High-efficiency cell concepts on low-cost silicon sheets

NASA Technical Reports Server (NTRS)

Bell, R. O.; Ravi, K. V.

1985-01-01

The limitations on sheet growth material in terms of the defect structure and minority carrier lifetime are discussed. The effect of various defects on performance are estimated. Given these limitations designs for a sheet growth cell that will make the best of the material characteristics are proposed. Achievement of optimum synergy between base material quality and device processing variables is proposed. A strong coupling exists between material quality and the variables during crystal growth, and device processing variables. Two objectives are outlined: (1) optimization of the coupling for maximum performance at minimal cost; and (2) decoupling of materials from processing by improvement in base material quality to make it less sensitive to processing variables.

Real time laser scanning of aggregate materials in highway construction : a transportation pooled fund study.

DOT National Transportation Integrated Search

2016-12-01

The quality and service life of the roadways that make up the highway transportation infrastructure are dependent upon : the selection and use of high quality aggregate materials. Five state transportation agencies participated in this Transportation...

The Method of Manufacturing Nonmetallic Test-Blocks on Different Sensitivity Classes

NASA Astrophysics Data System (ADS)

Kalinichenko, N. P.; Kalinichenko, A. N.; Lobanova, I. S.; Zaitseva, A. A.; Loboda, E. L.

2016-01-01

Nowadays in our modern world there is a vital question of quality control of details made from nonmetallic materials due to their wide spreading. Nondestructive penetrant testing is effective, and in some cases it is the only possible method of accidents prevention at high- risk sites. A brief review of check sample necessary for quality evaluation of penetrant materials is considered. There was offered a way of making agents for quality of penetrant materials testing according to different liquid penetrant testing sensibility classes.

Effects of fabrication methods on spin relaxation and crystallite quality in Tm-doped ? powders studied using spectral hole burning

NASA Astrophysics Data System (ADS)

Lutz, Thomas; Veissier, Lucile; Thiel, Charles W.; Woodburn, Philip J. T.; Cone, Rufus L.; Barclay, Paul E.; Tittel, Wolfgang

2016-01-01

High-quality rare-earth-ion (REI) doped materials are a prerequisite for many applications such as quantum memories, ultra-high-resolution optical spectrum analyzers and information processing. Compared to bulk materials, REI doped powders offer low-cost fabrication and a greater range of accessible material systems. Here we show that crystal properties, such as nuclear spin lifetime, are strongly affected by mechanical treatment, and that spectral hole burning can serve as a sensitive method to characterize the quality of REI doped powders. We focus on the specific case of thulium doped ? (Tm:YAG). Different methods for obtaining the powders are compared and the influence of annealing on the spectroscopic quality of powders is investigated on a few examples. We conclude that annealing can reverse some detrimental effects of powder fabrication and, in certain cases, the properties of the bulk material can be reached. Our results may be applicable to other impurities and other crystals, including color centers in nano-structured diamond.

Vapor Phase Growth of High-Quality Bi-Te Compounds Using Elemental Bi and Te Sources: A Comparison Between High Vacuum and Atmospheric Pressure

NASA Astrophysics Data System (ADS)

Concepción, O.; Escobosa, A.; de Melo, O.

2018-03-01

Bismuth telluride (Bi2Te3), traditionally used in the industry as thermoelectric material, has deserved much attention recently due to its properties as a topological insulator, a kind of material that might have relevant applications in spintronics or quantum computing, among other innovative uses. The preparation of high-quality material has become a very important technological task. Here, we compare the preparation of Bi2Te3 by physical vapor transport from the evaporation of elemental Bi and Te sources, under either low pressure or atmospheric pressure. The layers were characterized by different techniques to evaluate its structural properties. As a result, it is concluded that, as a consequence of the different transport regimes, films grown at atmospheric pressure present better crystal quality.

Sn-doped Bi 1.1Sb 0.9Te 2S bulk crystal topological insulator with excellent properties

DOE PAGES

S. K. Kushwaha; Pletikosic, I.; Liang, T.; ...

2016-04-27

A long-standing issue in topological insulator research has been to find a bulk single crystal material that provides a high quality platform for characterizing topological surface states without interference from bulk electronic states. This material would ideally be a bulk insulator, have a surface state Dirac point energy well isolated from the bulk valence and conduction bands, display quantum oscillations from the surface state electrons, and be growable as large, high quality bulk single crystals. Here we show that this materials obstacle is overcome by bulk crystals of lightly Sn-doped Bi 1.1Sb 0.9Te 2S grown by the Vertical Bridgeman method.more » We characterize Sn-BSTS via angle-resolved photoemission spectroscopy, scanning tunneling microscopy, transport studies, X-ray diffraction, and Raman scattering. We present this material as a high quality topological insulator that can be reliably grown as bulk single crystals and thus studied by many researchers interested in topological surface states.« less

High Temperature Semiconductor Process

NASA Technical Reports Server (NTRS)

1998-01-01

A sputtering deposition system capable of depositing large areas of high temperature superconducting materials was developed by CVC Products, Inc. with the support of the Jet Propulsion Laboratory SBIR (Small Business Innovative Research) program. The system was devleoped for NASA to produce high quality films of high temperature superconducting material for microwave communication system components. The system is also being used to deposit ferroelectric material for capacitors and the development of new electro-optical materials.2002103899

The effect of roofing material on the quality of harvested rainwater.

PubMed

Mendez, Carolina B; Klenzendorf, J Brandon; Afshar, Brigit R; Simmons, Mark T; Barrett, Michael E; Kinney, Kerry A; Kirisits, Mary Jo

2011-02-01

Due to decreases in the availability and quality of traditional water resources, harvested rainwater is increasingly used for potable and non-potable purposes. In this study, we examined the effect of conventional roofing materials (i.e., asphalt fiberglass shingle, Galvalume(®) metal, and concrete tile) and alternative roofing materials (i.e., cool and green) on the quality of harvested rainwater. Results from pilot-scale and full-scale roofs demonstrated that rainwater harvested from any of these roofing materials would require treatment if the consumer wanted to meet United States Environmental Protection Agency primary and secondary drinking water standards or non-potable water reuse guidelines; at a minimum, first-flush diversion, filtration, and disinfection are recommended. Metal roofs are commonly recommended for rainwater harvesting applications, and this study showed that rainwater harvested from metal roofs tends to have lower concentrations of fecal indicator bacteria as compared to other roofing materials. However, concrete tile and cool roofs produced harvested rainwater quality similar to that from the metal roofs, indicating that these roofing materials also are suitable for rainwater harvesting applications. Although the shingle and green roofs produced water quality comparable in many respects to that from the other roofing materials, their dissolved organic carbon concentrations were very high (approximately one order of magnitude higher than what is typical for a finished drinking water in the United States), which might lead to high concentrations of disinfection byproducts after chlorination. Furthermore the concentrations of some metals (e.g., arsenic) in rainwater harvested from the green roof suggest that the quality of commercial growing media should be carefully examined if the harvested rainwater is being considered for domestic use. Hence, roofing material is an important consideration when designing a rainwater catchment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Differences in Bone Quality between High versus Low Turnover Renal Osteodystrophy

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

Porter, Daniel S.; Pienkowski, David; Faugere, Marie-Claude

2012-01-01

Abnormal bone turnover is common in chronic kidney disease (CKD), but its effects on bone quality remain unclear. This study sought to quantify the relationship between abnormal bone turnover and bone quality. Iliac crest bone biopsies were obtained from CKD-5 patients on dialysis with low (n=18) or high (n=17) turnover, and from volunteers (n=12) with normal turnover and normal kidney function. Histomorphometric methods were used to quantify the microstructural parameters; Fourier transform infrared spectroscopy and nanoindentation were used to quantify the material and mechanical properties in bone. Reduced mineral-to-matrix ratio, mineral crystal size, stiffness and hardness were observed in bonemore » with high turnover compared to bone with normal or low turnover. Decreased cancellous bone volume and trabecular thickness were seen in bone with low turnover compared to bone with normal or high turnover. Bone quality, as defined by its microstructural, material, and mechanical properties, is related to bone turnover. These data suggest that turnover related alterations in bone quality may contribute to the known diminished mechanical competence of bone in CKD patients, albeit from different mechanisms for bone with high (material abnormality) vs. low (microstructural alteration) turnover. The present findings suggest that improved treatments for renal osteodystrophy should seek to avoid low or high bone turnover and aim for turnover rates as close to normal as possible.« less

Friendship Quality in Adolescents with and without an Intellectual Disability

ERIC Educational Resources Information Center

Tipton, Leigh A.; Christensen, Lisa; Blacher, Jan

2013-01-01

Background: High friendship quality is often defined by high levels of intimacy, companionship, closeness and low levels of conflict. Quality friendships develop over time and may be influenced by both behaviour problems and social skills. Materials and methods: Participants were 103, 13-year-old adolescents with or without intellectual…

Zerodur polishing process for high surface quality and high efficiency

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

Tesar, A.; Fuchs, B.

1992-08-01

Zerodur is a glass-ceramic composite importance in applications where temperature instabilities influence optical and mechanical performance, such as in earthbound and spaceborne telescope mirror substrates. Polished Zerodur surfaces of high quality have been required for laser gyro mirrors. Polished surface quality of substrates affects performance of high reflection coatings. Thus, the interest in improving Zerodur polished surface quality has become more general. Beyond eliminating subsurface damage, high quality surfaces are produced by reducing the amount of hydrated material redeposited on the surface during polishing. With the proper control of polishing parameters, such surfaces exhibit roughnesses of

Chemical and biotechnological processing of collagen-containing raw materials into functional components of feed suitable for production of high-quality meat from farm animals

NASA Astrophysics Data System (ADS)

Baburina, M. I.; Ivankin, A. N.; Stanovova, I. A.

2017-09-01

The process of chemical biotechnological processing of collagen-containing raw materials into functional components of feeds for effective pig rearing was studied. Protein components of feeds were obtained as a result of hydrolysis in the presence of lactic acid of the animal collagen from secondary raw materials, which comprised subcutaneous collagen (cuticle), skin and veined mass with tendons from cattle. For comparison, a method is described for preparing protein components of feeds by cultivating Lactobacillus plantarum. Analysis of the kinetic data of the conversion of a high-molecular collagen protein to an aminolyte polypeptide mixture showed the advantage of microbiological synthesis in obtaining a protein for feeds. Feed formulations have been developed to include the components obtained, and which result in high quality pork suitable for the production of quality meat products.

Photonic devices on planar and curved substrates and methods for fabrication thereof

DOEpatents

Bartl, Michael H.; Barhoum, Moussa; Riassetto, David

2016-08-02

A versatile and rapid sol-gel technique for the fabrication of high quality one-dimensional photonic bandgap materials. For example, silica/titania multi-layer materials may be fabricated by a sol-gel chemistry route combined with dip-coating onto planar or curved substrate. A shock-cooling step immediately following the thin film heat-treatment process is introduced. This step was found important in the prevention of film crack formation--especially in silica/titania alternating stack materials with a high number of layers. The versatility of this sol-gel method is demonstrated by the fabrication of various Bragg stack-type materials with fine-tuned optical properties by tailoring the number and sequence of alternating layers, the film thickness and the effective refractive index of the deposited thin films. Measured optical properties show good agreement with theoretical simulations confirming the high quality of these sol-gel fabricated optical materials.

Quality assessment of baby food made of different pre-processed organic raw materials under industrial processing conditions.

PubMed

Seidel, Kathrin; Kahl, Johannes; Paoletti, Flavio; Birlouez, Ines; Busscher, Nicolaas; Kretzschmar, Ursula; Särkkä-Tirkkonen, Marjo; Seljåsen, Randi; Sinesio, Fiorella; Torp, Torfinn; Baiamonte, Irene

2015-02-01

The market for processed food is rapidly growing. The industry needs methods for "processing with care" leading to high quality products in order to meet consumers' expectations. Processing influences the quality of the finished product through various factors. In carrot baby food, these are the raw material, the pre-processing and storage treatments as well as the processing conditions. In this study, a quality assessment was performed on baby food made from different pre-processed raw materials. The experiments were carried out under industrial conditions using fresh, frozen and stored organic carrots as raw material. Statistically significant differences were found for sensory attributes among the three autoclaved puree samples (e.g. overall odour F = 90.72, p < 0.001). Samples processed from frozen carrots show increased moisture content and decrease of several chemical constituents. Biocrystallization identified changes between replications of the cooking. Pre-treatment of raw material has a significant influence on the final quality of the baby food.

Material recycling of post-consumer polyolefin bulk plastics: Influences on waste sorting and treatment processes in consideration of product qualities achievable.

PubMed

Pfeisinger, Christian

2017-02-01

Material recycling of post-consumer bulk plastics made up of polyolefins is well developed. In this article, it is examined which effects on waste sorting and treatment processes influence the qualities of polyolefin-recyclats. It is shown that the properties and their changes during the product life-cycle of a polyolefin are defined by its way of polymerisation, its nature as a thermoplast, additives, other compound and composite materials, but also by the mechanical treatments during the production, its use where contact to foreign materials is possible and the waste sorting and treatment processes. Because of the sum of the effects influencing the quality of polyolefin-recyclats, conclusions are drawn for the material recycling of polyolefins to reach high qualities of their recyclats. Also, legal requirements like the EU regulation 1907/2006 concerning the registration, evaluation, authorisation and restrictions on chemicals are considered.

Advanced Materials for High Temperature, High Performance, Wide Bandgap Power Modules

NASA Astrophysics Data System (ADS)

O'Neal, Chad B.; McGee, Brad; McPherson, Brice; Stabach, Jennifer; Lollar, Richard; Liederbach, Ross; Passmore, Brandon

2016-01-01

Advanced packaging materials must be utilized to take full advantage of the benefits of the superior electrical and thermal properties of wide bandgap power devices in the development of next generation power electronics systems. In this manuscript, the use of advanced materials for key packaging processes and components in multi-chip power modules will be discussed. For example, to date, there has been significant development in silver sintering paste as a high temperature die attach material replacement for conventional solder-based attach due to the improved thermal and mechanical characteristics as well as lower processing temperatures. In order to evaluate the bond quality and performance of this material, shear strength, thermal characteristics, and void quality for a number of silver sintering paste materials were analyzed as a die attach alternative to solder. In addition, as high voltage wide bandgap devices shift from engineering samples to commercial components, passivation materials become key in preventing premature breakdown in power modules. High temperature, high dielectric strength potting materials were investigated to be used to encapsulate and passivate components internal to a power module. The breakdown voltage up to 30 kV and corresponding leakage current for these materials as a function of temperature is also presented. Lastly, high temperature plastic housing materials are important for not only discrete devices but also for power modules. As the operational temperature of the device and/or ambient temperature increases, the mechanical strength and dielectric properties are dramatically reduced. Therefore, the electrical characteristics such as breakdown voltage and leakage current as a function of temperature for housing materials are presented.

3D printing functional materials and devices (Conference Presentation)

NASA Astrophysics Data System (ADS)

McAlpine, Michael C.

2017-05-01

The development of methods for interfacing high performance functional devices with biology could impact regenerative medicine, smart prosthetics, and human-machine interfaces. Indeed, the ability to three-dimensionally interweave biological and functional materials could enable the creation of devices possessing unique geometries, properties, and functionalities. Yet, most high quality functional materials are two dimensional, hard and brittle, and require high crystallization temperatures for maximal performance. These properties render the corresponding devices incompatible with biology, which is three-dimensional, soft, stretchable, and temperature sensitive. We overcome these dichotomies by: 1) using 3D printing and scanning for customized, interwoven, anatomically accurate device architectures; 2) employing nanotechnology as an enabling route for overcoming mechanical discrepancies while retaining high performance; and 3) 3D printing a range of soft and nanoscale materials to enable the integration of a diverse palette of high quality functional nanomaterials with biology. 3D printing is a multi-scale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This three-dimensional blending of functional materials and `living' platforms may enable next-generation 3D printed devices.

High-quality digital color xerography

NASA Astrophysics Data System (ADS)

Takiguchi, Koichi

1993-06-01

Image noise, tone reproduction, color reproduction, fine line reproduction, and OHP performance are the most important characteristics for a high quality color copier. Technologies enabling such quality are use of fine toner, halftone algorithm to ensure good highlight reproduction, soft roll fuser with good release performance, smooth surface and high thermal conductivity, white and smooth paper, and selection of a coating material for the surface layer of the OHP sheets. These technologies are integrated in the Fuji Xerox `A- Color' product. Utilizing 7 micrometers color toner, `A-Color' can make very high quality color copies.

Development and testing of a superconducting link for an IR detector

NASA Technical Reports Server (NTRS)

Caton, R.; Selim, R.

1991-01-01

The development and testing of a ceramic superconducting link for an infrared detector is summarized. Areas of study included the materials used, the electrical contacts, radiation and temperature cycling effects, aging, thermal conductivity, and computer models of an ideal link. Materials' samples were processed in a tube furnace at temperatures of 840 C to 865 C for periods up to 17 days and transition temperatures and critical current densities were recorded. The project achieved better quality high superconducting transition temperature material through improved processing and also achieved high quality electrical contacts. Studies on effects of electron irradiation, temperature cycling, and aging on superconducting properties indicate that the materials will be suitable for space applications. Various presentations and publications on the study's results are reported.

Reel wheels : an application of material science

Treesearch

Robert L. Geimer

1979-01-01

Circular plates of reconstituted wood were fabricated and destructively tested to appraise the potential of such material for cable reel flanges. The reconstituted wood consisted of flakeboard from quality-cut flakes and also from factory residue. The high quality flakeboard used 0.020- by 1/2-by 2-inch southern pine flakes cut on a disk flaker, whereas the flakeboard...

10 CFR Appendix I to Part 110 - Illustrative List of Reprocessing Plant Components Under NRC Export Licensing Authority

Code of Federal Regulations, 2011 CFR

2011-01-01

... assurance and quality control techniques) out of low carbon stainless steels, titanium, zirconium or other... materials such as low carbon stainless steels, titanium or zirconium, or other high quality materials... features for control of nuclear criticality: (i) Walls or internal structures with a boron equivalent of at...

Evaluation of United States Department of Agriculture-sponsored consumer materials addressing food security.

PubMed

Tolma, Eleni; John, Robert; Garner, Jane

2007-01-01

Food insecurity in the United States is a major public health issue. The main objective of this study was to evaluate the availability and quality of printed materials addressing food security targeted to special populations by the United States Department of Agriculture (USDA). Nutrition education resources addressing food security available from USDA websites were selected for analysis. Not applicable. The review team consisted of project staff (n = 6), two of who were fluent in Spanish. Selection criteria were established to identify the food-security materials, and a group of reviewers assessed the quality of each publication both quantitatively and qualitatively. A consensus meeting among the reviewers was held to make final determinations of the quality of the materials. The quantitative data analysis consisted of basic descriptive statistics. Among the 27 materials initially identified, 20 were either irrelevant or of low relevance to food security. Moreover, very few of them were intended for minority populations. The quality of most of the materials ranged from "average" to "good." Some of the major weaknesses include readability level, lack of cultural relevance, and inadequate coverage of food insecurity. Very few materials on food insecurity are of high quality. In the development of such materials, emphasis should be given to the readability level, content, and cultural relevance.

Highly Non-Linear Optical (NLO) organic crystals

NASA Technical Reports Server (NTRS)

Harris, J. Milton

1987-01-01

This research project involves the synthesis and characterization of organic materials having powerful nonlinear optical (NLO) properties and the growth of highly ordered crystals and monomolecular films of these materials. Research in four areas is discussed: theoretical design of new materials, characterization of NLO materials, synthesis of new materials and development of coupling procedures for forming layered films, and improvement of the techniques for vapor phase and solution phase growth of high quality organic crystals. Knowledge gained from these experiments will form the basis for experiments in the growth of these crystals.

HPHT growth and x-ray characterization of high-quality type IIa diamond.

PubMed

Burns, R C; Chumakov, A I; Connell, S H; Dube, D; Godfried, H P; Hansen, J O; Härtwig, J; Hoszowska, J; Masiello, F; Mkhonza, L; Rebak, M; Rommevaux, A; Setshedi, R; Van Vaerenbergh, P

2009-09-09

The trend in synchrotron radiation (x-rays) is towards higher brilliance. This may lead to a very high power density, of the order of hundreds of watts per square millimetre at the x-ray optical elements. These elements are, typically, windows, polarizers, filters and monochromators. The preferred material for Bragg diffracting optical elements at present is silicon, which can be grown to a very high crystal perfection and workable size as well as rather easily processed to the required surface quality. This allows x-ray optical elements to be built with a sufficient degree of lattice perfection and crystal processing that they may preserve transversal coherence in the x-ray beam. This is important for the new techniques which include phase-sensitive imaging experiments like holo-tomography, x-ray photon correlation spectroscopy, coherent diffraction imaging and nanofocusing. Diamond has a lower absorption coefficient than silicon, a better thermal conductivity and lower thermal expansion coefficient which would make it the preferred material if the crystal perfection (bulk and surface) could be improved. Synthetic HPHT-grown (high pressure, high temperature) type Ib material can readily be produced in the necessary sizes of 4-8 mm square and with a nitrogen content of typically a few hundred parts per million. This material has applications in the less demanding roles such as phase plates: however, in a coherence-preserving beamline, where all elements must be of the same high quality, its quality is far from sufficient. Advances in HPHT synthesis methods have allowed the growth of type IIa diamond crystals of the same size as type Ib, but with substantially lower nitrogen content. Characterization of this high purity type IIa material has been carried out with the result that the crystalline (bulk) perfection of some of the HPHT-grown materials is approaching the quality required for the more demanding applications such as imaging applications and imaging applications with coherence preservation. The targets for further development of the type IIa diamond are size, crystal perfection, as measured by the techniques of white beam and monochromatic x-ray diffraction imaging (historically called x-ray topography), and also surface quality. Diamond plates extracted from the cubic growth sector furthest from the seed of the new low strain material produces no measurable broadening of the x-ray rocking curve width. One measures essentially the crystal reflectivity as defined by the intrinsic reflectivity curve (Darwin curve) width of a perfect crystal. In these cases the more sensitive technique of plane wave topography has been used to establish a local upper limit of the strain at the level of an 'effective misorientation' of 10(-7) rad.

Resources for Ensuring Quality School-to-Work Opportunities for Young Women. Draft.

ERIC Educational Resources Information Center

Wider Opportunities for Women, Inc., Washington, DC.

This annotated bibliography lists 49 resources for ensuring high quality school-to-work opportunities for young women. These resources are grouped into 10 categories: print material for middle and high school girls; videos for middle and high school girls; administrator/school guides; curriculum guides/resources for teachers; resources for…

Optical Computers and Space Technology

NASA Technical Reports Server (NTRS)

Abdeldayem, Hossin A.; Frazier, Donald O.; Penn, Benjamin; Paley, Mark S.; Witherow, William K.; Banks, Curtis; Hicks, Rosilen; Shields, Angela

1995-01-01

The rapidly increasing demand for greater speed and efficiency on the information superhighway requires significant improvements over conventional electronic logic circuits. Optical interconnections and optical integrated circuits are strong candidates to provide the way out of the extreme limitations imposed on the growth of speed and complexity of nowadays computations by the conventional electronic logic circuits. The new optical technology has increased the demand for high quality optical materials. NASA's recent involvement in processing optical materials in space has demonstrated that a new and unique class of high quality optical materials are processible in a microgravity environment. Microgravity processing can induce improved orders in these materials and could have a significant impact on the development of optical computers. We will discuss NASA's role in processing these materials and report on some of the associated nonlinear optical properties which are quite useful for optical computers technology.

Coached Peer Review: Developing the Next Generation of Authors.

PubMed

Sidalak, Daniel; Purdy, Eve; Luckett-Gatopoulos, S; Murray, Heather; Thoma, Brent; Chan, Teresa M

2017-02-01

Publishing in academic journals is challenging for learners. Those who pass the initial stages of internal review by an editor often find the anonymous peer review process harsh. Academic blogs offer alternate avenues for publishing medical education material. Many blogs, however, lack a peer review process, which some consumers argue compromises the quality of materials published. CanadiEM (formerly BoringEM) is an academic educational emergency medicine blog dedicated to publishing high-quality materials produced by learners (i.e., residents and medical students). The editorial team has designed and implemented a collaborative "coached peer review" process that comprises an open exchange among the learner-author, editors, and reviewers. The goal of this process is to facilitate the publication of high-quality academic materials by learner-authors while providing focused feedback to help them develop academic writing skills. The authors of this Innovation Report surveyed (February-June 2015) their blog's learner-authors and external expert "staff" reviewers who had participated in coached peer review for their reactions to the process. The survey results revealed that participants viewed the process positively compared with both traditional journal peer review and academic blog publication processes. Participants found the process friendly, easy, efficient, and transparent. Learner-authors also reported increased confidence in their published material. These outcomes met the goals of coached peer review. CanadiEM aims to inspire continued participation in, exposure to, and high-quality production of academic writing by promoting the adoption of coached peer review for online educational resources produced by learners.

Advances in High Temperature Materials for Additive Manufacturing

NASA Astrophysics Data System (ADS)

Nordin, Nurul Amira Binti; Johar, Muhammad Akmal Bin; Ibrahim, Mohd Halim Irwan Bin; Marwah, Omar Mohd Faizan bin

2017-08-01

In today’s technology, additive manufacturing has evolved over the year that commonly known as 3D printing. Currently, additive manufacturing have been applied for many industries such as for automotive, aerospace, medical and other commercial product. The technologies are supported by materials for the manufacturing process to produce high quality product. Plus, additive manufacturing technologies has been growth from the lowest to moderate and high technology to fulfil manufacturing industries obligation. Initially from simple 3D printing such as fused deposition modelling (FDM), poly-jet, inkjet printing, to selective laser sintering (SLS), and electron beam melting (EBM). However, the high technology of additive manufacturing nowadays really needs high investment to carry out the process for fine products. There are three foremost type of material which is polymer, metal and ceramic used for additive manufacturing application, and mostly they were in the form of wire feedstock or powder. In circumstance, it is crucial to recognize the characteristics of each type of materials used in order to understand the behaviours of the materials on high temperature application via additive manufacturing. Therefore, this review aims to provide excessive inquiry and gather the necessary information for further research on additive material materials for high temperature application. This paper also proposed a new material based on powder glass, which comes from recycled tempered glass from automotive industry, having a huge potential to be applied for high temperature application. The technique proposed for additive manufacturing will minimize some cost of modelling with same quality of products compare to the others advanced technology used for high temperature application.

Near-infrared Spectroscopy in the Brewing Industry.

PubMed

Sileoni, Valeria; Marconi, Ombretta; Perretti, Giuseppe

2015-01-01

This article offers an exhaustive description of the use of Near-Infrared (NIR) Spectroscopy in the brewing industry. This technique is widely used for quality control testing of raw materials, intermediates, and finished products, as well as process monitoring during malting and brewing. In particular, most of the reviewed works focus on the assessment of barley properties, aimed at quickly selecting the best barley varieties in order to produce a high-quality malt leading to high-quality beer. Various works concerning the use of NIR in the evaluation of raw materials, such as barley, malt, hop, and yeast, are also summarized here. The implementation of NIR sensors for the control of malting and brewing processes is also highlighted, as well as the use of NIR for quality assessment of the final product.

Methods for making deposited films with improved microstructures

DOEpatents

Patten, James W.; Moss, Ronald W.; McClanahan, Edwin D.

1982-01-01

Methods for improving microstructures of line-of-sight deposited films are described. Columnar growth defects ordinarily produced by geometrical shadowing during deposition of such films are eliminated without resorting to post-deposition thermal or mechanical treatments. The native, as-deposited coating qualities, including homogeneity, fine grain size, and high coating-to-substrate adherence, can thus be retained. The preferred method includes the steps of emitting material from a source toward a substrate to deposit a coating non-uniformly on the substrate surface, removing a portion of the coating uniformly over the surface, again depositing material onto the surface, but from a different direction, and repeating the foregoing steps. The quality of line-of-sight deposited films such as those produced by sputtering, progressively deteriorates as the angle of incidence between the flux and the surface becomes increasingly acute. Depositing non-uniformly, so that the coating becomes progressively thinner as quality deteriorates, followed by uniformly removing some of the coating, such as by resputtering, eliminates the poor quality portions, leaving only high quality portions of the coating. Subsequently sputtering from a different direction applies a high quality coating to other regions of the surface. Such steps can be performed either simultaneously or sequentially to apply coatings of a uniformly high quality, closed microstructure to three-dimensional or larger planar surfaces.

Deposited films with improved microstructures

DOEpatents

Patten, James W.; Moss, Ronald W.; McClanahan, Edwin D.

1984-01-01

Methods for improving microstructures of line-of-sight deposited films are described. Columnar growth defects ordinarily produced by geometrical shadowing during deposition of such films are eliminated without resorting to post-deposition thermal or mechanical treatments. The native, as-deposited coating qualities, including homogeneity, fine grain size, and high coating-to-substrate adherence, can thus be retained. The preferred method includes the steps of emitting material from a source toward a substrate to deposit a coating non-uniformly on the substrate surface, removing a portion of the coating uniformly over the surface, again depositing material onto the surface, but from a different direction, and repeating the foregoing steps. The quality of line-of-sight deposited films such as those produced by sputtering, progressively deteriorates as the angle of incidence between the flux and the surface becomes increasingly acute. Depositing non-uniformly, so that the coating becomes progressively thinner as quality deteriorates, followed by uniformly removing some of the coating, such as by resputtering, eliminates the poor quality portions, leaving only high quality portions of the coating. Subsequently sputtering from a different direction applies a high quality coating to other regions of the surface. Such steps can be performed either simultaneously or sequentially to apply coatings of a uniformly high quality, closed microstructure to three-dimensional or large planar surfaces.

[Special aspects of quality of Tibetan medicines--insights from over 40 years of manufacturing experience in Switzerland].

PubMed

Schwabl, Alexandra; Gämperle, Erich

2013-01-01

Tibetan recipes are complex formulas from plant and mineral ingredients. Padma Inc. has been producing selected formulas from Tibetan Medicine in Switzerland since more than 40 years. Modern quality standards and Good Manufacturing Practice (GMP) guidelines are followed, ensuring the quality of the raw materials through the manufacturing processes to the finished product. The aim is to provide these valuable formulas to people in the West in a consistently high quality 'made in Switzerland'. The production according to modern quality standards is challenging, draws on many resources, and requires specialized expertise, e.g. in the procurement of raw materials and the quality analysis including pharmacognostic and botanical knowledge.

Quality Managment Program (QMP) report: A review of quality management programs developed in response to Title 10, Section 35.32 of the Code of Federal Regulations

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

Witte, M.C.

1994-10-01

In July of 1991, the Nuclear Regulatory Commission published a Final Rule in the Federal Register amending regulations governing medical therapeutic administrations of byproduct material and certain uses of radioactive sodium iodide. These amendments required implementation of a Quality Management Program (QMP) to provide high confidence that the byproduct material -- or radiation from byproduct material -- will be administered as directed by an authorized user physician. Herein, this rule is referred to as the QM rule. The Final Rule was published after two proposed rules had been published in the Federal Register.

Anatomy and dry weight yields of two Populus clones grown under intensive culture.

Treesearch

John B. Crist; David H. Dawson

1975-01-01

Two Populus clones grown for short rotations at three dense planting spacings produced some extremely high yields of material of acceptable quality. However, variation in yields and quality illustrates that selection of genetic material and the cultured regime under which a species is growth are significant factors that must be determined in maximum-yield systems....

Supporting Excellence: A Framework for Developing, Implementing, and Sustaining a High-Quality District Curriculum. First Edition

ERIC Educational Resources Information Center

Council of the Great City Schools, 2017

2017-01-01

In the ongoing effort to improve instructional standards in our nation's urban public schools, the Council of the Great City Schools has released resources to help districts determine the quality and alignment of instructional materials at each grade level; to ensure that materials for English language learners are rigorous and aligned to district…

Comprehension and Writing Strategy Training Improves Performance on Content-Specific Source-Based Writing Tasks

ERIC Educational Resources Information Center

Weston-Sementelli, Jennifer L.; Allen, Laura K.; McNamara, Danielle S.

2016-01-01

Source-based essays are evaluated both on the quality of the writing and the content appropriate interpretation and use of source material. Hence, composing a high-quality source-based essay (an essay written based on source material) relies on skills related to both reading (the sources) and writing (the essay) skills. As such, source-based…

Comprehension and Writing Strategy Training Improves Performance on Content-Specific Source-Based Writing Tasks

ERIC Educational Resources Information Center

Weston-Sementelli, Jennifer L.; Allen, Laura K.; McNamara, Danielle S.

2018-01-01

Source-based essays are evaluated both on the quality of the writing and the content appropriate interpretation and use of source material. Hence, composing a high-quality source-based essay (an essay written based on source material) relies on skills related to both reading (the sources) and writing (the essay) skills. As such, source-based…

Metamorphic Epitaxy for Multijunction Solar Cells

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

France, Ryan M.; Dimroth, Frank; Grassman, Tyler J.

Multijunction solar cells have proven to be capable of extremely high efficiencies by combining multiple semiconductor materials with bandgaps tuned to the solar spectrum. Reaching the optimum set of semiconductors often requires combining high-quality materials with different lattice constants into a single device, a challenge particularly suited for metamorphic epitaxy. In this article, we describe different approaches to metamorphic multijunction solar cells, including traditional upright metamorphic, state-of-the-art inverted metamorphic, and forward-looking multijunction designs on silicon. We also describe the underlying materials science of graded buffers that enables metamorphic subcells with low dislocation densities. Following nearly two decades of research, recentmore » efforts have demonstrated high-quality lattice-mismatched multijunction solar cells with very little performance loss related to the mismatch, enabling solar-to-electric conversion efficiencies over 45%.« less

Sustainable waste management through end-of-waste criteria development.

PubMed

Zorpas, Antonis A

2016-04-01

The Waste Framework Directive 2000/98 (WFD) contains specific requirements to define end-of-waste criteria (EWC). The main goal of EWC is to remove and eliminate the administrative loads of waste legislation for safe and high-quality waste materials, thereby facilitating and assisting recycling. The target is to produce effective with high quality of recyclables materials, promoting product standardization and quality and safety assurance, and improving harmonization and legal certainty in the recyclable material markets. At the same time, those objectives aim to develop a plan in order to improve the development and wider use of environmental technologies, which reduce pressure on environment and at the same time address the three dimensions of the Lisbon strategy: growth, jobs and environment. This paper presents the importance of EWC, and the approach of setting EWC as EWC affect several management systems as well as sustainable and clean technologies.

Exploring Local Public Health Workflow in the Context of Automated Translation Technologies

PubMed Central

Mandel, Hannah; Turner, Anne M.

2013-01-01

Despite the growing limited English proficiency (LEP) population in the US, and federal regulations requiring multilingual health information be available for LEP individuals, there is a lack of available high quality multilingual health promotion materials. The costs and personnel time associated with creating high quality translations serve as barriers to their creation, especially in resource limited public health settings. To explore the potential adoption of novel machine translation and document dissemination technologies for improving the creation and sharing of translated public health materials, we interviewed key health department personnel in Washington State. We analyzed translation workflow, elucidated key themes regarding public health translation work, and assessed attitudes towards electronic document exchange and machine translation. Public health personnel expressed the need for human quality assurance and oversight, but appreciated the potential of novel information technologies to assist in the production and dissemination of translated materials for public health practice. PMID:24551385

Study of ceramic products and processing techniques in space. [using computerized simulation

NASA Technical Reports Server (NTRS)

Markworth, A. J.; Oldfield, W.

1974-01-01

An analysis of the solidification kinetics of beta alumina in a zero-gravity environment was carried out, using computer-simulation techniques, in order to assess the feasibility of producing high-quality single crystals of this material in space. The two coupled transport processes included were movement of the solid-liquid interface and diffusion of sodium atoms in the melt. Results of the simulation indicate that appreciable crystal-growth rates can be attained in space. Considerations were also made of the advantages offered by high-quality single crystals of beta alumina for use as a solid electrolyte; these clearly indicate that space-grown materials are superior in many respects to analogous terrestrially-grown crystals. Likewise, economic considerations, based on the rapidly expanding technological applications for beta alumina and related fast ionic conductors, reveal that the many superior qualities of space-grown material justify the added expense and experimental detail associated with space processing.

Improving quality and value of future hardwoods

Treesearch

Larry R. Frye

1989-01-01

The central hardwood area is highly regarded both in this country and abroad for the high quality timber grown on both public and private lands. Buyers of standing timber and logs for lumber and veneer often look to this region first to meet their needs for raw materials. And these buyers have traditionally paid a lot more for quality timber than the usual market price...

Value Added Processing of Aflatoxin Contaminated Peanut Meal

USDA-ARS?s Scientific Manuscript database

Peanut meal (PM) is the solid material remaining after commercial extraction of oil. Despite being an excellent source of high quality protein, applications of PM are limited to feed markets as this material typically contains high concentrations of aflatoxin. Our research group has developed a nov...

Phenomenally High Transduction Air/gas Transducers for Practical Non-Contact Ultrasonic Applications

NASA Astrophysics Data System (ADS)

Bhardwaj, Mahesh C.

2009-03-01

Based on novel acoustic impedance matching layers and high coupling piezoelectric materials this paper describes exceptionally high air/gas transduction ultrasonic transducers. By providing applications oriented performance of these transducers we also usher in the era of much desired Non-Contact Ultrasound (NCU) testing and analysis of a wide range of materials including early stage formation of materials such as uncured composite prepregs, green ceramics and powder metals, plastics, elastomers, porous, hygroscopic, chemically bonded and other materials. Besides quality control, ultimately NCU offers timely opportunities for cost-effective materials production, energy savings, and environment protection.

Top-down solid-phase fabrication of nanoporous cadmium oxide architectures.

PubMed

Yu, Haidong; Wang, Deshen; Han, Ming-Yong

2007-02-28

In this article, we have demonstrated one-step solid-phase transformation from high-quality cadmium carbonate microcrystals into highly nanoporous cadmium oxide. The high crystal quality of cadmium carbonate is critical for the successful fabrication of porous nanoarchitectures with predetermined morphology and well-controlled internal structure. This novel strategy has a good potential to prepare nanoporous materials at a large scale by using perfect monolithic carbonate crystals, and it is also useful to synthesize different nanoporous materials on metal-oxide-coated substrates. Meanwhile, this simple thermal transformation of cadmium carbonate into porous structures has further been extended to convert calcium carbonate into such porous structures.

Selective nanoscale growth of lattice mismatched materials

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

Lee, Seung-Chang; Brueck, Steven R. J.

Exemplary embodiments provide materials and methods of forming high-quality semiconductor devices using lattice-mismatched materials. In one embodiment, a composite film including one or more substantially-single-particle-thick nanoparticle layers can be deposited over a substrate as a nanoscale selective growth mask for epitaxially growing lattice-mismatched materials over the substrate.

Materials selection for long life in LEO: A critical evaluation of atomic oxygen testing with thermal atom systems

NASA Technical Reports Server (NTRS)

Koontz, S. L.; Kuminecz, J.; Leger, L.; Nordine, P.

1988-01-01

The use of thermal atom test methods as a materials selection and screening technique for low-Earth orbit (LEO) spacecraft is critically evaluated. The chemistry and physics of thermal atom environments are compared with the LEO environment. The relative reactivities of a number of materials determined to be in thermal atom environments are compared to those observed in LEO and in high quality LEO simulations. Reaction efficiencies measured in a new type of thermal atom apparatus are one-hundredth to one-thousandth those observed in LEO, and many materials showing nearly identical reactivities in LEO show relative reactivities differing by as much as a factor of 8 in thermal atom systems. A simple phenomenological kinetic model for the reaction of oxygen atoms with organic materials can be used to explain the differences in reactivity in different environments. Certain specific thermal test environments can be used as reliable materials screening tools. Using thermal atom methods to predict material lifetime in LEO requires direct calibration of the method against LEO data or high quality simulation data for each material.

Amorphous boron gasket in diamond anvil cell research

NASA Astrophysics Data System (ADS)

Lin, Jung-Fu; Shu, Jinfu; Mao, Ho-kwang; Hemley, Russell J.; Shen, Guoyin

2003-11-01

Recent advances in high-pressure diamond anvil cell experiments include high-energy synchrotron x-ray techniques as well as new cell designs and gasketing procedures. The success of high-pressure experiments usually depends on a well-prepared sample, in which the gasket plays an important role. Various gasket materials such as diamond, beryllium, rhenium, and stainless steel have been used. Here we introduce amorphous boron as another gasket material in high-pressure diamond anvil cell experiments. We have applied the boron gasket for laser-heating x-ray diffraction, radial x-ray diffraction, nuclear resonant inelastic x-ray scattering, and inelastic x-ray scattering. The high shear strength of the amorphous boron maximizes the thickness of the sample chamber and increases the pressure homogeneity, improving the quality of high-pressure data. Use of amorphous boron avoids unwanted x-ray diffraction peaks and reduces the absorption of incident and x rays exiting the gasket material. The high quality of the diffraction patterns makes it possible to refine the cell parameters with powder x-ray diffraction data under high pressure and high temperature. The reactivity of boron prevents its use at high temperatures, however. When heated, boron may also react with the specimen to produce unwanted phases. The relatively porous boron starting material at ambient conditions also poses some challenges for sample preparation.

Cost Models for MMC Manufacturing Processes

NASA Technical Reports Server (NTRS)

Elzey, Dana M.; Wadley, Haydn N. G.

1996-01-01

The quality cost modeling (QCM) tool is intended to be a relatively simple-to-use device for obtaining a first-order assessment of the quality-cost relationship for a given process-material combination. The QCM curve is a plot of cost versus quality (an index indicating microstructural quality), which is unique for a given process-material combination. The QCM curve indicates the tradeoff between cost and performance, thus enabling one to evaluate affordability. Additionally, the effect of changes in process design, raw materials, and process conditions on the cost-quality relationship can be evaluated. Such results might indicate the most efficient means to obtain improved quality at reduced cost by process design refinements, the implementation of sensors and models for closed loop process control, or improvement in the properties of raw materials being fed into the process. QCM also allows alternative processes for producing the same or similar material to be compared in terms of their potential for producing competitively priced, high quality material. Aside from demonstrating the usefulness of the QCM concept, this is one of the main foci of the present research program, namely to compare processes for making continuous fiber reinforced, metal matrix composites (MMC's). Two processes, low pressure plasma spray deposition and tape casting are considered for QCM development. This document consists of a detailed look at the design of the QCM approach, followed by discussion of the application of QCM to each of the selected MMC manufacturing processes along with results, comparison of processes, and finally, a summary of findings and recommendations.

Coherent scattering noise reduction method with wavelength diversity detection for holographic data storage system

NASA Astrophysics Data System (ADS)

Nakamura, Yusuke; Hoshizawa, Taku; Takashima, Yuzuru

2017-09-01

A new method, wavelength diversity detection (WDD), for improving signal quality is proposed and its effectiveness is numerically confirmed. We consider that WDD is especially effective for high-capacity systems having low hologram diffraction efficiencies. In such systems, the signal quality is primarily limited by coherent scattering noise; thus, effective improvement of the signal quality under a scattering-limited system is of great interest. WDD utilizes a new degree of freedom, the spectrum width, and scattering by molecules to improve the signal quality of the system. We found that WDD improves the quality by counterbalancing the degradation of the quality due to Bragg mismatch. With WDD, a higher-scattering-coefficient medium can improve the quality. The result provides an interesting insight into the requirements for material characteristics, especially for a large-M/# material. In general, a larger-M/# material contains more molecules; thus, the system is subject to more scattering, which actually improves the quality with WDD. We propose a pathway for a future holographic data storage system (HDSS) using WDD, which can record a larger amount of data than a conventional HDSS.

Reliable Exfoliation of Large-Area High-Quality Flakes of Graphene and Other Two-Dimensional Materials.

PubMed

Huang, Yuan; Sutter, Eli; Shi, Norman N; Zheng, Jiabao; Yang, Tianzhong; Englund, Dirk; Gao, Hong-Jun; Sutter, Peter

2015-11-24

Mechanical exfoliation has been a key enabler of the exploration of the properties of two-dimensional materials, such as graphene, by providing routine access to high-quality material. The original exfoliation method, which remained largely unchanged during the past decade, provides relatively small flakes with moderate yield. Here, we report a modified approach for exfoliating thin monolayer and few-layer flakes from layered crystals. Our method introduces two process steps that enhance and homogenize the adhesion force between the outermost sheet in contact with a substrate: Prior to exfoliation, ambient adsorbates are effectively removed from the substrate by oxygen plasma cleaning, and an additional heat treatment maximizes the uniform contact area at the interface between the source crystal and the substrate. For graphene exfoliation, these simple process steps increased the yield and the area of the transferred flakes by more than 50 times compared to the established exfoliation methods. Raman and AFM characterization shows that the graphene flakes are of similar high quality as those obtained in previous reports. Graphene field-effect devices were fabricated and measured with back-gating and solution top-gating, yielding mobilities of ∼4000 and 12,000 cm(2)/(V s), respectively, and thus demonstrating excellent electrical properties. Experiments with other layered crystals, e.g., a bismuth strontium calcium copper oxide (BSCCO) superconductor, show enhancements in exfoliation yield and flake area similar to those for graphene, suggesting that our modified exfoliation method provides an effective way for producing large area, high-quality flakes of a wide range of 2D materials.

Investigation of Mechanism of Action of Modifying Admixtures Based on Products of Petrochemical Synthesis on Concrete Structure

NASA Astrophysics Data System (ADS)

Tukhareli, V. D.; Tukhareli, A. V.; Cherednichenko, T. F.

2017-11-01

The creation of composite materials for generating structural elements with the desired properties has always been and still remains relevant. The basis of a modern concrete technology is the creation of a high-quality artificial stone characterized by low defectiveness and structure stability. Improving the quality of concrete compositions can be achieved by using chemical admixtures from local raw materials which is a very promising task of modern materials’ science for creation of a new generation of concretes. The new generation concretes are high-tech, high-quality, multicomponent concrete mixes and compositions with admixtures that preserve the required properties in service under all operating conditions. The growing complexity of concrete caused by systemic effects that allow you to control the structure formation at all stages of the technology ensures the obtaining of composites with "directional" quality, compositions, structure and properties. The possibility to use the organic fraction of oil refining as a multifunctional hydrophobic-plasticizing admixture in the effective cement concrete is examined.

Deoxyribonucleic acid (DNA)-based optical materials

NASA Astrophysics Data System (ADS)

Grote, James G.; Heckman, Emily M.; Hagen, Joshua A.; Yaney, Perry P.; Subramanyam, Guru; Clarson, Stephen J.; Diggs, Darnell E.; Nelson, Robert L.; Zetts, John S.; Hopkins, F. Kenneth; Ogata, Naoya

2004-12-01

Optical materials for waveguiding applications must possess the desired optical and electromagnetic properties for optimal device performance. Purified deoxyribonucleic acid (DNA), derived from salmon sperm, has been investigated for use as an optical waveguide material. In this paper we present the materials processing and optical and electromagnetic characterization of this purified DNA to render a high quality, low loss optical waveguide material.

Polyethersulfone-based ultrafiltration hollow fibre membrane for drinking water treatment systems

NASA Astrophysics Data System (ADS)

Chew, Chun Ming; Ng, K. M. David; Ooi, H. H. Richard

2017-12-01

Conventional media/sand filtration has been the mainstream water treatment process for most municipal water treatment plants in Malaysia. Filtrate qualities of conventional media/sand filtration are very much dependent on the coagulation-flocculation process prior to filtration and might be as high as 5 NTU. However, the demands for better quality of drinking water through public piped-water supply systems are growing. Polymeric ultrafiltration (UF) hollow fibre membrane made from modified polyethersulfone (PES) material is highly hydrophilic with high tensile strength and produces excellent quality filtrate of below 0.3 NTU in turbidity. This advanced membrane filtration material is also chemical resistance which allows a typical lifespan of 5 years. Comparisons between the conventional media/sand filtration and PES-based UF systems are carried out in this paper. UF has been considered as the emerging technology in municipal drinking water treatment plants due to its consistency in producing high quality filtrates even without the coagulation-flocculation process. The decreasing cost of PES-based membrane due to mass production and competitive pricing by manufacturers has made the UF technology affordable for industrial-scale water treatment plants.

Rupture testing for the quality control of electrodeposited copper interconnections in high-speed, high-density circuits

NASA Technical Reports Server (NTRS)

Zakraysek, Louis

1987-01-01

Printed Wiring Multilayer Board (PWMLB) structures for high speed, high density circuits are prone to failure due to the microcracking of electrolytic copper interconnections. The failure can occur in the foil that makes up the inner layer traces or in the plated through holes (PTH) deposit that forms the layer to layer interconnections. It is shown that there are some distinctive differences in the quality of Type E copper and that these differences can be detected before its use in a PWMLB. It is suggested that the strength of some Type E copper can be very low when the material is hot and that it is the use of this poor quality material in a PWMLB that results in PTH and inner layer microcracking. Since the PWMLB failure in question are induced by a thermal stress, and since the poorer grades of Type E materials used in these structures are susceptible to premature failure under thermal stress, the use of elevated temperature rupture and creep rupture testing is proposed as a means for screening copper foil, or its PTH equivalent, in order to eliminate the problem of Type E copper microcracking in advanced PWMLBs.

TiN-buffered substrates for photoelectrochemical measurements of oxynitride thin films

NASA Astrophysics Data System (ADS)

Pichler, Markus; Pergolesi, Daniele; Landsmann, Steve; Chawla, Vipin; Michler, Johann; Döbeli, Max; Wokaun, Alexander; Lippert, Thomas

2016-04-01

Developing novel materials for the conversion of solar to chemical energy is becoming an increasingly important endeavour. Perovskite compounds based on bandgap tunable oxynitrides represent an exciting class of novel photoactive materials. To date, literature mostly focuses on the characterization of oxynitride powder samples which have undeniable technological interest but do not allow the investigation of fundamental properties such as the role of the crystalline quality and/or the surface crystallographic orientation toward photo-catalytic activity. The challenge of growing high quality oxynitride thin films arises from the availability of a suitable substrate, owing to strict material and processing requirements: effective lattice matching, sufficiently high conductivities, stability under high temperatures and in strongly reducing environments. Here, we have established the foundations of a model system incorporating a TiN-buffer layer which enables fundamental investigations into crystallographic surface orientation and crystalline quality of the photocatalyst against photo(electro)chemical performance to be effectively performed. Furthermore, we find that TiN as current collector enables control over the nitrogen content of oxynitride thin films produced by a modified pulsed laser deposition method and allows the growth of highly ordered LaTiO3-xNx thin films.

[Husk of Venezuelan cocoa as raw material of infusions].

PubMed

Sangronis, Elba; José Soto, María; Valero, Yolmar; Buscema, Ignacio

2014-06-01

In the cocoa bean industry, some by-products go underutilized. Some of these components could provide other innovative products, and such is the case with the husk of the cocoa bean. Previous studies have attributed the husk with a high antioxidant capacity, which added to its relative low cost, makes it an attractive ingredient for the production of infusions. However, prior to promoting it as such, its quality needs to be guaranteed. This study evaluated the chemical composition of the husk of cocoa, its microbiologic quality and other parameters in order to be considered raw material in the preparation of infusions. The cocoa was cultivated in two different states in Venezuela. Moisture, protein, fat, ash, carbohydrates, microbiologic quality and ochratoxin A as well antioxidant properties, content of foreign matter, insoluble ash in HCL and aqueous extract were evaluated in the husk of cocoa seeds. Applied methods were in compliance with national and international norms. Significant differences were determined between the samples through the ANOVA application. A low level in moisture content, but high in ash, along with a microbiologic quality that met the norm, and an absence of ochratoxin A were observed in the totality of the analyzed samples. Low levels of foreign matter, the high value of its aqueous extract and high phenolic compounds content with antioxidant activity allow for the recommendation of the husk of cocoa as raw material for the preparation of infusions.

75 FR 34095 - Application(s) for Duty-Free Entry of Scientific Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

...: University of Minnesota (Dept. of Chemical Engineering and Materials Science), 151 Amundson Hall, 421... Scientific Instruments Pursuant to Section 6(c) of the Educational, Scientific and Cultural Materials... coatings, of very high crystalline quality materials known as complex oxides. A pertinent characteristic of...

Study on electroplating technology of diamond tools for machining hard and brittle materials

NASA Astrophysics Data System (ADS)

Cui, Ying; Chen, Jian Hua; Sun, Li Peng; Wang, Yue

2016-10-01

With the development of the high speed cutting, the ultra-precision machining and ultrasonic vibration technique in processing hard and brittle material , the requirement of cutting tools is becoming higher and higher. As electroplated diamond tools have distinct advantages, such as high adaptability, high durability, long service life and good dimensional stability, the cutting tools are effective and extensive used in grinding hard and brittle materials. In this paper, the coating structure of electroplating diamond tool is described. The electroplating process flow is presented, and the influence of pretreatment on the machining quality is analyzed. Through the experimental research and summary, the reasonable formula of the electrolyte, the electroplating technologic parameters and the suitable sanding method were determined. Meanwhile, the drilling experiment on glass-ceramic shows that the electroplating process can effectively improve the cutting performance of diamond tools. It has laid a good foundation for further improving the quality and efficiency of the machining of hard and brittle materials.

