Use of residues proceeding from marbles and granites finishing and manufacturing processes as raw material for structural ceramic

International Nuclear Information System (INIS)

Mello, Roberta Monteiro de

2006-01-01

In order to decrease environmental impact, caused by mud discarding and clay extraction in the ceramic industry, it was used residual mud from marble and granite companies for structural ceramic. Samples were collected in twelve different marble companies located at the metropolitan region of Sao Paulo. However, only four samples were selected, based on its different characteristics. Clay stone was the raw material chosen to prepare the structural ceramic, considering its high use in this segment. Samples and clay stone were both analysed by the following procedures: granulometric analysis, x-rays fluorescent chemical analysis and x-rays diffraction mineralogical analysis, besides, tests in the samples were conducted following NBR 10004 standards. Once raw materials were characterized, the plasticity test was conducted. Test specimen were molded with different levels of mud, then burned and submitted to technological tests, such as: mechanical resistance, water absorption, porosity, specific gravity and retraction, material dilation before burning process and scanning electron microscopy. The final results have shown the viability of using this kind of mud, and pointed some advantages on its usage, but taking in consideration some previous conditions to be adopted. (author)

Lightweight combustion residues-based structural materials for use in mines. Quarterly report, 1 December 1994--28 February 1995

Energy Technology Data Exchange (ETDEWEB)

Chugh, Yoginder P.; Zhang, Yuzhuo; Ghosh, A.K.; Palmer, S.R; Peng, Suping, Xiao, Y. [Southern Illinois Univ., Carbondale, IL (United States)

1995-12-31

The overall goal of this project is to develop, design and test artificial supports (post and crib members) for use in mines manufactured from coal combustion by-product (CCB) based lightweight structural materials. The lightweight cement-fly ash grout with density ranging from 70 to 110 pcf has been developed incorporating very high volume (50--60 % of whole solid materials) fly ash. Characterization of individual component materials for the CCB-based structural materials has been performed for Class F fly ash, ASTM Type I cement, lime, silica fume, polypropylene fibers, protein-based foam, water-reducing agents, and calcium chloride. During the past quarter, we emphasized on screening mix designs and establishing mixing and curing procedures. We have demonstrated for the first time that cellular cement-fly ash grout can be developed with very low water: cement ratio (0.32--0.45). After forming, all the samples in the molds were moist cured in a chamber for 24-hours, at 90% relatively humidity (RH) and at 72{degrees}F. They were then demolded and transferred to a low pressure steam chamber (150{degrees}F and 100% RH). After steaming for 24 hours the samples were removed to a moist cure chamber prior to testing.

Neutron diffraction measurement of residual stress in NPP construction materials

International Nuclear Information System (INIS)

Hinca, R.; Bokuchava, G.

2000-01-01

The aim of the investigation is to study the level of residual stresses induced by the surfacing in the weld deposit zone and in the base metal, where considerable thermal gradients are present. Surfacing high-nickel filler on an austenitic base metal is one of techniques in repair of primary collector the primary circuit of nuclear power plant type VVER. The repair technology was developed at Welding Research Institute Bratislava. Measurements of residual stresses in the weld overlay and the base metal are necessary for approving the mechanical analysis and verifying of residual stresses determination on welded material by numerical weld g computer simulation. Investigations of residual stresses are important for developing optimal welding techniques. (authors)

Data base on structural materials aging properties

International Nuclear Information System (INIS)

Oland, C.B.

1992-01-01

The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where long-term and environment-dependent properties of concretes and other structural materials are being collected and assembled into a data base. These properties will be used to evaluate the current condition of critical structural components in nuclear power plants and to estimate the future performance of these materials during the continued service period

Development of residual stress analysis procedure for fitness-for-service assessment of welded structure

International Nuclear Information System (INIS)

Kim, Jong Sung; Jin, Tae Eun; Dong, P.; Prager, M.

2003-01-01

In this study, a state of art review of existing residual stress analysis techniques and representative solutions is presented in order to develop the residual stress analysis procedure for Fitness-For-Service(FFS) assessment of welded structure. Critical issues associated with existing residual stress solutions and their treatments in performing FFS are discussed. It should be recognized that detailed residual stress evolution is an extremely complicated phenomenon that typically involves material-specific thermomechanical/metallurgical response, welding process physics, and structural interactions within a component being welded. As a result, computational procedures can vary significantly from highly complicated numerical techniques intended only to elucidate a small part of the process physics to cost-effective procedures that are deemed adequate for capturing some of the important features in a final residual stress distribution. Residual stress analysis procedure for FFS purposes belongs to the latter category. With this in mind, both residual stress analysis techniques and their adequacy for FFS are assessed based on both literature data and analyses performed in this investigation

Investigation of residual stress in laser welding dissimilar materials

International Nuclear Information System (INIS)

Mirim, Denilson de Camargo; Oliveira, Rene Ramos de; Berretta, Jose Roberto; Rossi, Wagner de; Lima, Nelson Batista de; Delijaicov, Sergio; Gomes, Diego Oliva

2010-01-01

One of the most critical problems found in the different materials welding is the residual stress formation, that happens mainly for the fact of those materials they possess coefficients of thermal expansion and different thermal conductivities. Like this in this work the residual tension was evaluated in the technique of welding laser among the steel low carbon, AISI 1010 and AISI 304. The materials were united for it welds autogenous of top with a laser of continuous Nd:YAG in that they were varied the potency, speed and the focus of the laser stayed constant in relation to surface of the sample. The main objective of the study went identification and to analysis of the residual stress in HAZ on both sides of seem. Um planning factorial of two factors at two levels each it was executed for optimization the combination of the factors potency and speed. The obtained answers were the residual stress in different depths in HAZ. In the surface of the sample measures of residual stress were accomplished by the technique of X-ray diffraction. The hole drilling strain gage method it was applied to measure the residual stress on both sides of the union. The results were analyzed using the variance analysis and the statistical regression based on the different influences of the entrance and combination of the factors in the residual stress generated in that union. The results indicate that the development of models can foresee the answers satisfactorily. (author)

Residual monomer content determination in some acrylic denture base materials and possibilities of its reduction

Directory of Open Access Journals (Sweden)

Kostić Milena

2009-01-01

Full Text Available Background/Aim. Polymethyl methacrylate is used for producing a denture basis. It is a material made by the polymerization process of methyl methacrylate. Despite of the polymerization type, there is a certain amount of free methyl methacrylate (residual monomer incorporated in the denture, which can cause irritation of the oral mucosa. The aim of this study was to determine the amount of residual monomer in four different denture base acrylic resins by liquid chromatography and the possibility of its reduction. Methods. After the polymerization, a postpolymerization treatment was performed in three different ways: in boiling water for thirty minutes, with 500 W microwaves for three minutes and in steam bath at 22º C for one to thirty days. Results. The obtained results showed that the amount of residual monomer is significantly higher in cold polymerizing acrylates (9.1-11%. The amount of residual monomer after hot polymerization was in the tolerance range (0.59- 0.86%. Conclusion. The obtained results denote a low content of residual monomer in the samples which have undergone postpolymerization treatment. A lower percent of residual monomer is established in samples undergone a hot polymerization.

Derivation of uranium residual radioactive material guidelines for the Ventron site

International Nuclear Information System (INIS)

Loureiro, C.; Yu, C.; Jones, L.

1992-03-01

Residual radioactive material guidelines for uranium were derived for the Ventron site in Beverly, Massachusetts. This site has been identified for remedial action under the Formerly Utilized Sites Remedial Action Program of the US Department of Energy (DOE). The derivations for the single radionuclides and the total uranium guidelines were based on the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the Ventron site should not exceed a dose of 100 mrem/yr following remedial action. The DOE residual radioactive material guideline computer code, RESRAD, which implements the methodology described in the DOE manual for implementing residual radioactive material guidelines, was used in this evaluation

Tungsten - Yttrium Based Nuclear Structural Materials

Science.gov (United States)

Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

2013-04-01

The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

Determination of structural fluctuations of proteins from structure-based calculations of residual dipolar couplings

International Nuclear Information System (INIS)

Montalvao, Rinaldo W.; De Simone, Alfonso; Vendruscolo, Michele

2012-01-01

Residual dipolar couplings (RDCs) have the potential of providing detailed information about the conformational fluctuations of proteins. It is very challenging, however, to extract such information because of the complex relationship between RDCs and protein structures. A promising approach to decode this relationship involves structure-based calculations of the alignment tensors of protein conformations. By implementing this strategy to generate structural restraints in molecular dynamics simulations we show that it is possible to extract effectively the information provided by RDCs about the conformational fluctuations in the native states of proteins. The approach that we present can be used in a wide range of alignment media, including Pf1, charged bicelles and gels. The accuracy of the method is demonstrated by the analysis of the Q factors for RDCs not used as restraints in the calculations, which are significantly lower than those corresponding to existing high-resolution structures and structural ensembles, hence showing that we capture effectively the contributions to RDCs from conformational fluctuations.

Mapping residual and internal stress in materials by neutron diffraction

International Nuclear Information System (INIS)

Withers, Ph.J.

2007-01-01

Neutron diffraction provides one of the few means of mapping residual stresses deep within the bulk of materials and components. This article reviews the basic scientific methodology by which internal strains and stresses are inferred from recorded diffraction peaks. Both conventional angular scans and time-of-flight measurements are reviewed and compared. Their complementarity with analogous synchrotron X-ray methods is also highlighted. For measurements to be exploited in structural integrity calculations underpinning the safe operation of engineering components, measurement standards have been defined and the major findings are summarised. Examples are used to highlight the unique capabilities of the method showing how it can provide insights ranging from the basic physics of slip mechanisms in hexagonal polycrystalline materials, through the materials optimisation of stress induced transformations in smart nano-materials, to the industrial introduction of novel friction welding processes exploiting stress residual measurements transferred from prototype sub-scale tests to the joining of full-scale aero-engine assemblies. (author)

Measurement of residual stress in materials using neutrons. Proceedings of a technical meeting

International Nuclear Information System (INIS)

2005-06-01

One of the objectives of the IAEA's project on effective utilization of research reactors is to promote the use of the existing research reactors based on their capabilities and is implemented through workshops and technical meetings. Measurement of residual stress is one of the techniques that find wide applications in materials development and testing. The Technical Meeting on Measurement of Residual Stress Using Neutrons was organized to meet this objective. This publication is the outcome of the deliberations during the meeting and the presentations by the participants and is addressed to the research reactor managers, users and designers of facilities for reactor utilization. It will especially benefit those seeking to develop new facilities or upgrade the existing ones to enhance the utilization of their research reactors. Experts with a long experience in developing and using neutron beam instruments in high flux and medium flux research reactors participated in this technical meeting. They presented the design, development and utilization of the facilities at their respective centres and reviewed the current status of the residual stress measurements using neutron beams from research reactors. The sessions included brainstorming on the methodology and data analysis, characterization and standardization of the equipment and identifying the scope for further development. This publication refers to the determination of residual and/or applied stresses in polycrystalline materials using neutron diffraction technique. Stress is developed during the synthesis and use of materials such as alloys and compounds. Measurement of residual stress is essential to improve the quality of synthesized materials and diagnosis of failure and/or reliability of fabricated components. Neutron scattering has played an important role in studying structure and dynamics of condensed matter. Neutron scattering is a non-destructive technique and is useful for testing large samples. The

Influence of the residual stresses on crack initiation in brittle materials and structures; Prise en compte des contraintes residuelles dans un critere d'amorcage en rupture fragile

Energy Technology Data Exchange (ETDEWEB)

Henninger, C

2007-11-15

Many material assemblies subjected to thermo-mechanical loadings develop thermal residual stresses which modify crack onset conditions. Besides if one of the components has a plastic behaviour, plastic residual deformations may also have a contribution. One of the issues in brittle fracture mechanics is to predict crack onset without any pre-existing defect. Leguillon proposed an onset criterion based on both a Griffth-like energetic condition and a maximum stress criterion. The analysis uses matched asymptotics and the theory of singularity. The good fit between the model and experimental measurements led on homogeneous isotropic materials under pure mechanical loading incited us to take into account residual stresses in the criterion. The comparison between the modified criterion and the experimental measurements carried out on an aluminum/epoxy assembly proves to be satisfying concerning the prediction of failure of the interface between the two components. Besides, it allows, through inversion, identifying the fracture properties of this interface. The modified criterion is also applied to the delamination of the tile/structure interface in the plasma facing components of the Tore Supra tokamak. Indeed thermal and plastic residual stresses appear in the metallic part of these coating tiles. (author)

Independency of Elasticity on Residual Stress of Room Temperature Rolled Stainless Steel 304 Plates for Structure Materials

Directory of Open Access Journals (Sweden)

Parikin Parikin

2015-12-01

Full Text Available Mechanical strengths of materials are widely expected in general constructions of any building. These properties depend on its formation (cold/hot forming during fabrication. This research was carried out on cold-rolled stainless steel (SS 304 plates, which were deformed to 0, 34, 84, and 152% reduction in thickness. The tests were conducted using Vickers method. Ultra micro indentation system (UMIS 2000 was used to determine the mechanical properties of the material, i.e.: hardness, modulus elasticity, and residual stresses. The microstructures showed lengthening outcropping due to stress corrosion cracking for all specimens. It was found that the tensile residual stress in a specimen was maximum, reaching 442 MPa, for a sample reducing 34% in thickness and minimum; and about 10 MPa for a 196% sample. The quantities showed that the biggest residual stress caused lowering of the proportional limit of material in stress-strain curves. The proportional modulus elasticity varied between 187 GPa and of about 215 GPa and was free from residual stresses.

Measurement of residual stresses in deposited films of SOFC component materials

Energy Technology Data Exchange (ETDEWEB)

Kato, T.; Momma, A.; Nagata, S.; Kasuga, Y. [Electrotechnical Lab., Ibaraki (Japan)

1996-12-31

The stress induced in Solid oxide fuel cells (SOFC)s has important influence on the lifetime of SOFC. But the data on stress in SOFC and mechanical properties of SOW component materials have not been accumulated enough to manufacture SOFC. Especially, the data of La{sub 1-x}Sr{sub x}MnO{sub 3} cathode and La{sub 1-x}Sr{sub x}CrO{sub 3} interconnection have been extremely limited. We have estimated numerically the dependences of residual stress in SOFC on the material properties, the cell structure and the fabrication temperatures of the components, but these unknown factors have caused obstruction to simulate the accurate behavior of residual stress. Therefore, the residual stresses in deposited La{sub 1-x}Sr{sub x}MnO{sub 3} and La{sub 1-x}Sr{sub x}CrO{sub 3} films are researched by the observation of the bending behavior of the substrate strips. The films of SOFC component materials were prepared by the RF sputtering method, because: (1) It can fabricate dense films of poor sinterable material such as La{sub 1-x}Sr{sub x}CrO{sub 3} compared with sintering or plasma spray method. (2) For the complicated material such as perovskite materials, the difference between the composition of a film and that of a target material is generally small. (3) It can fabricate a thick ceramics film by improving of the deposition rate. For example, Al{sub 2}O{sub 3} thick films of 50{mu}m can be fabricated with the deposition rate of approximately 5{mu}m/h industrially. In this paper, the dependence of residual stress on the deposition conditions is defined and mechanical properties of these materials are estimated from the results of the experiments.

Residual stress improving method for reactor structural component and residual stress improving device therefor

Energy Technology Data Exchange (ETDEWEB)

Enomoto, Kunio; Otaka, Masahiro; Kurosawa, Koichi; Saito, Hideyo; Tsujimura, Hiroshi; Tamai, Yasukata; Urashiro, Keiichi; Mochizuki, Masato

1996-09-03

The present invention is applied to a BWR type reactor, in which a high speed jetting flow incorporating cavities is collided against the surface of reactor structural components to form residual compression stresses on the surface layer of the reactor structural components thereby improving the stresses on the surface. Namely, a water jetting means is inserted into the reactor container filled with reactor water. Purified water is pressurized by a pump and introduced to the water jetting means. The purified water jetted from the water jetting means and entraining cavities is abutted against the surface of the reactor structural components. With such procedures, since the purified water is introduced to the water jetting means by the pump, the pump is free from contamination of radioactive materials. As a result, maintenance and inspection for the pump can be facilitated. Further, since the purified water injection flow entraining cavities is abutted against the surface of the reactor structural components being in contact with reactor water, residual compression stresses are exerted on the surface of the reactor structural components. As a result, occurrence of stress corrosion crackings of reactor structural components is suppressed. (I.S.)

Residual stress improving method for reactor structural component and residual stress improving device therefor

International Nuclear Information System (INIS)

Enomoto, Kunio; Otaka, Masahiro; Kurosawa, Koichi; Saito, Hideyo; Tsujimura, Hiroshi; Tamai, Yasukata; Urashiro, Keiichi; Mochizuki, Masato.

1996-01-01

The present invention is applied to a BWR type reactor, in which a high speed jetting flow incorporating cavities is collided against the surface of reactor structural components to form residual compression stresses on the surface layer of the reactor structural components thereby improving the stresses on the surface. Namely, a water jetting means is inserted into the reactor container filled with reactor water. Purified water is pressurized by a pump and introduced to the water jetting means. The purified water jetted from the water jetting means and entraining cavities is abutted against the surface of the reactor structural components. With such procedures, since the purified water is introduced to the water jetting means by the pump, the pump is free from contamination of radioactive materials. As a result, maintenance and inspection for the pump can be facilitated. Further, since the purified water injection flow entraining cavities is abutted against the surface of the reactor structural components being in contact with reactor water, residual compression stresses are exerted on the surface of the reactor structural components. As a result, occurrence of stress corrosion crackings of reactor structural components is suppressed. (I.S.)

Numerical simulation of residual stress in laser based additive manufacturing process

Science.gov (United States)

Kalyan Panda, Bibhu; Sahoo, Seshadev

2018-03-01

Minimizing the residual stress build-up in metal-based additive manufacturing plays a pivotal role in selecting a particular material and technique for making an industrial part. In beam-based additive manufacturing, although a great deal of effort has been made to minimize the residual stresses, it is still elusive how to do so by simply optimizing the processing parameters, such as beam size, beam power, and scan speed. Amid different types of additive manufacturing processes, Direct Metal Laser Sintering (DMLS) process uses a high-power laser to melt and sinter layers of metal powder. The rapid solidification and heat transfer on powder bed endows a high cooling rate which leads to the build-up of residual stresses, that will affect the mechanical properties of the build parts. In the present work, the authors develop a numerical thermo-mechanical model for the measurement of residual stress in the AlSi10Mg build samples by using finite element method. Transient temperature distribution in the powder bed was assessed using the coupled thermal to structural model. Subsequently, the residual stresses were estimated with varying laser power. From the simulation result, it found that the melt pool dimensions increase with increasing the laser power and the magnitude of residual stresses in the built part increases.

Residual Structures in Latent Growth Curve Modeling

Science.gov (United States)

Grimm, Kevin J.; Widaman, Keith F.

2010-01-01

Several alternatives are available for specifying the residual structure in latent growth curve modeling. Two specifications involve uncorrelated residuals and represent the most commonly used residual structures. The first, building on repeated measures analysis of variance and common specifications in multilevel models, forces residual variances…

The influence of punching process on residual stress and magnetic domain structure of non-oriented silicon steel

International Nuclear Information System (INIS)

Cao, Hongzhi; Hao, Linpo; Yi, Jingwen; Zhang, Xianglin; Luo, Zhonghan; Chen, Shenglin; Li, Rongfeng

2016-01-01

The main purpose of this paper is to investigate the influence of punching process on residual stress and magnetic domain structure. The residual stress in non-oriented silicon steel after punching process was measured by nanoindentation. The maximum depth was kept constant as 300 nm during nanoindentation. The material around indentation region exhibited no significant pile-up deformation. The calculation of residual stress was based on the Suresh theoretical model. Our experimental results show that residual compressive stress was generated around the sheared edge after punching. The width of residual stress affected zone by punching was around 0.4–0.5 mm. After annealing treatment, the residual stress was significantly decreased. Magnetic domain structure was observed according to the Bitter method. The un-annealed sample exhibited complicated domain patterns, and the widths of the magnetic domains varied between 3 µm and 8 µm. Most of the domain patterns of the annealed sample were 180°-domains and 90°-domains, and the widths of the domains decreased to 1–3 µm. - Highlights: • The residual stress distribution on sheared edge was measured. • The residual compressive stress was generated around the sheared edge. • The width of residual stress affected zone was about 0.4–0.5 mm. • The shape and width of the domain structure would be changed by annealing.

[Sulfur dioxide limit standard and residues in Chinese medicinal materials].

Science.gov (United States)

Kang, Chuan-Zhi; Yang, Wan-Zhen; Mo, Ge; Zhou, Li; Jiang, Jing-Yi; Lv, Chao-Geng; Wang, Sheng; Zhou, Tao; Yang, Ye; Guo, Lan-Ping

2018-01-01

The traditional sulfur fumigation processing method has been widely used in the initial processing and storage of traditional Chinese medicinal materials due to its economy, efficiency, convenience, high operability and effect on mold and insect prevention. However, excessive sulfur fumigation of traditional Chinese medicinal materials would lead to the changes in chemical compositions, and even endanger human health. This study showed that traditional Chinese medicinal materials were sulfur fumigated directly after being harvested for quick drying, or fumigated after being weted in the storage process for preventing mold and insects. We found that the sulfur dioxide limits for traditional Chinese medicinal materials were stricter than those for foods. Based on the existing limit standards, we obtained the data of sulfur dioxide residues for 35 types of traditional Chinese medicinal materials in a total of 862 batches. According to the limit standard in the Chinese Pharmacopoeia (150， 400 mg·kg⁻¹), the average over-standard rate of sulfur dioxide was as high as 52.43%, but it was reduced to 29.47% if calculated based on the limit for vegetable additive standard (500 mg·kg⁻¹). Sulfur fumigation issue shall be considered correctly: sulfur dioxide is a type of low toxic substance and less dangerous than aflatoxin and other highly toxic substances, and a small amount of residue would not increase the toxicity of traditional Chinese medicinal materials. However, sulfur fumigation might change the content of chemical substances and affect the quality of traditional Chinese medicinal materials. Furthermore, the exposure hazards of toxic substances are comprehensively correlated with exposure cycle, exposure frequency, and application method. In conclusion, it is suggested to strengthen the studies on the limit standard of traditional Chinese medicinal materials, formulate practical and feasible limit standard for sulfur dioxide residues in traditional Chinese

The effect of filler metal thickness on residual stress and creep for stainless-steel plate-fin structure

Energy Technology Data Exchange (ETDEWEB)

Jiang Wenchun [School of Mechanical and Power Engineering, Nanjing University of Technology, Nanjing 210009 (China)], E-mail: jiangwenchun@126.com; Gong Jianming; Chen Hu; Tu, S.T. [School of Mechanical and Power Engineering, Nanjing University of Technology, Nanjing 210009 (China)

2008-08-15

Stainless-steel plate-fin heat exchanger (PFHE) has been used as a high-temperature recuperator in microturbine for its excellent qualities in compact structure, high-temperature and pressure resistance. Plate-fin structure, as the core of PFHE, is fabricated by vacuum brazing. The main component fins and the parting sheets are joined by fusion of a brazing alloy cladded to the surface of parting sheets. Owing to the material mismatching between the filler metal and the base metal, residual stresses can arise and decrease the structure strength greatly. The recuperator serves at high temperature and the creep would happen. The thickness of the filler metal plays an important role in the joint strength. Hence this paper presented a finite element (FE) analysis of the brazed residual stresses and creep for a counterflow stainless-steel plate-fin structure. The effect of the filler metal thickness on residual stress and creep was investigated, which provides a reference for strength design.

Modeling the Residual Stresses in Reactive Resins-Based Materials: a Case Study of Photo-Sensitive Composites for Dental Applications

International Nuclear Information System (INIS)

Grassia, Luigi; D'Amore, Alberto

2010-01-01

Residual stresses in reactive resins-based composites are associated to the net volumetric contraction (shrinkage) arising during the cross-linking reactions. Depending on the restoration geometry (the ratio of the free surface area to the volume of the cavity) the frozen-in stresses can be as high as the strength of the dental composites. This is the main reason why the effectiveness and then the durability of restorations with composites remains quite lower than those realized with metal alloys based materials. In this paper we first explore the possibility to circumvent the mathematical complexity arising from the determination of residual stresses in reactive systems three-dimensionally constrained. Then, the results of our modeling approach are applied to a series of commercially available composites showing that almost all samples develop residual stresses such that the restoration undergoes failure as soon as it is realized.

Recovering recyclable materials from shredder residue

Science.gov (United States)

Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.; Brockmeier, Norman F.

1994-02-01

Each year, about 11 million tons of metals are recovered in the United States from about 10 million discarded automobiles. The recovered metals account for about 75 percent of the total weight of the discarded vehicles. The balance of the material, known as shredder residue, amounts to about three million tons annually and is currently landfilled. The residue contains a diversity of potentially recyclable materials, including polyurethane foams, iron oxides, and certain thermoplastics. This article discusses a process under development at Argonne National Laboratory to separate and recover the recyclable materials from this waste stream. The process consists essentially of two stages. First, a physical separation is used to recover the foams and the metal oxides, followed by a chemical process to extract certain thermoplastics. The status of the technology and the process economics are reviewed here.

RESRAD, Residual Radioactive Material Guideline Implementation

International Nuclear Information System (INIS)

1998-01-01

This code system is designed to calculate site-specific residual radioactive material guidelines, and radiation dose and excess cancer risk to an on-site resident (maximally exposed individual). A guideline is a radionuclide concentration or level of radioactivity that is acceptable if a site is to be used without radiological restrictions. Guidelines are expressed as concentrations of residual radionuclides in soil. Soil is unconsolidated earth material, including rubble and debris that may be present. The guidelines are based on the following principles: (1) the total effective dose equivalent should not exceed 100 mrem/yr for all plausible land uses and 30 mrem/yr for current and likely future land uses and (2) doses should be kept as low as reasonably achievable (ALARA). Nine environmental pathways are considered: direct exposure, inhalation of dust and radon, and ingestion of plant foods, meat, milk, aquatic foods, soil, and water. CCC-0552/04: A - Description of program or function: RESRAD-BUILD Version 2.36 is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material. The radioactive material in the building structure can be released into the indoor air by mechanisms such as diffusion (radon gas), mechanical removal (decontamination activities), or erosion (removable surface contamination). In the June 1998 update, RESRAD was updated to Version 5.82 and RESRAD-BUILD was updated to version 2.36. The following notes highlight new features: RESRAD5.82 (4/30/98): - Allow plot data to be exported to tab-delimited text file - Corrected Installation problem to Windows 3.1 - Corrected plotting problem for soil guidelines RESRAD-BUILD2.36 (4/9/98): - Corrected problem with simultaneously changing number of wall regions and their parameters - Added OK button to uncertainty window - Made sure first uncertainty variable in added on first try See the

Properties of Residue from Olive Oil Extraction as a Raw Material for Sustainable Construction Materials. Part I: Physical Properties

Directory of Open Access Journals (Sweden)

Almudena Díaz-García

2017-01-01

Full Text Available Action on climate, the environment, and the efficient use of raw materials and resources are important challenges facing our society. Against this backdrop, the construction industry must adapt to new trends and environmentally sustainable construction systems, thus requiring lines of research aimed at keeping energy consumption in new buildings as low as possible. One of the main goals of this research is to efficiently contribute to reducing the amount of residue from olive oil extraction using a two-phase method. This can be achieved by producing alternative structural materials to be used in the construction industry by means of a circular economy. The technical feasibility of adding said residue to ceramic paste was proven by analyzing the changes produced in the physical properties of the paste, which were then compared to the properties of the reference materials manufactured with clay without residue. Results obtained show that the heating value of wet pomace can contribute to the thermal needs of the sintering process, contributing 30% of energy in pieces containing 3% of said material. Likewise, adding larger amounts of wet pomace to the clay body causes a significant decrease in bulk density values.

Properties of Residue from Olive Oil Extraction as a Raw Material for Sustainable Construction Materials. Part I: Physical Properties.

Science.gov (United States)

Díaz-García, Almudena; Martínez-García, Carmen; Cotes-Palomino, Teresa

2017-01-25

Action on climate, the environment, and the efficient use of raw materials and resources are important challenges facing our society. Against this backdrop, the construction industry must adapt to new trends and environmentally sustainable construction systems, thus requiring lines of research aimed at keeping energy consumption in new buildings as low as possible. One of the main goals of this research is to efficiently contribute to reducing the amount of residue from olive oil extraction using a two-phase method. This can be achieved by producing alternative structural materials to be used in the construction industry by means of a circular economy. The technical feasibility of adding said residue to ceramic paste was proven by analyzing the changes produced in the physical properties of the paste, which were then compared to the properties of the reference materials manufactured with clay without residue. Results obtained show that the heating value of wet pomace can contribute to the thermal needs of the sintering process, contributing 30% of energy in pieces containing 3% of said material. Likewise, adding larger amounts of wet pomace to the clay body causes a significant decrease in bulk density values.

Stress-Softening and Residual Strain Effects in Suture Materials

Directory of Open Access Journals (Sweden)

Alex Elías-Zúñiga

2013-01-01

Full Text Available This work focuses on the experimental characterization of suture material samples of MonoPlus, Monosyn, polyglycolic acid, polydioxanone 2–0, polydioxanone 4–0, poly(glycolide-co-epsilon-caprolactone, nylon, and polypropylene when subjected to cyclic loading and unloading conditions. It is found that all tested suture materials exhibit stress-softening and residual strain effects related to the microstructural material damage upon deformation from the natural, undistorted state of the virgin suture material. To predict experimental observations, a new constitutive material model that takes into account stress-softening and residual strain effects is developed. The basis of this model is the inclusion of a phenomenological nonmonotonous softening function that depends on the strain intensity between loading and unloading cycles. The theory is illustrated by modifying the non-Gaussian average-stretch, full-network model to capture stress-softening and residual strains by using pseudoelasticity concepts. It is shown that results obtained from theoretical simulations compare well with suture material experimental data.

On the relationship between residue structural environment and sequence conservation in proteins.

Science.gov (United States)

Liu, Jen-Wei; Lin, Jau-Ji; Cheng, Chih-Wen; Lin, Yu-Feng; Hwang, Jenn-Kang; Huang, Tsun-Tsao

2017-09-01

Residues that are crucial to protein function or structure are usually evolutionarily conserved. To identify the important residues in protein, sequence conservation is estimated, and current methods rely upon the unbiased collection of homologous sequences. Surprisingly, our previous studies have shown that the sequence conservation is closely correlated with the weighted contact number (WCN), a measure of packing density for residue's structural environment, calculated only based on the C α positions of a protein structure. Moreover, studies have shown that sequence conservation is correlated with environment-related structural properties calculated based on different protein substructures, such as a protein's all atoms, backbone atoms, side-chain atoms, or side-chain centroid. To know whether the C α atomic positions are adequate to show the relationship between residue environment and sequence conservation or not, here we compared C α atoms with other substructures in their contributions to the sequence conservation. Our results show that C α positions are substantially equivalent to the other substructures in calculations of various measures of residue environment. As a result, the overlapping contributions between C α atoms and the other substructures are high, yielding similar structure-conservation relationship. Take the WCN as an example, the average overlapping contribution to sequence conservation is 87% between C α and all-atom substructures. These results indicate that only C α atoms of a protein structure could reflect sequence conservation at the residue level. © 2017 Wiley Periodicals, Inc.

Carbonaceous materials in the acid residue from the Orgueil carbonaceous chondrite meteorite

Science.gov (United States)

Garvie, Laurence A. J.; Buseck, Peter R.

2006-04-01

Insoluble organic matter (IOM) dominates the HF/HCl residue of the Orgueil (CI) carbonaceous chondrite meteorite. The IOM is composed primarily of two C-rich particle types. The first has a fluffy texture similar to crumpled tissue paper, and the second type occurs as solid or hollow nanospheres. High-resolution transmission electron microscope (HRTEM) images of the fluffy material show it is poorly ordered, with small, irregularly shaped regions having fringes with 0.34-0.38 nm spacings and locally 0.21 nm cross-fringes. Nanodiamonds occur in the fluffy material. The rounded C-rich particles are common in the residue and their HRTEM images show neither fringes nor nanodiamonds. Both types of carbonaceous materials have a high aromatic component, as revealed by electron energy-loss spectroscopy (EELS), with up to 10 at% substitution by S, N, and O. The average compositions of the fluffy material and nanospheres are C100S1.9N3.7O4.9 and C100S2.4N5.0O3.9, respectively. The structural and chemical heterogeneity of the carbonaceous materials may represent material from multiple sources.

An adjoint method of sensitivity analysis for residual vibrations of structures subject to impacts

Science.gov (United States)

Yan, Kun; Cheng, Gengdong

2018-03-01

For structures subject to impact loads, the residual vibration reduction is more and more important as the machines become faster and lighter. An efficient sensitivity analysis of residual vibration with respect to structural or operational parameters is indispensable for using a gradient based optimization algorithm, which reduces the residual vibration in either active or passive way. In this paper, an integrated quadratic performance index is used as the measure of the residual vibration, since it globally measures the residual vibration response and its calculation can be simplified greatly with Lyapunov equation. Several sensitivity analysis approaches for performance index were developed based on the assumption that the initial excitations of residual vibration were given and independent of structural design. Since the resulting excitations by the impact load often depend on structural design, this paper aims to propose a new efficient sensitivity analysis method for residual vibration of structures subject to impacts to consider the dependence. The new method is developed by combining two existing methods and using adjoint variable approach. Three numerical examples are carried out and demonstrate the accuracy of the proposed method. The numerical results show that the dependence of initial excitations on structural design variables may strongly affects the accuracy of sensitivities.

Minimizing residues and strain in 2D materials transferred from PDMS

Science.gov (United States)

Jain, Achint; Bharadwaj, Palash; Heeg, Sebastian; Parzefall, Markus; Taniguchi, Takashi; Watanabe, Kenji; Novotny, Lukas

2018-06-01

Integrating layered two-dimensional (2D) materials into 3D heterostructures offers opportunities for novel material functionalities and applications in electronics and photonics. In order to build the highest quality heterostructures, it is crucial to preserve the cleanliness and morphology of 2D material surfaces that come in contact with polymers such as PDMS during transfer. Here we report that substantial residues and up to ∼0.22% compressive strain can be present in monolayer MoS2 transferred using PDMS. We show that a UV-ozone pre-cleaning of the PDMS surface before exfoliation significantly reduces organic residues on transferred MoS2 flakes. An additional 200 ◦C vacuum anneal after transfer efficiently removes interfacial bubbles and wrinkles as well as accumulated strain, thereby restoring the surface morphology of transferred flakes to their native state. Our recipe is important for building clean heterostructures of 2D materials and increasing the reproducibility and reliability of devices based on them.

Residual-strength determination in polymetric materials

Energy Technology Data Exchange (ETDEWEB)

Christensen, R.M.

