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. 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.

  4. Aging of Polymeric Materials.

    DTIC Science & Technology

    1982-12-31

    the de- sired surface finish, and positioned inside a demountable Teflon form. Room- temperature vulcanizing silicone rubber (General Electric RTV ... 664 ) was mixed according to the manufacturer’s suggestions and poured into the form until the I TABLE 1. SAMPLE TYPES PREPARED FOR AGING STUDIES

  5. 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.

  6. [Evaluation of the dental pathology in archaeological skeletal material: prevalence of dental caries since prehistory to modern age].

    PubMed

    Stránská, Petra

    2013-01-01

    The evaluation of the dental health of past populations is an important part of the anthropological analysis of human skeletal remains uncovered during the archaeological excavations. The results provide the important information not only of the overall health of past populations, but also are reflective of the nutrition or the social status of our ancestors. We focused on the comparison of dental caries from prehistoric times to the present day. The aim was to evaluate the dental decay in several prehistoric, Early Medieval and modern populations and determine whether and to what extent the decay differ between the individual groups. METHODS AND RESULTS. We observed the permanent dentition in adult men and females, who were divided into three groups: the population of the younger Eneolithic to the Bronze Age, the population of the Early Middle Ages and the population of the modern times. We used the Index of Intensity of Caries I-CE and the Index of Caries Frequency F-CE to evaluate the incidence of caries and intra-vital losses. The comparison was carried out between groups, between both of jaws and between individual teeth. We took into account sex and age of the individuals studied. The highest value of F-CE was set in the population of the modern times (67.5). The difference in caries frequency among populations was not significant. The intensity of caries was the highest in modern population (I-CE: 13.2). Compared with the two older populations the difference was statistically highly significant (p 0.001).With regard to sex, the results differed between populations. It could be caused by a different frequency of men and females in individual groups.The correlation of intensity of caries with age was confirmed. Some partial results were affected by unequal frequency of age categories. CONCLUSION. The results showed the worst dental health in the population of the modern times. The null hypothesis,that tooth decay among the individual populations from different

  7. Evaluation of sorbent materials

    SciTech Connect

    Rankin, W.N.; Gomillion, S.L.; Luckenbach, R.L.

    1989-01-01

    The sorption efficiency of different types of liquid sorbent materials was determined under carefully controlled laboratory conditions. Results show that the sorption capacity is affected both by the type of material and by the form of the material. Attractive alternate sorbents to ''atomic wipes'' and Oil-Dry were identified. Small pillows of shredded synthetic sorbents are an attractive alternative to Oil-Dry as a sorbent and to ''atomic wipes'' as both a sorbent and in decontamination by wiping. Synthetic sorbents in cloth form offer an attractive alternative to ''atomic wipes'' in decontamination by wiping because these materials are compatible with nitric acid and they may be more fire resistant. A larger-scale evaluation is planned with the most promising sorbents. In addition, development is planned of a sorbent that will be efficient, compatible with nitric acid and fire resistant. 6 refs., 2 tabs.

  8. Evaluation of sorbent materials

    SciTech Connect

    Rankin, W N; Gomillion, S L; Luckenbach, R L

    1989-01-01

    The sorption efficiency of different types of liquid sorbent materials was determined under carefully controlled laboratory conditions. Results show that the sorption capacity is affected both by the type of material and by the form of the material. Attractive alternate sorbents to atomic wipes'' and Oil-Dry were identified. Small pillows of shredded synthetic sorbents are an attractive alternative to Oil-Dry as a sorbent and to atomic wipes'' as both a sorbent and in decontamination by wiping. Synthetic sorbents in cloth form offer an attractive alternative to atomic wipes'' in decontamination by wiping because theses materials are compatible with nitric acid and they may be more fire resistant. A larger-scale evaluation is planned with the most promising sorbents. In addition, development is planned of a sorbent that will be efficient, compatible with nitric acid, fire resistant. 6 refs., 2 tabs.

  9. 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.

  10. Accelerated Aging of Polymer Composite Bridge Materials

    SciTech Connect

    Carlson, Nancy Margaret; Blackwood, Larry Gene; Torres, Lucinda Laine; Rodriguez, Julio Gallardo; Yoder, Timothy Scott

    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.

  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. The Evaluation of Instructional Materials.

    ERIC Educational Resources Information Center

    Webster, William J.

    A review of four models of instructional materials evaluation is presented to synthesize the state of the art of such evaluation. A model for evaluation is then developed which includes the following elements: (1) context evaluation and needs assessment, (2) input evaluation, (3) determination of resources, (4) program planning, (5) program…

  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. 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.

  15. 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

  16. 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.

  17. Computational modeling of material aging effects

    SciTech Connect

    Fang, H.E.

    1996-07-01

    Progress is being made in our efforts to develop computational models for predicting material property changes in weapon components due to aging. The first version of a two-dimensional lattice code for modeling thermomechanical fatigue, such as has been observed in solder joints on electronic components removed from the stockpile, has been written and tested. The code does a good qualitative job of presenting intergranular and/or transgranular cracking in a polycrystalline material when under thermomechanical deformation. The current progress is an encouraging start for our long term effort to develop multi-level simulation capabilities, with the technology of high performance computing, for predicting age-related effects on the reliability of weapons.

  18. Method for evaluating material viscoelasticity

    NASA Astrophysics Data System (ADS)

    Fujii, Yusaku; Yamaguchi, Takao

    2004-01-01

    A method for evaluating the viscoelasticity of materials under oscillation load is proposed. In the method, a material under test is connected to a mass, which generates an oscillating inertial force after the mass is manually struck using a hammer. A pneumatic linear bearing is used to realize linear motion with sufficiently small friction acting on the mass that is the moving part of the bearing. The inertial force acting on the mass is determined highly accurately by means of measuring the velocity of the mass using an optical interferometer.

  19. 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.

  20. 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

  1. 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.

  2. 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…

  3. Aging and the Haptic Perception of Material Properties.

    PubMed

    Norman, J Farley; Adkins, Olivia C; Hoyng, Stevie C; Dowell, Catherine J; Pedersen, Lauren E; Gilliam, Ashley N

    2016-08-09

    The ability of 26 younger (mean age was 22.5 years) and older adults (mean age was 72.6 years) to haptically perceive material properties was evaluated. The participants manually explored (for 5 seconds) 42 surfaces twice and placed each of these 84 experimental stimuli into one of seven categories: paper, plastic, metal, wood, stone, fabric, and fur/leather. In general, the participants were best able to identify fur/leather and wood materials; in contrast, recognition performance was worst for stone and paper. Despite similar overall patterns of performance for younger and older participants, the younger adults' recognition accuracies were 26.5% higher. The participants' tactile acuities (assessed by tactile grating orientation discrimination) affected their ability to identify surface material. In particular, the Pearson r correlation coefficient relating the participants' grating orientation thresholds and their material identification performance was -0.8: The higher the participants' thresholds, the lower the material recognition ability. While older adults are able to effectively perceive the solid shape of environmental objects using the sense of touch, their ability to perceive surface materials is significantly compromised.

  4. 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…

  5. 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.

  6. 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.

  7. 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**.

  8. Evaluation of thermal insulation materials

    NASA Technical Reports Server (NTRS)

    Wilbers, O. J.; Conti, J. C.; Mcgee, J. V.; Mcpherson, J. I.

    1973-01-01

    Data was obtained on silicone-bonded fiberglass, isocyanurate foam, and two dozen other insulators. Materials were selected to withstand heat sterilization, outer space, and the Martian atmosphere. Significant environmental parameters were vibration, landing shock, and launch venting.

  9. Material Evaluation by Infrared Thermography

    NASA Astrophysics Data System (ADS)

    Holland, Stephen D.; Reusser, Ricky S.

    2016-07-01

    Infrared thermography uses the temperature-imaging capability of modern thermal cameras to characterize materials and detect flaws. An energy source—whether a pulse of light from a laser or flash lamp, an induction coil, or some other source—induces heat flow in a material, and the resulting temperature patterns are imaged with the thermal camera. In flash thermography, the most widely used form of quantitative thermography, a pulse of light is used as the energy source, and then the surface cooldown is imaged with the thermal camera. Calculations based on an elementary theory of 1D heat conduction can determine thickness (or, equivalently, thermal diffusivity), and nonuniformity in the cooldown will identify defects. This article reviews the methods, approaches, and models of thermography. It focuses on illustrating and identifying the materials, thicknesses, and flaw conditions under which thermography is an effective material characterization technique.

  10. Evaluation of waveguide coating materials

    NASA Technical Reports Server (NTRS)

    Chen, W. C. J.; Baker, B. W.

    1982-01-01

    Waveguide coating materials were tested at 8470 MHz for insertion loss. Samples of these coatings on waveguide pieces without flanges were tested in an environmental chamber to simulate the effects of high power microwave heating. Test results indicated that three types of coating materials are acceptable with regard to insertion loss. However, simulated microwave heating caused debonding of Metcot 7 and BD-991 coatings, resulting in peelings in the waveguide. The higher cost Chemglaze R104 does not exhibit this problem.

  11. Lithium hydride - A space age shielding material

    NASA Technical Reports Server (NTRS)

    Welch, F. H.

    1974-01-01

    Men and materials performing in the environment of an operating nuclear reactor require shielding from the escaping neutron particles and gamma rays. For efficient shielding from gamma rays, dense, high atomic number elements such as iron, lead, or tungsten are required, whereas light, low atomic number elements such as hydrogen, lithium, or beryllium are required for efficient neutron shielding. The use of lithium hydride (LiH) as a highly efficient neutron-shielding material is considered. It contains, combined into a single, stable compound, two of the elements most effective in attenuating and absorbing neutrons.

  12. 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

  13. 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)

  14. 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)

  15. Evaluating CAI Material for the Microcomputer.

    ERIC Educational Resources Information Center

    Ashmore, Timothy M.

    The relative worth of any evaluation instrument depends on user needs and the material being evaluated. Potential users of a good computer assisted instruction (CAI) instrument include purchasers, authors, reviewers, and publishers of CAI materials. Although each user has unique needs, a good instrument will serve both to educate and discriminate,…

  16. JT/LJT connector insert material evaluation

    SciTech Connect

    Baca, J.R.F.

    1991-10-01

    Different insert (insulator) materials are undergoing evaluation to replace the Fiberite E-3938 BE96 material currently used. Also being evaluated is the reconfiguration of the insert and metal shell-edge geometries for the purpose of reducing the alleged interference principally responsible for insert damage.

  17. An evaluation of dental operative simulation materials.

    PubMed

    He, Li-Hong; Foster Page, Lyndie; Purton, David

    2012-01-01

    The study was to evaluate the performance of different materials used in dental operative simulation and compare them with those of natural teeth. Three typical phantom teeth materials were compared with extracted permanent teeth by a nanoindentation system and evaluated by students and registered dentists on the drilling sensation of the materials. Moreover, the tool life (machinability) of new cylindrical diamond burs on cutting the sample materials was tested and the burs were observed. Although student and dentist evaluations were scattered and inconclusive, it was found that elastic modulus (E) and hardness (H) were not the main factors in determining the drilling sensation of the materials. The sensation of drilling is a reflection of cutting force and power consumption.An ideal material for dental simulation should be able to generate similar drilling resistance to that of natural tooth, which is the machinability of the material.

  18. 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.

  19. 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.

  20. Quantitative evaluation of material degradation by Barkhausen noise method

    SciTech Connect

    Yamaguchi, Atsunori; Maeda, Noriyoshi; Sugibayashi, Takuya

    1995-12-01

    Evaluation the life of nuclear power plant becomes inevitable to extend the plant operating period. This paper applied the magnetic method using Barkhausen noise (BHN) to detect the degradation by fatigue and thermal aging. Low alloy steel (SA 508 cl.2) was fatigued at the strain amplitudes of {+-}1% and {+-}0.4%, and duplex stainless steel (SCS14A) was heated at 400 C for a long period (thermal aging). For the degraded material by thermal aging, BHN was measured and good correlation between magnetic properties and absorption energy of the material was obtained. For fatigued material, BHNM was measured at each predetermined cycle and the effect of stress or strain of the material when it measured was evaluated, and good correlation between BHN and fatigue damage ratio was obtained.

  1. Evaluation of Coverall Materials for Pyrotechnic Operations

    DTIC Science & Technology

    1986-08-01

    Pyrotechnic fire Static discharge Thermal tests Fire resistant clothing Fireproof clothing Fire protection MMT-Safety ;Q- ABSTRACT r.adtu m geve0 a1f It... Clothing and Textile Research Facility for his assistance in the selection of the coverall materials, for providing samples of the materials, and for...of the test program was to evaluate the materials being used in the field and also any materials being developed for use in protective clothing . In

  2. 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.

  3. 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.

  4. Evaluation of History of Mathematics Materials.

    ERIC Educational Resources Information Center

    Koop, Anthony J.; Fraser, Barry J.

    1978-01-01

    From a set of history of mathematics materials, a play and an article were selected for evaluation through opinions of experts, survey of teachers, and changes in students' affective and cognitive outcomes. (MP)

  5. Material Handling Equipment Evaluation for Crater Repair

    DTIC Science & Technology

    2016-11-01

    material handling equipment with a reduced logistical footprint for use by crater repair teams in airfield damage repair (ADR) scenarios. A market ...compared to currently utilized material handling equipment. This report presents the results of the market survey and equipment evaluations. Results...2 2 Market Survey

  6. Developing and evaluating patient education materials.

    PubMed

    Monsivais, Diane; Reynolds, Audree

    2003-01-01

    Nurses should be involved in all aspects of patient education, including the development of print and web resources, but most nurses have not been educated in how to develop these resources. This article discusses the rationale for nurse involvement, describes guidelines for evaluating existing material for credibility and readability, and provides recommendations for rewriting material at an easier-to-read level.

  7. 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…

  8. 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.

  9. Accelerated materials evaluation for nuclear applications

    NASA Astrophysics Data System (ADS)

    Griffiths, M.; Walters, L.; Greenwood, L. R.; Garner, F. A.

    2017-05-01

    This paper addresses the opportunities and complexities of using materials test reactors with high neutron fluxes to perform accelerated studies of material aging in power reactors operating at lower neutron fluxes and with different neutron flux spectra. Radiation damage and gas production in different reactors have been compared using the code, SPECTER. This code provides a common standard from which to compare neutron damage data generated by different research groups using a variety of reactors.

  10. Accelerated materials evaluation for nuclear applications

    DOE PAGES

    Griffiths, Malcolm; Walters, L.; Greenwood, L. R.; ...

    2017-02-28

    Here, this paper addresses the opportunities and complexities of using materials test reactors with high neutron fluxes to perform accelerated studies of material aging in power reactors operating at lower neutron fluxes and with different neutron flux spectra. Radiation damage and gas production in different reactors have been compared using the code, SPECTER. This code provides a common standard from which to compare neutron damage data generated by different research groups using a variety of reactors.

  11. Evaluation of Learning Materials: A Holistic Framework

    ERIC Educational Resources Information Center

    Bundsgaard, Jeppe; Hansen, Thomas Illum

    2011-01-01

    This paper presents a holistic framework for evaluating learning materials and designs for learning. A holistic evaluation comprises investigations of the potential learning potential, the actualised learning potential, and the actual learning. Each aspect is explained and exemplified through theoretical models and definitions. (Contains 3 figures…

  12. Evaluation of Materials for Reading: Criteria for Evaluating.

    ERIC Educational Resources Information Center

    Wardeberg, Helen L.

    The evaluation of instructional material to be selected for the school situation is discussed. Changing values of present day society are noted, and three general criteria are suggested for selection of materials. (1) The economics of the matter may be least important in the long run. It is not what we protect students from but what we can expose…

  13. Transport suction apparatus and absorption materials evaluation

    NASA Technical Reports Server (NTRS)

    Krupa, Debra T.; Gosbee, John

    1991-01-01

    The specific objectives were as follows. The effectiveness and function was evaluated of the hand held, manually powered v-vac for suction during microgravity. The function was evaluated of the battery powered laerdal suction unit in microgravity. The two units in control of various types of simulated bodily fluids were compared. Various types of tubing and attachments were evaluated which are required to control the collection of bodily fluids during transport. Various materials were evaluated for absorption of simulated bodily fluids. And potential problems were identified for waste management and containment of secretions and fluids during transport. Test procedures, results, and conclusions are briefly discussed.

  14. Aging mechanisms in amorphous phase-change materials.

    PubMed

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

    2015-06-24

    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.

  15. 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.

  16. Materials for Documenting and Evaluating School Practice.

    ERIC Educational Resources Information Center

    Goddu, Roland

    Requests for evaluation instruments measuring program quality rather than program content have required the development of new measuring procedures. Two sets of materials are presented in this report--the first to identify objectives and expected outcomes for school programs and persons in the school, and the second to identify the actual climate…

  17. 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…

  18. Predictive aging results for cable materials in nuclear power plants

    SciTech Connect

    Gillen, K.T.; Clough, R.L.

    1990-11-01

    In this report, we provide a detailed discussion of methodology of predicting cable degradation versus dose rate, temperature, and exposure time and its application to data obtained on a number of additional nuclear power plant cable insulation (a hypalon, a silicon rubber and two ethylenetetrafluoroethylenes) and jacket (a hypalon) materials. We then show that the predicted, low-dose-rate results for our materials are in excellent agreement with long-term (7 to 9 years), low dose-rate results recently obtained for the same material types actually aged under nuclear power plant conditions. Based on a combination of the modelling and long-term results, we find indications of reasonably similar degradation responses among several different commercial formulations for each of the following generic'' materials: hypalon, ethylenetetrafluoroethylene, silicone rubber and PVC. If such generic'' behavior can be further substantiated through modelling and long-term results on additional formulations, predictions of cable life for other commercial materials of the same generic types would be greatly facilitated. Finally, to aid utilities in their cable life extension decisions, we utilize our modelling results to generate lifetime prediction curves for the materials modelled to data. These curves plot expected material lifetime versus dose rate and temperature down to the levels of interest to nuclear power plant aging. 18 refs., 30 figs., 3 tabs.

  19. 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…

  20. Age-Appropriate Leisure Materials for Students with Severe Disabilities.

    ERIC Educational Resources Information Center

    Blackbourn, J. M.; And Others

    1993-01-01

    Instructions are provided for adapting existing puzzles as low-cost, age-appropriate, and functional leisure materials for older secondary and adult students with severe disabilities. The process involves gluing a magazine picture over an existing puzzle base and cutting through the picture to create separate puzzle pieces. (JDD)

  1. 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)].

  2. Materialism and the future of aging in America.

    PubMed

    Almeder, R F

    1983-01-01

    In Growing Old in America, David Fischer argues that colonial America witnessed a sudden and revolutionary shift in social attitude from gerontophilia to gerontophobia. It is argued here that the shift can be explained as the necessary result of an emerging materialism which came to dominate mercantile America. It is shown how philosophical materialism requires an attitude of denigration toward aging and the elderly, and that the future of our collective attitude toward the elderly is wedded philosophically to the future success or failure of philosophical materialism. It is also suggested that the future of materialism in America looks dim and that there will emerge a strong philosophical base adequate for reforming ethical attitudes and engendering a much more favorable attitude toward the elderly in general. It is suggested that positive or negative attitudes toward aging and the elderly are rooted in unconscious commitments to non-materialistic (dualistic) or materialistic views on the nature of man. The two basically different views on the nature of man beget the two basically different views and attitudes toward aging and the elderly. Which attitude is right is a function of which philosophical view is correct and the paper closes with some evidence that materialism is on the wane.

  3. Evaluation of Four Elastomeric Interocclusal Recording Materials.

    PubMed

    Dua, P; Gupta, S H; Ramachandran, S; Sandhu, H S

    2007-07-01

    The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semi-adjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator. In this in vitro study, the linear dimensional change and compressive resistance of four commercially available elastomeric interocclusal recording media was tested. Three were addition silicones and the fourth was a polyether material. Cylindrical samples of 10mm diameter of each material were prepared in three different thicknesses of 2, 4 and 6mm. Ten samples each of thickness of 2, 4 and 6mm for all four materials were prepared (total of 120 samples). The linear dimensional changes of the samples were evaluated after 24 hours of fabrication. The compressive resistance was measured when each of these was subjected to a constant compressive load of 25 Newtons. The mean linear dimensional change in a horizontal plane was minimum for Kanibite Hard, an addition silicone. Ramitec showed the maximum linear dimensional change. The mean compression distance was least for Futar D Occlusion (an addition silicone) and maximum for Ramitec (a polyether). It was observed that the samples of thickness 2mm for all the materials underwent least compression. The compressive resistance of each elastomer was inversely proportional to the thickness of the sample. This implies that minimum thickness of the recording materials should be used for recording maxillomandibular relations without sacrificing the strength of the interocclusal record.

  4. 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.

  5. Nondestructive evaluation of advanced ceramic composite materials

    SciTech Connect

    Lott, L.A.; Kunerth, D.C.; Walter, J.B.

    1991-09-01

    Nondestructive evaluation techniques were developed to characterize performance degrading conditions in continuous fiber-reinforced silicon carbide/silicon carbide composites. Porosity, fiber-matrix interface bond strength, and physical damage were among the conditions studied. The material studied is formed by chemical vapor infiltration (CVI) of the matrix material into a preform of woven reinforcing fibers. Acoustic, ultrasonic, and vibration response techniques were studied. Porosity was investigated because of its inherent presence in the CVI process and of the resultant degradation of material strength. Correlations between porosity and ultrasonic attenuation and velocity were clearly demonstrated. The ability of ultrasonic transmission scanning techniques to map variations in porosity in a single sample was also demonstrated. The fiber-matrix interface bond was studied because of its importance in determining the fracture toughness of the material. Correlations between interface bonding and acoustic and ultrasonic properties were observed. These results are presented along with those obtained form acoustic and vibration response measurements on material samples subjected to mechanical impact damage. This is the final report on research sponsored by the US Department of Energy, Fossil Energy Advanced Research and Technology Development Materials Program. 10 refs., 24 figs., 2 tabs.

  6. 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.

  7. Translucency changes of direct esthetic restorative materials after curing, aging and treatment.

    PubMed

    Lee, Yong-Keun

    2016-11-01

    The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP) of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9). Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8). Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials.

  8. Translucency changes of direct esthetic restorative materials after curing, aging and treatment

    PubMed Central

    2016-01-01

    The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP) of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9). Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8). Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials. PMID:27847744

  9. 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.

  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...-5 Submission of evaluation materials. (a) The evaluation materials listed in § 30.30-3 should be... sent. (b) Updated materials may be submitted at any time during the evaluation process. ...

  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. Divertor materials evaluation system (DiMES)

    SciTech Connect

    Wong, C.P.C.; West, W.P.; Whyte, D.G.; Bastasz, R.J.; Brooks, J.; Wampler, W.R.

    1997-12-31

    The mission of the Divertor Materials Evaluation System (DiMES) in DIII-D is to establish an integrated data base from measurements in the divertor of a tokamak in order to address some of the ITER and fusion power reactor plasma material interaction issues. Carbon and metal coatings of Be, W, V, and Mo were exposed to the steady-state outer strike point on DIII-D for 4--18 s. These short exposure times ensure controlled exposure conditions, and the extensive arrays of DIII-D divertor diagnostics provide a well-characterized plasma for modeling efforts. Post-exposure analysis provides a direct measure of surface material erosion rates and the amount of retained deuterium. For carbon, these results match closely with the results of accumulated carbon deposition and erosion, and the corresponding deuterium retention of long term exposure tiles in DIII-D. Under the carbon-contaminated background plasma of DIII-D, metal coatings of Be, V, Mo, and W were exposed to the steady-state outer strike point under ELMing and ELM-free H-mode discharges. The rate of material erosion and deuterium retention were measured. As expected, W shows the lowest erosion rate at 0.1 mm/s and the lowest deuterium uptake of 2 {times} 10{sup 20}/m{sup 2}.

  13. Sodium fast reactor evaluation: Core materials

    NASA Astrophysics Data System (ADS)

    Cheon, Jin Sik; Lee, Chan Bock; Lee, Byoung Oon; Raison, J. P.; Mizuno, T.; Delage, F.; Carmack, J.

    2009-07-01

    In the framework of the Generation IV Sodium Fast Reactor (SFR) Program the Advanced Fuel Project has conducted an evaluation of the available fuel systems supporting future sodium cooled fast reactors. In this paper the status of available and developmental materials for SFR core cladding and duct applications is reviewed. To satisfy the Generation IV SFR fuel requirements, an advanced cladding needs to be developed. The candidate cladding materials are austenitic steels, ferritic/martensitic (F/M) steels, and oxide dispersion strengthened (ODS) steels. A large amount of irradiation testing is required, and the compatibility of cladding with TRU-loaded fuel at high temperatures and high burnup must be investigated. The more promising F/M steels (compared to HT9) might be able to meet the dose requirements of over 200 dpa for ducts in the GEN-IV SFR systems.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  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. Divertor Materials Evaluation System (DiMES)

    SciTech Connect

    Wong, C.P.; West, W.P.; Whyte, D.G.; Bastasz, R.J.; Brooks, J.; Wampler, W.R.

    1997-11-01

    The mission of the Divertor Materials Evaluation System (DiMES) in DIII-D is to establish an integrated data base from measurements in the divertor of a tokamak in order to address some of the ITER and fusion power reactor plasma material interaction issues. Carbon and metal coatings of Be, W, V, and Mo were exposed to the steady-state outer strike point on DIII-D for 4-18 s. These short exposure times ensure controlled exposure conditions, and the extensive arrays of DIII-D divertor diagnostics provide a well-characterized plasma for modeling efforts. Postexposure analysis provides a direct measure of surface material erosion rates and the amount of retained deuterium. For carbon, these results match closely with the results of accumulated carbon deposition and erosion, and the corresponding deuterium retention of long term exposure tiles in DIII-D. Deuterium retention of different materials was measured using the {sup 3}He(d,p) {sup 4}He nuclear reaction. For carbon, these measurements showed peak deuterium areal density of about 8 {times} 10 {sup 18} D/cm{sup 2} in a co-deposited layer about 6 {micro}m deep, mainly at the usually detached inboard divertor leg. That layer of carbon near the inner divertor strike point has an atomic saturation concentration of D/C {approx} 0.25, which is not significantly lower than the laboratory-measured saturation retention of 0.4. Under the carbon contaminated background plasma of DIII-D, metal coatings of Be, V, Mo, and W were exposed to the steady state outer strike point under ELMing and ELM-free H-mode discharges. The rate of material erosion and tritium retention were measured. As expected, W shows the lowest erosion rate at 0.1 nm/s and the lowest deuterium uptake.