Silicon-Based Optoelectronic Materials, Symposium Held in San Francisco, California on April 12-14, 1993. Materials Research Society Symposium Proceedings, Volume 298

DTIC Science & Technology

1993-12-14

requirements of band structure engineering and superlative crystal quality extend a considerable challenge to the materials scientist / crystal grower...to nearly the same temperature as the signal of the Si substrate, which indicates a comparable exciton binding energy. Even in high quality SiGe-MQWs...5621 (1986) 13. L. Colombo, R. Resta , and S. Baroni, Phys. Rev. B 44, 5572 (1991) 14. G. L. McVay and A. R. DuCharme, Phys. Rev. B 9, 627 (1974) 15. L.C

Synthesis of thin films and materials utilizing a gaseous catalyst

DOEpatents

Morse, Daniel E; Schwenzer, Birgit; Gomm, John R; Roth, Kristian M; Heiken, Brandon; Brutchey, Richard

2013-10-29

A method for the fabrication of nanostructured semiconducting, photoconductive, photovoltaic, optoelectronic and electrical battery thin films and materials at low temperature, with no molecular template and no organic contaminants. High-quality metal oxide semiconductor, photovoltaic and optoelectronic materials can be fabricated with nanometer-scale dimensions and high dopant densities through the use of low-temperature biologically inspired synthesis routes, without the use of any biological or biochemical templates.

Growth of CdZnTe Crystals for Radiation Detector Applications by Directional Solidification

NASA Technical Reports Server (NTRS)

Su, Ching-Hua

2014-01-01

Advances in Cadmium Zinc Telluride (Cd(sub 1-x)Zn(sub x)Te) growth techniques are needed for the production of large-scale arrays of gamma and x-ray astronomy. The research objective is to develop crystal growth recipes and techniques to obtain large, high quality CdZnTe single crystal with reduced defects, such as charge trapping, twinning, and tellurium precipitates, which degrade the performance of CdZnTe and, at the same time, to increase the yield of usable material from the CdZnTe ingot. A low gravity material experiment, "Crystal Growth of Ternary Compound Semiconductors in Low Gravity Environment", will be performed in the Material Science Research Rack (MSRR) on International Space Station (ISS). One section of the flight experiment is the melt growth of CdZnTe ternary compounds. This talk will focus on the ground-based studies on the growth of Cd(sub 0.80)Zn(sub 0.20)Te crystals for radiation detector applications by directional solidification. In this investigation, we have improved the properties that are most critical for the detector applications (electrical properties and crystalline quality): a) Electrical resistivity: use high purity starting materials (with reproducible impurity levels) and controlled Cd over pressure during growth to reproducibly balance the impurity levels and Cd vacancy concentration b) Crystalline quality: use ultra-clean growth ampoule (no wetting after growth), optimized thermal profile and ampoule design, as well as a technique for supercool reduction to growth large single crystal with high crystalline quality

High Power Laser Welding. [of stainless steel and titanium alloy structures

NASA Technical Reports Server (NTRS)

Banas, C. M.

1972-01-01

A review of recent developments in high power, carbon dixoide laser welding is presented. Deep penetration welding in stainless steel to 0.5-in. thick, high speed welding in thin gage rimmed steel and gas shielded welding in Ti-6Al-4V alloy are described. The effects of laser power, power density, focusing optics, gas-shielding techniques, material properties and weld speed on weld quality and penetration are discussed. It is shown that laser welding performance in thin materials is comparable to that of electron beams. It is further shown that high quality welds, as evidenced by NDT, mechanical and metal-lographic tests, can be achieved. The potential of the laser for industrial welding applications is indicated.

High power parallel ultrashort pulse laser processing

NASA Astrophysics Data System (ADS)

Gillner, Arnold; Gretzki, Patrick; Büsing, Lasse

2016-03-01

The class of ultra-short-pulse (USP) laser sources are used, whenever high precession and high quality material processing is demanded. These laser sources deliver pulse duration in the range of ps to fs and are characterized with high peak intensities leading to a direct vaporization of the material with a minimum thermal damage. With the availability of industrial laser source with an average power of up to 1000W, the main challenge consist of the effective energy distribution and disposition. Using lasers with high repetition rates in the MHz region can cause thermal issues like overheating, melt production and low ablation quality. In this paper, we will discuss different approaches for multibeam processing for utilization of high pulse energies. The combination of diffractive optics and conventional galvometer scanner can be used for high throughput laser ablation, but are limited in the optical qualities. We will show which applications can benefit from this hybrid optic and which improvements in productivity are expected. In addition, the optical limitations of the system will be compiled, in order to evaluate the suitability of this approach for any given application.

Choice of Substrate Material for Epitaxial CdTe Solar Cells

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

Song, Tao; Kanevce, Ana; Sites, James R.

2015-06-14

Epitaxial CdTe with high quality, low defect density, and high carrier concentration should in principle yield high-efficiency photovoltaic devices. However, insufficient effort has been given to explore the choice of substrate for high-efficiency epitaxial CdTe solar cells. In this paper, we use numerical simulations to investigate three crystalline substrates: silicon (Si), InSb, and CdTe each substrate material are generally discussed.

Removal of Lattice Imperfections that Impact the Optical Quality of Ti:Sapphire using Advanced Magnetorheological Finishing Techniques

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

Menapace, J A; Schaffers, K I; Bayramian, A J

2007-10-09

Ti:sapphire has become the premier lasing medium material for use in solid-state femtosecond high-peak power laser systems because of its wide wavelength tuning range. With a tuneable range from 680 to 1100 nm, peaking at 800 nm, Ti:sapphire lasing crystals can easily be tuned to the required pump wavelength and provide very high pump brightness due to their good beam quality and high output power of typically several watts. Femtosecond lasers are used for precision cutting and machining of materials ranging from steel to tooth enamel to delicate heart tissue and high explosives. These ultra-short pulses are too brief tomore » transfer heat or shock to the material being cut, which means that cutting, drilling, and machining occur with virtually no damage to surrounding material. Furthermore, these lasers can cut with high precision, making hairline cuts of less than 100 microns in thick materials along a computer-generated path. Extension of laser output to higher energies is limited by the size of the amplification medium. Yields of high quality large diameter crystals have been constrained by lattice distortions that may appear in the boule limiting the usable area from which high quality optics can be harvested. Lattice distortions affect the transmitted wavefront of these optics which ultimately limits the high-end power output and efficiency of the laser system, particularly when operated in multi-pass mode. To make matters even more complicated, Ti:sapphire is extremely hard (Mohs hardness of 9 with diamond being 10) which makes it extremely difficult to accurately polish using conventional methods without subsurface damage or significant wavefront error. In this presentation, we demonstrate for the first time that Magnetorheological finishing (MRF) can be used to compensate for the lattice distortions in Ti:sapphire by perturbing the transmitted wavefront. The advanced MRF techniques developed allow for precise polishing of the optical inverse of lattice distortions with magnitudes of about 70 nm in optical path difference onto one or both of the optical surfaces to produce high quality optics from otherwise unusable Ti:sapphire crystals. The techniques include interferometric, software, and machine modifications to precisely locate and polish sub-millimeter sites onto the optical surfaces that can not be polished into the optics conventionally. This work may allow extension of Ti:sapphire based systems to peak powers well beyond one petawatt.« less

Resource Materials To Support Your Environmental Education Efforts. EE-TIPS (Environmental Education Technical Information Packages).

ERIC Educational Resources Information Center

North American Association for Environmental Education, Troy, OH.

This collection gathers together over 50 high-quality materials to support environmental education (EE) curricula. Because each community has unique environmental and educational needs, the guide includes a broad set of educational materials that can be adapted to a variety of settings. The materials can be used to supplement educational…

Mechanisms of deterioration of nutrients. [freeze drying methods for space flight food

NASA Technical Reports Server (NTRS)

Karel, M.; Flink, J. M.

1974-01-01

Methods are reported by which freeze dried foods of improved quality will be produced. The applicability of theories of flavor retention has been demonstrated for a number of food polymers, both proteins and polysacchardies. Studies on the formation of structures during freeze drying have been continued for emulsified systems. Deterioration of organoleptic quality of freeze dried foods due to high temperature heating has been evaluated and improved procedures developed. The influence of water activity and high temperature on retention of model flavor materials and browning deterioration has been evaluated for model systems and food materials.

Developing a Culture of Readers: Complementary Materials That Engage

ERIC Educational Resources Information Center

Sailors, Misty; Kaambankadzanja, Davie

2017-01-01

Many professionals, including members of the International Literacy Association, are concerned with the lack of reading materials in classrooms across the world. In this paper, the authors present the creation of high-quality, locally produced, complementary reading materials in Malawi, where there are very few children's books and few…

Quality distribution of pallet parts from low-grade lumber

Treesearch

Hollis R. Large; Richard E. Frost

1974-01-01

To produce better pallets, the higher quality parts should be used in the more vulnerable positions in the pallet. To determine the feasibility of doing this, pallet parts cut from commonly used lumber mixes were graded into four quality levels. The distributions obtained indicate that sufficient numbers of high-quality parts can be cut from existing raw material to...

A novel cell line generated using the CRISPR/Cas9 technology as universal quality control material for KRAS G12V mutation testing.

PubMed

Jia, Shiyu; Zhang, Rui; Lin, Guigao; Peng, Rongxue; Gao, Peng; Han, Yanxi; Fu, Yu; Ding, Jiansheng; Wu, Qisheng; Zhang, Kuo; Xie, Jiehong; Li, Jinming

2018-06-01

KRAS mutations are the key indicator for EGFR monoclonal antibody-targeted therapy and acquired drug resistance, and their accurate detection is critical to the clinical decision-making of colorectal cancer. However, no proper quality control material is available for the current detection methods, particularly next-generation sequencing (NGS). The ideal quality control material for NGS needs to provide both the tumor mutation gene and the matched background genomic DNA, which is uncataloged in public databases, to accurately distinguish germline polymorphisms and somatic mutations. We developed a novel KRAS G12V mutant cell line using the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) technique to make up for the deficiencies in existing quality control material and further validated the feasibility of the cell line as quality control material by amplification refractory mutation system (ARMS), Sanger sequencing, digital PCR (dPCR), and NGS. We verified that the edited cell line specifically had the G12V mutation, and the validation results presented a high consistency among the four methods of detection. The three cell lines screened contained the G12V mutation and the mutation allele fractions of G12V-1, G12V-2, and G12V-3 were 52.01%, 82.06%, and 17.29%, respectively. The novel KRAS G12V cell line generated using the CRISPR/Cas9 gene editing system is suitable as a quality control material for all current detection methods and provides a new direction in the development of quality control material. © 2018 Wiley Periodicals, Inc.

Combinatorial materials synthesis and high-throughput screening: an integrated materials chip approach to mapping phase diagrams and discovery and optimization of functional materials.

PubMed

Xiang, X D

Combinatorial materials synthesis methods and high-throughput evaluation techniques have been developed to accelerate the process of materials discovery and optimization and phase-diagram mapping. Analogous to integrated circuit chips, integrated materials chips containing thousands of discrete different compositions or continuous phase diagrams, often in the form of high-quality epitaxial thin films, can be fabricated and screened for interesting properties. Microspot x-ray method, various optical measurement techniques, and a novel evanescent microwave microscope have been used to characterize the structural, optical, magnetic, and electrical properties of samples on the materials chips. These techniques are routinely used to discover/optimize and map phase diagrams of ferroelectric, dielectric, optical, magnetic, and superconducting materials.

Microwave plasma assisted supersonic gas jet deposition of thin film materials

DOEpatents

Schmitt, III, Jerome J.; Halpern, Bret L.

1993-01-01

An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.

Evaluation of cold mixes for winter pothole repair.

DOT National Transportation Integrated Search

1995-01-01

This study was conducted to evaluate the performance of 13 proprietary cold-mix patching materials, 4 of which are currently approved under a Virginia Department of Transportation (VDOT) Special Provision for High Quality Cold Patching Materials. Col...

[Preparation and certification of mussel reference material for organochlorine pesticides and polychlorinated biphenyls using isotope dilution-high resolution mass spectrometry].

PubMed

Lu, Xianbo; Chen, Jiping; Wang, Shuqiu; Zou, Lili; Tian, Yuzeng; Ni, Yuwen; Su, Fan

2012-09-01

A method for the preparation and certification of the reference material of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in mussel tissue is described. The mussel tissue from Dalian Bay was frozen-dried, comminuted, sieved, homogenized, packaged, and sterilized by 60Co radiation sterilization in turn. The certified values for 18 OCPs and 16 PCBs were determined by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) using isotope dilution and internal standard quantitation techniques. The certified values were validated and given based on seven accredited laboratories, and these values are traceable to the SI (international system of units) through gravimetrically prepared standards of established purity and measurement intercomparisons. The certified values of PCBs and OCPs in mussel span 4 orders of magnitude with a relative uncertainty of about 10%. This material is a natural biological material with confirmed good homogeneity and stability, and it was approved as the grade "primary reference material" (GBW10069) in June 2012 in China. This reference material provided necessary quality control products for our country to implement the Stockholm Treaty on the monitoring of persistent organic pollutants (POPs). The material is intended to be used for the method validation and quality control in the determination of OCPs and PCBs in biota samples.

Advanced industrial fluorescence metrology used for qualification of high quality optical materials

NASA Astrophysics Data System (ADS)

Engel, Axel; Becker, Hans-Juergen; Sohr, Oliver; Haspel, Rainer; Rupertus, Volker

2003-11-01

Schott Glas is developing and producing the optical material for various specialized applications in telecommunication, biomedical, optical, and micro lithography technology. The requirements on quality for optical materials are extremely high and still increasing. For example in micro lithography applications the impurities of the material are specified to be in the low ppb range. Usually the impurities in the lower ppb range are determined using analytical methods like LA ICP-MS and Neutron Activation Analysis. On the other hand absorption and laser resistivity of optical material is qualified with optical methods like precision spectral photometers and in-situ transmission measurements having UV lasers. Analytical methods have the drawback that they are time consuming and rather expensive, whereas the sensitivity for the absorption method will not be sufficient to characterize the future needs (coefficient much below 10-3 cm-1). In order to achieve the current and future quality requirements a Jobin Yvon FLUOROLOG 3.22 fluorescence spectrometer is employed to enable fast and precise qualification and analysis. The main advantage of this setup is the combination of highest sensitivity (more than one order of magnitude higher sensitivity that state of the art UV absorption spectroscopy) and fast measurement and evaluation cycles (several minutes compared to several hours necessary for chemical analytics). An overview is given for spectral characteristics and using specified standards. Moreover correlations to the material qualities are shown. In particular we have investigated the elementary fluorescence and absorption of rare earth element impurities as well as defects induced luminescence originated by impurities.

Mass Manufacturing Challenges For CPV Primary And Secondary Optics

NASA Astrophysics Data System (ADS)

Luce, Thomas; Cohen, Joel

2010-10-01

Crucial for the performance and longevity of CPV installations is the efficiency of the optics used. Low production cost and high performance are key for the economical success of a CPV concept. To be able to compete with existing energy sources, proven mass production methods as well as high performance materials have to be employed. The injection molding process is the ideal serial production process capable to deliver at the same time high part quantities, excellent part precision and repeatable part quality at low manufacturing cost. Primary and secondary optics require different materials to be applied. The Pros and Cons of these materials in terms of production properties and achievable part precision will be discussed. We will show quality results for primary Fresnel optics using PMMA and, alternatively Silicone on Glass. For secondary optics we will demonstrate the use of optical silicone lenses widely used for high power LED applications today. Optical grade silicone has an excellent environmental stability even when encountering high energy density levels. The experience of Eschenbach Optik in injection molding silicone optics shows that this material is a very cost competitive alternative for glass secondary optics providing both highest optical performance and precision.

An atomic-scale and high efficiency finishing method of zirconia ceramics by using magnetorheological finishing

NASA Astrophysics Data System (ADS)

Luo, Hu; Guo, Meijian; Yin, Shaohui; Chen, Fengjun; Huang, Shuai; Lu, Ange; Guo, Yuanfan

2018-06-01

Zirconia ceramics is a valuable crucial material for fabricating functional components applied in aerospace, biology, precision machinery, military industry and other fields. However, the properties of its high brittleness and high hardness could seriously reduce its finishing efficiency and surface quality by conventional processing technology. In this work, we present a high efficiency and high-quality finishing process by using magnetorheological finishing (MRF), which employs the permanent magnetic yoke with straight air gap as excitation unit. The sub-nanoscale surface roughness and damage free surface can be obtained after magnetorheological finishing. The XRD results and SEM morphologies confirmed that the mechanical shear removal with ductile modes are the dominant material removal mechanism for the magnetorheological finishing of zirconia ceramic. With the developed experimental apparatus, the effects of workpiece speed, trough speed and work gap on material removal rate and surface roughness were systematically investigated. Zirconia ceramics finished to ultra-smooth surface with surface roughness less than Ra 1 nm was repeatedly achieved during the parametric experiments. Additionally, the highest material removal rate exceeded 1 mg/min when using diamond as an abrasive particle. Magnetorheological finishing promises to be an adaptable and efficient method for zirconia ceramics finishing.

Effect of nano packaging on preservation quality of Nanjing 9108 rice variety at high temperature and humidity.

PubMed

Wang, Fan; Hu, Qiuhui; Mugambi Mariga, Alfred; Cao, Chongjiang; Yang, Wenjian

2018-01-15

A nano packaging material containing nano Ag, nano TiO 2 , nano attapulgite and SiO 2 was prepared, and its impact on quality of Nanjing 9108 rice at 37°C and 85% relative humidity was studied. Effects of the packaging on ambient gases and chromatic aberration of rice were determined. Moreover, oxidation level, molds growth and flavor of rice were also analyzed. Results showed that nano packaging material had antimicrobial effects and maintained low O 2 and high CO 2 content in the packages. The packages thereby inhibited the growth of molds and the production of fatty acids, restrained the increase of lipase activity, and reduced the oxidation of fats and proteins. As a result, the production of yellow and white-belly rice were inhibited. Furthermore, the color and flavor of rice were maintained. Therefore, the nano-packing material could be applied for preservation of rice to improve preservation quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Material quality frontiers of MOVPE grown AlGaAs for minority carrier devices

NASA Astrophysics Data System (ADS)

Heckelmann, S.; Lackner, D.; Dimroth, F.; Bett, A. W.

2017-04-01

In this study, secondary ion mass spectroscopy of oxygen, deep level transient spectroscopy and power dependent relative photoluminescence are compared regarding their ability to resolve differences in AlxGa1-xAs material quality. AlxGa1-xAs samples grown with two different trimethylaluminum sources showing low and high levels of oxygen contamination are compared. As tested in the growth of minority carrier devices, i.e. AlxGa1-xAs solar cells, the two precursors clearly lead to different device characteristics. It is shown that secondary ion mass spectroscopy could not resolve the difference in oxygen concentration, whereas deep level transient spectroscopy and photoluminescence based measurements indicate the influence of the precursor oxygen level on the material quality.

Epitaxial Growth of Molecular Crystals on van der Waals Substrates for High-Performance Organic Electronics

DTIC Science & Technology

2014-01-01

Taniguchi Advanced Materials Laboratory National Institute for Materials Science 1–1 Namiki, Tsukuba , 305–0044 , Japan Prof. J. Hone Department...of Mechanical Engineering Columbia University New York , NY , 10027 , USA DOI : 10.1002/adma.201304973 The growth of high-quality organic...vdW heterostructures, combined with recent progress on large-area growth of layered materials , [ 6,7 ] provides new opportunities for the scalable

Method and apparatus for improving the quality and efficiency of ultrashort-pulse laser machining

DOEpatents

Stuart, Brent C.; Nguyen, Hoang T.; Perry, Michael D.

2001-01-01

A method and apparatus for improving the quality and efficiency of machining of materials with laser pulse durations shorter than 100 picoseconds by orienting and maintaining the polarization of the laser light such that the electric field vector is perpendicular relative to the edges of the material being processed. Its use is any machining operation requiring remote delivery and/or high precision with minimal collateral dames.

[Research on the Application of Lean Management in Medical Consumables Material Logistics Management].

PubMed

Yang, Chai; Zhang, Wei; Gu, Wei; Shen, Aizong

2016-11-01

Solve the problems of high cost, low utilization rate of resources, low medical care quality problem in medical consumables material logistics management for scientific of medical consumables management. Analysis of the problems existing in the domestic medical consumables material logistics management in hospital, based on lean management method, SPD(Supply, Processing, Distribution) for specific applications, combined HBOS(Hospital Business Operation System), HIS (Hospital Information System) system for medical consumables material management. Achieve the lean management in medical consumables material purchase, warehouse construction, push, clinical use and retrospect. Lean management in medical consumables material can effectively control the cost in logistics management, optimize the alocation of resources, liberate unnecessary time of medical staff, improve the quality of medical care. It is a scientific management method.

Advanced Power Electronics Components

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2004-01-01

This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

New infrared transmitting material via inverse vulcanization of elemental sulfur to prepare high refractive index polymers.

PubMed

Griebel, Jared J; Namnabat, Soha; Kim, Eui Tae; Himmelhuber, Roland; Moronta, Dominic H; Chung, Woo Jin; Simmonds, Adam G; Kim, Kyung-Jo; van der Laan, John; Nguyen, Ngoc A; Dereniak, Eustace L; Mackay, Michael E; Char, Kookheon; Glass, Richard S; Norwood, Robert A; Pyun, Jeffrey

2014-05-21

Polymers for IR imaging: The preparation of high refractive index polymers (n = 1.75 to 1.86) via the inverse vulcanization of elemental sulfur is reported. High quality imaging in the near (1.5 μm) and mid-IR (3-5 μm) regions using high refractive index polymeric lenses from these sulfur materials was demonstrated. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High quality factor single-crystal diamond mechanical resonators

NASA Astrophysics Data System (ADS)

Ovartchaiyapong, P.; Pascal, L. M. A.; Myers, B. A.; Lauria, P.; Bleszynski Jayich, A. C.

2012-10-01

Single-crystal diamond is a promising material for microelectromechanical systems (MEMs) because of its low mechanical loss, compatibility with extreme environments, and built-in interface to high-quality spin centers. But its use has been limited by challenges in processing and growth. We demonstrate a wafer bonding-based technique to form diamond on insulator, from which we make single-crystal diamond micromechanical resonators with mechanical quality factors as high as 338 000 at room temperature. Variable temperature measurements down to 10 K reveal a nonmonotonic dependence of quality factor on temperature. These resonators enable integration of single-crystal diamond into MEMs technology for classical and quantum applications.

Development of an external ceramic insulation for the space shuttle orbiter. Part 3: Development of stabilized aluminum phosphate fibers

NASA Technical Reports Server (NTRS)

Ormiston, T.; Tanzilli, R. A.

1973-01-01

The development of reusable surface insulation materials that are thermal shock resistant and highly refractory is discussed. A stabilized, high-cristobalite, aluminum orthophosphate fiber was developed and found to possess the desired qualities. The application of such a material to heat shielding for space shuttles is examined.

Material quality development during the automated tow placement process

NASA Astrophysics Data System (ADS)

Tierney, John Joseph

Automated tow placement (ATP) of thermoplastic composites builds on the existing industrial base for equipment, robotics and kinematic placement of material with the aim of further cost reduction by eliminating the autoclave entirely. During ATP processing, thermoplastic composite tows are deposited on a preconsolidated substrate at rates ranging from 10--100mm/s and consolidated using the localized application of heat and pressure by a tow placement head mounted on a robot. The process is highly non-isothermal subjecting the material to multiple heating and cooling rates approaching 1000°C/sec. The requirement for the ATP process is to achieve the same quality in seconds (low void content, full translation of mechanical properties and degree of bonding and minimal warpage) as the autoclave process achieves in hours. The scientific challenge was to first understand and then model the relationships between processing, material response, microstructure and quality. The important phenomena affecting quality investigated in this study include a steady state heat transfer simulation, consolidation and deconsolidation (void dynamics), intimate contact and polymer interdiffusion (degree of bonding/mechanical properties) and residual stress and warpage (crystallization and viscoelastic response). A fundamental understanding of the role of materials related to these mechanisms and their relationship to final quality is developed and applied towards a method of process control and optimization.

The influence of DNA degradation in formalin-fixed, paraffin-embedded (FFPE) tissue on locus-specific methylation assessment by MS-HRM.

PubMed

Daugaard, Iben; Kjeldsen, Tina E; Hager, Henrik; Hansen, Lise Lotte; Wojdacz, Tomasz K

2015-12-01

Readily accessible formalin-fixed paraffin embedded (FFPE) tissues are a highly valuable source of genetic material for molecular analyses in both research and in vitro diagnostics but frequently genetic material in those samples is highly degraded. With locus-specific methylation changes being widely investigated for use as biomarkers in various aspects of clinical disease management, we aimed to evaluate to what extent standard laboratory procedures can approximate the quality of the DNA extracted from FFPE samples prior to methylation analyses. DNA quality in 107 FFPE non-small cell lung cancer (NSCLC) samples was evaluated using spectrophotometry and gel electrophoresis. Subsequently, the quality assessment results were correlated with the results of locus specific methylation assessment with methylation sensitive high resolution melting (MS-HRM). The correlation of template quality with PCR amplification performance and HRM based methylation detection indicated a significant influence of DNA quality on PCR amplification but not on methylation assessment. In conclusion, standard laboratory procedures fairly well approximate DNA degradation of FFPE samples and DNA degradation does not seem to considerably affect locus-specific methylation assessment by MS-HRM. Copyright © 2015 Elsevier Inc. All rights reserved.

Creating Printed Materials for Mathematics with a Macintosh Computer.

ERIC Educational Resources Information Center

Mahler, Philip

This document gives instructions on how to use a Macintosh computer to create printed materials for mathematics. A Macintosh computer, Microsoft Word, and objected-oriented (Draw-type) art program, and a function-graphing program are capable of producing high quality printed instructional materials for mathematics. Word 5.1 has an equation editor…

Highly controllable ICP etching of GaAs based materials for grating fabrication

NASA Astrophysics Data System (ADS)

Weibin, Qiu; Jiaxian, Wang

2012-02-01

Highly controllable ICP etching of GaAs based materials with SiCl4/Ar plasma is investigated. A slow etching rate of 13 nm/min was achieved with RF1 D 10 W, RF2 D 20 W and a high ratio of Ar to SiCl4 flow. First order gratings with 25 nm depth and 140 nm period were fabricated with the optimal parameters. AFM analysis indicated that the RMS roughness over a 10 × 10 μm2 area was 0.3 nm, which is smooth enough to regrow high quality materials for devices.

High-definition micropatterning method for hard, stiff and brittle polymers.

PubMed

Zhao, Yiping; Truckenmuller, Roman; Levers, Marloes; Hua, Wei-Shu; de Boer, Jan; Papenburg, Bernke

2017-02-01

Polystyrene (PS) is the most commonly used material in cell culture devices, such as Petri dishes, culture flasks and well plates. Micropatterning of cell culture substrates can significantly affect cell-material interactions leading to an increasing interest in the fabrication of topographically micro-structured PS surfaces. However, the high stiffness combined with brittleness of PS (elastic modulus 3-3.5GPa) makes high-quality patterning into PS difficult when standard hard molds, e.g. silicon and nickel, are used as templates. A new and robust scheme for easy processing of large-area high-density micro-patterning into PS film is established using nanoimprinting lithography and standard hot embossing techniques. Including an extra step through an intermediate PDMS mold alone does not result in faithful replication of the large area, high-density micropattern into PS. Here, we developed an approach using an additional intermediate mold out of OrmoStamp, which allows for high-quality and large-area micro-patterning into PS. OrmoStamp was originally developed for UV nanoimprint applications; this work demonstrates for the first time that OrmoStamp is a highly adequate material for micro-patterning of PS through hot embossing. Our proposed processing method achieves high-quality replication of micropatterns in PS, incorporating features with high aspect ratio (4:1, height:width), high density, and over a large pattern area. The proposed scheme can easily be adapted for other large-area and high-density micropatterns of PS, as well as other stiff and brittle polymers. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact compaction of a granular material

DOE PAGES

Fenton, Gregg; Asay, Blaine; Dalton, Devon

2015-05-19

The dynamic behavior of granular materials has importance to a variety of engineering applications. Structural seismic coupling, planetary science, and earth penetration mechanics, are just a few of the application areas. Although the mechanical behavior of granular materials of various types have been studied extensively for several decades, the dynamic behavior of such materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This study will describe how an instrumented plunger impact system can be used to measure pressure-density relationships for model materials at high and controlled strain rates and subsequentlymore » used for computational modeling.« less

Control of sinter quality for blast furnaces of SAIL through characterization of high temperature properties

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

Mishra, U.N.; Thakur, B.; Mediratta, S.R.

1996-12-31

Quality of blast furnace (BF) burden materials and their performance inside the furnace have attracted increased importance worldwide. High productivity, low fuel rate and stable operation of BF can be achieved by suitably controlling the quality of input materials particularly that of sinter which is the main constituent of the burden. Reduction Degradation Index (RDI), Reducibility Index (RI) and Softening-melting characteristics are some of the quality indicators of sinter. The effect of chemical composition of sinter in the ranges of CaO/SiO{sub 2} 1.4--2.0, FeO 4.0--8.0, Al{sub 2}O{sub 3} 1.3--2.0 and MgO 1.2--2.0 on the above mentioned properties have been reportedmore » in literature. Due to the peculiarity of Indian raw materials, i.e., high ash content of coke and high Al{sub 2}O{sub 3} content of iron ore, the sinter composition varies over a wide range of CaO/SiO{sub 2} 2.0--2.5, FeO 8--11%, Al{sub 2}O{sub 3} 2--4% and MgO 2--5% in different plants of SAIL. This paper discusses the effect of above constituents in higher ranges as compared to earlier study on RDI, RI and Softening-melting properties so that sinter composition can be optimized for achieving desirable properties for better BF performance.« less

Wire EDM for Refractory Materials

NASA Technical Reports Server (NTRS)

Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

1982-01-01

In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

Microwave plasma assisted supersonic gas jet deposition of thin film materials

DOEpatents

Schmitt, J.J. III; Halpern, B.L.

1993-10-26

An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures. 5 figures.

Amorphization induced by focused ion beam milling in metallic and electronic materials.

PubMed

Huh, Yoon; Hong, Ki Jung; Shin, Kwang Soo

2013-08-01

Focused ion beam (FIB) milling using high-energy gallium ions is widely used in the preparation of specimens for transmission electron microscopy (TEM). However, the energetic ion beam induces amorphization on the edge of specimens during milling, resulting in a mischievous influence on the clearness of high-quality transmission electron micrographs. In this work, the amorphization induced by the FIB milling was investigated by TEM for three kinds of materials, metallic materials in bulk shape, and semiconductive and electronic ceramic materials as a substrate for the deposition of thin films.

Changes in the Mg profile and in dislocations induced by high temperature annealing of blue LEDs

NASA Astrophysics Data System (ADS)

Meneghini, M.; Trivellin, N.; Berti, M.; Cesca, T.; Gasparotto, A.; Vinattieri, A.; Bogani, F.; Zhu, D.; Humphreys, C. J.; Meneghesso, G.; Zanoni, E.

2013-03-01

The efficiency of the injection and recombination processes in InGaN/GaN LEDs is governed by the properties of the active region of the devices, which strongly depend on the conditions used for the growth of the epitaxial material. To improve device quality, it is very important to understand how the high temperatures used during the growth process can modify the quality of the epitaxial material. With this paper we present a study of the modifications in the properties of InGaN/GaN LED structures induced by high temperature annealing: thermal stress tests were carried out at 900 °C, in nitrogen atmosphere, on selected samples. The efficiency and the recombination dynamics were evaluated by photoluminescence measurements (both integrated and time-resolved), while the properties of the epitaxial material were studied by Secondary Ion Mass Spectroscopy (SIMS) and Rutherford Backscattering (RBS) channeling measurements. Results indicate that exposure to high temperatures may lead to: (i) a significant increase in the photoluminescence efficiency of the devices; (ii) a decrease in the parasitic emission bands located between 380 nm and 400 nm; (iii) an increase in carrier lifetime, as detected by time-resolved photoluminescence measurements. The increase in device efficiency is tentatively ascribed to an improvement in the crystallographic quality of the samples.

77 FR 33231 - Notice of Application for Proposed Withdrawal Extension and Opportunity for Public Meeting; Alaska

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... United States mining laws, to aid in making high quality rock and gravel from the Spencer Glacier... Material Site in order to make high quality rock and gravel available to nearby communities for private and..., license, or permit or governing the disposal of the mineral or vegetative resources other than under the...

The use of ion beam cleaning to obtain high quality cold welds with minimal deformation

NASA Technical Reports Server (NTRS)

Sater, B. L.; Moore, T. J.

1978-01-01

This paper describes a variation of cold welding which utilizes an ion beam to clean mating surfaces prior to joining in a vacuum environment. High quality solid state welds were produced with minimal deformation. Due to experimental fixture limitation in applying pressure work has been limited to a few low yield strength materials.

Methods for producing monodispersed particles of barium titanate

DOEpatents

Hu, Zhong-Cheng

2001-01-01

The present invention is a low-temperature controlled method for producing high-quality, ultrafine monodispersed nanocrystalline microsphere powders of barium titanate and other pure or composite oxide materials having particles ranging from nanosized to micronsized particles. The method of the subject invention comprises a two-stage process. The first stage produces high quality monodispersed hydrous titania microsphere particles prepared by homogeneous precipitation via dielectric tuning in alcohol-water mixed solutions of inorganic salts. Titanium tetrachloride is used as an inorganic salt precursor material. The second stage converts the pure hydrous titania microsphere particles into crystalline barium titanate microsphere powders via low-temperature, hydrothermal reactions.

Novel technique of making thin target foil of high density material via rolling method

NASA Astrophysics Data System (ADS)

Gupta, C. K.; Rohilla, Aman; Singh, R. P.; Singh, Gurjot; Chamoli, S. K.

2018-05-01

The conventional rolling method fails to yield good quality thin foils of thicknesses less than 2 mg/cm2 for high density materials with Z ≥ 70 (e.g. gold, lead). A special and improved technique has been developed to obtain such low thickness good quality gold foils by rolling method. Using this technique thin gold foils of thickness in the range of 0.850-2.5 mg/cm2 were obtained in the present work. By making use of alcohol during rolling, foils of thickness 1 mg/cm2 can be obtained in shorter time with less effort.

Electroforming of optical tooling in high-strength Ni-Co alloy

NASA Astrophysics Data System (ADS)

Stein, Berl

2003-05-01

Plastic optics are often mass produced by injection, compression or injection-compression molding. Optical quality molds can be directly machined in appropriate materials (tool steels, electroless nickel, aluminum, etc.), but much greater cost efficiency can be achieved with electroformed modl inserts. Traditionally, electroforming of optical quality mold inserts has been carried out in nickel, a material much softer than tool steels which, when hardened to 45 - 50 HRc usually exhibit high wear resistance and long service life (hundreds of thousands of impressions per mold). Because of their low hardness (< 20 HRc), nickel molds can produce only tens of thousands of parts before they are scrapped due to wear or accidental damage. This drawback prevented their wider usage in general plastic and optical mold making. Recently, NiCoForm has developed a proprietary Ni-CO electroforming bath combining the high strength and wear resistance of the alloy with the low stress and high replication fidelity typical of pure nickel electroforming. This paper will outline the approach to electroforming of optical quality tooling in low stress, high strength Ni-Co alloy and present several examples of electroformed NiColoy mold inserts.

Accelerated loading evaluation of foamed asphalt treated RAP layers in pavement performance.

DOT National Transportation Integrated Search

2013-12-01

Due to a lack of locally produced high-quality stone base materials, the Louisiana Department of Transportation and Development (LADOTD) is : continuously seeking alternative base materials in lieu of crushed stones used for roadway construction. Thi...

High peak power solid-state laser for micromachining of hard materials

NASA Astrophysics Data System (ADS)

Herbst, Ludolf; Quitter, John P.; Ray, Gregory M.; Kuntze, Thomas; Wiessner, Alexander O.; Govorkov, Sergei V.; Heglin, Mike

2003-06-01

Laser micromachining has become a key enabling technology in the ever-continuing trend of miniaturization in microelectronics, micro-optics, and micromechanics. New applications have become commercially viable due to the emergence of innovative laser sources, such as diode pumped solid-state lasers (DPSSL), and the progress in processing technology. Examples of industrial applications are laser-drilled micro-injection nozzles for highly efficient automobile engines, or manufacturing of complex spinnerets for production of synthetic fibers. The unique advantages of laser-based techniques stem from their ability to produce high aspect ratio holes, while yielding low heat affected zones with exceptional surface quality, roundness and taper tolerances. Additionally, the ability to drill blind holes and slots in very hard materials such as diamond, silicon, sapphire, ceramics and steel is of great interest for many applications in microelectronics, semiconductor and automotive industry. This kind of high quality, high aspect ratio micromachining requires high peak power and short pulse durations.

Characteristics of iron corrosion scales and water quality variations in drinking water distribution systems of different pipe materials.

PubMed

Li, Manjie; Liu, Zhaowei; Chen, Yongcan; Hai, Yang

2016-12-01

Interaction between old, corroded iron pipe surfaces and bulk water is crucial to the water quality protection in drinking water distribution systems (WDS). Iron released from corrosion products will deteriorate water quality and lead to red water. This study attempted to understand the effects of pipe materials on corrosion scale characteristics and water quality variations in WDS. A more than 20-year-old hybrid pipe section assembled of unlined cast iron pipe (UCIP) and galvanized iron pipe (GIP) was selected to investigate physico-chemical characteristics of corrosion scales and their effects on water quality variations. Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Inductively Coupled Plasma (ICP) and X-ray Diffraction (XRD) were used to analyze micromorphology and chemical composition of corrosion scales. In bench testing, water quality parameters, such as pH, dissolved oxygen (DO), oxidation reduction potential (ORP), alkalinity, conductivity, turbidity, color, Fe 2+ , Fe 3+ and Zn 2+ , were determined. Scale analysis and bench-scale testing results demonstrated a significant effect of pipe materials on scale characteristics and thereby water quality variations in WDS. Characteristics of corrosion scales sampled from different pipe segments show obvious differences, both in physical and chemical aspects. Corrosion scales were found highly amorphous. Thanks to the protection of zinc coatings, GIP system was identified as the best water quality stability, in spite of high zinc release potential. It is deduced that the complicated composition of corrosion scales and structural break by the weld result in the diminished water quality stability in HP system. Measurement results showed that iron is released mainly in ferric particulate form. Copyright © 2016 Elsevier Ltd. All rights reserved.

Indoor Air Quality in 24 California Residences Designed as High-Performance Homes

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

Less, Brennan; Mullen, Nasim; Singer, Brett

2015-07-01

Today’s high performance green homes are reaching previously unheard of levels of airtightness and are using new materials, technologies and strategies, whose impacts on Indoor Air Quality (IAQ) cannot be fully anticipated from prior studies. This research study used pollutant measurements, home inspections, diagnostic testing and occupant surveys to assess IAQ in 24 new or deeply retrofitted homes designed to be high performance green buildings in California.

Effects of packaging materials on storage quality of peanut kernels

PubMed Central

Fu, Xiaoji; Xing, Shengping; Xiong, Huiwei; Min, Hua; Zhu, Xuejing; He, Jialin; Mu, Honglei

2018-01-01

In order to obtain optimum packaging materials for peanut kernels, the effects of four types of packaging materials on peanut storage quality (coat color, acid value, germination rate, relative damage, and prevention of aflatoxin contamination) were examined. The results showed that packaging materials had a major influence on peanut storage quality indexes. The color of the peanut seed coat packaged in the polyester/aluminum/polyamide/polyethylene (PET/AL/PA/PE) composite film bag did not change significantly during the storage period. Color deterioration was slower with polyamide/polyethylene (PA/PE) packaging materials than with polyethylene (PE) film bags and was slower in PE bags than in the woven bags. The use of PET/AL/PA/PE and PA/PE bags maintained peanut quality and freshness for more than one year and both package types resulted in better germination rates. There were significant differences between the four types of packaging materials in terms of controlling insect pests. The peanuts packaged in the highly permeable woven bags suffered serious invasion from insect pests, while both PET/AL/PA/PE and PA/PE bags effectively prevented insect infection. Peanuts stored in PET/AL/PA/PE and PA/PE bags were also better at preventing and controlling aflatoxin contamination. PMID:29518085

Nickel-cadmium cells

NASA Technical Reports Server (NTRS)

Rubin, E. J.; Turchan, M. J.

1974-01-01

A high energy density nickel cadmium cell of aerospace quality was designed. The approach used was to utilize manufacturing techniques which produce highly uniform and controlled starting materials in addition to improvements in the overall design. Parameters controlling the production of plaque and both positive and negative plate were studied. Quantities of these materials were produced and prototype cells were assembled to test the proposed design.

High quality InP-on-Si for solar cell applications

NASA Technical Reports Server (NTRS)

Shellenbarger, Zane A.; Goodwin, Thomas A.; Collins, Sandra R.; Dinetta, Louis C.

1994-01-01

InP on Si solar cells combine the low-cost and high-strength of Si with the high efficiency and radiation tolerance of InP. The main obstacle in the growth of single crystal InP-on-Si is the high residual strain and high dislocation density of the heteroepitaxial InP films. The dislocations result from the large differences in lattice constant and thermal expansion mismatch of InP and Si. Adjusting the size and geometry of the growth area is one possible method of addressing this problem. In this work, we conducted a material quality study of liquid phase epitaxy overgrowth layers on selective area InP grown by a proprietary vapor phase epitaxy technique on Si. The relationship between growth area and dislocation density was quantified using etch pit density measurements. Material quality of the InP on Si improved both with reduced growth area and increased aspect ratio (length/width) of the selective area. Areas with etch pit density as low as 1.6 x 10(exp 4) sq cm were obtained. Assuming dislocation density is an order of magnitude greater than etch pit density, solar cells made with this material could achieve the maximum theoretical efficiency of 23% at AMO. Etch pit density dependence on the orientation of the selective areas on the substrate was also studied.

Study on boring hardened materials dryly by ultrasonic vibration cutter

NASA Astrophysics Data System (ADS)

Zhang, Jiangzhong; Zhang, Heng; Zhang, Yue

2011-05-01

It has been one of the difficulties that high-precision hole on hardened materials is machined. The supersonic vibration boring acoustic system in the lathe in which supersonic wave energy is applied on tool is introduced to create pulse power on the cutting process. The separation vibration cutting is achieved by the pulse force. The comparative tests on boring accuracy and surface quality are carried. The quality of surface machined by this method is compared to that by grinding. This cutting is the green cutting. The boring process system is stability. Under the condition that the cutting speed is less than or equal to 1/3 the tool vibration speed, the cutting force is pulse force and the Cutting energy is of high concentration in time, space and direction. The pulse energy effects on the cutting unit in less than one ten-thousandth second. Traditional cutting of irregular movement elastic compression are eliminated. The cutting force is greatly reduced. The cutting temperature is at room temperature. The tool life is greatly increased. Shape precision and surface quality is greatly improved. The regulations of the ultrasonic vibration boring dry cutting of hardened material are also summarized. The test results show that the ultrasonic vibration cutting tool boring is of very superior cutting mechanism and is a high-precision deep-hole machining of hardened materials, efficient cutting methods.

Identification of High Performance, Low Environmental Impact Materials and Processes Using Systematic Substitution (SyS)

NASA Technical Reports Server (NTRS)

Dhooge, P. M.; Nimitz, J. S.

2001-01-01

Process analysis can identify opportunities for efficiency improvement including cost reduction, increased safety, improved quality, and decreased environmental impact. A thorough, systematic approach to materials and process selection is valuable in any analysis. New operations and facilities design offer the best opportunities for proactive cost reduction and environmental improvement, but existing operations and facilities can also benefit greatly. Materials and processes that have been used for many years may be sources of excessive resource use, waste generation, pollution, and cost burden that should be replaced. Operational and purchasing personnel may not recognize some materials and processes as problems. Reasons for materials or process replacement may include quality and efficiency improvements, excessive resource use and waste generation, materials and operational costs, safety (flammability or toxicity), pollution prevention, compatibility with new processes or materials, and new or anticipated regulations.

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.

High quality-factor fano metasurface comprising a single resonator unit cell

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

Sinclair, Michael B.; Warne, Larry K.; Basilio, Lorena I.

A new monolithic resonator metasurface design achieves ultra-high Q-factors while using only one resonator per unit cell. The metasurface relies on breaking the symmetry of otherwise highly symmetric resonators to induce intra-resonator mixing of bright and dark modes (rather than inter-resonator couplings), and is scalable from the near-infrared to radio frequencies and can be easily implemented in dielectric materials. The resulting high-quality-factor Fano metasurface can be used in many sensing, spectral filtering, and modulation applications.

WE-EF-207-09: Single-Scan Dual-Energy CT Using Primary Modulation

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

Petrongolo, M; Zhu, L

Purpose: Compared with conventional CT, dual energy CT (DECT) provides better material differentiation but requires projection data with two different effective x-ray spectra. Current DECT scanners use either a two-scan setting or costly imaging components, which are not feasible or available on open-gantry cone-beam CT systems. We propose a hardware-based method which utilizes primary modulation to enable single-scan DECT on a conventional CT scanner. The CT imaging geometry of primary modulation is identical to that used in our previous method for scatter removal, making it possible for future combination with effective scatter correction on the same CT scanner. Methods: Wemore » insert an attenuation sheet with a spatially-varying pattern - primary modulator-between the x-ray source and the imaged object. During the CT scan, the modulator selectively hardens the x-ray beam at specific detector locations. Thus, the proposed method simultaneously acquires high and low energy data. High and low energy CT images are then reconstructed from projections with missing data via an iterative CT reconstruction algorithm with gradient weighting. Proof-of-concept studies are performed using a copper modulator on a cone-beam CT system. Results: Our preliminary results on the Catphan(c) 600 phantom indicate that the proposed method for single-scan DECT is able to successfully generate high-quality high and low energy CT images and distinguish different materials through basis material decomposition. By applying correction algorithms and using all of the acquired projection data, we can reconstruct a single CT image of comparable image quality to conventional CT images, i.e., without primary modulation. Conclusion: This work shows great promise in using a primary modulator to perform high-quality single-scan DECT imaging. Future studies will test method performance on anthropomorphic phantoms and perform quantitative analyses on image qualities and DECT decomposition accuracy. We will use simulations to optimize the modulator material and geometry parameters.« less

Earth Day in the Classroom: Mathematics and Science Materials and Resources for Teachers.

ERIC Educational Resources Information Center

Crow, Tracy, Ed.

1995-01-01

The 25th anniversary of Earth Day is 1995. This issue highlights useful, high quality educational materials and other resources that can be used to discuss environmental issues in the classroom. Activities, resources, and teaching materials in this Earth Day issue include: ATLAS 1: Studying Mysteries in the Earth's Atmosphere; Completing the…

Exact Tuning of High-Q Optical Microresonators by Use of UV

NASA Technical Reports Server (NTRS)

Savchankov, Anaotliy; Maleki, Lute; Iltchenko, Vladimir; Handley, Timothy

2006-01-01

In one of several alternative approaches to the design and fabrication of a "whispering-gallery" optical microresonator of high resonance quality (high Q), the index of refraction of the resonator material and, hence, the resonance frequencies. In this approach, a microresonator structure is prepared by forming it from an ultraviolet-sensitive material. Then the structure is subjected to controlled exposure to UV light while its resonance frequencies are monitored.

Deterministic Coupling of Quantum Emitters in 2D Materials to Plasmonic Nanocavity Arrays.

PubMed

Tran, Toan Trong; Wang, Danqing; Xu, Zai-Quan; Yang, Ankun; Toth, Milos; Odom, Teri W; Aharonovich, Igor

2017-04-12

Quantum emitters in two-dimensional materials are promising candidates for studies of light-matter interaction and next generation, integrated on-chip quantum nanophotonics. However, the realization of integrated nanophotonic systems requires the coupling of emitters to optical cavities and resonators. In this work, we demonstrate hybrid systems in which quantum emitters in 2D hexagonal boron nitride (hBN) are deterministically coupled to high-quality plasmonic nanocavity arrays. The plasmonic nanoparticle arrays offer a high-quality, low-loss cavity in the same spectral range as the quantum emitters in hBN. The coupled emitters exhibit enhanced emission rates and reduced fluorescence lifetimes, consistent with Purcell enhancement in the weak coupling regime. Our results provide the foundation for a versatile approach for achieving scalable, integrated hybrid systems based on low-loss plasmonic nanoparticle arrays and 2D materials.

MOCVD Growth and Characterization of n-type Zinc Oxide Thin Films

NASA Astrophysics Data System (ADS)

Ben-Yaacov, Tammy

In the past decade, there has been widespread effort in the development of zinc oxide as a II-V1 semiconductor material. ZnO has potential advantages in optoelectronip device applications due to its unique electrical and optical properties. What stands out among these properties is its wide direct bandgap of 3.37 eV and its high electrical conductivity and transparency in the visible and near-UV regions of the spectrum. ZnO can be grown heteroepitaxially on GaN under near lattice-matched conditions and homoepitaxially as well, as high-quality bulk ZnO substrates are commercially available. This dissertation focuses on the development of the growth of high-quality, single crystal n-type ZnO films, control of n-type conductivity, as well as its application as a transparent contact material in GaN-based devices. The first part of this dissertation is an extensive heteroepitaxial and homoepitaxial growth study presenting the properties of ZnO(0001) layers grown on GaN(0001) templates and ZnO(0001) substrates. We show that deposition on GaN requires a two-step growth technique involving the growth of a low temperature nucleation layer before growing a high temperature epitaxial layer in order to obtain smooth ZnO films with excellent crystal quality and step-flow surface morphology. We obtained homoepitaxial ZnO(0001) films of structural quality and surface morphology that is comparable to the as-received substrates, and showed that a high growth temperature (≥1000°C) is needed in order to achieve step-flow growth mode. We performed n-type doping experiments, and established the conditions for which Indium effectively controls the n-type conductivity of ZnO films grown on GaN(0001) templates. A peak carrier concentration of 3.22x 10 19cm-3 and minimum sheet resistance of 97 O/square was achieved, while simultaneously maintaining good morphology and crystal quality. Finally, we present In-doped ZnO films implemented as p-contacts for GaN-based solar cells and LEDs, and we investigate the n-ZnO/p-GaN interface. We show that ZnO has potential as an effective p-contact for these devices, and determine properties that still need improvement in order for ZnO to compete with other contact materials. We also compare the device performance to metal-contacted devices. In summary, this thesis describes the growth of ZnO(0001) films by MOCVD, the progress in developing ZnO material with excellent surface morphology, high crystal quality, and controllable n-type doping, as well as its application to GaN-based optoelectronic devices as a p-contact material.

Principles of gas phase processing of ceramics during combustion

NASA Technical Reports Server (NTRS)

Zachariah, Michael R.

1993-01-01

In recent years, ceramic materials have found applications in an increasingly wider range of industrial processes, where their unique mechanical, electrical and optical properties are exploited. Ceramics are especially useful for applications in high temperature, corrosive environments, which impose particularly stringent requirements on mechanical reliability. One approach to provide such materials is the manufacture of submicron (and more recently nanometer scale) particles, which may subsequently be sintered to produce a material with extremely high mechanical integrity. However, high quality ceramic materials can only be obtained if particles of known size, polydispersity, shape and chemical purity can be produced consistently, under well controlled conditions. These requirements are the fundamental driving force for the renewed interest in studying particle formation and growth of such materials.

Electrode/Dielectric Strip For High-Energy-Density Capacitor

NASA Technical Reports Server (NTRS)

Yen, Shiao-Ping S.

1994-01-01

Improved unitary electrode/dielectric strip serves as winding in high-energy-density capacitor in pulsed power supply. Offers combination of qualities essential for high energy density: high permittivity of dielectric layers, thinness, and high resistance to breakdown of dielectric at high electric fields. Capacitors with strip material not impregnated with liquid.

Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication.

PubMed

Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

2017-02-01

In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80-100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

The efficiency of home composting programmes and compost quality.

PubMed

Vázquez, M A; Soto, M

2017-06-01

The efficiency of home composting programmes and the quality of the produced compost was evaluated in eight rural areas carrying out home composting programmes (up to 880 composting bins) for all household biowaste including meat and fish leftovers. Efficiency was analysed in terms of reduction of organic waste collected by the municipal services. An efficiency of 77% on average was obtained, corresponding to a composting rate of 126kg/person·year of biowaste (or 380kg/composter·year). Compost quality was determined for a total of 90 composting bins. The operation of composting bins by users was successful, as indicated by a low C/N ratio (10-15), low inappropriate materials (or physical contaminant materials, mean of 0.27±0.44% dry matter), low heavy metal content (94% of samples met required standards for agricultural use) and high nutrient content (2.1% N, 0.6% P, 2.5% K, 0.7% Mg and 3.7% Ca on average, dry matter). The high moisture (above 70% in 48% of the samples) did not compromise the compost quality. Results of this study show that home composting of household organic waste including meat and fish leftovers is a feasible practice. Home composting helps individuals and families to reduce the amount of household waste at the same time gaining a fertiliser material (compost) of excellent quality for gardens or vegetable plots. Copyright © 2017 Elsevier Ltd. All rights reserved.

