Excitons in scintillator materials: Optical properties and electron-energy loss spectra of NaI, LaBr 3, BaI 2, and SrI 2

DOE PAGES

Schleife, Andre; Zhang, Xiao; Li, Qi; ...

2016-11-03

In this paper, materials for scintillator radiation detectors need to fulfill a diverse set of requirements such as radiation hardness and highly specific response to incoming radiation, rendering them a target of current materials design efforts. Even though they are amenable to cutting-edge theoretical spectroscopy techniques, surprisingly many fundamental properties of scintillator materials are still unknown or not well explored. In this work, we use first-principles approaches to thoroughly study the optical properties of four scintillator materials: NaI, LaBr 3, BaI 2, and SrI 2. By solving the Bethe–Salpeter equation for the optical polarization function we study the influence ofmore » excitonic effects on dielectric and electron-energy loss functions. This work sheds light into fundamental optical properties of these four scintillator materials and lays the ground-work for future work that is geared toward accurate modeling and computational materials design of advanced radiation detectors with unprecedented energy resolution.« less

Thermionic Properties of Carbon Based Nanomaterials Produced by Microhollow Cathode PECVD

NASA Technical Reports Server (NTRS)

Haase, John R.; Wolinksy, Jason J.; Bailey, Paul S.; George, Jeffrey A.; Go, David B.

2015-01-01

Thermionic emission is the process in which materials at sufficiently high temperature spontaneously emit electrons. This process occurs when electrons in a material gain sufficient thermal energy from heating to overcome the material's potential barrier, referred to as the work function. For most bulk materials very high temperatures (greater than 1500 K) are needed to produce appreciable emission. Carbon-based nanomaterials have shown significant promise as emission materials because of their low work functions, nanoscale geometry, and negative electron affinity. One method of producing these materials is through the process known as microhollow cathode PECVD. In a microhollow cathode plasma, high energy electrons oscillate at very high energies through the Pendel effect. These high energy electrons create numerous radical species and the technique has been shown to be an effective method of growing carbon based nanomaterials. In this work, we explore the thermionic emission properties of carbon based nanomaterials produced by microhollow cathode PECVD under a variety of synthesis conditions. Initial studies demonstrate measureable current at low temperatures (approximately 800 K) and work functions (approximately 3.3 eV) for these materials.

Electronic materials high-T(sub c) superconductivity polymers and composites structural materials surface science and catalysts industry participation

NASA Technical Reports Server (NTRS)

1988-01-01

The fifth year of the Center for Advanced Materials was marked primarily by the significant scientific accomplishments of the research programs. The Electronics Materials program continued its work on the growth and characterization of gallium arsenide crystals, and the development of theories to understand the nature and distribution of defects in the crystals. The High Tc Superconductivity Program continued to make significant contributions to the field in theoretical and experimental work on both bulk materials and thin films and devices. The Ceramic Processing group developed a new technique for cladding YBCO superconductors for high current applications in work with the Electric Power Research Institute. The Polymers and Composites program published a number of important studies involving atomistic simulations of polymer surfaces with excellent correlations to experimental results. The new Enzymatic Synthesis of Materials project produced its first fluorinated polymers and successfully began engineering enzymes designed for materials synthesis. The structural Materials Program continued work on novel alloys, development of processing methods for advanced ceramics, and characterization of mechanical properties of these materials, including the newly documented characterization of cyclic fatigue crack propagation behavior in toughened ceramics. Finally, the Surface Science and Catalysis program made significant contributions to the understanding of microporous catalysts and the nature of surface structures and interface compounds.

Updated Trends in Materials' Outgassing Technology

NASA Technical Reports Server (NTRS)

Rosecrans, Glenn; Mlucciacciaro, Anthony

2010-01-01

This slide presentation reviews the trends in materials' outgassing. The work utilized a database of reports to identify common outgassing chemical species from flight hardware, spacecraft, and ground support equipment (GSE). This work updates an earlier work that reported on chemical analysis from 1970-1978.

29 CFR 1910.1026 - Chromium (VI).

Code of Federal Regulations, 2012 CFR

2012-07-01

... resembling the processes, types of material, control methods, work practices, and environmental conditions in... resembling the processes, types of material, control methods, work practices, and environmental conditions in..., work practices, or control methods that may result in new or additional exposures to chromium (VI), or...

29 CFR 1910.1026 - Chromium (VI).

Code of Federal Regulations, 2014 CFR

2014-07-01

... resembling the processes, types of material, control methods, work practices, and environmental conditions in... resembling the processes, types of material, control methods, work practices, and environmental conditions in..., work practices, or control methods that may result in new or additional exposures to chromium (VI), or...

Understanding the bond-energy, hardness, and adhesive force from the phase diagram via the electron work function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Hao; Huang, Xiaochen; Li, Dongyang, E-mail: dongyang.li@ualberta.ca

2014-11-07

Properties of metallic materials are intrinsically determined by their electron behavior. However, relevant theoretical treatment involving quantum mechanics is complicated and difficult to be applied in materials design. Electron work function (EWF) has been demonstrated to be a simple but fundamental parameter which well correlates properties of materials with their electron behavior and could thus be used to predict material properties from the aspect of electron activities in a relatively easy manner. In this article, we propose a method to extract the electron work functions of binary solid solutions or alloys from their phase diagrams and use this simple approachmore » to predict their mechanical strength and surface properties, such as adhesion. Two alloys, Fe-Ni and Cu-Zn, are used as samples for the study. EWFs extracted from phase diagrams show same trends as experimentally observed ones, based on which hardness and surface adhesive force of the alloys are predicted. This new methodology provides an alternative approach to predict material properties based on the work function, which is extractable from the phase diagram. This work may also help maximize the power of phase diagram for materials design and development.« less

Low-threshold field emission in planar cathodes with nanocarbon materials

NASA Astrophysics Data System (ADS)

Zhigalov, V.; Petukhov, V.; Emelianov, A.; Timoshenkov, V.; Chaplygin, Yu.; Pavlov, A.; Shamanaev, A.

2016-12-01

Nanocarbon materials are of great interest as field emission cathodes due to their low threshold voltage. In this work current-voltage characteristics of nanocarbon electrodes were studied. Low-threshold emission was found in planar samples where field enhancement is negligible (<10). Electron work function values, calculated by Fowler-Nordheim theory, are anomalous low (<1 eV) and come into collision with directly measured work function values in fabricated planar samples (4.1-4.4 eV). Non-applicability of Fowler-Nordheim theory for the nanocarbon materials was confirmed. The reasons of low-threshold emission in nanocarbon materials are discussed.

New Cork-Based Materials and Applications.

PubMed

Gil, Luís

2015-02-10

This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork) for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders), and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before.

New Cork-Based Materials and Applications

PubMed Central

Gil, Luís

2015-01-01

This review work is an update of a previous work reporting the new cork based materials and new applications of cork based materials. Cork is a material which has been used for multiple applications. The most known uses of cork are in stoppers (natural and agglomerated cork) for alcoholic beverages, classic floor covering with composite cork tiles (made by the binding of cork particles with different binders), and thermal/acoustic/vibration insulation with expanded corkboard in buildings and some other industrial fields. Many recent developments have been made leading to new cork based materials. Most of these newly developed cork materials are not yet on the market, but they represent new possibilities for engineers, architects, designers and other professionals which must be known and considered, potentially leading to their industrialization. This paper is a review covering the last five years of innovative cork materials and applications also mentioning previous work not reported before. PMID:28787962

Influence of Decontaminating Agents and Swipe Materials on Laboratory Simulated Working Surfaces Wet Spilled with Sodium Pertechnetate

PubMed Central

Akchata, Suman; Lavanya, K; Shivanand, Bhushan

2017-01-01

Context: Decontamination of various working surfaces with sodium pertechnetate minor spillage is essential for maintaining good radiation safety practices as well as for regulatory compliance. Aim: To observe the influences of decontaminating agents and swipe materials on different type of surfaces used in nuclear medicine laboratory work area wet spilled with 99m-technetium (99mTc) sodium pertechnetate. Settings and Design: Lab-simulated working surface materials. Experimental study design. Materials and Methods: Direct decontamination method on dust-free lab simulated new working surfaces [stainless steel, polyvinyl chloride (PVC), Perspex, resin] using four decontaminating agents [tap water, soap water (SW), Radiacwash, and spirit] with four different swipe material [cotton, tissue paper (TP), Whatman paper (WP), adsorbent sheet (AS)] was taken 10 samples (n = 10) for each group. Statistical Analysis: Parametric test two-way analysis of variance is used with significance level of 0.005, was used to evaluate statistical differences between different group of decontaminating agent and swipe material, and the results are expressed in mean ± SD. Results: Decontamination factor is calculated after five cleaning for each group. A total of 160 samples result calculated using four decontaminating agent (tap water, SW, Radiacwash, and spirit), four swipe material (cotton, TP, WP, and AS) for commonly used surface (stainless steel, PVC, Perspex, resin) using direct method by 10 samples (n = 10) for each group. Conclusions: Tap water is the best decontaminating agent compared with SW, Radiac wash and spirit for the laboratory simulated stainless steel, PVC, and Perspex surface material, whereas in case of resin surface material, SW decontaminating agent is showing better effectiveness. Cotton is the best swipe material compared to WP-1, AS and TP for the stainless steel, PVC, Perspex, and resin laboratory simulated surface materials. Perspex and stainless steel are the most suitable and recommended laboratory surface material compared to PVC and resin in nuclear medicine. Radiacwash may show better result for 99mTc labelled product and other radionuclide contamination on the laboratory working surface area. PMID:28680198

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements.... All components used in the construction of work vests must meet the applicable requirements of subpart...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements.... All components used in the construction of work vests must meet the applicable requirements of subpart...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements.... All components used in the construction of work vests must meet the applicable requirements of subpart...

The Use of Miniature Electret Microphones in Small Optoacoustic Cells.

DTIC Science & Technology

1980-06-30

conductivity. The work-horse material has been carnauba wax (used in floor polishes), but shellac, sealing wax , and naphthalene have been used. Such...electret is normally short with large area working faces. * The typical electret material is an organic wax or plastic, a material of poor electrical

Proyecto Leer Bulletin, Number 10.

ERIC Educational Resources Information Center

Benson, Susan Shattuck

This guide to instructional materials for teachers of Spanish contains references to commercially-prepared works in several classified areas. The works listed are intended for use in grades ranging from kindergarten through senior high school and also include materials for adult education. The 10 categories cover: (1) audiovisual materials, (2)…

Measuring the coefficient of restitution and more: a simple experiment to promote students’ critical thinking and autonomous work

NASA Astrophysics Data System (ADS)

González, Manuel Á.; González, Miguel Á.; Vegas, Jesús; Llamas, César

2017-09-01

A simple experiment on the determination of the coefficient of restitution of different materials is taken as the basis of an extendable work that can be done by students in an autonomous way. On the whole, the work described in this paper would involve concepts of kinematics, materials science, air drag and buoyancy, and would help students to think of physics as a whole subject instead of a set of, more or less, isolated parts. The experiment can be done either in teaching laboratories or as an autonomous work by students at home. Students’ smartphones and cheap balls of different materials are the only experimental materials required to do the experiment. The proposed work also permits the students to analyse the limitations of a physical model used in the experiment by analysing the approximations considered in it, and then enhancing their critical thinking.

Advanced numerical models and material characterisation techniques for composite materials subject to impact and shock wave loading

NASA Astrophysics Data System (ADS)

Clegg, R. A.; White, D. M.; Hayhurst, C.; Ridel, W.; Harwick, W.; Hiermaier, S.

2003-09-01

The development and validation of an advanced material model for orthotropic materials, such as fibre reinforced composites, is described. The model is specifically designed to facilitate the numerical simulation of impact and shock wave propagation through orthotropic materials and the prediction of subsequent material damage. Initial development of the model concentrated on correctly representing shock wave propagation in composite materials under high and hypervelocity impact conditions [1]. This work has now been extended to further concentrate on the development of improved numerical models and material characterisation techniques for the prediction of damage, including residual strength, in fibre reinforced composite materials. The work is focussed on Kevlar-epoxy however materials such as CFRP are also being considered. The paper describes our most recent activities in relation to the implementation of advanced material modelling options in this area. These enable refined non-liner directional characteristics of composite materials to be modelled, in addition to the correct thermodynamic response under shock wave loading. The numerical work is backed by an extensive experimental programme covering a wide range of static and dynamic tests to facilitate derivation of model input data and to validate the predicted material response. Finally, the capability of the developing composite material model is discussed in relation to a hypervelocity impact problem.

Efficiency of Cs-free materials for negative ion production in H2 and D2 plasmas

NASA Astrophysics Data System (ADS)

Friedl, R.; Kurutz, U.; Fantz, U.

2017-08-01

High power negative ion sources use caesium to reduce the work function of the converter surface which significantly increases the negative ion yield. Caesium, however, is a very reactive alkali-metal and shows complex redistribution dynamics in consequence of plasma-surface-interaction. Thus, maintaining a stable and homogenous low work function surface is a demanding task, which is not easily compatible with the RAMI issues (reliability, availability, maintainability, inspectability) for a future DEMO fusion reactor. Hence, Cs-free alternative materials for efficient negative ion formation are desirable. At the laboratory experiment HOMER materials which are referred to as promising are investigated under identical and ion source relevant parameters: the refractory metals Ta and W, non-doped and boron-doped diamond as well as materials with inherent low work function (lanthanum-doped molybdenum, MoLa and lanthanum hexaboride, LaB6). The results are compared to the effect of in-situ caesiation, which at HOMER leads to a maximal increase of the negative ion density by a factor of 2.5. Among the examined samples low work function materials are most efficient. In particular, MoLa leads to an increase of almost 50 % compared to pure volume formation. The difference to a caesiated surface can be attributed to the still higher work function of MoLa, which is expected to be slightly below 3 eV. Using deuterium instead of hydrogen leads to increased atomic and positive ion densities, while comparable negative ion densities are achieved. In contrast to the low work function materials, bulk samples of the refractory metals as well as carbon based materials have no enhancing effect on H-, where the latter materials furthermore show severe erosion due to the hydrogen plasma.

METHODS AND MATERIALS IN WORK EXPERIENCE EDUCATION.

ERIC Educational Resources Information Center

Thornton Fractional Township High School District 215, IL.

THIS DOCUMENT DEFINES WORK EXPERIENCE, DESCRIBES SOME TYPICAL PROGRAMS IN OPERATION, AND PRESENTS METHODS OF ORGANIZATION AND ADMINISTRATION. MATERIAL WAS OBTAINED THROUGH INTERVIEWS WITH LOCAL SCHOOL PERSONNEL, BY LETTER FROM DISTRICTS IN OTHER STATES, AND FROM RELATED LITERATURE. WORK EXPERIENCE IS DEFINED AS EMBRACING BOTH VOCATIONAL AND…

Optimal lattice-structured materials

DOE PAGES

Messner, Mark C.

2016-07-09

This paper describes a method for optimizing the mesostructure of lattice-structured materials. These materials are periodic arrays of slender members resembling efficient, lightweight macroscale structures like bridges and frame buildings. Current additive manufacturing technologies can assemble lattice structures with length scales ranging from nanometers to millimeters. Previous work demonstrates that lattice materials have excellent stiffness- and strength-to-weight scaling, outperforming natural materials. However, there are currently no methods for producing optimal mesostructures that consider the full space of possible 3D lattice topologies. The inverse homogenization approach for optimizing the periodic structure of lattice materials requires a parameterized, homogenized material model describingmore » the response of an arbitrary structure. This work develops such a model, starting with a method for describing the long-wavelength, macroscale deformation of an arbitrary lattice. The work combines the homogenized model with a parameterized description of the total design space to generate a parameterized model. Finally, the work describes an optimization method capable of producing optimal mesostructures. Several examples demonstrate the optimization method. One of these examples produces an elastically isotropic, maximally stiff structure, here called the isotruss, that arguably outperforms the anisotropic octet truss topology.« less

Extrusion-mixing compared with hand-mixing of polyether impression materials?

PubMed

McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

2010-12-01

The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

48 CFR 852.236-80 - Subcontracts and work coordination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... trades, subcontractors, and material suppliers. The contractor shall, in advance of the work, prepare... contractor shall also be responsible for coordination of the work of the trades, subcontractors, and material.... Drawings may be composite (with distinctive colors for the various trades) or may be separate but fully...

48 CFR 852.236-80 - Subcontracts and work coordination.

Code of Federal Regulations, 2014 CFR

2014-10-01

... trades, subcontractors, and material suppliers. The contractor shall, in advance of the work, prepare... contractor shall also be responsible for coordination of the work of the trades, subcontractors, and material.... Drawings may be composite (with distinctive colors for the various trades) or may be separate but fully...

48 CFR 852.236-80 - Subcontracts and work coordination.

Code of Federal Regulations, 2012 CFR

2012-10-01

... trades, subcontractors, and material suppliers. The contractor shall, in advance of the work, prepare... contractor shall also be responsible for coordination of the work of the trades, subcontractors, and material.... Drawings may be composite (with distinctive colors for the various trades) or may be separate but fully...

48 CFR 852.236-80 - Subcontracts and work coordination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... trades, subcontractors, and material suppliers. The contractor shall, in advance of the work, prepare... contractor shall also be responsible for coordination of the work of the trades, subcontractors, and material.... Drawings may be composite (with distinctive colors for the various trades) or may be separate but fully...

Working Memory Capacity and Resistance to Interference

ERIC Educational Resources Information Center

Oberauer, Klaus; Lange, Elke; Engle, Randall W.

2004-01-01

Single-task and dual-task versions of verbal and spatial serial order memory tasks were administered to 120 students tested for working memory capacity with four previously validated measures. In the dual-task versions, similarity between the memory material and the material of the secondary processing task was varied. With verbal material, three…

Improving sun-dried apricots (Prunus armeniaca) with photo-selective dryer cabinet materials (abstract)

USDA-ARS?s Scientific Manuscript database

Photo-selective materials have previously been studied for their effects on the pre-harvest quality of horticultural crops, but little work has been done on potential post-harvest effects. Thus, the aim of this work was to characterize the effects of 5 different photo-selective acrylic materials (u...

10 CFR 35.396 - Training for the parenteral administration of unsealed byproduct material requiring a written...

Code of Federal Regulations, 2013 CFR

2013-01-01

... radioactivity; (iv) Chemistry of byproduct material for medical use; and (v) Radiation biology; and (2) Has work...). The work experience must involve— (i) Ordering, receiving, and unpacking radioactive materials safely... meters; (iii) Calculating, measuring, and safely preparing patient or human research subject dosages; (iv...

10 CFR 35.396 - Training for the parenteral administration of unsealed byproduct material requiring a written...

Code of Federal Regulations, 2014 CFR

2014-01-01

... radioactivity; (iv) Chemistry of byproduct material for medical use; and (v) Radiation biology; and (2) Has work...). The work experience must involve— (i) Ordering, receiving, and unpacking radioactive materials safely... meters; (iii) Calculating, measuring, and safely preparing patient or human research subject dosages; (iv...

10 CFR 35.396 - Training for the parenteral administration of unsealed byproduct material requiring a written...

Code of Federal Regulations, 2012 CFR

2012-01-01

... radioactivity; (iv) Chemistry of byproduct material for medical use; and (v) Radiation biology; and (2) Has work...). The work experience must involve— (i) Ordering, receiving, and unpacking radioactive materials safely... meters; (iii) Calculating, measuring, and safely preparing patient or human research subject dosages; (iv...

10 CFR 35.396 - Training for the parenteral administration of unsealed byproduct material requiring a written...

Code of Federal Regulations, 2011 CFR

2011-01-01

... radioactivity; (iv) Chemistry of byproduct material for medical use; and (v) Radiation biology; and (2) Has work...). The work experience must involve— (i) Ordering, receiving, and unpacking radioactive materials safely... meters; (iii) Calculating, measuring, and safely preparing patient or human research subject dosages; (iv...

Hospitality Service: Hotel and Restaurant Management and Culinary Arts Curriculum Guide.

ERIC Educational Resources Information Center

Joliet Junior Coll., IL.

This publication contains competency-based materials for hotel/restaurant management and culinary arts. The materials are designed for students to learn from a work station concept by rotating through a variety of real work settings in a hotel/restaurant environment. In addition, the materials indicate whether or not the students have developed…

Tensile, Compression, Open-Hole Compression and Double Cantilever Beam Fracture Toughness Testing of Multiple NASA Langley Research Center Composite Materials

NASA Technical Reports Server (NTRS)

Adams, Donald F.

1999-01-01

The attached data summarizes the work performed by the Composite Materials Research Group at the University of Wyoming funded by the NASA LaRC Research Grant NAG-1-1294. The work consisted primarily of tension, compression, open-hole compression and double cantilever beam fracture toughness testing performed an a variety of NASA LaRC composite materials. Tests were performed at various environmental conditions and pre-conditioning requirements. The primary purpose of this work was to support the LaRC material development efforts. The data summaries are arranged in chronological order from oldest to newest.

Materials science and engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lesuer, D.R.

1997-02-01

During FY-96, work within the Materials Science and Engineering Thrust Area was focused on material modeling. Our motivation for this work is to develop the capability to study the structural response of materials as well as material processing. These capabilities have been applied to a broad range of problems, in support of many programs at Lawrence Livermore National Laboratory. These studies are described in (1) Strength and Fracture Toughness of Material Interfaces; (2) Damage Evolution in Fiber Composite Materials; (3) Flashlamp Envelope Optical Properties and Failure Analysis; (4) Synthesis and Processing of Nanocrystalline Hydroxyapatite; and (5) Room Temperature Creep Compliancemore » of Bulk Kel-E.« less

Effects of Thermally Induced Microcracking on the Quasi Static and Dynamic Response of Salem Limestone

DTIC Science & Technology

2017-06-30

description of a com- monly used material model that is modified in Chapter 5 based on the experimental data found in this work. 2.1 Background The quasi ...materials with varying levels of mi- crocracks. One of the intentions of this work is to establish experimental methods that can be applied to all quasi ...Projectile penetration into concrete target. To show how the experimental data obtained in this work can be used to improve quasi -brittle material

Preparations and properties of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials.

PubMed

Watanabe, Shoji

2008-01-01

This short review describes various types of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials. It is concerned with synthetic additives classified according to their functional groups; silicone compounds, carboxylic acids and dibasic acids, esters, Diels-Alder adducts, various polymers, nitrogen compounds, phosphoric esters, phosphonic acids, and others. Testing methods for water-soluble metal working fluids for aluminum alloy materials are described for a practical application in a laboratory.

Hydrogen isotopes transport parameters in fusion reactor materials

NASA Astrophysics Data System (ADS)

Serra, E.; Benamati, G.; Ogorodnikova, O. V.

1998-06-01

This work presents a review of hydrogen isotopes-materials interactions in various materials of interest for fusion reactors. The relevant parameters cover mainly diffusivity, solubility, trap concentration and energy difference between trap and solution sites. The list of materials includes the martensitic steels (MANET, Batman and F82H-mod.), beryllium, aluminium, beryllium oxide, aluminium oxide, copper, tungsten and molybdenum. Some experimental work on the parameters that describe the surface effects is also mentioned.

Computational Modeling of Multi-Scale Material Features in Cement Paste - An Overview

DTIC Science & Technology

2015-05-25

and concrete ; though commonly used are one of the most complex in terms of material morphology and structure than most materials, for example...across the multiple scales are required. In this paper, recent work from our research group on the nano to continuum level modeling of cementitious...of our research work consisting of, • Molecular Dynamics (MD) modeling for the nano scale features of the cementitious material chemistry. • Micro

Working memory and the design of health materials: a cognitive factors perspective.

PubMed

Wilson, Elizabeth A H; Wolf, Michael S

2009-03-01

Working memory and other supportive cognitive processes involved in learning are reviewed in the context of developing patient education materials. We specifically focus on the impact of certain design factors such as text format and syntax, the inclusion of images, and the choice of modality on individuals' ability to understand and remember health information. A selective review of relevant cognitive and learning theories is discussed with regard to their potential impact on the optimal design of health materials. Working memory is measured as an individual's capacity to hold and manipulate information in active consciousness. It is limited by necessity, and well-designed health materials can effectively minimize extraneous cognitive demands placed on individuals, making working memory resources more available to better process content-related information. Further research is needed to evaluate specific design principles and identify ideal uses of print versus video-based forms of communication for conveying information. The process of developing health materials should account for the cognitive demands that extrinsic factors such as modality place on patients.

Improvement of technical purpose materials performance characteristics with the radio frequency low pressure plasma

NASA Astrophysics Data System (ADS)

Makhotkina, L. Yu; Khristoliubova, V. I.

2017-11-01

The main aim of the work is to solve the actual problem of increasing the competitiveness of tanning products by reducing the prime cost and improving the quality of finished products due to the increased durability of the working elements of tanneries. The impact of the low pressure radio frequency (RF) plasma in the processes of treating for modification of the materials for special purposes is considered in the article. The results of working elements of tanneries and the materials for special purposes sample processing by a RF low pressure plasma are described. As a result of leather materials nano structuring and nano modifying physical, mechanical and hygienic characteristics were increased. Processing of the technical purpose materials allows to increase operational performance of products and extend their lifespan.

On-Board Hydrogen Gas Production System For Stirling Engines

DOEpatents

Johansson, Lennart N.

2004-06-29

A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed. A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed.

Numbers Start Here. Material from the Merseyside and Cheshire Numeracy Lift-Off Project.

ERIC Educational Resources Information Center

Adult Literacy and Basic Skills Unit, London (England).

This skills pack is intended to assist basic numeracy tutors working with adults needing help with prenumber work, number concepts up to 10, time telling, and British money handling. The package includes notes on using the materials provided; materials for use in assessing student skills with respect to color and shape recognition, number…

Improving the sun drying of apricots (Prunus armeniaca) with photo-selective dryer cabinet materials

USDA-ARS?s Scientific Manuscript database

Photo-selective materials have been studied for their effects on the pre-harvest quality of horticultural crops, but little work has been done on potential post-harvest effects. The aim of this work was to characterize the effects of 5 different photo-selective acrylic materials (used as the lid to...

Progress in development of coated indexable cemented carbide inserts for machining of iron based work piece materials

NASA Astrophysics Data System (ADS)

Czettl, C.; Pohler, M.

2016-03-01

Increasing demands on material properties of iron based work piece materials, e.g. for the turbine industry, complicate the machining process and reduce the lifetime of the cutting tools. Therefore, improved tool solutions, adapted to the requirements of the desired application have to be developed. Especially, the interplay of macro- and micro geometry, substrate material, coating and post treatment processes is crucial for the durability of modern high performance tool solutions. Improved and novel analytical methods allow a detailed understanding of material properties responsible for the wear behaviour of the tools. Those support the knowledge based development of tailored cutting materials for selected applications. One important factor for such a solution is the proper choice of coating material, which can be synthesized by physical or chemical vapor deposition techniques. Within this work an overview of state-of-the-art coated carbide grades is presented and application examples are shown to demonstrate their high efficiency. Machining processes for a material range from cast iron, low carbon steels to high alloyed steels are covered.

Assessment of workplace air concentrations of formaldehyde during and before working hours in medical facilities.

PubMed

Higashikubo, Ichiro; Miyauchi, Hiroyuki; Yoshida, Satoru; Tanaka, Shinsuke; Matsuoka, Mitsunori; Arito, Heihachiro; Araki, Akihiro; Shimizu, Hidesuke; Sakurai, Haruhiko

2017-04-07

Workplace air concentrations of formaldehyde (FA) in medical facilities where FA and FA-treated organs were stored and handled were measured before and during working hours and assessed by the official method specified by Work Environment Measurement Law. Sixty-percent of the total facilities examined were judged as inappropriately controlled work environment. The concentrations of FA before working hours by spot sampling were found to exceed 0.1 ppm in some facilities, and tended to increase with increasing volume of containers storing FA and FA-treated materials. Regression analysis revealed that logarithmic concentrations of FA during working hours by the Law-specified analytical method were highly correlated with those before working hours by spot sampling, suggesting the importance for appropriate storing methods of FA and FA-treated materials. The concentrations of FA during working hours are considered to be lowered by effective ventilation of FA-contaminated workplace air and appropriate storage of FA and FA-treated materials in plastic containers in the medical facilities. In particular, such improvement by a local exhaust ventilation system and tightly-sealed containment of FA-treated material were urgently needed for the dissecting room where FA-treated cadavers were prepared and handled for a gross anatomy course in a medical school.

Nanophase and Composite Optical Materials

NASA Technical Reports Server (NTRS)

2003-01-01

This talk will focus on accomplishments, current developments, and future directions of our work on composite optical materials for microgravity science and space exploration. This research spans the order parameter from quasi-fractal structures such as sol-gels and other aggregated or porous media, to statistically random cluster media such as metal colloids, to highly ordered materials such as layered media and photonic bandgap materials. The common focus is on flexible materials that can be used to produce composite or artificial materials with superior optical properties that could not be achieved with homogeneous materials. Applications of this work to NASA exploration goals such as terraforming, biosensors, solar sails, solar cells, and vehicle health monitoring, will be discussed.

Understanding the Effect of Plastic Deformation on Elastic Modulus of Metals Based on a Percolation Model with Electron Work Function

NASA Astrophysics Data System (ADS)

Li, Qingda; Hua, Guomin; Lu, Hao; Yu, Bin; Li, D. Y.

2018-05-01

The elastic modulus of materials is usually treated as a constant in engineering applications. However, plastic deformation may result in changes in the elastic modulus of metallic materials. Using brass, aluminum, and low-carbon steel as sample materials, it is demonstrated that plastic deformation decreased the elastic modulus of the materials by 10% to 20%. A percolation model incorporating the electron work function is proposed to correlate such plastic-strain-induced variations in the elastic modulus to corresponding changes in the electron work function. Efforts are made to understand the observed phenomenon on an electronic basis. The obtained experimental results are consistent with the theoretical analysis.

Background studies in support of a feasibility assessment on the use of copper-base materials for nuclear waste packages in a repository in tuff

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Konynenburg, R.A.; Kundig, K.J.A.; Lyman, W.S.

1990-06-01

This report combines six work units performed in FY`85--86 by the Copper Development Association and the International Copper Research Association under contract with the University of California. The work includes literature surveys and state-of-the-art summaries on several considerations influencing the feasibility of the use of copper-base materials for fabricating high-level nuclear waste packages for the proposed repository in tuff rock at Yucca Mountain, Nevada. The general conclusion from this work was that copper-base materials are viable candidates for inclusion in the materials selection process for this application. 55 refs., 48 figs., 22 tabs.

Methods and apparatuses for cutting, abrading, and drilling

DOEpatents

Bingham, Dennis N.; Swainston, Richard C.; Palmer, Gary L.; Ferguson, Russell L.

2001-01-01

Methods and apparatuses for treating a surface of a work piece are described. In one implementation, a laser delivery subsystem is configured to direct a laser beam toward a treatment zone on a work surface. A cryogenic material delivery subsystem is operably coupled with the laser delivery subsystem and is configured to direct a stream comprising cryogenic material toward the treatment zone. Both the laser beam and stream cooperate to treat material of the work surface within the treatment zone. In one aspect, a nozzle assembly provides the laser beam and stream of cryogenic material along a common flow axis. In another aspect, the laser beam and stream are provided along different axes.

Evaluation and recommendations for work group integration within the Materials and Processes Lab

NASA Technical Reports Server (NTRS)

Farrington, Phillip A.

1992-01-01

The goal of this study was to evaluate and make recommendations for improving the level of integration of several work groups within the Materials and Processes Lab at the Marshall Space Flight Center. This evaluation has uncovered a variety of projects that could improve the efficiency and operation of the work groups as well as the overall integration of the system. In addition, this study provides the foundation for specification of a computer integrated manufacturing test bed environment in the Materials and Processes Lab.

Advanced Industrial Materials Program

NASA Astrophysics Data System (ADS)

Stooksbury, F.

1994-06-01

The mission of the Advanced Industrial Materials (AIM) program is to commercialize new/improved materials and materials processing methods that will improve energy efficiency, productivity, and competitiveness. Program investigators in the DOE national laboratories are working with about 100 companies, including 15 partners in CRDA's. Work is being done on intermetallic alloys, ceramic composites, metal composites, polymers, engineered porous materials, and surface modification. The program supports other efforts in the Office of Industrial Technologies to assist the energy-consuming process industries. The aim of the AIM program is to bring materials from basic research to industrial application to strengthen the competitive position of US industry and save energy.

Instructional Techniques for Increasing the Mathematics Competencies of Young Children: Teacher/Assistant Teacher Staff Development Materials.

ERIC Educational Resources Information Center

Mississippi State Dept. of Education, Jackson. Bureau of School Improvement.

These training materials are designed to stress the importance of a close relationship between concepts and skills when teaching mathematics to young children, to present material on the important area of problem-solving, and to encourage adults to use a wide range of appropriate techniques in evaluating their work and children's work in…

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding Computational Analyses

DTIC Science & Technology

2011-12-30

which reduces the need for expensive post-weld machining; and (g) low environmental impact . However, some disadvantages of the FSW process have also...next set to that of AISI- H13 , a hot-worked tool steel, frequently used as the FSW-tool material (Ref 16). The work-piece material is assumed to be

Working memory training to improve speech perception in noise across languages

PubMed Central

Ingvalson, Erin M.; Dhar, Sumitrajit; Wong, Patrick C. M.; Liu, Hanjun

2015-01-01

Working memory capacity has been linked to performance on many higher cognitive tasks, including the ability to perceive speech in noise. Current efforts to train working memory have demonstrated that working memory performance can be improved, suggesting that working memory training may lead to improved speech perception in noise. A further advantage of working memory training to improve speech perception in noise is that working memory training materials are often simple, such as letters or digits, making them easily translatable across languages. The current effort tested the hypothesis that working memory training would be associated with improved speech perception in noise and that materials would easily translate across languages. Native Mandarin Chinese and native English speakers completed ten days of reversed digit span training. Reading span and speech perception in noise both significantly improved following training, whereas untrained controls showed no gains. These data suggest that working memory training may be used to improve listeners' speech perception in noise and that the materials may be quickly adapted to a wide variety of listeners. PMID:26093435

Working memory training to improve speech perception in noise across languages.

PubMed

Ingvalson, Erin M; Dhar, Sumitrajit; Wong, Patrick C M; Liu, Hanjun

2015-06-01

Working memory capacity has been linked to performance on many higher cognitive tasks, including the ability to perceive speech in noise. Current efforts to train working memory have demonstrated that working memory performance can be improved, suggesting that working memory training may lead to improved speech perception in noise. A further advantage of working memory training to improve speech perception in noise is that working memory training materials are often simple, such as letters or digits, making them easily translatable across languages. The current effort tested the hypothesis that working memory training would be associated with improved speech perception in noise and that materials would easily translate across languages. Native Mandarin Chinese and native English speakers completed ten days of reversed digit span training. Reading span and speech perception in noise both significantly improved following training, whereas untrained controls showed no gains. These data suggest that working memory training may be used to improve listeners' speech perception in noise and that the materials may be quickly adapted to a wide variety of listeners.

Working memory capacity predicts listwise directed forgetting in adults and children.

PubMed

Aslan, Alp; Zellner, Martina; Bäuml, Karl-Heinz T

2010-05-01

In listwise directed forgetting, participants are cued to forget previously studied material and to learn new material instead. Such cueing typically leads to forgetting of the first set of material and to memory enhancement of the second. The present study examined the role of working memory capacity in adults' and children's listwise directed forgetting. Working memory capacity was assessed with complex span tasks. In Experiment 1 working memory capacity predicted young adults' directed-forgetting performance, demonstrating a positive relationship between working memory capacity and each of the two directed-forgetting effects. In Experiment 2 we replicated the finding with a sample of first and a sample of fourth-grade children, and additionally showed that working memory capacity can account for age-related increases in directed-forgetting efficiency between the two age groups. Following the view that directed forgetting is mediated by inhibition of the first encoded list, the results support the proposal of a close link between working memory capacity and inhibitory function.

Effect of nanoscale size and medium on metal work function in oleylamine-capped gold nanocrystals

NASA Astrophysics Data System (ADS)

Abdellatif, M. H.; Ghosh, S.; Liakos, I.; Scarpellini, A.; Marras, S.; Diaspro, A.; Salerno, M.

2016-02-01

The work function is an important material property with several applications in photonics and optoelectronics. We aimed to characterize the work function of clusters resulting from gold nanocrystals capped with oleylamine surfactant and drop-casted onto gold substrate. We used scanning Kelvin probe microscopy to investigate the work function, and complemented our study mainly with X-ray diffraction and X-ray photoelectron spectroscopy. The oleylamine works as an electron blocking layer through which the electrical conduction takes place by tunneling effect. The surface potential appears to depend on the size of the clusters, which can be ascribed to their difference in effective work function with the substrate. The charge state of gold clusters is discussed in comparison with theory, and their capacitance is calculated from a semi-analytical equation. The results suggest that at the nanoscale the work function is not an intrinsic property of a material but rather depends on the size and morphology of the clusters, including also effects of the surrounding materials.

[Present state and problems of work environment control in the workplaces using hazardous materials based on the Occupational Safety and Health Act in Japan].

PubMed

Hori, Hajime

2013-10-01

In Japan, working environment measurement is prescribed in the designated workplaces using hazardous materials. Measurements should be carried out periodically and countermeasures are performed depending on the results. By introducing such a system, working environments have remarkably improved. However, in the designated workplaces, measurements should be continued even in work environments found safe. On the other hand, measurement need not be obliged for non-designated workplaces even if hazardous materials are utilized.In the United States of America and many European countries, work environment management and work management are carried out by measuring personal exposure concentrations. In Japan, the Ministry of Health, Labour and Welfare is now discussing the introduction of personal exposure monitoring. However, many problems exist to prevent the simple introduction of American and European methods. This paper describes the brief history, present state and problems of work environment control in Japan, comparing with the systems of American and European countries.

Accuracy of a new ring-opening metathesis elastomeric dental impression material with spray and immersion disinfection.

PubMed

Kronström, Mats H; Johnson, Glen H; Hompesch, Richard W

2010-01-01

A new elastomeric impression material has been formulated with a ring-opening metathesis chemistry. In addition to other properties of clinical significance, the impression accuracy must be confirmed. The purpose of this study was to compare the accuracy of the new elastomeric impression material with vinyl polysiloxane and polyether following both spray and immersion disinfection. Impressions of a modified dentoform with a stainless steel crown preparation in the lower right quadrant were made, and type IV gypsum working casts and dies were formed. Anteroposterior (AP), cross-arch (CA), buccolingual (BL), mesiodistal (MD), occlusogingivobuccal (OGB), and occlusogingivolingual (OGL) dimensions were measured using a microscope. Working cast and die dimensions were compared to those of the master model. The impression materials were a newly formulated, ring-opening metathesis-polymerization impression material (ROMP Cartridge Tray and ROMP Volume Wash), vinyl polysiloxane (VPS, Aquasil Ultra Monophase/LV), and a polyether (PE, Impregum Penta Soft/Permadyne Garant L). Fifteen impressions with each material were made, of which 5 were disinfected by spray for 10 minutes (CaviCide), 5 were disinfected by immersion for 90 minutes (ProCide D), and 5 were not disinfected. There were significant cross-product interactions with a 2-way ANOVA, so a 1-way ANOVA and Dunnett's T3 multiple comparison test were used to compare the dimensional changes of the 3 impression materials, by disinfection status and for each location (alpha=.05). For ROMP, there were no significant differences from the master, for any dimension, when comparing the control and 2 disinfectant conditions. No significant differences were detected among the 3 impression materials for CA, BL, and MD. The working die dimensions of OGB and OGL for VPS with immersion disinfection were significantly shorter than with PE and ROMP (P<.05). Overall, the AP dimension was more accurate than CA, and the BL of working dies was 0.040 mm greater in diameter than MD. The accuracy of gypsum working casts and working dies from the new and 2 existing types of impression material were similar, for both spray and immersion disinfection. Judicious application of a die spacer can compensate for the small differences observed. VPS may require additional laboratory accommodation to compensate for a shorter working die. Copyright 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Experimental Verification of an Instrument to Test Flooring Materials

NASA Astrophysics Data System (ADS)

Philip, Rony; Löfgren, Hans, Dr

2018-02-01

The focus of this work is to validate the fluid model with different flooring materials and the measurements of an instrument to test flooring materials and its force attenuating capabilities using mathematical models to describe the signature and coefficients of the floor. The main contribution of the present work focus on the development of a mathematical fluid model for floors. The aim of the thesis was to analyze, compare different floor materials and to study the linear dynamics of falling impacts on floors. The impact of the hammer during a fall is captured by an accelerometer and response is collected using a picoscope. The collected data was analyzed using matlab least square method which is coded as per the fluid model. The finding from this thesis showed that the fluid model works with more elastic model but it doesn’t work for rigid materials like wood. The importance of parameters like velocity, mass, energy loss and other coefficients of floor which influences the model during the impact of falling on floors were identified and a standardized testing method was set.

Liquid-assisted laser ablation of advanced ceramics and glass-ceramic materials

NASA Astrophysics Data System (ADS)

Garcia-Giron, A.; Sola, D.; Peña, J. I.

2016-02-01

In this work, results obtained by laser ablation of advanced ceramics and glass-ceramic materials assisted by liquids are reported. A Q-switched Nd:YAG laser at its fundamental wavelength of 1064 nm with pulse-width in the nanosecond range was used to machine the materials, which were immersed in water and ethylene glycol. Variation in geometrical parameters, morphology, and ablation yields were studied by using the same laser working conditions. It was observed that machined depth and removed volume depended on the thermal, optical, and mechanical features of the processed materials as well as on the properties of the surrounding medium in which the laser processing was carried out. Variation in ablation yields was studied in function of the liquid used to assist the laser process and related to refractive index and viscosity. Material features and working conditions were also related to the obtained results in order to correlate ablation parameters with respect to the hardness of the processed materials.

[Precarious matters. The radium economy, episteme of risk and the emergence of tracer technique in national socialism].

PubMed

von Schwerin, Alexander

2009-01-01

Following the traces of radioactive material is--as scholars have recently shown--a valuable historical approach in order to evaluate the material 'factor' of science in action. Even though the origins of materials like radium and artificial isotopes are quite different, their circulation is interconnected. A material pathway can be drawn from the radium industry to the scientific rise of artificial isotopes as indicator substances in the 1930s, continuing to the building of networks by German scientists working for the war efforts. Also, this pathway reveals the role of radiation protection in establishing that material culture. Finally, the dynamics of material traces and institutional linkages is shown by the tracer work of biophysicists and radiation biologists working at the Genetic Department of the Kaiser Wilhelm Institute for Brain Research in Berlin and at the Institut de Chimie Nucléaire at Paris, which at that time was occupied by German troops.

Generational changes in materialism and work centrality, 1976-2007: associations with temporal changes in societal insecurity and materialistic role modeling.

PubMed

Twenge, Jean M; Kasser, Tim

2013-07-01

We examined whether culture-level indices of threat, instability, and materialistic modeling were linked to the materialistic values of American 12th graders between 1976 and 2007 (N = 355,296). Youth materialism (such as the importance of money and of owning expensive material items) increased over the generations, peaking in the late 1980s to early 1990s with Generation X and then staying at historically high levels for Millennials (GenMe). Societal instability and disconnection (e.g., unemployment, divorce) and social modeling (e.g., advertising spending) had both contemporaneous and lagged associations with higher levels of materialism, with advertising most influential during adolescence and instability during childhood. Societal-level living standards during childhood predicted materialism 10 years later. When materialistic values increased, work centrality steadily declined, suggesting a growing discrepancy between the desire for material rewards and the willingness to do the work usually required to earn them.

The Entrepreneurial Training Center (ETC): A School-to-Work Transition Model Adapted for Out-of-School Adult Learners. ETC Methods and Materials Resource Book.

