries, electrical switches, thermometers, and fluorescent lights (Lindberg et al 2001). This will assist in determining appropriate abatement techniques for cleaning the work environment and environmental mitigation to determine waste stream components and risk assessment protocol. Determination of the by-products for personal protection equipment and personal exposure monitoring parameters are also part of this experimental work.

  18. All the things I have - handling one's material room in old age.

    PubMed

    Larsson Ranada, Asa; Hagberg, Jan-Erik

    2014-12-01

    The article explores how old people who live in their ordinary home, reason and act regarding their 'material room' (technical objects, such as household appliances, communication tools and things, such as furniture, personal belongings, gadgets, books, paintings, and memorabilia). The interest is in how they, as a consequence of their aging, look at acquiring new objects and phasing out older objects from the home. This is a broader approach than in most other studies of how old people relate to materiality in which attention is mostly paid either to adjustments to the physical environment or to the importance of personal possessions. In the latter cases, the focus is on downsizing processes (e.g. household disbandment or casser maison) in connection with a move to smaller accommodation or to a nursing home. The article is based on a study in which thirteen older people (median age 87), living in a Swedish town of medium size were interviewed (2012) for a third time. The questions concerned the need and desire for new objects, replacement of broken objects, sorting out the home or elsewhere, most cherished possessions, and the role of family members such as children and grandchildren. The results reveal the complexity of how one handles the material room. Most evident is the participants' reluctance to acquire new objects or even to replace broken things. Nearly all of them had considered, but few had started, a process of sorting out objects. These standpoints in combination resulted in a relatively intact material room, which was motivated by an ambition to simplify daily life or to facilitate the approaching dissolution of the home. Some objects of special value and other cherished objects materialized the connections between generations within a family. Some participants wanted to spare their children the burden of having to decide on what to do with their possessions. Others (mostly men), on the contrary, relied on their children to do the sorting out after

  19. Nuclear power plant cable materials : review of qualification and currently available aging data for margin assessments in cable performance.

    SciTech Connect

    Celina, Mathias Christopher; Gillen, Kenneth Todd; Lindgren, Eric Richard

    2013-05-01

    A selective literature review was conducted to assess whether currently available accelerated aging and original qualification data could be used to establish operational margins for the continued use of cable insulation and jacketing materials in nuclear power plant environments. The materials are subject to chemical and physical degradation under extended radiationthermal- oxidative conditions. Of particular interest were the circumstances under which existing aging data could be used to predict whether aged materials should pass loss of coolant accident (LOCA) performance requirements. Original LOCA qualification testing usually involved accelerated aging simulations of the 40-year expected ambient aging conditions followed by a LOCA simulation. The accelerated aging simulations were conducted under rapid accelerated aging conditions that did not account for many of the known limitations in accelerated polymer aging and therefore did not correctly simulate actual aging conditions. These highly accelerated aging conditions resulted in insulation materials with mostlyinert' aging processes as well as jacket materials where oxidative damage dropped quickly away from the air-exposed outside jacket surface. Therefore, for most LOCA performance predictions, testing appears to have relied upon heterogeneous aging behavior with oxidation often limited to the exterior of the cable cross-section - a situation which is not comparable with the nearly homogenous oxidative aging that will occur over decades under low dose rate and low temperature plant conditions. The historical aging conditions are therefore insufficient to determine with reasonable confidence the remaining operational margins for these materials. This does not necessarily imply that the existing 40-year-old materials would fail if LOCA conditions occurred, but rather that unambiguous statements about the current aging state and anticipated LOCA performance cannot be provided based on original

  20. An Evaluation of Graduates of a Toddlerhood Home Visiting Program at Kindergarten Age

    ERIC Educational Resources Information Center

    Allen, LaRue; Sethi, Anita; Astuto, Jennifer

    2007-01-01

    Overview: A recent evaluation of children who had participated in the Parent-Child Home Program (PCHP) as toddlers found that at kindergarten age, these children were performing at levels expected for their age, despite the fact that they had multiple factors putting them at risk for school failure. The Study: In the winter and spring of 2002, 135…

  1. Guidelines for the Evaluation of Dementia and Age-Related Cognitive Change

    ERIC Educational Resources Information Center

    American Psychologist, 2012

    2012-01-01

    Dementia in its many forms is a leading cause of functional limitation among older adults worldwide and will continue to ascend in global health importance as populations continue to age and effective cures remain elusive. The following guidelines were developed for psychologists who perform evaluations of dementia and age-related cognitive…

  2. The electrical performance of polymeric insulating materials under accelerated aging in a fog chamber

    SciTech Connect

    Gorur, R.S.; Cherney, E.A.; Hackam, R. ); Orbeck, T. )

    1988-07-01

    A comparative study of the ac (60 Hz) surface aging in a fog chamber is reported on cylindrical rod samples of high temperature vulcanized (HTV) silicone rubber and ethylene propylene diene monomer (EPDM) rubber containing various amounts of alumina trihydrate (ATH) and/or silica fillers. In low conductivity (250 ..mu..S/cm) fog, silicone rubber performed better than EPDM samples whereas in high conductivity (1000 ..mu..S/cm) fog, the order of performance was reversed. The mechanisms by which fillers impart tracking and erosion resistance to materials is discussed as influenced by the experimental conditions of the accelerated aging tests. Surface studies by ESCA (Electron Spectroscopy for Chemical Analysis) demonstrate that the hydrophobicity of silicone rubber, despite the accumulation of surface contamination, can be attributed to migration of low molecular weight polymer chains and/or mobile fluids, such as silicone oil.

  3. Quality framework proposal for Component Material Evaluation (CME) projects.

    SciTech Connect

    Christensen, Naomi G.; Arfman, John F.; Limary, Siviengxay

    2008-09-01

    This report proposes the first stage of a Quality Framework approach that can be used to evaluate and document Component Material Evaluation (CME) projects. The first stage of the Quality Framework defines two tools that will be used to evaluate a CME project. The first tool is used to decompose a CME project into its essential elements. These elements can then be evaluated for inherent quality by looking at the subelements that impact their level of quality maturity or rigor. Quality Readiness Levels (QRLs) are used to valuate project elements for inherent quality. The Framework provides guidance for the Principal Investigator (PI) and stakeholders for CME project prerequisites that help to ensure the proper level of confidence in the deliverable given its intended use. The Framework also Provides a roadmap that defined when and how the Framework tools should be applied. Use of these tools allow the Principal Investigator (PI) and stakeholders to understand what elements the project will use to execute the project, the inherent quality of the elements, which of those are critical to the project and why, and the risks associated to the project's elements.

  4. Evaluation of microelectrode materials for direct-current electrocorticography

    NASA Astrophysics Data System (ADS)

    Li, Chunyan; Narayan, Raj K.; Wu, Pei-Ming; Rajan, Neena; Wu, Zhizhen; Mehan, Neal; Golanov, Eugene V.; Ahn, Chong H.; Hartings, Jed A.

    2016-02-01

    Objective. Direct-current electrocorticography (DC-ECoG) allows a more complete characterization of brain states and pathologies than traditional alternating-current recordings (AC-ECoG). However, reliable recording of DC signals is challenging because of electrode polarization-induced potential drift, particularly at low frequencies and for more conducting materials. Further challenges arise as electrode size decreases, since impedance is increased and the potential drift is augmented. While microelectrodes have been investigated for AC-ECoG recordings, little work has addressed microelectrode properties for DC-signal recording. In this paper, we investigated several common microelectrode materials used in biomedical application for DC-ECoG. Approach. Five of the most common materials including gold (Au), silver/silver chloride (Ag/AgCl), platinum (Pt), Iridium oxide (IrOx), and platinum-iridium oxide (Pt/IrOx) were investigated for electrode diameters of 300 μm. The critical characteristics such as polarization impedance, AC current-induced polarization, long-term stability and low-frequency noise were studied in vitro (0.9% saline). The two most promising materials, Pt and Pt/lrOx were further investigated in vivo by recording waves of spreading depolarization, one of the most important applications for DC-ECoG in clinical and basic science research. Main results. Our experimental results indicate that IrOx-based microelectrodes, particularly with composite layers of nanostructures, are excellent in all of the common evaluation characteristics both in vitro and in vivo and are most suitable for multimodal monitoring applications. Pt electrodes suffer high current-induced polarization, but have acceptable long-term stability suitable for DC-ECoG. Major significance. The results of this study provide quantitative data on the electrical properties of microelectrodes with commonly-used materials and will be valuable for development of neural recordings inclusive of

  5. Evaluation and prediction of long-term environmental effects of nonmetallic materials

    NASA Technical Reports Server (NTRS)

    Papazian, H.

    1985-01-01

    The properties of a number of nonmetallic materials were evaluated experimentally in simulated space environments in order to develop models for accelerated test methods useful for predicting such behavioral changes. Graphite-epoxy composites were exposed to thermal cycling. Adhesive foam tapes were subjected to a vacuum environment. Metal-matrix composites were tested for baseline data. Predictive modeling designed to include strength and aging effects on composites, polymeric films, and metals under such space conditions (including the atomic oxygen environment) is discussed. The Korel 8031-00 high strength adhesive foam tape was shown to be superior to the other two tested.

  6. A novel facility for ageing materials with narrow-band ultraviolet radiation exposure

    SciTech Connect

    Kaerhae, Petri; Ruokolainen, Kimmo; Heikkilae, Anu

    2011-02-15

    A facility for exploring wavelength dependencies in ultraviolet (UV) radiation induced degradation in materials has been designed and constructed. The device is essentially a spectrograph separating light from a lamp to spectrally resolved UV radiation. It is based on a 1 kW xenon lamp and a flat-field concave holographic grating 10 cm in diameter. Radiation at the wavelength range 250-500 nm is dispersed onto the sample plane of 1.5 cm in height and 21 cm in width. The optical performance of the device has been characterized by radiometric measurements. Using the facility, test samples prepared of regular newspaper have been irradiated from 1 to 8 h. Color changes on the different locations of the aged samples have been quantified by color measurements. Yellowness indices computed from the color measurements demonstrate the capability of the facility in revealing wavelength dependencies of the material property changes in reasonable time frames.

  7. Bonding values of two contemporary ceramic inlay materials to dentin following simulated aging

    PubMed Central

    Khalil, Ashraf Abdelfattah

    2015-01-01

    PURPOSE To compare the push-out bond strength of feldspar and zirconia-based ceramic inlays bonded to dentin with different resin cements following simulated aging. MATERIALS AND METHODS Occlusal cavities in 80 extracted molars were restored in 2 groups (n=40) with CAD/CAM feldspar (Vitablocs Trilux forte) (FP) and zirconia-based (Ceramill Zi) (ZR) ceramic inlays. The fabricated inlays were luted in 2 subgroups (n=20) with either etch-and-bond (RelyX Ultimate Clicker) (EB) or self-adhesive (RelyX Unicem Aplicap) (SA) resin cement. Ten inlays in each subgroup were subjected to 3,500 thermal cycles and 24,000 loading cycles, while the other 10 served as control. Horizontal 3 mm thick specimens were cut out of the restored teeth for push out bond strength testing. Bond strength data were statistically analyzed using 1-way ANOVA and Tukey's comparisons at α=.05. The mode of ceramic-cement-dentin bond failure for each specimen was also assessed. RESULTS No statistically significant differences were noticed between FP and ZR bond strength to dentin in all subgroups (ANOVA, P=.05113). No differences were noticed between EB and SA (Tukey's, P>.05) bonded to either type of ceramics. Both adhesive and mixed modes of bond failure were dominant for non-aged inlays. Simulated aging had no significant effect on bond strength values (Tukey's, P>.05) of all ceramic-cement combinations although the adhesive mode of bond failure became more common (60-80%) in aged inlays. CONCLUSION The suggested cement-ceramic combinations offer comparable bonding performance to dentin substrate either before or after simulated aging that seems to have no adverse effect on the achieved bond. PMID:26816574

  8. Evaluation and design considerations of woven composite flywheel materials constructions

    SciTech Connect

    Sapowith, A.D.; Handy, W.E.; Gurson, A.L.; Lerner, G.R.

    1981-06-15

    Work performed from November 1979 to June 1981 on projects for evaluating the specific energy density capability of bidirectional woven flywheel materials and for developing design approaches for the optimization of those materials is reported. After demonstrating the basic geometry needed to construct a constant stress composite flywheel, a method of construction that can integrate radial and hoop fibers, control the relative stiffness in these two principal directions, and offer low cost in production is explained. Such a construction can be accomplished by weaving the radial fibers with the hoop fibers to form a cloth with a circular or spiral configuration. In this design, the warp fibers become the hoops and the pick fibers become the radials. The varying of radial stiffness is controlled by the choice of the pick pattern. In order to evaluate the circular weave, 0.2-in.-thick discs of approximately 20 in.-dia. were molded using S-glass weave and an epoxy matrix. Tensile specimens cut from the discs in both the radial and hoop directions were tested to failure. Further analyses and tests were performed to determine the optimum weave arrangement and the percent of fiber volume needed to optimize the specific material strength. These analyses show that there is a relatively wide range of pick to warp ratios which achieve optimum specific energy densities and that this range includes ratios that are relatively simple to fabricate. The tensile test data show that specific strengths of the fiberglass circular weave approximate 2.5 x 10/sup 6/ in. which results in energy densities at burst of 35 to 40 W-h/lb. A percent of active composite encompassed by the OD for the composite of 78% has been demonstrated. Fiberglass data suggest that the circular weave flywheel can operate over a life cycle equivalent to 10/sup 6/ deep cycles at the energy density level of 15 W-h/lb. (LCL)

  9. Evaluation of Solute Clusters Associated with Bake-Hardening Response in Isothermal Aged Al-Mg-Si Alloys Using a Three-Dimensional Atom Probe

    NASA Astrophysics Data System (ADS)

    Aruga, Yasuhiro; Kozuka, Masaya; Takaki, Yasuo; Sato, Tatsuo

    2014-12-01

    Temporal changes in the number density, size distribution, and chemical composition of clusters formed during natural aging at room temperature and pre-aging at 363 K (90 °C) in an Al-0.62Mg-0.93Si (mass pct) alloy were evaluated using atom probe tomography. More than 10 million atoms were examined in the cluster analysis, in which about 1000 clusters were obtained for each material after various aging treatments. The statistically proven records show that both number density and the average radius of clusters in pre-aged materials are larger than in naturally aged materials. It was revealed that the fraction of clusters with a low Mg/Si ratio after natural aging for a short time is higher than with other aging treatments, regardless of cluster size. This indicates that Si-rich clusters form more easily after short-period natural aging, and that Mg atoms can diffuse into the clusters or possibly form another type of Mg-Si cluster after prolonged natural aging. The formation of large clusters with a uniform Mg/Si ratio is encouraged by pre-aging. It can be concluded that an increase of small clusters with various Mg/Si ratios does not promote the bake-hardening (BH) response, whereas large clusters with a uniform Mg/Si ratio play an important role in hardening during the BH treatment at 443 K (170 °C).

  10. Evaluation of Solute Clusters Associated with Bake-Hardening Response in Isothermal Aged Al-Mg-Si Alloys Using a Three-Dimensional Atom Probe

    NASA Astrophysics Data System (ADS)

    Aruga, Yasuhiro; Kozuka, Masaya; Takaki, Yasuo; Sato, Tatsuo

    2014-09-01

    Temporal changes in the number density, size distribution, and chemical composition of clusters formed during natural aging at room temperature and pre-aging at 363 K (90 °C) in an Al-0.62Mg-0.93Si (mass pct) alloy were evaluated using atom probe tomography. More than 10 million atoms were examined in the cluster analysis, in which about 1000 clusters were obtained for each material after various aging treatments. The statistically proven records show that both number density and the average radius of clusters in pre-aged materials are larger than in naturally aged materials. It was revealed that the fraction of clusters with a low Mg/Si ratio after natural aging for a short time is higher than with other aging treatments, regardless of cluster size. This indicates that Si-rich clusters form more easily after short-period natural aging, and that Mg atoms can diffuse into the clusters or possibly form another type of Mg-Si cluster after prolonged natural aging. The formation of large clusters with a uniform Mg/Si ratio is encouraged by pre-aging. It can be concluded that an increase of small clusters with various Mg/Si ratios does not promote the bake-hardening (BH) response, whereas large clusters with a uniform Mg/Si ratio play an important role in hardening during the BH treatment at 443 K (170 °C).

  11. Production of Working Reference Materials for the Capability Evaluation Project

    SciTech Connect

    Phillip D. Noll, Jr.; Robert S. Marshall

    1999-03-01

    Nondestructive waste assay (NDA) methods are employed to determine the mass and activity of waste-entrained radionuclides as part of the National TRU (Trans-Uranic) Waste Characterization Program. In support of this program the Idaho National Engineering and Environmental Laboratory Mixed Waste Focus Area developed a plan to acquire capability/performance data on systems proposed for NDA purposes. The Capability Evaluation Project (CEP) was designed to evaluate the NDA systems of commercial contractors by subjecting all participants to identical tests involving 55 gallon drum surrogates containing known quantities and distributions of radioactive materials in the form of sealed-source standards, referred to as working reference materials (WRMs). Although numerous Pu WRMs already exist, the CEP WRM set allows for the evaluation of the capability and performance of systems with respect to waste types/configurations which contain increased amounts of {sup 241}Am relative to weapons grade Pu, waste that is dominantly {sup 241}Am, as well as wastes containing various proportions of depleted uranium. The CEP WRMs consist of a special mixture of PuO{sub 2}/AmO{sub 2} (IAP) and diatomaceous earth (DE) or depleted uranium (DU) oxide and DE and were fabricated at Los Alamos National Laboratory. The IAP WRMS are contained inside a pair of welded inner and outer stainless steel containers. The DU WRMs are singly contained within a stainless steel container equivalent to the outer container of the IAP standards. This report gives a general overview and discussion relating to the production and certification of the CEP WRMs.

  12. Thermostructural Analysis of Carbon Cloth Phenolic Material Tested at the Laser Hardened Material Evaluation Laboratory

    NASA Technical Reports Server (NTRS)

    Clayton, J. Louie; Ehle, Curt; Saxon, Jeff (Technical Monitor)

    2002-01-01

    RSRM nozzle liner components have been analyzed and tested to explore the occurrence of anomalous material performance known as pocketing erosion. Primary physical factors that contribute to pocketing seem to include the geometric permeability, which governs pore pressure magnitudes and hence load, and carbon fiber high temperature tensile strength, which defines a material limiting capability. The study reports on the results of a coupled thermostructural finite element analysis of Carbon Cloth Phenolic (CCP) material tested at the Laser Hardened Material Evaluation Laboratory (the LHMEL facility). Modeled test configurations will be limited to the special case of where temperature gradients are oriented perpendicular to the composite material ply angle. Analyses were conducted using a transient, one-dimensional flow/thermal finite element code that models pore pressure and temperature distributions and in an explicitly coupled formulation, passes this information to a 2-dimensional finite element structural model for determination of the stress/deformation behavior of the orthotropic fiber/matrix CCP. Pore pressures are generated by thermal decomposition of the phenolic resin which evolve as a multi-component gas phase which is partially trapped in the porous microstructure of the composite. The nature of resultant pressures are described by using the Darcy relationships which have been modified to permit a multi-specie mass and momentum balance including water vapor condensation. Solution to the conjugate flow/thermal equations were performed using the SINDA code. Of particular importance to this problem was the implementation of a char and deformation state dependent (geometric) permeability as describing a first order interaction between the flow/thermal and structural models. Material property models are used to characterize the solid phase mechanical stiffness and failure. Structural calculations were performed using the ABAQUS code. Iterations were made

  13. Materials Evaluation Test Series (METS) 04, 05, and 06

    SciTech Connect

    Zalk, D; Ingram, C; Simmons, L; Arganbright, R; Lyle, J; Wong, K

    2006-03-23

    The purpose of this work is to examine the environmental, safety, health and operational aspects of detonating a confined explosive test apparatus that has been designed to maximize the dynamics of impact on beryllium metal components for Contained Firing Facility (CFF) applications. A combination of experimental collection and evaluation methods were designed and implemented to provide an evaluation of immediately postdetonation by-products reflecting a potential worst-case scenario beryllium aerosolization explosive event. The collective Material Evaluation Test Series (METS) 04 - 06 provided explosive devices designed to scale for the dedicated METS firing tank that would provide a post-detonation internal environment comparable to the CFF. The experimental results provided appropriate information to develop operational parameters to be considered for conducting full-scale beryllium-containing experimental tests with similar designs within CFF and B801A. These operational procedures include the inclusion of chelating agents in pre-shot CFF cardboard containers with a minimum of 600 gallons content, an extended time period post-test before purging the CFF chamber, and an adaptation of approaches toward applications of the scrubber and HEPA systems during the post-shot sequence for an integrated environmental, safety, and health approach. In addition, re-entry and film retrieval procedures will be adapted, in line with abatement techniques for cleaning the chamber, that will be required for work inside a CFF that will contain an elevated concentration of spherical and highly aerosolizable beryllium particulate.

  14. Proficiency Testing for Evaluating Aerospace Materials Test Anomalies

    NASA Technical Reports Server (NTRS)

    Hirsch, D.; Motto, S.; Peyton, S.; Beeson, H.

    2006-01-01

    ASTM G 86 and ASTM G 74 are commonly used to evaluate materials susceptibility to ignition in liquid and gaseous oxygen systems. However, the methods have been known for their lack of repeatability. The inherent problems identified with the test logic would either not allow precise identification or the magnitude of problems related to running the tests, such as lack of consistency of systems performance, lack of adherence to procedures, etc. Excessive variability leads to increasing instances of accepting the null hypothesis erroneously, and so to the false logical deduction that problems are nonexistent when they really do exist. This paper attempts to develop and recommend an approach that could lead to increased accuracy in problem diagnostics by using the 50% reactivity point, which has been shown to be more repeatable. The initial tests conducted indicate that PTFE and Viton A (for pneumatic impact) and Buna S (for mechanical impact) would be good choices for additional testing and consideration for inter-laboratory evaluations. The approach presented could also be used to evaluate variable effects with increased confidence and tolerance optimization.

  15. Prevalence, Formation, Maintenance, and Evaluation of Interdisciplinary Student Aging Interest Groups

    ERIC Educational Resources Information Center

    Jones, Katherine J.; Vandenberg, Edward V.; Bottsford, Lisa

    2011-01-01

    The authors describe the prevalence, formation, maintenance, and evaluation of student aging interest groups. They conducted a cross-sectional electronic survey of the 46 academic medical centers funded by the Donald W. Reynolds Foundation. To evaluate their group of approximately 50 students, the authors conducted an electronic pretest and…

  16. Evaluation of Nontraditional Age Learners' Experiences in Internet-Based Clinical Social Work Courses

    ERIC Educational Resources Information Center

    Swanke, Jayme; Zeman, Laura Dreuth

    2015-01-01

    This study involves an evaluation of online learners' experiences with two Internet-based clinical social work courses. The evaluation sought to discover whether there were differences in learning between traditional (under 25 years old) and nontraditional age learners (25 years and over) who completed the asynchronous online course. The study…

  17. Computed tomography evaluation of the iliac crest apophysis: age estimation in living individuals.

    PubMed

    Ekizoglu, Oguzhan; Inci, Ercan; Erdil, Irem; Hocaoglu, Elif; Bilgili, Mustafa Gokhan; Kazimoglu, Cemal; Reisoglu, Ali; Can, Ismail Ozgur

    2016-07-01

    Determination of the ossification properties of the iliac apophysis is important not only in the clinical evaluation of patients undergoing orthopedic surgery but also in age estimation studies for forensic purposes. The literature includes both anthropological and radiological (conventional radiography, ultrasonography, and magnetic resonance imaging modalities) investigations of the different staging systems used for these purposes. In this study, we assessed the utility of computed tomography (CT) of the iliac crest apophysis in estimating forensic age. CT scans of the iliac crest apophysis of 380 patients (187 females, 193 males, and 10-29 years of age) were evaluated according to the four-stage system. Further subclassification did not give data properly due to the reference length measurement of the iliac wing with CT. Thus, in our series, stage 2 was first seen in 12 years of age and stage 3 in those 14 years of age in both sexes and on both sides of the pelvis. Stage 4 was first seen in 17 years of both sexes but only on the right side; on the left side, it appeared in females 18 years of age and in males 17 years of age. Present data was found consistent with previous pelvic radiographic findings. First seen ages for stage 2 and 3 are 12 and 14 years respectively which presented valuable information for legally important age thresholds. However, disadvantages of CT, including high-dose radiation exposure to gonads, the difficulty of evaluating the iliac crest, and the age boundary of 17 years, could make this method infeasible, as compared with hand wrist and pelvic radiographic methods. CT of the iliac crest has probably a greater utility where preexisting CT scans of the pelvic region are available, and it may be considered as a supportive method for age-estimation purposes. PMID:26914804

  18. Material Degradation during Isothermal Aging and Thermal Cycling of Hybrid Mica Seal with Ag Interlayer under SOFC Exposure Conditions

    SciTech Connect

    Chou, Y. S.; Stevenson, Jeffry W.; Hardy, John S.; Singh, Prabhakar

    2006-11-01

    Hybrid phlogopite mica seals with silver interlayers were evaluated in terms of materials degradation in a combined isothermal ageing and thermal cycling test. The hybrid mica seal was composed of a phlogopite mica paper sandwiched between two Ag foils. The hybrid micas were first aged at 800oC for ~1,000 hrs in a moist, dilute hydrogen fuel (~2.7% H2/bal. Ar + ~3% H2O), followed by short-term thermal cycling between ~100oC and 800oC. The combined test was repeated for 3 times for a total of 4,000 hrs ageing at 800oC and 119 thermal cycles. The results of high temperature leak rate tests showed very good thermal stability and thermal cycle stability with 800oC leak rates of ~0.02-0.03 sccm/cm. A hybrid mica seal tested in a high water content fuel (30 v% H2O/70 v% H2) demonstrated similar leakage during isothermal ageing and subsequent thermal cycles. Post-mortem analyses showed no extensive reaction between Ag and phlogopite mica as well as no significant mica degradation. Simple calculations to estimate the effect of measured leakage on the open circuit voltage and the total fuel loss for various SOFC stack sizes suggest very small fuel losses for the current hybrid mica seals, indicating that they are good candidates for SOFC sealing applications. Corresponding author: Yeong-Shyung Chou Tel: 509-375-2527, Fax: 509-375-2186, E-mail: yeong-shyung.chou@pnl.gov

  19. The ac and dc performance of polymeric insulating materials under accelerated aging in a fog chamber

    SciTech Connect

    Gorur, R.S. ); Cherney, E.A. ); Hackam, R. )

    1988-10-01

    The paper presents the results of the dc performance of polymeric insulating materials in a fog chamber. The materials evaluated in fog produced from low (250 ..mu..S/cm) and high (1000 ..mu..S/cm) conductivity water include cylindrical rod samples of high temperature vulcanized (HTV) silicone rubber and ethylene propylene diene monomer (EPDM) rubber containing various amounts of either alumina trihydrate (ATH) or silica fillers, or both. Comparison is made of material performance obtained with ac which was reported in an earlier study. In both low and high conductivity fog, the time to failure with ac and +dc was very similar, but a reduction by a factor of about four was observed in the time to failure with -dc. For both ac and dc, silicone rubber performed better than EPDM samples in low conductivity fog, while the order of performance was reversed in high conductivity fog. A theoretical model to determine the effect of dry band discharges on material is presented. Good agreement of the predicted behavior of materials with the experimental findings is shown.

  20. The impact of weathering and aging on a LIMB ash stockpile material

    SciTech Connect

    Beeghly, J.H.; Bigham, J.M.; Dick, W.A.; Stehouwer, R.C.; Wolfe, W.B.

    1995-03-01

    A 1,500 ton temporary storage pile of water conditioned LIMB (Lime Injected Multistage Burner) ash by-product from the Ohio Edison Edgewater plant Lorain, OH was constructed in July, 1991 at a coal company near New Philadelphia, Ohio. This stockpile was created for dry FGD by-product material to be held in reserve for a land application uses field demonstration. High volume, beneficial uses of dry FGD by-products, such as for mine reclamation and embankment stabilization, will require temporary stockpiling of the by-product. Purpose for constructing this pile was to study changes with time in the LIMB by-product material when exposed to weathering. This by-product material was studied over a 2 1/2 year period. The water to control fugitive dust was added in the ash conditioner at the power plant while being loaded into dump trucks. Amount of water normally added in the conditioning process is close to the optimum moisture content of 40--50 % (dry weight basis), to construct a compacted road embankment or road base. Four environmental operating permits required for construction of the storage pile were obtained, three from Ohio EPA (air, water and solid waste), and one from the Ohio Division of Reclamation (revised reclamation area permit). There was no significant environmental impacts from storm runoff or leachate water from the LIMB ash stockpile during the initial 18 month period through December, 1992. After 2 1/2 years of storage, the potential value of the LIMB material for use as a road embankment material or soil conditioner has declined significantly. Ettringite formation occurs. Aging allows the expansive reaction to take place before its potential use as compacted structural fill or embankment.

  1. Early-age characteristics of red mud-coal gangue cementitious material.

    PubMed

    Zhang, Na; Sun, Henghu; Liu, Xiaoming; Zhang, Jixiu

    2009-08-15

    This experimental research was to investigate the possibility of incorporating red mud and coal gangue as raw materials for the production of red mud-coal gangue cementitious material, abbreviated as RGC, including analyses of its chemical composition, physical properties, mechanical properties and hydration products. The red mud and coal gangue (at a ratio of 3:2) were mixed together and shaped in small spheres with a water to solid ratio of 0.30 and then calcined at 600 degrees C for 2h. Subsequently, the RGC was prepared by blending 50% the resultant red mud-coal gangue mixtures, 24% blast-furnace slag, 20% clinker and 6% gypsum. The hydration products of RGC were characterized by XRD, TG-DTA and SEM-EDS. The results showed that it is feasible to use red mud and coal gangue to replace up to 50% of the raw materials to produce cementitious material, which can be called as silica-alumina based cementitious material. The hydration products of RGC are mostly ettringite, calcium hydroxide and C-S-H gel. As the dominant products, C-S-H gel and ettringite are principally responsible for the strength development of RGC in early hydration process. The content of Ca(OH)(2) initially increased but later was depleted after reaching the peak value at 21 days. Moreover, it is found that the composition of the C-S-H gel shifted towards higher Si, Al and Na contents with the increase of hydration age, whereas that of Ca shifted towards lower content. PMID:19237241

  2. Microwave Nondestructive Evaluation of Dielectric Materials with a Metamaterial Lens

    NASA Technical Reports Server (NTRS)

    Shreiber, Daniel; Gupta, Mool; Cravey, Robin L.