1981-10-01

Kinetic theory of crack growth is used to predict the residual strength of polymetric materials acted upon by a previous history. Specifically, the kinetic theory is used to characterize the state of growing damage that occurs under a constant-stress (load) state. The load is removed before failure under creep-rupture conditions, and the residual instantaneous strength is determined from the theory by taking account of the damage accumulation under the preceding constant-load history. The rate of change of residual strength is found to be strongest when the duration of the preceding load history is near the ultimate lifetime under that condition. Physical explanations for this effect are given, as are numerical examples. Also, the theoretical prediction is compared with experimental data.

Residual-strength determination in polymetric materials

International Nuclear Information System (INIS)

Christensen, R.M.

1981-01-01

Kinetic theory of crack growth is used to predict the residual strength of polymetric materials acted upon by a previous history. Specifically, the kinetic theory is used to characterize the state of growing damage that occurs under a constant-stress (load) state. The load is removed before failure under creep-rupture conditions, and the residual instantaneous strength is determined from the theory by taking account of the damage accumulation under the preceding constant-load history. The rate of change of residual strength is found to be strongest when the duration of the preceding load history is near the ultimate lifetime under that condition. Physical explanations for this effect are given, as are numerical examples. Also, the theoretical prediction is compared with experimental data

A tool for calculating binding-site residues on proteins from PDB structures

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Hu Jing

2009-08-01

Full Text Available Abstract Background In the research on protein functional sites, researchers often need to identify binding-site residues on a protein. A commonly used strategy is to find a complex structure from the Protein Data Bank (PDB that consists of the protein of interest and its interacting partner(s and calculate binding-site residues based on the complex structure. However, since a protein may participate in multiple interactions, the binding-site residues calculated based on one complex structure usually do not reveal all binding sites on a protein. Thus, this requires researchers to find all PDB complexes that contain the protein of interest and combine the binding-site information gleaned from them. This process is very time-consuming. Especially, combing binding-site information obtained from different PDB structures requires tedious work to align protein sequences. The process becomes overwhelmingly difficult when researchers have a large set of proteins to analyze, which is usually the case in practice. Results In this study, we have developed a tool for calculating binding-site residues on proteins, TCBRP http://yanbioinformatics.cs.usu.edu:8080/ppbindingsubmit. For an input protein, TCBRP can quickly find all binding-site residues on the protein by automatically combining the information obtained from all PDB structures that consist of the protein of interest. Additionally, TCBRP presents the binding-site residues in different categories according to the interaction type. TCBRP also allows researchers to set the definition of binding-site residues. Conclusion The developed tool is very useful for the research on protein binding site analysis and prediction.

A pairwise residue contact area-based mean force potential for discrimination of native protein structure

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Pezeshk Hamid

2010-01-01

Full Text Available Abstract Background Considering energy function to detect a correct protein fold from incorrect ones is very important for protein structure prediction and protein folding. Knowledge-based mean force potentials are certainly the most popular type of interaction function for protein threading. They are derived from statistical analyses of interacting groups in experimentally determined protein structures. These potentials are developed at the atom or the amino acid level. Based on orientation dependent contact area, a new type of knowledge-based mean force potential has been developed. Results We developed a new approach to calculate a knowledge-based potential of mean-force, using pairwise residue contact area. To test the performance of our approach, we performed it on several decoy sets to measure its ability to discriminate native structure from decoys. This potential has been able to distinguish native structures from the decoys in the most cases. Further, the calculated Z-scores were quite high for all protein datasets. Conclusions This knowledge-based potential of mean force can be used in protein structure prediction, fold recognition, comparative modelling and molecular recognition. The program is available at http://www.bioinf.cs.ipm.ac.ir/softwares/surfield

Total gamma activity measurements for determining the radioactivity of residual materials from nuclear power stations

International Nuclear Information System (INIS)

Auler, I.; Meyer, M.; Stickelmann, J.

1995-01-01

Large amounts of residual materials from retrofitting measures and from decommissioning of nuclear power stations shows such a weak level of radioactivity that they could be released after decision measurements. Expenses incurred with complex geometry cannot be taken with common methods. NIS developed a Release Measurement Facility (RMF) based on total gamma activity measurements especially for these kind of residual materials. The RMF has been applied for decision measurements in different nuclear power plants. Altogether about 2,000 Mg of various types of materials have been measured up to now. More than 90 % of these materials could be released 0 without any restriction after decision measurements

Review of Repair Materials for Fire-Damaged Reinforced Concrete Structures

Science.gov (United States)

Zahid, MZA Mohd; Abu Bakar, BH; Nazri, FM; Ahmad, MM; Muhamad, K.

2018-03-01

Reinforced concrete (RC) structures perform well during fire and may be repaired after the fire incident because their low heat conductivity prevents the loss or degradation of mechanical strength of the concrete core and internal reinforcing steel. When an RC structure is heated to more than 500 °C, mechanical properties such as compressive strength, stiffness, and tensile strength start to degrade and deformations occur. Although the fire-exposed RC structure shows no visible damage, its residual strength decreases compared with that in the pre-fire state. Upon thorough assessment, the fire-damaged RC structure can be repaired or strengthened, instead of subjecting to partial or total demolition followed by reconstruction. The structure can be repaired using several materials, such as carbon fiber-reinforced polymer, glass fiber-reinforced polymer, normal strength concrete, fiber-reinforced concrete, ferrocement, epoxy resin mortar, and high-performance concrete. Selecting an appropriate repair material that must be compatible with the substrate or base material is a vital step to ensure successful repair. This paper reviews existing repair materials and factors affecting their performance. Of the materials considered, ultra-high-performance fiber-reinforced concrete (UHPFRC) exhibits huge potential for repairing fire-damaged RC structures but lack of information available. Hence, further studies must be performed to assess the potential of UHPFRC in rehabilitating fire-damaged RC structures.

Residual life estimation of cracked aircraft structural components

OpenAIRE

Maksimović, Mirko S.; Vasović, Ivana V.; Maksimović, Katarina S.; Trišović, Nataša; Maksimović, Stevan M.

2018-01-01

The subject of this investigation is focused on developing computation procedure for strength analysis of damaged aircraft structural components with respect to fatigue and fracture mechanics. For that purpose, here will be defined computation procedures for residual life estimation of aircraft structural components such as wing skin and attachment lugs under cyclic loads of constant amplitude and load spectrum. A special aspect of this investigation is based on using of the Strain Energy Den...

Structural and sequence features of two residue turns in beta-hairpins.

Science.gov (United States)

Madan, Bharat; Seo, Sung Yong; Lee, Sun-Gu

2014-09-01

Beta-turns in beta-hairpins have been implicated as important sites in protein folding. In particular, two residue β-turns, the most abundant connecting elements in beta-hairpins, have been a major target for engineering protein stability and folding. In this study, we attempted to investigate and update the structural and sequence properties of two residue turns in beta-hairpins with a large data set. For this, 3977 beta-turns were extracted from 2394 nonhomologous protein chains and analyzed. First, the distribution, dihedral angles and twists of two residue turn types were determined, and compared with previous data. The trend of turn type occurrence and most structural features of the turn types were similar to previous results, but for the first time Type II turns in beta-hairpins were identified. Second, sequence motifs for the turn types were devised based on amino acid positional potentials of two-residue turns, and their distributions were examined. From this study, we could identify code-like sequence motifs for the two residue beta-turn types. Finally, structural and sequence properties of beta-strands in the beta-hairpins were analyzed, which revealed that the beta-strands showed no specific sequence and structural patterns for turn types. The analytical results in this study are expected to be a reference in the engineering or design of beta-hairpin turn structures and sequences. © 2014 Wiley Periodicals, Inc.

Structure and magnetism in novel group IV element-based magnetic materials

Energy Technology Data Exchange (ETDEWEB)

Tsui, Frank [Univ. of North Carolina, Chapel Hill, NC (United States)

2013-08-14

The project is to investigate structure, magnetism and spin dependent states of novel group IV element-based magnetic thin films and heterostructures as a function of composition and epitaxial constraints. The materials systems of interest are Si-compatible epitaxial films and heterostructures of Si/Ge-based magnetic ternary alloys grown by non-equilibrium molecular beam epitaxy (MBE) techniques, specifically doped magnetic semiconductors (DMS) and half-metallic Heusler alloys. Systematic structural, chemical, magnetic, and electrical measurements are carried out, using x-ray microbeam techniques, magnetotunneling spectroscopy and microscopy, and magnetotransport. The work is aimed at elucidating the nature and interplay between structure, chemical order, magnetism, and spin-dependent states in these novel materials, at developing materials and techniques to realize and control fully spin polarized states, and at exploring fundamental processes that stabilize the epitaxial magnetic nanostructures and control the electronic and magnetic states in these complex materials. Combinatorial approach provides the means for the systematic studies, and the complex nature of the work necessitates this approach.

Non-destructive Residual Stress Analysis Around The Weld-Joint of Fuel Cladding Materials of ZrNbMoGe Alloys

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Parikin

2003-08-01

Full Text Available The residual stress measurements around weld-joint of ZrNbMoGe alloy have been carried out by using X-ray diffraction technique in PTBIN-BATAN. The research was performed to investigate the structure of a cladding material with high temperature corrosion resistance and good weldability. The equivalent composition of the specimens (in %wt. was 97.5%Zr1%Nb1%Mo½%Ge. Welding was carried out by using TIG (tungsten inert gas technique that completed butt-joint with a current 20 amperes. Three region tests were taken in specimen while diffraction scanning, While diffraction scanning, tests were performed on three regions, i.e., the weldcore, the heat-affected zone (HAZ and the base metal. The reference region was determined at the base metal to be compared with other regions of the specimen, in obtaining refinement structure parameters. Base metal, HAZ and weldcore were diffracted by X-ray, and lattice strain changes were calculated by using Rietveld analysis program. The results show that while the quantity of minor phases tend to increase in the direction from the base metal to the HAZ and to the weldcore, the quantity of the ZrGe phase in the HAZ is less than the quantity of the ZrMo2 phase due to tGe element evaporation. The residual stress behavior in the material shows that minor phases, i.e., Zr3Ge and ZrMo2, are more dominant than the Zr matrix. The Zr3Ge and ZrMo2 experienced sharp straining, while the Zr phase was weak-lined from HAZ to weldcore. The hydrostatic residual stress ( in around weld-joint of ZrNbMoGe alloy is compressive stress which has minimum value at about -2.73 GPa in weldcore region

Effects of lysine residues on structural characteristics and stability of tau proteins

International Nuclear Information System (INIS)

Lee, Myeongsang; Baek, Inchul; Choi, Hyunsung; Kim, Jae In; Na, Sungsoo

2015-01-01

Pathological amyloid proteins have been implicated in neuro-degenerative diseases, specifically Alzheimer's, Parkinson's, Lewy-body diseases and prion related diseases. In prion related diseases, functional tau proteins can be transformed into pathological agents by environmental factors, including oxidative stress, inflammation, Aβ-mediated toxicity and covalent modification. These pathological agents are stable under physiological conditions and are not easily degraded. This un-degradable characteristic of tau proteins enables their utilization as functional materials to capturing the carbon dioxides. For the proper utilization of amyloid proteins as functional materials efficiently, a basic study regarding their structural characteristic is necessary. Here, we investigated the basic tau protein structure of wild-type (WT) and tau proteins with lysine residues mutation at glutamic residue (Q2K) on tau protein at atomistic scale. We also reported the size effect of both the WT and Q2K structures, which allowed us to identify the stability of those amyloid structures. - Highlights: • Lysine mutation effect alters the structure conformation and characteristic of tau. • Over the 15 layers both WT and Q2K models, both tau proteins undergo fractions. • Lysine mutation causes the increment of non-bonded energy and solvent accessible surface area. • Structural instability of Q2K model was proved by the number of hydrogen bonds analysis.

Effects of lysine residues on structural characteristics and stability of tau proteins

Energy Technology Data Exchange (ETDEWEB)

Lee, Myeongsang; Baek, Inchul; Choi, Hyunsung; Kim, Jae In; Na, Sungsoo, E-mail: nass@korea.ac.kr

2015-10-23

Pathological amyloid proteins have been implicated in neuro-degenerative diseases, specifically Alzheimer's, Parkinson's, Lewy-body diseases and prion related diseases. In prion related diseases, functional tau proteins can be transformed into pathological agents by environmental factors, including oxidative stress, inflammation, Aβ-mediated toxicity and covalent modification. These pathological agents are stable under physiological conditions and are not easily degraded. This un-degradable characteristic of tau proteins enables their utilization as functional materials to capturing the carbon dioxides. For the proper utilization of amyloid proteins as functional materials efficiently, a basic study regarding their structural characteristic is necessary. Here, we investigated the basic tau protein structure of wild-type (WT) and tau proteins with lysine residues mutation at glutamic residue (Q2K) on tau protein at atomistic scale. We also reported the size effect of both the WT and Q2K structures, which allowed us to identify the stability of those amyloid structures. - Highlights: • Lysine mutation effect alters the structure conformation and characteristic of tau. • Over the 15 layers both WT and Q2K models, both tau proteins undergo fractions. • Lysine mutation causes the increment of non-bonded energy and solvent accessible surface area. • Structural instability of Q2K model was proved by the number of hydrogen bonds analysis.

Effects of interface edge configuration on residual stress in the bonded structures for a divertor application

International Nuclear Information System (INIS)

Kitamura, K.; Nagata, K.; Shibui, M.; Tachikawa, N.; Araki, M.

1998-01-01

Residual stresses in the interface region, that developed at the cool down during the brazing, were evaluated for several bonded structures to assess the mechanical strength of the bonded interface, using thermoelasto-plastic stress analysis. Normal stress components of the residual stresses around the interface edge of graphite-copper (C-Cu) bonded structures were compared for three types of bonded features such as flat-type, monoblock-type and saddle-type. The saddle-type structure was found to be favorable for its relatively low residual stress, easy fabrication accuracy on bonded interface and armor replacement. Residual stresses around the interface edge in three armor materials/copper bonded structures for a divertor plate were also examined for the C-Cu, tungsten-copper (W-Cu) and molybdenum alloy-copper (TZM-Cu), varying the interface wedge angle from 45 to 135 . An optimal bonded configuration for the least value of residual stress was found to have a wedge angle of 45 for the C-Cu, and 135 for both the W-Cu and TZM-Cu bonded ones. (orig.)

A manual for implementing residual radioactive material guidelines

International Nuclear Information System (INIS)

Gilbert, T.L.; Yu, C.; Yuan, Y.C.; Zielen, A.J.; Jusko, M.J.; Wallo, A. III; Argonne National Lab., IL; Dames and Moore, West Valley, NY; Argonne National Lab., IL; USDOE Assistant Secretary for Nuclear Energy, Washington, DC

1989-06-01

This manual presents information for implementing US Department of Energy (DOE) guidelines for residual radioactive material at sites identified by the Formerly Utilized Sites Remedial Action Program (FUSRAP) and the Surplus Facilities Management Program (SFMP). It describes the analysis and models used to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil and the design and use of the RESRAD computer code for calculating guideline values. It also describes procedures for implementing DOE policy for reducing residual radioactivity to levels that are as low as reasonably achievable. 36 refs., 16 figs, 22 tabs

Free-Suspension Residual Flexibility Testing of Space Station Pathfinder: Comparison to Fixed-Base Results

Science.gov (United States)

Tinker, Michael L.

1998-01-01

Application of the free-suspension residual flexibility modal test method to the International Space Station Pathfinder structure is described. The Pathfinder, a large structure of the general size and weight of Space Station module elements, was also tested in a large fixed-base fixture to simulate Shuttle Orbiter payload constraints. After correlation of the Pathfinder finite element model to residual flexibility test data, the model was coupled to a fixture model, and constrained modes and frequencies were compared to fixed-base test. modes. The residual flexibility model compared very favorably to results of the fixed-base test. This is the first known direct comparison of free-suspension residual flexibility and fixed-base test results for a large structure. The model correlation approach used by the author for residual flexibility data is presented. Frequency response functions (FRF) for the regions of the structure that interface with the environment (a test fixture or another structure) are shown to be the primary tools for model correlation that distinguish or characterize the residual flexibility approach. A number of critical issues related to use of the structure interface FRF for correlating the model are then identified and discussed, including (1) the requirement of prominent stiffness lines, (2) overcoming problems with measurement noise which makes the antiresonances or minima in the functions difficult to identify, and (3) the use of interface stiffness and lumped mass perturbations to bring the analytical responses into agreement with test data. It is shown that good comparison of analytical-to-experimental FRF is the key to obtaining good agreement of the residual flexibility values.

Programmable thermal emissivity structures based on bioinspired self-shape materials

Science.gov (United States)

Athanasopoulos, N.; Siakavellas, N. J.

2015-12-01

Programmable thermal emissivity structures based on the bioinspired self-shape anisotropic materials were developed at macro-scale, and further studied theoretically at smaller scale. We study a novel concept, incorporating materials that are capable of transforming their shape via microstructural rearrangements under temperature stimuli, while avoiding the use of exotic shape memory materials or complex micro-mechanisms. Thus, programmed thermal emissivity behaviour of a surface is achievable. The self-shape structure reacts according to the temperature of the surrounding environment or the radiative heat flux. A surface which incorporates self-shape structures can be designed to quickly absorb radiative heat energy at low temperature levels, but is simultaneously capable of passively controlling its maximum temperature in order to prevent overheating. It resembles a “game” of colours, where two or more materials coexist with different values of thermal emissivity/ absorptivity/ reflectivity. The transformation of the structure conceals or reveals one of the materials, creating a surface with programmable - and therefore, variable- effective thermal emissivity. Variable thermal emissivity surfaces may be developed with a total hemispherical emissivity ratio (ɛEff_H/ɛEff_L) equal to 28.

RANDOM FUNCTIONS AND INTERVAL METHOD FOR PREDICTING THE RESIDUAL RESOURCE OF BUILDING STRUCTURES

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Shmelev Gennadiy Dmitrievich

2017-11-01

Full Text Available Subject: possibility of using random functions and interval prediction method for estimating the residual life of building structures in the currently used buildings. Research objectives: coordination of ranges of values to develop predictions and random functions that characterize the processes being predicted. Materials and methods: when performing this research, the method of random functions and the method of interval prediction were used. Results: in the course of this work, the basic properties of random functions, including the properties of families of random functions, are studied. The coordination of time-varying impacts and loads on building structures is considered from the viewpoint of their influence on structures and representation of the structures’ behavior in the form of random functions. Several models of random functions are proposed for predicting individual parameters of structures. For each of the proposed models, its scope of application is defined. The article notes that the considered approach of forecasting has been used many times at various sites. In addition, the available results allowed the authors to develop a methodology for assessing the technical condition and residual life of building structures for the currently used facilities. Conclusions: we studied the possibility of using random functions and processes for the purposes of forecasting the residual service lives of structures in buildings and engineering constructions. We considered the possibility of using an interval forecasting approach to estimate changes in defining parameters of building structures and their technical condition. A comprehensive technique for forecasting the residual life of building structures using the interval approach is proposed.

HemeBIND: a novel method for heme binding residue prediction by combining structural and sequence information

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Hu Jianjun

2011-05-01

Full Text Available Abstract Background Accurate prediction of binding residues involved in the interactions between proteins and small ligands is one of the major challenges in structural bioinformatics. Heme is an essential and commonly used ligand that plays critical roles in electron transfer, catalysis, signal transduction and gene expression. Although much effort has been devoted to the development of various generic algorithms for ligand binding site prediction over the last decade, no algorithm has been specifically designed to complement experimental techniques for identification of heme binding residues. Consequently, an urgent need is to develop a computational method for recognizing these important residues. Results Here we introduced an efficient algorithm HemeBIND for predicting heme binding residues by integrating structural and sequence information. We systematically investigated the characteristics of binding interfaces based on a non-redundant dataset of heme-protein complexes. It was found that several sequence and structural attributes such as evolutionary conservation, solvent accessibility, depth and protrusion clearly illustrate the differences between heme binding and non-binding residues. These features can then be separately used or combined to build the structure-based classifiers using support vector machine (SVM. The results showed that the information contained in these features is largely complementary and their combination achieved the best performance. To further improve the performance, an attempt has been made to develop a post-processing procedure to reduce the number of false positives. In addition, we built a sequence-based classifier based on SVM and sequence profile as an alternative when only sequence information can be used. Finally, we employed a voting method to combine the outputs of structure-based and sequence-based classifiers, which demonstrated remarkably better performance than the individual classifier alone

Specific features of the determination of residual stresses in materials by diffraction techniques

Science.gov (United States)

Gorkunov, E. S.; Zadvorkin, S. M.; Goruleva, L. S.

2017-12-01

Residual stresses arising in separate machine parts and structural components during production and use to a large extent govern their lifetime. In this connection, the development and improvement of nondestructive methods for the determination of residual stresses is an important task for nondestructive testing. Standards regulate only the determination of macroscopic stresses, and in practice these stresses are most often determined with the application of the sin2ψ method. This paper, using quenched structural steels as an example, compares the results of residual stress determination by the sin2ψ method with those obtained by the method based on the analysis of the diffraction line profile as dependent on the value of the irradiated volume. It is demonstrated that, as the irradiated volume decreases, the value of residual stresses determined by the sin2ψ method may vary considerably, up to the change of the sign. For a more complete characteristic of residual stresses it is proposed to use, besides the determination of macrostresses by the shift of the diffraction lines, the value of microscopic stresses calculated from the line profile analysis.

Prediction of interface residue based on the features of residue interaction network.

Science.gov (United States)

Jiao, Xiong; Ranganathan, Shoba

2017-11-07

Protein-protein interaction plays a crucial role in the cellular biological processes. Interface prediction can improve our understanding of the molecular mechanisms of the related processes and functions. In this work, we propose a classification method to recognize the interface residue based on the features of a weighted residue interaction network. The random forest algorithm is used for the prediction and 16 network parameters and the B-factor are acting as the element of the input feature vector. Compared with other similar work, the method is feasible and effective. The relative importance of these features also be analyzed to identify the key feature for the prediction. Some biological meaning of the important feature is explained. The results of this work can be used for the related work about the structure-function relationship analysis via a residue interaction network model. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ball milled bauxite residue as a reinforcing filler in phosphate-based intumescent system

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Adiat Ibironke Arogundade

2018-01-01

Full Text Available Bauxite residue (BR is an alumina refinery waste with a global disposal problem. Of the 120 MT generated annually, only 3 MT is disposed via utilization. One of the significant challenges to sustainable utilization has been found to be the cost of processing. In this work, using ball milling, we achieved material modification of bauxite residue. Spectrometric imaging with FESEM showed the transformation from an aggregate structure to nano, platy particulates, leading to particle size homogeneity. BET analysis showed surface area was increased by 23%, while pH was reduced from 10.8 to 9.1 due to collapsing of the hydroxyl surface by the fracturing action of the ball mill. Incorporation of this into a phosphate-based fire retardant, intumescent formulation led to improved material dispersion and the formation of reinforcing heat shielding char nodules. XRD revealed the formation of ceramic metal phosphates which acted as an additional heat sink to the intumescent system, thereby reducing char oxidation and heat transfer to the substrate. Steel substrate temperature from a Bunsen burner test reduced by 33%. Therefore, ball milling can serve as a simple, low-cost processing route for the reuse of bauxite residue in intumescent composites.

Residual thermal stresses in a solid sphere cast from a thermosetting material

Science.gov (United States)

Levitsky, M.; Shaffer, B. W.

1975-01-01

Expressions are developed for the residual thermal stresses in a solid sphere cast from a chemically hardening thermosetting material in a rigid spherical mold. The description of the heat generation rate and temperature variation is derived from a first-order chemical reaction. Solidification is described by the continuous transformation of the material from an inviscid liquidlike state into an elastic solid, with intermediate properties determined by the degree of chemical reaction. Residual stress components are obtained as functions of the parameters of the hardening process and the properties of the hardening material. Variation of the residual stresses with a nondimensionalized reaction rate parameter and the relative compressibility of the hardened material is discussed in detail.

Annotating Protein Functional Residues by Coupling High-Throughput Fitness Profile and Homologous-Structure Analysis.

Science.gov (United States)

Du, Yushen; Wu, Nicholas C; Jiang, Lin; Zhang, Tianhao; Gong, Danyang; Shu, Sara; Wu, Ting-Ting; Sun, Ren

2016-11-01

Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp), we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 β-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available. To fully comprehend the diverse functions of a protein, it is essential to understand the functionality of individual residues. Current methods are highly dependent on evolutionary sequence conservation, which is

Prediction of residues in discontinuous B-cell epitopes using protein 3D structures

DEFF Research Database (Denmark)

Andersen, P.H.; Nielsen, Morten; Lund, Ole

2006-01-01

. We show that the new structure-based method has a better performance for predicting residues of discontinuous epitopes than methods based solely on sequence information, and that it can successfully predict epitope residues that have been identified by different techniques. DiscoTope detects 15...... experimental epitope mapping in both rational vaccine design and development of diagnostic tools, and may lead to more efficient epitope identification....

Residual stress improvement mechanism on metal material by underwater laser irradiation

International Nuclear Information System (INIS)

Sano, Yuji; Yoda, Masaki; Mukai, Naruhiko; Obata, Minoru; Kanno, Masanori

2000-01-01

Residual stress improvement technology for component surface by underwater pulsed laser irradiation has been developed as a method of preventing stress corrosion cracking (SCC) of core components in nuclear reactors. In order to optimize the laser irradiation conditions based on a complete understanding of the mechanism, the propagation of a shock wave induced by the impulse of laser irradiation and the dynamic response of the irradiated material were analyzed through time-dependent elasto-plastic calculations with a finite element program. The calculated results are compared with the measured results obtained by experiments in which laser pulses with an energy of 200 mJ are focused to a diameter of 0.8 mm on a water-immersed test piece of 20% cold-worked Type 304 austenitic stainless steel to simulate neutron irradiation hardening. A residual compressive stress, which is nearly equivalent to the yield stress of the processed material, remains on the material surface after passage of the shock wave with enough amplitude to induce a permanent strain. Multiple irradiation of laser pulses extends the stress-improved depth to about 1 mm, which would be the limit corresponding to the three-dimensional dispersion effect of the shock wave. (author)

Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

Science.gov (United States)

Nicole M. Stark; Zhiyong Cai; Charles Carll

2010-01-01

This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

Proposed residual stress model for roller bent wide flange sections

NARCIS (Netherlands)

Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.

2011-01-01

The manufacturing process of structural wide flange steel sections introduces residual stresses in the material. These stresses due to hot-rolling or welding influence the inelastic buckling response of structural steel members and need to be taken into account in the design. Based on experimental

Model-checking techniques based on cumulative residuals.

Science.gov (United States)

Lin, D Y; Wei, L J; Ying, Z

2002-03-01

Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided.

Neutron diffraction measurements of residual stresses in NPP construction materials

International Nuclear Information System (INIS)

Hinca, R.; Bokuchava, G.

2001-01-01

Neutron diffraction is one of the most powerful methods for condensed matter studies. This method is used for non-destructive determination of residual stresses in material. The fundamental aspects of neutron diffraction are discussed, together with a brief description of the experimental facility. The principal advantage of using neutrons rather than the more conventional X-rays is the fact that neutron can penetrate deeply (2-4 cm for steel and more than 10 cm for aluminium) into metals to determine internal parameters within the bulk of materials. We present results of measurements residual stresses in NPP construction material - austenitic stainless steel (Cr-18%, Ni-10%, Ti-1%) coated with high-nickel alloy. (authors)

The influence of plate thickness on the welding residual stresses from submerged arc welding in offshore steel structures

DEFF Research Database (Denmark)

Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen

2017-01-01

Welding-induced residual tensile stresses and distortion have become a major concern in relation to the structural integrity of welded structures within the offshore wind industry. The stresses have a negative impact on the integrity of the welded joint, as they promote distortion, reduce fatigue...... leading to a better understanding of the distribution and development of the welding residual stresses. This can later be used to optimize the fatigue design, providing a more efficient and improved design. In this context, the current research is expected to benefit the offshore industry by leading...... to an improved design, which consequently may be included in future norms and standards. Submerged Arc Welding (SAW) was used to make a fully penetrated butt weld in 10 mm and 40 mm thick steel plates with the same welding parameters as used in the production procedures. The base material is thermomechanical hot...

Energy Approach-Based Simulation of Structural Materials High-Cycle Fatigue

Science.gov (United States)

Balayev, A. F.; Korolev, A. V.; Kochetkov, A. V.; Sklyarova, A. I.; Zakharov, O. V.

2016-02-01

The paper describes the mechanism of micro-cracks development in solid structural materials based on the theory of brittle fracture. A probability function of material cracks energy distribution is obtained using a probabilistic approach. The paper states energy conditions for cracks growth at material high-cycle loading. A formula allowing to calculate the amount of energy absorbed during the cracks growth is given. The paper proposes a high- cycle fatigue evaluation criterion allowing to determine the maximum permissible number of solid body loading cycles, at which micro-cracks start growing rapidly up to destruction.

Residues from waste incineration. Final report

Energy Technology Data Exchange (ETDEWEB)

Astrup, T.; Juul Pedersen, A.; Hyks, J.; Frandsen, F.J.

2009-08-15

The overall objective of the project was to improve the understanding of the formation and characteristics of residues from waste incineration. This was done focusing on the importance of the waste input and the operational conditions of the furnace. Data and results obtained from the project have been discussed in this report according to the following three overall parts: i) mass flows and element distribution, ii) flue gas/particle partitioning and corrosion/deposition aspects, and iii) residue leaching. This has been done with the intent of structuring the discussion while tacitly acknowledging that these aspects are interrelated and cannot be separated. Overall, it was found that the waste input composition had significant impact of the characteristics of the generated residues. A similar correlation between operational conditions and residue characteristics could not be observed. Consequently, the project recommend that optimization of residue quality should focus on controlling the waste input composition. The project results showed that including specific waste materials (and thereby also excluding the same materials) may have significant effects on the residue composition, residue leaching, aerosol and deposit formation.It is specifically recommended to minimize Cl in the input waste. Based on the project results, it was found that a significant potential for optimization of waste incineration exist. (author)

Residual stresses analysis of friction stir welding using one-way FSI simulation

International Nuclear Information System (INIS)

Kang, Sung Wook; Jang, Beom Seon; Song, Ha Cheol

2015-01-01

When certain mechanisms, such as plastic deformations and temperature gradients, occur and are released in a structure, stresses remain because of the shape of the structure and external constraints. These stresses are referred to as residual stresses. The base material locally expands during heating in the welding process. When the welding is completed and cooled to room temperature, the residual stresses are left at nearly the yield strength level. In the case of friction stir welding, the maximum temperature is 80% to 90% of the melting point of the materials. Thus, the residual stresses in the welding process are smaller than those in other fusion welding processes; these stresses have not been considered previously. However, friction stir welding residual stresses are sometimes measured at approximately 70% or above. These residual stresses significantly affect fatigue behavior and lifetime. The present study investigates the residual stress distributions in various welding conditions and shapes of friction stir welding. In addition, the asymmetric feature is considered in temperature and residual stress distribution. Heat transfer analysis is conducted using the commercial computational fluid dynamics program Fluent, and results are used in the finite element structural analysis with the ANSYS Multiphysics software. The calculated residual stresses are compared with experimental values using the X-ray diffraction method.

Structure-based network analysis of activation mechanisms in the ErbB family of receptor tyrosine kinases: the regulatory spine residues are global mediators of structural stability and allosteric interactions.

Directory of Open Access Journals (Sweden)

Kevin A James

Full Text Available The ErbB protein tyrosine kinases are among the most important cell signaling families and mutation-induced modulation of their activity is associated with diverse functions in biological networks and human disease. We have combined molecular dynamics simulations of the ErbB kinases with the protein structure network modeling to characterize the reorganization of the residue interaction networks during conformational equilibrium changes in the normal and oncogenic forms. Structural stability and network analyses have identified local communities integrated around high centrality sites that correspond to the regulatory spine residues. This analysis has provided a quantitative insight to the mechanism of mutation-induced "superacceptor" activity in oncogenic EGFR dimers. We have found that kinase activation may be determined by allosteric interactions between modules of structurally stable residues that synchronize the dynamics in the nucleotide binding site and the αC-helix with the collective motions of the integrating αF-helix and the substrate binding site. The results of this study have pointed to a central role of the conserved His-Arg-Asp (HRD motif in the catalytic loop and the Asp-Phe-Gly (DFG motif as key mediators of structural stability and allosteric communications in the ErbB kinases. We have determined that residues that are indispensable for kinase regulation and catalysis often corresponded to the high centrality nodes within the protein structure network and could be distinguished by their unique network signatures. The optimal communication pathways are also controlled by these nodes and may ensure efficient allosteric signaling in the functional kinase state. Structure-based network analysis has quantified subtle effects of ATP binding on conformational dynamics and stability of the EGFR structures. Consistent with the NMR studies, we have found that nucleotide-induced modulation of the residue interaction networks is not

Annotating Protein Functional Residues by Coupling High-Throughput Fitness Profile and Homologous-Structure Analysis

Directory of Open Access Journals (Sweden)

Yushen Du

2016-11-01

Full Text Available Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp, we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 β-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available.

Derivation of residual radioactive material guidelines for the Laboratory for Energy-Related Health Research site

International Nuclear Information System (INIS)

Chapman, T.E.

1993-11-01

Residual radioactive material guidelines were derived for the Laboratory for Energy-Related Health Research (LEHR) Environmental Restoration (ER) site in Davis, California. The guideline derivation was based on a dose limit of 100 mrem/yr. The US Department of Energy (DOE) residual radioactive material guideline computer code was used in this evaluation. This code implements the methodology described in the DOE manual for implementing residual radioactive material guidelines. Three potential site utilization scenarios were considered with the assumption that following ER action, the site will be used without radiological restrictions. The defined scenarios vary with regard to use of the site, time spent at the site, and sources of food consumed. The results of the evaluation indicate that the basic dose limit of 100 mrem/yr will not be exceeded, provided that the soil concentrations of these radionuclides at the LEHR site do not exceed the scenario-specific values calculated by this study. Except for the extent of the contaminated zone (which is very conservative), assumptions used are as site-specific as possible, given available information. The derived guidelines are single- radionuclide guidelines and are linearly proportional to the dose limit used in the calculations. In setting the actual residual soil contamination guides for the LEHR site, DOE will apply the as low as reasonably achievable policy to the decision-making process, along with other factors such as whether a particular scenario is reasonable and appropriate, as well as using site-specific inputs to computer models based on data not yet fully determined

Residual stresses

International Nuclear Information System (INIS)

Sahotra, I.M.