ERIC Educational Resources Information Center

Sherow, Sheila M.; Scrimshaw, Roberta

This resource book provides materials and methods for a model Entrepreneurship Training Center (ETC) school-to-work program for rural out-of-school adults. Introductory materials include learning goals within ETC's four curriculum areas, instructional methods, and introduction to key concepts. The remainder of the book is divided into four…

Seminar on the Acquisition of Latin American Library Materials (13th, Lawrence, Kansas, June 20-22, 1968). Final Report and Working Papers. Vol. II.

ERIC Educational Resources Information Center

Jordan, Alma; Rovira, Carmen

The eight working papers used as documentation for the Thirteenth Seminar are included in volume II. They are: (1) "Progress Report on the Seminars on the Acquisition of Latin American Library Materials, 1968;" (2) "Significant Acquisitions of Latin American Material by U.S. Libraries, 1967/68;" (3) "A Report of…

Health Promotion at the Construction Work Site: The Lunch Truck Pilot Study.

PubMed

Caban-Martinez, Alberto J; Moore, Kevin J; Clarke, Tainya C; Davila, Evelyn P; Clark, John D; Lee, David J; Fleming, Lora E

2018-04-01

The transient nature of construction work makes it difficult to conduct longitudinal worksite-based health promotion activities. As part of a workplace health assessment pilot study, we worked with a commercial lunch truck company to disseminate four types of health education materials including cancer screening, workplace injury prevention, fruit and vegetable consumption, and smoking cessation to construction workers purchasing food items from the truck during their job breaks. Two weeks following the worksite assessment, we followed up with these workers to ascertain their use of the health promotion materials. Of the 54 workers surveyed, 83% reported reviewing and sharing the cancer screening materials with their families, whereas 44% discussed the cancer screening materials with coworkers. Similar proportions of workers reviewed, shared, and discussed the other health promotion materials with their family. Lunch trucks may be an effective strategy and delivery method for educating construction workers on healthy behaviors and injury prevention practices.

Combined Characterization of the Time Response of Impression Materials via Traditional and FTIR Measurements

PubMed Central

Derchi, Giacomo; Manca, Enrico; Shayganpour, Amirreza; Barone, Antonio; Diaspro, Alberto; Salerno, Marco

2015-01-01

We investigated the temporal response of four dental impression materials, namely three siloxanes (Imprint 4, Flexitime, Aquasil) and one polyether (Impregum). The null hypothesis was that the nominal working times are confirmed by instrumental laboratory tests. We also aimed to identify alternative techniques with strong physical-chemical background for the assessment of temporal response. Traditional characterization was carried out by shark fin test device and durometer at both ambient and body temperature. Additionally, Fourier-transform infrared spectroscopy was performed at room temperature. From shark fin height and Shore hardness versus time the working time and the setting time of the materials were evaluated, respectively. These were in reasonable agreement with the nominal values, except for Impregum, which showed longer working time. Spectroscopy confirmed the different character of the two types of materials, and provided for Imprint 4 and Aquasil an independent evaluation of both evolution times, consistent with the results of the other techniques. Shark fin test and durometer measurements showed deviations in setting time, low sensitivity to temperature for Flexitime, and longer working time at higher temperature for Impregum. Deviations of working time appear in operating conditions from what specified by the manufacturers. Fourier-transform infrared spectroscopy can provide insight in the correlation between material properties and their composition and structure.

48 CFR 31.205-26 - Material costs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Material costs. 31.205-26....205-26 Material costs. (a) Material costs include the costs of such items as raw materials, parts... material costs, the contractor shall consider reasonable overruns, spoilage, or defective work (unless...

48 CFR 31.205-26 - Material costs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Material costs. 31.205-26....205-26 Material costs. (a) Material costs include the costs of such items as raw materials, parts... material costs, the contractor shall consider reasonable overruns, spoilage, or defective work (unless...

Seminar on the Acquisition of Latin American Library Materials (15th, Toronto, Ontario, Canada, June 23-26, 1970). Final Report and Working Papers, Volume II.

ERIC Educational Resources Information Center

Benson, Susan Shattuck: Bresie, Mayellen

Volume 2 contains 13 working papers from the 15th Seminar on Acquisition of Latin American Library Materials. The papers are: (1) A Report on Bibliographic Activities; (2) Microfilm Projects Newsletter; (3) Role of Latin American Legal Material in the Social Science Research Library; (4) A description of sources for Legal and Social Science…

Draft Site Management and Monitoring Plan for Corpus Christi Maintenance and New Work Ocean Dredged Material Disposal Site

EPA Pesticide Factsheets

USEPA Region 6 and the US Army Corps of Engineers submit for public comment the Draft Site Management and Monitoring Plan for Corpus Christi Maintenance and New Work Ocean Dredged Material Disposal Site

CHARACTERISTICS OF FLORIDA FILL MATERIALS AND SOILS 1990

EPA Science Inventory

The report gives results of laboratory work by the University of Florida in support of the Foundation Fill Data Base project of the Foundation Fill Materials Specifications Task Area of the Florida Radon Research Program (FRRP). Work included determination of radon concentrations...

Detection and drug delivery from superhydrophobic materials

NASA Astrophysics Data System (ADS)

Falde, Eric John

The wetting of a rough material is controlled by surface chemistry and morphology, the liquid phase, solutes, and surfactants that affect the surface tension with the gas phase, and environmental conditions such as temperature and pressure. Materials with high (>150°) apparent contact angles are known as superhydrophobic and are very resistant to wetting. However, in complex biological mixtures eventually protein adsorbs, fouling the surface and facilitating wetting on time scales from seconds to months. The work here uses the partially-wetted (Cassie-Baxter) to fully-wetted (Wenzel) state transition to control drug delivery and to perform surfactant detection via surface tension using hydrophobic and superhydrophobic materials. First there is an overview of the physics of the non-wetting state and the transition to wetting. Then there is a review of how wetting can be controlled by outside stimuli and applications of these materials. Next there is work presented on controlling drug release using superhydrophobic materials with controlled wetting rates, with both in vitro and in vivo results. Then there is work on developing a sensor based on this wetting state transition and its applications toward detecting solute levels in biological fluids for point-of-care diagnosis. Finally, there is work presented on using these sensors for detecting the alcohol content in wine and spirits.

Painting with Clay: A Study of the Masters

ERIC Educational Resources Information Center

Skophammer, Karen

2010-01-01

Plasticine clay is a bendable material that is easily manipulated by students of all ages. It is a great material to work with because it does not dry out from day to day, so high-school students can work on an extended project. They do not have to worry about the clay drying and cracking, and the entire work of art does not have to be completed…

Fourth Collaborative Materials Exercise of the Nuclear Forensics International Technical Working Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwantes, J. M.; Marsden, O.; Reilly, D.

Abstract The Nuclear Forensics International Technical Working Group is a community of nuclear forensic practitioners who respond to incidents involving nuclear and other radioactive material out of regulatory control. The Group is dedicated to advancing nuclear forensic science in part through periodic participation in materials exercises. The Group completed its fourth Collaborative Materials Exercise in 2015 in which laboratories from 15 countries and one multinational organization analyzed three samples of special nuclear material in support of a mock nuclear forensic investigation. This special section of the Journal for Radioanalytical and Nuclear Chemistry is devoted to summarizing highlights from this exercise.

Optical materials and films applied in industrial lasers

NASA Astrophysics Data System (ADS)

Zhang, Peng; Liu, Shengyong

1999-09-01

Optical materials and films are often used in industrial lasers. Most of industrial lasers work at visible spectrum and near-infrared spectrum. Only CO2 laser works at far- infrared region (10.6 micrometers ). The optical materials and films are categorized in this article, and the properties of the materials and films are related. From visible to infrared spectrum, many optical materials can be used: K9 glass, fused silica, germanium, gallium arsenide, zinc selenide, silicon, copper, and so on. Optical films for lasers include reflection coating, antireflection coating, edge filter, VRM (variable reflectance mirror) coating and polarizer. The characteristic and application of them will be introduced.

Phosphorescent Organic Light-Emitting Devices: Working Principle and Iridium Based Emitter Materials

PubMed Central

Kappaun, Stefan; Slugovc, Christian; List, Emil J. W.

2008-01-01

Even though organic light-emitting device (OLED) technology has evolved to a point where it is now an important competitor to liquid crystal displays (LCDs), further scientific efforts devoted to the design, engineering and fabrication of OLEDs are required for complete commercialization of this technology. Along these lines, the present work reviews the essentials of OLED technology putting special focus on the general working principle of single and multilayer OLEDs, fluorescent and phosphorescent emitter materials as well as transfer processes in host materials doped with phosphorescent dyes. Moreover, as a prototypical example of phosphorescent emitter materials, a brief discussion of homo- and heteroleptic iridium(III) complexes is enclosed concentrating on their synthesis, photophysical properties and approaches for realizing iridium based phosphorescent polymers. PMID:19325819

40 CFR 466.30 - Applicability; description of the aluminum basis material subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... aluminum basis material subcategory. 466.30 Section 466.30 Protection of Environment ENVIRONMENTAL... Aluminum Basis Material Subcategory § 466.30 Applicability; description of the aluminum basis material... into publicly owned treatment works from porcelain enameling of aluminum basis materials. ...

40 CFR 466.40 - Applicability; description of the copper basis material subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... copper basis material subcategory. 466.40 Section 466.40 Protection of Environment ENVIRONMENTAL... Copper Basis Material Subcategory § 466.40 Applicability; description of the copper basis material... into publicly owned treatment works from porcelain enameling of copper basis materials. ...

40 CFR 466.40 - Applicability; description of the copper basis material subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... copper basis material subcategory. 466.40 Section 466.40 Protection of Environment ENVIRONMENTAL... Copper Basis Material Subcategory § 466.40 Applicability; description of the copper basis material... into publicly owned treatment works from porcelain enameling of copper basis materials. ...

Material engineering and fabrication experiences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Havn, T.

1995-10-01

Material selection for hydrocarbon and sea water systems is shortly described and experiences are explained. The risk of external stress corrosion cracking is discussed. Same is the need for isolation pipe spools to avoid galvanic corrosion. Possible corrosion as result of hot work reduction on platform modification work is discussed. Benefit from positive material identification is explained and the solution of a weld problem due to mix-up of filler material is shown. Experiences with cold bending and subsea material engineering are discussed and recommendations are given. Fracture mechanic techniques with purpose of avoiding costly replacement and repair welding are shownmore » by two examples. At the end the new cost reduction trend of using performance based specifications is shortly discussed with respect to material requirements.« less

Enhancing Women's Undergraduate Experience in Physics and Chemistry Through a PUI/MRSEC Collaboration Emphasizing Materials Research

NASA Astrophysics Data System (ADS)

Goldberg, Velda; Malliaras, George; Schember, Helene; Singhota, Nevjinder

2002-04-01

This three-year collaboration between a predominately undergraduate women's college (Simmons College) and a NSF-supported Materials Research Science and Engineering Center (the Cornell Center for Materials Research (CCMR)) provides opportunities for physics and chemistry students to participate in materials-related research throughout their undergraduate careers, have access to sophisticated instrumentation, and gain related work experience in industrial settings. As part of the project, undergraduate students are involved in all aspects of a collaborative Simmons/Cornell research program concentrating on degradation processes in electroluminescent materials. This work is particularly interesting because an understanding and control of these processes will ultimately influence the use of these materials in various types of consumer products.

Thermodynamic analysis of a thermal storage unit under the influence of nano-particles added to the phase change material and/or the working fluid

NASA Astrophysics Data System (ADS)

Abolghasemi, Mehran; Keshavarz, Ali; Mehrabian, Mozaffar Ali

2012-11-01

The thermal storage unit consists of two concentric cylinders where the working fluid flows through the internal cylinder and the annulus is filled with a phase change material. The system carries out a cyclic operation; each cycle consists of two processes. In the charging process the hot working fluid enters the internal cylinder and transfers heat to the phase change material. In the discharging process the cold working fluid enters the internal cylinder and absorbs heat from the phase change material. The differential equations governing the heat transfer between the two media are solved numerically. The numerical results are compared with the experimental results available in the literature. The performance of an energy storage unit is directly related to the thermal conductivity of nano-particles. The energy consumption of a residential unit whose energy is supplied by a thermal storage system can be reduced by 43 % when using nano-particles.

Investigation of Natural Radioactivity in a Monazite Processing Plant in Japan.

PubMed

Iwaoka, Kazuki; Yajima, Kazuaki; Suzuki, Toshikazu; Yonehara, Hidenori; Hosoda, Masahiro; Tokonami, Shinji; Kanda, Reiko

2017-09-01

Monazite is a naturally occurring radioactive material that is processed for use in a variety of domestic applications. At present, there is little information available on potential radiation doses experienced by people working with monazite. The ambient dose rate and activity concentration of natural radionuclides in raw materials, products, and dust in work sites as well as the Rn and Rn concentrations in work sites were measured in a monazite processing plant in Japan. Dose estimations for plant workers were also conducted. The activity concentration of the U series in raw materials and products for the monazite processing plant was found to be higher than the relevant values described in the International Atomic Energy Agency Safety Standards. The ambient dose rates in the raw material yard were higher than those in other work sites. Moreover, the activity concentrations of dust in the milling site were higher than those in other work sites. The Rn concentrations in all work sites were almost the same as those in regular indoor environments in Japan. The Rn concentrations in all work sites were much higher than those in regular indoor environments in Japan. The maximum value of the effective dose for workers was 0.62 mSv y, which is lower than the reference level range (1-20 mSv y) for abnormally high levels of natural background radiation published in the International Commission of Radiological Protection Publication 103.

An Overview of Promising Grades of Tool Materials Based on the Analysis of their Physical-Mechanical Characteristics

NASA Astrophysics Data System (ADS)

Kudryashov, E. A.; Smirnov, I. M.; Grishin, D. V.; Khizhnyak, N. A.

2018-06-01

The work is aimed at selecting a promising grade of a tool material, whose physical-mechanical characteristics would allow using it for processing the surfaces of discontinuous parts in the presence of shock loads. An analysis of the physical-mechanical characteristics of most common tool materials is performed and the data on a possible provision of the metal-working processes with promising composite grades are presented.

Device for providing high-intensity ion or electron beam

DOEpatents

McClanahan, Edwin D.; Moss, Ronald W.

1977-01-01

A thin film of a low-thermionic-work-function material is maintained on the cathode of a device for producing a high-current, low-pressure gas discharge by means of sputter deposition from an auxiliary electrode. The auxiliary electrode includes a surface with a low-work-function material, such as thorium, uranium, plutonium or one of the rare earth elements, facing the cathode but at a disposition and electrical potential so as to extract ions from the gas discharge and sputter the low-work-function material onto the cathode. By continuously replenishing the cathode film, high thermionic emissions and ion plasmas can be realized and maintained over extended operating periods.

Measuring the Coefficient of Restitution and More: A Simple Experiment to Promote Students' Critical Thinking and Autonomous Work

ERIC Educational Resources Information Center

González, Manuel Á.; González, Miguel Á.; Vegas, Jesús; Llamas, César

2017-01-01

A simple experiment on the determination of the coefficient of restitution of different materials is taken as the basis of an extendable work that can be done by students in an autonomous way. On the whole, the work described in this paper would involve concepts of kinematics, materials science, air drag and buoyancy, and would help students to…

Usewear studies of flint tools with microPIXE and microRBS

NASA Astrophysics Data System (ADS)

Christensen, Marianne; Grime, Geoff; Menu, Michel; Walter, Philippe

1993-05-01

The use of ancient stone tools leaves a polish (usewear) on the cutting edge which can be studied to determine the material the tool had worked during its use. The film is formed by high pressure intrusion of the worked material into the microcavities of the chipped flint surface and so the film can also be analysed directly to determine the nature of the worked material. This paper describes the analysis of experimental flint tools which had worked bone and ivory using microbeam PIXE and RBS. It is found that PIXE used simultaneously with RBS allows the thickness and composition of the film to be determined and ivory distinguished from bone while RBS mapping allows the three-dimensional structure of the film to be determined.

Analytic Thermoelectric Couple Modeling: Variable Material Properties and Transient Operation

NASA Technical Reports Server (NTRS)

Mackey, Jonathan A.; Sehirlioglu, Alp; Dynys, Fred

2015-01-01

To gain a deeper understanding of the operation of a thermoelectric couple a set of analytic solutions have been derived for a variable material property couple and a transient couple. Using an analytic approach, as opposed to commonly used numerical techniques, results in a set of useful design guidelines. These guidelines can serve as useful starting conditions for further numerical studies, or can serve as design rules for lab built couples. The analytic modeling considers two cases and accounts for 1) material properties which vary with temperature and 2) transient operation of a couple. The variable material property case was handled by means of an asymptotic expansion, which allows for insight into the influence of temperature dependence on different material properties. The variable property work demonstrated the important fact that materials with identical average Figure of Merits can lead to different conversion efficiencies due to temperature dependence of the properties. The transient couple was investigated through a Greens function approach; several transient boundary conditions were investigated. The transient work introduces several new design considerations which are not captured by the classic steady state analysis. The work helps to assist in designing couples for optimal performance, and also helps assist in material selection.

Z2Pack: Numerical implementation of hybrid Wannier centers for identifying topological materials

NASA Astrophysics Data System (ADS)

Gresch, Dominik; Autès, Gabriel; Yazyev, Oleg V.; Troyer, Matthias; Vanderbilt, David; Bernevig, B. Andrei; Soluyanov, Alexey A.

2017-02-01

The intense theoretical and experimental interest in topological insulators and semimetals has established band structure topology as a fundamental material property. Consequently, identifying band topologies has become an important, but often challenging, problem, with no exhaustive solution at the present time. In this work we compile a series of techniques, some previously known, that allow for a solution to this problem for a large set of the possible band topologies. The method is based on tracking hybrid Wannier charge centers computed for relevant Bloch states, and it works at all levels of materials modeling: continuous k .p models, tight-binding models, and ab initio calculations. We apply the method to compute and identify Chern, Z2, and crystalline topological insulators, as well as topological semimetal phases, using real material examples. Moreover, we provide a numerical implementation of this technique (the Z2Pack software package) that is ideally suited for high-throughput screening of materials databases for compounds with nontrivial topologies. We expect that our work will allow researchers to (a) identify topological materials optimal for experimental probes, (b) classify existing compounds, and (c) reveal materials that host novel, not yet described, topological states.

A Route to Dirac Liquid Theory: A Fermi Liquid Description for Dirac Materials

NASA Astrophysics Data System (ADS)

Gochan, Matthew; Bedell, Kevin

Since the pioneering work developed by L.V. Landau sixty years ago, Fermi Liquid Theory has seen great success in describing interacting Fermi systems. While much interest has been generated over the study of non-Fermi Liquid systems, Fermi Liquid theory serves as a formidable model for many systems and offers a rich amount of of results and insight. The recent classification of Dirac Materials, and the lack of a unifying theoretical framework for them, has motivated our study. Dirac materials are a versatile class of materials in which an abundance of unique physical phenomena can be observed. Such materials are found in all dimensions, with the shared property that their low-energy fermionic excitations behave as massless Dirac fermions and are therefore governed by the Dirac equation. The most popular Dirac material, graphene, is the focus of this work. We present our Fermi Liquid description of Graphene. We find many interesting results, specifically in the transport and dynamics of the system. Additionally, we expand on previous work regarding the Virial Theorem and its impact on the Fermi Liquid parameters in graphene. Finally, we remark on viscoelasticity of Dirac Materials and other unusual results that are consequences of AdS-CFT.

High pressure transport studies on Sb2Te3 and BiSbTe3

NASA Astrophysics Data System (ADS)

Jacobsen, Matthew; Cornelius, Andrew

2008-03-01

Interest regarding the abilities of thermoelectric materials has produced exciting results regarding their properties in the thin-film form [3]. However, little work has been done regarding the pressure tuning of the thermoelectric figure of merit for these materials materials. Some previous work has suggested that it would be useful to investigate this further using pressure tuning [1],[2]. Based upon this interest, facilities have been developed in our laboratory for the study of the relevant properties under high pressure up to near 20 GPa. Results of this work on Sb2Te3 and BiSbTe3 will be presented here from the use of these facilities. [1]Chen, G., Dresselhaus, M.S., Dresselhaus, G., Fleurial, J.-P., and Caillat, T. Recent developments in themoelectric materials. International Materials Reviews, 48, 45-66 (2003). [2]Rowe, D.M. CRC Handbook of Thermoelectric Materials. CRC Press, 1995. [3]Venkatasubramanian, R., Silvola, E., Colpitts, T., and O'Quinn, B. Thin-film thermoelectric devices with high room-temperature figures of merit. Nature, 413, 597-602, 2001.

Research notes : naturally occurring hazardous materials, natural doesn't always equal healthy.

DOT National Transportation Integrated Search

2009-05-01

The ultimate objective of this work is to assure that ODOT maintenance and construction activities take the presence of these hazardous materials into account. In this way, ODOT can protect the health of those who work on ODOT projects and the genera...

Transition: The Key.

ERIC Educational Resources Information Center

Gerweck, Debra R.; Chauza, Phyllis J.

This document consists of materials used in a presentation on the Brown County (Kansas) Vocational Work Program to train students in general work behaviors and skills and to prepare them for paid employment in the community. Introductory materials describe the program's purpose, structure, and objectives. The text of specific regulations governing…

Effect of a worktable position on head and shoulder posture and shoulder muscles in manual material handling.

PubMed

Kim, Min-Hee; Yoo, Won-Gyu

2015-06-05

According to a recent research, manual working with high levels of static contraction, repetitive loads, or extreme working postures involving the neck and shoulder muscles causes an increased risk of neck and shoulder musculoskeletal disorders. We investigated the effects of the forwardly worktable position on head and shoulder angles and shoulder muscle activity in manual material handling tasks. The forward head and shoulder angles and the activity of upper trapezius, levator scapulae, and middle deltoid muscle activities of 15 workers were measured during performing of manual material handling in two tasks that required different forward head and shoulder angles. The second manual material task required a significantly increased forward head and shoulder angle. The upper trapezius and levator scapulae muscle activity in second manual material task was increased significantly compared with first manual material task. The middle deltoid muscle activity in second manual material task was not significantly different compared with first manual material task. Based on this result, the forward head and shoulder angles while performing manual work need to be considered in selection of the forward distance of a worktable form the body. The high level contractions of the neck and shoulder muscles correlated with neck and shoulder pain. Therefore, the forward distance of a worktable can be an important factor in preventing neck and shoulder pain in manual material handling workers.

40 CFR 465.10 - Applicability; description of the steel basis material subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... steel basis material subcategory. 465.10 Section 465.10 Protection of Environment ENVIRONMENTAL... CATEGORY Steel Basis Material Subcategory § 465.10 Applicability; description of the steel basis material... pollutants into publicly owned treatment works from coil coating of steel basis material coils. ...

40 CFR 465.10 - Applicability; description of the steel basis material subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... steel basis material subcategory. 465.10 Section 465.10 Protection of Environment ENVIRONMENTAL... CATEGORY Steel Basis Material Subcategory § 465.10 Applicability; description of the steel basis material... pollutants into publicly owned treatment works from coil coating of steel basis material coils. ...

40 CFR 465.10 - Applicability; description of the steel basis material subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... steel basis material subcategory. 465.10 Section 465.10 Protection of Environment ENVIRONMENTAL... CATEGORY Steel Basis Material Subcategory § 465.10 Applicability; description of the steel basis material... pollutants into publicly owned treatment works from coil coating of steel basis material coils. ...

Energy Conversion Properties of ZnSiP2, a Lattice-Matched Material for Silicon-Based Tandem Photovoltaics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, Aaron D.; Warren, Emily L.; Gorai, Prashun

ZnSiP2 demonstrates promising potential as an optically active material on silicon. There has been a longstanding need for wide band gap materials that can be integrated with Si for tandem photovoltaics and other optoelectronic applications. ZnSiP2 is an inexpensive, earth abundant, wide band gap material that is stable and lattice matched with silicon. This conference proceeding summarizes our PV-relevant work on bulk single crystal ZnSiP2, highlighting the key findings and laying the ground work for integration into Si-based tandem devices.

Materials Research With Neutrons at NIST

PubMed Central

Cappelletti, R. L.; Glinka, C. J.; Krueger, S.; Lindstrom, R. A.; Lynn, J. W.; Prask, H. J.; Prince, E.; Rush, J. J.; Rowe, J. M.; Satija, S. K.; Toby, B. H.; Tsai, A.; Udovic, T. J.

2001-01-01

The NIST Materials Science and Engineering Laboratory works with industry, standards bodies, universities, and other government laboratories to improve the nation’s measurements and standards infrastructure for materials. An increasingly important component of this effort is carried out at the NIST Center for Neutron Research (NCNR), at present the most productive center of its kind in the United States. This article gives a brief historical account of the growth and activities of the Center with examples of its work in major materials research areas and describes the key role the Center can expect to play in future developments. PMID:27500021

A silicon sol-gel approach to the development of forensic blood substitutes: Design Considerations for Research and Training

NASA Astrophysics Data System (ADS)

Stotesbury, Theresa E.

The research and development of synthetic blood substitutes is a reported need within the forensic community. This work contributes to the growing body of knowledge in bloodstain pattern analysis by offering a materials science approach to designing, producing and testing synthetic forensic blood substitutes. A key deliverable from this research is the creation of a robust silicon-based material using the solution-gelation technique that has been validated for controlled passive drip and spatter simulation. The work investigates the physical properties (viscosity, surface tension and density) of forensic blood substitute formulations and describes the similarity in the spreading dynamics of the optimized material to whole human blood. It then explores how blood and other fluids behave in impact simulation using high-speed video analysis and supports the use of the optimized material for spatter simulation. Finally, the work highlights the practical value of the material as an educational tool for both basic and advanced bloodstain experimentation and training.

Analytical, Experimental, and Modelling Studies of Lunar and Terrestrial Rocks

NASA Technical Reports Server (NTRS)

Haskin, Larry A.

1997-01-01

The goal of our research has been to understand the paths and the processes of planetary evolution that produced planetary surface materials as we find them. Most of our work has been on lunar materials and processes. We have done studies that obtain geological knowledge from detailed examination of regolith materials and we have reported implications for future sample-collecting and on-surface robotic sensing missions. Our approach has been to study a suite of materials that we have chosen in order to answer specific geologic questions. We continue this work under NAG5-4172. The foundation of our work has been the study of materials with precise chemical and petrographic analyses, emphasizing analysis for trace chemical elements. We have used quantitative models as tests to account for the chemical compositions and mineralogical properties of the materials in terms of regolith processes and igneous processes. We have done experiments as needed to provide values for geochemical parameters used in the models. Our models take explicitly into account the physical as well as the chemical processes that produced or modified the materials. Our approach to planetary geoscience owes much to our experience in terrestrial geoscience, where samples can be collected in field context and sampling sites revisited if necessary. Through studies of terrestrial analog materials, we have tested our ideas about the origins of lunar materials. We have been mainly concerned with the materials of the lunar highland regolith, their properties, their modes of origin, their provenance, and how to extrapolate from their characteristics to learn about the origin and evolution of the Moon's early igneous crust. From this work a modified model for the Moon's structure and evolution is emerging, one of globally asymmetric differentiation of the crust and mantle to produce a crust consisting mainly of ferroan and magnesian igneous rocks containing on average 70-80% plagioclase, with a large, mafic, trace-element-rich geochemical province, and a regolith that globally contains trace-element-rich material distributed from this province by the Imbrium basin-forming impact. This contrasts with earlier models of a concentrically zoned Moon with a crust of ferroan anorthosite overlying a layer of urKREEP overlying ultramafic cumulates. From this work, we have learned lessons useful for developing strategies for studying regolith materials that help to maximize the information available about both the evolution of the regolith and the igneous differentiation of the planet. We believe these lessons are useful in developing strategies for on-surface geological, mineralogical, and geochemical studies, as well. The main results of our work are given in the following brief summaries of major tasks. Detailed accounts of these results have been submitted in the annual progress reports.

30 CFR 77.1710 - Protective clothing; requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... substances or other materials which might cause injury to the skin. (c) Protective gloves when handling materials or performing work which might cause injury to the hands; however, gloves shall not be worn where... footwear. (f) Snug-fitting clothing when working around moving machinery or equipment. (g) Safety belts and...

30 CFR 77.1710 - Protective clothing; requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... substances or other materials which might cause injury to the skin. (c) Protective gloves when handling materials or performing work which might cause injury to the hands; however, gloves shall not be worn where... footwear. (f) Snug-fitting clothing when working around moving machinery or equipment. (g) Safety belts and...

30 CFR 77.1710 - Protective clothing; requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... substances or other materials which might cause injury to the skin. (c) Protective gloves when handling materials or performing work which might cause injury to the hands; however, gloves shall not be worn where... footwear. (f) Snug-fitting clothing when working around moving machinery or equipment. (g) Safety belts and...

30 CFR 77.1710 - Protective clothing; requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... substances or other materials which might cause injury to the skin. (c) Protective gloves when handling materials or performing work which might cause injury to the hands; however, gloves shall not be worn where... footwear. (f) Snug-fitting clothing when working around moving machinery or equipment. (g) Safety belts and...

48 CFR 52.225-9 - Buy American Act-Construction Materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subcontractor for incorporation into the building or work. The term also includes an item brought to the site preassembled from articles, materials, or supplies. However, emergency life safety systems, such as emergency... building or work and that are produced as complete systems, are evaluated as a single and distinct...

ISO 14624 Series - Space Systems - Safety and Compatibility of Materials Flammability Assessment of Spacecraft Materials

NASA Technical Reports Server (NTRS)

Hirsch, David B.

2007-01-01

A viewgraph presentation on the flammability of spacecraft materials is shown. The topics include: 1) Spacecraft Fire Safety; 2) Materials Flammability Test; 3) Impetus for enhanced materials flammability characterization; 4) Exploration Atmosphere Working Group Recommendations; 5) Approach; and 6) Status of implementation

Fatal hand tool injuries in construction.

PubMed

Trent, R B; Wyant, W D

1990-08-01

Past research on occupational hand tool injuries has generally focused on nonfatal injuries. Most such injuries occur at the point where energy is transferred to the material being worked, eg, at the edge of a saw blade or the point of a drill. Assuming that hand tool injuries that are fatal will differ from nonfatal injuries, 62 Occupation Safety and Health Administration reports were analyzed. Four patterns emerged when the type of contact with energy was used to classify incidents. Fatal injuries occurred when (1) contact was made with energy that supplies power to the hand tool, (2) energy normally transferred to the material being worked is transferred to the worker, (3) workers or materials fall, and (4) potential energy is encountered in the work environment. Analysis showed that almost all such injuries could be prevented by application of existing safe work practices.

Electrochemical removal of material from metallic work

DOEpatents

Csakvary, Tibor; Fromson, Robert E.

1980-05-13

Deburring, polishing, surface forming and the like are carried out by electrochemical machining with conformable electrode means including an electrically conducting and an insulating web. The surface of the work to be processed is covered by a deformable electrically insulating web or cloth which is perforated and conforms with the work. The web is covered by a deformable perforated electrically conducting screen electrode which also conforms with, and is insulated from, the work by the insulating web. An electrolyte is conducted through the electrode and insulating web and along the work through a perforated elastic member which engages the electrode under pressure pressing the electrode and web against the work. High current under low voltage is conducted betwen the electrode and work through the insulator, removing material from the work. Under the pressure of the elastic member, the electrode and insulator continue to conform with the work and the spacing between the electrode and work is maintained constant.

Mixed Dimensional Van der Waals Heterostructures for Opto-Electronics.

NASA Astrophysics Data System (ADS)

Jariwala, Deep

The isolation of a growing number of two-dimensional (2D) materials has inspired worldwide efforts to integrate distinct 2D materials into van der Waals (vdW) heterostructures. While a tremendous amount of research activity has occurred in assembling disparate 2D materials into ``all-2D'' van der Waals heterostructures, this concept is not limited to 2D materials alone. Given that any passivated, dangling bond-free surface will interact with another via vdW forces, the vdW heterostructure concept can be extended to include the integration of 2D materials with non-2D materials that adhere primarily through noncovalent interactions. In the first part of this talk I will present our work on emerging mixed-dimensional (2D + nD, where n is 0, 1 or 3) heterostructure devices performed at Northwestern University. I will present two distinct examples of gate-tunable p-n heterojunctions 1. Single layer n-type MoS2\\ (2D) combined with p-type semiconducting single walled carbon nanotubes (1D) and 2. Single layer MoS2 combined with 0D molecular semiconductor, pentacene. I will present the unique electrical properties, underlying charge transport mechanisms and photocurrent responses in both the above systems using a variety of scanning probe microscopy techniques as well as computational analysis. This work shows that van der Waals interactions are robust across different dimensionalities of materials and can allow fabrication of semiconductor devices with unique geometries and properties unforeseen in bulk semiconductors. Finally, I will briefly discuss our recent work from Caltech on near-unity absorption in atomically-thin photovoltaic devices. This work is supported by the Materials Research Center at Northwestern University, funded by the National Science Foundation (NSF DMR-1121262) and the Resnick Sustainability Institute at Caltech.

Functional Characterization of a Novel Shape Memory Alloy

NASA Astrophysics Data System (ADS)

Collado, M.; Cabás, R.; San Juan, J.; López-Ferreño, I.

2014-07-01

A novel shape memory alloy (SMA) has been developed as an alternative to currently available alloys. This alloy, commercially known by its proprietary brand SMARQ, shows a higher working range of temperatures with respect to the SMA materials used until now in actuators, limited to environment temperatures below 90 °C. SMARQ is a high temperature SMA (HTSMA) based on a fully European material technology and production processes, which allows the manufacture of high quality products, with tuneable transformation temperatures up to 200 °C. Both, material and production processes have been evaluated for its use in space applications. A full characterization test campaign has been completed in order to obtain the material properties and check its suitability to be used as active material in space actuators. In order to perform the functional characterization of the material, it has been considered as the key element of a basic SMA actuator, consisting in the SMA wire and the mechanical and electrical interfaces. The functional tests presented in this work have been focused on the actuator behavior when heated by means of an electrical current. Alloy composition has been adjusted in order to match a transition temperature (As) of +145 °C, which satisfies the application requirements of operating temperatures in the range of -70 and +125 °C. Details of the tests and results of the characterization test campaign, focused in the material unique properties for their use in actuators, will be presented in this work. Some application examples in the field of space mechanisms and actuators, currently under development, will be summarized as part of this work, demonstrating the technology suitability as active material for space actuators.

Sintered wire cesium dispenser photocathode

DOEpatents

Montgomery, Eric J; Ives, R. Lawrence; Falce, Louis R

2014-03-04

A photoelectric cathode has a work function lowering material such as cesium placed into an enclosure which couples a thermal energy from a heater to the work function lowering material. The enclosure directs the work function lowering material in vapor form through a low diffusion layer, through a free space layer, and through a uniform porosity layer, one side of which also forms a photoelectric cathode surface. The low diffusion layer may be formed from sintered powdered metal, such as tungsten, and the uniform porosity layer may be formed from wires which are sintered together to form pores between the wires which are continuous from the a back surface to a front surface which is also the photoelectric surface.

Water-soluble metal working fluids additives derived from the esters of acid anhydrides with higher alcohols for aluminum alloy materials.

PubMed

Yamamoto, Syutaro; Tomoda, Hideyuki; Watanabe, Shoji

2007-01-01

Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short article describes properties of new additives in water-soluble metal working fluids for aluminum alloy materials. Many half esters or diesters were prepared from the reactions of higher alcohols with acid anhydrides. Interestingly, diesters of PTMG (tetrahydrofuran oligomer, MW = 650 and 1000) and polybutylene oxide (MW = 650) with maleic anhydride and succinic anhydride showed both of an excellent anti-corrosion property for aluminum alloy and a good hard water tolerance. The industrial soluble type processing oils including these additives also showed anti-corrosion property and hard water tolerance.

Material condition assessment with eddy current sensors

NASA Technical Reports Server (NTRS)

Goldfine, Neil J. (Inventor); Washabaugh, Andrew P. (Inventor); Sheiretov, Yanko K. (Inventor); Schlicker, Darrell E. (Inventor); Lyons, Robert J. (Inventor); Windoloski, Mark D. (Inventor); Craven, Christopher A. (Inventor); Tsukernik, Vladimir B. (Inventor); Grundy, David C. (Inventor)

2010-01-01

Eddy current sensors and sensor arrays are used for process quality and material condition assessment of conducting materials. In an embodiment, changes in spatially registered high resolution images taken before and after cold work processing reflect the quality of the process, such as intensity and coverage. These images also permit the suppression or removal of local outlier variations. Anisotropy in a material property, such as magnetic permeability or electrical conductivity, can be intentionally introduced and used to assess material condition resulting from an operation, such as a cold work or heat treatment. The anisotropy is determined by sensors that provide directional property measurements. The sensor directionality arises from constructs that use a linear conducting drive segment to impose the magnetic field in a test material. Maintaining the orientation of this drive segment, and associated sense elements, relative to a material edge provides enhanced sensitivity for crack detection at edges.

Challenges and Opportunities in Interdisciplinary Materials Research Experiences for Undergraduates

NASA Astrophysics Data System (ADS)

Vohra, Yogesh; Nordlund, Thomas

2009-03-01

The University of Alabama at Birmingham (UAB) offer a broad range of interdisciplinary materials research experiences to undergraduate students with diverse backgrounds in physics, chemistry, applied mathematics, and engineering. The research projects offered cover a broad range of topics including high pressure physics, microelectronic materials, nano-materials, laser materials, bioceramics and biopolymers, cell-biomaterials interactions, planetary materials, and computer simulation of materials. The students welcome the opportunity to work with an interdisciplinary team of basic science, engineering, and biomedical faculty but the challenge is in learning the key vocabulary for interdisciplinary collaborations, experimental tools, and working in an independent capacity. The career development workshops dealing with the graduate school application process and the entrepreneurial business activities were found to be most effective. The interdisciplinary university wide poster session helped student broaden their horizons in research careers. The synergy of the REU program with other concurrently running high school summer programs on UAB campus will also be discussed.

Nuclear Forensics: Report of the AAAS/APS Working Group

NASA Astrophysics Data System (ADS)

Tannenbaum, Benn

2008-04-01

This report was produced by a Working Group of the American Physical Society's Program on Public Affairs in conjunction with the American Association for the Advancement of Science Center for Science, Technology and Security Policy. The primary purpose of this report is to provide the Congress, U.S. government agencies and other institutions involved in nuclear forensics with a clear unclassified statement of the state of the art of nuclear forensics; an assessment of its potential for preventing and identifying unattributed nuclear attacks; and identification of the policies, resources and human talent to fulfill that potential. In the course of its work, the Working Group observed that nuclear forensics was an essential part of the overall nuclear attribution process, which aims at identifying the origin of unidentified nuclear weapon material and, in the event, an unidentified nuclear explosion. A credible nuclear attribution capability and in particular nuclear forensics capability could deter essential participants in the chain of actors needed to smuggle nuclear weapon material or carry out a nuclear terrorist act and could also encourage states to better secure such materials and weapons. The Working Group also noted that nuclear forensics result would take some time to obtain and that neither internal coordination, nor international arrangements, nor the state of qualified personnel and needed equipment were currently enough to minimize the time needed to reach reliable results in an emergency such as would be caused by a nuclear detonation or the intercept of a weapon-size quantity of material. The Working Group assesses international cooperation to be crucial for forensics to work, since the material would likely come from inadequately documented foreign sources. In addition, international participation, if properly managed, could enhance the credibility of the deterrent effect of attribution. Finally the Working Group notes that the U.S. forensics capability involved a number of agencies and other groups that would have to cooperate rapidly in an emergency and that suitable exercises to ensure such cooperation were needed.

Direct work function measurement by gas phase photoelectron spectroscopy and its application on PbS nanoparticles.

PubMed

Axnanda, Stephanus; Scheele, Marcus; Crumlin, Ethan; Mao, Baohua; Chang, Rui; Rani, Sana; Faiz, Mohamed; Wang, Suidong; Alivisatos, A Paul; Liu, Zhi

2013-01-01

Work function is a fundamental property of a material's surface. It is playing an ever more important role in engineering new energy materials and efficient energy devices, especially in the field of photovoltaic devices, catalysis, semiconductor heterojunctions, nanotechnology, and electrochemistry. Using ambient pressure X-ray photoelectron spectroscopy (APXPS), we have measured the binding energies of core level photoelectrons of Ar gas in the vicinity of several reference materials with known work functions (Au(111), Pt(111), graphite) and PbS nanoparticles. We demonstrate an unambiguously negative correlation between the work functions of reference samples and the binding energies of Ar 2p core level photoelectrons detected from the Ar gas near the sample surface region. Using this experimentally determined linear relationship between the surface work function and Ar gas core level photoelectron binding energy, we can measure the surface work function of different materials under different gas environments. To demonstrate the potential applications of this ambient pressure XPS technique in nanotechnology and solar energy research, we investigate the work functions of PbS nanoparticles with various capping ligands: methoxide, mercaptopropionic acid, and ethanedithiol. Significant Fermi level position changes are observed for PbS nanoparticles when the nanoparticle size and capping ligands are varied. The corresponding changes in the valence band maximum illustrate that an efficient quantum dot solar cell design has to take into account the electrochemical effect of the capping ligand as well.

23 CFR 140.908 - Materials and supplies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Materials and supplies. 140.908 Section 140.908 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES REIMBURSEMENT Reimbursement for Railroad Work § 140.908 Materials and supplies. (a) Procurement. Materials and supplies, if...

23 CFR 140.908 - Materials and supplies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Materials and supplies. 140.908 Section 140.908 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES REIMBURSEMENT Reimbursement for Railroad Work § 140.908 Materials and supplies. (a) Procurement. Materials and supplies, if...

Materials and Molecular Research Division annual report 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Searcy, A.W.; Muller, R.H.; Peterson, C.V.

1984-07-01

Progress is reported in the following fields: materials sciences (metallurgy and ceramics, solid-state physics, materials chemistry), chemical sciences (fundamental interactions, processes and techniques), actinide chemistry, fossil energy, electrochemical energy storage systems, superconducting magnets, semiconductor materials and devices, and work for others. (DLC)

Thermal management and design for optical refrigeration

NASA Astrophysics Data System (ADS)

Symonds, G.; Farfan, B. G.; Ghasemkhani, M. R.; Albrecht, A. R.; Sheik-Bahae, M.; Epstein, R. I.

2016-03-01

We present our recent work in developing a robust and versatile optical refrigerator. This work focuses on minimizing parasitic energy losses through efficient design and material optimization. The cooler's thermal linkage system and housing are studied using thermal analysis software to minimize thermal gradients through the device. Due to the extreme temperature differences within the device, material selection and characterization are key to constructing an efficient device. We describe the design constraints and material selections necessary for thermally efficient and durable optical refrigeration.

Magnetic Field-Induced Phase Transformation in Magnetic Shape Memory Alloys with High Actuation Stress and Work Output

DTIC Science & Technology

2010-05-03

Mechanisms for Advanced Properties in Phase Transforming Materials , Materials Science & Technology 2009 Conference, October 25-29, 2009, Pittsburgh, PA...Advanced Properties in Phase Transforming Materials , Materials Science & Technology 2009 Conference, October 25-29, 2009, Pittsburgh, PA, 2009. 11...observed materials behavior. Indeed, measured materials properties were found not to be the exact indication of the materials real response

23 CFR 140.908 - Materials and supplies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Reimbursement for Railroad Work § 140.908 Materials and supplies. (a) Procurement. Materials and supplies, if... projects where a company actually suffers loss by application of credits, the company shall have the...

Paraprofessional Bibliography: Training Materials and Resources for Paraprofessionals Working in Programs for People with Disabilities.

ERIC Educational Resources Information Center

Pickett, Anna Lou, Ed.