    2008-01-01

    A novel microwave Nondestructive Evaluation (NDE) sensor was developed in an attempt to increase the sensitivity of the microwave NDE method for detection of defects small relative to a wavelength. The sensor was designed on the basis of a negative index material (NIM) lens. Characterization of the lens was performed to determine its resonant frequency, index of refraction, focus spot size, and optimal focusing length (for proper sample location). A sub-wavelength spot size (3 dB) of 0.48 lambda was obtained. The proof of concept for the sensor was achieved when a fiberglass sample with a 3 mm diameter through hole (perpendicular to the propagation direction of the wave) was tested. The hole was successfully detected with an 8.2 cm wavelength electromagnetic wave. This method is able to detect a defect that is 0.037 lambda. This method has certain advantages over other far field and near field microwave NDE methods currently in use.

  3. Generation and Evaluation of Lunar Dust Adhesion Mitigating Materials

    NASA Technical Reports Server (NTRS)

    Wohl, Christopher J.; Connell, John W.; Lin, Yi; Belcher, Marcus A.; Palmieri, Frank L.

    2011-01-01

    Particulate contamination is of concern in a variety of environments. This issue is especially important in confined spaces with highly controlled atmospheres such as space exploration vehicles involved in extraterrestrial surface missions. Lunar dust was a significant challenge for the Apollo astronauts and will be of greater concern for longer duration, future missions. Passive mitigation strategies, those not requiring external energy, may decrease some of these concerns, and have been investigated in this work. A myriad of approaches to modify the surface chemistry and topography of a variety of substrates was investigated. These involved generation of novel materials, photolithographic techniques, and other template approaches. Additionally, single particle and multiple particle methods to quantitatively evaluate the particle-substrate adhesion interactions were developed.

  4. Evaluation and significance of fracture toughness in ceramic materials

    SciTech Connect

    Mutoh, Y.

    1995-12-31

    Fracture toughness tests of several ceramic materials were carried out according to the various test methods, that is the Bridge indentation (BI, SEPB), Fatigue precrack (FP), Controlled surface flaw (CSF), Chevron notch (CN) and Indentation fracture (IF) methods. Mutual comparison of the test results was made to discuss the validity and applicability of each test method. Significance of the apparent fracture toughness with stable crack growth was discussed. The intrinsic fracture toughness can be obtained by the CSF method, in which a small surface crack is used. At high temperatures, since nonlinear deformation due to softening of glass phase and stable crack growth occur, nonlinear fracture mechanics approach should be applied. J{sub IC}-value is successfully evaluated according to the R-curve method.

  5. Evaluation of materials proposed for use in space flight

    NASA Technical Reports Server (NTRS)

    Duncan, W. C.

    1981-01-01

    The primary irritancy and allergenicity of flame resistant treated cotton knit shirts proposed for use in space flight were evaluated. The knitted shirts were supplied by NASA as follows: knitted shirts with collars were made of two-ply mercerized single-knit cotton jersey. The fabric was treated with tetrakis (hydroxymethyl) phosphonium hydroxide and subsequently cured with gaseous ammonia (THPOH/NH3). The final treatment comprised adding on diammonium phosphate (DAP)/urea. The treated fabric was process scoured to remove extraneous materials, top softened and mechanically or chemically finished as required for specific needs. Diammonium phosphate is a more efficient flame inhabitant than the phosphonium; thus, the combination treatment served to impart higher resistance to ignition and sustained combustion as required by NASA test standard.

  6. Evaluation of an electric field sensor for nondestructive material inspection

    NASA Astrophysics Data System (ADS)

    Kalyanasundaram, Kayatri; Arunachalam, Kavitha

    2013-01-01

    An electric field sensor is fabricated on a 125 micron thick flexible dielectric substrate for electromagnetic (EM) nondestructive material inspection at 915 MHz. The sensor consists of an electrically short dipole antenna and a radio frequency (RF) diode detector connected to a pair of high impedance screen printed carbon lines. The DC component of the rectified diode voltage conveyed across the high impedance lines is measured using a data acquisition circuit. Sensor measurements are validated with simulated data for a conformal patch antenna operating at 915 MHz. Sensor performance for EM nondestructive testing (NDT) is evaluated using phantom defects in low loss dielectric slabs. Preliminary results indicate sensor utility for EM NDT and support further testing on realistic defects.

  7. LABORATORY EVALUATION OF THE LOW TEMPERATURE CHARACTERISTICS OF FOUR PROTECTIVE CLOTHING MATERIALS

    EPA Science Inventory

    The objective of this study was to evaluate several low-temperature characteristics of Challenge 5100, a new protective clothing material developed by Chemical Fabrics Corporation. he low temperature characteristics of three other protective clothing materials were also evaluated...

  8. LABORATORY EVALUATION OF THE LOW TEMPERATURE CHARACTERISTICS OF FOUR PROTECTIVE CLOTHING MATERIALS

    EPA Science Inventory

    The objective of the study was to evaluate several low-temperature characteristics of Challenge 5100, a new protective clothing material developed by Chemical Fabrics Corporation. The low temperature characteristics of three other protective clothing materials were also evaluated...

  9. [Study on objectively evaluating skin aging according to areas of skin texture].

    PubMed

    Shan, Gaixin; Gan, Ping; He, Ling; Sun, Lu; Li, Qiannan; Jiang, Zheng; He, Xiangqian

    2015-02-01

    Skin aging principles play important roles in skin disease diagnosis, the evaluation of skin cosmetic effect, forensic identification and age identification in sports competition, etc. This paper proposes a new method to evaluate the skin aging objectively and quantitatively by skin texture area. Firstly, the enlarged skin image was acquired. Then, the skin texture image was segmented by using the iterative threshold method, and the skin ridge image was extracted according to the watershed algorithm. Finally, the skin ridge areas of the skin texture were extracted. The experiment data showed that the average areas of skin ridges, of both men and women, had a good correlation with age (the correlation coefficient r of male was 0.938, and the correlation coefficient r of female was 0.922), and skin texture area and age regression curve showed that the skin texture area increased with age. Therefore, it is effective to evaluate skin aging objectively by the new method presented in this paper. PMID:25997282

  10. Material Model Evaluation of a Composite Honeycomb Energy Absorber

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Annett, Martin S.; Fasanella, Edwin L.; Polanco, Michael A.

    2012-01-01

    A study was conducted to evaluate four different material models in predicting the dynamic crushing response of solid-element-based models of a composite honeycomb energy absorber, designated the Deployable Energy Absorber (DEA). Dynamic crush tests of three DEA components were simulated using the nonlinear, explicit transient dynamic code, LS-DYNA . In addition, a full-scale crash test of an MD-500 helicopter, retrofitted with DEA blocks, was simulated. The four material models used to represent the DEA included: *MAT_CRUSHABLE_FOAM (Mat 63), *MAT_HONEYCOMB (Mat 26), *MAT_SIMPLIFIED_RUBBER/FOAM (Mat 181), and *MAT_TRANSVERSELY_ANISOTROPIC_CRUSHABLE_FOAM (Mat 142). Test-analysis calibration metrics included simple percentage error comparisons of initial peak acceleration, sustained crush stress, and peak compaction acceleration of the DEA components. In addition, the Roadside Safety Verification and Validation Program (RSVVP) was used to assess similarities and differences between the experimental and analytical curves for the full-scale crash test.

  11. Hot piston ring/cylinder liner materials: Selection and evaluation

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.

    1988-01-01

    In current designs of the automotive (kinematic) Stirling engine, the piston rings are made of a reinforced polymer and are located below the pistons because they cannot withstand the high temperatures in the upper cylinder area. Theoretically, efficiency could be improved if hot piston rings were located near the top of the pistons. Described is a program to select piston ring and cylinder coating materials to test this theory. Candidate materials were screened, then subjected to a pin or disk friction and wear test machine. Tests were performed in hydrogen at specimen temperatures up to 760 C to simulate environmental conditions in the region of the hot piston ring reversal. Based on the results of these tests, a cobalt based alloy, Stellite 6B, was chosen for the piston rings and PS200, which consists of a metal-bonded chromium carbide matrix with dispersed solid lubricants, was chosen as the cylinder coating. Tests of a modified engine and a baseline engine showed that the hot ring reduced specific fuel consumption by up to 7 percent for some operating conditions and averaged about 3 percent for all conditions evaluated. Related applications of high-temperature coatings for shaft seals and as back-up lubricants are also described.

  12. Evaluation of translucency of monolithic zirconia and framework zirconia materials

    PubMed Central

    Tuncel, İlkin; Üşümez, Aslıhan

    2016-01-01

    PURPOSE The opacity of zirconia is an esthetic disadvantage that hinders achieving natural and shade-matched restorations. The aim of this study was to evaluate the translucency of non-colored and colored framework zirconia and monolithic zirconia. MATERIALS AND METHODS The three groups tested were: non-colored framework zirconia, colored framework zirconia with the A3 shade according to Vita Classic Scale, and monolithic zirconia (n=5). The specimens were fabricated in the dimensions of 15×12×0.5 mm. A spectrophotometer was used to measure the contrast ratio, which is indicative of translucency. Three measurements were made to obtain the contrast ratios of the materials over a white background (L*w) and a black background (L*b). The data were analyzed using the one-way analysis of variance and Tukey HSD tests. One specimen from each group was chosen for scanning electron microscope analysis. The determined areas of the SEM images were divided by the number of grains in order to calculate the mean grain size. RESULTS Statistically significant differences were observed among all groups (P<.05). Non-colored zirconia had the highest translucency with a contrast ratio of 0.75, while monolithic zirconia had the lowest translucency with a contrast ratio of 0.8. The mean grain sizes of the non-colored, colored, and monolithic zirconia were 233, 256, and 361 nm, respectively. CONCLUSION The translucency of the zirconia was affected by the coloring procedure and the grain size. Although monolithic zirconia may not be the best esthetic material for the anterior region, it may serve as an alternative in the posterior region for the bilayered zirconia restorations. PMID:27350851

  13. Pb-207/Pb-206 ages of individual mineral phases in Luna 20 material by ion microprobe mass analysis.

    NASA Technical Reports Server (NTRS)

    Andersen, C. A.; Hinthorne, J. R.

    1973-01-01

    Ion microprobe analyses of returned lunar material have helped to demonstrate that U, Th, and radiogenic Pb are concentrated in small accessory mineral phases. It is possible to measure the isotopic composition of this Pb and obtain a radiometric Pb-207/Pb-206 age for the mineral. The ages so derived compare favorably with crystallization ages determined by conventional methods. A grain mount (22003,2/6) of Luna 20 material was searched for such accessory mineral phases, and two were found. One of these phases give an age of 4.12 plus or minus 0.04 b.y. and the other an age of 4.42 plus or minus 0.11 b.y. Ages of minerals dated by the ion probe in Apollo samples 14310 and 15555 are given for comparison. Data on the upper limit for Pb concentration in the outermost surface layers of free lunar soil particles are also given.

  14. Evaluation of the Mental Healthiness Aging Initiative: community program to promote awareness about mental health and aging issues.

    PubMed

    Zanjani, Faika; Kruger, Tina; Murray, Deborah

    2012-04-01

    The objective of this study is to evaluate the Mental Healthiness Aging Initiative, designed to promote community awareness and knowledge about mental health and aging issues. This study occurred during 2007-2009 in 67 of 120 counties in Kentucky. A rural region (11 counties) received the intervention, consisting of focus groups, Extension Agent training, and television-based social marketing campaign. Partial-intervention counties (29 counties) received only the television-based social marketing campaign. The control counties (27 counties) received no intervention activities. Results indicated that the intervention counties agreed more with being able to assist elder adults with a potential mental illness. Also, the intervention counties understood the risk of consuming alcohol and medications better, but had a poorer recognition of drinking problems in elder adults. These findings need to be considered within study limitations, such as measurement error, degree of intervention exposure, and regional differences across intervention groups. The study demonstrates that community interventions on mental health awareness and knowledge are feasible within majority rural regions, with Extension Agents being gatekeepers, for promoting positive messages about mental health and aging issues. PMID:21234684

  15. Evaluation of Coatings and Materials for Future Radiators

    NASA Technical Reports Server (NTRS)

    Tuan, George C.; Westheimer, David T.; Birur, Gajanana C.; Beach, Duane E.; Jaworske, Donald A.; Peters, Wanda C.; Triolo, Jack J.

    2006-01-01

    Radiators are used to reject energy from space vehicles through radiant heat transfer. They are typically the largest component in a vehicle's thermal control system and can have a large impact on the vehicle design and operation. NASA s current vision for exploration dictates that radiators for a Crew Exploration Vehicle (CEV), a Lunar Surface Access Module (LSAM), and a lunar base will need to be developed. These applications present new challenges when compared to previous radiators on the Space Shuttle and International Space Station (ISS). In addition, many technological advances have been made that could positively impact future radiator design. This paper outlines new requirements for future radiators and documents a trade study performed to select the some promising technologies for further evaluation. The technologies include K1100 based carbon composites for the radiator surface as well as Optical Solar Reflectors (OSRs), a lithium based white paint, and electrochromic thin films for optical coatings. Coupons were made using these materials and tests were performed to characterize their performance. Testing included evaluating structural and thermal properties of the carbon composites, thermal cycling, launch pad weather simulation, and exposure to solar wind, and Ultraviolet (UV) radiation.

  16. Evaluation of stone durability using a combination of ultrasound, mechanical and accelerated aging tests

    NASA Astrophysics Data System (ADS)

    Molina, E.; Cultrone, G.; Sebastián, E.; Alonso, F. J.

    2013-06-01

    The durability of a rock when exposed to decay agents is an important criterion when assessing its quality as a building material. Our study focuses on six varieties of natural stone (two limestones, one dolostone, one travertine and two sandstones) that are widely used in both new and historical buildings. In order to assess their quality, we measured and characterized their dynamic elastic properties using ultrasounds, we measured their compressive strength using the uniaxial compression test and we evaluated their durability by means of accelerated aging tests (freeze-thaw and salt crystallization). In order to get a full picture of the decay suffered by the different stones, we determined the composition and amount of the clay fraction of the six stones. We also observed small fragments subjected to the salt crystallization test under an environmental scanning electron microscope to study any textural change and measured the changes of colour on the surface with a spectrophotometer. Finally, we analysed the pore system of the stones before and after their deterioration using mercury injection porosimetry. We then compared the results for the different stones and found that dolostone obtained the best results, while the two limestones proved to be the least durable and had the lowest compressive strength.

  17. Fundamental investigations related to the mitigation of volume changes in cement-based materials at early ages

    NASA Astrophysics Data System (ADS)

    Sant, Gaurav Niteen

    The increased use of high-performance, low water-to-cement (w/c) ratio concretes has led to increased occurrences of early-age shrinkage cracking in civil engineering structures. To reduce the magnitude of early-age shrinkage and the potential for cracking, mitigation strategies using shrinkage reducing admixtures (SRAs), saturated lightweight aggregates, expansive cements and extended moist curing durations in construction have been recommended. However, to appropriately utilize these strategies, it is important to have a complete understanding of the driving forces of early-age volume change and how these methods work from a materials perspective to reduce shrinkage. This dissertation uses a first-principles approach to understand the mechanism of shrinkage reducing admixtures (SRAs) to generate an expansion and mitigate shrinkage at early-ages, quantify the influence of a CaO-based expansive additive in reducing unrestrained shrinkage, residual stress development and the cracking potential at early-ages and quantify the influence of shrinkage reducing admixtures (SRAs) and cement hydration (pore structure refinement) on the reduction induced in the fluid transport properties of the material. The effects of shrinkage reducing admixtures (SRAs) are described in terms of inducing autogenous expansions in cement pastes at early ages. An evaluation comprising measurements of autogenous deformation, x-ray diffraction (Rietveld analysis), pore solution and thermogravimetric analysis and electron microscopy is performed to understand the chemical nature and physical effects of the expansion. Thermodynamic calculations performed on the measured liquid-phase compositions indicate the SRA produces elevated Portlandite super-saturations in the pore solution which results in crystallization stress driven expansions. The thermodynamic calculations are supported by deformation measurements performed on cement pastes mixed in solutions saturated with Portlandite or containing

  18. The Development of Experimentation and Evidence Evaluation Skills at Preschool Age

    NASA Astrophysics Data System (ADS)

    Piekny, Jeanette; Grube, Dietmar; Maehler, Claudia

    2014-01-01

    Researchers taking a domain-general approach to the development of scientific reasoning long thought that the ability to engage in scientific reasoning did not develop until adolescence. However, more recent studies have shown that preschool children already have a basic ability to evaluate evidence and a basic understanding of experimentation. Data providing insights into when exactly in the preschool years significant gains in these abilities occur are scarce. Drawing on a sample of 138 preschool children, this longitudinal study therefore examined how children's ability to evaluate evidence and their understanding of experimentation develop between the ages of four and six. Findings showed that the ability to evaluate evidence was already well developed at age four and increased steadily and significantly over time as long as the pattern of covariation was perfect. In the case of imperfect covariation, the proportion of correct answers was low over the period of observation, but showed a significant increase between the ages of four and five. If the data did not allow relationship between variables to be inferred, the proportion of correct answers was low, with a significant increase between the ages of five and six. The children's understanding of experimentation increased significantly between the ages of five and six. The implications of these findings for age-appropriate science programs in preschool are discussed.

  19. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  20. Aging of nuclear station diesel generators: Evaluation of operating and expert experience: Workshop

    SciTech Connect

    Hoopingarner, K.R.; Vause, J.W.

    1987-08-01

    Pacific Northwest Laboratory (PNL) evaluated operational and expert experience pertaining to the aging degradation of diesel generators in nuclear service. The research, sponsored by the US Nuclear Regulatory Commission (NRC), identified and characterized the contribution of aging to emergency diesel generator failures. This report, Volume II, reports the results of an industry-wide workshop held on May 28 and 29, 1986, to discuss the technical issues associated with aging of nuclear service emergency diesel generators. The technical issues discussed most extensively were: man/machine interfaces, component interfaces, thermal gradients of startup and cooldown and the need for an accurate industry database for trend analysis of the diesel generator system.

  1. Evaluation of third molar development in the estimation of chronological age.

    PubMed

    Soares, Caio Belém Rodrigues Barros; Figueiroa, José Natal; Dantas, Renata Moura Xavier; Kurita, Lúcio Mitsuo; Pontual, Andréa dos Anjos; Ramos-Perez, Flávia Maria de Moraes; Perez, Danyel Elias da Cruz; Pontual, Maria Luiza dos Anjos

    2015-09-01

    The purpose of this study was to evaluate the correlation between chronological age and the degree of third molar mineralization by Demirjian's developmental stages (Demirjian et al., 1973) using panoramic radiography. From a total of 11.396 digital panoramic radiographs of patients from three oral radiology private clinics from the northeast region of Brazil, obtained from January to June 2009, 2097 radiographic images from patients aged between 6 and 22 years were selected. The images were analyzed individually by two obsevers using a 21-inch computer screen and Windows Picture and Fax Viewer. Reliability was achieved by intra- and interobserver evaluation, using the Kappa test. Chronological age, calcification stage, gender and third molar were interrelated using a multiple linear regression model, considering age as a response variable. There was reliability with Demirjian et al.'s developmental stage assesment, displaying a significant relationship between mineralization stages and patients' age (P<0.05). There was no significant difference between the average age and the calcification stage taking gender and localization of the third molar into consideration. It is possible to estimate chronological age based on Demirjian's stage of a third molar, regardless of gender and location. PMID:26164359

  2. Age-related changes in skin barrier function - quantitative evaluation of 150 female subjects.

    PubMed

    Luebberding, S; Krueger, N; Kerscher, M

    2013-04-01

    The protection against water loss and the prevention of substances and bacteria penetrating into the body rank as the most important functions of the skin. This so-called 'skin barrier function' is the natural frontier between the inner organism and the environment, and is primarily formed by the epidermis. An impairment of the skin barrier function is often found in diseased and damaged skin. An influence of ageing on skin barrier function is widely accepted, but has not been conclusively evaluated yet. Therefore, the aim of this clinical study was to assess the potential influence of ageing on skin barrier function, including transepidermal water loss (TEWL), stratum corneum hydration, sebum content and pH value. One hundred and fifty healthy women aged 18-80, divided into five age groups with 30 subjects each, were evaluated in this study. TEWL, hydration level, sebum secretion and pH value of hydro-lipid acid film were measured with worldwide acknowledged biophysical measuring methods at cheek, neck, décolleté, volar forearm and dorsum of hand. Whereas TEWL and stratum corneum hydration showed only very low correlation with subject's age, the sebum production decreased significantly with age, resulting in the lowest skin surface lipids levels measured in subjects older than 70 years. The highest skin surface pH was measured in subjects between 50 and 60 years, whereas the eldest age group had the lowest mean pH. The dorsum of the hand was the location with the highest TEWL and lowest stratum corneum hydration in all age groups. The results show that only some parameters related to skin barrier function are influenced by ageing. Whereas sebum production decreases significantly over lifetime and skin surface pH is significantly increased in menopausal woman, TEWL and stratum corneum hydration show only minor variations with ageing. PMID:23113564

  3. The Impact of Experienced Emotion on Evaluative Judgments: The Effects of Age and Emotion Regulation Style

    PubMed Central

    Hess, Thomas M.; Beale, Karen S.; Miles, Amanda

    2012-01-01

    Adults aged from 24 to 79 were exposed to four commercial advertisements within the context of television programs designed to induce either a positive or negative mood. Although age was associated with memory for the content of the commercials, it did not moderate the impact of mood on evaluations of the advertized products. Instead, participants who reported engaging in expressive suppression as a common emotion regulation strategy were more likely to make evaluations that were biased by moods than those individuals who reported low use of this strategy. The results suggest that the maintenance of emotion regulation ability in later adulthood may help people control certain affective influences on thought. PMID:20694860

  4. Health Physics Code System for Evaluating Accidents Involving Radioactive Materials.

    Energy Science and Technology Software Center (ESTSC)

    2014-10-01

    Version 03 The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculational tool for evaluating accidents involving radioactive materials. HOTSPOT codes provide a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. The developer's website is: http://www.llnl.gov/nhi/hotspot/. Four general programs, PLUME, EXPLOSION, FIRE, and RESUSPENSION, calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosivemore » release, fuel fire, or an area contamination event. Additional programs deal specifically with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. The FIDLER program can calibrate radiation survey instruments for ground survey measurements and initial screening of personnel for possible plutonium uptake in the lung. The HOTSPOT codes are fast, portable, easy to use, and fully documented in electronic help files. HOTSPOT supports color high resolution monitors and printers for concentration plots and contours. The codes have been extensively used by the DOS community since 1985. Tables and graphical output can be directed to the computer screen, printer, or a disk file. The graphical output consists of dose and ground contamination as a function of plume centerline downwind distance, and radiation dose and ground contamination contours. Users have the option of displaying scenario text on the plots. HOTSPOT 3.0.1 fixes three significant Windows 7 issues: � Executable installed properly under "Program Files/HotSpot 3.0". Installation package now smaller: removed dependency on older Windows DLL files which previously needed to \\ � Forms now properly scale based on DPI instead of font for users who change their screen resolution to something other than 100%. This is a more common feature in Windows 7

  5. Health Physics Code System for Evaluating Accidents Involving Radioactive Materials.

    SciTech Connect

    2014-10-01

    Version 03 The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculational tool for evaluating accidents involving radioactive materials. HOTSPOT codes provide a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. The developer's website is: http://www.llnl.gov/nhi/hotspot/. Four general programs, PLUME, EXPLOSION, FIRE, and RESUSPENSION, calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Additional programs deal specifically with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. The FIDLER program can calibrate radiation survey instruments for ground survey measurements and initial screening of personnel for possible plutonium uptake in the lung. The HOTSPOT codes are fast, portable, easy to use, and fully documented in electronic help files. HOTSPOT supports color high resolution monitors and printers for concentration plots and contours. The codes have been extensively used by the DOS community since 1985. Tables and graphical output can be directed to the computer screen, printer, or a disk file. The graphical output consists of dose and ground contamination as a function of plume centerline downwind distance, and radiation dose and ground contamination contours. Users have the option of displaying scenario text on the plots. HOTSPOT 3.0.1 fixes three significant Windows 7 issues: � Executable installed properly under "Program Files/HotSpot 3.0". Installation package now smaller: removed dependency on older Windows DLL files which previously needed to \\ � Forms now properly scale based on DPI instead of font for users who change their screen resolution to something other than 100%. This is a more common feature in Windows 7.

  6. Difference in radiocarbon ages of carbonized material from the inner and outer surfaces of pottery from a wetland archaeological site

    PubMed Central

    MIYATA, Yoshiki; MINAMI, Masayo; ONBE, Shin; SAKAMOTO, Minoru; MATSUZAKI, Hiroyuki; NAKAMURA, Toshio; IMAMURA, Mineo

    2011-01-01

    AMS (Accelerator Mass Spectrometry) radiocarbon dates for eight potsherds from a single piece of pottery from a wetland archaeological site indicated that charred material from the inner pottery surfaces (5052 ± 12 BP; N = 5) is about 90 14C years older than that from the outer surfaces (4961 ± 22 BP; N = 7). We considered three possible causes of this difference: the old wood effect, reservoir effects, and diagenesis. We concluded that differences in the radiocarbon ages between materials from the inner and outer surfaces of the same pot were caused either by the freshwater reservoir effect or by diagenesis. Moreover, we found that the radiocarbon ages of carbonized material on outer surfaces (soot) of pottery from other wetland archaeological sites were the same as the ages of material on inner surfaces (charred food) of the same pot within error, suggesting absence of freshwater reservoir effect or diagenesis. PMID:21986315

  7. Difference in radiocarbon ages of carbonized material from the inner and outer surfaces of pottery from a wetland archaeological site.

    PubMed

    Miyata, Yoshiki; Minami, Masayo; Onbe, Shin; Sakamoto, Minoru; Matsuzaki, Hiroyuki; Nakamura, Toshio; Imamura, Mineo

    2011-01-01

    AMS (Accelerator Mass Spectrometry) radiocarbon dates for eight potsherds from a single piece of pottery from a wetland archaeological site indicated that charred material from the inner pottery surfaces (5052 ± 12 BP; N = 5) is about 90 (14)C years older than that from the outer surfaces (4961 ± 22 BP; N = 7). We considered three possible causes of this difference: the old wood effect, reservoir effects, and diagenesis. We concluded that differences in the radiocarbon ages between materials from the inner and outer surfaces of the same pot were caused either by the freshwater reservoir effect or by diagenesis. Moreover, we found that the radiocarbon ages of carbonized material on outer surfaces (soot) of pottery from other wetland archaeological sites were the same as the ages of material on inner surfaces (charred food) of the same pot within error, suggesting absence of freshwater reservoir effect or diagenesis. PMID:21986315

  8. Development and Evaluation of Patient Education Materials for Elderly Lung Cancer Patients.

    PubMed

    Jewitt, Natalie; Hope, Andrew J; Milne, Robin; Le, Lisa W; Papadakos, Janet; Abdelmutti, Nazek; Catton, Pamela; Giuliani, Meredith E

    2016-03-01

    Patients treated for lung cancer are often elderly presenting a unique challenge for developing patient education materials. This study developed and evaluated a patient education pamphlet on lung stereotactic body radiotherapy (SBRT) designed specifically for an elderly population. The SBRT pamphlet was developed using a participatory design involving a convenience sample of patients. This prospective study assessed patient's opinions of pamphlet effectiveness through self-report questionnaires. The pamphlet was deemed "effective" if patients rated 16/18 evaluation statements as "strongly agree" or "agree." Demographic data and health literacy (Rapid Estimate of Adult Literacy in Medicine short-form (REALM-SF)) were also assessed. Patient opinion of pamphlet "effectiveness" was compared between patients with REALM-SF scores of 7 versus <7 using Fisher's exact test. The overall EQ-5D-5L score was compared for patients who did and did not find the pamphlet effective using the Wilcoxon-Mann-Whitney test. Thirty-seven patients participated. The median age was 76 years (range 56-93) and 22 patients (59 %) had ≤high school education. Most patients preferred to have verbal (65 %) or written (78 %) educational materials as opposed to online information or educational classes. Thirty-two patients (86 %) rated the pamphlet as effective. The proportion of patients who found the pamphlet effective was 85.7 versus 86.7 % (p = 1.00) in those with REALM 7 versus <7. The mean EQ-5D score was 67.5 (SD 19.1) versus 71.8 (SD 8.7) (p = 0.84) in those who found the pamphlet effective versus not. Participatory design is an effective method for developing education materials for challenging patient groups such as elderly patients. Despite advanced age and comorbidity, this patient group had adequate health literacy. PMID:25572462

  9. Evaluation of Aged Garlic Extract Neuroprotective Effect in a Focal Model of Cerebral Ischemia

    NASA Astrophysics Data System (ADS)

    Aguilera, Penélope; Maldonado, Perla D.; Ortiz-Plata, Alma; Barrera, Diana; Chánez-Cárdenas, María Elena

    2008-02-01

    The oxidant species generated in cerebral ischemia have been implicated as important mediators of neuronal injury through damage to lipids, DNA, and proteins. Since ischemia as well as reperfusion insults generate oxidative stress, the administration of antioxidants may limit oxidative damage and ameliorate disease progression. The present work shows the transitory neuroprotective effect of the aged garlic extract (AGE) administration (a proposed antioxidant compound) in a middle cerebral artery occlusion (MCAO) model in rats and established its therapeutic window. To determine the optimal time of administration, animal received AGE (1.2 mL/kg) intraperitoneally 30 min before onset of reperfusion (-0.5 R), at the beginning of reperfusion (0R), or 1 h after onset of reperfusion (1R). Additional doses were administrated after 1, 2, or 3 h after onset of reperfusion. To establish the therapeutic window of AGE, the infarct area was determined for each treatment after different times of reperfusion. Results show that the administration of AGE at the onset of reperfusion reduced the infarct area by 70% (evaluated after 2 h reperfusion). The therapeutic window of AGE was determined. Repeated doses did not extend the temporal window of protection. A significant reduction in the nitrotyrosine level was observed in the brain tissue subjected to MCAO after AGE treatment at the onset of reperfusion. Data in the present work show that AGE exerts a transitory neuroprotective effect in response to ischemia/reperfusion-induced neuronal injury.

  10. Evaluation of combined effects of ageing period and freezing rate on quality attributes of beef loins.

    PubMed

    Kim, Yuan H Brad; Liesse, Charlotte; Kemp, Robert; Balan, Prabhu

    2015-12-01

    The objective of our study was to evaluate the combined effects of ageing period and different freezing rates on meat quality attributes of beef loins. Pairs of loins (M. longissimus at 1 day post mortem) from 12 carcasses were divided into four equal portions and randomly assigned to four ageing/freezing treatments (aged only, frozen only, and 3 or 4 weeks ageing at -1.5°C then frozen). Two freezing methods (fast freezing by calcium chloride immersion or slow freezing by air freezer at -18°C) were applied to the loin sections. Fast freezing had no effect on shear force (P>0.05), but significantly improved the water-holding capacity of the aged/frozen loins by reducing purge and drip losses. Ageing-then-freezing significantly improved shear force values of loins compared to both the aged only and frozen only loins. These observations suggest that fast freezing will add more value to the aged/frozen/thawed meat by minimising the amount of water-loss due to the freezing/thawing process. PMID:26172242

  11. Re-Evaluating Neonatal-Age Models for Ungulates: Does Model Choice Affect Survival Estimates?

    PubMed Central

    Grovenburg, Troy W.; Monteith, Kevin L.; Jacques, Christopher N.; Klaver, Robert W.; DePerno, Christopher S.; Brinkman, Todd J.; Monteith, Kyle B.; Gilbert, Sophie L.; Smith, Joshua B.; Bleich, Vernon C.; Swanson, Christopher C.; Jenks, Jonathan A.