  20. A multidimensional environmental evaluation of packaging materials.

    PubMed

    Huang, Chien-Chung; Ma, Hwong-Wen

    2004-05-25

    To reduce environmental damage, the properties of environmental issues must be understood. Most previous research has performed relevant assessment either qualitatively or quantitatively. This paper provides a new comprehensive evaluative framework to integrate these two types of approaches. Three methods are combined: (1) life cycle assessment (LCA), a quantitative method, to assess environmental loading, (2) analytic hierarchy process (AHP), a qualitative method, to obtain opinions from experts, and (3) cluster analysis to integrate the results of the former two methods. This new framework could provide integrated information and avoid a bias towards either qualitative or quantitative approach. To present the process of this new evaluative framework, packaging materials are selected as the case study in this paper.

  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. 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.

  3. 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.

  4. 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)

  5. 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... Evaluating Vessel Personnel Licensing and Certification Programs of Foreign Countries § 30.30-3 Evaluation materials. The materials to be submitted for evaluation must include the English text of the following: (a...

  6. First Exploratory Study on the Ageing of Rammed Earth Material

    PubMed Central

    Bui, Quoc-Bao; Morel, Jean-Claude

    2014-01-01

    Rammed earth (RE) is attracting renewed interest throughout the world thanks to its “green” characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the “old” walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls’ soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls. PMID:28787920

  7. First Exploratory Study on the Ageing of Rammed Earth Material.

    PubMed

    Bui, Quoc-Bao; Morel, Jean-Claude

    2014-12-23

    Rammed earth (RE) is attracting renewed interest throughout the world thanks to its "green" characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the "old" walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls' soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls.

  8. 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

  9. 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.

  10. Simulated Aging of Spacecraft External Materials on Orbit

    NASA Astrophysics Data System (ADS)

    Khatipov, S.

    Moscow State Engineering Physics Institute (MIFI), in cooperation with Air Force Research Laboratory's Satellite Assessment Center (SatAC), the European Office of Aerospace Research and Development (EOARD), and the International Science and Technology Center (ISTC), has developed a database describing the changes in optical properties of materials used on the external surfaces of spacecraft due to space environmental factors. The database includes data acquired from tests completed under contract with the ISTC and EOARD, as well as from previous Russian materials studies conducted within the last 30 years. The space environmental factors studied are for those found in Low Earth Orbits (LEO) and Geosynchronous orbits (GEO), including electron irradiation at 50, 100, and 200 keV, proton irradiation at 50, 150, 300, and 500 keV, and ultraviolet irradiation equivalent to 1 sun-year. The material characteristics investigated were solar absorption (aS), spectral reflectance (rl), solar reflectance (rS), emissivity (e), spectral transmission coefficient (Tl), solar transmittance (TS), optical density (D), relative optical density (D/x), Bi-directional Reflectance Distribution Function (BRDF), and change of appearance and color in the visible wavelengths. The materials tested in the project were thermal control coatings (paints), multilayer insulation (films), and solar cells. The ability to predict changes in optical properties of spacecraft materials is important to increase the fidelity of space observation tools, better understand observation of space objects, and increase the longevity of spacecraft. The end goal of our project is to build semi-empirical mathematical models to predict the long-term effects of space aging as a function of time and orbit.

  11. 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.

  12. 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.

  13. 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.

  14. Materials compatibility and aging for flux and cleaner combinations

    SciTech Connect

    Archuleta, Kim M.; 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.

  15. Preclinical evaluation of injectable bone substitute materials.

    PubMed

    Bongio, Matilde; van den Beucken, Jeroen J J P; Leeuwenburgh, Sander C G; Jansen, John A

    2015-03-01

    Injectable bone substitutes (IBSs) represent an attractive class of ready-to-use biomaterials, both ceramic- and polymer-based, as they offer the potential benefit of minimally invasive surgery and optimal defect filling. Although in vitro assessments are the first step in the process of development, the safety and efficacy of an IBS strongly depend on validated preclinical research prior to clinical trials. However, the selection of a suitable preclinical model for performance evaluation of an IBS remains a challenge, as no gold standard exists to define the best animal model. In order to succeed in this attempt, we identified three stages of development, including (a) proof-of-principle, (b) predictive validity and (c) general scientific legitimacy, and the respective criteria that should be applied for such selection. The second part of this review provides an overview of commonly used animals for IBSs. Specifically, scientific papers published between January 1996 and March 2012 were retrieved that report the use of preclinical models for the evaluation of IBSs in situations requiring bone healing and bone augmentation. This review is meant not only to describe the currently available preclinical models for IBS application, but also to address critical considerations of such multi-factorial evaluation models (including animal species, strain, age, anatomical site, defect size and type of bone), which can be indicative but in most cases edge away from the human reality. Consequently, the ultimate goal is to guide researchers toward a more careful and meaningful interpretation of the results of experiments using animal models and their clinical applications. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Evaluating Reference Services in the Electronic Age.

    ERIC Educational Resources Information Center

    Whitlatch, Jo Bell

    2001-01-01

    In an electronic era, the evaluation of reference and related information services should still be based on the same principles used to evaluate traditional face-to-face reference services and printed reference tools. Traditional research methods can be utilized very effectively in an electronic environment. However, electronic technologies offer…

  17. Evaluation of dental and bone age in iron-deficient anemic children of South India

    PubMed Central

    Kumar, Vinod; Haridas, Harish; Hunsigi, Prahlad; Farooq, Umar; Erugula, Sridhar R.; Ealla, Kranti K. R.

    2016-01-01

    Aims and Objectives: Dental and bone age is very essential for the dental practitioner in planning treatments and is an extra source of information for the pediatrician, orthopedician, and endocrinologist. There are few published data regarding collation between dental age, bone age, and chronological age in iron-deficiency anemic children. This study has been undertaken to evaluate and compare dental age, bone age, and chronological age in children with iron-deficiency anemia. Materials and Methods: One hundred iron-deficiency anemic children were selected in the age group of 8–14 years. Chronological age of the child was recorded by asking birth date from parents or checking school records. Dental age was calculated by Demirjians method and bone age was evaluated using Bjork, Grave, and Brown's method. Unpaired student's t-test and Pearson's correlation coefficient were the two statistical tests applied to compare dental, bone, and chronological age. Results: Dental and bone age was significantly lower (P < 0.001) compared to chronological age. The correlation between the three ages was positive in both sexes. Conclusion: Dental and bone age retardation was a significant feature in our sample of 100 iron-deficient anemic children. Bone age and dental age are valuable parameters in assessing the overall growth of the child. Further studies are required to corroborate our findings. PMID:27891309

  18. Genomic evaluation of age at first calving

    USDA-ARS?s Scientific Manuscript database

    From their time of birth until their first lactation, dairy heifers incur management, health and feed expenses while not producing milk. Much effort has been made to estimate optimal ages of first calving (AFC) for cows to reduce these costs and ensure that animals are productive earlier in life. In...

  19. 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.

  20. Grading Principals: Administrator Evaluations Come of Age.

    ERIC Educational Resources Information Center

    Murphy, John A.; Pimentel, Susan

    1996-01-01

    The Charlotte-Mecklenburg (North Carolina) Public Schools have replaced checklists with a result-based, profit-sharing administrator evaluation system that rewards educational excellence and provides principals with needed assistance or support. Effective principals enjoy substantial autonomy; marginal principals receive massive central-office…

  1. 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…

  2. 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…

  3. 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:...

  4. 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... materials. The materials to be submitted for evaluation must include the English text of the following:...

  5. Self Instructional Material in Physiology: A Preliminary Evaluation.

    ERIC Educational Resources Information Center

    Davies, Mary

    1978-01-01

    Examines the preliminary evaluation of self-instructional material in physiology designed as remedial work by medical students. The materials are now used by science, veterinary, dental, and postgraduate medical students and have been distributed to 20 countries. Evaluation results indicate the materials are effective methods of study.

  6. The evaluation of GOES black paint materials

    NASA Technical Reports Server (NTRS)

    Chen, Philip T.; Kauder, Lonny R.; Triolo, Jack J.

    1992-01-01

    The purpose of this paper is to study the contamination effect of black paint materials on the GOES instrument performance. The GOES spacecraft materials were originally selected for their low outgassing properties. Samples of the materials were tested according to the ASTM E-595 test method to fulfill the total mass loss and collected volatile condensable materials criteria for traditional spacecraft material selection. Due to the instrument design, the cavity will experience high temperatures during operation greater than the specified temperature in the ASTM test. As a result of this high cavity temperature, normally stable paint materials on the painted surface may severely outgas even though they have passed the ASTM test. Further enhancement of the contaminant remaining on the mirror by UV irradiation is also a great consideration. This concern prompted an investigation into the outgassing characteristics of the black paints at the predicted operating temperatures.

  7. The evaluation of GOES black paint materials

    NASA Technical Reports Server (NTRS)

    Chen, Philip T.; Kauder, Lonny R.; Triolo, Jack J.

    1992-01-01

    The purpose of this paper is to study the contamination effect of black paint materials on the GOES instrument performance. The GOES spacecraft materials were originally selected for their low outgassing properties. Samples of the materials were tested according to the ASTM E-595 test method to fulfill the total mass loss and collected volatile condensable materials criteria for traditional spacecraft material selection. Due to the instrument design, the cavity will experience high temperatures during operation greater than the specified temperature in the ASTM test. As a result of this high cavity temperature, normally stable paint materials on the painted surface may severely outgas even though they have passed the ASTM test. Further enhancement of the contaminant remaining on the mirror by UV irradiation is also a great consideration. This concern prompted an investigation into the outgassing characteristics of the black paints at the predicted operating temperatures.

  8. Evaluation of Barrier Cable Impact Pad Materials

    DTIC Science & Technology

    1988-03-01

    ACTUAL BATCH DATA CU MATERIAL SOLID VOLUME SAT. SURF DRY SAT. . O,- DRY WATER ACT’.AL CU FT/BATCH BATCH WT. LB FACTOR EATCl ,9 CORRECTION. LB 1ATC. -T...POZZDOTHER CEMENT PROPORTIONS CALCULATED BATCH DATA (I CU YO) ACTUAL BATCH CATA CU =T SOLID VOLUME SAT. SURF DRY SAT. 3, DRY WATER MATERIAL CU FT

  9. 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.

  10. Evaluation of Encapsulant Materials for PV Applications

    SciTech Connect

    Kempe, M.

    2010-01-01

    Encapsulant materials used in PV modules serve multiple purposes. They physically hold components in place, provide electrical insulation, optically couple superstrate materials (e.g., glass) to PV cells, protect components from mechanical stress by mechanically de-coupling components via strain relief, and protect materials from corrosion. To do this, encapsulants must adhere well to all surfaces, remain compliant, and transmit light after exposure to temperature, humidity, and UV radiation histories. Encapsulant materials by themselves do not completely prevent water vapour ingress [1-3], but if they are well adhered, they will prevent the accumulation of liquid water providing protection against corrosion as well as electrical shock. Here, a brief review of some of the polymeric materials under consideration for PV applications is provided, with an explanation of some of their advantages and disadvantages.

  11. Evaluation of criteria for developing traffic safety materials for Latinos.

    PubMed

    Streit-Kaplan, Erica L; Miara, Christine; Formica, Scott W; Gallagher, Susan Scavo

    2011-03-01

    This quantitative study assessed the validity of guidelines that identified four key characteristics of culturally appropriate Spanish-language traffic safety materials: language, translation, formative evaluation, and credible source material. From a sample of 190, the authors randomly selected 12 Spanish-language educational materials for analysis by 15 experts. Hypotheses included that the experts would rate materials with more of the key characteristics as more effective (likely to affect behavioral change) and rate materials originally developed in Spanish and those that utilized formative evaluation (e.g., pilot tests, focus groups) as more culturally appropriate. Although results revealed a weak association between the number of key characteristics in a material and the rating of its effectiveness, reviewers rated materials originally created in Spanish and those utilizing formative evaluation as significantly more culturally appropriate. The findings and methodology demonstrated important implications for developers and evaluators of any health-related materials for Spanish speakers and other population groups.

  12. 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.

  13. 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.

  14. 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.

  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. 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

  17. 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.

  18. 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.

  19. A laboratory evaluation of core preservation materials

    SciTech Connect

    Auman, J.B.

    1986-01-01

    This paper documents the results of a laboratory study of the effectiveness of available state-of-the-art core preservation materials. The ability of the core sealing material to prevent post-preservation changes in fluid saturations may have a profound effect on subsequent laboratory measurements. Native-state (oil-cut) cores are often considered the best source of certain in-situ reservoir properties. Employing fluid saturations or relative permeability data from a core of this type, that has been altered due to the core drying out before measurements can be made, can significantly alter the results of a reservoir engineering study or simulation. Considering the expense involved in obtaining, storing and analyzing a native-state core, and the purpose for which it was cut, knowing exactly what materials can adequately preserve a core until laboratory measurements are made is critical and should not be overlooked. In this laboratory study, saturated Berea Sandstone core plugs were preserved in a number of commonly employed sealing materials. The sealed plugs were then stored in a humidity controlled environment and periodically weighed to ascertain the degree of change that had occurred in the saturation of the plug. In addition, this paper discusses and suggests procedures for applying recommended sealing materials.

  20. Training Methods and Materials: An Evaluation.

    ERIC Educational Resources Information Center

    Carter, Alex; Parker, Bill

    1993-01-01

    A survey of business, industry, government, medicine, and higher education investigated and ranked methods and materials for teaching factual and visual information; principles, concepts, and rules; procedures; motor skills; attitudes, opinions, and motivation. Findings show individual exercises to be most effective method and interactive video to…

  1. 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.

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

    PubMed

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

    2014-04-01

    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. 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). 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. This in vitro study revealed that aging can affect both the tear strength and cytotoxicity of soft denture materials depending on the composition.

  3. 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.

  4. 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.

  5. The use of information theory for the evaluation of biomarkers of aging and physiological age.

    PubMed

    Blokh, David; Stambler, Ilia

    2017-04-01

    The present work explores the application of information theoretical measures, such as entropy and normalized mutual information, for research of biomarkers of aging. The use of information theory affords unique methodological advantages for the study of aging processes, as it allows evaluating non-linear relations between biological parameters, providing the precise quantitative strength of those relations, both for individual and multiple parameters, showing cumulative or synergistic effect. Here we illustrate those capabilities utilizing a dataset on heart disease, including diagnostic parameters routinely available to physicians. The use of information-theoretical methods, utilizing normalized mutual information, revealed the exact amount of information that various diagnostic parameters or their combinations contained about the persons' age. Based on those exact informative values for the correlation of measured parameters with age, we constructed a diagnostic rule (a decision tree) to evaluate physiological age, as compared to chronological age. The present data illustrated that younger subjects suffering from heart disease showed characteristics of people of higher age (higher physiological age). Utilizing information-theoretical measures, with additional data, it may be possible to create further clinically applicable information-theory-based markers and models for the evaluation of physiological age, its relation to age-related diseases and its potential modifications by therapeutic interventions. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Evaluation of Polyurethane as a Cosmetic Glove Material.

    DTIC Science & Technology

    Polyurethane latex was evaluated for possible use as a cosmetic glove material. A two component latex system was used with a number of films and a... cosmetic glove being fabricated and evaluated with varying amounts of the two components. The mechanical properties indicate that the material is

  7. Researching Instructional Materials Evaluation: Adding Socio-Cultural Dimensions.

    ERIC Educational Resources Information Center

    Robinson, Rhonda S.; And Others

    A research project to evaluate materials for teacher education is described that reviews the development of evaluation tools, provides new measures, and applies the new measures to current visual materials. It is expected that as the study continues, it will reveal several explicit and implicit ideological stereotypes and assumptions about beliefs…

  8. 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.

  9. Evaluation of Ferroelectric Materials for Memory Applications

    DTIC Science & Technology

    1990-06-01

    or rhombohedral [Ref. 16: p.17]. M, ’of the materials of interest for memory applications are tetragonal, with the exception of potassium nitrate ( KNO3 ...PZT as the current favorite. Although KNO3 has many desirable properties and has been extensively studied, it is also extremely hygroscopic and has...niches where the application-specific capabilities outweigh the initially higher price . For applications where nonvolatility is required, ferroelectric

  10. The Effects of Aging on Material-Independent and Material-Dependent Neural Correlates of Source Memory Retrieval

    PubMed Central

    Duarte, Audrey

    2012-01-01

    Age-related declines in source memory have been observed for various stimuli and associated details. These impairments may be related to alterations in brain regions contributing to source memory via material-independent processes and/or regions specialized for processing specific materials. Using event-related functional magnetic resonance imaging, we investigate the effects of aging on source memory and associated neural activity for words and objects. Source accuracy was equally impaired in older adults for both materials. Imaging data revealed both groups recruited similar networks of regions to support source memory accuracy irrespective of material, including parietal and prefrontal cortices (PFC) and the hippocampus. Age-related decreases in material-independent activity linked to postretrieval monitoring were observed in right lateral PFC. Additionally, age-related increases in source accuracy effects were shown in perirhinal cortex, which were positively correlated with performance in older adults, potentially reflecting functional compensation. In addition to group differences in material-independent regions, age-related crossover interactions for material-dependent source memory effects were observed in regions selectively engaged by objects. These results suggest that older adults' source memory impairments reflect alterations in regions making material-independent contributions to source memory retrieval, primarily the lateral PFC, but may be further impacted by changes in regions sensitive to particular materials. PMID:21616984

  11. Echocardiographic evaluation of aged male cross country skiers.

    PubMed

    Grimsmo, J; Grundvold, I; Maehlum, S; Arnesen, H

    2011-06-01

    The aim of this echocardiographic study was to evaluate the effects of long-term endurance training on cardiac structure and function in three different age groups of 48 healthy middle-aged and old former or still active male cross country skiers (23 in age group I: age 58.6 ± 2.2 years; 21 in age group II: age 74.9 ± 2.2 years; four in age group III: age 89.5 ± 1.9 years). The two oldest age groups were combined and compared with age group I. No significant differences in left atrial or ventricular dimensions between these two age groups were found. A high proportion of enlarged left atrial dimensions were found among all subjects with 80% exceeding the upper reference limit of 40 mm in diameter (LADs) and 94% exceeding the upper reference limit of 20 cm(2) in area (LAAs). Mean values for LADs (mm) and LAAs (cm(2) ) were: group I: 41.9 ± 4.7 and 24.7 ± 3.3; group II: 43.5 ± 4.8 and 25.2 ± 3.7; group III: 44.5 ± 4.7 and 25.8 ± 3.7. Left ventricular diastolic diameter exceeded the upper reference limits of >54 mm in 20 subjects among all. The groups had preserved systolic and age-related diastolic function.

  12. Materials Evaluated as Potential Soil Stabilizers

    DTIC Science & Technology

    1977-09-01

    21.0 168 270 +153 Lithium hydroxide 0.59 20.8 168 198 +85 Sodium sulfite 1.0 21.2 168 322 +200 Sodium carbonate 1.0 20.5 168 375 +250 Sodium bicarbonate...fluoride, sodium 1.0, and 2.0% rates fluoborate , and sodium tetraborate Mixing Material Form* Type of Soil Treated Capability Powder Silt Good Effective...used (sodiun fluosilicate, sodium fluoride, sodium fluoborate , ET-218, and sodium tetraborate) were either detrimental when added to the cement or no

  13. 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.

  14. Exploratory Strategic Evaluation of Policies for Aging Americans.

    ERIC Educational Resources Information Center

    Williams, Charles; And Others

    This report analyzes federal policies and program for aging Americans in view of emerging socio-economic issues to determine if the present federal strategy has future viability. A conceptual framework and methodology were developed to evaluate federal programs in terms of individual needs. Based on this strategic evaluation, alternative…

  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. 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…

  17. Evaluations of diapers containing absorbent gelling material with conventional disposable diapers in newborn infants.

    PubMed

    Lane, A T; Rehder, P A; Helm, K

    1990-03-01

    We evaluated 149 infants diapered in either conventional cellulose core disposable diapers or diapers containing cellulose core with absorbent gelling material. The infants were evaluated from 1 day of age to 14 weeks of age for the prevalence and severity of diaper dermatitis. We identified a low prevalence of diaper dermatitis throughout the study period. At 14 weeks of age, we noted that infants in diapers containing absorbent gelling material had significantly less diaper dermatitis than those in conventional disposable diapers. Despite the overall low prevalence of diaper dermatitis in the newborn period, 7 of 204 infants evaluated had small skin erosions in the diaper area noted within the first 4 days of age. Both diaper types were associated with infants with erosions. This surprisingly high incidence of erosions in newborn infants suggests previously undocumented increased skin fragility of full-term infants.

  18. 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.

  19. 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).

  20. 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.

  1. 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.

  2. 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.

  3. Evaluating Age in the Field Triage of Injured Persons

    PubMed Central

    Nakamura, Yoko; Daya, Mohamud; Bulger, Eileen M.; Schreiber, Martin; Mackersie, Robert; Hsia, Renee Y.; Mann, N. Clay; Holmes, James F.; Staudenmayer, Kristan; Sturges, Zachary; Liao, Michael; Haukoos, Jason; Kuppermann, Nathan; Barton, Erik D.; Newgard, Craig D.

    2012-01-01

    Study Objective In this study, we evaluated (1) trauma under-triage by age group; (2) the association between age and serious injury after accounting for other field triage criteria and confounders; and (3) the potential impact of a mandatory age triage criterion for field triage. Methods This was a retrospective cohort study of injured children and adults transported by 48 EMS agencies to 105 hospitals in 6 regions of the Western U.S. from 2006 through 2008. We used probabilistic linkage to match EMS records to hospital records, including: trauma registries, state discharge databases and emergency department databases. The primary outcome measure was serious injury, as measured by an Injury Severity Score (ISS) ≥ 16. We assessed under-triage (ISS ≥ 16 and triage-negative or transport to a non-trauma center) by age decile and used multivariable logistic regression models to estimate the association (linear and non-linear) between age and ISS ≥ 16, adjusted for important confounders. We also evaluated the potential impact of age on triage efficiency and trauma center volume. Results 260,027 injured patients were evaluated and transported by EMS over the 3-year study period. Under-triage increased for patients over 60 years of age, reaching approximately 60% for those older than 90 years. There was a strong non-linear association between age and ISS ≥ 16. For patients not meeting other triage criteria, the probability of serious injury was most notable after 60 years. A mandatory age triage criterion would have decreased under-triage at the expense of over-triage, with one ISS ≥ 16 patient identified for every 60–65 additional patients transported to major trauma centers. Conclusion Trauma under-triage increases in patients older than 60 years. While the probability of serious injury increases among triage-negative patients with increasing age, the use of a mandatory age triage criterion appears inefficient for improving field triage. PMID:22633339

  4. 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.

  5. Trapped solar wind noble gases, kr81/kr exposure ages and k/ar ages in apollo 11 lunar material.

    PubMed

    Eberhardt, P; Geiss, J; Graf, H; Grögler, N; Krähenbühl, U; Schwaller, H; Schwarzmüller, J; Stettler, A

    1970-01-30

    Grain size and etching experiments show that the fine lunar material contains large amounts of trapped solar wind particles. Elemental and isotopic compositions of the noble gases in solar material and in the terrestrial atmosphere are significantly different, except for the Ar(36)/ Ar(38) and the Kr isotope ratios. Exposure ages of two rocks and of the fine material are between 380 and 510 x 10(6) years. Feldspar concentrates give K/Ar ages of 3220 and 3300 x 10(6) years, significantly higher than the unseparated rock.

  6. Evaluation of age determination techniques for gray wolves

    USGS Publications Warehouse

    Landon, D.B.; Waite, C.A.; Peterson, R.O.; Mech, L.D.

    1998-01-01

    We evaluated tooth wear, cranial suture fusion, closure of the canine pulp cavity, and cementum annuli as methods of age determination for known- and unknown-age gray wolves (Canis lupus) from Alaska, Minnesota, Ontario, and Isle Royale, Michigan. We developed age classes for cranial suture closure and tooth wear. We used measurement data obtained from known-age captive and wild wolves to generate a regression equation to predict age based on the degree of closure of the canine pulp cavity. Cementum annuli were studied in known- and unknown-age animals, and calcified, unstained thin sections were found to provide clear annulus patterns under polarized transmitted light. Annuli counts varied among observers, partly because of variation in the pattern of annuli in different regions of the cementum. This variation emphasizes the need for standardized models of cementum analysis. Cranial suture fusion is of limited utility in age determination, while tooth wear can be used to estimate age of adult wolves within 4 years. Wolves lt 7 years old could be aged to within 13 years with the regression equation for closure of the canine pulp cavity. Although inaccuracy remains a problem, cementum-annulus counts were the most promising means of estimating age for gray wolves.

  7. 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.

  8. The Effects of Aging on Clinical Vestibular Evaluations.

    PubMed

    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.