This annotated bibliography serves as a resource for program administrators and staff developers to enable them to strengthen and develop systematic training programs for paraprofessional staff. "Training and Instructional Materials: Publications" lists approximately 30 items developed to prepare paraprofessional personnel to work in educational,…

NREL Postdoc Awarded for Work on Breakthrough Solar Technology | News |

Science.gov Websites

widespread, new research must further these trends. One type of materials-halide perovskites-shows promise to group of Joseph M. Luther, working to develop a better understanding of halide perovskite materials fostered," Christians said. "This fellowship gives me the freedom to interact with a wide group

Multi-orifice deposition nozzle for additive manufacturing

DOEpatents

Lind, Randall F.; Post, Brian K.; Cini, Colin L.

2017-11-21

An additive manufacturing extrusion head includes a nozzle for accepting and depositing a heated material onto a work surface and/or part. The nozzle includes a valve body and an internal poppet body moveable between positions to permit deposition of at least two bead sizes of heated material onto a work surface and/or part.

Evaluating the Environmental Health Work Force. Final Report.

ERIC Educational Resources Information Center

Levine Associates, Inc., Rockville, MD.

This report contains all materials pertinent to an intensive evaluation of the environmental health work force conducted in 1986 and 1987. The materials relate to a workshop that was one of the key tools used in conducting the study to estimate environmental health personnel supply, demand, and need. The report begins with an overview and…

Opening Spaces of Possibility: The Teacher as Bricoleur

ERIC Educational Resources Information Center

Reilly, Mary Ann

2009-01-01

Bricolage is the make-do activities a handyperson employs while working. The bricoleur is one who tinkers with the materials at hand. Teachers can act as a bricoleur by continually cobbling materials together in the course of teaching. Such intellectual activity requires flexibility and the capacity to work with what is given while being…

ESL Teacher Training: Worksheets for Teachers of Adult Migrants.

ERIC Educational Resources Information Center

Dickie, J. A.; Lewis, Marilyn

Instructional materials are presented for teachers working with classes of adult migrants at technical institutes, high schools, or community centers in New Zealand. The materials are planned to be used in group training sessions, and the handbook includes suggestions for discussions, group tasks, and individual work. The handbook may be used for…

Romanian-Language Teaching: A Century of Pedagogical Materials Published Outside Romania.

ERIC Educational Resources Information Center

Carlton, Charles M.

1984-01-01

Reviews works published outside Romania for the purpose of the acquisition of the language by nonnatives and also a small number of works published in Romania but widely circulated in the West. Rates the material according to categories such as history and culture, audience, academic calendar, sequencing, magnitude, esthetics, and genre. (SED)

Looking south through east portion of Centralized Work Equipment (C.W.E.) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Looking south through east portion of Centralized Work Equipment (C.W.E.) Storage Shed (Bldg. 126). Note overhead monorails for material-handling hoists. This shed stored track maintenance materials - Atchison, Topeka, Santa Fe Railroad, Albuquerque Shops, C.W.E. Storage Shed, 908 Second Street, Southwest, Albuquerque, Bernalillo County, NM

Basic Skills Applications in Career Investigation: Mathematics, Science, Social Studies, Communications, Productive Work Habits. Revised.

ERIC Educational Resources Information Center

Hendrix, Mary W.

These materials allow instructors to provide learning experiences that stress the equal importance of academic and vocational education and the personal and social matters related to the work ethic. Instructional materials are provided in 15 clusters: agribusiness and natural resources; business and office; communications and media; construction;…

A comprehensive review on cold work of AISI D2 tool steel

NASA Astrophysics Data System (ADS)

Abdul Rahim, Mohd Aidil Shah bin; Minhat, Mohamad bin; Hussein, Nur Izan Syahriah Binti; Salleh, Mohd Shukor bin

2017-11-01

As a common material in mould and die application, AISI D2 cold work tool steel has proven to be a promising chosen material in the industries. However, challenges remain in using AISI D2 through a modified version with a considerable progress having been made in recent years. This paper provides a critical review of the original as-cast AISI D2 cold work tool steel up to the modified version. The main purpose is to develop an understanding of current modified tool steel trend; the machinability of AISI D2 (drilling, milling, turning, grinding and EDM/WEDM; and the microstructure evolution and mechanical properties of these cold work tool steels due to the presence of alloy materials in the steel matrix. The doping of rare earth alloy element, new steel fabrication processes, significant process parameter in machinability and surface treatment shows that there have been few empirical investigations into these cold work tool steel alloys. This study has discovered that cold work tool steel will remain to be explored in order to survive in the steel industries.

Parametric scramjet analysis

NASA Astrophysics Data System (ADS)

Choi, Jongseong

The performance of a hypersonic flight vehicle will depend on existing materials and fuels; this work presents the performance of the ideal scramjet engine for three different combustion chamber materials and three different candidate fuels. Engine performance is explored by parametric cycle analysis for the ideal scramjet as a function of material maximum service temperature and the lower heating value of jet engine fuels. The thermodynamic analysis is based on the Brayton cycle as similarly employed in describing the performance of the ramjet, turbojet, and fanjet ideal engines. The objective of this work is to explore material operating temperatures and fuel possibilities for the combustion chamber of a scramjet propulsion system to show how they relate to scramjet performance and the seven scramjet engine parameters: specific thrust, fuel-to-air ratio, thrust-specific fuel consumption, thermal efficiency, propulsive efficiency, overall efficiency, and thrust flux. The information presented in this work has not been done by others in the scientific literature. This work yields simple algebraic equations for scramjet performance which are similar to that of the ideal ramjet, ideal turbojet and ideal turbofan engines.

Establishment of a VISAR Measurement System for Material Model Validation in DSTO

DTIC Science & Technology

2013-02-01

advancements published in the works by L.M. Baker, E.R. Hollenbach and W.F. Hemsing [1-3] and results in the user-friendly interface and configuration of the...VISAR system [4] used in the current work . VISAR tests are among the mandatory instrumentation techniques when validating material models and...The present work reports on preliminary tests using the recently commissioned DSTO VISAR system, providing an assessment of the experimental set-up

CTH Implementation of a Two-Phase Material Model With Strength: Application to Porous Materials

DTIC Science & Technology

2012-07-01

he worked in the Lavrentyev Institute of Hydrodynamics (Russian Academy of Science) in the area of constitutive modelling for problems of high...velocity impact. Anatoly obtained a PhD in Physics and Mathematics from the Institute of Hydrodynamics in 1985. In 1996-1998 he worked in a private...silica in the present consideration. Further work is planned to account for a phase transition using the three-phase modelling approach [1]. In the

New water-soluble metal working fluids additives from phosphonic acid derivatives for aluminum alloy materials.

PubMed

Kohara, Ichitaro; Tomoda, Hideyuki; Watanabe, Shoji

2007-01-01

Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short paper describes properties of new additives for water-soluble cutting fluids for aluminum alloy materials. Some alkyldiphosphonic acids were prepared with known method. Amine salts of these phosphonic acids showed anti-corrosion property for aluminum alloy materials. However, they have no hard water tolerance. Monoesters of octylphosphonic acid were prepared by the reaction of octylphosphonic acid dichloride with various alcohols in the presence of triethylamine. Amine salts of monoester of octylphosphonic acid with diethyleneglycol monomethyl ether, ethyleneglycol monomethyl ether and triethyleneglycol monomethyl ether showed both of a good anti-corrosion property for aluminum alloy materials and hard water tolerance.

Significant aspects on thermal degradation of hybrid biocomposite material

NASA Astrophysics Data System (ADS)

Bavan, D. Saravana; Kumar, G. C. Mohan

2013-06-01

Interest in use of bio fibers is increasing rapidly in structural and automotive applications because of few important properties such as low density, mechanical properties, renewability, biodegradation and sustainability. The present work is focused on fabricating a hybrid bio-composite material processed through compression molding technique. Natural fibers of maize and jute with bio polymeric resin of epoxidized soya bean oil are used as a matrix in obtaining a hybrid bio composite material. Thermal degradation of the prepared material is studied through Thermal gravimetric analyzer. Chemical treatment of the fibers was performed to have a better adhesion between the fibers and the matrix. The work is also surveyed on various parameters influencing the thermal properties and other aspects for a hybrid bio composite material.

Grindability determination of torrefied biomass materials using the Hybrid Work index

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Essendelft, D.T.; Zhou, X.; Kang, B.S.-J.

2012-01-01

The grindability of torrefied biomass materials is a difficult parameter to evaluate due to its inhomogeneous character and non-uniform morphology. However, it is necessary to develop a grinding test that is representative of the wide ranging character of biomass and torrefied biomass materials. Previous research has shown that Resistance to Impact Milling (RIM) can be linearly correlated to thermally driven weight loss in biomass. In particular, the RIM equipment was found to supply the right energy level to physically break down structurally deficient biomass materials while leaving the un-touched material relatively intact [1–3]. However, the RIM procedure was not designedmore » to extract the comminution energy. Alternatively, the Bond Work Index (BWI) procedure was developed to accurately assess the grinding energy of brittle materials [4,5]. However, the milling energy is too low to be effective for biomass comminution. In this research, the BWI procedure was utilized with the ball–mill approach in the RIM test to evaluate torrefied biomass materials. The hybridized procedure has been shown to be both highly correlated to energy consumption and sensitive to degree of torrefaction. The proposed Hybrid Work Index (HWI) is certainly useful for assessing torrefaction in a laboratory environment, but it may also be correlated to grinding energy at industrial scales.« less

Establishing the traceability of a uranyl nitrate solution to a standard reference material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, C.H.; Clark, J.P.

1978-01-01

A uranyl nitrate solution for use as a Working Calibration and Test Material (WCTM) was characterized, using a statistically designed procedure to document traceability to National Bureau of Standards Reference Material (SPM-960). A Reference Calibration and Test Material (PCTM) was prepared from SRM-960 uranium metal to approximate the acid and uranium concentration of the WCTM. This solution was used in the characterization procedure. Details of preparing, handling, and packaging these solutions are covered. Two outside laboratories, each having measurement expertise using a different analytical method, were selected to measure both solutions according to the procedure for characterizing the WCTM. Twomore » different methods were also used for the in-house characterization work. All analytical results were tested for statistical agreement before the WCTM concentration and limit of error values were calculated. A concentration value was determined with a relative limit of error (RLE) of approximately 0.03% which was better than the target RLE of 0.08%. The use of this working material eliminates the expense of using SRMs to fulfill traceability requirements for uranium measurements on this type material. Several years' supply of uranyl nitrate solution with NBS traceability was produced. The cost of this material was less than 10% of an equal quantity of SRM-960 uranium metal.« less

The shear band controlled deformation in metallic glass: a perspective from fracture

NASA Astrophysics Data System (ADS)

Yang, G. N.; Shao, Y.; Yao, K. F.

2016-02-01

Different from the homogenous deformation in conventional crystalline alloys, metallic glasses and other work-softening materials deform discontinuously by localized plastic strain in shear bands. Here by three-point bending test on a typical ductile Pd-Cu-Si metallic glass, we found that the plastic deformed region during fracture didn’t follow the yielding stress distribution as the conventional material mechanics expected. We speculated that such special behavior was because the shear bands in metallic glasses could propagate easily along local shear stress direction once nucleated. Based on a 3D notch tip stress field simulation, we considered a new fracture process in a framework of multiple shear band deformation mechanism instead of conventional materials mechanics, and successfully reproduced the as-observed complicate shear band morphologies. This work clarifies many common misunderstandings on metallic glasses fracture, and might also provide a new insight to the shear band controlled deformation. It suggests that the deformation of metallic glasses is sensitive to local stress condition, and therefore their mechanical properties would depend on not only the material, but also other external factors on stress condition. We hope that start from this work, new methods, criteria, or definitions could be proposed to further study these work-softening materials, especially for metallic glasses.

What are the Dominant Factors of Students’ Productive Skills in Construction Services?

NASA Astrophysics Data System (ADS)

Oroh, R. R.; S, Haris A.; Sugandi, R. M.; Isnandar

2018-02-01

The purpose of this study to determine the dominant factors of students’ productive skills in doing the work of concrete structures that fit the needs of construction services. Sample of the respondents is vocational high school students from several districts and cities in North Sulawesi, Indonesia. Data are obtained through the performance test instruments of student. Whereas, data analysis is performed using factor analysis. The result of this research show the dominant factors of the students’ productive skills in doing the work of concrete structures that is according to the need of construction services, namely: (a) factor the working of concrete casting consists of making scaffolding from good materials and conducting concrete casting according to working method; and (b) factor the working of concrete reinforcing consists of read the working drawings for concrete reinforcement and make the concrete formwork from good material. Some of the respondent’s students in doing some concrete structure work have done well, but not yet according to working drawings, working methods and technical specifications of the work. The learning is done in accordance with the competency-oriented school curriculum but the teaching materials given have not been maximized in accordance with the needs of productive skills required construction services industry. The results have an impact on the low absorption of graduates in the implementation of the construction services industry.

Organizational influence on the occurrence of work accidents involving exposure to biological material.

PubMed

Marziale, Maria Helena Palucci; Rocha, Fernanda Ludmilla Rossi; Robazzi, Maria Lúcia do Carmo Cruz; Cenzi, Camila Maria; dos Santos, Heloisa Ehmke Cardoso; Trovó, Marli Elisa Mendes

2013-01-01

to analyze work accidents involving exposure to biological materials which took place among personnel working in nursing and to evaluate the influence of the organizational culture on the occurrence of these accidents. a retrospective, analytical study, carried out in two stages in a hospital that was part of the Network for the Prevention of Work Accidents. The first stage involved the analysis of the characteristics of the work accidents involving exposure to biological materials as recorded over a seven-year period by the nursing staff in the hospital studied, and registered in the Network databank. The second stage involved the analysis of 122 nursing staff members' perception of the institutional culture, who were allocated to the control group (workers who had not had an accident) and the case group (workers who had had an accident). 386 accidents had been recorded: percutaneous lesions occurred in 79% of the cases, needles were the materials involved in 69.7% of the accidents, and in 81.9% of the accident there was contact with blood. Regarding the influence of the organizational culture on the occurrence of accidents, the results obtained through the analysis of the two groups did not demonstrate significant differences between the average scores attributed by the workers in each organizational value or practice category. It is concluded that accidents involving exposure to biological material need to be avoided, however, it was not possible to confirm the influence of organizational values or practices on workers' behavior concerning the occurrence of these accidents.

ScienceCast 125: Genius Materials on the ISS

NASA Image and Video Library

2013-11-25

Researchers working with magnetic fluids on the International Space Station are taking "smart materials" to the next level. With proper coaxing, molecules can assemble themselves into "genius materials" with surprising properties.

Synthesis and electronic properties of nanophase semiconductor materials

NASA Astrophysics Data System (ADS)

Sailor, Michael J.

1993-05-01

The objective of the research effort is to understand and learn to control the morphologic and electronic properties of electrodeposited nanophase semiconductors. The initial work has focused on electrodeposition of nanophase CdSe, using a sequential monolayer deposition technique that we are developing. We are currently extending the synthesis phase of this project into silicon, silicon carbide, and phosphor materials. This work also encompasses studying semiconductor electrodeposition into materials with restricted dimensions, such as microporous alumina and porous silicon membranes. By growing films with very small grain sizes, we hope to produce and study materials that display unusual electronic or luminescent effects. We are primarily interested in the electronic properties of the II-VI and group IV materials, for potential applications in nanoscale electronics and optical detector technologies. The phosphors are being studied for their potential as efficient high-resolution display materials.

Environmentally-driven Materials Obsolescence: Material Replacements and Lessons Learned from NASA's Space Shuttle Program

NASA Technical Reports Server (NTRS)

Meinhold, Anne

2013-01-01

The Space Shuttle Program was terminated in 2011 with the last flight of the Shuttle Endeavour. During the 30 years of its operating history, the number of domestic and international environmental regulations increased rapidly and resulted in materials obsolescence risks to the program. Initial replacement efforts focused on ozone depleting substances. As pressure from environmental regulations increased, Shuttle worked on the replacement of heavy metals. volatile organic compounds and hazardous air pollutants. Near the end of the program. Shuttle identified potential material obsolescence driven by international regulations and the potential for suppliers to reformulate materials. During the Shuttle Program a team focused on environmentally-driven materials obsolescence worked to identify and mitigate these risks. Lessons learned from the Shuttle experience can be applied to new NASA Programs as well as other high reliability applications.

Experience of Application of Liquid Lubricating Materials during Wide Strip Hot Rolling

NASA Astrophysics Data System (ADS)

Platov, S. I.; Dema, R. R.; Kharchenko, M. V.; Amirov, R. N.

2017-12-01

The paper presents the results of the scientific and practical research of roller systems operation at feed of liquid lubricating materials through the example of the wide strip hot rolling Mill-2000 at PAO MMK. The experiments proved that application of lubricating materials leads to decrease of energy-power parameters of the process by 12 to 15 %, and reduction of work roll wear by 10 to 12%. The practical results of the study are developed recommendations on determination of consumption-volumetric parameters of the supplied lubricating material depending on rheological and geometrical parameters of the rolled strip and current wear of work rolls.

Operando XRD studies as a tool for determination of transport parameters of mobile ions in electrode materials

NASA Astrophysics Data System (ADS)

Kondracki, Łukasz; Kulka, Andrzej; Świerczek, Konrad; Ziąbka, Magdalena; Molenda, Janina

2017-11-01

In this work a detailed operando XRD investigations of structural properties of LixMn2O4 manganese spinel are shown to be a complementary, successful method of determination of diffusion coefficient D and surface exchange coefficient k in the working electrode. Kinetics of lithium ions transport are estimated on the basis of rate of structural changes of the cathode material during a relaxation stage after a high current charge, i.e. during structural relaxation of the material. The presented approach seems to be applicable as a complementary method of determination of transport coefficients for all intercalation-type electrode materials.

3D printed porous stainless steel for potential use in medicine

NASA Astrophysics Data System (ADS)

Fousová, M.; Kubásek, J.; Vojtěch, D.; Fojt, J.; Čapek, J.

2017-02-01

3D printing technologies like Selective Laser Melting (SLM) or Electron Beam Melting (EBM) produce components of very complicated shapes from various kinds of materials. In this work a highly porous (porosity of almost 90 vol. %) stainless steel component was manufactured by SLM. The material was characterized in terms of structure, surface chemistry and mechanical properties. It was observed that mechanical properties of the material were similar to those of trabecular human bone. The tests realized in this work confirmed suitability of the porous material prepared by SLM for the use in medicine, for example, for scaffolds designed to repair bone defects.

Nanostructure studies of strongly correlated materials.

PubMed

Wei, Jiang; Natelson, Douglas

2011-09-01

Strongly correlated materials exhibit an amazing variety of phenomena, including metal-insulator transitions, colossal magnetoresistance, and high temperature superconductivity, as strong electron-electron and electron-phonon couplings lead to competing correlated ground states. Recently, researchers have begun to apply nanostructure-based techniques to this class of materials, examining electronic transport properties on previously inaccessible length scales, and applying perturbations to drive systems out of equilibrium. We review progress in this area, particularly emphasizing work in transition metal oxides (Fe(3)O(4), VO(2)), manganites, and high temperature cuprate superconductors. We conclude that such nanostructure-based studies have strong potential to reveal new information about the rich physics at work in these materials.

Calcium Sulfate in Atacama Desert Basalt: A Possible Analog for Bright Material in Adirondack Basalt, Gusev Crater

NASA Technical Reports Server (NTRS)

Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

2007-01-01

The Atacama Desert in northern Chile is one of the driest deserts on Earth (< 2mm/y). The hyper-arid conditions allow extraordinary accumulations of sulfates, chlorides, and nitrates in Atacama soils. Examining salt accumulations in the Atacama may assist understanding salt accumulations on Mars. Recent work examining sulfate soils on basalt parent material observed white material in the interior vesicles of surface basalt. This is strikingly similar to the bright-white material present in veins and vesicles of the Adirondack basalt rocks at Gusev Crater which are presumed to consist of S, Cl, and/or Br. The abundance of soil gypsum/anhydrite in the area of the Atacama basalt suggested that the white material consisted of calcium sulfate (Ca-SO4) which was later confirmed by SEM/EDS analysis. This work examines the Ca-SO4 of Atacama basalt in an effort to provide insight into the possible nature of the bright material in the Adirondack basalt of Gusev Crater. The objectives of this work are to (i) discuss variations in Ca-SO4 crystal morphology in the vesicles and (ii) examine the Ca-SO4 interaction(s) with the basalt interior.

High-Temperature Structures, Adhesives, and Advanced Thermal Protection Materials for Next-Generation Aeroshell Design

NASA Technical Reports Server (NTRS)

Collins, Timothy J.; Congdon, William M.; Smeltzer, Stanley S.; Whitley, Karen S.

2005-01-01

The next generation of planetary exploration vehicles will rely heavily on robust aero-assist technologies, especially those that include aerocapture. This paper provides an overview of an ongoing development program, led by NASA Langley Research Center (LaRC) and aimed at introducing high-temperature structures, adhesives, and advanced thermal protection system (TPS) materials into the aeroshell design process. The purpose of this work is to demonstrate TPS materials that can withstand the higher heating rates of NASA's next generation planetary missions, and to validate high-temperature structures and adhesives that can reduce required TPS thickness and total aeroshell mass, thus allowing for larger science payloads. The effort described consists of parallel work in several advanced aeroshell technology areas. The areas of work include high-temperature adhesives, high-temperature composite materials, advanced ablator (TPS) materials, sub-scale demonstration test articles, and aeroshell modeling and analysis. The status of screening test results for a broad selection of available higher-temperature adhesives is presented. It appears that at least one (and perhaps a few) adhesives have working temperatures ranging from 315-400 C (600-750 F), and are suitable for TPS-to-structure bondline temperatures that are significantly above the traditional allowable of 250 C (482 F). The status of mechanical testing of advanced high-temperature composite materials is also summarized. To date, these tests indicate the potential for good material performance at temperatures of at least 600 F. Application of these materials and adhesives to aeroshell systems that incorporate advanced TPS materials may reduce aeroshell TPS mass by 15% - 30%. A brief outline is given of work scheduled for completion in 2006 that will include fabrication and testing of large panels and subscale aeroshell test articles at the Solar-Tower Test Facility located at Kirtland AFB and operated by Sandia National Laboratories. These tests are designed to validate aeroshell manufacturability using advanced material systems, and to demonstrate the maintenance of bondline integrity at realistically high temperatures and heating rates. Finally, a status is given of ongoing aeroshell modeling and analysis efforts which will be used to correlate with experimental testing, and to provide a reliable means of extrapolating to performance under actual flight conditions. The modeling and analysis effort includes a parallel series of experimental tests to determine TSP thermal expansion and other mechanical properties which are required for input to the analysis models.

Photocatalytic materials and technologies for air purification.

PubMed

Ren, Hangjuan; Koshy, Pramod; Chen, Wen-Fan; Qi, Shaohua; Sorrell, Charles Christopher

2017-03-05

Since there is increasing concern for the impact of air quality on human health, the present work surveys the materials and technologies for air purification using photocatalytic materials. The coverage includes (1) current photocatalytic materials for the decomposition of chemical contaminants and disinfection of pathogens present in air and (2) photocatalytic air purification systems that are used currently and under development. The present work focuses on five main themes. First, the mechanisms of photodegradation and photodisinfection are explained. Second, system designs for photocatalytic air purification are surveyed. Third, the photocatalytic materials used for air purification and their characteristics are considered, including both conventional and more recently developed photocatalysts. Fourth, the methods used to fabricate these materials are discussed. Fifth, the most significant coverage is devoted to materials design strategies aimed at improving the performance of photocatalysts for air purification. The review concludes with a brief consideration of promising future directions for materials research in photocatalysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Fracture and fatigue analysis of functionally graded and homogeneous materials using singular integral equation approach

NASA Astrophysics Data System (ADS)

Zhao, Huaqing

There are two major objectives of this thesis work. One is to study theoretically the fracture and fatigue behavior of both homogeneous and functionally graded materials, with or without crack bridging. The other is to further develop the singular integral equation approach in solving mixed boundary value problems. The newly developed functionally graded materials (FGMs) have attracted considerable research interests as candidate materials for structural applications ranging from aerospace to automobile to manufacturing. From the mechanics viewpoint, the unique feature of FGMs is that their resistance to deformation, fracture and damage varies spatially. In order to guide the microstructure selection and the design and performance assessment of components made of functionally graded materials, in this thesis work, a series of theoretical studies has been carried out on the mode I stress intensity factors and crack opening displacements for FGMs with different combinations of geometry and material under various loading conditions, including: (1) a functionally graded layer under uniform strain, far field pure bending and far field axial loading, (2) a functionally graded coating on an infinite substrate under uniform strain, and (3) a functionally graded coating on a finite substrate under uniform strain, far field pure bending and far field axial loading. In solving crack problems in homogeneous and non-homogeneous materials, a very powerful singular integral equation (SEE) method has been developed since 1960s by Erdogan and associates to solve mixed boundary value problems. However, some of the kernel functions developed earlier are incomplete and possibly erroneous. In this thesis work, mode I fracture problems in a homogeneous strip are reformulated and accurate singular Cauchy type kernels are derived. Very good convergence rates and consistency with standard data are achieved. Other kernel functions are subsequently developed for mode I fracture in functionally graded materials. This work provides a solid foundation for further applications of the singular integral equation approach to fracture and fatigue problems in advanced composites. The concept of crack bridging is a unifying theory for fracture at various length scales, from atomic cleavage to rupture of concrete structures. However, most of the previous studies are limited to small scale bridging analyses although large scale bridging conditions prevail in engineering materials. In this work, a large scale bridging analysis is included within the framework of singular integral equation approach. This allows us to study fracture, fatigue and toughening mechanisms in advanced materials with crack bridging. As an example, the fatigue crack growth of grain bridging ceramics is studied. With the advent of composite materials technology, more complex material microstructures are being introduced, and more mechanics issues such as inhomogeneity and nonlinearity come into play. Improved mathematical and numerical tools need to be developed to allow theoretical modeling of these materials. This thesis work is an attempt to meet these challenges by making contributions to both micromechanics modeling and applied mathematics. It sets the stage for further investigations of a wide range of problems in the deformation and fracture of advanced engineering materials.

Construct validity of functional capacity tests in healthy workers

PubMed Central

2013-01-01

Background Functional Capacity (FC) is a multidimensional construct within the activity domain of the International Classification of Functioning, Disability and Health framework (ICF). Functional capacity evaluations (FCEs) are assessments of work-related FC. The extent to which these work-related FC tests are associated to bio-, psycho-, or social factors is unknown. The aims of this study were to test relationships between FC tests and other ICF factors in a sample of healthy workers, and to determine the amount of statistical variance in FC tests that can be explained by these factors. Methods A cross sectional study. The sample was comprised of 403 healthy workers who completed material handling FC tests (lifting low, overhead lifting, and carrying) and static work FC tests (overhead working and standing forward bend). The explainable variables were; six muscle strength tests; aerobic capacity test; and questionnaires regarding personal factors (age, gender, body height, body weight, and education), psychological factors (mental health, vitality, and general health perceptions), and social factors (perception of work, physical workloads, sport-, leisure time-, and work-index). A priori construct validity hypotheses were formulated and analyzed by means of correlation coefficients and regression analyses. Results Moderate correlations were detected between material handling FC tests and muscle strength, gender, body weight, and body height. As for static work FC tests; overhead working correlated fair with aerobic capacity and handgrip strength, and low with the sport-index and perception of work. For standing forward bend FC test, all hypotheses were rejected. The regression model revealed that 61% to 62% of material handling FC tests were explained by physical factors. Five to 15% of static work FC tests were explained by physical and social factors. Conclusions The current study revealed that, in a sample of healthy workers, material handling FC tests were related to physical factors but not to the psychosocial factors measured in this study. The construct of static work FC tests remained largely unexplained. PMID:23758870

Advances In Microwave Metamaterials

NASA Astrophysics Data System (ADS)

Wigle, James A.

2011-12-01

Metamaterials are a new area of research showing significant promise for an entirely new set of materials, and material properties. Only recently has three-fourths of the entire electromagnetic material space been made available for discoveries, research, and applications. This thesis is a culmination of microwave metamaterial research that has transpired over numerous years at the University of Colorado. New work is presented; some is complete while other work has yet to be finished. Given the significant work efforts, and potential for new and interesting results, I have included some of my partial work to be completed in the future. This thesis begins with background theory to assist readers in fully understanding the mechanisms that drove my research and results obtained. I illustrate the design and manufacture of a metamaterial that can operate within quadrants I and II of the electromagnetic material space (epsilon r > 0 and mur > 0 or epsilonr < 0 and mu r > 0, respectively). Another metamaterial design is presented for operation within quadrant III of the electromagnetic material space (epsilonr < 0 and mur < 0). Lorentz reciprocity is empirically demonstrated for a quadrant I and II metamaterial, as well as a metamaterial enhanced antenna, or meta-antenna. Using this meta-antenna I demonstrate improved gain and directivity, and illuminate how the two are not necessarily coincident in frequency. I demonstrate a meta-lens which provides a double beam pattern for a normally hemispherical antenna, which also provides a null where the antenna alone would provide a peak on boresight. The thesis also presents two related, but different, novel tests intended to be used to definitively illustrate the negative angle of refraction for indices of refraction less than zero. It will be shown how these tests can be used to determine most bulk electromagnetic material properties of the material under test, for both right handed and left handed materials, such as epsilonr, mur, deltaloss, and n. The work concluding this thesis is an attempt to derive modified Fresnel Coefficients, for which I actually believe to be incorrect. Though, in transposing I have corrected a few mistakes, and now I can no longer find the conundrum. I have included this work to illuminate the need for modified Fresnel coefficients for cases of negative indices of refraction, identifying all disparate cases requiring a new set of equations, as well as to assist others in their efforts through illumination of the potential erroneous path chosen.

A comparison of neural network architectures for the prediction of MRR in EDM

NASA Astrophysics Data System (ADS)

Jena, A. R.; Das, Raja

2017-11-01

The aim of the research work is to predict the material removal rate of a work-piece in electrical discharge machining (EDM). Here, an effort has been made to predict the material removal rate through back-propagation neural network (BPN) and radial basis function neural network (RBFN) for a work-piece of AISI D2 steel. The input parameters for the architecture are discharge-current (Ip), pulse-duration (Ton), and duty-cycle (τ) taken for consideration to obtained the output for material removal rate of the work-piece. In the architecture, it has been observed that radial basis function neural network is comparatively faster than back-propagation neural network but logically back-propagation neural network results more real value. Therefore BPN may consider as a better process in this architecture for consistent prediction to save time and money for conducting experiments.

[HIV and the nursing professional in the face of needlestick accidents].

PubMed

Vieira, Mariana; Padilha, Maria Itayra Coelho de Souza

2008-12-01

The goal of this study was to identify the scientific production about work-related needlestick accidents among nursing professionals involving HIV-contaminated biological material, as well as to characterize the pre-existing factors to such accidents, such as procedures occurring after the exposure to potentially HIV-contaminated needlestick material. This is a literature review, whose bibliographic search for keywords was carried out within the LILACS databases from the year 2000 onward. This study confirms that pre-existing factors for the occurrence of work-related needlestick accidents are related to work conditions as much as to individual conditions. In face of these accidents, the nursing workers need to know the conducts concerning post-exposure to potentially HIV-contaminated needlestick material. We conclude that the adoption of standardized precautions when working in healthcare is a fundamental condition for worker safety, independently of their area of expertise, given the increasing number of HIV cases.

Randomized controlled clinical trial on the three-dimensional accuracy of fast-set impression materials.

PubMed

Rudolph, Heike; Quaas, Sebastian; Haim, Manuela; Preißler, Jörg; Walter, Michael H; Koch, Rainer; Luthardt, Ralph G

2013-06-01

The use of fast-setting impression materials with different viscosities for the one-stage impression technique demands precise working times when mixing. We examined the effect of varying working time on impression precision in a randomized clinical trial. Focusing on tooth 46, three impressions were made from each of 96 volunteers, using either a polyether (PE: Impregum Penta H/L DuoSoft Quick, 3 M ESPE) or an addition-curing silicone (AS: Aquasil Ultra LV, Dentsply/DeTrey), one with the manufacturer's recommended working time (used as a reference) and two with altered working times. All stages of the impression-taking were subject to randomization. The three-dimensional precision of the non-standard working time impressions was digitally analyzed compared to the reference impression. Statistical analysis was performed using multivariate models. The mean difference in the position of the lower right first molar (vs. the reference impression) ranged from ±12 μm for PE to +19 and -14 μm for AS. Significantly higher mean values (+62 to -40 μm) were found for AS compared to PE (+21 to -26 μm) in the area of the distal adjacent tooth. Fast-set impression materials offer high precision when used for single tooth restorations as part of a one-stage impression technique, even when the working time (mixing plus application of the light- and heavy-body components) diverges significantly from the manufacturer's recommended protocol. Best accuracy was achieved with machine-mixed heavy-body/light-body polyether. Both materials examined met the clinical requirements regarding precision when the teeth were completely syringed with light material.

Analytical Chemistry at the Interface Between Materials Science and Biology

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Brien, Janese C.

2000-09-21

Likedlessentid sciences, anal~cd chetis~continues toreinvent itself. Moving beyond its traditional roles of identification and quantification, analytical chemistry is now expanding its frontiers into areas previously reserved to other disciplines. This work describes several research efforts that lie at the new interfaces between analytical chemistry and two of these disciplines, namely materials science and biology. In the materials science realm, the search for new materials that may have useful or unique chromatographic properties motivated the synthesis and characterization of electrically conductive sol-gels. In the biology realm, the search for new surface fabrication schemes that would permit or even improve the detectionmore » of specific biological reactions motivated the design of miniaturized biological arrays. Collectively, this work represents some of analytical chemistry’s newest forays into these disciplines. The introduction section to this dissertation provides a literature review on several of the key aspects of this work. In advance of the materials science discussion, a brief introduction into electrochemically-modulated liquid chromatography (EMLC) and sol-gel chemistry is provided. In advance of the biological discussions, brief overviews of scanning force microscopy (SFM) and the oxidative chemistry used to construct our biological arrays are provided. This section is followed by four chapters, each of which is presented as a separate manuscript, and focuses on work that describes some of our cross-disciplinary efforts within materials science and biology. This dissertation concludes with a general summary and future prospectus.« less

Summary of the research work of the Trace Elements Section, Geochemistry and Petrology Branch, for the period January 1-March 31, 1951

USGS Publications Warehouse

Rabbitt, John C.

1951-01-01

This report summarized the research work of the Trace Elements Section, Geochemistry and Petrology Branch for the period January 1 - March 31, 1951. Work before that is summarized in an earlier report, "Summary of the research work of the Trace Elements Section, Geochemistry and Petrology Branch, for the period April 1, 1948 - December 31, 1950," by John C. Rabbitt (U.S. Geol. Survey Trace Elements Investigations Rept. 148, January 1951). This report will be referred to as TEIR 148. In TEIR 148 the purpose of each project was described and it is not thought necessary to repeat that material. The research work of the section consists of laboratory and related field studies in the following fields: 1. Mineralogic and petrologic investigations of radioactive rocks, minerals, and ores. 2. Investigations of chemical methods of analysis for uranium, thorium, and other elements and compounds in radioactive materials, and related chemical problems. 3. Investigations of spectographic method of analysis for a wide variety of elements in radioactive materials. 4. Investigation of radiometric methods of analysis is applied to radioactive materials. It should be emphasized that the work undertaken so far is almost entirely in the nature of investigations supporting the field appraisal of known uraniferous deposits. A program of more fundamental research, particularly in the mineralogy and geochemistry of uranium, is now being drawn up and will be submitted for approval soon. This report does not deal with the routine analytical work of the Section nor the public-sample program. The analytical work will be summarized in a report to be issued after the end of fiscal year 1951, and a report on the public-sample program is in process. Special thanks are due members of the Section who are engaged in the research work and who have supplied material for this report, the Early Ingerson, Chief of the Geochemistry and Petrology Branch for his critical review, to Jane Titcomb of the editorial staff of the Section for editing the report, and to Virginia Layne of the same staff, for typing the manuscript and the multilith mats.

Exploratory Investigation into the Durability of Beneficial Cold Worked Fastener Hole in Aluminum

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Clark, David A.

1999-01-01

Cold working fastener holes in aluminum alloys is a widely used technique in the aerospace industry for improving the fatigue performance of structures. A compressive tangential stress introduced in the material during the cold working of the hole reduces the natural tendency of the material to crack at the holes under cyclic tensile loading. It is a lucrative technique for the aerospace industry in that it provides an increase in performance without any weight cost.

Creating Quality Media Materials.

ERIC Educational Resources Information Center

Hortin, John A.; Bailey, Gerald D.

1982-01-01

Innovation, imagination, and student creativity are key ingredients in creating quality media materials for the small school. Student-produced media materials, slides without a camera, personalized slide programs and copy work, self-made task cards, self-made overhead transparencies, graphic materials, and utilization of the mass media are some of…

Materials for Secondary School Programs for the Educable Mentally Retarded Adolescent.

ERIC Educational Resources Information Center

Boston Univ., MA. New England Special Education Instructional Materials Center.

Compiled are materials related to work study programs for the educable mentally handicapped adolescent. Items listed include professional books, textbooks, resource aids, journals and articles, curriculum guides, instructional materials, and audiovisual aids. The materials are grouped according to academic areas (mathematics, science, social…

Bibliography of Multi-Ethnic and Sex-Fair Resource Materials.

ERIC Educational Resources Information Center

Massachusetts State Dept. of Education, Boston. Bureau of Equal Educational Opportunities.

This annotated bibliography lists both nondiscriminatory instructional materials (largely audio-visual) for classroom use and works for teachers' use that promote multi-ethnic and sex fair education. The materials listed include films, filmstrips, slide presentations and video tapes, bibliographies of curriculum materials, books, handbooks and…

Strain rate dependent hyperelastic stress-stretch behavior of a silica nanoparticle reinforced poly (ethylene glycol) diacrylate nanocomposite hydrogel.

PubMed

Zhan, Yuexing; Pan, Yihui; Chen, Bing; Lu, Jian; Zhong, Zheng; Niu, Xinrui

2017-11-01

Poly (ethylene glycol) diacrylate (PEGDA) derivatives are important biomedical materials. PEGDA based hydrogels have emerged as one of the popular regenerative orthopedic materials. This work aims to study the mechanical behavior of a PEGDA based silica nanoparticle (NP) reinforced nanocomposite (NC) hydrogel at physiological strain rates. The work combines materials fabrication, mechanical experiments, mathematical modeling and structural analysis. The strain rate dependent stress-stretch behaviors were observed, analyzed and quantified. Visco-hyperelasticity was identified as the deformation mechanism of the nano-silica/PEGDA NC hydrogel. NPs showed significant effect on both initial shear modulus and viscoelastic materials properties. A structure-based quasi-linear viscoelastic (QLV) model was constructed and capable to describe the visco-hyperelastic stress-stretch behavior of the NC hydrogel. A group of unified material parameters was extracted by the model from the stress-stretch curves obtained at different strain rates. Visco-hyperelastic behavior of NP/polymer interphase was not only identified but also quantified. The work could provide guidance to the structural design of next-generation NC hydrogel. Copyright © 2017. Published by Elsevier Ltd.

Work in the Navy--A Description of Navy Officer and Enlisted Occupations. Technical Report No. 923.

ERIC Educational Resources Information Center

McDermott, Michael N.; And Others

The manual contains career guidance materials describing occupations and career development opportunities in the Navy. The materials were developed for integration into the Oregon Career Information System, a career education program utilizing both computerized and manual information systems. The report includes a discussion of the general work of…

Enhancing composite durability : using thermal treatments

Treesearch

Jerrold E. Winandy; W. Ramsay Smith

2007-01-01

The use of thermal treatments to enhance the moisture resistance and aboveground durability of solid wood materials has been studied for years. Much work was done at the Forest Products Laboratory in the last 15 years on the fundamental process of both short-and long-term exposure to heat on wood materials and its interaction with various treatment chemicals. This work...

Identifying and Addressing Student Difficulties and Misconceptions: Examples from Physics and from Materials Science and Engineering

ERIC Educational Resources Information Center

Rosenblatt, Rebecca

2012-01-01

Here I present my work identifying and addressing student difficulties with several materials science and physics topics. In the first part of this thesis, I present my work identifying student difficulties and misconceptions about the directional relationships between net force, velocity, and acceleration in one dimension. This is accomplished…

FireWorks curriculum featuring ponderosa, lodgepole, and whitebark pine forests

Treesearch

Jane Kapler Smith; Nancy E. McMurray

2000-01-01

FireWorks is an educational program for students in grades 1-10. The program consists of the curriculum in this report and a trunk of laboratory materials, specimens, and reference materials. It provides interactive, hands-on activities for studying fire ecology, fire behavior, and the influences of people on three fire-dependent forest types - Pinus ponderosa...

In-Service Workshop Model. Development Work, Volunteer Service and Project Review. Core Curriculum Resource Materials.

ERIC Educational Resources Information Center

Edwards, Dan

A model is provided for an inservice workshop to provide systematic project review, conduct individual volunteer support and problem solving, and conduct future work planning. Information on model use and general instructions are presented. Materials are provided for 12 sessions covering a 5-day period. The first session on climate setting and…

INTRODUCTION TO BENGALI, PART I.

ERIC Educational Resources Information Center

DIMOCK, EDWARD, JR.; AND OTHERS

THE MATERIALS FOR A BASIC COURSE IN SPOKEN BENGALI PRESENTED IN THIS BOOK WERE PREPARED BY REVISION OF AN EARLIER WORK DATED 1959. THE REVISION WAS BASED ON EXPERIENCE GAINED FROM 2 YEARS OF CLASSROOM WORK WITH THE INITIAL COURSE MATERIALS AND ON ADVICE AND COMMENTS RECEIVED FROM THOSE TO WHOM THE FIRST DRAFT WAS SENT FOR CRITICISM. THE AUTHORS OF…

40 CFR 63.7900 - What emissions limitations and work practice standards must I meet for containers?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Pollutants: Site Remediation Containers § 63.7900 What emissions limitations and work practice standards must... your container except at the times the container is used for treatment of remediation material by a... either of the conditions in paragraphs (b)(3)(i) or (ii) apply to the remediation material placed in your...

High Vacuum Creep Facility in the Materials Processing Laboratory

NASA Image and Video Library

1973-01-21

Technicians at work in the Materials Processing Laboratory’s Creep Facility at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The technicians supported the engineers’ studies of refractory materials, metals, and advanced superalloys. The Materials Processing Laboratory contained laboratories and test areas equipped to prepare and develop these metals and materials. The ultra-high vacuum lab, seen in this photograph, contained creep and tensile test equipment. Creep testing is used to study a material’s ability to withstand long durations under constant pressure and temperatures. The equipment measured the strain over a long period of time. Tensile test equipment subjects the test material to strain until the material fails. The two tests were used to determine the strength and durability of different materials. The Materials Processing Laboratory also housed arc and electron beam melting furnaces, a hydraulic vertical extrusion press, compaction and forging equipment, and rolling mills and swagers. There were cryogenic and gas storage facilities and mechanical and oil diffusion vacuum pumps. The facility contained both instrumental and analytical chemistry laboratories for work on radioactive or toxic materials and the only shop to machine toxic materials in the Midwest.

Optimization study of direct morphology observation by cold field emission SEM without gold coating.

PubMed

He, Dan; Fu, Cheng; Xue, Zhigang

2018-06-01

Gold coating is a general operation that is generally applied on non-conductive or low conductive materials, during which the morphology of the materials can be examined by scanning electron microscopy (SEM). However, fatal deficiencies in the materials can result in irreversible distortion and damage. The present study directly characterized different low conductive materials such as hydroxyapatite, modified poly(vinylidene fluoride) (PVDF) fiber, and zinc oxide nanopillar by cold field emission scanning electron microscopy (FE-SEM) without a gold coating. According to the characteristics of the low conductive materials, various test conditions, such as different working signal modes, accelerating voltages, electron beam spots, and working distances, were characterized to determine the best morphological observations of each sample. Copyright © 2018 Elsevier Ltd. All rights reserved.