    2014-01-01

    New-hoof growth is regarded as the most reliable metric for predicting age of newborn ungulates, but variation in estimated age among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry models. We used known-age newborns to evaluate variation in age estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001–2009, we captured and radiocollared 174 newborn (≤24-hrs old) ungulates: 76 white-tailed deer (Odocoileus virginianus) in Minnesota and South Dakota, 61 mule deer (O. hemionus) in California, and 37 pronghorn (Antilocapra americana) in South Dakota. Estimated age of known-age newborns differed among hoof-growth models and varied by >15 days for white-tailed deer, >20 days for mule deer, and >10 days for pronghorn. Accuracy (i.e., the proportion of neonates assigned to the correct age) in aging newborns using published equations ranged from 0.0% to 39.4% in white-tailed deer, 0.0% to 3.3% in mule deer, and was 0.0% for pronghorns. Results of survival modeling indicated that variability in estimates of age-at-capture affected short-term estimates of survival (i.e., 30 days) for white-tailed deer and mule deer, and survival estimates over a longer time frame (i.e., 120 days) for mule deer. Conversely, survival estimates for pronghorn were not affected by estimates of age. Our analyses indicate that modeling survival in daily intervals is too fine a temporal scale when age-at-capture is unknown given the potential inaccuracies among equations used to estimate age of neonates. Instead, weekly survival intervals are more appropriate because most models accurately predicted ages within 1 week of the known age. Variation among results of neonatal-age models on short- and long-term estimates of survival for known-age young emphasizes the importance of selecting an appropriate hoof-growth equation and appropriately defining intervals (i.e., weekly

  12. Re-evaluating neonatal-age models for ungulates: Does model choice affect survival estimates?

    USGS Publications Warehouse

    Grovenburg, Troy W.; Monteith, Kevin L.; Jacques, Christopher N.; Klaver, Robert W.; DePerno, Christopher S.; Brinkman, Todd J.; Monteith, Kyle B.; Gilbert, Sophie L.; Smith, Joshua B.; Bleich, Vernon C.; Swanson, Christopher C.; Jenks, Jonathan A.

    2014-01-01

    New-hoof growth is regarded as the most reliable metric for predicting age of newborn ungulates, but variation in estimated age among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry models. We used known-age newborns to evaluate variation in age estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001–2009, we captured and radiocollared 174 newborn (≤24-hrs old) ungulates: 76 white-tailed deer (Odocoileus virginianus) in Minnesota and South Dakota, 61 mule deer (O. hemionus) in California, and 37 pronghorn (Antilocapra americana) in South Dakota. Estimated age of known-age newborns differed among hoof-growth models and varied by >15 days for white-tailed deer, >20 days for mule deer, and >10 days for pronghorn. Accuracy (i.e., the proportion of neonates assigned to the correct age) in aging newborns using published equations ranged from 0.0% to 39.4% in white-tailed deer, 0.0% to 3.3% in mule deer, and was 0.0% for pronghorns. Results of survival modeling indicated that variability in estimates of age-at-capture affected short-term estimates of survival (i.e., 30 days) for white-tailed deer and mule deer, and survival estimates over a longer time frame (i.e., 120 days) for mule deer. Conversely, survival estimates for pronghorn were not affected by estimates of age. Our analyses indicate that modeling survival in daily intervals is too fine a temporal scale when age-at-capture is unknown given the potential inaccuracies among equations used to estimate age of neonates. Instead, weekly survival intervals are more appropriate because most models accurately predicted ages within 1 week of the known age. Variation among results of neonatal-age models on short- and long-term estimates of survival for known-age young emphasizes the importance of selecting an appropriate hoof-growth equation and appropriately defining intervals (i.e., weekly

  13. Evaluation of simulated cross-formational travel times using water age measurements in layered aquifer systems

    NASA Astrophysics Data System (ADS)

    Papafotiou, Alexandros; Ewing, John; Deeds, Neil; Kreitler, Charlie

    2013-04-01

    The recent hydrologic droughts in the southwestern USA have brought forward the necessity for sustainable management of groundwater that was recharged several thousands of years ago, also known as fossil water, as this resource is not directly rechargeable even through heavy rain events. Groundwater age studies can enable water authorities to map the origins of groundwater, quantify water ages in aquifers and plan sustainable water resource policies on local and regional scales. In this study, numerical groundwater availability models (GAMs) are combined with water age measurements to perform a water age analysis of the Wilcox, Carrizo, Queen City, Sparta, Jackson and Yegua aquifers that span central Texas dipping toward the coast of the Gulf of Mexico. The 3D GAMs have initially been calibrated using well data. The water age analysis is carried out using 2D simulations to characterize down dip flow, cross-formational flow in the aquifers and the impact on associated water ages in representative transects extracted from the 3D models, including a discussion on bridging the gap between the 3D hydrogeological system and its simplified 2D representations. A systematic quantification of water age sensitivity to formation hydraulic conductivities and recharge at the aquifer outcrops is performed, whereby travel times in the simulated aquifers are compared to water age measurements obtained from C-14 and Tritium age dating techniques. The analysis therefore delivers the spectrum of water age isolines under consideration of model parameter uncertainty, evaluating the predictive ability of cross-formational water age studies when using 2D transect models.

  14. Reproducibility of polycarbonate reference material in toxicity evaluation

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, P. A.

    1981-01-01

    A specific lot of bisphenol A polycarbonate has been used for almost four years as the reference material for the NASA-USF-PSC toxicity screening test method. The reproducibility of the test results over this period of time indicate that certain plastics may be more suitable reference materials than the more traditional cellulosic materials.

  15. Mentoring Australian Emerging Researchers in Aging: Evaluation of a Pilot Mentoring Scheme

    ERIC Educational Resources Information Center

    Henwood, Tim; Bartlett, Helen; Carroll, Matthew

    2011-01-01

    A survey of Australian emerging researchers in aging identified the need for greater professional development and networking opportunities. To address this, a formal mentorship scheme was developed and evaluated. Fourteen postgraduate researchers (proteges) were matched by discipline and research interest to experienced academics (mentors).…

  16. Bilingualism in the Computer Age, 1989-90. Final Evaluation Report.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Office of Research, Evaluation, and Assessment.

    Bilingualism in the Computer Age, a project of the New York City (New York) Board of Education, completed its fourth year (the 1989-90 school year) and was evaluated. The project offered 241 limited-English-proficient Spanish-speaking students the opportunity to study career and vocational subjects while improving their English and native language…

  17. Attachment and Self-Evaluation in Chinese Adolescents: Age and Gender Differences

    ERIC Educational Resources Information Center

    Song, Hairong; Thompson, Ross A.; Ferrer, Emilio

    2009-01-01

    This study investigated age and gender differences in the quality of attachment to mothers, fathers, and peers, and the association of attachment with measures of self-evaluation in 584 Chinese adolescents in junior high, high school, and university. Their responses to the Inventory of Parent and Peer Attachment indexed attachment quality, and…

  18. The National Treatment Improvement Evaluation Study (NTIES): Profile of Clients Age 45 and Over.

    ERIC Educational Resources Information Center

    Caliber Associates, Fairfax, VA.

    This paper summarizes similarities and differences between two cohorts of the National Treatment Improvement Evaluation Study (NTIES) clients, those age 45 or older and those younger than 45. Results reveal the following: Clients in the 45+ cohort were considerably more likely to be treated for problems with alcohol or with heroin, and they were…

  19. Evaluative Language Used by Mandarin-Chinese-Speaking Dyads in Personal Narratives: Age and Socioeconomic Differences

    ERIC Educational Resources Information Center

    Lai, Wen-Feng; Chen, Yen-Yu

    2016-01-01

    The aim of this study was to determine the effects of age and family socioeconomic status (SES) on the evaluative language performance of Mandarin-Chinese-speaking young children and their mothers. The participants were 65 mother-child dyads recruited in Taiwan. Thirty-four of these dyads were from middle-class families and 31 were from…

  20. Evaluation of advanced materials through experimental mechanics and modelling

    NASA Astrophysics Data System (ADS)

    Yang, Yii-Ching

    1993-11-01

    Composite materials have been frequently used in aerospace vehicles. Very often defects are inherited during the manufacture and damages are inherited during the construction and services. It becomes critical to understand the mechanical behavior of such composite structure before it can be further used. One good example of these composite structures is the cylindrical bottle of solid rocket motor case with accidental impact damages. Since the replacement of this cylindrical bottle is expensive, it is valuable to know how the damages affects the material, and how it can be repaired. To reach this goal, the damage must be characterized and the stress/strain field must be carefully analyzed. First the damage area, due to impact, is surveyed and identified with a shearography technique which uses the principle of speckle shearing interferometry to measure displacement gradient. Within the damage area of a composite laminate, such as the bottle of solid rocket motor case, all layers are considered to be degraded. Once a lamina being degraded the stiffness as well as strength will be drastically decreased. It becomes a critical area of failure to the whole bottle. And hence the stress/strain field within and around a damage should be accurately evaluated for failure prediction. To investigate the stress/strain field around damages a Hybrid-Numerical method which combines experimental measurement and finite element analysis is used. It is known the stress or strain at the singular point can not be accurately measured by an experimental technique. Nevertheless, if the location is far away from the singular spot, the displacement can be found accurately. Since it reflects the true displacement field locally regardless of the boundary conditions, it is an excellent input data for a finite element analysis to replace the usually assumed boundary conditions. Therefore, the Hybrid-Numerical method is chosen to avoid the difficulty and to take advantage of both experimental

  1. Quantitative evaluation of stiffness of commercial suture materials.

    PubMed

    Chu, C C; Kizil, Z

    1989-03-01

    The bending stiffness of 22 commercial suture materials of varying size, chemical structure and physical form was quantitatively evaluated using a stiffness tester (Taber V-5, model 150B, Teledyne). The commercial sutures were Chromic catgut; Dexon (polyglycolic acid); Vicryl (polyglactin 910); PDS (polydioxanone); Maxon (polyglycolide-trimethylene carbonate); Silk (coated with silicone); Mersilene (polyester fiber); Tycron (polyester fiber); Ethibond (polyethylene terephthalate coated with polybutylene); Nurolon (nylon 66); Surgilon (nylon 66 coated with silicone); Ethilon (coated nylon 66), Prolene (polypropylene); Dermalene (polyethylene), and Gore-tex (polytetraflouroethylene). These are both natural and synthetic, absorbable and nonabsorbable and monofilament and multifilament sutures. All of these sutures were size 2-0, but Prolene sutures with sizes ranging from 1-0 to 9-0 were also tested to determine the effect of suture size on stiffness. The bending stiffness data obtained showed that a wide range of bending stiffness was observed among the 22 commercial sutures. The most flexible 2-0 suture was Gore-tex, followed by Dexon, Silk, Surgilon, Vicryl (uncoated), Tycron, Nurolon, Mersilene, Ethibond, Maxon, PDS, Ethilon, Prolene, Chromic catgut, coated Vicryl, and lastly, Dermalene. The large porous volume inherent in Gore-tex monofilament suture was the reason for its lowest flexural stiffness. Sutures with a braided structure were generally more flexible than those of a monofilament structure, irrespective of the chemical constituents. Coated sutures had significantly higher stiffness than the corresponding uncoated ones. This is particularly true when polymers rather than wax were used as the coating material. This increase in stiffness is attributable to the loss of mobility under bending force in the fibers and yarns that make up the sutures. An increase in the size of the suture significantly increased the stiffness, and the magnitude of increase

  2. Evaluation of advanced materials through experimental mechanics and modelling

    NASA Technical Reports Server (NTRS)

    Yang, Yii-Ching

    1993-01-01

    Composite materials have been frequently used in aerospace vehicles. Very often defects are inherited during the manufacture and damages are inherited during the construction and services. It becomes critical to understand the mechanical behavior of such composite structure before it can be further used. One good example of these composite structures is the cylindrical bottle of solid rocket motor case with accidental impact damages. Since the replacement of this cylindrical bottle is expensive, it is valuable to know how the damages affects the material, and how it can be repaired. To reach this goal, the damage must be characterized and the stress/strain field must be carefully analyzed. First the damage area, due to impact, is surveyed and identified with a shearography technique which uses the principle of speckle shearing interferometry to measure displacement gradient. Within the damage area of a composite laminate, such as the bottle of solid rocket motor case, all layers are considered to be degraded. Once a lamina being degraded the stiffness as well as strength will be drastically decreased. It becomes a critical area of failure to the whole bottle. And hence the stress/strain field within and around a damage should be accurately evaluated for failure prediction. To investigate the stress/strain field around damages a Hybrid-Numerical method which combines experimental measurement and finite element analysis is used. It is known the stress or strain at the singular point can not be accurately measured by an experimental technique. Nevertheless, if the location is far away from the singular spot, the displacement can be found accurately. Since it reflects the true displacement field locally regardless of the boundary conditions, it is an excellent input data for a finite element analysis to replace the usually assumed boundary conditions. Therefore, the Hybrid-Numerical method is chosen to avoid the difficulty and to take advantage of both experimental

  3. Morphometric evaluation of the frontal sinus in relation to age and gender in subjects residing in Davangere, Karnataka

    PubMed Central

    Soman, Bhakti A.; Sujatha, G. P.; Lingappa, Ashok

    2016-01-01

    Objective: The main objective of the study was morphometric evaluation of the frontal sinus in relation to age and gender and to establish its forensic importance and application. Materials and Method: The study group consisted of 200 subjects (100 males and 100 females) in the age groups 14-20 years, 21-30 years, 31-45 years, 45 years and above. Posteroanterior (PA) cephalogram radiographs were taken using standardized technique. The processed films were traced and frontal sinus pattern was established as per Yoshino's classification system. Results: The mean values for length, width, and area of the frontal sinus were found to be higher in males as compared to females and area of frontal sinuses increase with age except in males who were 45 years and above. The left width, left area, and bilateral asymmetry in relation to gender was found to be statistically significant. Conclusion: The morphologic evaluation of frontal sinus is a useful technique to determine gender and seems promising in personal identification. PMID:27051227

  4. An evaluation of the precision of fin ray, otolith, and scale age determinations for brook trout

    USGS Publications Warehouse

    Stolarski, J.T.; Hartman, K.J.

    2008-01-01

    The ages of brook trout Salvelinus fontinalis are typically estimated using scales despite a lack of research documenting the effectiveness of this technique. The use of scales is often preferred because it is nonlethal and is believed to require less effort than alternative methods. To evaluate the relative effectiveness of different age estimation methodologies for brook trout, we measured the precision and processing times of scale, sagittal otolith, and pectoral fin ray age estimation techniques. Three independent readers, age bias plots, coefficients of variation (CV = 100 x SD/mean), and percent agreement (PA) were used to measure within-reader, among-structure bias and within-structure, among-reader precision. Bias was generally minimal; however, the age estimates derived from scales tended to be lower than those derived from otoliths within older (age > 2) cohorts. Otolith, fin ray, and scale age estimates were within 1 year of each other for 95% of the comparisons. The measures of precision for scales (CV = 6.59; PA = 82.30) and otoliths (CV = 7.45; PA = 81.48) suggest higher agreement between these structures than with fin rays (CV = 11.30; PA = 65.84). The mean per-sample processing times were lower for scale (13.88 min) and otolith techniques (12.23 min) than for fin ray techniques (22.68 min). The comparable processing times of scales and otoliths contradict popular belief and are probably a result of the high proportion of regenerated scales within samples and the ability to infer age from whole (as opposed to sectioned) otoliths. This research suggests that while scales produce age estimates rivaling those of otoliths for younger (age > 3) cohorts, they may be biased within older cohorts and therefore should be used with caution. ?? Copyright by the American Fisheries Society 2008.

  5. Clinical studies with disposable diapers containing absorbent gelling materials: evaluation of effects on infant skin condition.

    PubMed

    Campbell, R L; Seymour, J L; Stone, L C; Milligan, M C

    1987-12-01

    Disposable infant diapers with absorbent gelling material (cross-linked sodium polyacrylates) incorporated into the core were clinically evaluated for their effect on infant skin condition. Absorbent gelling materials tightly hold water and provide pH control by a buffering capacity as well as by helping to segregate urine apart from feces. Four clinical studies were conducted with each following a rigid protocol that controlled for variables of diet and age in addition to the diaper material that may influence the development of diaper dermatitis and helped to control for any inherent bias in the study. This allowed for the controlled assessment of skin condition with respect to diaper type. Absorbent gelling material-containing disposable, conventional (100% cellulose core) disposable, and home-laundered cloth diapers were test products. In these studies 1614 infants were initially enrolled with 522 of them assigned to absorbent gelling material disposable, 738 to conventional disposable, and 354 to home-laundered cloth diapers. Objective measurements of skin wetness (transepidermal water loss) and skin pH, as well as double-blind grading of diaper dermatitis, were the measures of skin condition. Absorbent gelling material disposable diapers were associated with significantly reduced skin wetness, closer to normal skin pH, and lower degrees of diaper dermatitis when compared to conventional disposable or home-laundered cloth diapers. The results are consistent with the hypothesis that better control in the diaper area of skin wetness, skin pH, and the prevention of the mixing of urine and feces produces a better diaper environment. PMID:3323274

  6. An ecotoxicological evaluation of aged bottom ash for use in constructions.

    PubMed

    Stiernström, S; Enell, A; Wik, O; Borg, H; Breitholtz, M

    2014-01-01

    Municipal and Industrial Solid Waste Incineration (MISWI) bottom ash is mainly deposited in landfills, but natural resources and energy could be saved if these ash materials would be used in geotechnical constructions. To enable such usage, knowledge is needed on their potential environmental impact. The aim of this study was to evaluate the ecotoxicity of leachates from MISWI bottom ash, aged for five years, in an environmental relevant way using a sequential batch leaching method at the Liquid/Solid-ratio interval 1-3, and to test the leachates in a (sub)chronic ecotoxicity test. Also, the leachates were characterized chemically and with the technique of diffusive gradients in thin films (DGTs). By comparing established ecotoxicity data for each element with chemically analysed and labile concentrations in the leachates, potentially problematic elements were identified by calculating Hazard Quotients (HQ). Overall, our results show that the ecotoxicity was in general low and decreased with increased leaching. A strong correspondence between calculated HQs and observed toxicity over the full L/S range was observed for K. However, K will likely not be problematic from a long-term environmental perspective when using the ash, since it is a naturally occurring essential macro element which is not classified as ecotoxic in the chemical legislation. Although Cu was measured in total concentrations close to where a toxic response is expected, even at L/S 3, the DGT-analysis showed that less than 50% was present in a labile fraction, indicating that Cu is complexed by organic ligands which reduce its bioavailability. PMID:24188924

  7. Identification and evaluation of age-correlated DNA methylation markers for forensic use.

    PubMed

    Park, Jong-Lyul; Kim, Jong Hwan; Seo, Eunhye; Bae, Dong Hyuck; Kim, Seon-Young; Lee, Han-Chul; Woo, Kwang-Man; Kim, Yong Sung

    2016-07-01

    In forensics, age prediction is useful to narrow down the number of potential suspects because it can provide some general characteristics for predicting appearance. Previous genome-wide studies based on DNA methylation have reported age prediction algorithms using a penalized multivariate regression method known as elastic net and a few dozen to hundreds of CpG sites. Although more CpG sites may provide better accuracy than fewer CpG sites, this approach is not applicable to forensics because the amounts of crime-scene DNA are usually limited. In this study, we selected three age-correlated CpG sites, namely cg16867657 (ELOVL2), which is known to be an excellent age predictor, cg04208403 (ZNF423), and cg19283806 (CCDC102B), from HumanMethylation450 BeadChip datasets of 1415 individuals. Furthermore, we evaluated these markers in a 535-sample training set and a 230-sample validation set from Korean individuals using a pyrosequencing platform. From the training set, an age prediction model using the multiple linear regression method explained 91.44% of age-correlated variation in DNA methylation patterns. The standard error of estimate and mean absolute deviation were 6.320 and 3.156 years, respectively. In the validation set, the standard error of estimate and mean absolute deviation were estimated as 6.853 and 3.346 years, respectively. For the validation set, the model explained 91.08% of the variation in methylation and predicted age (±6years) with accuracy of 77.30% in the <60years age group and 57.30% in the older group (≥60 years). These results suggest that our three DNA methylation markers may be useful for age prediction in samples from Asian populations. PMID:27017110

  8. Recognition of Pictorial Material As A Function of Experiential Deprivation and Age.

    ERIC Educational Resources Information Center

    Misra, Girishwar; Shukla, Aradhana

    1984-01-01

    Investigated relative effects of chronological age and experiential deprivation upon pictorial recognition. Four age levels (ages four to five, five to six, six to seven, and seven to eight years) and two levels of deprivation were manipulated. The 50 subjects in each factorial cell performed tasks individually. (Author/RH)

  9. Evaluation of Dielectric-Barrier-Discharge Actuator Substrate Materials

    NASA Technical Reports Server (NTRS)

    Wilkinson, Stephen P.; Siochi, Emilie J.; Sauti, Godfrey; Xu, Tian-Bing; Meador, Mary Ann; Guo, Haiquan

    2014-01-01

    A key, enabling element of a dielectric barrier discharge (DBD) actuator is the dielectric substrate material. While various investigators have studied the performance of different homogeneous materials, most often in the context of related DBD experiments, fundamental studies focused solely on the dielectric materials have received less attention. The purpose of this study was to conduct an experimental assessment of the body-force-generating performance of a wide range of dielectric materials in search of opportunities to improve DBD actuator performance. Materials studied included commonly available plastics and glasses as well as a custom-fabricated polyimide aerogel. Diagnostics included static induced thrust, electrical circuit parameters for 2D surface discharges and 1D volume discharges, and dielectric material properties. Lumped-parameter circuit simulations for the 1D case were conducted showing good correspondence to experimental data provided that stray capacitances are included. The effect of atmospheric humidity on DBD performance was studied showing a large influence on thrust. The main conclusion is that for homogeneous, dielectric materials at forcing voltages less than that required for streamer formation, the material chemical composition appears to have no effect on body force generation when actuator impedance is properly accounted for.

  10. Teaching and Evaluation Materials Utilizing Multiple Representations in Mechanics

    ERIC Educational Resources Information Center

    Savinainen, A.; Nieminen, P.; Makynen, A.; Viiri, J.

    2013-01-01

    In this paper, we present materials and teaching ideas utilizing multiple representations in the contexts of kinematics and the force concept. These ideas and materials are substantiated by evidence and can be readily used in teaching with no special training. In addition, we briefly discuss two multiple-choice tests based on physics education…

  11. Evaluation of Student Outcomes in Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Piippo, Steven

    1996-01-01

    This paper specifies 14 benchmarks and exit standards for the introduction of Materials Science and Technology in a secondary school education. Included is the standard that students should be able to name an example of each category of technological materials including metals, glass/ceramics, polymers (plastics) and composites. Students should know that each type of solid material has specific properties that can be measured. Students will learn that all solid materials have either a long range crystalline structure or a short range amorphous structure (i.e., glassy). They should learn the choice of materials for a particular application depends on the properties of the material, and the properties of the material depends on its crystal structure and microstructure. The microstructure may be modified by the methods by which the material is processed; students should explain this by the example of sintering a ceramic body to reduce its porosity and increase its densification and strength. Students will receive exposure to the world of work, post secondary educational opportunities, and in general a learning that will lead to a technologically literate intelligent citizen.

  12. Development and evaluation of thermoplastic street maintenance material

    NASA Technical Reports Server (NTRS)

    Siemens, W. D.

    1973-01-01

    An all-weather permanent street patching material was investigated for flexible and rigid pavements. The economic, operational, and material requirements are discussed along with the results of field tests with various mixtures of EVA resins and asphalt. Cost analyses for thermoplastic patching methods are included.

  13. Effect of aging on the toughness of human cortical bone:Evaluation by R-curves

    SciTech Connect

    Nalla, Ravi K.; Kruzic, Jamie J.; Kinney, John H.; Ritchie,Robert O.

    2005-04-05

    Age-related deterioration of the fracture properties ofbone, coupled with increased life expectancy, is responsible forincreasing incidence of bone fracture in the elderly, and hence, anunderstanding of how its fracture properties degrade with age isessential. The present study describes ex vivo fracture experiments toquantitatively assess the effect of aging on the fracture toughnessproperties of human cortical bone in the longitudinal direction. Becausecortical bone exhibits rising crack-growth resistance with crackextension, unlike most previous studies, the toughness is evaluated interms of resistance-curve (R-curve) behavior, measured for bone takenfrom wide range of age groups (34-99 years). Using this approach, boththe ex vivo crack-initiation and crack-growth toughness are determinedand are found to deteriorate with age; the initiation toughness decreasessome 40 percent over 6 decades from 40 to 100 years, while the growthtoughness is effectively eliminated over the same age range. Thereduction in crack-growth toughness is considered to be associatedprimarily with a degradation in the degree of extrinsic toughening, inparticular, involving crack bridging in the wake of thecrack.

  14. Effect of Aging on the Toughness of Human Cortical Bone: Evaluation by R-Curves

    SciTech Connect

    Kinney, J

    2004-10-08

    Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, are responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. Because cortical bone exhibits rising crack-growth resistance with crack extension, unlike most previous studies the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the ex vivo crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; the initiation toughness decreases some 40% over six decades from 40 to 100 years, while the growth toughness is effectively eliminated over the same age range. The reduction in crack-growth toughness is considered to be associated primarily with a degradation in the degree of extrinsic toughening, in particular involving crack bridging in the wake of the crack.

  15. Thermal Performance of Aged and Weathered Spray-On Foam Insulation (SOFI) Materials Under Cryogenic Vacuum Conditions (Cryostat-4)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The NASA Cryogenics Test Laboratory at Kennedy Space Center conducted long-term testing of SOFI materials under actual-use cryogenic conditions with Cryostat-4. The materials included in the testing were NCFI 24-124 (acreage foam), BX-265 (close-out foam, including intertank flange and bipod areas), and a potential alternate material, NCFI 27-68, (acreage foam with the flame retardant removed). Specimens of these materials were placed at two locations: a site that simulated aging (the Vehicle Assembly Building [VAB]) and a site that simulated weathering (the Atmospheric Exposure Test Site [beach site]). After aging/weathering intervals of 3, 6, and 12 months, the samples were retrieved and tested for their thermal performance under cryogenic vacuum conditions with test apparatus Cryostat-4.

  16. Evaluation of rinse material and process for EUV lithography

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kazuma; Itani, Toshiro

    2015-03-01

    Extreme ultraviolet lithography (EUVL) is the most promising option for future manufacturing of IC devices at sub-10nm node. However, resist pattern collapse is one concern for high volume manufacturing. To mitigate resist pattern collapse, rinse material is applied for EUVL. However at narrow pitches, it was found that some rinse materials caused pattern bridging and critical dimension (CD) shift. In this study, we suggest a model of resist deformation by surfactant penetration to resist pattern. Moreover, we focused on affinity between resist and surfactant which is main components in rinse material to clarify the pattern bridging and CD-shift issue by inducing surfactant penetration to resist pattern. To define the affinity between each material, Solubility Parameter (SP) value and Difference of Solubility Parameter value (DSP) of each material was calculated. The relation between surfactant penetration and DSP of each material was investigated. To clarify the relation, stress test was applied to enhance pattern deformation. As a result, it can be said that there is good correlation between surfactant penetration and SP value. Using these studies, rinse material design with low affinity surfactant for resist was able to achieve no CD-shift and less pattern bridging defect number.

  17. Femtosecond laser processing of fuel injectors - a materials processing evaluation

    SciTech Connect

    Stuart, B C; Wynne, A

    2000-12-16

    Lawrence Livermore National Laboratory (LLNL) has developed a new laser-based machining technology that utilizes ultrashort-pulse (0.1-1.0 picosecond) lasers to cut materials with negligible generation of heat or shock. The ultrashort pulse laser, developed for the Department of Energy (Defense Programs) has numerous applications in operations requiring high precision machining. Due to the extremely short duration of the laser pulse, material removal occurs by a different physical mechanism than in conventional machining. As a result, any material (e.g., hardened steel, ceramics, diamond, silicon, etc.) can be machined with minimal heat-affected zone or damage to the remaining material. As a result of the threshold nature of the process, shaped holes, cuts, and textures can be achieved with simple beam shaping. Conventional laser tools used for cutting or high-precision machining (e.g., sculpting, drilling) use long laser pulses (10{sup -8} to over 1 sec) to remove material by heating it to the melting or boiling point (Figure 1.1a). This often results in significant damage to the remaining material and produces considerable slag (Figure 1.2a). With ultrashort laser pulses, material is removed by ionizing the material (Figure 1.1b). The ionized plasma expands away from the surface too quickly for significant energy transfer to the remaining material. This distinct mechanism produces extremely precise and clean-edged holes without melting or degrading the remaining material (Figures 1.2 and 1.3). Since only a very small amount of material ({approx} <0.5 microns) is removed per laser pulse, extremely precise machining can be achieved. High machining speed is achieved by operating the lasers at repetition rates up to 10,000 pulses per second. As a diagnostic, the character of the short-pulse laser produced plasma enables determination of the material being machined between pulses. This feature allows the machining of multilayer materials, metal on metal or metal on

  18. Quantitative non-destructive evaluation of composite materials based on ultrasonic parameters

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1987-01-01

    Research into the nondestructive evaluation of advanced reinforced composite laminates is summarized. The applicability of the Framers-Kronig equations to the nondestructive evaluation of composite materials is described.

  19. ENVIRONMENTAL, ECONOMIC AND ENERGY IMPACTS OF MATERIAL RECOVERY FACILITIES - A MITE PROGRAM EVALUATION

    EPA Science Inventory

    This report documents an evaluation of the environmental, economic, and energy impacts of material recovery facilities (MRFS) conducted under the Municipal Solid Waste Innovative Technology Evaluation (MITE) Program. he MITE Program is sponsored by the U.S. Environmental Protecti...

  20. Post Test Evaluation of NSWCCD Materials at EERC

    SciTech Connect

    Dr. Eric Wuchina

    2001-12-31

    The higher combustion temperatures, particulate erosion, multivalent metal impurities, and local gas composition variations will all have dramatic effects on the performance of materials used for the cyclone combustor deflector cone.

  1. Nondestructive evaluation of a ceramic matrix composite material

    NASA Technical Reports Server (NTRS)

    Grosskopf, Paul P.; Duke, John C., Jr.