Graphene-based smart materials

NASA Astrophysics Data System (ADS)

Yu, Xiaowen; Cheng, Huhu; Zhang, Miao; Zhao, Yang; Qu, Liangti; Shi, Gaoquan

2017-09-01

The high specific surface area and the excellent mechanical, electrical, optical and thermal properties of graphene make it an attractive component for high-performance stimuli-responsive or 'smart' materials. Complementary to these inherent properties, functionalization or hybridization can substantially improve the performance of these materials. Typical graphene-based smart materials include mechanically exfoliated perfect graphene, chemical vapour deposited high-quality graphene, chemically modified graphene (for example, graphene oxide and reduced graphene oxide) and their macroscopic assemblies or composites. These materials are sensitive to a range of stimuli, including gas molecules or biomolecules, pH value, mechanical strain, electrical field, and thermal or optical excitation. In this Review, we outline different graphene-based smart materials and their potential applications in actuators, chemical or strain sensors, self-healing materials, photothermal therapy and controlled drug delivery. We also introduce the working mechanisms of graphene-based smart materials and discuss the challenges facing the realization of their practical applications.

Laminated thermoplastic composite material from recycled high density polyethylene

NASA Technical Reports Server (NTRS)

Liu, Ping; Waskom, Tommy L.

1994-01-01

The design of a materials-science, educational experiment is presented. The student should understand the fundamentals of polymer processing and mechanical property testing of materials. The ability to use American Society for Testing and Materials (ASTM) standards is also necessary for designing material test specimens and testing procedures. The objectives of the experiment are (1) to understand the concept of laminated composite materials, processing, testing, and quality assurance of thermoplastic composites and (2) to observe an application example of recycled plastics.

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.

Superconducting proximity effect in MBE grown Nb-InAs junctions

NASA Astrophysics Data System (ADS)

Kan, Carolyn; Xue, Chi; Law, Stephanie; Eckstein, James

2013-03-01

Several proposals for the realization of Majorana fermions rely on excellent quality proximity coupling between a superconductor and a high-mobility semiconductor. We examine the long-range proximity coupling between MBE-grown InAs and in situ grown superconducting overlayers by fabricating transport devices, and investigate the effect of substrate choice and growth conditions on the quality of the MBE InAs. GaAs is commonly available as a high quality insulating substrate. Overcoming its lattice mismatch with InAs using GaSb and AlSb layers results in locally smooth terraced surfaces, but global spiral dislocation structures also appear and have a negative impact on the InAs mobility. Growing InAs on homoepitaxial GaSb results in improved morphology and increases the mean free path. We compare the proximity effect in devices made both ways. This material is based upon work supported by the U.S. Department of Energy, Division of Materials Sciences under Award No. DE-FG02 07ER46453, through the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign.

Contribution to applications of EBW in instrument techniques

NASA Astrophysics Data System (ADS)

Hrabovsky, Miroslav

1999-07-01

The electron beam welding belongs to so-called physical methods of welding and it is utilized to welding of most materials, that can be arc welded. It is of use there, where one taxing welding technics and structure technologyableless heavily. As a rule, the quality of weld is better than at most first-rate welds being done by inert gas shielded arc welding (WIG, Argoarc). In plant instrumentation, where the limitation of any welded material distortion is of extraordinary importance, this way of welding is significant at welding of thermal-treated Cu-Be alloys, used in measurement technics, structural members from Ti alloys and stainless steels in branches of biomedicine and cryotechnics. This technology positives, especially high weld purity, narrow and deep root penetration, high welding rate, together with low energy consumption, lead to applications and verification of optimum operating mode at welding of frequent materials. In the contribution the results of this proofs of selected welded materials from viewpoint of weld quality, their physical-mechanic properties and microhardness, are presented.

High School Students' Written Argumentation Qualities with Problem-Based Computer-Aided Material (PBCAM) Designed about Human Endocrine System

ERIC Educational Resources Information Center

Vekli, Gülsah Sezen; Çimer, Atilla

2017-01-01

This study investigated development of students' scientific argumentation levels in the applications made with Problem-Based Computer-Aided Material (PBCAM) designed about Human Endocrine System. The case study method was used: The study group was formed of 43 students in the 11th grade of the science high school in Rize. Human Endocrine System…

Characteristics of a promising new thermoelectric material - Ruthenium silicide

NASA Technical Reports Server (NTRS)

Ohta, Toshitaka; Vining, Cronin B.; Allevato, Camillo E.

1991-01-01

A preliminary study on arc-melted samples has indicated that ruthenium silicide has the potential to obtain figure-of-merit values four times higher than that of conventional silicon-germanium material. In order to realize the high figure-of-merit values, high-quality crystal from the melt is needed. A Bridgman-like method has been employed and has realized much better crystals than arc-melted ones.

Guidelines on design and construction of high performance thin HMA overlays.

DOT National Transportation Integrated Search

2016-08-01

Key Components of Mix Design and Material Properties: : High-quality aggregate - SAC A for high : volume roads : - PG 70 or 76 (Polymer Modified binders) : - RAP and RAS (shingles) not allowed : - Minimum binder content ( Over 6%) : - Pay for binder ...

Atomic Scale Understanding of Poly-Si/SiO2/c-Si Passivated Contacts: Passivation Degradation Due to Metallization

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

Aguiar, Jeffery A.; Young, David; Lee, Benjamin

2016-11-21

The key attributes for achieving high efficiency crystalline silicon solar cells include class leading developments in the ability to approach the theoretical limits of silicon solar technology (29.4% efficiency). The push for high efficiency devices is further compounded with the clear need for passivation to reduce recombination at the metal contacts. At the same time there is stringent requirement to retain the same material device quality, surface passivation, and performance characteristics following subsequent processing. The development of passivated silicon cell structures that retain active front and rear surface passivation and overall material cell quality is therefore a relevant and activemore » area of development. To address the potential outcomes of metallization on passivated silicon stack, we report on some common microstructural features of degradation due to metallization for a series of silicon device stacks. A fundamental materials understanding of the metallization process on retaining high-efficiency passivated Si devices is therefore gained over these series of results.« less

Extracting DNA from 'jaws': high yield and quality from archived tiger shark (Galeocerdo cuvier) skeletal material.

PubMed

Nielsen, E E; Morgan, J A T; Maher, S L; Edson, J; Gauthier, M; Pepperell, J; Holmes, B J; Bennett, M B; Ovenden, J R

2017-05-01

Archived specimens are highly valuable sources of DNA for retrospective genetic/genomic analysis. However, often limited effort has been made to evaluate and optimize extraction methods, which may be crucial for downstream applications. Here, we assessed and optimized the usefulness of abundant archived skeletal material from sharks as a source of DNA for temporal genomic studies. Six different methods for DNA extraction, encompassing two different commercial kits and three different protocols, were applied to material, so-called bio-swarf, from contemporary and archived jaws and vertebrae of tiger sharks (Galeocerdo cuvier). Protocols were compared for DNA yield and quality using a qPCR approach. For jaw swarf, all methods provided relatively high DNA yield and quality, while large differences in yield between protocols were observed for vertebrae. Similar results were obtained from samples of white shark (Carcharodon carcharias). Application of the optimized methods to 38 museum and private angler trophy specimens dating back to 1912 yielded sufficient DNA for downstream genomic analysis for 68% of the samples. No clear relationships between age of samples, DNA quality and quantity were observed, likely reflecting different preparation and storage methods for the trophies. Trial sequencing of DNA capture genomic libraries using 20 000 baits revealed that a significant proportion of captured sequences were derived from tiger sharks. This study demonstrates that archived shark jaws and vertebrae are potential high-yield sources of DNA for genomic-scale analysis. It also highlights that even for similar tissue types, a careful evaluation of extraction protocols can vastly improve DNA yield. © 2016 John Wiley & Sons Ltd.

The Adventure of the Deceitful Numbers

ERIC Educational Resources Information Center

Andrade-Molina, Melissa

2017-01-01

This article addresses access to high-quality education under a neoliberal mentality. It engages at both the discursive and material levels, by mapping how taken-for-granted truths about neoliberal policies circulate through the media. The media--newspapers, network channels, and news websites--have correlated quality education with socioeconomic…

A proteomics performance standard to support measurement quality in proteomics.

PubMed

Beasley-Green, Ashley; Bunk, David; Rudnick, Paul; Kilpatrick, Lisa; Phinney, Karen

2012-04-01

The emergence of MS-based proteomic platforms as a prominent technology utilized in biochemical and biomedical research has increased the need for high-quality MS measurements. To address this need, National Institute of Standards and Technology (NIST) reference material (RM) 8323 yeast protein extract is introduced as a proteomics quality control material for benchmarking the preanalytical and analytical performance of proteomics-based experimental workflows. RM 8323 yeast protein extract is based upon the well-characterized eukaryote Saccharomyces cerevisiae and can be utilized in the design and optimization of proteomics-based methodologies from sample preparation to data analysis. To demonstrate its utility as a proteomics quality control material, we coupled LC-MS/MS measurements of RM 8323 with the NIST MS Quality Control (MSQC) performance metrics to quantitatively assess the LC-MS/MS instrumentation parameters that influence measurement accuracy, repeatability, and reproducibility. Due to the complexity of the yeast proteome, we also demonstrate how NIST RM 8323, along with the NIST MSQC performance metrics, can be used in the evaluation and optimization of proteomics-based sample preparation methods. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-energy X-ray applications: current status and new opportunities

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

Šišak Jung, Dubravka; Donath, Tilman; Magdysyuk, Oxana

Characterization of semi and noncrystalline materials, monitoring structural phase transitionsin situ, and obtaining structural information together with spatial distribution of the investigated material are only a few applications that hugely benefitted from the combination of high-energy X-rays and modern algorithms for data processing. This work examines the possibility of advancing these applications by shortening the data acquisition and improving the data quality by using the new high-energy PILATUS3 CdTe detector.

Tailored laser beam shaping for efficient and accurate microstructuring

NASA Astrophysics Data System (ADS)

Häfner, T.; Strauß, J.; Roider, C.; Heberle, J.; Schmidt, M.

2018-02-01

Large-area processing with high material removal rates by ultrashort pulsed (USP) lasers is coming into focus by the development of high-power USP laser systems. However, currently the bottleneck for high-rate production is given by slow and inefficient beam manipulation. On the one hand, slow beam deflection with regard to high pulse repetition rates leads to heat accumulation and shielding effects, on the other hand, a conventional focus cannot provide the optimum fluence due to the Gaussian intensity profile. In this paper, we emphasize on two approaches of dynamic laser beam shaping with liquid crystal on silicon spatial light modulation and acousto-optic beam shaping. Advantages and limitations of dynamic laser beam shaping with regard to USP laser material processing and methods for reducing the influence of speckle are discussed. Additionally, the influence of optics induced aberrations on speckle characteristics is evaluated. Laser material processing results are presented correlating the achieved structure quality with the simulated and measured beam quality. Experimental and analytical investigations show a certain fluence dependence of the necessary number of alternative holograms to realize homogeneous microstructures.

Overview of CMC Development Activities in NASA's Ultra-Efficient Engine Technology (UEET) Program

NASA Technical Reports Server (NTRS)

Brewer, Dave

2001-01-01

The primary objective of the UEET (Ultra-Efficient Engine Technology) Program is to address two of the most critical propulsion issues: performance/efficiency and reduced emissions. High performance, low emissions engine systems will lead to significant improvement in local air quality, minimum impact on ozone depletion and level to an overall reduction in aviation contribution to global warming. The Materials and Structures for High Performance project will develop and demonstrate advanced high temperature materials to enable high-performance, high efficiency, and environmentally compatible propulsion systems.

Development and implementation of an automatic integration system for fibre optic sensors in the braiding process with the objective of online-monitoring of composite structures

NASA Astrophysics Data System (ADS)

Hufenbach, W.; Gude, M.; Czulak, A.; Kretschmann, Martin

2014-04-01

Increasing economic, political and ecological pressure leads to steadily rising percentage of modern processing and manufacturing processes for fibre reinforced polymers in industrial batch production. Component weights beneath a level achievable by classic construction materials, which lead to a reduced energy and cost balance during product lifetime, justify the higher fabrication costs. However, complex quality control and failure prediction slow down the substitution by composite materials. High-resolution fibre-optic sensors (FOS), due their low diameter, high measuring point density and simple handling, show a high applicability potential for an automated sensor-integration in manufacturing processes, and therefore the online monitoring of composite products manufactured in industrial scale. Integrated sensors can be used to monitor manufacturing processes, part tests as well as the component structure during product life cycle, which simplifies allows quality control during production and the optimization of single manufacturing processes.[1;2] Furthermore, detailed failure analyses lead to a enhanced understanding of failure processes appearing in composite materials. This leads to a lower wastrel number and products of a higher value and longer product life cycle, whereby costs, material and energy are saved. This work shows an automation approach for FOS-integration in the braiding process. For that purpose a braiding wheel has been supplemented with an appliance for automatic sensor application, which has been used to manufacture preforms of high-pressure composite vessels with FOS-networks integrated between the fibre layers. All following manufacturing processes (vacuum infiltration, curing) and component tests (quasi-static pressure test, programmed delamination) were monitored with the help of the integrated sensor networks. Keywords: SHM, high-pressure composite vessel, braiding, automated sensor integration, pressure test, quality control, optic-fibre sensors, Rayleigh, Luna Technologies

Low-temperature magnetotransport in Si/SiGe heterostructures on 300 mm Si wafers

NASA Astrophysics Data System (ADS)

Scappucci, Giordano; Yeoh, L.; Sabbagh, D.; Sammak, A.; Boter, J.; Droulers, G.; Kalhor, N.; Brousse, D.; Veldhorst, M.; Vandersypen, L. M. K.; Thomas, N.; Roberts, J.; Pillarisetty, R.; Amin, P.; George, H. C.; Singh, K. J.; Clarke, J. S.

Undoped Si/SiGe heterostructures are a promising material stack for the development of spin qubits in silicon. To deploy a qubit into high volume manufacturing in a quantum computer requires stringent control over substrate uniformity and quality. Electron mobility and valley splitting are two key electrical metrics of substrate quality relevant for qubits. Here we present low-temperature magnetotransport measurements of strained Si quantum wells with mobilities in excess of 100000 cm2/Vs fabricated on 300 mm wafers within the framework of advanced semiconductor manufacturing. These results are benchmarked against the results obtained in Si quantum wells deposited on 100 mm Si wafers in an academic research environment. To ensure rapid progress in quantum wells quality we have implemented fast feedback loops from materials growth, to heterostructure FET fabrication, and low temperature characterisation. On this topic we will present recent progress in developing a cryogenic platform for high-throughput magnetotransport measurements.

Growing Organic Crystals By The Czochralski Method

NASA Technical Reports Server (NTRS)

Shields, Angela; Frazier, Donald O.; Penn, Benjamin G.; Aggarwal, M. D.; Wang, W. S.

1994-01-01

Apparatus grows high-quality single crystals of organic compounds by Czochralski method. In Czochralski process, growing crystal lifted from middle of molten material without touching walls. Because of low melting temperatures of organic crystals, glass vessels usable. Traditional method for inorganic semiconductors adapted to optically nonlinear organic materials.

Quality of online pediatric orthopaedic education materials.

PubMed

Feghhi, Daniel P; Komlos, Daniel; Agarwal, Nitin; Sabharwal, Sanjeev

2014-12-03

Increased availability of medical information on the Internet empowers patients to look up answers to questions about their medical conditions. However, the quality of medical information available on the Internet is highly variable. Various tools for the assessment of online medical information have been developed and used to assess the quality and accuracy of medical web sites. In this study we used the LIDA tool (Minervation) to assess the quality of pediatric patient information on the AAOS (American Academy of Orthopaedic Surgeons) and POSNA (Pediatric Orthopaedic Society of North America) web sites. The accessibility, usability, and reliability of online medical information in the "Children" section of the AAOS web site and on the POSNA web site were assessed with use of the LIDA tool. Flesch-Kincaid (FK) and Flesch Reading Ease (FRE) values were also calculated to assess the readability of the pediatric education material. Patient education materials on each web site scored in the moderate range in assessments of accessibility, usability, and reliability. FK and FRE values indicated that the readability of each web site remained at a somewhat higher (more difficult) level than the recommended benchmark. The quality and readability of online information for children on the AAOS and POSNA web sites are acceptable but can be improved further. The quality of online pediatric orthopaedic patient education materials may affect communication with patients and their caregivers, and further investigation and modification of quality are needed. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.

Development of the Quality Assurance/Quality Control Procedures for a Neutron Interrogation System

NASA Astrophysics Data System (ADS)

Obhođaš, Jasmina; Sudac, Davorin; Valković, Vladivoj

2016-06-01

In order to perform Quality Assurance/Quality Control (QA/QC) procedures for a system dedicated to the neutron interrogation of objects for the presence of threat materials one needs to perform measurements of reference materials (RM) i.e. simulants having the same (or similar) atomic ratios as real materials. It is well known that explosives, drugs, and various other benign materials, contain chemical elements such as hydrogen, oxygen, carbon and nitrogen in distinctly different quantities. For example, a high carbon-to-oxygen ratio (C/O) is characteristic of drugs. Explosives can be differentiated by measurement of both (C/O) and nitrogen-to-oxygen (N/O) ratios. The C/N ratio of the chemical warfare agents, coupled with the measurement of elements such as fluorine and phosphorus, clearly differentiate them from the conventional explosives. Here we present the RM preparation, calibration procedure and correlations attained between theoretical values and experimentally obtained results in laboratory conditions for C/O and N/C ratios of prepared hexogen (RDX), TNT, DLM2, TATP, cocaine, heroin, yperite, tetranitromethane, peroxide methylethylketone, nitromethane and ethyleneglycol dinitrate simulants. We have shown that analyses of the gamma ray spectra by using simple unfolding model developed for this purpose gave a nice agreement with the chemical formula of created simulants, thus the calibration quality was successfully tested.

A quality assessment of cardiac auscultation material on YouTube.

PubMed

Camm, Christian F; Sunderland, Nicholas; Camm, A John

2013-02-01

YouTube is a highly utilized Web site that contains a large amount of medical educational material. Although some studies have assessed the education material contained on the Web site, little analysis of cardiology content has been made. This study aimed to assess the quality of videos relating to heart sounds and murmurs contained on YouTube. We hypothesized that the quality of video files purporting to provide education on heart auscultation would be highly variable. Videos were searched for using the terms "heart sounds," "heart murmur," and "heart auscultation." A built-in educational filter was employed, and manual rejection of non-English language and nonrelated videos was undertaken. Remaining videos were analyzed for content, and suitable videos were scored using a purpose-built tool. YouTube search located 3350 videos in total, and of these, 22 were considered suitable for scoring. The average score was 4.07 out of 7 (standard deviation, 1.35). Six videos scored 5.5 or greater and 5 videos scoring 2.5 or less. There was no correlation between video score and YouTube indices of preference (hits, likes, dislikes, or search page). The quality of videos found in this study was highly variable. YouTube indications of preference were of no value in determining the value of video content. Therefore, teaching institutions or professional societies should endeavor to identify and highlight good online teaching resources. YouTube contains many videos relating to cardiac auscultation, but very few are valuable education resources. © 2012 Wiley Periodicals, Inc.

Comparison of CIGS solar cells made with different structures and fabrication techniques

DOE PAGES

Mansfield, Lorelle M.; Garris, Rebekah L.; Counts, Kahl D.; ...

2016-11-03

Cu(In, Ga)Se2 (CIGS)-based solar cells from six fabricators were characterized and compared. The devices had differing substrates, absorber deposition processes, buffer materials, and contact materials. The effective bandgaps of devices varied from 1.05 to 1.22 eV, with the lowest optical bandgaps occurring in those with metal-precursor absorber processes. Devices with Zn(O, S) or thin CdS buffers had quantum efficiencies above 90% down to 400 nm. Most voltages were 250-300 mV below the Shockley-Queisser limit for their bandgap. Electroluminescence intensity tracked well with the respective voltage deficits. Fill factor (FF) was as high as 95% of the maximum for each device'smore » respective current and voltage, with higher FF corresponding to lower diode quality factors (~1.3). An in-depth analysis of FF losses determined that diode quality reflected in the quality factor, voltage-dependent photocurrent, and, to a lesser extent, the parasitic resistances are the limiting factors. As a result, different absorber processes and device structures led to a range of electrical and physical characteristics, yet this investigation showed that multiple fabrication pathways could lead to high-quality and high-efficiency solar cells.« less

Comparison of CIGS solar cells made with different structures and fabrication techniques

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

Mansfield, Lorelle M.; Garris, Rebekah L.; Counts, Kahl D.

Cu(In, Ga)Se2 (CIGS)-based solar cells from six fabricators were characterized and compared. The devices had differing substrates, absorber deposition processes, buffer materials, and contact materials. The effective bandgaps of devices varied from 1.05 to 1.22 eV, with the lowest optical bandgaps occurring in those with metal-precursor absorber processes. Devices with Zn(O, S) or thin CdS buffers had quantum efficiencies above 90% down to 400 nm. Most voltages were 250-300 mV below the Shockley-Queisser limit for their bandgap. Electroluminescence intensity tracked well with the respective voltage deficits. Fill factor (FF) was as high as 95% of the maximum for each device'smore » respective current and voltage, with higher FF corresponding to lower diode quality factors (~1.3). An in-depth analysis of FF losses determined that diode quality reflected in the quality factor, voltage-dependent photocurrent, and, to a lesser extent, the parasitic resistances are the limiting factors. As a result, different absorber processes and device structures led to a range of electrical and physical characteristics, yet this investigation showed that multiple fabrication pathways could lead to high-quality and high-efficiency solar cells.« less

The Curriculum Gap

ERIC Educational Resources Information Center

Carroll, Kathleen

2015-01-01

The challenge of updating curriculum to align with Common Core State Standards is a national one felt by states, districts, and teachers alike. Teachers generally express enthusiasm for the Common Core, but consistently cite a lack of high-quality curricula as an impediment to teaching them. The demand for core-aligned quality materials has far…

Practitioner Perspective: Assessing Child-Care Quality with a Telephone Interview.

ERIC Educational Resources Information Center

Ponder, Karen W.

2001-01-01

Discusses findings that child care quality can be measured effectively and efficiently through telephone interview. Notes that interview items were more highly correlated to the materials composite than to the interaction composite of the Environment Ratings Scales. Describes situations where on-site observation is necessary. Suggests that one…

GePb Alloy Growth Using Layer Inversion Method

NASA Astrophysics Data System (ADS)

Alahmad, Hakimah; Mosleh, Aboozar; Alher, Murtadha; Banihashemian, Seyedeh Fahimeh; Ghetmiri, Seyed Amir; Al-Kabi, Sattar; Du, Wei; Li, Bauhoa; Yu, Shui-Qing; Naseem, Hameed A.

2018-04-01

Germanium-lead films have been investigated as a new direct-bandgap group IV alloy. GePb films were deposited on Si via thermal evaporation of Ge and Pb solid sources using the layer inversion metal-induced crystallization method for comparison with the current laser-induced recrystallization method. Material characterization of the films using x-ray diffraction analysis revealed highly oriented crystallinity and Pb incorporation as high as 13.5% before and 5.2% after annealing. Transmission electron microscopy, scanning electron microscopy, and energy-dispersive x-ray mapping of the samples revealed uniform incorporation of elements and complete layer inversion. Optical characterization of the GePb films by Raman spectroscopy and photoluminescence techniques showed that annealing the samples resulted in higher crystalline quality as well as bandgap reduction. The bandgap reduction from 0.67 eV to 0.547 eV observed for the highest-quality material confirms the achievement of a direct-bandgap material.

GePb Alloy Growth Using Layer Inversion Method

NASA Astrophysics Data System (ADS)

Alahmad, Hakimah; Mosleh, Aboozar; Alher, Murtadha; Banihashemian, Seyedeh Fahimeh; Ghetmiri, Seyed Amir; Al-Kabi, Sattar; Du, Wei; Li, Bauhoa; Yu, Shui-Qing; Naseem, Hameed A.

2018-07-01

Germanium-lead films have been investigated as a new direct-bandgap group IV alloy. GePb films were deposited on Si via thermal evaporation of Ge and Pb solid sources using the layer inversion metal-induced crystallization method for comparison with the current laser-induced recrystallization method. Material characterization of the films using x-ray diffraction analysis revealed highly oriented crystallinity and Pb incorporation as high as 13.5% before and 5.2% after annealing. Transmission electron microscopy, scanning electron microscopy, and energy-dispersive x-ray mapping of the samples revealed uniform incorporation of elements and complete layer inversion. Optical characterization of the GePb films by Raman spectroscopy and photoluminescence techniques showed that annealing the samples resulted in higher crystalline quality as well as bandgap reduction. The bandgap reduction from 0.67 eV to 0.547 eV observed for the highest-quality material confirms the achievement of a direct-bandgap material.

High-quality collection and disposal of WEEE: Environmental impacts and resultant issues.

PubMed

Baxter, John; Lyng, Kari-Anne; Askham, Cecilia; Hanssen, Ole Jørgen

2016-11-01

Life cycle assessment of the collection, transport and recycling of various types of waste electrical and electronic equipment (WEEE) in Norway shows that small amounts of critical materials (refrigerants, precious/trace metals) are vital for the overall environmental accounts of the value chains. High-quality recycling ensures that materials and energy are effectively recovered from WEEE. This recovery means that responsible waste handling confers net environmental benefits in terms of global warming potential (GWP), for all types of WEEE analysed. For refrigeration equipment, the potential reduction of GWP by high-quality recycling is so large as to be of national significance. For all waste types, the magnitude of the net benefit from recovering materials and energy exceeds the negative consequences of irresponsible disposal. One outcome of this may be widespread misunderstanding of the need for recycling. Furthermore, framing public communication on recycling in terms of avoiding negative consequences, as is essentially universal, may not convey an appropriate message. The issue is particularly important where the consumer regards products as relatively disposable and environmentally benign, and/or where the "null option" of retaining the product at end-of-life is especially prevalent. The paper highlights the implications of all these issues for policy-makers, waste collectors and recyclers, and consumers. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Evaluation of the quality of poultry meat and its processing for vacuum packaging].

PubMed

Swiderski, F; Russel, S; Waszkiewicz-Robak, B; Cholewińska, E

1997-01-01

The aim of study was to evaluate the quality of poultry meat, roasted and smoked chicken and poultry pie packing under low and high vacuum. All investigated products were stored at +4 degrees C and evaluated by microbiological analysis. It was showed that packing under low and high vacuum inhibited development of aerobic microorganisms, proteolytic bacteria, yeasts and moulds. Vacuum-packaged storage of poultry meat and its products stimulated activity of anaerobic, nonsporeforming bacteria. The fast spoilage of fresh poultry meat was observed both under vacuum and conventional storage. The microbiology quality of poultry products depended on technology of production and microbiological quality of raw material.

Delta-doping optimization for high quality p-type GaN

NASA Astrophysics Data System (ADS)

Bayram, C.; Pau, J. L.; McClintock, R.; Razeghi, M.

2008-10-01

Delta (δ -) doping is studied in order to achieve high quality p-type GaN. Atomic force microscopy, x-ray diffraction, photoluminescence, and Hall measurements are performed on the samples to optimize the δ-doping characteristics. The effect of annealing on the electrical, optical, and structural quality is also investigated for different δ-doping parameters. Optimized pulsing conditions result in layers with hole concentrations near 1018 cm-3 and superior crystal quality compared to conventional p-GaN. This material improvement is achieved thanks to the reduction in the Mg activation energy and self-compensation effects in δ-doped p-GaN.

Synthesis and Superconducting Properties of the High Transition Temperature Superconductor BARIUM(1-X) Potassium(x)bismuth Trioxide

NASA Astrophysics Data System (ADS)

Folkerts, Timothy John

A systematic study of Ba_ {1-x}K_ xBiO_3 (BKBO) in the range 0 <= x <= 0.5 is presented in this work, concentrating especially on the superconducting range 0.35 <= x <= 0.5. Samples were studied using powder x-ray diffraction, thermal analysis, magnetization as a function of both temperature and applied field, and resistivity as a function of both temperature and pressure. Particular effort went into producing high quality samples. This proved difficult because of the moisture sensitivity of the starting materials and of the intermediate products, and because of the tendency of the material to phase separate into regions of varying potassium concentrations. Once synthesis techniques were developed which allowed production of high quality samples, systematic studies could be undertaken. The sharpness of the powder x-ray diffraction peaks, along with least squares fits, were used to determine phase purity and to exclude poor quality samples. The lattice parameters of the remaining samples were seen to obey Vegard's Law. Magnetization studies as a function of temperature were used to determine the superconducting transition temperature (T_ c). Onsets for superconductivity were observed as high as 30 K for samples with broad transitions, although samples with sharp transitions had a maximum T_ c of only 28.8 K. This high T_ c, as well as the crystal structure clearly link BKBO to the high T_ c superconductors. Hysteresis measurements were undertaken to determine the upper and lower critical fields, critical currents, and the normal state susceptibility. Estimates of the coherence length, penetration depth, and the electronic contribution to the specific heat based on these measurements agree well with BCS theory. Resistivity data are quit dependent on sample quality, as well as potassium doping. At low potassium concentrations, the material is semiconducting, while at higher potassium concentrations where the material is superconducting, the normal state resistivity of Ba_ {1-x}K_ xBiO_3 is nearly temperature independent. This is in contrast to other oxide superconductors, which typically show metallic behavior. We conclude that the BCS theory adequately describes the properties of Ba_{1-x }K_ xBiO_3, as determined in this study.

High contrast two-photon imaging of fingermarks

NASA Astrophysics Data System (ADS)

Stoltzfus, Caleb R.; Rebane, Aleksander

2016-04-01

Optically-acquired fingermarks are widely used as evidence across law enforcement agencies as well as in the courts of law. A common technique for visualizing latent fingermarks on nonporous surfaces consists of cyanoacrylate fuming of the fingerprint material, followed by impregnation with a fluorescent dye, which under ultra violet (UV) illumination makes the fingermarks visible and thus accessible for digital recording. However, there exist critical circumstances, when the image quality is compromised due to high background scattering, high auto-fluorescence of the substrate material, or other detrimental photo-physical and photo-chemical effects such as light-induced damage to the sample. Here we present a novel near-infrared (NIR), two-photon induced fluorescence imaging modality, which significantly enhances the quality of the fingermark images, especially when obtained from highly reflective and/or scattering surfaces, while at the same time reducing photo-damage to sensitive forensic samples.

HIDDEN DISPARITIES: HOW COURSES AND CURRICULA SHAPE OPPORTUNITIES IN MATHEMATICS DURING HIGH SCHOOL1

PubMed Central

Schiller, Kathryn S.; Schmidt, William H.; Muller, Chandra; Houang, Richard

2011-01-01

Efforts to promote academic achievement by increasing access to courses, especially in mathematics, may mask educational disparities if variations in curriculum are not also monitored. A multi-dimensional description of students’ mathematics curricula during high school was obtained from analyses of surveys, transcripts, and textbooks collected for a nationally representative study of adolescents during the mid-1990s. Few gaps in the number of years or credits in mathematics coursework were found. However, the quantity and cognitive challenge of instructional materials in textbooks adopted for those courses differed significantly both across and within mathematics tracks. Differences in the quality of curriculum accumulating during high school were also related to parents’ education level. Reducing such gaps in learning opportunities would require teachers to supplement adopted instructional materials to ensure that all students receive a high quality mathematics curriculum. PMID:23554547

Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication

PubMed Central

Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert

2017-01-01

In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80–100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes. PMID:28145513

21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Quality control material for cystic fibrosis... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a) Identification. Quality control material for cystic fibrosis nucleic acid assays. A quality control material for...

21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Quality control material for cystic fibrosis... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a) Identification. Quality control material for cystic fibrosis nucleic acid assays. A quality control material for...

21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Quality control material for cystic fibrosis... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a) Identification. Quality control material for cystic fibrosis nucleic acid assays. A quality control material for...

21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Quality control material for cystic fibrosis... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a) Identification. Quality control material for cystic fibrosis nucleic acid assays. A quality control material for...

A review in high early strength concrete and local materials potential

NASA Astrophysics Data System (ADS)

Yasin, A. K.; Bayuaji, R.; Susanto, T. E.

2017-11-01

High early strength concrete is one of the type in high performance concrete. A high early strength concrete means that the compressive strength of the concrete at the first 24 hours after site-pouring could achieve structural concrete quality (compressive strength > 21 MPa). There are 4 (four) important factors that must be considered in the making process, those factors including: portland cement type, cement content, water to cement ratio, and admixture. In accordance with its high performance, the production cost is estimated to be 25 to 30% higher than conventional concrete. One effort to cut the production cost is to utilize local materials. This paper will also explain about the local materials which were abundantly available, cheap, and located in strategic coast area of East Java Province, that is: Gresik, Tuban and Bojonegoro city. In addition, the application of this study is not limited only to a large building project, but also for a small scale building which has one to three-story. The performance of this concrete was apparently able to achieve the quality of compressive strength of 27 MPa at the age of 24 hours, which qualified enough to support building structurally.

Development of Course Material in a Multi-Author Environment

ERIC Educational Resources Information Center

Schlotter, Michael

2009-01-01

Software for text processing and presentation design is becoming increasingly sophisticated. Nevertheless, it is difficult to find a good solution for collaborative writing of technical course material, allowing the creation of high quality lecture notes and presentation slides from a single source. This article presents a new editing framework…

Thumbs Up: High-Quality, Low-Cost Teaching Aids.

ERIC Educational Resources Information Center

Paine, Carolyn

1982-01-01

Exemplary teaching aids--games, workbooks, student and teacher resource books, reading materials, and records--are recommended by subject area and grade level. Materials include an ice cream cone game for mathematics, a "Life Skills Reading" book on telephone usage, a "Dictionary of Recent American History," and many other items. (PP)

Using Computer Conferencing Techniques To Maximize Student Learning.

ERIC Educational Resources Information Center

Norton, Robert E.; Stammen, Ronald M.

The Consortium for the Development of Professional Materials for Vocational Education at Ohio State University was organized in 1978 for the purpose of developing high-quality curriculum materials for training leadership personnel in vocational and technical education in the United States, and to pilot test and demonstrate new instructional…

Designing Educative Curriculum Materials: A Theoretically and Empirically Driven Process

ERIC Educational Resources Information Center

Davis, Elizabeth A.; Palincsar, Annemarie Sullivan; Arias, Anna Maria; Bismack, Amber Schultz; Marulis, Loren M.; Iwashyna, Stefanie K.

2014-01-01

In this article, the authors argue for a design process in the development of educative curriculum materials that is theoretically and empirically driven. Using a design-based research approach, they describe their design process for incorporating educative features intended to promote teacher learning into existing, high-quality curriculum…

Evaluation of the quality and health literacy demand of online renal diet information.

PubMed

Lambert, K; Mullan, J; Mansfield, K; Koukomous, A; Mesiti, L

2017-10-01

Dietary modification is critical in the self-management of chronic kidney disease. The present study describes the accuracy, quality and health literacy demand of renal diet information for adults with kidney disease obtained from the Internet and YouTube (www.youtube.com). A comprehensive content analysis was undertaken in April and July 2015 of 254 eligible websites and 161 YouTube videos. The accuracy of the renal diet information was evaluated by comparing the key messages with relevant evidence-based guidelines for the dietary management of people with kidney disease. The DISCERN tool (www.discern.org.uk) was used to evaluate the quality of the material. Health literacy demand was evaluated using the Patient Education Material Assessment Tool (www.ahrq.gov/professionals/prevention-chronic-care/improve/self-mgmt/pemat/index.html) and seven validated readability calculators. The most frequent renal diet topic found online was generic dietary information for people with chronic kidney disease. The proportion of renal diet information obtained from websites that was accurate was 73%. However, this information was mostly of poor quality with extensive shortcomings, difficult to action and written with a high health literacy demand. By contrast, renal diet information available from YouTube was highly understandable and actionable, although only 18% of the videos were accurate, and a large proportion were of poor quality with extensive shortcomings. The most frequent authors of accurate, good quality, understandable, material were government bodies, dietitians, academic institutions and medical organisations. Renal diet information found online that is written by government bodies, dietitians, academic institutions and medical organisations is recommended. Further work is required to improve the quality and, most importantly, the actionability of renal diet information found online. © 2017 The British Dietetic Association Ltd.

Overcoming systemic roadblocks to sustainability: The evolutionary redesign of worldviews, institutions, and technologies

PubMed Central

Beddoe, Rachael; Costanza, Robert; Farley, Joshua; Garza, Eric; Kent, Jennifer; Kubiszewski, Ida; Martinez, Luz; McCowen, Tracy; Murphy, Kathleen; Myers, Norman; Ogden, Zach; Stapleton, Kevin; Woodward, John

2009-01-01

A high and sustainable quality of life is a central goal for humanity. Our current socio-ecological regime and its set of interconnected worldviews, institutions, and technologies all support the goal of unlimited growth of material production and consumption as a proxy for quality of life. However, abundant evidence shows that, beyond a certain threshold, further material growth no longer significantly contributes to improvement in quality of life. Not only does further material growth not meet humanity's central goal, there is mounting evidence that it creates significant roadblocks to sustainability through increasing resource constraints (i.e., peak oil, water limitations) and sink constraints (i.e., climate disruption). Overcoming these roadblocks and creating a sustainable and desirable future will require an integrated, systems level redesign of our socio-ecological regime focused explicitly and directly on the goal of sustainable quality of life rather than the proxy of unlimited material growth. This transition, like all cultural transitions, will occur through an evolutionary process, but one that we, to a certain extent, can control and direct. We suggest an integrated set of worldviews, institutions, and technologies to stimulate and seed this evolutionary redesign of the current socio-ecological regime to achieve global sustainability. PMID:19240221

Modeling of liquid flow in surface discontinuities

NASA Astrophysics Data System (ADS)

Lobanova, I. S.; Meshcheryakov, V. A.; Kalinichenko, A. N.

2018-01-01

Polymer composite and metallic materials have found wide application in various industries such as aviation, rocket, car manufacturing, ship manufacturing, etc. Many design elements need permanent quality control. Ensuring high quality and reliability of products is impossible without effective nondestructive testing methods. One of these methods is penetrant testing using penetrating substances based on liquid penetration into defect cavities. In this paper, we propose a model of liquid flow to determine the rates of filling the defect cavities with various materials and, based on this, to choose optimal control modes.

Final-impression techniques and materials for making complete and removable partial dentures.

PubMed

Jayaraman, Srinivasan; Singh, Balendra P; Ramanathan, Balasubramanian; Pazhaniappan Pillai, Murukan; MacDonald, Laura; Kirubakaran, Richard

2018-04-04

Edentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures (CD) and removable partial dentures (RPD) using different techniques and materials. Applying the correct impression technique and material, based on an individual's oral condition, improves the quality of the prosthesis, which may improve quality of life. To assess the effects of different final-impression techniques and materials used to make complete dentures, for retention, stability, comfort, and quality of life in completely edentulous people.To assess the effects of different final-impression techniques and materials used to make removable partial dentures, for stability, comfort, overextension, and quality of life in partially edentulous people. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 22 November 2017), MEDLINE Ovid (1946 to 22 November 2017), and Embase Ovid (21 December 2015 to 22 November 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases, however the search of Embase was restricted by date due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL. We included randomised controlled trials (RCTs) comparing different final-impression techniques and materials for treating people with complete dentures (CD) and removable partial dentures (RPD). For CD, we included trials that compared different materials or different techniques or both. In RPD for tooth-supported conditions, we included trials comparing the same material and different techniques, or different materials and the same technique. In tooth- and tissue-supported RPD, we included trials comparing the same material and different dual-impression techniques, and different materials with different dual-impression techniques. Two review authors independently, and in duplicate, screened studies for eligibility, extracted data, and assessed the risk of bias for each included trial. We expressed results as risk ratios (RR) for dichotomous outcomes, and as mean differences (MD) or standardised mean differences (SMD) for continuous outcomes, with 95% confidence intervals (CI), using the random-effects model. We constructed 'Summary of findings' tables for the main comparisons and outcomes (participant-reported oral health-related quality of life, quality of the denture, and denture border adjustments). We included nine studies in this review. Eight studies involved 485 participants with CD. We assessed six of the studies to be at high risk of bias, and two to be at low risk of bias. We judged one study on RPD with 72 randomised participants to be at high risk of bias.Overall, the quality of the evidence for each comparison and outcome was either low or very low, therefore, results should be interpreted with caution, as future research is likely to change the findings.Complete denturesTwo studies compared the same material and different techniques (one study contributed data to a secondary outcome only); two studies compared the same technique and different materials; and four studies compared different materials and techniques.One study (10 participants) evaluated two stage-two step, Biofunctional Prosthetic system (BPS) using additional silicone elastomer compared to conventional methods, and found no evidence of a clear difference for oral health-related quality of life, or quality of the dentures (denture satisfaction). The study reported that BPS required fewer adjustments. We assessed the quality of the evidence as very low.One study (27 participants) compared selective pressure final-impression technique using wax versus polysulfide elastomeric (rubber) material. The study did not measure quality of life or dentures, and found no evidence of a clear difference between interventions in the need for adjustments (RR 0.81, 95% CI 0.38 to 1.70). We assessed the quality of the evidence as very low.One study compared two stage-two step final impression with alginate versus silicone elastomer. Oral health-related quality of life measured by the OHIP-EDENT seemed to be better with silicone (MD 7.20, 95% CI 2.71 to 11.69; 144 participants). The study found no clear differences in participant-reported quality of the denture (comfort) after a two-week 'confirmation' period, but reported that silicone was better for stability and chewing efficiency. We assessed the quality of the evidence as low.Three studies compared single-stage impressions with alginate versus two stage-two step with elastomer (silicone, polysulfide, or polyether) impressions. There was no evidence of a clear difference in the OHIP-EDENT at one month (MD 0.05, 95% CI -2.37 to 2.47; two studies, 98 participants). There was no evidence of a clear difference in participant-rated general satisfaction with dentures at six months (MD 0.00, 95% CI -8.23 to 8.23; one study, 105 participants). We assessed the quality of the evidence as very low.One study compared single-stage alginate versus two stage-two step using zinc-oxide eugenol, and found no evidence of a clear difference in OHIP-EDENT (MD 0.50, 95% CI -2.67 to 3.67; 39 participants), or general satisfaction (RR 3.15, 95% CI 0.14 to 72.88; 39 participants) at six months. We assessed the quality of the evidence as very low.Removable partial denturesOne study randomised 72 participants and compared altered-cast technique versus one-piece cast technique. The study did not measure quality of life, but reported that most participants were satisfied with the dentures and there was no evidence of any clear difference between groups for general satisfaction at one-year follow-up (low-quality evidence). There was no evidence of a clear difference in number of intaglio adjustments at one year (RR 1.43, 95% CI 0.61 to 3.34) (very low-quality evidence). We conclude that there is no clear evidence that one technique or material has a substantial advantage over another for making complete dentures and removable partial dentures. Available evidence for the relative benefits of different denture fabrication techniques and final-impression materials is limited and is of low or very low quality. More high-quality RCTs are required.

Explosive Welding in the 1990's

NASA Technical Reports Server (NTRS)

Lalwaney, N. S.; Linse, V. D.

1985-01-01

Explosive bonding is a unique joining process with the serious potential to produce composite materials capable of fulfilling many of the high performance materials capable of fulfilling many of the high performance materials needs of the 1990's. The process has the technological versatility to provide a true high quality metallurgical compatible and incompatible systems. Metals routinely explosively bonded include a wide variety of combinations of reactive and refractory metals, low and high density metals and their alloys, corrosion resistant and high strength alloys, and common steels. The major advantage of the process is its ability to custom design and engineer composites with physical and/or mechanical properties that meet a specific or unusual performance requirement. Explosive bonding offers the designer unique opportunities in materials selection with unique combinations of properties and high integrity bonds that cannot be achieved by any other metal joining process. The process and some applications are discussed.

Heterogeneous Monolithic Integration of Single-Crystal Organic Materials.

PubMed

Park, Kyung Sun; Baek, Jangmi; Park, Yoonkyung; Lee, Lynn; Hyon, Jinho; Koo Lee, Yong-Eun; Shrestha, Nabeen K; Kang, Youngjong; Sung, Myung Mo

2017-02-01

Manufacturing high-performance organic electronic circuits requires the effective heterogeneous integration of different nanoscale organic materials with uniform morphology and high crystallinity in a desired arrangement. In particular, the development of high-performance organic electronic and optoelectronic devices relies on high-quality single crystals that show optimal intrinsic charge-transport properties and electrical performance. Moreover, the heterogeneous integration of organic materials on a single substrate in a monolithic way is highly demanded for the production of fundamental organic electronic components as well as complex integrated circuits. Many of the various methods that have been designed to pattern multiple heterogeneous organic materials on a substrate and the heterogeneous integration of organic single crystals with their crystal growth are described here. Critical issues that have been encountered in the development of high-performance organic integrated electronics are also addressed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Web-Based Interactive Video Vignettes Create a Personalized Active Learning Classroom for Introducing Big Ideas in Introductory Biology

ERIC Educational Resources Information Center

Wright, L. Kate; Newman, Dina L.; Cardinale, Jean A.; Teese, Robert

2016-01-01

The typical "flipped classroom" delivers lecture material in video format to students outside of class in order to make space for active learning in class. But why give students passive material at all? We are developing a set of high-quality online educational materials that promote active, hands-on science learning to aid in teaching…

Method of improving superconducting qualities of fabricated constructs by shock preprocessing of precursor materials

DOEpatents

Nellis, William J.; Maple, M. Brian

1992-01-01

Disclosed is a method of improving the physical properties of superconducting materials which comprises: a. applying a high strain rate deformation to said materi The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California, for the operation of Lawrence Livermore National Laboratory.

Evaluation of analytical markers characterising different drying methods of parsley leaves (Petroselinum crispum L.).

PubMed

Lechtenberg, M; Zumdick, S; Gerhards, C; Schmidt, T J; Hensel, A

2007-12-01

Drying process of parsley leaves from Petroselinum crispum L. can influence the sensory qualities and aromatic taste of this herbal product. Beside oven-dried material, freeze-dried parsley is getting increasingly into the market. In the course of a search for analytical tools to differentiate oven-dried and lyophilised parsley, a HPLC determination of the 6"-O-malonylapiin to apiin ratio was shown to be a suitable marker system. While the ratio is high for fresh and lyophilised leave material, oven-drying leads to demalonylation and, subsequently, to a low malonylapiin--apiin ratio. Additionally, L*a*b colour measurement can be used for quality control to differentiate between different dried parsley raw materials.

Impact Compaction of a Granular Material

NASA Astrophysics Data System (ADS)

Fenton, Gregg; Asay, Blaine; Todd, Steve; Grady, Dennis

2017-06-01

The dynamic behavior of granular materials has importance to a variety of engineering applications. Although, the mechanical behavior of granular materials have been studied extensively for several decades, the dynamic behavior of these materials remains poorly understood. High-quality experimental data are needed to improve our general understanding of granular material compaction physics. This paper describes how an instrumented plunger impact system can be used to measure the compaction process for granular materials at high and controlled strain rates and subsequently used for computational modelling. The experimental technique relies on a gas-gun driven plunger system to generate a compaction wave through a volume of granular material. This volume of material has been redundantly instrumented along the bed length to track the progression of the compaction wave, and the piston displacement is measured with Photon Doppler Velocimetry (PDV). Using the gathered experimental data along with the initial material tap density, a granular material equation of state can be determined.

Application of ICME Methods for the Development of Rapid Manufacturing Technologies

NASA Astrophysics Data System (ADS)

Maiwald-Immer, T.; Göhler, T.; Fischersworring-Bunk, A.; Körner, C.; Osmanlic, F.; Bauereiß, A.

Rapid manufacturing technologies are lately gaining interest as alternative manufacturing method. Due to the large parameter sets applicable in these manufacturing methods and their impact on achievable material properties and quality, support of the manufacturing process development by the use of simulation is highly attractive. This is especially true for aerospace applications with their high quality demands and controlled scatter in the resulting material properties. The applicable simulation techniques to these manufacturing methods are manifold. The paper will focus on the melt pool simulation for a SLM (selective laser melting) process which was originally developed for EBM (electron beam melting). It will be discussed in the overall context of a multi-scale simulation within a virtual process chain.

Growth performance, carcass trait, meat quality and oxidative stability of beef cattle offered alternative silages in a finishing ration.

PubMed

He, L; Yang, J; Chen, W; Zhou, Z; Wu, H; Meng, Q

2018-03-01

As lack of forage resource, alternative roughage sources have been developed for ruminant production and their inclusion would exert a great effect on the dietary nutrition, consequently affecting animal performance. Four silages (corn silage (CS), corn stalk silage (SS), inoculated CS and inoculated SS) were separately offered to 60 Bohai Black cattle (15 cattle/group) during a 24-week finishing period, in which the growth performance, carcass trait, beef quality and oxidative stability of steers were determined. Neither silage material nor silage inoculant exerted a significant effect on the growth performance, carcass trait and oxidative stability of beef cattle (P>0.05). As to beef quality, cattle offered CS had higher (P0.05) on the proximate components and fatty acids profile of beef muscle. There was neither an interaction (P>0.05) between inoculated treatment and silage material. There were no differences (P>0.05) in cholesterol content and meat quality traits in animals fed alternative silages. The collective findings suggest that it is not economical to substitute high-quality forage for relative low-quality forage in a high-concentrate finishing ration of beef cattle and silage inoculant inclusion would not exert a direct effect on animal performance.

Development of New Sensing Materials Using Combinatorial and High-Throughput Experimentation

NASA Astrophysics Data System (ADS)

Potyrailo, Radislav A.; Mirsky, Vladimir M.

New sensors with improved performance characteristics are needed for applications as diverse as bedside continuous monitoring, tracking of environmental pollutants, monitoring of food and water quality, monitoring of chemical processes, and safety in industrial, consumer, and automotive settings. Typical requirements in sensor improvement are selectivity, long-term stability, sensitivity, response time, reversibility, and reproducibility. Design of new sensing materials is the important cornerstone in the effort to develop new sensors. Often, sensing materials are too complex to predict their performance quantitatively in the design stage. Thus, combinatorial and high-throughput experimentation methodologies provide an opportunity to generate new required data to discover new sensing materials and/or to optimize existing material compositions. The goal of this chapter is to provide an overview of the key concepts of experimental development of sensing materials using combinatorial and high-throughput experimentation tools, and to promote additional fruitful interactions between computational scientists and experimentalists.

Marketing Schools: Consumer Goods and Competitive Incentives for Consumer Information

ERIC Educational Resources Information Center

Lubienski, Christopher

2007-01-01

Effective school-choice plans depend on the quality of information available to families. Examining the promotional materials provided by different schools in a highly competitive and diverse urban area tells us not only about the quality of that information but also how schools respond to competitive incentives. This analysis outlines an economic…

Influence of man-made aluminosilicate raw materials on physical and mechanical properties of building materials.

NASA Astrophysics Data System (ADS)

Volodchenko, A. A.; Lesovik, V. S.; Stoletov, A. A.; Glagolev, E. S.; Volodchenko, A. N.; Magomedov, Z. G.

2018-03-01

It has been identified that man-made aluminosilicate raw materials represented by clay rock of varied genesis can be used as energy-efficient raw materials to obtain efficient highly-hollow non-autoclaved silicate materials. A technique of structure formation in the conditions of pressureless steam treatment has been offered. Cementing compounds of non- autoclaved silicate materials based on man-made aluminosilicate raw materials possess hydraulic properties that are conditioned by the process of further formation and recrystallization of calcium silicate hydrates, which optimizes the ratio between gellike and crystalline components and densifies the cementing compound structure, which leads to improvement of performance characteristics. Increasing the performance characteristics of the obtained products is possible by changing the molding conditions. For this reason, in order to create high-density material packaging and, as a result, to increase the strength properties of the products, it is reasonable to use higher pressure, under which raw brick is formed, which will facilitate the increase of quality of highly-hollow products.