3D polypyrrole structures as a sensing material for glucose detection

NASA Astrophysics Data System (ADS)

Cysewska, Karolina; Szymańska, Magdalena; Jasiński, Piotr

2016-11-01

In this work, 3D polypyrrole (PPy) structures as material for glucose detection is proposed. Polypyrrole was electrochemically polymerized on platinum screen-printed electrode from an aqueous solution of lithium perchlorate and pyrrole. The growth mechanism of such PPy structures was studied by ex-situ scanning electron microscopy. Preliminary studies show that studied here PPy film is a good candidate as a sensing material for glucose biosensor. It exhibits very high sensitivity (28.5 mA·mM-1·cm-2) and can work without any additional dopants, mediators or enzymes. It was also shown that glucose detection depends on the PPy morphology. The same PPy material was immobilized with the glucose oxidase enzyme. Such material exhibited higher signal response, however it lost its stability very fast.

Experimental determination of the effects of annealing on the micro-structures and mechanical properties of cold-worked alpha-brass

NASA Astrophysics Data System (ADS)

Edward, Aghogho Bright; Izelu, Christopher

2013-12-01

Experimental determination of the effect of annealing on the microstructure and mechanical properties of a cold work 70 - 30 brass, was carried out by subjecting specimens of the material to various degrees of cold-work (20%, 40% and 60%), by straining using a tensile machine. The specimens for each degree of cold work were then annealed at 250°C, 350°C, 450°C and 600°C, for 30 minutes. The approach involves the use of metallographic techniques: grinding, polishing and etching to reveal the microstructure while tensile test was carried out on the specimen using a Monsanto tensometer so as to obtain the load/extension graph from which the tensile strength and hardness values were obtained. From the results obtained, it was conclusive that annealing produced finer grains and eliminates prior cold work whereby the material becomes ductile. However, there should be an appreciable deformation for this effect to be noticed. One important aspect of re-crystallization in structural materials is that there is a loss of strength which accompanies disappearance of the cold-worked grains when subjected to high temperature applications. Yet, it is often difficult to establish the exact range of permissible temperature. This work establishes a range for the re-crystallization of alpha brass as 350°C < TC < 450°C, where TC is the re-crystallization temperature. Thus, it will be safe to apply this material at temperatures below 350°C, without fear of structural changes with accompanying lost in strength.

40 CFR 63.3094 - What work practice standards must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., mixing, and conveying of coatings, thinners, and cleaning materials used in, and waste materials... approved alternative. (A) Use of masking materials (contact paper, plastic sheet, or other similar type of... (paper, foil, plastic, or similar type of material). (B) Use of manual and/or mechanical scrubbers, rags...

40 CFR 63.4493 - What work practice standards must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... National Emission Standards for Hazardous Air Pollutants for Surface Coating of Plastic Parts and Products... materials used in, and waste materials generated by the controlled coating operation(s) for which you use..., thinners and/or other additives, cleaning materials, and waste materials must be stored in closed...

40 CFR Table 9 to Subpart Wwww of... - Initial Compliance With Work Practice Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... have demonstrated initial compliance if . . . 1. a new or existing closed molding operation using... adding materials, and materials are recovered after slitting. 2. a new or existing cleaning operation not...-containing materials storage operation keep containers that store HAP-containing materials closed or covered...

Materials by Design—A Perspective From Atoms to Structures

PubMed Central

Buehler, Markus J.

2013-01-01

Biological materials are effectively synthesized, controlled, and used for a variety of purposes—in spite of limitations in energy, quality, and quantity of their building blocks. Whereas the chemical composition of materials in the living world plays a some role in achieving functional properties, the way components are connected at different length scales defines what material properties can be achieved, how they can be altered to meet functional requirements, and how they fail in disease states and other extreme conditions. Recent work has demonstrated this by using large-scale computer simulations to predict materials properties from fundamental molecular principles, combined with experimental work and new mathematical techniques to categorize complex structure-property relationships into a systematic framework. Enabled by such categorization, we discuss opportunities based on the exploitation of concepts from distinct hierarchical systems that share common principles in how function is created, linking music to materials science. PMID:24163499

Porous carbon derived from aniline-modified fungus for symmetrical supercapacitor electrodes

DOE PAGES

Wang, Keliang; Xu, Ming; Wang, Xiaomin; ...

2017-01-23

N incorporated carbon materials are proven to be efficient EDLCs electrode materials. In this work, aniline modified fungus served as a raw material, and N-doped porous activated carbon is prepared via an efficient KOH activation method. A porous network with a high specific surface area of 2339 m 2g -1 is displayed by the prepared carbon material, resulting in a high accessible surface area and low ion diffusion resistance which is desirable for EDLC electrode materials. In assembled EDLCs, the N–AC based electrode exhibits a specific capacitance of 218 F g -1 at a current density of 0.1 A gmore » -1. Besides, excellent stability is displayed after 5000 continuous cycles at different current densities ranging from 0.1 to 10 A g -1. Thus, the present work reveals a promising candidate for electrode materials of EDLCs.« less

Representations of Complexity: How Nature Appears in Our Theories

PubMed Central

2013-01-01

In science we study processes in the material world. The way these processes operate can be discovered by conducting experiments that activate them, and findings from such experiments can lead to functional complexity theories of how the material processes work. The results of a good functional theory will agree with experimental measurements, but the theory may not incorporate in its algorithmic workings a representation of the material processes themselves. Nevertheless, the algorithmic operation of a good functional theory may be said to make contact with material reality by incorporating the emergent computations the material processes carry out. These points are illustrated in the experimental analysis of behavior by considering an evolutionary theory of behavior dynamics, the algorithmic operation of which does not correspond to material features of the physical world, but the functional output of which agrees quantitatively and qualitatively with findings from a large body of research with live organisms. PMID:28018044

Parametric Study on the Tensile Properties of Ni-Based Alloy for a VHTR

NASA Astrophysics Data System (ADS)

Kim, Dong-Jin; Jung, Su Jin; Mun, Byung Hak; Kim, Sung Woo; Lim, Yun Soo

2015-01-01

A very high-temperature reactor (VHTR) has been studied among generation IV nuclear power plants owing to its many advantages such as high-electric efficiency and massive hydrogen production. The material used for the heat exchanger should sustain structural integrity for its life even though the material is exposed to a harsh environment at 1223 K (950 °C) in an impure helium coolant. Therefore, an enhancement of the material performance at high temperature gives a margin in determining the operating temperature and life time. This work is an effort to find an optimum combination of alloying elements and processing parameters to improve the material performance. The tensile property and microstructure for nickel-based alloys fabricated in a laboratory were evaluated as a function of the heat treatment, cold working, and grain boundary strengthener using a tension test at 1223 K (950 °C), scanning electron microscopy, and transmission electron microscopy. Elongation to rupture was increased by additional heat treatment and cold working, followed by additional heat treatment in the temperature range from 1293 K to 1383 K (1020 °C to 1110 °C) implying that the intergranular carbide contributes to grain boundary strengthening. The temperature at which the grain boundary is improved by carbide decoration was higher for a cold-worked specimen, which was described by the difference in carbide stability and carbide formation kinetics between no cold-worked and cold-worked specimens. Zr and Hf played a scavenging effect of harmful elements causing an increase in ductility.

Mechanical characterization of composite materials by optical techniques: A review

NASA Astrophysics Data System (ADS)

Bruno, Luigi

2018-05-01

The present review provides an overview of work published in recent years dealing with the mechanical characterization of composite materials performed by optical techniques. The paper emphasizes the strengths derived from the employment of full-field methods when the strain field of an anisotropic material must be evaluated. This is framed in contrast to the use of conventional measurement techniques, which provide single values of the measured quantities unable to offer thorough descriptions of deformation distribution. The review outlines the intensity and articulation of work in this research field to date and its ongoing importance not only in the academy, but also in industrial sectors where composite materials represent a strategic resource for development.

The Influence of Mechanical Parameters on Dielectric Characteristics of Rigid Electrical Insulating Materials

NASA Astrophysics Data System (ADS)

Buică, G.; Antonov, A. E.; Beiu, C.; Dobra, R.; Risteiu, M.

2018-06-01

Rigid electrical insulating materials are used in the manufacture of work equipment with electric safety function, being mainly intended for use in the energy sector. The paper presents the results of the research on the identification of the technical and safety requirements for rigid electrical insulating materials that are part of the electrical insulating work equipment. The paper aims to show the behaviour of rigid electrical insulating materials under the influence of mechanical risk factors, in order to check the functionality and to ensure the safety function for the entire life time. There were tested rigid electrical insulating equipment designed to be used as safety means in electrical power stations and overhead power lines.

Interaction between adsorbed hydrogen and potassium on a carbon nanocone containing material as studied by photoemission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Xiaofeng; Raaen, Steinar, E-mail: sraaen@ntnu.no

2015-09-14

Hydrogen adsorption on a potassium doped carbon nanocone containing material was studied by photoelectron spectroscopy and work function measurement. The valence band spectra indicate that there is charge transfer from potassium to carbon. Upon deposition on carbon potassium is in its ionic state for lower doping and shows both ionic and metallic behavior at higher doping. Adsorption of hydrogen facilitates diffusion of potassium on the carbon material as seen by changes in the K{sub 2p} core level spectrum. Variations in the measured sample work function indicate that hydrogen initially adsorb on the K dopants and subsequently adsorb on the carbonmore » cone containing material.« less

Tool wear mechanisms in turning titanium-aluminum-vanadium using tungsten carbide and polycrystalline diamond inserts

NASA Astrophysics Data System (ADS)

Schrock, David James

The objective of this work is to identify some of the tool wear mechanisms at the material level for the machining of titanium and to provide some understanding of these mechanisms for use in physics based tool wear models. Turning experiments were conducted at cutting speeds of 61m/min, 91m/min, and 122m/min on Ti-6Al-4V, an alloy of titanium, using two different grades of tungsten carbide cutting inserts and one grade of polycrystalline diamond inserts. Three-dimensional wear data and two-dimensional wear profiles of the rake face were generated using Confocal Laser Scanning Microscopy to quantify the tool wear mechanisms. Additionally, the microstructure of the deformed work material (chip) and un-deformed parent material (work piece) were studied using Orientation Imaging Microscopy (OIM). Observations from tool wear studies on the PCD inserts revealed the presence of two fundamentally different wear mechanisms operating at the different cutting speeds. Microstructural analyses of the chip and the work material showed phase dependent tool wear mechanisms for machining titanium. There is a high likelihood of phase change occurring in the work material during machining, with a transformation from the alpha phase to the beta phase. The observed dramatic increase in wear is attributed to a combination of increased diffusivity in the beta phase of the titanium alloy in conjunction with a higher degree of recrystallization of the prior beta phase upon cooling. Results of other observations such as the influence of carbide grain size on tool wear are also discussed.

Atomic Oxygen Task

NASA Technical Reports Server (NTRS)

Hadaway, James B.

1997-01-01

This report details work performed by the Center for Applied Optics (CAO) at the University of Alabama in Huntsville (UAH) on the contract entitled 'Atomic Oxygen Task' for NASA's Marshall Space Flight Center (contract NAS8-38609, Delivery Order 109, modification number 1). Atomic oxygen effects on exposed materials remain a critical concern in designing spacecraft to withstand exposure in the Low Earth Orbit (LEO) environment. The basic objective of atomic oxygen research in NASA's Materials & Processes (M&P) Laboratory is to provide the solutions to material problems facing present and future space missions. The objective of this work was to provide the necessary research for the design of specialized experimental test configurations and development of techniques for evaluating in-situ space environmental effects, including the effects of atomic oxygen and electromagnetic radiation on candidate materials. Specific tasks were performed to address materials issues concerning accelerated environmental testing as well as specifically addressing materials issues of particular concern for LDEF analysis and Space Station materials selection.

[Hazardous material and safety conditions in veterinary practice. 2: Flammable liquid, disinfectants and cleansing media, cytostatics, pressurized gases, liquid nitrogen, narcotic gases, mailing of diagnostic samples, hazardous waste].

PubMed

Sliwinski-Korell, A; Lutz, F

1998-05-01

In the last years the standards for professional handling of hazardous material as well as health and safety in the veterinary practice became considerably more stringent. This is expressed in various safety regulations, particularly the decree of hazardous material and the legislative directives concerning health and safety at work. In part 1, a definition based on the law for hazardous material was given and the potential risks were mentioned. The correct documentation regarding the protection of personal and the purchase, storage, working conditions and removal of hazardous material was explained. General rules for the handling of hazardous material were described. In part 2, partial emphasis is put on the handling of flammable liquids, disinfectants, cytostatica, pressurised gases, liquid nitrogen, narcotics, mailing of potentially infectious material and safe disposal of hazardous waste. Advice about possible unrecognized hazards and references are also given.

Materials characterization with MeV ions

NASA Astrophysics Data System (ADS)

Conlon, T. W.

1989-04-01

The inherent atomic and nuclear properties of energetic ions in materials can be exploited to characterize as well as to modify materials' properties. In nuclear reactors keV ions from neutron collisions damage containment materials. However, basic studies of the interactions of such ions has yielded improved understanding of their properties and has even led to a tailoring of conditions so that the ions can be made to beneficially modify structures (by ion implantation). At higher energies an understanding of the ion-material interaction provides techniques such as PIXE, RBS, and ERD for nondestructive analysis, either in broad beam or "microbeam" mode. At high energies still penetration of the Coulomb barrier opens up activation methods for materials' characterization (CPAA, NRA, TLA etc.). A short discussion of the general properties of energetic ions in materials is followed by a brief introduction to our generic work in these areas, and some examples of current work in the areas of: activation for the radioisotope labelling of nonmetals, mass resolved ERDA using TOF techniques and submicron MeV microprobes.

Morphological effects on sensitivity of heterogeneous energetic materials

NASA Astrophysics Data System (ADS)

Roy, Sidhartha; Rai, Nirmal; Sen, Oishik; Udaykumar, H. S.

2017-06-01

The mesoscale physical response under shock loading in heterogeneous energetics is inherently linked to the microstructural characteristics. The current work demonstrates the connection between the microstructural features of porous energetic material and its sensitivity. A unified levelset based framework is developed to characterize the microstructures of a given sample. Several morphological metrics describing the mesoscale geometry of the materials are extracted using the current tool including anisotropy, tortuosity, surface to volume, nearest neighbors, size and curvature distributions. The relevant metrics among the ones extracted are identified and correlated to the mesoscale response of the energetic materials under shock loading. Two classes of problems are considered here: (a) field of idealized voids embedded in the HMX material and (b) real samples of pressed HMX. The effects of stochasticity associated with void arrangements on the sensitivity of the energetic material samples are shown. In summary, this work demonstrates the relationship between the mesoscale morphology and shock response of heterogeneous energetic materials using a levelset based framework.

[Upgrading of complete removable prosthetic appliance of stomatological patients by the use of new base materials].

PubMed

Кузь, Виталий С; Дворник, Валентин Н; Тесленко, Александра И; Кузь, Гельфира М; Мартыненко, Игорь Н

2016-01-01

The effectiveness of orthopedic treatment of edentulous patients depends on the properties of the basic materials. The main group of materials for manufacturing of such structures are acrylic plastics of thermal polymerization. However, many years of experience in the use of plastics has revealed a number of shortcomings. One of the main is insufficient functional durability of prostheses, and as a consequence - the fragility of acrylic constructions. At present, more and more dentists use nonacrylic thermoplastics, which can improve the functional quality of full removable dentures, as well as, avoid the above disadvantages of acrylic basic plastic. The work is devoted to the study of comparative clinical effectiveness of dental prosthetic in edentulous patients using a variety of basic materials for the production of removable dentures. In this work we used the following materials - "Ftorax" - acrylic plastic of hot polymerization and «Vertex Thermosense» - nonacrylic thermoplastic plastic. As a result of the performed work it can be concluded that the use of the basic thermoplastic materials, namely «Vertex Thermosense», allows to get more rapid adaptation of the patient to full removable dentures due to better fixation and stabilization. Based on the results of our comparative clinical study it can be recommended using of base material «Vertex Thermosense» in the clinic of prosthetic dentistry in treatment of edentulous patients.

When and Why Does Materialism Relate to Employees' Attitudes and Well-being: The Mediational Role of Need Satisfaction and Need Frustration.

PubMed

Unanue, Wenceslao; Rempel, Konrad; Gómez, Marcos E; Van den Broeck, Anja

2017-01-01

Materialistic values may be detrimental for people's well-being. However, we know little about why (i.e., explaining mechanisms) and when (i.e., boundary conditions) this is the case. Although low satisfaction of the psychological needs is said to play a key role in this process, a recent meta-analysis indicates that the explaining power of need satisfaction is limited and suggests that need frustration may be more important. Moreover, although materialism may be detrimental in some life domains, studies in materialistic contexts such as work are lacking, particularly in the non-Western world. In response, we put need frustration to the fore and examine both need satisfaction and frustration as the underlying processes in the relation between materialism and employee attitudes and well-being in two Latin-American countries. The Chilean sample ( N = 742) shows that materialism at work is associated with less positive (work satisfaction and engagement) and more negative (burnout and turnover intentions) outcomes, even when controlling for workers' income. Notably, need frustration explained the detrimental effects of materialism alongside need satisfaction in a unique manner, showing that it is essential to distinguish both constructs. Results were replicated in Paraguay ( N = 518) using different positive (organizational commitment and meaning at work) and negative (negative emotions and job insecurity) outcomes, adding to the generalizability of our results across samples of different nations.

A theory of viscoplasticity accounting for internal damage

NASA Technical Reports Server (NTRS)

Freed, A. D.; Robinson, D. N.

1988-01-01

A constitutive theory for use in structural and durability analyses of high temperature isotropic alloys is presented. Constitutive equations based upon a potential function are determined from conditions of stability and physical considerations. The theory is self-consistent; terms are not added in an ad hoc manner. It extends a proven viscoplastic model by introducing the Kachanov-Rabotnov concept of net stress. Material degradation and inelastic deformation are unified; they evolve simultaneously and interactively. Both isotropic hardening and material degradation evolve with dissipated work which is the sum of inelastic work and internal work. Internal work is a continuum measure of the stored free energy resulting from inelastic deformation.

77 FR 46257 - Access Authorization Fees; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-03

[email protected] . List of Subjects 10 CFR Part 11 Hazardous materials--transportation, Investigations, Nuclear materials, Reporting and recordkeeping requirements, Security measures, Special nuclear... authorization fees charged to licensees for work performed under the Material Access Authorization Program (MAAP...

77 FR 26213 - Access Authorization Fees

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... and Regulations section of this Federal Register. List of Subjects 10 CFR Part 11 Hazardous materials--transportation, Investigations, Nuclear materials, Reporting and recordkeeping requirements, Security measures... amend its access authorization fees charged to licensees for work performed under the Material Access...

Control of Nanoscale Materials under the Toxic Substances Control Act

EPA Pesticide Factsheets

Many nanoscale materials are regarded as chemical substances, but they may have different properties than their larger counterparts. EPA is working to ensure that nanoscale materials are manufactured and used in ways that prevent risk to health.

Innovative contracting practices for ITS : task E final

DOT National Transportation Integrated Search

1997-07-01

An important property of materials that defines the viscoelastic and inelastic characteristics of materials is the dissipated work or dissipated energy of the material. Dissipated energy has been used in the asphalt concrete fatigue area for many yea...

A Simple Workstation for the Conservation of Library Materials.

ERIC Educational Resources Information Center

Conservation Correspondence, 1984

1984-01-01

The first step in designing a work station that is appropriate for both the maintenance and repair of library materials is to determine procedures likely to be necessary based on the nature of the collection and the type of use it receives. Necessary equipment includes a work station with a bench and storage space (an illustration and a list of…

Ethics and the New Materialism: A Brief Genealogy of the "Post" Philosophies in the Social Sciences

ERIC Educational Resources Information Center

Davies, Bronwyn

2018-01-01

This paper explores the relation between poststructuralist theorising and new materialism with a particular focus on the work of Barad. Tracing the lines of thought, particularly as they relate to ethics, through the works of Foucault, Butler, Cixous and Deleuze the paper finds a range of concepts that anticipate and link directly with Barad's…

Development of highly porous crystalline titania photocatalysts

NASA Astrophysics Data System (ADS)

Marszewski, Michal

The objectives of this dissertation are the design, synthesis, and characterization of titania materials with surface area, porosity, crystallinity and doping tailored toward photocatalytic applications. Ultimately, the research should result in a strategy allowing the synthesis of titania with all these important features. The synthetic methods investigated in this research will include: i) soft-templating, ii) hard-templating, and iii) modified precursor strategy. Soft-templating strategy uses organic templates--either block copolymers or surfactants--that under specific conditions assemble into micelles, and later, these micelles are used to template the desired material around them. The resulting organic-inorganic composite is then calcined in air to remove the organic template and recover the final material with high surface area and large pore volume. This work explores 1) synthesis of titania materials in the presence of polymer templates, and the effects of different synthetic conditions on the structure of the resulting materials. Hard-templating, in contrast to soft-templating, uses inorganic templates. The hard template is introduced during the synthesis to cast its shape onto the fabricated material and removed afterwards, when the material has formed. The final material is an inverse replica of the hard template used, typically with a well-developed mesostructure. This work explores 1) hard templating synthesis of titania materials using silica and alumina, and 2) the effects of the template amount and type. The modified precursor strategy is a novel synthetic method, developed in this research, and designed specifically to achieve titania material with high surface area, large pore volume, high crystallinity, and possibly doping. The modified precursors are prepared by reacting generic titania precursors, such as titanium isopropoxide (TIPO), with organic acids, which results in substitution of some or all alkoxide groups in TIPO structure. The goal is to introduce new, easily carbonizable groups in TIPO structure so that the modified precursor can serve as titania and carbon precursor simultaneously. Subsequently, during carbonization in inert atmosphere, a carbon framework is formed that works as a scaffold, protecting titania during its crystallization. Afterwards, the carbon scaffold is removed by calcination in air. This work explores the modified precursor strategy by 1) preparing titania materials from TIPO modified with different carboxylic acids and 2) investigating the effect of the modifying acid on the properties of the carbon-titania composites and the final titania materials.

Two-stage agglomeration of fine-grained herbal nettle waste

NASA Astrophysics Data System (ADS)

Obidziński, Sławomir; Joka, Magdalena; Fijoł, Olga

2017-10-01

This paper compares the densification work necessary for the pressure agglomeration of fine-grained dusty nettle waste, with the densification work involved in two-stage agglomeration of the same material. In the first stage, the material was pre-densified through coating with a binder material in the form of a 5% potato starch solution, and then subjected to pressure agglomeration. A number of tests were conducted to determine the effect of the moisture content in the nettle waste (15, 18 and 21%), as well as the process temperature (50, 70, 90°C) on the values of densification work and the density of the obtained pellets. For pre-densified pellets from a mixture of nettle waste and a starch solution, the conducted tests determined the effect of pellet particle size (1, 2, and 3 mm) and the process temperature (50, 70, 90°C) on the same values. On the basis of the tests, we concluded that the introduction of a binder material and the use of two-stage agglomeration in nettle waste densification resulted in increased densification work (as compared to the densification of nettle waste alone) and increased pellet density.

Advancements in the Quantification of the Crystal Structure of ZNS Materials Produced in Variable Gravity

NASA Astrophysics Data System (ADS)

Castillo, Martin

2016-07-01

Screens and displays consume tremendous amounts of power. Global trends to significantly consume less power and increase battery life have led to the reinvestigation of electroluminescent materials. The state of the art in ZnS materials has not been furthered in the past 30 years and there is much potential in improving electroluminescent properties of these materials with advanced processing techniques. Self-propagating high temperature synthesis (SHS) utilises a rapid exothermic process involving high energy and nonlinearity coupled with a high cooling rate to produce materials formed outside of normal equilibrium boundaries thus possessing unique properties. The elimination of gravity during this process allows capillary forces to dominate mixing of the reactants which results in a superior and enhanced homogeneity in the product materials. ZnS type materials have been previously conducted in reduced gravity and normal gravity. It has been claimed in literature that a near perfect phases of ZnS wurtzite was produced. Although, the SHS of this material is possible at high pressures, there has been no quantitative information on the actual crystal structures and lattice parameters that were produced in this work. Utilising this process with ZnS doped with Cu, Mn, or rare earth metals such as Eu and Pr leads to electroluminescence properties, thus making this an attractive electroluminescent material. The work described here will revisit the synthesis of ZnS via high pressure SHS and will re-examine the work performed in both normal gravity and in reduced gravity within the ZARM drop tower facility. Quantifications in the lattice parameters, crystal structures, and phases produced will be presented to further explore the unique structure-property performance relationships produced from the SHS of ZnS materials.

Half-Heusler Alloys as Promising Thermoelectric Materials

NASA Astrophysics Data System (ADS)

Page, Alexander A.

This thesis describes Ph.D. research on the half-Heusler class of thermoelectric materials. Half-Heusler alloys are a versatile class of materials that have been studied for use in photovoltaics, phase change memory, and thermoelectric power generation. With respect to thermoelectric power generation, new approaches were recently developed in order to improve the thermoelectric figure of merit, ZT, of half-Heusler alloys. Two of the strategies discussed in this work are adding excess Ni within MNiSn (M = Ti, Zr, or Hf) compounds to form full-Heusler nanostructures and using isoelectronic substitution of Ti, Zr, and Hf in MNiSn compounds to create microscale grain boundaries. This work uses computational simulations based on density functional theory, combined with the cluster expansion method, to predict the stable phases of pseudo-binary and pseudo-ternary composition systems. Statistical mechanics methods were used to calculate temperature-composition phase diagrams that relate the equilibrium phases. It is shown that full-Heusler nanostructures are predicted to remain stable even at high temperatures, and the microscale grain boundaries observed in (Ti,Zr,Hf)NiSn materials are found to be thermodynamically unstable at equilibrium. A new strategy of combining MNiSn materials with ZrNiPb has also recently emerged, and theoretical and experimental work show that a solid solution of the two materials is stable.

Flutter Phenomenon in Flow Driven Energy Harvester–A Unified Theoretical Model for “Stiff” and “Flexible” Materials

PubMed Central

Chen, Yu; Mu, Xiaojing; Wang, Tao; Ren, Weiwei; Yang, Ya; Wang, Zhong Lin; Sun, Chengliang; Gu, Alex Yuandong

2016-01-01

Here, we report a stable and predictable aero-elastic motion in the flow-driven energy harvester, which is different from flapping and vortex-induced-vibration (VIV). A unified theoretical frame work that describes the flutter phenomenon observed in both “stiff” and “flexible” materials for flow driven energy harvester was presented in this work. We prove flutter in both types of materials is the results of the coupled effects of torsional and bending modes. Compared to “stiff” materials, which has a flow velocity-independent flutter frequency, flexible material presents a flutter frequency that almost linearly scales with the flow velocity. Specific to “flexible” materials, pre-stress modulates the frequency range in which flutter occurs. It is experimentally observed that a double-clamped “flexible” piezoelectric P(VDF-TrFE) thin belt, when driven into the flutter state, yields a 1,000 times increase in the output voltage compared to that of the non-fluttered state. At a fixed flow velocity, increase in pre-stress level of the P(VDF-TrFE) thin belt up-shifts the flutter frequency. In addition, this work allows the rational design of flexible piezoelectric devices, including flow-driven energy harvester, triboelectric energy harvester, and self-powered wireless flow speed sensor. PMID:27739484

Fabrication of brittle materials -- current status

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scattergood, R.O.

The research initiatives in the area of precision fabrication will be continued in the upcoming year. Three students, T. Bifano (PhD), P. Blake (PhD) and E. Smith (MS), finished their research programs in the last year. Sections 13 and 14 will summarize the essential results from the work of the Materials Engineering students Blake and Smith. Further details will be presented in forthcoming publications that are now in preparation. The results from Bifano`s thesis have been published in adequate detail and need not be summarized further. Three new students, S. Blackley (MS), H. Paul (PhD), and S. Smith (PhD) havemore » joined the program and will continue the research efforts in precision fabrication. The programs for these students will be outlined in Sections 15 and 16. Because of the success of the earlier work in establishing new process models and experimental techniques for the study of diamond turning and diamond grinding, the new programs will, in part, build upon the earlier work. This is especially true for investigations concerned with brittle materials. The basic understanding of material response of nominally brittle materials during machining or grinding operations remains as a challenge. The precision fabrication of brittle materials will continue as an area of emphasis for the Precision Engineering Center.« less

Flutter Phenomenon in Flow Driven Energy Harvester-A Unified Theoretical Model for "Stiff" and "Flexible" Materials.

PubMed

Chen, Yu; Mu, Xiaojing; Wang, Tao; Ren, Weiwei; Yang, Ya; Wang, Zhong Lin; Sun, Chengliang; Gu, Alex Yuandong

2016-10-14

Here, we report a stable and predictable aero-elastic motion in the flow-driven energy harvester, which is different from flapping and vortex-induced-vibration (VIV). A unified theoretical frame work that describes the flutter phenomenon observed in both "stiff" and "flexible" materials for flow driven energy harvester was presented in this work. We prove flutter in both types of materials is the results of the coupled effects of torsional and bending modes. Compared to "stiff" materials, which has a flow velocity-independent flutter frequency, flexible material presents a flutter frequency that almost linearly scales with the flow velocity. Specific to "flexible" materials, pre-stress modulates the frequency range in which flutter occurs. It is experimentally observed that a double-clamped "flexible" piezoelectric P(VDF-TrFE) thin belt, when driven into the flutter state, yields a 1,000 times increase in the output voltage compared to that of the non-fluttered state. At a fixed flow velocity, increase in pre-stress level of the P(VDF-TrFE) thin belt up-shifts the flutter frequency. In addition, this work allows the rational design of flexible piezoelectric devices, including flow-driven energy harvester, triboelectric energy harvester, and self-powered wireless flow speed sensor.

Apparatus for depositing a low work function material

DOEpatents

Balooch, Mehdi; Dinh, Long N.; Siekhaus, Wigbert J.

2006-10-10

Short-wavelength photons are used to ablate material from a low work function target onto a suitable substrate. The short-wavelength photons are at or below visible wavelength. The elemental composition of the deposit is controlled by the composition of the target and the gaseous environment in which the ablation process is performed. The process is carried out in a deposition chamber to which a short-wavelength laser is mounted and which includes a substrate holder which can be rotated, tilted, heated, or cooled. The target material is mounted onto a holder that spins the target during laser ablation. In addition, the deposition chamber is provided with a vacuum pump, an external gas supply with atomizer and radical generator, a gas generator for producing a flow of molecules on the substrate, and a substrate cleaning device, such as an ion gun. The substrate can be rotated and tilted, for example, whereby only the tip of an emitter can be coated with a low work function material.

The Materiality of Fieldwork: An Ontology of Feminist Becoming

ERIC Educational Resources Information Center

Childers, Sara M.

2013-01-01

Through the materiality of fieldwork at a high-achieving high-poverty high school, I discuss how the collision between practices of feminist methodology and the materiality of fieldwork forced me to rethink the "feminist" in feminist research. Using the work of Karen Barad, this material-discursive account of methodology as ontology…

46 CFR 52.01-40 - Materials and workmanship.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Materials and workmanship. 52.01-40 Section 52.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-40 Materials and workmanship. All materials to be used in any of the work specified in the...

46 CFR 52.01-40 - Materials and workmanship.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Materials and workmanship. 52.01-40 Section 52.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-40 Materials and workmanship. All materials to be used in any of the work specified in the...

46 CFR 52.01-40 - Materials and workmanship.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Materials and workmanship. 52.01-40 Section 52.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-40 Materials and workmanship. All materials to be used in any of the work specified in the...

46 CFR 52.01-40 - Materials and workmanship.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Materials and workmanship. 52.01-40 Section 52.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-40 Materials and workmanship. All materials to be used in any of the work specified in the...

46 CFR 52.01-40 - Materials and workmanship.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Materials and workmanship. 52.01-40 Section 52.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-40 Materials and workmanship. All materials to be used in any of the work specified in the...

QUECHUA LANGUAGE MATERIALS PROJECT, GUIDE TO THE MATERIALS.

ERIC Educational Resources Information Center

SOLA, DONALD F.

THIS GUIDEBOOK DESCRIBES THE NATURE AND USE OF THE MATERIALS PREPARED FOR TEACHING THREE OF THE MAIN DIALECTS OF QUECHUA TO SPEAKERS OF ENGLISH INTERESTED IN WORKING OR DOING RESEARCH IN THE ANDEAN REGION. DESCRIPTIVE AND PEDAGOGICAL MATERIALS HAVE BEEN PREPARED FOR EACH OF THREE IMPORTANT DIALECTS--CUZCO AND AYACUCHO IN PERU, AND COCHABAMBA IN…

Recent progress of atomic layer deposition on polymeric materials.

PubMed

Guo, Hong Chen; Ye, Enyi; Li, Zibiao; Han, Ming-Yong; Loh, Xian Jun

2017-01-01

As a very promising surface coating technology, atomic layer deposition (ALD) can be used to modify the surfaces of polymeric materials for improving their functions and expanding their application areas. Polymeric materials vary in surface functional groups (number and type), surface morphology and internal structure, and thus ALD deposition conditions that typically work on a normal solid surface, usually do not work on a polymeric material surface. To date, a large variety of research has been carried out to investigate ALD deposition on various polymeric materials. This paper aims to provide an in-depth review of ALD deposition on polymeric materials and its applications. Through this review, we will provide a better understanding of surface chemistry and reaction mechanism for controlled surface modification of polymeric materials by ALD. The integrated knowledge can aid in devising an improved way in the reaction between reactant precursors and polymer functional groups/polymer backbones, which will in turn open new opportunities in processing ALD materials for better inorganic/organic film integration and potential applications. Copyright © 2016 Elsevier B.V. All rights reserved.

A hyperspectral X-ray computed tomography system for enhanced material identification

NASA Astrophysics Data System (ADS)

Wu, Xiaomei; Wang, Qian; Ma, Jinlei; Zhang, Wei; Li, Po; Fang, Zheng

2017-08-01

X-ray computed tomography (CT) can distinguish different materials according to their absorption characteristics. The hyperspectral X-ray CT (HXCT) system proposed in the present work reconstructs each voxel according to its X-ray absorption spectral characteristics. In contrast to a dual-energy or multi-energy CT system, HXCT employs cadmium telluride (CdTe) as the x-ray detector, which provides higher spectral resolution and separate spectral lines according to the material's photon-counter working principle. In this paper, a specimen containing ten different polymer materials randomly arranged was adopted for material identification by HXCT. The filtered back-projection algorithm was applied for image and spectral reconstruction. The first step was to sort the individual material components of the specimen according to their cross-sectional image intensity. The second step was to classify materials with similar intensities according to their reconstructed spectral characteristics. The results demonstrated the feasibility of the proposed material identification process and indicated that the proposed HXCT system has good prospects for a wide range of biomedical and industrial nondestructive testing applications.

Improving patient care through work-based learning.

PubMed

Chapman, Linda

To record post-registration community nurses' perceptions of the impact of work-based learning on the quality of patient care. Ten nurses were interviewed. Each interviewee, who had successfully completed work-based learning programmes, was asked to describe their impact on the quality of patient care. The participants valued work-based learning. Four themes emerged where work-based learning contributed to improving the quality of care: increased health promotion, increased access to services, increased patient choice and reduced risk of infection. The relevance of studies and distance learning materials were perceived to be the main aspects that influenced changes in practice. The study provides insight into how work-based learning helped staff develop practice. It highlights that time for learning and mentoring are paramount for changes in practice to occur through work-based learning. Further studies are required to establish the best structure and style of distance learning materials needed to meet the needs of post-registration community nurses.

Happiness and Satisfaction with Work Commute.

PubMed

Olsson, Lars E; Gärling, Tommy; Ettema, Dick; Friman, Margareta; Fujii, Satoshi

2013-03-01

Research suggests that for many people happiness is being able to make the routines of everyday life work, such that positive feelings dominate over negative feelings resulting from daily hassles. In line with this, a survey of work commuters in the three largest urban areas of Sweden show that satisfaction with the work commute contributes to overall happiness. It is also found that feelings during the commutes are predominantly positive or neutral. Possible explanatory factors include desirable physical exercise from walking and biking, as well as that short commutes provide a buffer between the work and private spheres. For longer work commutes, social and entertainment activities either increase positive affects or counteract stress and boredom. Satisfaction with being employed in a recession may also spill over to positive experiences of work commutes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11205-012-0003-2) contains supplementary material, which is available to authorized users.

Work stress among university teachers: gender and position differences.

PubMed

Slišković, Ana; Maslić Seršić, Darja

2011-12-01

The aim of this study was to investigate exposure to stress at work in university teachers and see if there were differences between men and women as well as between positions. The study was carried out online and included a representative sample of 1,168 teachers employed at universities in Croatia. This included all teaching positions: assistants (50%), assistant professors (18%), associate professors (17%), and full professors (15%). Fifty-seven percent of the sample were women. The participants answered a questionnaire of our own design that measured six groups of stressors: workload, material and technical conditions at work, relationships with colleagues at work, work with students, work organisation, and social recognition and status. Women reported greater stress than men. Assistant professors, associate professors, and full professors reported greater stress related to material and technical conditions of work and work organisation than assistants, who, in turn, found relationships with colleagues a greater stressor. Full professors, reported lower exposure to stress at work than associate professors, assistant professors, and assistants.

77 FR 26149 - Access Authorization Fees

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... Regulatory Affairs of OMB. List of Subjects 10 CFR Part 11 Hazardous materials--transportation... licensees for work performed under the Material Access Authorization Program (MAAP) and the Information... assigned duties which require access to special nuclear material (plutonium, uranium-233, and uranium...

School/Work Transition. A Bibliography.

ERIC Educational Resources Information Center

Florida State Univ., Tallahassee. Center for Instructional Development and Services.

This annotated bibliography contains 55 citations of materials that contain information on transitional programs for the physically or mentally challenged or disadvantaged students. Citations include descriptive, evaluative, and research reports; guides; information analyses; opinion papers; and reference materials. Materials for inclusion in this…

Exposure to radiation from the natural radioactivity in Tunisian building materials.

PubMed

Gharbi, F; Oueslati, M; Abdelli, W; Samaali, M; Ben Tekaya, M

2012-12-01

Building materials can expose public and workers to radiation because of their content of radium, thorium and potassium isotopes. This is why it is very important from the radiological point of view to survey the natural radioactivity content of commonly used building materials in any country. This work consists of the measurement of (226)Ra, (232)Th and (40)K activity concentrations in a variety of commonly used building materials in Tunisia and on the estimation of their radiological hazard. The maximum value of radium equivalent for the studied materials was equal to 169 Bq kg(-1) and corresponds to the clay brick, which is lower than the recommended value of 370 Bq kg(-1). In this work, several radiological indexes were calculated and were found to be under their highest permitted limit.

77 FR 29317 - Fiscal Year 2011 Draft Work Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

... DENALI COMMISSION Fiscal Year 2011 Draft Work Plan AGENCY: Denali Commission. ACTION: Notice... develop proposed work plans for future spending and that the annual Work Plan be published in the Federal... Work Plan for Federal Fiscal Year 2011. DATES: Comments and related material to be received by June 10...

Improving the Sun Drying of Apricots (Prunus armeniaca) with Photo-Selective Dryer Cabinet Materials.

PubMed

Milczarek, Rebecca R; Avena-Mascareno, Roberto; Alonzo, Jérôme; Fichot, Mélissa I

2016-10-01

Photo-selective materials have been studied for their effects on the preharvest quality of horticultural crops, but little work has been done on potential postharvest processing effects. The aim of this work was to characterize the effects of 5 different photo-selective acrylic materials (used as the lid to a single-layer sun drying cabinet) on the drying rate and quality of apricots (Prunus armeniaca). Photo-selective cabinet materials that transmit light in the visible portion of the solar spectrum accelerate the apricots' drying rate in both the early period of drying and the course of drying as a whole. These materials do not significantly affect the measured quality metrics during the first day of sun drying. However, when drying is taken to completion, some minor but significant quality differences are observed. Infrared-blocking material produces dried apricot with lower red color, compared to clear, opaque black, and ultraviolet-blocking materials. Clear material produced dried apricot with significantly lower antioxidant activity, compared to black and infrared-blocking materials. Using appropriate photo-selective drying cabinet materials can reduce the required sun drying time for apricots by 1 to 2 d, compared with fully shaded drying. Ultraviolet-blocking material is recommended to maximize drying rate and minimize quality degradation. © 2016 Institute of Food Technologists®.

Rapid microfluidic thermal cycler for nucleic acid amplification

DOEpatents

Beer, Neil Reginald; Vafai, Kambiz

2015-10-27

A system for thermal cycling a material to be thermal cycled including a microfluidic heat exchanger; a porous medium in the microfluidic heat exchanger; a microfluidic thermal cycling chamber containing the material to be thermal cycled, the microfluidic thermal cycling chamber operatively connected to the microfluidic heat exchanger; a working fluid at first temperature; a first system for transmitting the working fluid at first temperature to the microfluidic heat exchanger; a working fluid at a second temperature, a second system for transmitting the working fluid at second temperature to the microfluidic heat exchanger; a pump for flowing the working fluid at the first temperature from the first system to the microfluidic heat exchanger and through the porous medium; and flowing the working fluid at the second temperature from the second system to the heat exchanger and through the porous medium.

1974-75 NCTE Guide to Teaching Materials for English, Grades 7-12: An Annotated Listing of Textbooks and Related Materials for Secondary Schools Prepared by the NCTE Staff.

ERIC Educational Resources Information Center

National Council of Teachers of English, Urbana, IL.

This guide contains 550 annotations for English anthologies, textbooks, workbooks, multimedia packages, and other materials for grades 7-12. Works of literature, audiovisual materials, and professional publications are included only when integrally related to specific, listed instructional materials. Entries are grouped into the following subject…

Cyberpeace Through Cyberspace: Nation-Building Against Transnational Terrorism

DTIC Science & Technology

2010-12-01

Haiti,” The Seattle Times, January 27, 2010 at: http://seattletimes.nwsource.com/html/nationworld/2010910268_haiti28.html? syndication =rss (accessed...March 30, 2010 at: http://www.thebulletin.org/web-edition/ columnists /fissile-materials- working-group/reduce-the-civilian-use-of-heu-now (accessed...Bulletin of the Atomic Scientists, March 30, 2010. http://www.thebulletin.org/web- edition/ columnists /fissile-materials-working-group/reduce-the

Intelligence Preparation for Operational Resilience (IPOR)

DTIC Science & Technology

2015-12-01

unlimited distribution except as restricted below. Internal use:* Permission to reproduce this material and to prepare derivative works from this...material for internal use is granted, provided the copyright and “No Warranty” statements are included with all reproductions and de- rivative works...legal coun- sel regarding the latest state of jurisprudence . 2.1.3 Determine the Technological Environment Changes in the technical landscape can also

U.S. Navy Advanced Receiving: A Better Approach to the Basics.

DTIC Science & Technology

1987-04-01

the Navy and DLA should begin now to plan for electronic interchange of data between their inventory management systems. This would eliminate the...labor savings from work simplification, improved material handling, and better work load planning 0 Material savings from reduced packaging and use of... planning purposes, source distribution managers use the following equa- tion to determine maximum consolidation time: Maximum consolidation time = 21

Federal Information Resources for Professional Counselors. A Sourcebook of Free and Low-Cost Resources To Support and Enrich Your Work as a Professional Counselor.