    1992-01-01

    Monolithic ceramic materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited because of their sensitivity to small imperfections. To overcome this extreme sensitivity to small imperfections, ceramic matrix composite materials have been developed that have the ability to withstand some distributed damage. A borosilicate glass reinforced with several layers of silicon-carbide fiber mat has been studied. Four-point flexure and tension tests were performed not only to determine some of the material properties, but also to initiate a controlled amount of damage within each specimen. Acousto-ultrasonic (AU) measurements were performed periodically during mechanical testing. This paper will compare the AU results to the mechanical test results and data from other nondestructive methods including acoustic emission monitoring and X-ray radiography. It was found that the AU measurements were sensitive to the damage that had developed within the material.

  2. Development and evaluation of elastomeric materials for geothermal applications

    NASA Technical Reports Server (NTRS)

    Mueller, W. A.; Kalfayan, S. H.; Reilly, W. W.; Ingham, J. D.

    1978-01-01

    A material for a casing packer for service for 24 hours in a geothermal environment was developed by synthesis of new elastomers and formulation of available materials. Formulation included use of commercial elastomer gumstocks and also crosslinking of plastic (high Tg) materials. Fibrous reinforcement of fluorocarbon rubbers was emphasized. Organic fiber reinforcement did not increase hot properties significantly. Glass fiber reinforcement gave significant increase in tensile properties. Elongation was reduced, and the glass-reinforced composition examined so far did not hold up well in the geothermal environment. Colloidal asbestos fibers were also investigated. A few experiments with polyphenyl ether gave material with low tensile and high compression set. Available high styrene SBR compositions were studied. Work to date suggests that new synthetic polymers will be required for service in geothermal environments.

  3. Evaluation of Skin Anti-aging Potential of Citrus reticulata Blanco Peel

    PubMed Central

    Apraj, Vinita D.; Pandita, Nancy S.

    2016-01-01

    Background: The peel of Citrus reticulata Blanco is traditionally used as tonic, stomachic, astringent, and carminative. It is also useful in skin care. Objective: To study the anti-aging potential of alcoholic extracts of C. reticulata Blanco peel using in vitro antioxidant and anti-enzyme assays. Materials and Methods: Plant extracts were obtained by Soxhlation (CR HAE- Hot Alcoholic Extract of Citrus reticulata) and maceration method (CR CAE- Cold Alcoholic Extract of Citrus reticulata). Qualitative and quantitative phytochemical analysis was performed. Further, in vitro antioxidant, anti-enzyme, and gas chromatography-mass spectrometry (GC-MS) analyses were performed. Results: Total phenolic and flavonoid contents of CR HAE were found to be higher than CR CAE. EC50 value of CR HAE and CR CAE for 1,1-Diphenyl-2-picrylhydrazyl, Superoxide anion, and 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays were 250.33 ± 40.16 μg/ml and 254.73 ± 15.78 μg/ml, 221.27 ± 11.25 μg/ml and 354.20 ± 23.79 μg/ml, and 59.16 ± 2.17 μg/ml and 59.12 ± 6.21 μg/ml, respectively. Oxygen radical absorbance capacity values for CR HAE and CR CAE were found to be 1243 and 1063 μmoles 6-hydroxy-2,5,7,8-tetra methylchromane-2-carboxylic acid equivalent/g of substance, respectively. Anti-collagenase and anti-elastase activities were evaluated for both CR HAE and CR CAE. EC50 values of CR HAE and CR CAE for anti-collagenase and anti-elastase were 329.33 ± 6.38 μg/ml, 466.93 ± 8.04 μg/ml and 3.22 ± 0.24 mg/ml, 5.09 ± 0.30 mg/ml, respectively. CR HAE exhibited stronger anti-collagenase and anti-elastase activity than CR CAE. GC-MS analysis of CR HAE was carried out because CR HAE exhibited higher antioxidant and anti-enzyme potential than CR CAE. Conclusion: C. reticulata peel can be utilized in anti-wrinkle skin care formulations. SUMMARY Skin anti-aging potential of Citrus reticulata Blanco peel was evaluated throughIn vitro antioxidant and anti-enzyme assays

  4. Evaluating the information content of multiple groundwater age tracers in projecting nitrate vulnerability

    NASA Astrophysics Data System (ADS)

    Alikhani, J.; Massoudieh, A.; Deinhart, A.; Visser, A.; Esser, B.; Moran, J. E.

    2015-12-01

    Nitrate is one of the major sources of contamination of groundwater in the United States and around the world. In this study the applicability of multiple groundwater age tracers including 3H, 3He, 4He, 14C, 13C, and 85Kr in projecting future trends of nitrate concentration in several long-screened, public drinking water wells in Turlock, California, where nitrate concentrations are increasing toward the regulatory limit, is studied. Several lumped parameter models (LPM)s were considered to represent the groundwater age distribution at each well, including binary mixtures between Inverse Gaussian(young) and Dirac(old), generalized inverse Gaussian, and Levy distributions . LPM model parameters and unknown physical parameters (crustal production rate of 4He, dissolved inorganic carbon contribution from rock dissolution) were estimated using a Bayesian inference, resulting in the posterior probability distribution of the parameters and therefore the uncertainty associated with each. The performance of each LPM in reproducing the data while accounting for the level of model complexity is evaluated using deviance information criteria (DIC) and Bayes Factors (BF). Historical nitrate concentration data are also evaluated as an additional tracer to refine the age distribution. We found that historical nitrate levels can reduce the uncertainty about the age distribution. LPMs with a distinct feature to represent the old fraction of groundwater (for example Inverse Gaussian-Dirac) are better at reproducing the tracer data but with the price of a larger number of parameters, which results in a larger uncertainty about the age distribution itself. Although the uncertainty regarding the shape of the age distribution remains relatively high, whether nitrate is included as a tracer or not, different models predict similar future trends in nitrate concentration.

  5. A comparative evaluation of mechanical properties of nanofibrous materials

    NASA Astrophysics Data System (ADS)

    Lyubun, German P.; Bessudnova, Nadezda O.

    2014-01-01

    Restoration or replacement of lost or damaged hard tooth tissues remain a reconstructive clinical dentistry challenge. One of the most promising solutions to this problem is the development of novel concepts and methodologies of tissue engineering for the synthesis of three-dimensional graft constructs that are equivalent to original organs and tissues. This structural and functional compatibility can be reached by producing ultra-thin polymer filament scaffolds. This research aims through a series of studies to examine different methods of polymer filament material special preparation and test mechanical properties of the produced materials subjected to a tensile strain. Nanofibrous material preparation using chemically pure acetone and mixtures of ethanol/water has shown no significant changes in sample surface morphology. The high temperature impact on material morphology has resulted in the modification of fiber structure. In the course of mechanical tests it has been revealed the dependence of the material strength on the spinning solution compositions. The results achieved point to the possibility to develop nanofibrous materials with required parameters changing the methodology of spinning solution production.

  6. Evaluation of Neutron Poison Materials for DOE SNF Disposal Systems

    SciTech Connect

    Vinson, D.W.; Caskey, G.R. Jr.; Sindelar, R.L.

    1998-09-01

    Aluminum-based spent nuclear fuel (Al-SNF) from foreign and domestic research reactors is being consolidated at the Savannah River Site (SRS) for ultimate disposal in the Mined Geologic Disposal System (MGDS). Most of the aluminum-based fuel material contains highly enriched uranium (HEU) (more than 20 percent 235U), which challenges the preclusion of criticality events for disposal periods exceeding 10,000 years. Recent criticality analyses have shown that the addition of neutron absorbing materials (poisons) is needed in waste packages containing DOE SNF canisters fully loaded with Al-SNF under flooded and degraded configurations to demonstrate compliance with the requirement that Keff less than 0.95. Compatibility of poison matrix materials and the Al-SNF, including their relative degradation rate and solubility, are important to maintain criticality control. An assessment of the viability of poison and matrix materials has been conducted, and an experimental corrosion program has been initiated to provide data on degradation rates of poison and matrix materials and Al-SNF materials under repository relevant vapor and aqueous environments. Initial testing includes Al6061, Type 316L stainless steel, and A516Gr55 in synthesized J-13 water vapor at 50 degrees C, 100 degrees C, and 200 degrees C and in condensate water vapor at 100 degrees C. Preliminary results are presented herein.

  7. Bioreceptivity evaluation of cementitious materials designed to stimulate biological growth.

    PubMed

    Manso, Sandra; De Muynck, Willem; Segura, Ignacio; Aguado, Antonio; Steppe, Kathy; Boon, Nico; De Belie, Nele

    2014-05-15

    Ordinary Portland cement (OPC), the most used binder in construction, presents some disadvantages in terms of pollution (CO2 emissions) and visual impact. For this reason, green roofs and façades have gain considerable attention in the last decade as a way to integrate nature in cities. These systems, however, suffer from high initial and maintenance costs. An alternative strategy to obtain green facades is the direct natural colonisation of the cementitious construction materials constituting the wall, a phenomenon governed by the bioreceptivity of such material. This work aims at assessing the suitability of magnesium phosphate cement (MPC) materials to allow a rapid natural colonisation taking carbonated OPC samples as a reference material. For that, the aggregate size, the w/c ratio and the amount of cement paste of mortars made of both binders were modified. The assessment of the different bioreceptivities was conducted by means of an accelerated algal fouling test. MPC samples exhibited a faster fouling compared to OPC samples, which could be mainly attributed to the lower pH of the MPC binder. In addition to the binder, the fouling rate was governed by the roughness and the porosity of the material. MPC mortar with moderate porosity and roughness appears to be the most feasible material to be used for the development of green concrete walls. PMID:24602907

  8. Evaluation and ranking of candidate ceramic wafer engine seal materials

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.

    1991-01-01

    Modern engineered ceramics offer high temperature capabilities not found in even the best superalloy metals. The high temperature properties of several selected ceramics including aluminum oxide, silicon carbide, and silicon nitride are reviewed as they apply to hypersonic engine seal design. A ranking procedure is employed to objectively differentiate among four different monolithic ceramic materials considered, including: a cold-pressed and sintered aluminum oxide; a sintered alpha-phase silicon carbide; a hot-isostatically pressed silicon nitride; and a cold-pressed and sintered silicon nitride. This procedure is used to narrow the wide range of potential ceramics considered to an acceptable number for future detailed and costly analyses and tests. The materials are numerically scored according to their high temperature flexural strength; high temperature thermal conductivity; resistance to crack growth; resistance to high heating rates; fracture toughness; Weibull modulus; and finally according to their resistance to leakage flow, where materials having coefficients of thermal expansion closely matching the engine panel material resist leakage flow best. The cold-pressed and sintered material (Kyocera SN-251) ranked the highest in the overall ranking especially when implemented in engine panels made of low expansion rate materials being considered for the engine, including Incoloy and titanium alloys.

  9. Evaluation and ranking of candidate ceramic wafer engine seal materials

    SciTech Connect

    Steinetz, B.M.

    1991-05-01

    Modern engineered ceramics offer high temperature capabilities not found in even the best superalloy metals. The high temperature properties of several selected ceramics including aluminum oxide, silicon carbide, and silicon nitride are reviewed as they apply to hypersonic engine seal design. A ranking procedure is employed to objectively differentiate among four different monolithic ceramic materials considered, including: a cold-pressed and sintered aluminum oxide; a sintered alpha-phase silicon carbide; a hot-isostatically pressed silicon nitride; and a cold-pressed and sintered silicon nitride. This procedure is used to narrow the wide range of potential ceramics considered to an acceptable number for future detailed and costly analyses and tests. The materials are numerically scored according to their high temperature flexural strength; high temperature thermal conductivity; resistance to crack growth; resistance to high heating rates; fracture toughness; Weibull modulus; and finally according to their resistance to leakage flow, where materials having coefficients of thermal expansion closely matching the engine panel material resist leakage flow best. The cold-pressed and sintered material (Kyocera SN{sup -251}) ranked the highest in the overall ranking especially when implemented in engine panels made of low expansion rate materials being considered for the engine, including Incoloy and titanium alloys.

  10. A Step Forward: Investigating Expertise in Materials Evaluation

    ERIC Educational Resources Information Center

    Johnson, Keith; Kim, Mija; Ya-Fang, Liu; Nava, Andrea; Perkins, Dawn; Smith, Anne Margaret; Soler-Canela, Oscar; Lu, Wang

    2008-01-01

    This article reports on a study investigating the textbook evaluation techniques of novice and experienced teachers, which was conducted by the Language Teaching Expertise Research Group (or LATEX) within Lancaster University's Department of Linguistics and English Language. Three ELT teachers were chosen to evaluate the student and teacher…

  11. The medico-legal evaluation of injuries from falls in pediatric age groups.

    PubMed

    Kafadar, Safiye; Kafadar, Hüseyin

    2015-04-01

    Blunt trauma from accidental falls or intentional jumping from great heights occurs frequently in forensic medicine. The goal of this study was to investigate injuries due to falls in children under 19 years of age. Injuries from falls are the leading cause of visits to emergency departments and to deaths due to injuries. Various methods are used in the classification of falls. In this study, we have classified falls as "high-level" (≥ 5 m), "low-level" (<5 m) and "ground-level". We have retrospectively evaluated 814 boys (61.18%) and 512 girls (38.62%), making up a total of 1326 children (under 19 years old) with the mean age of 7.85 ± 3.46, that were admitted to State Hospital between January 2009 and December 2013 due to falls from heights and falls on ground-level. Falls were low-level in 738 cases, high-level in 176 cases, and ground-level in 412 cases. Cases were categorized by gender, age, age group, fall height, Glasgow Coma Scale (GCS), injured body part(s), mortality rate, and distribution according to months. In conclusion, falls merit attention because of their high risk of mortality and morbidity, as well as their burden on medical budgets. If the medico-legal aspects of falls were evaluated with regard to preventive event or death, the importance of the topic could be better understood. PMID:25735785

  12. Microstructural evolution and hardness changes in the interface of Cu/316L joint materials under aging and ion irradiation

    NASA Astrophysics Data System (ADS)

    Xu, Q.; Yoshiie, T.; Muroga, T.; Yoshida, N.; Iwai, T.; Edwards, D. J.

    2004-08-01

    The effects of aging and ion irradiation on microstructure stability and hardness change in the joint materials of CuNiBe/316L and CuAl25/316L have been investigated in the present study. The aging at 673 K for 1000 h or Ni ion irradiation at 573 and 673 K to 10 dpa did not promote the interdiffusion and void swelling at the interface. The hardness in both Cu alloys and stainless steel was increased by irradiation, however, it was decreased by aging except for CuNiBe alloy. The hardness change in CuNiBe alloy was larger than that in CuAl25 alloy. The hardness changes would have a significant effect on the mechanical properties of joint materials.

  13. Critical Evaluation of Radiometric Ages Used for Tracking Hotspots in the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Baksi, A. K.

    2004-12-01

    One of the pillars supporting the plume hypothesis, is the progression of ages for numerous hotspot tracks in oceans. These ages should be based on radiometric measurements. The argon dating methods have been the tool most commonly used. Since most of the rocks selected for dating have suffered (considerable) alteration, K-Ar dates should not be used as accurate measures of the age of crystallization. 40Ar/39Ar total fusion ages, though better than K-Ar dates in general, do not pinpoint samples that (a) contain excess argon or (b) have suffered partial loss of 40Ar* due to alteration. Hence 40Ar/39Ar incremental heating studies remain as the (only) tool of choice. From such experiments, at a minimum, ages must be based on plateau and/or isochron sections that meet the necessary statistical requirements to be considered crystallization ages. Earlier (Baksi, 1999, Jour. Geol.) it has been shown that almost all the purported crystallization ages for hotspot tracks in the Atlantic and Indian Oceans, are invalid (see also www.mantleplumes.org/ArAr.html). Herein, I apply the tests outlined therein, to evaluate ages available in the literature for hotspot tracks in the Pacific Ocean. These can be divided into five main groups. (1) Those with reliable age data (e.g. Dalrymple and Garcia,1980; Dalrymple et al., 1980, DSDP 55, Hawaiian-Emperor Chain); the authors use care in selecting valid ages from their data sets. (2) Others (e.g. Pringle, 1993, AGU Monograph 77, Musicians Seamounts), most ages are statistically valid, though some fail the requisite test. In addition, many samples show high levels of atmospheric argon, suggesting the samples are (quite) altered; this could lead to incorrect plateau ages. (3) The next set (e.g. Winterer et al., 1993, AGU Monograph 77, Cretaceous guyots in the Northwest Pacific; Ozima et al., 1977, JGRAS, Western Pacific guyots; Saito and Ozima, 1977, EPSL, Western Pacific area) have few, if any, valid ages. Most plateaux/isochrons clearly

  14. Numerical Evaluation of Mode 1 Stress Intensity Factor as a Function of Material Orientation For BX-265 Foam Insulation Material

    NASA Technical Reports Server (NTRS)

    Knudsen, Erik; Arakere, Nagaraj K.

    2006-01-01

    Foam; a cellular material, is found all around us. Bone and cork are examples of biological cell materials. Many forms of man-made foam have found practical applications as insulating materials. NASA uses the BX-265 foam insulation material on the external tank (ET) for the Space Shuttle. This is a type of Spray-on Foam Insulation (SOFI), similar to the material used to insulate attics in residential construction. This foam material is a good insulator and is very lightweight, making it suitable for space applications. Breakup of segments of this foam insulation on the shuttle ET impacting the shuttle thermal protection tiles during liftoff is believed to have caused the space shuttle Columbia failure during re-entry. NASA engineers are very interested in understanding the processes that govern the breakup/fracture of this complex material from the shuttle ET. The foam is anisotropic in nature and the required stress and fracture mechanics analysis must include the effects of the direction dependence on material properties. Material testing at NASA MSFC has indicated that the foam can be modeled as a transversely isotropic material. As a first step toward understanding the fracture mechanics of this material, we present a general theoretical and numerical framework for computing stress intensity factors (SIFs), under mixed-mode loading conditions, taking into account the material anisotropy. We present mode I SIFs for middle tension - M(T) - test specimens, using 3D finite element stress analysis (ANSYS) and FRANC3D fracture analysis software, developed by the Cornel1 Fracture Group. Mode I SIF values are presented for a range of foam material orientations. Also, NASA has recorded the failure load for various M(T) specimens. For a linear analysis, the mode I SIF will scale with the far-field load. This allows us to numerically estimate the mode I fracture toughness for this material. The results represent a quantitative basis for evaluating the strength and

  15. A test of the 40Ar/39Ar age spectrum technique on some terrestrial materials

    USGS Publications Warehouse

    Lanphere, M.A.; Brent, Dalrymple G.

    1971-01-01

    40Ar/39Ar age spectra were determined for 10 terrestrial rock and mineral samples whose geologic history is known from independent evidence. The spectra for six mineral and whole rock samples, including biotite, feldspar, hornblende, muscovite, and granodiorite, that have experienced post-crystallization heating did not reveal the age of crystallization in any obvious way. Minima in the spectra, however, give reasonable maximum ages for reheating and high-temperature maxima can be interpreted as minimum crystallization ages. High-temperature ages of microcline and albite that have not been reheated are approximately 10% younger than the known crystallization age. Apparently there are no domains in these feldspars that have retained radiogenic 40Ar quantitatively. Spectra from two diabase samples that contain significant quantities of excess argon might mistakenly be interpreted as spectra from reheated samples and do not give the age of emplacement. The 40Ar/39Ar age spectrum technique may be a potentially valuable tool for the study of geologic areas with complex histories, but the interpretation of age spectra from terrestrial samples seems to be more difficult than suggested by some previous studies. ?? 1971.

  16. In vivo MR evaluation of age-related increases in brain iron

    SciTech Connect

    Bartzokis, G.; Mintz, J.; Sultzer, D.; Marx, P.; Herzberg, J.S.; Phelan, C.K.

    1994-06-01

    To assess the validity of an MR method of evaluating tissue iron. The difference between the transverse relaxation rate (R{sub 2}) measured with a high-field MR instrument and the R{sub 2} measured with a lower field instrument defines a measure termed the field-dependent R{sub 2} increase (FDRI). Previous in vivo and in vitro studies indicated that FDRI is a specific measure of tissue iron stores (ferritin). T2 relaxation times were obtained using two clinical MR instruments operating at 0.5 T and 1.5 T. T2 relaxation times were measured in the frontal white matter, caudate nucleus, putamen, and globus pallidus of 20 health adult male volunteers with an age range of 20 to 81 years. R{sub 2} was calculated as the reciprocal of T2 relaxation time. These in vivo MR results were correlated with previously published postmortem data on age-related increases of nonheme iron levels. The FDRI was very highly correlated with published brain iron levels for the four regions examined. In the age range examined, robust and highly significant age-related increases in FDRI were observed in the caudate and putamen. The correlations of age and FDRI in the globus pallidus and white matter were significantly lower and did not have statistical significance. The data provide additional evidence that FDRI is a specific measure of tissue iron stores. The data also show that age-related increases in tissue iron stores can be quantified in vivo despite significant age-related processes that oppose the increase in R{sub 2} caused by iron. These results are relevant to the investigation of neurodegenerative processes in which iron may catalyze toxic free-radical reactions. 63 refs., 4 figs., 2 tabs.

  17. Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials

    SciTech Connect

    Sleiman, Mohamad; Kirchstetter, Thomas W.; Berdahl, Paul; Gilbert, Haley E.; Quelen, Sarah; Marlot, Lea; Preble, Chelsea V.; Chen, Sharon; Montalbano, Amandine; Rosseler, Olivier; Akbari, Hashem; Levinson, Ronnen; Destaillats, Hugo

    2014-01-09

    Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon, humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roof Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products₋single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles₋and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. In conclusion, this accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.

  18. Evaluation of Wear Resistance of Friction Materials Prepared by Granulation.

    PubMed

    Ma, Yunhai; Liu, Yucheng; Menon, Carlo; Tong, Jin

    2015-10-21

    The tribological properties of friction materials prepared by hot-pressing pellets of different sizes were experimentally investigated. Friction and wear tests of the specimens were performed and morphological analysis was carried out by investigating images acquired with both scanning electron and confocal laser microscopes. The highest friction coefficient of friction materials was obtained with pellets having 1-5 mm size. The lowest wear rate was obtained with pellets having 8-10 mm size. Specimens processed by mixing pellets of different sizes had the highest density and the lowest roughness and were the least expensive to fabricate. The results show that granulation generally enabled increasing the friction coefficient, decreasing the wear rate, and reducing the number of defects on the surface of friction materials. PMID:26335031

  19. Materials evaluations with the pulsed black liquor burner test facility

    SciTech Connect

    Stein, A.

    1997-08-01

    A pulsed burner was designed to provide sufficient heat to convert a fluidized bed of black Kraft liquor into combustible gas which would be used to produce process steam. The pulsed burner design provides a significant increase in the heat transfer capability and consequently significantly increases the efficiency of the conversion process. High temperature corrosion tests were performed in a fluidized bed of black Kraft liquor using a pulsed burner process to determine the optimum materials for use in a commercial application. The materials tested included three different austenitic stainless steels, Type 446 martensitic stainless steel, a high temperature carbon steel, 153MA, and four nickel base alloys. All materials performed well with no corrosion attributed to the environment created by the decomposition of a black Kraft liquor. This behavior was contrary to what was expected due to the high concentration of H{sub 2}S present in the high temperature, 562 C, atmosphere.

  20. Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants

    SciTech Connect

    Simmons, Kevin L.; Ramuhalli, Pradeep; Brenchley, David L.; Coble, Jamie B.; Hashemian, Hash; Konnik, Robert; Ray, Sheila

    2012-09-14

    The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), NDE instrumentation development, universities, commercial NDE services and cable manufacturers, and Electric Power Research Institute (EPRI). The motivation for the R&D roadmap comes from the need to address the aging management of in-containment cables at nuclear power plants (NPPs).

  1. Material compatibility evaluation for liquid oxygen turbopump fluid foil bearings

    NASA Technical Reports Server (NTRS)

    Stoltzfus, J. M.; Dees, J.; Gu, A.; Dolan, F.

    1992-01-01

    Three series of tests were carried out on three polymer-coated Inconel substrate materials, Teflon S, polyimide bonded graphite fluoride (PBGF), and Teflon, which are considered for use in fluid foil bearings for a liquid oxygen turbopump. All the candidate materials passed the liquid oxygen frictional heating test. During the gaseous oxygen frictional heating test, all coatings wore off before ignition occured. Both Teflon S and PBGF coated foils passed 100 start/stop cycles against chrome-plated Inconel 718 shaft in the direct foil bearing lift-off simulation test in liquid oxygen.

  2. Evaluation of refractory materials for a nuclear waste incinerator

    SciTech Connect

    Grotzky, V. K.; Kneale, P. A.; Teter, A. R.

    1980-07-21

    An experiment to find a suitable refractory lining for a nuclear waste incinerator has been completed. Eleven brick and six castable products were analyzed by optical and scanning microscopy. All the materials were fashioned into cup shapes and subjected to temperatures ranging from 800 to 1200/sup 0/C for as long as six weeks. Some of the cups were charged weekly with pellets made from ash materials that would contact an incinerator liner. Refractory products containing a high percentage of aluminum oxide had the greatest resistance to cracking and slag buildup. 35 figures.

  3. An innovative technique for evaluating fracture toughness of graphite materials

    NASA Astrophysics Data System (ADS)

    Wang, Jy-An John; Liu, Ken C.

    2008-10-01

    Spiral notch torsion fracture toughness test (SNTT) was developed recently to measure the intrinsic fracture toughness ( KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45° pitch. The KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments, including others such as ceramics, their composites, and concrete.

  4. Concepts and techniques for ultrasonic evaluation of material mechanical properties

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    Ultrasonic methods that can be used for material strength are reviewed. Emergency technology involving advanced ultrasonic techniques and associated measurements is described. It is shown that ultrasonic NDE is particularly useful in this area because it involves mechanical elastic waves that are strongly modulated by morphological factors that govern mechanical strength and also dynamic failure modes. These aspects of ultrasonic NDE are described in conjunction with advanced approaches and theoretical concepts for signal acquisition and analysis for materials characterization. It is emphasized that the technology is in its infancy and that much effort is still required before the techniques and concepts can be transferred from laboratory to field conditions.

  5. Methods and Materials for Infusing Aging Issues into the Rehabilitation Curriculum

    ERIC Educational Resources Information Center

    Kampfe, Charlene M.; Harley, Debra A.; Wadsworth, John S.; Smith, S. Mae

    2007-01-01

    In order to better prepare rehabilitation counselors to meet the needs of older workers, Kampfe, Wadsworth, Smith, and Harley (2005) suggested that aging issues can be infused into the curriculum of rehabilitation education programs. This article is a follow-up to the earlier publication that called for infusion of aging issues into the…

  6. Manufacturing Processes: New Methods for the "Materials Age." Resources in Technology.

    ERIC Educational Resources Information Center

    Technology Teacher, 1990

    1990-01-01

    To make the best use of new materials developed for everything from computers to artificial hearts to more fuel-efficient cars, improved materials syntheses and manufacturing processes are needed. This instructional module includes teacher materials, a student quiz, and possible student outcomes. (JOW)

  7. Shade material evaluation based on physiological response of cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle produced in open feedlots are vulnerable to a variety of weather events; under certain conditions heat events can be especially detrimental. Shade structures are often considered as one method of reducing cattle stress. A variety of shading materials are available; selection of a suitable m...

  8. Development and Evaluation of Elastomeric Materials for Geothermal Applications

    NASA Technical Reports Server (NTRS)

    Mueller, W. A.; Kalfayan, S. H.; Reilly, W. W.; Yavrouian, A. H.; Mosesman, I. D.; Ingham, J. D.

    1979-01-01

    A material was formulated having about 250-350 psi tensile strength and 30-80 percent elongation at 260 C for at least 24 hours in simulated brine. The relationship between these laboratory test results and sealing performance in actual or simulated test conditions is not entirely clear; however, it is believed that no conventional formation or casing packer design is likely to perform well using these materials. The synthetic effort focused on high temperature block copolymers and development of curable polystyrene. Procedures were worked out for synthesizing these new materials. Initial results with heat-cured unfilled polystyrene 'gum' at 260 C indicate a tensile strength of about 50 psi. Cast films of the first sample of polyphenyl quinoxaline-polystyrene block copolymer, which has 'graft-block' structure consisting of a polystyrene chain with pendant polyphenyl quinoxaline groups, show elastomeric behavior in the required temperature range. Its tensile strength and elongation at 260 C were 220-350 psi and 18-36 percent, respectively. All of these materials also showed satisfactory hydrolytic stability.

  9. A new perspective on the mechanical evaluation of granular material.

    PubMed

    Chan, Steven H; Wang, Steve S Y; Lai, Chiajen; Grosso, John

    2013-07-01

    The mechanical strength of granules is an important parameter to be determined prior to any further downstream formulation processing. It is important to have a good gauge on the granule integrity to forecast any foreseeable powder issues associated with the material processability such as segregation, content uniformity, and material flow-ability. In this study, a systematic methodology has been developed to quantify the integrity of these granules subjected to a low frequency acoustic field to arrive at the Granule Integrity (GI) index. This methodology has been compared to existing well-established bulk characterization techniques reported in the literature such as Heckel analysis, Kawakita analysis, and Young's modulus for four different processed samples. Heckel analysis is more amenable to examine the material deformability while Kawakita analysis is better suited to understand the mechanics of granular material. Individual granule strength measurements to determine Young's modulus often show large variations across the bulk sample. The GI index in conjunction with the Kawakita analysis provides us with more mechanistic insight and understanding into the formation of these granules from a processing perspective. This paper shows the benefits of using the GI index as a practical and direct methodology to characterize the GI of bulk samples in an industrial setting. PMID:22934612

  10. Developing, Implementing and Evaluating Case Studies in Materials Science

    ERIC Educational Resources Information Center

    Davis, Claire; Wilcock, Elizabeth

    2005-01-01

    The use of case studies to teach materials science undergraduates is an exciting and interesting educational approach. As well as helping learners to connect theory and practice, the case method is also useful for creating an active learning environment, developing key skills and catering for a range of different learning styles. This paper…

  11. Shade Material Evaluation Using a Cattle Response Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle produced in open feedlots are vulnerable to a variety of weather events; under certain conditions heat events can be especially detrimental. Shade structures are often considered as one method of reducing cattle stress. A variety of shading materials are available; selection of a suitable mat...

  12. Evaluation and prediction of long-term environmental effects of nonmetallic materials, second phase

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Changes in the functional properties of a number of nonmetallic materials were evaluated experimentally as a function of simulated space environments and to use such data to develop models for accelerated test methods useful for predicting such behavioral changes. The effects of changed particle irradiations on candidate space materials are evaluated.

  13. EFL Learners' Perspectives on ELT Materials Evaluation Relative to Learning Styles

    ERIC Educational Resources Information Center

    Lee, Bokyung

    2015-01-01

    This paper presents the relationship between Korean EFL learners' self-reporting learning style preferences and their perspectives on ELT materials evaluation. Quantitative data was acquired from 521 subjects' responses to a learning style survey and a questionnaire of materials evaluation checklist. The findings show that Korean EFL learners'…

  14. 48 CFR 625.204 - Evaluating offers of foreign construction material.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Evaluating offers of foreign construction material. 625.204 Section 625.204 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Buy American Act-Construction Materials 625.204 Evaluating offers of foreign construction...