Synthesis of Germanium-Tin Alloys by Ion Implantation and Pulsed Laser Melting: Towards a Group IV Direct Band Gap Semiconductor

NASA Astrophysics Data System (ADS)

Tran, Tuan Thien

The germanium-tin (Ge1-xSnx) material system is expected to be a direct bandgap group IV semiconductor at a Sn content of 6.5-11 at.%. Hence there has been much interest in preparing such alloys since they are compatible with silicon and they raise the possibility of integrating photonics functionality into silicon circuitry. However, the maximum solid solubility of Sn in Ge is around 0.5 at.% and non-equilibrium deposition techniques such as molecular beam epitaxy or chemical vapour deposition have been used to achieve the desired high Sn concentrations. In this PhD work, the combination of ion implantation and pulsed laser melting (PLM) is demonstrated to be an alternative promising method to produce a highly Sn concentrated alloy with good crystal quality. In initial studies, it was shown that 100 keV Sn implants followed by PLM produced high quality alloys with up to 6.2 at.%Sn but above these Sn concentrations the crystal quality was poor. The structural properties of the ≤6.2 at.% alloys such as soluble Sn concentration, strain distribution and crystal quality have been characterised by Rutherford backscattering spectrometry (RBS), Raman spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The optical properties and electronic band structure have been studied by spectroscopic ellipsometry. The introduction of substitutional Sn into Ge is shown to either induce a splitting between light and heavy hole subbands or lower the conduction band at the Gamma valley. However, at higher implant doses needed to achieve >6.2 at.% Sn, ion-beam-induced porosity in Ge starts to occur, which drastically reduces the retained amount of the implanted Sn and such microstructure also hinders good crystallisation of the material during PLM. To solve this problem, it was shown that a nanometer thick SiO2 layer deposited on the Ge substrate prior to the implantation can largely eliminate the formation of porosity. This capping SiO2 layer also helps to increase the retained Sn concentration up to 15 at.% after implantation, as well as significantly improving the crystal quality of the Ge-Sn layer after PLM. With the use of the capping layer, a good quality Ge-Sn layer with 9 at.% Sn has been achieved using Sn implants at an energy of 120 keV. However, the thin film alloys produced by 100 keV or 120 keV Sn implantation and PLM are shown to contain compressive strain as a result of the large lattice mismatch between Ge and high Sn content alloys. Such strain compromises the tendency towards a direct bandgap material and hence strain relaxation is highly desirable. A thermal stability study showed that the thin film strained material is metastable up to 400°C, but thereafter Sn comes out of solution and diffuses to the material surface. To investigate a possible pathway to the synthesis of strain-relaxed material, a higher Sn implant energy of 350 keV was used to produce thicker alloy layers. XRD/reciprocal space mapping showed that this thicker alloy material is largely relaxed after PLM, which is beneficial for the direct band gap transition and solves the trade-off between higher Sn concentration and compressive strain. However, RBS indicates a sub-surface band of disorder which suggested a possible mechanism for the strain relaxation. Indeed, TEM examination of such material showed the material relaxed via the generation of non-equilibrium threading defects. Despite such defects, a PL study of this relaxed material found photon emission at a wavelength of 2150 nm for 6-9 at.% Sn alloys. However, the intensity of the emission was variable across different Sn content alloys, presumably as a result of the threading defects. A possible pathway to removing such defects is given that may enable both photodetectors and lasers to be fabricated at wavelengths above 2mum.

Surface ablation of inorganic transparent materials using 70W femtosecond pulses at 1MHz (Conference Presentation)

NASA Astrophysics Data System (ADS)

Mishchik, Konstantin; Gaudfrin, Kevin; Audouard, Eric F.; Mottay, Eric P.; Lopez, John

2017-03-01

Nowadays processing of transparent materials, such as glass, quartz, sapphire and others, is a subject of high interest for worldwide industry since these materials are widely used for mass markets such as consumer electronics, flat display panels manufacturing, optoelectronics or watchmaking industry. The key issue is to combine high throughput, low residual stress and good processing quality in order to avoid chipping and any post-processing step such as grinding or polishing. Complimentary to non-ablative techniques used for zero-kerf glass cutting, surface ablation of such materials is interesting for engraving, grooving as well as full ablation cutting. Indeed this technique enables to process complex parts including via or blind, open or closed, straight or small radius of curvature patterns. We report on surface ablation experiments on transparent materials using a high average power (70W) and high repetition rate (1 MHz) femtosecond laser. These experiments have been done at 1030nm and 515nm on different inorganic transparent materials, such as regular and strengthened glass, borosilicate glass or sapphire, in order to underline their different ablation behavior. Despite the heat accumulation that occurs above 100 kHz we have reached a good compromise between throughput and processing quality. The effects of fluence, pulse-to-pulse overlap and number of passes are discussed in terms of etch rate, ablation efficiency, optimum fluence, maximum achievable depth, micro cracks formation and residual stresses. These experimental results will be also compared with numerical calculations obtained owing to a simple engineering model based on the two-temperature description of the ultrafast ablation.

21 CFR 862.1660 - Quality control material (assayed and unassayed).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Quality control material (assayed and unassayed... Test Systems § 862.1660 Quality control material (assayed and unassayed). (a) Identification. A quality... that may arise from reagent or analytical instrument variation. A quality control material (assayed and...

Use of artificial intelligence in the production of high quality minced meat

NASA Astrophysics Data System (ADS)

Kapovsky, B. R.; Pchelkina, V. A.; Plyasheshnik, P. I.; Dydykin, A. S.; Lazarev, A. A.

2017-09-01

A design for an automatic line for minced meat production according to new production technology based on an innovative meat milling method is proposed. This method allows the necessary degree of raw material comminution at the stage of raw material preparation to be obtained, which leads to production intensification due to the traditional meat mass comminution equipment being unnecessary. To ensure consistent quality of the product obtained, the use of on-line automatic control of the technological process for minced meat production is envisaged. This system has been developed using artificial intelligence methods and technologies. The system is trainable during the operation process, adapts to changes in processed raw material characteristics and to external impacts that affect the system operation, and manufactures meat shavings with minimal dispersion of the typical particle size. The control system includes equipment for express analysis of the chemical composition of the minced meat and its temperature after comminution. In this case, the minced meat production process can be controlled strictly as a function of time, which excludes subjective factors for assessing the degree of finished product readiness. This will allow finished meat products with consistent, targeted high quality to be produced.

The quality study of recycled glass phosphor waste for LED

NASA Astrophysics Data System (ADS)

Tsai, Chun-Chin; Chen, Guan-Hao; Yue, Cheng-Feng; Chen, Cin-Fu; Cheng, Wood-Hi

2017-02-01

To study the feasibility and quality of recycled glass phosphor waste for LED packaging, the experiments were conducted to compare optical characteristics between fresh color conversion layer and that made of recycled waste. The fresh color conversion layer was fabricated through sintering pristine mixture of Y.A.G. powder [yellow phosphor (Y3AlO12 : Ce3+). Those recycled waste glass phosphor re-melted to form Secondary Molten Glass Phosphor (S.M.G.P.). The experiments on such low melting temperature glass results showed that transmission rates of S.M.G.P. are 9% higher than those of first-sintered glass phosphor, corresponding to 1.25% greater average bubble size and 36% more bubble coverage area in S.M.G.P. In the recent years, high power LED modules and laser projectors have been requiring higher thermal stability by using glass phosphor materials for light mixing. Nevertheless, phosphor and related materials are too expensive to expand their markets. It seems a right trend and research goal that recycling such waste of high thermal stability and quality materials could be preferably one of feasible cost-down solutions. This technical approach could bring out brighter future for solid lighting and light source module industries.

Optimal Recycling of Steel Scrap and Alloying Elements: Input-Output based Linear Programming Method with Its Application to End-of-Life Vehicles in Japan.

PubMed

Ohno, Hajime; Matsubae, Kazuyo; Nakajima, Kenichi; Kondo, Yasushi; Nakamura, Shinichiro; Fukushima, Yasuhiro; Nagasaka, Tetsuya

2017-11-21

Importance of end-of-life vehicles (ELVs) as an urban mine is expected to grow, as more people in developing countries are experiencing increased standards of living, while the automobiles are increasingly made using high-quality materials to meet stricter environmental and safety requirements. While most materials in ELVs, particularly steel, have been recycled at high rates, quality issues have not been adequately addressed due to the complex use of automobile materials, leading to considerable losses of valuable alloying elements. This study highlights the maximal potential of quality-oriented recycling of ELV steel, by exploring the utilization methods of scrap, sorted by parts, to produce electric-arc-furnace-based crude alloy steel with minimal losses of alloying elements. Using linear programming on the case of Japanese economy in 2005, we found that adoption of parts-based scrap sorting could result in the recovery of around 94-98% of the alloying elements occurring in parts scrap (manganese, chromium, nickel, and molybdenum), which may replace 10% of the virgin sources in electric arc furnace-based crude alloy steel production.

Material quality assurance risk assessment : [summary].

DOT National Transportation Integrated Search

2013-01-01

With the shift from quality control (QC) of materials and placement techniques : to quality assurance (QA) and acceptance over the years, the role of the Office : of Materials Technology (OMT) has been shifting towards assurance of : material quality...

Composition and luminescence studies of InGaN epilayers grown at different hydrogen flow rates

NASA Astrophysics Data System (ADS)

Taylor, E.; Fang, F.; Oehler, F.; Edwards, P. R.; Kappers, M. J.; Lorenz, K.; Alves, E.; McAleese, C.; Humphreys, C. J.; Martin, R. W.

2013-06-01

Indium gallium nitride (InxGa1 - xN) is a technologically important material for many optoelectronic devices, including LEDs and solar cells, but it remains a challenge to incorporate high levels of InN into the alloy while maintaining sample quality. A series of InGaN epilayers was grown with different hydrogen flow rates (0-200 sccm) and growth temperatures (680-750 °C) to obtain various InN fractions and bright emission in the range 390-480 nm. These 160-nm thick epilayers were characterized through several compositional techniques (wavelength dispersive x-ray spectroscopy, x-ray diffraction, Rutherford backscattering spectrometry) and cathodoluminescence hyperspectral imaging. The compositional analysis with the different techniques shows good agreement when taking into account compositional gradients evidenced in these layers. The addition of small amounts of hydrogen to the gas flow at lower growth temperatures is shown to maintain a high surface quality and luminescence homogeneity. This allowed InN fractions of up to ˜16% to be incorporated with minimal peak energy variations over a mapped area while keeping a high material quality.

High quality transmission Kikuchi diffraction analysis of deformed alloys - Case study

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

Tokarski, Tomasz, E-mail: tokarski@agh.edu.pl

Modern scanning electron microscopes (SEM) equipped with thermally assisted field emission guns (Schottky FEG) are capable of imaging with a resolution in the range of several nanometers or better. Simultaneously, the high electron beam current can be used, which enables fast chemical and crystallographic analysis with a higher resolution than is normally offered by SEM with a tungsten cathode. The current resolution that limits the EDS and EBSD analysis is related to materials' physics, particularly to the electron-specimen interaction volume. The application of thin, electron-transparent specimens, instead of bulk samples, improves the resolution and allows for the detailed analysis ofmore » very fine microstructural features. Beside the typical imaging mode, it is possible to use a standard EBSD camera in such a configuration that only transmitted and scattered electrons are detected. This modern approach was successfully applied to various materials giving rise to significant resolution improvement, especially for the light element magnesium based alloys. This paper presents an insight into the application of the transmission Kikuchi diffraction (TKD) technique applied to the most troublesome, heavily-deformed materials. In particular, the values of the highest possible acquisition rates for high resolution and high quality mapping were estimated within typical imaging conditions of stainless steel and magnesium-yttrium alloy. - Highlights: •Monte Carlo simulations were used to simulate EBSD camera intensity for various measuring conditions. •Transmission Kikuchi diffraction parameters were evaluated for highly deformed, light and heavy elements based alloys. •High quality maps with 20 nm spatial resolution were acquired for Mg and Fe based alloys. •High speed TKD measurements were performed at acquisition rates comparable to the reflection EBSD.« less

The development of silicon carbide-based power electronics devices

NASA Astrophysics Data System (ADS)

Hopkins, Richard H.; Perkins, John F.

1995-01-01

In 1989 Westinghouse created an internally funded initiative to develop silicon carbide materials and device technology for a variety of potential commercial and military applications. Westinghouse saw silicon carbide as having the potential for dual use. For space applications, size and weight reductions could be achieved, together with increased reliability. Terrestrially, uses in harsh-temperature environments would be enabled. Theoretically, the physical and electrical properties of silicon carbide were highly promising for high-power, high-temperature, radiation-hardened electronics. However, bulk material with the requisite electronic qualities was not available, and the methods needed to produce a silicon carbide wafer—to fabricate high-quality devices—and to transition these technologies into a commercial product were considered to be a high-risk investment. It was recognized that through a collaborative effort, the CCDS could provide scientific expertise in several areas, thus reducing this risk. These included modeling of structures, electrical contacts, dielectrics, and epitaxial growth. This collaboration has been very successful, with developed technologies being transferred to Westinghouse.

Durable high strength cement concrete topping for asphalt roads

NASA Astrophysics Data System (ADS)

Vyrozhemskyi, Valerii; Krayushkina, Kateryna; Bidnenko, Nataliia

2017-09-01

Work on improving riding qualities of pavements by means of placing a thin cement layer with high roughness and strength properties on the existing asphalt pavement were conducted in Ukraine for the first time. Such pavement is called HPCM (High Performance Cementitious Material). This is a high-strength thin cement-layer pavement of 8-9 mm thickness reinforced with metal or polymer fiber of less than 5 mm length. Increased grip properties are caused by placement of stone material of 3-5 mm fraction on the concrete surface. As a result of the research, the preparation and placement technology of high-strength cement thin-layer pavement reinforced with fiber was developed to improve friction properties of existing asphalt pavements which ensures their roughness and durability. It must be emphasized that HPCM is a fundamentally new type of thin-layer pavement in which a rigid layer of 10 mm thickness is placed on a non-rigid base thereby improving riding qualities of asphalt pavement at any season of a year.

Do English healthcare settings use 'Choice Architecture' principles in promoting healthy lifestyles for people with psoriasis? An observational study.

PubMed

Keyworth, Chris; Nelson, Pauline A; Griffiths, Christopher E M; Cordingley, Lis; Bundy, Chris

2015-06-02

The influence of environmental factors in shaping behaviour is becoming increasingly prominent in public health policy, but whether health promotion strategies use this knowledge is unknown. Health promotion is important in the management of psoriasis, a long-term inflammatory skin condition, and health centre waiting areas are ideal places to promote health information to such patients. We systematically examined patient information materials containing either general, or specific, health messages for patients with psoriasis. An observation schedule was used to record the frequency and quality of leaflets and posters addressing lifestyle behaviour change in health centre waiting areas. Content analysis was used to analyse: frequency, characteristics and standard of the materials. Across 24 health centres 262 sources of lifestyle information were recorded (median per site = 10; range = 0-40). These were mainly: generic posters/displays of lifestyle support (n = 113); and generic materials in waiting areas (n = 98). Information quality was poor and poorly displayed, with no high quality psoriasis-specific patient materials evident. There is little attempt to promote healthy lifestyle as an important aspect of psoriasis management in the clinic environment. Evidence about using environmental cues/techniques to prompt behaviour change in people with psoriasis does not currently inform the design and display of such information in standard health centre settings, which are prime locations for communicating messages about healthy lifestyle. Future research should test the efficacy and impact of theory-informed, high quality health promotion messages on health outcomes for patients with psoriasis.

Design, quality, and quality assurance of solid recovered fuels for the substitution of fossil feedstock in the cement industry.

PubMed

Sarc, R; Lorber, K E; Pomberger, R; Rogetzer, M; Sipple, E M

2014-07-01

This paper describes the requirements for the production, quality, and quality assurance of solid recovered fuels (SRF) that are increasingly used in the cement industry. Different aspects have to be considered before using SRF as an alternative fuel. Here, a study on the quality of SRF used in the cement industry is presented. This overview is completed by an investigation of type and properties of input materials used at waste splitting and SRF production plants in Austria. As a simplified classification, SRF can be divided into two classes: a fine, high-calorific SRF for the main burner, or coarser SRF material with low calorific value for secondary firing systems, such as precombustion chambers or similar systems. In the present study, SRFs coming from various sources that fall under these two different waste fuel classes are discussed. Both SRFs are actually fired in the grey clinker kiln of the Holcim (Slovensko) plant in Rohožnik (Slovakia). The fine premium-quality material is used in the main burner and the coarse regular-quality material is fed to a FLS Hotdisc combustion device. In general, the alternative fuels are used instead of their substituted fossil fuels. For this, chemical compositions and other properties of SRF were compared to hard coal as one of the most common conventional fuels in Europe. This approach allows to compare the heavy metal input from traditional and alternative fuels and to comment on the legal requirements on SRF that, at the moment, are under development in Europe. © The Author(s) 2014.

Elements of Effective E-Learning Design

ERIC Educational Resources Information Center

Brown, Andrew R.; Voltz, Bradley D.

2005-01-01

Preparing and developing e-learning materials is a costly and time consuming enterprise. This paper highlights the elements of effective design that we consider assist in the development of high quality materials in a cost efficient way. We introduce six elements of design and discuss each in some detail. These elements focus on paying attention…

Nutrient concentrations in leachate and runoff from dairy cattle lots with different surface materials

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) and phosphorus (P) loss from agriculture persists as a water quality issue, and outdoor cattle lots can have a high loss potential. We monitored hydrology and nutrient concentrations in leachate and runoff from dairy heifer lots constructed with three surface materials (soil, sand, bark...

Laser Crystal

NASA Technical Reports Server (NTRS)

1998-01-01

Lightning Optical Corporation, under an SBIR (Small Business Innovative Research) agreement with Langley Research Center, manufactures oxide and fluoride laser gain crystals, as well as various nonlinear materials. The ultimate result of this research program is the commercial availability in the marketplace of a reliable source of high-quality, damage resistant laser material, primarily for diode-pumping applications.

Stamps, Sarcophagi, and Songs: Teaching World History with Online Resources

ERIC Educational Resources Information Center

Schrum, Kelly

2012-01-01

Teaching world history is challenging. In addition to covering the history of the world geographically and chronologically, it is difficult to find high quality, translated materials ready for classroom use. The Roy Rosenzweig Center for History and New Media at George Mason University offers free, online materials, including primary sources,…

Investigation of single crystal ferrite thin films

NASA Technical Reports Server (NTRS)

Mee, J. E.; Besser, P. J.; Elkins, P. E.; Glass, H. L.; Whitcomb, E. C.

1972-01-01

Materials suitable for use in magnetic bubble domain memories were developed for aerospace applications. Practical techniques for the preparation of such materials in forms required for fabrication of computer memory devices were considered. The materials studied were epitaxial films of various compositions of the gallium-substituted yttrium gadolinium iron garnet system. The major emphasis was to determine their bubble properties and the conditions necessary for growing uncracked, high quality films.

Strong Photoluminescence Enhancement in All-Dielectric Fano Metasurface with High Quality Factor.

PubMed

Yuan, Shuai; Qiu, Xingzhi; Cui, Chengcong; Zhu, Liangqiu; Wang, Yuxi; Li, Yi; Song, Jinwen; Huang, Qingzhong; Xia, Jinsong

2017-11-28

All-dielectric metamaterials offer great flexibility for controlling light-matter interaction, owing to their strong electric and magnetic resonances with negligible loss at wavelengths above the material bandgap. Here, we propose an all-dielectric asymmetric metasurface structure exhibiting high quality factor and prominent Fano line shape. Over three-orders photoluminescence enhancement is demonstrated in the fabricated all-dielectric metasurface with record-high quality factor of 1011. We find this strong emission enhancement is attributed to the coherent Fano resonances, which originate from the destructive interferences of antisymmetric displacement currents in the asymmetric all-dielectric metasurface. Our observations show a promising approach to realize light emitters based on all-dielectric metasurfaces.

Controlled Synthesis of Atomically Layered Hexagonal Boron Nitride via Chemical Vapor Deposition.

PubMed

Liu, Juanjuan; Kutty, R Govindan; Liu, Zheng

2016-11-29

Hexagonal boron nitrite (h-BN) is an attractive material for many applications including electronics as a complement to graphene, anti-oxidation coatings, light emitters, etc. However, the synthesis of high-quality h-BN is still a great challenge. In this work, via controlled chemical vapor deposition, we demonstrate the synthesis of h-BN films with a controlled thickness down to atomic layers. The quality of as-grown h-BN is confirmed by complementary characterizations including high-resolution transition electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray photo-electron spectroscopy. This work will pave the way for production of large-scale and high-quality h-BN and its applications as well.

Spectroscopic detection and analysis of atomic emissions during industrial pulsed laser-drilling of structural aerospace alloys

NASA Astrophysics Data System (ADS)

Bright, Robin Michael

The ability to adequately cool internal gas-turbine engine components in next-generation commercial and military aircraft is of extreme importance to the aerospace industry as the demand for high-efficiency engines continues to push operating temperatures higher. Pulsed laser-drilling is rapidly becoming the preferred method of creating cooling holes in high temperature components due a variety of manufacturing advantages of laser-drilling over conventional hole-drilling techniques. As cooling requirements become more demanding, the impact of drilling conditions on material removal behavior and subsequent effects on hole quality becomes critical. In this work, the development of emission spectroscopy as a method to probe the laser-drilling process is presented and subsequently applied to the study of material behavior of various structural aerospace materials during drilling. Specifically, emitted photons associated with energy level transitions within excited neutral atoms in material ejected during drilling were detected and analyzed. Systematic spectroscopic studies indicated that electron energy level populations and calculated electron temperatures within ejected material are dependent on both laser pulse energy and duration. Local thermal conditions detected by the developed method were related to the characteristics of ejected material during drilling and to final hole quality. Finally, methods of utilizing the observed relationships for spectroscopic process monitoring and control were demonstrated.

Heterogeneous Integration of Epitaxial Ge on Si using AlAs/GaAs Buffer Architecture: Suitability for Low-power Fin Field-Effect Transistors

PubMed Central

Hudait, Mantu K.; Clavel, Michael; Goley, Patrick; Jain, Nikhil; Zhu, Yan

2014-01-01

Germanium-based materials and device architectures have recently appeared as exciting material systems for future low-power nanoscale transistors and photonic devices. Heterogeneous integration of germanium (Ge)-based materials on silicon (Si) using large bandgap buffer architectures could enable the monolithic integration of electronics and photonics. In this paper, we report on the heterogeneous integration of device-quality epitaxial Ge on Si using composite AlAs/GaAs large bandgap buffer, grown by molecular beam epitaxy that is suitable for fabricating low-power fin field-effect transistors required for continuing transistor miniaturization. The superior structural quality of the integrated Ge on Si using AlAs/GaAs was demonstrated using high-resolution x-ray diffraction analysis. High-resolution transmission electron microscopy confirmed relaxed Ge with high crystalline quality and a sharp Ge/AlAs heterointerface. X-ray photoelectron spectroscopy demonstrated a large valence band offset at the Ge/AlAs interface, as compared to Ge/GaAs heterostructure, which is a prerequisite for superior carrier confinement. The temperature-dependent electrical transport properties of the n-type Ge layer demonstrated a Hall mobility of 370 cm2/Vs at 290 K and 457 cm2/Vs at 90 K, which suggests epitaxial Ge grown on Si using an AlAs/GaAs buffer architecture would be a promising candidate for next-generation high-performance and energy-efficient fin field-effect transistor applications. PMID:25376723

Transplant Options When You Don't Have a 'Good Match'

MedlinePlus

... for Transplant Nurses , Second Edition. Visit Online Store Patient Education ITNS offers high quality patient education materials in multiple languages. Download Educational Booklets Symposium ...

Quality inspection guided laser processing of irregular shape objects by stereo vision measurement: application in badminton shuttle manufacturing

NASA Astrophysics Data System (ADS)

Qi, Li; Wang, Shun; Zhang, Yixin; Sun, Yingying; Zhang, Xuping

2015-11-01

The quality inspection process is usually carried out after first processing of the raw materials such as cutting and milling. This is because the parts of the materials to be used are unidentified until they have been trimmed. If the quality of the material is assessed before the laser process, then the energy and efforts wasted on defected materials can be saved. We proposed a new production scheme that can achieve quantitative quality inspection prior to primitive laser cutting by means of three-dimensional (3-D) vision measurement. First, the 3-D model of the object is reconstructed by the stereo cameras, from which the spatial cutting path is derived. Second, collaborating with another rear camera, the 3-D cutting path is reprojected to both the frontal and rear views of the object and thus generates the regions-of-interest (ROIs) for surface defect analysis. An accurate visual guided laser process and reprojection-based ROI segmentation are enabled by a global-optimization-based trinocular calibration method. The prototype system was built and tested with the processing of raw duck feathers for high-quality badminton shuttle manufacture. Incorporating with a two-dimensional wavelet-decomposition-based defect analysis algorithm, both the geometrical and appearance features of the raw feathers are quantified before they are cut into small patches, which result in fully automatic feather cutting and sorting.

Strain-free bulk-like GaN grown by hydride-vapor-phase-epitaxy on two-step epitaxial lateral overgrown GaN template

NASA Astrophysics Data System (ADS)

Gogova, D.; Kasic, A.; Larsson, H.; Hemmingsson, C.; Monemar, B.; Tuomisto, F.; Saarinen, K.; Dobos, L.; Pécz, B.; Gibart, P.; Beaumont, B.

2004-07-01

Crack-free bulk-like GaN with high crystalline quality has been obtained by hydride-vapor-phase-epitaxy (HVPE) growth on a two-step epitaxial lateral overgrown GaN template on sapphire. During the cooling down stage, the as-grown 270-μm-thick GaN layer was self-separated from the sapphire substrate. Plan-view transmission electron microscopy images show the dislocation density of the free-standing HVPE-GaN to be ˜2.5×107 cm-2 on the Ga-polar face. A low Ga vacancy related defect concentration of about 8×1015 cm-3 is extracted from positron annihilation spectroscopy data. The residual stress and the crystalline quality of the material are studied by two complementary techniques. Low-temperature photoluminescence spectra show the main neutral donor bound exciton line to be composed of a doublet structure at 3.4715 (3.4712) eV and 3.4721 (3.4718) eV for the Ga- (N-) polar face with the higher-energy component dominating. These line positions suggest virtually strain-free material on both surfaces with high crystalline quality as indicated by the small full width at half maximum values of the donor bound exciton lines. The E1(TO) phonon mode position measured at 558.52 cm-1 (Ga face) by infrared spectroscopic ellipsometry confirms the small residual stress in the material, which is hence well suited to act as a lattice-constant and thermal-expansion-coefficient matched substrate for further homoepitaxy, as needed for high-quality III-nitride device applications.

Use of Pressure Activation in Food Quality Improvement.

PubMed

Shigematsu, Toru

2015-01-01

Beside intensive studies on inactivation microorganisms by high hydrostatic pressure (HP) for food storage, pressure effects on property of food materials have also been studied based on knowledge in pressure effect on biomolecules. Pressure effects on biological membranes and mass transfer in cellular biological materials and on enzyme activity would give an idea that HP treatment can introduce two types of activations into food materials: improved mass transfer and enzyme activity. Studies focusing on these pressure activations on food materials were then reviewed. Rice flour with an exclusively fine mean particle size and small starch damage was obtained due to improved water absorption properties and/or enzyme activity by HP. HP treatment increased of free amino acids and γ-aminobutyric acid (GABA) in rice and soybeans due to improved proteolysis and amino acid metabolism. Improvement of antioxidant activity and alteration of polyphenolic-compounds composition in food materials were also demonstrated by HP treatment. The HP-induced activations on food materials could contribute towards processing technologies for food quality improvement.

High-Quality TiS2 For Li/TiS2 Cells

NASA Technical Reports Server (NTRS)

Huang, Chen-Kuo; Surampudi, Subbarao; Shen, David H.; Delgiannis, Fotios; Halpert, Gerald

1992-01-01

Modified process for synthesis of battery-grade titanium sulfide (TiS2) yields substantially improved material for Li/TiS2 electrochemical cells. Includes all-vapor-phase reaction between sulfur and titanium. Product less dense and more homogeneous, consists of smaller particles of higher crystalline quality, and purer. Cells have high cathode utilization and long cycle life performance. Expected to find applications in rechargeable lithium batteries for spacecraft, military equipment, telecommunication systems, automobiles, and consumer products.

Transmission and reflection SHSG holograms

NASA Astrophysics Data System (ADS)

Kim, Jong Man; Choi, Byung S.; Choi, Yoon S.; Kim, Sun I.; Kim, Jong-Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

2001-06-01

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra- fine grain silver halide (AgHal) emulsions. In particular, high spatial frequency fringes associated with HOEs of the reflection type are difficult to convert employing SHSG processing methods. Therefore, an optimized processing techniques for reflection HOEs recorded in the new AgHal- materials is introduced. Diffraction efficiencies over 90 percent can be obtained for both transmission and reflection diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs, including also high-quality display holograms of the reflection type, both monochrome and full color.

Holographic Optical Elements Recorded in Silver Halide Sensitized Gelatin Emulsions. Part 2. Reflection Holographic Optical Elements

NASA Astrophysics Data System (ADS)

Kim, Jong Man; Choi, Byung So; Choi, Yoon Sun; Kim, Jong Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

2002-03-01

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-fine-grain silver halide (AgHal) emulsions. In particular, high spatial-frequency fringes associated with HOEs of the reflection type are difficult to construct when SHSG processing methods are employed. Therefore an optimized processing technique for reflection HOEs recorded in the new AgHal materials is introduced. Diffraction efficiencies over 90% can be obtained repeatably for reflection diffraction gratings. Understanding the importance of a selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs, also including high-quality display holograms of the reflection type in both monochrome and full color.

Management of MSW in Spain and recovery of packaging steel scrap.

PubMed

Tayibi, Hanan; Peña, Carmen; López, Félix A; López-Delgado, Aurora

2007-01-01

Packaging steel is more advantageously recovered and recycled than other packaging material due to its magnetic properties. The steel used for packaging is of high quality, and post-consumer waste therefore produces high-grade ferrous scrap. Recycling is thus an important issue for reducing raw material consumption, including iron ore, coal and energy. Household refuse management consists of collection/disposal, transport, and processing and treatment - incineration and composting being the most widely used methods in Spain. Total Spanish MSW production exceeds 21 million tons per year, of which 28.1% and 6.2% are treated in compost and incineration plants, respectively. This paper presents a comprehensive study of incineration and compost plants in Spain, including a review of the different processes and technologies employed and the characteristics and quality of the recovered ferrous scrap. Of the total amount of packaging steel scrap recovered from MSW, 38% comes from compost plants and 14% from incineration plants. Ferrous scrap from incineration plants presents a high degree of chemical alteration as a consequence of the thermal process to which the MSW is subjected, particularly the conditions in which the slag is cooled, and accordingly its quality diminishes. Fragmentation and magnetic separation processes produce an enhancement of the scrap quality. Ferrous scrap from compost plants has a high tin content, which negatively affects its recycling. Cleaning and detinning processes are required prior to recycling.

Advances in photonic MOEMS-MEMS device thinning and polishing

NASA Astrophysics Data System (ADS)

McAneny, James J.; Kennedy, Mark; McGroggan, Tom

2010-02-01

As devices continue to increase in density and complexity, ever more stringent specifications are placed on the wafer scale equipment manufacturers to produce higher quality and higher output. This results in greater investment and more resource being diverted into producing tools and processes which can meet the latest demanding criteria. Substrate materials employed in the fabrication process range from Silicon through InP and include GaAs, InSb and other optical networking or waveguide materials. With this diversity of substrate materials presented, controlling the geometries and surfaces grows progressively more challenging. This article highlights the key parameters which require close monitoring and control in order to produce highly precise wafers as part of the fabrication process. Several as cut and commercially available standard polished wafer materials were used in empirical trials to test tooling options in generating high levels of geometric control over the dimensions while producing high quality surface finishes. Specific attention was given to the measurement and control of: flatness; parallelism/TTV; surface roughness and final target thickness as common specifications required by the industry. By combining the process variables of: plate speed, download pressure, slurry flow rate and concentration, pad type and wafer travel path across the polish pad, the effect of altering these variables was recorded and analysed to realize the optimum process conditions for the materials under test. The results being then used to design improved methods and tooling for the thinning and polishing of photonic materials applied to MOEMS-MEMS device fabrication.

Performance characterization of water recovery and water quality from chemical/organic waste products

NASA Technical Reports Server (NTRS)

Moses, W. M.; Rogers, T. D.; Chowdhury, H.; Cullingford, H. S.

1989-01-01

The water reclamation subsystems currently being evaluated for the Space Shuttle Freedom are briefly reviewed with emphasis on a waste water management system capable of processing wastes containing high concentrations of organic/inorganic materials. The process combines low temperature/pressure to vaporize water with high temperature catalytic oxidation to decompose volatile organics. The reclaimed water is of potable quality and has high potential for maintenance under sterile conditions. Results from preliminary experiments and modifications in process and equipment required to control reliability and repeatability of system operation are presented.

Heteroepitaxial Growth of Germanium-on-Silicon Using Ultrahigh-Vacuum Chemical Vapor Deposition with RF Plasma Enhancement

NASA Astrophysics Data System (ADS)

Alharthi, Bader; Grant, Joshua M.; Dou, Wei; Grant, Perry C.; Mosleh, Aboozar; Du, Wei; Mortazavi, Mansour; Li, Baohua; Naseem, Hameed; Yu, Shui-Qing

2018-05-01

Germanium (Ge) films have been grown on silicon (Si) substrate by ultrahigh-vacuum chemical vapor deposition with plasma enhancement (PE). Argon plasma was generated using high-power radiofrequency (50 W) to assist in germane decomposition at low temperature. The growth temperature was varied in the low range of 250°C to 450°C to make this growth process compatible with complementary metal-oxide-semiconductor technology. The material and optical properties of the grown Ge films were investigated. The material quality was determined by Raman and x-ray diffraction techniques, revealing growth of crystalline films in the temperature range of 350°C to 450°C. Photoluminescence spectra revealed improved optical quality at growth temperatures of 400°C and 450°C. Furthermore, material quality study using transmission electron microscopy revealed existence of defects in the Ge layer grown at 400°C. Based on the etch pit density, the average threading dislocation density in the Ge layer obtained at this growth temperature was measured to be 4.5 × 108 cm-2. This result was achieved without any material improvement steps such as use of graded buffer or thermal annealing. Comparison between PE and non-plasma-enhanced growth, in the same machine at otherwise the same growth conditions, indicated increased growth rate and improved material and optical qualities for PE growth.

High-frequency and high-quality silicon carbide optomechanical microresonators

PubMed Central

Lu, Xiyuan; Lee, Jonathan Y.; Lin, Qiang

2015-01-01

Silicon carbide (SiC) exhibits excellent material properties attractive for broad applications. We demonstrate the first SiC optomechanical microresonators that integrate high mechanical frequency, high mechanical quality, and high optical quality into a single device. The radial-breathing mechanical mode has a mechanical frequency up to 1.69 GHz with a mechanical Q around 5500 in atmosphere, which corresponds to a fm · Qm product as high as 9.47 × 1012 Hz. The strong optomechanical coupling allows us to efficiently excite and probe the coherent mechanical oscillation by optical waves. The demonstrated devices, in combination with the superior thermal property, chemical inertness, and defect characteristics of SiC, show great potential for applications in metrology, sensing, and quantum photonics, particularly in harsh environments that are challenging for other device platforms. PMID:26585637

Advanced Electrical Materials and Component Development

NASA Technical Reports Server (NTRS)

Schwarze, Gene E.

2003-01-01

The primary means to develop advanced electrical components is to develop new and improved materials for magnetic components (transformers, inductors, etc.), capacitors, and semiconductor switches and diodes. This paper will give a description and status of the internal and external research sponsored by NASA Glenn Research Center on soft magnetic materials, dielectric materials and capacitors, and high quality silicon carbide (SiC) atomically smooth substrates. The rationale for and the benefits of developing advanced electrical materials and components for the PMAD subsystem and also for the total power system will be briefly discussed.

Microbiological Spoilage of Spices, Nuts, Cocoa, and Coffee

NASA Astrophysics Data System (ADS)

Pinkas, Joan M.; Battista, Karen; Morille-Hinds, Theodora

Spices, nuts, cocoa, and coffee are raw materials that may be used alone or as ingredients in the manufacture of processed food products. The control of microbiological spoilage of these raw materials at the ingredient stage will enable the food processor to better assure the production of high-quality foods with an acceptable shelf life. While this chapter is limited to four materials, many of the spoilage control procedures recommended can also be applied to other raw materials of a similar nature.

Choosing a Family Doctor

MedlinePlus

... of Family Physicians (AAFP). The AAFP provides high-quality learning opportunities for family physicians, as well as patient education materials and practice management support. When to see a doctor Congratulations on ...

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

Boxley, Chett J.; Kadota, Rod

This research program performed by Ceramatec may significantly increase the beneficial utilization of fly ash, and improve the overall performance of high quality animal litter products. Ceramatec has developed a novel high surface area material, which is capable of ammonia adsorption. High surface area zeolites when combined with agglomerated fly ash can significantly reduce the use of naturally mined materials (i.e. clay bentonite) for animal litter manufacture. This not only preserves natural resources and the natural environment, but it also will reduce CO 2 emissions, via the reduced need for heavy mining equipment. This novel animal litter is made withmore » over 85% of recycled materials, thus preventing their disposition to landfills. The novel litter material is similar to traditional clay-like litters, and it is clumpable and has superior odor control properties.« less

Fish gelatin.

PubMed

Boran, Gokhan; Regenstein, Joe M

2010-01-01

Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed. Copyright © 2010 Elsevier Inc. All rights reserved.

Web portal for dynamic creation and publication of teaching materials in multiple formats from a single source representation

NASA Astrophysics Data System (ADS)

Roganov, E. A.; Roganova, N. A.; Aleksandrov, A. I.; Ukolova, A. V.

2017-01-01

We implement a web portal which dynamically creates documents in more than 30 different formats including html, pdf and docx from a single original material source. It is obtained by using a number of free software such as Markdown (markup language), Pandoc (document converter), MathJax (library to display mathematical notation in web browsers), framework Ruby on Rails. The portal enables the creation of documents with a high quality visualization of mathematical formulas, is compatible with a mobile device and allows one to search documents by text or formula fragments. Moreover, it gives professors the ability to develop the latest technology educational materials, without qualified technicians' assistance, thus improving the quality of the whole educational process.

Practical applications of nondestructive materials characterization

NASA Astrophysics Data System (ADS)

Green, Robert E., Jr.

1992-10-01

Nondestructive evaluation (NDE) techniques are reviewed for applications to the industrial production of materials including microstructural, physical, and chemical analyses. NDE techniques addressed include: (1) double-pulse holographic interferometry for sealed-package leak testing; (2) process controls for noncontact metals fabrication; (3) ultrasonic detections of oxygen contamination in titanium welds; and (4) scanning acoustic microscopy for the evaluation of solder bonds. The use of embedded sensors and emerging NDE concepts provides the means for controlling the manufacturing and quality of quartz crystal resonators, nickel single-crystal turbine blades, and integrated circuits. Advances in sensor technology and artificial intelligence algorithms and the use of embedded sensors combine to make NDE technology highly effective in controlling industrial materials manufacturing and the quality of the products.

Technology development of fabrication techniques for advanced solar dynamic concentrators

NASA Technical Reports Server (NTRS)

Richter, Scott W.

1991-01-01

The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

Femtopulse laser-based mask repair in the DUV wavelength regime

NASA Astrophysics Data System (ADS)

Ghadiali, Firoz; Tolani, Vikram; Nagpal, Rajesh; Robinson, Tod; LeClaire, Jeff; Bozak, Ron; Lee, David A.; White, Roy

2006-05-01

Deep ultraviolet (DUV) femtosecond-pulsed laser ablation has numerous highly desirable properties for subtractive photomask defect repair. These qualities include high removal rates, resolution better than the focused spot size, minimized redeposition of the ablated material (rollup and splatter), and a negligible heat affected zone. The optical properties of the photomask result in a broad repair process window because the absorber film (whether Cr or MoSi) and the transmissive substrate allow for a high degree of material removal selectivity. Repair results and process parameters from such a system are examined in light of theoretical considerations. In addition, the practical aspects of the operation of this system in a production mask house environment are reviewed from the standpoint of repair quality, capability, availability, and throughput. Focus is given to the benefit received by the mask shop, and to the technical performance of the system.

The Architecture Design of Detection and Calibration System for High-voltage Electrical Equipment

NASA Astrophysics Data System (ADS)

Ma, Y.; Lin, Y.; Yang, Y.; Gu, Ch; Yang, F.; Zou, L. D.

2018-01-01

With the construction of Material Quality Inspection Center of Shandong electric power company, Electric Power Research Institute takes on more jobs on quality analysis and laboratory calibration for high-voltage electrical equipment, and informationization construction becomes urgent. In the paper we design a consolidated system, which implements the electronic management and online automation process for material sampling, test apparatus detection and field test. In the three jobs we use QR code scanning, online Word editing and electronic signature. These techniques simplify the complex process of warehouse management and testing report transferring, and largely reduce the manual procedure. The construction of the standardized detection information platform realizes the integrated management of high-voltage electrical equipment from their networking, running to periodic detection. According to system operation evaluation, the speed of transferring report is doubled, and querying data is also easier and faster.

Recent progress on biomass co-pyrolysis conversion into high-quality bio-oil.

PubMed

Hassan, H; Lim, J K; Hameed, B H

2016-12-01

Co-pyrolysis of biomass with abundantly available materials could be an economical method for production of bio-fuels. However, elimination of oxygenated compounds poses a considerable challenge. Catalytic co-pyrolysis is another potential technique for upgrading bio-oils for application as liquid fuels in standard engines. This technique promotes the production of high-quality bio-oil through acid catalyzed reduction of oxygenated compounds and mutagenic polyaromatic hydrocarbons. This work aims to review and summarize research progress on co-pyrolysis and catalytic co-pyrolysis, as well as their benefits on enhancement of bio-oils derived from biomass. This review focuses on the potential of plastic wastes and coal materials as co-feed in co-pyrolysis to produce valuable liquid fuel. This paper also proposes future directions for using this technique to obtain high yields of bio-oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polymer matrix composites research at NASA Lewis Research Center

NASA Technical Reports Server (NTRS)

Serafini, T. T.

1982-01-01

The in situ polymerization of monomer reactants (PMR) approach was demonstrated to be a powerful approach for solving many of the processing difficulties associated with the use of high temperature resistant polymers as matrix resins in high performance composites. The PMR-15 polyimide provides the best overall balance of processing characteristics and elevated temperature properties. The excellent properties and commercial availability of composite materials based on PMR-15 led to their acceptance as viable engineering materials. The PMR-15 composites are used to produce a variety of high quality structural components.

Suleika and Hatem Revisited: Uncovering the Material Advantages of Identifying as a Male Composer

ERIC Educational Resources Information Center

Legg, Robert; Jeffery, David

2018-01-01

Persuasive arguments have been made for the existence of pedagogical discourses that invoke gender as a factor in the ascription of quality to musical compositions, and previous research has shown that some music teachers ascribe "maleness" to the characteristics that they regard as markers of high quality. Drawing upon Lucy Green's…

Precision manufacturing for clinical-quality regenerative medicines.

PubMed

Williams, David J; Thomas, Robert J; Hourd, Paul C; Chandra, Amit; Ratcliffe, Elizabeth; Liu, Yang; Rayment, Erin A; Archer, J Richard

2012-08-28

Innovations in engineering applied to healthcare make a significant difference to people's lives. Market growth is guaranteed by demographics. Regulation and requirements for good manufacturing practice-extreme levels of repeatability and reliability-demand high-precision process and measurement solutions. Emerging technologies using living biological materials add complexity. This paper presents some results of work demonstrating the precision automated manufacture of living materials, particularly the expansion of populations of human stem cells for therapeutic use as regenerative medicines. The paper also describes quality engineering techniques for precision process design and improvement, and identifies the requirements for manufacturing technology and measurement systems evolution for such therapies.

Lattice Cleaving: A Multimaterial Tetrahedral Meshing Algorithm with Guarantees

PubMed Central

Bronson, Jonathan; Levine, Joshua A.; Whitaker, Ross

2014-01-01

We introduce a new algorithm for generating tetrahedral meshes that conform to physical boundaries in volumetric domains consisting of multiple materials. The proposed method allows for an arbitrary number of materials, produces high-quality tetrahedral meshes with upper and lower bounds on dihedral angles, and guarantees geometric fidelity. Moreover, the method is combinatoric so its implementation enables rapid mesh construction. These meshes are structured in a way that also allows grading, to reduce element counts in regions of homogeneity. Additionally, we provide proofs showing that both element quality and geometric fidelity are bounded using this approach. PMID:24356365

Indoor Air Quality in Central Appalachia Homes Impacted by Wood and Coal Use

PubMed Central

Paulin, Laura M.; Williams, D’Ann; Oberweiser, Charles; Diette, Gregory B.; Breysse, Patrick N.; McCormack, Meredith M.; Matsui, Elizabeth C.; Peng, Roger; Metts, Tricia A.; Hansel, Nadia N.

2016-01-01

Though the high prevalence of biomass fuel use in the developing world is widely known, the use of burning biomass for cooking and heating in the developed world is under-recognized. Combustion materials including coal and wood are also used for heating in some areas of the United States. We conducted a pilot study to assess the feasibility of conducting indoor environmental monitoring in rural Appalachia. We sought to explore the type of biomass being used for home heating and its impact upon indoor air quality in non-heating and heating seasons. Residential indoor air monitoring for particulate matter (PM) and nitrogen dioxide (NO2) was conducted in Lee County, Virginia. Homes had evidence of poor indoor air quality with high concentrations of indoor PM and a large burden of cigarette smoking. Further characterization of indoor combustion material use in this region to determine the health impacts associated with such exposures is warranted. PMID:27738549

Effects of crystalline quality and electrode material on fatigue in Pb(Zr,Ti)O3 thin film capacitors

NASA Astrophysics Data System (ADS)

Lee, J.; Johnson, L.; Safari, A.; Ramesh, R.; Sands, T.; Gilchrist, H.; Keramidas, V. G.

1993-07-01

Pb(Zr(0.52)Ti(0.48))O3 (PZT)/Y1Ba2Cu3O(x) (YBCO) heterostructures were grown by pulsed laser deposition, in which PZT films were epitaxial, highly oriented, or polycrystalline. These PZT films were obtained by varying the deposition temperature from 550 to 760 C or by using various substrates such as SrTiO3 (100), MgO (100), and r-plane sapphire. PZT films with Pt top electrodes exhibited large fatigue with 35-50 percent loss of the remanent polarization after 10 exp 9 cycles, depending on the crystalline quality. Polycrystalline films showed better fatigue resistance than epitaxial or highly oriented films. However, PZT films with both top and bottom YBCO electrodes had significantly improved fatigue resistance for both epitaxial and polycrystalline films. Electrode material seems to be a more important parameter in fatigue than the crystalline quality of the PZT films.

Hybrid friction stir welding for dissimilar materials through electro-plastic effect

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

Liu, Xun; Lan, Shuhuai; Ni, Jun

A hybrid Friction Stir Welding approach and device for dissimilar materials joining employing Electro-Plastic Effect. The approach and device include an introduction of high density, short period current pulses into traditional friction stir welding process, which therefore can generate a localized softened zone in the workpiece during plastic stirring without significant additional temperature increase. This material softened zone is created by high density current pulses based on Electro-Plastic Effect and will move along with the friction stir welding tool. Smaller downward force, larger processing window and better joint quality for dissimilar materials are expected to be achieved through this hybridmore » welding technique.« less

Material characterization and defect inspection in ultrasound images

NASA Astrophysics Data System (ADS)

Zmola, Carl; Segal, Andrew C.; Lovewell, Brian; Mahdavieh, Jacob; Ross, Joseph; Nash, Charles

1992-08-01

The use of ultrasonic imaging to analyze defects and characterize materials is critical in the development of non-destructive testing and non-destructive evaluation (NDT/NDE) tools for manufacturing. To develop better quality control and reliability in the manufacturing environment advanced image processing techniques are useful. For example, through the use of texture filtering on ultrasound images, we have been able to filter characteristic textures from highly textured C-scan images of materials. The materials have highly regular characteristic textures which are of the same resolution and dynamic range as other important features within the image. By applying texture filters and adaptively modifying their filter response, we have examined a family of filters for removing these textures.

NDE standards for high temperature materials

NASA Technical Reports Server (NTRS)

Vary, Alex

1991-01-01

High temperature materials include monolithic ceramics for automotive gas turbine engines and also metallic/intermetallic and ceramic matrix composites for a range of aerospace applications. These are materials that can withstand extreme operating temperatures that will prevail in advanced high-efficiency gas turbine engines. High temperature engine components are very likely to consist of complex composite structures with three-dimensionality interwoven and various intermixed ceramic fibers. The thermomechanical properties of components made of these materials are actually created in-place during processing and fabrication stages. The complex nature of these new materials creates strong incentives for exact standards for unambiguous evaluations of defects and microstructural characteristics. NDE techniques and standards that will ultimately be applicable to production and quality control of high temperature materials and structures are still emerging. The needs range from flaw detection to below 100 micron levels in monolithic ceramics to global imaging of fiber architecture and matrix densification anomalies in composites. The needs are different depending on the processing stage, fabrication method, and nature of the finished product. The standards are discussed that must be developed in concert with advances in NDE technology, materials processing research, and fabrication development. High temperature materials and structures that fail to meet stringent specifications and standards are unlikely to compete successfully either technologically or in international markets.

High-performance flexible microwave passives on plastic

NASA Astrophysics Data System (ADS)

Ma, Zhenqiang; Seo, Jung-Hun; Cho, Sang June; Zhou, Weidong

2014-06-01

We report the demonstration of bendable inductors, capacitors and switches fabricated on a polyethylene terephthalate (PET) substrate that can operate at high microwave frequencies. By employing bendable dielectric and single crystalline semiconductor materials, spiral inductors and metal-insulator-metal (MIM) capacitors with high quality factors and high resonance frequencies and single-pole, single-throw (SPST) switches were archived. The effects of mechanical bending on the performance of inductors, capacitors and switches were also measured and analyzed. We further investigated the highest possible resonance frequencies and quality factors of inductors and capacitors and, high frequency responses and insertion loss. These demonstrations will lead to flexible radio-frequency and microwave systems in the future.

Fast Neutron Tomography of Low-Z Object in High-Z Material Shielding

NASA Astrophysics Data System (ADS)

Babai, Ruth Weiss; Sabo-Napadensky, Iris; Bar, Doron; Mor, Ilan; Tamim, Noam; Dangendorf, Volker; Tittelmeier, Kai; Bromberger, Benjamin; Weierganz, Mathias

The technique and first results of Fast Neutron Tomography (FNCT) experiments are presented which are performed at the accelerator facility of PTB, Germany. A high-intensity neutron beam of broad spectral distribution with an average energy of 5.5 MeV, was produced by 11.5 MeV deuterons impinging upon a thick beryllium target. The capability of FNCT for high contrast imaging of low-Z materials embedded in thick high-Z shielding materials is demonstrated, which is superior to more conventional high-energy X-ray imaging techniques. For demonstrating the method special test objects were prepared: One consisted of an assembled polyethylene cylinder with holes of various diameters and directions drilled in its surface and inner parts. The plastic phantom was inserted into lead cylinders of different thicknesses. The detector system consisted of a plastic scintillator along with a dedicated optics, image-intensifier and a CCD camera. Two scintillator screens were compared: a bulk plastic scintillator screen and a fibres optical scintillator screen. The tomographic scans were taken in two geometrical configurations: cone beam and semi-fan beam configuration. The image quality favours the semi-fan beam configuration which on the other hand is more time consuming The obtained tomographic images and a comparison of the imaging quality between the different experimental conditions will be presented.

A comparative study of zirconium and titanium implants in rat: osseointegration and bone material quality.

PubMed

Hoerth, Rebecca M; Katunar, María R; Gomez Sanchez, Andrea; Orellano, Juan C; Ceré, Silvia M; Wagermaier, Wolfgang; Ballarre, Josefina

2014-02-01

Permanent metal implants are widely used in human medical treatments and orthopedics, for example as hip joint replacements. They are commonly made of titanium alloys and beyond the optimization of this established material, it is also essential to explore alternative implant materials in view of improved osseointegration. The aim of our study was to characterize the implant performance of zirconium in comparison to titanium implants. Zirconium implants have been characterized in a previous study concerning material properties and surface characteristics in vitro, such as oxide layer thickness and surface roughness. In the present study, we compare bone material quality around zirconium and titanium implants in terms of osseointegration and therefore characterized bone material properties in a rat model using a multi-method approach. We used light and electron microscopy, micro Raman spectroscopy, micro X-ray fluorescence and X-ray scattering techniques to investigate the osseointegration in terms of compositional and structural properties of the newly formed bone. Regarding the mineralization level, the mineral composition, and the alignment and order of the mineral particles, our results show that the maturity of the newly formed bone after 8 weeks of implantation is already very high. In conclusion, the bone material quality obtained for zirconium implants is at least as good as for titanium. It seems that the zirconium implants can be a good candidate for using as permanent metal prosthesis for orthopedic treatments.

Radiation hardness studies of CdTe thin films for clinical high-energy photon beam detectors

NASA Astrophysics Data System (ADS)

Shvydka, Diana; Parsai, E. I.; Kang, J.

2008-02-01

In radiation oncology applications, the need for higher-quality images has been driven by recent advances in radiation delivery systems that require online imaging. The existing electronic imaging devices commonly used to acquire portal images implement amorphous silicon (a-Si) detector, which exhibits poor image quality. Efforts for improvement have mostly been in the areas of noise and scatter reduction through software. This has not been successful due to inherent shortcomings of a-Si material. Cadmium telluride (CdTe) semiconductor has long been recognized as highly suitable for use in X-ray detectors in both spectroscopic and imaging applications. Development of such systems has mostly concentrated on single crystal CdTe. Recent advances in thin-film deposition technology suggest replacement of crystalline material with its polycrystalline counterpart, offering ease of large-area device fabrication and achievement of higher resolution as well as a favorable cost difference. While bulk CdTe material was found to have superior radiation hardness, thin films have not been evaluated from that prospective, in particular under high-energy photon beam typical of radiation treatment applications. We assess the performance of thin-film CdTe devices utilizing 6 MeV photon beam and find no consistent trend for material degradation under doses far exceeding the typical radiation therapy detector lifetime dose.