ERIC Educational Resources Information Center

Lum, Christie

This publication is a sourcebook of free and low-cost resources to support the work of professional counselors. The information includes: (1) synthesis of current research, statistics, and research reports; (2) background material about current and emerging policy issues; (3) information about model programs and policies; (4) materials and…

Room-temperature ferromagnetism in Fe-based perovskite solid solution in lead-free ferroelectric Bi0.5Na0.5TiO3 materials

NASA Astrophysics Data System (ADS)

Hung, Nguyen The; Bac, Luong Huu; Trung, Nguyen Ngoc; Hoang, Nguyen The; Van Vinh, Pham; Dung, Dang Duc

2018-04-01

The integration of ferromagnetism in lead-free ferroelectric materials is important to fabricate smart materials for electronic devices. In this work, (1 - x)Bi0.5Na0.5TiO3 + xMgFeO3-δ materials (x = 0-9 mol%) were prepared through sol-gel method. X-ray diffraction characterization indicated that MgFeO3-δ materials existed as a well solid solution in lead-free ferroelectric Bi0.5Na0.5TiO3 materials. The rhombohedral structure of Bi0.5Na0.5TiO3 materials was distorted due to the random distribution of Mg and Fe cations into the host lattice. The reduced optical band gap and the induced room-temperature ferromagnetism were due to the spin splitting of transition metal substitution at the B-site of perovskite Bi0.5Na0.5TiO3 and the modification by A-site co-substitution. This work elucidates the role of secondary phase as solid solution in Bi0.5Na0.5TiO3 material for development of lead-free multiferroelectric materials.

Complex Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooper, Valentino

2014-04-17

Valentino Cooper uses some of the world's most powerful computing to understand how materials work at subatomic levels, studying breakthroughs such as piezoelectrics, which convert mechanical stress to electrical energy.

Complex Materials

ScienceCinema

Cooper, Valentino

2018-05-16

Valentino Cooper uses some of the world's most powerful computing to understand how materials work at subatomic levels, studying breakthroughs such as piezoelectrics, which convert mechanical stress to electrical energy.

Thermal analysis of friction riveting of dissimilar materials

NASA Astrophysics Data System (ADS)

Vignesh, N. J.; Hynes, N. Rajesh Jesudoss

2018-05-01

Friction riveting is a new technique which finds its applications in a variety of domains, where there is a need to join dissimilar materials for the sake of achieving weight reduction of the components produced especially in the fields of aerospace and automobile. In this present work, a numerical simulation on the heat transfer analysis has been done to predict the variation of temperature on the surface of the components being joined. Owing to the applications, Aluminum rivet is chosen for friction riveting on Poly Methyl Metha Acrylate base material. Abaqus explicit version 6.14 has been used to simulate the results of the process. Heat flux at the joint interface has been computed and thermal distribution at the work material is predicted.

Millwright Instructional Materials.

ERIC Educational Resources Information Center

Hendrix, Laborn J.; Pierce, Greg

This manual contains instructional materials for use in training millwrights working in industrial and commercial construction sites. Intended as an innovative complement to on-the-job training in construction, the material is written in terms of student performance using behavioral objectives and measured by criterion-referenced evaluation…

Powertrain Materials: The Road to Higher Efficiencies

ScienceCinema

None

2018-01-16

Advanced powertrain materials are critical for automakers to meet new fuel economy standards. Researchers at the Department of Energy’s Oak Ridge National Laboratory are working with industry to develop new propulsion materials that offer improved performance at lower costs.

Electrochemical micro sensor

DOEpatents

Setter, Joseph R.; Maclay, G. Jordan

1989-09-12

A micro-amperometric electrochemical sensor for detecting the presence of a pre-determined species in a fluid material is disclosed. The sensor includes a smooth substrate having a thin coating of solid electrolytic material deposited thereon. The working and counter electrodes are deposited on the surface of the solid electrolytic material and adhere thereto. Electrical leads connect the working and counter electrodes to a potential source and an apparatus for measuring the change in an electrical signal caused by the electrochemical oxidation or reduction of the species. Alternatively, the sensor may be fabricated in a sandwich structure and also may be cylindrical, spherical or other shapes.

A Comparative Evaluation of Accuracy of the Dies Affected by Tray Type, Material Viscosity, and Pouring Sequence of Dual and Single Arch Impressions- An In vitro Study

PubMed Central

Kulkarni, Rahul S.; Shah, Rupal J.; Chhajlani, Rahul; Saklecha, Bhuwan; Maru, Kavita

2017-01-01

Introduction The clinician’s skill, impression techniques, and materials play a very important role in recording fine details in an impression for accuracy of fixed partial denture prosthesis. Impression of prepared teeth and of the opposing arch can be recorded simultaneously by dual-arch trays, while the full arch metal trays are used for impressions of prepared teeth in one arch. Aim To measure and compare the accuracy of working dies made from impressions with metal and plastic dual arch trays and metal full arch trays, for two viscosities of impression material and by changing the sequence of pour of working and non-working sides. Materials and Methods A balanced design with independent samples was used to study the three variables (tray type, impression material viscosity, and pouring sequence). An impression made by dual arch trays and single arch trays were divided in to three groups (Group A-plastic dual arch tray, Group B-metal dual arch tray, Group C-full arch metal stock tray). Out of these three groups, two groups (Group A and B) were subdivided in to four subgroups each and one group (Group C) was subdivided in to two subgroups. A sample size of 30 was used in each subgroup yielding a total 300 impressions in three groups or ten subgroups. Impressions were made of a machined circular stainless steel die. All three dimensions (Occlusogingival, Mesiodistal, and Buccolingual) of the working dies as well as stainless steel standard die were measured three times, and the mean was used for the three standard sample values to which all working dies means were compared. Statistical analysis used for this study was a 3-factor analysis of variance with hypothesis testing at α =0.05. Results With respect to the selection of impression material viscosity statistically significant differences were found in the dies for the buccolingual and mesiodistal dimensions. Metal dual arch trays were slightly more accurate in the mesiodistal dimension in comparison to the plastic trays in reference of tray selection and in view of pouring sequence no differences were observed in occlusogingival dimension but in buccolingual and mesiodistal dimensions nonworking side was more accurate. Conclusion The gypsum dies produced from the dual arch impressions were generally smaller in all three dimensions than the stainless steel standard die. Plastic dual-arch trays were more accurate with rigid impression material and there was not statistically significant difference for sequence of pouring. Metal dual-arch trays were more accurate with monophase impression material and working side was more accurate. Stock metal full arch trays were more accurate for monophase impression material. PMID:28571280

Space Exploration: Oh, the Materials You'll Need!

NASA Technical Reports Server (NTRS)

Johnson, Sylvia M.

2016-01-01

Space exploration has many challenges and materials are critical for many of the systems required to enable robotic or human space exploration. This talk will highlight challenges for materials with an emphasis on thermal protection materials and systems. Solving the materials issues will require thinking about materials in the systems and environments where are they to be used. In many cases the materials must be designed for the application, and the system needs to be designed with the materials in mind. The talk will conclude with some thoughts on the skills needed for materials scientists and engineers working on materials for space.

Anisotropy of machine building materials

NASA Technical Reports Server (NTRS)

Ashkenazi, Y. K.

1981-01-01

The results of experimental studies of the anisotropy of elastic and strength characteristics of various structural materials, including pressure worked metals and alloys, laminated fiberglass plastics, and laminated wood plastics, are correlated and classified. Strength criteria under simple and complex stresses are considered as applied to anisotropic materials. Practical application to determining the strength of machine parts and structural materials is discussed.

Measurements needed for on-line control of retention and drainage

Treesearch

Allan M. Springer; Jeffrey S. Noe; T. H. Wegner

1987-01-01

In a retention and drainage control strategy, it is necessary to monitor the concentration of dissolved inorganic material and the concentration of dissolved and colloidal organic material. Conductivity is successful as a sensor to monitor inorganic material. We studied TOC as a means to monitor dissolved and colloidal organic material and found it to work well. Both...

Learning Materials for Open Learning in Further Education. Coombe Lodge Working Paper. Information Bank Number 1606.

ERIC Educational Resources Information Center

Latcham, J.

Arguing that extensive efforts to produce open learning materials should not be undertaken until the possibility of using or adapting existing materials is considered, this paper identifies current sources of materials available in Great Britain for non-advanced further education. The first sections of the paper review common types of open…

Implementing Title IX and Attaining Sex Equity. Application Materials for Counselors.

ERIC Educational Resources Information Center

National Foundation for the Improvement of Education, Washington, DC. Resource Center on Sex Roles in Education.

The materials included in this booklet are designed for use by participants in Application Sessions A and B for counselors working with elementary-secondary schools. These materials are initial drafts prepared for field testing only. They are not the final products to be delivered at the completion of the project. The materials are organized…

Reception and study of lunar surface material in inert gas medium. [considering laboratory vacuum receiving chamber

NASA Technical Reports Server (NTRS)

Surkov, Y. A.; Rudnitskiy, Y. M.; Glotov, V. A.

1974-01-01

The reception and study of lunar material returned by the Luna 16 space station is described. The layout of a vacuum receiving chamber for working with material in a helium atmosphere is examined along with the main operations involved in extracting the material from the ampule and drill.

Using a detailed inventory of a large wastewater treatment plant to estimate the relative importance of construction to the overall environmental impacts.

PubMed

Morera, Serni; Corominas, Lluís; Rigola, Miquel; Poch, Manel; Comas, Joaquim

2017-10-01

The aim of this work is to quantify the relative contribution to the overall environmental impact of the construction phase compared to the operational phase for a large conventional activated sludge wastewater treatment plant (WWTP). To estimate these environmental impacts, a systematic procedure was designed to obtain the detailed Life Cycle Inventories (LCI) for civil works and equipment, taking as starting point the construction project budget and the list of equipment installed at the Girona WWTP, which are the most reliable information sources of materials and resources used during the construction phase. A detailed inventory is conducted by including 45 materials for civil works and 1,240 devices for the equipment. For most of the impact categories and different life spans of the WWTP, the contribution of the construction phase to the overall burden is higher than 5% and, especially for metal depletion, the impact of construction reaches 63%. When comparing to the WWTP inventories available in Ecoinvent the share of construction obtained in this work is about 3 times smaller for climate change and twice higher for metal depletion. Concrete and reinforcing steel are the materials with the highest contribution to the civil works phase and motors, pumps and mobile and transport equipment are also key equipment to consider during life cycle inventories of WWTPs. Additional robust inventories for similar WWTP can leverage this work by applying the factors (kg of materials and energy per m 3 of treated water) and guidance provided. Copyright © 2017 Elsevier Ltd. All rights reserved.

Embodied labour in music work.

PubMed

Pettinger, Lynne

2015-06-01

This paper frames the work of performance as embodied labour in order to understand the contingent production of particular music performances. It is an interdisciplinary account that sits at the intersection of the sociology of work, culture and the body. The concept of embodied labour is developed with reference to the complex account of materiality - of bodies and things - present in Tim Ingold's account of skill. This material account of skill is used to inform use to develop already of well established conceptualizations of body labour: craft, emotional and aesthetic labour through a reading of how these dimensions of embodied labour make possible the work of performance. © London School of Economics and Political Science 2015.

77 FR 24759 - Aviation Rulemaking Advisory Committee Meeting on Transport Airplane and Engine Issues

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-25

... Harmonization Working Group Report. Materials Flammability Working Group Report. Aging Airplanes Working Group... meeting documents, please contact the person listed in the FOR FURTHER INFORMATION CONTACT section. Sign...

48 CFR 1352.271-70 - Inspection and manner of doing work.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Department of the Navy. The welder's qualifications shall be appropriate for the particular service... waste material or rubbish caused by contractor employees or the work, and at the completion of the work...

48 CFR 1352.271-70 - Inspection and manner of doing work.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Department of the Navy. The welder's qualifications shall be appropriate for the particular service... waste material or rubbish caused by contractor employees or the work, and at the completion of the work...

48 CFR 1352.271-70 - Inspection and manner of doing work.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Department of the Navy. The welder's qualifications shall be appropriate for the particular service... waste material or rubbish caused by contractor employees or the work, and at the completion of the work...

48 CFR 1352.271-70 - Inspection and manner of doing work.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Department of the Navy. The welder's qualifications shall be appropriate for the particular service... waste material or rubbish caused by contractor employees or the work, and at the completion of the work...

48 CFR 1352.271-70 - Inspection and manner of doing work.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Department of the Navy. The welder's qualifications shall be appropriate for the particular service... waste material or rubbish caused by contractor employees or the work, and at the completion of the work...

76 FR 80970 - Records Schedules; Availability and Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... studies working groups and other senior bodies, and substantive working papers. 11. Office of the Director... external web page material, and non-substantive working papers and drafts. Proposed for permanent retention... correspondence, staff-level working groups and committees, advisory program background information, non...

Engineering Ultra-Low Work Function of Graphene.

PubMed

Yuan, Hongyuan; Chang, Shuai; Bargatin, Igor; Wang, Ning C; Riley, Daniel C; Wang, Haotian; Schwede, Jared W; Provine, J; Pop, Eric; Shen, Zhi-Xun; Pianetta, Piero A; Melosh, Nicholas A; Howe, Roger T

2015-10-14

Low work function materials are critical for energy conversion and electron emission applications. Here, we demonstrate for the first time that an ultralow work function graphene is achieved by combining electrostatic gating with a Cs/O surface coating. A simple device is built from large-area monolayer graphene grown by chemical vapor deposition, transferred onto 20 nm HfO2 on Si, enabling high electric fields capacitive charge accumulation in the graphene. We first observed over 0.7 eV work function change due to electrostatic gating as measured by scanning Kelvin probe force microscopy and confirmed by conductivity measurements. The deposition of Cs/O further reduced the work function, as measured by photoemission in an ultrahigh vacuum environment, which reaches nearly 1 eV, the lowest reported to date for a conductive, nondiamond material.

Deep Boreholes Seals Subjected to High P, T conditions – Preliminary Experimental Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caporuscio, Florie Andre; Norskog, Katherine Elizabeth; Maner, James Lavada

The objective of this planned experimental work is to evaluate physio-chemical processes for ‘seal’ components and materials relevant to deep borehole disposal. These evaluations will encompass multi-laboratory efforts for the development of seals concepts and application of Thermal-Mechanical-Chemical (TMC) modeling work to assess barrier material interactions with subsurface fluids, their stability at high temperatures, and the implications of these processes to the evaluation of thermal limits. Deep borehole experimental work will constrain the Pressure, Temperature (P, T) conditions which “seal” material will experience in deep borehole crystalline rock repositories. The rocks of interest to this study include the silicic (graniticmore » gneiss) end members. The experiments will systematically add components to capture discrete changes in both water and EBS component chemistries.« less

Engineering management technologies of increasing energy efficiency processes in the investment and construction projects

NASA Astrophysics Data System (ADS)

Borisovich Zelentsov, Leonid; Dmitrievna Mailyan, Liya; Sultanovich Shogenov, Murat

2017-10-01

The article deals with the problems of using the energy-efficient materials and engineering technologies during the construction of buildings and structures. As the analysis showed, one of the most important problems in this sphere is the infringement of production technologies working with energy-efficient materials. To improve the given situation, it is offered to set a technological normal at the design stage by means of working out the technological maps studying the set and the succession of operations in details, taking in mind the properties of energy-efficient materials. At Don State Technical University (DSTU) the intelligent systems of management are being developed providing organizational and technological and also informational integration of design and production stages by means of creating the single database of technological maps, volumes of work and resources.

Modeling liquid crystal polymeric devices

NASA Astrophysics Data System (ADS)

Gimenez Pinto, Vianney Karina

The main focus of this work is the theoretical and numerical study of materials that combine liquid crystal and polymer. Liquid crystal elastomers are polymeric materials that exhibit both the ordered properties of the liquid crystals and the elastic properties of rubbers. Changing the order of the liquid crystal molecules within the polymer network can induce shape change. These materials are very valuable for applications such as actuators, sensors, artificial muscles, haptic displays, etc. In this work we apply finite element elastodynamics simulations to study the temperature induced shape deformation in nematic elastomers with complex director microstructure. In another topic, we propose a novel numerical method to model the director dynamics and microstructural evolution of three dimensional nematic and cholesteric liquid crystals. Numerical studies presented in this work are in agreement with experimental observations and provide insight into the design of application devices.

Experiments With Small Animals Rarely Go This Well

NASA Technical Reports Server (NTRS)

2005-01-01

In the mid-1950s, a young U.S. Air Force engineer named Clark Beck began work with what is now one of NASA s most prolific spinoffs, the radiant barrier technology. Beck s work involved creating materials that could withstand the immense heat created by passage through the Earth s atmosphere. He was working on structures and resources that could withstand the fluctuations in temperature created by a skip reentry, where a craft would skip along the surface of the atmosphere, gradually making inroads sufficient for reentry, a process that took the craft from extreme heat to frigid cold every few seconds. The material also needed to withstand millions of pounds of pressure per inch of bending without twisting, the simulated force of reentry. Without reflective material, the craft would get what Beck refers to as "red hot wings," and without the required flexibility, the craft would break apart. One result of Beck s work was the discovery of the useful properties of radiant barrier material. The Space Agency used Beck s design work for the materials that went into building the space capsules, heat resistant instrument panels, and, in conjunction with the Air Force, an early spacecraft prototype, the DynaSoar, that looks remarkably similar to the present-day Space Shuttle. NASA used the thin, shiny, silver material to protect the first space explorers from the harsh environment of space, which could range from -460 F to 541 F. If the engineers had used conventional insulation for the space suits, the fabric would have been 7-feet thick, a little awkward for even the most nimble of astronauts to maneuver. Radiant barrier technology was clearly the solution. It reflected the astronaut s body heat back into the suit to keep him warm, while at the same time reflecting radiant energy from the Sun outward to keep him cool. The radiant barrier material reflected more than 95 percent of the radiant energy away from the wearer, while tiny holes in the fabric allowed moisture to escape and longer heat waves to get through. This amazing fabric had an added benefit that made it ideal for its space-bound application: It weighed only 17 pounds per 1,000 square feet. NASA has used this material ever since the Gemini and Apollo missions, on virtually all of its spacecraft, and even on unmanned missions as thermal protection for instruments.

Annotated Bibliography of Materials for Elementary Foreign Language Programs.

ERIC Educational Resources Information Center

Dobb, Fred

An annotated bibliography contains about 70 citations of instructional materials and materials concerning curriculum development for elementary school foreign language programs. Citations are included for Arabic, classical languages, French, German, Hebrew, Italian, Japanese, and Spanish. Items on exploratory language courses and general works on…

Meeting Materials for OECD Expert Meeting on Categorization of Manufactured Nanomaterials on September 17-19, 2014

EPA Pesticide Factsheets

Here are materials for the OECD Working Party on Nanomanufactured Materials Expert Meeting on Categorization of Nanomaterials (developing nanomaterial categories) took place on September 17-19, 2014 in Washington, D.C hosted by U.S. EPA.

Multi-material composites prepared by additive manufacturing and melt casting

NASA Astrophysics Data System (ADS)

Murialdo, Maxwell; Sullivan, Kyle; White, Bradley; LLNL MSD Collaboration

2017-06-01

Recent advances in additive manufacturing have disrupted not only means of production, but also have enabled a new parameter space of multiscale materials designs. Understanding the role of architecture to control material response is being investigated for a wide range of applications, from light-weight structural components to energetic materials. In this work, we combine 3D printing of scaffold structures with a subsequent melt-infiltration step to render an architected multi-material composite article. Both the scaffold architecture and material type were investigated. The processing challenges of filling such scaffolds using a melt-infiltration step will be discussed, along with our progress in this area. Using the combined method of printing and casting, we will discuss our path forward for testing the mechanical properties and the high-strain response of our composite architected parts. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. IM release: LLNL-ABS-725497-DRAFT.

When and Why Does Materialism Relate to Employees’ Attitudes and Well-being: The Mediational Role of Need Satisfaction and Need Frustration

PubMed Central

Unanue, Wenceslao; Rempel, Konrad; Gómez, Marcos E.; Van den Broeck, Anja

2017-01-01

Materialistic values may be detrimental for people’s well-being. However, we know little about why (i.e., explaining mechanisms) and when (i.e., boundary conditions) this is the case. Although low satisfaction of the psychological needs is said to play a key role in this process, a recent meta-analysis indicates that the explaining power of need satisfaction is limited and suggests that need frustration may be more important. Moreover, although materialism may be detrimental in some life domains, studies in materialistic contexts such as work are lacking, particularly in the non-Western world. In response, we put need frustration to the fore and examine both need satisfaction and frustration as the underlying processes in the relation between materialism and employee attitudes and well-being in two Latin–American countries. The Chilean sample (N = 742) shows that materialism at work is associated with less positive (work satisfaction and engagement) and more negative (burnout and turnover intentions) outcomes, even when controlling for workers’ income. Notably, need frustration explained the detrimental effects of materialism alongside need satisfaction in a unique manner, showing that it is essential to distinguish both constructs. Results were replicated in Paraguay (N = 518) using different positive (organizational commitment and meaning at work) and negative (negative emotions and job insecurity) outcomes, adding to the generalizability of our results across samples of different nations. PMID:29066992

Technical Assistance to Developers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rockward, Tommy; Borup, Rodney L.; Garzon, Fernando H.

2012-07-17

This task supports the allowance of technical assistance to fuel-cell component and system developers as directed by the DOE. This task includes testing of novel materials and participation in the further development and validation of single cell test protocols. This task also covers technical assistance to DOE Working Groups, the U.S. Council for Automotive Research (USCAR) and the USCAR/DOE Driving Research and Innovation for Vehicle efficiency and Energy sustainability (U.S. Drive) Fuel Cell Technology Team. Assistance includes technical validation of new fuel cell materials and methods, single cell fuel cell testing to support the development of targets and test protocols,more » and regular advisory participation in other working groups and reviews. This assistance is made available to PEM fuel cell developers by request and DOE Approval. The objectives are to: (1) Support technically, as directed by DOE, fuel cell component and system developers; (2) Assess fuel cell materials and components and give feedback to developers; (3) Assist the DOE Durability Working Group with the development of various new material durability Testing protocols; and (4) Provide support to the U.S. Council for Automotive Research (USCAR) and the USCAR/DOE Fuel Cell Technology Team. FY2012 specific technical objectives are: (1) Evaluate novel MPL materials; (2) Develop of startup/ shutdown protocol; (3) Test the impact of hydrophobic treatment on graphite bi-polar plates; (4) Perform complete diagnostics on metal bi-polar plates for corrosion; and (5) Participate and lead efforts in the DOE Working Groups.« less

FY2010 Annual Progress Report for Propulsion Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Patrick B.; Schutte, Carol L.; Gibbs, Jerry L.

The Propulsion Materials Technology actively supports the energy security and reduction of greenhouse emissions goals of the Vehicle Technologies Program by developing advanced materials that enable development of higher efficiency powertrains for ground transportation. Propulsion Materials works closely with the other disciplines within the VT Program to identify the materials properties essential for the development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light duty powertrains.

BOOK REVIEW: Heterogeneous Materials I and Heterogeneous Materials II

NASA Astrophysics Data System (ADS)

Knowles, K. M.

2004-02-01

In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field\

Rubber-based carbon electrode materials derived from dumped tires for efficient sodium-ion storage.

PubMed

Wu, Zhen-Yue; Ma, Chao; Bai, Yu-Lin; Liu, Yu-Si; Wang, Shi-Feng; Wei, Xiao; Wang, Kai-Xue; Chen, Jie-Sheng

2018-04-03

The development of sustainable and low cost electrode materials for sodium-ion batteries has attracted considerable attention. In this work, a carbon composite material decorated with in situ generated ZnS nanoparticles has been prepared via a simple pyrolysis of the rubber powder from dumped tires. Upon being used as an anode material for sodium-ion batteries, the carbon composite shows a high reversible capacity and rate capability. A capacity as high as 267 mA h g-1 is still retained after 100 cycles at a current density of 50 mA g-1. The well dispersed ZnS nanoparticles in carbon significantly enhance the electrochemical performance. The carbon composites derived from the rubber powder are proposed as promising electrode materials for low-cost, large-scale energy storage devices. This work provides a new and effective method for the reuse of dumped tires, contributing to the recycling of valuable waste resources.

Refractory materials for high-temperature thermoelectric energy conversion

NASA Technical Reports Server (NTRS)

Wood, C.; Emin, D.

1983-01-01

Theoretical work of two decades ago adequately explained the transport behavior and effectively guided the development of thermoelectric materials of high conversion efficiencies of conventional semiconductors (e.g., SiGe alloys). The more significant contributions involved the estimation of optimum doping concentrations, the reduction of thermal conductivity by solid solution doping and the development of a variety of materials with ZT approx. 1 in the temperature range 300 K to 1200 K. ZT approx. 1 is not a theoretical limitation although, experimentally, values in excess of one were not achieved. Work has continued with emphasis on higher temperature energy conversion. A number of promising materials have been discovered in which it appears that ZT 1 is realizable. These materials are divided into two classes: (1) the rare-earth chalcogenides which behave as itinerant highly-degenerate n-type semiconductors at room-temperature, and (2) the boron-rich borides, which exhibit p-type small-polaronic hopping conductivity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Fang; Yao, Yuze; Wang, Haiyan

Rational and precise control of the structure and dimension of electrode materials is an efficient way to improve their electrochemical performance. In this work, solvothermal or co-precipitation method is used to synthesize lithium-rich layered oxide materials of Li1.2Mn0.56Co0.12Ni0.12O2 (LLO) with various morphologies and structures, including microspheres, microrods, nanoplates, and irregular nanoparticles. These materials exhibit strong structure- dependent electrochemical properties. The porous hierarchical structured LLO microrods exhibit the best performance, delivering a discharge capacity of 264.6 mAh g(-1) at 0.5 C with over 91% retention after 100 cycles. At a high rate of 5 C, a high discharge capacity of 173.6more » mAh g(-1) can be achieved. This work reveals the relationship between the morphologies and electrochemical properties of LLO cathode materials, and provides a feasible approach to fabricating robust and high-performance electrode materials for lithium-ion batteries.« less

US Air Force perspective on validated NDE - Past, present, and future

NASA Astrophysics Data System (ADS)

Lindgren, Eric A.

2016-02-01

The concept of inspection has accompanied aviation since the work of the Wright Brothers. Inspection for both initial quality/materials acceptance and readiness for flight have been coupled with US Air Force (USAF) since its inception as the US Army Signal Corps. Initial nondestructive evaluation work expanded beyond visual inspection to include radiography and magnetic particle in the 1920's and 1930's as air frames transitioned to metal and engines used higher strength steels. Within the USAF Research and Development community, a Nondestructive Test Section was stood up in 1952 and the Nondestructive Evaluation Branch (NDE) was established in 1974. In 2012 the name was changed to the Materials State Awareness Branch. This name change reflects the evolution from a primary focus on inspections for damage and defects in materials to the characterization of the underlying materials structure that governs properties of the materials of interest for Air Force applications.

Two-Component Additive Manufacturing of Nanothermite by Reactive Inkjet Printing

NASA Astrophysics Data System (ADS)

Murray, Allison; Novotny, Whitney; Fleck, Trevor; Gunduz, Emre; Son, Steven; Chiu, George; Rhoads, Jeffrey

2017-06-01

To broaden the type of energetic materials that can be selectively deposited and improve the safety of their deposition, this work demonstrates the use of combinatorial inkjet printing for the selective deposition of energetic material. Two inert colloidal suspensions of nano-aluminum and nano-copper (II) oxide in dimethylformamide (DMF) with polyvinylpyrrolidone (PVP) were sequentially deposited on a substrate using piezoelectric inkjet printing. By depositing the materials at the same location, in situ mixing produced a reactive nanothermite. This process was continued to produce layers of nanothermite until the desired quantity of material was deposited. Samples with precise geometric control and high fidelity energetic performance were achieved. This work proves the feasibility of reactive inkjet printing as a means for depositing energetic materials from two largely-inert suspensions. In doing so, it opens the doors for safe material handling and the development of a wide array of energetic materials that were previously deemed incompatible with inkjet printing. This research is supported by the U.S. Department of Defense, Defense Threat Reduction Agency through Grant No. HDTRA1-15-1-0010.

Thermophysical and mechanical characterization of clay bricks reinforced by alfa or straw fibers

NASA Astrophysics Data System (ADS)

Elhamdouni, Y.; Khabbazi, A.; Benayad, C.; Mounir, S.; Dadi, A.

2017-03-01

This work is part of the valuation of local materials such as clay (earth), alfa fiber and straw fiber. The goal is to use these materials as bricks in rural construction. These materials are abundant, natural, and renewable. The objective of this work is to study the thermal and mechanical behavior of a new material by mixing clay (chosen as the binder) with different mass percentages of alfa fiber (0.5%, 1%, 2%, 3%, 4%), and to compare these results with those of materials often used in the construction of individual houses in rural Morocco (clay + straw). The results obtained prove to us that using straw fibers can reduce the thermal conductivity compared to alfa fiber, which allows to have energy savings of 2% to 7%. By against, alfa fibers can improve the mechanical behavior of clay-based materials when compared to the clay + straw material (an increase of 8% to 17% in the tractive resistance by bending and 6% to 18% for compression resistance). These results also specify the optimal usage conditions of these fibers (alfa and straw) in the clay bricks.

Development of Surface Mechanical Attrition Treatment (SMAT) and Electrodeposition Process for Generating Nanostructured Materials and Study of Their Tensile Properties

NASA Astrophysics Data System (ADS)

Chan, Hoi Lam

This work systematically investigates two of the most promising synthesis methods for producing nanostructured (NS) materials: surface mechanical attrition treatment (SMAT) and the electrodeposition (ED) process, and obtains the proper conditions for fabricating NS materials in bulk form and studies the properties of these materials. SMAT is one of the recently developed processes to form nano-crystallized surface layer and refine grains in the subsurface layers, by actuating a number of spherical projectiles to impact the sample surface. In this work, the detailed measurement of ball impinging velocity is presented, and the resulted strain-rate and strains are theoretically modeled. Consequently the relation between plastic strain history and the observed microstructures is established. The SMAT process with different numbers of balls is explored to manifest that an optimum number of balls exists for the highest efficiency. ED process is widely used in producing NS materials these days. In this work, the relationships among non-metallic substrates, current type, current densities, microstructure and crystallographic textures, and mechanical properties is presented in order to demonstrate the influences of the deposition parameters in obtaining nano-grains and nano-twins microstructures. This work also examines the availability of obtaining bulk NS materials with desirable ductility in production-scale conditions through understanding these relationships. In the last part of the study, the effect of SMAT on the electrodeposits is studied. Tensile properties, microstructures and textures of the SMATed electrodeposits have been examined. The results demonstrate that the NS matrix obtained by the ED process with sufficient thickness retains desirable ductility after employing SMAT technology, and the SMAT process further enhances the strength of the electrodeposits.

Does the psychosocial quality of unpaid family work contribute to educational disparities in mental health among employed partnered mothers?

PubMed

Janzen, Bonnie; Hellsten, Laurie-Ann M

2018-04-24

The contribution of unpaid family work quality to understanding social inequalities in women's mental health has been understudied and further limited by a scarcity of psychometrically sound instruments available to measure family work. Therefore, using a multi-item scale of family work quality with evidence of validity and reliability, the overall aim of the present study was to determine whether psychosocial qualities of unpaid family work contribute to educational inequities in women's mental health. Study participants in this cross-sectional study were 512 employed partnered mothers living in a Canadian province and recruited from an online research panel. The dependent variable was psychological distress. In addition to a 28-item measure assessing five dimensions of unpaid family work quality, independent variables included material deprivation, job decision latitude, job demands and several measures of the work-family interface. Multiple linear regression was the primary analysis. Compared to women with high school or less, university educated women reported lower psychological distress [b = - 2.23 (SE = 0.50) p = 0.001]. The introduction of material deprivation into the model resulted in the largest reduction to the education disparity (51%), followed by equity in responsibility for unpaid family work (25%), family-to-work facilitation (22%), and decision latitude in paid work (21%). When entered simultaneously into the final model, the association between education and psychological distress was reduced by 70% and became statistically non-significant [b = - 0.68 (SE = 0.47) p = 0.10]. In addition to the more established mechanisms of material conditions and decision latitude to explain mental health disparities, inequity in responsibility for unpaid family work may also play a role.

Evaluating and Mitigating the Impact of Complexity in Software Models

DTIC Science & Technology

2015-12-01

Internal use:* Permission to reproduce this material and to prepare derivative works from this material for internal use is granted, provided the...introduction) provides our motivation to study complexity and the essential re- search questions that we address in this effort. Some background information... provides the reader with a basis for the work and related areas explored. Section 2 (The Impact of Complexity) discusses the impact of model-based

High temperature refrigerator

DOEpatents

Steyert, Jr., William A.

1978-01-01

A high temperature magnetic refrigerator which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle said working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot.

Expanding Knowledge Gaps: The Function of Fictions in Teaching Materials after the 2011 Swedish High School Reform

ERIC Educational Resources Information Center

Graeske, Caroline

2016-01-01

The aim in the study is to analyze how work with fiction is organized in six textbooks for senior high school in Sweden after the school reform 2011. Research into Swedish teaching materials has been neglected in recent years and there is a knowledge gap about how the work with fictions is affected by the reform in 2011. In the study quantitative…

Advanced Colloids Experiment-1 (ACE-1)

NASA Image and Video Library

2013-07-22

ISS036-E-023770 (22 July 2013) --- NASA astronaut Chris Cassidy, Expedition 36 flight engineer, conducts science work with the ongoing experiment Advanced Colloids Experiment-1 (ACE-1) inside the Fluids Integrated Rack. The experiment observes colloids, microscopic particles evenly dispersed throughout materials, with the potential for manufacturing improved materials and products on Earth. Cassidy is working at the Light Microscopy Module (LMM) in the Destiny laboratory of the International Space Station.

[Occupational accidents due to exposure to biological material in the multidisciplinary team of the emergency service].

PubMed

Oliveira, Adriana Cristina; Lopes, Aline Cristine Souza; Paiva, Maria Henriqueta Rocha Siqueira

2009-09-01

This transversal, survey-based research was carried out with a multiprofessional emergency care team in Belo Horizonte, between June and December 2006. The study aimed at estimating the incidence of occupational accidents by exposure to biological material, post-accidents conducts and demographic determinant factors. The study applied a structured questionnaire and descriptive analyses, as well as incidence calculations and logistic regression. The incidence of accidents with biological material reached 20.6%, being 40.8% by sharp materials and 49.0% by body fluids; 35.3% of the accidents took place among physicians and 24.0% among nurses. Post-accidents procedures: no medical assessment, 63.3%; under-notification, 81.6%; no conduct, 55.0%; and no serological follow-up, 61.2%. Factors associated with accidents: working time in the institution (Odds Ratio--OR, 2.84; Credible Interval--CI 95%-1.22-6.62); working in advanced support units (OR = 4.18; CI 95%--1.64-10.64); and interaction between working time in the institution and working in Basic Support Unit (OR 0.27; CI 95%--0.07-1.00). In order to reduce accidents, the implementation of post-accident protocols and follow-up, as well as under-notification norms, are suggested.

Work with Us | Chemistry and Nanoscience Research | NREL

Science.gov Websites

Work with Us Work with Us We are eager to pursue materials science research with partners in Nanoscience Center: Garry Rumbles John Turner, Emeritus Art Nozik, Emeritus For lead researcher contacts, see

Modifications in the AA5083 Johnson-Cook Material Model for Use in Friction Stir Welding Computational Analyses

NASA Astrophysics Data System (ADS)

Grujicic, M.; Pandurangan, B.; Yen, C.-F.; Cheeseman, B. A.

2012-11-01

Johnson-Cook strength material model is frequently used in finite-element analyses of various manufacturing processes involving plastic deformation of metallic materials. The main attraction to this model arises from its mathematical simplicity and its ability to capture the first-order metal-working effects (e.g., those associated with the influence of plastic deformation, rate of deformation, and the attendant temperature). However, this model displays serious shortcomings when used in the engineering analyses of various hot-working processes (i.e., those utilizing temperatures higher than the material recrystallization temperature). These shortcomings are related to the fact that microstructural changes involving: (i) irreversible decrease in the dislocation density due to the operation of annealing/recrystallization processes; (ii) increase in grain-size due to high-temperature exposure; and (iii) dynamic-recrystallization-induced grain refinement are not accounted for by the model. In this study, an attempt is made to combine the basic physical-metallurgy principles with the associated kinetics relations to properly modify the Johnson-Cook material model, so that the model can be used in the analyses of metal hot-working and joining processes. The model is next used to help establish relationships between process parameters, material microstructure and properties in friction stir welding welds of AA5083 (a non-age-hardenable, solid-solution strengthened, strain-hardened/stabilized Al-Mg-Mn alloy).

Simplified training for hazardous materials management in developing countries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braithwaite, J.

1994-12-31

There are thousands of dangerous situations happening daily in developing countries around the world involving untrained workers and hazardous materials. There are very few if any agencies in developing countries that are charged with ensuring safe and healthful working conditions. In addition to the problem of regulation and enforcement, there are potential training problems due to the level of literacy and degree of scientific background of these workers. Many of these workers are refugees from poorly developed countries who are willing to work no matter what the conditions. Training methods (standards) accepted as state of the art in the Unitedmore » States and other developed countries may not work well under the conditions found in developing countries. Because these methods may not be appropriate, new and novel ways to train workers quickly, precisely and economically in hazardous materials management should be developed. One approach is to develop training programs that use easily recognizable graphics with minimal verbal instruction, programs similar to the type used to teach universal international driving regulations and safety. The program as outlined in this paper could be tailored to any sized plant and any hazardous material handling or exposure situation. The situation in many developing countries is critical, development of simplified training methods for workers exposed to hazardous materials hold valuable market potential and are an opportunity for many underdeveloped countries to develop indigenous expertise in hazardous materials management.« less

77 FR 17569 - United States-Canada Regulatory Cooperation Council (RCC)-Transportation-Dangerous Goods Working...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-26

... identified in the Joint Action Plan, the Transportation--Dangerous Goods Working Group led by senior...)-- Transportation--Dangerous Goods Working Group AGENCY: Pipeline and Hazardous Materials Safety Administration...--Dangerous Goods Working Group, of the United States-Canada Regulatory Cooperation Council (RCC). Comments...

Ceramic Technology Project semiannual progress report, October 1992--March 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, D.R.

1993-09-01

This project was developed to meet the ceramic technology requirements of the OTS`s automotive technology programs. Although progress has been made in developing reliable structural ceramics, further work is needed to reduce cost. The work described in this report is organized according to the following work breakdown structure project elements: Materials and processing (monolithics [Si nitride, carbide], ceramic composites, thermal and wear coatings, joining, cost effective ceramic machining), materials design methodology (contact interfaces, new concepts), data base and life prediction (structural qualification, time-dependent behavior, environmental effects, fracture mechanics, nondestructive evaluation development), and technology transfer.

Electrochemical characterization of nanodimensional metal oxide materials

NASA Astrophysics Data System (ADS)

Tang, Paul Enle

Energy storage devices have become a bottleneck in performance improvements for portable electronics. This research seeks to answer basic science questions that may lead to the necessary improvements. First, this work demonstrates that insertion of multivalent ions into vanadium oxide greatly exceeds the storage capacity of materials presently used. Second, this work demonstrates that potassium ferrate exhibits a uniquely large pseudocapacitive effect. This effect can be used to great advantage when high power density and high energy density are required. Lastly, this work proposes a model of pseudocapacitance that has a greater descriptive power than that of previous models.

Nanoscale Materials for Human Space Exploration: Regenerable CO2 Removal

NASA Technical Reports Server (NTRS)

Arepalli, Sivaram; Nikolaev, Pasha; Gorelik, Olga; Huffman, Chad; Moloney, Padraig; Allada, Ram; Yowell, Leonard

2005-01-01

This viewgraph presentation reviews the use of Nanoscale materials in CO2 removal. It presented the background and review work on regenerable CO2 removal for spaceflight application. It demonstrated a new strategy for developing solid-supported amine absorbents based on carbon nanotube materials.

32 CFR 701.53 - FOIA fee schedule.

Code of Federal Regulations, 2010 CFR

2010-07-01

... above 45.00 (e) Audiovisual documentary materials. Search costs are computed as for any other record... the work. Audiovisual materials provided to a requester need not be in reproducible format or quality... shall be computed in the manner described for audiovisual documentary material. (g) Costs for special...

47 CFR 36.181 - Material and supplies-Account 1220.

Code of Federal Regulations, 2010 CFR

2010-10-01

... JURISDICTIONAL SEPARATIONS PROCEDURES; STANDARD PROCEDURES FOR SEPARATING TELECOMMUNICATIONS PROPERTY COSTS... Material and Supplies and Cash Working Capital § 36.181 Material and supplies—Account 1220. (a) The amount included in Account 1220 is apportioned among the operations on the basis of the apportionment of the cost...

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…

29 CFR 1926.953 - Material handling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Material handling. (a) Unloading. Prior to unloading steel, poles, cross arms and similar material, the.... During framing operations, employees shall not work under a pole or a structure suspended by a crane, A-frame or similar equipment unless the pole or structure is adequately supported. (g) Attaching the load...

29 CFR 1926.953 - Material handling.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Material handling. (a) Unloading. Prior to unloading steel, poles, cross arms and similar material, the.... During framing operations, employees shall not work under a pole or a structure suspended by a crane, A-frame or similar equipment unless the pole or structure is adequately supported. (g) Attaching the load...

29 CFR 1926.953 - Material handling.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Material handling. (a) Unloading. Prior to unloading steel, poles, cross arms and similar material, the.... During framing operations, employees shall not work under a pole or a structure suspended by a crane, A-frame or similar equipment unless the pole or structure is adequately supported. (g) Attaching the load...

Exhibit Positive Work Attitudes. Work Skills: Work Maturity Skills Competency 2.0. Connections. School and Work Transitions.

ERIC Educational Resources Information Center

Lankard, Bettina A.

This learning module is one of a series that teaches the competencies of "Job Search Skills," part of the "Work Skills" package--a set of competency-based instructional materials written for low-level readers that prepares students with specific job search and job keeping skills. ("Work Skills" is part of the "Connections" package, which…

Method and apparatus for optimizing the efficiency and quality of laser material processing

DOEpatents

Susemihl, Ingo

1990-01-01

The efficiency of laser welding and other laser material processing is optimized according to this invention by rotating the plane of polarization of a linearly polarized laser beam in relation to a work piece of the material being processed simultaneously and in synchronization with steering the laser beam over the work piece so as to keep the plane of polarization parallel to either the plane of incidence or the direction of travel of the beam in relation to the work piece. Also, depending to some extent on the particular processing being accomplished, such as welding or fusing, the angle of incidence of the laser beam on the work piece is kept at or near the polarizing or Brewster's angle. The combination of maintaining the plane of polarization parallel to plane of incidence while also maintaining the angle of incidence at or near the polarizing or Brewster's angle results in only minimal, if any, reflection losses during laser welding. Also, coordinating rotation of the plane of polarization with the translation or steering of a work piece under a laser cutting beam maximizes efficiency and kerf geometry, regardless of the direction of cut.

Method and apparatus for optimizing the efficiency and quality of laser material processing

DOEpatents

Susemihl, I.

1990-03-13

The efficiency of laser welding and other laser material processing is optimized according to this invention by rotating the plane of polarization of a linearly polarized laser beam in relation to a work piece of the material being processed simultaneously and in synchronization with steering the laser beam over the work piece so as to keep the plane of polarization parallel to either the plane of incidence or the direction of travel of the beam in relation to the work piece. Also, depending to some extent on the particular processing being accomplished, such as welding or fusing, the angle of incidence of the laser beam on the work piece is kept at or near the polarizing or Brewster's angle. The combination of maintaining the plane of polarization parallel to plane of incidence while also maintaining the angle of incidence at or near the polarizing or Brewster's angle results in only minimal, if any, reflection losses during laser welding. Also, coordinating rotation of the plane of polarization with the translation or steering of a work piece under a laser cutting beam maximizes efficiency and kerf geometry, regardless of the direction of cut. 7 figs.