  9. Effect of Aging Regimens on Resin Nanoceramic Chairside CAD/CAM Material.

    PubMed

    Al-Harbi, Fahad A; Ayad, Neveen M; ArRejaie, Aws S; Bahgat, Hala A; Baba, Nadim Z

    2017-07-01

    To evaluate the effect of cyclic mechanical loading, thermal cycling, and storage in water on a resin nanoceramic chairside computer-aided designed/computer-aided manufactured (CAD/CAM) material compared to a control leucite-reinforced glass-ceramic material. One hundred twenty specimens (18 × 4 × 3 mm) were milled from two chairside CAD/CAM materials' blocks (Lava Ultimate: LU; Vitablock Mark II: VM). Each group included four subgroups (A: n = 20 control; B: n = 20 cyclic loading [105 cycles, 80 N]; C: n = 20 thermal cycling [5 to 55°C]; D: n = 60 water storage [20: 3 months; 20: 6 months; 20: 9 months at 37°C]). Each subgroup included 10 specimens tested for flexure strength using three-point bending in a universal testing machine. The other 10 specimens were tested for surface roughness using an automated profiler followed by testing for surface hardness using a microhardness tester. LU displayed higher flexure strength than VM before and after all the aging conditions. The surface roughness for VM was lower than LU for the control, but both materials showed comparable values and significant increases after 9 months storage in water. After cyclic loading, only VM displayed a significant increase in the surface roughness value (p < 0.05). The surface hardness of VM was higher than LU for the control. VM did not show significant changes in hardness after any aging condition. LU showed significant reduction in surface hardness value only after storage in water (p < 0.05). The resin nanoceramic Lava Ultimate can be used as a durable substitute for glass-ceramic chairside CAD/CAM material. © 2015 by the American College of Prosthodontists.

  10. The Aging of Cork-Rubber Decoupling Materials.

    DTIC Science & Technology

    1981-03-09

    either the Gibbs function or the Helmholtz function is done by Berlincourt, Curran, and Jaffe and can be found in Mason [8]. In this work matrix nota...materials tested in thf, acoustic impedance tube. CALL ERIISET63.. FASE ...FALSE.,,) CALL ERRSET(64,,.FALSE.,..FALSE.,,) IITE(6,903) 903 FOWLMT/, I

  11. 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.

  12. 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.

  13. Dredged Material Testing and Evaluation for Ocean Disposal

    EPA Pesticide Factsheets

    Evaluation and testing of dredged material proposed for ocean dumping is conducted to help protect human health and the marine environment. National guidance is provided by the Green Book. Regional Implementation Manuals are provided.

  14. 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.

  15. 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

  16. The Need for New Materials in Aging Aircraft Structures

    DTIC Science & Technology

    2000-04-01

    15% higher spectrum fatigue stress allowable. Although Al-Li alloys are more expensive than conventional aluminum alloys, the replacement of 2124 by...STRUCTURES R.J. Bucci and C.J. Warren Aluminum Company of America Alcoa Center, PA 15069 USA E.A. Starke, Jr. Department of Materials Science and...an effort to extend the life of many aircraft that are the backbone of NATO operational forces. Although some are designated to be replaced with new

  17. Evaluation Echoes; A Teachers Guide for Selecting Bilingual Education Materials.

    ERIC Educational Resources Information Center

    Puerto Rican Congress of New Jersey, Trenton.

    In this teacher's guide for selecting bilingual education materials, program materials are evaluated for the following subject areas: English language arts, Spanish language arts, fine arts, social studies, science and mathematics. A general profile matrix covering all programs and subjects appears at the beginning of the guide. It provides for…

  18. 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…

  19. 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…

  20. First Chance Products: A Catalogue of Instructional and Evaluative Materials.

    ERIC Educational Resources Information Center

    North Carolina Univ., Chapel Hill. Technical Assistance Development System.

    Presented in the catalog are approximately 150 listings of instructional or evaluative materials developed by the First Chance Network of model preschool intervention programs for handicapped children. Materials are alphabetically indexed by title and cross-referenced by target population (children, parents, or staff) and function (instructional…

  1. Towards aging mechanisms of cross-linked polyethylene (XLPE) cable insulation materials in nuclear power plants

    SciTech Connect

    Liu, Shuaishuai; Fifield, Leonard S.; Bowler, Nicola

    2016-12-19

    Cross-linked polyethylene (XLPE) cable insulation material undergoes simultaneous, accelerated thermal and gamma-radiation aging to simulate the long-term aging environment within nuclear power plants (NPPs). A variety of materials characterization tests, including scanning electron microscopy, thermo-gravimetric analysis, differential scanning calorimetry, oxidation induction time, gel-fraction and dielectric properties measurement, are conducted on pristine and differently aged XLPE samples. A preliminary model of one possible aging mechanism of XLPE cable insulation material under gamma radiation at elevated temperature of 115 °C is suggested.

  2. 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

  3. 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.

  4. Active thermography in qualitative evaluation of protective materials.

    PubMed

    Gralewicz, Grzegorz; Wiecek, Bogusław

    2009-01-01

    This is a study of the possibilities of a qualitative evaluation of protective materials with active thermography. It presents a simulation of a periodic excitation of a multilayer composite material. Tests were conducted with lock-in thermography on Kevlar composite consisting of 16 layers of Kevlar fabric reinforced with formaldehyde resin with implanted delamination defects. Lock-in thermography is a versatile tool for nondestructive evaluation. It is a fast, remote and nondestructive procedure. Hence, it was used to detect delaminations in the composite structure of materials used in the production of components designed for personal protection. This method directly contributes to an improvement in safety.

  5. 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.

  6. Evaluating School Library Information Services in the Digital Age.

    ERIC Educational Resources Information Center

    Everhart, Nancy

    2000-01-01

    Discusses criteria for evaluating school library information services. Highlights include types of services; physical facilities; library usage; circulation statistics; changes due to technology; fill rate, or the percentage of successful searches for library materials; OPAC (online public access catalog) reports; observation; and examining…

  7. Age 60 Study, Part 4: Experimental Evaluation of Pilot Performance

    DTIC Science & Technology

    1994-10-01

    and aging. Computerized cognitive test batteries, COGSREEN and WOMBAT , were selected as the domain-independent measures. Flitescript and whole task...were assessed. COGSCREEN total composite scores were significantly correlated with evaluator ratings on emergency/abnormal maneuvers. Neither WOMBAT ...B-3 WOMBAT Questionnaire .......................................... B-4 Sim ulator Post-flight Questionnaire

  8. 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)

  9. Age-Relevance of Content Material on Relativistic and Dialectical Reasoning.

    ERIC Educational Resources Information Center

    Kramer, Deirdre A.; And Others

    The effects of age-relevance of content material on reasoning were systematically studied in 120 adolescents, young adults, middle-aged adults, and older adults. Subjects were presented with either an adolescent, young adult, middle-aged, or older adult interpersonal dilemma and asked a series of structured questions assessing relativistic and…

  10. 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.

  11. Evaluating restorative materials and procedures in dental practice.

    PubMed

    Burke, F J T

    2005-12-01

    A wide variety of research methods are appropriate to general dental practice, including clinical trials of materials, assessment of materials and techniques, treatment trends, and assessment of behavior and attitudes, of dentists as well as patients. This paper will describe the use of practice-based networks to evaluate the effectiveness of materials and techniques in dental practice. Several practice-based research groups are presently in operation in the UK and the USA, generally carrying out evaluations of the handling of materials, but with increasing emphasis on the clinical evaluation of restorations. Use of the Dental Practice Board (of England and Wales) database has proved to be a fruitful source of data on the long-term outcome of restorations. Dental practice can provide the large pool of patients available for research. To utilize this pool of patients, dental practitioners and their support staff require training in collecting data.

  12. 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.

  13. 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.

  14. Re-evaluating the age of the Haughton impact event

    NASA Astrophysics Data System (ADS)

    Sherlock, Sarah C.; Kelley, Simon P.; Parnell, John; Green, Paul; Lee, Pascal; Osinski, Gordon R.; Cockell, Charles S.

    2005-12-01

    We have re-evaluated the published age information for the Haughton impact structure, which was believed to have formed ˜23 Ma ago during the Miocene age, and report new Ar/Ar laser probe data from shocked basement clasts. This reveals an Eocene age, which is at odds with the published Miocene stratigraphic, apatite fission track and Ar/Ar data; we discuss our new data within this context. We have found that the age of the Haughton impact structure is ˜39 Ma, which has implications for both crater recolonization models and post-impact hydrothermal activity. Future work on the relationship between flora and fauna within the crater, and others at high latitude, may resolve this paradox.

  15. 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.

  16. H1259 Container Foams: Performance Data on Aged Materials

    SciTech Connect

    Linda Domeier

    2002-05-01

    Samples of the three cushioning foams used in the H1259 weapon storage container were obtained in 1997, 1998, 2000 and 2001 and tested for density, compression set and compressive strength using the same procedures specified for acceptance testing. Foams from six containers, all about 30 years old and located at Pantex, were evaluated. The bottom cushioning foam is a General Plastics polyurethane foam and the two side pads are rebonded polyurethane foams. All the tests were carried out at room temperature. When compared to the original acceptance requirements the foams were generally in-spec for density and compressive strength at 10% strain and were generally out-of-spec for compression set and compressive strength at 50% strain. Significant variability was noted in the performance of each foam sample and even more in the container-to-container foam performance. The container-to-container variability remains the major unknown in predicting the long-term suitability of these containers for continued use. The performance of the critical bottom cushion foams was generally more uniform and closer to the specified performance than that of the rebonded foams. It was judged that all the foams were adequate for continued use as storage container foams (not shipping) under controlled conditions to mitigate temperature extremes or high impact. This archived information is important in evaluations of the continued suitability for weapon storage use of the H1259 containers and other containers using the same foam cushions.

  17. IMPORTANCE OF MATERIAL BALANCES AND THEIR STATISTICAL EVALUATION IN RUSSIAN MATERIAL, PROTECTION, CONTROL AND ACCOUNTING

    SciTech Connect

    FISHBONE,L.G.

    1999-07-25

    While substantial work has been performed in the Russian MPC&A Program, much more needs to be done at Russian nuclear facilities to complete four necessary steps. These are (1) periodically measuring the physical inventory of nuclear material, (2) continuously measuring the flows of nuclear material, (3) using the results to close the material balance, particularly at bulk processing facilities, and (4) statistically evaluating any apparent loss of nuclear material. The periodic closing of material balances provides an objective test of the facility's system of nuclear material protection, control and accounting. The statistical evaluation using the uncertainties associated with individual measurement systems involved in the calculation of the material balance provides a fair standard for concluding whether the apparent loss of nuclear material means a diversion or whether the facility's accounting system needs improvement. In particular, if unattractive flow material at a facility is not measured well, the accounting system cannot readily detect the loss of attractive material if the latter substantially derives from the former.

  18. 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 A; 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.

  19. 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.

  20. Printed health information materials: evaluation of readability and suitability.

    PubMed

    Shieh, Carol; Hosei, Barbara

    2008-01-01

    This study examined readability and suitability of printed health information materials colleted from multiple sources. In phase I, nursing students used Simple Measure of Gobbledygook (SMOG; McLaughlin, 1969) to assess the readability of 21 materials collected from the community. In phases II and III, nursing students and registered nurses used SMOG and the Suitability Assessment of Materials (SAM; Doak, Doak, & Root, 1996) to evaluate 15 prenatal materials from a Healthy Start program. SMOG assigns a reading grade level based on the number of words with 3 or more syllables. SAM has 22 items in 6 evaluation areas: content, literacy demand, graphics, layout and typography, learning stimulation and motivation, and cultural appropriateness. Major findings included that 53% to 86% of the printed materials had a reading level at or higher than 9th grade; materials lacked summary, interaction, and modeled behaviors, and registered nurses rated more materials as not suitable and fewer as superior for suitability qualities than students. Improving printed materials to have lower reading levels and better suitability qualities are indicated.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Polymer materials and component evaluation in acidic-radiation environments

    NASA Astrophysics Data System (ADS)

    Celina, M.; Gillen, K. T.; Malone, G. M.; Clough, R. L.; Nelson, W. H.

    2001-07-01

    Polymeric materials used for cable/wire insulation, electrical connectors, O-rings, seals, and in critical components such as motors, level switches and resistive thermo-devices were evaluated under accelerated degradation conditions in combined radiation-oxidative elevated-temperature acidic-vapor (nitric/oxalic) environments relevant to conditions in isotope processing facilities. Experiments included the assessment of individual materials such as PEEK, polyimides, polyolefin based cable insulation, EPDM rubbers, various epoxy systems, commercial caulking materials as well as some functional testing of components. We discuss how to conduct laboratory experiments to simulate such complex hostile environments, describe some degradation effects encountered, and evaluate the impact on appropriate material and component selection.

  6. Pin bearing evaluation of LTM25 composite materials

    NASA Technical Reports Server (NTRS)

    Shah, C. H.; Postyn, A. S.

    1996-01-01

    This report summarizes pin bearing evaluations of LTM25 composite materials. Northrop Grumman Corporation conducted pin bearing testing and fabricate two panels from composite materials that cure at low temperatures. These materials are being incorporated into Unmanned Aerial Vehicles (UAVS) to reduce manufacturing costs since they allow the use of low-cost tooling and facilities. Two composite prepreg product forms were evaluated; MR50/LTM25 unidirectional tape, batch 2881vd and CFS003/LTM25 woven cloth, batch 2216. Northrop Grumman fabricated, machined, and tested specimens to determine the bearing strength in accordance with MIL-HDBK-17D, Volume 1, Section 7.2.4. Quasi-isotropic laminates from the two product forms were fabricated for these tests. In addition, 2 quasi-isotropic panels of dimensions 12 in. x 28 in. were fabricated (one each from the two product forms), inspected, and shipped to NASA Langley for further evaluation.

  7. Reliability of Tethered Swimming Evaluation in Age Group Swimmers

    PubMed Central

    Amaro, Nuno; Marinho, Daniel A; Batalha, Nuno; Marques, Mário C; Morouço, Pedro

    2014-01-01

    The aim of the present study was to examine the reliability of tethered swimming in the evaluation of age group swimmers. The sample was composed of 8 male national level swimmers with at least 4 years of experience in competitive swimming. Each swimmer performed two 30 second maximal intensity tethered swimming tests, on separate days. Individual force-time curves were registered to assess maximum force, mean force and the mean impulse of force. Both consistency and reliability were very strong, with Cronbach’s Alpha values ranging from 0.970 to 0.995. All the applied metrics presented a very high agreement between tests, with the mean impulse of force presenting the highest. These results indicate that tethered swimming can be used to evaluate age group swimmers. Furthermore, better comprehension of the swimmers ability to effectively exert force in the water can be obtained using the impulse of force. PMID:25114742

  8. 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.

  9. Evaluation of materials for high performance solar arrays

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F.; Smith, C. F., Jr.; Peacock, C. L., Jr.; Little, S. A.

    1978-01-01

    A program has been underway to evaluate materials for advanced solar arrays which are required to provide power to weight ratios up to 100 W/kg. Severe mission environments together with the lack of knowledge of space environmental materials degradation rates require the generation of irradiation and outgassing engineering data for use in the initial design phase of the flight solar arrays. Therefore, approximately 25 candidate array materials were subjected to selected mission environments of vacuum, UV, and particle irradiation, and their mechanical and/or optical properties were determined where appropriate.

  10. Evaluating Degradation on Thermal Control Materials for GPM/DPR

    NASA Astrophysics Data System (ADS)

    Ishizawa, Junichiro; Hyakusoku, Yasutoshi; Shimamura, Hiroyuki; Kimoto, Yugo; Kojima, Masahiro

    Thermal control materials such as white paints and germanium-coated polyimide film were evaluated with respect to their space environmental tolerance for materials selection of the Dual-frequency Precipitation Radar of the Global Precipitation Measurement satellite (GPM/DPR). Though peeling off and cracking occurred in one paint material during the thermal shock test, other paints showed good tolerance against thermal shock, atomic oxygen, and ultraviolet ray irradiation. Germanium coating on polyimide film was also verified as high atomic oxygen tolerant barrier. Comparing different thickness germanium coatings, it seems that a 1000 angstrom Germanium film has fewer defects and risk of AO undercutting than a 525 angstrom Germanium film.

  11. Heterogeneity evaluation of research materials for microanalysis standards certification.

    PubMed

    Marinenko, Ryna; Leigh, Stefan

    2004-08-01

    Electron microprobe testing and evaluation procedures to determine the extent of within- and between-specimen heterogeneity of reference materials and the experimental uncertainty are described. These procedures have been developed and used at NIST in the certification of several NIST Standard Reference Materials (SRMs). In this article, they have been simplified and updated for general use. Suggestions for experimental testing of specimens are described and a detailed description of the statistical evaluation process is included with an example of a data spreadsheet and instructions for its preparation.

  12. 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.

  13. 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.

  14. Clinical evaluation of ridge augmentation using autogenous tooth bone graft material: case series study.

    PubMed

    Lee, Ji-Young; Kim, Young-Kyun; Yi, Yang-Jin; Choi, Joon-Ho

    2013-08-01

    Interest in bone graft material has increased with regard to restoration in cases of bone defect around the implant. Autogenous tooth bone graft material was developed and commercialized in 2008. In this study, we evaluated the results of vertical and horizontal ridge augmentation with autogenous tooth bone graft material. This study targeted patients who had vertical or horizontal ridge augmentation using AutoBT from March 2009 to April 2010. We evaluated the age and gender of the subject patients, implant stability, adjunctive surgery, additional bone graft material and barrier membrane, post-operative complication, implant survival rate, and crestal bone loss. We performed vertical and horizontal ridge augmentation using powder- or block-type autogenous tooth bone graft material, and implant placement was performed on nine patients (male: 7, female: 2). The average age of patients was 49.88±12.98 years, and the post-operative follow-up period was 35±5.31 months. Post-operative complications included wound dehiscence (one case), hematoma (one case), and implant osseointegration failure (one case; survival rate: 96%); however, there were no complications related to bone graft material, such as infection. Average marginal bone loss after one-year loading was 0.12±0.19 mm. Therefore, excellent clinical results can be said to have been obtained. Excellent clinical results can be said to have been obtained with vertical and horizontal ridge augmentation using autogenous tooth bone graft material.

  15. 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.

  16. Comparative evaluation of liner materials for inactive uranium-mill-tailings piles

    SciTech Connect

    Buelt, J.L.; Barnes, S.M.

    1981-01-01

    Under the funding of the Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Program, Pacific Northwest Laboratory (PNL) has completed the initial accelerated testing phase of eight candidate liner materials. The tests were designed to comparatively evaluate the long term effectiveness of liner materials as a radionuclide and hazardous chemical leachate barrier. The eight materials tested were selected from a technical review of published literature and industrial specialists. Conditions were then identified that would accelerate the aging processes expected in a uranium tailings environment for 1000 years. High calcium leachates were forced through thin layers of clay liners to accelerate the ion exchange rate of sodium and calcium. Asphalt and synthetic materials were accelerated by exposure to elevate temperatures, high concentrations of oxygen, and increased strengths of aqueous oxidizing agents. By comparing the changes of permeability with time of exposure, the most acceptable materials were then identified. These materials are a catalytically airblown asphalt membrane and natural soil amended with sodium bentonite. Both materials showed an increased resistance to leachate penetration throughout the exposure period with final permeabilities less than 10/sup -7/ cm/s. In addition, the asphalt membrane and sodium bentonite are among the least expensive materials to install at a disposal site. Therefore based on their economic and technical merits, these two materials are being evaluated further in field tests at Grand Junction, Colorado.

  17. 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.

  18. Evaluation of the shedding potential of textile materials.

    PubMed

    De Wael, K; Lepot, L; Lunstroot, K; Gason, F

    2010-12-01

    A practical method is proposed to assess the shedding potential of textile materials. The evaluation of the sheddability is based on the use of adhesive tapes and on comparison, using three different sheddability scales for cotton, wool and fine man-made fibres.

  19. Impact fracture toughness evaluation for high-density polyethylene materials

    NASA Astrophysics Data System (ADS)

    Cherief, M. N. D.; Elmeguenni, M.; Benguediab, M.

    2017-03-01

    The impact fracture behavior of a high-density polyethylene (HDPE) material is investigated experimentally and theoretically. Single-edge notched bending (SENB) specimens are tested in experiments with three-point bending and in the Charpy impact tests. An energy model is proposed for evaluating the HDPE impact toughness, which provides a description of both brittle and ductile fracture.

  20. 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.

  1. How effective are your patient education materials? Guidelines for developing and evaluating written educational materials.

    PubMed

    Farrell-Miller, P; Gentry, P

    1989-01-01

    Written educational materials are an essential component of a comprehensive education program. To be effective and useful, educational materials must meet the specific needs of the target patient population. Many available educational materials may not meet the needs of your patients, therefore efforts to develop appropriate written educational tools may be necessary. Developing quality educational materials include several steps: conducting a needs assessment, establishing learning objectives, writing the text, and evaluating the piece. The quality of the text is often determined by readability. The text should be written on a level that is appropriate for the patient group. Content and style, layout, color, and illustrations all influence readability and quality. Most important, good quality educational materials help promote the relationship between the patient and the health care professional as well as enhance patient knowledge and self-care.

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

    PubMed

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

    2014-08-01

    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.

  3. Suitability of Asthma Education Materials for School-age Children: Implications for Health Literacy.

    PubMed

    Tzeng, Yu-Fen; Gau, Bih-Shya

    2017-08-09

    This study investigated the suitability of asthma education materials for school-age children with asthma and elucidated how these children used their health-literacy abilities to identify whether the materials can be accepted, comprehended, and applied. Effective asthma self-management education is influenced by the suitability of materials and an individual's health literacy. A mixed-method research design was developed using quantitative and qualitative surveys. The suitability of the materials was assessed on the basis of the Chinese version of the Suitability Assessment of Materials by five experts. In addition, five school-age children (age: 8-12 years) were recruited and interviewed. In total, 25 pieces of asthma education material for children were collected. On the basis of their type, the materials were categorized as 9 brochures, 11 leaflets, and 5 videos. Of the 25 materials, 17 were rated as superior materials, whereas 8 were rated as adequate materials. The suitability scores of the video-based materials were significantly higher than those of the brochures and leaflets (p = .006). One print material was considered to have a reading level suitable for fifth-grade or younger children, whereas the remaining materials were considered suitable for sixth-grade or older children. The following six health-literacy domains were identified: recognizing asthma through body knowledge, posing reflective questions, identifying self-care difficulties, receiving adult guidance, learning with enjoyment, and addressing learning requirements. The video-based materials had integrated content and were appealing to children. Cartoon animations, interactive computer games, and skill demonstrations may enhance learning stimulation and motivation and increase learning effects in children. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  4. 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

  5. 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

  6. Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials

    SciTech Connect

    Gillen, K.T.; Clough, R.L.

    1991-06-01

    In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs.

  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. 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.

  9. 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

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

    PubMed Central

    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

    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

  11. 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.

  12. Purity Evaluation of Bulk Single Wall Carbon Nanotube Materials

    NASA Astrophysics Data System (ADS)

    Dettlaff-Weglikowska, U.; Wang, J.; Liang, J.; Hornbostel, B.; Cech, J.; Roth, S.

    2005-09-01

    We report on our experience using a preliminary protocol for quality control of bulk single wall carbon nanotube (SWNT) materials produced by the electric arc-discharge and laser ablation method. The first step in the characterization of the bulk material is mechanical homogenization. Quantitative evaluation of purity has been performed using a previously reported procedure based on solution phase near-infrared spectroscopy. Our results confirm that this method is reliable in determining the nanotube content in the arc-discharge sample containing carbonaceous impurities (amorphous carbon and graphitic particles). However, the application of this method to laser ablation samples gives a relative purity value over 100 %. The possible reason for that might be different extinction coefficient meaning different oscillator strength of the laser ablation tubes. At the present time, a 100 % pure reference sample of laser ablation SWNT is not available, so we chose to adopt the sample showing the highest purity as a new reference sample for a quantitative purity evaluation of laser ablation materials. The graphitic part of the carbonaceous impurities has been estimated using X-ray diffraction of 1:1 mixture of nanotube material and C60 as an internal reference. To evaluate the metallic impurities in the as prepared and homogenized carbon nanotube soot inductive coupled plasma (ICP) has been used.

  13. Evaluation of alternate construction materials for a lithium electrolysis cell

    SciTech Connect

    Keiser, J.R.; Olsen, A.R.; DiStefano, J.R.

    1988-05-01

    Electrolytic cells currently used for the production of lithium metal are constructed of A285 Grade A steel (carbon content less than 0.15%). Failures of the cell wall have frequently occurred after 2 to 5 years of service, and these failures have been attributed to corrosion resulting from the reaction of iron carbide with lithium. An examination of a recent failure confirmed this conclusion. In an effort to identify alternate construction materials with better corrosion resistance for this application, five materials with very low carbon levels and/or carbides more stable than those in A285 were selected for evaluation. Materials were evaluated after exposure in an operating electrolytic cell, after exposure to pure lithium, and after exposure to a moist air-chlorine mixture. Results show that all five of the alternative materials selected are more corrosion resistant than A285, but two were eliminated from further consideration because of other potential shortcomings. Additional long-term corrosion tests are recommended for the remaining three candidate materials. Final selection should be based on considerations of cost, availability, and fabricability in addition to compatibility. 26 refs., 9 figs., 8 tabs.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Discoloration of different esthetic restorative materials: A spectrophotometric evaluation

    PubMed Central

    Ceci, Matteo; Viola, Matteo; Rattalino, Davide; Beltrami, Riccardo; Colombo, Marco; Poggio, Claudio

    2017-01-01

    Objective: A crucial property of esthetic restorative materials is their long-term color stability. The aim of this in vitro study was to evaluate the color stability of esthetic restorative materials (one microfilled flowable composite, one nanofilled composite, one nanoybrid composite, one microfilled composite, and one nanoybrid ormocer-based composite) after surface roughening with cola and exposure to different staining solutions (coffee and red wine). Materials and Methods: All materials were polymerized into silicone rubber rings (2 mm × 6 mm × 8 mm) to obtain 150 specimens identical in size. Seventy-five specimens of Group A were first exposed to cola for 24 h, and then samples were immersed in coffee or red wine over a 28-day test period. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at 7, 14, 21, 28 days. Shapiro–Wilk test and Kruskal–Wallis analysis of variance were applied to assess significant differences among restorative materials. Means were compared with Scheffe's multiple comparison test at the 0.05 level of significance. Results: Specimens of Group A showed higher variations when compared with Group B's specimens (P < 0.05). After 28 days, the immersion protocols caused a clinically perceivable color change for all materials tested (P < 0.05). CeramX Universal and Admira Fusion showed the lowest ΔE variations (P < 0.05). Conclusions: Staining beverages caused significant discolorations for all the materials tested. The first exposure to cola enhanced the subsequent staining with coffee or red wine. Nanohybrid composites reported the lowest color variations. PMID:28729784

  19. 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.