A novel x-ray detector design with higher DQE and reduced aliasing: Theoretical analysis of x-ray reabsoprtion in detector converter material

NASA Astrophysics Data System (ADS)

Nano, Tomi; Escartin, Terenz; Karim, Karim S.; Cunningham, Ian A.

2016-03-01

The ability to improve visualization of structural information in digital radiography without increasing radiation exposures requires improved image quality across all spatial frequencies, especially at high frequencies. The detective quantum efficiency (DQE) as a function of spatial frequency quantifies image quality given by an x-ray detector. We present a method of increasing DQE at high spatial frequencies by improving the modulation transfer function (MTF) and reducing noise aliasing. The Apodized Aperature Pixel (AAP) design uses a detector with micro-elements to synthesize desired pixels and provide higher DQE than conventional detector designs. A cascaded system analysis (CSA) that incorporates x-ray interactions is used for comparison of the theoretical MTF, noise power spectrum (NPS), and DQE. Signal and noise transfer through the converter material is shown to consist of correlated an uncorrelated terms. The AAP design was shown to improve the DQE of both material types that have predominantly correlated transfer (such as CsI) and predominantly uncorrelated transfer (such as Se). Improvement in the MTF by 50% and the DQE by 100% at the sampling cut-off frequency is obtained when uncorrelated transfer is prevalent through the converter material. Optimizing high-frequency DQE results in improved image contrast and visualization of small structures and fine-detail.

Challenges in the quality assurance of elemental and isotopic analyses in the nuclear domain benefitting from high resolution ICP-OES and sector field ICP-MS.

PubMed

Krachler, Michael; Alvarez-Sarandes, Rafael; Van Winckel, Stefaan

Accurate analytical data reinforces fundamentally the meaningfulness of nuclear fuel performance assessments and nuclear waste characterization. Regularly lacking matrix-matched certified reference materials, quality assurance of elemental and isotopic analysis of nuclear materials remains a challenging endeavour. In this context, this review highlights various dedicated experimental approaches envisaged at the European Commission-Joint Research Centre-Institute for Transuranium Elements to overcome this limitation, mainly focussing on the use of high resolution-inductively coupled plasma-optical emission spectrometry (HR-ICP-OES) and sector field-inductively coupled plasma-mass spectrometry (SF-ICP-MS). However, also α- and γ-spectrometry are included here to help characterise extensively the investigated actinide solutions for their actual concentration, potential impurities and isotopic purity.

Selective Laser Melting of Hot Gas Turbine Components: Materials, Design and Manufacturing Aspects

NASA Astrophysics Data System (ADS)

Goutianos, Stergios

2017-07-01

Selective Laser Melting (SLM) allows the design and manufacturing of novel parts and structures with improved performance e.g. by incorporating complex and more efficient cooling schemes in hot gas turbine parts. In contrast to conventional manufacturing of removing material, with SLM parts are built additively to nearly net shape. This allows the fabrication of arbitrary complex geometries that cannot be made by conventional manufacturing techniques. However, despite the powerful capabilities of SLM, a number of issues (e.g. part orientation, support structures, internal stresses), have to be considered in order to manufacture cost-effective and high quality parts at an industrial scale. These issues are discussed in the present work from an engineering point of view with the aim to provide simple quidelines to produce high quality SLM parts.

Genetic Improvement of Switchgrass and Other Herbaceous Plants for Use as Biomass Fuel Feedstock

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

Vogel, K.P.

2001-01-11

It should be highly feasible to genetically modify the feedstock quality of switchgrass and other herbaceous plants using both conventional and molecular breeding techniques. Effectiveness of breeding to modify herbages of switchgrass and other perennial and annual herbaceous species has already been demonstrated. The use of molecular markers and transformation technology will greatly enhance the capability of breeders to modify the plant structure and cell walls of herbaceous plants. It will be necessary to monitor gene flow to remnant wild populations of plants and have strategies available to curtail gene flow if it becomes a potential problem. It also willmore » be necessary to monitor plant survival and long-term productivity as affected by genetic changes that improve forage quality. Information on the conversion processes that will be used and the biomass characteristics that affect conversion efficiency and rate is absolutely essential as well as information on the relative economic value of specific traits. Because most forage or biomass quality characteristics are highly affected by plant maturity, it is suggested that plant material of specific maturity stages be used in research to determining desirable feedstock quality characteristics. Plant material could be collected at various stages of development from an array of environments and storage conditions that could be used in conversion research. The same plant material could be used to develop NIRS calibrations that could be used by breeders in their selection programs and also to develop criteria for a feedstock quality assessment program. Breeding for improved feedstock quality will likely affect the rate of improvement of biomass production per acre. If the same level of resources are used, multi-trait breeding simply reduces the selection pressure and hence the breeding progress that can be made for a single trait unless all the traits are highly correlated. Since desirable feedstock traits are likely to be similar to IVDMD, it is likely that they will not be highly positively correlated with yield. Hence to achieve target yields and improve specific quality traits, it will likely be necessary to increase the resources available to plant breeders. Marker assisted selection will be extremely useful in breeding for quality traits, particularly for traits that can be affected by modifying a few genes. Genetic markers are going to be needed for monitoring gene flow to wild populations. Transformation will be a very useful tool for determining the affects of specific genes on biomass feedstock quality.« less

Superconducting cavity material for the European XFEL

NASA Astrophysics Data System (ADS)

Singer, W.; Singer, X.; Brinkmann, A.; Iversen, J.; Matheisen, A.; Navitski, A.; Tamashevich, Y.; Michelato, P.; Monaco, L.

2015-08-01

Analysis of the strategy for superconducting cavity material procurement and quality management is done on the basis of the experience with the cavity production for the European x-ray free electron laser (EXFEL) facility. An adjustment of the material specification to EXFEL requirements, procurement of material, quality control (QC), documentation, and shipment to cavity producers have been worked out and carried out by DESY. A multistep process of qualification of the material suppliers included detailed material testing, single- and nine-cell cavity fabrication, and cryogenic radiofrequency tests. Production of about 25 000 semi-finished parts of high purity niobium and niobium-titanium alloy in a period of three years has been divided finally between companies Heraeus, Tokyo Denkai, Ningxia OTIC, and PLANSEE. Consideration of large-grain (LG) material as a possible option for the EXFEL has resulted in the production of one cryogenic module consisting of seven (out of eight) LG cavities. LG materials fulfilled the EXFEL requirements and showed even 25% to 30% higher unloaded quality factor. A possible shortage of the required quantity of LG material on the market led, however, to the choice of conventional fine-grain (FG) material. Eddy-current scanning (ECS) has been applied as an additional QC tool for the niobium sheets and contributed significantly to the material qualification and sorting. Two percent of the sheets have been rejected, which potentially could affect up to one-third of the cavities. The main imperfections and defects in the rejected sheets have been analyzed. Samples containing foreign material inclusions have been extracted from the sheets and electrochemically polished. Some inclusions remained even after 150 μm surface layer removal. Indications of foreign material inclusions have been found in the industrially fabricated and treated cavities and a deeper analysis of the defects has been performed.

Molecular Beam Epitaxy of lithium niobium oxide multifunctional materials

NASA Astrophysics Data System (ADS)

Tellekamp, M. Brooks; Shank, Joshua C.; Doolittle, W. Alan

2017-04-01

The role of stoichiometry and growth temperature in the preferential nucleation of material phases in the Li-Nb-O family are explored yielding an empirical growth phase diagram. It is shown that while single parameter variation often produces multi-phase films, combining substrate temperature control with the previously published lithium flux limited growth allows the repeatable growth of high quality single crystalline films of many different oxide phases. Higher temperatures (800-1050 °C) than normally used in MBE were necessary to achieve high quality materials. At these temperatures the desorption of surface species is shown to play an important role in film composition. Using this method single phase films of NbO, NbO2, LiNbO2, Li3NbO4, LiNbO3, and LiNb3O8 have been achieved in the same growth system, all on c-plane sapphire. Finally, the future of these films in functional oxide heterostructures is briefly discussed.

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

Levin, Barnaby D. A.; Padgett, Elliot; Chen, Chien-Chun

Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co 2 P nanocrystal, platinum nanoparticles on a carbonmore » nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.« less

High Quality 3D Photonics using Nano Imprint Lithography of Fast Sol-gel Materials.

PubMed

Bar-On, Ofer; Brenner, Philipp; Siegle, Tobias; Gvishi, Raz; Kalt, Heinz; Lemmer, Uli; Scheuer, Jacob

2018-05-18

A method for the realization of low-loss integrated optical components is proposed and demonstrated. This approach is simple, fast, inexpensive, scalable for mass production, and compatible with both 2D and 3D geometries. The process is based on a novel dual-step soft nano imprint lithography process for producing devices with smooth surfaces, combined with fast sol-gel technology providing highly transparent materials. As a concrete example, this approach is demonstrated on a micro ring resonator made by direct laser writing (DLW) to achieve a quality factor improvement from one hundred thousand to more than 3 million. To the best of our knowledge this also sets a Q-factor record for UV-curable integrated micro-ring resonators. The process supports the integration of many types of materials such as light-emitting, electro-optic, piezo-electric, and can be readily applied to a wide variety of devices such as waveguides, lenses, diffractive elements and more.

Epitaxial thin film growth in outer space

NASA Technical Reports Server (NTRS)

Ignatiev, Alex; Chu, C. W.

1988-01-01

A new concept for materials processing in space exploits the ultravacuum component of space for thin-film epitaxial growth. The unique LEO space environment is expected to yield 10-ftorr or better pressures, semiinfinite pumping speeds, and large ultravacuum volume (about 100 cu m) without walls. These space ultravacuum properties promise major improvement in the quality, unique nature, and throughput of epitaxially grown materials, including semiconductors, magnetic materials, and thin-film high-temperature superconductors.

Method for producing high quality oxide films on substrates

DOEpatents

Ruckman, Mark W.; Strongin, Myron; Gao, Yong L.

1993-01-01

A method for providing an oxide film of a material on the surface of a substrate using a reactive deposition of the material onto the substrate surface in the presence of a solid or liquid layer of an oxidizing gas. The oxidizing gas is provided on the substrate surface in an amount sufficient to dissipate the latent heat of condensation occurring during deposition as well as creating a favorable oxidizing environment for the material.

High quality oxide films on substrates

DOEpatents

Ruckman, Mark W.; Strongin, Myron; Gao, Yong L.

1994-01-01

A method for providing an oxide film of a material on the surface of a substrate using a reactive deposition of the material onto the substrate surface in the presence of a solid or liquid layer of an oxidizing gas. The oxidizing gas is provided on the substrate surface in an amount sufficient to dissipate the latent heat of condensation occurring during deposition as well as creating a favorable oxidizing environment for the material.

Measuring the Rebound Resilience of a Bouncing Ball

ERIC Educational Resources Information Center

Wadhwa, Ajay

2012-01-01

Some balls which are made of high-quality rubber (an elastomeric) material, such as tennis or squash balls, could be used for the determination of an important property of such materials called resilience. Since a bouncing ball involves a single impact we call this property "rebound resilience" and express it as the ratio of the rebound height to…

Making Materials Based on TeX and CAS/DGS--Reports on CADGME 2012 Conference Working Group

ERIC Educational Resources Information Center

Kaneko, Masataka; Yamashita, Satoshi; Kitahara, Kiyoshi; Maeda, Yoshifumi; Usui, Hisashi; Takato, Setsuo

2014-01-01

TeX has become one of the most popular tools for editing teaching materials or textbooks in collegiate mathematics education, since it enables usual mathematics teachers to easily produce high-quality mathematical documents. Its capabilities for visualization and computation are fairly limited, so that many teachers simultaneously use various…

Drilling Holes in Graphite/Epoxy

NASA Technical Reports Server (NTRS)

Minlionica, Ronald

1987-01-01

Relatively long-lived bit produces high-quality holes. Effective combination of cutting-tool design, feed, and speed determined for drilling 3/16-and-1/4-in. (0.48-and 0.65-cm) diameter holes in 0.18 in. (0.46cm) thick GM3013A or equivalent graphite/epoxy corrugated spar without backup material and without coolant. Developed to produce holes in blind areas, optimal techniques yielded holes of high quality, with minimal or acceptable delamination and/or fiber extension on drill-exit side.

Compaction behavior of out-of-autoclave prepreg materials

NASA Astrophysics Data System (ADS)

Serrano, Léonard; Olivier, Philippe; Cinquin, Jacques

2017-10-01

The main challenges with composite parts manufacturing are related to the curing means, mainly autoclaves, the length of their cycles and their operating costs. In order to decrease this dependency, out of autoclave materials have been considered as a solution for high production rate parts such as spars, flaps, etc… However, most out-of-autoclave process do not possess the same maturity as their counterpart, especially concerning part quality1. Some pre-cure processes such as compaction and ply lay-up are usually less of a concern for autoclave manufacturing: the pressure applied during the cycle participates to reduce the potential defects (porosity caused by a poor quality lay-up, bad compaction, entrapped air or humidity…). For out-of-autoclave parts, those are crucial steps which may have many consequences on the final quality of the laminate2. In order to avoid this quality loss, those steps must be well understood.

Physico-chemical characterisation of material fractions in residual and source-segregated household waste in Denmark.

PubMed

Götze, R; Pivnenko, K; Boldrin, A; Scheutz, C; Astrup, T Fruergaard

2016-08-01

Physico-chemical waste composition data are paramount for the assessment and planning of waste management systems. However, the applicability of data is limited by the regional, temporal and technical scope of waste characterisation studies. As Danish and European legislation aims for higher recycling rates evaluation of source-segregation and recycling chains gain importance. This paper provides a consistent up-to-date dataset for 74 physico-chemical parameters in 49 material fractions from residual and 24 material fractions from source-segregated Danish household waste. Significant differences in the physico-chemical properties of residual and source-segregated waste fractions were found for many parameters related to organic matter, but also for elements of environmental concern. Considerable differences in potentially toxic metal concentrations between the individual recyclable fractions within one material type were observed. This indicates that careful planning and performance evaluation of recycling schemes are important to ensure a high quality of collected recyclables. Rare earth elements (REE) were quantified in all waste fractions analysed, with the highest concentrations of REE found in fractions with high content of mineral raw materials, soil materials and dust. The observed REE concentrations represent the background concentration level in non-hazardous waste materials that may serve as a reference point for future investigations related to hazardous waste management. The detailed dataset provided here can be used for assessments of waste management solutions in Denmark and for the evaluation of the quality of recyclable materials in waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-Speed Friction Stir Welding of AA7075-T6 Sheet: Microstructure, Mechanical Properties, Micro-texture, and Thermal History

NASA Astrophysics Data System (ADS)

Zhang, Jingyi; Upadhyay, Piyush; Hovanski, Yuri; Field, David P.

2018-01-01

Friction stir welding (FSW) is a cost-effective and high-quality joining process for aluminum alloys (especially heat-treatable alloys) that is historically operated at lower joining speeds (up to hundreds of millimeters per minute). In this study, we present a microstructural analysis of friction stir welded AA7075-T6 blanks with high welding speeds up to 3 M/min. Textures, microstructures, mechanical properties, and weld quality are analyzed using TEM, EBSD, metallographic imaging, and Vickers hardness. The higher welding speed results in narrower, stronger heat-affected zones (HAZs) and also higher hardness in the nugget zones. The material flow direction in the nugget zone is found to be leaning towards the welding direction as the welding speed increases. Results are coupled with welding parameters and thermal history to aid in the understanding of the complex material flow and texture gradients within the welds in an effort to optimize welding parameters for high-speed processing.

Far Ultraviolet Refractive Index of Optical Materials for Solar Blind Channel (SBC) Filters for HST Advanced Camera for Surveys

NASA Technical Reports Server (NTRS)

Leviton, Douglas B.; Madison, Timothy J.; Petrone, Peter

1998-01-01

Refractive index measurements using the minimum deviation method have been carried out for prisms of a variety of far ultraviolet optical materials used in the manufacture of Solar Blind Channel (SBC) filters for the HST Advanced Camera for Surveys (ACS). Some of the materials measured are gaining popularity in a variety of high technology applications including high power excimer lasers and advanced microlithography optics operating in a wavelength region where high quality knowledge of optical material properties is sparse. Our measurements are of unusually high accuracy and precision for this wavelength region owing to advanced instrumentation in the large vacuum chamber of the Diffraction Grating Evaluation Facility (DGEF) at Goddard Space Flight Center (GSFC). Index values for CaF2, BaF2, LiF, and far ultraviolet grades of synthetic sapphire and synthetic fused silica are reported and compared with values from the literature.

Reusable shielding material for neutron- and gamma-radiation

NASA Astrophysics Data System (ADS)

Calzada, Elbio; Grünauer, Florian; Schillinger, Burkhard; Türck, Harald

2011-09-01

At neutron research facilities all around the world radiation shieldings are applied to reduce the background of neutron and gamma radiation as far as possible in order to perform high quality measurements and to fulfill the radiation protection requirements. The current approach with cement-based compounds has a number of shortcomings: "Heavy concrete" contains a high amount of elements, which are not desired to obtain a high attenuation of neutron and/or gamma radiation (e.g. calcium, carbon, oxygen, silicon and aluminum). A shielding material with a high density of desired nuclei such as iron, hydrogen and boron was developed for the redesign of the neutron radiography facility ANTARES at beam tube 4 (located at a cold neutron source) of FRM-II. The composition of the material was optimized by help of the Monte Carlo code MCNP5. With this shielding material a considerable higher attenuation of background radiation can be obtained compared to usual heavy concretes.

Development of quality standards for inclusion of high recycled asphalt pavement content in asphalt mixtures - phase II, [tech brief].

DOT National Transportation Integrated Search

2015-03-01

The objective of this research is to 1) build a test section utilizing HMA : mix designs with up to 40% RAP materials, 2) evaluate the moisture : sensitivity of High-RAP mixtures, 3) characterize the low-temperature : fracture behavior of High-RAP mi...

Qualification and initial characterization of a high-purity 233U spike for use in uranium analyses

DOE PAGES

Mathew, K. J.; Canaan, R. D.; Hexel, C.; ...

2015-08-20

Several high-purity 233U items potentially useful as isotope dilution mass spectrometry standards for safeguards, non-proliferation, and nuclear forensics measurements are identified and rescued from downblending. By preserving the supply of 233U materials of different pedigree for use as source materials for certified reference materials (CRMs), it is ensured that the safeguards community has high quality uranium isotopic standards required for calibration of the analytical instruments. One of the items identified as a source material for a high-purity CRM is characterized for the uranium isotope-amount ratios using thermal ionization mass spectrometry (TIMS). Additional verification measurements on this material using quadrupole inductivelymore » coupled plasma mass spectrometry (ICPMS) are also performed. As a result, the comparison of the ICPMS uranium isotope-amount ratios with the TIMS data, with much smaller uncertainties, validated the ICPMS measurement practices. ICPMS is proposed for the initial screening of the purity of items in the rescue campaign.« less

Experiments in the EMRP project KEY-VOCs: Adsorption/desorption effects of VOCs in different tubing materials and preparation and analysis of a zero gas

NASA Astrophysics Data System (ADS)

Englert, Jennifer; Claude, Anja; Kubistin, Dagmar; Tensing, Erasmus; Michl, Katja; Plass-Duelmer, Christian

2017-04-01

Atmospheric chemistry and composition are influenced by volatile organic compounds (VOCs) emitted from natural and anthropogenic sources. Due to their toxicity and their crucial role in ozone and aerosol formation VOCs impact air quality and climate change and high quality observations are demanded. The European Metrology Research Programme (EMRP) project KEY-VOCs has targeted the improvement of VOC measurement capabilities with the focus on VOCs relevant for indoor air as well as for air quality and climate monitoring programmes. One major uncertainty is the influence of surface effects of the measurement devices. By developing a test system the adsorption/desorption effects of certain VOCs can be systematically examined. Different tubing materials e.g. stainless steel and PFA were analysed with the oxygenated VOC methanol and results of these experiments will be presented. In air quality monitoring very low levels of VOCs have to be measured. Purified air or nitrogen is widely used as a zero gas to characterize measurement systems and procedures as well as for instrument calibration. A high quality zero gas is an important contributor to the quality of the measurements and generally achieved by using state-of-the-art purification technologies. The efficiency of several air purifiers was assessed and the results have been analysed.

Experimental Study in Taguchi Method on Surface Quality Predication of HSM

NASA Astrophysics Data System (ADS)

Ji, Yan; Li, Yueen

2018-05-01

Based on the study of ball milling mechanism and machining surface formation mechanism, the formation of high speed ball-end milling surface is a time-varying and cumulative Thermos-mechanical coupling process. The nature of this problem is that the uneven stress field and temperature field affect the machined surface Process, the performance of the processing parameters in the processing interaction in the elastic-plastic materials produced by the elastic recovery and plastic deformation. The surface quality of machining surface is characterized by multivariable nonlinear system. It is still an indispensable and effective method to study the surface quality of high speed ball milling by experiments.

Epitaxial growth of single-orientation high-quality MoS2 monolayers

NASA Astrophysics Data System (ADS)

Bana, Harsh; Travaglia, Elisabetta; Bignardi, Luca; Lacovig, Paolo; Sanders, Charlotte E.; Dendzik, Maciej; Michiardi, Matteo; Bianchi, Marco; Lizzit, Daniel; Presel, Francesco; De Angelis, Dario; Apostol, Nicoleta; Das, Pranab Kumar; Fujii, Jun; Vobornik, Ivana; Larciprete, Rosanna; Baraldi, Alessandro; Hofmann, Philip; Lizzit, Silvano

2018-07-01

We present a study on the growth and characterization of high-quality single-layer MoS2 with a single orientation, i.e. without the presence of mirror domains. This single orientation of the MoS2 layer is established by means of x-ray photoelectron diffraction. The high quality is evidenced by combining scanning tunneling microscopy with x-ray photoelectron spectroscopy measurements. Spin- and angle-resolved photoemission experiments performed on the sample revealed complete spin-polarization of the valence band states near the K and -K points of the Brillouin zone. These findings open up the possibility to exploit the spin and valley degrees of freedom for encoding and processing information in devices that are based on epitaxially grown materials.

Classification of soft-shell materials for leisure outdoor jackets by clo defined from thermal properties testing

NASA Astrophysics Data System (ADS)

Tesinova, P.; Steklova, P.; Duchacova, T.

2017-10-01

Materials for outdoor activities are produced in various combinations and lamination helps to combine two or more components for gaining high comfort properties and lighten the structure. Producers can choose exact suitable material for construction of part or set of so called layered clothing for expected activity. Decreasing the weight of materials when preserving of high quality of water-vapour permeability, wind resistivity and hydrostatic resistivity and other comfort and usage properties is a big task nowadays. This paper is focused on thermal properties as an important parameter for being comfort during outdoor activities. Softshell materials were chosen for testing and computation of clo. Results compared with standardised clo table helps us to classify thermal insulation of the set of fabrics when defining proper clothing category.

The Physics and Chemistry of carbides, Nitrides and Borides. Volume 185

DTIC Science & Technology

1990-01-01

and C-B-C chains [15,17]. Clearly, the use of boron-rich solids as electronic materials will place new demands on the quality of materials. In this...first heated in a pyrolytic boron nitride (PBN) crucible ( Union Carbide Corp.) under high vacuum (< 50 mTorr) to 1900°C. This removed surface...contamination of the sample. The powders were loaded into a graphite die with a high-purity BN die liner ( Union Carbide Grade HBC) with inner diameter of 3/8

Pseudomorphic Narrow Gap Materials for High Performance Devices

DTIC Science & Technology

1993-04-14

research under this program is ito obtain hiigh quality pseudomorphic (strained) narrow gap materials for high performance device applicatjons During...1993 ELECTE """ ’I ~01lG:9395 APR21 W93 Dr. Max N. Yoder Scientific Officer, Code 114SS Office of Naval Research 800 N. Quincy Street Arlington, VA...Mr. V. Morano - w/cy each/ ...- Administrative Grants Officer Office of Naval Research . r. - Resident Representative, N6Z9g7 -- _ z 33 Third Avenue

Grinding model and material removal mechanism of medical nanometer zirconia ceramics.

PubMed

Zhang, Dongkun; Li, Changhe; Jia, Dongzhou; Wang, Sheng; Li, Runze; Qi, Xiaoxiao

2014-01-01

Many patents have been devoted to developing medical nanometer zirconia ceramic grinding techniques that can significantly improve both workpiece surface integrity and grinding quality. Among these patents is a process for preparing ceramic dental implants with a surface for improving osseo-integration by sand abrasive finishing under a jet pressure of 1.5 bar to 8.0 bar and with a grain size of 30 µm to 250 µm. Compared with other materials, nano-zirconia ceramics exhibit unmatched biomedical performance and excellent mechanical properties as medical bone tissue and dentures. The removal mechanism of nano-zirconia materials includes brittle fracture and plastic removal. Brittle fracture involves crack formation, extension, peeling, and chipping to completely remove debris. Plastic removal is similar to chip formation in metal grinding, including rubbing, ploughing, and the formation of grinding debris. The materials are removed in shearing and chipping. During brittle fracture, the grinding-led transverse and radial extension of cracks further generate local peeling of blocks of the material. In material peeling and removal, the mechanical strength and surface quality of the workpiece are also greatly reduced because of crack extension. When grinding occurs in the plastic region, plastic removal is performed, and surface grinding does not generate grinding fissures and surface fracture, producing clinically satisfactory grinding quality. With certain grinding conditions, medical nanometer zirconia ceramics can be removed through plastic flow in ductile regime. In this study, we analyzed the critical conditions for the transfer of brittle and plastic removal in nano-zirconia ceramic grinding as well as the high-quality surface grinding of medical nanometer zirconia ceramics by ELID grinding.

Investigation on Effect of Material Hardness in High Speed CNC End Milling Process.

PubMed

Dhandapani, N V; Thangarasu, V S; Sureshkannan, G

2015-01-01

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results.

Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

PubMed Central

Dhandapani, N. V.; Thangarasu, V. S.; Sureshkannan, G.

2015-01-01

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results. PMID:26881267

[Which one is more important, raw materials or productive technology?--a case study for quality consistency control of Gegen Qinlian decoction].

PubMed

Zhong, Wen; Chen, Sha; Zhang, Jun; Wang, Yu-Sheng; Liu, An

2016-03-01

To investigate the effect of Chinese medicine raw materials and production technology on quality consistency of Chinese patent medicines with Gegen Qinlian decoction as an example, and establish a suitable method for the quality consistency control of Chinese patent medicines. The results showed that the effect of production technology on the quality consistency was generally not more than 5%, while the effect of raw materials was even more than 30%, indicating that the effect of raw materials was much greater than that of the production technology. In this study, blend technology was used to improve the quality consistency of raw materials. As a result, the difference between the product produced by raw materials and reference groups was less than 5%, thus increasing the quality consistence of finished products. The results showed that under the current circumstances, the main factor affecting the quality consistency of Chinese patent medicines was raw materials, so we shall pay more attention to the quality of Chinese medicine's raw materials. Finally, a blend technology can improve the quality consistency of Chinese patent medicines. Copyright© by the Chinese Pharmaceutical Association.

Optical Sensing of Polarization States Changes in Meat due to the Ageing

NASA Astrophysics Data System (ADS)

Tománek, Pavel; Mikláš, Jan; Abubaker, Hamed Mohamed; Grmela, Lubomír

2010-11-01

Food materials or biological materials display large compositional variations, inhomogeneities, and anisotropic structures. The biological tissues consist of cells which dimensions are bigger than a wavelength of visible light, therefore Mie scattering of transmitted and reflected light occurs and different polarization states arise. The meat industry needs reliable meat quality information throughout the production process in order to guarantee high-quality meat products for consumers. The minor importance is still given to the food quality control and inspection during processing operations or storing conditions. The paper presents a quite simple optical method allowing measure the freshness or ageing of products. The principle is to study temporal characteristics of polarization states of forward or backward scattered laser light in the samples in function of meat ageing.

[Establishing and operating a human biobank. Ethical aspects].

PubMed

Jahns, Roland

2016-03-01

Particularly in the past decade which has been marked by efforts to foster individualized/personalized medicine the need for well-characterized high-quality collections of human biological material has significantly increased. When establishing and operating a human biobank the interests and the "freedom" of biomedical research must always be weighed against the interests and rights of patients and/or donors; in this process ethical aspects should be considered systematically. In addition, the importance of quality control and quality assurance has largely increased in human biobanking, both from a scientific and even more from an ethical point of view, because donated biological materials are potentially stored for decades and (on request) might serve for currently not foreseeable biomedical research purposes. In addition, the compatibility of national human biobanks with international biobank networks becomes increasingly important.

Broken symmetry dielectric resonators for high quality factor Fano metasurfaces

DOE PAGES

Campione, Salvatore; Liu, Sheng; Basilio, Lorena I.; ...

2016-10-25

We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurfacemore » that achieves a quality factor of ~1300 at ~10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (~1 μm): a silicon-based implementation that achieves a quality factor of ~350; and a gallium arsenide-based structure that achieves a quality factor of ~600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. Here, we envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.« less

Broken symmetry dielectric resonators for high quality factor Fano metasurfaces

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

Campione, Salvatore; Liu, Sheng; Basilio, Lorena I.

We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurfacemore » that achieves a quality factor of ~1300 at ~10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (~1 μm): a silicon-based implementation that achieves a quality factor of ~350; and a gallium arsenide-based structure that achieves a quality factor of ~600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. Here, we envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.« less

Assessment of aggregate sources in Michigan for high speed railroad ballast.

DOT National Transportation Integrated Search

2014-01-01

MDOT purchased 135 miles of the Norfolk-Southern railroad in 2012 to upgrade for high speed rail travel : between Chicago and the Detroit area. An important part of the upgrade is to assess the current quality of : the ballast material and to determi...

Strategies for Increasing the Market Share of Recycled Products—A Games Theory Approach

NASA Astrophysics Data System (ADS)

Batzias, Dimitris F.; Pollalis, Yannis A.

2009-08-01

A methodological framework (including 28 activity stages and 10 decision nodes) has been designed under the form of an algorithmic procedure for the development of strategies for increasing the market share of recycled products within a games theory context. A case example is presented referring to a paper market, where a recycling company (RC) is in competition with a virgin-raw-material-using company (VC). The strategies of the VC, for increasing its market share, are the strengthening of (and advertisement based on) the high quality (VC1), the high reliability (VC2), the combination quality and reliability, putting emphasis on the first component (VC3), the combination quality and reliability, putting emphasis on the second component (VC4). The strategies of the RC, for increasing its market share, are proper advertisement based on the low price of produced recycled paper satisfying minimum quality requirements (RC1), the combination of low price with sensitization of the public as regards environmental and materials-saving issues, putting emphasis on the first component (RC2), the same combination, putting emphasis on the second component (RC3). Analysis of all possible situations for the case example under examination is also presented.

High-quality multilayer graphene on an insulator formed by diffusion controlled Ni-induced layer exchange

NASA Astrophysics Data System (ADS)

Murata, H.; Saitoh, N.; Yoshizawa, N.; Suemasu, T.; Toko, K.

2017-12-01

The Ni-induced layer-exchange growth of amorphous carbon is a unique method used to fabricate uniform multilayer graphene (MLG) directly on an insulator. To improve the crystal quality of MLG, we prepare AlOx or SiO2 interlayers between amorphous C and Ni layers, which control the extent of diffusion of C atoms into the Ni layer. The growth morphology and Raman spectra observed from MLG formed by layer exchange strongly depend on the material type and thickness of the interlayers; a 1-nm-thick AlOx interlayer is found to be ideal for use in experiments. Transmission electron microscopy and electron energy-loss spectra reveal that the crystal quality of the resulting MLG is much higher than that of a sample without an interlayer. The grain size reaches a few μm, leading to an electrical conductivity of 1290 S/cm. The grain size and the electrical conductivity are the highest among MLG synthesized using a solid-phase reaction including metal-induced crystallization. The direct synthesis of uniform, high-quality MLG on arbitrary substrates will pave the way for advanced electronic devices integrated with carbon materials.

Physics considerations in MV-CBCT multi-layer imager design.

PubMed

Hu, Yue-Houng; Fueglistaller, Rony; Myronakis, Marios E; Rottmann, Joerg; Wang, Adam; Shedlock, Daniel; Morf, Daniel; Baturin, Paul; Huber, Pascal; Star-Lack, Josh M; Berbeco, Ross I

2018-05-30

Megavoltage (MV) cone-beam computed tomography (CBCT) using an electronic portal imaging (EPID) offers advantageous features, including 3D mapping, treatment beam registration, high-z artifact suppression, and direct radiation dose calculation. Adoption has been slowed by image quality limitations and concerns about imaging dose. Developments in imager design, including pixelated scintillators, structured phosphors, inexpensive scintillation materials, and multi-layer imager (MLI) architecture have been explored to improve EPID image quality and reduce imaging dose. The present study employs a hybrid Monte Carlo and linear systems model to determine the effect of detector design elements, such as multi-layer architecture and scintillation materials. We follow metrics of image quality including modulation transfer function (MTF) and noise power spectrum (NPS) from projection images to 3D reconstructions to in-plane slices and apply a task based figure-of-merit, the ideal observer signal-to-noise ratio (d') to determine the effect of detector design on object detectability. Generally, detectability was limited by detector noise performance. Deploying an MLI imager with a single scintillation material for all layers yields improvement in noise performance and d' linear with the number of layers. In general, improving x-ray absorption using thicker scintillators results in improved DQE(0). However, if light yield is low, performance will be affected by electronic noise at relatively high doses, resulting in rapid image quality degradation. Maximizing image quality in a heterogenous MLI detector (i.e. multiple different scintillation materials) is most affected by limiting imager noise. However, while a second-order effect, maximizing total spatial resolution of the MLI detector is a balance between the intensity contribution of each layer against its individual MTF. So, while a thinner scintillator may yield a maximal individual-layer MTF, its quantum efficiency will be relatively low in comparison to a thicker scintillator and thus, intensity contribution may be insufficient to noticeably improve the total detector MTF. © 2018 Institute of Physics and Engineering in Medicine.

Copper Oxide Nanomaterials Prepared by Solution Methods, Some Properties, and Potential Applications: A Brief Review

PubMed Central

Tran, Thi Ha; Nguyen, Viet Tuyen

2014-01-01

Cupric oxide (CuO), having a narrow bandgap of 1.2 eV and a variety of chemophysical properties, is recently attractive in many fields such as energy conversion, optoelectronic devices, and catalyst. Compared with bulk material, the advanced properties of CuO nanostructures have been demonstrated; however, the fact that these materials cannot yet be produced in large scale is an obstacle to realize the potential applications of this material. In this respect, chemical methods seem to be efficient synthesis processes which yield not only large quantities but also high quality and advanced material properties. In this paper, the effect of some general factors on the morphology and properties of CuO nanomaterials prepared by solution methods will be overviewed. In terms of advanced nanostructure synthesis, microwave method in which copper hydroxide nanostructures are produced in the precursor solution and sequentially transformed by microwave into CuO may be considered as a promising method to explore in the near future. This method produces not only large quantities of nanoproducts in a short reaction time of several minutes, but also high quality materials with advanced properties. A brief review on some unique properties and applications of CuO nanostructures will be also presented. PMID:27437488

Method for depositing high-quality microcrystalline semiconductor materials

DOEpatents

Guha, Subhendu [Bloomfield Hills, MI; Yang, Chi C [Troy, MI; Yan, Baojie [Rochester Hills, MI

2011-03-08

A process for the plasma deposition of a layer of a microcrystalline semiconductor material is carried out by energizing a process gas which includes a precursor of the semiconductor material and a diluent with electromagnetic energy so as to create a plasma therefrom. The plasma deposits a layer of the microcrystalline semiconductor material onto the substrate. The concentration of the diluent in the process gas is varied as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited. Also disclosed is the use of the process for the preparation of an N-I-P type photovoltaic device.

Cybermaterials: materials by design and accelerated insertion of materials

NASA Astrophysics Data System (ADS)

Xiong, Wei; Olson, Gregory B.

2016-02-01

Cybermaterials innovation entails an integration of Materials by Design and accelerated insertion of materials (AIM), which transfers studio ideation into industrial manufacturing. By assembling a hierarchical architecture of integrated computational materials design (ICMD) based on materials genomic fundamental databases, the ICMD mechanistic design models accelerate innovation. We here review progress in the development of linkage models of the process-structure-property-performance paradigm, as well as related design accelerating tools. Extending the materials development capability based on phase-level structural control requires more fundamental investment at the level of the Materials Genome, with focus on improving applicable parametric design models and constructing high-quality databases. Future opportunities in materials genomic research serving both Materials by Design and AIM are addressed.

"Liquid-liquid-solid"-type superoleophobic surfaces to pattern polymeric semiconductors towards high-quality organic field-effect transistors.

PubMed

Wu, Yuchen; Su, Bin; Jiang, Lei; Heeger, Alan J

2013-12-03

Precisely aligned organic-liquid-soluble semiconductor microwire arrays have been fabricated by "liquid-liquid-solid" type superoleophobic surfaces directed fluid drying. Aligned organic 1D micro-architectures can be built as high-quality organic field-effect transistors with high mobilities of >10 cm(2) ·V(-1) ·s(-1) and current on/off ratio of more than 10(6) . All these studies will boost the development of 1D microstructures of organic semiconductor materials for potential application in organic electronics. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High quality oxide films on substrates

DOEpatents

Ruckman, M.W.; Strongin, M.; Gao, Y.L.

1994-02-01

A method is described for providing an oxide film of a material on the surface of a substrate using a reactive deposition of the material onto the substrate surface in the presence of a solid or liquid layer of an oxidizing gas. The oxidizing gas is provided on the substrate surface in an amount sufficient to dissipate the latent heat of condensation occurring during deposition as well as creating a favorable oxidizing environment for the material. 4 figures.

Method for producing high quality oxide films on substrates

DOEpatents

Ruckman, M.W.; Strongin, M.; Gao, Y.L.

1993-11-23

A method is described for providing an oxide film of a material on the surface of a substrate using a reactive deposition of the material onto the substrate surface in the presence of a solid or liquid layer of an oxidizing gas. The oxidizing gas is provided on the substrate surface in an amount sufficient to dissipate the latent heat of condensation occurring during deposition as well as creating a favorable oxidizing environment for the material. 4 figures.

Thermal Characterization of Carbon Nanotubes by Photothermal Techniques

NASA Astrophysics Data System (ADS)

Leahu, G.; Li Voti, R.; Larciprete, M. C.; Sibilia, C.; Bertolotti, M.; Nefedov, I.; Anoshkin, I. V.

2015-06-01

Carbon nanotubes (CNTs) are multifunctional materials commonly used in a large number of applications in electronics, sensors, nanocomposites, thermal management, actuators, energy storage and conversion, and drug delivery. Despite recent important advances in the development of CNT purity assessment tools and atomic resolution imaging of individual nanotubes by scanning tunnelling microscopy and high-resolution transmission electron microscopy, the macroscale assessment of the overall surface qualities of commercial CNT materials remains a great challenge. The lack of quantitative measurement technology to characterize and compare the surface qualities of bulk manufactured and engineered CNT materials has negative impacts on the reliable and consistent nanomanufacturing of CNT products. In this paper it is shown how photoacoustic spectroscopy and photothermal radiometry represent useful non-destructive tools to study the optothermal properties of carbon nanotube thin films.

The image enhancement and region of interest extraction of lobster-eye X-ray dangerous material inspection system

NASA Astrophysics Data System (ADS)

Zhan, Qi; Wang, Xin; Mu, Baozhong; Xu, Jie; Xie, Qing; Li, Yaran; Chen, Yifan; He, Yanan

2016-10-01

Dangerous materials inspection is an important technique to confirm dangerous materials crimes. It has significant impact on the prohibition of dangerous materials-related crimes and the spread of dangerous materials. Lobster-Eye Optical Imaging System is a kind of dangerous materials detection device which mainly takes advantage of backscatter X-ray. The strength of the system is its applicability to access only one side of an object, and to detect dangerous materials without disturbing the surroundings of the target material. The device uses Compton scattered x-rays to create computerized outlines of suspected objects during security detection process. Due to the grid structure of the bionic object glass, which imitate the eye of a lobster, grids contribute to the main image noise during the imaging process. At the same time, when used to inspect structured or dense materials, the image is plagued by superposition artifacts and limited by attenuation and noise. With the goal of achieving high quality images which could be used for dangerous materials detection and further analysis, we developed effective image process methods applied to the system. The first aspect of the image process is the denoising and enhancing edge contrast process, during the process, we apply deconvolution algorithm to remove the grids and other noises. After image processing, we achieve high signal-to-noise ratio image. The second part is to reconstruct image from low dose X-ray exposure condition. We developed a kind of interpolation method to achieve the goal. The last aspect is the region of interest (ROI) extraction process, which could be used to help identifying dangerous materials mixed with complex backgrounds. The methods demonstrated in the paper have the potential to improve the sensitivity and quality of x-ray backscatter system imaging.

A proposal for epitaxial thin film growth in outer space

NASA Technical Reports Server (NTRS)

Ignatiev, Alex; Chu, C. W.

1988-01-01

A new concept for materials processing in space exploits the ultravacuum component of space for thin film epitaxial growth. The unique low earth orbit space environment is expected to yield 10 to the -14th torr or better pressures, semiinfinite pumping speeds, and large ultravacuum volume without walls. These space ultravacuum properties promise major improvement in the quality, unique nature, and the throughput of epitaxially grown materials. Advanced thin film materials to be epitaxially grown in space include semiconductors, magnetic materials, and thin film high temperature superconductors.

Recovery technologies for building materials

NASA Astrophysics Data System (ADS)

Karu, Veiko; Nurme, Martin; Valgma, Ingo

2015-04-01

Mining industry provides building materials for construction. Civil engineers have settled the quality parameters for construction materials. When we produce high quality building materials from carbonate rock (limestone, dolostone), then the estimated waste share is 25% to 30%, depending on crushing principles and rock quality. The challenge is to find suitable technology for waste recovery. During international mining waste related cooperation project MIN-NOVATION (www.min-novation.eu), partners mapped possibilities for waste recovery in mining industry and pointed out good examples and case studies. One example from Estonia showed that when we produce limestone aggregate, then we produce up to 30% waste material (fines with size 0-4mm). This waste material we can see as secondary raw material for building materials. Recovery technology for this fine grained material has been achieved with CDE separation plant. During the process the plant washes out minus 63 micron material from the limestone fines. This technology allows us to use 92% of all limestone reserves. By-product from 63 microns to 4 mm we can use as filler in concrete or as fine limestone aggregate for building or building materials. MIN-NOVATION project partners also established four pilot stations to study other mineral waste recovery technologies and solutions. Main aims on this research are to find the technology for recovery of mineral wastes and usage for new by-products from mineral mining waste. Before industrial production, testing period or case studies are needed. This research is part of the study of Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

A novel approach to rapidly explore analytical markers for quality control of Radix Salviae Miltiorrhizae extract granules by robust principal component analysis with ultra-high performance liquid chromatography-ultraviolet-quadrupole time-of-flight mass spectrometry.

PubMed

Song, Jing-Zheng; Li, Song-Lin; Zhou, Yan; Qiao, Chun-Feng; Chen, Shi-Lin; Xu, Hong-Xi

2010-11-02

In a well-controlled experiment, outliers discriminated by robust principal component analysis (RPCA) represent contents in samples which are of particular quality distinguishable from the rest of the others, therefore chemical constituents in a natural product causing discrimination between outliers and the majority of samples could be considered as analytical markers for quality control. Based on this strategy, a novel approach for rapidly exploring characteristic analytical markers was proposed for the quality control of extract granules of Radix Salviae Miltiorrhizae (EGRSM). In this study, large sizes of samples were analyzed via high-throughput ultra-high performance liquid chromatography-ultraviolet-quadrupole time-of-flight mass spectrometry (UHPLC-UV-Q-Tof MS). RPCA was first performed on the three groups of samples: RSM (the raw material), the in-house prepared aqueous extract of Radix Salviae Miltiorrhizae (AERSM) and commercial product of EGRSM, to determine the variation of specific constituents between raw material and the final products as well as the effect of manufacturing process on the overall quality. Then RPCA was performed on the commercial products of EGRSM to explore the applicability of identified characteristic markers for the quality control of EGRSM. Candidate markers were extracted by RPCA, and their molecular formulae were determined by high resolution electrospray ionization-mass spectrometric (ESI-MS) analysis. The suitability of identified markers was then evaluated by determining the relationship between quantities of the identified markers with their antioxidant activities biologically, and further confirmed in a variety of samples. In conclusion, the combination of RPCA with UHPLC-UV-Q-Tof MS is a reliable means to identify chemical markers for evaluating quality of herbal medicines. Copyright (c) 2010 Elsevier B.V. All rights reserved.

FennoFlakes: a project for identifying flake graphite ores in the Fennoscandian shield and utilizing graphite in different applications

NASA Astrophysics Data System (ADS)

Palosaari, Jenny; Eklund, O.; Raunio, S.; Lindfors, T.; Latonen, R.-M.; Peltonen, J.; Smått, J.-H.; Kauppila, J.; Lund, S.; Sjöberg-Eerola, P.; Blomqvist, R.; Marmo, J.

2016-04-01

Natural graphite is a strategic mineral, since the European Commission stated (Report on critical raw materials for the EU (2014)) that graphite is one of the 20 most critical materials for the European Union. The EU consumed 13% of all flake graphite in the world but produced only 3%, which stresses the demand of the material. Flake graphite, which is a flaky version of graphite, forms under high metamorphic conditions. Flake graphite is important in different applications like batteries, carbon brushes, heat sinks etc. Graphene (a single layer of graphite) can be produced from graphite and is commonly used in many nanotechnological applications, e.g. in electronics and sensors. The steps to obtain pure graphene from graphite ore include fragmentation, flotation and exfoliation, which can be cumbersome and resulting in damaging the graphene layers. We have started a project named FennoFlakes, which is a co-operation between geologists and chemists to fill the whole value chain from graphite to graphene: 1. Exploration of graphite ores (geological and geophysical methods). 2. Petrological and geochemical analyses on the ores. 3. Development of fragmentation methods for graphite ores. 4. Chemical exfoliation of the enriched flake graphite to separate flake graphite into single and multilayer graphene. 5. Test the quality of the produced material in several high-end applications with totally environmental friendly and disposable material combinations. Preliminary results show that flake graphite in high metamorphic areas has better qualities compared to synthetic graphite produced in laboratories.

Second NATO Workshop on Passive Infrared Optical Materials and Coatings

DTIC Science & Technology

1987-12-01

sponsor, NATO AC/243 ( Panel III tion is sprayed through a furnace at RSG 2). This is an abridged version of about 1000*C. A 7-hour operation yields the...strength, generate high-quality optical surfaces Cl, of the monocrystalline material is 4 162 MPa at a load increase rate of 18 MPa due to removal of water

Bioluminescence for determining energy state of plants

NASA Technical Reports Server (NTRS)

Ching, T. M.

1975-01-01

Bioluminescence produced by the luciferin-luciferase system is a very sensitive assay for ATP content in extracts of plant materials. The ATP test for seed and pollen viability and vigor is presented, along with prediction of high growth potential and productivity in new crosses and selections of breeding materials. ATP as an indicator for environmental quality, stresses, and metabolic regulation is also considered.

Purification of HgI.sub.2 for nuclear detector fabrication

DOEpatents

Schieber, Michael M.

1978-01-01

A process for purification of mercuric iodide (HgI.sub.2) to be used as a source material for the growth of detector quality crystals. The high purity HgI.sub.2 raw material is produced by a combination of three stages: synthesis of HgI.sub.2 from Hg and I.sub.2, repeated sublimation, and zone refining.

Microstructure, Friction and Wear of Aluminum Matrix Composites

NASA Astrophysics Data System (ADS)

Florea, R. M.

2018-06-01

MMCs are made by dispersing a reinforcing material into a metal matrix. They are prepared by casting, although several technical challenges exist with casting technology. Achieving a homogeneous distribution of reinforcement within the matrix is one such challenge, and this affects directly on the properties and quality of composite. The aluminum alloy composite materials consist of high strength, high stiffness, more thermal stability, more corrosion and wear resistance, and more fatigue life. Aluminum alloy materials found to be the best alternative with its unique capacity of designing the materials to give required properties. In this work a composite is developed by adding silicon carbide in Aluminum metal matrix by mass ratio 5%, 10% and 15%. Mechanical tests such as hardness test and microstructure test are conducted.

Development of a knowledge-based system for the design of composite automotive components

NASA Astrophysics Data System (ADS)

Moynihan, Gary P.; Stephens, J. Paul

1997-01-01

Composite materials are comprised of two or more constituents possessing significantly different physical properties. Due to their high strength and light weight, there is an emerging trend to utilize composites in the automotive industry. There is an inherent link between component design and the manufacturing processes necessary for fabrication. To many designers, this situation may be intimidating, since there is frequently little available understanding of composites and their processes. A direct results is high rates of product scrap and rework. Thus, there is a need to implement a systematic approach to composite material design. One such approach is quality function deployment (QFD). By translating customer requirements into design parameters, through the use of heuristics, QFD supports the improvement of product quality during the planning stages prior to actual production. The purpose of this research is to automate the use of knowledge pertaining to the design and application of composite materials within the automobile industry. This is being accomplished through the development of a prototype expert system incorporating a QFD approach. It will provide industry designers with access to knowledge of composite materials that might not be otherwise available.

High-quality LaVO 3 films as solar energy conversion material

DOE PAGES

Zhang, Hai -Tian; Brahlek, Matthew; Ji, Xiaoyu; ...

2017-03-21

Mott insulating oxides and their heterostructures have recently been identified as potential photovoltaic materials with favorable absorption properties and an intrinsic built-in electric field that can efficiently separate excited electron hole pairs. At the same time, they are predicted to overcome the Shockley-Queisser limit due to strong electron electron interaction present. Despite these premises a high concentration of defects commonly observed in Mott insulating films acting as recombination centers can derogate the photovoltaic conversion efficiency. With use of the self-regulated growth kinetics in hybrid molecular beam epitaxy, this obstacle can be overcome. High-quality, stoichiometric LaVO 3 films were grown withmore » defect densities of in-gap states up to 2 orders of magnitude lower compared to the films in the literature, and a factor of 3 lower than LaVO 3 bulk single crystals. Photoconductivity measurements revealed a significant photoresponsivity increase as high as tenfold of stoichiometric LaVO 3 films compared to their nonstoichiometric counterparts. Furthermore, this work marks a critical step toward the realization of high-performance Mott insulator solar cells beyond conventional semiconductors.« less

High-Quality LaVO3 Films as Solar Energy Conversion Material.

PubMed

Zhang, Hai-Tian; Brahlek, Matthew; Ji, Xiaoyu; Lei, Shiming; Lapano, Jason; Freeland, John W; Gopalan, Venkatraman; Engel-Herbert, Roman

2017-04-12

Mott insulating oxides and their heterostructures have recently been identified as potential photovoltaic materials with favorable absorption properties and an intrinsic built-in electric field that can efficiently separate excited electron-hole pairs. At the same time, they are predicted to overcome the Shockley-Queisser limit due to strong electron-electron interaction present. Despite these premises a high concentration of defects commonly observed in Mott insulating films acting as recombination centers can derogate the photovoltaic conversion efficiency. With use of the self-regulated growth kinetics in hybrid molecular beam epitaxy, this obstacle can be overcome. High-quality, stoichiometric LaVO 3 films were grown with defect densities of in-gap states up to 2 orders of magnitude lower compared to the films in the literature, and a factor of 3 lower than LaVO 3 bulk single crystals. Photoconductivity measurements revealed a significant photoresponsivity increase as high as tenfold of stoichiometric LaVO 3 films compared to their nonstoichiometric counterparts. This work marks a critical step toward the realization of high-performance Mott insulator solar cells beyond conventional semiconductors.

LEC GaAs for integrated circuit applications

NASA Technical Reports Server (NTRS)

Kirkpatrick, C. G.; Chen, R. T.; Homes, D. E.; Asbeck, P. M.; Elliott, K. R.; Fairman, R. D.; Oliver, J. D.

1984-01-01

Recent developments in liquid encapsulated Czochralski techniques for the growth of semiinsulating GaAs for integrated circuit applications have resulted in significant improvements in the quality and quantity of GaAs material suitable for device processing. The emergence of high performance GaAs integrated circuit technologies has accelerated the demand for high quality, large diameter semiinsulating GaAs substrates. The new device technologies, including digital integrated circuits, monolithic microwave integrated circuits and charge coupled devices have largely adopted direct ion implantation for the formation of doped layers. Ion implantation lends itself to good uniformity and reproducibility, high yield and low cost; however, this technique also places stringent demands on the quality of the semiinsulating GaAs substrates. Although significant progress was made in developing a viable planar ion implantation technology, the variability and poor quality of GaAs substrates have hindered progress in process development.