Participatory Training to Improve Safety and Health in Small Construction Sites in Some Countries in Asia: Development and Application of the WISCON Training Program.

PubMed

Kawakami, Tsuyoshi

2016-08-01

A participatory training program, Work Improvement in Small Construction Sites, was developed to provide practical support measures to the small construction sector. Managers and workers from selected small sites were interviewed about their occupational safety and health risks. The Work Improvement in Small Construction Sites training program comprised a 45-item action checklist, photos, and illustrations showing local examples and group work methods. Pilot training workshops were carried out with workers and employers in Cambodia, Laos, Mongolia, Thailand, and Vietnam. Participants subsequently planned, and using locally available low-cost materials, implemented their own improvements such as hand-made hand trucks to carry heavy materials, removal of projecting nails from timber materials, and fences to protect roof workers from falling. Local Work Improvement in Small Construction Sites trainers consisting of government officials, workers, employers, and nongovernment organization representatives were then trained to implement the Work Improvement in Small Construction Sites training widely. Keys to success were easy-to-apply training tools aiming at immediate, low-cost improvements, and collaboration with various local people's networks. © The Author(s) 2016.

Mathematics Teachers at Work: Connecting Curriculum Materials and Classroom Instruction. Studies in Mathematical Thinking and Learning Series

ERIC Educational Resources Information Center

Remillard, Janine T., Ed.; Herbel-Eisenmann, Beth A., Ed.; Lloyd, Gwendolyn M., Ed.

2011-01-01

This book compiles and synthesizes existing research on teachers' use of mathematics curriculum materials and the impact of curriculum materials on teaching and teachers, with a particular emphasis on--but not restricted to--those materials developed in the 1990s in response to the NCTM's Principles and Standards for School Mathematics. Despite…

Development of advanced thermoelectric materials, phase A

NASA Technical Reports Server (NTRS)

1980-01-01

Work performed on the chemical system characterized by chrome sulfide, chrome selenide, lanthanum selenide, and lanthanum sulfide is described. Most materials within the chemical systems possess the requisites for attractive thermoelectric materials. The preparation of the alloys is discussed. Graphs show the Seebeck coefficient, electrical resistivity, and thermal conductivity of various materials within the chemical systems. The results of selected doping are included.

77 FR 43780 - Federal Acquisition Regulation; Changes to Time-and-Materials and Labor-Hour Contracts and Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-26

... Federal Acquisition Regulation; Changes to Time-and-Materials and Labor-Hour Contracts and Orders AGENCIES... changing the scope of work for a time-and-materials (T&M) or labor-hour (LH) contract or order. DATES...-043, ``Time-and-Materials and Labor-Hour Contracts for Commercial Items'', was published as a final...

78 FR 13766 - Federal Acquisition Regulation; Changes to Time-and-Materials and Labor-Hour Contracts and Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-28

..., Sequence 1] RIN 9000-AM28 Federal Acquisition Regulation; Changes to Time-and-Materials and Labor-Hour... raising the ceiling price or otherwise changing the scope of work for a time-and-materials (T&M) or labor... summarized as follows: In finalizing FAR rule 2009-043 Time-and-Materials and Labor- Hour Contracts for...

Materials science with muon spin rotation

NASA Technical Reports Server (NTRS)

1988-01-01

During this reporting period, the focus of activity in the Materials Science with Muon Spin Rotation (MSMSR) program was muon spin rotation studies of superconducting materials, in particular the high critical temperature and heavy-fermion materials. Apart from these studies, work was continued on the analysis of muon motion in metal hydrides. Results of these experiments are described in six papers included as appendices.

Data-driven discovery of new Dirac semimetal materials

NASA Astrophysics Data System (ADS)

Yan, Qimin; Chen, Ru; Neaton, Jeffrey

In recent years, a significant amount of materials property data from high-throughput computations based on density functional theory (DFT) and the application of database technologies have enabled the rise of data-driven materials discovery. In this work, we initiate the extension of the data-driven materials discovery framework to the realm of topological semimetal materials and to accelerate the discovery of novel Dirac semimetals. We implement current available and develop new workflows to data-mine the Materials Project database for novel Dirac semimetals with desirable band structures and symmetry protected topological properties. This data-driven effort relies on the successful development of several automatic data generation and analysis tools, including a workflow for the automatic identification of topological invariants and pattern recognition techniques to find specific features in a massive number of computed band structures. Utilizing this approach, we successfully identified more than 15 novel Dirac point and Dirac nodal line systems that have not been theoretically predicted or experimentally identified. This work is supported by the Materials Project Predictive Modeling Center through the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-05CH11231.

Friction and abrasion of elastomeric materials

NASA Technical Reports Server (NTRS)

Gent, A. N.

1975-01-01

An abrasion apparatus is described. Experimental measurements are reported for four representative elastomeric materials, including a typical high-quality tire tread material and a possible replacement material for aircraft tire treads based on transpolypentenamer (TPPR). Measurements are carried out at different levels of frictional work input, corresponding to different severities of wear, and at both ambient temperature and at 100 C. Results indicate the marked superiority in abrasion resistance of the material based on TPPR, especially at 100 C, in comparison with the other materials examined.

48 CFR 970.2303 - Hazardous materials identification and material safety.

Code of Federal Regulations, 2014 CFR

2014-10-01

... OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Environment, Energy and Water Efficiency, Renewable Energy Technologies, Occupational Safety and Drug-Free Work Place 970...

48 CFR 970.2303 - Hazardous materials identification and material safety.

Code of Federal Regulations, 2010 CFR

2010-10-01

... OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Environment, Energy and Water Efficiency, Renewable Energy Technologies, Occupational Safety and Drug-Free Work Place 970...

48 CFR 970.2303 - Hazardous materials identification and material safety.

Code of Federal Regulations, 2013 CFR

2013-10-01

... OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Environment, Energy and Water Efficiency, Renewable Energy Technologies, Occupational Safety and Drug-Free Work Place 970...

48 CFR 970.2303 - Hazardous materials identification and material safety.

Code of Federal Regulations, 2012 CFR

2012-10-01

... OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Environment, Energy and Water Efficiency, Renewable Energy Technologies, Occupational Safety and Drug-Free Work Place 970...

48 CFR 970.2303 - Hazardous materials identification and material safety.

Code of Federal Regulations, 2011 CFR

2011-10-01

... OF ENERGY AGENCY SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Environment, Energy and Water Efficiency, Renewable Energy Technologies, Occupational Safety and Drug-Free Work Place 970...

Tough Composite Materials

NASA Technical Reports Server (NTRS)

Vosteen, L. F. (Compiler); Johnson, N. J. (Compiler); Teichman, L. A. (Compiler)

1984-01-01

Papers and working group summaries are presented which address composite material behavior and performance improvement. Topic areas include composite fracture toughness and impact characterization, constituent properties and interrelationships, and matrix synthesis and characterization.

Quantum ballistic analysis of transition metal dichalcogenides based double gate junctionless field effect transistor and its application in nano-biosensor

NASA Astrophysics Data System (ADS)

Shadman, Abir; Rahman, Ehsanur; Khosru, Quazi D. M.

2017-11-01

To reduce the thermal budget and the short channel effects in state of the art CMOS technology, Junctionless field effect transistor (JLFET) has been proposed in the literature. Numerous experimental, modeling, and simulation based works have been done on this new FET with bulk materials for various geometries until now. On the other hand, the two-dimensional layered material is considered as an alternative to current Si technology because of its ultra-thin body and high mobility. Very recently few simulation based works have been done on monolayer molybdenum disulfide based JLFET mainly to show the advantage of JLFET over conventional FET. However, no comprehensive simulation-based work has been done for double gate JLFET keeping in mind the prominent transition metal dichalcogenides (TMDC) to the authors' best knowledge. In this work, we have studied quantum ballistic drain current-gate voltage characteristics of such FETs within non-equilibrium Green's function (NEGF) framework. Our simulation results reveal that all these TMDC materials are viable options for implementing state of the art Junctionless MOSFET with emphasis on their performance at short gate lengths. Besides evaluating the prospect of TMDC materials in the digital logic application, the performance of Junctionless Double Gate trilayer TMDC heterostructure FET for the label-free electrical detection of biomolecules in dry environment has been investigated for the first time to the authors' best knowledge. The impact of charge neutral biomolecules on the electrical characteristics of the biosensor has been analyzed under dry environment situation. Our study shows that these materials could provide high sensitivity in the sub-threshold region as a channel material in nano-biosensor, a trend demonstrated by silicon on insulator FET sensor in the literature. Thus, going by the trend of replacing silicon with these novel materials in device level, TMDC heterostructure could be a viable alternative to silicon for potentiometric biosensing.

First-principles Electronic Structure Calculations for Scintillation Phosphor Nuclear Detector Materials

NASA Astrophysics Data System (ADS)

Canning, Andrew

2013-03-01

Inorganic scintillation phosphors (scintillators) are extensively employed as radiation detector materials in many fields of applied and fundamental research such as medical imaging, high energy physics, astrophysics, oil exploration and nuclear materials detection for homeland security and other applications. The ideal scintillator for gamma ray detection must have exceptional performance in terms of stopping power, luminosity, proportionality, speed, and cost. Recently, trivalent lanthanide dopants such as Ce and Eu have received greater attention for fast and bright scintillators as the optical 5d to 4f transition is relatively fast. However, crystal growth and production costs remain challenging for these new materials so there is still a need for new higher performing scintillators that meet the needs of the different application areas. First principles calculations can provide a useful insight into the chemical and electronic properties of such materials and hence can aid in the search for better new scintillators. In the past there has been little first-principles work done on scintillator materials in part because it means modeling f electrons in lanthanides as well as complex excited state and scattering processes. In this talk I will give an overview of the scintillation process and show how first-principles calculations can be applied to such systems to gain a better understanding of the physics involved. I will also present work on a high-throughput first principles approach to select new scintillator materials for fabrication as well as present more detailed calculations to study trapping process etc. that can limit their brightness. This work in collaboration with experimental groups has lead to the discovery of some new bright scintillators. Work supported by the U.S. Department of Homeland Security and carried out under U.S. Department of Energy Contract no. DE-AC02-05CH11231 at Lawrence Berkeley National Laboratory.

Modeling of the interfacial separation work in relation to impurity concentration in adjoining materials

NASA Astrophysics Data System (ADS)

Alekseev, Ilia M.; Makhviladze, Tariel M.; Minushev, Airat Kh.; Sarychev, Mikhail E.

2009-10-01

On the basis of the general thermodynamic approach developed in a model describing the influence of point defects on the separation work at an interface of solid materials is developed. The kinetic equations describing the defect exchange between the interface and the material bulks are formulated. The model have been applied to the case when joined materials contain such point defects as impurity atoms (interstitial and substitutional), concretized the main characteristic parameters required for a numerical modeling as well as clarified their domains of variability. The results of the numerical modeling concerning the dependences on impurity concentrations and the temperature dependences are obtained and analyzed. Particularly, the effects of interfacial strengthening and adhesion incompatibility predicted analytically for the case of impurity atoms are verified and analyzed.

Modeling of the interfacial separation work in relation to impurity concentration in adjoining materials

NASA Astrophysics Data System (ADS)

Alekseev, Ilia M.; Makhviladze, Tariel M.; Minushev, Airat Kh.; Sarychev, Mikhail E.

2010-02-01

On the basis of the general thermodynamic approach developed in a model describing the influence of point defects on the separation work at an interface of solid materials is developed. The kinetic equations describing the defect exchange between the interface and the material bulks are formulated. The model have been applied to the case when joined materials contain such point defects as impurity atoms (interstitial and substitutional), concretized the main characteristic parameters required for a numerical modeling as well as clarified their domains of variability. The results of the numerical modeling concerning the dependences on impurity concentrations and the temperature dependences are obtained and analyzed. Particularly, the effects of interfacial strengthening and adhesion incompatibility predicted analytically for the case of impurity atoms are verified and analyzed.

Occupational accidents involving biological material among public health workers.

PubMed

Chiodi, Mônica Bonagamba; Marziale, Maria Helena Palucci; Robazzi, Maria Lúcia do Carmo Cruz

2007-01-01

This descriptive research aimed to recognize the occurrence of work accidents (WA) involving exposure to biological material among health workers at Public Health Units in Ribeirão Preto-SP, Brazil. A quantitative approach was adopted. In 2004, 155 accidents were notified by means of the Work Accident Communication (WAC). Sixty-two accidents (40%) involved exposure to biological material that could cause infections like Hepatitis and Aids. The highest number of victims (42 accidents) came from the category of nursing aids and technicians. Needles were responsible for 80.6% of accidents and blood was the biological material involved in a majority of occupational exposure cases. This subject needs greater attention, so that prevention measures can be implemented, which consider the peculiarities of the activities carried out by the different professional categories.

Modified Composite Materials Workshop

NASA Technical Reports Server (NTRS)

Dicus, D. L. (Compiler)

1978-01-01

The reduction or elimination of the hazard which results from accidental release of graphite fibers from composite materials was studied at a workshop. At the workshop, groups were organized to consider six topics: epoxy modifications, epoxy replacement, fiber modifications, fiber coatings and new fibers, hybrids, and fiber release testing. Because of the time required to develop a new material and acquire a design data base, most of the workers concluded that a modified composite material would require about four to five years of development and testing before it could be applied to aircraft structures. The hybrid working group considered that some hybrid composites which reduce the risk of accidental fiber release might be put into service over the near term. The fiber release testing working group recommended a coordinated effort to define a suitable laboratory test.

Ultrasonic Sound Field Mapping Through Coarse Grained Cast Austenitic Stainless Steel Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-08-01

The Pacific Northwest National Laboratory (PNNL) has been involved with nondestructive examination (NDE) of coarse-grained cast austenitic stainless steel (CASS) components for over 30 years. More recent work has focused on mapping the ultrasonic sound fields generated by low-frequency phased array probes that are typically used for the evaluation of CASS materials for flaw detection and characterization. The casting process results in the formation of large grained material microstructures that are nonhomogeneous and anisotropic. The propagation of ultrasonic energy for examination of these materials results in scattering, partitioning and redirection of these sound fields. The work reported here provides anmore » assessment of sound field formation in these materials and provides recommendations on ultrasonic inspection parameters for flaw detection in CASS components.« less

Materials for the General Aviation Industry: Effect of Environment on Mechanical Properties of Glass Fabric/Rubber Toughened Vinyl Ester Laminates

NASA Technical Reports Server (NTRS)

McBride, Timothy M.

1995-01-01

A screening evaluation is being conducted to determine the performance of several glass fabric/vinyl ester composite material systems for use in primary General Aviation aircraft structures. In efforts to revitalize the General Aviation industry, the Integrated Design and Manufacturing Work Package for General Aviation Airframe and Propeller Structures is seeking to develop novel composite materials and low-cost manufacturing methods for lighter, safer and more affordable small aircraft. In support of this Work Package, this study is generating material properties for several glass fabric/rubber toughened vinyl ester composite systems and investigates the effect of environment on property retention. All laminates are made using the Seemann Composites Resin Infusion Molding Process (SCRIMP), a potential manufacturing method for the General Aviation industry.

Characterization of DWPF recycle condensate materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bannochie, C. J.; Adamson, D. J.; King, W. D.

2015-04-01

A Defense Waste Processing Facility (DWPF) Recycle Condensate Tank (RCT) sample was delivered to the Savannah River National Laboratory (SRNL) for characterization with particular interest in the concentration of I-129, U-233, U-235, total U, and total Pu. Since a portion of Salt Batch 8 will contain DWPF recycle materials, the concentration of I-129 is important to understand for salt batch planning purposes. The chemical and physical characterizations are also needed as input to the interpretation of future work aimed at determining the propensity of the RCT material to foam, and methods to remediate any foaming potential. According to DWPF themore » Tank Farm 2H evaporator has experienced foaming while processing DWPF recycle materials. The characterization work on the RCT samples has been completed and is reported here.« less

ATF Neutron Irradiation Program Technical Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geringer, J. W.; Katoh, Yutai

The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post-irradiation examination and characterization ofmore » irradiated materials and the shipment of irradiated materials to JAEA in Japan. This report discusses the technical plan of the experimental study.« less

ATF Neutron Irradiation Program Irradiation Vehicle Design Concepts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geringer, J. W.; Katoh, Yutai; Howard, Richard H.

The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post irradiation examination and characterizationmore » of irradiated materials and the shipment of irradiated materials to Japan. This report discusses the conceptual design, the development and irradiation of the test vehicles.« less

Non-destructive inspection approach using ultrasound to identify the material state for amorphous and semi-crystalline materials

NASA Astrophysics Data System (ADS)

Jost, Elliott; Jack, David; Moore, David

2018-04-01

At present, there are many methods to identify the temperature and phase of a material using invasive techniques. However, most current methods require physical contact or implicit methods utilizing light reflectance of the specimen. This work presents a nondestructive inspection method using ultrasonic wave technology that circumvents these disadvantages to identify phase change regions and infer the temperature state of a material. In the present study an experiment is performed to monitor the time of flight within a wax as it undergoes melting and the subsequent cooling. Results presented in this work show a clear relationship between a material's speed of sound and its temperature. The phase change transition of the material is clear from the time of flight results, and in the case of the investigated material, this change in the material state occurs over a range of temperatures. The range of temperatures over which the wax material melts is readily identified by speed of sound represented as a function of material temperature. The melt temperature, obtained acoustically, is validated using Differential Scanning Calorimetry (DSC), which uses shifts in heat flow rates to identify phase transition temperature ranges. The investigated ultrasonic NDE method has direct applications in many industries, including oil and gas, food and beverage, and polymer composites, in addition to many implications for future capabilities of nondestructive inspection of multi-phase materials.

A comparative study based on physical characteristics of suitable packing materials in biofiltration.

PubMed

Dorado, A D; Lafuente, F J; Gabriel, D; Gamisans, X

2010-02-01

In the present work, 10 packing materials commonly used as support media in biofiltration are analysed and compared to evaluate their suitability according to physical characteristics. The nature of the packing material in biofilters is an important factor for the success in their construction and operation. Different packing materials have been used in biofiltration without a global agreement about which ones are the most adequate for biofiltration success. The materials studied were chosen according to previous works in the field of biofiltration including both organic and inorganic (or synthetic) materials. A set of nine different parameters were selected to cope with well-established factors, such as a material-specific surface area, pressure drop, nutrient supply, water retentivity, sorption capacity, and purchase cost. One ranking of packing materials was established for each parameter studied in order to define a relative suitability degree. Since biofiltration success generally depends on a combination of the ranked parameters, a procedure was defined to compare packing materials suitability under common situations in biofiltration. The selected scenarios, such as biofiltration of intermittent loads of pollutants and biofiltration of waste gases with low relative humidity, were investigated. The results indicate that, out of the packing materials studied, activated carbons were ranked top of several parameter rankings and were shown to be a significantly better packing material when parameters were combined to assess such selected scenarios.

Transparent amorphous oxide semiconductors for organic electronics: Application to inverted OLEDs

PubMed Central

Hosono, Hideo; Toda, Yoshitake; Kamiya, Toshio; Watanabe, Satoru

2017-01-01

Efficient electron transfer between a cathode and an active organic layer is one key to realizing high-performance organic devices, which require electron injection/transport materials with very low work functions. We developed two wide-bandgap amorphous (a-) oxide semiconductors, a-calcium aluminate electride (a-C12A7:e) and a-zinc silicate (a-ZSO). A-ZSO exhibits a low work function of 3.5 eV and high electron mobility of 1 cm2/(V · s); furthermore, it also forms an ohmic contact with not only conventional cathode materials but also anode materials. A-C12A7:e has an exceptionally low work function of 3.0 eV and is used to enhance the electron injection property from a-ZSO to an emission layer. The inverted electron-only and organic light-emitting diode (OLED) devices fabricated with these two materials exhibit excellent performance compared with the normal type with LiF/Al. This approach provides a solution to the problem of fabricating oxide thin-film transistor-driven OLEDs with both large size and high stability. PMID:28028243

Computational Modeling of Sinkage of Objects into Porous Bed under Cyclic Loading

NASA Astrophysics Data System (ADS)

Sheikh, B.; Qiu, T.; Liu, X.

2017-12-01

This work is a companion of another abstract submitted to this session on the computational modeling for the prediction of underwater munitions. In the other abstract, the focus is the hydrodynamics and sediment transport. In this work, the focus is on the geotechnical aspect and granular material behavior when the munitions interact with the porous bed. The final goal of the project is to create and utilize a comprehensive modeling framework, which integrates the flow and granular material models, to simulate and investigate the motion of the munitions. In this work, we present the computational modeling of one important process: the sinkage of rigid-body objects into porous bed under cyclic loading. To model the large deformation of granular bed materials around sinking objects under cyclic loading, a rate-independent elasto-plastic constitutive model is implemented into a Smoothed Particle Hydrodynamics (SPH) model. The effect of loading conditions (e.g., amplitude and frequency of shaking), object properties (e.g., geometry and density), and granular bed material properties (e.g., density) on object singkage is discussed.

Navigating the Risky Terrain of Children's Working Theories

ERIC Educational Resources Information Center

Areljung, Sofie; Kelly-Ware, Janette

2017-01-01

"Working theories" encompass children's theorising about the social and material worlds. This article looks explicitly at power relations involved in pedagogy around children's working theories by focusing on the teacher's control of what and whose working theories get unpacked and extended. From an analysis of four cases from early…

Using Worked Examples Assignments in Classroom Instruction

ERIC Educational Resources Information Center

Paré-Blagoev, Juliana; Booth, Julie; Elliot, Andrew; Koedinger, Ken

2013-01-01

As highlighted by the National Math Panel Report (2008), consistent results from laboratory studies have demonstrated that interleaving worked examples with problems to solve improves learning for novices. The purpose of this work is to create materials and tests that can be used flexibly in classrooms and which employ worked examples interleaved…

Organisational characteristics associated with shift work practices and potential opportunities for intervention: findings from a Canadian study.

PubMed

Hall, Amy L; Smit, Andrea N; Mistlberger, Ralph E; Landry, Glenn J; Koehoorn, Mieke

2017-01-01

Shift work is a common working arrangement with wide-ranging implications for worker health. Organisational determinants of shift work practices are not well characterised; such information could be used to guide evidence-based research and best practices to mitigate shift work's negative effects. This exploratory study aimed to describe and assess organisational-level determinants of shift work practices thought to affect health, across a range of industry sectors. Data on organisational characteristics, shift work scheduling, provision of shift work education materials/training to employees and night-time lighting policies in the workplace were collected during phone interviews with organisations across the Canadian province of British Columbia. Relationships between organisational characteristics and shift work practices were assessed using multivariable logistic regression models. The study sample included 88 participating organisations, representing 30 700 shift workers. Long-duration shifts, provision of shift work education materials/training to employees and night-time lighting policies were reported by approximately one-third of participating organisations. Odds of long-duration shifts increased in larger workplaces and by industry. Odds of providing shift work education materials/training increased in larger workplaces, in organisations reporting concern for shift worker health and in organisations without seasonal changes in shift work. Odds of night-time lighting policies in the workplace increased in organisations reporting previous workplace accidents or incidents that occurred during non-daytime hours, site maintenance needs and client service or care needs. This study points to organisational determinants of shift work practices that could be useful for targeting research and workplace interventions. Results should be interpreted as preliminary in an emerging body of literature on shift work and health. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

LATIN AMERICAN AND CARIBBEAN WORKSHOP ON THE SUSTAINABILITY OF RADIOACTIVE SOURCE PHYSICAL PROTECTION UPGRADES HOSTED IN GUATEMALA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenberg, Raymond; Watson, Erica E.; Morris, Frederic A.

2009-10-07

The Global Threat Reduction Initiative (GTRI) reduces and protects vulnerable nuclear and radiological material located at civilian sites worldwide. The GTRI program has worked successfully to remove and protect nuclear and radioactive materials, including orphaned and disused high-activity sources, and is now working to ensure sustainability. Internationally, over 40 countries are cooperating with GTRI to enhance the security of radiological materials. GTRI is now seeking to develop and enhance sustainability by coordinating its resources with those of the partner country, other donor countries, and international organizations such as the International Atomic Energy Agency (IAEA).

Design Principles Guide Educators in Choosing and Using Curriculum Materials. Research Review

ERIC Educational Resources Information Center

Foster, Elizabeth

2018-01-01

Engaging with materials can shape the teaching experience, teachers' practices and mindsets, and, ultimately, students' learning experiences. This issue of "Learning Professional" looks at an area of emerging interest: curriculum materials and the role they play in the daily work of educators and leaders. Educators, researchers, and…

Materials and Equipment: ECI-4. Early Childhood Intervention Catalog Module.

ERIC Educational Resources Information Center

Evans, Joyce; Bricker, Donna

The fourth of seven modules for professionals working with young (birth to age 3) handicapped children provides information on equipment, materials, and activities in early intervention. Background information discusses ways to catalog materials and equipment and describes teaching approaches using toys and manipulatives. A variety of teaching…

Sculpture: Creative Designs with Modern Materials (Tentative Course Outline).

ERIC Educational Resources Information Center

Dubocq, Edward R.

This document reports on a course in comprehension and application of various techniques of sculpture and collage, using a contemporary point of view. Students will work with contemporary materials such as wood, metals, plaster, plastics, styrofoam, and many other cardboard basic materials suitable for creative design products. This unit will…

23 CFR 140.908 - Materials and supplies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Reimbursement for Railroad Work § 140.908 Materials and supplies. (a) Procurement. Materials and supplies, if... job, less a consideration for loss in service life at 10 percent for rails, angle bars, tie plates and... measures for restoration of affected areas as required by the physical construction or by reason of safety...

Interactions of DNA coated upconversion nanoparticles with 2D materials

NASA Astrophysics Data System (ADS)

Giust, Davide; Lucío, María. Isabel; Muskens, Otto L.; Kanaras, Antonios G.

2018-02-01

In this work we investigated the nature of quenching between different types of 2D materials (WS2, MoS2 and graphene oxide) and oligonucleotide coated-upconversion nanoparticles. This study contributes towards the efficient design of biosensors based on 2D materials and DNA-coated upconversion nanoparticles.

29 CFR 1926.953 - Material handling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Material handling. (a) Unloading. Prior to unloading steel, poles, cross arms and similar material, the... stored in temporary containers other than those required in § 1926.152, such as pillow tanks. (f) Framing. During framing operations, employees shall not work under a pole or a structure suspended by a crane, A...

29 CFR 1926.953 - Material handling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Material handling. (a) Unloading. Prior to unloading steel, poles, cross arms and similar material, the... stored in temporary containers other than those required in § 1926.152, such as pillow tanks. (f) Framing. During framing operations, employees shall not work under a pole or a structure suspended by a crane, A...

Food Stamps. Learning Packet No. 2.

ERIC Educational Resources Information Center

American Bar Association, Washington, DC. Clearinghouse for Offender Literacy Programs.

This package of instructional materials is designed to aid adults in prison to perform the functional skill of applying for food stamps. The materials consist of instructions for teachers, a sample application for food stamps, a student's work sheet and answer sheet, vocabulary flash cards, and resource materials on food stamps. (MKM)

Job Grading Standard for Materials Expediter WG-6705.

ERIC Educational Resources Information Center

Civil Service Commission, Washington, DC. Bureau of Policies and Standards.

The standard is used to grade nonsupervisory jobs involved in routing and expediting the movement of parts, end items, supplies, and materials within production and repair facilities to meet priority needs. The work requires knowledge of material characteristics, uses, condition, industrial production shop procedures, shop layout, and internal…

Sintered wire cathode

DOEpatents

Falce, Louis R [San Jose, CA; Ives, R Lawrence [Saratoga, CA

2009-06-09

A porous cathode structure is fabricated from a plurality of wires which are placed in proximity to each other in elevated temperature and pressure for a sintering time. The sintering process produces the porous cathode structure which may be divided into a plurality of individual porous cathodes, one of which may be placed into a dispenser cathode support which includes a cavity for containing a work function reduction material such as BaO, CaO, and Al.sub.2O.sub.3. The work function reduction material migrates through the pores of the porous cathode from a work replenishment surface adjacent to the cavity of the dispenser cathode support to an emitting cathode surface, thereby providing a dispenser cathode which has a uniform work function and therefore a uniform electron emission.

Magnetic Shielding Design for Coupler of Wireless Electric Vehicle Charging Using Finite Element Analysis

NASA Astrophysics Data System (ADS)

Zhao, W. N.; Yang, X. J.; Yao, C.; Ma, D. G.; Tang, H. J.

2017-10-01

Inductive power transfer (IPT) is a practical and preferable method for wireless electric vehicle (EV) charging which proved to be safe, convenient and reliable. Due to the air gap between the magnetic coupler, the magnetic field coupling decreases and the magnetic leakage increases significantly compared to traditional transformer, and this may lead to the magnetic flux density around the coupler more than the safety limit for human. So magnetic shielding should be adding to the winding made from litz wire to enhance the magnetic field coupling effect in the working area and reduce magnetic field strength in non-working area. Magnetic shielding can be achieved by adding high-permeability material or high-conductivity material. For high-permeability material its magnetic reluctance is much lower than the surrounding air medium so most of the magnetic line goes through the high-permeability material rather than surrounding air. For high-conductivity material the eddy current in the material can produce reverse magnetic field to achieve magnetic shielding. This paper studies the effect of the two types of shielding material on coupler for wireless EV charging and designs combination shielding made from high-permeability material and high-conductivity material. The investigation of the paper is done with the help of finite element analysis.

A practical guide to using boron doped diamond in electrochemical research.

PubMed

Macpherson, Julie V

2015-02-07

Conducting, boron doped diamond (BDD), in addition to its superior material properties, offers several notable attributes to the electrochemist making it an intriguing material for electrochemical research. These include the widest solvent window of all electrode materials; low background and capacitive currents; reduced fouling compared to other electrodes and; the ability to withstand extreme potentials, corrosive and high temperature/pressure environments. However, BDD is not your typical electrode material, it is a semi-conductor doped degenerately with boron to present semi-metallic characteristics. Input from materials scientists, chemists and physicists has been required to aid understanding of how to work with this material from an electrochemical viewpoint and improve electrode quality. Importantly, depending on how the BDD has been grown and then subsequently treated, prior to electrochemical measurement, the resulting material properties can vary quite significantly from one electrode to the next. This likely explains the variability seen by different researchers working on the same experimental systems. The aim of this "protocols" article is not to provide a state-of-the-art review of diamond electrochemistry, suitable references are provided to the interested reader, but instead serves as a reference point for any researcher wishing to commence work with diamond electrodes and interpret electrochemical data. It provides information on how best to characterise the material properties of the electrode before use and outlines the interplay between boron dopant density, non-diamond-carbon content, grain morphology, surface chemistry and redox couple identity. All should ideally be considered when interpretating electrochemical data arising from the diamond electrode. This will aid the reader in making meaningful comparisons between data obtained by different researchers using different diamond electrodes. The guide also aims to help educate the researcher in choosing which form of BDD is best suited to their research application.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garabedian, G.

This document details the decontamination and decommissioning (D&D) process of Rooms 248 and 250 of Building 62 at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL). The document describes the D&D efforts for the rooms, their contents, and adjacent areas containing ancillary equipment. The rooms and equipment, before being released, were required to meet the unrestricted release criteria and requirements set forth in DOE orders 5400.5 and 5480.11, LBNL`s internal release-criteria procedure (EH&S Procedure 708), and the LBNL Radiological Control Manual. The radioactive material and items not meeting the release criteria were either sent to the Hazardous Waste Handling Facilitymore » (HWHF) for disposal or transferred to other locations approved for radioactive material. The D&D was undertaken by the Radiation Protection Group of LBNL`s Environment, Health and Safety (EH&S) Division at the request of the Materials Sciences Division. Current and past use of radioactive material in both Rooms 248 and 250 necessitated the D&D in order to release both rooms for nonradioactive work. (1) Room 248 was designated a {open_quotes}controlled area.{close_quotes} There was contained radioactive material in some of the equipment. The previous occupants of Room 248 had worked with radioactive materials. (2) Room 250 was designated a {open_quotes}Radioactive Materials Management Area{close_quotes} (RMMA) because the current occupants used potentially dispersible radioisotopes. Both laboratories, during the occupancy of U.C. Berkeley Professor Leo Brewer and Ms. Karen Krushwitz, were kept in excellent condition. There was a detailed inventory of all radioactive materials and chemicals. All work and self surveys were documented. The labs were kept extremely orderly, clean, and in compliance. In October 1993 Ms. Krushwitz received an award in recognition of her efforts in Environmental Protection, Health, and Safety at LBNL.« less

What LDEF means for development and testing of materials

NASA Technical Reports Server (NTRS)

Whitaker, Ann F.; Stuckey, Wayne K.; Stein, Bland A.

1993-01-01

The Long Duration Exposure Facility (LDEF) served as the ultimate laboratory to provide combined space environmental effects on materials. The LDEF structure and its 57 experiments contained an estimated 12,000 to 14,000 specimens of materials and materials processes. It not only provided information about the resistance of these materials to the space environment but gives us direction into future needs for spacecraft materials development and testing. This paper provides an overview of the materials effects observed on the satellite and suggests recommendations for the future work in space-qualified materials development and space environmental simulation.

Draft report: Results of stainless steel canister corrosion studies and environmental sample investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, Charles R.; Enos, David

2014-09-01

This progress report describes work being done at Sandia National Laboratories (SNL) to assess the localized corrosion performance of container/cask materials used in the interim storage of used nuclear fuel. The work involves both characterization of the potential physical and chemical environment on the surface of the storage canisters and how it might evolve through time, and testing to evaluate performance of the canister materials under anticipated storage conditions.

Lithium Fast-Ion Conductors: Polymer Based Materials.

DTIC Science & Technology

1987-05-30

significant ambient temperature ionic conductivities. Some of the -aterials may be of interest in other contexts. A study of lithium tetra...This work was a search for lithium-containing materials with ambient temperature ionic conductivities of 10- 5 (ohm-cm) " or larger. The work began with...1-8). The discovery of solids, e.g., sodium.8-alumina(l), and polymer-salt complexes, e.g., (PEO) 8 LiCIO 4 (3), with ionic conductivities approaching

Sensing and Tactile Artificial Muscles from Reactive Materials

PubMed Central

Conzuelo, Laura Valero; Arias-Pardilla, Joaquín; Cauich-Rodríguez, Juan V.; Smit, Mascha Afra; Otero, Toribio Fernández

2010-01-01

Films of conducting polymers can be oxidized and reduced in a reversible way. Any intermediate oxidation state determines an electrochemical equilibrium. Chemical or physical variables acting on the film may modify the equilibrium potential, so that the film acts as a sensor of the variable. The working potential of polypyrrole/DBSA (Dodecylbenzenesulfonic acid) films, oxidized or reduced under constant currents, changes as a function of the working conditions: electrolyte concentration, temperature or mechanical stress. During oxidation, the reactive material is a sensor of the ambient, the consumed electrical energy being the sensing magnitude. Devices based on any of the electrochemical properties of conducting polymers must act simultaneously as sensors of the working conditions. Artificial muscles, as electrochemical actuators constituted by reactive materials, respond to the ambient conditions during actuation. In this way, they can be used as actuators, sensing the surrounding conditions during actuation. Actuating and sensing signals are simultaneously included by the same two connecting wires. PMID:22319265

Using compression calorimetry to characterize powder compaction behavior of pharmaceutical materials.

PubMed

Buckner, Ira S; Friedman, Ross A; Wurster, Dale Eric

2010-02-01

The process by which pharmaceutical powders are compressed into cohesive compacts or tablets has been studied using a compression calorimeter. Relating the various thermodynamic results to relevant physical processes has been emphasized. Work, heat, and internal energy change values have been determined with the compression calorimeter for common pharmaceutical materials. A framework of equations has been proposed relating the physical processes of friction, reversible deformation, irreversible deformation, and inter-particle bonding to the compression calorimetry values. The results indicate that irreversible deformation dominated many of the thermodynamic values, especially the net internal energy change following the compression-decompression cycle. The relationships between the net work and the net heat from the complete cycle were very clear indicators of predominating deformation mechanisms. Likewise, the ratio of energy stored as internal energy to the initial work input distinguished the materials according to their brittle or plastic deformation tendencies. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association.

Magnetic refrigeration for low-temperature applications

NASA Technical Reports Server (NTRS)

Barclay, J. A.

1985-01-01

The application of refrigeration at low temperatures ranging from production of liquid helium for medical imaging systems to cooling of infrared sensors on surveillance satellites is discussed. Cooling below about 15 K with regenerative refrigerators is difficult because of the decreasing thermal mass of the regenerator compared to that of the working material. In order to overcome this difficulty with helium gas as the working material, a heat exchanger plus a Joule-Thomson or other exponder is used. Regenerative magnetic refrigerators with magnetic solids as the working material have the same regenerator problem as gas refrigerators. This problem provides motivation for the development of nonregenerative magnetic refrigerators that span approximately 1 K to approximately 0 K. Particular emphasis is placed on high reliability and high efficiency. Calculations indicate considerable promise in this area. The principles, the potential, the problems, and the progress towards development of successful 4 to 20 K magnetic refrigerators are discussed.

How to get between the sheets: a review of recent works on the electrochemical exfoliation of graphene materials from bulk graphite

NASA Astrophysics Data System (ADS)

Abdelkader, A. M.; Cooper, A. J.; Dryfe, R. A. W.; Kinloch, I. A.

2015-04-01

Since the beginning of the `graphene era' post-2004, there has been significant interest in developing a high purity, high yield, and scalable fabrication route toward graphene materials for both primary research purposes and industrial production. One suitable approach to graphene production lies in the realm of electrochemical exfoliation, in which a potential difference is applied between a graphite anode/cathode in the presence of an electrolyte-containing medium. Herein we review various works on the electrochemical fabrication of graphene materials specifically through the use of electrochemical intercalation and exfoliation of a graphite source electrode, focusing on the quality and purity of products formed. We categorise the most significant works in terms of anodic and cathodic control, highlighting the merits of the respective approaches, as well as indicating the challenges associated with both procedures.

Exploiting epoxidized natural rubber latex (ENRL) as a starting raw material for latex-based products

NASA Astrophysics Data System (ADS)

Siti Nor Qamarina, M.; Fatimah Rubaizah, M. R.; Nurul Suhaira, A.; Norhanifah, M. Y.

2017-12-01

Epoxidized natural rubber latex (ENRL) is a chemically modified natural rubber latex produced from epoxidation process that involves usage of organic peracids. Conversion of the ENRL into dry rubber products has been known to exhibit many beneficial properties, however limited published works were found on diversifiying the ENRL latex-based products applications. In this preliminary work, different source of raw materials and neutralization systems were investigated. The objective was to explore possibilities in producing distinctive ENRL. Findings have demonstrated that different source of raw materials and neutralization systems influenced the typical ENRL specifications, stability behavior and particle size distribution. Morphological observations performed on these ENRL systems appeared to agree with the ENRL characteristics achieved. Since experimenting these two main factors resulted in encouraging ENRL findings, detailed work shall be further scrutinized to search for an optimum condition in producing marketable ENRL specifically for latex-based products applications.

Integrated Prediction and Mitigation Methods of Materials Damage and Lifetime Assessment during Plasma Operation and Various Instabilities in Fusion Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassanein, Ahmed

2015-03-31

This report describes implementation of comprehensive and integrated models to evaluate plasma material interactions during normal and abnormal plasma operations. The models in full3D simulations represent state-of-the art worldwide development with numerous benchmarking of various tokamak devices and plasma simulators. In addition, significant number of experimental work has been performed in our center for materials under extreme environment (CMUXE) at Purdue to benchmark the effect of intense particle and heat fluxes on plasma-facing components. This represents one-year worth of work and resulted in more than 23 Journal Publications and numerous conferences presentations. The funding has helped several students to obtainmore » their M.Sc. and Ph.D. degrees and many of them are now faculty members in US and around the world teaching and conducting fusion research. Our work has also been recognized through many awards.« less

Vapor-barrier Vacuum Isolation System

NASA Technical Reports Server (NTRS)

Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

2014-01-01

A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

Auditing of suppliers as the requirement of quality management systems in construction

NASA Astrophysics Data System (ADS)

Harasymiuk, Jolanta; Barski, Janusz

2017-07-01

The choice of a supplier of construction materials can be important factor of increase or reduction of building works costs. Construction materials present from 40 for 70% of investment task depending on kind of works being provided for realization. There is necessity of estimate of suppliers from the point of view of effectiveness of construction undertaking and necessity from the point of view of conformity of taken operation by executives of construction job and objects within the confines of systems of managements quality being initiated in their organizations. The estimate of suppliers of construction materials and subexecutives of special works is formal requirement in quality management systems, which meets the requirements of the ISO 9001 standard. The aim of this paper is to show possibilities of making use of anaudit for estimate of credibility and reliability of the supplier of construction materials. The article describes kinds of audits, that were carried in quality management systems, with particular taking into consideration audits called as second-site. One characterizes the estimate criterions of qualitative ability and method of choice of the supplier of construction materials. The paper shows also propositions of exemplary questions, that would be estimated in audit process, the way of conducting of this estimate and conditionality of estimate.

Characterization of the harvesting capabilities of an ionic polymer metal composite device

NASA Astrophysics Data System (ADS)

Brufau-Penella, J.; Puig-Vidal, M.; Giannone, P.; Graziani, S.; Strazzeri, S.

2008-02-01

Harvesting systems capable of transforming dusty environmental energy into electrical energy have aroused considerable interest in the last two decades. Several research works have focused on the transformation of mechanical environmental vibrations into electrical energy. Most of the research activity refers to classic piezoelectric ceramic materials, but more recently piezoelectric polymer materials have been considered. In this paper, a novel point of view regarding harvesting systems is proposed: using ionic polymer metal composites (IPMCs) as generating materials. The goal of this paper is the development of a model able to predict the energy harvesting capabilities of an IPMC material working in air. The model is developed by using the vibration transmission theory of an Euler-Bernoulli cantilever IPMC beam. The IPMC is considered to work in its linear elastic region with a viscous damping contribution ranging from 0.1 to 100 Hz. An identification process based on experimental measurements performed on a Nafion® 117 membrane is used to estimate the material parameters. The model validation shows a good agreement between simulated and experimental results. The model is used to predict the optimal working region and the optimal geometrical parameters for the maximum power generation capacity of a specific membrane. The model takes into account two restrictions. The first is due to the beam theory, which imposes a maximum ratio of 0.5 between the cantilever width and length. The second restriction is to force the cantilever to oscillate with a specific strain; in this paper a 0.3% strain is considered. By considering these two assumptions as constraints on the model, it is seen that IPMC materials could be used as low-power generators in a low-frequency region. The optimal dimensions for the Nafion® 117 membrane are length = 12 cm and width = 6.2 cm, and the electric power generation is 3 nW at a vibrating frequency of 7.09 rad s-1. IPMC materials can sustain big yield strains, so by increasing the strain allowed on the material the power will increase dramatically, the expected values being up to a few microwatts.

Solution processing of chalcogenide materials using thiol-amine "alkahest" solvent systems.