  20. 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.

  1. Evaluation of forensic examination of extremely aged seminal stains.

    PubMed

    Nakanishi, Hiroaki; Hara, Masaaki; Takahashi, Shirushi; Takada, Aya; Saito, Kazuyuki

    2014-09-01

    The results of forensic tests, such as semen identification and short tandem repeat (STR) analysis of extremely aged seminal stains from unsolved sex crimes can provide important evidence. In this study we evaluated whether current forensic methods could be applied to seminal stains that were stored at room temperature for 33-56years (n=2, 33years old; n=1, 41years old; n=1, 44years old; n=1, 56years old). The prostatic acid phosphatase (SM-test reagent), microscopic (Baecchi stain method) and semenogelin (RSID™ Semen Laboratory Kit) tests were performed as discriminative tests for semen. In addition, the mRNA levels of the semen-specific proteins semenogelin 1 (SEMG1) and protamine 2 (PRM2) were investigated. STRs were analyzed using the AmpFlSTR® Identifiler™ PCR Amplification Kit. All samples were positive in the prostatic acid phosphatase and semenogelin tests, and sperm heads were identified in all samples. The staining degree of the aged sperm heads was similar to that of fresh sperm. Although SEMG1 mRNA was not detected in any sample, PRM2 mRNA was detected in three samples. In the STR analysis, all loci were detected in the 33-years-old sample and five loci were detected in the 56-years-old sample. We confirmed that current forensic examinations - including STR analysis - could be applied to extremely aged seminal stains. These results could be useful for forensic practice.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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…

  10. 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…

  11. Discoloration of different esthetic restorative materials: A spectrophotometric evaluation.

    PubMed

    Ceci, Matteo; Viola, Matteo; Rattalino, Davide; Beltrami, Riccardo; Colombo, Marco; Poggio, Claudio

    2017-01-01

    A crucial property of esthetic restorative materials is their long-term color stability. The aim of this in vitro study was to evaluate the color stability of esthetic restorative materials (one microfilled flowable composite, one nanofilled composite, one nanoybrid composite, one microfilled composite, and one nanoybrid ormocer-based composite) after surface roughening with cola and exposure to different staining solutions (coffee and red wine). All materials were polymerized into silicone rubber rings (2 mm × 6 mm × 8 mm) to obtain 150 specimens identical in size. Seventy-five specimens of Group A were first exposed to cola for 24 h, and then samples were immersed in coffee or red wine over a 28-day test period. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at 7, 14, 21, 28 days. Shapiro-Wilk test and Kruskal-Wallis analysis of variance were applied to assess significant differences among restorative materials. Means were compared with Scheffe's multiple comparison test at the 0.05 level of significance. Specimens of Group A showed higher variations when compared with Group B's specimens (P < 0.05). After 28 days, the immersion protocols caused a clinically perceivable color change for all materials tested (P < 0.05). CeramX Universal and Admira Fusion showed the lowest ΔE variations (P < 0.05). Staining beverages caused significant discolorations for all the materials tested. The first exposure to cola enhanced the subsequent staining with coffee or red wine. Nanohybrid composites reported the lowest color variations.

  12. 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.

  13. Laboratory Evaluation of Nitrile Fuel Tank Materials (Phase 2)

    DTIC Science & Technology

    2013-09-01

    control number . PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) September 2013 2. REPORT TYPE Final 3. DATES...COVERED (From - To) October 2011–March 2013 4. TITLE AND SUBTITLE Laboratory Evaluation of Nitrile Fuel Tank Materials (Phase II) 5a. CONTRACT NUMBER ...5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) James M. Sloan, David Flanagan, Daniel DeSchepper, Paul Touchet,* and Henry Feuer† 5d

  14. Development and Evaluation of Nonmetallic Materials for Belt Links

    DTIC Science & Technology

    1974-11-01

    75-008 2. GOVT ACCESSION NO 3 . RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) DEVELOPMENT AND EVALUATION OF NONMETALLIC MATERIALS FOR...Conllnua on ravataa aida It nacaaaaxy and Idantlty by block number) 1. Belt Links 2. Reinforced Plastic 3 . Elastoplastic U. Plastic 20. ABSTRACT...automatic weapon systems were reviewed and are presented in Table 3 . The maximum tensile load for assembled links was dOO pounds for the M17A1 link used

  15. 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.

  16. Potential inert matrix materials: Materials synthesis and evaluation of in-service engineering parameters

    NASA Astrophysics Data System (ADS)

    Xu, Peng

    Containing no fertile materials, inert matrix fuel (IMF) has been introduced as a potential transmutation solution for the increasing inventory of both weapon grade and reactor grade plutonium (Pu). In the present work, the MgO-pyrochlore (Nd2Zr2O7) composites and spinel magnesium stannate (Mg2SnO4) were selected as potential inert matrix (IM) materials. A comprehensive investigation was conducted on evaluation of the engineering parameters of the potential IM materials. The MgO-Nd2Zr2O7 composites and Mg 2SnO4 were fabricated through conventional solid state processing. The crystal structure and microstructure of the synthesized composites and Mg2SnO4 were studied. The irradiation tolerance of the potential IM materials was first assessed. The resistance of Mg2SnO 4 against irradiation induced amorphization was assessed experimentally using in situ TEM technique. The critical amorphization doses for Mg2SnO4 irradiated by 1 MeV Kr2+ ions were determined to be 5.5 dpa at 50 K and 11.0 dpa at 150 K, respectively. The obtained results were compared with other spinels especially MgAl 2O4, and the radiation tolerance of spinels were discussed. The next evaluation was water corrosion resistance of the potential IM materials. Homogeneous MgO-Nd2Zr2O7 composites exhibited an improved hydrothermal corrosion resistance than inhomogeneous composites and pure MgO. Even though spinel Mg2SnO4 was not stable in water at 300°C and saturation pressure, the corrosion was limited only to the surface, and the volume and mass changes were less than 1 % after 720 h corrosion. Feasibility of aqueous reprocessing was evaluated by studying the dissolution behavior of the potential IM materials in acidic solutions, with an emphasis on nitric acid. Dissolution of the MgO-Nd2Zr2O 7 composites in HNO3 resulted in a selective dissolution of MgO. Mechanical agitation such as magnetic bar stirring was necessary to achieve a completed dissolution of MgO and disintegration of porous Nd 2Zr2O7

  17. Creep evaluation of (orthotic) cast materials during simulated clubfoot correction.

    PubMed

    Cohen, Tamara L; Altiok, Haluk; Tarima, Sergey; Smith, Peter A; Harris, Gerald F

    2012-01-01

    The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot that relies on weekly manipulations and cast applications. However, the material behavior of the cast in the Ponseti technique has not been investigated. The current study sought to characterize the ability of two standard casting materials to maintain the Ponseti corrected foot position by evaluating creep response. A dynamic cast testing device (DCTD) was built to simulate a typical pediatric clubfoot. Semi-rigid fiberglass and rigid fiberglass casting materials were applied to the device, and the rotational creep was measured at various constant torques. The movement was measured using a 3D motion capture system. A 2-way ANOVA was performed on the creep displacement data at a significance level of 0.05. Among cast materials, the rotational creep displacement was found to be significantly different (p-values ≪ 0.001). The most creep displacement occurs in the semi-rigid fiberglass (approximately 1.0 degrees), then the rigid fiberglass (approximately 0.4 degrees). There was no effect of torque magnitude on the creep displacement. All materials maintained the corrected position with minimal change in position over time.

  18. 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

  19. Nanoglasses: A New Kind of Noncrystalline Material and the Way to an Age of New Technologies?

    PubMed

    Gleiter, Herbert

    2016-04-27

    Today's technologies are primarily based on crystalline materials (metals, semiconductors, etc.), as their properties can be controlled by varying their chemical and/or defect microstructures. This is not possible in today's glasses. The new features of nanoglasses--consisting of nanometer-sized glassy regions connected by interfaces--are that their properties may be controlled by varying their chemical and/or defect microstructures, and that their interfaces have a new kind of non-crystalline structure. By utilizing these new features, an age of new technologies based on non-crystalline materials (a "glass age") may be initiated.

  20. [Problems associated with age estimation of underage persons who appear in child pornography materials].

    PubMed

    Łabecka, Marzena; Lorkiewicz-Muszyńska, Dorota; Jarzabek-Bielecka, Grazyna

    2011-01-01

    Among opinions issued by the Forensic Medicine Department, Medical Science University in Poznan, in the last six years, there are opinions concerning age estimation in child pornography materials. The issue subject to research is indicating persons under the age of 15 years in pornographic materials, since possession of pornographic materials featuring underage persons is considered a crime and is subject to article 202 of the Penal Code. The estimation of the age of teenagers based on secondary and tertiary sexual characteristics is increasingly more difficult and the available data in professional literature regarding the standard time of development differ among various authors of such studies. In the report, an attempt has been made at determining the agreement regarding different characteristics in the data included in the Tanner's scale, which has been modified to accommodate the research done on persons registered by electronic means. The modified scale, which up to now has been used in research of registered subjects in classified public prosecutors' materials, has been employed in children seen in a pediatric outpatient department. The goal has been a comparison of the outcome of the research to prove its usefulness so that in the future, the modified scale could be used as a research tool in estimation of age of persons appearing in pornography materials. medical forms of 205 children seen in a pediatric outpatient department, based on the scale created by the present authors us and later processed using Excel.

  1. Study of the Influence of Construction Materials on the Ageing Properties of High Rate Gas Detectors

    NASA Astrophysics Data System (ADS)

    Abuhoza, Alhussain; Biswas, S.; Frankenfeld, U.; Hehner, J.; Schmidt, C. J.; Schmidt, H. R.

    An infrastructure has been set up at the GSI detector laboratory to study the influence of construction materials on the ageing properties of gas filled detectors such as multi wire proportional chambers (MWPC), gas electron multipliers (GEM) etc. As a first step an ageing test of silicone-based glue (RTV-3145)(Dow Corning) has been performed. In this article details of the experimental set-up and the first result on (RTV3145) will be presented.

  2. Cleaning Aged EPDM Rubber Roofing Membrane Material for Patching: Laboratory Investigations and Recommendations

    DTIC Science & Technology

    1992-08-01

    preparation on the surface characteristics of a cleaned sheet of aged EPDM rubber and the bond strength of seam specimens fabricated from it. This report...aged EPDM membrane material under creep conditions was compared with that of specimens fabricated from new, well cleaned EPDM rubber . 5. The results...field seams fabricated from solvent-based adhesives and new EPDM rubber .1 9 Only three of the surface cleaning methods (No. 2, 4, and 11) produced

  3. Children's Moral Evaluations of Reporting the Transgressions of Peers: Age Differences in Evaluations of Tattling

    ERIC Educational Resources Information Center

    Loke, Ivy Chiu; Heyman, Gail D.; Forgie, Julia; McCarthy, Anjanie; Lee, Kang

    2011-01-01

    The way children evaluate the reporting of peers' transgressions to authority figures was investigated. Participants, ages 6-11 years (N = 60), were presented with a series of vignettes, each of which depicted a child who committed either a minor transgression (such as not finishing the vegetables at lunch) or a more serious transgression (such as…

  4. Age-dependent recall bias for material of internal versus external origin.

    PubMed

    Barrett, Anna M; Crucian, Gregory P; Wingard, Ellen M; Graybeal, Laura A; Heilman, Kenneth M

    2003-09-01

    To learn whether young and aged subjects exhibit different recall biases for internally derived (Internal) versus externally supplied (External) material. Internally derived knowledge, prized by educators and therapists, can bring about dramatic behavioral change. Such information, seldom assessed on formal memory testing, may be preferentially recalled compared with external-origin material. Under some circumstances, however, subjects may demonstrate a recall advantage for externally supplied over internally generated material. We compared Internal and External word recall in young and aged subjects with and without explicit intent to remember. Although overall the young and aged subjects recalled the same number of words, we did find a word-origin recall bias. This recall bias differed by age group (P = 0.005). When not instructed to remember words, the young subjects tended to remember more External words, while aged subjects remembered more Internal words. The differences in the brain mechanisms mediating Internal versus External recall bias are unknown. However, aging may modify an Internal-External memory bias.

  5. Grinding with Diamond Burs and Hydrothermal Aging of a Y-TZP Material: Effect on the Material Surface Characteristics and Bacterial Adhesion.

    PubMed

    Dutra, Dam; Pereira, Gkr; Kantorski, K Z; Exterkate, Ram; Kleverlaan, C J; Valandro, L F; Zanatta, F B

    2017-10-04

    The aim of this study was to evaluate the effect of grinding with diamond burs and low-temperature aging on the material surface characteristics and bacteria adhesion on a yttrium-stabilized tetragonal zirconia polycrystalline (Y-TZP) surface. Y-TZP specimens were made from presintered blocks, sintered as recommended by the manufacturer, and assigned into six groups according to two factors-grinding (three levels: as sintered, grinding with extra-fine diamond bur [25-μm grit], and grinding with coarse diamond bur [181-μm grit]) and hydrothermal aging-to promote low-temperature degradation (two levels: presence/absence). Phase transformation (X-ray diffractometer), surface roughness, micromorphological patterns (atomic force microscopy), and contact angle (goniometer) were analyzed. Bacterial adhesion (colony-forming units [CFU]/biofilm) was quantified using an in vitro polymicrobial biofilm model. Both the surface treatment and hydrothermal aging promoted an increase in m-phase content. Roughness values increased as a function of increasing bur grit sizes. Grinding with a coarse diamond bur resulted in significantly lower values of contact angle (p<0.05) when compared with the extra-fine and control groups, while there were no differences (p<0.05) after hydrothermal aging simulation. The CFU/biofilm results showed that neither the surface treatment nor hydrothermal aging simulation significantly affected the bacteria adherence (p>0.05). Grinding with diamond burs and hydrothermal aging modified the Y-TZP surface properties; however, these properties had no effect on the amount of bacteria adhesion on the material surface.

  6. Degradation mechanisms of cable insulation materials during radiation-thermal ageing in radiation environment

    NASA Astrophysics Data System (ADS)

    Seguchi, Tadao; Tamura, Kiyotoshi; Ohshima, Takeshi; Shimada, Akihiko; Kudoh, Hisaaki

    2011-02-01

    Radiation and thermal degradation of ethylene-propylene rubber (EPR) and crosslinked polyethylene (XLPE) as cable insulation materials were investigated by evaluating tensile properties, gel-fraction, and swelling ratio, as well as by the infrared (FTIR) analysis. The activation energy of thermal oxidative degradation changed over the range 100-120 °C for both EPR and XLPE. This may be attributed to the fact that the content of an antioxidant used as the stabilizer for polymers decreases by evaporation during thermal ageing at high temperatures. The analysis of antioxidant content and oxidative products in XLPE as a model sample showed that a small amount of antioxidant significantly reduced the extent of thermal oxidation, but was not effective for radiation induced oxidation. The changes in mechanical properties were well reflected by the degree of oxidation. A new model of polymer degradation mechanisms was proposed where the degradation does not take place by chain reaction via peroxy radical and hydro-peroxide. The role of the antioxidant in the polymer is the reduction of free radical formation in the initiation step in thermal oxidation, and it could not stop radical reactions for either radiation or thermal oxidation.

  7. Evaluation and utilization of Illinois FBC residues for construction materials

    SciTech Connect

    Ghafoori, N.

    1991-01-01

    The overall objective of this program is to investigate the extent to which fluidized bed combustion (FBC) by-products can be properly utilized as the viable construction materials. This investigation focuses primarily on the properties of residues derived from fluidized combustion burning of Illinois high-sulfur coal. The research plan calls for evaluation of physico-chemical and engineering characteristics of the FBC-based cement and non-cement mixes. The results of this study will be used to compare the physical and mechanical properties of the FBC-based mixtures with those of conventional mixes. The suitability of using FBC residues as a filler or binder aggregate for construction applications such as structural concrete members, precast building products, and as base or surface course for gravity dams and pavements in the form of conventional and roller compacted materials will then be evaluated. During this reporting period, the literature survey, preparation of raw materials, and chemical analyses were completed. Some of the physical properties and preconditioning studies were determined and efforts are in progress to complete these tasks.

  8. Study Materials for Economic Education in the Schools. Reports of Materials Evaluation Committees to the Joint Council on Economic Education.

    ERIC Educational Resources Information Center

    Joint Council on Economic Education, New York, NY.

    The Materials Evaluation Committee of the Joint Council reviewed both print and non-print supplementary student materials for economics in order to make this selected list of those materials thought to be suitable according to: 1) whether the materials are genuinely concerned with economic matters; 2) whether they are analytical in nature; and, 3)…

  9. Performance evaluation of PRIDE UNDA system with pyroprocessing feed material.

    PubMed

    An, Su Jung; Seo, Hee; Lee, Chaehun; Ahn, Seong-Kyu; Park, Se-Hwan; Ku, Jeong-Hoe

    2017-04-01

    The PRIDE (PyRoprocessing Integrated inactive DEmonstration) is an engineering-scale pyroprocessing test-bed facility that utilizes depleted uranium (DU) instead of spent fuel as a process material. As part of the ongoing effort to enhance pyroprocessing safeguardability, UNDA (Unified Non-Destructive Assay), a system integrating three different non-destructive assay techniques, namely, neutron, gamma-ray, and mass measurement, for nuclear material accountancy (NMA) was developed. In the present study, UNDA's NMA capability was evaluated by measurement of the weight, (238)U mass, and U enrichment of oxide-reduction-process feed material (i.e., porous pellets). In the (238)U mass determination, the total neutron counts for porous pellets of six different weights were measured. The U enrichment of the porous pellets, meanwhile, was determined according to the gamma spectrums acquired using UNDA's NaI-based enrichment measurement system. The results demonstrated that the UNDA system, after appropriate corrections, could be used in PRIDE NMA applications with reasonable uncertainty. It is expected that in the near future, the UNDA system will be tested with next-step materials such as the products of the oxide-reduction and electro-refining processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Radiopacity of Esthetic Post Materials: Evaluation with Digital Analysis Technique.

    PubMed

    Kaval, Mehmet Emin; Akin, Hakan; Guneri, Pelin

    2017-07-01

    To evaluate the radiopacity of five post materials using a digital image analysis method. Twelve specimens from each post type (two zirconia and three fiber based) of 2 mm in thickness were obtained using a diamond blade mounted on a cutting machine, and digital radiographs were taken along with aluminum step-wedge and dentin discs under standard exposure conditions. The mean gray-values of specimens were measured using a computer graphics program. Data were analyzed using one-way ANOVA followed by Holm-Sidak multicomparison test (p = 0.05). The highest radiopacity was observed in custom zirconia (5.842 millimeters of equivalent Al [mmAl]), and the lowest value was detected with FRC-Postec (Ivoclar Vivadent) (1.716 mmAl). Significant differences were revealed between the radiopacity values among all groups (p < 0.05), except the Zr post materials (p = 0.56). All tested post materials had higher radiopacity than dentin. Further studies will be required to clarify optimum radiopacity properties of the post materials to provide a precise clinical observation. © 2015 by the American College of Prosthodontists.

  11. Clinical Evaluation of Restorative Materials in Primary Teeth Class II Lesions.

    PubMed

    Sengul, F; Gurbuz, T

    2015-01-01

    The aim of this study was to evaluate clinical success of primary teeth class II lesions restored with different restorative materials [Hybrid Composite Resin (HCR), Resin Modified Glass Ionomer Cement (RMGIC), compomer, and Giomer Composite Resin (GCR)] followed up for 24 months. This study was carried out on 146 primary molars of 41 children in the age range of 5-7 years. The class II lesions in primary molars of a patient were restored using different restorative materials. Restorations were evaluated according to FDI-criteria and their survival rates were determined. Data were analysed with Pearson chi-square, Kaplan-Meier and Wilcoxon (Breslow) tests (α = 0.05). The failure rates of restorative materials were as follows: compomer 33.3%, RMGIC 28.1%, HCR 22.5% and GCR 21.1%. While the functional failure was the most important factor in restorative material failure, RMGIC was the most successful material in terms of biological evaluation criterion and GCR had the longest survival rate.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Preparation and evaluation of biocomposites as wound dressing material.

    PubMed

    Ramnath, V; Sekar, S; Sankar, S; Sankaranarayanan, C; Sastry, T P

    2012-12-01

    Collagen was isolated from the chrome containing leather waste (CCLW) which is a major solid waste in leather industry. Composite films were made using sago starch (SG), soya protein (SY), and collagen (C) and were cross linked with glutaraldehyde (G).The films prepared were characterized for their physico chemical properties like tensile strength, infrared spectra, thermogravimetric analysis, surface morphology, and water absorption studies. Better mechanical properties and surface morphology were observed for SG-SY-G-C films compared to other films prepared using collagen. The composite films prepared were used as wound dressing material on the experimental wounds of rats and healing pattern was evaluated using planimetric, biochemical, and histopathological studies. These studies have revealed better wound healing capacity of SG-SY-G-C film and utilization of CCLW in the preparation of value added product like wound dressing material.

  19. 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.

  20. A SYNTHETIC APPROACH TO LIP READING, MATERIALS FOR THE CHILD OF GRADE SCHOOL AGE.

    ERIC Educational Resources Information Center

    HASPIEL, GEORGE S.

    LESSONS DESIGNED TO ASSIST TEACHERS AND PARENTS IN TEACHING SYNTHETIC LIPREADING TO HARD-OF-HEARING ELEMENTARY AGE CHILDREN ARE GROUPED INTO PRIMARY AND INTERMEDIATE LEVELS. EACH LESSON PLAN IS BASED ON THE PREVIOUS LESSON AND INCLUDES SEVERAL RELATED SPECIFIC ACTIVITIES. INSTRUCTIONS ABOUT MATERIALS, PROCEDURE, AND THE EXACT SENTENCES TO BE USED…

  1. Strategies and Materials for a College Course in Communication and Aging.

    ERIC Educational Resources Information Center

    Hawkins, Robert

    The components of a college course on communication and aging are described and discussed in this paper. The first section of the paper focuses on appropriate assignments, their underlying strategies, and necessary materials for enhancing young people's communication with older adults and their appreciation of the situations that elderly people…

  2. 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

  3. 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.

  4. An electromagnetic microscope for eddy current evaluation of materials

    SciTech Connect

    Podney, W.N.; Czipott, P.V. )

    1991-03-01

    This paper presents the concept of a new instrument for nondestructive evaluation (NDE). Called an electromagnetic microscope, formed by superconductive microprobes arrayed in parallel rows. When moved over a test piece, the array generates a scanned image of flaws, stress variations, or changes in composition. Each microprobe comprises drive coils a few mm in radius that encircle pickup loops forming a concentric, coplanar gradiometer 1 mm or less in diameter coupled to a superconducting quantum interference device (SQUID). Drive coils transmit an oscillating magnetic field that induces eddy or magnetization currents in conductive or ferromagnetic materials, respectively. The gradiometer senses distortions in paths of induced currents.

  5. Spectroscopic characterization of the oligomeric surface structures on polyamide materials formed during accelerated aging.

    PubMed

    Chernev, Boril S; Eder, Gabriele C

    2011-10-01

    Crystalline surface species were observed at the surface of polyamide 12 materials upon accelerated aging. After detection of the depositions with scanning electron microscopy (SEM), the crystalline surface precipitations were analyzed with Fourier transform infrared (FT-IR) and Raman imaging microscopy. These surface species were supposed to be cyclic oligomers (dimer and trimer) of the PA12 monomer laurolactam, which are usually present in polyamide materials and tend to migrate to the surface when the material is subjected to accelerated aging. The evidence for the chemical identity of the crystalline surface structures to be mainly the cyclic dimer and trimer of laurolactam was given by melting-point identification and mass spectroscopic analysis of the methanol eluate of the surface. The Raman and FT-IR spectra of the mixture were extracted from the recorded images.

  6. [Evaluation of cervical vertebrae for determination of skeletal age].

    PubMed

    Caltabiano, M; Leonardi, R; Zaborra, G

    1990-01-01

    The relationship among cervical vertebral maturation and skeletal, dental and chronological ages were assessed by the Authors in lateral cephalometric, hand and orthopantomographic x-rays on 72 italian young subjects from 10 to 15 years of age. Statistically significant correlations were found between cervical vertebral maturation and skeletal age both in males and females, while vertebrae age was correlated with dental and chronological ages only in the females.

  7. 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

  8. Evaluation of microelectrode materials for direct-current electrocorticography.

    PubMed

    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

    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. 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. 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 low frequencies.

  9. Subretinal Hyperreflective Material in the Comparison of Age-Related Macular Degeneration Treatments Trials.

    PubMed

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

    2015-09-01

    To evaluate the association of subretinal hyperreflective material (SHRM) with visual acuity (VA), geographic atrophy (GA), and scar in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT). Prospective cohort study within a randomized clinical trial. The 1185 CATT participants. Masked readers graded scar and GA on fundus photography and fluorescein angiography and graded SHRM on time-domain and spectral-domain (SD) optical coherence tomography (OCT) throughout 104 weeks. Measurements of SHRM height and width in the fovea, within the center 1 mm(2), or outside the center 1mm(2) were obtained on SD OCT images at 56 (n = 76) and 104 (n = 66) weeks. Presence of SHRM, as well as location and size, and associations with VA, scar, and GA. Among CATT participants, the percentage with SHRM at enrollment was 77%, decreasing to 68% at 4 weeks after treatment and to 54% at 104 weeks. At 104 weeks, scar was present more often in eyes with persistent SHRM than in 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 VA letter score was 73.5 (standard error [SE], 2.8), 73.1 (SE, 3.4), 65.3 (SE, 3.5), and 63.9 (SE, 3.7) when SHRM was absent, present outside the central 1 mm(2), present within the central 1 mm(2) but not the foveal center, or present at the foveal center (P = 0.02), respectively. When SHRM was present, the median maximum height under the fovea, within the central 1 mm(2) including the fovea and anywhere within the scan, was 86 μm, 120 μm, and 122 μm, respectively. Visual acuity was decreased with greater SHRM height and width (P < 0.05). In eyes with neovascular age-related macular degeneration (AMD), SHRM is common and often persists after anti-vascular endothelial growth factor treatment. At 2 years, eyes with scar were more likely to have SHRM than other eyes. Greater SHRM dimensions were associated with worse VA. In eyes with neovascular AMD

  10. Laboratory evaluation of low cobalt wear materials for nuclear applications

    SciTech Connect

    Shiels, S.A.; Wilson, W.L.; Rosengarth, K.W.; Wire, G.L.