Assessment of aggregate quality and petrographic properties' influence on rock quality: A case study from Nordland county, Norway

NASA Astrophysics Data System (ADS)

Kløve Keiding, Jakob; Erichsen, Eyolf; Heldal, Tom; Aslaksen Aasly, Kari

2017-04-01

Good access to construction materials is crucial for future infrastructure development and continued economic growth. In Norway >80 % of construction materials come from crushed aggregates and represent an growing share of the consumption. Although recycling to some extend can cover the need for construction materials, economic growth, increasing population and urbanization necessitates exploitation of new rock resources in Norway as well as many other parts of the world. Aggregates must fulfill a number of technical requirements to ensure high quality and long life expectancy of new roads, buildings and structures. Aggregates also have to be extracted near the consumer market. Particularly for road construction strict criteria are in place for wearing course for roads with high traffic density. Thus knowledge of mechanical rock quality is paramount for both exploitation as well as future resource and land-use planning but is often not assessed or mapped beyond the quarry scale. The Geological survey of Norway runs a database with information about crushed aggregate deposits from >1500 Norwegian quarries and sample sites. Here we use mechanical test analyses from the database to assess the aggregate quality in the Nordland county, Norway. Maps have been produced linking bed rock geology with rock quality parameters. The survey documents that the county is challenged in meeting the requirements for roads with high traffic density and especially in the middle parts of the county many samples have weak mechanical properties. This to some degree reflect that weak Cambro-Silurian rocks like phyllite, schist, carbonate and greenstone are abundant in Nordland. Typically mechanically stronger rock types such as gabbro, monzonite and granite are also exposed in large parts of the county, but are also characterized by relative poor or very variable mechanical test quality. Preliminary results indicate that many intrinsic parameters influence the mechanical rock strength, but variable degrees of deformation in the different tectonostratigraphic units exposed in Nordland affects the rock mechanical properties and is a prominent feature of our mapping. Unsurprisingly rock type, mineralogy, grain size and rock texture are all important factors that have a major control on the mechanical behaviour of the rocks. However, this assessment shows that there is an intricate interaction between these parameters and the resulting mechanical properties at present making it difficult to assess mechanical quality accurately only based on petrographic examination.

Digital processing of radiographic images for print publication.

PubMed

Cockerill, James W

2002-01-01

Digital imaging of X-rays yields high quality, evenly exposed negatives and prints. This article outlines the method used, materials and methods of this technique and discusses the advantages of digital radiographic images.

Carbon-doped single-crystalline SiGe/Si thermistor with high temperature coefficient of resistance and low noise level

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

Radamson, H. H.; Kolahdouz, M.; Shayestehaminzadeh, S.

2010-11-29

SiGe (C)/Si(C) multiquantum wells have been studied as a thermistor material for future bolometers. A thermistor material for uncooled Si-based thermal detectors with thermal coefficient of resistance of 4.5%/K for 100x100 {mu}m{sup 2} pixel sizes and low noise constant (K{sub 1/f}) value of 4.4x10{sup -15} is presented. The outstanding performance of the devices is due to Ni-silicide contacts, smooth interfaces, and high quality multiquantum wells containing high Ge content.

Growth of 2D Materials and Application in Electrochemical Energy Conversion

NASA Astrophysics Data System (ADS)

Ye, Gonglan

The discovery of graphene in 2004 has generated numerous interests among scientists for graphene's versatile potentials. The enthusiasm for graphene has recently been extended to other members of two-dimensional (2D) materials for applications in electronics, optoelectronics, and catalysis. Different from graphene, atomically-thin transition metal dichalcogenides (TMDs) have varied band gaps and would benefit for applications in the semiconductor industry. One of the promising applications of 2D TMDs is for 2D integrated circuits to replace current Si based electronics. In addition to electronic applications, 2D materials are also good candidates for electrochemical energy storage and conversion due to their large surface area and atomic thickness. This thesis mainly focuses on the synthesis of 2D materials and their application in energy conversion. Firstly, we focus on the synthesis of two-dimensional Tin Disulfide (SnS2). SnS2 is considered to be a novel material in 2D family. 2D SnS2 has a large band gap ( 2.8 eV) and high carrier mobility, which makes it a potential applicant for electronics. Monolayer SnS2 with large scale and high crystal quality was successfully synthesized by chemical vapor deposition (CVD), and its performance as a photodetector was examined. The next chapter demonstrated a generic method for growing millimeter-scale single crystals as well as wafer-scale thin films of TMDs. This generic method was obtained by studying the precursors' behavior and the flow dynamics during the CVD process of growing MoSe2, and was extended to other TMD layers such as millimeter-scale WSe2 single crystals. Understanding the growth processes of high quality large area monolayers of TMDs is crucial for further fundamental research as well as future development for scalable complex electronics. Besides the synthesis of 2D materials with high qualities, we further explored the relationship between defects and electrochemical properties. By directly observing and correlating the microscale structural changes of TMD monolayers such as MoS2 to the catalytic properties, we were able to provide insight on the fundamental catalytic mechanism for hydrogen evolution reaction. Finally, we used the 2D materials to build up 3D architectures, showing excellent performance in energy storage and conversion. For example, we used graphene as a conductive scaffold to support vanadium oxide (V 2O5) on nanoscale, and achieved high performances for supercapacitors. Also, we applied the Pt anchored N-doped graphene nanoribbons as the catalyst for methanol electro oxidation, and reported the best performance among Pt/Carbon-based catalysts.

Machining approach of freeform optics on infrared materials via ultra-precision turning.

PubMed

Li, Zexiao; Fang, Fengzhou; Chen, Jinjin; Zhang, Xiaodong

2017-02-06

Optical freeform surfaces are of great advantage in excellent optical performance and integrated alignment features. It has wide applications in illumination, imaging and non-imaging, etc. Machining freeform surfaces on infrared (IR) materials with ultra-precision finish is difficult due to its brittle nature. Fast tool servo (FTS) assisted diamond turning is a powerful technique for the realization of freeform optics on brittle materials due to its features of high spindle speed and high cutting speed. However it has difficulties with large slope angles and large rise-and-falls in the sagittal direction. In order to overcome this defect, the balance of the machining quality on the freeform surface and the brittle nature in IR materials should be realized. This paper presents the design of a near-rotational freeform surface (NRFS) with a low non-rotational degree (NRD) to constraint the variation of traditional freeform optics to solve this issue. In NRFS, the separation of the surface results in a rotational part and a residual part denoted as a non-rotational surface (NRS). Machining NRFS on germanium is operated by FTS diamond turning. Characteristics of the surface indicate that the optical finish of the freeform surface has been achieved. The modulation transfer function (MTF) of the freeform optics shows a good agreement to the design expectation. Images of the final optical system confirm that the fabricating strategy is of high efficiency and high quality. Challenges and prospects are discussed to provide guidance of future work.

Laser Processing of Multilayered Thermal Spray Coatings: Optimal Processing Parameters

NASA Astrophysics Data System (ADS)

Tewolde, Mahder; Zhang, Tao; Lee, Hwasoo; Sampath, Sanjay; Hwang, David; Longtin, Jon

2017-12-01

Laser processing offers an innovative approach for the fabrication and transformation of a wide range of materials. As a rapid, non-contact, and precision material removal technology, lasers are natural tools to process thermal spray coatings. Recently, a thermoelectric generator (TEG) was fabricated using thermal spray and laser processing. The TEG device represents a multilayer, multimaterial functional thermal spray structure, with laser processing serving an essential role in its fabrication. Several unique challenges are presented when processing such multilayer coatings, and the focus of this work is on the selection of laser processing parameters for optimal feature quality and device performance. A parametric study is carried out using three short-pulse lasers, where laser power, repetition rate and processing speed are varied to determine the laser parameters that result in high-quality features. The resulting laser patterns are characterized using optical and scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electrical isolation tests between patterned regions. The underlying laser interaction and material removal mechanisms that affect the feature quality are discussed. Feature quality was found to improve both by using a multiscanning approach and an optional assist gas of air or nitrogen. Electrically isolated regions were also patterned in a cylindrical test specimen.

Implementation of ZnO/ZnMgO strained-layer superlattice for ZnO heteroepitaxial growth on sapphire

NASA Astrophysics Data System (ADS)

Petukhov, Vladimir; Bakin, Andrey; Tsiaoussis, Ioannis; Rothman, Johan; Ivanov, Sergey; Stoemenos, John; Waag, Andreas

2011-05-01

The main challenge in fabrication of ZnO-based devices is the absence of reliable p-type material. This is mostly caused by insufficient crystalline quality of the material and not well-enough-developed native point defect control of ZnO. At present high-quality ZnO wafers are still expensive and ZnO heteroepitaxial layers on sapphire are the most reasonable alternative to homoepitaxial layers. But it is still necessary to improve the crystalline quality of the heteroepitaxial layers. One of the approaches to reduce defect density in heteroepitaxial layers is to introduce a strained-layer superlattice (SL) that could stop dislocation propagation from the substrate-layer interface. In the present paper we have employed fifteen periods of a highly strained SL structure. The structure was grown on a conventional double buffer layer comprising of high-temperature MgO/low-temperature ZnO on sapphire. The influence of the SLs on the properties of the heteroepitaxial ZnO layers is investigated. Electrical measurements of the structure with SL revealed very high values of the carrier mobility up to 210 cm2/Vs at room temperature. Structural characterization of the obtained samples showed that the dislocation density in the following ZnO layer was not reduced. The high mobility signal appears to come from the SL structure or the SL/ZnO interface.

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement 33, 1988.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

The Environmental Quality Instructional Resources Center in Columbus, Ohio, acquires, reviews, indexes, and announces both print (books, modules, units, etc.) and non-print (films, slides, video tapes, etc.) materials related to water quality and water resources education and instruction. In addition some materials related to hazardous materials,…

[Preparation of freeze - drying control materials of IgG antibody against Schistosoma japonicum for immunodetection kits].

PubMed

Jin, Huang; Chun-Lian, Tang; Zu-Wu, Tu; Li, Tang; Ke-Hui, Zhang; Qian, Li; Jun, Ye

2018-04-18

To prepare freeze-drying control materials of IgG antibody against Schistosoma japonicum for detection kits. The serum samples of schistosomiasis patients from endemic areas and normal people without history of schistosome infection or contact with infested water in Hubei Province were collected. All the sera were detected by the method approved by China Food and Drug Administration and selected for preparation of quality control samples. Totally twelve positive quality control materials, ten negative quality control materials, and one sensitive and one precision quality control materials were screened. According to the positive serum level, the positive degrees of quality control materials were divided into strong, medium and weak levels. The stability could be valid for one year. The freeze-drying quality control materials of IgG antibody against S. japonicum for detection kits are prepared. They are easy to use and have good stability, and therefore, they may meet the requirement of quality control for the detection of schistosomiasis diagnostics kits.

New PLAD apparatus and fabrication of epitaxial films and junctions of functional materials: SiC, GaN, ZnO, diamond and GMR layers

NASA Astrophysics Data System (ADS)

Muto, Hachizo; Kusumori, Takeshi; Nakamura, Toshiyuki; Asano, Takashi; Hori, Takahiro

2006-04-01

We have developed a new pulsed laser ablation-deposition (PLAD) apparatus and techniques for fabricating films of high-temperature or functional materials, including two short-wavelength lasers: (a) a YAG 5th harmonic (213 nm) and (b) Raman-shifted lasers containing vacuum ultraviolet light; also involved are (c) a high-temperature heater with a maximum temperature of 1350 °C, (d) dual-target simultaneous ablation mechanics, and (e) hybrid PLAD using a pico-second YAG laser combined with (c) and/or (d). Using the high-T heater, hetero-epitaxial films of 3C-, 2H- and 4H-SiC have been prepared on sapphire-c. In situ p-doping for GaN epitaxial films is achieved by simultaneous ablation of GaN and Mg targets by (d) during film growth. Junctions such as pGaN (Mg-doped)-film/n-SiC(0 0 0 1) substrate and pGaN/n-Si(1 1 1) show good diode characteristics. Epitaxial films with a diamond lattice can be grown on the sapphire-c plane by hybrid PLAD (e) with a high-T heater using a 6H-SiC target. High quality epitaxial films of ZnO are grown by PLAD by introducing a low-temperature self-buffer layer; magnetization of ferromagnetic materials is enforced by overlaying on a ferromagnetic lattice plane of an anti-ferromagnetic material, showing the value of the layer-overlaying method in improving quality. The short-wavelength lasers are useful in reducing surface particles on functional films, including superconductors.

Effect of steel structure and defects on reliability of parts of impact mechanisms

NASA Astrophysics Data System (ADS)

Popelyukh, AI; Repin, AA; Alekseev, SE

2018-03-01

The paper discusses selection of materials suitable for manufacturing critical parts of impact mechanisms. It is shown that in order to extend life of parts exposed to high dynamic loading, it is expedient to use medium- and high-carbon alloy-treated steels featuring low impurity with nonmetallic inclusions and high hardening characteristics. Application of thermally untreated parts is undesirable as steel having ferrite–pearlite structure possesses low fatigue strength. Aimed to ensure high reliability of parts with a hardness of 42–55 HRC, steel should be reinforced by thermal treatement with the formation of multicomponent martensite–bainite structure. High-quality production should include defectoscopy and incoming material control.

A study with ESI PAM-STAMP® on the influence of tool deformation on final part quality during a forming process

NASA Astrophysics Data System (ADS)

Vrolijk, Mark; Ogawa, Takayuki; Camanho, Arthur; Biasutti, Manfredi; Lorenz, David

2018-05-01

As a result from the ever increasing demand to produce lighter vehicles, more and more advanced high-strength materials are used in automotive industry. Focusing on sheet metal cold forming processes, these materials require high pressing forces and exhibit large springback after forming. Due to the high pressing forces deformations occur in the tooling geometry, introducing dimensional inaccuracies in the blank and potentially impact the final springback behavior. As a result the tool deformations can have an impact on the final assembly or introduce cosmetic defects. Often several iterations are required in try-out to obtain the required tolerances, with costs going up to as much as 30% of the entire product development cost. To investigate the sheet metal part feasibility and quality, in automotive industry CAE tools are widely used. However, in current practice the influence of the tool deformations on the final part quality is generally neglected and simulations are carried out with rigid tools to avoid drastically increased calculation times. If the tool deformation is analyzed through simulation it is normally done at the end of the drawing prosses, when contact conditions are mapped on the die structure and a static analysis is performed to check the deflections of the tool. But this method does not predict the influence of these deflections on the final quality of the part. In order to take tool deformations into account during drawing simulations, ESI has developed the ability to couple solvers efficiently in a way the tool deformations can be real-time included in the drawing simulation without high increase in simulation time compared to simulations with rigid tools. In this paper a study will be presented which demonstrates the effect of tool deformations on the final part quality.

Cluster Beam Studies.

DTIC Science & Technology

1988-04-01

Continue on reverse if necessary and identify by block number) Cluster beams offer a means of depositing high-quality thin films at low...either directly inclustered vapors of nonvolatile materials or Indirectly by bombarding the film duringdeposition with clusters of inert gases. When a...electron volt energy per atom. The suprathermal energy of thej depositing atoms is thought to produce unique thin films (either in quality, or in the ability

Using aspen for artist stretcher frames: adding value through quality service, direct marketing, and careful material selection

Treesearch

Chris Polson

2001-01-01

Aspen wood, when carefully selected and kiln dried, makes excellent stock for artist stretcher frames. Direct marketing techniques including the Internet and word of mouth give access to national markets, providing a more diverse and stable customer base for operations from a rural area. High-quality service, as shown by product performance and rapid order fulfillment...

A computational method for selecting short peptide sequences for inorganic material binding.

PubMed

Nayebi, Niloofar; Cetinel, Sibel; Omar, Sara Ibrahim; Tuszynski, Jack A; Montemagno, Carlo

2017-11-01

Discovering or designing biofunctionalized materials with improved quality highly depends on the ability to manipulate and control the peptide-inorganic interaction. Various peptides can be used as assemblers, synthesizers, and linkers in the material syntheses. In another context, specific and selective material-binding peptides can be used as recognition blocks in mining applications. In this study, we propose a new in silico method to select short 4-mer peptides with high affinity and selectivity for a given target material. This method is illustrated with the calcite (104) surface as an example, which has been experimentally validated. A calcite binding peptide can play an important role in our understanding of biomineralization. A practical aspect of calcite is a need for it to be selectively depressed in mining sites. © 2017 Wiley Periodicals, Inc.

Diagnosing Key Drivers of Job Impact and Business Results Attributable to Training at the Defense Acquisition University

DTIC Science & Technology

2011-10-01

expenditures related to training are instruction and materi - als. High levels of instructor quality are synonymous with effective learning. This positivist...Whether the materials are physical in the form of books and notes, or online, students grasp difficult concepts by reading them over and over again... materials are adequate, students often have pre-conceived notions with regards to the value of a course before it has been completed. To be accurate

Water Quality Monitoring in Developing Countries; Can Microbial Fuel Cells be the Answer?

PubMed Central

Chouler, Jon; Di Lorenzo, Mirella

2015-01-01

The provision of safe water and adequate sanitation in developing countries is a must. A range of chemical and biological methods are currently used to ensure the safety of water for consumption. These methods however suffer from high costs, complexity of use and inability to function onsite and in real time. The microbial fuel cell (MFC) technology has great potential for the rapid and simple testing of the quality of water sources. MFCs have the advantages of high simplicity and possibility for onsite and real time monitoring. Depending on the choice of manufacturing materials, this technology can also be highly cost effective. This review covers the state-of-the-art research on MFC sensors for water quality monitoring, and explores enabling factors for their use in developing countries. PMID:26193327

Water Quality Monitoring in Developing Countries; Can Microbial Fuel Cells be the Answer?

PubMed

Chouler, Jon; Di Lorenzo, Mirella

2015-07-16

The provision of safe water and adequate sanitation in developing countries is a must. A range of chemical and biological methods are currently used to ensure the safety of water for consumption. These methods however suffer from high costs, complexity of use and inability to function onsite and in real time. The microbial fuel cell (MFC) technology has great potential for the rapid and simple testing of the quality of water sources. MFCs have the advantages of high simplicity and possibility for onsite and real time monitoring. Depending on the choice of manufacturing materials, this technology can also be highly cost effective. This review covers the state-of-the-art research on MFC sensors for water quality monitoring, and explores enabling factors for their use in developing countries.

Regional distribution and losses of end-of-life steel throughout multiple product life cycles-Insights from the global multiregional MaTrace model.

PubMed

Pauliuk, Stefan; Kondo, Yasushi; Nakamura, Shinichiro; Nakajima, Kenichi

2017-01-01

Substantial amounts of post-consumer scrap are exported to other regions or lost during recovery and remelting, and both export and losses pose a constraint to desires for having regionally closed material cycles. To quantify the challenges and trade-offs associated with closed-loop metal recycling, we looked at the material cycles from the perspective of a single material unit and trace a unit of material through several product life cycles. Focusing on steel, we used current process parameters, loss rates, and trade patterns of the steel cycle to study how steel that was originally contained in high quality applications such as machinery or vehicles with stringent purity requirements gets subsequently distributed across different regions and product groups such as building and construction with less stringent purity requirements. We applied MaTrace Global, a supply-driven multiregional model of steel flows coupled to a dynamic stock model of steel use. We found that, depending on region and product group, up to 95% of the steel consumed today will leave the use phase of that region until 2100, and that up to 50% can get lost in obsolete stocks, landfills, or slag piles until 2100. The high losses resulting from business-as-usual scrap recovery and recycling can be reduced, both by diverting postconsumer scrap into long-lived applications such as buildings and by improving the recovery rates in the waste management and remelting industries. Because the lifetimes of high-quality (cold-rolled) steel applications are shorter and remelting occurs more often than for buildings and infrastructure, we found and quantified a tradeoff between low losses and high-quality applications in the steel cycle. Furthermore, we found that with current trade patterns, reduced overall losses will lead to higher fractions of secondary steel being exported to other regions. Current loss rates, product lifetimes, and trade patterns impede the closure of the steel cycle.

Design and development of green roof substrate to improve runoff water quality: plant growth experiments and adsorption.

PubMed

Vijayaraghavan, K; Raja, Franklin D

2014-10-15

Many studies worldwide have investigated the potential benefits achievable by transforming brown roofs of buildings to green roofs. However, little literature examined the runoff quality/sorption ability of green roofs. As the green roof substrate is the main component to alter the quality of runoff, this investigation raises the possibility of using a mixture of low-cost inorganic materials to develop a green roof substrate. The tested materials include exfoliated vermiculite, expanded perlite, crushed brick and sand along with organic component (coco-peat). Detailed physical and chemical analyses revealed that each of these materials possesses different characteristics and hence a mix of these materials was desirable to develop an optimal green roof substrate. Using factorial design, 18 different substrate mixes were prepared and detailed examination indicated that mix-12 exhibited desirable characteristics of green roof substrate with low bulk density (431 kg/m(3)), high water holding capacity (39.4%), air filled porosity (19.5%), and hydraulic conductivity (4570 mm/h). The substrate mix also provided maximum support to Portulaca grandiflora (380% total biomass increment) over one month of growth. To explore the leaching characteristics and sorption capacity of developed green roof substrate, a down-flow packed column arrangement was employed. High conductivity and total dissolved solids along with light metal ions (Na, K, Ca and Mg) were observed in the leachates during initial stages of column operation; however the concentration of ions ceased during the final stages of operation (600 min). Experiments with metal-spiked deionized water revealed that green roof substrate possess high sorption capacity towards various heavy metal ions (Al, Fe, Cr, Cu, Ni, Pb, Zn and Cd). Thus the developed growth substrate possesses desirable characteristics for green roofs along with high sorption capacity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Si-Based Germanium Tin Semiconductor Lasers for Optoelectronic Applications

NASA Astrophysics Data System (ADS)

Al-Kabi, Sattar H. Sweilim

Silicon-based materials and optoelectronic devices are of great interest as they could be monolithically integrated in the current Si complementary metal-oxide-semiconductor (CMOS) processes. The integration of optoelectronic components on the CMOS platform has long been limited due to the unavailability of Si-based laser sources. A Si-based monolithic laser is highly desirable for full integration of Si photonics chip. In this work, Si-based germanium-tin (GeSn) lasers have been demonstrated as direct bandgap group-IV laser sources. This opens a completely new avenue from the traditional III-V integration approach. In this work, the material and optical properties of GeSn alloys were comprehensively studied. The GeSn films were grown on Ge-buffered Si substrates in a reduced pressure chemical vapor deposition system with low-cost SnCl4 and GeH4 precursors. A systematic study was done for thin GeSn films (thickness 400 nm) with Sn composition 5 to 17.5%. The room temperature photoluminescence (PL) spectra were measured that showed a gradual shift of emission peaks towards longer wavelength as Sn composition increases. Strong PL intensity and low defect density indicated high material quality. Moreover, the PL study of n-doped samples showed bandgap narrowing compared to the unintentionally p-doped (boron) thin films with similar Sn compositions. Finally, optically pumped GeSn lasers on Si with broad wavelength coverage from 2 to 3 mum were demonstrated using high-quality GeSn films with Sn compositions up to 17.5%. The achieved maximum Sn composition of 17.5% broke the acknowledged Sn incorporation limit using similar deposition chemistry. The highest lasing temperature was measured at 180 K with an active layer thickness as thin as 270 nm. The unprecedented lasing performance is due to the achievement of high material quality and a robust fabrication process. The results reported in this work show a major advancement towards Si-based electrically pumped mid-infrared laser sources for integrated photonics.

Tests on a pilot plant for reheating desulfurized flue gases with the help of heat pipes

NASA Astrophysics Data System (ADS)

Schug, W.

1982-02-01

Desulfurized flue gases were reheated with a heat pipe heat exchanger. Finned heat pipes, with a coating or made of high quality steel were subjected to different operating conditions for 1000 hr. The coating proved to be unsuitable for heat transfer because it swells and detaches itself from the background material. The high quality steels showed pitting and surface corrosion. The possibilities of cleaning were also studied to prevent deposits forming on the heat pipes, but no solution was found.

Electron tubes for industrial applications

NASA Astrophysics Data System (ADS)

Gellert, Bernd

1994-05-01

This report reviews research and development efforts within the last years for vacuum electron tubes, in particular power grid tubes for industrial applications. Physical and chemical effects are discussed that determine the performance of todays devices. Due to the progress made in the fundamental understanding of materials and newly developed processes the reliability and reproducibility of power grid tubes could be improved considerably. Modern computer controlled manufacturing methods ensure a high reproducibility of production and continuous quality certification according to ISO 9001 guarantees future high quality standards. Some typical applications of these tubes are given as an example.

High quality factor surface Fabry-Perot cavity of acoustic waves

NASA Astrophysics Data System (ADS)

Xu, Yuntao; Fu, Wei; Zou, Chang-ling; Shen, Zhen; Tang, Hong X.

2018-02-01

Surface acoustic wave (SAW) resonators are critical components in wireless communications and many sensing applications. They have also recently emerged as a subject of study in quantum acoustics at the single phonon level. Acoustic loss reduction and mode confinement are key performance factors in SAW resonators. Here, we report the design and experimental realization of high quality factor Fabry-Perot SAW resonators formed in between the tapered phononic crystal mirrors patterned on a GaN-on-sapphire material platform. The fabricated SAW resonators are characterized by both an electrical network analyzer and an optical heterodyne vibrometer. We observed standing Rayleigh waves inside the cavity, with an intrinsic quality factor exceeding 1.3 × 104 at ambient conditions.

Hall effect measurements of high-quality M n3CuN thin films and the electronic structure

NASA Astrophysics Data System (ADS)

Matsumoto, Toshiki; Hatano, Takafumi; Urata, Takahiro; Iida, Kazumasa; Takenaka, Koshi; Ikuta, Hiroshi

2017-11-01

The physical properties of M n3CuN were studied using thin films. We found that an annealing process was very effective to improve the film quality, the key of which was the use of Ti that prevented the formation of oxide impurities. Using these high-quality thin films, we found strong strain dependence for the ferromagnetic transition temperature (TC) and a sign change of the Hall coefficient at TC. The analysis of Hall coefficient data revealed a sizable decrease of hole concentration and a large increase of electron mobility below TC, which is discussed in relation to the electronic structure of this material.

Blue 450nm high power semiconductor continuous wave laser bars exceeding rollover output power of 80W

NASA Astrophysics Data System (ADS)

König, H.; Lell, A.; Stojetz, B.; Ali, M.; Eichler, C.; Peter, M.; Löffler, A.; Strauss, U.; Baumann, M.; Balck, A.; Malchus, J.; Krause, V.

2018-02-01

Industrial material processing like cutting or welding of metals is rather energy efficient using direct diode or diode pumped solid state lasers. However, many applications cannot be addressed by established infrared laser technology due to fundamental material properties of the workpiece: For example materials like copper or gold have too low absorption in the near infrared wavelength range to be processed efficiently by use of existing high power laser systems. The huge interest to enable high power kW systems with more suitable wavelengths in the blue spectral range triggered the German funded research project 'BLAULAS': Therein the feasibility and capability of CW operating high power laser bars based on the GaN material system was investigated by Osram and Laserline. High performance bars were enabled by defeating fundamental challenges like material quality as well as the chip processes, both of which differ significantly from well-known IR laser bars. The research samples were assembled on actively cooled heat sinks with hard solder technology. For the first time an output power of 98W per bar at 60A drive current was achieved. Conversion efficiency as high as 46% at 50W output power was demonstrated.

High-dimensional nested analysis of variance to assess the effect of production season, quality grade and steam pasteurization on the phenolic composition of fermented rooibos herbal tea.

PubMed

Stanimirova, I; Kazura, M; de Beer, D; Joubert, E; Schulze, A E; Beelders, T; de Villiers, A; Walczak, B

2013-10-15

A nested analysis of variance combined with simultaneous component analysis, ASCA, was proposed to model high-dimensional chromatographic data. The data were obtained from an experiment designed to investigate the effect of production season, quality grade and post-production processing (steam pasteurization) on the phenolic content of the infusion of the popular herbal tea, rooibos, at 'cup-of-tea' strength. Specifically, a four-way analysis of variance where the experimental design involves nesting in two of the three crossed factors was considered. For the purpose of the study, batches of fermented rooibos plant material were sampled from each of four quality grades during three production seasons (2009, 2010 and 2011) and a sub-sample of each batch was steam-pasteurized. The phenolic content of each rooibos infusion was characterized by high performance liquid chromatography (HPLC)-diode array detection (DAD). In contrast to previous studies, the complete HPLC-DAD signals were used in the chemometric analysis in order to take into account the entire phenolic profile. All factors had a significant effect on the phenolic content of a 'cup-of-tea' strength rooibos infusion. In particular, infusions prepared from the grade A (highest quality) samples contained a higher content of almost all phenolic compounds than the lower quality plant material. The variations of the content of isoorientin and orientin in the different quality grade infusions over production seasons are larger than the variations in the content of aspalathin and quercetin-3-O-robinobioside. Ferulic acid can be used as an indicator of the quality of rooibos tea as its content generally decreases with increasing tea quality. Steam pasteurization decreased the content of the majority of phenolic compounds in a 'cup-of-tea' strength rooibos infusion. © 2013 Elsevier B.V. All rights reserved.

Resistivity, carrier trapping, and polarization phenomenon in semiconductor radiation detection materials

NASA Astrophysics Data System (ADS)

Du, Mao-Hua; Biswas, Koushik; Singh, David J.

2012-10-01

In this paper, we report theoretical studies of native defects and dopants in a number of room-temperature semiconductor radiation detection materials, i.e., CdTe, TlBr, and Tl6SeI4. We address several important questions, such as what causes high resistivity in these materials, what explains good μτ product (carrier mobility-lifetime product) in soft-lattice ionic compounds that have high defect density, and how to obtain high resistivity and low carrier trapping simultaneously. Our main results are: (1) shallow donors rather than deep ones are responsible for high resistivity in high-quality detectorgrade CdTe; (2) large dielectric screening and the lack of deep levels from low-energy native defects may contribute to the good μτ products for both electrons and holes in TlBr; (3) the polarization phenomenon in Tl6SeI4 is expected to be much reduced compared to that in TlBr.

Separation of pigment formulations by high-performance thin-layer chromatography with automated multiple development.

PubMed

Stiefel, Constanze; Dietzel, Sylvia; Endress, Marc; Morlock, Gertrud E

2016-09-02

Food packaging is designed to provide sufficient protection for the respective filling, legally binding information for the consumers like nutritional facts or filling information, and an attractive appearance to promote the sale. For quality and safety of the package, a regular quality control of the used printing materials is necessary to get consistently good print results, to avoid migration of undesired ink components into the food and to identify potentially faulty ink batches. Analytical approaches, however, have hardly been considered for quality assurance so far due to the lack of robust, suitable methods for the analysis of rarely soluble pigment formulations. Thus, a simple and generic high-performance thin-layer chromatography (HPTLC) method for the separation of different colored pigment formulations was developed on HPTLC plates silica gel 60 by automated multiple development. The gradient system provided a sharp resolution for differently soluble pigment constituents like additives and coating materials. The results of multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes (e.g., lipophilic components), enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Hyphenation of HPTLC with high resolution mass spectrometry and infrared spectroscopy allowed the characterization of single unknown pigment constituents, which may partly be responsible for known quality problems during printing. The newly developed, precise and selective HPTLC method can be used as part of routine quality control for both, incoming pigment batches and monitoring of internal pigment production processes, to secure a consistent pigment composition resulting in consistent ink quality, a faultless print image and safe products. Hyphenation of HPTLC with the A. fischeri bioassay gave first information on the bioactivity or rather on the toxicological potential of different compounds of the pigment formulations. The results of the bioassay might be helpful to choose pigment compositions that provide both, a high printing quality but at the same time guarantee a high consumer safety, especially in regard to smaller pigment components, which tend to migrate through the packaging. Copyright © 2016 Elsevier B.V. All rights reserved.

Automatic orbital GTAW welding: Highest quality welds for tomorrow's high-performance systems

NASA Technical Reports Server (NTRS)

Henon, B. K.

1985-01-01

Automatic orbital gas tungsten arc welding (GTAW) or TIG welding is certain to play an increasingly prominent role in tomorrow's technology. The welds are of the highest quality and the repeatability of automatic weldings is vastly superior to that of manual welding. Since less heat is applied to the weld during automatic welding than manual welding, there is less change in the metallurgical properties of the parent material. The possibility of accurate control and the cleanliness of the automatic GTAW welding process make it highly suitable to the welding of the more exotic and expensive materials which are now widely used in the aerospace and hydrospace industries. Titanium, stainless steel, Inconel, and Incoloy, as well as, aluminum can all be welded to the highest quality specifications automatically. Automatic orbital GTAW equipment is available for the fusion butt welding of tube-to-tube, as well as, tube to autobuttweld fittings. The same equipment can also be used for the fusion butt welding of up to 6 inch pipe with a wall thickness of up to 0.154 inches.

Low optical-loss facet preparation for silica-on-silicon photonics using the ductile dicing regime

NASA Astrophysics Data System (ADS)

Carpenter, Lewis G.; Rogers, Helen L.; Cooper, Peter A.; Holmes, Christopher; Gates, James C.; Smith, Peter G. R.

2013-11-01

The efficient production of high-quality facets for low-loss coupling is a significant production issue in integrated optics, usually requiring time consuming and manually intensive lapping and polishing steps, which add considerably to device fabrication costs. The development of precision dicing saws with diamond impregnated blades has allowed optical grade surfaces to be machined in crystalline materials such as lithium niobate and garnets. In this report we investigate the optimization of dicing machine parameters to obtain optical quality surfaces in a silica-on-silicon planar device demonstrating high optical quality in a commercially important glassy material. We achieve a surface roughness of 4.9 nm (Sa) using the optimized dicing conditions. By machining a groove across a waveguide, using the optimized dicing parameters, a grating based loss measurement technique is used to measure precisely the average free space interface loss per facet caused by scattering as a consequence of surface roughness. The average interface loss per facet was calculated to be: -0.63 dB and -0.76 dB for the TE and TM polarizations, respectively.

Development and Application of High Performance Quenched and Tempered Wear Resistant Steels in Material Handling and Construction Machinery

NASA Astrophysics Data System (ADS)

Su, Fenwei; Sidiras, Evangelos

The demand for more sustainable development promotes the need for components and steel structures with a longer useful life and better performance. Upgrade of wear steel plate used in key industry segments such as mining, recycling and road building results in the stable growth of global market with high quality grade Q&T wear plates (Hardness HBW≥400, and Yield strength ≥690 Mpa). SSAB has now expanded its wear steel product range by both thicker and thinner Q&T plate to meet the needs of the market, and can offer wear plates from 0.7 mm to 160 mm. The continuous research and development is being done to offer even thicker plates. This article introduces the performance and advantages of high quality grade Q&T wear resistant steel products (plate, strip, tube and round bars) produced in SSAB, and also describes typical applications in some industrial segments such as material handling and construction machinery.

Utilization of different waste proteins to create a novel PGPR-containing bio-organic fertilizer

PubMed Central

Huang, Yan; Sun, Li; Zhao, Jianshu; Huang, Rong; Li, Rong; Shen, Qirong

2015-01-01

High-quality bio-organic fertilizers (BIOs) cannot be produced without the addition of some proteins, while many waste proteins are haphazardly disposed, causing serious environmental pollution. In this study, several waste proteins were used as additives to assist with the reproduction of the functional microbe (Bacillus amyloliquefaciens SQR9) inoculated into matured composts to produce BIOs. An optimized composition of solid-state fermentation (SSF) raw materials was predicted by response surface methodology and experimental validation. The results showed that 7.61% (w/w, DW, the same below) rapeseed meal, 8.85% expanded feather meal, 6.47% dewatered blue algal sludge and 77.07% chicken compost resulted in maximum biomass of strain SQR-9 and the maximum amount of lipopeptides 7 days after SSF. Spectroscopy experiments showed that the inner material structural changes in the novel SSF differed from the control and the novel BIO had higher dissolved organic matter. This study offers a high value-added utilization of waste proteins for producing economical but high-quality BIO. PMID:25586328

Utilization of different waste proteins to create a novel PGPR-containing bio-organic fertilizer

NASA Astrophysics Data System (ADS)

Huang, Yan; Sun, Li; Zhao, Jianshu; Huang, Rong; Li, Rong; Shen, Qirong

2015-01-01

High-quality bio-organic fertilizers (BIOs) cannot be produced without the addition of some proteins, while many waste proteins are haphazardly disposed, causing serious environmental pollution. In this study, several waste proteins were used as additives to assist with the reproduction of the functional microbe (Bacillus amyloliquefaciens SQR9) inoculated into matured composts to produce BIOs. An optimized composition of solid-state fermentation (SSF) raw materials was predicted by response surface methodology and experimental validation. The results showed that 7.61% (w/w, DW, the same below) rapeseed meal, 8.85% expanded feather meal, 6.47% dewatered blue algal sludge and 77.07% chicken compost resulted in maximum biomass of strain SQR-9 and the maximum amount of lipopeptides 7 days after SSF. Spectroscopy experiments showed that the inner material structural changes in the novel SSF differed from the control and the novel BIO had higher dissolved organic matter. This study offers a high value-added utilization of waste proteins for producing economical but high-quality BIO.

Printed Biopolymer-Based Electro-Optic Device Components

DTIC Science & Technology

2013-07-01

devices and fabricated e-beam lithography-based master molds. Printed micro and nanostructures using a newly developed spin-on nanoprinting (SNAP...polymeric materials. Among the natural biopolymers , deoxyribonucleic acid (DNA) is an attractive material which can be used to make electronic and...photonic devices [2, 3]. If patterned on the micro and nanoscale using a soft lithography technique, high quality biodegradable optical devices can be

X-Ray Topographic Studies of Energetic Materials.

DTIC Science & Technology

1987-03-01

role of these defects in crystal growth and in the microplasticity of the solid. 1.1 Experimental Techniques The method chosen for the detailed...the electron microscope. The examinations can be readily extended to detailed studies of the microplasticity of the materials using stress/strain...the availability of large, high quality, single crystals. A considerable part of the initial contract was devoted to the determination of conditions

The Accessibility of Learning Content for All Students, Including Students with Disabilities, Must Be Addressed in the Shift to Digital Instructional Materials. SETDA Policy Brief

ERIC Educational Resources Information Center

Fletcher, Geoff; Levin, Doug; Lipper, Katherine; Leichty, Reg

2014-01-01

This is a time of rapid technological advancement, with innovations in education holding great promise for improving teaching and learning, particularly for students with unique needs. High-quality digital educational materials, tools, and resources offer students relevant, up-to-date, and innovative ways to acquire knowledge and skills. Created…

PMMA-Etching-Free Transfer of Wafer-scale Chemical Vapor Deposition Two-dimensional Atomic Crystal by a Water Soluble Polyvinyl Alcohol Polymer Method

PubMed Central

Van Ngoc, Huynh; Qian, Yongteng; Han, Suk Kil; Kang, Dae Joon

2016-01-01

We have explored a facile technique to transfer large area 2-Dimensional (2D) materials grown by chemical vapor deposition method onto various substrates by adding a water-soluble Polyvinyl Alcohol (PVA) layer between the polymethyl-methacrylate (PMMA) and the 2D material film. This technique not only allows the effective transfer to an arbitrary target substrate with a high degree of freedom, but also avoids PMMA etching thereby maintaining the high quality of the transferred 2D materials with minimum contamination. We applied this method to transfer various 2D materials grown on different rigid substrates of general interest, such as graphene on copper foil, h-BN on platinum and MoS2 on SiO2/Si. This facile transfer technique has great potential for future research towards the application of 2D materials in high performance optical, mechanical and electronic devices. PMID:27616038

Epoxy Resins in Electron Microscopy

PubMed Central

Finck, Henry

1960-01-01

A method of embedding biological specimens in araldite 502 (Ciba) has been developed for materials available in the United States. Araldite-embedded tissues are suitable for electron microscopy, but the cutting qualities of the resin necessitates more than routine attention during microtomy. The rather high viscosity of araldite 502 also seems to be an unnecessary handicap. The less viscous epoxy epon 812 (Shell) produces specimens with improved cutting qualities, and has several features—low shrinkage and absence of specimen damage during cure, minimal compression of sections, relative absence of electron beam-induced section damage, etc.—which recommends it as a routine embedding material. The hardness of the cured resin can be easily adjusted by several methods to suit the materials embedded in it. Several problems and advantages of working with sections of epoxy resins are also discussed. PMID:13822825

Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

DOE PAGES

Levin, Barnaby D. A.; Padgett, Elliot; Chen, Chien-Chun; ...

2016-06-07

Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co 2 P nanocrystal, platinum nanoparticles on a carbonmore » nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.« less

Nanomaterial datasets to advance tomography in scanning transmission electron microscopy.

PubMed

Levin, Barnaby D A; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

2016-06-07

Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.

Out-of-Autoclave Cure Composites

NASA Technical Reports Server (NTRS)

Hayes, Brian S.

2015-01-01

As the size of aerospace composite parts exceeds that of even the largest autoclaves, the development of new out-of-autoclave processes and materials is necessary to ensure quality and performance. Many out-of-autoclave prepreg systems can produce high-quality composites initially; however, due to long layup times, the resin advancement commonly causes high void content and variations in fiber volume. Applied Poleramic, Inc. (API), developed an aerospace-grade benzoxazine matrix composite prepreg material that offers more than a year out-time at ambient conditions and provides exceptionally low void content when out-of-autoclave cured. When compared with aerospace epoxy prepreg systems, API's innovation offers significant improvements in terms of out-time at ambient temperature and the corresponding tack retention. The carbon fiber composites developed with the optimized matrix technology have significantly better mechanical performance in terms of hot-wet retention and compression when compared with aerospace epoxy matrices. These composites also offer an excellent overall balance of properties. This matrix system imparts very low cure shrinkage, low coefficient of thermal expansion, and low density when compared with most aerospace epoxy prepreg materials.

Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

PubMed Central

Levin, Barnaby D.A.; Padgett, Elliot; Chen, Chien-Chun; Scott, M.C.; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D.; Robinson, Richard D.; Ercius, Peter; Kourkoutis, Lena F.; Miao, Jianwei; Muller, David A.; Hovden, Robert

2016-01-01

Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data. PMID:27272459

Large-Scale Production of Carbon Nanotubes Using the Jefferson Lab Free Electron Laser

NASA Technical Reports Server (NTRS)

Holloway, Brian C.

2003-01-01

We report on our interdisciplinary program to use the Free Electron Laser (FEL) at the Thomas Jefferson National Accelerator Facility (J-Lab) for high-volume pulsed laser vaporization synthesis of carbon nanotubes. Based in part on the funding of from this project, a novel nanotube production system was designed, tested, and patented. Using this new system nanotube production rates over 100 times faster than conventional laser systems were achieved. Analysis of the material produced shows that it is of as high a quality as the standard laser-based materials.

High Res at High Speed: Automated Delivery of High-Resolution Images from Digital Library Collections

ERIC Educational Resources Information Center

Westbrook, R. Niccole; Watkins, Sean

2012-01-01

As primary source materials in the library are digitized and made available online, the focus of related library services is shifting to include new and innovative methods of digital delivery via social media, digital storytelling, and community-based and consortial image repositories. Most images on the Web are not of sufficient quality for most…

Far-ultraviolet refractive index of optical materials for solar blind channel (SBC) filters for the HST advanced camera for surveys (ACS)

NASA Astrophysics Data System (ADS)

Leviton, Douglas B.; Madison, Timothy J.; Petrone, Peter

1998-10-01

Refractive index measurements using the minimum deviation method have been carried out for prisms of a variety of far ultraviolet optical materials used in the manufacture of Solar Blind Channel (SBC) filters for the HST Advanced Camera for Surveys (ACS). Some of the materials measured are gaining popularity in a variety of high technology applications including high power excimer lasers and advanced microlithography optics operating in a wavelength region where high quality knowledge of optical material properties is sparse yet critical. Our measurements are of unusually high accuracy and precision for this wavelength region owing to advanced instrumentation in the large vacuum chamber of the Diffraction Grating Evaluation Facility (DGEF) at Goddard Space Flight Center (GSFC) used to implement a minimum deviation method refractometer. Index values for CaF2, BaF2, LiF, and far ultraviolet grades of synthetic sapphire and synthetic fused silica are reported and compared with values from the literature.

Optical properties of spin-on deposited low temperature titanium oxide thin films

NASA Astrophysics Data System (ADS)

Rantala, J. T.; Kärkkäinen, A. H. O.

2003-06-01

This letter presents a method to fabricate high quality, high refractive index titanium oxide thin films by applying liquid phase spin-on deposition combined with low temperature annealing. The synthesis of the liquid form titanium oxide material is carried out using a sol-gel synthesis technique. The material can be annealed at low temperature (150 C°) to achieve relatively high refractive index of 1.94 at 632.8 nm wavelength, whereas annealing at 350 C° results in index of 2.03 at 632.8 nm. Film depositions are demonstrated on silicon substrates with 0.5% uniformity in thickness. Refractive indices and extinction coefficients are characterized over a broad wavelength range to demonstrate the optical performance of this novel aqueous phase spin-on deposited hybrid titanium oxide material.

InGaAlAsPN: A Materials System for Silicon Based Optoelectronics and Heterostructure Device Technologies

NASA Technical Reports Server (NTRS)

Broekaert, T. P. E.; Tang, S.; Wallace, R. M.; Beam, E. A., III; Duncan, W. M.; Kao, Y. -C.; Liu, H. -Y.

1995-01-01

A new material system is proposed for silicon based opto-electronic and heterostructure devices; the silicon lattice matched compositions of the (In,Ga,Al)-(As,P)N 3-5 compounds. In this nitride alloy material system, the bandgap is expected to be direct at the silicon lattice matched compositions with a bandgap range most likely to be in the infrared to visible. At lattice constants ranging between those of silicon carbide and silicon, a wider bandgap range is expected to be available and the high quality material obtained through lattice matching could enable applications such as monolithic color displays, high efficiency multi-junction solar cells, opto-electronic integrated circuits for fiber communications, and the transfer of existing 3-5 technology to silicon.

78 FR 51277 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... and materials received, as well as supporting documentation used in preparing this final rule is... Salado salamanders; however, molecular evidence strongly supports that there is a high level of... al. 2001, p. 268). Habitat Each species inhabits water of high quality with a narrow range of...

Improved method for recovery of organic solids from diluted swine manure in 3rd generation treatment system

USDA-ARS?s Scientific Manuscript database

Solid-liquid separation of the raw manure increases the capacity of decision making and opportunities for treatment. The high-rate separation up-front using flocculants allows recovery of most of the organic compounds, which can be used for manufacture of high-quality compost materials. However, t...

Beyond PD: Teacher Professional Learning in High-Performing Systems. Teacher Quality Systems in Top Performing Countries

ERIC Educational Resources Information Center

Jensen, Ben; Sonnemann, Julie; Roberts-Hull, Katie; Hunter, Amélie

2016-01-01

This report illustrates how four high-performing systems--British Columbia (Canada), Hong Kong, Shanghai (China) and Singapore--developed their teacher professional learning. The report and accompanying materials are designed as a resource for teachers, school leaders and policymakers wanting to improve teacher professional learning in their…

Synchronous exfoliation and assembly of graphene on 3D Ni(OH)2 for supercapacitors.

PubMed

Ma, Liguo; Zheng, Maojun; Liu, Shaohua; Li, Qiang; You, Yuxiu; Wang, Faze; Ma, Li; Shen, Wenzhong

2016-11-08

Nowadays, new approaches to fabricate high-performance electrode materials are of vital importance in the renewable energy field. Here, we present a facile synthesis procedure of 3D Ni(OH) 2 /graphene hybrids for supercapacitors via synchronous electrochemical-assisted exfoliation and assembly of graphene on 3D Ni(OH) 2 networks. With the assistance of an electric field, the electrochemically exfoliated high-quality graphene can be readily, uniformly assembled on the surfaces of 3D Ni(OH) 2 . When serving as electrode materials for supercapacitors, the resulting 3D Ni(OH) 2 /graphene composites exhibited excellent specific capacitance (263 mF cm -2 at 2 mA cm -2 ), remarkable rate capability and super-long cycle life (retention of 94.1% even after 10 000 continuous charge-discharge cycles), which may be attributed to their highly porous, stable 3D architecture as well as uniform, firm anchoring of ultrathin graphene on their surfaces. Therefore, our approach provides a facile strategy for the large-scale synthesis of high-quality graphene based composites towards various applications.

Non-invasive pre-lens tear film assessment with high-speed videokeratoscopy.

PubMed

Llorens-Quintana, Clara; Mousavi, Maryam; Szczesna-Iskander, Dorota; Iskander, D Robert

2018-02-01

To evaluate the effect of two types of daily contact lenses (delefilcon A and omafilcon A) on the tear film and establish whether it is dependent on pre-corneal tear film characteristics using a new method to analyse high-speed videokeratoscopy recordings, as well as to determine the sensitivity of the method in differentiating between contact lens materials on eye. High-speed videokeratoscopy recordings were analysed using a custom made automated algorithm based on a fractal dimension approach that provides a set of parameters directly related to tear film stability. Fifty-four subjects participated in the study. Baseline measurements, in suppressed and natural blinking conditions, were taken before subjects were fitted with two different daily contact lenses and after four hours of contact lens wear. The method for analysing the stability of the tear film provides alternative parameters to the non-invasive break up time to assess the quality of the pre-corneal and pre-lens tear film. Both contact lenses significantly decreased the quality of the tear film in suppressed and natural blinking conditions (p<0.001). The utilised method was able to distinguish between contact lens materials on eye in suppressed blinking conditions. The pre-corneal tear film characteristics were not correlated with the decrease in pre-lens tear film quality. High-speed videokeratoscopy equipped with an automated method to analyse the dynamics of the tear film is able to distinguish between contact lens materials in vivo. Incorporating the assessment of pre-lens tear film to the clinical practice could aid improving contact lens fitting and understand contact lens comfort. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Adaptive texture filtering for defect inspection in ultrasound images

NASA Astrophysics Data System (ADS)

Zmola, Carl; Segal, Andrew C.; Lovewell, Brian; Nash, Charles

1993-05-01

The use of ultrasonic imaging to analyze defects and characterize materials is critical in the development of non-destructive testing and non-destructive evaluation (NDT/NDE) tools for manufacturing. To develop better quality control and reliability in the manufacturing environment advanced image processing techniques are useful. For example, through the use of texture filtering on ultrasound images, we have been able to filter characteristic textures from highly-textured C-scan images of materials. The materials have highly regular characteristic textures which are of the same resolution and dynamic range as other important features within the image. By applying texture filters and adaptively modifying their filter response, we have examined a family of filters for removing these textures.

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

Gogotsi, Yury

Here, the research community has been steadily expanding the family of few-atom-thick crystals beyond graphene, discovering new materials or producing known materials in a 2D state and demonstrating their unique properties 1, 2. Recently, nanometre-thin 2D transition metal carbides have also joined this family 3. Writing in Nature Materials, Chuan Xu and colleagues now report a significant advance in the field, showing the synthesis of large-area, high-quality, nanometre-thin crystals of molybdenum carbide that demonstrate low-temperature 2D superconductivity 4. Moreover, they also show that other ultrathin carbide crystals, such as tungsten and tantalum carbides, can be grown by chemical vapour depositionmore » with a high crystallinity and very low defect concentration.« less

Laser Surface Treatment of Sintered Alumina

NASA Astrophysics Data System (ADS)

Hagemann, R.; Noelke, C.; Kaierle, S.; Wesling, V.

Sintered alumina ceramics are used as refractory materials for industrial aluminum furnaces. In this environment the ceramic surface is in permanent contact with molten aluminum resulting in deposition of oxidic material on its surface. Consequently, a lower volume capacity as well as thermal efficiency of the furnaces follows. To reduce oxidic adherence of the ceramic material, two laser-based surface treatment processes were investigated: a powder- based single-step laser cladding and a laser surface remelting. Main objective is to achieve an improved surface quality of the ceramic material considering the industrial requirements as a high process speed.

High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method

PubMed Central

Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

2015-01-01

Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]nRS[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures. PMID:26153533

Dependable water supplies from valley alluvium in arid regions.

PubMed

Van Haveren, Bruce P

2004-12-01

Reliable sources of high-quality water for domestic use are much needed in arid regions. Valley alluvium, coarse sand and gravel deposited by streams and rivers, provides an ideal storage medium for water in many regions of the world. However, river sediments will not accumulate in a valley without a natural or artificial barrier to slow the water. Sediments will deposit upstream of a barrier dam and form an alluvial deposit of relatively well-sorted material. The alluvium then acts as both an underground water-supply reservoir and a water filter, yielding a constant flow of high-quality water. Trap dams that store water in alluvial sediments and slowly release the filtered water represent an appropriate and inexpensive technology for combating desertification and mitigating the effects of drought at the community level. Small trap dams may be built as a community project using local materials and local labor.