2006-01-01

The principal effect of unloading a material strained into the plastic range is to create a permanent set (plastic deformation), which if restricted somehow, gives rise to a system of self-balancing within the same member or reaction balanced by other members of the structure., known as residual stresses. These stresses stay there as locked-in stresses, in the body or a part of it in the absence of any external loading. Residual stresses are induced during hot-rolling and welding differential cooling, cold-forming and extruding: cold straightening and spot heating, fabrication and forced fitting of components constraining the structure to a particular geometry. The areas which cool more quickly develop residual compressive stresses, while the slower cooling areas develop residual tensile stresses, and a self-balancing or reaction balanced system of residual stresses is formed. The phenomenon of residual stresses is the most challenging in its application in surface modification techniques determining endurance mechanism against fracture and fatigue failures. This paper discusses the mechanism of residual stresses, that how the residual stresses are fanned and what their behavior is under the action of external forces. Such as in the case of a circular bar under limit torque, rectangular beam under limt moment, reclaiming of shafts welds and peening etc. (author)

Utilization of stabilized municipal waste combustion ash residues as construction material

International Nuclear Information System (INIS)

Shieh, C.S.

1992-01-01

Stabilized municipal waste combustion (MWC) ash residues were investigated for their potential as construction material that can be beneficially used in terrestrial and marine environments. End-use products, such as patio stones, brick pavers, solid blocks, and reef units, were fabricated and tested for their engineering and chemical characteristics. engineering feasibility and environmental acceptability of using stabilized ash residues as construction material are discussed in this paper. Ash samples were collected from two mass-burn facilities and one refuse derived fuel (RDF) facility in Florida

The influence of texture on residual stress measurements

International Nuclear Information System (INIS)

Lima, N.B. de.

1991-01-01

A computer program to calculate the orientation distribution function (ODF) from incomplete pole figures has been developed for rolled materials with a cubic structure. This program is based on Bunge's series expansion. The use of incomplete pole figures results in the loss of orthogonality among symmetric spherical harmonic functions and makes it necessary to explicitly evaluate the integrals. The ODF has been used to quantitatively evaluate the influence of texture in determining residual stresses. This has been done by calculating theoretically the strain undergone by each cell as a function of its orientation to residual stress relationship. To test the ODF program, cold rolled Cu and Al specimens were used and to evaluate residual stresses as a function of texture, cold rolled AISI 430 and 324 specimens were used. Simulations have also be presented based on the texture for each of the materials, to verify the nature of the curve d x sin 2 ψ as a function of each stress tensor components. (author)

Degradation of Alkali-Based Photocathodes from Exposure to Residual Gases: A First-Principles Study

International Nuclear Information System (INIS)

Wang, Gaoxue; Batista, Enrique R.

2017-01-01

Photocathodes are a key component in the production of electron beams in systems such as X-ray free-electron lasers and X-ray energy-recovery linacs. Alkali-based materials display high quantum efficiency (QE), however, their QE undergoes degradation faster than metal photocathodes even in the high vacuum conditions where they operate. The high reactivity of alkali-based surfaces points to surface reactions with residual gases as one of the most important factors for the degradation of QE. In order to advance the understanding on the degradation of the QE, we investigated the surface reactivity of common residual gas molecules (e.g., O 2 , CO 2 , CO, H 2 O, N 2 , and H 2 ) on one of the best-known alkali-based photocathode materials, cesium antimonide (Cs 3 Sb), using first-principles calculations based on density functional theory. Furthermore, the reaction sites, adsorption energy, and effect in the local electronic structure upon reaction of these molecules on (001), (110), and (111) surfaces of Cs 3 Sb were computed and analyzed. The adsorption energy of these molecules on Cs3Sb follows the trend of O 2 (-4.5 eV) > CO 2 (-1.9 eV) > H 2 O (-1.0 eV) > CO (-0.8 eV) > N 2 (-0.3 eV) ≈ H 2 (-0.2 eV), which agrees with experimental data on the effect of these gases on the degradation of QE. The interaction strength is determined by the charge transfer from the surfaces to the molecules. The adsorption and dissociation of O containing molecules modify the surface chemistry such as the composition, structure, charge distribution, surface dipole, and work function of Cs 3 Sb, resulting in the degradation of QE with exposure to O 2 , CO 2 , H 2 O, and CO.

Experimental and theoretical study of the residual nuclide production in 40-2600 MeV proton-irradiated thin targets of ads structure materials

International Nuclear Information System (INIS)

Titarenko, Yu.E.; Batyaev, V.F.; Belonozhenko, A.A.; Borovlev, S.P.; Butko, M.A.; Florya, S.N.; Pavlov, K.V.; Rogov, V.I.; Tikhonov, R.S.; Titarenko, A.Yu.; Zhivun, V.M.

2011-10-01

The Project is aimed at experimental and theoretical studying the independent and cumulative yields of residual radioactive nuclei produced in high-energy proton-irradiated structure materials intended for constructing the high-power Accelerator-Driven Systems (ADS) with a high-current proton accelerator. The Project is an extension of the researches carried out earlier under the ISTC Projects #017, #839, and #2002 which provided more 10000 residual nuclide production cross sections mainly in materials intended to use as target materials of the ADS. This Project includes 57 measurement runs carried out using the 97 targets made only of the ADS structural materials of both monoisotopic ( 56 Fe, 93 Nb, 181 Ta) and natural ( nat Cr, nat Ni, nat W) compositions within minutely fractionated proton energy range, namely, at 0.04, 0.07, 0.1, 0.15, 0.25, 0.4, 0.6, 0.8, 1.2, 1.6 and 2.6GeV. All the targets were irradiated using the ITEP U-10 proton synchrotron. The experimental nuclide yields are determined by the direct γ-spectrometry and α-spectrometry methods. As a result, 3839 cumulative and independent yields of residual β-radioactive product nuclei with lifetimes range from 6 minutes to 10 years as well as 12 cumulative yields of α- radioactive 148 Gd whose lifetime is 74.6 years have been measured. Besides, the cross sections for the 27 Al(p,x) 22 Na , 27 Al(p,x) 24 Na and 27 Al(p,x) 7 Be monitor reactions have been measured at the same proton energies with the use of the current transformer technique. The γ-spectrometer resolution is 1.8 keV in the 1332 keV 60 Co γ-line. The experimental γ-spectra were processed by the GENIE2000 code. The γ-lines were identified, and the cross sections calculated, by the ITEP-developed SIGMA code using the PCNUDAT database. The proton fluence was monitored by the 27 Al(p,x) 22 Na reaction. Measurement data have been compared with the calculation results of the BERTINI and ISABEL models of MCNPX code, CEM03.02, INCL 4.2, INCL4

POLYMER RESIDUE BASED HYDROPHOBIC-FUNGICIDAL ADDITIVE AND PLASTER DRY MIX BASED ON IT

Directory of Open Access Journals (Sweden)

Chikichev Artur Andreevich

2017-07-01

Full Text Available Subject of study is the effect of additives on the structure formation of cement. Improvement of the re-sistance to aggressive media of materials for wet rooms. Objective is to develop a scientifically grounded composition of a plaster dry construction mix with increased water resistance and funginertness, with the use of locally available materials and man-made waste.The study was carried out by standard methods of research using XRF and DTA. The hydrophobic fungicidal additive based on the polymer residue of turpentine production and fly ash with the ratio by weight ZU: PO = 1.15: 1 was developed. It has been established that while adding the de-veloped additive in an amount of 2.5 % of the mass of cement, the rate of hydration of cement minerals and resistibility of the sand-cement mortar decrease in early strength with medium workability concrete mix. This creates conditions for the formation of a dense structure with increased resistance to aggressive envi-ronments.Using new hydrophobic fungicidal additive, a dry plaster mortar for wet rooms has been developed. It has increased water resistance values corresponding to the W8 grade and funginertness especially with respect to A. Niger, the pathogen and widespread decomposer.The additive is effective; it is developed on the basis of industrial wastes and recycled materials. Its use in the composition of materials with increased requirements for watertightness and biostability makes it pos-sible to reduce their cost and environmental stress, to increase the efficiency of the use of natural re-sources. The use of the developed plaster mixture will increase the resistance of walls of wet rooms to aggressive environments.

Development and Characterization of Edible Films Based on Fruit and Vegetable Residues.

Science.gov (United States)

Andrade, Roberta M S; Ferreira, Mariana S L; Gonçalves, Édira C B A

2016-02-01

Edible films were developed from the solid residue of the processing of whole fruits and vegetables. The solid residue, processed into flour (FVR flour) was chemically and structurally characterized by microstructure, elemental composition, structural links, and moisture sorption isotherm. Films were prepared by casting using aqueous extracts of 8% and 10% of flour (w/w) and characterized in terms of thickness, water solubility, mechanical properties, water vapor permeability, and Fourier transform infrared (FTIR). The analysis of microstructure and elemental composition, performed on flour (mean particle size 350 μm), showed an essentially granular aspect, with the presence of fibrous particles having potassium as one of the most abundant elements. FTIR results showed similarity between the characteristic bands of other raw materials used in edible films. The sorption isotherm of FVR flour showed a typical profile of foods rich in soluble components, such as sugars. Dried films presented an average thickness of 0.263 ± 0.003 mm, a homogenous aspect, bright yellow color, pronounced fruit flavor, and high water solubility. The FTIR spectra of the edible films revealed that addition of potato skin flour did not change the molecular conformation. Moreover, the films presented low tensile strength at break when compared with fruit starch-based films. © 2016 Institute of Food Technologists®

Analysis and radiological assessment of residues containing NORM materials resulting from earlier activities including modelling of typical industrial residues. Pt. 1. Historical investigation of the radiological relevance of NORM residues and concepts for site identification

International Nuclear Information System (INIS)

Reichelt, Andreas; Niedermayer, Matthias; Sitte, Beate; Hamel, Peter Michael

2007-01-01

Natural radionuclides are part of the human environment and of the raw materials used. Technical processes may cause their accumulation in residues, and the result will be so-called NORM materials (Naturally occurring radioactive material). The amended Radiation Protection Ordinance (StrlSchV 2001) specifies how the public should be protected, but there are also residues dating back before the issuing of the StrlSchV 2001, the so-called NORM residues. The project intended to assess the risks resulting from these residues. It comprises four parts. Part 1 was for clarification of the radiological relevance of NORM residues and for the development of concepts to detect them. The criterion for their radiological relevance was their activity per mass unit and the material volume accumulated through the centuries. The former was calculated from a wide bibliographic search in the relevant literature on radiation protection, while the mass volume was obtained by a detailed historical search of the consumption of materials that may leave NORM residues. These are, in particular, residues from coal and ore mining and processing. To identify concrete sites, relevant data sources were identified, and a concept for identification of concrete NORM residues was developed on this basis. (orig.) [de

Investigating Resulting Residual Stresses during Mechanical Forming Process

Science.gov (United States)

Akinlabi, Stephen A.; Fatoba, Olawale S.; Mashinini, Peter M.; Akinlabi, Esther T.

2018-03-01

Most manufacturing processes such as machining, welding, heat treatment, laser forming, laser cladding and, laser metal deposition, etc. are subjected to a form of heat or energy to change the geometrical shape thus changing the inherent engineering and structural properties of the material. These changes often cause the development of locked up stresses referred to as residual stresses as a result of these activities. This study reports on the residual stresses developed due to the mechanical forming process to maintain a suitable structural integrity for the formed components. The result of the analysis through the X-ray diffraction confirmed that residual stresses were induced in the manufactured parts and further revealed that residual stresses were compressive in nature as found in the parent material but with values less than the parent material.

A protein relational database and protein family knowledge bases to facilitate structure-based design analyses.

Science.gov (United States)

Mobilio, Dominick; Walker, Gary; Brooijmans, Natasja; Nilakantan, Ramaswamy; Denny, R Aldrin; Dejoannis, Jason; Feyfant, Eric; Kowticwar, Rupesh K; Mankala, Jyoti; Palli, Satish; Punyamantula, Sairam; Tatipally, Maneesh; John, Reji K; Humblet, Christine

2010-08-01

The Protein Data Bank is the most comprehensive source of experimental macromolecular structures. It can, however, be difficult at times to locate relevant structures with the Protein Data Bank search interface. This is particularly true when searching for complexes containing specific interactions between protein and ligand atoms. Moreover, searching within a family of proteins can be tedious. For example, one cannot search for some conserved residue as residue numbers vary across structures. We describe herein three databases, Protein Relational Database, Kinase Knowledge Base, and Matrix Metalloproteinase Knowledge Base, containing protein structures from the Protein Data Bank. In Protein Relational Database, atom-atom distances between protein and ligand have been precalculated allowing for millisecond retrieval based on atom identity and distance constraints. Ring centroids, centroid-centroid and centroid-atom distances and angles have also been included permitting queries for pi-stacking interactions and other structural motifs involving rings. Other geometric features can be searched through the inclusion of residue pair and triplet distances. In Kinase Knowledge Base and Matrix Metalloproteinase Knowledge Base, the catalytic domains have been aligned into common residue numbering schemes. Thus, by searching across Protein Relational Database and Kinase Knowledge Base, one can easily retrieve structures wherein, for example, a ligand of interest is making contact with the gatekeeper residue.

Development of the Structural Materials Information Center

International Nuclear Information System (INIS)

Oland, C.B.; Naus, D.J.

1990-01-01

The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where data and information on the time variation of concrete and other structural material properties under the influence of pertinent environmental stressors and aging factors are being collected and assembled into a data base. This data base will be used to assist in the prediction of potential long-term deterioration of critical structural components in nuclear power plants and to establish limits on hostile environmental exposure for these structures and materials. Two complementary data base formats have been developed. The Structural Materials Handbook is an expandable, hard-copy reference document that contains complete sets of data and information for selected portland cement concrete, metallic reinforcement, prestressing tendon, and structural steel materials. Baseline data, reference properties and environmental information are presented in the handbook as tables, notes and graphs. The handbook, which will be published in four volumes, serves as the information source for the electronic data base. The Structural Materials Electronic Data Base is accessible by an IBM-compatible personal computer and provides an efficient means for searching the various data base files to locate materials with similar properties. Properties will be reported in the International System of Units (SI) and in customary units whenever possible. 7 refs., 3 figs., 4 tabs

Terahertz non-destructive imaging of cracks and cracking in structures of cement-based materials

Directory of Open Access Journals (Sweden)

Shujie Fan

2017-11-01

Full Text Available Cracks and crack propagation in cement-based materials are key factors leading to failure of structures, affecting safety in construction engineering. This work investigated the application of terahertz (THz non-destructive imaging to inspections on structures of cement-based materials, so as to explore the potential of THz imaging in crack detection. Two kinds of disk specimens made of plain cement mortar and UHMWPE fiber concrete were prepared respectively. A mechanical expansion load device was deployed to generate cracks and control the whole process of cracking. Experimental tests were carried out on cracked specimens by using a commercial THz time domain spectroscopy (THz-TDS during loading. The results show that crack opening and propagation could be examined by THz clearly and the material factors influence the ability of crack resistance significantly. It was found that the THz imaging of crack initiation and propagation agrees with the practical phenomenon and supplies more information about damage of samples. It is demonstrated that the damage behavior of structures of cement-based materials can be successfully detected by THz imaging.

Terahertz non-destructive imaging of cracks and cracking in structures of cement-based materials

Science.gov (United States)

Fan, Shujie; Li, Tongchun; Zhou, Jun; Liu, Xiaoqing; Liu, Xiaoming; Qi, Huijun; Mu, Zhiyong

2017-11-01

Cracks and crack propagation in cement-based materials are key factors leading to failure of structures, affecting safety in construction engineering. This work investigated the application of terahertz (THz) non-destructive imaging to inspections on structures of cement-based materials, so as to explore the potential of THz imaging in crack detection. Two kinds of disk specimens made of plain cement mortar and UHMWPE fiber concrete were prepared respectively. A mechanical expansion load device was deployed to generate cracks and control the whole process of cracking. Experimental tests were carried out on cracked specimens by using a commercial THz time domain spectroscopy (THz-TDS) during loading. The results show that crack opening and propagation could be examined by THz clearly and the material factors influence the ability of crack resistance significantly. It was found that the THz imaging of crack initiation and propagation agrees with the practical phenomenon and supplies more information about damage of samples. It is demonstrated that the damage behavior of structures of cement-based materials can be successfully detected by THz imaging.

Lifetime and residual strength of materials

DEFF Research Database (Denmark)

Nielsen, Lauge Fuglsang

1997-01-01

of load amplitude, load average, fractional time under maximum load, and load frequency.The analysis includes prediction of residual strength (re-cycle strength) during the process of load cycling. It is concluded that number of cycles to failure is a very poor design criterion. It is demonstrated how...... the theory developed can be generalized also to consider non-harmonic load variations.Algorithms are presented for design purposes which may be suggested as qualified alternatives to the Palmgren-Miner's methods normally used in fatigue analysis of materials under arbitrary load variations. Prediction...

Investigation of Kevlar fabric-based materials for use with inflatable structures

Science.gov (United States)

Niccum, R. J.; Munson, J. B.; Rueter, L. L.

1977-01-01

Design, manufacture and testing of laminated and coated composite materials incorporating a structural matrix of Kevlar are reported. The practicality of using Kevlar in aerostat materials is demonstrated, and data are provided on practical weaves, lamination and coating particulars, rigidity, strength, weight, elastic coefficients, abrasion resistance, crease effects, peel strength, blocking tendencies, helium permeability, and fabrication techniques. Properties of the Kevlar-based materials are compared with conventional Dacron-reinforced counterparts. A comprehensive test and qualification program is discussed, and considerable quantitative biaxial tensile and shear test data are provided.

XRD Investigation of Some Thermal Degraded Starch Based Materials

Directory of Open Access Journals (Sweden)

Mihai Todica

2016-01-01

Full Text Available The thermal degradation of some starch based materials was investigated using XRD method. The samples were obtained by thermal extrusion of mixtures of different proportions of starch, glycerol, and water. Such materials are suitable for the manufacturing of low pollutant packaging. Thermal degradation is one of the simplest ways to destroy such materials and this process is followed by structural modification of the local ordering of samples, water evaporation, crystallization, oxidation, or destruction of the chemical bonds. These modifications need to be studied in order to reduce to the minimum production of pollutant residues by burning process. XRD measurements show modification of the local ordering of the starch molecules depending on the temperature and initial composition of the samples. The molecular ordering perturbation is more pronounced in samples with low content of starch.

Structural transformations in thermal treatment of carbon material based on Slantsy coke

Energy Technology Data Exchange (ETDEWEB)

Tyumentsev, V.A.; Semenov, P.V.; Podkopaev, S.A.; Noneshneva, N.P.; Golovin, A.V. [Chelyabinsk State University, Chelyabinsk (Russian Federation)

2000-07-01

Structural transformations occurring in a carbon material based on high-sulfur Slantsy coke during isothermal treatment (1200-2400{degree}C) under normal pressure in a nitrogen atmosphere were studied.

Efficiency Improvement of Some Agricultural Residue Modified Materials for Textile Dyes Absorption

Science.gov (United States)

Boonsong, P.; Paksamut, J.

2018-03-01

In this work, the adsorption efficiency was investigated of some agricultural residue modified materials as natural bio-adsorbents which were rice straw (Oryza sativa L.) and pineapple leaves (Ananas comosus (L.) Merr.) for the removal of textile dyes. Reactive dyes were used in this research. The improvement procedure of agricultural residue materials properties were alkali-acid modification with sodium hydroxide solution and hydrochloric acid solution. Adsorption performance has been investigated using batch experiments. Investigated adsorption factors consisted of adsorbent dose, contact time, adsorbent materials and pH of solution. The results were found that rice straw had higher adsorption capacity than pineapple leaves. The increasing of adsorption capacity depends on adsorbent dose and contact time. Moreover, the optimum pH for dye adsorption was acidic range because lowering pH increased the positively charges on the adsorbent surface which could be attacked by negatively charge of acid dyes. The agricultural residue modified materials had significant dye removal efficiency which these adsorbents could be used for the treatment of textile effluent in industries.

Photonic Structure-Integrated Two-Dimensional Material Optoelectronics

Directory of Open Access Journals (Sweden)

Tianjiao Wang

2016-12-01

Full Text Available The rapid development and unique properties of two-dimensional (2D materials, such as graphene, phosphorene and transition metal dichalcogenides enable them to become intriguing candidates for future optoelectronic applications. To maximize the potential of 2D material-based optoelectronics, various photonic structures are integrated to form photonic structure/2D material hybrid systems so that the device performance can be manipulated in controllable ways. Here, we first introduce the photocurrent-generation mechanisms of 2D material-based optoelectronics and their performance. We then offer an overview and evaluation of the state-of-the-art of hybrid systems, where 2D material optoelectronics are integrated with photonic structures, especially plasmonic nanostructures, photonic waveguides and crystals. By combining with those photonic structures, the performance of 2D material optoelectronics can be further enhanced, and on the other side, a high-performance modulator can be achieved by electrostatically tuning 2D materials. Finally, 2D material-based photodetector can also become an efficient probe to learn the light-matter interactions of photonic structures. Those hybrid systems combine the advantages of 2D materials and photonic structures, providing further capacity for high-performance optoelectronics.

A residual life prediction model based on the generalized σ -N curved surface

Directory of Open Access Journals (Sweden)

Zongwen AN

2016-06-01

Full Text Available In order to investigate change rule of the residual life of structure under random repeated load, firstly, starting from the statistic meaning of random repeated load, the joint probability density function of maximum stress and minimum stress is derived based on the characteristics of order statistic (maximum order statistic and minimum order statistic; then, based on the equation of generalized σ -N curved surface, considering the influence of load cycles number on fatigue life, a relationship among minimum stress, maximum stress and residual life, that is the σmin(n- σmax(n-Nr(n curved surface model, is established; finally, the validity of the proposed model is demonstrated by a practical case. The result shows that the proposed model can reflect the influence of maximum stress and minimum stress on residual life of structure under random repeated load, which can provide a theoretical basis for life prediction and reliability assessment of structure.

Measurement of fatigue crack growth rate of reactor structural material in air based on DCPD method

International Nuclear Information System (INIS)

Du Donghai; Chen Kai; Yu Lun; Zhang Lefu; Shi Xiuqiang; Xu Xuelian

2014-01-01

The principles and details of direct current potential drop (DCPD) in monitoring the crack growth of reactor structural materials was introduced in this paper. Based on this method, the fatigue crack growth rate (CGR) of typical structural materials in nuclear power systems was measured. The effects of applied load, load ratio and loading frequency on the fatigue crack growth rate of reactor structural materials were discussed. The result shows that the fatigue crack growth rate of reactor structural materials depends on the hardness of materials, and the harder the material is, the higher the rate of crack growth is. (authors)

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

Energy Technology Data Exchange (ETDEWEB)

Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

2018-01-01

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Control criteria for residual contamination in materials considered for recycle and reuse

International Nuclear Information System (INIS)

Kennedy, W.E. Jr.; Hill, R.L.; Aaberg, R.L.

1993-11-01

Pacific Northwest Laboratory (PNL) is collecting data and conducting technical analyses to support the US Department of Energy (DOE), Office of Environmental Guidance, Air, Water, and Radiation Division (DOE/EH-232) in determining the feasibility of developing radiological control criteria for recycling or reuse of metals or equipment containing residual radioactive contamination from DOE operations. The criteria, framed as acceptable concentrations for release of materials for recycling or reuse, will be risk-based and will be developed through analysis of radiation exposure scenarios and pathways. The analysis will include evaluation of relevant radionuclides, potential mechanisms of exposure, and non-health-related impacts of residual radioactivity on electronics and film. The analyses will consider 42 key radionuclides that are generated during DOE operations and may be contained in recycled or reused metals or equipment

Near-surface residual stresses and microstructural changes after turning of a nickel-based superalloy

Energy Technology Data Exchange (ETDEWEB)

Schlauer, Christian

2003-07-01

Nickel-based superalloys are precipitation hardened alloys with complex compositions. They are used in aircraft engines and land-based gas turbines in load bearing structural components that are exposed to high temperatures. Failure mechanisms in this environment are high and low cycle fatigue, creep, and corrosion. During manufacturing, residual stresses are often introduced into the material due to inhomogeneous plastic deformations, both intentionally and unintentionally. One such manufacturing process is metal cutting, which introduces residual stresses in the surface layer. The stress state in the near-surface zone of components is of special interest as the surface often experiences peak loads and cracks have their starting point there. In this thesis, near-surface residual stress distributions and microstructural changes are studied in the nickel-based superalloy Inconel 718 for two different turning operations, face grooving and facing. Process variables are in both cases cutting speed and feed that have been varied between (10 and 1200) m/min and (0.01 and 0.5) mm, respectively. The first turning technique face grooving, which gives cutting conditions similar to orthogonal cutting, showed a clear dependency of the residual stresses on the cutting speed. The tensile stress at the surface, the maximum compressive stress below the surface, and the thickness of the affected layer increase with increasing cutting speed. The tensile stresses are constrained to a thin surface layer and compressive residual stresses below the surface dominate the depth profile of the residual stresses. Only at low cutting speed, residual stresses were largely avoided. The second turning technique facing confirmed the dependency of the residual stresses on the cutting speed and revealed a similar dependency on the feed. Microstructural investigations of near-surface cross-sections by means of transmission electron microscopy showed a zone where the grains had undergone plastic

Structure formation in fibrous materials based on poly-3-hydroxybutyrate for traumatology

Science.gov (United States)

Olkhov, A. A.; Sklyanchuk, E. D.; Staroverova, O. V.; Abbasov, T. A.; Guryev, V. V.; Akatov, V. S.; Fadeyeva, I. S.; Fesenko, N. I.; Filatov, Yu. N.; Iordanskii, A. L.

2015-10-01

The paper reviews the structure formation of fibrous materials based on poly-3-hydroxybutyrate depending on parameters of electrospinning and characteristics of polymer solution. Fiber structure was studied by DSC, ESR and SEM. The molecular weight affects the diameter and uniformity of the fiber. An electromechanical impact leads to an orientation of crystalline structure in the fiber. The design of an artificial bioresorbable implant based on nano- and microfibers of poly-3-hydroxybutyrate is created. Dynamics of growth of mesenchymal stem cells on poly-3-hydroxybutyrate scaffolds is studied. Successful field tests of implants of the Achilles tendon in Wistar rats are conducted.

Residues from waste incineration. Final report. Rev. ed.

Energy Technology Data Exchange (ETDEWEB)

Astrup, T.; Juul Pedersen, A.; Hyks, J.; Frandsen, F.J.

2010-04-15

The overall objective of the project was to improve the understanding of the formation and characteristics of residues from waste incineration. This was done focusing on the importance of the waste input and the operational conditions of the furnace. Data and results obtained from the project have been discussed in this report according to the following three overall parts: i) mass flows and element distribution, ii) flue gas/particle partitioning and corrosion/deposition aspects, and iii) residue leaching. This has been done with the intent of structuring the discussion while tacitly acknowledging that these aspects are interrelated and cannot be separated. Overall, it was found that the waste input composition had significant impact of the characteristics of the generated residues. A similar correlation between operational conditions and residue characteristics could not be observed. Consequently, the project recommend that optimization of residue quality should focus on controlling the waste input composition. The project results showed that including specific waste materials (and thereby also excluding the same materials) may have significant effects on the residue composition, residue leaching, aerosol and deposit formation.It is specifically recommended to minimize Cl in the input waste. Based on the project results, it was found that a significant potential for optimization of waste incineration exist. (Author)

Standard Guide for Unrestricted Disposition of Bulk Materials Containing Residual Amounts of Radioactivity

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 This guide covers the techniques for obtaining approval for release of materials encountered in decontamination and decommissioning (D&D) from restricted use. This would be addressed in the decommissioning plan (E 1281). It applies to materials that do not meet any of the requirements for regulatory control because of radioactivity content. Fig. 1 shows the logic diagram for determining the materials that could be considered for release. Materials that negotiate this logic tree are referred to as “candidate for release based on dose.” 1.2 The objective of this guide is to provide a methodology for distinguishing between material that must be carefully isolated to prevent human contact from that that can be recycled or otherwise disposed of. It applies to material in which the radioactivity is dispersed more or less uniformly throughout the volume of the material (termed residual in bulk form) as opposed to surface contaminated objects. 1.3 Surface contaminated objects are materials externally co...

Investigation of the Residual Stress State in an Epoxy Based Specimen

DEFF Research Database (Denmark)

Baran, Ismet; Jakobsen, Johnny; Andreasen, Jens Henrik

2015-01-01

Abstract. Process induced residual stresses may play an important role under service loading conditions for fiber reinforced composite. They may initiate premature cracks and alter the internal stress level. Therefore, the developed numerical models have to be validated with the experimental...... observations. In the present work, the formation of the residual stresses/strains are captured from experimental measurements and numerical models. An epoxy/steel based sample configuration is considered which creates an in-plane biaxial stress state during curing of the resin. A hole drilling process...... material models, i.e. cure kinetics, elastic modulus, CTE, chemical shrinkage, etc. together with the drilling process using the finite element method. The measured and predicted in-plane residual strain states are compared for the epoxy/metal biaxial stress specimen....

Crop residues as raw materials for biorefinery systems - A LCA case study

International Nuclear Information System (INIS)

Cherubini, Francesco; Ulgiati, Sergio

2010-01-01

Our strong dependence on fossil fuels results from the intensive use and consumption of petroleum derivatives which, combined with diminishing oil resources, causes environmental and political concerns. The utilization of agricultural residues as raw materials in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, thus mitigating climate change and enhancing energy security. This paper focuses on a biorefinery concept which produces bioethanol, bioenergy and biochemicals from two types of agricultural residues, corn stover and wheat straw. These biorefinery systems are investigated using a Life Cycle Assessment (LCA) approach, which takes into account all the input and output flows occurring along the production chain. This approach can be applied to almost all the other patterns that convert lignocellulosic residues into bioenergy and biochemicals. The analysis elaborates on land use change aspects, i.e. the effects of crop residue removal (like decrease in grain yields, change in soil N 2 O emissions and decrease of soil organic carbon). The biorefinery systems are compared with the respective fossil reference systems producing the same amount of products/services from fossils instead of biomass. Since climate change mitigation and energy security are the two most important driving forces for biorefinery development, the assessment focuses on greenhouse gas (GHG) emissions and cumulative primary energy demand, but other environmental categories are evaluated as well. Results show that the use of crop residues in a biorefinery saves GHG emissions and reduces fossil energy demand. For instance, GHG emissions are reduced by about 50% and more than 80% of non-renewable energy is saved. Land use change effects have a strong influence in the final GHG balance (about 50%), and their uncertainty is discussed in a sensitivity analysis. Concerning the investigation of the other impact categories, biorefinery systems

EBER - development of evaluation methods for shipping and storage containers with an increased content of metallic residual materials

International Nuclear Information System (INIS)

Droste, B.; Voelzke, H.

1995-01-01

Containers which are manufactured using recycled metallic residual materials from decommissioned nuclear facilities must be designed in accordance with the requirements of transport, interim and ultimate storage of radioactive waste. When metallic residual materials are added to the melt in the manufacture of containers made of cast iron with nodular graphite (GGG 40), how the effect on and characteristics of materials are to be observed as well as the permissible limits. The influence on charcteristics of relevance to safety, such as fracture toughness and the types and magnitudes of defects in construction components are the most important factors. In BAM's 'EBER' project presented here, the studies concentrate on design-based safety against the mechanical effects of accidents. (orig./DG) [de

Automated monitoring of fissile and fertile materials in incinerator residue

International Nuclear Information System (INIS)

Schoenig, F.C. Jr.; Glendinning, S.G.; Tunnell, G.W.; Zucker, M.S.

1986-01-01

This patent describes an apparatus for determining the fissile and fertile material content of incinerator residue contained in a manipulatable container. The apparatus comprises a main body member formed of neutron moderating material and formed with a well for receiving the container; a first plug formed of neutron reflecting material for closing the top of the well; and a second plug containing a first neutron source for alternatively closing the top of the well and for directing neutrons into the well. It also includes a second neutron source selectively positionable in the bottom of the well for directing neutrons into the well; manipulating means for placing the container in the well and removing the container therefrom and for selectively placing one of the first and second plugs in the top of the well. Neutron detectors are positioned within the neutron moderating material of the main body member around the sides of the well. At least one gamma ray detector is positioned adjacent the bottom of the well. A means receives and processes the signals from the neutron and gamma ray detectors when the container is in the well for determining the fissile and fertile material content of the incinerator residue in the container

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

Science.gov (United States)

Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

2018-01-01

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay γ-quanta by the residuals in the activated structures and scoring the prompt doses of these γ-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and against experimental data from the CERF facility at CERN, and FermiCORD showed reasonable agreement with these. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Modeling of the fatigue damage accumulation processes in the material of NPP design units under thermomechanical unstationary effects. Estimation of spent life and forecast of residual life

International Nuclear Information System (INIS)

Kiriushin, A.I.; Korotkikh, Yu.G.; Gorodov, G.F.

2002-01-01

Full text: The estimation problems of spent life and forecast of residual life of NPP equipment design units, operated at unstationary thermal force loads are considered. These loads are, as a rule, unregular and cause rotation of main stress tensor platforms of the most loaded zones of structural elements and viscoelastic plastic deformation of material in the places of stresses concentrations. The existing engineering approaches to the damages accumulation processes calculation in the material of structural units, their advantages and disadvantages are analyzed. For the processes of fatigue damages accumulation a model is proposed, which allows to take into account the unregular pattern of deformation multiaxiality of stressed state, rotation of main platforms, non-linear summation of damages at the loading mode change. The model in based on the equations of damaged medium mechanics, including the equations of viscoplastic deformation of the material and evolutionary equations of damages accumulation. The algorithms of spent life estimation and residual life forecast of the controlled equipment and systems zones are made on the bases of the given model by the known real history of loading, which is determined by real model of NPP operation. The results of numerical experiments on the basis of given model for various processes of thermal force loads and their comparison with experimental results are presented. (author)

Investigation of Kevlar fabric based materials for use with inflatable structures

Science.gov (United States)

Niccum, R. J.; Munson, J. B.

1974-01-01

Design, manufacture and testing of laminated and coated composite materials incorporating a structural matrix of Kevlar are reported in detail. The practicality of using Kevlar in aerostat materials is demonstrated and data are provided on practical weaves, lamination and coating particulars, rigidity, strength, weight, elastic coefficients, abrasion resistance, crease effects, peel strength, blocking tendencies, helium permeability, and fabrication techniques. Properties of the Kevlar based materials are compared with conventional, Dacron reinforced counterparts. A comprehensive test and qualification program is discussed and quantitative biaxial tensile and shear test data are provided. The investigation shows that single ply laminates of Kevlar and plastic films offer significant strength to weight improvements, are less permeable than two ply coated materials, but have a lower flex life.

Conceptual framework and technical basis for clearance of materials with residual radioactivity

International Nuclear Information System (INIS)

Chen, S.Y.

1997-01-01

The primary impediment to the release of materials containing residual radioactivity from a controlled environment is the lack of a suitable framework within which release standards can be developed. Recently, the 'risk-based' approach has been proposed as an appropriate means of setting standards. The term 'clearance' has been introduced by the International Atomic Energy Commission as a regulatory process for releasing radioactive materials posing trivial risks. A 'trivial' risk level has been determined to be on the order of 10[sup -6] to 10[sup -7] annual risk to an exposed individual, and a population risk of no more than 0.1 annually. Under these strict constraints, exposure scenarios may account for processing, disposal, and product end-use of materials. This paper discusses these scenarios and also describes the technical basis for deriving release levels under the suggested risk (or dose) constraints

Fe-Ti/Fe (II)-loading on ceramic filter materials for residual chlorine removal from drinking water.