    1994-09-01

    Laboratory wear and corrosion screening tests were conducted on several commercially available, low-cobalt and cobalt-free hardsurfacing alloys to evaluate their relative wear and corrosion performance under simulated Pressurized Water Reactor (PWR) primary heat transport circuit conditions. Wear tests were performed under reciprocating, sliding contact. Corrosion performance was evaluated in both steady state and off-normal chemistry conditions. The wear behavior of the candidate hardsurfacing alloys was generally comparable to or better than that of Stellite 6, a material of proven wear performance under PWR operating conditions. With the exception of Tristelle 5183, the iron base alloys exhibited unacceptable corrosion behavior under wet layup conditions. The Tristelle 5183 experienced minor corrosion attack in primary coolant having elevated oxygen levels. The twelve percent cobalt alloy, Tristelle TS-2, performed well but exhibited some attack after a simulated decontamination treatment.

  11. Research strategies for safety evaluation of nanomaterials, part VII: evaluating consumer exposure to nanoscale materials.

    PubMed

    Thomas, Treye; Thomas, Karluss; Sadrieh, Nakissa; Savage, Nora; Adair, Patricia; Bronaugh, Robert

    2006-05-01

    Considerable media attention has recently been given to novel applications for products that contain nanoscale materials. These products could have utility in several industries that market consumer products, including textiles, sporting equipment, cosmetics, consumer electronics, and household cleaners. Some of the purported benefits of these products include improved performance, convenience, lower cost, as well as other desirable features, when compared to the conventional products that do not contain nanoscale materials. Although there are numerous likely consumer advantages from products containing nanoscale materials, there is very little information available regarding consumer exposure to the nanoscale materials in these products or any associated risks from these exposures. This paper seeks to review a limited subset of products that contain nanoscale materials, assess the available data for evaluating the consumer exposures and potential hazards associated with these products, and discuss the capacity of U.S. regulatory agencies to address the potential risks associated with these products.

  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. 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.

  14. An Evaluation of Coating Material Dependent Toxicity of Silver Nanoparticles

    NASA Astrophysics Data System (ADS)

    Silva, Thilini Upekshika

    Silver nanoparticles (AgNPs) synthesized using numerous types of coating materials may exhibit different toxicity effects. The study evaluated coating material dependent toxicity by selecting 3 types of AgNP synthesis methods with different coating materials (citrate, polyvinyl pyrrolidone, and branched polyethyleneimine, coated AgNPs as citrate-AgNPs, PVP-AgNPs, and BPEI-AgNPs respectively). Two acute aquatic toxicity tests were performed; 48hr D. magna and MetPLATE E. coli toxicity tests. Significantly different toxicity effects were observed in D. magna test exhibiting lethal median concentrations (LC50) for citrate-AgNPs, PVP-AgNPs, and BPEI AgNPs respectively as, 2.7, 11.2, and 0.57microg/L. Median inhibitory concentrations (EC50) for MetPLATE tests were 1.27, 1.73, and 0.31mg/L respectively with significant different toxicity effects. Silver ion fractions were detected in the range of 2.4-19.2% in tested NP suspensions. Study suggests the toxicity effects are due to the cumulative action of ionic and nanoparticle fractions in the suspensions.

  15. Long-term thermal aging of Celion/V378A composite materials

    NASA Technical Reports Server (NTRS)

    Nelson, J. B.

    1985-01-01

    Celion 6000/V378A graphite/bismaleimide composite materials were aged in air at temperatures of 177, 204, 232 and 260 deg C for various times up to 15,000 hours. Three unidirectional specimen types were aged: short beam shear (SBS), flexure, and 153 mm square panels. Aged specimens of V378A laminates exhibited excellent thermal stability. Extensive cracking was observed during aging on the 0 deg edges of the unidirectional laminates. These cracks penetrated as deep as 12 mm from the edge. The cracking appeared to have little or no effect on the observed properties of the laminates. The study indicates that the useful life of unrestrained unidirectional graphite/V378A laminates is 10,000 hours or greater at 177 C to 232 C and 2,000 to 2,000 hour at 260 C.

  16. Aging effects on fire-retardant additives in organic materials for nuclear-plant applications

    SciTech Connect

    Clough, R.L.

    1982-08-01

    Inhibiting fire is a major concern of nuclear safety. One of the most widely used commercial fire-retardant additives incorporated into cable insulation and other organic materials to reduce their flammability has been the halocarbon (usually a chlorinated hydrocarbon), typically in combination with antimony oxide. Such materials may be installed for the design lifetime of a nuclear plant; this report describes an investigation of the long-term aging behavior of these fire-retardant additives in polymeric materials. Extensive aging experiments on fire-retarded formulations of ethylene propylene rubber (EPR) and of chlorosulfonated polyethylene (CSPE) have been carried out, with chemical analysis of halogen and antimony content performed as a function of aging time and conditions. Oxygen index flammability measurements were also performed on selected samples. Significant fire-retardant losses (both chlorine (Cl) and antimony (Sb)) were found to occur in certain of the fire-retardant materials but not in others, depending on the molecular structure of the particular halogen-containing component. The data indicate that the loss of halogen- and antimony-based fire retardants appears to be insignificant under ambient conditions expected for nuclear plants.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

    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

    2016-08-01

    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.

  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. 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.

  4. Comparison of methods to evaluate bacterial contact-killing materials.

    PubMed

    van de Lagemaat, Marieke; Grotenhuis, Arjen; van de Belt-Gritter, Betsy; Roest, Steven; Loontjens, Ton J A; Busscher, Henk J; van der Mei, Henny C; Ren, Yijin

    2017-09-01

    Cationic surfaces with alkylated quaternary-ammonium groups kill adhering bacteria upon contact by membrane disruption and are considered increasingly promising as a non-antibiotic based way to eradicate bacteria adhering to surfaces. However, reliable in vitro evaluation methods for bacterial contact-killing surfaces do not yet exist. More importantly, results of different evaluation methods are often conflicting. Therefore, we compared five methods to evaluate contact-killing surfaces. To this end, we have copolymerized quaternary-ammonium groups into diurethane dimethacrylate/glycerol dimethacrylate (UDMA/GDMA) and determined contact-killing efficacies against five different Gram-positive and Gram-negative strains. Spray-coating bacteria from an aerosol onto contact-killing surfaces followed by air-drying as well as ASTM E2149-13a (American Society for Testing and Materials) were found unsuitable, while the Petrifilm® system and JIS Z 2801 (Japanese Industrial Standards) were found to be excellent methods to evaluate bacterial contact-killing surfaces. It is recommended however, that these methods be used in combination with a zone of inhibition on agar assay to exclude that leakage of antimicrobials from the material interferes with the contact-killing ability of the surface. Bacterial adhesion to surfaces of biomaterials implants can be life-threatening. Antimicrobials to treat biomaterial-associated infections often fail due to the bacterial biofilm-mode-of-growth or are ineffective due to antibiotic-resistance of causative organisms. Positively-charged, quaternized surfaces can kill bacteria upon contact and are promising as a non-antibiotic-based treatment of biomaterial-associated infections. Reliable methods to determine efficacies of contact-killing surfaces are lacking, however. Here, we show that three out of five methods compared, including an established ASTM, are unsuitable. Methods found suitable should be used in combination with a zone

  5. 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

  6. Non-destructive evaluation of polyolefin thermal aging using infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Fifield, Leonard S.; Shin, Yongsoon; Simmons, Kevin L.

    2017-04-01

    Fourier transform infrared (FTIR) spectroscopy is an information-rich method that reveals chemical bonding near the surface of polymer composites. FTIR can be used to verify composite composition, identify chemical contaminants and expose composite moisture content. Polymer matrix changes due to thermal exposure including loss of additives, chain scission, oxidation and changes in crystallinity may also be determined using FTIR spectra. Portable handheld instruments using non-contact reflectance or surface contact attenuated total reflectance (ATR) may be used for nondestructive evaluation (NDE) of thermal aging in polymer and composite materials of in-service components. We report the use of ATR FTIR to track oxidative thermal aging in ethylene-propylene rubber (EPR) and chlorinated polyethylene (CPE) materials used in medium voltage nuclear power plant electrical cable insulation and jacketing. Mechanical property changes of the EPR and CPE materials with thermal degradation for correlation with FTIR data are tracked using indenter modulus (IM) testing. IM is often used as a local NDE metric of cable jacket health. The FTIR-determined carbonyl index was found to increase with IM and may be a valuable NDE metric with advantages over IM for assessing cable remaining useful life.

  7. Recent advances of ultrasonic testing of cement based materials at early ages.

    PubMed

    Trtnik, Gregor; Gams, Matija

    2014-01-01

    To summarize some of the most important findings in the field of ultrasonic (US) testing of early age hydration and formation of structure of different cement based materials (CBMs), a review of literature with focus on US P-wave transmission and S-wave reflection methods is presented in this paper. The review shows a great ability of both US techniques to observe setting phenomena and to determine different milestones during the early age formation of CBM's microstructure. Clear physical basis, high accuracy, and non-destructive nature of the method indicate that US methods could become standardized in the near future. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. 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.

  9. 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.

  10. Influence of artificial ageing on surface properties and Streptococcus mutans adhesion to dental composite materials.

    PubMed

    Hahnel, Sebastian; Henrich, Anne; Rosentritt, Martin; Handel, Gerhard; Bürgers, Ralf

    2010-02-01

    The aim of this in vitro study was to investigate the influence of artificial ageing on the surface properties and early Streptococcus mutans adhesion to current dental composites for the direct restoration of class II defects. Three hundred and thirty specimens each were prepared from five dental composites, and were randomly allotted to various artificial ageing protocols (storage in distilled water/ethanol/artificial saliva for 7/90/365 days; thermal cycling, 6,000 cycles 5/55 degrees C). Prior and after each treatment, surface roughness (R(a)) and hydrophobicity were determined, and S. mutans adhesion (ATCC 25175; 2.5 h, 37 degrees C) was simulated with and without prior exposition to human whole saliva (2 h, 37 degrees C). Adherence of S. mutans was determined fluorometrically. Means and standard deviations were calculated, and analyzed using three-way ANOVA and post-hoc analysis (alpha = 0.05). For both R(a) and S. mutans adherence to uncoated and saliva-coated specimens, significant influences of the composite material, the ageing medium and the ageing duration have been observed; for surface hydrophobicity, significant influences of the composite material and the ageing duration were found. For uncoated specimens, significant increases in S. mutans adhesion were observed with prolonged artificial ageing, whereas significant decreases in S. mutans adhesion were found for the saliva-coated specimens. The data indicate influences of the artificial ageing method on surface parameters such as R(a) and hydrophobicity as well as microbial adhesion. The results underline the relevance of saliva coating on the outcome of studies simulating microbial adhesion, and highlight differences in the susceptibility of dental composites for the adhesion of oral bacteria.

  11. Development of a methodology to evaluate material accountability in pyroprocess

    NASA Astrophysics Data System (ADS)

    Woo, Seungmin

    sampling calculated by the central limit theorem and the Geary-Hinkley transformation. Then, the uncertainty propagation through the key-pyroprocess is conducted to analyze the Material Unaccounted For (MUF), which is a random variable defined as a receipt minus a shipment of a process, in the system. The random variable, LOPu, is defined for evaluating the non-detection probability at each Key Measurement Point (KMP) as the original Pu mass minus the Pu mass after a missing scenario. A number of assemblies for the LOPu to be 8 kg is considered in this calculation. The probability of detection for the 8 kg LOPu is evaluated with respect the size of granule and powder using the event tree analysis and the hypothesis testing method. We can observe there are possible cases showing the probability of detection for the 8 kg LOPu less than 95%. In order to enhance the detection rate, a new Material Balance Area (MBA) model is defined for the key-pyroprocess. The probabilities of detection for all spent fuel types based on the new MBA model are greater than 99%. Furthermore, it is observed that the probability of detection significantly increases by increasing granule sample sizes to evaluate the Pu-to-244Cm-ratio before the key-pyroprocess. Based on these observations, even though the Pu material accountability in pyroprocess is affected by the non-uniformity of nuclide composition when the Pu-to-244Cm-ratio method is being applied, that is surmounted by decreasing the uncertainty of measured ratio by increasing sample sizes and modifying the MBAs and KMPs. (Abstract shortened by ProQuest.).

  12. 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.

  13. PROPERTIES OF FIBERBOARD OVERPACK MATERIAL IN THE 9975 SHIPPING PACKAGE FOLLOWING THERMAL AGING

    SciTech Connect

    Daugherty, W

    2007-01-10

    Many radioactive material shipping packages incorporate cane fiberboard overpacks for thermal insulation and impact resistance. Mechanical, thermal and physical properties have been measured on cane fiberboard following thermal aging in several temperature/humidity environments. Several of the measured properties change significantly over time in the more severe environments, while other properties are relatively constant. These properties continue to be tracked, with the goal of developing a model for predicting a service life under long-term storage conditions.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Evaluation of materials for on-board laser diagnostics

    NASA Astrophysics Data System (ADS)

    Luke, James R.; Thomas, David; Lewis, Jay; Phipps, Claude R.

    2008-05-01

    The AEgis Technologies Group and RTI International are developing microsensors for High Energy Laser (HEL) diagnostic applications. The conformal sensor array will measure the irradiance profile of an incident laser beam, and concomitant rise in surface temperature of the target. The open mesh architecture allows 90% of the beam to impact the surface. A critical part of this program is developing a protective coating that ensures sensor survivability at high irradiance levels for operational lifetimes on the order of 10 seconds. The protective coating must transmit a measurable amount of light to the irradiance sensor. We have conducted experiments to evaluate candidate heat shield materials. In the first round of experiments, a 10kW CO2 laser was used to irradiate pure materials, including metals and carbon foils. Although many of the metal foils were perforated by the laser, no significant amount of material was ablated away. In fact, most of the test samples gained mass, presumably due to oxidation. Analysis of high speed video shows that once the metal melted, surface tension caused the molten metal to coalesce into droplets around the rim of the hole. The second and third rounds of testing, conducted with a 3kW, 1.07μm fiber laser, included samples of highly reflective metals and ceramics, standard plasma-sprayed coatings, and multilayer stacks. We have also measured the performance of temperature sensors and irradiance sensors fabricated from nanoparticle solutions deposited by advanced printing technology and have completed a preliminary investigation of high temperature adhesives.

  1. 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.

  2. Nondestructive evaluation of composite materials via scanning laser ultrasound spectroscopy

    NASA Astrophysics Data System (ADS)

    Koskelo, Elise Anne C.; Flynn, Eric B.

    2017-04-01

    Composite materials pose a complex problem for ultrasonic nondestructive evaluation due to their unique material properties, greater damping, and often complicated geometry. In this study, we explored acoustic wavenumber spectroscopy (AWS) as a means of rapid inspection of laminate and honeycomb composites. Each aerospace sample was tested at different ultrasonic frequencies using steady-state excitation via a piezo electric actuator. We measured the velocity response of the composite at each pixel via a raster scan using a laser Doppler vibrometer. We were able to detect radial inserts along corners, delamination, and facing-core separation by analyzing local amplitude and wavenumber responses. For each honeycomb composite, we excited the sample at the first resonant frequency of the individual cells. The local mode shape for each cell was extracted from the local amplitude response. Analyzing local amplitude and phase responses for each cell provided an accurate indication as to the presence, size, shape, and type of defect present in the composite. We detected both delamination and deformation of cells within a honeycomb composite. For the laminar composites, we analyzed the non-resonance steady-state response at several excitation frequencies.

  3. 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.

  4. Solubility evaluation of different root canal sealing materials.

    PubMed

    Bayram, Emre; Dalat, Dilek; Bayram, Melike

    2015-02-01

    To evaluate the solubility of five different root canal sealers (AH Plus Jet, RealSeal SE, MTA Fillapex, Tubli-Seal, and Acroseal) in chloroform, eucalyptol and Endosolv-E solvents. Ninety root canal sealer samples were prepared and then divided into three groups for immersion in a solvent for 2, 5 or 10 minutes. The mean values of the root canal sealers' dissolution in the solvents were obtained by the difference between the preimmersion original weight and the post-immersion weight on a digital analytical scale. Data were statistically analyzed by a Kruskal-Wallis test with a Bonferroni correction. Chloroform was a more effective solvent than eucaly-ptol or Endosolv E for all root canal sealers, except for RealSeal SE, at all time points (p < 0.003). RealSeal SE was the least soluble sealer in all solvents at all time points. Chloroform demonstrated a superior ability over other solvents in dissolving canal sealing materials, and eucaly-ptol was found to be the least effective solvent in this study. This study can help to the clinicians about which solvent should be preferred for solving the filling materials in retreatment cases.

  5. 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

  6. Age effects on the material and mechanical properties of bone at the osteocyte lacuna

    NASA Astrophysics Data System (ADS)

    Potter, Ryan Shawn

    This is an exploratory study aimed at characterizing the microenvironment of bone tissue around osteocyte lacunae, referred to as peri-lacunar tissue, as a function of age. Comprising nearly 90% of all bone cells, osteocytes are ideally situated to sense mechanical strain and translate mechanical signals into biochemical signals to regulate bone modeling and remodeling. Previous work has shown that there is an amplification of globally applied macroscopic bone strains at the microstructural level of the osteocyte due to a strain concentrating effect around the osteocyte lacuna and surrounding extracellular matrix. This peri-lacunar region is believed to have different material and mechanical properties than bone tissue not associated with an osteocyte lacuna. These alterations in bone tissue at the osteocyte lacuna are believed to have a significant impact on the tissue strains sensed by the osteocyte. The global hypotheses are two-fold. First, peri-lacunar tissue is significantly different from non peri-lacunar bone tissue. Second, the mechanotransduction signal---the translation of mechanical stimuli to cellular signal---acting on the osteocyte is altered as the peri-lacunar tissue's mechanical and material properties change with aging. These hypotheses are tested using Raman spectroscopy, two dimensional displacement/strain mapping, and nanoindentation. Using these three techniques the mechanical and material properties of the peri-lacunar tissue were found to be significantly different from the surrounding non peri-lacunar tissue in its young crystalline structure, but not in its old crystalline structure, mineralization, carbonate substitution, collagen cross-linking, effective strains, and elastic modulus. Age effects on the bone tissue irrespective of location with respect to the lacuna were significant as carbonate substitution, crystallinity, collagen cross-linking, and effective strains near the loaded crack tip showed significant differences. These

  7. Electroglottographic evaluation of age and gender effects during sustained phonation and connected speech.

    PubMed

    Ma, Estella P-M; Love, Amanda L

    2010-03-01

    The aim of the present study was to evaluate the effects of age and gender on selected vocal fold vibratory behaviors during vowel prolongation and connected speech using electroglottography (EGG). Forty-six young and older individuals (23 males and 23 females) with normal voices participated in this study. EGG parameters including fundamental frequency and contact quotient were measured during sustained vowel prolongation and connected speech tasks. Significant age-by-gender interactions were found for both parameters. Moreover, results from discriminant function analyses revealed that the overall accuracies of the parameters in predicting different age and gender groups were higher for the connected speech tasks than for the sustained vowel prolongation task (89.1% and 73.9% for passage and phrase tasks vs 71.7% for vowel prolongation). These findings suggest that reliability of EGG measures can be affected by the test stimuli. Therefore, one should carefully consider the use of the speech material when assessing vocal fold behaviors using EGG. The findings also support the use of connected speech stimulus, preferably at passage level, in electroglottographic evaluation for a better representation of vocal fold vibrating behaviors. Copyright (c) 2010 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  8. 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).

  9. A protocol to evaluate the fibrogenic potential of inhaled materials.

    PubMed

    Bennett, I P; Pigott, G H; Isaacs, K

    1988-12-01

    A protocol to provide a more rapid assessment of the fibrogenic potential of an inhaled particulate has been developed. Young rats are exposed nose-only for 6 h/day, 7 days a week for 28 days to a respirable aerosol of the test compound. After exposure the rats are kept for up to 1 year, followed by histopathological assessment of the lung. Interim sacrifices could allow an estimate of the rate and severity of the development of any fibrogenic lesion. The protocol has been evaluated for chrysotile asbestos, alpha-quartz and titanium dioxide using rats of both sexes and two different ages at first exposure. The results indicate that there are no significant differences in either the rate, type or extent of lesion provoked by a 28-day exposure period when compared with the more conventional 1-year exposure period studies. It can be concluded that neither sex nor age at first exposure cause any biologically significant differences in response, although young rats would be used in practice. Only one sex need be investigated. The protocol offers considerable benefits over conventional inhalation studies for fibrogenicity (where a 1-year exposure period followed by a further 1-year holding period is usual) by virtue of time, specificity (in the absence of continued exposure the development of any lesion can be studied free from initial inflammatory response) and cost, and could be incorporated into a standard subacute inhalation study design. The results obtained are also of more physiological relevance than studies based on intratracheal instillation.

  10. 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

  11. 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...

  12. 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...

  13. 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…

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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…

  3. 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…

  4. Order of aging of major human organs or systems and evaluation of health status based on aging.

    PubMed

    Wang, Chengfang; Liu, Chunqing; Gao, Hanboya; Liu, Hui

    2017-03-01

    To determine the functional age of an individual, a quantitative system for the assessment of aging status was developed in the present study. A total of 1579 subjects were selected randomly from patients undergoing physical examination. The index of organic mild impairment (IOMI) and IOMI corrected for age (COMI) were calculated. By receiver operating characteristic (ROC) curve analysis of the IOMIs of younger and elderly subjects, a cutoff value for COMI of 30% was obtained. About 95% of <30-year-old subjects were healthy. These data suggest that organs and systems reflect the aging status of an individual and may be a useful tool for evaluating health status.

  5. 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.

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

    PubMed Central

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

    2017-01-01

    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 14C-derived age of the material. PMID:24681438

  7. Photo-crosslinkable hybrid material with improved aging stability for integrated optics

    NASA Astrophysics Data System (ADS)

    Kusevic, Maja; Maaninen, Arto; Hiltunen, Jussi; Hiltunen, Marianne; Tuominen, Jarkko; Karioja, Pentti

    2004-08-01

    In the last decade, the processing of the waveguide structures on various substrates under mild conditions has been an appealing aim. The lithographic patterning of organic-inorganic hybrid materials processed by means of sol-gel technology allows the production of waveguides and other optical components. We describe the synthesis of a new, photo-patternable, organically modified material with an improved ageing stability. Synthesis step does not involve widely used zirconia precursors, but it retains the same possibility of altering the refractive index by tailoring of the material composition. Refractive index values varied from 1.4700 to 1.5100. Measured birefringence values meet the requirements of most integrated planar optic applications. The synthesized material is compatible with silicon, glass and plastic substrates. Material was analyzed using 29Si NMR techniques. The processed slab waveguides were characterized by using the prism coupling technique at various wavelengths. The attenuation in the waveguide was determined by the cut-back method, and it was found to be less than 0.5dB/cm at the wavelength of 830 nm. The morphology of the microstructures was measured by using the interferometer equipment. Slab waveguides rms values were in order of only 2 nm.

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

    PubMed

    Tuncel, İlkin; Turp, Işıl; Üşümez, Aslıhan

    2016-06-01

    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. 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. 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. 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.

  9. 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

  10. 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; Windows installer

  11. 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 4.5 kg 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.

  12. Dental age estimation on Bosnian-Herzegovinian children aged 6-14 years: evaluation of Chaillet's international maturity standards.

    PubMed

    Galić, Ivan; Vodanović, Marin; Janković, Stipan; Mihanović, Frane; Nakaš, Enita; Prohić, Samir; Galić, Elizabeta; Brkić, Hrvoje

    2013-01-01

    Dental age estimation in children plays an important role in forensic dentistry. The most commonly used method for age estimation was developed by Demirjian in 1973 on a French-Canadian sample. It generally overestimates dental age in many populations. International maturity standards were formed to obtain a predicted age with more confidence when ethnic origin was not available. The aim of this study was to evaluate the applicability of Chaillet's international scores in the dental age assessment on Bosnian Herzegovinian (BH) children. Orthopantomograms of 1772 children, 980 girls and 792 boys aged 6.04-14.90 years, were assessed using Chaillet's international maturity tables and curves. The dental ages for both genders were compared to the chronological ages through a paired t-test. Mean overestimation using Chaillet's international maturity standards were 0.09 ± 0.83 for girls and 0.28 ± 0.90 for boys. The absolute accuracy of residuals between the dental and chronological age were 0.65 ± 0.52 years for girls (Median: 0.52 years) and 0.73 ± 0.60 years for boys (Median: 0.57 years). The Polynomial compound formula was recommended to predict dental age with more accuracy for results of international maturity standards on BH children. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  13. Evaluation of Mechanical Properties of Nuclear Materials Using Non-Destructive Ball Indentation Technique

    SciTech Connect

    Mathew, M.D.; Linga Murty, K.

    2002-07-01

    Integrity of structural components depends on the deformation and fracture behavior of materials. For evaluating the material condition in-service, it is generally not feasible or practical or advisable to cut samples from operating structures. Non-destructive testing (NDT) techniques are required to evaluate the mechanical properties. Although several NDT techniques such as ultrasound, magnetic strength, Barkhausen noise, microhardness etc., are employed for estimating the mechanical property degradation, these methodologies are generally empirical and indirect. Automated Ball Indentation (ABI) is a non-destructive testing technique for direct measurement of mechanical and fracture properties of metallic engineering materials. Because of the small area over which the test is carried out, it is possible to determine point to point variations in the mechanical and fracture properties, such as those that exist in weldments. Although ABI technique is non-intrusive, it is a state-of-the-art mechanical test that measures directly the current/local deformation behavior of the material. In this paper, we present results from studies on the application of ABI technique to determine tensile and fracture properties of ferritic steels, an austenitic stainless steel, a nickel base superalloy and Zircaloy in different thermo-mechanical conditions. The effects of aging and cold work on these properties were determined from the ABI tests. Gradients in mechanical properties of ferritic steel welds, particularly in the narrow heat-affected zone, were clearly established. ABI technique was found to be useful in determining the anisotropy in the tensile properties of Zircaloy cladding tubes. The technique has potential as a non-destructive method for assessing structural integrity of aged components. (authors)

  14. 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.