  15. 40 CFR 230.60 - General evaluation of dredged or fill material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false General evaluation of dredged or fill material. 230.60 Section 230.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL Evaluation and Testing § 230.60...

  16. 40 CFR 230.60 - General evaluation of dredged or fill material.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false General evaluation of dredged or fill material. 230.60 Section 230.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL Evaluation and Testing § 230.60...

  17. Performance prediction evaluation of ceramic materials in point-focusing solar receivers

    NASA Technical Reports Server (NTRS)

    Ewing, J.; Zwissler, J.

    1979-01-01

    A performance prediction was adapted to evaluate the use of ceramic materials in solar receivers for point focusing distributed applications. System requirements were determined including the receiver operating environment and system operating parameters for various engine types. Preliminary receiver designs were evolved from these system requirements. Specific receiver designs were then evaluated to determine material functional requirements.

  18. 235U–231Pa age dating of uranium materials for nuclear forensic investigations

    SciTech Connect

    Eppich, Gary R.; Williams, Ross W.; Gaffney, Amy M.; Schorzman, Kerri C.

    2013-04-03

    Here, age dating of nuclear material can provide insight into source and suspected use in nuclear forensic investigations. We report here a method for the determination of the date of most recent chemical purification for uranium materials using the 235U-231Pa chronometer. Protactinium is separated from uranium and neptunium matrices using anion exchange resin, followed by sorption of Pa to an SiO2 medium. The concentration of 231Pa is measured by isotope dilution mass spectrometry using 233Pa spikes prepared from an aliquot of 237Np and calibrated in-house using the rock standard Table Mountain Latite and the uranium isotopic standard U100. Combined uncertainties of age dates using this method are 1.5 to 3.5 %, an improvement over alpha spectrometry measurement methods. Model ages of five uranium standard reference materials are presented; all standards have concordant 235U-231Pa and 234U-230Th model ages.

  19. Building Library Media Collections: Policies and Procedures for Evaluation and Selection of Instructional Materials.

    ERIC Educational Resources Information Center

    Maryland State Dept. of Education, Baltimore.

    This compilation of legal documents and guidelines is intended for use when designing new policies or revising existing policies for the evaluation and selection of print and nonprint instructional materials for elementary and secondary schools and their media centers. These materials focus on the following: (1) textbooks, materials of…

  20. Survey and evaluation of available thermal insulation materials for use on solar heating and cooling systems

    SciTech Connect

    Not Available

    1980-03-01

    This is the final report of a survey and evaluation of insulation materials for use with components of solar heating and cooling systems. The survey was performed by mailing questionnaires to manufacturers of insulation materials and by conducting an extensive literature search to obtain data on relevant properties of various types of insulation materials. The study evaluated insulation materials for active and passive solar heating and cooling systems and for multifunction applications. Primary and secondary considerations for selecting insulation materials for various components of solar heating and cooling systems are presented.

  1. Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

    NASA Astrophysics Data System (ADS)

    Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

    2016-06-01

    Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

  2. Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

    NASA Astrophysics Data System (ADS)

    Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

    2016-08-01

    Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

  3. The evaluation and hazard classification of toxicological information for Workplace Hazardous Materials Information System material safety data sheets.

    PubMed

    Côté, R; Davis, H; Dimock, C; Korpan, M; Loewen, K; Segal, L M

    1998-02-01

    Hazardous materials used occupationally in Canada are subject to the legislated requirements of the Workplace Hazardous Materials Information System (WHMIS). This paper describes the administrative framework of WHMIS and how toxicological data are evaluated to determine if a substance triggers WHMIS classification for the toxicological endpoints of acute toxicity, skin irritation, eye irritation, corrosion, dermal sensitization, respiratory sensitization, chronic toxicity, mutagenicity, teratogenicity/embryotoxicity, and carcinogenicity. Problems encountered with the information on material safety data sheets are also discussed for each of the toxicological endpoints. PMID:9629597

  4. The evaluation and hazard classification of toxicological information for workplace hazardous materials information system material safety data sheets

    PubMed

    Cote; Davis; Dimock; Korpan; Loewen; Segal

    1998-02-01

    Hazardous materials used occupationally in Canada are subject to the legislated requirements of the Workplace Hazardous Materials Information System (WHMIS). This paper describes the administrative framework of WHMIS and how toxicological data are evaluated to determine if a substance triggers WHMIS classification for the toxicological endpoints of acute toxicity, skin irritation, eye irritation, corrosion, dermal sensitization, respiratory sensitization, chronic toxicity, mutagenicity, teratogenicity/embryotoxicity, and carcinogenicity. Problems encountered with the information on material safety data sheets are also discussed for each of the toxicological endpoints. Copyright 1998 Academic Press. PMID:9618324

  5. Declines with Age in Childhood Asthma Symptoms and Health Care Use. An Adjustment for Evaluations

    PubMed Central

    Ko, Yi-An; Clark, Noreen M.

    2014-01-01

    Rationale: Asthma is a variable condition with an apparent tendency for a natural decline in asthma symptoms and health care use occurring as children age. As a result, asthma interventions using a pre-post design may overestimate the intervention effect when no proper control group is available. Objectives: Investigate patterns of natural decline over time with increasing age in asthma symptoms and health care use of children. Develop a statistical procedure that enables adjustment that accounts for expected declines in these outcomes and is useable when intervention evaluations must rely solely on pre-post data. Methods: Mixed-effects models with mixture distributions were used to describe the pattern of symptoms and health care use in 3,021 children aged 2 to 15 years in a combined sample from three controlled trials. An adaptive least squares estimation was used to account for overestimation of intervention effects and make adjustments for pre-post only data. Termed “Adjustment for Natural Declines in Asthma Outcomes (ANDAO),” the adjustment method uses bootstrap sampling to create control cohorts comparable to subjects in the intervention study from existing control subjects. ANDAO accounts for expected declines in outcomes and is beneficial when intervention evaluations must rely solely on pre-post data. Measurements and Main Results: Children under 10 years of age experienced 18% (95% confidence interval, 15–21%) fewer symptom days and 28% (95% confidence interval, 24–32%) fewer symptom nights with each additional year of age. The decline was less than 10% after age 10 years, depending on baseline asthma severity. Emergency department visits declined regardless of baseline symptom frequency (P = 0.02). The adjustment method corrected estimates to within 2.4% of true effects through simulations using control cohorts. Conclusions: Because of the declines in symptoms and health care use expected with increasing age of children with asthma, pre

  6. Quantitative ultrasonic evaluation of mechanical properties of engineering materials

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1978-01-01

    Current progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength properties of engineering materials is reviewed. Even where conventional NDE techniques have shown that a part is free of overt defects, advanced NDE techniques should be available to confirm the material properties assumed in the part's design. There are many instances where metallic, composite, or ceramic parts may be free of critical defects while still being susceptible to failure under design loads due to inadequate or degraded mechanical strength. This must be considered in any failure prevention scheme that relies on fracture analysis. This review will discuss the availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions.

  7. MIC: Material and circuit evaluation for millimeter wave applications

    NASA Astrophysics Data System (ADS)

    Arndt, F.; Bornemann, J.; Grauerholz, D.; Vahldieck, R.; Christ, U.; Stolze, H.

    1981-02-01

    Surface roughness, dielectric constant, quality factor, and loss were measured and a literature survey was conducted to determine materials and circuits suitable for microwave application. The best materials found are RT/Duroid, Rexolite, Polyguide, SiOz, and Al2O3. Fin line, dielectric image line, microstrip line, slot line, waveguide coplanar line, and suspended substrate line are suitable circuits, as shown by the performance of 2 high Q fin line filters up to 33.7 GHz, 3 microstrip 3 dB-hybrid couplers up to 28.3 GHz, a fin line mixer up to 40 GHz, and a fin line printed probe coupler for 31.3 GHz. The design theory for high Q fin line filters is given, including the higher order mode propagation. The measured results vefify the theory. Two of the circuits built were successfully vibration tested.

  8. Technical evaluation of Russian aircraft stealth coating and structural materials

    SciTech Connect

    Gac, F.D.; Young, A.T. Jr.; Migliori, A.

    1996-10-01

    Treating aircraft, missiles, and ships with materials that absorb electromagnetic energy continues to be an important technique for reducing a vehicle`s radar cross section (RCS) and improving tis combat effectiveness and survivability. Work at the Russian Scientific Center for Applied Problems in Electrodynamics (SCAPE) has produced and experimentally validated an accurate predictor of the interaction of electromagnetic radiation with discontinuous composite materials consisting of magnetic and/or dielectric particles dispersed in a non-conductive matrix (i.e. percolation systems). The primary purpose of this project was to analyze rf-absorbing coatings and validate manufacturing processes associated with the Russian percolation system designs. An additional objective was to apply the percolation methodology toward a variety of civilian applications by transferring the technology to US industry.

  9. Evaluation of aged concrete structures for continued service in nuclear power plants

    SciTech Connect

    Naus, D.J.; Marchbanks, M.F.; Arndt, E.G.

    1988-01-01

    Results are summarized of a study on concrete component aging and its significance relative to continued service of nuclear power plants (NPPs) beyond the initial period for which they were granted operating licenses. Progress is presented of a second study being conducted to identify and provide acceptance criteria for structural safety issues which the USNRC staff will need to address when applications are submitted for continued service of NPPs. Major activities under this program include: development of a materials property data base, establishment of structural component assessment and repair procedures, and development of a methodology for determination of structural reliability. 19 refs., 5 figs., 3 tabs.

  10. Evaluation of aged concrete structures for continued service in nuclear power plants

    SciTech Connect

    Naus, D.J.; Marchbanks, M.F.; Arndt, E.G.

    1988-01-01

    Results are summarized of a study on concrete component aging and its significance relative to continued service of nuclear power plants (NPPs) beyond the initial period for which they were granted operating licenses. Progress is presented of a second study being conducted to identify and provide acceptance criteria for structural safety issues which the USNRC staff will need to address when applications are submitted for continued service of NPPs. Major activities under this program include: development of a materials property data base, establishment of structural component assessment and repair procedures, and development of a methodology for determination of structural reliability.

  11. Evaluation of dimensional stability of autoclavable elastomeric impression material.

    PubMed

    Surendra, G P; Anjum, Ayesha; Satish Babu, C L; Shetty, Shilpa

    2011-03-01

    Impressions are important sources of cross contamination between patients and dental laboratories. As a part of infection control impressions contaminated with variety of micro-organisms via blood and oral secretions should be cleaned and disinfected or sterilized before being handled in dental laboratory. The purpose of this study was to determine the effect of autoclaving on dimensional stability of elastomeric impression material (polyvinyl siloxane-Affinis). In this in vitro study standardized stainless steel die as per ADA specification number 19 was fabricated. Polyvinyl siloxane (Affinis) light body and putty viscosity elastomeric impression materials were used. A total of 40 impressions of the stainless steel die were made and numeric coding system was used to identify the samples. Measurements were made using a measuring microscope. Distance between the cross lines CD and C'D' reproduced in the impression were measured before autoclaving, immediately after autoclaving and 24 hours after autoclaving and dimensional change was calculated. The data obtained was subjected to statistical analysis. The mean difference in dimensional change between the three groups was not statistically significant (P > 0.05). However the results revealed that there was higher mean dimensional change immediately after autoclaving when compared to the other 2 time intervals. It is desirable to delay the casting of an autoclavable elastomeric impression material by about 24 hours. Though disinfection of impression is routinely followed autoclaving of impression is an effective method of sterilization. PMID:22379308

  12. Evaluation of Materials and Concepts for Aircraft Fire Protection

    NASA Technical Reports Server (NTRS)

    Anderson, R. A.; Price, J. O.; Mcclure, A. H.; Tustin, E. A.

    1976-01-01

    Woven fiberglass fluted-core simulated aircraft interior panels were flame tested and structurally evaluated against the Boeing 747 present baseline interior panels. The NASA-defined panels, though inferior on a strength-to-weight basis, showed better structural integrity after flame testing, due to the woven fiberglass structure.

  13. Interprofessional education in practice: Evaluation of a work integrated aged care program.

    PubMed

    Lawlis, Tanya; Wicks, Alison; Jamieson, Maggie; Haughey, Amy; Grealish, Laurie

    2016-03-01

    Health professional clinical education is commonly conducted in single discipline modes, thus limiting student collaboration skills. Aged care residential facilities, due to the chronic and complex health care needs of residents, provide an ideal placement to provide a collaborative experience. Interprofessional education is widely acknowledged as the pedagogical framework through which to facilitate collaboration. The aim of the evaluation was to assess student attitudes towards collaboration after active involvement in an interprofessional education program. Students studying nursing, occupational therapy, and aged care were invited to complete a version of the Readiness for Interprofessional Learning Scale before and after participating in a three-week pilot interprofessional program. A positive change in student attitudes towards other health professionals and the importance of working in interprofessional teams was reported with significant differences between two statements indicated: Learning with health-care students before qualifications would improve relationships after qualifications; and I learned a lot from the students from the other disciplines. The innovative pilot project was found to enhance student learning in interprofessional teams and the aged care environment. Further development of this and similar interprofessional programs is required to develop sustainable student projects that have health benefits for residents in aged care residential facilities. PMID:26733460

  14. Considering maturation status and relative age in the longitudinal evaluation of junior rugby league players.

    PubMed

    Till, K; Cobley, S; O' Hara, J; Cooke, C; Chapman, C

    2014-06-01

    This study longitudinally evaluated whether maturation and relative age interact with time during adolescence to differentially affect the development of anthropometric and fitness characteristics in junior rugby league players. Anthropometric and fitness characteristics of 81 junior players selected into the UK Rugby Football League's talent identification and development process were assessed over three consecutive occasions (i.e., under-13s, -14s, -15s). Players were grouped and compared in relation to maturational status (i.e., early, average, late) and relative age quartile (i.e., quartile 1). Repeated measures multivariate analysis of variance identified significant (P < 0.001) overall main effects for maturation group, relative age quartile and importantly a maturation group by time interaction. Findings showed that the early-maturing group had the greatest anthropometric characteristics and medicine ball throw across the three occasions. However, the late-maturing group increased their height (early = 5.0 cm, late = 10.3 cm), medicine ball throw and 60-m sprint (early = -0.46 s, late = -0.85 s) the most throughout the 2-year period. Early (de)selection policies currently applied in talent identification and development programs are questionable when performance-related variables are tracked longitudinally. During adolescence, maturation status alongside relative age should be considered and controlled for when assessing athlete potential for future progression. PMID:23289942

  15. The importance of age and smoking in evaluating adverse cytogenetic effects of exposure to environmental agents

    SciTech Connect

    Tucker, J.D.; Moore, D.H. II

    1995-08-01

    Fluorescence in situ hybridization with chromosome-specific composite DNA probes (``chromosome painting``) is a reliable and efficient method for detecting structural chromosome aberrations. Painting is now being used to quantify chromosome damage in many human populations. In one such study we evaluated 91 unexposed people ranging in age from birth (cord bloods) to 79. We established a baseline frequency of stable aberrations that showed a highly significant curvi-linear increase with age (p < 0.00001) that accounted for 70% of the variance between donors. The magnitude of this effect illustrates the importance of understanding the cytogenetic changes that occur with age, which is particularly important for quantifying the effects of prior adverse environmental, occupational, or accidental exposure. In this paper we use the data obtained in our previous study to characterize the distribution of stable aberrations by age and pack-years of cigarette smoking. We also provide estimates of the number of cell equivalents that need to be scored to detect a given increase in aberrations above the background level surveyed in this population.

  16. Nuclear Energy Plant Optimization (NEPO) final report on aging and condition monitoring of low-voltage cable materials.

    SciTech Connect

    Assink, Roger Alan; Gillen, Kenneth Todd; Bernstein, Robert

    2005-11-01

    This report summarizes results generated on a 5-year cable-aging program that constituted part of the Nuclear Energy Plant Optimization (NEPO) program, an effort cosponsored by the U. S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI). The NEPO cable-aging effort concentrated on two important issues involving the development of better lifetime prediction methods as well as the development and testing of novel cable condition-monitoring (CM) techniques. To address improved life prediction methods, we first describe the use of time-temperature superposition principles, indicating how this approach improves the testing of the Arrhenius model by utilizing all of the experimentally generated data instead of a few selected and processed data points. Although reasonable superposition is often found, we show several cases where non-superposition is evident, a situation that violates the constant acceleration assumption normally used in accelerated aging studies. Long-term aging results over extended temperature ranges allow us to show that curvature in Arrhenius plots for elongation is a common occurrence. In all cases the curvature results in a lowering of the Arrhenius activation energy at lower temperatures implying that typical extrapolation of high temperature results over-estimates material lifetimes. The long-term results also allow us to test the significance of extrapolating through the crystalline melting point of semi-crystalline materials. By utilizing ultrasensitive oxygen consumption (UOC) measurements, we show that it is possible to probe the low temperature extrapolation region normally inaccessible to conventional accelerated aging studies. This allows the quantitative testing of the often-used Arrhenius extrapolation assumption. Such testing indicates that many materials again show evidence of ''downward'' curvature (E{sub a} values drop as the aging temperature is lowered) consistent with the limited elongation results and

  17. State Education Department: Security over Pupil Evaluation Program and Program Evaluation Test Materials Needs Improvement. Report 91-S-2.

    ERIC Educational Resources Information Center

    New York State Office of the Comptroller, Albany.

    Findings of an audit of the New York State Education Department's procedures to maintain security over Pupil Evaluation Program (PEP) and Program Evaluation Test (PET) examination materials are presented in this report. The audit sought to determine whether the department's security procedures adequately prevented unauthorized access to exam…

  18. Uranium isotopes in Pleistocene permafrost: evaluating the age of ancient ice

    NASA Astrophysics Data System (ADS)

    Ewing, S. A.; Paces, J. B.; O'Donnell, J.; Kanevskiy, M. Z.; Aiken, G.; Jorgenson, T.; Shur, Y.; Striegl, R. G.

    2010-12-01

    The age of ice in permafrost is an indicator of past climate history, and of the resilience and response of high-latitude ecosytems to global change. Methods such as radiocarbon dating and tephrachronology are limited in permafrost because they provide indirect age control, and could overestimate ages when ice is intermittently absent. Development of geochemical indicators of water/ice residence time in permafrost is critical for understanding the circumstances and primary controls of permafrost formation, preservation, and thaw in response to climate change. We analyzed uranium isotopes to evaluate the age of segregated ice in ice-rich loess permafrost (yedoma) cores from central Alaska. Activity ratios of 234U vs. sup>238U (234/238U ARs) in thawed waters exceed 1.000 due to extended contact of ice with mineral surfaces over time. Ice is expected to increase in age with depth at this location based on the presence of deep loess, cryostructures associated with syngenetic permafrost aggracation, high segregated ice content, and frequent wedge ice. These features indicate that permafrost formed syngenetically as loess was deposited. Consequently, (234/238U ARs are expected to increase with depth as recoil 234U, derived from in situ decay of (238U in loess particles, accumulates in ice without being flushed over time. Values of (234/238U ARs measured for ice from a series of five neighboring cores up to 21 m deep increase with depth, consistent with downhole increases in permafrost age. Additional variability of (234/238U ARs with depth can be attributed to variations in surface area of solids determined by analysis of particle size distribution. Radiocarbon analysis of dissolved organic carbon indicates that the ages of ice are greater than ~36ky below the upper few meters, consistent with previous work on soil organic-matter profiles in this area. Using these measured parameters, a model of (234/238U AR evolution indicates minimum ages up to a minimum of ~100ky in

  19. Evaluation of Ion Exchange Materials in K Basin Floor Sludge and Potential Solvents for PCB Extraction from Ion Exchange Materials

    SciTech Connect

    Schmidt, A.J.; Klinger, G.S.; Bredt, P.R.

    1999-04-10

    Approximately 73 m{sup 3} of heterogeneous solid material, ''sludge,'' (upper bound estimate, Packer 1997) have accumulated at the bottom of the K Basins in the 100 K Area of the Hanford Site. This sludge is a mixture of spent fuel element corrosion products, ion exchange materials (organic and inorganic), graphite-based gasket materials, iron and aluminum metal corrosion products, sand, and debris (Makenas et al. 1996, 1997). In addition, small amounts of polychlorinated biphenyls (PCBs) have been found. These small amounts are significant from a regulatory standpoint. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). Chemical pretreatment is required to address criticality issues and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Eleven technologies have been evaluated (Papp 1997) as potential pretreatment methods. Based on the evaluations and engineering studies and limited testing, Fluor Daniel Hanford recommended solvent washing of the K Basin sludge, followed by nitric acid dissolution and, potentially, peroxide addition (FDH 1997). The solvent washing (extraction) and peroxide addition would be used to facilitate PCB removal and destruction. Following solvent extraction, the PCBs could be distilled and concentrated for disposal as a low-level waste. The purpose of the work reported here was to continue investigating solvent extraction, first by better identifying the ion exchange materials in the actual sludge samples and then evaluating various solvents for removing the PCBs or possibly dissolving the resins. This report documents some of the process knowledge on ion exchange materials used and spilled in the K Basins and describes the materials identified from wet sieving KE Basin floor and canister sludge and the results of other analyses. Several photographs are included to compare materials and illustrate material behavior. A summary of previous tests on

  20. Evaluation of the normal fetal kidney length and its correlation with gestational age.

    PubMed

    Seilanian Toosi, Farrokh; Rezaie-Delui, Hossein

    2013-01-01

    A true estimation of gestational age (GA) plays an important role in quality maternity care and scheduling the labor date. This study aimed to evaluate the normal fetal kidney length (KL) and its correlation with GA. A cross-sectional study on 92 pregnant women between 8th and 10th week of gestation with normal singleton pregnancy underwent standard ultrasound fetal biometry and kidney length measurement. univariate and multivariate linear regression analysis was used to create a predictive equation to estimate GA on the KL and fetobiometry parameters. A significant correlation was found between GA and KL (r=0.83, P<0.002). The best GA predictor was obtained by combining head circumference, fetal biparietal diameter, femur length and KL with a standard error (SE) about 14.2 days. Our findings showed that KL measurements combination with other fetal biometric parameters could predict age of pregnancy with a better precision. PMID:23737313

  1. Evaluation of Cadmium-Free Thick Film Materials on Alumina Substrates

    SciTech Connect

    L. H. Perdieu

    2009-09-01

    A new cadmium-free material system was successfully evaluated for the fabrication of thick film hybrid microcircuits at Honeywell Federal Manufacturing & Technologies (FM&T). The characterization involved screen printing, drying and firing two groups of resistor networks which were made using the current material system and the cadmium-free material system. Electrical, environmental and adhesion tests were performed on both groups to determine the more suitable material system. Additionally, untrimmed test coupons were evaluated to further characterize the new materials. The cadmiumfree material system did as well or better than the current material system. Therefore, the new cadmium-free material system was approved for use on production thick film product.

  2. Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations.

    PubMed

    Yamauchi-Kawaura, C; Fujii, K; Akahane, K; Yamauchi, M; Narai, K; Aoyama, T; Katsu, T; Obara, S; Imai, K; Ikeda, M

    2015-02-01

    In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations. PMID:24821932

  3. Acousto-ultrasonic evaluation of ceramic matrix composite materials

    NASA Technical Reports Server (NTRS)

    Dosreis, Henrique L. M.

    1991-01-01

    Acousto-ultrasonic nondestructive evaluation of ceramic composite specimens with a lithium-alumino-silicate glass matrix reinforced with unidirectional silicon carbide (NICALON) fibers was conducted to evaluate their reserve of strength. Ceramic composite specimens with different amount of damage were prepared by four-point cyclic fatigue loading of the specimens at 500 C for a different number of cycles. The reserve of strength of the specimens was measured as the maximum bending stress recorded during four-pointed bending test with the load monotonically increased until failure occurs. It was observed that the reserve of strength did not correlate with the number of fatigue cycles. However, it was also observed that higher values of the stress wave factor measurements correspond to higher values of the reserve of strength test data. Therefore, these results show that the acousto-ultrasonic approach has the potential of being used to monitor damage and to estimate the reserve of strength of ceramic composites.

  4. Detecting nuclear materials smuggling: performance evaluation of container inspection policies.

    PubMed

    Gaukler, Gary M; Li, Chenhua; Ding, Yu; Chirayath, Sunil S

    2012-03-01

    In recent years, the United States, along with many other countries, has significantly increased its detection and defense mechanisms against terrorist attacks. A potential attack with a nuclear weapon, using nuclear materials smuggled into the country, has been identified as a particularly grave threat. The system for detecting illicit nuclear materials that is currently in place at U.S. ports of entry relies heavily on passive radiation detectors and a risk-scoring approach using the automated targeting system (ATS). In this article we analyze this existing inspection system and demonstrate its performance for several smuggling scenarios. We provide evidence that the current inspection system is inherently incapable of reliably detecting sophisticated smuggling attempts that use small quantities of well-shielded nuclear material. To counter the weaknesses of the current ATS-based inspection system, we propose two new inspection systems: the hardness control system (HCS) and the hybrid inspection system (HYB). The HCS uses radiography information to classify incoming containers based on their cargo content into "hard" or "soft" containers, which then go through different inspection treatment. The HYB combines the radiography information with the intelligence information from the ATS. We compare and contrast the relative performance of these two new inspection systems with the existing ATS-based system. Our studies indicate that the HCS and HYB policies outperform the ATS-based policy for a wide range of realistic smuggling scenarios. We also examine the impact of changes in adversary behavior on the new inspection systems and find that they effectively preclude strategic gaming behavior of the adversary. PMID:22043828

  5. Evaluation of Pyro-optic Materials for Infrared Imaging

    NASA Astrophysics Data System (ADS)

    Pandey, R. K.; Kotru, Sushma; Song, Xiuyu; Donnelly, David

    2004-03-01

    Infrared detectors are needed for a wide range of applications. IR detectors operate either on the principles of photon detection or pyroelectric detection. Both these systems have their respective advantages and disadvantages. However, both of them inherently have difficulties in management of noise to signal ratio and in read-out circuitory. One of the most serious handicaps of photon detectors is requirement of cryogenic cooling for satisfactory operation. In this respect uncooled pyroelectric detectors operating at above room temperature have an advantage. An alternative to these approaches can be pyro-optic based detectors. Only a handful of materials have been found with some satisfactory level of pyro-optic coefficients appropriate for imaginig devices. Some of them are: antimony-sulfo-iodide (SbSI), molybdenum sulfide (MoS2), bismuth vanadate (BiVO4) and Pb-based titanates. Pyrooptic coefficients of these materials have been reported using presumably bulk single crystals. However, no such data are available for their thin films which would be very important for light weight integrated structured devices.In this paper we will describe the parameters and optimization protocol for the growh of thin films of these materials on thermally insulating substrates. We will also discuss their structural, electrical and optical properties. Our investigations suggest that SbSI, BiVO4 and PNZT films are attractive options for advancing the IR detecting technology by utilizing the pyro-optic effect. Integrated thin film structures might lead to the fabrication of light weight, low cost, noise immune and efficient imaging devices based on pyro-optic properties. This research is sponsored by the DEPSCoR program of the U.S. Army Research Office.

  6. AN EVALUATION OF THE USE OF ENGLISH INSTITUTE MATERIALS CENTER CURRICULUM MATERIALS IN NDEA SUMMER INSTITUTES IN ENGLISH.

    ERIC Educational Resources Information Center

    SHUGRUE, MICHAEL F.; AND OTHERS

    IN THE SUMMER OF 1966, THE MODERN LANGUAGE ASSOCIATION OF AMERICA CONDUCTED A REVIEW OF THE USE AND EFFECTIVENESS OF EXPERIMENTAL CURRICULUM UNITS DISTRIBUTED BY THE ENGLISH INSTITUTE MATERIALS CENTER (EIMC) TO NATIONAL DEFENSE EDUCATION ACT (NDEA) SUMMER INSTITUTES IN ENGLISH AND CLOSELY RELATED AREAS. THE EVALUATORS VISITED 27 INSTITUTES,…

  7. Cscibox: A Software System for Age-Model Construction and Evaluation

    NASA Astrophysics Data System (ADS)

    Bradley, E.; Anderson, K. A.; Marchitto, T. M., Jr.; de Vesine, L. R.; White, J. W. C.; Anderson, D. M.

    2014-12-01

    CSciBox is an integrated software system for the construction and evaluation of age models of paleo-environmetal archives, both directly dated and cross dated. The time has come to encourage cross-pollinization between earth science and computer science in dating paleorecords. This project addresses that need. The CSciBox code, which is being developed by a team of computer scientists and geoscientists, is open source and freely available on github. The system employs modern database technology to store paleoclimate proxy data and analysis results in an easily accessible and searchable form. This makes it possible to do analysis on the whole core at once, in an interactive fashion, or to tailor the analysis to a subset of the core without loading the entire data file. CSciBox provides a number of 'components' that perform the common steps in age-model construction and evaluation: calibrations, reservoir-age correction, interpolations, statistics, and so on. The user employs these components via a graphical user interface (GUI) to go from raw data to finished age model in a single tool: e.g., an IntCal09 calibration of 14C data from a marine sediment core, followed by a piecewise-linear interpolation. CSciBox's GUI supports plotting of any measurement in the core against any other measurement, or against any of the variables in the calculation of the age model-with or without explicit error representations. Using the GUI, CSciBox's user can import a new calibration curve or other background data set and define a new module that employs that information. Users can also incorporate other software (e.g., Calib, BACON) as 'plug ins.' In the case of truly large data or significant computational effort, CSciBox is parallelizable across modern multicore processors, or clusters, or even the cloud. The next generation of the CSciBox code, currently in the testing stages, includes an automated reasoning engine that supports a more-thorough exploration of plausible age models

  8. Evaluation of CBS 600 carburized steel as a gear material

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Parker, R. J.; Zaretsky, E. V.

    1979-01-01

    Gear endurance tests were conducted with one lot of consumable-electrode vacuum-melted (CVM) AISI 9310 gears and one lot of air-melt CBS 600 gears. The gears were 8 pitch with a pitch diameter of 8.89 centimeters (3.5 in.). Bench-type rolling-element fatigue tests were also conducted with one lot of CVM AISI 9310, three lots of CVM CBS 600, and one of air-melt CBS 600 material. The rolling-element bars were 0.952 centimeter (0.375 in.) in diameter. The CBS 600 material exhibited pitting fatigue lives in both rolling-element specimens and gears at least equivalent to that of CVM AISI 9310. Tooth fracture failure occurred with the CBS 600 gears after overrunning a fatigue spall, but it did not occur with the CVM AISI 9310 gears. Tooth fracture in the CBS 600 was attributed to excessive carbon content in the case, excessive case depth, and a higher than normal core hardness.

  9. An environmental cracking evaluation of fastener materials for seawater applications

    SciTech Connect

    Aylor, D.M.