Science.gov (United States)

Man, Kexin; Zhu, Qi; Guo, Zheng; Xing, Zipeng

2018-06-01

Ceramic filter material was prepared with silicon dioxide (SiO 2 ), which was recovered from red mud and then modified with Fe (II) and Fe-Ti bimetal oxide. Ceramic filter material can be used to reduce the content of residual chlorine from drinking water. The results showed that after a two-step leaching process with 3 M hydrochloric acid (HCl) and 90% sulfuric acid (H 2 SO 4 ), the recovery of SiO 2 exceeded 80%. Fe (II)/Fe-Ti bimetal oxide, with a high adsorption capacity of residual chlorine, was prepared using a 3:1 M ratio of Fe/Ti and a concentration of 0.4 mol/L Fe 2+ . According to the zeta-potential, scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis, Fe (II) and Fe-Ti bimetal oxide altered the zeta potential and structural properties of the ceramic filter material. There was a synergistic interaction between Fe and Ti in which FeOTi bonds on the material surface and hydroxyl groups provided the active sites for adsorption. Through a redox reaction, Fe (II) transfers hypochlorite to chloride, and FeOTiCl bonds were formed after adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Thermodamage Strength Theoretical Model of Ceramic Materials Taking into Account the Effect of Residual Stress

Directory of Open Access Journals (Sweden)

Weiguo Li

2012-01-01

Full Text Available A thermodamage strength theoretical model taking into account the effect of residual stress was established and applied to each temperature phase based on the study of effects of various physical mechanisms on the fracture strength of ultrahigh-temperature ceramics. The effects of SiC particle size, crack size, and SiC particle volume fraction on strength corresponding to different temperatures were studied in detail. This study showed that when flaw size is not large, the bigger SiC particle size results in the greater effect of tensile residual stress in the matrix grains on strength reduction, and this prediction coincides with experimental results; and the residual stress and the combined effort of particle size and crack size play important roles in controlling material strength.

Correlation Between the Microstructural Defects and Residual Stress in a Single Crystal Nickel-Based Superalloy During Different Creep Stages

Science.gov (United States)

Mo, Fangjie; Wu, Erdong; Zhang, Changsheng; Wang, Hong; Zhong, Zhengye; Zhang, Jian; Chen, Bo; Hofmann, Michael; Gan, Weimin; Sun, Guangai

2018-03-01

The present work attempts to reveal the correlation between the microstructural defects and residual stress in the single crystal nickel-based superalloy, both of which play the significant role on properties and performance. Neutron diffraction was employed to investigate the microstructural defects and residual stresses in a single crystal (SC) nickel-based superalloy, which was subjected to creeping under 220 MPa and 1000 °C for different times. The measured superlattice and fundamental lattice reflections confirm that the mismatch and tetragonal distortions with c/a > 1 exist in the SC superalloy. At the initially unstrained state, there exists the angular distortion between γ and γ' phases with small triaxial compressive stresses, ensuring the structural stability of the superalloy. After creeping, the tetragonal distortion for the γ phase is larger than that for the γ' phase. With increasing the creeping time, the mismatch between γ and γ' phases increases to the maximum, then decreases gradually and finally remains unchanged. The macroscopic residual stress shows a similar behavior with the mismatch, indicating the correlation between them. Based on the model of shear and dislocations, the evolution of microstructural defects and residual stress are reasonably explained. The effect of shear is dominant at the primary creep stage, which greatly enlarges the mismatch and the residual stress. The dislocations weaken the effect of shear for the further creep stage, resulting in the decrease of the mismatch and relaxation of the residual stress. Those findings add some helpful understanding into the microstructure-performance relationship in the SC nickel-based superalloy, which might provide the insight to materials design and applications.

Enhancing Reactivity in Structural Energetic Materials

Science.gov (United States)

Glumac, Nick

2017-06-01

In many structural energetic materials, only a small fraction of the metal oxidizes, and yet this provides a significant boost in the overall energy release of the system. Different methodologies to enhance this reactivity include alloying and geometric modifications of microstructure of the reactive material (RM). In this presentation, we present the results of several years of systematic study of both chemical (alloy) and mechanical (geometry) effects on reactivity for systems with typical charge to case mass ratios. Alloys of aluminum with magnesium and lithium are considered, as these are common alloys in aerospace applications. In terms of geometric modifications, we consider surface texturing, inclusion of dense additives, and inclusion of voids. In all modifications, a measurable influence on output is observed, and this influence is related to the fragment size distribution measured from the observed residue. Support from DTRA is gratefully acknowledged.

Electric field responsive origami structures using electrostriction-based active materials

Science.gov (United States)

Ahmed, Saad; Arrojado, Erika; Sigamani, Nirmal; Ounaies, Zoubeida

2015-04-01

The objective of origami engineering is to combine origami principles with advanced materials to yield active origami shapes, which fold and unfold in response to external stimuli. We are investigating the use of P(VDF-TrFE-CTFE), a relaxor ferroelectric terpolymer, to realize origami-inspired folding and unfolding of structures and to actuate so-called action origami structures. To accomplish these two objectives, we have explored different approaches to the P(VDF-TrFECTFE) polymer actuator construction, ranging from unimorph to multilayered stacks. Electromechanical characterization of the terpolymer-based actuators is conducted with a focus on free strain, force-displacement and blocked force. Moreover dynamic thickness strains of P(VDF-TrFE-CTFE) terpolymer at different frequencies ranging from 0.1Hz to 10Hz is also measured. Quantifying the performance of terpolymer-based actuators is important to the design of action origami structures. Following these studies, action origami prototypes based on catapult, flapping butterfly wings and barking fox are actuated and characterization of these prototypes are conducted by studying impact of various parameters such as electric field magnitude and frequency, number of active layers, and actuator dimensions.

Radiation effects on residual voltage of polyethylene films

International Nuclear Information System (INIS)

Kyokane, Jun; Park, Dae-Hee; Yoshino, Katsumi.

1986-01-01

It has recently been pointed out that diagnosis of deterioration in insulating materials for electric cables used in nuclear power plants and outer space (communications satellite in particular) can be effectively performed based on measurements of residual voltage. In the present study, polyethylene films are irradiated with γ-rays or electron beam to examine the changes in residual voltage characteristics. Irradiation of electron beam and γ-rays are carried out to a dose of 0 - 90 Mrad and 0 - 100 Mrad, respectively. Measurements are made of the dependence of residual voltage on applied voltage, electron beam and γ-ray irradiation, annealing temperature and annealing time. Results show that carriers, which are once trapped after being released from the electrode, move within the material after the opening of the circuit to produce resiual voltage. The residual voltage increases with increasing dose of electron beam or γ-ray and levels off at high dose. Residual voltage is increased about several times by either electron beam or γ-rays, but electron beam tends to cause greater residual voltage than γ-ray. Polyethylene films irradiated with electron beam can recover upon annealing. It is concluded from observations made that residual voltage has close relations with defects in molecular structures caused by radiations, particularly the breaking of backbone chains and alteration in superstructures. (Nogami, K.)

Residual strength evaluation of concrete structural components ...

Indian Academy of Sciences (India)

This paper presents methodologies for residual strength evaluation of concrete structural components using linear elastic and nonlinear fracture mechanics principles. The effect of cohesive forces due to aggregate bridging has been represented mathematically by employing tension softening models. Various tension ...

Synthesis and study of nano-structured cellulose acetate based materials for energy applications

International Nuclear Information System (INIS)

Fischer, F.

2006-12-01

Nano-structured materials have unique properties (high exchange areas, containment effect) because of their very low characteristic dimensions. The elaboration way set up in this PhD work consists in applying the classical processes for the preparation of aerogel-like materials (combining sol-gel synthesis and CO 2 supercritical extraction) to cellulosic polymers. This work is divided in four parts: a literature review, the presentation and the study of the chemical synthesis that leads to cellulose acetate-based aerogel, the characterizations (chemical, structural and thermal) of the elaborated nano-materials, and finally the study of the first carbons that were obtained after pyrolysis of the organic matrix. The formulations and the sol-gel protocol lead to chemical gels by crosslinking cellulose acetate using a poly-functional iso-cyanate. The dry materials obtained after solvent extraction with supercritical CO 2 are nano-structured and mainly meso-porous. Correlations between chemical synthesis parameters (reagent concentrations, crosslinking rate and degree of polymerisation) and porous properties (density, porosity, pore size distribution) were highlighted thanks to structural characterizations. An ultra-porous reference aerogel, with a density equals to 0,245 g.cm -3 together with a meso-porous volume of 3,40 cm 3 .g -1 was elaborated. Once in granular shape, this material has a thermal conductivity of 0,029 W.m -1 .K -1 . In addition, carbon materials produced after pyrolysis of the organic matrix and after grinding are nano-structured and nano-porous, even if important structural modifications have occurred during the carbonization process. The elaborated materials are evaluated for applications in relation with energy such as thermal insulation (organic aerogels) but also for energy conversion and storage through electrochemical way (carbon aerogels). (author)

Residual radioactive material guidelines: Methodology and applications

International Nuclear Information System (INIS)

Yu, C.; Yuan, Y.C.; Zielen, A.J.; Wallo, A. III.

1989-01-01

A methodology to calculate residual radioactive material guidelines was developed for the US Department of Energy (DOE). This methodology is coded in a menu-driven computer program, RESRAD, which can be run on IBM or IBM-compatible microcomputers. Seven pathways of exposure are considered: external radiation, inhalation, and ingestion of plant foods, meat, milk, aquatic foods, and water. The RESRAD code has been applied to several DOE sites to calculate soil cleanup guidelines. This experience has shown that the computer code is easy to use and very user-friendly. 3 refs., 8 figs

The Relationship Between Low-Frequency Motions and Community Structure of Residue Network in Protein Molecules.

Science.gov (United States)

Sun, Weitao

2018-01-01

The global shape of a protein molecule is believed to be dominant in determining low-frequency deformational motions. However, how structure dynamics relies on residue interactions remains largely unknown. The global residue community structure and the local residue interactions are two important coexisting factors imposing significant effects on low-frequency normal modes. In this work, an algorithm for community structure partition is proposed by integrating Miyazawa-Jernigan empirical potential energy as edge weight. A sensitivity parameter is defined to measure the effect of local residue interaction on low-frequency movement. We show that community structure is a more fundamental feature of residue contact networks. Moreover, we surprisingly find that low-frequency normal mode eigenvectors are sensitive to some local critical residue interaction pairs (CRIPs). A fair amount of CRIPs act as bridges and hold distributed structure components into a unified tertiary structure by bonding nearby communities. Community structure analysis and CRIP detection of 116 catalytic proteins reveal that breaking up of a CRIP can cause low-frequency allosteric movement of a residue at the far side of protein structure. The results imply that community structure and CRIP may be the structural basis for low-frequency motions.

A novel biaxial specimen for inducing residual stresses in thermoset polymers and fibre composite material

DEFF Research Database (Denmark)

Jakobsen, Johnny; Andreasen, Jens Henrik; Jensen, Martin

2015-01-01

engineers when they challenge the material limits in present and future thermoset and composite component. In addition to the new specimen configuration, this paper presents an analytical solution for the residual stress state in the specimen. The analytical solution assumes linear elastic and isotropic......A new type of specimen configuration with the purpose of introducing a well-defined biaxial residual (axisymmetric) stress field in a neat thermoset or a fibre composite material is presented. The ability to experimentally validate residual stress predictions is an increasing need for design...

Tunable elastic parity-time symmetric structure based on the shunted piezoelectric materials

Science.gov (United States)

Hou, Zhilin; Assouar, Badreddine

2018-02-01

We theoretically and numerically report on the tunable elastic Parity-Time (PT) symmetric structure based on shunted piezoelectric units. We show that the elastic loss and gain can be archived in piezoelectric materials when they are shunted by external circuits containing positive and negative resistances. We present and discuss, as an example, the strongly dependent relationship between the exceptional points of a three-layered system and the impedance of their external shunted circuit. The achieved results evidence that the PT symmetric structures based on this proposed concept can actively be tuned without any change of their geometric configurations.

Development of residual thermal stress-relieving structure of CFC monoblock target for JT-60SA divertor

Energy Technology Data Exchange (ETDEWEB)

Tsuru, Daigo, E-mail: tsuru.daigo@jaea.go.jp; Sakurai, Shinji; Nakamura, Shigetoshi; Ozaki, Hidetsugu; Seki, Yohji; Yokoyama, Kenji; Suzuki, Satoshi

2015-10-15

Highlights: • We carried out numerical simulations on residual thermal stress of targets for the JT-60SA divertor. • We developed three measures to reduce residual thermal stress. • We proposed two structures of CFC monoblock target for the JT-60SA divertor. • We confirmed the effectiveness of the structure by infrared thermography inspection and high heat flux test. - Abstract: Carbon fibre-reinforced carbon composite (CFC) monoblock target for JT-60SA divertor is under development towards the mass-production. CFC monoblocks, WCu interlayers and a CuCrZr cooling tube at the centre of the monoblocks were bonded by vacuum brazing in a high temperature, to a target. If residual thermal stress due to difference of thermal expansions between CFC and CuCrZr exceeds the maximum allowable stress of the CFC after the bonding, cracks are generated in the CFC monoblock and heat removal capacity of the target degrades. In this paper, new structures of the targets were proposed, to reduce residual thermal stress and to mitigate the degradation of heat removal capacity of the targets. Some measures, including slitting of the CFC monoblock aside of the cooling tube, replacement of the interlayer material and shifting the position of the cooling tube, were implemented. The effectiveness of the measures was evaluated by numerical simulations. Target mock-ups with the proposed structures were manufactured. Infrared thermography inspection and high heat flux test were carried out on the mock-ups in order to evaluate the heat removal capacity.

Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures

DEFF Research Database (Denmark)

Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen

2016-01-01

In the offshore industry, welding-induced distortion and tensile residual stresses have become a major concern in relation to the structural integrity of a welded structure. Particularly, the continuous increase in size of welded plates and joints needs special attention concerning welding induced...... residual stresses. These stresses have a negative impact on the integrity of the welded joint as they promote distortion, reduce fatigue life, and contribute to corrosion cracking and premature failure in the weld components. This paper deals with the influence and impact of welding method on the welding...... induced residual stresses. It is also investigated whether the assumption of residual stresses up to yield strength magnitude are present in welded structures as stated in the design guidelines. The fatigue strength for welded joints is based on this assumption. The two welding methods investigated...

Eddy Current Nondestructive Residual Stress Assessment in Shot-Peened Nickel-Base Superalloys

International Nuclear Information System (INIS)

Blodgett, M.P.; Yu, F.; Nagy, P.B.

2005-01-01

Shot peening and other mechanical surface enhancement methods improve the fatigue resistance and foreign-object damage tolerance of metallic components by introducing beneficial near-surface compressive residual stresses and hardening the surface. However, the fatigue life improvement gained via surface enhancement is not explicitly accounted for in current engine component life prediction models because of the lack of accurate and reliable nondestructive methods that could verify the presence of compressive near-surface residual stresses in shot-peened hardware. In light of its frequency-dependent penetration depth, the measurement of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation of subsurface residual stresses in surface-treated components. This technique is based on the so-called piezoresistivity effect, i.e., the stress-dependence of electrical resistivity. We found that, in contrast with most other materials, surface-treated nickel-base superalloys exhibit an apparent increase in electrical conductivity at increasing inspection frequencies, i.e., at decreasing penetration depths. Experimental results are presented to illustrate that the excess frequency-dependent apparent eddy current conductivity of shot-peened nickel-base superalloys can be used to estimate the absolute level and penetration depth of the compressive residual stress layer both before and after partial thermal relaxation

Effects of material non-linearity on the residual stresses in a dendritic silicon crystal ribbon

Science.gov (United States)

Ray, Sujit K.; Utku, Senol

1990-01-01

Thermal stresses developed in a dendritic silicon crystal ribbon have been shown to cause plastic deformation and residual stresses in the ribbon. This paper presents an implementation of a numerical model proposed for thermoelastoplastic behavior of a material. The model has been used to study the effects of plasticity of silicon on the residual stresses. The material properties required to implement this model are all assumed, and the response of the material to the variations in these assumed parameters of the constitutive law and in the finite element mesh is investigated. The steady state growth process is observed to be periodic with nonzero residual stresses. Numerical difficulties are also encountered in the computer solution process, resulting in sharp jumps and large oscillations in the stress responses.

Development of structural materials on the base of new technology

International Nuclear Information System (INIS)

Belov, A.F.; Anoshkin, N.F.

1982-01-01

Some results are considered and possibilities which discovered in development of structural materials connected with development of such new technological processes as skull melting of titanium alloys, granule metallurgy, hot isostatic, diffusion welding are estimated. The method of skull melting with remelted skull is developed. The method assures sufficient possibilities for dissolving of high-heat components of charge and obtaining homogeneous ingots of series of new alloys. Granule metallurgy based on crystallization of the metal with high rate in the form of small (up to 300 μkm) particles and subsequent consolidation of them into compact billet discoveres a wide possibilities of creation of new structural material with more high operation indexes. It is noted that developed processes of granule production, their treatment, compacting and thermal treatment of the billets assure production of metal of high quality, satisfied the strong requirements of present standards. The process of hot isostatic pressing at which the workable metal is subjected to through uniform pressure by compressed gas after heating or semultaneously with its heating up to the temperatures of working in gasostats is one of new technological processes. A certain experience of the HIP use for production of compact billets from granules for diffusion welding of the billets is accumulated. This process has a great possibilities for densification of shaped castings. Investigation and application of the diffusion welding represent combination of elements into details of complex form in vacuum at the temperatures low of melting point under effect of small pressures are investigated both in our country and abroad. Diffusion welding gives a wide possibilities in the development of materials with higher properties at the expence of production of products of large dimensions from thin elements with fine-grained structure as well as products with assigned gradient of chemical composition, structure

Use of residues proceeding from marbles and granites finishing and manufacturing processes as raw material for structural ceramic; Utilizacao do residuo proveniente do acabamento e manufatura de marmores e granitos como materia-prima em ceramica vermelha

Energy Technology Data Exchange (ETDEWEB)

Mello, Roberta Monteiro de

2006-07-01

In order to decrease environmental impact, caused by mud discarding and clay extraction in the ceramic industry, it was used residual mud from marble and granite companies for structural ceramic. Samples were collected in twelve different marble companies located at the metropolitan region of Sao Paulo. However, only four samples were selected, based on its different characteristics. Clay stone was the raw material chosen to prepare the structural ceramic, considering its high use in this segment. Samples and clay stone were both analysed by the following procedures: granulometric analysis, x-rays fluorescent chemical analysis and x-rays diffraction mineralogical analysis, besides, tests in the samples were conducted following NBR 10004 standards. Once raw materials were characterized, the plasticity test was conducted. Test specimen were molded with different levels of mud, then burned and submitted to technological tests, such as: mechanical resistance, water absorption, porosity, specific gravity and retraction, material dilation before burning process and scanning electron microscopy. The final results have shown the viability of using this kind of mud, and pointed some advantages on its usage, but taking in consideration some previous conditions to be adopted. (author)

A Robust Transform Estimator Based on Residual Analysis and Its Application on UAV Aerial Images

Directory of Open Access Journals (Sweden)

Guorong Cai

2018-02-01

Full Text Available Estimating the transformation between two images from the same scene is a fundamental step for image registration, image stitching and 3D reconstruction. State-of-the-art methods are mainly based on sorted residual for generating hypotheses. This scheme has acquired encouraging results in many remote sensing applications. Unfortunately, mainstream residual based methods may fail in estimating the transform between Unmanned Aerial Vehicle (UAV low altitude remote sensing images, due to the fact that UAV images always have repetitive patterns and severe viewpoint changes, which produce lower inlier rate and higher pseudo outlier rate than other tasks. We performed extensive experiments and found the main reason is that these methods compute feature pair similarity within a fixed window, making them sensitive to the size of residual window. To solve this problem, three schemes that based on the distribution of residuals are proposed, which are called Relational Window (RW, Sliding Window (SW, Reverse Residual Order (RRO, respectively. Specially, RW employs a relaxation residual window size to evaluate the highest similarity within a relaxation model length. SW fixes the number of overlap models while varying the length of window size. RRO takes the permutation of residual values into consideration to measure similarity, not only including the number of overlap structures, but also giving penalty to reverse number within the overlap structures. Experimental results conducted on our own built UAV high resolution remote sensing images show that the proposed three strategies all outperform traditional methods in the presence of severe perspective distortion due to viewpoint change.

Bioinspired twisted composites based on Bouligand structures

Science.gov (United States)

Pinto, F.; Iervolino, O.; Scarselli, G.; Ginzburg, D.; Meo, M.

2016-04-01

The coupling between structural support and protection makes biological systems an important source of inspiration for the development of advanced smart composite structures. In particular, some particular material configurations can be implemented into traditional composites in order to improve their impact resistance and the out-of-plane properties, which represents one of the major weakness of commercial carbon fibres reinforced polymers (CFRP) structures. Based on this premise, a three-dimensional twisted arrangement shown in a vast multitude of biological systems (such as the armoured cuticles of Scarabei, the scales of Arapaima Gigas and the smashing club of Odontodactylus Scyllarus) has been replicated to develop an improved structural material characterised by a high level of in-plane isotropy and a higher interfacial strength generated by the smooth stiffness transition between each layer of fibrils. Indeed, due to their intrinsic layered nature, interlaminar stresses are one of the major causes of failure of traditional CFRP and are generated by the mismatch of the elastic properties between plies in a traditional laminate. Since the energy required to open a crack or a delamination between two adjacent plies is due to the difference between their orientations, the gradual angle variation obtained by mimicking the Bouligand Structures could improve energy absorption and the residual properties of carbon laminates when they are subjected to low velocity impact event. Two different bioinspired laminates were manufactured following a double helicoidal approach and a rotational one and were subjected to a complete test campaign including low velocity impact loading and compared to a traditional quasi-isotropic panel. Fractography analysis via X-Ray tomography was used to understand the mechanical behaviour of the different laminates and the residual properties were evaluated via Compression After Impact (CAI) tests. Results confirmed that the biological

Homology modeling and docking analyses of M. leprae Mur ligases reveals the common binding residues for structure based drug designing to eradicate leprosy.

Science.gov (United States)

Shanmugam, Anusuya; Natarajan, Jeyakumar

2012-06-01

Multi drug resistance capacity for Mycobacterium leprae (MDR-Mle) demands the profound need for developing new anti-leprosy drugs. Since most of the drugs target a single enzyme, mutation in the active site renders the antibiotic ineffective. However, structural and mechanistic information on essential bacterial enzymes in a pathway could lead to the development of antibiotics that targets multiple enzymes. Peptidoglycan is an important component of the cell wall of M. leprae. The biosynthesis of bacterial peptidoglycan represents important targets for the development of new antibacterial drugs. Biosynthesis of peptidoglycan is a multi-step process that involves four key Mur ligase enzymes: MurC (EC:6.3.2.8), MurD (EC:6.3.2.9), MurE (EC:6.3.2.13) and MurF (EC:6.3.2.10). Hence in our work, we modeled the three-dimensional structure of the above Mur ligases using homology modeling method and analyzed its common binding features. The residues playing an important role in the catalytic activity of each of the Mur enzymes were predicted by docking these Mur ligases with their substrates and ATP. The conserved sequence motifs significant for ATP binding were predicted as the probable residues for structure based drug designing. Overall, the study was successful in listing significant and common binding residues of Mur enzymes in peptidoglycan pathway for multi targeted therapy.

Fact Sheet for Friction Materials Manufacturing Facilities Residual Risk and Technology Review

Science.gov (United States)

proposed amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Friction Materials Manufacturing Facilities to address the results of the residual risk and technology review

Analysis of lifetime and residual strength of wood

DEFF Research Database (Denmark)

Nielsen, Lauge Fuglsang

1997-01-01

The present paper is thought of as a working paper for the CTBA-seminar on Thematic network in the field for reliability based design of timber structures, Topic: Numerical methods for structural analysis. It is preliminary and quite informal in its structure. The intention is to present some wood...... technological problems which can be solved with respect to lifetime and residual strength by the so-called DVM-theory (Damaged Viscoelastic Material). The outlines of the paper is straight on: Expressions are presented by which the analysis is made. then some examples are considered with solutions presented...

Characterization of the Young's modulus and residual stresses for a sputtered silicon oxynitride film using micro-structures

International Nuclear Information System (INIS)

Dong, Jian; Du, Ping; Zhang, Xin

2013-01-01

Silicon oxynitride (SiON) is an important material to fabricate micro-electro-mechanical system (MEMS) devices due to its composition-dependent tunability in electronic and mechanical properties. In this work, the SiON film with 41.45% silicon, 32.77% oxygen and 25.78% nitrogen content was deposited by RF magnetron sputtering. Two types of optimized micro-structures including micro-cantilevers and micro-rotating-fingers were designed and fabricated using MEMS surface micromachining technology. The micro-cantilever bending tests were conducted using a nanoindenter to characterize the Young's modulus of the SiON film. Owing to the elimination of the residual stress effect on the micro-cantilever structure, higher accuracy in the Young's modulus was achieved from this technique. With the information of Young's modulus of the film, the residual stresses were characterized from the deflection of the micro-rotating-fingers. This structure was able to locally measure a large range of tensile or compressive residual stresses in a thin film with sufficient sensitivities. The results showed that the Young's modulus of the SiON film was 122 GPa and the residual stresses of the SiON film were 327 MPa in the crystallographic orientation of the wafer and 334 MPa in the direction perpendicular to the crystallographic orientation, both in compression. This work presents a comprehensive methodology to measure the Young's modulus and residual stresses of a thin film with improved accuracy, which is promising for applications in mechanical characterization of MEMS devices. - Highlight: • We measured the Young's modulus and residual stress of SiON film by microstructure. • Micro cantilever structure improved the Young's modulus' measurement accuracy. • We explored the reason for the deviations of residual stress value of SiON film

Residual strain dependence on the matrix structure in RHQ-Nb3Al wires by neutron diffraction measurement

International Nuclear Information System (INIS)

Jin Xinzhe; Nakamoto, Tatsushi; Tsuchiya, Kiyosumi; Ogitsu, Toru; Yamamoto, Akira; Ito, Takayoshi; Harjo, Stefanus; Kikuchi, Akihiro; Takeuchi, Takao; Hemmi, Tsutomu

2012-01-01

We prepared three types of non-Cu RHQ-Nb 3 Al wire sample with different matrix structures: an all-Ta matrix, a composite matrix of Nb and Ta with a Ta inter-filament, and an all-Nb matrix. Neutron diffraction patterns of the wire samples were measured at room temperature in the J-PARC ‘TAKUMI’. To obtain the residual strains of the materials, we estimated the lattice constant a by multi-peak analysis in the wires. A powder sample of each wire was measured, where the powder was considered to be strain free. The grain size of all the powder samples was below 0.02 mm. For the wire sample with the all-Nb matrix, we also obtained the lattice spacing d by a single-peak analysis. The residual strains of the Nb 3 Al filament were estimated from the two analysis results and were compared. The resulting residual strains obtained from the multi-peak analysis showed a good accuracy with small standard deviation. The multi-peak analysis results for the residual strains of the Nb 3 Al filaments in the three samples (without Cu plating) were all tensile residual strain in the axial direction, of 0.12%, 0.12%, and 0.05% for the all-Ta matrix, the composite matrix, and the all-Nb matrix, respectively. The difference in the residual strain of the Nb 3 Al filament between the composite and all-Nb matrix samples indicates that the type of inter-filament material shows a great effect on the residual strain. In this paper, we report the method of measurement, method of analysis, and results for the residual strain in the three types of non-Cu RHQ-Nb 3 Al wires. (paper)

Polyphosphazine-based polymer materials

Science.gov (United States)

Fox, Robert V.; Avci, Recep; Groenewold, Gary S.

2010-05-25

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

FIB-based measurement of local residual stresses on microsystems

Science.gov (United States)

Vogel, Dietmar; Sabate, Neus; Gollhardt, Astrid; Keller, Juergen; Auersperg, Juergen; Michel, Bernd

2006-03-01

The paper comprises research results obtained for stress determination on micro and nanotechnology components. It meets the concern of controlling stresses introduced to sensors, MEMS and electronics devices during different micromachining processes. The method bases on deformation measurement options made available inside focused ion beam equipment. Removing locally material by ion beam milling existing stresses / residual stresses lead to deformation fields around the milled feature. Digital image correlation techniques are used to extract deformation values from micrographs captured before and after milling. In the paper, two main milling features have been analyzed - through hole and through slit milling. Analytical solutions for stress release fields of in-plane stresses have been derived and compared to respective experimental findings. Their good agreement allows to settle a method for determination of residual stress values, which is demonstrated for thin membranes manufactured by silicon micro technology. Some emphasis is made on the elimination of main error sources for stress determination, like rigid body object displacements and rotations due to drifts of experimental conditions under FIB imaging. In order to illustrate potential application areas of the method residual stress suppression by ion implantation is evaluated by the method and reported here.

Healing agent in cement-based materials and structures, and process for its preparation

NARCIS (Netherlands)

Jonkers, H.M.

2009-01-01

The present invention relates to healing agent in cement-based materials and structures, wherein said healing agent comprises organic compounds and/or bacteria-loaded porous particles, which porous particles comprise expanded clay- or sintered fly ash. Furthermore, said porous particles are intact

Fatigue behaviour of 304L steel welded structures: influence of residual stresses and surface mechanical finishing

International Nuclear Information System (INIS)

Magnier-Monin, L.

2007-12-01

This study focuses on the influence of residual stresses and surface mechanical finishing on lifetime of stainless steel 304L welded structures. Residual stresses are determined on specific specimens of three types: base-metal, as-welded and ground-welded specimens. Each type is submitted to fatigue tests in order to assess the influence of these parameters on the lifetime, and to determine their evolution. The experiments show that an important surface stress concentration is located in the weld root of as-welded structures, which has a negative effect on the fatigue life. The grinding operation generates high-level surface residual stresses but the lifetime is higher thanks to the reduction of the notch effect. The fatigue test results are compared to the nuclear industry best-fit S-N curves. This enables the determination of correction factors related to fatigue test results of polished specimens, and to assess the lifetime of structures. (author)

Statistically generated weighted curve fit of residual functions for modal analysis of structures

Science.gov (United States)

Bookout, P. S.

1995-01-01

A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure for modal testing large structures in an external constraint-free environment to measure the effects of higher order modes and interface stiffness. This test method is applicable to structures with distinct degree-of-freedom interfaces to other system components. A theoretical residual function in the displacement/force domain has the characteristics of a relatively flat line in the lower frequencies and a slight upward curvature in the higher frequency range. In the test residual function, the above-mentioned characteristics can be seen in the data, but due to the present limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of ragged data. A second order polynomial curve fit is required to obtain the residual flexibility term. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value can be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure. The residual flexibility modal test method is applied to a straight beam with a trunnion appendage and a space shuttle payload pallet simulator.

Graphene-based hybrid structures combined with functional materials of ferroelectrics and semiconductors.

Science.gov (United States)

Jie, Wenjing; Hao, Jianhua

2014-06-21

Fundamental studies and applications of 2-dimensional (2D) graphene may be deepened and broadened via combining graphene sheets with various functional materials, which have been extended from the traditional insulator of SiO2 to a versatile range of dielectrics, semiconductors and metals, as well as organic compounds. Among them, ferroelectric materials have received much attention due to their unique ferroelectric polarization. As a result, many attractive characteristics can be shown in graphene/ferroelectric hybrid systems. On the other hand, graphene can be integrated with conventional semiconductors and some newly-discovered 2D layered materials to form distinct Schottky junctions, yielding fascinating behaviours and exhibiting the potential for various applications in future functional devices. This review article is an attempt to illustrate the most recent progress in the fabrication, operation principle, characterization, and promising applications of graphene-based hybrid structures combined with various functional materials, ranging from ferroelectrics to semiconductors. We focus on mechanically exfoliated and chemical-vapor-deposited graphene sheets integrated in numerous advanced devices. Some typical hybrid structures have been highlighted, aiming at potential applications in non-volatile memories, transparent flexible electrodes, solar cells, photodetectors, and so on.

Distribution, utilization structure and potential of biomass resources in rural China: With special references of crop residues

Energy Technology Data Exchange (ETDEWEB)

Liu, H [Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Jiang, G M [Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093 (China); Agronomy Department, Shandong Agricultural University, Tai' an 271018, Shandong Province (China); Zhuang, H Y [National Bio-Energy CO., LTD, No. 26B, Financial Street, Xicheng District, Beijing 100032 (China); Shandong Academy of Sciences, No. 19, Keyuan Road, Ji' nan 250014, Shandong Province (China); Wang, K J [Agronomy Department, Shandong Agricultural University, Tai' an 271018, Shandong Province (China)

2008-06-15

As the largest developing country in the world, China is urgently in short of energy and natural resources. However, biological resources such as crop residues are burnt in the field, which cause serious environmental pollution. Still it is not clear how much storage and potential of these huge crop residues are in China. This paper firstly reported the distribution, utilization structure and potential of crop biomass and provided the tangible information of crop residues in rural China through careful collecting and recalculating data. From 1995 to 2005, China produces some 630 million tons of crop residues per year, 50% of which comes from east and central south of China. The amount of crop residues is 1.3 times of the total yield of crops, 2 times of the total fodder of grassland, which covers 41% of China's territory. Crop residues of corn, wheat and rice amounted to 239, 137 and 116 million tons, respectively, accounting for nearly 80% of the total crop residues. Unfortunately, the utilizing structure is seriously improper for such abundant biomass resources. Although 23% of the crop residues are used for forage, 4% for industry materials and 0.5% for biogas, the large parts are used with lower efficiency or wasted, with 37% being directly combusted by farmers, 15% lost during collection and the rest 20.5% discarded or directly burnt in the field. Reasonable adjustment of the utilizing pattern and popularization of the recycling agriculture are essential out-ways for residues, with the development of the forage industry being the breakthrough point. We suggested that utilizing the abandoned 20.5% of the total residues for forage and combining agriculture and stock raising can greatly improve the farm system and cut down fertilizer pollution. Through the development of forage industries, the use efficiency of crop residues could be largely enhanced. Commercializing and popularizing technologies of biomass gasification and liquefaction might be substitute

Virtual Welded-Joint Design Integrating Advanced Materials and Processing Technologies

Energy Technology Data Exchange (ETDEWEB)

Yang, Z.; Dong, P.; Liu, S.; Babu, S.; Olson, G.; DebRoy, T.