PubMed

McCarthy, Carrie L; Brutchey, Richard L

2017-05-02

Macroelectronics is a major focus in electronics research and is driven by large area applications such as flat panel displays and thin film solar cells. Innovations for these technologies, such as flexible substrates and mass production, will require efficient and affordable semiconductor processing. Low-temperature solution processing offers mild deposition methods, inexpensive processing equipment, and the possibility of high-throughput processing. In recent years, the discovery that binary "alkahest" mixtures of ethylenediamine and short chain thiols possess the ability to dissolve bulk inorganic materials to yield molecular inks has lead to the wide study of such systems and the straightforward recovery of phase pure crystalline chalcogenide thin films upon solution processing and mild annealing of the inks. In this review, we recount the work that has been done toward elucidating the scope of this method for the solution processing of inorganic materials for use in applications such as photovoltaic devices, electrocatalysts, photodetectors, thermoelectrics, and nanocrystal ligand exchange. We also take stock of the wide range of bulk materials that can be used as soluble precursors, and discuss the work that has been done to reveal the nature of the dissolved species. This method has provided a vast toolbox of over 65 bulk precursors, which can be utilized to develop new routes to functional chalcogenide materials. Future studies in this area should work toward a better understanding of the mechanisms involved in the dissolution and recovery of bulk materials, as well as broadening the scope of soluble precursors and recoverable functional materials for innovative applications.

Emerging Insights into Directed Assembly: Taking Examples from Nature to Design Synthetic Processes

NASA Astrophysics Data System (ADS)

de Pablo, Juan J.

There is considerable interest in controlling the assembly of polymeric material in order to create highly ordered materials for applications. Such materials are often trapped in metastable, non-equilibrium states, and the processes through which they assemble become an important aspect of the materials design strategy. An example is provided by di-block copolymer directed self-assembly, where a decade of work has shown that, through careful choice of process variables, it is possible to create ordered structures whose degree of perfection meets the constraints of commercial semiconductor manufacturing. As impactful as that work has been, it has focused on relatively simple materials neutral polymers, consisting of two or at most three blocks. Furthermore, the samples that have been produced have been limited to relatively thin films, and the assembly has been carried out on ideal, two-dimensional substrates. The question that arises now is whether one can translate those achievements to polymeric materials having a richer sequence, to monomers that include charges, to three-dimensional substrates, or to active systems that are in a permanent non-equilibrium state. Building on discoveries from the biophysics literature, this presentation will review recent work from our group and others that explains how nature has evolved to direct the assembly of nucleic acids into intricate, fully three-dimensional macroscopic functional materials that are not only active, but also responsive to external cues. We will discuss how principles from polymer physics serve to explain those assemblies, and how one might design a new generation of synthetic systems that incorporate some of those principles.

Electronic and Ionic Conductors from Ordered Microporous Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dincă, Mircea

The proposed work aimed to establish metal-organic frameworks (MOFs) as new classes of high-surface area microporous electronic and ionic conductors. MOFs are crystalline materials with pore sizes ranging from 0.2 to ~ 2 nm (or larger for the latter) defined by inorganic or organic building blocks connected by rigid organic linkers. Myriad applications have been found or proposed for these materials, yet those that require electron transport or conductivity in combination with permanent porosity still lag behind because the vast majority of known frameworks are electrical insulators. Prior to our proposal and subsequent work, there were virtually no studies exploringmore » the possibility of electronic delocalization in these materials. Therefore, our primary goal was to understand and control, at a fundamental level, the electron and ion transport properties of this class of materials, with no specific application proposed, although myriad applications could be envisioned for high surface area conductors. Our goals directly addressed one of the DOE-identified Grand Challenges for Basic Energy Sciences: designing perfect atom- and energy-efficient syntheses of revolutionary new forms of matter with tailored properties. Indeed, the proposed work is entirely synthetic in nature; owing to the molecular nature of the building blocks in MOFs, there is the possibility of unprecedented control over the structure and properties of solid crystalline matter. The goals also tangentially addressed the Grand Challenge of controlling materials processes at the level of electrons: the scope of our program is to create new materials where charges (electrons and/or ions) move according to predefined pathways.« less

Influence of Custom Trays, Dual-Arch Passive, Flexed Trays and Viscosities of Elastomeric Impression Materials on Working Dies

PubMed Central

Kohli, Shivani; Kalsi, Rupali

2016-01-01

Introduction Dual arch impression technique signifies an essential improvement in fixed prosthodontics and has numerous benefits over conventional impression techniques. The accuracy of working dies fabricated from dual arch impression technique remains in question because there is little information available in the literature. Aim This study was conducted to compare the accuracy of working dies fabricated from impressions made from two different viscosities of impression materials using metal, plastic dual arch trays and custom made acrylic trays. Materials and Methods The study samples were grouped into two groups based on the viscosity of impression material used i.e. Group I (monophase), whereas Group II consisted of Dual Mix technique using a combination of light and heavy body material. These were further divided into three subgroups A, B and C depending on the type of impression tray used (metal dual arch tray, plastic dual arch tray and custom made tray). Measurements of the master cast were made using profile projector. Descriptive statistics like mean, Standard Deviation (SD) were calculated for all the groups. One way analysis of variance (ANOVA) was used for multiple group comparisons. A p-value of 0.05 or less was considered statistically significant. Results The gypsum dies obtained with the three types of impression trays using two groups of impression materials were smaller than the master models in dimensions. Conclusion The plastic dual arch trays produced dies which were the least accurate of the three groups. There was no significant difference in the die dimensions obtained using the two viscosities of impression materials. PMID:27437342

Laser-Gyro Materials Studies

DTIC Science & Technology

1986-03-01

mean-square (rms) have been measured on fused quartz and Zerodur surfaces polished by manufacturers of ring- laser gyros. The measurements were made...Sizes and Percent Crystallinity of Laser Gyro Materials. Crystallite Crystallinity, Material size, :-100 A ±10 vol% Zerodur 800 79 Quartz 500 53...Based on t data presented in this rel ort, Cervit, Zerodur , and RLA 559,122 from Corning Glass Works have acceptable material properties for laser

Aligning Curriculum Materials with the Australian Curriculum: What Is Happening in the Field and What Needs to Be Done?

ERIC Educational Resources Information Center

Watt, Michael

2016-01-01

The purpose of this study was to inform the deliberations of a policymakers' working group by investigating what key actors in the materials' marketplace are doing to align digital and print-based materials with the Australian Curriculum and what steps need to be taken to deliver aligned materials to schools. Content analysis method was used to…

The Impact of Including Writing Materials in Early Childhood Classrooms on the Early Literacy Development of Children from Low-Income Families

ERIC Educational Resources Information Center

Clark, Patricia; Kragler, Sherry

2005-01-01

The purpose of this research was to determine the effect of incorporating writing materials in all areas of the preschool classroom on the early literacy development of young children from low-income families. The researchers worked with six teachers in three preschool classrooms to incorporate literacy materials--particularly those materials that…

Extraction of volatile and metals from extraterrestrial materials

NASA Technical Reports Server (NTRS)

Lewis, John S.

1990-01-01

Since March 1, 1989, attention was concentrated on the extraction of ilmenite from extraterrestrial materials and on the planning and development of laboratory facilities for carbonyl extraction of ferrous metal alloys. Work under three subcontracts was administered by this project: (1) electrolytic production of oxygen from molten lunar materials; (2) microwave processing of lunar materials; and (3) production of a resource-oriented space science data base.

Doped polymer semiconductors with ultrahigh and ultralow work functions for ohmic contacts.

PubMed

Tang, Cindy G; Ang, Mervin C Y; Choo, Kim-Kian; Keerthi, Venu; Tan, Jun-Kai; Syafiqah, Mazlan Nur; Kugler, Thomas; Burroughes, Jeremy H; Png, Rui-Qi; Chua, Lay-Lay; Ho, Peter K H

2016-11-24

To make high-performance semiconductor devices, a good ohmic contact between the electrode and the semiconductor layer is required to inject the maximum current density across the contact. Achieving ohmic contacts requires electrodes with high and low work functions to inject holes and electrons respectively, where the work function is the minimum energy required to remove an electron from the Fermi level of the electrode to the vacuum level. However, it is challenging to produce electrically conducting films with sufficiently high or low work functions, especially for solution-processed semiconductor devices. Hole-doped polymer organic semiconductors are available in a limited work-function range, but hole-doped materials with ultrahigh work functions and, especially, electron-doped materials with low to ultralow work functions are not yet available. The key challenges are stabilizing the thin films against de-doping and suppressing dopant migration. Here we report a general strategy to overcome these limitations and achieve solution-processed doped films over a wide range of work functions (3.0-5.8 electronvolts), by charge-doping of conjugated polyelectrolytes and then internal ion-exchange to give self-compensated heavily doped polymers. Mobile carriers on the polymer backbone in these materials are compensated by covalently bonded counter-ions. Although our self-compensated doped polymers superficially resemble self-doped polymers, they are generated by separate charge-carrier doping and compensation steps, which enables the use of strong dopants to access extreme work functions. We demonstrate solution-processed ohmic contacts for high-performance organic light-emitting diodes, solar cells, photodiodes and transistors, including ohmic injection of both carrier types into polyfluorene-the benchmark wide-bandgap blue-light-emitting polymer organic semiconductor. We also show that metal electrodes can be transformed into highly efficient hole- and electron-injection contacts via the self-assembly of these doped polyelectrolytes. This consequently allows ambipolar field-effect transistors to be transformed into high-performance p- and n-channel transistors. Our strategy provides a method for producing ohmic contacts not only for organic semiconductors, but potentially for other advanced semiconductors as well, including perovskites, quantum dots, nanotubes and two-dimensional materials.

Laser-gyro materials studies

NASA Astrophysics Data System (ADS)

Covino, J.; Bennett, J. M.

1986-03-01

Material properties of low-expansion glass and glass-ceramic materials have been measured. The materials that have been characterized are ultralow-expansion (ULE) type 7971 quartz, a new glass-ceramic material RLA 559,122 from Corning Glass Works, fused quartz from General Electric, Zerodur from Schott Glaswerke, and Cervit C-101 from Owens-Illinois. Characterization has included measurements of X-ray powder diffraction patterns, some elemental analyses, helium permeability, thermal expansion, particle-size distributions, optical properties, and optical finish studies.

NCTE (National Council of Teachers of English) Guide to Teaching Materials for English, Grades 7-12; An Annotated Listing of Textbooks and Related Materials for Secondary Schools Prepared by the NCTE Staff. 1975-76 Supplement.

ERIC Educational Resources Information Center

National Council of Teachers of English, Urbana, IL.

This supplement to the "NCTE Guide to Teaching Materials for English, Grades 7-12" contains annotations for English anthologies, textbooks, workbooks, multimedia packages, and other materials for the junior high and high school levels. Works of literature, audiovisual materials, and professional publications are included when related to specific,…

29 CFR 1910.176 - Handling materials-general.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (b) Secure storage. Storage of material shall not create a hazard. Bags, containers, bundles, etc... on spur railroad tracks where a rolling car could contact other cars being worked, enter a building...

29 CFR 1910.176 - Handling materials-general.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (b) Secure storage. Storage of material shall not create a hazard. Bags, containers, bundles, etc... on spur railroad tracks where a rolling car could contact other cars being worked, enter a building...

29 CFR 1910.176 - Handling materials-general.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... (b) Secure storage. Storage of material shall not create a hazard. Bags, containers, bundles, etc... on spur railroad tracks where a rolling car could contact other cars being worked, enter a building...

29 CFR 1910.176 - Handling materials-general.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... (b) Secure storage. Storage of material shall not create a hazard. Bags, containers, bundles, etc... on spur railroad tracks where a rolling car could contact other cars being worked, enter a building...

29 CFR 1910.176 - Handling materials-general.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... (b) Secure storage. Storage of material shall not create a hazard. Bags, containers, bundles, etc... on spur railroad tracks where a rolling car could contact other cars being worked, enter a building...

Auditory Attention and Comprehension During a Simulated Night Shift: Effects of Task Characteristics.

PubMed

Pilcher, June J; Jennings, Kristen S; Phillips, Ginger E; McCubbin, James A

2016-11-01

The current study investigated performance on a dual auditory task during a simulated night shift. Night shifts and sleep deprivation negatively affect performance on vigilance-based tasks, but less is known about the effects on complex tasks. Because language processing is necessary for successful work performance, it is important to understand how it is affected by night work and sleep deprivation. Sixty-two participants completed a simulated night shift resulting in 28 hr of total sleep deprivation. Performance on a vigilance task and a dual auditory language task was examined across four testing sessions. The results indicate that working at night negatively impacts vigilance, auditory attention, and comprehension. The effects on the auditory task varied based on the content of the auditory material. When the material was interesting and easy, the participants performed better. Night work had a greater negative effect when the auditory material was less interesting and more difficult. These findings support research that vigilance decreases during the night. The results suggest that auditory comprehension suffers when individuals are required to work at night. Maintaining attention and controlling effort especially on passages that are less interesting or more difficult could improve performance during night shifts. The results from the current study apply to many work environments where decision making is necessary in response to complex auditory information. Better predicting the effects of night work on language processing is important for developing improved means of coping with shiftwork. © 2016, Human Factors and Ergonomics Society.

Basic Facts about the United Nations.

ERIC Educational Resources Information Center

United Nations, New York, NY. Office of Public Information.

The work of the United Nations is described in summary form. Material is divided into sections on the origin, programs, purpose, principles, and structure of the United Nations; the United Nations at work for International Peace; the United Nations at Work for Economic and Social Development; The United Nations at Work for Decolonization; the…

Rethinking Difficulties of Teaching Inquiry-Based Practical Work: Stories from Elementary Pre-Service Teachers

ERIC Educational Resources Information Center

Kim, Mijung; Tan, Aik-Ling

2011-01-01

To alleviate teachers' reluctance toward practical work, there has been much discussion on teachers' pedagogical content knowledge, teaching materials, and failsafe strategies for practical work. Despite these efforts, practical work is still regarded as a challenging task for many elementary science teachers. To understand the complexity of…

46 CFR 151.03-37 - Maximum allowable working pressure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Maximum allowable working pressure. 151.03-37 Section 151.03-37 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-37 Maximum allowable working pressure. The maximum allowable working...

46 CFR 151.03-37 - Maximum allowable working pressure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Maximum allowable working pressure. 151.03-37 Section 151.03-37 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-37 Maximum allowable working pressure. The maximum allowable working...

46 CFR 151.03-37 - Maximum allowable working pressure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Maximum allowable working pressure. 151.03-37 Section 151.03-37 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-37 Maximum allowable working pressure. The maximum allowable working...

46 CFR 151.03-37 - Maximum allowable working pressure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Maximum allowable working pressure. 151.03-37 Section 151.03-37 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-37 Maximum allowable working pressure. The maximum allowable working...

46 CFR 151.03-37 - Maximum allowable working pressure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Maximum allowable working pressure. 151.03-37 Section 151.03-37 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-37 Maximum allowable working pressure. The maximum allowable working...

Leading Work with Young People

ERIC Educational Resources Information Center

Harrison, Roger, Ed.; Benjamin, Cathy, Ed.; Curran, Sheila, Ed.; Hunter, Rob, Ed.

2007-01-01

"Leading Work with Young People" provides a selection of writing from a complex and dynamic field of work. The editors bring together key readings and newly commissioned material to present a variety of theoretical and practical perspectives on leading and managing work with young people. The book will equip students with the knowledge, skills,…

Proxy-Produced Ethnographic Work: What Are the Problems, Issues, and Dilemmas Arising from Proxy-Ethnography?

ERIC Educational Resources Information Center

Martinussen, Marie; Højbjerg, Karin; Tamborg, Andreas Lindenskov

2018-01-01

This article addresses the implications of researcher-student cooperation in the production of empirical material. For the student to replace the experienced researcher and work under the researcher's supervision, we call such work proxy-produced ethnographic work. Although there are clear advantages, the specific relations and positions arising…

48 CFR 227.7107-2 - Contracts for construction supplies and research and development work.

Code of Federal Regulations, 2010 CFR

2010-10-01

... supplies and research and development work. 227.7107-2 Section 227.7107-2 Federal Acquisition Regulations... research and development work. Use the provisions and clauses required by 227-7103-6 and 227.7203-6 when..., or research work, or test and evaluation studies of structures, equipment, processes, or materials...

How Does Working Memory Work in the Classroom?

ERIC Educational Resources Information Center

Alloway, Tracy Packiam

2006-01-01

Working memory plays a key role in supporting children's learning over the school years, and beyond this into adulthood. It is proposed here that working memory is crucially required to store information while other material is being mentally manipulated during the classroom learning activities that form the foundations for the acquisition of…

Advanced Materials for Exploration Task Research Results

NASA Technical Reports Server (NTRS)

Cook, M. B. (Compiler); Murphy, K. L.; Schneider, T.

2008-01-01

The Advanced Materials for Exploration (AME) Activity in Marshall Space Flight Center s (MSFC s) Exploration Science and Technology Directorate coordinated activities from 2001 to 2006 to support in-space propulsion technologies for future missions. Working together, materials scientists and mission planners identified materials shortfalls that are limiting the performance of long-term missions. The goal of the AME project was to deliver improved materials in targeted areas to meet technology development milestones of NASA s exploration-dedicated activities. Materials research tasks were targeted in five areas: (1) Thermal management materials, (2) propulsion materials, (3) materials characterization, (4) vehicle health monitoring materials, and (5) structural materials. Selected tasks were scheduled for completion such that these new materials could be incorporated into customer development plans.

Microstructure Evolution During Creep of Cold Worked Austenitic Stainless Steel

NASA Astrophysics Data System (ADS)

Krishan Yadav, Hari; Ballal, A. R.; Thawre, M. M.; Vijayanand, V. D.

2018-04-01

The 14Cr–15Ni austenitic stainless steel (SS) with additions of Ti, Si, and P has been developed for their superior creep strength and better resistance to void swelling during service as nuclear fuel clad and wrapper material. Cold working induces defects such as dislocations that interact with point defects generated by neutron irradiation and facilitates recombination to make the material more resistant to void swelling. In present investigation, creep properties of the SS in mill annealed condition (CW0) and 40 % cold worked (CW4) condition were studied. D9I stainless steel was solution treated at 1333 K for 30 minutes followed by cold rolling. Uniaxial creep tests were performed at 973 K for various stress levels ranging from 175-225 MPa. CW4 samples exhibited better creep resistance as compared to CW0 samples. During creep exposure, cold worked material exhibited phenomena of recovery and recrystallization wherein new strain free grains were observed with lesser dislocation network. In contrast CW0 samples showed no signs of recovery and recrystallization after creep exposure. Partial recrystallization on creep exposure led to higher drop in hardness in cold worked sample as compared to that in mill annealed sample. Accelerated precipitation of carbides at the grain boundaries was observed during creep exposure and this phenomenon was more pronounced in cold worked sample.

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Foam § 160.053-3 Materials, construction and workmanship. (a) General. Except as otherwise specifically... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Foam § 160.053-3 Materials, construction and workmanship. (a) General. Except as otherwise specifically... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements...

Camp Minden Draft QASP and Work Plan for Public Feedback

EPA Pesticide Factsheets

ESI has developed these operational plans, technical approaches, and related required resources based upon extensive review and planning for material removal, transportation, staging, and Contained Burn Chamber (CBC) destruction of materials.

Materials and Chemical Sciences Division annual report, 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1988-07-01

Research programs from Lawrence Berkeley Laboratory in materials science, chemical science, nuclear science, fossil energy, energy storage, health and environmental sciences, program development funds, and work for others is briefly described. (CBS)

29 CFR 1917.11 - Housekeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sharp objects not necessary for the work in progress. (b) Hatch beams, covers and pontoons placed in..., dunnage or other suitable material shall be used under and between tiers. (c) Cargo and material shall not...

10 CFR 72.78 - Nuclear material transaction reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... writing to the U.S. Nuclear Regulatory Commission, Division of Fuel Cycle Safety and Safeguards... instructions no later than the close of business the next working day. Each licensee who receives the material...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunc, Vlastimil; Lindahl, John M.; Minneci, Robert P.

ORNL worked with The DOW Chemical Company to validate the feasibility of 3D printing DOW’s polyurethane (PU) materials using ORNL’s equipment and know-how. This led to the development of the first directly-3D-printable PU material.

Carbon-carbon mirrors for exoatmospheric and space applications

NASA Astrophysics Data System (ADS)

Krumweide, Duane E.; Wonacott, Gary D.; Woida, Patrick M.; Woida, Rigel Q.; Shih, Wei

2007-09-01

The cost and leadtime associated with beryllium has forced the MDA and other defense agencies to look for alternative materials with similar structural and thermal properties. The use of carbon-carbon material, specifically in optical components has been demonstrated analytically in prior SBIR work at San Diego Composites. Carbon-carbon material was chosen for its low in-plane and through-thickness CTE (athermal design), high specific stiffness, near-zero coefficient of moisture expansion, availability of material (specifically c-c honeycomb for lightweight substrates), and compatibility with silicon monoxide (SiO) and silicon dioxide (SiO II) coatings. Subsequent development work has produced shaped carbon-carbon sandwich substrates which have been ground, polished, coated and figured using traditional optical processing. Further development has also been done on machined monolithic carbon-carbon mirror substrates which have also been processed using standard optical finishing techniques.

Heat-Affected Zone Liquation Cracking Resistance of Friction Stir Processed Aluminum-Copper Alloy AA 2219

NASA Astrophysics Data System (ADS)

Karthik, G. M.; Janaki Ram, G. D.; Kottada, Ravi Sankar

2017-04-01

In the current work, the effect of friction stir processing on heat-affected zone (HAZ) liquation cracking resistance of aluminum-copper alloy AA 2219 was evaluated. In Gleeble hot-ductility tests and longitudinal Varestraint tests, the FSPed material, despite its very fine dynamically recrystallized equiaxed grain structure, showed considerably higher susceptibility to HAZ liquation cracking when compared to the base material. Detailed microstructural studies showed that the increased cracking susceptibility of the FSPed material is due to (i) increase in the amount of liquating θ phase (equilibrium Al2Cu) and (ii) increase in the population of grain boundary θ particles. An important learning from the current work is that, in certain materials like alloy 2219, the use of FSP as a pretreatment to fusion welding can be counterproductive.

Modeling and additive manufacturing of bio-inspired composites with tunable fracture mechanical properties.

PubMed

Dimas, Leon S; Buehler, Markus J

2014-07-07

Flaws, imperfections and cracks are ubiquitous in material systems and are commonly the catalysts of catastrophic material failure. As stresses and strains tend to concentrate around cracks and imperfections, structures tend to fail far before large regions of material have ever been subjected to significant loading. Therefore, a major challenge in material design is to engineer systems that perform on par with pristine structures despite the presence of imperfections. In this work we integrate knowledge of biological systems with computational modeling and state of the art additive manufacturing to synthesize advanced composites with tunable fracture mechanical properties. Supported by extensive mesoscale computer simulations, we demonstrate the design and manufacturing of composites that exhibit deformation mechanisms characteristic of pristine systems, featuring flaw-tolerant properties. We analyze the results by directly comparing strain fields for the synthesized composites, obtained through digital image correlation (DIC), and the computationally tested composites. Moreover, we plot Ashby diagrams for the range of simulated and experimental composites. Our findings show good agreement between simulation and experiment, confirming that the proposed mechanisms have a significant potential for vastly improving the fracture response of composite materials. We elucidate the role of stiffness ratio variations of composite constituents as an important feature in determining the composite properties. Moreover, our work validates the predictive ability of our models, presenting them as useful tools for guiding further material design. This work enables the tailored design and manufacturing of composites assembled from inferior building blocks, that obtain optimal combinations of stiffness and toughness.

Study of the time varying properties of flax fiber reinforced composites

NASA Astrophysics Data System (ADS)

Stochioiu, Constantin; Chettah, Ameur; Piezel, Benoit; Fontaine, Stéphane; Gheorghiu, Horia-Miron

2018-02-01

Bio materials have seen an increase of interest from the scientific community and the industry as a possible future generation of mass produced materials, some of the main arguments being their renewability, low production costs and recyclability. The current work is focused on the experimental data required for the viscoelastic characterization of a composite material. Similar work has been conducted on different types of composite materials by Tuttle and Brinson [1] who verified for a carbon epoxy laminate the possibility of long term predicament of creep. Nordin et al [2] studied paper impregnated with phenol-formaldehyde under compression. Muliana [3] conducted experiments on E-glass/vinyl ester materials. Behavior characterization was based on a model presented by Schapery [4]. The main objective of this work is to understand the mechanical behaviors of bio-laminates structures subjected to long and severe operating conditions. The studied material is a bio composite laminate consisting in long flax fibers embedded in an epoxy resin system. The laminates were obtained from pre-impregnated unidirectional fibers, which were cured though a thermo-compression cycle followed by a post curing cycle. Test specimens were cut down to sizes, with the help of an electric saw. The concerned fiber direction was 0° with sample dimensions of 250x25x2 mm. First, testing consisted in quasi static mechanical tests. Second, to characterize linear viscoelastic behavior of the bio-laminates, creep - recovery tests with multiple load levels have been performed for the chosen fiber direction.

Engaging Children through the Use of Cartoons and Comics

ERIC Educational Resources Information Center

Weitkamp, Emma; Featherstone, Helen

2010-01-01

ScienceComics project originally involved a set of theatre performances that sought to highlight the importance of materials by exploring what happens when one uses the "wrong" material. As part of this early work, two plays were created that featured a young alien girl, called Selenia, who could change materials. In this article, the…

Recalling Prerequisite Material in a Calculus II Course to Improve Student Success

ERIC Educational Resources Information Center

Mokry, Jeanette

2016-01-01

This article discusses preparation assignments used in a Calculus II course that cover material from prerequisite courses. Prior to learning new material, students work on problems outside of class involving concepts from algebra, trigonometry, and Calculus I. These problems are directly built upon in order to answer Calculus II questions,…

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2011 CFR

2011-07-01

... material balance that includes the pertinent data used to determine the percent reduction of total sulfide... material balance; and (3) complying with the continuous compliance requirements for closed-vent systems. 2... material balance that includes the pertinent data used to determine the percent reduction of toluene...

40 CFR Table 5 to Subpart Uuuu of... - Continuous Compliance With Emission Limits and Work Practice Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... material balance that includes the pertinent data used to determine the percent reduction of total sulfide... material balance; and (3) complying with the continuous compliance requirements for closed-vent systems. 2... material balance that includes the pertinent data used to determine the percent reduction of toluene...

77 FR 44059 - Federal Acquisition Regulation; Payments Under Time-and-Materials and Labor-Hour Contracts

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-26

...) Payments of this clause, but the ``hourly rate'' for labor hours expended in furnishing work not delivered...] RIN 9000-AM01 Federal Acquisition Regulation; Payments Under Time-and-Materials and Labor-Hour... the authorization to use time-and-materials and labor-hour contract payment requirements. DATES...

In Search of Canadian Materials, Revised.

ERIC Educational Resources Information Center

Phillips, Donna, Comp.

Designed as an aid to the selection of Canadian materials for the school library, this revised edition lists 2,100 titles and provides a new separate section on women's studies. Major subdivisions of the work include periodical and reference materials sections, as well as sections by subject category: business and consumer education; fine arts,…

Dental Charting. Learning Activities, Unit Tests, Progress Chart, and Work Sheet.

ERIC Educational Resources Information Center

Texas Univ., Austin. Center for Occupational Curriculum Development.

These materials are part of a series dealing with skills and information needed by students in dental assisting. The individualized student materials are suitable for classroom, laboratory, or cooperative training programs. These student materials, designed to be used with the Dental Charting Student Manual, consist of learning activities, unit…

Copyright. CET Information Sheet No. 6.

ERIC Educational Resources Information Center

Council for Educational Technology, London (England).

The United Kingdom (UK) is a large producer of published materials and as such has a strong copyright law (the Copyright Act of 1956). The law protects eight categories of materials--literary, dramatic, musical, and artistic works; sound recordings; film; broadcasts; and published editions--but the law varies from one type of material to another.…

The Market System: Does It Work? Teacher's Edition.

ERIC Educational Resources Information Center

O'Neill, James B.

This document is the teacher's guide for SO 008 864. Developed for secondary students, the materials aid students in the understanding of the United States economic system. Along with the narrative found in the student materials, the guide presents objectives, concepts, procedures, and evaluation for completing the unit. The materials are arranged…

Teaching Qualitative Research: Experiential Learning in Group-Based Interviews and Coding Assignments

ERIC Educational Resources Information Center

DeLyser, Dydia; Potter, Amy E.

2013-01-01

This article describes experiential-learning approaches to conveying the work and rewards involved in qualitative research. Seminar students interviewed one another, transcribed or took notes on those interviews, shared those materials to create a set of empirical materials for coding, developed coding schemes, and coded the materials using those…

Material Encounters and Media Events: What Kind of Mathematics Can a Body Do?

ERIC Educational Resources Information Center

de Freitas, Elizabeth

2016-01-01

This paper contributes to research on the material dimensions of teaching and learning mathematics, arguing that perception is not sensory integration or synthesis of multi-modal information, but rather a speculative investment in specific material encounters. This approach entails sociopolitical consequences for how we work with dis/ability in…

Experimental Investigation of the Role of Defects in Detonation Sensitivity of Energetic Materials: Development of Techniques for Characterization

DTIC Science & Technology

2009-12-31

materials. The initial work was focused on design and construction of an apparatus for injecting defects into the crystals using PZT ceramics ...in the energy partitioning (Table 2), which offers some insight into the nature of the energetic texture of crystalline materials not apparent in

Bilingual/E.S.L. Materials Development, Grades 1-8, 1987. OREA Report.

ERIC Educational Resources Information Center

Berney, Tomi D.; Friedman, Grace Ibanez

New York City's program in Bilingual/E.S.L. Materials Development, Grade 1-8 was established to develop and/or update curricula and informational materials relevant to bilingual and English-as-a-Second-Language instruction. Curriculum development teams worked on independent activities. The project had 10 proposed curriculum initiatives, but the…

An Annotated Guide to Audio-Visual Materials for Teaching Shakespeare.

ERIC Educational Resources Information Center

Albert, Richard N.

Audio-visual materials, found in a variety of periodicals, catalogs, and reference works, are listed in this guide to expedite the process of finding appropriate classroom materials for a study of William Shakespeare in the classroom. Separate listings of films, filmstrips, and recordings are provided, with subdivisions for "The Plays"…

Instructional Materials in Spanish for Agriculture. Final Report.

ERIC Educational Resources Information Center

Mainous, Bruce H.

A federally funded project to develop Spanish for Agricultural Purposes, a set of instructional materials for agricultural specialists planning to work in Latin America, is reported. The materials are intended for use by individuals with at least a year's college-level study of Spanish. They include: a series of authentic readings, each with an…

Materials management: stretching the "household" budget.

PubMed

Carpe, R H; Carroll, P E

1987-11-01

As CFOs assume responsibility for the materials management function because of the potential to maximize cash flow, achieve economies of scale, decrease costs, and streamline operations, they look for guidelines to evaluate performance. Conducting a systems operations audit can aid in assessing that performance. CFOs can determine whether materials management processes are working "smarter, nor harder."

49 CFR Appendix B to Part 209 - Federal Railroad Administration Guidelines for Initial Hazardous Materials Assessments

Code of Federal Regulations, 2010 CFR

2010-10-01

... hazardous materials are only safe for transportation when they are securely sealed in a proper package...) that a container or package for transportation of a hazardous material is safe, certified, or in.... —Listing an unauthorized, incorrect, non-working, or unmonitored (24 hrs. a day) emergency response...

Bibliography of Law-Related Curriculum Materials: Annotated (Second Edition). Working Notes No. 10.

ERIC Educational Resources Information Center

Davison, Susan E., Ed.

This annotated bibliography cites over 1,000 elementary- and secondary-level materials dealing with the philosophy, substance, and pedagogy of law-related education. It lists textbooks, curriculum kits and guides, journals and newsletters, and books that can serve as reference or supplementary materials. The bibliography is divided by topic into…

Typing: Creating a Laboratory Atmosphere

ERIC Educational Resources Information Center

Leonard, Jane A.

1976-01-01

Using materials clipped from newspapers, students in a Typing I laboratory learn how to tabulate, proofread, type letters, and reports, etc., and work independently and evaluate other students' work. (TA)

Machining of Fibre Reinforced Plastic Composite Materials.

PubMed

Caggiano, Alessandra

2018-03-18

Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented.

Insights to regenerate materials: learning from nature

NASA Astrophysics Data System (ADS)

García-Aznar, J. M.; Valero, C.; Gómez-Benito, M. J.; Javierre, E.

2016-08-01

Self-healing materials, both biological and engineered, integrate the ability to repair themselves and recover their functionality using the resources inherently available to them. Although significant advances have been made, in recent years, for the design of different concepts of self-healing materials, this work aims to provide some insights into how living materials are able to regenerate or heal when a fracture or injury occurs. The main sensors that regulate this adaptive and regenerative behavior are the cells. These are able to sense the mechanical alterations in their surroundings and regulate their activity in order to remove dead tissue and/or create new tissue. Therefore, understanding how cells are able to regenerate tissues under complex and multiphysics conditions can define the biomimetics guidelines to heal through inert or traditional engineering materials. In this work, we present a combination of experiments and different kinds of multiscale and multiphysics models in order to understand how mechanics regulate some mechanisms at cell and tissue level. This combination of results aims to gain insight into the development of novel strategies for self-healing materials, mimicking the behavior induced by cells and biological tissues.

Machining of Fibre Reinforced Plastic Composite Materials

PubMed Central

2018-01-01

Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented. PMID:29562635

Developing Carbon Nanotube Standards at NASA

NASA Technical Reports Server (NTRS)

Nikolaev, Pasha; Arepalli, Sivaram; Sosa, Edward; Gorelik, Olga; Yowell, Leonard

2007-01-01

Single wall carbon nanotubes (SWCNTs) are currently being produced and processed by several methods. Many researchers are continuously modifying existing methods and developing new methods to incorporate carbon nanotubes into other materials and utilize the phenomenal properties of SWCNTs. These applications require availability of SWCNTs with known properties and there is a need to characterize these materials in a consistent manner. In order to monitor such progress, it is critical to establish a means by which to define the quality of SWCNT material and develop characterization standards to evaluate of nanotube quality across the board. Such characterization standards should be applicable to as-produced materials as well as processed SWCNT materials. In order to address this issue, NASA Johnson Space Center has developed a protocol for purity and dispersion characterization of SWCNTs (Ref.1). The NASA JSC group is currently working with NIST, ANSI and ISO to establish purity and dispersion standards for SWCNT material. A practice guide for nanotube characterization is being developed in cooperation with NIST (Ref.2). Furthermore, work is in progress to incorporate additional characterization methods for electrical, mechanical, thermal, optical and other properties of SWCNTs.

Developing Carbon Nanotube Standards at NASA

NASA Technical Reports Server (NTRS)

Nikolaev, Pasha; Arepalli, Sivaram; Sosa, Edward; Gorelik, Olga; Yowell, Leonard

2007-01-01

Single wall carbon nanotubes (SWCNTs) are currently being produced and processed by several methods. Many researchers are continuously modifying existing methods and developing new methods to incorporate carbon nanotubes into other materials and utilize the phenomenal properties of SWCNTs. These applications require availability of SWCNTs with known properties and there is a need to characterize these materials in a consistent manner. In order to monitor such progress, it is critical to establish a means by which to define the quality of SWCNT material and develop characterization standards to evaluate of nanotube quality across the board. Such characterization standards should be applicable to as-produced materials as well as processed SWCNT materials. In order to address this issue, NASA Johnson Space Center has developed a protocol for purity and dispersion characterization of SWCNTs. The NASA JSC group is currently working with NIST, ANSI and ISO to establish purity and dispersion standards for SWCNT material. A practice guide for nanotube characterization is being developed in cooperation with NIST. Furthermore, work is in progress to incorporate additional characterization methods for electrical, mechanical, thermal, optical and other properties of SWCNTs.

Electric Motor Thermal Management Research: Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennion, Kevin S.

Past work in the area of active convective cooling provided data on the average convective heat transfer coefficients of circular orifice automatic transmission fluid (ATF) jets impinging on stationary targets intended to represent the wire bundle surface of the motor end-winding. Work during FY16 focused on the impact of alternative jet geometries that could lead to improved cooling over a larger surface of the motor winding. Results show that the planar jet heat transfer coefficients over a small (12.7-mm-diameter) target surface are not too much lower than for the circular orifice jet in which all of the ATF from themore » jet impinges on the target surface. The planar jet has the potential to achieve higher heat transfer over a larger area of the motor end winding. A new test apparatus was constructed to measure the spatial dependence of the heat transfer relative to the jet nozzle over a larger area representative of a motor end-winding. The tested planar flow geometry has the potential to provide more uniform cooling over the full end-winding surface versus the conventional jet configuration. The data will be used by motor designers to develop thermal management strategies to improve motor power density. Work on passive thermal design in collaboration with Oak Ridge National Laboratory to measure the thermal conductivity of wire bundle samples representative of end-winding and slot-winding materials was completed. Multiple measurement techniques were compared to determine which was most suitable for measuring composite wire bundle samples. NREL used a steady-state thermal resistance technique to measure the direction-dependent thermal conductivity. The work supported new interactions with industry to test new materials and reduce passive-stack thermal resistance in motors, leading to motors with increased power density. NREL collaborated with Ames Laboratory in the area of material characterization. The work focused on measuring the transverse rupture strength of new magnet materials developed at Ames. The impact of the improved transverse rupture strength is a mechanically stronger magnet that is easier for manufacturers to implement into motor designs. The thermal conductivity of the new magnet materials was also measured in comparison to two commercially available AlNiCo magnet materials. The impact of the thermal conductivity of the magnet material will need to be analyzed in the context of a motor application.« less

Biplanes and Bombsights, British Bombing in World War I

DTIC Science & Technology

1999-05-01

each started at 1.35 and 10.40 a.m. respectively to bomb the Chemical Works at LUDWIGSHAFEN (MANNHEIM). One machine was forced to return to its...teams and German officials, material results were incommensurate with effort. Nor did material results at German munitions and chemical works entirely...city do not include the 41st Wing day mission of 14 January 1918.159 Newall’s force attacked enemy munitions and chemical tar- gets on four occasions

Improved Synthesis Of Potassium Beta' '-Alumina

NASA Technical Reports Server (NTRS)

Williams, Roger M.; Jeffries-Nakamura, Barbara; Ryan, Margaret A.; O'Connor, Dennis E.; Kisor, Adam; Underwood, Mark

1996-01-01

Improved formulations of precursor materials synthesize nearly-phase-pure potassium beta' '-alumina solid electrolyte (K-BASE) powder. Materials are microhomogeneous powders (or, alternatively, gels) containing K(+,) Mg(2+), and Al(3+). K-BASE powder produced used in potassium-working-fluid alkali-metal thermal-to-electric conversion (K-AMTEC), in which heat-input and heat-rejection temperatures lower than sodium-working-fluid AMTEC (Na-AMTEC). Additional potential use lies in purification of pottassium by removal of sodium and calcium.

Intermediate Temperature Fluids Life Tests - Theory

NASA Technical Reports Server (NTRS)

Tarau, Calin; Sarraf, David B.; Locci, Ivan E.; Anderson, William G.

2008-01-01

There are a number of different applications that could use heat pipes or loop heat pipes (LHPs) in the intermediate temperature range of 450 to 750 K, including space nuclear power system radiators, and high temperature electronics cooling. Potential working fluids include organic fluids, elements, and halides, with halides being the least understood, with only a few life tests conducted. Potential envelope materials for halide working fluids include pure aluminum, aluminum alloys, commercially pure (CP) titanium, titanium alloys, and corrosion resistant superalloys. Life tests were conducted with three halides (AlBr3, SbBr3, and TiCl4) and water in three different envelopes: two aluminum alloys (Al-5052, Al-6061) and Cp-2 titanium. The AlBr3 attacked the grain boundaries in the aluminum envelopes, and formed TiAl compounds in the titanium. The SbBr3 was incompatible with the only envelope material that it was tested with, Al-6061. TiCl4 and water were both compatible with CP2-titanium. A theoretical model was developed that uses electromotive force differences to predict the compatibility of halide working fluids with envelope materials. This theory predicts that iron, nickel, and molybdenum are good envelope materials, while aluminum and titanium halides are good working fluids. The model is in good agreement with results form previous life tests, as well as the current life tests.

Transition metal oxide as anode interface buffer for impedance spectroscopy

NASA Astrophysics Data System (ADS)

Xu, Hui; Tang, Chao; Wang, Xu-Liang; Zhai, Wen-Juan; Liu, Rui-Lan; Rong, Zhou; Pang, Zong-Qiang; Jiang, Bing; Fan, Qu-Li; Huang, Wei

2015-12-01

Impedance spectroscopy is a strong method in electric measurement, which also shows powerful function in research of carrier dynamics in organic semiconductors when suitable mathematical physical models are used. Apart from this, another requirement is that the contact interface between the electrode and materials should at least be quasi-ohmic contact. So in this report, three different transitional metal oxides, V2O5, MoO3 and WO3 were used as hole injection buffer for interface of ITO/NPB. Through the impedance spectroscopy and PSO algorithm, the carrier mobilities and I-V characteristics of the NPB in different devices were measured. Then the data curves were compared with the single layer device without the interface layer in order to investigate the influence of transitional metal oxides on the carrier mobility. The careful research showed that when the work function (WF) of the buffer material was just between the work function of anode and the HOMO of the organic material, such interface material could work as a good bridge for carrier injection. Under such condition, the carrier mobility measured through impedance spectroscopy should be close to the intrinsic value. Considering that the HOMO (or LUMO) of most organic semiconductors did not match with the work function of the electrode, this report also provides a method for wide application of impedance spectroscopy to the research of carrier dynamics.

Metal Sulfides as Sensing Materials for Chemoresistive Gas Sensors

PubMed Central

Gaiardo, Andrea; Fabbri, Barbara; Guidi, Vincenzo; Bellutti, Pierluigi; Giberti, Alessio; Gherardi, Sandro; Vanzetti, Lia; Malagù, Cesare; Zonta, Giulia

2016-01-01

This work aims at a broad overview of the results obtained with metal-sulfide materials in the field of chemoresistive gas sensing. Indeed, despite the well-known electrical, optical, structural and morphological features previously described in the literature, metal sulfides present lack of investigation for gas sensing applications, a field in which the metal oxides still maintain a leading role owing to their high sensitivity, low cost, small dimensions and simple integration, in spite of the wide assortment of sensing materials. However, despite their great advantages, metal oxides have shown significant drawbacks, which have led to the search for new materials for gas sensing devices. In this work, Cadmium Sulfide and Tin (IV) Sulfide were investigated as functional materials for thick-film chemoresistive gas-sensors fabrication and they were tested both in thermo- and in photo-activation modes. Furthermore, electrical characterization was carried out in order to verify their gas sensing properties and material stability, by comparing the results obtained with metal sulfides to those obtained by using their metal-oxides counterparts. The results highlighted the possibility to use metal sulfides as a novel class of sensing materials, owing to their selectivity to specific compounds, stability, and the possibility to operate at room temperature. PMID:26927120

Adjoint-based optimization of mechanical performance in polycrystalline materials and structures through texture control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Grace; Brown, Judith Alice; Bishop, Joseph E.

The texture of a polycrystalline material refers to the preferred orientation of the grains within the material. In metallic materials, texture can significantly affect the mechanical properties such as elastic moduli, yield stress, strain hardening, and fracture toughness. Recent advances in additive manufacturing of metallic materials offer the possibility in the not too distant future of controlling the spatial variation of texture. In this work, we investigate the advantages, in terms of mechanical performance, of allowing the texture to vary spatially. We use an adjoint-based gradient optimization algorithm within a finite element solver (COMSOL) to optimize several engineering quantities ofmore » interest in a simple structure (hole in a plate) and loading (uniaxial tension) condition. As a first step to general texture optimization, we consider the idealized case of a pure fiber texture in which the homogenized properties are transversely isotropic. In this special case, the only spatially varying design variables are the three Euler angles that prescribe the orientation of the homogenized material at each point within the structure. This work paves a new way to design metallic materials for tunable mechanical properties at the microstructure level.« less

Analytical characterization of polymers used in conservation and restoration by ATR-FTIR spectroscopy.