    1994-12-31

    Slow strain rate tests (SSRT) were conducted on various nickel-base, titanium base, and copper-nickel (Cu-Ni) alloys in order to identify a replacement material for Alloy K-500 in seawater fastener applications. SSRT data and fracture surface analysis of the test specimens identified a susceptibility to environmental cracking in cathodically polarized environments for Alloy K-500, Alloy 625 Plus, and Alloy 625PH. Alloy 625 Plus exhibited slightly increased environmental cracking resistance-at {minus}850 mV vs. SCE over Alloy K-500 and Alloy 625PH. Ti-6Al-4V ELI, Beta C, and Beta 21S titanium displayed no susceptibility to environmental cracking in freely corroding 3.5% NaCl or cathodically polarized conditions. Precharging these titanium alloys for 8 weeks at {minus}1,250 mV vs. SCE did not adversely affect their environmental cracking resistance. The Cu-3Ni and Cu-15Ni-7Sn spray formed alloys exhibited extensive scatter and low measured maximum loads, presumably due to macroporosity present in the as-fabricated material.

  10. Low velocity impact testing and nondestructive evaluation of transparent materials

    SciTech Connect

    Brennan, R. E.; Green, W. H.

    2011-06-23

    Advanced transparent materials are used in protective systems for enhancing the survivability of ground vehicles, air vehicles, and personnel in applications such as face shields, riot gear, and vehicle windows. Low velocity impact damage can limit visibility and compromise the structural integrity of a transparent system, increasing the likelihood of further damage or penetration from a high velocity impact strike. For this reason, it is critical to determine damage tolerance levels of transparent systems to indicate whether or not a component should be replaced. In this study, transparent laminate systems will be tested by comparing baseline conditions to experimentally controlled damage states. Destructive testing including air gun and sphere impact testing will be used to replicate low velocity impacts in the field. Characterization of the damaged state will include basic visual inspection as well as nondestructive techniques including cross-polarization, x-ray, and ultrasound. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for materials used in protective systems.

  11. In vitro evaluation of a new injectable calcium phosphate material.

    PubMed

    Grimandi, G; Weiss, P; Millot, F; Daculsi, G

    1998-03-15

    The purpose of this study was to develop an injectable bone substitute (IBS) for percutaneous orthopedic surgery. The multiphasic material used was composed of a 2% aqueous solution of methylhydroxypropylcellulose (MHPC) and biphasic calcium phosphate (BCP, 60% hydroxyapatite and 40% beta-tricalcium phosphate) in which MHPC served as the carrier for 80-200 microm of BCP granules. The best BCP/polymer ratio was determined by the rheological properties and higher BCP content of the material. Steam sterilization was more effective than gamma irradiation in maintaining the stability of the mixture and conserving its physiochemical and mechanical properties. The in vitro biocompatibility of the composite was checked by direct-contact cytotoxicity and cell-proliferation assays. A preliminary in vivo test was performed in the rabbit using intraosseous implantations in the femoral epiphysis. Histological analysis was done after 1, 2, 4, and 10 weeks. Bone ingrowth into the IBS, in close association with BCP granules, was observed after 1 week and increased regularly from the surface inward at 2, 4, and 10 weeks. At the same time, smaller BCP granules (less than 80 microns in diameter) were degraded and resorbed. This injectable biomaterial proved suitable for cavity filling. The water solubility and viscosity of the polymer allow cells to recolonize, with in situ bonding of the mineral phase. PMID:9492229

  12. Standards for Evaluation of Instructional Materials with Respect to Social Content.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Curriculum Framework and Instructional Materials Unit.

    The purpose of this document is to provide reasonable, systematic standards for evaluation of instructional materials upon which evaluators may base their judgments, so that the results of the evaluation process will be as nearly consistent and therefore, as equitable, as possible. The guidelines are based on the social content requirements of the…

  13. Evaluation of serum transferrin receptor for iron deficiency in women of child-bearing age.

    PubMed

    Lin, Xiao-Ming; Zhang, Juan; Zou, Zhi-Yong; Long, Zhu; Tian, Wei

    2008-11-01

    The objective was to study the evaluation of serum transferrin receptor (sTfR) for Fe deficiency in women of child-bearing age. Primary screening was performed in 942 women ranging in child-bearing age. Serum ferritin (SF), Zn protoporphyrin (ZPP) and Hb were determined. Then the subjects were divided into four groups: normal, Fe store depletion (IDs), Fe-deficiency erythropoiesis and Fe-deficiency anaemia. sTfR was determined and sTfR/SF (sTfR/logSF and log(sTfR/SF)) was calculated. Changes of sTfR in women of different Fe status were observed. A receiver-operating characteristic (ROC) curve was used to evaluate whether sTfR had proper diagnostic efficacy for functional Fe deficiency. The levels of sTfR increased significantly along with the aggravation of Fe deficiency. Increase of STfR/SF along with the aggravation of Fe deficiency was more significant than that of sTfR. STfR had a significant negative correlation with SF and Hb, while it had a significant positive correlation with ZPP. The ROC curve showed that the diagnostic effective rate of sTfR for Fe deficiency could reach 83 %. At this point, the sensitivity was 79 % and the specificity was 63 %. Log(sTfR/SF) could be considered to have the highest effective ratio in detecting IDs, since it reached 99 %. STfR and sTfR/SF could both reflect body Fe-deficiency status specifically. They could be used as reliable indicators for evaluating Fe status and diagnosing Fe deficiency in women of child-bearing age. PMID:18377683

  14. [Delphi method to identify education material on healthy food for teachers, school-age children and their parents].

    PubMed

    Vio, Fernando; Lera, Lydia; Fuentes-García, Alejandra; Salinas, Judith

    2012-09-01

    Delphi method to identify education material on healthy food for teachers, school-age children and their parents. Delphi method applied to get expert consensus about healthy food topics to include in educational materials for preschool and school-age children, their parents and teachers is described. The questionnaire was developed with the results of surveys and focus groups in children, parents and teachers made previously. The questionnaire was mailed to 54 experts in nutrition, education and communication in a first round. The results were analyzed and forwarded in a second round with the subjects without consensus. The cycle was completed by a validation conducted with teachers and parents and were prioritized by audiovisual educational materials on the writings, favoring participatory activities such as cooking workshops, games, activities over the passive (information at parent meetings, delivery of educational materials and conferences of experts). There was consensus on education in health behaviors such as not giving them money to carry to school, make healthy food choices on family outings and recreational activities associated with healthy eating during weekends; prefer healthy food prepared at home instead of the processed food; restrict eating out candy and prefer family meals without watching TV and food instead of taking a snack in the evening. These results are critical to design educational materials on healthy eating plans to change current eating habits that are contributing significantly to increase the childhood obesity. PMID:24617030

  15. Electrostatic Evaluation of the ARES I FTS Antenna Materials

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Calle, Carlos I.

    2010-01-01

    Surface resistivity and volume resistivity data show all the tested non-metallic materials of the Ares I FTS antenna assembly to be insulative. The external materials (White foam, phenolic) should be able to develop a large surface charge density upon tribocharging with ice crystal impingement. Dielectric breakdown tests on the FTS antenna housing materials show that each of the insulative materials are very resistive to electrical breakdown. The thicknesses of these materials in a nominal housing should protect the antenna from direct breakdown from external triboelectric charging potentials. Per data from the Air Force study, a maximum external electric potential in the range of 100kV can be developed on surfaces tribocharged by ice crystal impingement. Testing showed that under operational pressure ranges, this level of exterior voltage can result in a potential of about 6 kV induced on the electrically floating interior antenna vanes. Testing the vanes up to this voltage level showed that electrostatic discharges can occur between the electrically floating vanes and the center, grounded screw heads. Repeated tests with multiple invisible and visible discharges caused only superficial physical damage to the vanes. Fourier analysis of the discharge signals showed that the frequency range of credible discharges would not interfere with the nominal operation of the FTS antenna. However, due to the limited scope, short timetable, and limited funding of this study, a direct measurement of the triboelectric charge that could be generated on the Ares I antenna housing when the rocket traverses an ice cloud at supersonic speeds was not performed. Instead, data for the limited Air Force study [3] was used as input for our experiments. The Air Force data used was not collected with a sensor located to provide us with the best approximation at the geometry of the Ares I rocket, namely that of the windshield electrometer, because brush discharges to the metal frame of the

  16. Instrumental analysis for differentiation of beers and evaluation of beer ageing

    NASA Astrophysics Data System (ADS)

    Dreve, Simina; Voica, Cezara; Dragan, Felicia; Georgiu, Monica

    2013-11-01

    A representative selection of 5 different beers commercially available were measured spectrophotometrically in UV-Vis spectral region and by fluorescence spectroscopy, in order to determine qualitative differentiation due to the mainly iso-R-acids (with a five member ring) originating from R-acids present in hops. Minerals and trace elements analysis were also performed by ICP-MS method. The determination of the bitter organic acids in beers and of the content in metallic ions can be used as indicators for differentiation of beers and evaluation of beer ageing.

  17. Influence of artificially accelerated ageing on the adhesive joint of plasma treated polymer materials

    NASA Astrophysics Data System (ADS)

    Lehocký, M.; Lapčik, L.; Dlabaja, R.; Rachünek, L.; Stoch, J.

    2004-03-01

    An influence of simulated ageing on the adhesive joint of plasma treated polyethylene (PE) and polypropylene (PP) was tested. Plasma surface treatment was performed in the rf-plasma reactor operating at 13,56 MHz. The simulated ageing of prepared specimens for following tensile testing was carried out under conditions given by Volkswagen standard P-VW 1200. Temperature of ageing was regularly oscillating between -40°C and 80°C (relative humidity 80%) for required time. The mechanical tensile properties of adhesive joint were measured according to the standard ISO 527. Surface analysis of treated polymer substrates was characterized by XPS measurement. The observation of surface structure and morphology was obtained using SEM. We used convenient cyanoacrylate adhesive Loctite E 406 for PE and PP joints. Tested adhesive joints were prepared in compliance with the standard ISO 4587.

  18. CW laser generated ultrasound techniques for microstructure material properties evaluation

    NASA Astrophysics Data System (ADS)

    Thursby, Graham; Culshaw, Brian; Pierce, Gareth; Cleary, Alison; McKee, Campbell; Veres, Istvan

    2009-03-01

    Mechanical properties of materials may be obtained from the inversion of ultrasonic Lamb wave dispersion curves. In order to do this broadband excitation and detection of ultrasound is required. As sample size and, in particular, thickness, are reduced to those of microstructures, ultrasound frequencies in the range of the gigahertz region will be required. We look at two possible cw laser excitation techniques which, having far lower peak powers than the more frequently used Q-switched lasers, therefore give a negligible risk of damaging the sample through ablation. In the first method the modulation frequency of a sinusoidally modulated laser is swept over the required range. In the second, the laser is modulated with a series of square pulses whose timing is given by a PRBS (pseudo random binary sequence) in the form of a modified m-sequence.

  19. Evaluation of materials for the MHD steam bottoming plant

    SciTech Connect

    Natesan, K.; Swift, W.M.

    1989-05-01

    Test data have been obtained on the corrosion of several commercial ASME-coded alloys and their weldments by exposing internally cooled ring specimens to simulated magnetohydrodynamics (MHD) environments. The specimens, coated with a K/sub 2/SO/sub 4/-rich deposit, were exposed for times up to 2000 h at metal temperatures of 762, 593, and 567/degree/C to simulated MHD conditions for the intermediate-temperature air heater (ITAH), ITAH transition region (transition from a low- to medium-chromium alloy to a high-chromium steel), and secondary superheater (SSH), respectively. This paper discusses, in detail, the observed corrosion scale morphologies of various exposed specimens. Data on scale thickness, depth of intergranular penetration, and metal recession are presented, and the results are used to assess the corrosion behavior of various materials for application in the MHD steam bottoming plant. 6 refs., 7 figs., 3 tabs.

  20. High-throughput evaluation of descriptors for thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Madsen, Georg

    2015-03-01

    Achieving optimal carrier and minimal thermal conductivity is necessary for a given material to be suitable for thermoelectric energy conversion. Both properties are computationally too demanding for brute force approaches which demands that simplified descriptors are developed. Based on the recent computational discovery of favorable thermoelectric performance in the commercially viable an environmentally friendly Ag:SnS, we discuss how doping limits can be computationally screened. We will discuss the effects of two ubiquitous effects that can result in decreasing the hole concentration and show how the surprising results of Li doping can be rationalized based on data made available through on-line repositories. Furthermore, we show how the lattice thermal conductivity can be rapidly and reliably screened based on the quasi harmonic approximation. We contrast this to the information covered by the available phase space for three-phonon scattering processes.

  1. A new method for evaluating age distributions of detrital zircon datasets by incorporating discordant data

    NASA Astrophysics Data System (ADS)

    Reimink, Jesse; Davies, Joshua; Rojas, Xavier; Waldron, John

    2015-04-01

    U-Pb ages from detrital zircons play an important role in sediment provenance studies. However, U-Pb ages from detrital zircon populations often contain a discordant component, which is traditionally removed before the age data are interpreted. Many different processes can create discordant analyses, with the most important being Pb-loss and mixing of distinct zircon age domains during analysis. Discordant ages contain important information regarding the history of a detrital zircon population, for example the timing of Pb-loss or metamorphism, and removing these analyses may significantly bias a zircon dataset. Here we present a new technique for analyzing detrital zircon populations that uses all U-Pb analyses, independent of discordance. We have developed computer code that evaluates the relative likelihood of discordia lines based on their proximity to discordant data points. When two or more data points lie on or near a discordia line the likelihood associated with that line increases. The upper and lower intercepts of each discordia line, as well as the relative likelihood along that line, are stored, and the likelihood of upper and lower intercepts are plotted with age. There are many benefits to using this technique for analysis of detrital zircon datasets. By utilizing the discordant analyses we allow for the addition of upper and lower intercept information to conventional analysis techniques (i.e. probability density functions or kernel density estimators). We are then able to use a much stricter discordance filter (e.g. < 3%) when analyzing 'concordant' data, thereby increasing the reliability of Pb/Pb ages used in the traditional analysis. Additionally, by not rejecting discordant data from zircon datasets we potentially reduce the overall bias in the analysis, which is a critical step in detrital zircon studies. This new technique is relatively quick and uses traditional analytical results, while the upper and lower intercept information is obtained

  2. Self-healing of early age cracks in cement-based materials by mineralization of carbonic anhydrase microorganism

    PubMed Central

    Qian, Chunxiang; Chen, Huaicheng; Ren, Lifu; Luo, Mian

    2015-01-01

    This research investigated the self-healing potential of early age cracks in cement-based materials incorporating the bacteria which can produce carbonic anhydrase. Cement-based materials specimens were pre-cracked at the age of 7, 14, 28, 60 days to study the repair ability influenced by cracking time, the width of cracks were between 0.1 and 1.0 mm to study the healing rate influenced by width of cracks. The experimental results indicated that the bacteria showed excellent repairing ability to small cracks formed at early age of 7 days, cracks below 0.4 mm was almost completely closed. The repair effect reduced with the increasing of cracking age. Cracks width influenced self-healing effectiveness significantly. The transportation of CO2and Ca2+ controlled the self-healing process. The computer simulation analyses revealed the self-healing process and mechanism of microbiologically precipitation induced by bacteria and the depth of precipitated CaCO3 could be predicted base on valid Ca2+. PMID:26583014

  3. Older adults' evaluations of middle-aged children's attempts to initiate discussion of care needs.

    PubMed

    Fowler, Craig; Fisher, Carla L; Pitts, Margaret J

    2014-01-01

    We explored how older adults evaluated the strategies used by an adult child to initiate discussion of future care needs, and subsequently, whether these judgments affected older adults' willingness to engage in discussions about eldercare if approached in a similar fashion by one of their own children. One hundred and thirty older adults were randomly assigned to read one of four scripts depicting efforts by a middle-aged daughter to raise the topic of future care needs with her mother by implementing a variety of facework behaviors. Scripts manipulated the degree to which the daughter conveyed respect for her mother's desires for autonomy (negative face) and connection (positive face). The daughter's facework significantly predicted older parents' evaluation of her as supportive, which in turn predicted their willingness to discuss future care needs with one of their own children if they were to approach the conversation in a similar way. PMID:24156501

  4. Evaluation of materials proposed for use in space flight

    NASA Technical Reports Server (NTRS)

    Duncan, W. C.

    1981-01-01

    The cutaneous primary irritancy and allergenicity potential of cotton shirts/fabrics treated with flame retardants were evaluated in order to establish their suitability for spacecraft crew use. Twenty-five volunteer human subjects were patch tested on the back utilizing standard methodology, with both treated and untreated cotton fabric. The fabric was treated with tetrakis (hydroxymethyl) phosphonium hydroxide and subsequently cured with gaseous ammonia. The final treatment comprised adding on dicyandiamine phosphoric acid. None of the individuals experienced primary irritant or allergic reactions attributable to the fabric during induction or challenge patch testing. Likewise, there were no reactions to treated or untreated fabric patches placed on ten subjects of the usage panel at the conclusion of the study.

  5. A Behavioral Paradigm to Evaluate Hippocampal Performance in Aged Rodents for Pharmacological and Genetic Target Validation

    PubMed Central

    Gerstein, Hilary; Hullinger, Rikki; Lindstrom, Mary J.; Burger, Corinna

    2013-01-01

    Aged-related cognitive ability is highly variable, ranging from unimpaired to severe impairments. The Morris water maze (a reliable tool for assessing memory) has been used to distinguish aged rodents that are superior learners from those that are learning impaired. This task, however, is not practical for pre- and post-pharmacological treatment, as the memory of the task is long lasting. In contrast, the object location memory task, also a spatial learning paradigm, results in a less robust memory that decays quickly. We demonstrate for the first time how these two paradigms can be used together to assess hippocampal cognitive impairments before and after pharmacological or genetic manipulations in rodents. Rats were first segregated into superior learning and learning impaired groups using the object location memory task, and their performance was correlated with future outcome on this task and on the Morris water maze. This method provides a tool to evaluate the effect of treatments on cognitive impairment associated with aging and neurodegenerative disorders. PMID:23667471

  6. Highway crash rates and age-related driver limitations: Literature review and evaluation of data bases

    SciTech Connect

    Hu, P.S.; Young, J.R.; Lu, An

    1993-08-01

    American society is undergoing a major demographic transformation that is resulting in a larger proportion of older individuals in the population. Moreover, recent travel surveys show that an increasing number of older individuals are licensed to drive and that they drive more than their same age cohort a decade ago. However, they continue to take shorter trips than younger drivers and they avoid driving during congested hours. This recent demographic transformation in our society, the graying of America, coupled with the increasing mobility of the older population impose a serious highway safety issue that cannot be overlooked. Some of the major concerns are the identification of ``high-risk`` older drivers and the establishment of licensing guidelines and procedures that are based on conclusive scientific evidence. Oak Ridge National Laboratory`s (ORNL) objectives in this project can be characterized by the following tasks: Review and evaluate the 1980 American Association of Motor Vehicle Administrators (AAMVA) and National Highway Traffic Safety Administration (NHTSA) licensing guidelines. Determine whether the license restriction recommended in the 1980 AAMVA and NHTSA guidelines was based on scientific evidence or on judgement of medical advisors. Identify in the scientific literature any medical conditions which are found to be highly associated with highway crashes, and which are not mentioned in the 1980 guidelines. Summarize States` current licensing practices for drivers with age-related physical and mental limitations. Identify potential data sources to establish conclusive evidence on age-related functional impairments and highway crashes.

  7. Safeguards Measurement Evaluation Program nuclear materials measurement data: Phase 1: Final report, 1985 through 1986

    SciTech Connect

    Cacic, C.G.

    1988-08-01

    The New Brunswick Laboratory has been tasked by the US Department of Energy Office of Safeguards and Security to assess and evaluate the adequacy of measurement technology as applied to materials accounting in US Department of Energy nuclear facilities. The Safeguards Measurement Evaluation Program was developed as a means to monitor and evaluate the quality and effectiveness of accounting measurements by site, material balance area, or unit process. Phase 1 of the Safeguards Measurement Evaluation Program, initiated during 1985, involved evaluation of the primary accountability measurement methods at six US Department of Energy Defense Programs facilities. Resulting data are presented and evaluated as indicators of current state-of-the-practice accountability measurement methodology, deficiencies in materials accounting practices, and areas for possible assistance in upgrading measurement capabilities. 22 figs., 5 tabs.

  8. Material selection and evaluation aimed at resolving deficiencies of a space technology material

    NASA Technical Reports Server (NTRS)

    Ray, Asit K.; Bryan, Coleman J.

    1992-01-01

    NASA-Kennedy Space Center propellant handlers' visors are undergoing conversion from Plexiglass G to a Surlyn 8920-based material; various Surlyn compositions are here subjected to a battery of environmental and mechanical-properties tests under the relevant conditions. Specially-molded Surlyn samples have exhibited much higher impact strengths than either Plexiglass G or Lexan, and passed the ANSI weight-drop test. DSC results show that Surlyn and Plexiglass G exhibit strikingly different thermal transitions.

  9. Superconductive microprobes for eddy current evaluation of materials

    NASA Astrophysics Data System (ADS)

    Podney, Walter N.

    1989-07-01

    Superconductive quantum interference devices (SQUIDS) offer new technology for locating materials flaws electromagnetically that promises to increase sensitivity, depth of magnetic flux enables use of microscopic pickup loops in a gradiometer configuration to give high resolution. A cryogenic umbilical connects pickup loops to a remote cryostat housing SQUID sensors to ease scanning. A pair of drive coils a few millimeters in radius that encircle pickup loops forming a coplanar gradiometer 1 mm or less in radius comprise a superconductive microprobe. It provides a depth of field of several millimeters to a 0.1 mm flaw in an aluminum plate, when operating with a drive current a 1 A oscillating at a frequency of 1kHz. Its field of view ranges to several millimeters, for flaws a few millimeters deep, and its horizontal resolution is 1 mm or so, for flaw depths out to its depth of field. An array of microprobes form receptors much like rods in the retina of a magnetic eye. The eye leads to an electromagnetic microscope for imaging internal flaws in aluminum plates. It gives multiple images that enable resolving depth of a 0.1 mm flaw to a few tenths of a millimeter with a horizontal resolution of one millimeter or so.

  10. Evaluation, development, and characterization of superconducting materials for space applications

    NASA Technical Reports Server (NTRS)

    Thorpe, Arthur N.

    1990-01-01

    The anisotropic electromagnetic features of a grain-aligned YBa2Cu3O(x) bulk sample derived from a process of long-time partial melt growth were investigated by the measurements of direct current magnetization (at 77 K) and alternating current susceptibility as a function of temperature, with the fields applied parallel and perpendicular to the c axis, respectively. The extended Bean model was further studied and applied to explain the experimental results. Upon comparison of the grain-aligned sample with pure single crystal materials, it is concluded that because of the existence of more effective pinning sites in the grain-aligned sample, not only its critical current density perpendicular to the c axis is improved, but the one parallel to the c axis is improved even more significantly. The anisotropy in the critical current densities in the grain-aligned sample at 77 K is at least one to two orders of magnitude smaller than in the pure single crystal. The measurement of anisotropy of alternating current susceptibility as a function of temperature, especially its imaginary part, shows that there are still some residues of interlayer weak links in the grain-aligned samples, but they are quite different from and far less serious than the weak links in the sintered sample.

  11. An evaluation of epoxy resin phantom materials for electron dosimetry

    NASA Astrophysics Data System (ADS)

    Nisbet, A.; Thwaites, D. I.

    1998-06-01

    The use of epoxy resin `solid water' (water substitute) phantoms is becoming increasingly common in radiotherapy dosimetry, and depth ionization curves and conversion factors from ionization to dose identical to water have often been assumed. Fluence ratios of water to solid water for WTe (produced by Radiation Physics, St Bartholomew's Hospital, London) and RMI 457 (produced by Radiation Measurements Inc., Middleton, Wisconsin) have therefore been determined and have been found to decrease with energy, which, within measurement uncertainty, can be described with a linear function dependent on mean electron beam energy at the depth of measurement, . The fluence ratios for WTe are very close to unity (i.e. within the measuring uncertainty) for most of the energies examined, the exception being a nominal 20 MeV beam. The results also show that an assumption of unity for the fluence ratios of RMI 457 may introduce a systematic error of the order of 1% in electron beam dosimetry at lower energies. As regards the depth ionization curves measured in the respective solid water materials, these are shown to be in agreement with those measured in water within the limits of the measuring uncertainty.

  12. Evaluation of Serum Lipid Profiles in Turkish Children Aged Two to Eighteen Years

    PubMed Central

    Toprak, D; Bukulmez, A; Dogan, N; Oztekin, O; Koken, T

    2014-01-01

    ABSTRACT Objective: The purpose of this study was to evaluate dyslipidaemia in children according to age, gender, percentiles, mother's education level, breastfeeding duration and areas of residence. Methods: A total of 285 children (137 girls; 148 boys), aged between two and 18 years, were enrolled in this cross-sectional, epidemiologic study. Lipid profiles were assessed and its relation with socio-demographic features was evaluated. Results: Dyslipidaemia prevalence was 37.4% (n = 107). High very low-density lipoprotein cholesterol (VLDL-C) and low high-density lipoprotein cholesterol (HDL-C) levels are related with percentiles of the children (p = 0.006, p = 0.03, respectively). Gender was a significant factor for VLDL-C, which was higher in girls than boys (p = 0.04). Total cholesterol levels were high in 14 children (4.9%); 72 of the study group (25.3%) had high triglyceride levels; HDL-C levels were low in 52 children (18.2%). Conclusion: All the parameters of dyslipidaemia are not so high in our region. However, as early detection of dyslipidaemia should begin in childhood, we should perform periodic checks to prevent cardiovascular risks. PMID:25803372

  13. Plexogenic arteriopathy in broiler lungs: Evaluation of line, age, and sex influences1

    PubMed Central

    Wideman, R. F.; Mason, J. G.; Anthony, N. B.; Cross, D.

    2015-01-01

    Plexiform lesions form in the terminal pulmonary arterioles of human patients suffering from prolonged pulmonary arterial hypertension. Plexiform lesions also develop in broiler lungs, but lesion incidences are not strongly correlated with sustained pulmonary hypertension as reflected by right to total ventricular weight (RVTV) ratios. The present study was conducted to assess plexiform lesion incidences in broiler lines that have been divergently selected for susceptibility or resistance to pulmonary hypertension. Broilers from susceptible (SUS) and resistant (RES) lines were reared together and only clinically healthy (nonascitic, noncyanotic) individuals were evaluated to minimize potential line differences in cardiopulmonary hemodynamics. The objective was to determine if an innate genetic predisposition for plexogenic arteriopathy would be exposed in SUS broilers when compared with RES broilers in the absence of extreme differences in cardiopulmonary hemodynamics. Broilers up to 12 wk age from the SUS and RES lines had essentially equivalent BW, indices of cardiopulmonary function (left ventricle + septum weight, total ventricle weight, and RVTV ratios), and lung volumes within a sex. Average RVTV ratios for broilers from both lines were indicative of normal pulmonary arterial pressures at all ages sampled. Nevertheless, plexiform lesions were detected in SUS and RES broiler lungs immediately posthatch and thereafter at all ages sampled. Lesion incidences were consistently low and did not differ between the lines within any of the sampling ages. This evidence demonstrates that plexiform lesions develop extremely rapidly in broiler chicks, apparently without the prerequisite for vascular stress caused by severe, prolonged pulmonary arterial hypertension. No innate genetic predisposition for complex vascular lesion development appeared to exist in the SUS line when compared with the RES line. PMID:25681478

  14. Evaluation of the Durability of Flexible Barrier Materials

    SciTech Connect

    Kempe, Michael D.; Nobles, Dylan L.; Weigel, Mark D.; Nachtigal, Alan K.; Roehrig, Mark A.; Berniard, Tracie J.; Spagnola, Joseph C.; Schubert, Charlene M.

    2015-06-14

    To enable the production of lightweight photovoltaic modules, it is desired to use thin film absorbers on metal substrates in a flexible package. To do this with a polymer based frontsheet, it is estimated that a water vapor transmission rate (WVTR) less than 10-4 g/m2/day must be achieved and maintained through the expected life of the module. Barrier-frontsheet films have been developed at 3M with very low permeation rates and evaluated for their long term durability with respect to WVTR and optical transmittance. After exposure to 2500 h of 10 UV suns at 105 degrees C, one design was found which experienced negligible loss in optical transmission while maintaining a WVTR well below the required 10-4 g/m2/day. Further accelerated tests were conducted at different stress levels. For some less durable designs we were able to obtain degradation acceleration factors suggesting the highest exposure was equal to between 4.4 and 10 y on a roof.

  15. Electrochemical evaluation of superheater materials in coal ash corrosion atmosphere

    SciTech Connect

    Nakagawa, K.; Ando, S.; Kawamoto, T.; Kihara, S.; Ohtomo, A.

    1983-01-01

    The corrosion behavior of AISI TYPE 347, TYPE 310, 17-14THCuMo steel and IN671 (50Cr-50Ni) in molten ternary eutectic of Li/sub 2/SO/sub 4//K/sub 2/SO/sub 4//Na/sub 2/SO/sub 4/, at 650/sup 0/C in air and under synthetic flue gas atmosphere: 14%CO/sub 2/, 4%O/sub 2/, two levels of SO/sub 2/ (0.25% and 1%), N/sub 2/ balance has been evaluated by potentiodynamic and free corrosion potential measurement. In air and 0.25%SO/sub 2/ containing synthetic flue gas atmosphere breakthrough potentials were observed in their potential curves. For the alloys examined the values of breakthrough potentials increased in the following order: IN671 > 310 > 347 > 17-14THCuMo. On the other hand in 1%SO/sub 2/ containing synthetic flue gas atmosphere breakthrough potentials were not observed but Tafel Type polarization response were observed. The i/SUB corr/ obtained from their polarization curves were increased in the following order: 310 < 347 < 17-14THCuMo.

  16. Initial ACTR retrieval technology evaluation test material recommendations

    SciTech Connect

    Powell, M.R.

    1996-04-01

    Millions of gallons of radiaoctive waste are contained in underground storage tanks at Hanford (SE Washington). Techniques for retrieving much of this waste from the storage tanks have been developed. Current baseline approach is to use sluice jets for single-shell tanks and mixer pumps for double-shell tanks. The Acquire Commercial Technology for Retrieval (ACTR) effort was initiated to identify potential improvements in or alternatives to the baseline waste retrieval methods. Communications with a variety of vendors are underway to identify improved methods that can be implemented at Hanford with little or no additional development. Commercially available retrieval methods will be evaluated by a combination of testing and system-level cost estimation. Current progress toward developing waste simulants for testing ACTR candidate methods is reported; the simulants are designed to model 4 different types of tank waste. Simulant recipes are given for wet sludge, hardpan/dried sludge,hard saltcake, and soft saltcake. Comparisons of the waste and simulant properties are documented in this report.