2005-04-15

The primary goal of this project is to increase the fatigue life of a welded-joint by 10 times and to reduce energy use by 25% through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of a welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve high fatigue strength in a welded-joint it is necessary to manage the weld bead shape for lower stress concentration, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the optimization of the welding process, the welding consumable, the base material, as well as the structure design. The concept of virtual welded-joint design has been proposed and established in this project. The goal of virtual welded-joint design is to develop a thorough procedure to predict the relationship of welding process, microstructure, property, residual stress, and the ultimate weld fatigue strength by a systematic modeling approach. The systematic approach combines five sub-models: weld thermal-fluid model, weld microstructure model, weld material property model, weld residual stress model, and weld fatigue model. The systematic approach is thus based on interdisciplinary applied sciences including heat transfer, computational fluid dynamics, materials science, engineering mechanics, and material fracture mechanics. The sub-models are based on existing models with further development. The results from modeling have been validated with critical experiments. The systematic modeling approach has been used to design high fatigue resistant welds considering the combined effects of weld bead geometry, residual stress, microstructure, and material property. In particular, a special welding wire has been developed in this project to introduce

Thermal Aging Effects on Residual Stress and Residual Strain Distribution on Heat Affected Zone of Alloy 600 in Dissimilar Metal Weld

Energy Technology Data Exchange (ETDEWEB)

Ham, Junhyuk; Choi, Kyoung Joon; Kim, Ji Hyun [UNIST, Ulsan (Korea, Republic of)

2016-10-15

Dissimilar metal weld (DMW), consisting of Alloy 600, Alloy 182, and A508 Gr.3, has been widely used as a joining material of the reactor pressure vessel penetration nozzle and the steam generator tubing for pressurized water reactors (PWR) because of its good mechanical strength, thermal conductivity, and corrosion resistance. Residual tensile stress is mainly nominated as a cause of SCC in light water reactors by IAEA report. So, to relax the residual stress, post-weld heat treatment is required after manufacturing process such as welding. However, thermal treatment has a great effect on the microstructure and the chromium depletion profile on Alloy 600, so called sensitization. By this reason, HAZ on Alloy 600 is critical to crack. According to G.A. Young et al., Crack growth rates (CGR) in the Alloy 600 HAZ were about 30 times faster than those in the Alloy 600 base metal tested under the same conditions. And according to Z.P. Lu et al., CGR in the Alloy 600 HAZ can be more than 20 times higher than that in its base metal. There are some methods to measure the exact value of residual stress on the material surface. The most common way is X-ray diffraction method (XRD). The principle of XRD is based on lattice strains and depends on the changes in the spacing of the atomic planes in material. And there is a computer simulation method to estimate residual stress distribution which is called ANSYS. This study was conducted to investigate how thermal aging affects residual stress and residual strain distribution of Alloy 600 HAZ. Following conclusions can be drawn from this study. According to preceding researches and this study, both the relaxation of residual stress and the change of residual strain follow as similar way, spreading out from concentrated region. The result of Vickers micro-hardness tester shows that tensile residual stresses are distributed broadly on the material aged by 15 years. Therefore, HT400{sub Y}15 material is weakest state for PWSCC. The

Control levels for residual contamination in materials considered for recycle and reuse

International Nuclear Information System (INIS)

Hill, R.L.; Aaberg, R.L.; Baker, D.A.; Kennedy, W.E. Jr.

1993-09-01

Pacific Northwest Laboratory (PNL) is collecting data and conducting technical analyses to support joint efforts by the U.S. Department of Energy (DOE), Office of Environmental Guidance, Air, Water and Radiation Division (DOE/EH-232); by the U.S. Environmental Protection Agency (EPA); and by the U.S. Nuclear Regulatory Commission (NRC) to develop radiological control criteria for the recycle and reuse of scrap materials and equipment that contain residual radioactive contamination. The initial radiological control levels are the concentrations in or on materials considered for recycle or reuse that meet the individual (human) or industrial (electronics/film) dose criteria. The analysis identifies relevant radionuclides, potential mechanisms of exposure, and methods to determine possible non-health-related impacts from residual radioactive contamination in materials considered for recycle or reuse. The generic methodology and scenarios described here provide a basic framework for numerically deriving radiological control criteria for recycle or reuse. These will be adequately conservative for most situations

Energy and raw material potentials of wood residue in the Pacific Coast States: a summary of a preliminary feasibility investigation.

Science.gov (United States)

John B. Grantham; Eldon Estep; John M. Pierovich; Harold Tarkow; Thomas C. Adams

1974-01-01

Results are reported of a preliminary investigation of feasibility of using wood residue to meet energy and raw material needs in the Pacific Coast States. Magnitude of needs was examined and volume of logging-residue and unused mill residue was estimated. Costs of obtaining and preprocessing logging residue for energy and pulp and particle board raw material were...

An Investigation of Porous Structure of TiNi-Based SHS-Materials Produced at Different Initial Synthesis Temperatures

Science.gov (United States)

Khodorenko, V. N.; Anikeev, S. G.; Kokorev, O. V.; Yasenchuk, Yu. F.; Gunther, V. É.

2018-02-01

An investigation of structural characteristics and behavior of TiNi-based pore-permeable materials manufactured by the methods of selfpropagating high-temperature synthesis (SHS) at the initial synthesis temperatures T = 400 and 600°C is performed. It is shown that depending on the temperature regime, the resulting structure and properties of the material can differ. It is found out that the SHS-material produced at the initial synthesis temperature T = 400°C possesses the largest number of micropores in the pore wall surface structure due to a high phase inhomogeneity of the alloy. The regime of structure optimization of the resulting materials is described and the main stages of formation of the pore wall microporous surfaces are revealed. It is demonstrated that after optimization of the surface structure of a TiNi-based fine-pore alloy by its chemical etching, the fraction of micropores measuring in size less than 50 nm increased from 59 to 68%, while the number of pores larger than 1 μm increased twofold from 11 to 22%. In addition, peculiar features of interaction between certain cell cultures with the surface of the SHS-material manufactured at different initial synthesis temperatures are revealed. It is found out that the dynamics of the cell material integration depends on the pore wall surface morphology and dimensions of macropores.

Residual stresses

International Nuclear Information System (INIS)

Macherauch, E.

1978-01-01

Residual stresses are stresses which exist in a material without the influence of external powers and moments. They come into existence when the volume of a material constantly changes its form as a consequence of mechanical, thermal, and/or chemical processes and is hindered by neighbouring volumes. Bodies with residual stress are in mechanical balance. These residual stresses can be manifested by means of all mechanical interventions disturbing this balance. Acoustical, optical, radiological, and magnetical methods involving material changes caused by residual stress can also serve for determining residual stress. Residual stresses have an ambivalent character. In technical practice, they are feared and liked at the same time. They cause trouble because they can be the cause for unexpected behaviour of construction elements. They are feared since they can cause failure, in the worst case with catastrophical consequences. They are appreciated, on the other hand, because, in many cases, they can contribute to improvements of the material behaviour under certain circumstances. But they are especially liked for their giving convenient and (this is most important) mostly uncontrollable explanations. For only in very few cases we have enough knowledge and possibilities for the objective evaluation of residual stresses. (orig.) [de

Structural Materials: 95. Concrete

International Nuclear Information System (INIS)

Naus, Dan J.

2012-01-01

Nuclear power plant concrete structures and their materials of construction are described, and their operating experience noted. Aging and environmental factors that can affect the durability of the concrete structures are identified. Basic components of a program to manage aging of these structures are identified and described. Application of structural reliability theory to devise uniform risk-based criteria by which existing facilities can be evaluated to achieve a desired performance level when subjected to uncertain demands and to quantify the effects of degradation is outlined. Finally, several areas are identified where additional research is desired.

Life prediction technology of structural materials

International Nuclear Information System (INIS)

Nagata, Norio

1992-01-01

There is empirically the time limit of use in all industrial plants and components. By defining the loss of functions as the expiration of life, if the forecast of life time or residual life of plants and components can be done, a very useful means becomes available for safety and economical efficiency. The life of plants is controlled by the occurrence and extension of defects in materials, and by the life of the material which is placed under most severe condition. Such severe condition is the environment of use itself with high temperature, corrosive environment, load, vibration and so on. The forecast of material life is to quantitatively grasp the damage behavior of materials under such condition, and to carry out the time control of the functions of plants by defect control. The time dependence of material damage such as fatigue damage, creep damage and corrosion damage is discussed. The forecast of material life by empirical knowledge and theoretical inference and the forecast of residual life are explained. Finally, the forecast of the life time of light water reactors is described as those constructed in initial period approach their design life. (K.I.)

Effects of LSP on micro-structures and residual stresses in a 4 mm CLAM steel weld joints

Energy Technology Data Exchange (ETDEWEB)

Chen, Xizhang, E-mail: chenxizhang@wzu.edu.cn [School of Mechanical and Electrical Engineering, Wenzhou University., Wenzhou 325035 (China); School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu (China); Fang, Yuanyuan [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu (China); Zhang, Shuyan; Kelleher, Joe F. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Zhou, Jianzhong [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu (China)

2015-05-15

The effects of laser shock processing (LSP) on the distribution of residual stress and micro-structure of China Low Activation Martensitic (CLAM) steel weldment were investigated via neutron diffraction and optical microscope (OM). A pair of 4 mm CLAM steel plates joined by GTA welding. Special attention is paid to the generation of high level compressive residual stresses introduced by LSP. Residual stress in longitudinal, normal and transversal direction at weldment surface and longitudinal stress through thickness are evaluated via neutron diffraction. Compressive residual stress after LSP occurred at more than 90% areas within the weld joint, it is almost double the areas of compressive stress compare to weldment surface before LSP. The maximum compressive normal residual stress becomes to −183 MPa after LSP from −63 MPa before LSP. The Modification of surface micro-structures including weld zone (WZ), heat affected zone (HAZ) and base metal (BM) are also discussed. Results to date demonstrate that laser shock processing has been a great potential method for the improvement of mechanical performance of components.

SNBRFinder: A Sequence-Based Hybrid Algorithm for Enhanced Prediction of Nucleic Acid-Binding Residues.

Directory of Open Access Journals (Sweden)

Xiaoxia Yang

Full Text Available Protein-nucleic acid interactions are central to various fundamental biological processes. Automated methods capable of reliably identifying DNA- and RNA-binding residues in protein sequence are assuming ever-increasing importance. The majority of current algorithms rely on feature-based prediction, but their accuracy remains to be further improved. Here we propose a sequence-based hybrid algorithm SNBRFinder (Sequence-based Nucleic acid-Binding Residue Finder by merging a feature predictor SNBRFinderF and a template predictor SNBRFinderT. SNBRFinderF was established using the support vector machine whose inputs include sequence profile and other complementary sequence descriptors, while SNBRFinderT was implemented with the sequence alignment algorithm based on profile hidden Markov models to capture the weakly homologous template of query sequence. Experimental results show that SNBRFinderF was clearly superior to the commonly used sequence profile-based predictor and SNBRFinderT can achieve comparable performance to the structure-based template methods. Leveraging the complementary relationship between these two predictors, SNBRFinder reasonably improved the performance of both DNA- and RNA-binding residue predictions. More importantly, the sequence-based hybrid prediction reached competitive performance relative to our previous structure-based counterpart. Our extensive and stringent comparisons show that SNBRFinder has obvious advantages over the existing sequence-based prediction algorithms. The value of our algorithm is highlighted by establishing an easy-to-use web server that is freely accessible at http://ibi.hzau.edu.cn/SNBRFinder.

SNBRFinder: A Sequence-Based Hybrid Algorithm for Enhanced Prediction of Nucleic Acid-Binding Residues.

Science.gov (United States)

Yang, Xiaoxia; Wang, Jia; Sun, Jun; Liu, Rong

2015-01-01

Protein-nucleic acid interactions are central to various fundamental biological processes. Automated methods capable of reliably identifying DNA- and RNA-binding residues in protein sequence are assuming ever-increasing importance. The majority of current algorithms rely on feature-based prediction, but their accuracy remains to be further improved. Here we propose a sequence-based hybrid algorithm SNBRFinder (Sequence-based Nucleic acid-Binding Residue Finder) by merging a feature predictor SNBRFinderF and a template predictor SNBRFinderT. SNBRFinderF was established using the support vector machine whose inputs include sequence profile and other complementary sequence descriptors, while SNBRFinderT was implemented with the sequence alignment algorithm based on profile hidden Markov models to capture the weakly homologous template of query sequence. Experimental results show that SNBRFinderF was clearly superior to the commonly used sequence profile-based predictor and SNBRFinderT can achieve comparable performance to the structure-based template methods. Leveraging the complementary relationship between these two predictors, SNBRFinder reasonably improved the performance of both DNA- and RNA-binding residue predictions. More importantly, the sequence-based hybrid prediction reached competitive performance relative to our previous structure-based counterpart. Our extensive and stringent comparisons show that SNBRFinder has obvious advantages over the existing sequence-based prediction algorithms. The value of our algorithm is highlighted by establishing an easy-to-use web server that is freely accessible at http://ibi.hzau.edu.cn/SNBRFinder.

Polylactide-based renewable green composites from agricultural residues and their hybrids.

Science.gov (United States)

Nyambo, Calistor; Mohanty, Amar K; Misra, Manjusri

2010-06-14

Agricultural natural fibers like jute, kenaf, sisal, flax, and industrial hemp have been extensively studied in green composites. The continuous supply of biofibers in high volumes to automotive part makers has raised concerns. Because extrusion followed by injection molding drastically reduces the aspect ratio of biofibers, the mechanical performance of injection molded agricultural residue and agricultural fiber-based composites are comparable. Here, the use of inexpensive agricultural residues and their hybrids that are 8-10 times cheaper than agricultural fibers is demonstrated to be a better way of getting sustainable materials with better performance. Green renewable composites from polylactide (PLA), agricultural residues (wheat straw, corn stover, soy stalks, and their hybrids) were successfully prepared through twin-screw extrusion, followed by injection molding. The effect on mechanical properties of varying the wheat straw amount from 10 to 40 wt % in PLA-wheat straw composites was studied. Tensile moduli were compared with theoretical calculations from the rule of mixture (ROM). Combination of agricultural residues as hybrids is proved to reduce the supply chain concerns for injection molded green composites. Densities of the green composites were found to be lower than those of conventional glass fiber composites.

Residual stresses in weld-clad reactor pressure vessel steel

International Nuclear Information System (INIS)

Bertram, W.

1975-01-01

Cladding of low alloy nuclear reactor pressure vessel steel with austenitic stainless steel introduces in heavy section components high residual stresses which may cause microcrack formation in stress relief heat treatment. In this investigation an attempt is made to contribute to the solution of the stress relief cracking problem by determining quantitatively the magnitude and distribution of the residual stresses after cladding and after subsequent stress relief heat treatment. The distribution of residual stresses was determined on the basis of a combined experimental-mathematical procedure. Heavy section plate specimens of low alloy steel as base material were given an austenitic monolayer-cladding using the techniques of strip electrode and plasma hot wire cladding, respectively. A number of plates was stress relief heat treated. Starting from the cladded surface the thickness of the plates was reduced by subsequent removal of layers of material. The elastic strain reaction to the removal of each layer was measured by strain gauges. From the data obtained the biaxial residual stress distribution was computed as a function of thickness using relations which are derived for this particular case. In summary, lower residual stresses are caused by reduced thickness of the components. As the heat input, is decreased at identical base material thickness, the residual stresses are lowered also. The height of the tensile residual stress peak, however, remains approximataly constant. In stress relief annealed condition the residual stresses in the cladding are in tension; in the base material the residual stresses are negligibly small

Radiological assessment of an area with uranium residual material

International Nuclear Information System (INIS)

Perez-Sanchez, Danyl; Cancio, David; Alvarez, Alicia

2008-01-01

As a result of a pilot project developed at the old Spanish 'Junta de Energia Nuclear' to extract uranium from ores, tailings materials were generated. Most of these residual materials were sent back to different uranium mines, but a small amount of it was mixed with conventional building materials and deposited near the old plant until the surrounding ground was flattened. The affected land is included in an area under institutional control and used as recreational area. At the time of processing, uranium isotopes were separated but other radionuclides of the uranium decays series as 230 Th, 226 Ra and daughters remain in the residue. Recently, the analyses of samples taken at different ground's depths confirm their presence. This paper presents the methodology used to calculate the derived concentration level to ensure the reference dose level of 0.1 mSv y-1 used as radiological criteria. In this study, a radiological impact assessment was performed modelling the area as recreational scenario. The modelization study was carried out with the code RESRAD considering as exposure pathways, external irradiation, inadvertent ingestion of soil, inhalation of resuspended particles, and inhalation of outdoor radon ( 222 Rn). As result was concluded that, if the concentration of 226 Ra in the first 15 cm of soil is lower than, 0.34 Bq g-1 , the dose would not exceed the reference dose. Applying this value as a derived concentration level and comparing with the results of measurements on the ground, some areas with a concentration of activity slightly higher than latter were found. In these zones the remediation proposal has been to cover with a layer of 15 cm of clean material. This action represents a reduction of 85% of the dose and ensures compliance with the reference dose. (author)

PREvaIL, an integrative approach for inferring catalytic residues using sequence, structural, and network features in a machine-learning framework.

Science.gov (United States)

Song, Jiangning; Li, Fuyi; Takemoto, Kazuhiro; Haffari, Gholamreza; Akutsu, Tatsuya; Chou, Kuo-Chen; Webb, Geoffrey I

2018-04-14

Determining the catalytic residues in an enzyme is critical to our understanding the relationship between protein sequence, structure, function, and enhancing our ability to design novel enzymes and their inhibitors. Although many enzymes have been sequenced, and their primary and tertiary structures determined, experimental methods for enzyme functional characterization lag behind. Because experimental methods used for identifying catalytic residues are resource- and labor-intensive, computational approaches have considerable value and are highly desirable for their ability to complement experimental studies in identifying catalytic residues and helping to bridge the sequence-structure-function gap. In this study, we describe a new computational method called PREvaIL for predicting enzyme catalytic residues. This method was developed by leveraging a comprehensive set of informative features extracted from multiple levels, including sequence, structure, and residue-contact network, in a random forest machine-learning framework. Extensive benchmarking experiments on eight different datasets based on 10-fold cross-validation and independent tests, as well as side-by-side performance comparisons with seven modern sequence- and structure-based methods, showed that PREvaIL achieved competitive predictive performance, with an area under the receiver operating characteristic curve and area under the precision-recall curve ranging from 0.896 to 0.973 and from 0.294 to 0.523, respectively. We demonstrated that this method was able to capture useful signals arising from different levels, leveraging such differential but useful types of features and allowing us to significantly improve the performance of catalytic residue prediction. We believe that this new method can be utilized as a valuable tool for both understanding the complex sequence-structure-function relationships of proteins and facilitating the characterization of novel enzymes lacking functional annotations

Residual Motion and Duty Time in Respiratory Gating Radiotherapy Using Individualized or Population-Based Windows

International Nuclear Information System (INIS)

Fuji, Hiroshi; Asada, Yoshihiro; Numano, Masumi; Yamashita, Haruo; Nishimura, Tetsuo; Hashimoto, Takayuki; Harada, Hideyuki; Asakura, Hirofumi; Murayama, Shigeyuki

2009-01-01

Purpose: The efficiency and precision of respiratory gated radiation therapy for tumors is affected by variations in respiration-induced tumor motion. We evaluated the use of individualized and population-based parameters for such treatment. Methods and Materials: External respiratory signal records and images of respiration-induced tumor motion were obtained from 42 patients undergoing respiratory gated radiation therapy for liver tumors. Gating window widths were calculated for each patient, with 2, 4, and 10 mm of residual motion, and the mean was defined as the population-based window width. Residual motions based on population-based and predefined window widths were compared. Duty times based on whole treatment sessions, at various window levels, were calculated. The window level giving the longest duty time was defined as the individualized most efficient level (MEL). MELs were also calculated based on the first 10 breathing cycles. The duty times for population-based MELs (defined as mean MELs) and individualized MELs were compared. Results: Tracks of respiration-induced tumor motion ranged from 3 to 50 mm. Half of the patients had larger actual residual motions than the assigned residual motions. Duty times were greater when based on individualized, rather than population-based, window widths. The MELs established during whole treatment sessions for 2 mm and 4 mm of residual motion gave significantly increased duty times, whereas those calculated using the first 10 breathing cycles showed only marginal increases. Conclusions: Using individualized window widths and levels provided more precise and efficient respiratory gated radiation therapy. However, methods for predicting individualized window levels before treatment remain to be explored.

Graphene-based structure, method of suspending graphene membrane, and method of depositing material onto graphene membrane

Science.gov (United States)

Zettl, Alexander K.; Meyer, Jannik Christian

2013-04-02

An embodiment of a method of suspending a graphene membrane across a gap in a support structure includes attaching graphene to a substrate. A pre-fabricated support structure having the gap is attached to the graphene. The graphene and the pre-fabricated support structure are then separated from the substrate which leaves the graphene membrane suspended across the gap in the pre-fabricated support structure. An embodiment of a method of depositing material includes placing a support structure having a graphene membrane suspended across a gap under vacuum. A precursor is adsorbed to a surface of the graphene membrane. A portion of the graphene membrane is exposed to a focused electron beam which deposits a material from the precursor onto the graphene membrane. An embodiment of a graphene-based structure includes a support structure having a gap, a graphene membrane suspended across the gap, and a material deposited in a pattern on the graphene membrane.

Steels from materials science to structural engineering

CERN Document Server

Sha, Wei

2013-01-01

Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

A hierarchical structure through imprinting of a polyimide precursor without residual layers

International Nuclear Information System (INIS)

Pai, I-Ting; Hon, Min-Hsiung; Leu, Ing-Chi

2008-01-01

A patterned polyimide without a residual layer is obtained by imprinting with the assistance of a residual solvent. The effects of the wetting behaviors of the poly-amic acid (PAA) solution coated on various surfaces are examined and the formation of hierarchical patterns without residual layers is demonstrated. polydimethylsiloxane (PDMS) and PEI/PDMS are used as imprinting molds with Si and 300 nm SiO 2 /Si as substrates. The results indicate that the various ambits of patterns without a residual layer are formed due to the dewetting phenomena caused by surface tension (Suh 2006 Small 2 832). During imprinting, PDMS with a low surface energy makes the PAA solution flow away from its surface exposing the contact area due to dewetting. Self-organized hierarchical structures are also obtained from this process due to effective dewetting. The present study provides a new approach for fabricating patterns without residual layers and the consequent preparation of hierarchical structures, which is considered to be impossible using the lithographic technique

CO₂ Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues.

Science.gov (United States)

Bermúdez, José M; Dominguez, Pablo Haro; Arenillas, Ana; Cot, Jaume; Weber, Jens; Luque, Rafael

2013-10-18

Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO₂ adsorption properties, with interestingly high gas selectivities for CO₂ (α > 200 at a gas composition of 15% CO₂/85% N₂, 273K, 1 bar) and capacities (>2 mmol·g -1 at 273 K). Both CO₂ isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO₂ which may be correlated with both: N content in the leather residues and ultrasmall pore sizes.

New materials and structures for photovoltaics

Science.gov (United States)

Zunger, Alex; Wagner, S.; Petroff, P. M.

1993-01-01

Despite the fact that over the years crystal chemists have discovered numerous semiconducting substances, and that modern epitaxial growth techniques are able to produce many novel atomic-scale architectures, current electronic and opto-electronic technologies are based but on a handful of ˜10 traditional semiconductor core materials. This paper surveys a number of yet-unexploited classes of semiconductors, pointing to the much-needed research in screening, growing, and characterizing promising members of these classes. In light of the unmanageably large number of a-priori possibilities, we emphasize the role that structural chemistry and modern computer-aided design must play in screening potentially important candidates. The basic classes of materials discussed here include nontraditional alloys, such as non-isovalent and heterostructural semiconductors, materials at reduced dimensionality, including superlattices, zeolite-caged nanostructures and organic semiconductors, spontaneously ordered alloys, interstitial semiconductors, filled tetrahedral structures, ordered vacancy compounds, and compounds based on d and f electron elements. A collaborative effort among material predictor, material grower, and material characterizer holds the promise for a successful identification of new and exciting systems.

Overview and applicability of residual stress estimation of film-substrate structure

International Nuclear Information System (INIS)

Chou, Tsung-Lin; Yang, Shin-Yueh; Chiang, Kuo-Ning

2011-01-01

Residual stresses arising from thermal mismatch in layered structures rank among the major causes of mechanical failures in light-emitting diodes, integrated circuits, electronic packages, and micro-electro-mechanical systems. Applying analytical solutions to predict or calculate residual stresses' magnitude and distribution in multilayer film-substrate system has been widely adopted by many researchers. These researches are based on multilayer theories of film-substrate systems, such as Suhir's formula, Stoney's equation, and extend Stoney's equations. To discuss and distinguish the characteristics of these approaches, finite element analysis numerical solutions and multilayer theory analytical solutions are compared and analyzed. This encompasses the theories' application spectrum as well as their prediction capability. In addition, this work not only discusses the theories' property and workability but also demonstrate the feasibility of the finite element method (FEM) and bilayer theories in experiment. The experimental result demonstrates that FEM is a reliable approach in predicting the mechanical behavior of multilayer structures. Hence, when calculating or predicting thin film stress using the aforementioned theories, the methodology proposed in this research can be employed to effectively validate the feasibility of these theories.

Fast-neutron capture in structural materials

International Nuclear Information System (INIS)

Froehner, F.H.

1982-01-01

The discussions of developments in the field of capture data of structural materials since the 1977 Geel meeting were mainly based on the invited paper presented by G. Rohr and on information from the other participants about their own activities. There was not much input about recent work in japan, where the new version JENDL-2 of the Japanese Evaluated Nuclear Data Library has been issued, or on the resonance analysis work on iron and nickel isotopes going on at ORNL. Moreover, the discussion was restricted to the three principal structural material elements Cr, Fe and Ni. Some of the remaining structural materials such as Zr and Mo were covered by the Working Group on Fission Product Nuclides

Cementing Material From Rice Husk-Broken Bricks-Spent Bleaching Earth-Dried Calcium Carbide Residue

Directory of Open Access Journals (Sweden)

Muthengia Jackson Washira

2012-10-01

Full Text Available A cementious material, coded CSBR (Carbide residue Spent bleaching earth Broken bricks and Rice husks, was made from dried calcium carbide residue (DCCR and an incinerated mix of rice husks (RH, broken bricks (BB and spent bleaching earth (SBE. Another material, coded SBR (Spent bleaching earth Broken bricks and Rice husk ash, was made from mixing separately incinerated RH, SBE and ground BB in the same ash ratio as in CSBR. When CSBR was inter-ground with Ordinary Portland Cement (OPC, it showed a continued decrease in Ca(OH2 in the hydrating cement as a function of curing time and replacement levels of the cement. Up to 45 % replacement of the OPC by CSBR produced a Portland pozzolana cement (PPC material that passed the relevant Kenyan Standard. Incorporation of the CSBR in OPC reduces the resultant calcium hydroxide from hydrating Portland cement. The use of the waste materials in production of cementitious material would rid the environment of wastes and lead to production of low cost cementitious material.

Defining an essence of structure determining residue contacts in proteins.

Science.gov (United States)

Sathyapriya, R; Duarte, Jose M; Stehr, Henning; Filippis, Ioannis; Lappe, Michael

2009-12-01

The network of native non-covalent residue contacts determines the three-dimensional structure of a protein. However, not all contacts are of equal structural significance, and little knowledge exists about a minimal, yet sufficient, subset required to define the global features of a protein. Characterisation of this "structural essence" has remained elusive so far: no algorithmic strategy has been devised to-date that could outperform a random selection in terms of 3D reconstruction accuracy (measured as the Ca RMSD). It is not only of theoretical interest (i.e., for design of advanced statistical potentials) to identify the number and nature of essential native contacts-such a subset of spatial constraints is very useful in a number of novel experimental methods (like EPR) which rely heavily on constraint-based protein modelling. To derive accurate three-dimensional models from distance constraints, we implemented a reconstruction pipeline using distance geometry. We selected a test-set of 12 protein structures from the four major SCOP fold classes and performed our reconstruction analysis. As a reference set, series of random subsets (ranging from 10% to 90% of native contacts) are generated for each protein, and the reconstruction accuracy is computed for each subset. We have developed a rational strategy, termed "cone-peeling" that combines sequence features and network descriptors to select minimal subsets that outperform the reference sets. We present, for the first time, a rational strategy to derive a structural essence of residue contacts and provide an estimate of the size of this minimal subset. Our algorithm computes sparse subsets capable of determining the tertiary structure at approximately 4.8 A Ca RMSD with as little as 8% of the native contacts (Ca-Ca and Cb-Cb). At the same time, a randomly chosen subset of native contacts needs about twice as many contacts to reach the same level of accuracy. This "structural essence" opens new avenues in the

Structure, microstructure and residual stresses in borided steels

Czech Academy of Sciences Publication Activity Database

Pala, Z.; Mušálek, Radek; Kyncl, J.; Harcuba, P.; Stráský, J.; Kolařík, K.

2013-01-01

Roč. 20, č. 2 (2013), s. 93-95 ISSN 1211-5894. [Struktura 2013 - Kolokvium Krystalografické společnosti. Češkovice (Blansko), 09.09.2013-13.09.2013] Institutional support: RVO:61389021 Keywords : boriding * surface hardening * iron borides * tooth-shaped microstructure * residual stresses Subject RIV: JK - Corrosion ; Surface Treatment of Materials http://www.xray.cz/ms/bul2013-2/s6.pdf

Applications of bauxite residue: A mini-review.

Science.gov (United States)

Verma, Ajay S; Suri, Narendra M; Kant, Suman

2017-10-01

Bauxite residue is the waste generated during alumina production by Bayer's process. The amount of bauxite residue (40-50 wt%) generated depends on the quality of bauxite ore used for the processing. High alkalinity and high caustic content in bauxite residue causes environmental risk for fertile soil and ground water contamination. The caustic (NaOH) content in bauxite residue leads to human health risks, like dermal problems and irritation to eyes. Moreover, disposal of bauxite residue requires a large area; such problems can only be minimised by utilising bauxite residue effectively. For two decades, bauxite residue has been used as a binder in cement industries and filler/reinforcement for composite materials in the automobile industry. Valuable metals and oxides, like alumina (Al 2 O 3 ), titanium oxide (TiO 2 ) and iron oxide Fe 2 O 3 , were extracted from bauxite residue to reduce waste. Bauxite residue was utilised in construction and structure industries to make geopolymers. It was also used in the making of glass-ceramics and a coating material. Recently bauxite residue has been utilised to extract rare earth elements like scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd) and dysprosium (Dy). In this review article, the mineralogical characteristics of bauxite residue are summarised and current progresses on utilisation of bauxite residue in different fields of science and engineering are presented in detail.

Status of LWR primary pressure boundary structural materials

Energy Technology Data Exchange (ETDEWEB)

Chi, Se Hwan; Hong, Jun Hwa; Byun, Taek Sang; Kang, Sung Sik; Ryu, Woo Seog; Lee, Bong Sang; Kook, Il Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-07-01

The integrity of major systems, structures and components is a prerequisite to the economy and safety of an existing light water reactor and also for the next generation reactors. As few reactor structural materials are being manufactured by domestic companies, based on economic and safety reasons, a new demand to improve the quality of domestic reactor structural materials and to develop reactor structural steels has arisen. Investigations on the state-of-the-art of the materials specifications, performance and current state of structural materials development were performed as a first step to domestic reactor structural steel development and summarized the result in the present report. (Author) 10 refs., 10 figs., 21 tabs.

A Refined Model for the Structure of Acireductone Dioxygenase from Klebsiella ATCC 8724 Incorporating Residual Dipolar Couplings

Energy Technology Data Exchange (ETDEWEB)

Pochapsky, Thomas C., E-mail: pochapsk@brandeis.edu; Pochapsky, Susan S.; Ju Tingting [Brandeis University, Department of Chemistry (United States); Hoefler, Chris [Brandeis University, Department of Biochemistry (United States); Liang Jue [Brandeis University, Department of Chemistry (United States)

2006-02-15

Acireductone dioxygenase (ARD) from Klebsiella ATCC 8724 is a metalloenzyme that is capable of catalyzing different reactions with the same substrates (acireductone and O{sub 2}) depending upon the metal bound in the active site. A model for the solution structure of the paramagnetic Ni{sup 2+}-containing ARD has been refined using residual dipolar couplings (RDCs) measured in two media. Additional dihedral restraints based on chemical shift (TALOS) were included in the refinement, and backbone structure in the vicinity of the active site was modeled from a crystallographic structure of the mouse homolog of ARD. The incorporation of residual dipolar couplings into the structural refinement alters the relative orientations of several structural features significantly, and improves local secondary structure determination. Comparisons between the solution structures obtained with and without RDCs are made, and structural similarities and differences between mouse and bacterial enzymes are described. Finally, the biological significance of these differences is considered.

Behaviour of bound residues of carbon-14 labelled organic environmental chemicals in vegetable materials

International Nuclear Information System (INIS)

Wallnoefer, P.; Koeniger, M.; Ziegler, W.

1991-01-01

Growing cultures of cell suspensions of tomato and maize were capable of partly integrating (radioactively labelled) chemicals like 4-nitrophenol or 2-nitroaniline into the cell wall structure. The rates of integration found range from 1.1 per cent (4-NP in tomato) to 7.7 per cent (2-NA in maize). Maize is more prone to form bound residues than tomato; moreover, the results point to a dependence on the chemical structure of the xenobiotic substance. Enzymatic-chemical disaggregation of the cell wall material revealed an uneven distribution of radioactivity in the individual fractions: Tomato cells stored 4-NP above all in the starch fraction and to a smaller extent in the protein fraction, while storage of 2-NA in starch, protein and hemicellulose was about equal. Maize cells integrated both substances preferably into lignin and to a distinctly smaller extent also into starch and protein. (orig.) [de

Improvement of hydrogen bond geometry in protein NMR structures by residual dipolar couplings - an assessment of the interrelation of NMR restraints

Energy Technology Data Exchange (ETDEWEB)

Jensen, Pernille Rose; Axelsen, Jacob Bock [University of Copenhagen, Institute of Molecular Biology (Denmark); Lerche, Mathilde Hauge [Amersham Health (Sweden); Poulsen, Flemming M. [University of Copenhagen, Institute of Molecular Biology (Denmark)], E-mail: fmp@apk.molbio.ku.dk

2004-01-15

We have examined how the hydrogen bond geometry in three different proteins is affected when structural restraints based on measurements of residual dipolar couplings are included in the structure calculations. The study shows, that including restraints based solely on {sup 1}H{sup N}-{sup 15}N residual dipolar couplings has pronounced impact on the backbone rmsd and Ramachandran plot but does not improve the hydrogen bond geometry. In the case of chymotrypsin inhibitor 2 the addition of {sup 13}CO-{sup 13}C{sup {alpha}} and {sup 15}N-{sup 13}CO one bond dipolar couplings as restraints in the structure calculations improved the hydrogen bond geometry to a quality comparable to that obtained in the 1.8 A resolution X-ray structure of this protein. A systematic restraint study was performed, in which four types of restraints, residual dipolar couplings, hydrogen bonds, TALOS angles and NOEs, were allowed in two states. This study revealed the importance of using several types of residual dipolar couplings to get good hydrogen bond geometry. The study also showed that using a small set of NOEs derived only from the amide protons, together with a full set of residual dipolar couplings resulted in structures of very high quality. When reducing the NOE set, it is mainly the side-chain to side-chain NOEs that are removed. Despite of this the effect on the side-chain packing is very small when a reduced NOE set is used, which implies that the over all fold of a protein structure is mainly determined by correct folding of the backbone.