  15. An experimental and clinical evaluation of lens transparency and aging.

    PubMed

    Lerman, S

    1983-05-01

    The normal human lens is a precisely formed structure containing about 65% water and 35% organic matter, the latter being mainly (greater than 90%) structural proteins. The lens becomes encapsulated at the 13 mm embryonic stage and is consequently divorced from a direct blood supply for life. It provides the investigator with an organ that exists in an environment analogous to a single-cell type of tissue culture system and can be reproduced in vitro. Since the cornea and lens are transparent one can directly monitor morphologic and biochemical aging changes in vivo. Recent developments now permit us to monitor certain molecular changes as well. Thus this organ can serve as a unique model for studying in vivo aging parameters. In vivo UV slit lamp densitography to monitor lens fluorescence provides us with a useful diagnostic and prognostic screening method to identify lens photodamage due to excess UV exposure (occupational or accidental), photosensitizers (e.g. psoralens) as well as the normal age related increase in lenticular fluorescence. Cortical opacities are also a common finding in older individuals. In vitro NMR (human and animal lenses) and in vivo (animal experiments) currently in progress are rapidly elucidating the physicochemical basis for the development of light scattering areas in the aging lens cortex. This review demonstrates the feasibility of utilizing biophysical methods, in particular, optical spectroscopy and NMR analyses to delineate and monitor specific age related parameters in the ocular lens, in vivo as well as in vitro.

  16. The Roberts' Checklist--Selecting and Evaluating Social Studies Material.

    ERIC Educational Resources Information Center

    Roberts, Arthur D.

    1980-01-01

    Provides a checklist to aid the elementary and secondary educator in selecting a social studies textbook or curriculum package. The three-page checklist considers the textbook's philosophy and objectives, instructional materials, teacher's manual, supplementary materials, and administrative concerns. (KC)

  17. Non-destructive evaluation of mechanical properties of magnetic materials

    SciTech Connect

    Kankolenski, K.P.; Hua, S.Z.; Yang, D.X.; Hicho, G.E.; Swartzendruber, L.J.; Zang, Z.; Chopra, H.D.

    2000-07-01

    A magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.

  18. Evaluation of scaffold materials for tooth tissue engineering.

    PubMed

    Ohara, Takayuki; Itaya, Toshimitsu; Usami, Kazutada; Ando, Yusuke; Sakurai, Hiroya; Honda, Masaki J; Ueda, Minoru; Kagami, Hideaki

    2010-09-01

    Recently, the possibility of tooth tissue engineering has been reported. Although there are a number of available materials, information about scaffolds for tooth tissue engineering is still limited. To improve the manageability of tooth tissue engineering, the effect of scaffolds on in vivo tooth regeneration was evaluated. Collagen and fibrin were selected for this study based on the biocompatibility to dental papilla-derived cells and the results were compared with those of polyglycolic acid (PGA) fiber and beta-tricalcium phosphate (beta-TCP) porous block, which are commonly used for tooth, dentin and bone tissue engineering. Isolated porcine tooth germ-derived cells were seeded onto one of those scaffolds and transplanted to the back of nude mice. Tooth bud-like structures were observed more frequently in collagen and fibrin gels than on PGA or beta-TCP, while the amount of hard tissue formation was less. The results showed that collagen and fibrin gel support the initial regeneration process of tooth buds possibly due to their ability to support the growth of epithelial and mesenchymal cells. On the other hand, maturation of tooth buds was difficult in fibrin and collagen gels, which may require other factors. (c) 2010 Wiley Periodicals, Inc.

  19. 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

  20. Developing a Principled Framework for Materials Evaluation: Some Considerations

    ERIC Educational Resources Information Center

    Alkhaldi, Ali Ata

    2010-01-01

    Published language materials are widely used around the world, but many Foreign Language (FL) and/or Second Language (SL) learners still fail to develop their communicative competence satisfactorily and they are still not happy with their language materials. Materials design has recently been characterized by two important developments: first,…

  1. Evaluation of steam resistance of gravel-packing materials

    SciTech Connect

    Weaver, J.D.; Knox, J.A. )

    1992-05-01

    This paper compares the steam stability of common gravel-packing materials. The scope was limited to one set of downhole conditions. Results indicated that none of the commonly used materials were entirely satisfactory, but another material not normally used in the petroleum industry was found to give excellent results.

  2. 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.

  3. The Old Imbrium Hypothesis. [revision for KREEP materials formation age and distribution

    NASA Technical Reports Server (NTRS)

    Schonfeld, E.; Meyer, C., Jr.

    1973-01-01

    It is proposed that the order of lunar events was such that the Imbrium event predates the formation of the lunar rock type called KREEP. This hypothesis is used to explain the distribution of KREEP in the regions of Imbrium ejecta and the location of KREEP within the Imbrium and Procellarum mare regions. Model ages of KREEP materials have been previously interpreted to mean that their 'formation' age (time of initial extrusion) is about 4.3 to 4.4 AE. Consequently it is suggested that the Imbrium impact was before 4.3 to 4.4 AE rather than at about 3.9 AE, as is currently believed. This Old Imbrium Hypothesis is not yet proven, but seems to be consistent with a large variety of basic lunar observations.

  4. 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.

  5. Solubility and strength of zirconia-based dental materials after artificial aging.

    PubMed

    Kvam, Ketil; Karlsson, Stig

    2013-10-01

    Advanced high-strength dental ceramics based on zirconium oxide are widely used for dental restorations. However, their durability in liquids has been questioned. The purpose of this study was to compare the flexure strength of zirconium dioxide materials designed for different sintering techniques before and after surface exposure to an acidic solution and to correlate the dissolution of the materials with strength data. An accelerated aging test, immersion in hot (80°C) 4 vol% acetic acid was used to study the solubility of elements from the surface and the effect on the strength of 3 dental zirconia products: DY: Y-TZP material, milled in HIPed state (Denzir); DM: Mg-PSZ material, milled in dense-sintered state (Denzir M); and CY: Y-TZP material, milled from presintered block and then dense-sintered (Cercon base). Disks were prepared with a surface conditioning as for copings provided for dental restorations. After immersion for 1 week, the liquid was analyzed for a range of elements with ICP-MS. Biaxial flexure strength was measured for 3 samples (n=15) of each material: ground on a 20 µm diamond disk without immersion; after 1 week's immersion in acetic acid; and after 1 week's immersion, grinding, and 1 more week in acid. Fracture probability was analyzed by maximum likelihood attribution of individual measurements to 1 or 2 Weibull distributions, each with 2 free parameters. Dissolution was found to be limited. The total mass loss was less than 0.7 µg/cm(2) for Y-TZP and 3.5 µg/cm(2) for Mg-PSZ. The mean strength was reduced for all materials after immersion in the fluid. Weibull statistics revealed 2 fracture mechanisms in Y-TZP milled in fully sintered condition. For DY only, 2 distributions significantly (P>.99) improved the description of individual treatment data. Y-TZP materials showed the highest biaxial flexure strength. Immersion for 1 week in hot 4 vol% acetic acid weakened all 3 zirconia materials by 100 to 200 MPa. Milling in the presintered

  6. 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.

  7. Composites Associated with Pulp-Protection Material: Color-Stability Analysis after Accelerated Artificial Aging

    PubMed Central

    Cruvinel, Diogo Rodrigues; Garcia, Lucas da Fonseca Roberti; Consani, Simonides; de Carvalho Panzeri Pires-de-Souza, Fernanda

    2010-01-01

    Objectives: This study assessed the color stability of two composites associated with two pulp protectors submitted to accelerated artificial aging (AAA). Methods: 60 test specimens were made with 0.5 mm of protection material (calcium hydroxide - CH or glass ionomer cement - GIC) and 2.5 mm of restoration material (Concept or QuixFil) and divided into 3 groups (n=10) according to the type of protection material/composite, and the control group (no protection). After polishing, color readings were obtained with a spectrophotometer (PCB 6807 Byk Gardner) before and after AAA for 384 hours, and L*, a*, and b* coordinates and total color variation (ΔE) were analyzed (2-way ANOVA, Bonferroni, α=05). Results: Composites placed on CH presented lower L* levels than those on GIC, which presented higher L* values than the control group and lower b* values than those of the CH group. The Concept composite presented higher ΔE levels for all groups, differing statistically from QuixFil, except when placed on GIC. Conclusions: It was concluded that the protection material could affect the color stability and AAA is a factor that enhances this effect, depending on the type of composite used. PMID:20046473

  8. 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

  9. The Evaluation of Vehicle Mass Reduction and Material ...

    EPA Pesticide Factsheets

    Developments in the realm of lightweight materials for automotive use continue to be announced by the industry and by academia. This session will provide new and updated information on new generation of materials. Additionally, this session will focus on the key topics involved in Life-Cycle-Analysis of light-weight materials including practices and developments in material recyclability. This presentation will review key findings from recent LCAs for vehicle mass reduction. Presentation for panel session on advanced materials/lightweighting for light duty vehicles at the Society of Automotive Engineers (SAE) Government/Industry Meeting, Washington, DC (January 25, 2017)

  10. The Evaluation of Vehicle Mass Reduction and Material ...

    EPA Pesticide Factsheets

    Developments in the realm of lightweight materials for automotive use continue to be announced by the industry and by academia. This session will provide new and updated information on new generation of materials. Additionally, this session will focus on the key topics involved in Life-Cycle-Analysis of light-weight materials including practices and developments in material recyclability. This presentation will review key findings from recent LCAs for vehicle mass reduction. Presentation for panel session on advanced materials/lightweighting for light duty vehicles at the Society of Automotive Engineers (SAE) Government/Industry Meeting, Washington, DC (January 25, 2017)

  11. Job characteristics, core self-evaluations, and job satisfaction: what's age got to do with it?

    PubMed

    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 to which several job characteristics and core self-evaluations varied in their relationships with job satisfaction for workers of different ages. Findings suggest that the positive relationships between job satisfaction and skill variety, autonomy, and friendship weaken as employee age increases, while the positive relationships between job satisfaction and dealing with others, task identity, task significance, feedback, and core self-evaluations did not vary with age. The findings extend previous research by examining how the factors important for job satisfaction vary for employees of different ages.

  12. 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

  13. Validation of an instrument to evaluate quality of life in the aging population: WHOQOL-AGE

    PubMed Central

    2013-01-01

    Background There is a need for short, specific instruments that assess quality of life (QOL) adequately in the older adult population. The aims of the present study were to obtain evidence on the validity of the inferences that could be drawn from an instrument to measure QOL in the aging population (people 50+ years old), and to test its psychometric properties. Methods The instrument, WHOQOL-AGE, comprised 13 positive items, assessed on a five-point rating scale, and was administered to nationally representative samples (n = 9987) from Finland, Poland, and Spain. Cronbach’s alpha was employed to assess internal consistency reliability, whereas the validity of the questionnaire was assessed by means of factor analysis, graded response model, Pearson’s correlation coefficient and unpaired t-test. Normative values were calculated across countries and for different age groups. Results The satisfactory goodness-of-fit indices confirmed that the factorial structure of WHOQOL-AGE comprises two first-order factors. Cronbach’s alpha was 0.88 for factor 1, and 0.84 for factor 2. Evidence supporting a global score was found with a second-order factor model, according to the goodness-of-fit indices: CFI = 0.93, TLI = 0.91, RMSEA = 0.073. Convergent validity was estimated at r = 0.75 and adequate discriminant validity was also found. Significant differences were found between healthy individuals (74.19 ± 13.21) and individuals with at least one chronic condition (64.29 ± 16.29), supporting adequate known-groups validity. Conclusions WHOQOL-AGE has shown good psychometric properties in Finland, Poland, and Spain. Therefore, considerable support is provided to using the WHOQOL-AGE to measure QOL in older adults in these countries, and to compare the QOL of older and younger adults. PMID:24152691

  14. Flash and fire test: Evaluation of the behavior of nonmetallic materials in hydrogen

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Tests conducted to evaluate the behavior of nonmetallic materials in hydrogen are described. The results of the flash and fire test are presented. The flash and fire test is used to evaluate the tendency of heated materials to ignite in a hydrogen atmosphere when subjected to an ignition source. The test represents a hydrogen parallel to a hazard condition known to exist in oxygen systems. Ten nonmetallic materials were evaluated to establish baseline data on the behavior of the materials and to characterize one mode of material failure considered to be a factor pertinent to the safe use of a material in hydrogen.

  15. A Practice-Based Clinical Evaluation of a Bulk Fill Restorative Material.

    PubMed

    Burke, F J Trevor; Crisp, Russell John; Panchal, Ditesh; Redfearn, Philip; Sands, Peter

    2016-09-01

    To evaluate the handling, by a group of practice-based researchers, of a recently introduced bulk fill resin-based composite restorative material, Filtek Bulk Fill Restorative (3M ESPE). The twelve selected evaluators were sent explanatory letters, a pack of the material under investigation to use for 8 weeks, and a questionnaire. The evaluators rated the ease of use of the bulk fill restorative the same as the previously used posterior composite material. The provision of one shade only for evaluation may have compromised the score for aesthetic quality. No post-operative sensitivity was reported. The bulk fill material was well received as indicated by the high number of evaluators who would both purchase the material and recommend it to colleagues. A recently introduced bulk fill restorative material achieved a rating for handling which was similar to the evaluators' previously used resin composite, although there were some concerns regarding the translucency of the material.

  16. 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. © Thieme Medical Publishers.

  17. Mathematical phantoms for evaluation of age-specific internal dose

    SciTech Connect

    Cristy, M.

    1980-01-01

    A series of mathematical phantoms representing children has been developed for use with photon transport codes. These phantoms, patterned after the Fisher-Snyder adult phantom, consist of simple mathematical expressions for the boundaries of the major organs and body sections. The location and shape of the organs are consistent with drawings depicting developmental anatomy, with the organ volumes assigned such that the masses at the various ages conform closely with the data presented in Reference Man. The explicit mathematical expressions for the various ages overcome the potential misrepresentation of organ sizes that occurred in phantoms derived from simple mathematical transformations of the adult phantom. Female breast tissue has been added to the phantoms, including the adult, now allowing assessment of doses to this organ.

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

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Changes in functional properties of a broad spectrum of nonmetallic materials as a function of environment and exposure time were evaluated. Models for predicting long-term material performance are discussed. A literature search on specific materials in the space and simulated space environment was carried out and evaluated.

  19. 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.

  20. 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

  1. Effect of Aging on Bond Strength of Two Soft Lining Materials to a Denture Base Polymer.

    PubMed

    Salloum, Alaa'a M

    2014-12-01

    The purpose of this study was evaluation the effect of immersion in distilled water and inorganic artificial saliva on the shear bond strength of a heat-polymerized and an auto-polymerized silicone-based denture lining materials. The denture liners investigated were Molloplast-B (heat-polymerized), and Mollosil plus (auto-polymerized). The soft liner specimens were 10 × 10 × 2.5 mm and were processed between two poly(methylmethacrylate) plates. Thirty shear specimens for each type of test lining material were prepared. Specimens were divided equally into three groups for each test lining material: first group, specimens were tested after 48 h of preparation without immersion; second group, specimens were tested following immersion in distilled water at 37 °C for 12 months; and third group, specimens were tested following immersion in inorganic artificial saliva at 37 °C for 12 months. Shear bond strength was measured using an universal testing machine at a crosshead speed of 40 mm/min and failure mode (adhesive, cohesive and mixed) after debonding was assessed. Data were statistically analyzed with one-way analysis of variance (ANOVA) (α = 0.05). ANOVA was followed by Bonferroni post hoc tests for pairwise comparisons. A significant difference in shear bond strength was detected between Molloplast-B and Mollosil plus following immersion in distilled water and artificial saliva. Molloplast-B demonstrated considerably higher shear strength than Mollosil plus after immersion. Shear strengths of the lining materials investigated reduced significantly after immersion in both solutions. Visual examination after separation revealed that the soft materials tested exhibited mostly adhesive failure. The effect of immersion in distilled water and inorganic artificial saliva on bond strength of test lining materials was perceivable; however, both of them had acceptable bond strength and might be proper for long-term use.

  2. FIRST STATUS REPORT: TESTING OF AGED SOFTWOOD FIBERBOARD MATERIAL FOR THE 9975 SHIPPING PACKAGE

    SciTech Connect

    Daugherty, W.

    2010-01-08

    Samples have been prepared from a softwood fiberboard lower subassembly. 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. Some of the observed differences result from the limited exposure periods of the softwood fiberboard samples, and the impact of seasonal humidity levels. Testing following additional conditioning will continue and should eliminate this bias. Post-conditioning data have been measured on 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 much of the compression strength data tends toward the lower end of that range. Further understanding of the variability of softwood fiberboard properties will require testing of additional material. Cane fiberboard wall sheathing is specified for thermal insulation and impact resistance in 9975 shipping packages. Softwood fiberboard manufactured by Knight-Celotex was approved as an acceptable substitute for transportation in 2008. Data in the literature [1] show a consistent trend in thermal properties of fiberboard as a function of temperature, density and/or moisture content regardless of material source. Thermal and mechanical properties were measured for un-aged softwood fiberboard samples, and found to be sufficiently similar to those of un-aged cane fiberboard to support the acceptance of 9975 packages with softwood fiberboard overpack into KAMS for storage. The continued acceptability of aged softwood fiberboard to meet KAMS storage requirements was the subject of subsequent

  3. 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.

  4. In vitro evaluation of surface roughness and microhardness of restorative materials submitted to erosive challenges.

    PubMed

    Briso, A L F; Caruzo, L P; Guedes, A P A; Catelan, A; dos Santos, P H

    2011-01-01

    The aim of this study was to evaluate the effect of different acidic solutions on the microhardness and surface roughness of restorative materials. The 120 specimens of restorative materials (Fuji II LC, Vitremer, Supreme XT, and Supreme XT + Biscover LV) were randomly divided into three groups according to the immersion media: hydrochloric acid, soft drink, or distilled water. Over a period of five weeks, the groups were immersed in the solutions, which were changed weekly. Data were tested using analysis of variance and the Fisher protected least significant difference test (p<0.05). The results showed that the glass ionomer materials showed the highest surface roughness values (Fuji II LC: 0.111 ± 0.014 μm before and 0.139 ± 0.016 μm after immersion; Vitremer: 0.177 ± 0.012 μm before and 0.084 ± 0.012 μm after immersion), whereas the lowest values were found for the resin sealed with Biscover LV before (0.047 ± 0.011 μm) and after exposure in distilled water (0.043 ± 0.007 μm), soft drink (0.040 ± 0.005 μm), and hydrochloric acid (0.045 ± 0.005 μm). The Supreme XT showed the highest microhardness values before (44.96 ± 2.51 KHN) and after the aging process (41.26 ± 1.22 KHN in water, 35.96 ± 0.81 KHN in soft drink, and 34.74 ± 0.97 KHN in HCl), with significant differences from the other materials (p<0.0001). The lowest microhardness values were found for glass ionomer materials. The solutions used in this study decreased the microhardness of all studied materials, whereas the sealed surface suffered minor changes in microhardness and surface roughness after exposure to acidic solutions.

  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.

  6. 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

  7. Evaluating the safety of aging nuclear reactor pressure vessels

    SciTech Connect

    Pennell, W.E.

    1996-05-01

    Regulatory requirements limit the permissible accumulation of irradiation damage in RPV material such that adequate fracture prevention margins are maintained throughout the licensed operating period of a nuclear plant. Experience with application of those requirements has identified a number of areas where they could be further refined to eliminate excess conservatism. Research is ongoin to provide the data required to support refinement of the regulatory requirements. Research programs are investigating theeffects of local brittle zones, shallow flaws, biaxial loading, and stainless steel cladding. Preliminary results from this research indicate a potential for beneficial changes in the P-T curve and PTS analysis rules.

  8. Follow-Up Evaluation of a Faculty Training Program in Aging Research

    ERIC Educational Resources Information Center

    Mehrotra, Chandra M.

    2006-01-01

    In collaboration with distinguished scholars and National Institute on Aging (NIA) staff, we designed, implemented, and evaluated a research training program in aging for psychology faculty from 4-year colleges. The goal of the program was to build and sustain a community of college faculty committed to conducting aging research, incorporating…

  9. Follow-Up Evaluation of a Faculty Training Program in Aging Research

    ERIC Educational Resources Information Center

    Mehrotra, Chandra M.

    2006-01-01

    In collaboration with distinguished scholars and National Institute on Aging (NIA) staff, we designed, implemented, and evaluated a research training program in aging for psychology faculty from 4-year colleges. The goal of the program was to build and sustain a community of college faculty committed to conducting aging research, incorporating…

  10. 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 evidence...

  11. 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 evidence...

  12. 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 evidence...

  13. 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 evidence...

  14. 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 evidence...

  15. 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.

  16. 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.

  17. 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.

  18. 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…

  19. 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.

  20. 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…

  1. A laboratory evaluation of core-preservation materials

    SciTech Connect

    Auman, J.B.

    1989-03-01

    This paper documents the results of a laboratory study of the effectiveness of available state-of-the-art core-preservation materials. The ability of the core-sealing material to prevent postpreservation changes in fluid saturations may have a profound effect on subsequent laboratory measurements. Considering the expense involved in obtaining, storing, and analyzing a native-state (oil-cut) core and the purpose for which it was cut, knowledge of exactly what materials can adequately preserve a core until laboratory measurements are made is critical and should not be overlooked. In this laboratory study, saturated Berea sandstone core plugs were preserved in a number of commonly used sealing materials. The sealed plugs were then stored in a humidity-controlled environment and periodically weighed to ascertain the degree of change that had occurred in the saturation of the plug. In addition, this paper discusses and suggests procedures for applying the recommended sealing material.

  2. Development of a Healthy Aging Score in the Population-Based Rotterdam Study: Evaluating Age and Sex Differences.

    PubMed

    Jaspers, Loes; Schoufour, Josje D; Erler, Nicole S; Darweesh, Sirwan K L; Portegies, Marileen L P; Sedaghat, Sanaz; Lahousse, Lies; Brusselle, Guy G; Stricker, Bruno H; Tiemeier, Henning; Ikram, M Arfan; Laven, Joop S E; Franco, Oscar H; Kavousi, Maryam

    2017-03-01

    To develop a healthy aging score (HAS), to assess age and sex differences in HAS, and to evaluate the association of the HAS with survival. Prospective population-based cohort. Inhabitants of Ommoord, Rotterdam, The Netherlands. A total of 1405 men and 2122 women, mean (standard deviation) age 75.9 (6.4) years. We included 7 domains in the total score of HAS: chronic diseases, mental health, cognitive function, physical function, pain, social support, and quality of life; each scored 0, 1, or 2 in each domain. A total score (range 0-14) was constructed and was assessed continuously and in tertiles (13-14: healthy aging, 11-12: intermediate aging, 0-10: poor aging). Sex-specific change in the mean HAS was computed for the age categories of 65-69, 70-74, 75-79, 80-84, and ≥85 years. The association between HAS and mortality was assessed with Cox proportional hazards models. Mean follow-up was 8.6 (3.4) years. Men had poorer scores in the chronic disease domain than women. However, women had poorer mental health, worse physical function, more pain, and lower quality of life compared with men. The prevalence of healthy aging was higher in men (n = 396, 28.2%), than in women (n = 526, 24.8%). The mean (standard deviation) HAS was 11.1 (2.2) in men and 10.7 (2.3) in women. Mean HAS was higher in men than in women for all age categories. The β for change in mean HAS across the 5 increasing age categories was -0.55 (-0.65 to -0.45) in men and -0.65 (-0.73 to -0.57) in women. The age-adjusted hazard ratio per unit increase in HAS with mortality was 0.86 (0.83-0.89) in men, and 0.89 (0.87-0.91) in women. Levels of HAS were lower in women compared with men, in all age categories. The HAS declined with increasing age for both sexes, albeit slightly steeper in women. The HAS was strongly associated with mortality in both sexes. A better understanding of population healthy aging and sex differences in this regard could aid to implement strategies for sustainable

  3. Evaluation and recognition of skin images with aging by support vector machine

    NASA Astrophysics Data System (ADS)

    Hu, Liangjun; Wu, Shulian; Li, Hui

    2016-10-01

    Aging is a very important issue not only in dermatology, but also cosmetic science. Cutaneous aging involves both chronological and photoaging aging process. The evaluation and classification of aging is an important issue with the medical cosmetology workers nowadays. The purpose of this study is to assess chronological-age-related and photo-age-related of human skin. The texture features of skin surface skin, such as coarseness, contrast were analyzed by Fourier transform and Tamura. And the aim of it is to detect the object hidden in the skin texture in difference aging skin. Then, Support vector machine was applied to train the texture feature. The different age's states were distinguished by the support vector machine (SVM) classifier. The results help us to further understand the mechanism of different aging skin from texture feature and help us to distinguish the different aging states.

  4. Refinement of Foam Backfill Technology for Expedient Airfield Damage - Phase I: Laboratory Evaluation of Foam Materials

    DTIC Science & Technology

    2016-11-01

    Materials En gi ne er R es ea rc h an d D ev el op m en t Ce nt er Luke Gurtowski, Mariely Mejías-Santiago, Christopher Griggs, Jared...Airfield Damage Repair Phase I: Laboratory Evaluation of Foam Materials Mariely Mejías-Santiago and Bryan Ruiz-Cruz Geotechnical and Structures...a number of foam materials for their suitability as crater-backfill materials . Seven foam formulations were evaluated between the summer of 2015 and

  5. 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

  6. 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

  7. 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.