  17. Eddy current nondestructive material evaluation based on HTS SQUIDs

    NASA Astrophysics Data System (ADS)

    Mück, M.; Kreutzbruck, M. v.; Baby, U.; Tröll, J.; Heiden, C.

    1997-08-01

    High Temperature Superconductor (HTS) Superconducting Quantum Interference Devices (SQUIDs) are promising sensors for applications in eddy current nondestructive evaluation (NDE). Due to their high field sensitivity at low frequencies, they are especially suitable for applications, where a large penetration depth is required. We have investigated two different SQUID-based NDE systems, one of which is optimised for testing felloes of aircraft wheels. The second system allows for testing planar structures using a motorised x-y-stage, which moves the cryostat above the planar samples. As sensors 3 GHz rf SQUIDs made from YBCO were used, having a field noise of about 1 pT/√Hz. This results in a dynamic range of our SQUID system of about 155 dB/√Hz. In most cases, the SQUIDs have been cooled by immersing them in liquid nitrogen. We have however also developed a cryosystem, which allows for cooling the sensors by a Ne-gas flow. In planar test structures we could detect flaws with lengths of 10 mm, having a height of 0.6 mm in a depth of 13 mm. In aircraft felloes, flaws located at the inner surface of the felloe (thickness 8 mm) were easily detectable despite a high static background field of up to 0.5 G caused by ferromagnetic structures inside the felloe. For flaws in a depth of 5 mm, the spatial resolution of both systems was about 8 mm without applying image postprocessing.

  18. The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures

    SciTech Connect

    Sant, Gaurav; Lothenbach, Barbara; Juilland, Patrick; Le Saout, Gwenn; Weiss, Jason; Scrivener, Karen

    2011-03-15

    Studies on the early-age shrinkage behavior of cement pastes, mortars, and concretes containing shrinkage reducing admixtures (SRAs) have indicated these mixtures frequently exhibit an expansion shortly after setting. While the magnitude of the expansion has been noted to be a function of the chemistry of the cement and the admixture dosage; the cause of the expansion is not clearly understood. This investigation uses measurements of autogenous deformation, X-ray diffraction, pore solution analysis, thermogravimetry, and scanning electron microscopy to study the early-age properties and describe the mechanism of the expansion in OPC pastes made with and without SRA. The composition of the pore solution indicates that the presence of the SRA increases the portlandite oversaturation level in solution which can result in higher crystallization stresses which could lead to an expansion. This observation is supported by deformation calculations for the systems examined.

  19. Evaluation and Modeling of Edge-Seal Materials for Photovoltaic Applications

    SciTech Connect

    Kempe, M. D.; Dameron, A. A.; Moricone, T. J.; Reese, M. O.

    2011-02-01

    Because of the sensitivity of some photovoltaic devices to moisture-induced corrosion, they are packaged using impermeable front- and back-sheets along with an edge seal to prevent moisture ingress. Evaluation of edge seal materials can be difficult because of the low permeation rates involved and/or non-Fickian behavior. Here, using a Ca film deposited on a glass substrate, we demonstrate the evaluation of edge seal materials in a manner that effectively duplicates their use in a photovoltaic application and compare the results with standard methods for measuring water vapor transport. We demonstrate how moisture permeation data from polymer films can be used to estimate moisture ingress rates and compare the results of these two methods. Encapsulant materials were also evaluated for comparison and to highlight the need for edge seals. Of the materials studied, desiccant filled polyisobutylene materials demonstrate by far the best potential to keep moisture out for a 20 to 30 year lifetime.

  20. Calcium Based Test Method for Evaluation of Photovoltaic Edge-Seal Materials (Presentation)

    SciTech Connect

    Kempe, M.; Dameron, A.; Reese, M.

    2011-02-01

    Because of the sensitivity of some photovoltaic devices to moisture-induced corrosion, they are packaged using impermeable front- and back-sheets with an edge seal to prevent moisture ingress. Evaluation of edge seal materials can be difficult because of the low permeation rates involved and/or non-Fickian behavior. Here, using a Ca film deposited on a glass substrate, we demonstrate the evaluation of edge seal materials in a manner that effectively duplicates their use in a photovoltaic application and compare the results with standard methods for measuring water vapor transport. We demonstrate how moisture permeation data from polymer films can be used to estimate moisture ingress rates and compare the results of these two methods. Encapsulant materials were also evaluated for comparison and to highlight the need for edge seals. Of the materials studied, dessicant-filled polyisobutene materials demonstrate by far the best potential to keep moisture out for a 20 to 30 year lifetime.

  1. The Evaluation of Existing Federal Interagency Day Care Requirements: Day Care for the School-Age Child.

    ERIC Educational Resources Information Center

    Bergstrom, Joan M.; Dreher, Donna L.

    As part of an evaluation of the existing Federal Interagency Day Care Requirements (FIDCR), this paper reviews the current regulations and presents recommendations for modifications in the requirements as they relate to group or family day care services for school age children from 5 to 14 years of age. The paper is divided into five major…

  2. Assessing Defense Structure in School-Age Children Using the Response Evaluation Measure-71-Youth Version (REM-Y-71)

    ERIC Educational Resources Information Center

    Araujo, Katy B.; Medic, Sanja; Yasnovsky, Jessica; Steiner, Hans

    2006-01-01

    This study used the Response Evaluation Measure-Youth (REM-Y-71), a self-report measure of 21 defense reactions, among school-age children. Participants were elementary and middle school students (n=290; grades 3-8; age range: 8-15; mean=11.73). Factor analysis revealed a 2-factor defense structure consistent with structure among high school and…

  3. EVALUATION OF THREE FISH SPECIES AS BIOASSAY ORGANISMS FOR DREDGED MATERIAL TESTING

    EPA Science Inventory

    Three fish species, Cyprinodon variegatus, Fundulus similis, and Menidia menidia, were evaluated to determine which is most suitable as a bioassay organism for solid phase testing of dredged material. Acute toxicity and bioaccumulation of polychlorinated biphenyls (PCBs) were mon...

  4. Evaluation of Dairy Whey as a Subsurface Reactive Barrier Material

    NASA Astrophysics Data System (ADS)

    Semkiw, E.; Barcelona, M.; Kim, M.

    2006-05-01

    Subsurface permeable reactive barriers (PRBs) in remediation of contaminated ground water are currently being utilized and refined as an alternative/supplement to costly pump-and-treat remediation. Identification of efficient reactive materials that are effective in the long-term is essential for the ultimate success of PRBs in ground water remediation. A variety of enhancements have been used: oxidants, reductants or sorbents. Electron donors create/strengthen reducing conditions that are favorable for microbial degradation of chlorinated hydrocarbons. Inexpensive, food-grade electron donors effectively enhance dechlorination activity, and those that are solids that can be slurried and then pressure grouted are the best candidates for maintaining an active biobarrier at low cost. Dried dairy whey (~70% alpha-lactose), a slowly dissolving solid, is a prime candidate. To determine the efficiency of whey in promoting dechlorination, it is essential to identify the aerobic and anaerobic metabolic pathways and perform quantitative analysis of breakdown products. We hypothesize that dissolved whey will undergo microbial degradation (aerobic and anaerobic) to form carboxylic acids, and that in a suboxic/reducing environment the anaerobic products will stimulate the microbial dechlorination of chlorinated hydrocarbons PCE, TCE, and DCE. Analysis of the breakdown products in the absence as well as the presence of chlorinated hydrocarbons will result in the calculation of rate constants. Kinetics will, in turn, provide us with residence time, loading (whey mass), and projected lifetime of the whey PRB under estimated loads of total chlorinated hydrocarbon contamination. Early results from our field-scale effort to treat a TCE-contaminated site show increased concentrations of cis- DCE and VC downgradient from the whey PRBs, indicative of enhanced TCE dechlorination. Results from an initial microcosm experiment show complete disappearance of chlorinated hydrocarbons in the

  5. Geography in an Urban Age: Trials of High School Geography Project Materials in New Zealand Schools

    ERIC Educational Resources Information Center

    Renner, John; Slater, Frances

    1974-01-01

    The High School Geography Project was used and evaluated by 15-year old students in New Zealand. The program, highly innovative in approaches in teaching Geography, is found to be highly adapted to Australian needs in Geography instruction. (JR)

  6. LWR Aging Management Using a Proactive Approach to Control Materials Degradation

    SciTech Connect

    Bond, Leonard J.; Doctor, Steven R.; Cumblidge, Stephen E.; Bruemmer, Stephen M.; Taylor, W Boyd; Hull, Amy; Malik, Shah

    2009-05-12

    Material issues can be the limiting factor for the operation of nuclear power plants. There is growing interest in new and improved philosophies and methodolgies for plant life management, which include the migration from reliance on periodic inservice inspection to include condition-based maintenance. A further step in the development of plant management is the move from proactive responses based on ISI to become proactive, through the investigation of the potential for implementation of a proactive management of materials degradation program and its potential impact on the managements of LWRs

  7. Light Water Reactor Sustainability (LWRS) Program – Non-Destructive Evaluation (NDE) R&D Roadmap for Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants

    SciTech Connect

    Simmons, K.L.; Ramuhali, P.; Brenchley, D.L.; Coble, J.B.; Hashemian, H.M.; Konnick, R.; Ray, S.

    2012-09-01

    Executive Summary [partial] The purpose of the non-destructive evaluation (NDE) R&D Roadmap for Cables is to support the Materials Aging and Degradation (MAaD) R&D pathway. A workshop was held to gather subject matter experts to develop the NDE R&D Roadmap for Cables. The focus of the workshop was to identify the technical gaps in detecting aging cables and predicting their remaining life expectancy. The workshop was held in Knoxville, Tennessee, on July 30, 2012, at Analysis and Measurement Services Corporation (AMS) headquarters. The workshop was attended by 30 experts in materials, electrical engineering, and NDE instrumentation development from the U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE) National Laboratories (Oak Ridge National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and Idaho National Engineering Laboratory), universities, commercial NDE service vendors and cable manufacturers, and the Electric Power Research Institute (EPRI).

  8. Nondestructive evaluation of composite materials by electrical resistance measurement

    NASA Astrophysics Data System (ADS)

    Mei, Zhen

    This dissertation investigates electrical resistance measurement for nondestructive evaluation of carbon fiber (CF) reinforced polymer matrix composites. The method involves measuring the DC electrical resistance in either the longitudinal or through thickness direction. The thermal history and thermal properties of thermoplastic/CF composites were studied by longitudinal and through-thickness resistance measurements. The resistance results were consistent with differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) results. The resistance measurements gave more information on the melting of the polymer matrix than TMA. They were more sensitive to the glass transition of the polymer matrix than DSC. The through-thickness resistance decreased as autohesion progressed. The activation energy of autohesion was 21.2 kJ/mol for both nylon-6 and polyphenylene sulfide (PPS)/CF composites. Adhesive bonding and debonding were monitored in real-time by measurement of the through-thickness resistance between the adherends in an adhesive joint during heating and subsequent cooling. Debonding occurred during cooling when the pressure or temperature during prior bonding was not sufficiently high. A long heating time below the melting temperature (T m) was found to be detrimental to subsequent PPS adhesive joint development above Tm, due to curing reactions below Tm and consequent reduced mass flow response above Tm. A high heating rate (small heating time) enhanced the bonding more than a high pressure. The longitudinal resistance measurement was used to investigate the effects of temperature and stress on the interface between a concrete substrate and its epoxy/CF composite retrofit. The resistance of the retrofit was increased by bond degradation, whether the degradation was due to heat or stress. The degradation was reversible. Irreversible disturbance in the fiber arrangement occurred slightly as thermal or load cycling occurred, as indicated by the

  9. Evaluation available encapsulation materials for low-cost long-life silicon photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Carmichael, D. C.; Gaines, G. B.; Noel, G. T.; Sliemers, F. A.; Nance, G. P.; Bunk, A. R.; Brockway, M. C.

    1978-01-01

    Experimental evaluation of selected encapsulation designs and materials based on an earlier study which have potential for use in low cost, long-life photovoltaic arrays are reported. The performance of candidate materials and encapsulated cells were evaluated principally for three types of encapsulation designs based on their potentially low materials and processing costs: (1) polymeric coatings, transparent conformal coatings over the cell with a structural-support substrate; (2) polymeric film lamination, cells laminated between two films or sheets of polymeric materials; and (3) glass-covered systems, cells adhesively bonded to a glass cover (superstrate) with a polymeric pottant and a glass or other substrate material. Several other design types, including those utilizing polymer sheet and pottant materials, were also included in the investigation.

  10. Effect of Age of Models in Print Ads on Evaluation of Product and Sponsor.

    ERIC Educational Resources Information Center

    Rotfeld, Herbert J.; And Others

    1982-01-01

    Details a study that investigated how middle-aged housewives responded to different age portrayals for different age-oriented products in advertisements. Concludes that there was a clear interaction between age-orientation of product and age of model in an advertisement, but no pervasive "younger is better" effect. (FL)

  11. Short term aging of LaNi{sub 4.25}Al{sub 0.75} tritide storage material

    SciTech Connect

    Holder, J.S.

    1994-10-01

    In support of the Tritium Facilities at the Savannah River Site (SRS), the Tritium Exposure Program (TEP) was initiated in 1986 to investigate the effects of tritium aging on metal hydride materials used in tritium processing applications. The primary material selected for tritium storage was the substituted LaNi{sub 5} alloy, LaNi{sub 4.25}Al{sub 0.75} (LANA.75). The substitution of Al for Ni served to lower the plateau pressure of the tritide, and to stabilize the material to cycling and tritium aging effects. The sub-atmospheric plateau pressure, of LANA.75 tritide at room temperature, made it a safe tritium storage medium, and the tritium aging effects were reduced from that of LaNi{sub 5} tritide, but not eliminated. LANA.75 tritides retain the {sup 3}He decay product of absorbed tritium in the metal lattice. As the concentration of {sup 3}He grows, the lattice becomes strained due to the insoluble species. This strain is manifest in tritium aging effects. These effects include (1) a decrease in the equilibrium plateau pressure, (2) an increase in the plateau slope, (3) a reduction in the reversible storage capacity, and (4) the evolution of a tritium heel. The long term aging effects have been studied over the years, however the short term (less than one year) tritium aging effects have not been investigated until now. The acquisition of desorption isotherms at more than one temperature allows the thermodynamic parameters of change in enthalpy, {Delta}H, and change in entropy, {Delta}S, for the {beta}-{alpha} phase transition of the metal tritide to be determined. These parameters are related to the equilibrium pressure, P, and the isothermal temperature, T, through the following relation: where R is the gas constant, and the factor of 1/2 yields results per mole of atomic tritium. A van`t Hoff plot of 1/2 Ln(P) versus 1/T may be fitted to a straight line, with the slope and intercept used to determine {Delta}H and {Delta}S through equation.

  12. Development and Evaluation of a Calibrator Material for Nucleic Acid-Based Assays for Diagnosing Aspergillosis

    PubMed Central

    Abdul-Ali, Deborah; Loeffler, Juergen; White, P. Lewis; Wickes, Brian; Herrera, Monica L.; Alexander, Barbara D.; Baden, Lindsey R.; Clancy, Cornelius; Denning, David; Nguyen, M. Hong; Sugrue, Michele; Wheat, L. Joseph; Wingard, John R.; Donnelly, J. Peter; Barnes, Rosemary; Patterson, Thomas F.; Caliendo, Angela M.

    2013-01-01

    Twelve laboratories evaluated candidate material for an Aspergillus DNA calibrator. The DNA material was quantified using limiting-dilution analysis; the mean concentration was determined to be 1.73 × 1010 units/ml. The calibrator can be used to standardize aspergillosis diagnostic assays which detect and/or quantify nucleic acid. PMID:23616459

  13. 48 CFR 625.204 - Evaluating offers of foreign construction material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Evaluating offers of foreign construction material. 625.204 Section 625.204 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Buy American Act-Construction Materials...

  14. Evaluation of heat sink materials for thermal management of lithium batteries

    NASA Technical Reports Server (NTRS)

    Dimpault-Darcy, E. C.; Miller, K.

    1988-01-01

    Aluminum, neopentyl glycol (NPG), and resins FT and KT are evaluated theoretically and experimentally as heat sink materials for lithium battery packs. The thermal performances of the two resins are compared in a thermal vacuum experiment. As solutions to the sublimation property were not immediately apparent, a theoretical comparison of the thermal performance of NPG versus KT, Al, and no material, is presented.

  15. SAND SPIKED WITH COPPER AS A REFERENCE TOXICANT MATERIAL FOR SEDIMENT TOXICITY TESTING: A PRELIMINARY EVALUATION

    EPA Science Inventory

    Routine use of solid-phase sediment toxicity tests for scientific and regulatory purposes necessitates the development of solid-phase reference toxicant materials. n order to evaluate an approach for developing such materials, 12 solid-phase 96-h reference toxicant tests were con...

  16. 48 CFR 625.204 - Evaluating offers of foreign construction material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Evaluating offers of foreign construction material. 625.204 Section 625.204 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Buy American Act-Construction Materials...

  17. 48 CFR 625.204 - Evaluating offers of foreign construction material.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Evaluating offers of foreign construction material. 625.204 Section 625.204 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Buy American Act-Construction Materials...

  18. 48 CFR 625.204 - Evaluating offers of foreign construction material.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Evaluating offers of foreign construction material. 625.204 Section 625.204 Federal Acquisition Regulations System DEPARTMENT OF STATE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Buy American Act-Construction Materials...

  19. Development and Evaluation of Consumer-Based Mathematics Materials in Adult Basic Education.

    ERIC Educational Resources Information Center

    Campbell, Patricia F.; Kulm, Gerald

    1980-01-01

    In creating mathematics materials for adult basic education students, researchers (1) interviewed students and teachers to determine needs and objectives; (2) developed materials based on consumer mathematics skills; and (3) evaluated effectiveness by a pretest/posttest and student, teacher, and administrator questionnaires. Results showed the…

  20. A Systematic Approach to Evaluating Career Education Materials at the Local Level.

    ERIC Educational Resources Information Center

    Peat, Marwick, Mitchell and Co., Washington, DC.

    The document contains an assessment instrument, developed by three teams of educators, designed to assist career education practitioners in identifying, classifying, and evaluating career education instructional materials to determine the usefulness of a particular unit of material in a specific local situation. It also contains suggestions of…

  1. An evaluation of the land and material requirements for the satellite power system

    NASA Technical Reports Server (NTRS)

    Ankerbrandt, S. D.

    1980-01-01

    Current research and evaluation of the physical resources requirements for the Satellite Power System (SPS) concentrates on three topics: land requirements and the siting of rectennas; the environmental impacts of the rectenna siting; and the materials requirements. The first two focus exclusively on the Earth based element of the SPS while the materials assessment considered requirements for both the space and Earth systems.

  2. Spectral evaluation of aging effects on blood pressure and heart rate variations in healthy subjects.

    PubMed

    Singh, D; Vinod, K; Saxena, S C; Deepak, K K

    2006-01-01

    The background to heart rate variability (HRV) and blood pressure variability (BPV), and their determinants and physiological correlates, remain obscure. The impact of age must be taken into account if HRV and BPV are used for predictive purposes in clinical settings. Healthy subjects show wide inter-individual variation in their heart rate behaviour and the factors affecting heart rate dynamics are not well known. This paper has undertaken to evaluate heart rate variability (HRV) and baroreflex sensitivity (BRS) in a random sample of subjects without evidence of heart disease, and to estimate the relation of HRV and BPV behaviour to age. The aim of this study was to analyse the effects of ageing on HRV and BPV for simultaneous recordings of electrocardiograph (ECG) and blood pressure (BP) signals at rest in healthy subjects. We studied eight young (21-34 years old) and eight elderly (68-85 years old) rigorously screened subjects from the Fantasia Database to make the reproducibility and comparability of the results more extensive. Time- and frequency-domain analysis of HRV and BPV was performed on 5-minute ectopic-free recordings. BRS on the heart was estimated by frequency-domain analysis of spontaneous variability of systolic blood pressure (SBP) and RR interval. It has been observed that compared to young the elderly subjects have (i) diminished HRV; (ii) a shift in the power spectral density and median frequency to low frequency side for HRV and to higher frequency side for BPV; and (iii) increased low-frequency alpha index and decreased high-frequency alpha index of BRS with overall alpha index augmented. The results convey that normal ageing in the absence of disease is associated with lesser parasympathetic regulation of heart rate. Thus it is concluded that the age is an important factor to be considered for prognosis and diagnosis by HRV and BPV. For reliable clinical applications, more research needs to be done on a broad spectrum of subjects. In

  3. PBX 9404 detonation copper cylinder tests: a comparison of new and aged material

    SciTech Connect

    Hill, Larry G; Mier, Robert; Briggs, Matthew E

    2009-01-01

    We present detonation copper cylinder test results on aged PBX 9404 (94 wt% HMX, 3 wt% CEF, 2.9 wt% NC, 0.1 wt% DPA) explosive. The charges were newly pressed from 37.5 year-old molding powder. We compare these results to equivalent data performed on the same lot when it was 3.5 years old. Comparison of the detonation energy inferred from detonation speed to that inferred from wall motion suggests that the HMX energy is unchanged but the NC energy has decreased to {approx}25% of its original value. The degradation of explosives and their binders is a subject of continual interest. Secondary explosives such as HMX are sufficiently stable near room temperature that they do not measurably degrade over a period of at least several decades. For formulated systems the bigger concern is binder degradation, for which the three main issues are strength, initiation safety, and (if the binder is energetic) energy content. In this paper we examine the detonation energy of new and aged PBX 9404 (94 wt% HMX, 3 wt% tris-{beta} chloroethylphosphate (CEF), 2.9 wt% nitrocellulose (NC), 0.1 wt% diphenylamine (DPA) [1, 2]), measured via the detonation copper cylinder test. In 1959, two independent PBX 9404 accidents [3] raised serious concerns about the safety of the formulation. Over about a decade's time, Los Alamos pursued a safer, energetically equivalent replacement, which ultimately became PBX 9501. In order to accurately compare the performance of the PBX 9404 and PBX 9501 formulations, W. Campbell and R. Engelke (C & E) developed a stringent cylinder test protocol that they called the Los Alamos Precision Cylinder Test [4]. The present aging study is possible because excellent PBX 9404 data from those qualification tests endures.

  4. Neural stem cells could serve as a therapeutic material for age-related neurodegenerative diseases

    PubMed Central

    Suksuphew, Sarawut; Noisa, Parinya

    2015-01-01

    Progressively loss of neural and glial cells is the key event that leads to nervous system dysfunctions and diseases. Several neurodegenerative diseases, for instance Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, are associated to aging and suggested to be a consequence of deficiency of neural stem cell pool in the affected brain regions. Endogenous neural stem cells exist throughout life and are found in specific niches of human brain. These neural stem cells are responsible for the regeneration of new neurons to restore, in the normal circumstance, the functions of the brain. Endogenous neural stem cells can be isolated, propagated, and, notably, differentiated to most cell types of the brain. On the other hand, other types of stem cells, such as mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells can also serve as a source for neural stem cell production, that hold a great promise for regeneration of the brain. The replacement of neural stem cells, either endogenous or stem cell-derived neural stem cells, into impaired brain is highly expected as a possible therapeutic mean for neurodegenerative diseases. In this review, clinical features and current routinely treatments of age-related neurodegenerative diseases are documented. Noteworthy, we presented the promising evidence of neural stem cells and their derivatives in curing such diseases, together with the remaining challenges to achieve the best outcome for patients. PMID:25815135

  5. Electromagnetic Nondestructive Evaluation of Wire Insulation and Models of Insulation Material Properties

    NASA Technical Reports Server (NTRS)

    Bowler, Nicola; Kessler, Michael R.; Li, Li; Hondred, Peter R.; Chen, Tianming

    2012-01-01

    Polymers have been widely used as wiring electrical insulation materials in space/air-craft. The dielectric properties of insulation polymers can change over time, however, due to various aging processes such as exposure to heat, humidity and mechanical stress. Therefore, the study of polymers used in electrical insulation of wiring is important to the aerospace industry due to potential loss of life and aircraft in the event of an electrical fire caused by breakdown of wiring insulation. Part of this research is focused on studying the mechanisms of various environmental aging process of the polymers used in electrical wiring insulation and the ways in which their dielectric properties change as the material is subject to the aging processes. The other part of the project is to determine the feasibility of a new capacitive nondestructive testing method to indicate degradation in the wiring insulation, by measuring its permittivity.

  6. A primer on wound healing in colorectal surgery in the age of bioprosthetic materials.

    PubMed

    Lundy, Jonathan B

    2014-12-01

    Wound healing is a complex, dynamic process that is vital for closure of cutaneous injuries, restoration of abdominal wall integrity after laparotomy closure, and to prevent anastomotic dehiscence after bowel surgery. Derangements in healing have been described in multiple processes including diabetes mellitus, corticosteroid use, irradiation for malignancy, and inflammatory bowel disease. A thorough understanding of the process of healing is necessary for clinical decision making and knowledge of the current state of the science may lead future researchers in developing methods to enable our ability to modulate healing, ultimately improving outcomes. An exciting example of this ability is the use of bioprosthetic materials used for abdominal wall surgery (hernia repair/reconstruction). These bioprosthetic meshes are able to regenerate and remodel from an allograft or xenograft collagen matrix into site-specific tissue; ultimately being degraded and minimizing the risk of long-term complications seen with synthetic materials. The purpose of this article is to review healing as it relates to cutaneous and intestinal trauma and surgery, factors that impact wound healing, and wound healing as it pertains to bioprosthetic materials. PMID:25435821

  7. A Primer on Wound Healing in Colorectal Surgery in the Age of Bioprosthetic Materials

    PubMed Central

    Lundy, Jonathan B.

    2014-01-01

    Wound healing is a complex, dynamic process that is vital for closure of cutaneous injuries, restoration of abdominal wall integrity after laparotomy closure, and to prevent anastomotic dehiscence after bowel surgery. Derangements in healing have been described in multiple processes including diabetes mellitus, corticosteroid use, irradiation for malignancy, and inflammatory bowel disease. A thorough understanding of the process of healing is necessary for clinical decision making and knowledge of the current state of the science may lead future researchers in developing methods to enable our ability to modulate healing, ultimately improving outcomes. An exciting example of this ability is the use of bioprosthetic materials used for abdominal wall surgery (hernia repair/reconstruction). These bioprosthetic meshes are able to regenerate and remodel from an allograft or xenograft collagen matrix into site-specific tissue; ultimately being degraded and minimizing the risk of long-term complications seen with synthetic materials. The purpose of this article is to review healing as it relates to cutaneous and intestinal trauma and surgery, factors that impact wound healing, and wound healing as it pertains to bioprosthetic materials. PMID:25435821

  8. Interim Guidelines for Evaluation of Instructional Materials with Respect to Social Content.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Curriculum Framework and Instructional Materials Unit.

    The purpose of these guidelines is to provide consistent, systematic standards for evaluating instructional materials proposed for use in California's public schools to ensure compliance with the Education Code. Though they are not intended to supplant the evaluator's judgment, the guidelines do comprise the minimum standards for acceptability in…

  9. Applicability of Standards for Evaluations of Educational Programs, Projects and Materials in an International Setting.

    ERIC Educational Resources Information Center

    Marklund, Sixten

    1984-01-01

    While the "Standards for Evaluations of Educational Programs, Projects and Materials" provides a good checklist of prerequisites, such standards do not guarantee indisputable outcomes. Reanalysis of reading comprehension and mathematics mean achievement data from an international evaluation study illustrates how political bias can complicate…

  10. EVALUATION OF AEROSOLIZATION OF ASBESTOS AND RELATED FIBERS FROM BULK MATERIALS

    EPA Science Inventory

    1. Status Report on the Evaluation of the Alternative Asbestos Control Method – A Comparison to the NESHAP Method of Demolition of Asbestos Containing Buildings; and, 2. Update on the Evaluation of Aerosolization of Asbestos and Related Fibers from Bulk Materials. This abstract a...

  11. Toolkit for Evaluating Alignment of Instructional and Assessment Materials to the Common Core State Standards

    ERIC Educational Resources Information Center

    Achieve, Inc., 2014

    2014-01-01

    In joint partnership, Achieve, The Council of Chief State School Officers, and Student Achievement Partners have developed a Toolkit for Evaluating the Alignment of Instructional and Assessment Materials to the Common Core State Standards (CCSS). The Toolkit is a set of interrelated, freely available instruments for evaluating alignment to the…

  12. Toolkit for Evaluating Alignment of Instructional and Assessment Materials to the Common Core State Standards

    ERIC Educational Resources Information Center

    Achieve, Inc., 2014

    2014-01-01

    In joint partnership, Achieve, The Council of Chief State School Officers, and Student Achievement Partners have developed a Toolkit for Evaluating the Alignment of Instructional and Assessment Materials to the Common Core State Standards. The Toolkit is a set of interrelated, freely available instruments for evaluating alignment to the CCSS; each…

  13. Evaluation of between- and within-breed variation in measures of weight-age relationships.

    PubMed

    Jenkins, T G; Kaps, M; Cundiff, L V; Ferrell, C L

    1991-08-01

    Variation between- and within-breeds was evaluated for accretion of weight from birth to 7 yr of age and hip height at 7 yr for 1,577 cows sired by Angus, Brahman, Brown Swiss, Charolais, Chianina, Gelbvieh, Hereford, Jersey, Limousin, Maine Anjou, Pinzgauer, Sahiwal, Simmental, South Devon, and Tarentaise and from either Angus or Hereford dams. Parameters from Wt = A (1 - Be-kt) were estimated by nonlinear regressions and provided estimates of mature body weight (A) and rate of weight accretion relative to change in age (k) for each cow. Actual weight at birth, linear adjusted weights at 200, 365, and 500 d of age, ratios of these weights to mature weight, and height at the hip at 7 yr were analyzed. Beyond 20 mo, weights were adjusted to a constant condition score within breed of sire. Variance and covariance components were derived for breed (sigma 2 b), sires within breed (sigma 2 s), and progeny within sire (sigma 2 w). For all traits, the sigma 2 b estimate of genetic variance ranged from two to four times greater than the variance component for sigma 2 s. Between-breed heritabilities were .91 +/- .27 and .54 +/- .17 for A and k, respectively. Estimates of within-breed heritability for these two traits were .61 +/- .11 and .27 +/- .09. Estimates, both between- and within-breed, of the genetic correlation between A and k were moderate to large and negative; those between A and weights at 200, 365, and 500 d and height at maturity were large and positive. Selection for immediate change in measures of growth would be most effective among breeds. Sufficient direct genetic variation exists between breeds to enhance breed improvement of growth characters through breed substitution. Greater opportunity to alter the shape of the growth curve exists through selection for within-breed selection than through breed substitution. PMID:1894547

  14. Evaluation of Experimental Parameters in the Accelerated Aging of Closed-Cell Foam Insulation

    SciTech Connect

    Stovall, Therese K; Vanderlan, Michael; Atchley, Jerald Allen

    2012-12-01

    The thermal conductivity of many closed-cell foam insulation products changes over time as production gases diffuse out of the cell matrix and atmospheric gases diffuse into the cells. Thin slicing has been shown to be an effective means of accelerating this process in such a way as to produce meaningful results. Efforts to produce a more prescriptive version of the ASTM C1303 standard test method led to the ruggedness test described here. This test program included the aging of full size insulation specimens for time periods of five years for direct comparison to the predicted results. Experimental parameters under investigation include: slice thickness, slice origin (at the surface or from the core of the slab), thin slice stack composition, product facings, original product thickness, product density, and product type. The test protocol has been completed and this report provides a detailed evaluation of the impact of the test parameters on the accuracy of the 5-year thermal conductivity prediction.