The effect of Residual Stress on the Stress Intensity Factor of Nuclear Material

International Nuclear Information System (INIS)

Song, Taek Ho

2008-01-01

As NPP (Nuclear Power Plant) gets aged, the importance of the pressure boundary integrity increases very much to those who are trying to operate their plant beyond its design life. Not long ago, Boric acid crystal was found at the RPV outlet nozzle of V.C. Summer plant during the visual examination in 2000. After this finding, non-destructive examination was taken to find out what's taken place. As a result of this examination, circumferential and axial cracks were found. With Metallurgical structure examination, it was shown that crack had been developed at the mid-point between Inco-alloy buttering and weld metal. It was turned out that high welding residual stress was the main cause of the cracking. Because of the through wall crack, nozzle and welding parts were replaced. Many other nuclear power plants experienced similar pressure boundary stress corrosion cracks (SCCs). KEPRI (Korea Electric Power Research Institute) has carried out research projects for managing and preventing these kinds of cracks in nuclear power plants (NPPs). The titles of these research projects are 'Development of Stress Corrosion Cracking Management Technology and Aging Monitor for NPP Main Components' and 'Development of Analysis Technology for Crack Management of Dissimilar Metal Weld'. Through these projects, residual stress measurement techniques have been exercised at various points in mock-up test specimens to simulate nuclear power plant dissimilar base metal and weldment residual stress. X-ray test and hole drilling method have been reviewed to measure residual stresses of the dissimilar metal welds. This paper shows some point of view in residual stress measurement. Fracture mechanics analysis has been performed to explain the importance of residual stress measurement in association with nuclear power plant safety

Analysis of macro and micro residual stresses in functionally graded materials by diffraction methods

CERN Document Server

Dantz, D; Reimers, W

1999-01-01

The residual stress state in microwave sintered metal-ceramic functionally graded materials (FGM) consisting of 8Y-ZrO/sub 2//Ni and 8Y-ZrO/sub 2//NiCr8020, respectively, was analysed by non- destructive diffraction methods. In $9 order to get knowledge of the complete residual stress state in the near surface region as well as in the interior of the material, complementary methods were applied. Whereas the surface was characterised by X-ray techniques using $9 conventional sources, the stresses within the bulk of the material were investigated by means of high energy synchrotron radiation. The stress state was found to obey the differences in the coefficients of thermal expansion $9 (micro-stresses) on the one hand and the inhomogeneous cooling conditions (macrostresses) on the other hand. (7 refs).

Feasibility Study on 3-D Printing of Metallic Structural Materials with Robotized Laser-Based Metal Additive Manufacturing

Science.gov (United States)

Ding, Yaoyu; Kovacevic, Radovan

2016-07-01

Metallic structural materials continue to open new avenues in achieving exotic mechanical properties that are naturally unavailable. They hold great potential in developing novel products in diverse industries such as the automotive, aerospace, biomedical, oil and gas, and defense. Currently, the use of metallic structural materials in industry is still limited because of difficulties in their manufacturing. This article studied the feasibility of printing metallic structural materials with robotized laser-based metal additive manufacturing (RLMAM). In this study, two metallic structural materials characterized by an enlarged positive Poisson's ratio and a negative Poisson's ratio were designed and simulated, respectively. An RLMAM system developed at the Research Center for Advanced Manufacturing of Southern Methodist University was used to print them. The results of the tensile tests indicated that the printed samples successfully achieved the corresponding mechanical properties.

Adjoint-based optimization of mechanical performance in polycrystalline materials and structures through texture control

Energy Technology Data Exchange (ETDEWEB)

Gu, Grace [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brown, Judith Alice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bishop, Joseph E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-08-01

The texture of a polycrystalline material refers to the preferred orientation of the grains within the material. In metallic materials, texture can significantly affect the mechanical properties such as elastic moduli, yield stress, strain hardening, and fracture toughness. Recent advances in additive manufacturing of metallic materials offer the possibility in the not too distant future of controlling the spatial variation of texture. In this work, we investigate the advantages, in terms of mechanical performance, of allowing the texture to vary spatially. We use an adjoint-based gradient optimization algorithm within a finite element solver (COMSOL) to optimize several engineering quantities of interest in a simple structure (hole in a plate) and loading (uniaxial tension) condition. As a first step to general texture optimization, we consider the idealized case of a pure fiber texture in which the homogenized properties are transversely isotropic. In this special case, the only spatially varying design variables are the three Euler angles that prescribe the orientation of the homogenized material at each point within the structure. This work paves a new way to design metallic materials for tunable mechanical properties at the microstructure level.

Determination of residual monomers released from soft lining materials with the use of HPLC

International Nuclear Information System (INIS)

Sofou, A.; Tsoupi, I.; Karayannia, M.

2007-01-01

A study was carried out to examine the post polymerized leachability of three non phthalic and four phthalic residual monomers, from twelve commercially available soft lining materials, using HPLC. Specimens of equal: dimensions were constructed from each brand of material following a standardized procedure and were stored in three different conditions of storage i.e. distilled water, artificial saliva and a binary mixture of ethanol-water with the resulting liquids providing samples for analysis in the HPLC apparatus. Three different experiments were performed for each brand of material and each condition of storage, in order to examine the parameters time and temperature. The results obtained from this study suggest that a wide spectrum of residues is diffusing out of the twelve examined soft lining materials. The non phthalic compounds were leaching at high concentrations while all the phthalates examined exhibited different degrees of elusion commensurate with the storage condition, brand of material and type of experiment. The main non phthalic component extracted from all the materials was methyl methacrylate, while the mainly extracted phthalic compound was different from each material. The level of elusion seems to be increasing dependent on time, medium of storage and temperature as well. (author)

Structural characterization of complex O-linked glycans from insect-derived material.

Science.gov (United States)

Garenaux, Estelle; Maes, Emmanuel; Levêque, S; Brassart, Colette; Guerardel, Yann

2011-07-01

Although insects are among the most diverse groups of the animal kingdom and may be found in nearly all environments, one can observe an obvious lack of structural data on their glycosylation ability. Hymenoptera is the second largest of all insect orders with more than 110,000 identified species and includes the most famous examples of social insects' species such as wasps, bees and ants. In this report, the structural variety of O-glycans has been studied in two Hymenoptera species. In a previous study, we showed that major O-glycans from common wasp (Vespula germanica) salivary mucins correspond to T and Tn antigen, eventually substituted by phosphoethanolamine or phosphate groups. More detailed structural analysis performed by mass spectrometry revealed numerous minor O-glycan structures bearing Gal, GlcNAc, GalNAc and Fuc residues. Thus, in order to investigate glycosylation diversity in insects, we used common wasp nest (V. germanica) and hornet nest (Vespa cabro) as starting materials. These materials were submitted to reductive β-elimination and the released oligosaccharide-alditols further fractionated by multidimensional HPLC. Tandem mass spectrometry analyses combined with NMR data revealed the presence of various families of complex O-glycans differing accordingly to both core structures and external motifs. Glycans from wasp were characterized by the presence of core types 1 and 2, Lewis X and internal Gal-Gal motifs. We also observed unusual O-glycans containing a reducing GalNAc unit directly substituted by a fucose residue. In contrast, hornet O-glycans appeared as a rather homogeneous family of core 1 type O-glycans extended by galactose oligomers. Copyright © 2011 Elsevier Ltd. All rights reserved.

An entropy-variables-based formulation of residual distribution schemes for non-equilibrium flows

Science.gov (United States)

Garicano-Mena, Jesús; Lani, Andrea; Degrez, Gérard

2018-06-01

In this paper we present an extension of Residual Distribution techniques for the simulation of compressible flows in non-equilibrium conditions. The latter are modeled by means of a state-of-the-art multi-species and two-temperature model. An entropy-based variable transformation that symmetrizes the projected advective Jacobian for such a thermophysical model is introduced. Moreover, the transformed advection Jacobian matrix presents a block diagonal structure, with mass-species and electronic-vibrational energy being completely decoupled from the momentum and total energy sub-system. The advantageous structure of the transformed advective Jacobian can be exploited by contour-integration-based Residual Distribution techniques: established schemes that operate on dense matrices can be substituted by the same scheme operating on the momentum-energy subsystem matrix and repeated application of scalar scheme to the mass-species and electronic-vibrational energy terms. Finally, the performance gain of the symmetrizing-variables formulation is quantified on a selection of representative testcases, ranging from subsonic to hypersonic, in inviscid or viscous conditions.

Silica-Based and Borate-Based, Titania-Containing Bioactive Coatings Characterization: Critical Strain Energy Release Rate, Residual Stresses, Hardness, and Thermal Expansion

Directory of Open Access Journals (Sweden)

Omar Rodriguez

2016-12-01

Full Text Available Silica-based and borate-based glass series, with increasing amounts of TiO2 incorporated, are characterized in terms of their mechanical properties relevant to their use as metallic coating materials. It is observed that borate-based glasses exhibit CTE (Coefficient of Thermal Expansion closer to the substrate’s (Ti6Al4V CTE, translating into higher mode I critical strain energy release rates of glasses and compressive residual stresses and strains at the coating/substrate interface, outperforming the silica-based glasses counterparts. An increase in the content of TiO2 in the glasses results in an increase in the mode I critical strain energy release rate for both the bulk glass and for the coating/substrate system, proving that the addition of TiO2 to the glass structure enhances its toughness, while decreasing its bulk hardness. Borate-based glass BRT3, with 15 mol % TiO2 incorporated, exhibits superior properties overall compared to the other proposed glasses in this work, as well as 45S5 Bioglass® and Pyrex.

Derivation of uranium residual radioactive material guidelines for the former Alba Craft Laboratory site, Oxford, Ohio

International Nuclear Information System (INIS)

Nimmagadda, M.; Faillace, E.; Yu, C.

1994-01-01

Residual radioactive material guidelines for uranium were derived for the former Alba Craft Laboratory site in Oxford, Ohio. This site has been identified for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy (DOE). Single nuclide and total uranium guidelines were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the former Alba Craft Laboratory site should not exceed a dose of 30 mrem/yr following remedial action for the current use and likely future use scenarios or a dose of 100 mrem/yr for less likely future use scenarios (Yu et al. 1993). The DOE residual radioactive material guideline computer code, RESRAD, which implements the methodology described in the DOE manual for implementing residual radioactive material guidelines, was used in this evaluation

Assessment of the Residual Life of Steam Pipeline Material beyond the Computational Working Time

Directory of Open Access Journals (Sweden)

Marek Sroka

2017-03-01

Full Text Available This paper presents the evaluation of durability for the material of repair welded joints made from (13HMF 14MoV6-3 steel after long-term service, and from material in the as-received condition and after long-term service. Microstructure examinations using a scanning electron microscope, hardness measurements and creep tests of the basic material and welded joints of these steels were carried out. These tests enabled the time of further safe service of the examined repair welded joints to be determined in relation to the residual life of the materials. The evaluation of residual life and disposable life, and thus the estimation and determination of the time of safe service, is of great importance for the operation of components beyond the design service life. The obtained test results are part of the materials’ characteristics developed by the Institute for Ferrous Metallurgy for steels and welded joints made from these steels to work under creep conditions.

Removal of polycyclic aromatic hydrocarbons from aqueous solution using plant residue materials as a biosorbent

Energy Technology Data Exchange (ETDEWEB)

Chen Baoliang, E-mail: blchen@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Yuan Miaoxin; Liu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

2011-04-15

Graphical abstract: The structure-effect relationship provides a reference to select and modify plant residues as a biosorbent with high efficiency to tackle organic pollutants. Research highlights: {yields} Polycyclic aromatic hydrocarbons are effectively removed by plant residues. {yields} Biosorption mechanism of plant residues to abate PAHs is a partitioning process. {yields} Partition coefficients are negatively related with sugar contents of biosorbent. {yields} The aromatic component and K{sub ow} exhibit positive effects on biosorption. {yields} The structure-effect relationship guides plant residue using as a biosorbent. - Abstract: To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N{sub 2} surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (K{sub d}) followed the order of PN > BL > OP > RR > WC, ranged from 2484 {+-} 24.24 to 5306 {+-} 92.49 L/kg. Except the WC sample, the K{sub d} values were negatively correlated with sugar content, polar index [(N + O)/C] of the biosorbents, while the aromatic component exhibited positive effects. For a given biosorbent of bamboo leaves, the carbon-normalized partition coefficients (K{sub oc}) were linearly correlated with octanol-water partition coefficients (K{sub ow}) of PAHs, i.e., log K{sub oc} = 1.16 log K{sub ow} - 1.21. The structure-effect relationship provides a reference to select and modify plant residues as a

Role of long- and short-range hydrophobic, hydrophilic and charged residues contact network in protein’s structural organization

Directory of Open Access Journals (Sweden)

Sengupta Dhriti

2012-06-01

Full Text Available Abstract Background The three-dimensional structure of a protein can be described as a graph where nodes represent residues and the strength of non-covalent interactions between them are edges. These protein contact networks can be separated into long and short-range interactions networks depending on the positions of amino acids in primary structure. Long-range interactions play a distinct role in determining the tertiary structure of a protein while short-range interactions could largely contribute to the secondary structure formations. In addition, physico chemical properties and the linear arrangement of amino acids of the primary structure of a protein determines its three dimensional structure. Here, we present an extensive analysis of protein contact subnetworks based on the London van der Waals interactions of amino acids at different length scales. We further subdivided those networks in hydrophobic, hydrophilic and charged residues networks and have tried to correlate their influence in the overall topology and organization of a protein. Results The largest connected component (LCC of long (LRN-, short (SRN- and all-range (ARN networks within proteins exhibit a transition behaviour when plotted against different interaction strengths of edges among amino acid nodes. While short-range networks having chain like structures exhibit highly cooperative transition; long- and all-range networks, which are more similar to each other, have non-chain like structures and show less cooperativity. Further, the hydrophobic residues subnetworks in long- and all-range networks have similar transition behaviours with all residues all-range networks, but the hydrophilic and charged residues networks don’t. While the nature of transitions of LCC’s sizes is same in SRNs for thermophiles and mesophiles, there exists a clear difference in LRNs. The presence of larger size of interconnected long-range interactions in thermophiles than mesophiles, even at

Derivation of guidelines for uranium residual radioactive material in soil at the New Brunswick Site, Middlesex County, New Jersey

International Nuclear Information System (INIS)

Dunning, D.; Kamboj, S.; Nimmagadda, M.; Yu, C.

1996-02-01

Residual radioactive material guidelines for uranium in soil were derived for the New Brunswick Site, located in Middlesex County, New Jersey. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program of the US Department of Energy (DOE). Residual radioactive material guidelines for individual radionuclides of concern and total uranium were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the New Brunswick Site should not exceed a dose of 30 mrem/yr following remedial action for the current-use and likely future-use scenarios or a dose of 100 mrem/yr for less likely future-use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation; RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines. The guidelines derived in this report are intended to apply to the remediation of these remaining residual radioactive materials at the site. The primary radionuclides of concern in these remaining materials are expected to be radium-226 and, to a lesser extent, natural uranium and thorium. The DOE has established generic cleanup guidelines for radium and thorium in soil; however, cleanup guidelines for other radionuclides must be derived on a site-specific basis

Residual Stress Analysis of Severe Plastic Deformed Materials using the Finite Element Method and the Neutron Diffraction Method

International Nuclear Information System (INIS)

Kang, Mi Hyun; Seong, Back Suck; Kim, Hyoung Seop

2009-01-01

Severe plastic deformation (SPD) is one of the most promising top-down techniques, moving towards industrialization to fabricate bulk ultrafine grain materials. The strain distribution and deformation behavior during the ECAP (equal channel angular pressing), influenced by tool angles, friction and material behavior, was studied through experimental and numerical analyses. The residual stress of work piece which was straight before ECAP produces many serious problems in the next processing e.g. input of the work piece for the next ECAP. The bent work piece needs additional straightening or surface polishing even if the amount of bending is small, and residual stress need to be released before service applications. Residual stress, particularly tensile residual stress can be a very important factor in affecting the reliability and integrity of working parts. The formation of tensile residual stress may result in initiation of fatigue cracks, stress corrosion cracking, or other types of fracture. Hence, residual stress and resulting bending need to be controlled during ECAP. Thus, in current study the bending behavior and the residual stress of the work piece in ECAP are analyzed through experimental and finite element analyses by considering the effects of material, geometric, and processing parameters individually. The stress states in the ECAP processed work piece were measured by the non-destructive way using neutron diffraction. Efforts were made to suggest the alternate routes to reduce the residual stress and bending of work piece in ECAP

Prediction of welding residual distortions of large structures using a local/global approach

International Nuclear Information System (INIS)

Duan, Y. G.; Bergheau, J. M.; Vincent, Y.; Boitour, F.; Leblond, J. B.

2007-01-01

Prediction of welding residual distortions is more difficult than that of the microstructure and residual stresses. On the one hand, a fine mesh (often 3D) has to be used in the heat affected zone for the sake of the sharp variations of thermal, metallurgical and mechanical fields in this region. On the other hand, the whole structure is required to be meshed for the calculation of residual distortions. But for large structures, a 3D mesh is inconceivable caused by the costs of the calculation. Numerous methods have been developed to reduce the size of models. A local/global approach has been proposed to determine the welding residual distortions of large structures. The plastic strains and the microstructure due to welding are supposed can be determined from a local 3D model which concerns only the weld and its vicinity. They are projected as initial strains into a global 3D model which consists of the whole structure and obviously much less fine in the welded zone than the local model. The residual distortions are then calculated using a simple elastic analysis, which makes this method particularly effective in an industrial context. The aim of this article is to present the principle of the local/global approach then show the capacity of this method in an industrial context and finally study the definition of the local model

Structure based alignment and clustering of proteins (STRALCP)

Science.gov (United States)

Zemla, Adam T.; Zhou, Carol E.; Smith, Jason R.; Lam, Marisa W.

2013-06-18

Disclosed are computational methods of clustering a set of protein structures based on local and pair-wise global similarity values. Pair-wise local and global similarity values are generated based on pair-wise structural alignments for each protein in the set of protein structures. Initially, the protein structures are clustered based on pair-wise local similarity values. The protein structures are then clustered based on pair-wise global similarity values. For each given cluster both a representative structure and spans of conserved residues are identified. The representative protein structure is used to assign newly-solved protein structures to a group. The spans are used to characterize conservation and assign a "structural footprint" to the cluster.

Evaluation of residual life of material of power plant construction elements after long-term operation

International Nuclear Information System (INIS)

Osasyuk, V.V.

1989-01-01

Existing methods are analyzed for estimation of residual resource of elements of constructions, working in creep conditions. A suggested and experimentally verified new method of residual durability forecasting is described permitting the value of the supplementary resource to be specified according to the real state of the material after preoperation. Evaluation results are given for residual life of steam lines received by different methods and advantages of the technique proposed are shown. Reliability of the new technique is confirmed by steam line operation at thermal power plants

Residual Strength Characterization of Unitized Structures Fabricated Using Different Manufacturing Technologies

Science.gov (United States)

Seshadri, B. R.; Smith, S. W.; Johnston, W. M.

2008-01-01

This viewgraph presentation describes residual strength analysis of integral structures fabricated using different manufacturing procedures. The topics include: 1) Built-up and Integral Structures; 2) Development of Prediction Methodology for Integral Structures Fabricated using different Manufacturing Procedures; 3) Testing Facility; 4) Fracture Parameters Definition; 5) Crack Branching in Integral Structures; 6) Results and Discussion; and 7) Concluding Remarks.

On the Feasibility of Eddy Current Characterization of the Near-Surface Residual Stress Distribution in Nickel-Base Superalloys

International Nuclear Information System (INIS)

Blodgett, Mark P.; Nagy, Peter B.

2004-01-01

In light of its frequency-dependent penetration depth, the measurement of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation of subsurface residual stresses in shot-peened specimens. This technique is based on the so-called electroelastic effect, i.e., the stress-dependence of the electrical conductivity. Unfortunately, the relatively small (∼1%) change in electrical conductivity caused by the presence of compressive residual stresses is often distorted, or even completely overshadowed, by the accompanying conductivity loss caused by cold work and surface roughness effects. Recently, it was observed that, in contrast with most other materials, shot-peened Waspaloy and IN100 specimens exhibit an apparent increase in electrical conductivity at increasing inspection frequencies. This observation by itself indicates that in these materials the measured conductivity change is probably dominated by residual stress effects, since both surface roughness and increased dislocation density are known to decrease rather than increase the conductivity and the presence of crystallographic texture does not affect the electrical conductivity of these materials, which crystallize in cubic symmetry. Our preliminary experiments indicate that probably there exists a unique 'window of opportunity' for eddy current NDE in nickel-base superalloys. We identified five major effects that contribute to this fortunate constellation of material properties, which will be reviewed in this presentation

Determination of Residual Monomers Released from Soft Lining Materials with the use of HPLC

Directory of Open Access Journals (Sweden)

Afrodite Sofou

2007-12-01

Full Text Available A study was carried out to examine the post polymerized leachability of three non phthalic and four phthalic residual monomers, from twelve commercially available soft lining materials, using HPLC. Specimens of equal dimensions were constructed from each brand of material following a standardized procedure and were stored in three different conditions of storage i.e. distilled water, artificial saliva and a binary mixture of ethanol-water, with the resulting liquids providing samples for analysis in the HPLC apparatus. Three different experiments were performed for each brand of material and each condition of storage, in order to examine the parameters time and temperature. The results obtained from this study suggest that a wide spectrum of residues is diffusing out of the twelve examined soft lining materials. The non phthalic compounds were leaching at high concentrations while all the phthalates examined exhibited different degrees of elusion commensurate with the storage condition, brand of material and type of experiment. The main non phthalic component extracted from all the materials was methyl methacrylate, while the mainly extracted phthalic compound was different from each material. The level of elusion seems to be increasing dependent on time, medium of storage, and temperature as well.

Report on residual radioactive materials on public or acquired lands of the United States

Energy Technology Data Exchange (ETDEWEB)

None

1979-07-01

This report identifies sites located on public or acquired lands of the United States containing residual radioactive materials and other radioactive waste (excluding waste resulting from the production of electric energy) and was developed in accordance with the provisions of Section 114(b) of Public Law 95-604, "Uranium Mill Tailings Radiation Control Act of 1978," enacted on November 8, 1978. Additionally, the report specifies which Federal agency has jurisdiction over such sites and, where appropriate data were available, provides a description of the radiological status of each of the sites reported. For purpose of providing a timely report t o t h e Congress, a termination date of May 31, 1979 was established for the receipt, correlation, and analysis of the input data. As of this date, residual radioactive materials and other radioactive waste have been identified by six Federal agencies at 48 sites throughout the United States. Table 1 on page vi provides a summary listing of the number of sites under the jurisdiction of each of these reporting agencies. A cross listing in tabular form by affected state is presented in Table 2 on page viii. Of the 48 sites reported, 36 are located i n three western states - Colorado (27 sites), Wyoming (5 sites), and Utah (4 sites). Based upon t h e data submitted, the sites were categorized into three broad radiological status categories -- controlled, unstabilized, and risk to the public. At controlled sites, the residue is stabilized, access t o t h e site is controlled, the s i t e is well monitored, and does not currently constitute a risk to the public. At sites in the unstabilized category, a probability exists for the spread of contamination. Sites in the risk category contain residue which represents a long-term risk to the public under present conditions. Of the 48 reported sites,. 9 (approximately 19%) could be classified in the controlled category; 38 (approximately 79%) were in the unstabilized category and

Structural protein descriptors in 1-dimension and their sequence-based predictions.

Science.gov (United States)

Kurgan, Lukasz; Disfani, Fatemeh Miri

2011-09-01

The last few decades observed an increasing interest in development and application of 1-dimensional (1D) descriptors of protein structure. These descriptors project 3D structural features onto 1D strings of residue-wise structural assignments. They cover a wide-range of structural aspects including conformation of the backbone, burying depth/solvent exposure and flexibility of residues, and inter-chain residue-residue contacts. We perform first-of-its-kind comprehensive comparative review of the existing 1D structural descriptors. We define, review and categorize ten structural descriptors and we also describe, summarize and contrast over eighty computational models that are used to predict these descriptors from the protein sequences. We show that the majority of the recent sequence-based predictors utilize machine learning models, with the most popular being neural networks, support vector machines, hidden Markov models, and support vector and linear regressions. These methods provide high-throughput predictions and most of them are accessible to a non-expert user via web servers and/or stand-alone software packages. We empirically evaluate several recent sequence-based predictors of secondary structure, disorder, and solvent accessibility descriptors using a benchmark set based on CASP8 targets. Our analysis shows that the secondary structure can be predicted with over 80% accuracy and segment overlap (SOV), disorder with over 0.9 AUC, 0.6 Matthews Correlation Coefficient (MCC), and 75% SOV, and relative solvent accessibility with PCC of 0.7 and MCC of 0.6 (0.86 when homology is used). We demonstrate that the secondary structure predicted from sequence without the use of homology modeling is as good as the structure extracted from the 3D folds predicted by top-performing template-based methods.

Multifunctional Material Structures Based on Laser-Etched Carbon Nanotube Arrays

Directory of Open Access Journals (Sweden)

Aline Emplit

2014-09-01

Full Text Available High-power electronics in the transportation and aerospace sectors need size and weight reduction. Multifunctional and multistructured materials are currently being developed to couple electromagnetic (EM and thermal properties, i.e., shielding against electromagnetic impulsions, and thermal management across the thermal interface material (TIM. In this work, we investigate laser-machined patterned carbon nanotube (CNT micro-brushes as an alternative to metallic structures for driving simultaneously EM and heat propagation. The thermal and electromagnetic response of the CNT array is expected to be sensitive to the micro-structured pattern etched in the CNT brush.

Derivation of cesium-137 residual radioactive material guidelines for the Peek Street site, Schenectady, New York

International Nuclear Information System (INIS)

Jones, L.; Nimmagadda, M.; Yu, C.

1992-01-01

Residual radioactive material guidelines for cesium-137 were derived for the Peek rk. The derivation was based on the requirement that the Street site in Schenectady, New York. The derivation was based on the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the Peek Street site should not exceed a dose of 100 mrem/yr following remedial action. The US Department of Energy (DOE) residual radioactive material guideline computer code, RESRAD was used in this evaluation. Three potential scenarios were considered for the site on the assumption that for a period of 1,000 years following remedial action, the site wig be utilized without radiological restrictions. The scenarios vary with regard to use of the site, time spent at the site, and sources of food consumed. Results indicate that the basic dose limit of 100 mrem/yr will not be exceeded for cesium-137 within 1,000 years, provided that the soil concentration of cesium-137 at the Peek Street site does not exceed the following levels: 98 pCi/g for Scenario A (industrial worker: the expected scenario), 240 pCi/g for Scenario B (recreationist: a plausible scenario), and 34 pCi/g for Scenario C (resident farmer ingesting food produced in the decontaminated area: a plausible scenario)

A unified momentum equation approach for computing thermal residual stresses during melting and solidification

Science.gov (United States)

Yeo, Haram; Ki, Hyungson

2018-03-01

In this article, we present a novel numerical method for computing thermal residual stresses from a viewpoint of fluid-structure interaction (FSI). In a thermal processing of a material, residual stresses are developed as the material undergoes melting and solidification, and liquid, solid, and a mixture of liquid and solid (or mushy state) coexist and interact with each other during the process. In order to accurately account for the stress development during phase changes, we derived a unified momentum equation from the momentum equations of incompressible fluids and elastoplastic solids. In this approach, the whole fluid-structure system is treated as a single continuum, and the interaction between fluid and solid phases across the mushy zone is naturally taken into account in a monolithic way. For thermal analysis, an enthalpy-based method was employed. As a numerical example, a two-dimensional laser heating problem was considered, where a carbon steel sheet was heated by a Gaussian laser beam. Momentum and energy equations were discretized on a uniform Cartesian grid in a finite volume framework, and temperature-dependent material properties were used. The austenite-martensite phase transformation of carbon steel was also considered. In this study, the effects of solid strains, fluid flow, mushy zone size, and laser heating time on residual stress formation were investigated.

Neutron diffraction measurements of residual stress in additively manufactured stainless steel

International Nuclear Information System (INIS)

Brown, D.W.; Bernardin, J.D.; Carpenter, J.S.; Clausen, B.; Spernjak, D.; Thompson, J.M.

2016-01-01

Charpy test specimens were additively manufactured (AM) on a single stainless steel plate from a 17–4 class stainless steel using a powder-bed, laser melting technique on an EOS M280 direct metal laser sintering (DMLS) machine. Cross-hatched mesh support structures for the Charpy test specimens were varied in strut width and density to parametrically study their influence on the build stability and accuracy as the DMLS process has been known to generate parts with large amounts of residual stress. Neutron diffraction was used to profile the residual stresses in several of the AM samples before and after the samples were removed from the support structure for the purpose of determining residual stresses. The residual stresses were found to depend very little on the properties of the support structure over the limited range studied here. The largest stress component was in the long direction of each of the samples studied and was roughly 2/3 of the yield stress of the material. The stress field was altered considerably when the specimen was removed from the support structure. It was noted in this study that a single Charpy specimen developed a significant tear between the growth plate and support structure. The presence of the tear in the support structure strongly affected the observed stress field: the asymmetric tear resulted in a significantly asymmetric stress field that propagated through removal of the sample from the base plate. The altered final residual stress state of the sample as well as its observed final shape indicates that the tear initiated during the build and developed without disrupting the fabrication process, suggesting a need for in-situ monitoring.

Neutron diffraction measurements of residual stress in additively manufactured stainless steel

Energy Technology Data Exchange (ETDEWEB)

Brown, D.W.; Bernardin, J.D.; Carpenter, J.S.; Clausen, B.; Spernjak, D.; Thompson, J.M.

2016-12-15

Charpy test specimens were additively manufactured (AM) on a single stainless steel plate from a 17–4 class stainless steel using a powder-bed, laser melting technique on an EOS M280 direct metal laser sintering (DMLS) machine. Cross-hatched mesh support structures for the Charpy test specimens were varied in strut width and density to parametrically study their influence on the build stability and accuracy as the DMLS process has been known to generate parts with large amounts of residual stress. Neutron diffraction was used to profile the residual stresses in several of the AM samples before and after the samples were removed from the support structure for the purpose of determining residual stresses. The residual stresses were found to depend very little on the properties of the support structure over the limited range studied here. The largest stress component was in the long direction of each of the samples studied and was roughly 2/3 of the yield stress of the material. The stress field was altered considerably when the specimen was removed from the support structure. It was noted in this study that a single Charpy specimen developed a significant tear between the growth plate and support structure. The presence of the tear in the support structure strongly affected the observed stress field: the asymmetric tear resulted in a significantly asymmetric stress field that propagated through removal of the sample from the base plate. The altered final residual stress state of the sample as well as its observed final shape indicates that the tear initiated during the build and developed without disrupting the fabrication process, suggesting a need for in-situ monitoring.

Pharyngeal Residue Severity Rating Scales Based on Fiberoptic Endoscopic Evaluation of Swallowing: A Systematic Review.

Science.gov (United States)

Neubauer, Paul D; Hersey, Denise P; Leder, Steven B

2016-06-01

Identification of pharyngeal residue severity located in the valleculae and pyriform sinuses has always been a primary goal during fiberoptic endoscopic evaluation of swallowing (FEES). Pharyngeal residue is a clinical sign of potential prandial aspiration making an accurate description of its severity an important but difficult challenge. A reliable, validated, and generalizable pharyngeal residue severity rating scale for FEES would be beneficial. A systematic review of the published English language literature since 1995 was conducted to determine the quality of existing pharyngeal residue severity rating scales based on FEES. Databases were searched using controlled vocabulary words and synonymous free text words for topics of interest (deglutition disorders, pharyngeal residue, endoscopy, videofluoroscopy, fiberoptic technology, aspiration, etc.) and outcomes of interest (scores, scales, grades, tests, FEES, etc.). Search strategies were adjusted for syntax appropriate for each database/platform. Data sources included MEDLINE (OvidSP 1946-April Week 3 2015), Embase (OvidSP 1974-2015 April 20), Scopus (Elsevier), and the unindexed material in PubMed (NLM/NIH) were searched for relevant articles. Supplementary efforts to identify studies included checking reference lists of articles retrieved. Scales were compared using qualitative properties (sample size, severity definitions, number of raters, and raters' experience and training) and psychometric analyses (randomization, intra- and inter-rater reliability, and construct validity). Seven articles describing pharyngeal residue severity rating scales met inclusion criteria. Six of seven scales had insufficient data to support their use as evidenced by methodological weaknesses with both qualitative properties and psychometric analyses. There is a need for qualitative and psychometrically reliable, validated, and generalizable pharyngeal residue severity rating scales that are anatomically specific, image-based

Protein structure modelling and evaluation based on a 4-distance description of side-chain interactions

Directory of Open Access Journals (Sweden)

Inbar Yuval

2010-07-01

Full Text Available Abstract Background Accurate evaluation and modelling of residue-residue interactions within and between proteins is a key aspect of computational structure prediction including homology modelling, protein-protein docking, refinement of low-resolution structures, and computational protein design. Results Here we introduce a method for accurate protein structure modelling and evaluation based on a novel 4-distance description of residue-residue interaction geometry. Statistical 4-distance preferences were extracted from high-resolution protein structures and were used as a basis for a knowledge-based potential, called Hunter. We demonstrate that 4-distance description of side chain interactions can be used reliably to discriminate the native structure from a set of decoys. Hunter ranked the native structure as the top one in 217 out of 220 high-resolution decoy sets, in 25 out of 28 "Decoys 'R' Us" decoy sets and in 24 out of 27 high-resolution CASP7/8 decoy sets. The same concept was applied to side chain modelling in protein structures. On a set of very high-resolution protein structures the average RMSD was 1.47 Å for all residues and 0.73 Å for buried residues, which is in the range of attainable accuracy for a model. Finally, we show that Hunter performs as good or better than other top methods in homology modelling based on results from the CASP7 experiment. The supporting web site http://bioinfo.weizmann.ac.il/hunter/ was developed to enable the use of Hunter and for visualization and interactive exploration of 4-distance distributions. Conclusions Our results suggest that Hunter can be used as a tool for evaluation and for accurate modelling of residue-residue interactions in protein structures. The same methodology is applicable to other areas involving high-resolution modelling of biomolecules.