  8. Evaluation of Environmental Aging of Polypropylene Irradiated Versus Pristine

    NASA Astrophysics Data System (ADS)

    Romano, Rebeca S. Grecco; Oliani, Washington Luiz; Parra, Duclerc Fernandes; Lugao, Ademar Benevolo

    Polypropylene (PP) is the most common thermoplastic resin of the plastic market due to its very interesting physical, chemical and processing properties at very low market price, however after its use the resin does not degrade in the environment or it degrades at very low rate. This study has the objective of comparing the environmental exposure of PP irradiated with 20 kGy and pristine PP. Dumbbell samples were manufactured by injection molding and exposed to the environment during 90 days; another one set was subjected to gamma irradiation at 20 kGy total dose and exposed at the same conditions too. The samples were characterized by mechanical testing, visual inspection, infrared spectroscopy (IR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The irradiated samples, after environmental aging, showed oxidation and presence of cracks in samples of the PP 20 kGy.

  9. 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

  10. No aging bias favoring memory for positive material: evidence from a heterogeneity-homogeneity list paradigm using emotionally toned words.

    PubMed

    Grühn, Daniel; Smith, Jacqui; Baltes, Paul B

    2005-12-01

    Some authors argue for a memory advantage of older adults for positively toned material. To investigate the contribution of selective processing to a positivity effect, the authors investigated young (n = 72, aged 18 to 31) and older (n = 72, aged 64 to 75) adults' memory for emotionally toned words using a multitrial paradigm that compares performance for heterogeneous (mixed valence) and homogeneous (single valence) lists. Regarding the age comparison, there was no evidence for an aging bias favoring positive material. Moreover, older adults' memory was less affected by emotion-based processing prioritization. Although there was no support for age-specific processing biases in memory for emotionally toned words, the findings are consistent with proposals that negative information receives processing priority in some contexts. Possible limits to the generalizability of the present findings (e.g., to nonverbal material) are discussed.

  11. 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.

  12. 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.

  13. 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.

  14. Aged-Care Professionals' and Health Care Professionals' Self-Reported Impact of Printed Educational Material on Clinical Practice.

    PubMed

    Pham, Duc H T; Ibrahim, Joseph E; Kitching, Fiona; Bohensky, Megan

    2016-01-01

    This study aimed to evaluate the impact of the printed educational material (PEM), the Residential Aged-Care (RAC) Communiqué, on the changing clinical practice of health and aged-care professionals. The RAC Communiqué is a PEM that contains case narratives from Coroners' investigations into potentially preventable deaths in nursing homes. A population-based cross-sectional study was conducted, using an anonymous electronic survey distributed to all subscribers of the RAC Communiqué. The questionnaire consisted of 40 questions in five sections, such as respondent characteristics, respondent preferences and reading behavior, respondent opinion about the RAC Communiqué content, and the mode of its delivery, impact of the RAC Communiqué, and the details of changes in professional practice. The response rate was 58.3% (367/630). Respondents were mostly women aged 45 years and older (n = 319, 86.9%) with more than 10 years of experience (n = 241, 65.7%) in management (n = 171, 46.6%) or nursing (n = 65, 17.7%). Of the 367 respondents, 204 (55.6%) reported changing their practice. Multivariate analysis revealed that women (odds ratio [OR] = 2.10, 95% confidence interval [CI] = 1.01-4.35) aged between 45 and 54 (OR = 2.06, CI = 1.13-3.75), who read most of the RAC Communiqué (OR = 2.77, CI = 1.34-5.72) and were subscribed for more than 1 year (OR = 3.58, CI = 1.61-7.95) were significantly associated with practice change. More than half of the survey respondents who read the RAC Communiqué self-reported a change in practice highlighting its impact and efficacy as PEM.

  15. 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

    ... whether it functionally equals the listings (see § 416.926a). Except in the case of certain premature... the existence and severity of your impairment(s). (b) Correcting chronological age of premature... corrected chronological age in these situations— (i) When we evaluate developmental delay in premature...

  16. 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.

  17. 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.

  18. 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.

  19. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. 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.

  1. Sorption/Desorption and Transport of Trichloroethene in Freshly-amended, Synthetically- aged, and Field-contaminated Aquifer Material

    NASA Astrophysics Data System (ADS)

    Johnson, G. R.; Norris, D. K.; Brusseau, M. L.

    2008-12-01

    This study investigates the effect of long-term contaminant aging on the sorption/desorption and transport of trichloroethene in a low organic-carbon content aquifer material collected from the source zone of a chlorinated-solvent contaminated federal Superfund site in Arizona. This was accomplished by comparing elution behavior for field-contaminated, synthetically-aged (contact times of approximately four years), and freshly-amended aquifer material. Elution of trichloroethene exhibited extensive low-concentration tailing, despite minimal retention of trichloroethene by the aquifer material. The observed nonideal behavior indicates significant mass-transfer constraints influenced trichloroethene transport in this aquifer material. The elution behavior of trichloroethene for the field-contaminated and aged treatments was essentially identical to that observed for the fresh treatments. In addition, the results of three independent mass- balance analyses, total mass eluted, solvent-extraction analysis of residual sorbed mass, and flow- interruption rebound, showed equivalent recoveries for the aged and fresh treatments. These results indicate that long-term contaminant aging did not significantly influence the transport and fate behavior of trichloroethene in this low organic-carbon aquifer material. The observed nonideal behavior of trichloroethene (i.e., nonlinear sorption and significantly rate-limited sorption/desorption) suggests physically condensed carbonaceous material, comprising 61% of this media's organic-carbon content, mediates the transport and fate behavior of trichloroethene in this low organic-carbon content aquifer material.

  2. Evaluation of an aged care nurse practitioner service: quality of care within a residential aged care facility hospital avoidance service.

    PubMed

    Dwyer, Trudy; Craswell, Alison; Rossi, Dolene; Holzberger, Darren

    2017-01-13

    Reducing avoidable hospitialisation of aged care facility (ACF) residents can improve the resident experience and their health outcomes. Consequently many variations of hospital avoidance (HA) programs continue to evolve. Nurse practitioners (NP) with expertise in aged care have the potential to make a unique contribution to hospital avoidance programs. However, little attention has been dedicated to service evaluation of this model and the quality of care provided. The purpose of this study was to evaluate the quality of an aged care NP model of care situated within a HA service in a regional area of Australia. Donabedian's structure, process and outcome framework was applied to evaluate the quality of the NP model of care. The Australian Nurse Practitioner Study standardised interview schedules for evaluating NP models of care guided the semi-structured interviews of nine health professionals (including ACF nurses, medical doctors and allied health professionals), four ACF residents and their families and two NPs. Theory driven coding consistent with the Donabedian framework guided analysis of interview data and presentation of findings. Structural dimensions identified included the 'in-reach' nature of the HA service, distance, limitations of professional regulation and the residential care model. These dimensions influenced the process of referring the resident to the NP, the NPs timely response and interactions with other professionals. The processes where the NPs take time connecting with residents, initiating collaborative care plans, up-skilling aged care staff and function as intra and interprofessional boundary spanners all contributed to quality outcomes. Quality outcomes in this study were about timely intervention, HA, timely return home, partnering with residents and family (knowing what they want) and resident and health professional satisfaction. This study provides valuable insights into the contribution of the NP model of care within an aged care

  3. 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.

  4. "The closer you get …": age, attitudes and self-serving evaluations about older drivers.

    PubMed

    Ferring, Dieter; Tournier, Isabelle; Mancini, Denis

    2015-09-01

    The present study investigates the attitudes of older drivers and road safety measures with a particular focus on self-serving evaluations. Driving capacity is considered here as an indicator of awareness of age-related changes that may lead to a higher risk of self-stereotyping, motivating self-serving evaluations with advancing age. In order to test this notion, we used the perceived distance between one's chronological age and the age assigned to the social categories of "older driver" and "old person" as an indicator of age-group dissociation or identification, respectively. Self-serving evaluations were expected depending on the distance between chronological and subjective age estimates. In addition to this, we tested gender and age effects on the specific evaluations. A sample of 350 participants aged 19-88 completed an online questionnaire on negative and positive stereotypes about older drivers and road safety measures. Results indicated in general a more positive than negative view of older drivers; approval with measures to increase road safety by regulating older drivers was comparatively low. Female participants tended to agree more with negative stereotypes and regulative measures than male participants. Regression analyses revealed as well that increasing chronological age was associated with less agreement with negative stereotypes and measures for road safety. Differences between chronological age and subjective age estimates of when a person is old or an old driver were differentially related with the criteria. The closer the chronological age and subjective age estimates were the lower was the agreement with negative stereotypes and measures to regulate road safety. Findings underline in general that road safety enhancing efforts should avoid highlighting chronological age as the sole driving risk factor to circumvent negative stereotyping with ageing and unjustified driving cessation.

  5. 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.

  6. 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.

  7. 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.

  8. Novel utilisation of a circular multi-reflection cell applied to materials ageing experiments

    NASA Astrophysics Data System (ADS)

    Knox, D. A.; King, A. K.; McNaghten, E. D.; Brooks, S. J.; Martin, P. A.; Pimblott, S. M.

    2015-04-01

    We report on the novel utilisation of a circular multi-reflection (CMR) cell applied to materials ageing experiments. This enabled trace gas detection within a narrow interfacial region located between two sample materials and remotely interrogated with near-infrared sources combined with fibre-optic coupling. Tunable diode laser absorption spectroscopy was used to detect water vapour and carbon dioxide at wavelengths near 1,358 and 2,004 nm, respectively, with corresponding detection limits of 7 and 1,139 ppm m Hz-0.5. The minimum detectable absorption was estimated to be 2.82 × 10-3 over a 1-s average. In addition, broadband absorption spectroscopy was carried out for the detection of acetic acid, using a super-luminescent light emitting diode centred around 1,430 nm. The 69 cm measurement pathlength was limited by poor manufacturing tolerances of the spherical CMR mirrors and the consequent difficulty of collecting all the cell output light.

  9. Evaluation of material dispersion using a nanosecond optical pulse radiator.

    PubMed

    Horiguchi, M; Ohmori, Y; Miya, T

    1979-07-01

    To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-microm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO(2)-P(2)0(5)-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO(2)-P(2)O(5)-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 microm of the material dispersion free wavelength region and 1.82 at 1.55 microm of the lowest-loss wavelength region in silica-based optical fiber waveguides.

  10. 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

  11. Stability of ethyl glucuronide in hair reference materials after accelerated aging.

    PubMed

    Ammann, D; Becker, R; Nehls, I

    2015-12-01

    Two different hair reference materials, one produced from authentic hair displaying an ethyl glucuronide (EtG) content of about 25 pg/mg and one obtained by fortification of blank hair to an EtG level of 85 pg/mg were submitted to accelerated aging between 4 °C and 60 °C for periods between one and 24 months. Subsequently, the EtG content was determined in the aged samples and untreated reference samples stored at -22 °C under repeatability conditions following the so-called isochronous approach. The EtG content remained stable even at 40 °C for 24 months and at 60 °C over six months. This is in contrast to many organic analytes contained in trace concentrations in diverse matrices. A slight but significant increase of the recovered EtG in case of authentic hair samples having been exposed for 24 months between 4 °C and 60 °C may be due to a temperature-driven process that allows increased recoveries of the physiologically embedded EtG. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Aging response and characterization of precipitates in Zr alloy Excel pressure tube material

    NASA Astrophysics Data System (ADS)

    Sattari, M.; Holt, R. A.; Daymond, M. R.

    2014-09-01

    Precipitation hardening in the Zr-based alloy Excel (Zr-3.5 wt.% Sn-0.8 wt.% Mo-0.8 wt.% Nb) was studied using hardness testing and transmission electron microscopy (TEM). Solution treatment at 890 °C, in the αZr + βZr region, and 980 °C, in the βZr region, followed by water-quenching and aging resulted in an increase of hardness, of up to 47% compared to the annealed material. The optimum condition for aging heat treatment was found to be 450 °C for 1-2 h. The precipitates were observed only in the transformed βZr martensitic phase. Energy dispersive X-ray spectroscopy (EDS) in TEM showed the precipitate composition to be Zr-30 wt.% Mo-25 wt.% Nb-2 wt.% Fe. The crystal structure of the precipitates was determined to be hexagonal with a = 0.294 nm and c = 0.448 nm, i.e. c/a = 1.526.

  13. Reaction propagation test. Evaluation of the behavior of nonmetallic materials in hydrogen

    NASA Technical Reports Server (NTRS)

    Smith, I. D.

    1972-01-01

    Results of tests conducted to evaluate the behavior of nonmetallic materials in hydrogen are described. The reaction propagation test simulates the conditions resulting from the interaction of an electrical wire in an overload condition in contract with a material in the test medium. The test is designed to evaluate the behavior of a material subjected to an energy input (usually heat) sufficient to cause a reaction which propagates to consume larger quantities of the material. Ten nonmetallic materials were evaluated to establish baseline data on the behavior of nonmetallic materials in hydrogen and to characterize, on an initial basis, one mode of material failure considered to be a factor pertinent to the safe use of a material in hydrogen.

  14. 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...

  15. 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.

  16. Clinical and radiological evaluation of calcium sulfate as direct pulp capping material in primary teeth.

    PubMed

    Ulusoy, A T; Bayrak, S; Bodrumlu, E H

    2014-06-01

    To evaluate the clinical and radiological response of primary molars to direct pulp capping with calcium sulfate hemihydrate. Forty primary molar teeth in 40 healthy children aged 5-9 years were treated by direct pulp capping. Teeth were randomly assigned to two groups (n=20) according to material used for capping, as follows: Group 1: calcium hydroxide cement (Dycal); Group 2: calcium sulfate hemihydrate (Dentogen). All teeth were restored with a conventional glass ionomer base (Fuji IX) and amalgam. After 12 months, the overall success rate of direct pulp capping was approximately 75% (24/32 teeth, excluding exfoliations). The success rate did not differ significantly between calcium hydroxide and calcium sulfate hemihydrate treatment. Calcium sulfate hemihydrate was found to be as successful as calcium hydroxide for direct pulp capping of primary molars with Class I cavities. Further histological studies are needed to support these findings.

  17. Evaluation of optical-materials samples. Final report

    SciTech Connect

    Not Available

    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.

  18. Bioactivity evaluation of three calcium silicate-based endodontic materials.

    PubMed

    Han, L; Okiji, T

    2013-09-01

    To compare white ProRoot MTA (WMTA), EndoSequence BC sealer (BC sealer) and Biodentine with regard to their ability to produce apatites and cause Ca and Si incorporation in adjacent human root canal dentine after immersion in phosphate-buffered saline (PBS). Root sections of human single-rooted teeth were filled with one of the materials and immersed in PBS for 1, 7, 30 or 90 days (n = 5 each). Morphology and elemental composition of surface precipitates and interfacial dentine were analysed using a wavelength-dispersive X-ray spectroscopy electron probe microanalyser with image observation function. Ca- and Si-incorporation depths in the interfacial dentine were measured. In addition, the amount of Ca ions released from the test materials was measured by EDTA titration. All materials produced surface precipitates of acicular or lath-like morphology with Ca/P ratio of 1.6 : 2.0. Within dentinal tubules, the three materials formed tag-like structures that were frequently composed of Ca- and P-rich and Si-poor materials, suggesting intratubular precipitation. Ca- and Si-incorporation depths were in the order of Biodentine > WMTA > BC sealer, with a significant difference between BC sealer and the others at several time-points (P < 0.05, anova and Tukey's honestly significant difference test). The concentration of released Ca ions was in the order of Biodentine > WMTA > BC sealer with significant differences between the materials (P < 0.05). Compared with Biodentine and WMTA, BC sealer showed less Ca ion release and did not show Ca and Si incorporation as deeply in human root canal dentine when immersed in PBS for up to 90 days. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. Formative Evaluation of Instructional Materials: An Overview of Approaches.

    ERIC Educational Resources Information Center

    Weston, Cynthia B.

    1986-01-01

    Describes and compares formative evaluation approaches: expert review, developmental testing, three-stage model, learner verification and revision, and general approach to formative evaluation. Discussion of differences among approaches related to duration of try-out/revision cycle and recommendations for effective acquisition of data are…

  20. 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…

  1. 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…

  2. 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.

  3. Fire-resistant aircraft materials development and evaluation program

    NASA Technical Reports Server (NTRS)

    Bricker, R. W.; Stuckey, R. N.

    1974-01-01

    The overall objectives of this program are to provide a more fire-resistant commercial aircraft interior and to improve the fuselage insulation barrier between the cabin interior and an exterior fuel fire. Significant secondary objectives are to reduce the smoke and toxic gas production of the materials and to meet the end item use requirements pertaining to wearability, color fastness, and aesthetic appeal. It is shown that the fuselage insulation materials must meet stringent requirements pertaining to acoustic attenuation, low density, and water repellency.

  4. 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.

  5. Fire-resistant aircraft materials development and evaluation program

    NASA Technical Reports Server (NTRS)

    Bricker, R. W.; Stuckey, R. N.

    1974-01-01

    The overall objectives of this program are to provide a more fire-resistant commercial aircraft interior and to improve the fuselage insulation barrier between the cabin interior and an exterior fuel fire. Significant secondary objectives are to reduce the smoke and toxic gas production of the materials and to meet the end item use requirements pertaining to wearability, color fastness, and aesthetic appeal. It is shown that the fuselage insulation materials must meet stringent requirements pertaining to acoustic attenuation, low density, and water repellency.

  6. 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…

  7. 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…

  8. PHYSICAL EVALUATION OF THIN FILMS OF SOLID STATE MATERIALS.

    DTIC Science & Technology

    microscopy and X-ray and electron diffraction methods. These materials include vapor deposited thin films of boron and boron phosphide on single...crystal silicon substrates via halide reduction, electrodeposits of copper onto single crystal copper substrates, thin films of carbon deposited onto

  9. Shade material evaluation based on physiological response of cattle

    USDA-ARS?s Scientific Manuscript database

    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...

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Magnetic properties evaluation of ageing behaviour in water-quenched 5Cr-0.5Mo steel

    NASA Astrophysics Data System (ADS)

    Mohapatra, J. N.; Panda, A. K.; Mitra, A.

    2009-05-01

    Magnetic Barkhausen emissions and magnetic hysteresis measurements were carried out on water-quenched 5Cr-0.5Mo steel subjected to ageing at 600 °C up to 5000 h. During initial ageing, this steel exhibited magnetic softening, which was attributed to relaxation of quenching stress in the material as well as decrease in dislocation density and migration of interstitial carbon atoms towards the grain boundary. Further ageing resulted in magnetic hardening owing to the restricted movement of the domain wall by the precipitation of carbides such as M3C2, M2C, M7C3 where M stands for Fe, Cr or a combination of them. At longer ageing periods, magnetic behaviour was affected by a change in the composition and morphology of the carbides. Massive M23C6 types of carbides were formed during longer periods of ageing. The coarsening of carbides decreased the pinning density for the domain wall motion and affected the magnetic properties of the steel. The effect of demagnetizing field from voids and non-magnetic massive carbides also affected the magnetic behaviour. Magnetic behaviour and Vickers hardness measurements during ageing have been effectively supported by microstructural evaluations suggesting the capability of the magnetic techniques for assessment of damage during ageing in high temperature 5Cr-0.5Mo steel components.

  16. Evaluation of age-related changes with cross-sectional CT imaging of teeth

    NASA Astrophysics Data System (ADS)

    Fukui, Tatsumasa; Kita, Kanade; Kamemoto, Hiromasa; Nishiyama, Wataru; Yoshida, Hiroyasu; Iida, Yukihiro; Katsumata, Akitoshi; Muramatsu, Chisako; Fujita, Hiroshi

    2017-03-01

    Tooth pulp atrophy occurs with increasing age. An age estimation procedure using dental cone beam computed tomography (CBCT) imaging was developed. Clinical dental CBCT images of 60 patients (aged from 20 to 80 years) were evaluated. The ratio of the cross-sectional area of the pulp cavity to the cross-sectional area of the tooth (pulp cavity ratio) was calculated. The pulp cavity ratio in the labio-lingual plane of the mandibular anterior teeth and the mesio-distal plane of the maxillary anterior teeth was strongly correlated with the patients' age. The pulp cavity ratio of anterior teeth may be a useful parameter for estimating age.

  17. Effect of pad location relative to glass weave on cratering and underfill process improvement and material evaluation

    NASA Astrophysics Data System (ADS)

    Quran, Mohammad M.

    This research contains two studies. First study investigated one of the factors that affect the performance of pads; the locations of pads relative to glass weave. Dage 4000plus bond tester was used in conducting a joint-level testing of pads on 370HR printed circuit board that has 1080 glass fabric. Scanning acoustic microscopy (SAM) was utilized to image pads with respect to upper layer of glass weave. It was found that locations of pads do not affect their strength, but it has a weak effect on fatigue performance. The second part of this research is underfill process improvement and material selection. This study evaluated four underfill materials against a flow model. Assemblies were made of transparent glass slides and then underfilled. Different factors that affect this flow were investigated: substrate temperature, standoff, and material age. In addition, the materials' tendency to form voids during flow or curing was observed.

  18. Evaluation of a Web Based Mathematics Teaching Material on the Subject of Functions

    ERIC Educational Resources Information Center

    Baki, A.; Guveli, E.

    2008-01-01

    The aim of the study is to develop a web-based mathematics teaching (WBMT) material and to evaluate the effectiveness of the WBMT material for 9th grade students learning the concept of mathematical function. Firstly, a WBMT material was designed and piloted. As a result of this pilot study the site was revised as a final form. The study was…

  19. 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.

  20. An Evaluation of Some Motivational Materials Related to the History of Mathematics.

    ERIC Educational Resources Information Center

    Fraser, Barry J.; Koop, Anthony J.

    This report evaluates motivational materials related to the history of mathematics. Materials produced included plays, written articles, slide-tape presentations, and videotapes. Two of these, plays and written articles, were chosen for intensive study. The study included a survey of teacher opinion, a student questionnaire, and evaluations by…

  1. 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'…

  2. Final Report on the Evaluation of the National Science Foundation's Instructional Materials Development Program.

    ERIC Educational Resources Information Center

    Tushnet, Naida C.; Millsap, Mary Ann; Abdullah-Welsh, Noraini; Brigham, Nancy; Cooley, Elizabeth; Elliott, Jeanne; Johnston, Karen; Martinez, Alina; Nierenberg, Marla; Rosenblum, Sheila

    This document presents the final report on the evaluation of the Instructional Materials Development (IMD) program of the National Science Foundation (NSF) and focuses on issues related to the development, dissemination, adoption, implementation, and impact of new instructional materials. The IMD program evaluates products at each step, from…

  3. Customer Overview of Pulsed Laser Heating for Evaluation of Gun Bore Materials

    DTIC Science & Technology

    2015-05-01

    Technical Report ARWSB-TR-15003 Customer Overview of Pulsed Laser Heating for Evaluation of Gun Bore Materials Mark E. Todaro...SUBTITLE Customer Overview of Pulsed Laser Heating for Evaluation of Gun Bore Materials 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  4. Programming for the Language Disabled Child: Booklet 4: Functional Approach to the Evaluation of Materials.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    The booklet describes a functional approach to evaluation of instructional materials which resulted from Project CHILD, a research effort to validate identification, intervention, and teacher education programs for use with language disabled children. Explained is a summer training program for teachers in the evaluation of materials which stressed…

  5. 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'…

  6. 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.

  7. 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.

  8. Thermography multidimensional manifold space projection and principal curves extraction for material state evaluation

    NASA Astrophysics Data System (ADS)

    Yin, Aijun; Gou, Yanli; Ran, Hongbin; Li, Jiang

    2017-08-01

    Eddy current pulsed thermography (ECPT) has been extensively used for detection and evaluation of conductive material defect, in that spatial-transient-stage thermography implies crucial information about material properties. This paper presents a material state evaluation method using multidimensional manifold space projection and similarity measurement of principal curves to characterize and track the variation of material properties. The mathematical theories about manifold space projection and principal curves extraction have been introduced and the corresponding physical models are established. The simulations and real experiments are conducted to validate the proposed method. The combination of manifold learning method with ECPT has shown promising potential in characterizing and tracking material properties.

  9. Effect of ageing and immersion in different beverages on properties of denture lining materials

    PubMed Central

    LEITE, Vanessa M. F.; PISANI, Marina X.; PARANHOS, Helena F. O.; SOUZA, Raphael F.; SILVA-LOVATO, Cláudia H.

    2010-01-01

    Objectives To evaluate the color stability and hardness of two denture liners obtained by direct and indirect techniques, after thermal cycling and immersion in beverages that can cause staining of teeth. Material and Methods Seventy disc-shaped specimens (18 x 3 mm) processed by direct (DT) and indirect techniques (IT) were made from elite soft (n=35) and Kooliner (n=35) denture liners. For each material and technique, 10 specimens were subjected to thermal cycling (3,000 cycles) and 25 specimens were stored in water, coffee, tea, soda and red wine for 36 days. The values of color change, Shore A hardness (elite soft) and Knoop hardness (Kooliner) were obtained. The data were subjected to ANOVA, Tukey’s multiple-comparison test, and Kruskal-Wallis test (P<0.05). Results The thermal cycling promoted a decrease on hardness of Kooliner regardless of the technique used (Initial: 9.09±1.61; Thermal cycling: 7.77±1.47) and promoted an increase in the hardness in the DT for elite Soft (Initial: 40.63±1.07; Thermal cycling: 43.53±1.03); hardness of Kooliner (DT: 8.76±0.95; IT: 7.70±1.62) and elite Soft (DT: 42.75±1.54; IT=39.30±2.31) from the DT suffered an increase after the immersion in the beverages. The thermal cycling promoted color change only for Kooliner in the IT. Immersion in the beverages did not promote color change for elite in both techniques. The control group of the DT of Kooliner showed a significant color change. Wine and coffee produced the greatest color change in the DT only for elite Soft when compared to the other beverages. Conclusion The three variation factors promoted alteration on hardness and color of the tested denture lining materials. PMID:20835572

  10. 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.

  11. 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.