  15. COMPLEX EVALUATION OF THE HEALTH STATUS OF PRIMARY-SCHOOL AGED CHILDREN (ADJARA REGION).

    PubMed

    Jorjoliani, Ts; Jorjoliani, L; Adamia, N

    2016-06-01

    Goal of the research was complex evaluation of the health status of the primary-school aged children residing in various regions (urban, rural) of Adjaria. Cross-section, one-stage research was conducted in the City of Batumi and village Tsikhisdziri. In the process of survey health status of children of 4 public schools, from 6 to 9 years old was studied. Observations covered up to 800 school children in total. Screening included consultations of the multidisciplinary group of specialists, additional laboratory and instrumental studies intended for the purpose of accurate diagnostics. Performed studied showed that 28.3% of the studied population was actually healthy, 55% had functional disorders and 16.7% - chronic diseases. In both, urban and rural areas the share of the digestion system, blood and blood-generating organs, nervous system, ophthalmological pathologies and locomotion system diseases prevailed. PMID:27441536

  16. [SCREENING-EVALUATION OF THE CARDIAC ARTERY DISEASE IN CIVIL PILOTS OF THE SENIOR AGE GROUP].

    PubMed

    Kuzmina A Yu

    2015-01-01

    Early diagnostics of cardiac artery disease (CAD) is essential for annual medical flight certification. The investigation was aimed at screening-evaluation of senior civil pilots for CAD using the criteria of ECG findings during the submaximal bicycle ergometry test (BT). The investigation embraced 1189 civil pilots, on reaching the age of 55 years and older in 2009-2010. BT with ECG recording was completed by 976 pilots (82.1%). The test was considered CAD negative in 909 pilots (93.1 %) and CAD positive in 9 pilots (0.9%); of 53 doubtful tests (5.5%), CAD was stated by the ST-criterion in 40 pilots (4.1%) and because of arrhythmias in 13 pilots (1.4%). In 5 cases (0.5%) test results were uninterpretable. Further analysis of the screening results led to diagnosing of clinically significant atherosclerosis of coronary arteries in 17 pilots (1.75%). PMID:26738309

  17. Normative Data of Thyroid Volume-Ultrasonographic Evaluation of 422 Subjects Aged 0-55 Years

    PubMed Central

    Aydıner, Ömer; Karakoç Aydıner, Elif; Akpınar, İhsan; Turan, Serap; Bereket, Abdullah

    2015-01-01

    Objective: To establish local normative data of thyroid volume assessed by ultrasonography in subjects aged 0-55 years living in İstanbul, Turkey. Methods: Subjects without any known history of thyroid disease, of major surgery and/or chronic disease were enrolled in the study and evaluated by physical examination and thyroid ultrasonography. Thyroid gland and isthmus at usual location, each lateral lobe volume with three dimensions, ectopic thyroid tissue and echogenicity of the gland were assessed. Results: Initially, 494 subjects were enrolled in the study. Subjects showing heterogeneous thyroid parenchyma (n=21) and/or nodule (n=51) in ultrasonography were excluded. Final analysis covered 422 subjects (216 males, 206 females). Thyroid volume was found to significantly correlate with height, weight, age and body surface area (r=0.661, r=0.712, r=0.772 and r=0.779, respectively; p<0.0001 for all). These correlations were even stronger in subjects younger than 18 years (r=0.758, r=0.800, r=0.815 and r=0.802, respectively; p<0.0001 for all). Conclusion: The study provides updated reference norms for thyroid volume in Turkish subjects which can be used in the diagnosis and follow-up of patients with thyroid diseases. PMID:26316430

  18. Development and evaluation of measurement devices used to support testing of radioactive material transportation packages

    SciTech Connect

    Uncapher, W. L.; Ammerman, D. J.; Stenberg, D R; Bronowski, D. R.; Arviso, M.

    1992-01-01

    Radioactive material package designers use structural testing to verify and demonstrate package performance. A major part of evaluating structural response is the collection of instrumentation measurement data. Sandia National Laboratories (SNL) has an ongoing program to develop and evaluate measurement devices to support testing of radioactive material packages. Measurement devices developed in support of this activity include evaluation channels, ruggedly constructed linear variable differential transformers, and piezoresistive accelerometers with enhanced measurement capabilities. In addition to developing measurement devices, a method has been derived to evaluate accelerometers and strain gages for measurement repeatability, ruggedness, and manufacturers' calibration data under both laboratory and field conditions. The developed measurement devices and evaluation technique will be discussed and the results of the evaluation will be presented.

  19. Improving Evaluation in the Nonprofit Sector: The Promise of Evaluation Capacity Building for Nonprofit Social Service Organizations in an Age of Accountability

    ERIC Educational Resources Information Center

    Pejsa, Laura J.

    2011-01-01

    The purpose of this study was to explore the real-world practice of evaluation capacity building (ECB) in the small-medium sized nonprofit context. The study aimed to map the activities, processes, and outcomes of ECB in these nonprofits in light of the competing external and internal evaluation contexts facing nonprofits in an age of…

  20. Gen IV Materials Handbook Beta Release for Structural and Functional Evaluation

    SciTech Connect

    Ren, Weiju; Luttrell, Claire

    2006-09-12

    Development of the Gen IV Materials Handbook is briefly summarized up to date. Current status of the Handbook website construction is described. The developed Handbook components and access control of the beta version are discussed for the present evaluation release. Detailed instructions and examples are given to provide guidance for evaluators to browse the constructed parts and use all the currently developed functionalities of the Handbook in evaluation.

  1. Ageing of organic electrical insulating materials due to radiation. Physical properties of a cycloaliphatic epoxy resin irradiated under vacuum

    NASA Astrophysics Data System (ADS)

    Sparado, G.; Calderaro, E.; Schifani, R.; Tutone, R.; Rizzo, G.

    Physical properties of a cycloaliphatic epoxy resin irradiated under vacuum have been investigated. In particular dynamic-mechanical, dielectric and tensile measurements have been performed. This is a useful basis with a view to studying the ageing phenomenon of organic insulating materials due to radiation under the combined effect of environmental conditions. The results indicate that, in the dose range investigated (0-1.5 x 10 6Gy), the main effect of γ-rays under vacuum is to increase the degree of crosslinking

  2. Empirical evaluation of diving wet suit material heat transfer and thermal conductivity

    SciTech Connect

    West, P.B.

    1993-10-01

    This wet suit material testing program provides a quantitative thermal conductivity and heat transfer analysis, and comparison of various materials used in skin diving and SCUBA diving. Thermal resistance represents the primary subject examined, but due to compressibility of the baseline materials and its effect on heat transfer, this program also examines compression at simulated depth. This article reports the empirical heat transfer coefficients for both thermal conductivity and convection. Due to the limitations of the test apparatus, this analysis must restrict the convection evaluation to an approximately 20-cm-height, free-convection model. As a consequence, this model best simulates the overall heat transfer coefficient of a diver hovering in a horizontal position. This program also includes evaluations of some nonstandard materials in an effort to identify alternative wet suit materials.

  3. A study of the stress wave factor technique for evaluation of composite materials

    NASA Technical Reports Server (NTRS)

    Duke, J. C., Jr.; Henneke, E. G., II; Kiernan, M. T.; Grosskopf, P. P.

    1989-01-01

    The acousto-ultrasonic approach for nondestructive evaluation provides a measurement procedure for quantifying the integrated effect of globally distributed damage characteristic of fiber reinforced composite materials. The evaluation procedure provides a stress wave factor that correlates closely with several material performance parameters. The procedure was investigated for a variety of materials including advanced composites, hybrid structure bonds, adhesive bonds, wood products, and wire rope. The research program focused primarily on development of fundamental understanding and applications advancements of acousto-ultrasonics for materials characterization. This involves characterization of materials for which detection, location, and identification of imperfections cannot at present be analyzed satisfactorily with mechanical performance prediction models. In addition to presenting definitive studies on application potentials, the understanding of the acousto-ultrasonic method as applied to advanced composites is reviewed.

  4. Development and Evaluation of a Novel Delivery System Containing Phytophospholipid Complex for Skin Aging.

    PubMed

    Damle, Monica; Mallya, Rashmi

    2016-06-01

    Citrus auranticum and Glycyrrhiza glabra are rich in anti-oxidant polyphenols helpful in prevention of skin aging. Polyphenols have high polarity and lower skin penetration resulting in lower cutaneous delivery. The present work is attempted to develop a novel polyherbal phospholipid complex cream to improve cutaneous delivery of polyphenols for sustained anti-oxidant action. Phytochemical and in vitro anti-oxidant evaluation was done on methanolic extracts of orange peel and liquorice powder. Total phenolic content, total flavonoid content, and anti-oxidant assays were done on different ratios of orange peel and liquorice extract. Ratio 1:2 gave highest total phenolic content (TPC) (530.00 ± 1.56 mg gallic acid equivalent (GAE) g(-1) extract), total flavonoid content (TFC) (246.25 ± 1.03 mg rutin equivalent (RUE) g(-1) extract), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (87.99 ± 0.64%), and H2O2 scavenging activity (72.47 ± 0.86%) and hence was used for formulation. Solvent evaporation method using methanol with 1:1 extract to phospholipid ratio was found to have entrapment efficiency of 93.22 ± 0.26%. Evaluation parameters like scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FT-IR), and differential scanning calorimetry (DSC) confirmed formation of complex. The complex was formulated as oil-in-water cream and evaluated for various parameters. The optimized cream containing 1% complex was non-irritant and was found to be stable for 3-month period under conditions of stability study. Ex vivo diffusion studies showed that extract phospholipid complex cream had better retention of polyphenols in the skin when compared to conventional extract cream giving prolonged and stronger topical action. The cream had an anti-elastase activity of 28.02 ± 0.95% at concentration of 3000 μg ml(-1) (w/v). Thus, the developed safe and stable polyherbal phytophospholipid complex cream exhibited

  5. Inorganic raw materials economy and provenance of chipped industry in some stone age sites of northern and central Italy.

    PubMed

    Bietti, Amilcare; Boschian, Giovanni; Crisci, Gino Mirocle; Danese, Ermanno; De Francesco, Anna Maria; Dini, Mario; Fontana, Federica; Giampietri, Alessandra; Grifoni, Renata; Guerreschi, Antonio; Liagre, Jérémie; Negrino, Fabio; Radi, Giovanna; Tozzi, Carlo; Tykot, Robert

    2004-06-01

    An opportunistic and local choice of raw materials is typically attested in the Lower and Middle Paleolithic industries throughout Italy. The quality of the raw material usually affected the flaking technology and quality of the products. In the Upper Paleolithic and the Mesolithic, raw material procurement strategies were more complex. Flint was exploited both locally, in areas where abundant outcrops of raw materials were available (such as the Lessini mountains), and in distant localities, after which it was transported or exchanged over medium/long distances. Different routes of exchange were thus followed in the various periods; good reconstruction of these routes have been provided by a study of the Garfagnana sites in Northern Tuscany, and the Mesolithic deposit of Mondeval de Sora (Dolomites). An interesting example of a Late Upper Paleolithic flint quarry and workshop were found in Abruzzo, in the San Bartolomeo shelter. The extended trade of obsidian from Lipari, Palmarola and Sardinia to the Italian Peninsula is attested in the Neolithic, with some differences concerning the age and different areas. PMID:15636064

  6. Constraints on the formation age of cometary material from the NASA Stardust mission.

    PubMed

    Matzel, J E P; Ishii, H A; Joswiak, D; Hutcheon, I D; Bradley, J P; Brownlee, D; Weber, P K; Teslich, N; Matrajt, G; McKeegan, K D; MacPherson, G J

    2010-04-23

    We measured the 26Al-26Mg isotope systematics of a approximately 5-micrometer refractory particle, Coki, returned from comet 81P/Wild 2 in order to relate the time scales of formation of cometary inclusions to their meteoritic counterparts. The data show no evidence of radiogenic 26Mg and define an upper limit to the abundance of 26Al at the time of particle formation: 26Al/27Al < 1 x 10(-5). The absence of 26Al indicates that Coki formed >1.7 million years after the oldest solids in the solar system, calcium- and aluminum-rich inclusions (CAIs). The data suggest that high-temperature inner solar system material formed, was subsequently transferred to the Kuiper Belt, and was incorporated into comets several million years after CAI formation. PMID:20185683

  7. Constraints on the Formation Age of Cometary Material from the NASA Stardust Mission

    SciTech Connect

    Matzel, J; Ishii, H; Joswiak, D; Hutcheon, I; Bradley, J; Brownlee, D; Weber, P K; Teslich, N; Matrajt, G; McKeegan, K; MacPherson, G

    2009-11-13

    We measured the {sup 26}Al-{sup 26}Mg isotope systematics of a {approx} 5-micrometer refractory particle, Coki, returned from comet 81P/Wild 2 in order to relate the time scales of formation of cometary inclusions to their meteoritic counterparts. The data show no evidence of radiogenic {sup 26}Mg and define an upper limit to the abundance of {sup 26}Al at the time of particle formation: {sup 26}Al/{sup 27}Al < 1 x 10-5. The absence of {sup 26}Al indicates that Coki formed >1.7 million years after the oldest solids in the solar system, calcium- and aluminum-rich inclusions (CAIs). The data suggest that high-temperature inner solar system material formed, was subsequently transferred to the Kuiper Belt, and was incorporated into comets several million years after CAI formation.

  8. Accelerated Aging Experiments for Prognostics of Damage Growth in Composite Materials

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Goebel, Kai Frank; Larrosa, Cecilia C.; Janapati, Vishnuvardhan; Roy, Surajit; Chang, Fu-Kuo

    2011-01-01

    Composite structures are gaining importance for use in the aerospace industry. Compared to metallic structures their behavior is less well understood. This lack of understanding may pose constraints on their use. One possible way to deal with some of the risks associated with potential failure is to perform in-situ monitoring to detect precursors of failures. Prognostic algorithms can be used to predict impending failures. They require large amounts of training data to build and tune damage model for making useful predictions. One of the key aspects is to get confirmatory feedback from data as damage progresses. These kinds of data are rarely available from actual systems. The next possible resource to collect such data is an accelerated aging platform. To that end this paper describes a fatigue cycling experiment with the goal to stress carbon-carbon composite coupons with various layups. Piezoelectric disc sensors were used to periodically interrogate the system. Analysis showed distinct differences in the signatures of growing failures between data collected at conditions. Periodic X-radiographs were taken to assess the damage ground truth. Results after signal processing showed clear trends of damage growth that were correlated to damage assessed from the X-ray images.

  9. Fusion materials: Technical evaluation of the technology of vandium alloys for use as blanket structural materials in fusion power systems

    SciTech Connect

    Not Available

    1993-08-04

    The Committee`s evaluation of vanadium alloys as a structural material for fusion reactors was constrained by limited data and time. The design of the International Thermonuclear Experimental Reactor is still in the concept stage, so meaningful design requirements were not available. The data on the effect of environment and irradiation on vanadium alloys were sparse, and interpolation of these data were made to select the V-5Cr-5Ti alloy. With an aggressive, fully funded program it is possible to qualify a vanadium alloy as the principal structural material for the ITER blanket in the available 5 to 8-year window. However, the data base for V-5Cr-5Ti is United and will require an extensive development and test program. Because of the chemical reactivity of vanadium the alloy will be less tolerant of system failures, accidents, and off-normal events than most other candidate blanket structural materials and will require more careful handling during fabrication of hardware. Because of the cost of the material more stringent requirements on processes, and minimal historical worlding experience, it will cost an order of magnitude to qualify a vanadium alloy for ITER blanket structures than other candidate materials. The use of vanadium is difficult and uncertain; therefore, other options should be explored more thoroughly before a final selection of vanadium is confirmed. The Committee views the risk as being too high to rely solely on vanadium alloys. In viewing the state and nature of the design of the ITER blanket as presented to the Committee, h is obvious that there is a need to move toward integrating fabrication, welding, and materials engineers into the ITER design team. If the vanadium allay option is to be pursued, a large program needs to be started immediately. The commitment of funding and other resources needs to be firm and consistent with a realistic program plan.

  10. Fusion materials: Technical evaluation of the technology of vandium alloys for use as blanket structural materials in fusion power systems

    NASA Astrophysics Data System (ADS)

    1993-08-01

    The Committee's evaluation of vanadium alloys as a structural material for fusion reactors was constrained by limited data and time. The design of the International Thermonuclear Experimental Reactor is still in the concept stage, so meaningful design requirements were not available. The data on the effect of environment and irradiation on vanadium alloys were sparse, and interpolation of these data were made to select the V-5Cr-5Ti alloy. With an aggressive, fully funded program it is possible to qualify a vanadium alloy as the principal structural material for the ITER blanket in the available 5 to 8-year window. However, the data base for V-5Cr-5Ti is limited and will require an extensive development and test program. Because of the chemical reactivity of vanadium the alloy will be less tolerant of system failures, accidents, and off-normal events than most other candidate blanket structural materials and will require more careful handling during fabrication of hardware. Because of the cost of the material more stringent requirements on processes, and minimal historical working experience, it will cost an order of magnitude to qualify a vanadium alloy for ITER blanket structures than other candidate materials. The use of vanadium is difficult and uncertain; therefore, other options should be explored more thoroughly before a final selection of vanadium is confirmed. The Committee views the risk as being too high to rely solely on vanadium alloys. In viewing the state and nature of the design of the ITER blanket as presented to the Committee, it is obvious that there is a need to move toward integrating fabrication, welding, and materials engineers into the ITER design team. If the vanadium alloy option is to be pursued, a large program needs to be started immediately. The commitment of funding and other resources needs to be firm and consistent with a realistic program plan.

  11. A database model for evaluating material accountability safeguards effectiveness against protracted theft

    SciTech Connect

    Sicherman, A.; Fortney, D.S.; Patenaude, C.J.

    1993-07-01

    DOE Material Control and Accountability Order 5633.3A requires that facilities handling special nuclear material evaluate their effectiveness against protracted theft (repeated thefts of small quantities of material, typically occurring over an extended time frame, to accumulate a goal quantity). Because a protracted theft attempt can extend over time, material accountability-like (MA) safeguards may help detect a protracted theft attempt in progress. Inventory anomalies, and material not in its authorized location when requested for processing are examples of MA detection mechanisms. Crediting such detection in evaluations, however, requires taking into account potential insider subversion of MA safeguards. In this paper, the authors describe a database model for evaluating MA safeguards effectiveness against protracted theft that addresses potential subversion. The model includes a detailed yet practical structure for characterizing various types of MA activities, lists of potential insider MA defeat methods and access/authority related to MA activities, and an initial implementation of built-in MA detection probabilities. This database model, implemented in the new Protracted Insider module of ASSESS (Analytic System and Software for Evaluating Safeguards and Security), helps facilitate the systematic collection of relevant information about MA activity steps, and ``standardize`` MA safeguards evaluations.

  12. Obtaining appropriate interval estimates for age when multiple indicators are used: evaluation of an ad-hoc procedure.

    PubMed

    Fieuws, Steffen; Willems, Guy; Larsen-Tangmose, Sara; Lynnerup, Niels; Boldsen, Jesper; Thevissen, Patrick

    2016-03-01

    When an estimate of age is needed, typically multiple indicators are present as found in skeletal or dental information. There exists a vast literature on approaches to estimate age from such multivariate data. Application of Bayes' rule has been proposed to overcome drawbacks of classical regression models but becomes less trivial as soon as the number of indicators increases. Each of the age indicators can lead to a different point estimate ("the most plausible value for age") and a prediction interval ("the range of possible values"). The major challenge in the combination of multiple indicators is not the calculation of a combined point estimate for age but the construction of an appropriate prediction interval. Ignoring the correlation between the age indicators results in intervals being too small. Boldsen et al. (2002) presented an ad-hoc procedure to construct an approximate confidence interval without the need to model the multivariate correlation structure between the indicators. The aim of the present paper is to bring under attention this pragmatic approach and to evaluate its performance in a practical setting. This is all the more needed since recent publications ignore the need for interval estimation. To illustrate and evaluate the method, Köhler et al. (1995) third molar scores are used to estimate the age in a dataset of 3200 male subjects in the juvenile age range. PMID:26024791

  13. Method for on-line evaluation of materials using prompt gamma ray analysis

    DOEpatents

    Akers, Douglas W.

    2009-12-08

    A method for evaluating a material specimen comprises: Mounting a neutron source and a detector adjacent the material specimen; bombarding the material specimen with neutrons from the neutron source to create prompt gamma rays within the material specimen, some of the prompt gamma rays being emitted from the material specimen, some of the prompt gamma rays resulting in the formation of positrons within the material specimen by pair production; collecting positron annihilation data by detecting with the detector at least one emitted annihilation gamma ray resulting from the annihilation of a positron; storing the positron annihilation data on a data storage system for later retrieval and processing; and continuing to collect and store positron annihilation data, the continued collected and stored positron annihilation data being indicative of an accumulation of lattice damage over time.

  14. EVALUATION AND RECOMMENDATION OF SALTSTONE MIXER AUGER/PADDLES MATERIALS OF CONSTRUCTION FOR IMPROVED WEAR RESISTANCE

    SciTech Connect

    Mickalonis, J.; Torres, R.

    2012-08-15

    Wear and corrosion testing were conducted to evaluate alternate materials of construction for the Saltstone mixer auger and paddles. These components have been degraded by wear from the slurry processed in the mixer. Material test options included PVD coatings (TiN, TiCN, and ZrN), weld overlays (Stellite 12 and Ultimet) and higher hardness steels and carbides (D2 and tungsten carbide). The corrosion testing demonstrated that the slurry is not detrimental to the current materials of construction or the new candidates. The ASTM G75 Miller wear test showed that the high hardness materials and the Stellite 12 weld overlay provide superior wear relative to the Astralloy and CF8M stainless steel, which are the current materials of construction, as well as the PVD coatings and Ultimet. The following recommendations are made for selecting new material options and improving the overall wear resistance of the Saltstone mixer components: A Stellite 12 weld overlay or higher hardness steel (with toughness equivalent to Astralloy) be used to improve the wear resistance of the Saltstone mixer paddles; other manufacturing specifications for the mixer need to be considered in this selection. The current use of the Stellite 12 weld overlay be evaluated so that coverage of the 316 auger can be optimized for improved wear resistance of the auger. The wear surfaces of the Saltstone mixer auger and paddles be evaluated so that laboratory data can be better correlated to actual service. The 2-inch Saltstone mixer prototype be used to verify material performance.

  15. Ageing of nickel used as sensitive material for early detection of sudomotor dysfunction

    NASA Astrophysics Data System (ADS)

    Ayoub, Hanna; Lair, Virginie; Griveau, Sophie; Galtayries, Anouk; Brunswick, Philippe; Bedioui, Fethi; Cassir, Michel

    2012-01-01

    The surface ageing of nickel electrodes was studied in the frame of the development of non-invasive biomedical devices, dedicated to the detection of sudomotor dysfunction manifested by an alteration of the ionic balance in human sweat. In this kind of technology, low voltage potentials with variable amplitudes are applied to nickel electrodes, placed on skin regions with a high density of sweat glands, and the electrical responses are measured. The trick is that nickel electrodes play alternately the role of anode and cathode, thus the analysis of the temporal evolution of the physico-chemical properties of nickel is of prime importance to ensure the good performance of the device. Electrochemical measurements coupled to surface chemical characterizations (X-ray photoelectron spectroscopy (XPS), Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS)) were performed on pure Ni samples, immersed in buffered chloride solutions mimicking human sweat. The shapes of voltammograms, recorded in a restricted anodic potential range, show that the nickel surface was gradually passivated as a function of the number of scans. This was confirmed by XPS data, with the formation of a 1 nm thick duplex layer composed by nickel hydroxide (outermost layer) and nickel oxide (inner layer). In a negative extended potential range, though the electrochemical behavior of electrodes was not modified upon cycling the potential, XPS data show that the inner layer was thickening, indicating a surface degradation of the nickel electrode. Below pitting potentials, adsorbed chloride was only hardly detected by XPS, and the surface composition of the nickel samples was similar after treatments in chloride or chloride-free buffered solutions. In a larger potential range enabling to reach the breakdown potential, the highly chemically sensitive ToF-SIMS characterization pointed out that the surface concentration of adsorbed chloride was higher in pits than elsewhere on the surface sample.

  16. Test Procedures for Characterizing, Evaluating, and Managing Separator Materials used in Secondary Alkaline Batteries

    NASA Technical Reports Server (NTRS)

    Guasp, Edwin; Manzo, Michelle A.

    1997-01-01

    Secondary alkaline batteries, such as nickel-cadmium and silver-zinc, are commonly used for aerospace applications. The uniform evaluation and comparison of separator properties for these systems is dependent upon the measurement techniques. This manual presents a series of standard test procedures that can be used to evaluate, compare, and select separator materials for use in alkaline batteries. Detailed test procedures evaluating the following characteristics are included in this manual: physical measurements of thickness and area weight, dimensional stability measurements, electrolyte retention, resistivity, permeability as measured via bubble pressure, surface evaluation via SEM, chemical stability, and tensile strength.

  17. Evaluation of the Materials Technology Required for a 760?C Power Steam Boiler

    SciTech Connect

    Shingledecker, John P; Wright, Ian G

    2006-01-01

    The U.S. Ultra-supercritical (USC) Steam Boiler Consortium, funded by the U.S. Department of Energy and the Ohio Coal Development Office, has been working to develop the necessary materials technology to construct a steam power boiler with maximum steam conditions of 760 C and 35MPa. One large component of this work is to evaluate the properties of the materials chosen for such a boiler. While long-term creep strength of base metal is initially used to set temperatures, stresses, and simple design rules, it is clear that base metal creep strength is not always the material property of most importance when selecting an alloy. The fabrication issues (typically weldability), the properties of materials after fabrication, the corrosion resistance of the material, and material cost all need to be considered in addition to baseline mechanical properties. Work is ongoing at Oak Ridge National Laboratory to evaluate the material technologies being developed by the USC Steam Boiler Consortium and perform additional advanced research activities in areas where new materials developments and better fundamental understanding are needed to ensure the long-term success of a 760 C power steam boiler.

  18. Evaluation of properties of irreversible hydrocolloid impression materials mixed with disinfectant liquids

    PubMed Central

    Amalan, Arul; Ginjupalli, Kishore; Upadhya, Nagaraja

    2013-01-01

    Background: Addition of disinfectant to irreversible hydrocolloid impression materials can eliminate the disinfection step to avoid dimensional changes associated with it. The aim of the present study was to evaluate the effect of various disinfectant mixing liquids on the properties of commercially available irreversible hydrocolloid impression materials. Materials and Methods: Four commercially available irreversible hydrocolloid impression materials (Zelgan, Vignette, Tropicalgin, and Algitex) were mixed with disinfectant liquid containing chlorhexidine (0.1 and 0.2%) and sodium hypochlorite (0.1 and 0.5%). After mixing with disinfectant liquids, materials were evaluated for pH changes during gelation, gelation time, flow, gel strength, permanent deformation and detail reproduction. Results: Significant changes in gelation time were observed in irreversible hydrocolloid impression materials upon mixing with disinfectant liquids. In general, chlorhexidine increased the gelation time, whereas sodium hypochlorite reduced it. However, no significant changes in the flow were observed both with chlorhexidine and sodium hypochlorite. Gel strength was found to decrease when mixed with chlorhexidine, whereas an increase in gel strength was observed upon mixing with sodium hypochlorite. Permanent deformation of the most irreversible hydrocolloid impression materials was below the specification limit even after mixing with disinfectant liquids. Sodium hypochlorite significantly reduced the surface detail reproduction, whereas no change in detail reproduction was observed with chlorhexidine. Conclusion: Chlorhexidine solution can be used to mix irreversible hydrocolloid impression materials in regular dental practice as it did not significantly alter the properties. This may ensure effective disinfection of impressions. PMID:23878566

  19. Toxicity of Functional Nano-Micro Zinc Oxide Tetrapods: Impact of Cell Culture Conditions, Cellular Age and Material Properties

    PubMed Central

    Papavlassopoulos, Heike; Mishra, Yogendra K.; Kaps, Sören; Paulowicz, Ingo; Abdelaziz, Ramzy; Elbahri, Mady; Maser, Edmund; Adelung, Rainer; Röhl, Claudia

    2014-01-01

    With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development. PMID:24454775

  20. PLANETARY-SCALE STRONTIUM ISOTOPIC HETEROGENEITY AND THE AGE OF VOLATILE DEPLETION OF EARLY SOLAR SYSTEM MATERIALS

    SciTech Connect

    Moynier, Frederic; Podosek, Frank A.; Day, James M. D.; Okui, Wataru; Yokoyama, Tetsuya; Bouvier, Audrey; Walker, Richard J. E-mail: fap@levee.wustl.edu E-mail: rjwalker@umd.edu E-mail: tetsuya.yoko@geo.titech.ac.jp

    2012-10-10

    Isotopic anomalies in planetary materials reflect both early solar nebular heterogeneity inherited from presolar stellar sources and processes that generated non-mass-dependent isotopic fractionations. The characterization of isotopic variations in heavy elements among early solar system materials yields important insight into the stellar environment and formation of the solar system, and about initial isotopic ratios relevant to long-term chronological applications. One such heavy element, strontium, is a central element in the geosciences due to wide application of the long-lived {sup 87}Rb-{sup 87}Sr radioactive as a chronometer. We show that the stable isotopes of Sr were heterogeneously distributed at both the mineral scale and the planetary scale in the early solar system, and also that the Sr isotopic heterogeneities correlate with mass-independent oxygen isotope variations, with only CI chondrites plotting outside of this correlation. The correlation implies that most solar system material formed by mixing of at least two isotopically distinct components: a CV-chondrite-like component and an O-chondrite-like component, and possibly a distinct CI-chondrite-like component. The heterogeneous distribution of Sr isotopes may indicate that variations in initial {sup 87}Sr/{sup 86}Sr of early solar system materials reflect isotopic heterogeneity instead of having chronological significance, as interpreted previously. For example, given the differences in {sup 84}Sr/{sup 86}Sr between calcium aluminum inclusions and eucrites ({epsilon}{sup 84}Sr > 2), the difference in age between these materials would be {approx}6 Ma shorter than previously interpreted, placing the Sr chronology in agreement with other long- and short-lived isotope systems, such as U-Pb and Mn-Cr.