Carbon material formation on SBA-15 and Ni-SBA-15 and residue constituents during acetylene decomposition

Energy Technology Data Exchange (ETDEWEB)

Chiang, Hung-Lung, E-mail: hlchiang@mail.cmu.edu.tw [Department of Risk Management, China Medical University, Taichung 40402, Taiwan (China); Wu, Trong-Neng [Department of Public Health, China Medical University, Taichung 40402, Taiwan (China); Ho, Yung-Shou [Department of Applied Chemistry and Materials Science, Fooyin University, Kaohsiung 831, Taiwan (China); Zeng, Li-Xuan [Department of Risk Management, China Medical University, Taichung 40402, Taiwan (China)

2014-07-15

Highlights: • Acetylene was decomposed on SBA-15 and Ni-SBA-15 at 650–850 °C. • Carbon spheres and filaments were formed after acetylene decomposition. • PAHs were determined in tar and residues. • Exhaust constituents include CO{sub 2}, H{sub 2}, NO{sub x} and hydrocarbon species. - Abstract: Carbon materials including carbon spheres and nanotubes were formed from acetylene decomposition on hydrogen-reduced SBA-15 and Ni-SBA-15 at 650–850 °C. The physicochemical characteristics of SBA-15, Ni-SBA-15 and carbon materials were analyzed by field emission scanning electronic microscopy (FE-SEM), Raman spectrometry, and energy dispersive spectrometry (EDS). In addition, the contents of polyaromatic hydrocarbons (PAHs) in the tar and residue and volatile organic compounds (VOCs) in the exhaust were determined during acetylene decomposition on SBA-15 and Ni-SBA-15. Spherical carbon materials were observed on SBA-15 during acetylene decomposition at 750 and 850 °C. Carbon filaments and ball spheres were formed on Ni-SBA-15 at 650–850 °C. Raman spectroscopy revealed peaks at 1290 (D-band, disorder mode, amorphous carbon) and 1590 (G-band, graphite sp{sup 2} structure) cm{sup −1}. Naphthalene (2 rings), pyrene (4 rings), phenanthrene (3 rings), and fluoranthene (4 rings) were major PAHs in tar and residues. Exhaust constituents of hydrocarbon (as propane), H{sub 2}, and C{sub 2}H{sub 2} were 3.9–2.6/2.7–1.5, 1.4–2.8/2.6–4.3, 4.2–2.4/3.2–1.7% when acetylene was decomposed on SBA-15/Ni-SBA-15, respectively, corresponding to temperatures ranging from 650 to 850 °C. The concentrations of 52 VOCs ranged from 9359 to 5658 and 2488 to 1104 ppm for SBA-15 and Ni-SBA-15 respectively, at acetylene decomposition temperatures from 650 to 850 °C, and the aromatics contributed more than 87% fraction of VOC concentrations.

Mechanical Testing of Carbon Based Woven Thermal Protection Materials

Science.gov (United States)

Pham, John; Agrawal, Parul; Arnold, James O.; Peterson, Keith; Venkatapathy, Ethiraj

2013-01-01

Three Dimensional Woven thermal protection system (TPS) materials are one of the enabling technologies for mechanically deployable hypersonic decelerator systems. These materials have been shown capable of serving a dual purpose as TPS and as structural load bearing members during entry and descent operations. In order to ensure successful structural performance, it is important to characterize the mechanical properties of these materials prior to and post exposure to entry-like heating conditions. This research focuses on the changes in load bearing capacity of woven TPS materials after being subjected to arcjet simulations of entry heating. Preliminary testing of arcjet tested materials [1] has shown a mechanical degradation. However, their residual strength is significantly more than the requirements for a mission to Venus [2]. A systematic investigation at the macro and microstructural scales is reported here to explore the potential causes of this degradation. The effects of heating on the sizing (an epoxy resin coating used to reduce friction and wear during fiber handling) are discussed as one of the possible causes for the decrease in mechanical properties. This investigation also provides valuable guidelines for margin policies for future mechanically deployable entry systems.

CO2 Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues

Directory of Open Access Journals (Sweden)

Ana Arenillas

2013-10-01

Full Text Available Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO2 adsorption properties, with interestingly high gas selectivities for CO2 (α > 200 at a gas composition of 15% CO2/85% N2, 273K, 1 bar and capacities (>2 mmol·g−1 at 273 K. Both CO2 isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO2 which may be correlated with both: N content in the leather residues and ultrasmall pore sizes.

CO2 Separation and Capture Properties of Porous Carbonaceous Materials from Leather Residues

Science.gov (United States)

Bermúdez, José M.; Dominguez, Pablo Haro; Arenillas, Ana; Cot, Jaume; Weber, Jens; Luque, Rafael

2013-01-01

Carbonaceous porous materials derived from leather skin residues have been found to have excellent CO2 adsorption properties, with interestingly high gas selectivities for CO2 (α > 200 at a gas composition of 15% CO2/85% N2, 273K, 1 bar) and capacities (>2 mmol·g−1 at 273 K). Both CO2 isotherms and the high heat of adsorption pointed to the presence of strong binding sites for CO2 which may be correlated with both: N content in the leather residues and ultrasmall pore sizes. PMID:28788352

Materials Chemistry and Performance of Silicone-Based Replicating Compounds.

Energy Technology Data Exchange (ETDEWEB)

Brumbach, Michael T.; Mirabal, Alex James; Kalan, Michael; Trujillo, Ana B; Hale, Kevin

2014-11-01

Replicating compounds are used to cast reproductions of surface features on a variety of materials. Replicas allow for quantitative measurements and recordkeeping on parts that may otherwise be difficult to measure or maintain. In this study, the chemistry and replicating capability of several replicating compounds was investigated. Additionally, the residue remaining on material surfaces upon removal of replicas was quantified. Cleaning practices were tested for several different replicating compounds. For all replicating compounds investigated, a thin silicone residue was left by the replica. For some compounds, additional inorganic species could be identified in the residue. Simple solvent cleaning could remove some residue.

Increased component safety through improved methods for residual stress analysis. Subprojects. Consideration of the elastic-plastic material properties (phase 1). Final report

International Nuclear Information System (INIS)

Mirbach, David von

2014-01-01

Residual stresses in mechanical components can result in both detrimental but also beneficial effects on the strength and lifetime of the components. The most detailed knowledge of the residual stress state is of advantage or a pre-requisite for the assessment of the component performance. The mechanical methods for residual stress measurement are divided into the groups of non-destructive and destructive methods. Two commonly used mechanical methods for determination of residual stresses are the hole drilling method and the ring core method which can be regarded as semi-destructive methods. In the context of reactor safety research of the German Federal Ministry of Economic and Technology (BMWi) two fundamental and interacting weak points of the hole drilling method as well as of the ring core method, respectively, in order to determine residual stresses are going to be investigated. As a consequence reliability of the methods will be improved in this joint research project. On the one hand there are effects of geometrical boundary conditions of the components and on the other hand there is the influence of plasticity due to notch effects both affecting the released strain field after removing material and after all the calculated residual stresses. The first issue mentioned above is under the responsibility of the Institute of Materials Engineering (Kassel University) and the last one is investigated by Universitaet of Stuttgart-Otto-Graf-Institut - materials testing institute. As a consequence of a successful project the knowledge base will be considerably improved resulting in benefits for various engineering fields. Especially the quantitative consideration of real residual stress states for optimized component designs will be possible and after all the consequences of residual stresses on safety of components which are used in nuclear facilities can be evaluated. The state of art was reground in the first research chapter and the analysed strain gauges where

Structural materials challenges for fusion power systems

International Nuclear Information System (INIS)

Kurtz, Richard J.

2009-01-01

Full text: Structural materials in a fusion power system must function in an extraordinarily demanding environment that includes various combinations of high temperatures, reactive chemicals, time-dependent thermal and mechanical stresses, and intense damaging radiation. The fusion neutron environment produces displacement damage equivalent to displacing every atom in the material about 150 times during its expected service life, and changes in chemical composition by transmutation reactions, which includes creation of reactive and insoluble gases. Fundamental materials challenges that must be resolved to effectively harness fusion power include (1) understanding the relationships between material strength, ductility and resistance to cracking, (2) development of materials with extraordinary phase stability, high-temperature strength and resistance to radiation damage, (3) establishment of the means to control corrosion of materials exposed to aggressive environments, (4) development of technologies for large-scale fabrication and joining, and (5) design of structural materials that provide for an economically attractive fusion power system while simultaneously achieving safety and environmental acceptability goals. The most effective approach to solve these challenges is a science-based effort that couples development of physics-based, predictive models of materials behavior with key experiments to validate the models. The U.S. Fusion Materials Sciences program is engaged in an integrated effort of theory, modeling and experiments to develop structural materials that will enable fusion to reach its safety, environmental and economic competitiveness goals. In this presentation, an overview of recent progress on reduced activation ferritic/martensitic steels, nanocomposited ferritic alloys, and silicon carbide fiber reinforced composites for fusion applications will be given

Structure and properties of compositions based on petroleum sulfonic acids

Energy Technology Data Exchange (ETDEWEB)

Tutorskii, I.A.; Sultanova, A.S.; Belkina, E.V.; Fomin, A.G. [Lomonosov Academy of Fine Chemical Technology, Moscow (Russian Federation)

1995-03-01

Colloidal characteristics of compositions based on petroleum sulfonic acids were studied. Neutralized heavy oil residue exhibits surface-active properties and contains an ultradisperse filler. Analysis of the compositions by size-exclusion-chromatography shows deep structural changes in the heavy acid residue upon neutralization with calcium carbonate.

Analysis of residual stress relief mechanisms in post-weld heat treatment

International Nuclear Information System (INIS)

Dong, Pingsha; Song, Shaopin; Zhang, Jinmiao

2014-01-01

This paper presents a recent study on weld residual stress relief mechanisms associated with furnace-based uniform post-weld heat treatment (PWHT). Both finite element and analytical methods are used to quantitatively examine how plastic deformation and creep relaxation contribute to residual stress relief process at different stages of PWHT process. The key contribution of this work to an improved understanding of furnace based uniform PWHT can be summarized as follows: (1)Plastic deformation induced stress relief during PWHT can be analytically expressed by the change in material elastic deformation capacity (or elastic deformation limit) measured in terms of material yield strength to Young's modulus ratio, which has a rather limited role in overall residual stress relief during furnace based uniform PWHT. (2)The most dominant stress relief mechanism is creep strain induced stress relaxation, as expected. However, a rapid creep strain development accompanied by a rapid residual stress reduction during heating stage before reaching PWHT temperature is shown to contribute to most of the stress relief seen in overall PWHT process, suggesting PWHT hold time can be significantly reduced as far as residual stress relief is concerned. (3)A simple engineering scheme for estimating residual stress reduction is proposed based on this study by relating material type, PWHT temperature, and component wall thickness. - Highlights: • The paper clarified effects of plastic deformation and creep relaxation on weld residual stress relief during uniform PWHT. • Creep strain development is far more important than plastic strain, mostly completed even before hold time starts. • Plastic strain development is insignificant and be analytically described by a material elastic deformation capacity parameter. • An engineering estimation scheme is proposed for determining residual stress reduction resulted from furnace based PWHT

Magnesium and aluminium-base products. For use as structural materials; Magnesium, aluminium et alliages. Emploi comme materiaux de structure

Energy Technology Data Exchange (ETDEWEB)

Bernard, J; Boudouresques, B; Alfille, L; Klersy, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper deals with the ability of some Mg and Al-base products to be used as structural materials in thermal reactors. The results presented here are relating to investigations carried out for completing the design of french reactors. (author)Fren. [French] Les auteurs traitent de l'aptitude de quelques materiaux legers et ultra-legers a l'utilisation comme elements de structure des reacteurs thermiques. Les resultats presentes sont relatifs aux etudes effectuees pour l'etablissement des projets de piles fran ises. (auteur)

Theoretical and experimental investigations concerning the problem of quasi-static crack propagation in two-component materials subject to residual stresses

International Nuclear Information System (INIS)

Braun, H.P.

1979-01-01

With the aim of obtaining microstructural information of multi-component materials fracture-mechanical calculations on continuum-mechanical models of fiber composites were performed. There were ideal sections of material permitting the formulation of suitable mixed boundary value problems of static thermoelasticity whose solutions could be obtained by means of appropriate numerical methods from continuum mechanics. As model loads exclusively thermally induced residual stresses were assumed, being of special interest because of the thermomechanically inhomogeneous structure of composite materials on one hand and having got decisive significance for a number of important areas of application as e.g. aero-space industry, reactor technology and chemical apparatus engineering on the other. The results evaluated numerically are exemplarily examined by means of photoelasticity. (orig./IHOE) [de

Recovery and residual stress of SMA wires and applications for concrete structures

International Nuclear Information System (INIS)

Choi, Eunsoo; Cho, Sung-Chul; Park, Taehyo; Hu, Jong Wan; Chung, Young-Soo

2010-01-01

In general, NiTi shape memory alloys are used for applications in civil structures. NiTi SMAs show good superelasticity and shape memory effect properties. However, for application of the shape memory effect, it is desirable for SMAs to show a wide temperature hysteresis, especially for civil structures which are exposed to severe environmental conditions. NiTiNb SMAs, in general, show a wider temperature hysteresis than NiTi SMAs and are more applicable for civil structures. This study examines the temperature hysteresis of NiTiNb and NiTi SMAs, and their recovery and residual stress are investigated. In addition, the tensile behaviors of SMA wires under residual stress are evaluated. This study explains the possible applications for concrete structures with the shape memory effect and illustrates two experimental results of concrete cylinders and reinforced concrete columns. For both tests, SMA wires of NiTiNb and NiTi are used to confine concrete using residual stress. The SMA wire jackets on the concrete cylinders increase the peak strength and the ductility compared to the plain concrete cylinders. In addition, the SMA wire jackets on reinforced concrete columns increase the ductility greatly without flexural strength degradation

Residual stress studies of austenitic and ferritic steels

International Nuclear Information System (INIS)

Chrenko, R.M.

1978-01-01

Residual studies have been made on austenitic and ferritic steels of the types used as structural materials. The residual stress results presented here will include residual stress measurements in the heat-affected zone on butt welded Type 304 stainless steel pipes, and the stresses induced in Type 304 austenitic stainless steel and Type A508 ferritic steel by several surface preparations. Such surface preparation procedures as machining and grinding can induce large directionality effects in the residual stresses determined by X-ray techniques and some typical data will be presented. A brief description is given of the mobile X-ray residual stress apparatus used to obtain most of the data in these studies. (author)

Cost structure of and competition for forest-based biomass

International Nuclear Information System (INIS)

Lundmark, Robert

2007-01-01

Biomass has become a popular alternative to satisfy expanding energy demand and as a substitute for fossil fuels and phased-out nuclear energy in Europe. The European Union White Paper stipulates that the utilization of biomass shall increase to 1566 TWh by 2010. However it is often overlooked that the forest resources are already, to a large extent, used by the forest industries. When promoting biomass for energy generation the consequences for the forest industries also need to be considered. Sweden is an excellent case study, as there are vast quantities of forest resources, nuclear power is starting to be phased out, there are restrictions on expanding hydropower and the political desire exists to 'set an example' with respect to carbon dioxide emissions. This paper attempts to estimate and analyse the supply of two types of forest resource, namely, roundwood and harvesting residues derived from final harvesting and commercial thinnings. Two separate supply curves are estimated: one for roundwood and one for harvesting residues. The cost structure is based on an economic-engineering approach where the separate cost components are constructed from the lowest cost element into aggregates for labour, capital, materials and overhead costs for each forest resource. The results indicate an unutilized economic supply of 12 TWh of harvesting residues in Sweden. However, after these 12 TWh have been recovered it becomes more profitable to use roundwood for energy purposes than to continue extracting further amounts of harvesting residues

Derivation of uranium residual radioactive material guidelines for the Shpack site

International Nuclear Information System (INIS)

Cheng, J.J.; Yu, C.; Monette, F.; Jones, L.

1991-08-01

Residual radioactive material guidelines for uranium were derived for the Shpack site in Norton, Massachusetts. This site has been identified for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy (DOE). The uranium guidelines were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the Shpack site should not exceed a dose of 100 mrem/yr following decontamination. The DOE residual radioactive material guideline computer code, RESRAD, which implements the methodology described in the DOE manual for implementing residual radioactive material guidelines, was used in this evaluation. Three potential scenarios were considered for the site; the scenarios vary with regard to time spent at the site, sources of water used, and sources of food consumed. The results of the evaluation indicate that the basic dose limit of 100 mrem/yr will not be exceeded for uranium (including uranium-234, uranium-235, and uranium-238) within 1000 years, provided that the soil concentration of combined uranium (uranium-234 and uranium-238) at the Shpack site does not exceed the following levels: 2500 pCi/g for Scenario A (recreationist: the expected scenario); 1100 pCi/g for Scenario B (industrial worker: a plausible scenario); and 53 pCi/g for Scenario C (resident farmer using a well water as the only water source: a possible but unlikely scenario). The uranium guidelines derived in this report apply to the combined activity concentration of uranium-234 and uranium-238 and were calculated on the basis of a dose of 100 mrem/yr. In setting the actual uranium guidelines for the Shpack site, DOE will apply the as low as reasonably achievable (ALARA) policy to the decision-making process, along with other factors, such as whether a particular scenario is reasonable and appropriate. 8 refs., 2 figs., 8 tabs

Magnesium and aluminium-base products. For use as structural materials; Magnesium, aluminium et alliages. Emploi comme materiaux de structure

Energy Technology Data Exchange (ETDEWEB)

Bernard, J.; Boudouresques, B.; Alfille, L.; Klersy, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper deals with the ability of some Mg and Al-base products to be used as structural materials in thermal reactors. The results presented here are relating to investigations carried out for completing the design of french reactors. (author)Fren. [French] Les auteurs traitent de l'aptitude de quelques materiaux legers et ultra-legers a l'utilisation comme elements de structure des reacteurs thermiques. Les resultats presentes sont relatifs aux etudes effectuees pour l'etablissement des projets de piles fran ises. (auteur)

Densified ultra-light cement-based materials

DEFF Research Database (Denmark)

Esteves, Luis Pedro

2015-01-01

be used as a “clean technology” in the production of cement-based materials for structural applications with a low carbon footprint. This paper describes the principles of this concept coupled with experimental results on the basic properties of this enhanced type of cement-based materials with combined...

Microfabrication of hierarchical structures for engineered mechanical materials

Science.gov (United States)

Vera Canudas, Marc

Materials found in nature present, in some cases, unique properties from their constituents that are of great interest in engineered materials for applications ranging from structural materials for the construction of bridges, canals and buildings to the fabrication of new lightweight composites for airplane and automotive bodies, to protective thin film coatings, amongst other fields. Research in the growing field of biomimetic materials indicates that the micro-architectures present in natural materials are critical to their macroscopic mechanical properties. A better understanding of the effect that structure and hierarchy across scales have on the material properties will enable engineered materials with enhanced properties. At the moment, very few theoretical models predict mechanical properties of simple materials based on their microstructures. Moreover these models are based on observations from complex biological systems. One way to overcome this challenge is through the use of microfabrication techniques to design and fabricate simple materials, more appropriate for the study of hierarchical organizations and microstructured materials. Arrays of structures with controlled geometry and dimension can be designed and fabricated at different length scales, ranging from a few hundred nanometers to centimeters, in order to mimic similar systems found in nature. In this thesis, materials have been fabricated in order to gain fundamental insight into the complex hierarchical materials found in nature and to engineer novel materials with enhanced mechanical properties. The materials fabricated here were mechanically characterized and compared to simple mechanics models to describe their behavior with the goal of applying the knowledge acquired to the design and synthesis of future engineered materials with novel properties.

Influence of residual stresses during eddy current testing of zircaloy bar material

International Nuclear Information System (INIS)

Saibaba, N.; Das, G.; Pratap, Y.; Acharya, S.; Chaube, R.K.; Jayaraj, R.N.

2009-01-01

Full text: Zirconium alloy bar is the input material for making end plugs required for encapsulating the fuel tubes after loading of uranium di-oxide pellets. These bars are manufactured through extrusion followed by multi-pass swaging and intermediate vacuum annealing. The bar is subjected to 100% Ultrasonic testing to ensure that defect free material is used for making the end plugs. The elements thus welded are subjected to helium leak testing for checking the weld integrity. However, stray cases of helium leakage from fuel elements were observed on few occasions. On investigation, it was found that the leakage was from small porosity present in the plugs. In order to isolate such an eventuality, stricter ultrasonic standards were adopted and additionally eddy current testing was introduced. It was observed that a number of eddy current signals equal to the defect standard were noticed and the reasons for these indications could not be identified. This led to a significant fall in the material recovery. An in-depth study with various heat treatment cycles and process steps was carried out. It was finally concluded that the indications observed in eddy current testing were due to the residual stresses on the periphery of the bar material caused due by improper straightening being carried out at the final stage of the bar manufacture. This paper presents the systematic studies carried out and correlation established between the eddy current signals and the residual stresses

FIRE PROTECTION OF TIMBER STRUCTURES STRENGTHENED WITH FRP MATERIALS

Directory of Open Access Journals (Sweden)

Radek Zigler

2015-12-01

Full Text Available Modern, progressive methods of structures’ strengthening based on the use of composite materials composed of high strength fibers (carbon, glass, aramid or basalt and matrices based on epoxy resins brings, among many indisputable advantages (low weight, high effectiveness, easy application etc. also some disadvantages. One of the major disadvantages is a low fire resistance of these materials due to the low glass transition temperature Tg of the resin used. Based on an extensive research of strengthening of historic structures with FRP materials [1], the article outlines possible approaches to this problem, especially while strengthening timber load- bearing structures of historic buildings.

Structural characterization of asphaltenes from vacuum residue distillation

International Nuclear Information System (INIS)

Silva, Ronaldo C.; Seidl, Peter R.; Menezes, Sonia M.C. de; Teixeira, Marco A.G.

2001-01-01

The aim of this work was to do structural characterization of asphaltenes from different vacuum residues distillation. Several average molecular parameters using some analytical techniques were obtained and these techniques were: nuclear magnetic resonance ( 1 H and 13 C NMR), elemental analysis (C,H,N,O and S content), Fourier transform infrared (FT-IR), vapor pressure osmometry and gel permeation chromatography. Particularly from NMR, some important molecular parameters were obtained, such as aromatic carbon fraction, aliphatic carbons fraction, alkyl substituted aromatic carbons, unsubstituted aromatic carbons, etc. Molecular modeling will be employed to build the structure of asphaltenes using the experimental data. (author)

Derivation of guidelines for uranium residual radioactive material in soil at the Colonie Site, Colonie, New York

International Nuclear Information System (INIS)

Dunning, D.

1996-05-01

Residual radioactive material guidelines for uranium in soil were derived for the Colonie site located in Colonie, New York. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the U.S. Department of Energy (DOE). The site became contaminated with radioactive material as a result of operations conducted by National Lead (NL) Industries from 1958 to 1984; these activities included brass foundry operations, electroplating of metal products, machining of various components using depleted uranium, and limited work with small amounts of enriched uranium and thorium. The Colonie site comprises the former NL Industries property, now designated the Colonie Interim Storage Site (CISS), and 56 vicinity properties contaminated by fallout from airborne emissions; 53 of the vicinity properties were previously remediated between 1984 and 1988. In 1984, DOE accepted ownership of the CISS property from NL Industries. Residual radioactive material guidelines for individual radionuclides and total uranium were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the site should not exceed a dose of 30 mrem/yr following remedial action for the current use and likely future use scenarios or a dose of 100 mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation; RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines

Structural integrity assessment based on the HFR Petten neutron beam facilities

CERN Document Server

Ohms, C; Idsert, P V D

2002-01-01

Neutrons are becoming recognized as a valuable tool for structural-integrity assessment of industrial components and advanced materials development. Microstructure, texture and residual stress analyses are commonly performed by neutron diffraction and a joint CEN/ISO Pre-Standard for residual stress analysis is under development. Furthermore neutrons provide for defects analyses, i.e. precipitations, voids, pores and cracks, through small-angle neutron scattering (SANS) or radiography. At the High Flux Reactor, 12 beam tubes have been installed for the extraction of thermal neutrons for such applications. Two of them are equipped with neutron diffractometers for residual stress and structure determination and have been extensively used in the past. Several other facilities are currently being reactivated and upgraded. These include the SANS and radiography facilities as well as a powder diffractometer. This paper summarizes the main characteristics and current status of these facilities as well as recently in...

Investigation of laboratory test procedures for assessing the structural capacity of geogrid-reinforced aggregate base materials.

Science.gov (United States)

2015-04-01

The objective of this research was to identify a laboratory test method that can be used to quantify improvements in structural capacity of aggregate base materials reinforced with geogrid. For this research, National Cooperative Highway Research Pro...

Development of Fe-B Based Bulk Metallic Glasses: Morphology of Residual Phases in Fe50Ni16Mo6B18Zr10 Glass

Directory of Open Access Journals (Sweden)

Tiburce A. Aboki

2013-04-01

Full Text Available Iron-boron based bulk metallic glasses (BMG development has been initiated using Fe40Ni38Mo4B18 as precursor. Addition of zirconium up to 10 atomic % along with the reduction of Ni proportion improves the glass forming ability (GFA, which is optimum when Ni is suppressed in the alloy. However melting instability occurred during the materials fabrication resulting in the formation of residual crystalline phases closely related to the amorphous phase. Microstructure study shows an evolution from amorphous structure to peculiar acicular structure, particularly for Fe50Ni16Mo6B18Zr10, suggesting the amorphous structure as interconnected atomic sheets like “atomic mille feuilles” whose growth affects the alloys’ GFA.

Chemical structure investigation on SFEF fractions of Dagang vacuum residue

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z.; Yan, G.; Zhao, S.; Guo, S. [China Univ. of Petroleum, Beijing (China). State Key Laboratory of Heavy Oil Processing; Zhang, Z. [Beijing Aeronautical Technology Research Center, Beijing (China)

2006-07-01

One of the most important problems in petroleum chemistry is the molecular structure and composition of heavy oil fractions and its importance in applications pertaining to the recovery, refining, and upgrading of petroleum. This paper presented an investigation into the chemical structure on supercritical fluid extraction and fraction (SFEF) factions of Dagang vacuum residue. Dagang vacuum residue was cut into sixteen fractions and a tailing with SFEF instrument. Then, using a chromatography, all SFEF fractions were further separated into four group compositions, notably saturated hydrocarbons, aromatic hydrocarbons, resins and asphaltenes (SARA). Last, the chemical structure was explored through a thorough analysis of the products from the ruthenium ions-catalyzed oxidation (RICO) reaction of those aromatics, resins and asphaltenes. The paper discussed the experiment in terms of samples and chemicals; supercritical fluid extraction and fraction; SARA separation; and RICO. The results and discussions focused on alkyl side chains attached to aromatic carbon; polymethylene bridges connecting two aromatic units; benzenecarboxylic acids an aromatic units; and others. The study has brought to light useful characterization on covalent molecular structure of two typical SFEF fractions, notably the tenth and fifteen fraction. 17 refs., 6 tabs., 16 figs., 1 appendix.

Oscillations and residual displacements of buildings of varying heights and widths, constructed on elastic-plastic base

Directory of Open Access Journals (Sweden)

Ter-Martirosyan Zaven

2016-01-01

Full Text Available Modern regulations in the field of design and construction of buildings in seismically dangerous areas provide for stability calculation of bases, foundations and underground structures, i.e. calculations for the first group of limited states. At the same time, calculations for the second group of limited states, like deformations (yields, relative difference in yields, as a rule, are not fulfilled. This state of affairs is due to insufficient knowledge of the issues of appearance and development of additional stress and strain in ground arrays during seismic influences, that ultimately leads to residual yields and rolls of foundations of industrial and civil buildings. Essentially, residual displacements depend on the type and intensity of dynamic effects, as well as on the model foundation soils. At the same time, the most important factor is the compulsory registration of collaboration between the subgrade and the structure. Therefore, quantification of additional residual displacements of foundations of industrial buildings and structures under dynamic loads, is an actual problem of the modern earthquake-resistant construction.

Enzymatic hydrolyses of pretreated eucalyptus residues, wheat straw or olive tree pruning, and their mixtures towards flexible sugar-based biorefineries

DEFF Research Database (Denmark)

Silva-Fernandes, Talita; Marques, Susana; Rodrigues, Rita C. L. B.

2016-01-01

Eucalyptus residues, wheat straw, and olive tree pruning are lignocellulosic materials largely available in Southern Europe and have high potential to be used solely or in mixtures in sugar-based biorefineries for the production of biofuels and other bio-based products. Enzymatic hydrolysis...

Recovery of fissile materials from plutonium residues, miscellaneous spent nuclear fuel, and uranium fissile wastes

International Nuclear Information System (INIS)

Forsberg, C.W.

1997-01-01

A new process is proposed that converts complex feeds containing fissile materials into a chemical form that allows the use of existing technologies (such as PUREX and ion exchange) to recover the fissile materials and convert the resultant wastes to glass. Potential feed materials include (1) plutonium scrap and residue, (2) miscellaneous spent nuclear fuel, and (3) uranium fissile wastes. The initial feed materials may contain mixtures of metals, ceramics, amorphous solids, halides, and organics. 14 refs., 4 figs

A residual life prediction model based on the generalized σ -N curved surface

OpenAIRE

Zongwen AN; Xuezong BAI; Jianxiong GAO

2016-01-01

In order to investigate change rule of the residual life of structure under random repeated load, firstly, starting from the statistic meaning of random repeated load, the joint probability density function of maximum stress and minimum stress is derived based on the characteristics of order statistic (maximum order statistic and minimum order statistic); then, based on the equation of generalized σ -N curved surface, considering the influence of load cycles number on fatigue life, a relation...

Overview of U.S. LMFBR structural materials mechanical properties program

International Nuclear Information System (INIS)

Horak, J.A.; Purdy, C.M.

This paper presents the objective, scope, and status of the U.S. Department of Energy's Materials and Structures Program to develop a data base on mechanical properties of structural materials for out-of-core structures and components for LMFBRs. Information on the development of a reference data base on materials for the reactor system, reactor enclosure system, primary heat transport system, intermediate heat transport system, and steam generator system is included. In addition, the development of the data and analyses to account for the effects of temperature and stress, as well as water/steam, sodium, and radiation environments, is described. Plans for the development of alternative materials for future out-of-core applications are presented. (author)

Graphene materials having randomly distributed two-dimensional structural defects

Science.gov (United States)

Kung, Harold H; Zhao, Xin; Hayner, Cary M; Kung, Mayfair C

2013-10-08

Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

Thermo-visco-plasticity and creep in structural-material response of folded-plate structures

Directory of Open Access Journals (Sweden)

Milašinović Dragan D.

2017-01-01

Full Text Available Many structural parts are exposed to high temperatures and loading. It is then important to have data about material inelastic behaviour under such exploiting conditions. Influence of temperature on mechanical characteristics of a material may be inserted via the creep coefficient in the range of visco-elasto-plastic (VEP strains. This damage parameter is implemented in this paper in conjunction with mathematical material modelling approach named rheological-dynamical analogy (RDA in order to address structural stiffness reduction due to inelastic material behaviour. The aim of this paper is to define structural-material internal damping based on both the RDA dynamic modulus and modal damping ratio, by modelling critically damped dynamic systems in the steady-state response. These systems are credible base for explanation of the phenomenon of thermo-visco-plasticity and creep in structural-material response due to high temperatures and loading. Though elastic buckling information for folded-plate structures is not a direct predictor of capacity or collapse behaviour on its own, both the mode and the load (moment are important proxies for the actual behaviour. In current design codes, such as AISI S100, New Zealand/Australia, and European Union, the design formulae are calibrated through the calculation of elastic critical buckling loads (or moments to predict the ultimate strength, thus the ability to calculate the associated elastic buckling loads (or moments has great importance. Moreover, the buckling mode shapes are commonly employed into non-linear collapse modelling as initial geometric imperfections and thermal performance of folded-plate structures in fire. To examine the buckling behaviour of folded-plate structures, the main numerical solution methods are used such as the finite element method (FEM and finite strip method (FSM. This paper aims at providing a unified frame for quasi-static inelastic buckling and thermal loading of

CaTiO.sub.3 Interfacial template structure on semiconductor-based material and the growth of electroceramic thin-films in the perovskite class

Science.gov (United States)

McKee, Rodney Allen; Walker, Frederick Joseph

1998-01-01

A structure including a film of a desired perovskite oxide which overlies and is fully commensurate with the material surface of a semiconductor-based substrate and an associated process for constructing the structure involves the build up of an interfacial template film of perovskite between the material surface and the desired perovskite film. The lattice parameters of the material surface and the perovskite of the template film are taken into account so that during the growth of the perovskite template film upon the material surface, the orientation of the perovskite of the template is rotated 45.degree. with respect to the orientation of the underlying material surface and thereby effects a transition in the lattice structure from fcc (of the semiconductor-based material) to the simple cubic lattice structure of perovskite while the fully commensurate periodicity between the perovskite template film and the underlying material surface is maintained. The film-growth techniques of the invention can be used to fabricate solid state electrical components wherein a perovskite film is built up upon a semiconductor-based material and the perovskite film is adapted to exhibit ferroelectric, piezoelectric, pyroelectric, electro-optic or large dielectric properties during use of the component.

Timber - Material of the Future - Examples of Small Wooden Architectural Structures

Science.gov (United States)

Żmijewki, Tomasz; Wojtowicz-Jankowska, Dorota

2017-10-01

The aim of this article is to present various types of wood-based products, classified as engineered timber, while specifying the implications of their structural properties for their forms. Timber is used as a construction material due to its fire resistance, good structural characteristics and insulating properties. The advent of new technologies of wood processing and wood-based materials production has converted timber into a high-tech material, thus encouraging the architects to consider it ever more often in their projects. As wooden technologies overcome constraints, timber begins to compete with steel and concrete. The design characteristics of new wood-based products allow wooden structures to be higher, have larger spans, and more diverse forms than ever. Wood-based materials include materials made of solid wood, veneers, strand, and wood which, due to its inferior quality, would otherwise be unfit for constructions. Elements and layers of these products are glued using different kinds of strong and water-resistant adhesives. The article presents the history of development of new wood technologies, discussing increasingly popular wood-based materials such as glued laminated timber, cross-laminated timber, or structural composite lumber. The paper analyses their technical and fire-resistance properties, and points to ecological aspect, as factors contributing to the growing popularity of these materials. Finally, the timber’s characteristics are contrasted with those of steel and concrete. The article lists examples of wooden objects representing the so-called small architecture structures from across Europe. They illustrate the potential, the uniqueness and the versatility that wood-based materials offer for constructors and architects. All these features form sufficient grounds for stating that timber truly is a construction material of the 21st century.

Artificially structured materials

International Nuclear Information System (INIS)

Cho, A.Y.

1988-01-01

Recent developments in crystal growth methods such as molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) allow us to artifically structure new materials on an atomic scale. These structures may have electrical or optical properties that cannot be obtained in bulk crystals. There has been a dramatic increase in the study of layered structures during the past decade which has led to the discovery of many unexpected physical phenomena and opened a completely new branch of device physics. Since the advanced crystal growth techniques can tailor the compositions and doping profiles of the material to atomic scales, it pushes the frontier of devices to the ultimate imagination of device physicists and engineers. It is likely that for the next century the new generation of devices will rely heavily on artifically structured materials. This article will be limited to a discussion of recent developments in the area of semiconductor thin epitaxial films which may have technological impact. 21 refs., 12 figs

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

DEFF Research Database (Denmark)

Götze, Ramona; Pivnenko, Kostyantyn; Boldrin, Alessio

2016-01-01

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......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...