Process Development of Porcelain Ceramic Material with Binder Jetting Process for Dental Applications

NASA Astrophysics Data System (ADS)

Miyanaji, Hadi; Zhang, Shanshan; Lassell, Austin; Zandinejad, Amirali; Yang, Li

2016-03-01

Custom ceramic structures possess significant potentials in many applications such as dentistry and aerospace where extreme environments are present. Specifically, highly customized geometries with adequate performance are needed for various dental prostheses applications. This paper demonstrates the development of process and post-process parameters for a dental porcelain ceramic material using binder jetting additive manufacturing (AM). Various process parameters such as binder amount, drying power level, drying time and powder spread speed were studied experimentally for their effect on geometrical and mechanical characteristics of green parts. In addition, the effects of sintering and printing parameters on the qualities of the densified ceramic structures were also investigated experimentally. The results provide insights into the process-property relationships for the binder jetting AM process, and some of the challenges of the process that need to be further characterized for the successful adoption of the binder jetting technology in high quality ceramic fabrications are discussed.

Perovskite Solar Cells: From the Atomic Level to Film Quality and Device Performance.

PubMed

Saliba, Michael; Correa-Baena, Juan-Pablo; Grätzel, Michael; Hagfeldt, Anders; Abate, Antonio

2018-03-01

Organic-inorganic perovskites have made tremendous progress in recent years due to exceptional material properties such as high panchromatic absorption, charge carrier diffusion lengths, and a sharp optical band edge. The combination of high-quality semiconductor performance with low-cost deposition techniques seems to be a match made in heaven, creating great excitement far beyond academic ivory towers. This is particularly true for perovskite solar cells (PSCs) that have shown unprecedented gains in efficiency and stability over a time span of just five years. Now there are serious efforts for commercialization with the hope that PSCs can make a major impact in generating inexpensive, sustainable solar electricity. In this Review, we will focus on perovskite material properties as well as on devices from the atomic to the thin film level to highlight the remaining challenges and to anticipate the future developments of PSCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of SiC/SiO2 core-shell nanowires via molten salt mediated carbothermal reduction route

NASA Astrophysics Data System (ADS)

Zhang, Ju; Yan, Shuai; Jia, Quanli; Huang, Juntong; Lin, Liangxu; Zhang, Shaowei

2016-06-01

The growth of silicon carbide (SiC) crystal generally requires a high temperature, especially when low quality industrial wastes are used as the starting raw materials. In this work, SiC/SiO2 core-shell nanowires (NWs) were synthesized from low cost silica fume and sucrose via a molten salt mediated carbothermal reduction (CR) route. The molten salt was found to be effective in promoting the SiC growth and lowering the synthesis temperature. The resultant NWs exhibited a heterostructure composed of a 3C-SiC core of 100 nm in diameter and a 5-10 nm thick amorphous SiO2 shell layer. The photoluminescence spectrum of the achieved SiC NWs displayed a significant blue shift (a dominant luminescence at round 422 nm), which suggested that they were high quality and could be a promising candidate material for future optoelectronic applications.

On-chip purification via liquid immersion of arc-discharge synthesized multiwalled carbon nanotubes

NASA Astrophysics Data System (ADS)

Hokkanen, Matti J.; Lautala, Saara; Shao, Dongkai; Turpeinen, Tuomas; Koivistoinen, Juha; Ahlskog, Markus

2016-07-01

Arc-discharge synthesized multiwalled carbon nanotubes (AD-MWNT) have been proven to be of high quality, but their use is very limited due to difficulties in obtaining them in a clean and undamaged form. Here, we present a simple method that purifies raw AD-MWNT material in laboratory scale without damage, and that in principle can be scaled up. The method consists of depositing raw AD-MWNT material on a flat substrate and immersing the substrate slowly in water, whereby the surface tension force of the liquid-substrate contact line selectively sweeps away the larger amorphous carbon debris and leaves relatively clean MWNTs on the substrate. We demonstrate the utility of the method by preparing clean individual MWNTs for measurement of their Raman spectra. The spectra exhibit the characteristics of high-quality tubes free from contaminants. We also show how one concomitantly with the purification process can obtain large numbers of clean suspended MWNTs.

Out of the Autoclave Fabrication of LaRC[TradeMark] PETI-9 Polyimide Laminates

NASA Technical Reports Server (NTRS)

Cano, Robert J.; Jensen, Brian J.

2013-01-01

The NASA Langley Research Center developed polyimide system, LaRC PETI-9, has successfully been processed into composites by high temperature vacuum assisted resin transfer molding (HT-VARTM). To extend the application of this high use temperature material to other out-of-autoclave (OOA) processing techniques, the fabrication of PETI- 9 laminates was evaluated using only a vacuum bag and oven cure. A LaRC PETI-9 polyimide solution in NMP was prepared and successfully utilized to fabricate unidirectional IM7 carbon fiber prepreg that was subsequently processed into composites with a vacuum bag and oven cure OOA process. Composite panels of good quality were successfully fabricated and mechanically tested. Processing characteristics, composite panel quality and mechanical properties are presented in this work. The resultant properties are compared to previously developed LaRC material systems processed by both autoclave and OOA techniques including the well characterized, autoclave processed LaRC PETI-5.

Opto-electronic oscillator: moving toward solutions based on polymer materials

NASA Astrophysics Data System (ADS)

Nguyên, Lâm Duy; Journet, Bernard; Zyss, Joseph

2008-02-01

Optoelectronic oscillators have been studied since many years now, their high spectral purity being one of their most interesting quality for photonics signal processing, communication or radio over fiber systems. One part of the structure is a long fiber optic feedback loop acting as a delay line. Different techniques have been introduced such as multiple loops in order to get very narrow spectral lines and large mode spacing. One of the problems due to long fiber loops is the size and the requirement of temperature control. In order to go toward integrated solutions it is also possible to introduce optical resonators instead of a delay line structure (as for classical electronic oscillators). But such resonators should present very high quality factor. In this paper we demonstrate solutions using resonators based on polymer materials such as PMMA-DCM. Structures such as micro-rings, micro-disks or stadium-shaped resonator have been realized at the laboratory. Quality factor of 6000 have already been achieved leading to an equivalent fiber loop of 19 m for an oscillator at 10 GHz. But it has been already theoretically proved that quality factor greater than one thousand hundred could be obtained. These resonators can be directly implemented with Mach-Zehnder optical modulators based on electro-optic polymer such as PMMA-DR1 leading to integrated solutions. And in the future it should be also possible to add a laser made with polymer material, with a structure as stadium-shape polymer micro-laser. The fully integrated photonic chip is not so far. The last important function to be implemented is the tuning of the oscillation frequency.

A New Thermal Treatment Process of Low Value Volcanic Glass towards the Production of Expanded Material and its Use on CNTs’ Synthesis as Substrate Material

NASA Astrophysics Data System (ADS)

Angelopoulos, Panagiotis M.; Samouhos, Michail; Taxiarchou, Maria; Tsakiridis, P.; Haggman, John; Joyce, Paul

2018-05-01

Pitchstone is a naturally occurring volcanic glass that contains considerable amount of chemically bound water (> 6 % wt). Due to its high water content, its direct thermal processing in conventional expansion furnaces towards the production of lightweight material, similar to expanded perlite, is practically impossible. In the current research paper a sophisticated 2 stage process is presented that consists of a partial dehydration and an expansion stage towards the production of high quality expanded material. After proper treatment, low-value volcanic glass is transformed to frothy, lightweight material of closed external surface and apparent density of 52 kg·m-3 that can be used in various branches of the industry. The material produced is used as substrate for the development of multiwall CNTs through CVD method. Dense multiwall CNT clusters were identified on expanded pitchstone surface, thus rendering the material suitable for such application.

Highly resistive C-doped hydride vapor phase epitaxy-GaN grown on ammonothermally crystallized GaN seeds

NASA Astrophysics Data System (ADS)

Iwinska, Malgorzata; Piotrzkowski, Ryszard; Litwin-Staszewska, Elzbieta; Sochacki, Tomasz; Amilusik, Mikolaj; Fijalkowski, Michal; Lucznik, Boleslaw; Bockowski, Michal

2017-01-01

GaN crystals were grown by hydride vapor phase epitaxy (HVPE) and doped with C. The seeds were high-structural-quality ammonothermally crystallized GaN. The grown crystals were highly resistive at 296 K and of high structural quality. High-temperature Hall effect measurements revealed p-type conductivity and a deep acceptor level in the material with an activation energy of 1 eV. This is in good agreement with density functional theory calculations based on hybrid functionals as presented by the Van de Walle group. They obtained an ionization energy of 0.9 eV when C was substituted for N in GaN and acted as a deep acceptor.

Formation of 3D graphene foams on soft templated metal monoliths

NASA Astrophysics Data System (ADS)

Tynan, Michael K.; Johnson, David W.; Dobson, Ben P.; Coleman, Karl S.

2016-07-01

Graphene foams are leading contenders as frameworks for polymer thermosets, filtration/pollution control and for use as an electrode material in energy storage devices, taking advantage of graphene's high electrical conductivity and the porous structure of the foam. Here we demonstrate a simple synthesis of a macroporous 3D graphene material templated from a dextran/metal salt gel, where the metal was cobalt, nickel, copper, and iron. The gel was annealed to form a metal oxide foam prior to a methane chemical vapour deposition (CVD). Cobalt metal gels were shown to afford the highest quality material as determined by electron microscopy (SEM and TEM) and Raman spectroscopy.Graphene foams are leading contenders as frameworks for polymer thermosets, filtration/pollution control and for use as an electrode material in energy storage devices, taking advantage of graphene's high electrical conductivity and the porous structure of the foam. Here we demonstrate a simple synthesis of a macroporous 3D graphene material templated from a dextran/metal salt gel, where the metal was cobalt, nickel, copper, and iron. The gel was annealed to form a metal oxide foam prior to a methane chemical vapour deposition (CVD). Cobalt metal gels were shown to afford the highest quality material as determined by electron microscopy (SEM and TEM) and Raman spectroscopy. Electronic supplementary information (ESI) available: Raman, EDX, PXRD, TGA, electrical conductivity data and SEM. See DOI: 10.1039/c6nr02455f

Ultrashort pulse laser machining of metals and alloys

DOEpatents

Perry, Michael D.; Stuart, Brent C.

2003-09-16

The invention consists of a method for high precision machining (cutting, drilling, sculpting) of metals and alloys. By using pulses of a duration in the range of 10 femtoseconds to 100 picoseconds, extremely precise machining can be achieved with essentially no heat or shock affected zone. Because the pulses are so short, there is negligible thermal conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond approximately 0.1-1 micron (dependent upon the particular material) from the laser machined surface. Due to the short duration, the high intensity (>10.sup.12 W/cm.sup.2) associated with the interaction converts the material directly from the solid-state into an ionized plasma. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces with negligible redeposition either within the kerf or on the surface. Since there is negligible heating beyond the depth of material removed, the composition of the remaining material is unaffected by the laser machining process. This enables high precision machining of alloys and even pure metals with no change in grain structure.

Status and Progress of High-efficiency Silicon Solar Cells

NASA Astrophysics Data System (ADS)

Xiao, Shaoqing; Xu, Shuyan

High-efficiency Si solar cells have attracted more and more attention from researchers, scientists, engineers of photovoltaic (PV) industry for the past few decades. Many high-quality researchers and engineers in both academia and industry seek solutions to improve the cell efficiency and reduce the cost. This desire has stimulated a growing number of major research and research infrastructure programmes, and a rapidly increasing number of publications in this filed. This chapter reviews materials, devices and physics of high-efficiency Si solar cells developed over the last 20 years. In this chapter there is a fair number of topics, not only from the material viewpoint, introducing various materials that are required for high-efficiency Si solar cells, such as base materials (FZ-Si, CZ-Si, MCZ-Si and multi-Si), emitter materials (diffused emitter and deposited emitter), passivation materials (Al-back surface field, high-low junction, SiO2, SiO x , SiN x , Al2O3 and a-Si:H), and other functional materials (antireflective layer, TCO and metal electrode), but also from the device and physics point of view, elaborating on physics, cell concept, development and status of all kinds of high-efficiency Si solar cells, such as passivated emitter and rear contact (PERC), passivated emitter and rear locally diffused (PERL), passivated emitter and rear totally diffused (PERT), Pluto, interdigitated back-contacted (IBC), emitter-wrap-through (EWT), metallization-wrap-through (MWT), Heterojunction with intrinsic thin-layer (HIT) and so on. Some representative examples of high-efficiency Si solar cell materials and devices with excellent performance and competitive advantages are presented.

Material quality assurance risk assessment.

DOT National Transportation Integrated Search

2013-01-01

Over the past two decades the role of SHA has shifted from quality control (QC) of materials and : placement techniques to quality assurance (QA) and acceptance. The role of the Office of Materials : Technology (OMT) has been shifting towards assuran...

[Establishment of traceability system of Chinese medicinal materials' quality].

PubMed

Qi, Yao-dong; Gao, Shi-man; Liu, Hai-tao; Li, Xi-wen; Wei, Jian-he; Zhang, Ben-gang; Sun, Xiao-bo; Xiao, Pei-gen

2015-12-01

The quality of Chinese medicinal materials relates greatly to the clinical curative effect and security. In order to ensure the quality and safety of Chinese medicinal materials, a systematic and operable traceability system needs to be established. It can realize the whole process of quality and safety management of Chinese medicinal materials "from production to consumption" through recording and inquiring information and recalling defective products, which is an important direction for the future development of traditional Chinese medicine. But it is still at the exploration and trial stage. In this paper, a framework of Chinese medicinal materials' quality and safety traceability system was established on the basis of the domestic and international experience about the construction of food and agricultural products traceability systems. The relationship between traceability system of Chinese medicinal materials' quality and GAP, GMP, GSP was analyzed, and the possible problems and the corresponding solutions were discussed.

Impact of growth rate on graphene lattice-defect formation within a single crystalline domain.

PubMed

Chin, Hao-Ting; Lee, Jian-Jhang; Hofmann, Mario; Hsieh, Ya-Ping

2018-03-06

Chemical vapor deposition (CVD) is promising for the large scale production of graphene and other two-dimensional materials. Optimization of the CVD process for enhancing their quality is a focus of ongoing effort and significant progress has been made in decreasing the defectiveness associated with grain boundaries and nucleation spots. However, little is known about the quality and origin of structural defects in the outgrowing lattice which are present even in single-crystalline material and represent the limit of current optimization efforts. We here investigate the formation kinetics of such defects by controlling graphene's growth rate over a wide range using nanoscale confinements. Statistical analysis of Raman spectroscopic results shows a clear trend between growth rate and defectiveness that is in quantitative agreement with a model where defects are healed preferentially at the growth front. Our results suggest that low growth rates are required to avoid the freezing of lattice defects and form high quality material. This conclusion is confirmed by a fourfold enhancement in graphene's carrier mobility upon optimization of the growth rate.

Food structure: Its formation and relationships with other properties.

PubMed

Joardder, Mohammad U H; Kumar, Chandan; Karim, M A

2017-04-13

Food materials are complex in nature as it has heterogeneous, amorphous, hygroscopic and porous properties. During processing, microstructure of food materials changes which significantly affects other properties of food. An appropriate understanding of the microstructure of the raw food material and its evolution during processing is critical in order to understand and accurately describe dehydration processes and quality anticipation. This review critically assesses the factors that influence the modification of microstructure in the course of drying of fruits and vegetables. The effect of simultaneous heat and mass transfer on microstructure in various drying methods is investigated. Effects of changes in microstructure on other functional properties of dried foods are discussed. After an extensive review of the literature, it is found that development of food structure significantly depends on fresh food properties and process parameters. Also, modification of microstructure influences the other properties of final product. An enhanced understanding of the relationships between food microstructure, drying process parameters and final product quality will facilitate the energy efficient optimum design of the food processor in order to achieve high-quality food.

Multi Response Optimization of Process Parameters Using Grey Relational Analysis for Turning of Al-6061

NASA Astrophysics Data System (ADS)

Deepak, Doreswamy; Beedu, Rajendra

2017-08-01

Al-6061 is one among the most useful material used in manufacturing of products. The major qualities of Aluminium are reasonably good strength, corrosion resistance and thermal conductivity. These qualities have made it a suitable material for various applications. While manufacturing these products, companies strive for reducing the production cost by increasing Material Removal Rate (MRR). Meanwhile, the quality of surface need to be ensured at an acceptable value. This paper aims at bringing a compromise between high MRR and low surface roughness requirement by applying Grey Relational Analysis (GRA). This article presents the selection of controllable parameters like longitudinal feed, cutting speed and depth of cut to arrive at optimum values of MRR and surface roughness (Ra). The process parameters for experiments were selected based on Taguchi’s L9 array with two replications. Grey relation analysis being most suited method for multi response optimization, the same is adopted for the optimization. The result shows that feed rate is the most significant factor that influences MRR and Surface finish.

[Study of genuineness based on changes of ancient herbal origin--taking Astragalus membranaceus and Salvia miltiorrhiza as examples].

PubMed

Zhan, Zhi-Lai; Deng, Ai-Ping; Peng, Hua-Sheng; Zhang, Xiao-Bo; Guo, Lan-Ping; Huang, Lu-Qi

2016-09-01

Basically, Dao-di hers are produced in specific area which has a long history, good quality, good medicine, curative effect. However genuine medicinal material area in history is not static, this makes the establishment of genuine medicinal material origin and the in-depth research be very difficult. This paper has profoundly analyzed the origin of different historical periods taking Astragalus membranaceus and Salvia miltiorrhiza as examples, and then summarized the reasons of herbal origin changes from the humanities, social and natural three aspects. This paper provides a basis for establishment and the further research of high-quality genuine producing area. Copyright© by the Chinese Pharmaceutical Association.

78 FR 29016 - Establishing Quality Assurance Programs for Packaging Used in Transport of Radioactive Material

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-16

... Establishing Quality Assurance Programs for Packaging Used in Transport of Radioactive Material AGENCY: Nuclear..., ``Establishing Quality Assurance Programs for Packaging Used in Transport of Radioactive Material.'' This draft... regulations for the packaging and transportation of radioactive material in Part 71 of Title 10 of the Code of...

ON THE DEGREE OF CONVERSION AND COEFFICIENT OF THERMAL EXPANSION OF A SINGLE FIBER COMPOSITE USING A FBG SENSOR

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

Lai, M.; Botsis, J.; Coric, D.

2008-08-28

The increasing needs of extending the lifetime in high-technology fields, such as space and aerospace, rail transport and naval systems, require quality enhancing of the composite materials either from a processing standing point or in the sense of resistance to service conditions. It is well accepted that the final quality of composite materials and structures is strongly influenced by processing parameters like curing and post-curing temperatures, rate of heating and cooling, applied vacuum, etc. To optimize manufacturing cycles, residual strains evolution due to chemical shrinkage and other physical parameters of the constituent materials must be characterized in situ. Such knowledgemore » can lead to a sensible reduction in defects and to improved physical and mechanical properties of final products. In this context continuous monitoring of strains distribution developed during processing is important in understanding and retrieving components' and materials' characteristics such as local strains gradients, degree of curing, coefficient of thermal expansion, moisture absorption, etc.« less

Growth and characterization of materials for tunable lasers in the near infrared spectral region

NASA Technical Reports Server (NTRS)

Powell, Richard C.; Martin, Joel J.

1988-01-01

During this reporting period, work proceeded in two directions. The first was the development of crystal growth procedures for rare earth doped LiYF4 crystals. The procedures for growth and pre-growth treatment of starting materials for undoped LiYF4 crystals were established and good optical quality materials were grown. A significant amount of time was spent trying to establish the optimum growth parameters for Yb(3+)-doped crystals. Unfortunately, it has proven difficult to obtain large size boules of high optical quality crystals of LiYF4 with doping concentrations of Yb(3+) of several percent. Because of these problems, this research is to be changed to attempt doping with other trivalent rare earth ions such as Ho, Er, and Tm. The second research area was investigating the potential of LiNbO3:Mg,Cr and LiNbO3:Mg,Cr,Yb as possible laser materials. The results are summarized.

High-frequency Total Focusing Method (TFM) imaging in strongly attenuating materials with the decomposition of the time reversal operator associated with orthogonal coded excitations

NASA Astrophysics Data System (ADS)

Villaverde, Eduardo Lopez; Robert, Sébastien; Prada, Claire

2017-02-01

In the present work, the Total Focusing Method (TFM) is used to image defects in a High Density Polyethylene (HDPE) pipe. The viscoelastic attenuation of this material corrupts the images with a high electronic noise. In order to improve the image quality, the Decomposition of the Time Reversal Operator (DORT) filtering is combined with spatial Walsh-Hadamard coded transmissions before calculating the images. Experiments on a complex HDPE joint demonstrate that this method improves the signal-to-noise ratio by more than 40 dB in comparison with the conventional TFM.

Concrete density estimation by rebound hammer method

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

Ismail, Mohamad Pauzi bin, E-mail: pauzi@nm.gov.my; Masenwat, Noor Azreen bin; Sani, Suhairy bin

Concrete is the most common and cheap material for radiation shielding. Compressive strength is the main parameter checked for determining concrete quality. However, for shielding purposes density is the parameter that needs to be considered. X- and -gamma radiations are effectively absorbed by a material with high atomic number and high density such as concrete. The high strength normally implies to higher density in concrete but this is not always true. This paper explains and discusses the correlation between rebound hammer testing and density for concrete containing hematite aggregates. A comparison is also made with normal concrete i.e. concrete containingmore » crushed granite.« less

Building a case for using technology: health literacy and patient education.

PubMed

Cassey, Margaret Z

2007-01-01

The interplay of a mobile population can affect the quality of patient outcomes and the economics of health care delivery significantly. Helping patients with limited English proficiency understand the basics of self-care for optimal health will continue to be a challenge in the delivery of the highest quality nursing care. Becoming familiar with high-quality, peer-reviewed, and reliable health education materials and Web sites is the responsibility of every health care provider so that patients receive culturally and linguistically appropriate resources to support healthy lifestyles and choices.

HPLC for quality control of polyimides

NASA Technical Reports Server (NTRS)

Young, P. R.; Sykes, G. F.

1979-01-01

High Pressure Liquid Chromatography (HPLC) as a quality control tool for polyimide resins and prepregs are presented. A data base to help establish accept/reject criteria for these materials was developed. This work is intended to supplement, not replace, standard quality control tests normally conducted on incoming resins and prepregs. To help achieve these objectives, the HPLC separation of LARC-160 polyimide precursor resin was characterized. Room temperature resin aging effects were studied. Graphite reinforced composites made from fresh and aged resin were fabricated and tested to determine if changes observed by HPLC were significant.

Application of CaO-Based Bed Material for Dual Fluidized Bed Steam Biomass Gasification

NASA Astrophysics Data System (ADS)

Koppatz, S.; Pfeifer, C.; Kreuzeder, A.; Soukup, G.; Hofbauer, H.

Gasification of biomass is a suitable option for decentralized energy supply based on renewable sources in the range of up to 50 MW fuel input. The paper presents the dual fluidized bed (DFB) steam gasification process, which is applied to generate high quality and nitrogen-free product gas. Essential part of the DFB process is the bed material used in the fluidized reactors, which has significant impact on the product gas quality. By the use of catalytically active bed materials the performance of the overall process is increased, since the bed material favors reactions of the steam gasification. In particular, tar reforming reactions are favored. Within the paper, the pilot plant based on the DFB process with 100kW fuel input at Vienna University of Technology, Austria is presented. Actual investigations with focus on CaO-based bed materials (limestone) as well as with natural olivine as bed material were carried out at the pilot plant. The application of CaO-based bed material shows mainly decreased tar content in the product gas in contrast to experiments with olivine as bed material. The paper presents the results of steam gasification experiments with limestone and olivine, whereby the product gas composition as well as the tar content and the tar composition are outlined.

Using Wild Olives in Breeding Programs: Implications on Oil Quality Composition.

PubMed

León, Lorenzo; de la Rosa, Raúl; Velasco, Leonardo; Belaj, Angjelina

2018-01-01

A wide genetic diversity has been reported for wild olives, which could be particularly interesting for the introgression of some agronomic traits and resistance to biotic and abiotic stresses in breeding programs. However, the introgression of some beneficial wild traits may be paralleled by negative effects on some other important agronomic and quality traits. From the quality point of view, virgin olive oil (VOO) from olive cultivars is highly appreciated for its fatty acid composition (high monounsaturated oleic acid content) and the presence of several minor components. However, the composition of VOO from wild origin and its comparison with VOO from olive cultivars has been scarcely studied. In this work, the variability for fruit characters (fruit weight and oil content, OC), fatty acid composition, and minor quality components (squalene, sterols and tocopherols content and composition) was studied in a set of plant materials involving three different origins: wild genotypes ( n = 32), cultivars ( n = 62) and genotypes belonging to cultivar × wild progenies ( n = 62). As expected, values for fruit size and OC in wild olives were lower than those obtained in cultivated materials, with intermediate values for cultivar × wild progenies. Wild olives showed a remarkably higher C16:0 percentage and tocopherol content in comparison to the cultivars. Contrarily, lower C18:1 percentage, squalene and sterol content were found in the wild genotypes, while no clear differences were found among the different plant materials regarding composition of the tocopherol and phytosterol fractions. Some common highly significant correlations among components of the same chemical family were found in all groups of plant materials. However, some other correlations were specific for one of the groups. The results of the study suggested that the use of wild germplasm in olive breeding programs will not have a negative impact on fatty acid composition, tocopherol content, and tocopherol and phytosterol profiles provided that selection for these compounds is conducted from early generations. Important traits such as tocopherol content could be even improved by using wild parents.

Some Nutritional Characteristics of a Naturally Occurring Alga (Microcystis sp.) in a Guatemalan Lake

PubMed Central

de la Fuente, Gabriel; Flores, Antonio; Molina, Mario R.; Almengor, Leticia; Bressani, Ricardo

1977-01-01

The nutritional characteristics of an alga (Microcystis sp.) that occurs naturally in a Guatemalan lake were determined. The sun-dried material proved to have a high protein content (55.6%) and to be a possible good source of calcium and phosphorus (1, 169.1 and 633.4 mg/100 mg, respectively). Amino acid analysis showed that total sulfur amino acids were the most deficient ones, giving a protein score of 42 to the material. The in vitro protein digestibility of the material was 69.5%. Biological trials demonstrated that when the material was offered as the only protein source, very low consumption and a high mortality rate were obtained whether or not the diet was supplemented with 0.4% dl-methionine. However, when the material supplied 25% of the total protein of a corn-algae diet, the protein quality of the cereal was significantly improved (P < 0.05). PMID:16345191

Trade-off between Photon Management Efficacy and Material Quality in Thin-Film Solar Cells on Nanostructured Substrates of High Aspect Ratio Structures

DOE PAGES

Chin, Alan; Keshavarz, Majid; Wang, Qi

2018-04-13

Although texturing of the transparent electrode of thin-film solar cells has long been used to enhance light absorption via light trapping, such texturing has involved low aspect ratio features. With the recent development of nanotechnology, nanostructured substrates enable improved light trapping and enhanced optical absorption via resonances, a process known as photon management, in thin-film solar cells. Despite the progress made in the development of photon management in thin-film solar cells using nanostructures substrates, the structural integrity of the thin-film solar cells deposited onto such nanostructured substrates is rarely considered. Here, we report the observation of the reduction in themore » open circuit voltage of amorphous silicon solar cells deposited onto a nanostructured substrate with increasing areal number density of high aspect ratio structures. For a nanostructured substrate with the areal number density of such nanostructures increasing in correlation with the distance from one edge of the substrate, a correlation between the open circuit voltage reduction and the increase of the areal number density of high aspect ratio nanostructures of the front electrode of the small-size amorphous silicon solar cells deposited onto different regions of the substrate with graded nanostructure density indicates the effect of the surface morphology on the material quality, i.e., a trade-off between photon management efficacy and material quality. Lastly, this observed trade-off highlights the importance of optimizing the morphology of the nanostructured substrate to ensure conformal deposition of the thin-film solar cell.« less

Trade-off between Photon Management Efficacy and Material Quality in Thin-Film Solar Cells on Nanostructured Substrates of High Aspect Ratio Structures

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

Chin, Alan; Keshavarz, Majid; Wang, Qi

Although texturing of the transparent electrode of thin-film solar cells has long been used to enhance light absorption via light trapping, such texturing has involved low aspect ratio features. With the recent development of nanotechnology, nanostructured substrates enable improved light trapping and enhanced optical absorption via resonances, a process known as photon management, in thin-film solar cells. Despite the progress made in the development of photon management in thin-film solar cells using nanostructures substrates, the structural integrity of the thin-film solar cells deposited onto such nanostructured substrates is rarely considered. Here, we report the observation of the reduction in themore » open circuit voltage of amorphous silicon solar cells deposited onto a nanostructured substrate with increasing areal number density of high aspect ratio structures. For a nanostructured substrate with the areal number density of such nanostructures increasing in correlation with the distance from one edge of the substrate, a correlation between the open circuit voltage reduction and the increase of the areal number density of high aspect ratio nanostructures of the front electrode of the small-size amorphous silicon solar cells deposited onto different regions of the substrate with graded nanostructure density indicates the effect of the surface morphology on the material quality, i.e., a trade-off between photon management efficacy and material quality. Lastly, this observed trade-off highlights the importance of optimizing the morphology of the nanostructured substrate to ensure conformal deposition of the thin-film solar cell.« less

High-quality cell block preparation from scraping of conventional cytology slide: a technical report on a modified cytoscrape cell block technique.

PubMed

Choi, Y I; Jakhongir, M; Choi, S J; Kim, L; Park, I S; Han, J Y; Kim, J M; Chu, Y C

2016-12-01

Immunocytochemistry (ICC) on formalin-fixed paraffin embedded cell blocks is an ancillary tool commonly recruited for differential diagnoses of fine needle aspiration cytology (FNAC) samples. However, the quality of conventional cell blocks in terms of adequate cellularity and evenness of distribution of cytologic material is not always satisfactory for ICC. We introduce a modified agarose-based cytoscrape cell block (CCB) technique that can be effectively used for the preparation of cell blocks from scrapings of conventional FNAC slides. A decoverslipped FNAC slide was mounted with a small amount of water. The cytological material was scraped off the slide into a tissue mold by scraping with a cell scraper. The cytoscrape material was pelleted by centrifugation and pre-embedded in ultra-low gelling temperature agarose and then re-embedded in conventional agarose. The final agarose gel disk was processed and embedded in paraffin. The quality of the ICC on the CCB sections was identical to that of the immunohistochemical stains on histological sections. By scrapping and harvesting the entirety of the cytological material off the cytology slide into a compact agarose cell button, we could avoid the risk of losing diagnostic material during the CCB preparation. This modified CCB technique enables concentration and focusing of minute material while maintaining the entire amount of the cytoscrape material on the viewing spot of the CCB sections. We believe this technique can be effectively used to improve the level of confidence in diagnosis of FNAC especially when the FNAC slides are the only sample available.

Engineering and biotechnological aspects for the manufacturing of high quality fried potato products.

PubMed

Reimerdes, Ernst H; Franke, Knut

2006-04-01

Fried potato products have become very popular foods over the last decades. High quality standards have been established for these products by the food industry including uniform brown color and crispness. During frying, Maillard reactions takes place which contribute to color and taste development in these products. However, safety aspects are also influenced by these reactions, e.g., acrylamide formation. Maintaining high safety standards as well as the expected quality requires systematic research based on an integrated approach including all relevant variables, e.g., raw material properties, processing conditions and equipment concepts. Selected results of these investigations are presented and discussed, regarding influence of composition, e.g., precursor levels for Maillard reactions, treatment of raw materials and addition of reactants to frying fat. It has been demonstrated that a combined treatment of the potato sticks by coating of product surfaces and partial pre-drying can be successfully applied to produce well-browned French fries with lower acrylamide contents. Reductions up to 75% could be reached compared to samples without treatment. Furthermore, addition of a water/oil emulsion containing glutamine in the aqueous phase has been shown to influence Maillard reactions at the product surface, resulting in lower acrylamide contents at the same state of browning.

A Monte Carlo study of the quality dependence factors of common TLD materials in photon and electron beams.

PubMed

Mobit, P N; Nahum, A E; Mayles, P

1998-08-01

A Monte Carlo simulation of the quality dependence of different TL materials, in the form of discs 3.61 mm in diameter and 0.9 mm thick, in radiotherapy photon beams relative to 60Co gamma-rays has been performed. The beam qualities ranged from 50 kV to 25 MV x-rays. The TL materials were: CaF2, CaSO4, LiF and Li2B4O7. The effects of the dopants on energy deposition in the TL material have also been determined for the highly sensitive LiF:Mg:Cu:P (TLD-100H) and for CaF2:Mn. It was found that there was a significant difference in the quality dependence factor derived from Monte Carlo simulations between LiF and LiF:Mg:Cu:P but not between CaF2 and CaF2:Mn. The quality dependence factors for Li2B4O7 varied from 0.990 +/- 0.008 (1 sd) for 25 MV x-rays to 0.940 +/- 0.009 (1 sd) for 50 kV x-rays relative to 60Co gamma-rays; Monte Carlo simulations were also performed for Li2B4O7 in megavoltage electron beams. For CaF2, the quality dependence factor varied from 0.927 +/- 0.008 (1 sd) for 25 MV x-rays to 10.561 +/- 0.008 (1 sd) for 50 kV x-rays. The figure for CaSO4 ranged from 0.943 +/- 0.008 (1 sd) for 25 MV x-rays to 9.010 +/- 0.008 (1 sd) for 50 kV x-rays. The quality dependence factor for CaF2 increases by up to 5% with depth and by up to 15% with field size for the kilovoltage x-ray beams. For LiF-TLD, however, there was no significant dependence on the field size or depth of irradiation in the kilovoltage energy range.

ENVIRONMENTAL AND ENERGY QUALITY TECHNOLOGIES Task Order 0005: Organic Finishing Technologies Sub Task 11: High Speed, Substrate Safe Specialty Coating Laser Stripping

DTIC Science & Technology

2015-06-22

hazardous materials and eliminating the hazardous waste streams associated with wheat starch , chemical strippers and hand sanding. Additionally, the laser...chemical attack resistance and other special characteristics while providing corrosion protection. The materials used for these purposes are designed...inspection and/or replacement. Standard coating removal methods include chemical strippers, media blasting (i.e., wheat starch , plastic

Separation of plastic waste via the hydraulic separator Multidune under different geometric configurations.

PubMed

La Marca, Floriana; Moroni, Monica; Cherubini, Lorenzo; Lupo, Emanuela; Cenedese, Antonio

2012-07-01

The recovery of high-quality plastic materials is becoming an increasingly challenging issue for the recycling sector. Technologies for plastic recycling have to guarantee high-quality secondary raw material, complying with specific standards, for use in industrial applications. The variability in waste plastics does not always correspond to evident differences in physical characteristics, making traditional methodologies ineffective for plastic separation. The Multidune separator is a hydraulic channel allowing the sorting of solid particles on the basis of differential transport mechanisms by generating particular fluid dynamic conditions due to its geometric configuration and operational settings. In this paper, the fluid dynamic conditions were investigated by an image analysis technique, allowing the reconstruction of velocity fields generated inside the Multidune, considering two different geometric configurations of the device, Configuration A and Configuration B. Furthermore, tests on mono- and bi-material samples were completed with varying operational conditions under both configurations. In both series of experiments, the bi-material samples were composed of differing proportions (85% vs. 15%) to simulate real conditions in an industrial plant for the purifying of a useful fraction from a contaminating fraction. The separation results were evaluated in terms of grade and recovery of the useful fraction. Copyright © 2012 Elsevier Ltd. All rights reserved.

Development of a reference material of a single DNA molecule for the quality control of PCR testing.

PubMed

Mano, Junichi; Hatano, Shuko; Futo, Satoshi; Yoshii, Junji; Nakae, Hiroki; Naito, Shigehiro; Takabatake, Reona; Kitta, Kazumi

2014-09-02

We developed a reference material of a single DNA molecule with a specific nucleotide sequence. The double-strand linear DNA which has PCR target sequences at the both ends was prepared as a reference DNA molecule, and we named the PCR targets on each side as confirmation sequence and standard sequence. The highly diluted solution of the reference molecule was dispensed into 96 wells of a plastic PCR plate to make the average number of molecules in a well below one. Subsequently, the presence or absence of the reference molecule in each well was checked by real-time PCR targeting for the confirmation sequence. After an enzymatic treatment of the reaction mixture in the positive wells for the digestion of PCR products, the resultant solution was used as the reference material of a single DNA molecule with the standard sequence. PCR analyses revealed that the prepared samples included only one reference molecule with high probability. The single-molecule reference material developed in this study will be useful for the absolute evaluation of a detection limit of PCR-based testing methods, the quality control of PCR analyses, performance evaluations of PCR reagents and instruments, and the preparation of an accurate calibration curve for real-time PCR quantitation.

Evaluation of commercial DNA and RNA extraction methods for high-throughput sequencing of FFPE samples.

PubMed

Kresse, Stine H; Namløs, Heidi M; Lorenz, Susanne; Berner, Jeanne-Marie; Myklebost, Ola; Bjerkehagen, Bodil; Meza-Zepeda, Leonardo A

2018-01-01

Nucleic acid material of adequate quality is crucial for successful high-throughput sequencing (HTS) analysis. DNA and RNA isolated from archival FFPE material are frequently degraded and not readily amplifiable due to chemical damage introduced during fixation. To identify optimal nucleic acid extraction kits, DNA and RNA quantity, quality and performance in HTS applications were evaluated. DNA and RNA were isolated from five sarcoma archival FFPE blocks, using eight extraction protocols from seven kits from three different commercial vendors. For DNA extraction, the truXTRAC FFPE DNA kit from Covaris gave higher yields and better amplifiable DNA, but all protocols gave comparable HTS library yields using Agilent SureSelect XT and performed well in downstream variant calling. For RNA extraction, all protocols gave comparable yields and amplifiable RNA. However, for fusion gene detection using the Archer FusionPlex Sarcoma Assay, the truXTRAC FFPE RNA kit from Covaris and Agencourt FormaPure kit from Beckman Coulter showed the highest percentage of unique read-pairs, providing higher complexity of HTS data and more frequent detection of recurrent fusion genes. truXTRAC simultaneous DNA and RNA extraction gave similar outputs as individual protocols. These findings show that although successful HTS libraries could be generated in most cases, the different protocols gave variable quantity and quality for FFPE nucleic acid extraction. Selecting the optimal procedure is highly valuable and may generate results in borderline quality specimens.

High Curie temperature drive layer materials for ion-implanted magnetic bubble devices

NASA Technical Reports Server (NTRS)

Fratello, V. J.; Wolfe, R.; Blank, S. L.; Nelson, T. J.

1984-01-01

Ion implantation of bubble garnets can lower the Curie temperature by 70 C or more, thus limiting high temperature operation of devices with ion-implanted propagation patterns. Therefore, double-layer materials were made with a conventional 2-micron bubble storage layer capped by an ion-implantable drive layer of high Curie temperature, high magnetostriction material. Contiguous disk test patterns were implanted with varying doses of a typical triple implant. Quality of propagation was judged by quasistatic tests on 8-micron period major and minor loops. Variations of magnetization, uniaxial anisotropy, implant dose, and magnetostriction were investigated to ensure optimum flux matching, good charged wall coupling, and wide operating margins. The most successful drive layer compositions were in the systems (SmDyLuCa)3(FeSi)5O12 and (BiGdTmCa)3(FeSi)5O12 and had Curie temperatures 25-44 C higher than the storage layers.

High-efficiency machining methods for aviation materials

NASA Astrophysics Data System (ADS)

Kononov, V. K.

1991-07-01

The papers contained in this volume present results of theoretical and experimental studies aimed at increasing the efficiency of cutting tools during the machining of high-temperature materials and titanium alloys. Specific topics discussed include a study of the performance of disk cutters during the machining of flexible parts of a high-temperature alloy, VZhL14N; a study of the wear resistance of cutters of hard alloys of various types; effect of a deformed electric field on the precision of the electrochemical machining of gas turbine engine components; and efficient machining of parts of composite materials. The discussion also covers the effect of the technological process structure on the residual stress distribution in the blades of gas turbine engines; modeling of the multiparameter assembly of engineering products for a specified priority of geometrical output parameters; and a study of the quality of the surface and surface layer of specimens machined by a high-temperature pulsed plasma.

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 30, 1987.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

The Environmental Quality Instructional Resources Center acquires, reviews, indexes, and announces both print (books, modules, units, etc.) and non-print (films, slides, video tapes, etc.) materials related to water quality and water resources education and instruction. This publication contains abstracts and indexes to selected materials related…

Industrial waste utilization in the panels production for high buildings facade and socle facing

NASA Astrophysics Data System (ADS)

Vitkalova, Irina; Torlova, Anastasiya; Pikalov, Evgeniy; Selivanov, Oleg

2018-03-01

The research presents comprehensive utilization of such industrial waste as galvanic sludge, broken window glass as functional additives for producing ceramics for facade and socle paneling in high-rise construction. The basic charge component is low-plasticity clay, which does not allow producing high-quality products if used without any functional additives. The application of the mentioned above components broadens the resource base, reduces production cost and the mass of the products in comparison with the currently used facing ceramics. The decrease of product mass helps to reduce the load on the basement and to use ceramic material in high-rise construction more effectively. Additional advantage of the developed composition is the reducing of production energy intensity due to comparatively low pressing pressure and firing temperature thus reducing the overall production cost. The research demonstrates the experimental results of determining density, compressive strength, water absorption, porosity and frost resistance of the produced ceramic material. These characteristics prove that the material can be applied for high buildings outdoor paneling. Additional research results prove ecologic safety of the produced ceramic material.

How students' achievement goals shape their beliefs about effective teaching: a 'build-a-professor' study.

PubMed

Senko, Corwin; Belmonte, Kimberly; Yakhkind, Anastasyia

2012-09-01

Which instructor qualities do students consider most important? The answer likely depends on the student. This study attempted to trace beliefs about the most essential instructor qualities to students' academic achievement goals. The present study tested the hypothesis that students pursuing mastery goals favour instructors who stimulate and challenge them intellectually, whereas those pursuing performance goals favour instructors who present material clearly and provide clear cues about how to succeed. Participants were 157 students at a 4-year public university. Participants designed the ideal professor through a hypothetical combination of nine widely valued instructor qualities, such as enthusiasm, presentation clarity, and an interactive teaching style. The more they acquired of any one instructor quality, the less they could acquire of the others, thus compelling students to distinguish necessary qualities from desirable luxury qualities. Students' achievement goals corresponded to their views about the most essential instructor qualities. Mastery goals predicted greater demand for professors who intellectually challenge students and possess topic expertise, whereas performance goals predicted high demand for professors who present material clearly and provide cues about how to succeed in the course. The findings support emerging theorizing about how mastery and performance goals nudge students to pursue different learning agendas, with distinct consequences to their learning experience. ©2011 The British Psychological Society.

Low Temperature Photoluminescence Characterization of Orbitally Grown CdZnTe

NASA Technical Reports Server (NTRS)

Ritter, Timothy M.; Larson, D. J.

1998-01-01

The II-VI ternary alloy CdZnTe is a technologically important material because of its use as a lattice matched substrate for HgCdTe based devices. The increasingly stringent requirements on performance that must be met by such large area infrared detectors also necessitates a higher quality substrate. Such substrate material is typically grown using the Bridgman technique. Due to the nature of bulk semiconductor growth, gravitationally dependent phenomena can adversely affect crystalline quality. The most direct way to alleviate this problem is by crystal growth in a reduced gravity environment. Since it requires hours, even days, to grow a high quality crystal, an orbiting space shuttle or space station provides a superb platform on which to conduct such research. For well over ten years NASA has been studying the effects of microgravity semiconductor crystal growth. This paper reports the results of photoluminescence characterization performed on an arbitrary grown CdZnTe bulk crystal.

[Ambulant compression therapy for crural ulcers; an effective treatment when applied skilfully].

PubMed

de Boer, Edith M; Geerkens, Maud; Mooij, Michael C

2015-01-01

The incidence of crural ulcers is high. They reduce quality of life considerably and create a burden on the healthcare budget. The key treatment is ambulant compression therapy (ACT). We describe two patients with crural ulcers whose ambulant compression treatment was suboptimal and did not result in healing. When the bandages were applied correctly healing was achieved. If correctly applied ACT should provide sufficient pressure to eliminate oedema, whilst taking local circumstances such as bony structures and arterial qualities into consideration. To provide pressure-to-measure regular practical training, skills and regular quality checks are needed. Knowledge of the properties of bandages and the proper use of materials for padding under the bandage enables good personalised ACT. In trained hands adequate compression and making use of simple bandages and dressings provides good care for patients suffering from crural ulcers in contrast to inadequate ACT using the same materials.

Aggregate resource availability in the conterminous United States, including suggestions for addressing shortages, quality, and environmental concerns

USGS Publications Warehouse

Langer, William H.

2011-01-01

Although potential sources of aggregate are widespread throughout the United States, many sources may not meet certain physical property requirements, such as soundness, hardness, strength, porosity, and specific gravity, or they may contain contaminants or deleterious materials that render them unusable. Encroachment by conflicting land uses, permitting considerations, environmental issues, and societal pressures can prevent or limit development of otherwise suitable aggregate. The use of sustainable aggregate resource management can help ensure an economically viable supply of aggregate. Sustainable aggregate resource management techniques that have successfully been used include (1) protecting potential resources from encroachment; (2) using marginal-quality local aggregate for applications that do not demand a high-quality resource; (3) using substitute materials such as clinker, scoria, and recycled asphalt and concrete; and (4) using rail and water to transport aggregates from remote sources.

GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies.

PubMed

Yoon, Jongseung; Jo, Sungjin; Chun, Ik Su; Jung, Inhwa; Kim, Hoon-Sik; Meitl, Matthew; Menard, Etienne; Li, Xiuling; Coleman, James J; Paik, Ungyu; Rogers, John A

2010-05-20

Compound semiconductors like gallium arsenide (GaAs) provide advantages over silicon for many applications, owing to their direct bandgaps and high electron mobilities. Examples range from efficient photovoltaic devices to radio-frequency electronics and most forms of optoelectronics. However, growing large, high quality wafers of these materials, and intimately integrating them on silicon or amorphous substrates (such as glass or plastic) is expensive, which restricts their use. Here we describe materials and fabrication concepts that address many of these challenges, through the use of films of GaAs or AlGaAs grown in thick, multilayer epitaxial assemblies, then separated from each other and distributed on foreign substrates by printing. This method yields large quantities of high quality semiconductor material capable of device integration in large area formats, in a manner that also allows the wafer to be reused for additional growths. We demonstrate some capabilities of this approach with three different applications: GaAs-based metal semiconductor field effect transistors and logic gates on plates of glass, near-infrared imaging devices on wafers of silicon, and photovoltaic modules on sheets of plastic. These results illustrate the implementation of compound semiconductors such as GaAs in applications whose cost structures, formats, area coverages or modes of use are incompatible with conventional growth or integration strategies.

Design of a thin-plate based tunable high-quality narrow passband filter for elastic transverse waves propagate in metals

NASA Astrophysics Data System (ADS)

Zhang, J.; Zeng, L. H.; Hu, C. L.; Yan, W. S.; Pennec, Yan; Hu, N.

2018-03-01

For the elastic SV (transverse) waves in metals, a high-quality narrow passband filter that consists of aligned parallel thin plates with small gaps is designed. In order to obtain a good performance, the thin plates should be constituted by materials with a smaller mass density and Young's modulus, such as polymethylmethacrylate (PMMA), compared to the embedded materials in which the elastic SV waves propagate. Both the theoretical model and the full numerical simulation show that the transmission spectrum of the designed filter demonstrates several peaks with flawless transmission within 0 KHz ˜20 KHz frequency range. The peaks can be readily tuned by manipulating the geometrical parameters of the plates. Therefore, the current design works well for both low and high frequencies with a controllable size. Even for low frequencies on the order of kilohertz, the size of this filter can be still limited to the order of centimeters, which significantly benefits the real applications. The investigation also finds that the same filter is valid when using different metals and the reason behind this is explained theoretically. Additionally, the effect of bonding conditions of interfaces between thin plates and the base material is investigated using a spring model.

Growth and characterization of high quality UPt(3) single crystals and high resolution NMR study of superfluid He-3-B

NASA Astrophysics Data System (ADS)

Kycia, Jan Bronislaw

An ultra-high-vacuum crystal growth facility using the electron beam float zone refining method was designed and built. High quality single crystals of UPtsb3 were grown. Material quality was characterized by mass spectrometry and x-ray scattering techniques. Low temperature resistivity, AC susceptibility and specific heat measurements were also conducted. We find that the transition temperature of the material can be varied systematically by annealing. The suppression of the superconducting transition from defects is consistent with a modified Abrikosov-Gorkov formula that includes anisotropic pairing, Fermi surface anisotropy and anisotropic scattering by defects. High resolution nuclear magnetic resonance (NMR) measurements of bulk superfluid sp3He-B were performed at temperatures above 0.5 mK and at pressures from 0.3 to 28.8 bar. The resonance frequency of the bulk superfluid sp3He-B is shifted from the Larmor frequency of the normal fluid. According to the theory of Greaves the frequency shift at the superfluid transition determines a specific combination, betasb{345}, of the five fourth-order coefficients of the order parameter invariants used in the Ginzburg-Landau description of superfluid sp3He. NMR measurements were performed to determine the coefficient betasb{345} and its dependence on pressure. The results are in agreement with the theoretical calculations of Sauls and Serene that are based on strong coupling contributions which are enhanced at higher pressures.

Physics and chemistry of complex oxide etching and redeposition control

NASA Astrophysics Data System (ADS)

Margot, Joëlle

2012-10-01

Since its introduction in the 1970s, plasma etching has become the universal method for fine-line pattern transfer onto thin films and is anticipated to remain so in foreseeable future. Despite many success stories, plasma etching processes fail to meet the needs for several of the newest materials involved in advanced devices for photonic, electronic and RF applications like ferroelectrics, electro-optic materials, high-k dielectrics, giant magnetoresistance materials and unconventional conductors. In this context, the work achieved over the last decade on the etching of multicomponent oxides thin films such as barium strontium titanate (BST), strontium titanate (STO) and niobate of calcium and barium (CBN) will be reviewed. These materials present a low reactivity with usual etching gases such as fluorinated and chlorinated gases, their etching is mainly governed by ion sputtering and reactive gases sometimes interact with surface materials to form compounds that inhibit etching. The etching of platinum will also be presented as an example of unconventional conductor materials for which severe redeposition limits the achievable etching quality. Finally, it will be shown how simulation can help to understand the etching mechanisms and to define avenues for higher quality patterning.

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement VIII.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials; related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and…

Housing Quality and Access to Material and Learning Resources within the Home Environment in Developing Countries

ERIC Educational Resources Information Center

Bradley, Robert H.; Putnick, Diane L.

2012-01-01

This study examined home environment conditions (housing quality, material resources, formal and informal learning materials) and their relations with the Human Development Index (HDI) in 28 developing countries. Home environment conditions in these countries varied widely. The quality of housing and availability of material resources at home were…

Freshness indices of roasted coffee: monitoring the loss of freshness for single serve capsules and roasted whole beans in different packaging.

PubMed

Glöss, Alexia N; Schönbächler, Barbara; Rast, Markus; Deuber, Louis; Yeretzian, Chahan

2014-01-01

With the growing demand for high-quality coffee, it is becoming increasingly important to establish quantitative measures of the freshness of coffee, or the loss thereof, over time. Indeed, freshness has become a critical quality criterion in the specialty coffee scene, where the aim is to deliver the most pleasant flavor in the cup, from highest quality beans. A series of intensity ratios of selected volatile organic compounds (VOC) in the headspace of coffee (by gas chromatography-mass spectrometry) were revisited, with the aim to establish robust indicators of freshness of coffee - called freshness indices. Roasted whole beans in four different packaging materials and four commercial capsule systems from the Swiss market were investigated over a period of up to one year of storage time. These measurements revealed three types of insight. First, a clear link between barrier properties of the packaging material and the evolution of selected freshness indices was observed. Packaging materials that contain an aluminum layer offer better protection. Second, processing steps prior to packaging are reflected in the absolute values of freshness indices. Third, differences in the standard deviations of freshness-indices for single serve coffee capsule systems are indicative of differences in the consistency among systems, consistency being an important quality attribute of capsules.

Tough and deformable glasses with bioinspired cross-ply architectures.