  12. Evaluation of hybrid composite materials in cylindrical specimen geometries

    NASA Technical Reports Server (NTRS)

    Liber, T.; Daniel, I. M.

    1976-01-01

    Static and fatigue properties of three composite materials and hybrids were examined. The materials investigated were graphite/epoxy, S-glass/epoxy, PRD-49 (Kevlar 49)/epoxy, and hybrids in angle-ply configurations. A new type of edgeless cylindrical specimen was developed. It is a flattened tube with two flat sides connected by curved sections and it is handled much like the standard flat coupon. Special specimen fabrication, tabbing, and tab region reinforcing techniques were developed. Axial modulus, Poisson's ratio, strength, and ultimate strain were obtained under static loading from flattened tube specimens of nine laminate configurations. In the case of graphite/epoxy the tubular specimens appeared to yield somewhat higher strength and ultimate strain values than flat specimens. Tensile fatigue tests were conducted with all nine types of specimens and S-N curves obtained. Specimens surviving 10 million cycles of tensile loading were subsequently tested statically to failure to determine residual properties.

  13. 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.

  14. 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

  15. Development and Evaluation of Deep-Sea Swimsuit Materials.

    DTIC Science & Technology

    1973-06-01

    great sea depths for long periods of time . Two chemically distinct, flexible, syntactic foams--a Unit-developed, polyurethane, hollow-glass-microsphere...applications in deep-sea environments down to 1000 FSW. Tests showed that both materials were essentially incompressible to depths of 1000 FSW (less than 3...verification of sample thermal-conductivity data. Suit conductivity tests performed on an instrumented copper manikin substantially confirmed the

  16. Property Screening and Evaluation of Ceramic Turbine Engine Materials

    DTIC Science & Technology

    1979-10-01

    doped with 1% MgO, 8% Y2 03, and 15% Y20 3 ) were of lower strength than the Norton NC-132 and NCX- 34 materials, Slow crick growth was in evidence...T.L. Francis and R.L. Coble, "Creep of Polycrystalline Silicon Carbide," Jour. Amer. Ceram. Soc., 51(2) pp. 115-6 (1968). 44. P.L. Farnsworth and R.L

  17. 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.

  18. Evaluation of ilmenite as weight material in drilling fluids

    SciTech Connect

    Blomberg, N.E.; Aarrestad, S.; Boe, A.; Jacobsen, E.A.; Melberg, B.

    1982-09-01

    This paper discusses the prospect of using ilmenite as weight material in drilling fluids. The discussion is based on two field tests and laboratory experiments. Flow induced abrasion was found to be a considerable problem in the field tests using ilmenite as weight material. The abrasiveness was highly dependent on the particle size distribution, and the experiments clearly showed that the abrasiveness of ilmenite can be reduced to that of standard barite by removing the largest ilmenite particles. From experimental results, the authors recommend the particle size distribution of ilemenite to contain less than 3.0% above 45 ..mu..m. The field tests also demonstrated problems with dust, dispersion of ilmenite in water, air entrainment and foaming, which, as found by laboratory investigations, can be eliminated by reducing the content of flotation chemicals. Based on the field tests and the subsequent laboratory studies, the authors conclude that ilmenite is well suited for use as weight material in drilling fluids since the presently observed disadvantages to a large extent can be eliminated.

  19. In vitro evaluation of cytotoxicity of permanent prosthetic materials.

    PubMed

    Sabaliauskas, Vaidotas; Juciute, Rima; Bukelskiene, Virginija; Rutkunas, Vygandas; Trumpaite-Vanagiene, Rita; Puriene, Alina

    2011-01-01

    To assess qualitative and quantitative cytotoxicity effect on permanent prosthetic materials to human gingival fibroblasts. Human gingival tissues were collected (with informed consent) from patients undergoing periodontal surgical procedures and fibroblasts were cultured in vitro. Cell type was determined by performing proteomic analysis. Selected prosthetic materials including titanium, feldspathic ceramic, gold and chrome-cobalt alloy specimens (5×2 mm) were fabricated. The toxicity of prepared specimens was tested by exposing them to cell culture medium for 48, 72, 96 and 120 hours at 37°C under sterile conditions. Cell viability was estimated using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The data concerning cell viability were statistically analyzed using two-way ANOVA test and Tukey multiple comparison test. Results obtained after 48 hours showed no toxic effect of titanium compared to control group. Cytotoxic effect was observed in gold alloy and feldspathic ceramic, however, it was not significant compared to control group. Chrome-cobalt alloy significantly reduced cell viability compared to control group (p≤0.001). Cytotoxicity diminished with increasing incubation time of specimens. After 120 hours of incubation all tested materials, except chrome-cobalt alloy, had no cytotoxicity. Titanium proved to be non-toxic. Gold alloy and feldspathic ceramic had short-term cytotoxic effect. Chrome-cobalt alloy had highest cytotoxic effect on fibroblast cells.

  20. 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.

  1. 75 FR 70949 - Proposed Information Collection for the Evaluation of the Aging Worker Initiative; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... Employment and Training Administration Proposed Information Collection for the Evaluation of the Aging Worker Initiative; Comment Request AGENCY: Employment and Training Administration, Labor. ACTION: Notice. SUMMARY... burden conducts a preclearance consultation program to provide the general public and federal...

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

    USGS Publications Warehouse

    Olive, J.A.; Schramm, Harold; 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.

  3. 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.

  4. e-ageing: development and evaluation of a flexible online geriatric medicine educational resource for diverse learners.

    PubMed

    Watson, Natasha; Massarotto, Alicia; Caputo, Lisa; Flicker, Leon; Beer, Christopher

    2013-12-01

    To determine preferred content and format for online education modules in aged care among inter-professional learners; to develop resources that meet user preferences. Stakeholders were interviewed. A survey was administered to all health/medical students and teachers at The University of Western Australia. An iterative process was used to develop modules, and user feedback was collated. The educational needs of each discipline related primarily to foundation level knowledge in major aged care topics. Stakeholders sought modules incorporating communication skills, cultural and social issues and the importance of a multidisciplinary approach to aged care. Students from all disciplines sought online materials that are interactive, engaging, case-based and locally relevant. Online modules were developed. Evaluation of the modules by users has been strongly positive. There was consensus regarding the major curricular areas that online resources should encompass. The e-ageing modules developed in this project have been evaluated positively by users. © 2012 The Authors. Australasian Journal on Ageing © 2012 ACOTA.

  5. 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…

  6. 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…

  7. Growing Old in a New Age: National and International Evaluation of a Gerontology Telecourse.

    ERIC Educational Resources Information Center

    Dubanoski, Joan Pabst; Goodman, Rebecca J.; Braun, Kathryn L.; Roberts, Ellen; Lenzer, Anthony M.

    1999-01-01

    "Growing Old in a New Age," a Public Broadcasting Service telecourse, was evaluated by 40 faculty, 29 state aging administrators, 2 international public broadcasting users, and a training specialist. The course was generally considered effective, but improvements were recommended in content, integration of video and text, and updated…

  8. 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…

  9. 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…

  10. Toward sustainable material usage: evaluating the importance of market motivated agency in modeling material flows.

    PubMed

    Gaustad, Gabrielle; Olivetti, Elsa; Kirchain, Randolph

    2011-05-01

    Increasing recycling will be a key strategy for moving toward sustainable materials usage. There are many barriers to increasing recycling, including quality issues in the scrap stream. Repeated recycling can compound this problem through the accumulation of tramp elements over time. This paper explores the importance of capturing recycler decision-making in accurately modeling accumulation and the value of technologies intended to mitigate it. A method was developed combining dynamic material flow analysis with allocation of those materials into production portfolios using blending models. Using this methodology, three scrap allocation methods were explored in the context of a case study of aluminum use: scrap pooling, pseudoclosed loop, and market-based. Results from this case analysis suggest that market-driven decisions and upgrading technologies can partially mitigate the negative impact of accumulation on scrap utilization, thereby increasing scrap use and reducing greenhouse gas emissions. A market-based allocation method for modeling material flows suggests a higher value for upgrading strategies compared to a pseudoclosed loop or pooling allocation method for the scenarios explored.

  11. Effect of disinfectant, water age, and pipe material on occurrence and persistence of Legionella, mycobacteria, Pseudomonas aeruginosa, and two amoebas.

    PubMed

    Wang, Hong; Masters, Sheldon; Hong, Yanjuan; Stallings, Jonathan; Falkinham, Joseph O; Edwards, Marc A; Pruden, Amy

    2012-11-06

    Opportunistic pathogens represent a unique challenge because they establish and grow within drinking water systems, yet the factors stimulating their proliferation are largely unknown. The purpose of this study was to examine the influence of pipe materials, disinfectant type, and water age on occurrence and persistence of three opportunistic pathogens (Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa), broader genera (Legionella and mycobacteria), and two amoeba hosts (Acanthamoeba spp. and Hartmanella vermiformis). Triplicate simulated distribution systems (SDSs) compared iron, cement, and PVC pipe materials fed either chlorinated or chloraminated tap water and were sampled at water ages ranging from 1 day to 5.7 days. Quantitative polymerase chain reaction quantified gene copies of target microorganisms in both biofilm and bulk water. Legionella, mycobacteria, P. aeruginosa, and both amoebas naturally colonized the six SDSs, but L. pneumophila and M. avium were not detected. Disinfectant type and dose was observed to have the strongest influence on the microbiota. Disinfectant decay was noted with water age, particularly in chloraminated SDSs (due to nitrification), generally resulting in increased microbial detection frequencies and densities with water age. The influence of pipe material became apparent at water ages corresponding to low disinfectant residual. Each target microbe appeared to display a distinct response to disinfectant type, pipe materials, water age, and their interactions. Differences between the first and the second samplings (e.g., appearance of Legionella, reduction in P. aeruginosa and Acanthamoeba) suggest a temporally dynamic drinking water microbial community.

  12. Scanning Probe Evaluation of Electronic, Mechanical and Structural Material Properties

    NASA Astrophysics Data System (ADS)

    Virwani, Kumar

    2011-03-01

    We present atomic force microscopy (AFM) studies of a range of properties from three different classes of materials: mixed ionic electronic conductors, low-k dielectrics, and polymer-coated magnetic nanoparticles. (1) Mixed ionic electronic conductors are being investigated as novel diodes to drive phase-change memory elements. Their current-voltage characteristics are measured with direct-current and pulsed-mode conductive AFM (C-AFM). The challenges to reliability of the C-AFM method include the electrical integrity of the probe, the sample and the contacts, and the minimization of path capacitance. The role of C-AFM in the optimization of these electro-active materials will be presented. (2) Low dielectric constant (low-k) materials are used in microprocessors as interlayer insulators, a role directly affected by their mechanical performance. The mechanical properties of nanoporous silicate low-k thin films are investigated in a comparative study of nanomechanics measured by AFM and by traditional nanoindentation. Both methods are still undergoing refinement as reliable analytical tools for determining nanomechanical properties. We will focus on AFM, the faster of the two methods, and its developmental challenges of probe shape, cantilever force constant, machine compliance and calibration standards. (3) Magnetic nanoparticles are being explored for their use in patterned media for magnetic storage. Current methods for visualizing the core-shell structure of polymer-coated magnetic nanoparticles include dye-staining the polymer shell to provide contrast in transmission electron microscopy. AFM-based fast force-volume measurements provide direct visualization of the hard metal oxide core within the soft polymer shell based on structural property differences. In particular, the monitoring of adhesion and deformation between the AFM tip and the nanoparticle, particle-by-particle, provides a reliable qualitative tool to visualize core-shell contrast without the use

  13. 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.

  14. 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. © 2011 Society for Risk Analysis.

  15. Evaluation of Insulation Materials and Combinations for Bulkhead Fire Protection

    DTIC Science & Technology

    1982-01-20

    fire. (This evaluation condition was suggested by Mr. J. Morris to Mr. R. C. Manahan of Johns - Manville during a visit by Mr. Manahan to the Naval Ship...and Concord Pike Wilmington, Delaware 19897 Telephone: (302) 575-3000 5. Johns - Manville Corporation CERAFELT, CERABLANKET P. 0. Box 5108 Flexible MIN

  16. 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.

  17. Evaluation of forest thinning materials for TMP production

    Treesearch

    John H. Klungness; Roland Gleisner; Doreen Mann; Karen L. Scallon; J.Y. Zhu; Eric G. Horn; Louis L. Edwards

    2005-01-01

    We used SilviScan analysis and tracheid measurement to evaluate the effect of suppressed growth on the fundamental properties of wood fiber. Suppressed growth reduced cell tracheid length, but the high content of mature wood may translate into longer fibers overall. In pilot-scale refining experiments, blending 25% chips from small-diameter trees (SMD) with 75% mill...

  18. Roofing Repair Materials for Korean Relocatable Buildings - Test and Evaluation

    DTIC Science & Technology

    1980-05-01

    cleaning it by from which solvent evaporates, leaving solid material rubbing lightly with a clean cloth and xylene, a grease which cures into a rubber, and... rubbing it lightly by hand. A hard. Polyseal specimens had a hardness of more than 95 ness reading was taken at 70OF (21.1°C) using the at -40OF (-400C...Fort McClellan AFE, Taegu Fort Monroe Cold Regions Research Engineering Lab Fort Rucker OLA ATTN: DLA-W ATTN: Library Fort Sill Fort Leonard Wood USA

  19. Promising quantitative nondestructive evaluation techniques for composite materials

    NASA Technical Reports Server (NTRS)

    Williams, J. H., Jr.; Lee, S. S.

    1985-01-01

    Some recent results in the area of the ultrasonic, acoustic emission, thermographic, and acousto-ultrasonic NDE of composites are reviewed. In particular, attention is given to the progress in the use of ultrasonic attenuation, acoustic emission (parameter) delay, liquid-crystal thermography, and the stress wave factor in structural integrity monitoring of composite materials. The importance of NDE flaw significance characterizations is emphasized since such characterizations can directly indicate the appropriate NDE technique sensitivity requirements. The role of the NDE of flawed composites with and without overt defects in establishing quantitative accept/reject criteria for structural integrity assessment is discussed.

  20. Evaluation of air permeability in layered unsaturated materials.

    PubMed

    Switzer, Christine; Kosson, David S

    2007-03-20

    Field estimation of air permeability is important in the design and operation of soil-vapor extraction systems. Previous models have examined airflow in homogenous soils, incorporating leakage through a low-permeability cap either as a correction to the airflow equation or as a boundary condition. The dual leakage model solution developed here improves upon the previous efforts by adding a leaky lower boundary condition, allowing for the examination of airflow in heterogeneous layered soils. The dual leakage model is applied to the evaluation of pump tests at a pilot soil-vapor extraction system at the Savannah River Site in South Carolina. A thick, low-permeability, stiff clay layer divides the stratigraphy at the site into two units for evaluation. A modified version of the previous model, using the water table as the impermeable lower boundary, is used to evaluate the permeability of the low-permeability stiff clay layer (3.2 x 10(-10) cm(2)) and permeable sand (7.2 x 10(-7) cm(2)) beneath it. The stiff clay permeability estimate is used in the evaluation of the shallow unit. Permeability estimates of the shallow sand (3.8 x 10(-7) cm(2)) and kaolin cap (1.5 x 10(-9)cm(2)) were obtained with the dual leakage model. The shallow unit was evaluated using the previous model for comparison. The effects of anisotropy were investigated with a series of model simulations based on the shallow unit solution. The anisotropy sensitivity analysis suggests that increased anisotropy ratio or decreased axial permeability has a significant impact on the velocity profile at the lower boundary, especially at high values of the anisotropy ratio. This result may increase estimates of SVE removal rates for contaminants located at the interface of the lower boundary, typical of chlorinated solvent contamination.

  1. A structured approach to evaluating aging of the advanced test reactor

    SciTech Connect

    Dwight, J.E.

    1990-01-01

    An aging evaluation program has been developed for the United States Department of Energy's Advanced Test Reactor to support the current goal of operation through the year 2014 and beyond. The Aging Evaluation and Life Extension Program (AELEX) employs a three-phased approach. In Phases 1 and 2, now complete, components were identified, categorized and prioritized. Critical components were selected and aging mechanisms for the critical components identified. An initial evaluation of the critical components was performed and extended life operation for the plant appears to be both technically and economically feasible. Detailed evaluations of the critical components are now in progress in the early stages of Phase 3. Some results are available. Evaluations of many non-critical components and refinements to the program based on probabilistic risk assessment results will follow in later stages of Phase 3. 6 refs., 2 figs., 5 tabs.

  2. 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).

  3. 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.

  4. 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.

  5. Micromagnetic surface studies of materials for nondestructive evaluation

    SciTech Connect

    Sipahi, L.B.

    1992-11-25

    A system which employs the magnetic Barkhausen effect to measure micromagnetic Barkhausen emissions (E) in ferromagnetic materials using a time varying magnetic field was developed. A patent application was made (US patent application temporary no. 754,904 pending). It was observed that E is dependent on microstructure in different Fe, Ni, Co alloys, steel, and rare earth-Fe alloys. The ac excitation field used in the present developed system is essential, since superposition of ac excitation field on quasi dc field gives cleaner, more reproducible magnetic Barkhausen pulse waveforms. 30 Hz was found optimal for the excitation frequency, for very fast in situ measurements. E can be generated at different depths in the material by altering the excitation frequency; using a band pass filter, E can be detected over different frequency ranges. Instead of conventional count rate, techniques for analyzing the E were developed: pulse height spectrum analysis, frequency spectrum analysis, RMS voltage analysis, and pulse waveform analysis. A model was developed for the magnetic Barkhausen effect.

  6. Material Characterization of Power Plant Steel in the Virgin and Artificially-Aged Conditions

    NASA Astrophysics Data System (ADS)

    Rayes, Magdy M. El; El-Danaf, Ehab A.

    In the present study the microstructural and mechanical properties including high-temperature tensile test of martensitic-ferritic steel 9-12% Cr were assessed. This steel, which is usually used in gas turbine power plants serving as shroud, was tested in the as-received (virgin) and artificially-aged condition for 1344hrs (8 weeks) at 700 °C and the results were compared and analyzed. The high-temperature service of this steel suggested investigating the high temperature tensile behavior and the deformation mechanism occurring at different testing temperature and strain rates which were 540, 580 and 620 °C and 10-3, 10-4 and 10-5 s-1, respectively. The results showed that the microstructural features such as phases and carbides are factors which influence the high temperature mechanical properties. The stress- strain rate curves showed a large stress exponent of ≈ 15, indicating that the materials behavior lie in the power law breakdown regime. Based on stress vs. the reciprocal of temperature, the apparent activation energy was calculated as 443 kJ/ Mole. Plotting Zener Holloman parameter versus true stress made it possible to mathematically model all test results into a unified model.

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

    SciTech Connect

    Daugherty, W.

    2010-12-27

    Samples have been prepared from a softwood fiberboard lower subassembly. 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. On the positive side, the softwood fiberboard data to date shows less sample-to-sample variation in physical properties than cane fiberboard, and the thermal conductivity decreases at a slower rate at 250F for softwood fiberboard than for cane fiberboard. On the other hand, the softwood fiberboard physical property samples generally show degradation rates greater than cane fiberboard samples in the 185F 30%RH environment. Testing following additional conditioning will continue and the addition of samples in other elevated humidity environment(s) will be pursued to identify the extent of these trends. 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.

  8. 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

  9. Evaluation of suspected appendicitis in children using limited helical CT and colonic contrast material.

    PubMed

    Mullins, M E; Kircher, M F; Ryan, D P; Doody, D; Mullins, T C; Rhea, J T; Novelline, R A

    2001-01-01

    Colonic contrast material evaluation of suspected appendicitis in pediatric patients is technically more challenging than in adults because less intraabdominal fat is present. To determine the accuracy and feasibility of focused CT for pediatric patients, we carried out this retrospective investigation. Between November 1995 and July 1999, 199 pediatric patients (1-18 years old; mean age, 12 years) were examined with focused CT in the emergency division for suspected appendicitis. The findings on CT were compared with the findings at surgery, pathology, and clinical follow-up. There were 64 true-positive CT scans, two false-negative, 128 true-negative, one false-positive, and four indeterminate. Seventy-four patients underwent appendectomy, with a negative appendectomy rate of 9%. One hundred twenty-five patients without appendicitis were treated nonoperatively. The true-positive rate was 32%, true-negative rate was 64%, sensitivity was 97%, specificity was 99%, positive predictive value was 98%, negative predictive value was 98%, and overall accuracy was 96%. Pediatric patients tolerated the procedure well. Colonic contrast material saved time and provided improved identification of the cecum and appendix. In 62 patients without appendicitis, focused CT provided alternative diagnoses. Focused CT appears to be nearly as accurate in pediatric patients as in adults. Focused CT provided alternative diagnoses in 48% of the patients for whom CT findings were negative for appendicitis.

  10. 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.

  11. Evaluation of Anti-fouling Materials for Optical Sensors

    DTIC Science & Technology

    1997-09-30

    Hani R., Waldron C. and Farmer D. A. (1994) Gel-Free Paint Containing Zinc Pyrithione , Cuprous Oxide, and Carboxylic Acid. U.S. Patent 5342437, Olin Corp...2. Hani R., Waldron C. and Farmer D. A. Jr. (1992) Stabilization of Paints Containing Zinc Pyrithione and Cuprous Oxide Antifouling Agents. U.S...using ESEM. The following commercially prepared formulations provided by Magellan Co., Inc. were evaluated: 1) 10,000 ppm zinc pyrithione1,2,3 + 300 ppm

  12. Evaluation of Corrosion Preventive Compounds for Aviation Materials Applications

    DTIC Science & Technology

    2005-04-01

    Orange Peel Solvent for Removal of Carwell AR500 85 Appendix B. U.S. Army Aviation and Missile Command’s Carwell AR500 Debris Test Report 87 Appendix...an alternative wash method employing environmentally friendly citrus oil limonene based cleaners. The manufacturer’s proposal detailing the...procedure is supplied in appendix A. One commercial brand of citrus cleaner from Inland Technology Incorporated known as “Citrex” was evaluated and found

  13. Evaluation of the tensor polynomial failure criterion for composite materials

    NASA Technical Reports Server (NTRS)

    Tennyson, R. C.; Macdonald, D.; Nanyaro, A. P.

    1978-01-01

    A comprehensive experimental and analytical evaluation of the tensor polynomial failure criterion was undertaken to determine its capability for predicting the ultimate strength of laminated composite structures subject to a plane stress state. Results are presented demonstrating that a quadratic formulation is too conservative and a cubic representation is required. Strength comparisons with test data derived from glass/epoxy and graphite/epoxy tubular specimens are also provided to validate the cubic strength criterion.

  14. 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

  15. Material selection and evaluation aimed at resolving deficiencies of a space technology material

    NASA Astrophysics Data System (ADS)

    Ray, Asit K.; Bryan, Coleman J.

    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.

  16. 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.

  17. Materials evaluation programs at the Defense Waste Processing Facility

    SciTech Connect

    Gee, J.T.; Iverson, D.C.; Bickford, D.F.

    1992-01-01

    The Savannah River Site (SRS) has been operating a nuclear fuel cycle since the 1950s to produce nuclear materials in support of the national defense effort. About 83 million gallons of high-level waste produced since operations began has been consolidated by evaporation into 33 million gallons at the waste tank farm. The Department of Energy authorized the construction of the Defense Waste Processing Facility (DWPF), the function of which is to immobilize the waste as a durable borosilicate glass contained in stainless steel canisters prior to the placement of the canisters in a federal repository. The DWPF is now mechanically complete and is undergoing commissioning and run-in activities. A brief description of the DWPF process is provided.

  18. Materials evaluation programs at the Defense Waste Processing Facility

    SciTech Connect

    Gee, J.T.; Iverson, D.C.; Bickford, D.F.

    1992-12-31

    The Savannah River Site (SRS) has been operating a nuclear fuel cycle since the 1950s to produce nuclear materials in support of the national defense effort. About 83 million gallons of high-level waste produced since operations began has been consolidated by evaporation into 33 million gallons at the waste tank farm. The Department of Energy authorized the construction of the Defense Waste Processing Facility (DWPF), the function of which is to immobilize the waste as a durable borosilicate glass contained in stainless steel canisters prior to the placement of the canisters in a federal repository. The DWPF is now mechanically complete and is undergoing commissioning and run-in activities. A brief description of the DWPF process is provided.

  19. Fracture Mechanics Evaluation of B-1 Materials. Volume I. Text

    DTIC Science & Technology

    1976-10-01

    cation with- ti fication E = Kisec In a material number) lot ( pieLe number on ’ layout drawing) For weldments, the specimen orientation is that of the...directio’n of 1.5" Ti-6-4 plate 8-07 _____OhI A. 62N~w4-32 (M.A.) --- B- 62NEw4-291 (STOA) -c- 62N~w 4-34 (DBTC .- -. .- , Puw 62NRw 4- 281 (B.A...DEL fA K ( PIel FJ ( t) A. Figure 8.2.1.6-18 Effect of test direction on STW-FGR at __R.T., R=0.08, 60 epm in 2.5" TI-6-4 ring 8-52 ~Vi rolled plus

  20. Cyclic deformation, fracture, and nondestructive evaluation of advanced materials

    SciTech Connect

    Mitchell, M.R.; Buck, O.

    1992-01-01

    Papers are presented on cyclic fatigue of alumnia, fatigue crack growth in ceramics and ceramic-matrix composites, fatigue test methodology and results for ceramic matrix composites at room and elevated temperatures, and modeling crack growth resistance in ceramics and ceramic-matrix composites. Attention is also given to thermomechanical cyclic deformation of metal-matrix composites, the effect of tensile mean stress on the fatigue behavior of single-crystal and directionally solidified superalloys, the influence of constituent properties on the compression behavior of aluminates with discontinuities, and cyclic creep effects in single-overlap bonded joints under constant-amplitude testing. Other papers discuss an ultrasonic wave technique to assess cyclic-load fatigue damage in silicon-carbide whisker-reinforced 2124 aluminum alloy composites, nondestructive characterization for metal-matrix composite fabrication, NDE of a ceramic matrix composite material, and split spectrum processing of backscattered Rayleigh wave signals to improve detectability of fatigue microcracks.