PubMed

Chércoles Asensio, Ruth; San Andrés Moya, Margarita; de la Roja, José Manuel; Gómez, Marisa

2009-12-01

In the last few decades many new polymers have been synthesized that are now being used in cultural heritage conservation. The physical and chemical properties and the long-term behaviors of these new polymers are determined by the chemical composition of the starting materials used in their synthesis along with the nature of the substances added to facilitate their production. The practical applications of these polymers depend on their composition and form (foam, film, sheets, pressure-sensitive adhesives, heat-seal adhesives, etc.). Some materials are used in restoration works and others for the exhibition, storage and transport of works of art. In all cases, it is absolutely necessary to know their compositions. Furthermore, many different materials that are manufactured for other objectives are also used for conservation and restoration. The technical information about the materials provided by the manufacturer is usually incomplete, so it is necessary to analytically characterize such materials. FTIR spectrometry is widely used for polymer identification, and, more recently, ATR-FTIR has been shown to give excellent results. This paper reports the ATR-FTIR analysis of samples of polymeric materials used in the conservation of artworks. These samples were examined directly in the solid material without sample preparation.

Data Mining for New Two- and One-Dimensional Weakly Bonded Solids and Lattice-Commensurate Heterostructures.

PubMed

Cheon, Gowoon; Duerloo, Karel-Alexander N; Sendek, Austin D; Porter, Chase; Chen, Yuan; Reed, Evan J

2017-03-08

Layered materials held together by weak interactions including van der Waals forces, such as graphite, have attracted interest for both technological applications and fundamental physics in their layered form and as an isolated single-layer. Only a few dozen single-layer van der Waals solids have been subject to considerable research focus, although there are likely to be many more that could have superior properties. To identify a broad spectrum of layered materials, we present a novel data mining algorithm that determines the dimensionality of weakly bonded subcomponents based on the atomic positions of bulk, three-dimensional crystal structures. By applying this algorithm to the Materials Project database of over 50,000 inorganic crystals, we identify 1173 two-dimensional layered materials and 487 materials that consist of weakly bonded one-dimensional molecular chains. This is an order of magnitude increase in the number of identified materials with most materials not known as two- or one-dimensional materials. Moreover, we discover 98 weakly bonded heterostructures of two-dimensional and one-dimensional subcomponents that are found within bulk materials, opening new possibilities for much-studied assembly of van der Waals heterostructures. Chemical families of materials, band gaps, and point groups for the materials identified in this work are presented. Point group and piezoelectricity in layered materials are also evaluated in single-layer forms. Three hundred and twenty-five of these materials are expected to have piezoelectric monolayers with a variety of forms of the piezoelectric tensor. This work significantly extends the scope of potential low-dimensional weakly bonded solids to be investigated.

General Nonlinear Ferroelectric Model v. Beta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Wen; Robbins, Josh

2017-03-14

The purpose of this software is to function as a generalized ferroelectric material model. The material model is designed to work with existing finite element packages by providing updated information on material properties that are nonlinear and dependent on loading history. The two major nonlinear phenomena this model captures are domain-switching and phase transformation. The software itself does not contain potentially sensitive material information and instead provides a framework for different physical phenomena observed within ferroelectric materials. The model is calibrated to a specific ferroelectric material through input parameters provided by the user.

[Role of an educational-and-methodological complex in the optimization of teaching at the stage of additional professional education of physicians in the specialty "anesthesiology and reanimatology"].

PubMed

Buniatian, A A; Sizova, Zh M; Vyzhigina, M A; Shikh, E V

2010-01-01

An educational-and-methodological complex (EMC) in the specialty 'Anesthesiology and Reanimatology", which promotes manageability, flexibility, and dynamism of an educational process, is of great importance in solving the problem in the systematization of knowledge and its best learning by physicians at a stage of additional professional education (APE). EMC is a set of educational-and-methodological materials required to organize and hold an educational process for the advanced training of anesthesiologists and resuscitation specialists at the stage of APE. EMC includes a syllabus for training in the area "Anesthesiology and Reanimatology" by the appropriate training pattern (certification cycles, topical advanced training cycles); a work program for training in the specialty "Anesthesiology and Reanimatology"; a work curriculums for training in allied specialties (surgery, traumatology and orthopedics, obstetrics and gynecology, and pediatrics); work programs on basic disciplines (pharmacology, normal and pathological physiology, normal anatomy, chemistry and biology); working programs on the area "Public health care and health care service", guidelines for the teacher; educational-and-methodological materials for the student; and quiz programs. The main point of EMC in the specialty "Anesthesiology and Reanimatology" is a work program. Thus, educational-and-methodological and teaching materials included into the EMC in the specialty 'Anesthesiology and Reanimatology" should envisage the logically successive exposition of a teaching material, the use of currently available methods and educational facilities, which facilitates the optimization of training of anesthesiologists and resuscitation specialists at the stage of APE.

Laser-launched flyers with organic working fluids

NASA Astrophysics Data System (ADS)

Mulford, Roberta; Swift, Damian

2003-10-01

The TRIDENT laser has been used to launch flyers by depositing IR energy in a thin layer of material - the working fluid - sandwiched between the flyer and a transparent substrate. We have investigated the use of working fluids based on organics, chosen as they are quite efficient absorbers of IR energy and should also convert heat to mechanical work more efficiently than materials such as carbon. A thermodynamically complete equation of state was developed for one of the fluids investigated experimentally - a carbohydrate solution - by chemical equilibrium calculations using the CHEETAH program. Continuum mechanics simulations were made of the flyer launch process, modeling the effect of the laser as energy deposition in the working fluid, and taking into account the compression and recoil of the substrate. We compare the simulations with a range of experiments and demonstrate the optimization of substrate and fluid thickness for a given flyer thickness and speed.

The development of all-polymer-based piezoelectrically active photocurable resin for 3D printing process (Conference Presentation)

NASA Astrophysics Data System (ADS)

Baker, Evan; Chu, Weishen; Ware, Henry Oliver T.; Farsheed, Adam C.; Sun, Cheng

2017-02-01

We present in this work the development and experimental validation of a new piezoelectric material (V-Ink) designed for compatibility with projection stereolithography additive manufacturing techniques. Piezoelectric materials generate a voltage output when a stress is applied to the material, and also can be actuated by using an external voltage and power source. This new material opens up new opportunities for functional devices to be developed and rapidly produced at low cost using emerging 3D printing techniques. The new piezoelectric material was able to generate 115mV under 1N of strain after being polled at 80°C for 40 minutes and the optimal results had a piezoelectric coefficient of 105x10^(-3)V.m/N. The current iteration of the material is a suspension, although further work is ongoing to make the resin a true solution. The nature of the suspension was characterized by a time-lapse monitoring and through viscosity testing. The potential exists to further increase the piezoelectric properties of this material by integrating a mechanical to electrical enhancer such as carbon nanotubes or barium titanate into the material. Such materials need to be functionalized to be integrated within the material, which is currently being explored. Printing with this material on a "continuous SLA" printer that we have developed will reduce build times by an order of magnitude to allow for mass manufacturing. Pairing those two advancements will enable faster printing and enhanced piezoelectric properties.

Carbon nanotube-like materials in the exhaust from a diesel engine using gas oil/ethanol mixing fuel with catalysts and sulfur.

PubMed

Suzuki, Shunsuke; Mori, Shinsuke

2017-08-01

Particulate matter from a diesel engine, including soot and carbon nanomaterials, was collected on a sampling holder and the structure of the materials was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). As a result of employing gas oil/ethanol mixing fuel with sulfur and ferrocene/molybdenum as catalyst sources, formation of carbon nanotubes (CNT)-like materials in addition to soot was observed in the exhaust gas from a diesel engine. It was revealed that CNT-like materials were included among soot in our system only when the following three conditions were satisfied simultaneously: high ethanol fraction in fuel, high sulfur loading, and presence of catalyst sources in fuel. This study confirmed that if at least one of these three conditions was not satisfied, CNT-like materials were not observed in the exhaust from a diesel engine. These experimental results shown in this work provide insights into understanding CNT-like material formation mechanism in a diesel engine. Recent papers reported that carbon nanotube-like materials were included in the exhaust gas from engines, but conditions for carbon nanotube-like material formation have not been well studied. This work provides the required conditions for carbon nanotube-like material growth in a diesel engine, and this will be helpful for understanding the carbon nanotube-like material formation mechanism and taking countermeasures to preventing carbon nanotube-like material formation in a diesel engine.

Contact angle of unset elastomeric impression materials.

PubMed

Menees, Timothy S; Radhakrishnan, Rashmi; Ramp, Lance C; Burgess, John O; Lawson, Nathaniel C

2015-10-01

Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic materials have been developed. The purpose of this in vitro study was to compare contact angles of water and saliva on 7 unset elastomeric impression materials at 5 time points from the start of mixing. Two traditional polyvinyl siloxane (PVS) (Aquasil, Take 1), 2 modified PVS (Imprint 4, Panasil), a polyether (Impregum), and 2 hybrid (Identium, EXA'lence) materials were compared. Each material was flattened to 2 mm and a 5 μL drop of distilled water or saliva was dropped on the surface at 25 seconds (t0) after the start of mix. Contact angle measurements were made with a digital microscope at initial contact (t0), t1=2 seconds, t2=5 seconds, t3=50% working time, and t4=95% working time. Data were analyzed with a generalized linear mixed model analysis, and individual 1-way ANOVA and Tukey HSD post hoc tests (α=.05). For water, materials grouped into 3 categories at all time-points: the modified PVS and one hybrid material (Identium) produced the lowest contact angles, the polyether material was intermediate, and the traditional PVS materials and the other hybrid (EXA'lence) produced the highest contact angles. For saliva, Identium, Impregum, and Imprint 4 were in the group with the lowest contact angle at most time points. Modified PVS materials and one of the hybrid materials are more hydrophilic than traditional PVS materials when measured with water. Saliva behaves differently than water in contact angle measurement on unset impression material and produces a lower contact angle on polyether based materials. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Near-infrared long-persistent phosphor of Zn₃Ga ₂Ge ₂O₁₀: Cr³⁺ sintered in different atmosphere.

PubMed

Wu, Yiling; Li, Yang; Qin, Xixi; Chen, Ruchun; Wu, Dakun; Liu, Shijian; Qiu, Jianrong

2015-01-01

A variety of materials sintered in different atmosphere have been well investigated, but there are few reports on the long-persistent phosphorescent materials, especially the near-infrared long-persistent phosphorescent materials sintered in various atmosphere. Changing the surrounding atmosphere is an effective method to improve the afterglow properties of the materials. In this work, we fabricate a typical kind of near-infrared long-persistent phosphorescent materials of Zn3Ga2Ge2O10: 0.5% Cr(3+) in neutral, oxidizing, and reducing atmosphere. By analyzing the XRD patterns, afterglow spectra, decay and thermo-luminescence curves, we discuss the great effects on the structure, long persistent properties and trap properties of the phosphor. This work of obtaining the Zn3Ga2Ge2O10: 0.5% Cr(3+) is of great potential in the applications in night-vision surveillance and in vivo bio-imaging. Copyright © 2015 Elsevier B.V. All rights reserved.

Decision method for optimal selection of warehouse material handling strategies by production companies

NASA Astrophysics Data System (ADS)

Dobos, P.; Tamás, P.; Illés, B.

2016-11-01

Adequate establishment and operation of warehouse logistics determines the companies’ competitiveness significantly because it effects greatly the quality and the selling price of the goods that the production companies produce. In order to implement and manage an adequate warehouse system, adequate warehouse position, stock management model, warehouse technology, motivated work force committed to process improvement and material handling strategy are necessary. In practical life, companies have paid small attantion to select the warehouse strategy properly. Although it has a major influence on the production in the case of material warehouse and on smooth costumer service in the case of finished goods warehouse because this can happen with a huge loss in material handling. Due to the dynamically changing production structure, frequent reorganization of warehouse activities is needed, on what the majority of the companies react basically with no reactions. This work presents a simulation test system frames for eligible warehouse material handling strategy selection and also the decision method for selection.

Recent advances on the understanding of structural and composition evolution of LMR cathodes for Li-ion batteries

DOE PAGES

Yan, Pengfei; Zheng, Jianming; Xiao, Jie; ...

2015-06-08

Lithium-rich, magnesium-rich (LMR) cathode materials have been regarded as one of the very promising cathodes for Li-ion battery applications. However, their practical application is still limited by several challenges, especially by their limited electrochemical stability rate capability. In this work, we present recent progresses on the understanding of the structural and composition evolution of LMR cathode materials with emphasis being placed on the correlation between structural/chemical evolution and electrochemical properties. In particular, using Li [Li 0.2Ni 0.2Mn 0.6O 2 as a typical example, we clearly illustrate the structural characteristics of the pristine materials and their dependence on the materials processingmore » history, cycling induced structural degradation/chemical partition and their correlation with degradation of electrochemical performance. The fundamental understanding obtained in this work may also guide the design and preparation of new cathode materials based on ternary system of transitional metal oxide.« less

Fused Deposition Modeling 3D Printing for (Bio)analytical Device Fabrication: Procedures, Materials, and Applications

PubMed Central

2017-01-01

In this work, the use of fused deposition modeling (FDM) in a (bio)analytical/lab-on-a-chip research laboratory is described. First, the specifications of this 3D printing method that are important for the fabrication of (micro)devices were characterized for a benchtop FDM 3D printer. These include resolution, surface roughness, leakage, transparency, material deformation, and the possibilities for integration of other materials. Next, the autofluorescence, solvent compatibility, and biocompatibility of 12 representative FDM materials were tested and evaluated. Finally, we demonstrate the feasibility of FDM in a number of important applications. In particular, we consider the fabrication of fluidic channels, masters for polymer replication, and tools for the production of paper microfluidic devices. This work thus provides a guideline for (i) the use of FDM technology by addressing its possibilities and current limitations, (ii) material selection for FDM, based on solvent compatibility and biocompatibility, and (iii) application of FDM technology to (bio)analytical research by demonstrating a broad range of illustrative examples. PMID:28628294

Mirror Material Properties Compiled for Preliminary Design of the Next Generation Space Telescope (30 to 294 Kelvin)

NASA Technical Reports Server (NTRS)

Luz, P. L.; Rice, T.

1998-01-01

This technical memorandum reports on the mirror material properties that were compiled by NASA Marshall Space Flight Center (MSFC) from April 1996 to June 1997 for preliminary design of the Next Generation Space Telescope (NGST) Study. The NGST study began in February 1996, when the Program Development Directorate at NASA MSFC studied the feasibility of the NGST and developed the pre-phase A program for it. After finishing some initial studies and concepts development work on the NGST, MFSC's Program Development Directorate handed this work to the Observatory Projects Office at MSFC and then to NASA Goddard Space Flight Center (GSFC). This technical memorandum was written by MSFC's Preliminary Design Office and Materials and Processes Laboratory for the NGST Optical Telescope Assembly (OTA) team, in Support of NASA GSFC. It contains material properties for 9 mirror Substrate materials, using information from at least 6 industrial Suppliers, 16 textbooks, 44 technical papers, and 130 technical abstracts.

The Development of High Temperature Thermoplastic Composite Materials for Additive Manufactured Autoclave Tooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunc, Vlastimil; Duty, Chad E.; Lindahl, John M.

2017-08-01

In this work, ORNL and Techmer investigated and screened different high temperature thermoplastic reinforced materials to fabricate composite molds for autoclave processes using Additive Manufacturing (AM) techniques. This project directly led to the development and commercial release of two printable, high temperature composite materials available through Techmer PM. These new materials are targeted for high temperature tooling made via large scale additive manufacturing.

Material model validation for laser shock peening process simulation

NASA Astrophysics Data System (ADS)

Amarchinta, H. K.; Grandhi, R. V.; Langer, K.; Stargel, D. S.

2009-01-01

Advanced mechanical surface enhancement techniques have been used successfully to increase the fatigue life of metallic components. These techniques impart deep compressive residual stresses into the component to counter potentially damage-inducing tensile stresses generated under service loading. Laser shock peening (LSP) is an advanced mechanical surface enhancement technique used predominantly in the aircraft industry. To reduce costs and make the technique available on a large-scale basis for industrial applications, simulation of the LSP process is required. Accurate simulation of the LSP process is a challenging task, because the process has many parameters such as laser spot size, pressure profile and material model that must be precisely determined. This work focuses on investigating the appropriate material model that could be used in simulation and design. In the LSP process material is subjected to strain rates of 106 s-1, which is very high compared with conventional strain rates. The importance of an accurate material model increases because the material behaves significantly different at such high strain rates. This work investigates the effect of multiple nonlinear material models for representing the elastic-plastic behavior of materials. Elastic perfectly plastic, Johnson-Cook and Zerilli-Armstrong models are used, and the performance of each model is compared with available experimental results.

Two-Dimensional Materials for Halide Perovskite-Based Optoelectronic Devices.

PubMed

Chen, Shan; Shi, Gaoquan

2017-06-01

Halide perovskites have high light absorption coefficients, long charge carrier diffusion lengths, intense photoluminescence, and slow rates of non-radiative charge recombination. Thus, they are attractive photoactive materials for developing high-performance optoelectronic devices. These devices are also cheap and easy to be fabricated. To realize the optimal performances of halide perovskite-based optoelectronic devices (HPODs), perovskite photoactive layers should work effectively with other functional materials such as electrodes, interfacial layers and encapsulating films. Conventional two-dimensional (2D) materials are promising candidates for this purpose because of their unique structures and/or interesting optoelectronic properties. Here, we comprehensively summarize the recent advancements in the applications of conventional 2D materials for halide perovskite-based photodetectors, solar cells and light-emitting diodes. The examples of these 2D materials are graphene and its derivatives, mono- and few-layer transition metal dichalcogenides (TMDs), graphdiyne and metal nanosheets, etc. The research related to 2D nanostructured perovskites and 2D Ruddlesden-Popper perovskites as efficient and stable photoactive layers is also outlined. The syntheses, functions and working mechanisms of relevant 2D materials are introduced, and the challenges to achieving practical applications of HPODs using 2D materials are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of Water on the Work of Adhesion at Epoxy Interfaces by Molecular Dynamics Simulation

NASA Technical Reports Server (NTRS)

Hinkley, J.A.; Frankland, S.J.V.; Clancy, T.C.

2009-01-01

Molecular dynamics simulation can be used to explore the detailed effects of chemistry on properties of materials. In this paper, two different epoxies found in aerospace resins are modeled using molecular dynamics. The first material, an amine-cured tetrafunctional epoxy, represents a composite matrix resin, while the second represents a 177 C-cured adhesive. Surface energies are derived for both epoxies and the work of adhesion values calculated for the epoxy/epoxy interfaces agree with experiment. Adding water -- to simulate the effect of moisture exposure -- reduced the work of adhesion in one case, and increased it in the other. To explore the difference, the various energy terms that make up the net work of adhesion were compared and the location of the added water was examined.

Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities

DOE Office of Scientific and Technical Information (OSTI.GOV)

MM Hall

2006-01-31

A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing.

CONTIN XPCS: software for inverse transform analysis of X-ray photon correlation spectroscopy dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, Ross N.; Narayanan, Suresh; Zhang, Fan

X-ray photon correlation spectroscopy (XPCS) and dynamic light scattering (DLS) reveal materials dynamics using coherent scattering, with XPCS permitting the investigation of dynamics in a more diverse array of materials than DLS. Heterogeneous dynamics occur in many material systems. The authors' recent work has shown how classic tools employed in the DLS analysis of heterogeneous dynamics can be extended to XPCS, revealing additional information that conventional Kohlrausch exponential fitting obscures. The present work describes the software implementation of inverse transform analysis of XPCS data. This software, calledCONTIN XPCS, is an extension of traditionalCONTINanalysis and accommodates the various dynamics encountered inmore » equilibrium XPCS measurements.« less

CONTIN XPCS: software for inverse transform analysis of X-ray photon correlation spectroscopy dynamics

DOE PAGES

Andrews, Ross N.; Narayanan, Suresh; Zhang, Fan; ...

2018-02-01

X-ray photon correlation spectroscopy (XPCS) and dynamic light scattering (DLS) reveal materials dynamics using coherent scattering, with XPCS permitting the investigation of dynamics in a more diverse array of materials than DLS. Heterogeneous dynamics occur in many material systems. The authors' recent work has shown how classic tools employed in the DLS analysis of heterogeneous dynamics can be extended to XPCS, revealing additional information that conventional Kohlrausch exponential fitting obscures. The present work describes the software implementation of inverse transform analysis of XPCS data. This software, calledCONTIN XPCS, is an extension of traditionalCONTINanalysis and accommodates the various dynamics encountered inmore » equilibrium XPCS measurements.« less

Multiphase Equations of State for Polymer Materials at High Dynamic Pressures

NASA Astrophysics Data System (ADS)

Khishchenko, Konstantin V.

2015-06-01

Equations of state for materials over a wide range of pressures and temperatures are necessary for numerical simulations of shock-wave processes in condensed matter. Accuracy of calculation results is determined mainly by adequacy of equation of state of a medium. In this work, a new multiphase equation-of-state model is proposed with taking into account the polymorphic phase transformations, melting and evaporation. Thermodynamic calculations are carried out for 2 polymer materials (polymethylmethacrylate and polytetrafluoroethylene) in a broad region of the phase diagram. Obtained results are presented in comparison with available data of experiments at high dynamic pressures in shock and release waves. This work is supported by RSF, Grant 14-50-00124.

Environmental, Safety, and Health Considerations: Composite Materials in the Aerospace Industry

NASA Technical Reports Server (NTRS)

Chu, Huai-Pu (Compiler)

1994-01-01

The Aerospace Industries Association, Suppliers of Advanced Composite Materials Association, and the National Aeronautics and Space Administration co-sponsored a conference on 'Environmental, Safety, and Health Considerations--Composite Materials in the Aerospace Industry.' The conference was held in Mesa, Arizona, on October 20-21, 1994. Seventeen papers were presented in four sessions including general information, safety, waste, and emissions from composites. Topics range from product stewardship, best work practice, biotransformation of uncured composite materials, to hazardous waste determination and offgassing of composite materials.

Electrochemical Performance of Ni-MOFs for Supercapacitors

NASA Astrophysics Data System (ADS)

Li, Yujuan; Song, Lili; Han, Yinghui; Wang, Guangyou

2018-03-01

In this work, the Ni-MOFs of electrode material has been synthesized, characterized and studied for the electrochemical properties of electrode materials. The effects of the doping amount of Ni, calcination temperature and time were studied in detail. The results suggested that the electrochemical properties were obviously improved by the Ni-MOFs of electrode material and the best preparation conditions can also improve the electrochemical properties of electrode materials. These results open a way for the design of tailored MOFs as electrode materials for supercapacitors.

TAGGING, TRACKING AND LOCATING WITHOUT GPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cordaro, J.; Coleman, T.; Shull, D.

The Savannah River National Laboratory (SRNL) was requested to lead a Law Enforcement Working Group that was formed to collaborate on common operational needs. All agencies represented on the working group ranked their need to tag, track, and locate a witting or unwitting target as their highest priority. Specifically, they were looking for technologies more robust than Global Positioning Satellite (GPS), could communicate back to the owner, and worked where normal cell phone communications did not work or were unreliable. SRNL brought together multiple technologies in a demonstration that was held in in various Alaska venues, including metropolitan, wilderness, andmore » at-sea that met the working group's requirements. Using prototypical technologies from Boeing, On Ramp, and Fortress, SRNL was able to demonstrate the ability to track personnel and material in all scenarios including indoors, in heavily wooden areas, canyons, and in parking garages. In all cases GPS signals were too weak to measure. Bi-directional communication was achieved in areas that Wi-Fi, cell towers, or traditional radios would not perform. The results of the exercise will be presented. These technologies are considered ideal for tracking high value material such has nuclear material with a platform that allows seamless tracking anywhere in the world, indoors or outdoors.« less

Analysis of the NASA White Sands Test Facility (WSTF) Test System for Friction-Ignition of Metallic Materials

NASA Technical Reports Server (NTRS)

Shoffstall, Michael S.; Wilson, D. Bruce; Stoltzfus, Joel M.

2000-01-01

Friction is a known ignition source for metals in oxygen-enriched atmospheres. The test system developed by the NASA White Sands Test Facility in response to ASTM G-94 has been used successfully to determine the relative ignition from friction of numerous metallic materials and metallic materials pairs. These results have been ranked in terms of a pressure-velocity product (PV) as measured under the prescribed test conditions. A high value of 4.1(exp 8) watts per square meter for Inconel MA 754 is used to imply resistance to friction ignition, whereas a low value of 1.04(exp 8) watts per square meter for stainless steel 304 is taken as indicating material susceptible to friction ignition. No attempt has been made to relate PV values to other material properties. This work reports the analysis of the WSTF friction-ignition test system for producing fundamental properties of metallic materials relating to ignition through friction. Three materials, aluminum, titanium, and nickel were tested in the WSTF frictional ignition instrument system under atmospheres of oxygen or nitrogen. Test conditions were modified to reach a steady state of operation, that is applied, the force was reduced and the rotational speed was reduced. Additional temperature measurements were made on the stator sample. The aluminum immediately galled on contact (reproducible) and the test was stopped. Titanium immediately ignited as a result of non-uniform contact of the stator and rotor. This was reproducible. A portion of the stator sampled burned, but the test continued. Temperature measurements on the stator were used to validate the mathematical model used for estimating the interface (stator/rotor) temperature. These interface temperature measurements and the associate thermal flux into the stator were used to distinguish material-phase transitions, chemical reaction, and mechanical work. The mechanical work was used to analyze surface asperities in the materials and to estimate a coefficient of fiction. The coefficient of fiction was analyzed in terms of material properties that is, hardness, Young's modulus and elasticity/plasticity of the material.

40 CFR 170.112 - Entry restrictions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of work clothing are not considered personal protective equipment for the purposes of this section... such work clothing be worn during some activities. (iii) When “chemical-resistant” personal protective... fingers. Work gloves made from lightweight cotton or poly-type material are considered to be glove liners...

Bibliographies. The Librarian's Bookshelf.

ERIC Educational Resources Information Center

Bourdon, Cathleen

2002-01-01

This bibliography for materials helpful to librarians includes works relating to administration and personnel; bibliographic instruction; information literacy; cataloging and classification; children's and adolescent services and materials; collection development; copyright; distance education; electronic libraries; evaluation; fund raising;…

40 CFR 63.3493 - What work practice standards must I meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... or the control efficiency/outlet concentration option to comply with the emission limitations, you... materials, and waste materials must be conveyed from one location to another in closed containers or pipes...

30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE... materials produced from an underground mine and not disposed in underground workings or used in backfilling...

Construction and material specification

DOT National Transportation Integrated Search

2002-01-01

These Construction and Material Specifications are written to the Bidder before award of the : Contract and to the Contractor after award of the Contract. The sentences that direct the Contractor to perform Work are written as commands. For example, ...

A comparison of CH4, N2O and CO2 emissions from three different cover types in a municipal solid waste landfill.

PubMed

Wang, Xiaojun; Jia, Mingsheng; Lin, Xiangyu; Xu, Ying; Ye, Xin; Kao, Chih Ming; Chen, Shaohua

2017-04-01

High-density polyethylene (HDPE) membranes are commonly used as a cover component in sanitary landfills, although only limited evaluations of its effect on greenhouse gas (GHG) emissions have been completed. In this study, field GHG emission were investigated at the Dongbu landfill, using three different cover systems: HDPE covering; no covering, on the working face; and a novel material-Oreezyme Waste Cover (OWC) material as a trial material. Results showed that the HDPE membrane achieved a high CH 4 retention, 99.8% (CH 4 mean flux of 12 mg C m -2 h -1 ) compared with the air-permeable OWC surface (CH4 mean flux of 5933 mg C m -2 h -1 ) of the same landfill age. Fresh waste at the working face emitted a large fraction of N 2 O, with average fluxes of 10 mg N m -2 h -2 , while N 2 O emissions were small at both the HDPE and the OWC sections. At the OWC section, CH 4 emissions were elevated under high air temperatures but decreased as landfill age increased. N 2 O emissions from the working face had a significant negative correlation with air temperature, with peak values in winter. A massive presence of CO 2 was observed at both the working face and the OWC sections. Most importantly, the annual GHG emissions were 4.9 Gg yr -1 in CO 2 equivalents for the landfill site, of which the OWC-covered section contributed the most CH 4 (41.9%), while the working face contributed the most N 2 O (97.2%). HDPE membrane is therefore, a recommended cover material for GHG control. Monitoring of GHG emissions at three different cover types in a municipal solid waste landfill during a 1-year period showed that the working face was a hotspot of N 2 O, which should draw attention. High CH 4 fluxes occurred on the permeable surface covering a 1- to 2-year-old landfill. In contrast, the high-density polyethylene (HDPE) membrane achieved high CH 4 retention, and therefore is a recommended cover material for GHG control.

Materials, Strands, and Cables for Superconducting Accelerator Magnets. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sumption, Mike D.; Collings, Edward W.

2014-09-19

This report focuses on Materials, Strands and Cables for High Energy Physics Particle accelerators. In the materials area, work has included studies of basic reactions, diffusion, transformations, and phase assemblage of Nb 3Sn. These materials science aspects have been married to results, in the form of flux pinning, B c2, B irr, and transport J c, with an emphasis on obtaining the needed J c for HEP needs. Attention has also been paid to the “intermediate-temperature superconductor”, magnesium diboride emphasis being placed on (i) irreversibility field enhancement, (ii) critical current density and flux pinning, and (iii) connectivity. We also reportmore » on studies of Bi-2212. The second area of the program has been in the area of “Strands” in which, aside from the materials aspect of the conductor, its physical properties and their influence on performance have been studied. Much of this work has been in the area of magnetization estimation and flux jump calculation and control. One of the areas of this work was strand instabilities in high-performance Nb 3Sn conductors due to combined fields and currents. Additionally, we investigated quench and thermal propagation in YBCO coated conductors at low temperatures and high fields. The last section, “Cables”, focussed on interstrand contact resistance, ICR, it origins, control, and implications. Following on from earlier work in NbTi, the present work in Nb 3Sn has aimed to make ICR intermediate between the two extremes of too little contact (no current sharing) and too much (large and unacceptable magnetization and associated beam de-focussing). Interstrand contact and current sharing measurements are being made on YBCO based Roebel cables using transport current methods. Finally, quench was investigated for YBCO cables and the magnets wound from them, presently with a focus on 50 T solenoids for muon collider applications.« less

30 CFR 57.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Work or travel on overhead crane bridges. 57... MINES Materials Storage and Handling § 57.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with...

30 CFR 56.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Work or travel on overhead crane bridges. 56... Materials Storage and Handling § 56.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with substantial...

Making Work: Demonstrating Thermodynamic Concepts with Solar-Powered Wax and Rubber Heat Engines

ERIC Educational Resources Information Center

Appleyard, S. J.

2007-01-01

Construction details are provided for simple heat engines that use candle wax and elastomers as working substances. The engines are constructed using common household materials and can be easily constructed in a school classroom or at home. They work reliably and are useful tools for demonstrating the conversion of heat to mechanical work. They…

Working Memory and Learning: A Practical Guide for Teachers

ERIC Educational Resources Information Center

Gathercole, Susan E.; Alloway, Tracy Packiam

2008-01-01

A good working memory is crucial to becoming a successful leaner, yet there is very little material available in an easy-to-use format that explains the concept and offers practitioners ways to support children with poor working memory in the classroom. This book provides a coherent overview of the role played by working memory in learning during…

33 CFR 149.329 - How must work vests and deck suits be marked?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false How must work vests and deck... Lifesaving Equipment Manned Deepwater Port Requirements § 149.329 How must work vests and deck suits be marked? All work vests and deck suits must be fitted with Type I retroreflective material, approved under...

33 CFR 149.329 - How must work vests and deck suits be marked?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false How must work vests and deck... Lifesaving Equipment Manned Deepwater Port Requirements § 149.329 How must work vests and deck suits be marked? All work vests and deck suits must be fitted with Type I retroreflective material, approved under...

33 CFR 149.329 - How must work vests and deck suits be marked?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false How must work vests and deck... Lifesaving Equipment Manned Deepwater Port Requirements § 149.329 How must work vests and deck suits be marked? All work vests and deck suits must be fitted with Type I retroreflective material, approved under...

33 CFR 149.329 - How must work vests and deck suits be marked?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false How must work vests and deck... Lifesaving Equipment Manned Deepwater Port Requirements § 149.329 How must work vests and deck suits be marked? All work vests and deck suits must be fitted with Type I retroreflective material, approved under...

33 CFR 149.329 - How must work vests and deck suits be marked?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false How must work vests and deck... Lifesaving Equipment Manned Deepwater Port Requirements § 149.329 How must work vests and deck suits be marked? All work vests and deck suits must be fitted with Type I retroreflective material, approved under...

30 CFR 57.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work or travel on overhead crane bridges. 57... MINES Materials Storage and Handling § 57.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with...

30 CFR 56.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work or travel on overhead crane bridges. 56... Materials Storage and Handling § 56.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with substantial...

Visual and Spatial Working Memory Are Not that Dissociated after All: A Time-Based Resource-Sharing Account

ERIC Educational Resources Information Center

Vergauwe, Evie; Barrouillet, Pierre; Camos, Valerie

2009-01-01

Examinations of interference between visual and spatial materials in working memory have suggested domain- and process-based fractionations of visuo-spatial working memory. The present study examined the role of central time-based resource sharing in visuo-spatial working memory and assessed its role in obtained interference patterns. Visual and…

CAUT Guidelines for the Use of Copyrighted Material

ERIC Educational Resources Information Center

Canadian Association of University Teachers, 2013

2013-01-01

Copyright protects the users, creators and owners of expressive works such as paintings, literature, video and music. It does this by setting the rules governing the reproduction of such works. One of these rules is that in certain circumstances it is lawful to reproduce works (or parts of works) without permission or payment. The purpose of this…

MoS2: a two-dimensional hole-transporting material for high-efficiency, low-cost perovskite solar cells

NASA Astrophysics Data System (ADS)

Kohnehpoushi, Saman; Nazari, Pariya; Abdollahi Nejand, Bahram; Eskandari, Mehdi

2018-05-01

In this work MoS2 thin film was studied as a potential two-dimensional (2D) hole-transporting material for fabrication of low-cost, durable and efficient perovskite solar cells. The thickness of MoS2 was studied as a potential factor in reaching high power conversion efficiency in perovskite solar cells. The thickness of the perovskite layer and the different metal back contacts gave distinct photovoltaic properties to the designed cells. The results show that a single sheet of MoS2 could considerably improve the power conversion efficacy of the device from 10.41% for a hole transport material (HTM)-free device to 20.43% for a device prepared with a 0.67 nm thick MoS2 layer as a HTM. On the back, Ag and Al collected the carriers more efficiently than Au due to the value of their metal contact work function with the TiO2 conduction band. The present work proposes a new architecture for the fabrication of low-cost, durable and efficient perovskite solar cells made from a low-cost and robust inorganic HTM and electron transport material.

Laser micro-structuring of surfaces for applications in materials and biomedical science

NASA Astrophysics Data System (ADS)

Sarzyński, Antoni; Marczak, Jan; Strzelec, Marek; Rycyk, Antoni; CzyŻ, Krzysztof; Chmielewska, Danuta

2016-12-01

Laser radiation is used, among others, for surface treatment of various materials. At the Institute of Optoelectronics, under the direction of the late Professor Jan Marczak, a number of works in the field of laser materials processing were performed. Among them special recognition deserves flagship work of Professor Jan Marczak: implementation in Poland laser cleaning method of artworks. Another big project involved the direct method of laser interference lithography. These two projects have already been widely discussed in many national and international scientific conferences. They will also be discussed at SLT2016. In addition to these two projects in the Laboratory of Lasers Applications many other works have been carried out, some of which will be separately presented at the SLT2016 Conference. These included laser decorating of ceramics and glass (three projects completed in cooperation with the Institute of Ceramics and Building Materials), interference structuring medical implants (together with the Warsaw University of Technology), testing the adhesion of thin layers (project implemented together with IFTR PAS), structuring layers of DLC for growing endothelial cells (together with IMMS PAS), engraving glass for microfluidic applications, metal marking, sapphire cutting and finally the production of microsieves for separating of blood cells.

Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lisa M. Daniels

2002-05-08

This project was very successful in terms of providing a unique source of information for rural communities and landowners. We are very pleased with the overall results and believe that this is a vital program for the sustainable development of wind energy. The outreach materials created by Windustry are filling a serious void in information about how local communities and rural landowners can participate in wind development projects. In our program implementation we learned how great the demand is for this type of information both through our hotline calls and website usage. We also realized that the materials require constantmore » updating and maintenance. There is a balance that needs to be found in printing the materials to have handouts ready at meetings for our primary target audience and more research and revisions for the website materials. All of this work is of an ongoing nature. Since this funding was awarded for one year, Windustry will be seeking other funding sources to continue the work in future years. Below is a summary of the Windustry accomplishments as well a sampling of website usage reports. Windustry is appreciative of the US DOE for its support of this wind energy industry work and the Wind Powering America initiative.« less

MoS2: a two-dimensional hole-transporting material for high-efficiency, low-cost perovskite solar cells.

PubMed

Kohnehpoushi, Saman; Nazari, Pariya; Nejand, Bahram Abdollahi; Eskandari, Mehdi

2018-05-18

In this work MoS 2 thin film was studied as a potential two-dimensional (2D) hole-transporting material for fabrication of low-cost, durable and efficient perovskite solar cells. The thickness of MoS 2 was studied as a potential factor in reaching high power conversion efficiency in perovskite solar cells. The thickness of the perovskite layer and the different metal back contacts gave distinct photovoltaic properties to the designed cells. The results show that a single sheet of MoS 2 could considerably improve the power conversion efficacy of the device from 10.41% for a hole transport material (HTM)-free device to 20.43% for a device prepared with a 0.67 nm thick MoS 2 layer as a HTM. On the back, Ag and Al collected the carriers more efficiently than Au due to the value of their metal contact work function with the TiO 2 conduction band. The present work proposes a new architecture for the fabrication of low-cost, durable and efficient perovskite solar cells made from a low-cost and robust inorganic HTM and electron transport material.

Design of phononic band gaps in functionally graded piezocomposite materials by using topology optimization

NASA Astrophysics Data System (ADS)

Vatanabe, Sandro L.; Silva, Emílio C. N.

2011-04-01

One of the properties of composite materials is the possibility of having phononic band gaps, within which sound and vibrations at certain frequencies do not propagate. These materials are called Phononic Crystals (PCs). PCs with large band gaps are of great interest for many applications, such as transducers, elastic/ acoustic filters, noise control, and vibration shields. Most of previous works concentrates on PCs made of elastic isotropic materials; however, band gaps can be enlarged by using non-isotropic materials, such as piezoelectric materials. Since the main property of PCs is the presence of band gaps, one possible way to design structures which have a desired band gap is through Topology Optimization Method (TOM). TOM is a computational technique that determines the layout of a material such that a prescribed objective is maximized. Functionally Graded Materials (FGM) are composite materials whose properties vary gradually and continuously along a specific direction within the domain of the material. One of the advantages of applying the FGM concept to TOM is that it is not necessary a discrete 0-1 result, once the material gradation is part of the solution. Therefore, the interpretation step becomes easier and the dispersion diagram obtained from the optimization is not significantly modified. In this work, the main objective is to optimize the position and width of piezocomposite materials band gaps. Finite element analysis is implemented with Bloch-Floquet theory to solve the dynamic behavior of two-dimensional functionally graded unit cells. The results demonstrate that phononic band gaps can be designed by using this methodology.

Engineered Zircaloy Cladding Modifications for Improved Accident Tolerance of LWR Nuclear Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heuser, Brent; Stubbins, James; Kozlowski, Tomasz

The DOE NEUP sponsored IRP on accident tolerant fuel (ATF) entitled Engineered Zircaloy Cladding Modifications for Improved Accident Tolerance of LWR Nuclear Fuel involved three academic institutions, Idaho National Laboratory (INL), and ATI Materials (ATI). Detailed descriptions of the work at the University of Illinois (UIUC, prime), the University of Florida (UF), the University of Michigan (UMich), and INL are included in this document as separate sections. This summary provides a synopsis of the work performed across the IRP team. Two ATF solution pathways were initially proposed, coatings on monolithic Zr-based LWR cladding material and selfhealing modifications of Zr-based alloys.more » The coating pathway was extensively investigated, both experimentally and in computations. Experimental activities related to ATF coatings were centered at UIUC, UF, and UMich and involved coating development and testing, and ion irradiation. Neutronic and thermal hydraulic aspects of ATF coatings were the focus of computational work at UIUC and UMich, while materials science aspects were the focus of computational work at UF and INL. ATI provided monolithic Zircaloy 2 and 4 material and a binary Zr-Y alloy material. The selfhealing pathway was investigated with advanced computations only. Beryllium was identified as a valid self-healing additive early in this work. However, all attempts to fabricate a Zr-Be alloy failed. Several avenues of fabrication were explored. ATI ultimately declined our fabrication request over health concerns associated with Be (we note that Be was not part of the original work scope and the ATI SOW). Likewise, Ames Laboratory declined our fabrication request, citing known litigation dating to the 1980s and 1990s involving the U.S. Federal government and U.S. National Laboratory employees involving the use of Be. Materion (formerly, Brush Wellman) also declined our fabrication request, citing the difficulty in working with a highly reactive Zr and Be. International fabrication options were explored in Europe and Asia, but this proved to be impractical, if not impossible. Consequently, experimental investigation of the Zr-Be binary system was dropped and exploration binary Zr-Y binary system was initiated. The motivation behind the Zr-Y system is the known thermodynamic stability of yttria over zirconia.« less

PREFACE 2nd International Conference on Materials Physics and Applications (JIPMA 2009/MATERIAUX 2009)

NASA Astrophysics Data System (ADS)

Cheikhrouhou, Abdelwaheb

2010-11-01

The 'Tunisian Materials Research Society: Tu-MRS' organized the International Days on Materials Physics and Applications 'JIPMA 2009' and the National Conference on Materials 'MATERIAUX 2009' in Gafsa (Tunisia) During the period 20-24 December 2009. The first International Days on Materials Physics and Applications 'JIPMA 2007' were organized in Annaba (Algeria) in November 2007 while the first National Conference on Materials 'MATERIAUX 2006' was organized in Douz (Tunisia) in December 2006. The 'JIPMA' conference series together with the 'MATERIAUX' intend to provide an excellent opportunity for international, Maghreb and Tunisian researchers to make their own works on materials known to a wider audience and to have discussions with other participants. This conference will also be an opportunity to exchange experiences, create and consolidate cooperation between different research structures in the Maghreb countries. This conference will equally promote research development, contribute to collaboration between universities and the socio-economical milieu. More than 300 senior researchers, Professors, PhD and Master students attended this conference from Tunisia, Algeria, Morocco, France, and Spain. Several researchers, engineers and managers from industrial firms also attended this scientific meeting. The conference consists of plenary and semi-plenary talks, oral contributions and poster presentations. The topics of the conference are: Nano-materials, nano-systems, thin films, surfaces and interfaces Multifonctional Materials, Magnetic Materials, Dielectric Materials, Superconducting Materials, Applications, ... Materials for Electronics, Informatics and Communications (Semi-conducting Materials, Electronic devices, Spintronic, ... Optoelectronic Materials, Sensors Ceramics, Glasses, Polymers, ... Natural Materials: Phosphates, Clay, ... Metallic Materials, alloys, ... Materials and Environment Materials and Energy Biomaterials Elaborating Methods and Characterization Techniques I want to thank the organizing committee and everyone else who participated in the organization of this meeting for their invaluable efforts to guarantee the full success of this conference. I want also to thank very warmly all the Scientific committee and all other reviewers for their hard work reviewing the submitted papers. Professor Abdelwaheb CHEIKHROUHOU Chairman of the Conference