PubMed

Yin, Zhen; Dastjerdi, Ahmad; Barthelat, Francois

2018-05-15

Glasses are optically transparent, hard materials that have been in sustained demand and usage in architectural windows, optical devices, electronics and solar panels. Despite their outstanding optical qualities and durability, their brittleness and low resistance to impact still limits wider applications. Here we present new laminated glass designs that contain toughening cross-ply architectures inspired from fish scales and arthropod cuticles. This seemingly minor enrichment completely transforms the way laminated glass deforms and fractures, and it turns a traditionally brittle material into a stretchy and tough material with little impact on surface hardness and optical quality. Large ply rotation propagates over large volumes, and localization is delayed in tension, even if a strain softening interlayer is used, in a remarkable mechanism which is generated by the kinematics of the plies and geometrical hardening. Compared to traditional laminated glass which degrades significantly in performance when damaged, our cross-ply architecture glass is damage-tolerant and 50 times tougher in energy terms. Despite the outstanding optical qualities and durability of glass, its brittleness and low resistance to impact still limits its wider application. Here we present new laminated glass designs that contain toughening cross-ply architectures inspired from fish scales and arthropod cuticles. Enriching laminated designs with crossplies completely transforms the material deforms and fractures, and turns a traditionally brittle material into a stretchy and tough material - with little impact on surface hardness and optical quality. Large ply rotation propagates over large volumes and localization is delayed in tension because of a remarkable and unexpected geometrical hardening effect. Compared to traditional laminated glass which degrades significantly in performance when damaged, our cross-ply architecture glass is damage-tolerant and it is 50 times tougher in energy terms. Our glass-based, transparent material is highly innovative and it is the first of its kind. We believe it will have impact in broad range of applications in construction, coatings, chemical engineering, electronics, photovoltaics. Copyright © 2018. Published by Elsevier Ltd.

Experimental investigation on the effects of cooling system on surface quality in high speed milling of an aluminium alloy

NASA Astrophysics Data System (ADS)

Chirita, B.; Tampu, N. C.; Brabie, G.; Radu, M. C.

2016-08-01

Surface quality is often an important feature of industrial products, not only from the impact it has on the aesthetic aspect but also for the functional role of the parts. High quality surface increases corrosion resistance, assures a longer life cycle for the product and lowers the wear. For a machined part, surface quality is influenced by a series of factors such as the material of the part, the process type, tool geometry, cutting parameters or the cooling system. The choice of the cooling system is especially important, taking into account that the proper conditions will not only assure a superior surface quality, but will also lower the costs and reduce the environmental impact and health risks. The present study aims to investigate the performance of the cooling system and the effect of the cutting parameters on the characteristics of the surfaces resulted from high speed face milling of some parts made of Al 7050-T7451 aluminium alloy. Dry cutting conditions and minimum quantity lubrication (MQL) where used. The results were analysed using analysis of variance (ANOVA).

Quantifying the environmental impact of a Li-rich high-capacity cathode material in electric vehicles via life cycle assessment.

PubMed

Wang, Yuqi; Yu, Yajuan; Huang, Kai; Chen, Bo; Deng, Wensheng; Yao, Ying

2017-01-01

A promising Li-rich high-capacity cathode material (xLi 2 MnO 3 ·(1-x)LiMn 0.5 Ni 0.5 O 2 ) has received much attention with regard to improving the performance of lithium-ion batteries in electric vehicles. This study presents an environmental impact evaluation of a lithium-ion battery with Li-rich materials used in an electric vehicle throughout the life cycle of the battery. A comparison between this cathode material and a Li-ion cathode material containing cobalt was compiled in this study. The battery use stage was found to play a large role in the total environmental impact and high greenhouse gas emissions. During battery production, cathode material manufacturing has the highest environmental impact due to its complex processing and variety of raw materials. Compared to the cathode with cobalt, the Li-rich material generates fewer impacts in terms of human health and ecosystem quality. Through the life cycle assessment (LCA) results and sensitivity analysis, we found that the electricity mix and energy efficiency significantly influence the environmental impacts of both battery production and battery use. This paper also provides a detailed life cycle inventory, including firsthand data on lithium-ion batteries with Li-rich cathode materials.

Development of a biotechnological process for the production of high quality linen fibers.

PubMed

Valladares Juárez, Ana Gabriela; Rost, Gernot; Heitmann, Uwe; Heger, Egon; Müller, Rudolf

2011-10-01

A novel biotechnological process for the production of high-quality flax fibers was developed. In this process, decorticated fibers from green flax were washed with 0.5% soda solution and treated with the pectinolytic strain Geobacillus thermoglucosidasius PB94A. Before drying the fibers, they were treated with the textile softener Adulcinol BUN. If the fibers contained contaminant shives, a bleaching step with hydrogen peroxide was performed before the softener treatment. In experiments where fibers were treated by the new process, and in which the bacterial solutions were reused seven times, the fiber quality was similar in all batches. The resolution of the treated fibers was 2.7 ± 0.4 and the fineness was 11.1 ± 1.1 dtex, while the starting material had a resolution of 7.3 and a fineness of 37 dtex. The new biotechnological treatment eliminates the weather-associated risks of the traditional fiber retting completely and produces consistently high-quality fibers that can be used to produce fine linen yarns.

Development and quality evaluation of quick cooking dhal-A convenience product.

PubMed

Sethi, Shruti; Samuel, D V K; Khan, Islam

2014-03-01

Owing to rapid urbanization and more women joining the workforce, use of ready-to-eat and ready-to-use convenience foods is gaining increasing popularity. Women require dhal that cooks fast and increases in volume when cooked. In an attempt to prepare quick cooking dhal from pigeon pea, variety UPAS 120 was milled, pre-treated with sodium chloride solution (1%), flaked and dried. The quick cooking dhal was packed in three packaging materials, namely, high molecular weight high density polyethylene (HMHDPE), high density polyethylene (HDPE) and laminated pouches. The quality evaluation of the prepared flakes with respect to the cooking quality attributes, changes in proximate composition, free fatty acid (FFA) and peroxide value (PV) were carried out during storage at ambient temperature (8-36°C) at regular intervals for a period of 10 months. During storage, quick cooking dhal packed in laminated pouches performed better than samples stored in other pouches with respect to the changes in the overall quality and acceptability of the product.

Cutting of optical materials by using femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Nolte, Stefan; Will, Matthias; Augustin, Markus; Triebel, Peter; Zoellner, Karsten; Tuennermann, Andreas

2001-11-01

In the past years, ultrashort pulse lasers have been established as precise and universal tools for the microstructuring of solid materials. Since thermal and mechanical influences are minimized, the application of this technology is also suitable for the structuring of optical materials and opens new possibilities. In this paper, the influence of pulse duration, pulse energy (fluence) and polarization on the cutting quality for glass and silicon will be discussed. As a concrete application, the cutting and micromarking of dielectric coated mirrors for high power fiber lasers will be highlighted.

Class II composite resin restorations: faster, easier, predictable.

PubMed

Jackson, R D

2016-11-18

Composite resin continues to displace amalgam as the preferred direct restorative material in developed countries. Even though composite materials have evolved to include nanoparticles with high physical properties and low shrinkage stress, dentists have been challenged to efficiently create quality, long lasting, predictable restorations. Unlike amalgam, composite resin cannot be condensed making the establishment of a predictable, proper contact more difficult. In addition, composite requires an understanding of adhesives and an appreciation for their exacting application. These facts combined with the precise adaptation and light-curing of multiple layers makes placement of quality Class II composite restorations tedious and time-consuming. For private practicing dentists, it can also have an effect on economic productivity. Clinicians have always wanted an easier, efficient placement technique for posterior composite restorations that rivals that for amalgam. It appears that advances in instrumentation, materials and technology have finally delivered it.

Novel materials for high-efficiency solar cells

NASA Astrophysics Data System (ADS)

Kojima, Nobuaki; Natori, Masato; Suzuki, Hidetoshi; Inagaki, Makoto; Ohshita, Yoshio; Yamaguchi, Masafumi

2009-08-01

Our Toyota Technological Institute group has investigated various novel materials for solar cells from organic to III-V compound materials. In this paper, we report our recent results in conductivity control of C60 thin films by metal-doping for organic solar cells, and mobility improvement of (In)GaAsN compounds for III-V tandem solar cells. The epitaxial growth of Mg-doped C60 films was attempted. It was found that the epitaxial growth of Mg-doped C60 film was enabled by using mica (001) substrate in the low Mg concentration region (Mg/C60 molar ratio < 1). The crystal quality of the epitaxial Mg-doped C60 film was improved drastically in compared with micro-crystalline film on glass substrate. Such drastic improvement of crystal quality in the epitaxial films resulted significant increase in conductivity. This result may indicate the significant increase of carrier mobility. Crystal quality improvement of CBE-grown GaAsN materials was investigated. We achieved the reduction of residual impurity concentration by chemical reaction control on the growing surface by modifying flow sequence of precursors and by increasing step density on the surface by using a vicinal GaAs substrate. Furthermore, the improvement in carrier mobility was observed, and it was suggested that the reduction of both residual impurities and N-related defects leads this improvement.

The System of Russian Education as Assessed by the Population: The Problem of Level and Quality

ERIC Educational Resources Information Center

Dubin, Boris; Zorkaia, Nataliia

2010-01-01

Russians are less concerned about the poor material conditions of institutions or inadequate textbooks than about the commercialization of education and high tuition. Also of great concern is the gap between educational achievement and employment opportunities, especially for the more highly educated. The perception that a higher education is a…

Compound Walls For Vacuum Chambers

NASA Technical Reports Server (NTRS)

Frazer, Robert E.

1988-01-01

Proposed compound-wall configuration enables construction of large high-vacuum chambers without having to use thick layers of expensive material to obtain necessary strength. Walls enclose chambers more than 1 m in diameter and several kilometers long. Compound wall made of strong outer layer of structural-steel culvert pipe welded to thin layer of high-quality, low-outgassing stainless steel.

Multilayer Anti-Reflective Coating Development for PMMA Fresnel Lenses

DTIC Science & Technology

2010-06-07

been sputter deposited on UV transparent polymethylmethacrylate (UVT-PMMA) windows. The amorphous coatings are deposited using reactive sputtering in a...SUBJECT TERMS Anti-reflective coatings, Fresnel lens, polymethylmethacrylate , PMMA 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...high quality dielectric materials deposited on a variety of substrates including polymethylmethacrylate (PMMA)  Highly amorphous films achieved

State Policy Recommendations for Providing Educators Access to College- and Career-Ready Open Educational Resources

ERIC Educational Resources Information Center

Voss, Hans

2015-01-01

As states and districts transition to college- and career-ready standards and aligned assessments, the need for high-quality instructional materials is clear. Open Educational Resources (OER) offer a low-cost solution with high potential to assist teachers nationwide in helping students meet the demands of higher standards. More and more…

Relationship between three cotton trash measurements: High Volume Instrumentation (HVI), Shirley Analyzer (SA), and Advanced Fiber Information System (AFIS)

USDA-ARS?s Scientific Manuscript database

Presence of non-lint materials (trashes) in commercial cotton bales at various amounts degrades the market values and further influences the end-use qualities. In order to ensure a fair trading, the USDA’s AMS has introduced the high volume instrument (HVI) measurement as a universal standard index....

Recent progress in low-voltage cathodoluminescent materials: synthesis, improvement and emission properties.

PubMed

Li, Guogang; Lin, Jun

2014-01-01

Nowadays there are several technologies used for flat panel displays (FPDs) and the development of FPDs with enhanced energy efficiency and improved display quality is strongly required. Field emission displays (FEDs) have been considered as one of the most promising next generation flat panel display technologies due to their excellent display performance and low energy consumption. For the development of FEDs, phosphors are irreplaceable components. In the past decade, the study of highly efficient low-voltage cathodoluminescent materials, namely FED phosphors, has become the focus of enhancing energy efficiency and realizing high-quality displays. This review summaries the recent progress in the chemical synthesis and improvement of novel, rare-earth and transition metal ions activated inorganic cathodoluminescent materials in powder and thin film forms. The discussion is focused on the modification of morphology, size, surface, composition and conductivity of phosphors and the corresponding effects on their cathodoluminescent properties. Special emphases are given to the selection of host and luminescent centers, the adjustment of emission colors through doping concentration optimization, energy transfer and mono- or co-doping activator ions, the improvement of chromaticity, color stability and color gamut as well as the saturation behavior and the degradation behavior of phosphors under the excitation of a low-voltage electron beam. Finally, the research prospects and future directions of FED phosphors are discussed with recommendations to facilitate the further study of new and highly efficient low-voltage cathodoluminescent materials.

Laser transmission welding of Acrylonitrile-Butadiene-Styrene (ABS) using a tailored high power diode-laser optical fiber coupled system

NASA Astrophysics Data System (ADS)

Rodríguez-Vidal, E.; Quintana, I.; Etxarri, J.; Otaduy, D.; González, F.; Moreno, F.

2012-06-01

Laser transmission welding (LTW) of polymers is a direct bonding technique which is already used in different industrial applications sectors such as automobile, microfluidic, electronic and biomedicine. This technique offers several advantages over conventional methods, especially when a local deposition of energy and minimum thermal distortions are required. In LTW one of the polymeric materials needs to be transparent to the laser wavelength and the second part needs to be designed to be absorbed in IR spectrum. This report presents a study of laser weldability of ABS (acrylonitrile/butadiene/styrene) filled with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). These additives are used as infrared absorbing components in the laser welding process, affecting the thermal and optical properties of the material and, hence, the final quality of the weld seam. A tailored laser system has been designed to obtain high quality weld seams with widths between 0.4 and 1.0mm. It consists of two diode laser bars (50W per bar) coupled into an optical fiber using a non-imaging solution: equalization of the beam quality factor (M2) in the slow and fast axes by a pair of micro step-mirrors. The beam quality factor has been analyzed at different laser powers with the aim to guarantee a coupling efficiency to the multimode optical fiber. The power scaling is carried out by means of multiplexing polarization technique. The analysis of energy balance and beam quality is performed in two linked steps: first by means ray tracing simulations (ZEMAX®) and second, by validation. Quality of the weld seams is analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. The optimum laser power range for three different welding speeds is determinate meanwhile the clamping pressure is held constant. Additionally, the corresponding mechanical shear tests were carried out to analyze the mechanical properties of the weld seams. This work provides a detailed study concerning the effect of the material microstructure and laser beam quality on the final weld formation and surface integrity.

Relationships between sedimentation, depositional environments, and coal quality: upper Potomac coalfield, West Virginia and Maryland

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

Jake, T.R.

1987-09-01

Evaluations were made of sedimentation patterns and depositional environments from approximately 450 core logs and 225 surface exposures in the Upper Potomac coalfield. The relationships between the clastic depositional facies and the distribution and quality of the Bakerstown and upper Freeport coals were also investigated. Data from 61 Bakerstown and 35 upper Freeport coal samples from selected cores indicate a change from uniform coal quality to highly variable coal quality when moving from related interchannel and bay-fill facies to channel, channel-fill, levee, and crevasse-splay facies. Areas of uniform coal quality range from 20-26% ash and 55-62% fixed carbon (weight percent,more » dry basis), whereas areas of highly variable coal quality range from 26-54% ash and 33-55% fixed carbon. The channel and related facies represent areas where increased fresh water was introduced into the topogenous swamp system, causing increased microbial degradation and the concentration of authigenic minerals within the peat material. These conditions, combined with the introduction of detrital minerals, resulted in areas of lower quality coal.« less

Development of III-V p-MOSFETs with high-kappa gate stack for future CMOS applications

NASA Astrophysics Data System (ADS)

Nagaiah, Padmaja

As the semiconductor industry approaches the limits of traditional silicon CMOS scaling, non-silicon materials and new device architectures are gradually being introduced to improve Si integrated circuit performance and continue transistor scaling. Recently, the replacement of SiO2 with a high-k material (HfO2) as gate dielectric has essentially removed one of the biggest advantages of Si as channel material. As a result, alternate high mobility materials are being considered to replace Si in the channel to achieve higher drive currents and switching speeds. III-V materials in particular have become of great interest as channel materials, owing to their superior electron transport properties. However, there are several critical challenges that need to be addressed before III-V based CMOS can replace Si CMOS technology. Some of these challenges include development of a high quality, thermally stable gate dielectric/III-V interface, and improvement in III-V p-channel hole mobility to complement the n-channel mobility, low source/drain resistance and integration onto Si substrate. In this thesis, we would be addressing the first two issues i.e. the development high performance III-V p-channels and obtaining high quality III-V/high-k interface. We start with using the device architecture of the already established InGaAs n-channels as a baseline to understand the effect of remote scattering from the high-k oxide and oxide/semiconductor interface on channel transport properties such as electron mobility and channel electron concentration. Temperature dependent Hall electron mobility measurements were performed to separate various scattering induced mobility limiting factors. Dependence of channel mobility on proximity of the channel to the oxide interface, oxide thickness, annealing conditions are discussed. The results from this work will be used in the design of the p-channel MOSFETs. Following this, InxGa1-xAs (x>0.53) is chosen as channel material for developing p-channel MOSFETs. Band engineering, strain induced valence band splitting and quantum confinement is used to improve channel hole mobility. Experimental results on the Hall hole mobility is presented for InxGa1-xAs channels with varying In content, thickness of the quantum well and temperature. Then, high mobility InxGa 1-xAs heterostructure thus obtained are integrated with in-situ deposited high-k gate oxide required for high performance p-MOSFET and discuss the challenges associated with the gated structure and draw conclusions on this material system. Antimonide based channel materials such as GaSb and InxGa 1-xSb are explored for III-V based p-MOSFETs in last two chapters. Options for Sb based strained QW channels to obtain maximum hole mobility by varying the strain, channel and barrier material, thickness of the layers etc. is discussed followed by the growth of these Sb channels on GaAs and InP substrates using molecular beam epitaxy. The physical properties of the structures such as the heterostructure quality, alloy content and surface roughness are examined via TEM, XRD and AFM. Following this, electrical measurement results on Hall hole mobility is presented. The effect of strain, alloy content, temperature and thickness on channel mobility and concentration is reported. Development of GaSb n- and p-MOS capacitor structures with in-situ deposited HfO2 gate oxide dielectric using in-situ deposited amorphous Si (a-Si) interface passivation layer (IPL) to improve the interface quality of high-k oxide and (In)GaSb surface is presented. In-situ deposited gate oxides such as Al2O3 and combination oxide of Al 2O3 and HfO2 with and without the a-Si IPL are also explored as alternate gate dielectrics. Subsequently, MOS capacitor structures using buried InGaSb QWs are demonstrated. Development of an inversion type bulk GaSb with implanted source-drain contacts and in-situ deposited gate oxide HfO2 gate oxide is discussed. The merits of biaxial compressive strain is demonstrated on strained surface and buried channel In0.36 Ga0.64Sb QW MOSFETs with thin top barrier and in-situ deposited a-Si IPL and high-k HfO2 as well as combination Al 2O3+HfO2 gate stacks and ex-situ atomic layer deposited (ALD) combination gate oxide and with thin 2 nm InAs surface passivation layer is presented. Finally, summary of the salient results from the different chapters is provided with recommendations for future research.

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement 32, 1987.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

The Environmental Quality Instructional Resources Center in Columbus, Ohio, acquires, reviews, indexes, and announces both print (books, modules, units, etc.) and non-print (films, slides, video tapes, etc.) materials related to water quality and water resources education and instruction. In addition some materials related to pesticides, hazardous…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement 34, 1988.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

The Environmental Quality Instructional Resources Center in Columbus, Ohio, acquires, reviews, indexes, and announces both print (books, modules, units, etc.) and non-print (films, slides, video tapes, etc.) materials related to water quality and water resources education and instruction. In addition some materials related to pesticides, hazardous…

Building-In Quality Rather than Assessing Quality Afterwards: A Technological Solution to Ensuring Computational Accuracy in Learning Materials

ERIC Educational Resources Information Center

Dunn, Peter

2008-01-01

Quality encompasses a very broad range of ideas in learning materials, yet the accuracy of the content is often overlooked as a measure of quality. Various aspects of accuracy are briefly considered, and the issue of computational accuracy is then considered further. When learning materials are produced containing the results of mathematical…

Picosecond and femtosecond lasers for industrial material processing

NASA Astrophysics Data System (ADS)

Mayerhofer, R.; Serbin, J.; Deeg, F. W.

2016-03-01

Cold laser materials processing using ultra short pulsed lasers has become one of the most promising new technologies for high-precision cutting, ablation, drilling and marking of almost all types of material, without causing unwanted thermal damage to the part. These characteristics have opened up new application areas and materials for laser processing, allowing previously impossible features to be created and also reducing the amount of post-processing required to an absolute minimum, saving time and cost. However, short pulse widths are only one part of thee story for industrial manufacturing processes which focus on total costs and maximum productivity and production yield. Like every other production tool, ultra-short pulse lasers have too provide high quality results with maximum reliability. Robustness and global on-site support are vital factors, as well ass easy system integration.

Assessment of Quality of Life in a Cohort of Newly Diagnosed Patients on HAART Regimen, in Resource Restricted Tribal Region of Chhattisgarh, India: A Prospective Study

PubMed Central

Singh, Harminder; Kaur, Kamalpreet; Dulhani, Navin; Bansal, Akash; Kumar, Bithika N.; Chouhan, Vinod Kumar Singh

2013-01-01

Background: Highly active antiretroviral therapy regimens have resulted in the systemic/clinical healing for human immune deficiency virus-infected patients but the consequence of antiretroviral therapy on the whole quality of life has become a major concern. The current study correlates the relationship of quality of life with successful highly active antiretroviral therapy. Aim: To determine the health-related quality of life in human immune deficiency virus-infected patients on highly active anti-retroviral therapy regimen in tribal region of Chhattisgarh. Design: An open label prospective study. Materials and Methods: Health-related quality of life was assessed using a standardized questionnaire, the Medical Outcomes Survey Short Form 36. Physical health summary scores and mental health summary scores were compared of pre-Highly Active Anti-Retroviral Therapy (at baseline) and post 12 months of therapy. Results: The increase in CD4 cell counts was extremely significant (P < 0.0001). The Physical Composite Summary (P value = 0.0003) improved significantly, whereas the Mental Composite Summary (with a baseline value of 40.7), post 12 months, was calculated as 42.8 (P value = 0.2371) and was statistically not significant. Conclusion: Efficacy measurement is the key ingredient of highly active anti-retroviral therapy, which must also include assessment of health-related quality of life to maximize the holistic approach towards disease. PMID:24049364

Evaluation of the Quality, Accuracy, and Readability of Online Patient Resources for the Management of Articular Cartilage Defects.

PubMed

Wang, Dean; Jayakar, Rohit G; Leong, Natalie L; Leathers, Michael P; Williams, Riley J; Jones, Kristofer J

2017-04-01

Objective Patients commonly use the Internet to obtain their health-related information. The purpose of this study was to investigate the quality, accuracy, and readability of online patient resources for the management of articular cartilage defects. Design Three search terms ("cartilage defect," "cartilage damage," "cartilage injury") were entered into 3 Internet search engines (Google, Bing, Yahoo). The first 25 websites from each search were collected and reviewed. The quality and accuracy of online information were independently evaluated by 3 reviewers using predetermined scoring criteria. The readability was evaluated using the Flesch-Kincaid (FK) grade score. Results Fifty-three unique websites were evaluated. Quality ratings were significantly higher in websites with a FK score >11 compared to those with a score of ≤11 ( P = 0.021). Only 10 websites (19%) differentiated between focal cartilage defects and diffuse osteoarthritis. Of these, 7 (70%) were elicited using the search term "cartilage defect" ( P = 0.038). The average accuracy of the websites was high (11.7 out of maximum 12), and the average FK grade level (13.4) was several grades higher than the recommended level for readable patient education material (eighth grade level). Conclusions The quality and readability of online patient resources for articular cartilage defects favor those with a higher level of education. Additionally, the majority of these websites do not distinguish between focal chondral defects and diffuse osteoarthritis, which can fail to provide appropriate patient education and guidance for available treatment. Clinicians should help guide patients toward high-quality, accurate, and readable online patient education material.

Films, Preimpregnated Tapes and Composites Made from Polyimide "Salt-Like" Solutions

NASA Technical Reports Server (NTRS)

Cano, Roberto J. (Inventor); Weiser, Erik S. (Inventor); St.Clair, Terry L. (Inventor); Echigo, Yoshiaki (Inventor); Kaneshiro, Hisayasu (Inventor)

2001-01-01

High quality films, preimpregnated tape (prepegs), and composites have been fabricated from polyimide precursor 'saltlike' solutions. These salt-like solutions have a low viscosity (5,000 to 10,000 cp) and a high solids content (50-65% by weight) and can be coated onto reinforcing fiber to produce prepegs with excellent tack and drape at 12-15% residual solvent (approximately 4-6% water from thermal imidization reaction). The processing of these types of prepegs significantly overcomes solvent removal problems and allows excellent fiber wet out. In addition, the physical characteristics of the polyimide precursor salt-like solutions permits processing into high-performance materials through the use of standard prepregging and composite fabrication equipment. The resultant composites are of high quality.

Achieving High Performance Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Yang, Yang

2015-03-01

Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

High-performance fused indium gallium arsenide/silicon photodiode

NASA Astrophysics Data System (ADS)

Kang, Yimin

Modern long haul, high bit rate fiber-optic communication systems demand photodetectors with high sensitivity. Avalanche photodiodes (APDs) exhibit superior sensitivity performance than other types of photodetectors by virtual of its internal gain mechanism. This dissertation work further advances the APD performance by applying a novel materials integration technique. It is the first successful demonstration of wafer fused InGaAs/Si APDs with low dark current and low noise. APDs generally adopt separate absorption and multiplication (SAM) structure, which allows independent optimization of materials properties in two distinct regions. While the absorption material needs to have high absorption coefficient in the target wavelength range to achieve high quantum efficiency, it is desirable for the multiplication material to have large discrepancy between its electron and hole ionization coefficients to reduce noise. According to these criteria, InGaAs and Si are the ideal materials combination. Wafer fusion is the enabling technique that makes this theoretical ideal an experimental possibility. APDs fabricated on the fused InGaAs/Si wafer with mesa structure exhibit low dark current and low noise. Special device fabrication techniques and high quality wafer fusion reduce dark current to nano ampere level at unity gain, comparable to state-of-the-art commercial III/V APDs. The small excess noise is attributed to the large difference in ionization coefficients between electrons and holes in silicon. Detailed layer structure designs are developed specifically for fused InGaAs/Si APDs based on principles similar to those used in traditional InGaAs/InP APDs. An accurate yet straightforward technique for device structural parameters extraction is also proposed. The extracted results from the fabricated APDs agree with device design parameters. This agreement also confirms that the fusion interface has negligible effect on electric field distributions for devices fabricated from high quality fusion materials. The feasibility of fused InGaAs/Si APD for analog systems is also explored. Preliminary two-tone measurement shows that a moderately high dynamic range of 70 dBc/Hz1/2 for broadband Spur Free Dynamic Range (SFDR) or 82 dBc/Hz2/3 suboctave SFDR, up to 50 muA of optical current, can be achieved. The theoretical analyses of SNR show that fused InGaAs/Si APD receivers can provide larger Signal-to-Noise Ratio (SNR) than their III/V counterparts.

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 28, 1986.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and nonprint materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 29, 1987.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 23 (1985).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement XII.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement XIX (1984).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 25 (1986).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to hazardous wastes and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS). A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement XVI.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement IX.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 24 (l985).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS). A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement XIII.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS). A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement XV.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement XI.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement X.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 26, 1986.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of governmental, private concerns, and…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement XX (1984).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 22 (1985).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS). A Compilation of Abstracts to Water Quality and Water Resources Materials. Supplement XVII.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 21 (1985).

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement 27, 1986.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials, Supplement XVIII.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracted/indexed materials include all levels of government, private concerns, and educational…

Contoured Orifice for Silicon-Ribbon Die

NASA Technical Reports Server (NTRS)

Mackintosh, B. H.

1985-01-01

Die configuration encourages purity and stable growth. Contour of die orifice changes near ribbon edges. As result, silicon ribbon has nearly constant width and little carbon contamination. Die part of furnace being developed to produce high-quality, low-cost material for solar cells.

Superconductors

DOEpatents

Newkirk, Lawrence R.; Valencia, Flavio A.

1977-02-01

The structural quality of niobium germanide as a high-transition-temperature superconducting material is substantially improved by the presence of about 5 at. % oxygen. Niobium germanide having this oxygen content may readily be prepared as a bulk coating bonded to a metallic substrate by chemical vapor deposition techniques.

Potential use and applications for reclaimed millings.

DOT National Transportation Integrated Search

2015-06-01

The purpose of this project was to provide support to PennDOT District 1-0 in the effective use of milled asphalt material. Specifically, : District 1-0 has a shortage of high-quality available coarse aggregate and has developed the innovative proced...

Thin overlay guidelines : project selection, design, and construction.

DOT National Transportation Integrated Search

2015-04-01

Thin hot mix asphalt (HMA) overlays are : cost-effective, high-performance maintenance : treatments. They can be laid at 1.0 to 0.5 inches : thick and consist of quality aggregate and binder : materials. The costs are generally more (per ton) : than ...

Safe, High-Performance, Sustainable Precast School Design

ERIC Educational Resources Information Center

Finsen, Peter I.

2011-01-01

School design utilizing integrated architectural and structural precast and prestressed concrete components has gained greater acceptance recently for numerous reasons, including increasingly sophisticated owners and improved learning environments based on material benefits such as: sustainability, energy efficiency, indoor air quality, storm…

Service quality and patient experiences of ambulatory care in a specialized clinic vs. a general hospital.

PubMed

De Regge, Melissa; De Groote, Hélène; Trybou, Jeroen; Gemmel, Paul; Brugada, Pedro

2017-04-01

Health care organizations are constantly looking for ways to establish a differential advantage to attract customers. To this end, service quality has become an important differentiator in the strategy of health care organizations. In this study, we compared the service quality and patient experience in an ambulatory care setting of a physician-owned specialized facility with that of a general hospital. A comparative case study with a mixed method design was employed. Data were gathered through a survey on health service quality and patient experience, completed with observations, walkthroughs, and photographic material. Service quality and patient experiences are high in both the investigated health care facilities. A significant distinction can be made between the two facilities in terms of interpersonal quality (p = 0.001) and environmental quality (P ≤ 0.001), in favor of the medical center. The difference in environmental quality is also indicated by the scores given by participants who had been in both facilities. Qualitative analysis showed higher administrative quality in the medical center. Environmental quality and patient experience can predict the interpersonal quality; for environmental quality, interpersonal quality and age are significant predictors. Service quality and patient experiences are high in both facilities. The medical center has higher service quality for interpersonal and environmental service quality and is more process-centered.

A systematic review on the composting of green waste: Feedstock quality and optimization strategies.

PubMed

Reyes-Torres, M; Oviedo-Ocaña, E R; Dominguez, I; Komilis, D; Sánchez, A

2018-04-27

Green waste (GW) is an important fraction of municipal solid waste (MSW). The composting of lignocellulosic GW is challenging due to its low decomposition rate. Recently, an increasing number of studies that include strategies to optimize GW composting appeared in the literature. This literature review focuses on the physicochemical quality of GW and on the effect of strategies used to improve the process and product quality. A systematic search was carried out, using keywords, and 447 papers published between 2002 and 2018 were identified. After a screening process, 41 papers addressing feedstock quality and 32 papers on optimization strategies were selected to be reviewed and analyzed in detail. The GW composition is highly variable due to the diversity of the source materials, the type of vegetation, and climatic conditions. This variability limits a strict categorization of the GW physicochemical characteristics. However, this research established that the predominant features of GW are a C/N ratio higher than 25, a deficit in important nutrients, namely nitrogen (0.5-1.5% db), phosphorous (0.1-0.2% db) and potassium (0.4-0.8% db) and a high content of recalcitrant organic compounds (e.g. lignin). The promising strategies to improve composting of GW were: i) GW particle size reduction (e.g. shredding and separation of GW fractions); ii) addition of energy amendments (e.g. non-refined sugar, phosphate rock, food waste, volatile ashes), bulking materials (e.g. biocarbon, wood chips), or microbial inoculum (e.g. fungal consortia); and iii) variations in operating parameters (aeration, temperature, and two-phase composting). These alternatives have successfully led to the reduction of process length and have managed to transform recalcitrant substances to a high-quality end-product. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of high-purity 82Se-enriched ZnSe for double-beta decay bolometer/scintillation detectors

NASA Astrophysics Data System (ADS)

Silva, B. C.; de Oliveira, R.; Ribeiro, G. M.; Cury, L. A.; Leal, A. S.; Nagorny, S.; Krambrock, K.

2018-02-01

Zinc selenide (ZnSe), when enriched with 82Se isotope, is one of the most promising materials for the construction of a bolometer/scintillation detector to study neutrinoless double beta decay (0νDBD). Because the 0νDBD is a very rare event, a high quantity of high-purity monocrystalline ZnSe is needed, which means high costs. Therefore, the knowledge of the best material parameters, especially the presence of point defects, is essential to make feasible the construction of such a detector. In this work, both the as-grown and thermally annealed ZnSe enriched to 95% with the 82Se isotope grown by the Bridgman technique from high-purity starting materials were characterized by electron paramagnetic resonance (EPR), photo-EPR, neutron activation, photoluminescence, and electrical measurements. It is shown that although thermal annealing increases crystal homogeneity and reduces microcracks, the scintillation efficiency is much better for the as-grown material. The higher scintillation efficiency is due to the presence of donor acceptor pairs in the as-grown material, which are responsible for strong luminescence/scintillation in the red spectral region. By photo-EPR, the donor acceptor pairs are identified as closed VZn - AlZn pairs which are lost during the annealing procedure. Electrical characterization shows that the as-grown material is of good quality as it has high electron mobility at low temperatures. Excellent material parameters for the construction of the bolometer/scintillation detector based on enriched Zn82Se are discussed.

The Toronto outcome measure for craniofacial prosthetics: reliability and validity of a condition-specific quality-of-life instrument.

PubMed

Anderson, James D; Johnston, Dennis A; Haugh, Gil S; Kiat-Amnuay, Sudarat; Gettleman, Lawrence

2013-01-01

The purpose of this study was to refine the Toronto Outcome Measure for Craniofacial Prosthetics (TOMCP), present evidence for its reliability and validity, and use the instrument to explore differences in quality of life between prostheses made with chlorinated polyethylene (CPE) (experimental) and silicone (control). As part of a multicenter prospective controlled randomized double-blind single-crossover clinical trial of the two materials, the TOMCP was administered at the start and end of two 4-month study arms, during which 42 patients wore prostheses made from one material then the other. Reliability was assessed at the crossover. To determine validity of the TOMCP, the Linear Analogue Self-Assessment (LASA-12) and the Short-Form 8 (SF-8) were also administered with the TOMCP. The TOMCP was reduced by removing items that were unreliable, had poorly distributed answers, showed increased internal consistency after their removal, or were too highly correlated with more than one other item. The tests of reliability and validity were then repeated. Finally, the reduced instrument was used to test for differences in quality of life between prostheses made of the two materials. The item reduction tactics pared the 52-item instrument down to 27 items. The correlations of both TOMCP versions with the LASA-12 and the SF-8 were found to be statistically significant, providing evidence of the validity of the TOMCP. The instrument revealed significantly better quality of life with silicone rather than CPE prostheses. Both versions of the TOMCP were found to be reliable and valid. The instrument was able to show differences in quality of life between two materials.

Low-Temperature Solution Processable Electrodes for Piezoelectric Sensors Applications

NASA Astrophysics Data System (ADS)

Tuukkanen, Sampo; Julin, Tuomas; Rantanen, Ville; Zakrzewski, Mari; Moilanen, Pasi; Lupo, Donald

2013-05-01

Piezoelectric thin-film sensors are suitable for a wide range of applications from physiological measurements to industrial monitoring systems. The use of flexible materials in combination with high-throughput printing technologies enables cost-effective manufacturing of custom-designed, highly integratable piezoelectric sensors. This type of sensor can, for instance, improve industrial process control or enable the embedding of ubiquitous sensors in our living environment to improve quality of life. Here, we discuss the benefits, challenges and potential applications of piezoelectric thin-film sensors. The piezoelectric sensor elements are fabricated by printing electrodes on both sides of unmetallized poly(vinylidene fluoride) film. We show that materials which are solution processable in low temperatures, biocompatible and environmental friendly are suitable for use as electrode materials in piezoelectric sensors.

Chemical vapour deposition: Transition metal carbides go 2D

DOE PAGES

Gogotsi, Yury

2015-08-17

Here, the research community has been steadily expanding the family of few-atom-thick crystals beyond graphene, discovering new materials or producing known materials in a 2D state and demonstrating their unique properties 1, 2. Recently, nanometre-thin 2D transition metal carbides have also joined this family 3. Writing in Nature Materials, Chuan Xu and colleagues now report a significant advance in the field, showing the synthesis of large-area, high-quality, nanometre-thin crystals of molybdenum carbide that demonstrate low-temperature 2D superconductivity 4. Moreover, they also show that other ultrathin carbide crystals, such as tungsten and tantalum carbides, can be grown by chemical vapour depositionmore » with a high crystallinity and very low defect concentration.« less

Supercooling of Hydrogen on Template Materials to Deterministically Seed Ignition-Quality Solid Fuel Layers

DOE PAGES

Shin, S. J.; Zepeda-Ruiz, L. A.; Lee, J. R. I.; ...

2016-09-01

In this study, we explored templating effects of various materials for hydrogen (H 2 and D 2) solidification by measuring the degree of supercooling required for liquid hydrogen to solidify below each triple point. The results show high supercooling (>100 mK) for most metallic, covalent, and ionic solids, and low supercooling (<100 mK) for van der Waals (vdW) solids. We attribute the low supercooling of vdW solids to the weak interaction of the substrate and hydrogen. Highly ordered pyrolytic graphite showed the lowest supercooling among materials that are solid at room temperature, but did not exhibit a templating effect withinmore » a fill-tube and capsule assembly.« less

DOE-DARPA High-Performance Corrosion-Resistant Materials (HPCRM), Annual HPCRM Team Meeting & Technical Review

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

Farmer, J; Brown, B; Bayles, B

The overall goal is to develop high-performance corrosion-resistant iron-based amorphous-metal coatings for prolonged trouble-free use in very aggressive environments: seawater & hot geothermal brines. The specific technical objectives are: (1) Synthesize Fe-based amorphous-metal coating with corrosion resistance comparable/superior to Ni-based Alloy C-22; (2) Establish processing parameter windows for applying and controlling coating attributes (porosity, density, bonding); (3) Assess possible cost savings through substitution of Fe-based material for more expensive Ni-based Alloy C-22; (4) Demonstrate practical fabrication processes; (5) Produce quality materials and data with complete traceability for nuclear applications; and (6) Develop, validate and calibrate computational models to enable lifemore » prediction and process design.« less

Thick phase holographic gratings recorded on BB-640 and PFG-01 silver halide materials

NASA Astrophysics Data System (ADS)

Neipp, Cristian; Márquez, Andrés; Pascual, Inmaculada; Beléndez, Augusto

2003-09-01

Photographic emulsions are still widely used to record holographic optical elements. In particular, if high diffraction efficiencies are needed, phase volume holograms are preferably recorded on these emulsions. Two particular techniques producing high-quality volume phase holograms are fixation-free rehalogenating bleaching and the use of silver-halide-sensitized gelatin. In this work we compare these two particular techniques applied to three different red-sensitive emulsions: Agfa 8E75 HD, BB-640, and Slavich PFG-01 emulsions. The differences between these emulsions determine the particular experimental conditions needed to record high-quality volume holograms on them. In this work these differences are analysed, and also their influence on the experimental procedure.

Baseline Assessment of 25-Hydroxyvitamin D Reference Material and Proficiency Testing/External Quality Assurance Material Commutability: A Vitamin D Standardization Program Study.

PubMed

Phinney, Karen W; Sempos, Christopher T; Tai, Susan S-C; Camara, Johanna E; Wise, Stephen A; Eckfeldt, John H; Hoofnagle, Andrew N; Carter, Graham D; Jones, Julia; Myers, Gary L; Durazo-Arvizu, Ramon; Miller, W Greg; Bachmann, Lorin M; Young, Ian S; Pettit, Juanita; Caldwell, Grahame; Liu, Andrew; Brooks, Stephen P J; Sarafin, Kurtis; Thamm, Michael; Mensink, Gert B M; Busch, Markus; Rabenberg, Martina; Cashman, Kevin D; Kiely, Mairead; Galvin, Karen; Zhang, Joy Y; Kinsella, Michael; Oh, Kyungwon; Lee, Sun-Wha; Jung, Chae L; Cox, Lorna; Goldberg, Gail; Guberg, Kate; Meadows, Sarah; Prentice, Ann; Tian, Lu; Brannon, Patsy M; Lucas, Robyn M; Crump, Peter M; Cavalier, Etienne; Merkel, Joyce; Betz, Joseph M

2017-09-01

The Vitamin D Standardization Program (VDSP) coordinated a study in 2012 to assess the commutability of reference materials and proficiency testing/external quality assurance materials for total 25-hydroxyvitamin D [25(OH)D] in human serum, the primary indicator of vitamin D status. A set of 50 single-donor serum samples as well as 17 reference and proficiency testing/external quality assessment materials were analyzed by participating laboratories that used either immunoassay or LC-MS methods for total 25(OH)D. The commutability test materials included National Institute of Standards and Technology Standard Reference Material 972a Vitamin D Metabolites in Human Serum as well as materials from the College of American Pathologists and the Vitamin D External Quality Assessment Scheme. Study protocols and data analysis procedures were in accordance with Clinical and Laboratory Standards Institute guidelines. The majority of the test materials were found to be commutable with the methods used in this commutability study. These results provide guidance for laboratories needing to choose appropriate reference materials and select proficiency or external quality assessment programs and will serve as a foundation for additional VDSP studies.

Environmental and Energy Quality Technologies. Task Order 0005: Organic Finishing Technologies, Sub Task 11: High Speed, Substrate Safe Specialty Coating Laser Stripping : Project: WP 2146

DTIC Science & Technology

2015-06-22

hazardous materials and eliminating the hazardous waste streams associated with wheat starch , chemical strippers and hand sanding. Additionally, the laser...chemical attack resistance and other special characteristics while providing corrosion protection. The materials used for these purposes are designed...inspection and/or replacement. Standard coating removal methods include chemical strippers, media blasting (i.e., wheat starch , plastic

Rational preparation of waste coal mixture for production of bricks by the method of compression molding

NASA Astrophysics Data System (ADS)

Stolboushkin, A. Yu; Ivanov, A. I.; Temlyantsev, M. V.; Fomina, O. A.

2016-10-01

Rational preparation of the mixture containing technogenic raw material - waste coal for the production of wall ceramics is developed. It was established that the technology of high-quality ceramic bricks requires: grinding of raw materials to class 0.3 + 0 mm, its aggregation in the intensive mixers into granules 1-3 mm, compression molding of adobe to plastic deformation of granules, drying and firing.

Libros bilingues, traducciones desparpajadas y traducciones pobres: libros en espanol publicados en los Estados Unidos (Bilingual Books, Careless Translations, and Bad Translations: Books in Spanish Published in the United States).

ERIC Educational Resources Information Center

Schon, Isabel

2003-01-01

Discusses the importance of providing Spanish-speaking students with high-quality reading materials in Spanish and avoiding materials that have been badly translated into Spanish. Provides an annotated list of 10 books recommended for young children and a Spanish grammar for more advanced readers. Lists 29 badly translated books. Describes a Web…

Stability of the tungsten diselenide and silicon carbide heterostructure against high energy proton exposure

NASA Astrophysics Data System (ADS)

Walker, Roger C.; Shi, Tan; Jariwala, Bhakti; Jovanovic, Igor; Robinson, Joshua A.

2017-10-01

Single layers of tungsten diselenide (WSe2) can be used to construct ultra-thin, high-performance electronics. Additionally, there has been considerable progress in controlled and direct growth of single layers on various substrates. Based on these results, high-quality WSe2-based devices that approach the limit of physical thickness are now possible. Such devices could be useful for space applications, but understanding how high-energy radiation impacts the properties of WSe2 and the WSe2/substrate interface has been lacking. In this work, we compare the stability against high energy proton radiation of WSe2 and silicon carbide (SiC) heterostructures generated by mechanical exfoliation of WSe2 flakes and by direct growth of WSe2 via metal-organic chemical vapor deposition (MOCVD). These two techniques produce WSe2/SiC heterostructures with distinct differences due to interface states generated during the MOCVD growth process. This difference carries over to differences in band alignment from interface states and the ultra-thin nature of the MOCVD-grown material. Both heterostructures are not susceptible to proton-induced charging up to a dose of 1016 protons/cm2, as measured via shifts in the binding energy of core shell electrons and a decrease in the valence band offset. Furthermore, the MOCVD-grown material is less affected by the proton exposure due to its ultra-thin nature and a greater interaction with the substrate. These combined effects show that the directly grown material is suitable for multi-year use in space, provided that high quality devices can be fabricated from it.

How Deformation Behavior Controls Product Performance After Twin Screw Granulation With High Drug Loads and Crospovidone as Disintegrant.

PubMed

Meier, Robin; Moll, Klaus-Peter; Krumme, Markus; Kleinebudde, Peter

2017-01-01

This study addresses the quantitative influence of 12 different materials (active pharmaceutical ingredients and excipients as surrogate active pharmaceutical ingredients) on the critical quality attributes of twin screw granulated products and subsequently produced tablets. Prestudies demonstrated the significant influence of the chosen model materials (in combination with crospovidone) on the disintegration behavior of the resulting tablets, despite comparable tablet porosities. This study elucidates possible reasons for the varying disintegration behavior by investigating raw material, granule, and tablet properties. An answer could be found in the mechanical properties of the raw materials and the produced granules. Through compressibility studies, the materials could be classified into materials with high compressibility, which deform rather plastically under compression stress, and low compressibility, which display breakages under compression stress. In general, and apart from (pseudo)-polymorphic transformations, brittle materials featured excellent disintegration performance, even at low resulting tablet porosities <8%, whereas plastically deformable materials mostly did not reveal any disintegration. These findings must be considered in the development of simplified formulations with high drug loads, in which the active pharmaceutical ingredient predominantly defines the deformation behavior of the granule. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

CESAME: Providing High Quality Professional Development in Science and Mathematics for K-12 Teachers

NASA Astrophysics Data System (ADS)

Hickman, Paul

2002-04-01

It is appropriate that after almost half a century of Science and Mathematics education reform we take a look back and a peek forward to understand the present state of this wonderfully complex system. Each of the components of this system including teaching, professional development, assessment, content and the district K-12 curriculum all need to work together if we hope to provide quality science, mathematics and technology education for ALL students. How do the state and national standards drive the system? How do state policies on student testing and teacher licensure come into play? How do we improve the preparation, retention and job satisfaction of our K-12 teachers? What initiatives have made or are making a difference? What else needs to be done? What can the physics community do to support local efforts? This job is too big for any single organization or individual but we each can contribute to the effort. Our Center at Northeastern University, with support from the National Science Foundation, has a sharply defined focus: to get high quality, research-based instructional materials into the hands of K-12 classroom teachers and provide the support they need to use the materials effectively in their classrooms.

Alternative soilless media for growing Petunia x hybrida and Impatiens wallerana: physical behavior, effect of fertilization and nitrate losses.

PubMed

Chavez, Walter; Di Benedetto, Adalberto; Civeira, Gabriela; Lavado, Raúl

2008-11-01

The use of alternative soilless media for the production of potted plants requires knowledge of their physical and chemical characteristics to result in the best conditions for plant growth. We investigated the use of alternative soilless media based on river waste and Sphagnun sp. and Carex sp. from Argentinean peatlands on Petuniaxhybrida and Impatiens wallerana production at two fertilization levels (200 and 400mgl(-1)N). River waste or 'temperate peat' is the name given to a material, resulting from the accumulation of aquatic plant residues under an anaerobic subtropical environment, which is dredged from river banks. Our results showed that alternative substrates based on river waste can be used to grow high quality plants. This result was not fully explained on the basis of established methods to evaluate substrate quality. Highly concentrated fertigation solution decreased the substrate quality parameters and plant growth. Nitrate leaching from the alternative substrates containing river waste was lower than the standard peat-based materials, which makes river waste desirable from a sustainable pot production system perspective. River waste and Carex peat are suitable alternatives to Sphagnum peat from the Northern Hemisphere.

High quality methylome-wide investigations through next-generation sequencing of DNA from a single archived dry blood spot

PubMed Central

Aberg, Karolina A.; Xie, Lin Y.; Nerella, Srilaxmi; Copeland, William E.; Costello, E. Jane; van den Oord, Edwin J.C.G.

2013-01-01

The potential importance of DNA methylation in the etiology of complex diseases has led to interest in the development of methylome-wide association studies (MWAS) aimed at interrogating all methylation sites in the human genome. When using blood as biomaterial for a MWAS the DNA is typically extracted directly from fresh or frozen whole blood that was collected via venous puncture. However, DNA extracted from dry blood spots may also be an alternative starting material. In the present study, we apply a methyl-CpG binding domain (MBD) protein enrichment-based technique in combination with next generation sequencing (MBD-seq) to assess the methylation status of the ~27 million CpGs in the human autosomal reference genome. We investigate eight methylomes using DNA from blood spots. This data are compared with 1,500 methylomes previously assayed with the same MBD-seq approach using DNA from whole blood. When investigating the sequence quality and the enrichment profile across biological features, we find that DNA extracted from blood spots gives comparable results with DNA extracted from whole blood. Only if the amount of starting material is ≤ 0.5µg DNA we observe a slight decrease in the assay performance. In conclusion, we show that high quality methylome-wide investigations using MBD-seq can be conducted in DNA extracted from archived dry blood spots without sacrificing quality and without bias in enrichment profile as long as the amount of starting material is sufficient. In general, the amount of DNA extracted from a single blood spot is sufficient for methylome-wide investigations with the MBD-seq approach. PMID:23644822

High quality methylome-wide investigations through next-generation sequencing of DNA from a single archived dry blood spot.

PubMed

Aberg, Karolina A; Xie, Lin Y; Nerella, Srilaxmi; Copeland, William E; Costello, E Jane; van den Oord, Edwin J C G

2013-05-01

The potential importance of DNA methylation in the etiology of complex diseases has led to interest in the development of methylome-wide association studies (MWAS) aimed at interrogating all methylation sites in the human genome. When using blood as biomaterial for a MWAS the DNA is typically extracted directly from fresh or frozen whole blood that was collected via venous puncture. However, DNA extracted from dry blood spots may also be an alternative starting material. In the present study, we apply a methyl-CpG binding domain (MBD) protein enrichment-based technique in combination with next generation sequencing (MBD-seq) to assess the methylation status of the ~27 million CpGs in the human autosomal reference genome. We investigate eight methylomes using DNA from blood spots. This data are compared with 1,500 methylomes previously assayed with the same MBD-seq approach using DNA from whole blood. When investigating the sequence quality and the enrichment profile across biological features, we find that DNA extracted from blood spots gives comparable results with DNA extracted from whole blood. Only if the amount of starting material is ≤ 0.5µg DNA we observe a slight decrease in the assay performance. In conclusion, we show that high quality methylome-wide investigations using MBD-seq can be conducted in DNA extracted from archived dry blood spots without sacrificing quality and without bias in enrichment profile as long as the amount of starting material is sufficient. In general, the amount of DNA extracted from a single blood spot is sufficient for methylome-wide investigations with the MBD-seq approach.

Water Quality Instructional Resources Information System (IRIS): A Compilation of Abstracts to Water Quality and Water Resources Materials. Includes May 1979 edition and Supplements 1-15.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus, OH. Information Reference Center for Science, Mathematics, and Environmental Education.

Compiled are abstracts and indexes to selected print and non-print materials related to wastewater treatment and water quality education and instruction, as well as materials related to pesticides, hazardous wastes, and public participation. Sources of abstracts/indexed materials include all levels of government, private concerns, and educational…

Fabrication of microwave guides using high-Tc superconductors. Final report, 15 July 1989-14 January 1990

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

Trivedi, S.B.

1990-01-14

The objective of this study was to produce bulk high Tc superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} with microwave conductivity at least as good or better than that of copper. The subsequent aim was to fabricate cylindrical wave guide using this material. The ultimate goal of this study is to produce YBa{sub 2}Cu{sub 3}O{sub 7-x} with microwave conductivity exceedingly higher (at least two orders of magnitude better) than that of copper. In principle, this is possible if the microstructure of the superconductor material is carefully controlled. The above-stated goal could be easily achieved if the large single crystals of YBa{sub 2}Cu{submore » 3}O{sub 7-x} are available or if the inside surface of a suitable substrate material in the form of hollow cylinder, could be coated with the superconductor material of high quality. The former approach, currently, seems to be far from practical realization.« less

Effect of Temperature Change on Interfacial Behavior of an Acoustically Levitated Droplet

NASA Astrophysics Data System (ADS)

Kawakami, Masanori; Abe, Yutaka; Kaneko, Akiko; Yamamoto, Yuji; Hasegawa, Koji

2010-04-01

Under the microgravity environment, new and high quality materials with a homogeneous crystal structure are expected to be manufactured by undercooling solidification, since the material manufacturing under the microgravity environment is more static than that under the normal gravity. However, the temperature change on the interface of the material in space can affect on the material processing. The purpose of the present study is to investigate effect of the temperature change of interface on the large levitated droplet interface. A water droplet levitated by the acoustic standing wave is heated by YAG laser. In order to heat the water droplet by the laser heating, rhodamine 6G is solved in it to achieve high absorbance of the laser. The droplet diameter is from 4 to 5.5 mm. The deformation of the droplet interface is observed by high speed video camera. The temperature of droplet is measured by the radiation thermometer. It is noticed that the larger droplet under the higher sound pressure tends to oscillate remarkably by the laser heating.