Hazardous Materials Verification and Limited Characterization Report on Sodium and Caustic Residuals in Materials and Fuel Complex Facilities MFC-799/799A

Energy Technology Data Exchange (ETDEWEB)

Gary Mecham

2010-08-01

This report is a companion to the Facilities Condition and Hazard Assessment for Materials and Fuel Complex Sodium Processing Facilities MFC-799/799A and Nuclear Calibration Laboratory MFC-770C (referred to as the Facilities Condition and Hazards Assessment). This report specifically responds to the requirement of Section 9.2, Item 6, of the Facilities Condition and Hazards Assessment to provide an updated assessment and verification of the residual hazardous materials remaining in the Sodium Processing Facilities processing system. The hazardous materials of concern are sodium and sodium hydroxide (caustic). The information supplied in this report supports the end-point objectives identified in the Transition Plan for Multiple Facilities at the Materials and Fuels Complex, Advanced Test Reactor, Central Facilities Area, and Power Burst Facility, as well as the deactivation and decommissioning critical decision milestone 1, as specified in U.S. Department of Energy Guide 413.3-8, “Environmental Management Cleanup Projects.” Using a tailored approach and based on information obtained through a combination of process knowledge, emergency management hazardous assessment documentation, and visual inspection, this report provides sufficient detail regarding the quantity of hazardous materials for the purposes of facility transfer; it also provides that further characterization/verification of these materials is unnecessary.

Radiological dose assessment for residual radioactive material in soil at the clean slate sites 1, 2, and 3, Tonopah Test Range

International Nuclear Information System (INIS)

1997-06-01

A radiological dose assessment has been performed for Clean Slate Sites 1, 2, and 3 at the Tonopah Test Range, approximately 390 kilometers (240 miles) northwest of Las Vegas, Nevada. The assessment demonstrated that the calculated dose to hypothetical individuals who may reside or work on the Clean Slate sites, subsequent to remediation, does not exceed the limits established by the US Department of Energy for protection of members of the public and the environment. The sites became contaminated as a result of Project Roller Coaster experiments conducted in 1963 in support of the US Atomic Energy Commission (Shreve, 1964). Remediation of Clean Slate Sites 1, 2, and 3 is being performed to ensure that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works on a Clean Slate site should not exceed 100 millirems per year. The DOE residual radioactive material guideline (RESRAD) computer code was used to assess the dose. RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines (Yu et al., 1993a). In May and June of 1963, experiments were conducted at Clean Slate Sites 1, 2, and 3 to study the effectiveness of earth-covered structures for reducing the dispersion of nuclear weapons material as a result of nonnuclear explosions. The experiments required the detonation of various simulated weapons using conventional chemical explosives (Shreve, 1964). The residual radioactive contamination in the surface soil consists of weapons grade plutonium, depleted uranium, and their radioactive decay products

Radiological dose assessment for residual radioactive material in soil at the clean slate sites 1, 2, and 3, Tonopah Test Range

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

A radiological dose assessment has been performed for Clean Slate Sites 1, 2, and 3 at the Tonopah Test Range, approximately 390 kilometers (240 miles) northwest of Las Vegas, Nevada. The assessment demonstrated that the calculated dose to hypothetical individuals who may reside or work on the Clean Slate sites, subsequent to remediation, does not exceed the limits established by the US Department of Energy for protection of members of the public and the environment. The sites became contaminated as a result of Project Roller Coaster experiments conducted in 1963 in support of the US Atomic Energy Commission (Shreve, 1964). Remediation of Clean Slate Sites 1, 2, and 3 is being performed to ensure that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works on a Clean Slate site should not exceed 100 millirems per year. The DOE residual radioactive material guideline (RESRAD) computer code was used to assess the dose. RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines (Yu et al., 1993a). In May and June of 1963, experiments were conducted at Clean Slate Sites 1, 2, and 3 to study the effectiveness of earth-covered structures for reducing the dispersion of nuclear weapons material as a result of nonnuclear explosions. The experiments required the detonation of various simulated weapons using conventional chemical explosives (Shreve, 1964). The residual radioactive contamination in the surface soil consists of weapons grade plutonium, depleted uranium, and their radioactive decay products.

Manual for implementing residual radioactive material guidelines using RESRAD, Version 5.0

Energy Technology Data Exchange (ETDEWEB)

Yu, C.; Zielen, A.J.; Cheng, J.J. [and others

1993-09-01

This manual presents information for implementing US Department of Energy (DOE) guidelines for residual radioactive material. It describes the analysis and models used to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil and the design and use of the RESRAD computer code for calculating doses, risks, and guideline values. It also describes procedures for implementing DOE policy for reducing residual radioactivity to levels that are as low as reasonably achievable. Two new pathways, radon inhalation and soil ingestion, have been added to RESRAD. Twenty-seven new radionuclides have also been added, and the cutoff half-life for associated radionuclides has been reduced to six months. Other major improvements to the RESRAD code include the ability to run sensitivity analyses, the addition of graphical output, user-specified dose factors, updated databases, an improved groundwater transport model, optional input of a groundwater concentration and a solubility constant, special models for tritium and carbon-14, calculation of cancer incidence risk, and the use of a mouse with menus.

Manual for implementing residual radioactive material guidelines using RESRAD, Version 5.0

International Nuclear Information System (INIS)

Yu, C.; Zielen, A.J.; Cheng, J.J.

1993-09-01

This manual presents information for implementing US Department of Energy (DOE) guidelines for residual radioactive material. It describes the analysis and models used to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil and the design and use of the RESRAD computer code for calculating doses, risks, and guideline values. It also describes procedures for implementing DOE policy for reducing residual radioactivity to levels that are as low as reasonably achievable. Two new pathways, radon inhalation and soil ingestion, have been added to RESRAD. Twenty-seven new radionuclides have also been added, and the cutoff half-life for associated radionuclides has been reduced to six months. Other major improvements to the RESRAD code include the ability to run sensitivity analyses, the addition of graphical output, user-specified dose factors, updated databases, an improved groundwater transport model, optional input of a groundwater concentration and a solubility constant, special models for tritium and carbon-14, calculation of cancer incidence risk, and the use of a mouse with menus

Estimated quantities of residual materials in a KBS-3H repository at Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Hagros, Annika (Sannio and Riekkola OY (Finland))

2008-12-15

The quantities of residual materials in a KBS-3H type repository have been estimated in this report. The repository is assumed to be constructed at Olkiluoto in Eurajoki, Western Finland. Both the total quantities of the materials introduced into the repository and the quantities of materials that remain in the repository after closure have been calculated. The calculations are largely based on a similar work regarding the material quantities in the Finnish KBS-3V repository and the main goal has been to identify the differences between the KBS-3H and KBS-3V repositories with respect to the type and quantities of residual materials. As the design of the KBS-3H repository is not final yet, the results are only preliminary. Several alternative designs were assumed in the calculations, resulting in different total quantities of materials. The design alternatives that had the greatest effect on the total material quantities were the two different tunnel backfill options, bentonite-crushed rock and Friedland clay. If Friedland clay is used instead of a bentonite-crushed rock mixture, the total quantity of pyrite remaining in the repository is 20 times larger and the quantities of organic materials and gypsum are also increased significantly. The other design alternatives did not have a substantial effect on the total material quantities. The remaining quantity of cement can be reduced by some 20% by selecting the silica grouting alternative in the sealing of the rock mass and low-pH cement in the shotcreting of the repository, instead of using the ordinary cement alternatives. If the total quantity of steel should be minimised, the use of the DAWE design alternative would be better than the Basic Design, although the total reduction would be less than 10%. The main difference between the different drift end plug alternatives is related to the total remaining quantity of silica, which is some 80% smaller if the rock plug is used instead of the LHHP (Low Heat High

Estimated quantities of residual materials in a KBS-3H repository at Olkiluoto

International Nuclear Information System (INIS)

Hagros, Annika

2008-12-01

The quantities of residual materials in a KBS-3H type repository have been estimated in this report. The repository is assumed to be constructed at Olkiluoto in Eurajoki, Western Finland. Both the total quantities of the materials introduced into the repository and the quantities of materials that remain in the repository after closure have been calculated. The calculations are largely based on a similar work regarding the material quantities in the Finnish KBS-3V repository and the main goal has been to identify the differences between the KBS-3H and KBS-3V repositories with respect to the type and quantities of residual materials. As the design of the KBS-3H repository is not final yet, the results are only preliminary. Several alternative designs were assumed in the calculations, resulting in different total quantities of materials. The design alternatives that had the greatest effect on the total material quantities were the two different tunnel backfill options, bentonite-crushed rock and Friedland clay. If Friedland clay is used instead of a bentonite-crushed rock mixture, the total quantity of pyrite remaining in the repository is 20 times larger and the quantities of organic materials and gypsum are also increased significantly. The other design alternatives did not have a substantial effect on the total material quantities. The remaining quantity of cement can be reduced by some 20% by selecting the silica grouting alternative in the sealing of the rock mass and low-pH cement in the shotcreting of the repository, instead of using the ordinary cement alternatives. If the total quantity of steel should be minimised, the use of the DAWE design alternative would be better than the Basic Design, although the total reduction would be less than 10%. The main difference between the different drift end plug alternatives is related to the total remaining quantity of silica, which is some 80% smaller if the rock plug is used instead of the LHHP (Low Heat High

Development, simulation and testing of structural materials for DEMO

International Nuclear Information System (INIS)

Laesser, R.; Baluc, N.; Boutard, J.-L.; Diegele, E.; Gasparotto, M.; Riccardi, B.; Dudarev, S.; Moeslang, A.; Pippan, R.; Schaaf, B. van der

2006-01-01

In DEMO the structural and functional materials of the in-vessel components will be exposed to a very intense flux of fusion neutrons with energies up to 14 MeV creating displacement cascades and gaseous transmutation products. Point defects and transmutations will induce new microstructures leading to changes in mechanical and physical properties such as hardening, swelling, loss of fracture toughness and creep strength. The kinetics of microstructural evolution depends on time, temperature and defect production rates. The structural materials to be used in DEMO should have very special properties: high radiation resistance up to the dose of 100 dpa, low residual activation, high creep strength and good compatibility with the cooling media in as wide a temperature operational window as possible for the achievement of high thermal efficiency. The most promising materials are: Reduced Activation Ferritic Martensitic (RAFM) steels (Eurofer and F82H), Oxide Dispersion Strengthened (ODS) RAFM and RAF steels, SiC fibres reinforced SiC matrix composites (SiCf/SiC), tungsten (W) and W-alloys. Each of these materials has its advantages and drawbacks and will be best used under certain conditions. Presently the best studied group of materials are the RAFM steels. They require the smallest extrapolation for use in DEMO but also offer the lowest upper temperature limit of operation (550 o C) and thus the lowest thermal efficiency. The other materials foreseen for more advanced breeder blanket and divertor concepts require intense fundamental R(and)D and testing before their acceptance, whereas the so-called Test Blanket Modules (TBMs) will be constructed using RAFM steel and tested in ITER. Validation of the DEMO structural materials will be done in IFMIF, the International Fusion Materials Irradiation Facility, which will produce neutron damage and transmutation products very similar to those characterising a fusion device and will allow accelerated testing with damage rates

Non-Destructive Measurement of Residual Strain in Connecting Rods Using Neutrons

Energy Technology Data Exchange (ETDEWEB)

Ikeda, Tomohiro [Honda R& D; Bunn, Jeffrey R. [ORNL; Fancher, Christopher M. [ORNL; Seid, Alan [Honda R& D; Motani, Ryuta [Honda R& D; Matsuda, Hideki [Honda R& D; Okayama, Tatsuya [Honda R& D

2018-04-01

Increasing the strength of materials is effective in reducing weight and boosting structural part performance, but there are cases in where the residual strain generated during the process of manufacturing of high-strength materials results in a decline of durability. It is therefore important to understand how the residual strain in a manufactured component changes due to processing conditions. In the case of a connecting rod, because the strain load on the connecting rod rib sections is high, it is necessary to clearly understand the distribution of strain in the ribs. However, because residual strain is generally measured by using X-ray diffractometers or strain gauges, measurements are limited to the surface layer of the parts. Neutron beams, however, have a higher penetration depth than X-rays, allowing for strain measurement in the bulk material. The research discussed within this paper consists of non-destructive residual strain measurements in the interior of connecting rods using the 2nd Generation Neutron Residual Stress Mapping Facility (NRSF2) at Oak Ridge National Laboratory, measuring the Fe (211) diffraction peak position of the ferrite phase. The interior strain distribution of connecting rod, which prepared under different manufacturing processes, was revealed. By the visualization of interior strains, clear understandings of differences in various processing conditions were obtained. In addition, it is known that the peak width, which is also obtained during measurement, is suggestive of the size of crystallites in the structure; however the peak width can additionally be caused by microstresses and material dislocations.

Assessment of interplay between UV wavelengths, material surfaces and food residues in open surface hygiene validation

DEFF Research Database (Denmark)

Abban, Stephen; Jakobsen, Mogens; Jespersen, Lene

2014-01-01

The use of UV-visible radiation for detecting invisible residue on different surfaces as a means of validating cleanliness was investigated. Wavelengths at 365, 395, 435, 445, 470 and 490 nm from a monochromator were used to detect residues of beef, chicken, apple, mango and skim milk. These were....... It is important when UV-systems are used as real-time tools for assessing cleanliness of surfaces that the surface materials being illuminated are taken into account in the choice of lamp wavelength, in addition to expected residue. This will ensure higher confidence in results during the use of UV-light for real...

Recent Advances in the Sound Insulation Properties of Bio-based Materials

Directory of Open Access Journals (Sweden)

Xiaodong Zhu

2013-12-01

Full Text Available Many bio-based materials, which have lower environmental impact than traditional synthetic materials, show good sound absorbing and sound insulation performances. This review highlights progress in sound transmission properties of bio-based materials and provides a comprehensive account of various multiporous bio-based materials and multilayered structures used in sound absorption and insulation products. Furthermore, principal models of sound transmission are discussed in order to aid in an understanding of sound transmission properties of bio-based materials. In addition, the review presents discussions on the composite structure optimization and future research in using co-extruded wood plastic composite for sound insulation control. This review contributes to the body of knowledge on the sound transmission properties of bio-based materials, provides a better understanding of the models of some multiporous bio-based materials and multilayered structures, and contributes to the wider adoption of bio-based materials as sound absorbers.

Prediction of residual stress using explicit finite element method

Directory of Open Access Journals (Sweden)

W.A. Siswanto

2015-12-01

Full Text Available This paper presents the residual stress behaviour under various values of friction coefficients and scratching displacement amplitudes. The investigation is based on numerical solution using explicit finite element method in quasi-static condition. Two different aeroengine materials, i.e. Super CMV (Cr-Mo-V and Titanium alloys (Ti-6Al-4V, are examined. The usage of FEM analysis in plate under normal contact is validated with Hertzian theoretical solution in terms of contact pressure distributions. The residual stress distributions along with normal and shear stresses on elastic and plastic regimes of the materials are studied for a simple cylinder-on-flat contact configuration model subjected to normal loading, scratching and followed by unloading. The investigated friction coefficients are 0.3, 0.6 and 0.9, while scratching displacement amplitudes are 0.05 mm, 0.10 mm and 0.20 mm respectively. It is found that friction coefficient of 0.6 results in higher residual stress for both materials. Meanwhile, the predicted residual stress is proportional to the scratching displacement amplitude, higher displacement amplitude, resulting in higher residual stress. It is found that less residual stress is predicted on Super CMV material compared to Ti-6Al-4V material because of its high yield stress and ultimate strength. Super CMV material with friction coefficient of 0.3 and scratching displacement amplitude of 0.10 mm is recommended to be used in contact engineering applications due to its minimum possibility of fatigue.

A Critical Review of Spinel Structured Iron Cobalt Oxides Based Materials for Electrochemical Energy Storage and Conversion

Directory of Open Access Journals (Sweden)

Hongyan Gao

2017-11-01

Full Text Available Iron cobalt oxides, such as typical FeCo2O4 and CoFe2O4, are two spinel structured transitional metal oxide materials with excellent electrochemical performance. As the electrodes, they have been widely applied in the current energy storage and conversion processes such as supercapacitors, Lithium-ion batteries and fuel cells. Based on synthesis approaches and controlled conditions, these two materials exhibited broad morphologies and nanostructures and thus distinct electrochemical performance. Some of them have shown promising applications as electrodes in energy storage and conversion. The incorporation with other materials to form composites further improved their performance. This review briefly summarized the recent applications of FeCo2O4 and CoFe2O4 in energy storage and conversion, current understandings on mechanisms and especially the relevance of morphologies and structures and composites to electrochemical performance. Some recommendations were finally put forward addressing current issues and future prospects on electrodes of FeCo2O4 and CoFe2O4 based materials in energy storage and conversion, implying there was still space to further optimize their performance.

Techniques of material-flow-specific residual waste treatment; Techniken der stoffstromspezifischen Restabfallbehandlung

Energy Technology Data Exchange (ETDEWEB)

Maak, D.; Collins, H.J. [Technische Univ. Braunschweig, Leichtweiss - Inst. fuer Wasserbau (Germany)

1998-09-01

The success achieved with large-scale plants for mechanical-biological residual waste treatment has led to a change of course in waste pretreatment. In view of the low emissions via the water and gas routes from landfilled wastes and the low costs of waste treatment some authorising authorities have meanwhile issued special licences pursuant to clause no. 2.4 of the Technical Code on Household Waste, thus enabling mechanical-biological residual waste treatment plants to continue operations beyond the year 2005. Beside offering a means of treatment and disposal, cost-effective mechanical-biological pretreatment also provides an opportunity for going over to material-flow-specific residual waste treatment. These process stages permit recirculating valuable materials and using other materials for energy production. They can be retrofitted on a modular basis in existing plants. If these advantages of the present innovative pretreatment methods are not used, then mechanical-biological pretreatment can still serve as a preparatory stage for thermal treatment. To date there has been no practical experience with this innovative method of residual waste treatment. However, industrial-scale trials have shown that each individual treatment stage is capable of being carried out successfully. [Deutsch] Die guten Erfolge im grosstechnischen Betrieb von Anlagen zur mechanisch-biologischen Restabfallbehandlung haben zu einer Kursaenderung bei der Vorbehandlung von Abfaellen gefuehrt. Geringe Emissionen der deponierten Abfaelle auf dem Gas- und Wasserpfad sowie geringe Kosten fuer die Behandlung der Abfaelle haben dazu gefuehrt, dass inzwischen bereits einige Genehmigungsbehoerden eine Ausnahmegenehmigung nach Nr. 2.4 der TA Siedlungsabfall erteilt haben und damit der Betrieb von mechanisch-biologischen Restabfallbehandlungsanlagen auch nach 2005 ermoeglicht wird. Neben der alleinigen Behandlung und Deponierung bietet die kostenguenstige Vorbehandlung mit mechanisch

Water dynamics clue to key residues in protein folding

International Nuclear Information System (INIS)

Gao, Meng; Zhu, Huaiqiu; Yao, Xin-Qiu; She, Zhen-Su

2010-01-01

A computational method independent of experimental protein structure information is proposed to recognize key residues in protein folding, from the study of hydration water dynamics. Based on all-atom molecular dynamics simulation, two key residues are recognized with distinct water dynamical behavior in a folding process of the Trp-cage protein. The identified key residues are shown to play an essential role in both 3D structure and hydrophobic-induced collapse. With observations on hydration water dynamics around key residues, a dynamical pathway of folding can be interpreted.

Residual stress measurement of the jacket material for ITER coil by neutron diffraction

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, Yoshinori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Nickel-Iron based super alloy INCOLOY 908 is used for the jacket of a central solenoid coil (CS coil) of the International Thermonuclear Experimental Reactor (ITER). INCOLOY 908, however, has a possibility of fracture due to Stress Accelerated Grain Boundary Oxidation (SAGBO) under a tensile residual stress beyond 200MPa. Therefore it is necessary to measure the residual stress of the jacket to avoid SAGBO. We performed residual stress measurement of the jacket by neutron diffraction using the neutron diffractometer for residual stress analysis (RESA) installed at JRR-3M in JAERI. A sample depth dependence of internal strain was obtained from the (111) plane spacing. A residual stress distribution was calculated from the strain using Young`s modulus and Poisson`s ratio that were evaluated by a tensile test with neutron diffraction. The result shows that the tensile residual stress exceeds 200MPa of the SAGBO condition in some regions inside the jacket. (author)

An Evaluation on Radiation Shielding and Activation Properties of ISOL-bunker Structural Materials for Radiation Safety in RAON Accelerator

Energy Technology Data Exchange (ETDEWEB)

Kim, Do Hyun; Kim, Song Hyun; Woo, Myeong Hyeon; Lee, Jae Yong; Kim, Jong Woo; Shin, Chang Ho [Hanyang University, Seoul (Korea, Republic of); Nam, Shin Woo [Institute for Basic Science, Daejeon (Korea, Republic of)

2015-10-15

RAON heavy ion accelerator has been designed by the Institute for Basic Science (IBS). ISOL is one of RAON facilities to generate and separate rare isotopes. For generating rare isotopes, high intensity proton beam, which has 70 MeV energy, is induced into UCx target. From this reaction, lots of neutrons are concomitantly generated. To meet our design goal, it was required that the structural material of ISOL-bunker should be carefully selected. In this study, to select the structural material which has lower activation property with higher performance for radiation shielding, following aspects were evaluated: (i) residual dose, (ii) radioactive wastes, and (iii) shielding performance in ISOL-bunker. In this study, to effectively design the radiation shielding of the RAON ISOL-bunker, two methods were proposed. No.1 strategy is a method to replace the normal concrete to specific concretes. No.2 strategy is to design dual-layer radiation shields that a specific shielding material is located inner side of the normal concrete. Using the strategies, performance evaluations were evaluated for three aspects, which are residual dose, radioactive waste, and prompt radiation. The results show that the residual radiation can be effectively reduced using B{sub 4}C, borated polyethylene and polyethylene with No.2 strategy. Also, the colemanite concrete and B{sub 4}C shielding give a good ability to reduce the radioactive wastes.

NASA-UVA Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft

Science.gov (United States)

Starke, E. A., Jr.

1997-01-01

This is the final report of the study "Aluminum-Based Materials for High Speed Aircraft" which had the objectives (1) to identify the most promising aluminum-based materials with respect to major structural use on the HSCT and to further develop those materials and (2) to assess the materials through detailed trade and evaluation studies with respect to their structural efficiency on the HSCT. The research team consisted of ALCOA, Allied-Signal, Boeing, McDonnell Douglas, Reynolds Metals and the University of Virginia. Four classes of aluminum alloys were investigated: (1) I/M 2XXX containing Li and I/M 2XXX without Li, (2) I/M 6XXX, (3) two P/M 2XXX alloys, and (4) two different aluminum-based metal matrix composites (MMC). The I/M alloys were targeted for a Mach 2.0 aircraft and the P/M and MMC alloys were targeted for a Mach 2.4 aircraft. Design studies were conducted using several different concepts including skin/stiffener (baseline), honeycomb sandwich, integrally stiffened and hybrid adaptations (conventionally stiffened thin-sandwich skins). Alloy development included fundamental studies of coarsening behavior, the effect of stress on nucleation and growth of precipitates, and fracture toughness as a function of temperature were an integral part of this program. The details of all phases of the research are described in this final report.

Nuclear reactor structural material forming less radioactive corrosion product

International Nuclear Information System (INIS)

Nakazawa, Hiroshi.

1988-01-01

Purpose: To provide nuclear reactor structural materials forming less radioactive corrosion products. Constitution: Ni-based alloys such as inconel alloy 718, 600 or inconel alloy 750 and 690 having excellent corrosion resistance and mechanical property even in coolants at high temperature and high pressure have generally been used as nuclear reactor structural materials. However, even such materials yield corrosion products being attacked by coolants circulating in the nuclear reactor, which produce by neutron irradiation radioactive corrosion products, that are deposited in primary circuit pipeways to constitute exposure sources. The present invention dissolves dissolves this problems by providing less activating nuclear reactor structural materials. That is, taking notice on the fact that Ni-58 contained generally by 68 % in Ni changes into Co-58 under irradiation of neutron thereby causing activation, the surface of nuclear reactor structural materials is applied with Ni plating by using Ni with a reduced content of Ni-58 isotopes. Accordingly, increase in the radiation level of the nuclear reactor structural materials can be inhibited. (K.M.)

Ferrocement: A versatile composite structural material - A Review

International Nuclear Information System (INIS)

Memon, N. A.; Sumadi, S. R.

2006-01-01

The use of-based composites for structural application is becoming more popular with the introduction of new high performance materials. Ferrocement as a structural material has evolved from an appropriate technology applied for rural development to high performance and high durability construction material. The efficient use of ferrocement technology as per the requirements of the structures must be studied and developed in order to assist all the concerned parties concerned with structural activities. This paper is aimed to present the research made continuously to improve the ferrocement properties and performance and its uses in the different application and to encourage practical application of ferrocement especially in developing countries like Pakistan. This paper covers the theoretical, experimental and numerical studies conducted by several researchers to investigate the mechanical and structural properties of ferrocement. Also the efforts made to develop the design code offerrocement have been reviewed. (author)

Benchmarking residual dose rates in a NuMI-like environment

Energy Technology Data Exchange (ETDEWEB)

Igor L. Rakhno et al.

2001-11-02

Activation of various structural and shielding materials is an important issue for many applications. A model developed recently to calculate residual activity of arbitrary composite materials for arbitrary irradiation and cooling times is presented in the paper. Measurements have been performed at the Fermi National Accelerator Laboratory using a 120 GeV proton beam to study induced radioactivation of materials used for beam line components and shielding. The calculated residual dose rates for the samples studied behind the target and outside of the thick shielding are presented and compared with the measured ones. Effects of energy spectra, sample material and dimensions, their distance from the shielding, and gaps between the shielding modules and walls as well as between the modules themselves were studied in detail.

Structural transformations in Mn2NiGa due to residual stress

International Nuclear Information System (INIS)

Singh, Sanjay; Maniraj, M.; D'Souza, S. W.; Barman, S. R.; Ranjan, R.

2010-01-01

Powder x-ray diffraction study of Mn 2 NiGa ferromagnetic shape memory alloy shows the existence of a 7M monoclinic modulated structure at room temperature (RT). The structure of Mn 2 NiGa is found to be highly dependent on residual stress. For higher stress, the structure is tetragonal at RT, and for intermediate stress it is 7M monoclinic. However, only when the stress is considerably relaxed, the structure is cubic, as is expected at RT since the martensitic transition temperature is 230 K.

Improving material and energy recovery from the sewage sludge and biomass residues

International Nuclear Information System (INIS)

Kliopova, Irina; Makarskienė, Kristina

2015-01-01

Highlights: • SRF production from 10–40 mm fraction of pre-composted sludge and biomass residues. • The material and energy balance of compost and SRF production. • Characteristics of raw materials and classification of produced SRF. • Results of the efficiency of energy recovery, comparison analysis with – sawdust. - Abstract: Sewage sludge management is a big problem all over the world because of its large quantities and harmful impact on the environment. Energy conversion through fermentation, compost production from treated sludge for agriculture, especially for growing energetic plants, and treated sludge use for soil remediation are widely used alternatives of sewage sludge management. Recently, in many EU countries the popularity of these methods has decreased due to the sewage sludge content (heavy metals, organic pollutions and other hazards materials). This paper presents research results where the possibility of solid recovered fuel (SRF) production from the separate fraction (10–40 mm) of pre-composted materials – sewage sludge from municipal waste water treatment plant and biomass residues has been evaluated. The remaining fractions of pre-composted materials can be successfully used for compost or fertiliser production, as the concentration of heavy metals in the analysed composition is reduced in comparison with sewage sludge. During the experiment presented in this paper the volume of analysed biodegradable waste was reduced by 96%: about 20% of input biodegradable waste was recovered to SRF in the form of pellets with 14.25 MJ kg −1 of the net calorific value, about 23% were composted, the rest – evaporated and discharged in a wastewater. The methods of material-energy balances and comparison analysis of experiment data have been chosen for the environmental impact assessment of this biodegradable waste management alternative. Results of the efficiency of energy recovery from sewage sludge by SRF production and burning

Improving material and energy recovery from the sewage sludge and biomass residues

Energy Technology Data Exchange (ETDEWEB)

Kliopova, Irina, E-mail: irina.kliopova@ktu.lt; Makarskienė, Kristina

2015-02-15

Highlights: • SRF production from 10–40 mm fraction of pre-composted sludge and biomass residues. • The material and energy balance of compost and SRF production. • Characteristics of raw materials and classification of produced SRF. • Results of the efficiency of energy recovery, comparison analysis with – sawdust. - Abstract: Sewage sludge management is a big problem all over the world because of its large quantities and harmful impact on the environment. Energy conversion through fermentation, compost production from treated sludge for agriculture, especially for growing energetic plants, and treated sludge use for soil remediation are widely used alternatives of sewage sludge management. Recently, in many EU countries the popularity of these methods has decreased due to the sewage sludge content (heavy metals, organic pollutions and other hazards materials). This paper presents research results where the possibility of solid recovered fuel (SRF) production from the separate fraction (10–40 mm) of pre-composted materials – sewage sludge from municipal waste water treatment plant and biomass residues has been evaluated. The remaining fractions of pre-composted materials can be successfully used for compost or fertiliser production, as the concentration of heavy metals in the analysed composition is reduced in comparison with sewage sludge. During the experiment presented in this paper the volume of analysed biodegradable waste was reduced by 96%: about 20% of input biodegradable waste was recovered to SRF in the form of pellets with 14.25 MJ kg{sup −1} of the net calorific value, about 23% were composted, the rest – evaporated and discharged in a wastewater. The methods of material-energy balances and comparison analysis of experiment data have been chosen for the environmental impact assessment of this biodegradable waste management alternative. Results of the efficiency of energy recovery from sewage sludge by SRF production and burning

Materials with structural hierarchy

Science.gov (United States)

Lakes, Roderic

1993-01-01

The role of structural hierarchy in determining bulk material properties is examined. Dense hierarchical materials are discussed, including composites and polycrystals, polymers, and biological materials. Hierarchical cellular materials are considered, including cellular solids and the prediction of strength and stiffness in hierarchical cellular materials.

Structural materials for high-heat flux applications

International Nuclear Information System (INIS)

Rybin, V.V.; Smith, D.L.

1991-01-01

The structural materials for the ITER, (International Thermonuclear Experimental Reactor) divertor must perform reliably under complex and diverse operating requirements. Only a limited number of materials offer a potential for meeting these requirements for the wide temperature range of interest. The candidate materials considered in the ITER design activity include copper, molybdenum, niobium alloys. Molybdenum alloys being considered include dilute alloys of the TZM type and the Mo-Re system. Niobium alloys under consideration include Nb-V-Zr and Nb-Zr systems. Copper alloys being considered include precipitation strengthened alloys of the Glidcop and MAGT type, alloys of Cu-Mo system and dispersion hardened bronzes. The projected operating conditions for the ITER divertor and the criteria for evaluating the candidate materials are reviewed. This paper summarizes the data base and presents recent experimental results on these candidate divertor structural alloys

Urban Mining: Quality and quantity of recyclable and recoverable material mechanically and physically extractable from residual waste

International Nuclear Information System (INIS)

Di Maria, Francesco; Micale, Caterina; Sordi, Alessio; Cirulli, Giuseppe; Marionni, Moreno

2013-01-01

Highlights: • Material recycling and recovery from residual waste by physical and mechanical process has been investigated. • About 6% of recyclable can be extracted by NIR and 2-3Dimension selector. • Another 2% of construction materials can be extracted by adopting modified soil washing process. • Extracted material quality is quite high even some residual heavy metal have been detected by leaching test. - Abstract: The mechanically sorted dry fraction (MSDF) and Fines (<20 mm) arising from the mechanical biological treatment of residual municipal solid waste (RMSW) contains respectively about 11% w/w each of recyclable and recoverable materials. Processing a large sample of MSDF in an existing full-scale mechanical sorting facility equipped with near infrared and 2-3 dimensional selectors led to the extraction of about 6% w/w of recyclables with respect to the RMSW weight. Maximum selection efficiency was achieved for metals, about 98% w/w, whereas it was lower for Waste Electrical and Electronic Equipment (WEEE), about 2% w/w. After a simulated lab scale soil washing treatment it was possible to extract about 2% w/w of inert exploitable substances recoverable as construction materials, with respect to the amount of RMSW. The passing curve showed that inert materials were mainly sand with a particle size ranging from 0.063 to 2 mm. Leaching tests showed quite low heavy metal concentrations with the exception of the particles retained by the 0.5 mm sieve. A minimum pollutant concentration was in the leachate from the 10 and 20 mm particle size fractions

Biomimetic superwettable materials with structural colours.

Science.gov (United States)

Wang, Zelinlan; Guo, Zhiguang

2017-12-05

Structural colours and superwettability are of great interest due to their unique characteristics. However, the application of materials with either structural colours or superwettability is limited. Moreover, materials possessing both structural colours and superwettability are crucial for many practical applications. The combination of structural colours and superwettability can result in materials for use various applications, such as in sensors, detectors, bioassays, anti-counterfeiting, and liquid actuators, by controlling surfaces to repel or absorb liquids. Regarding superwettability and structural colours, surface texture and chemical composition are two factors for the construction of materials with superwettable structural colours. This review aims at offering a comprehensive elaboration of the mechanism, recent biomimetic research, and applications of biomimetic superwettable materials with structural colours. Furthermore, this review provides significant insight into the design, fabrication, and application of biomimetic superwettable materials with structural colours.

A study on the bonding residual thermal stress analysis of dissimilar materials using boundary element method

International Nuclear Information System (INIS)

Yi, Won; Yu, Yeong Chul; Jeong, Eui Seob; Lee, Chang Ho

1995-01-01

It is very important to evaluate the bonding residual thermal stress in dissimilar materials such as LSI package. In this study, the bonding residual thermal stress was calculated using the boundary element method, varing with the sub-element, geometry of specimen and adhesive thickness. The present results reveal a stress singularity at the edge of the interface, therefore the bonding strength of metal/resin interface can be estimated by taking into account it.

Structural materials issues for the next generation fission reactors

Science.gov (United States)

Chant, I.; Murty, K. L.

2010-09-01

Generation-IV reactor design concepts envisioned thus far cater to a common goal of providing safer, longer lasting, proliferation-resistant, and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-W reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses, and extremely corrosive environments, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This article addresses the material requirements for these advanced fission reactor types, specifically addressing structural materials issues depending on the specific application areas.

Structure-sensitive film materials based on polyvinyl alcohol compositions with polyacids

Science.gov (United States)

Lazareva, Tatjana G.; Iljushenko, Irina A.

1995-05-01

The influence of polyacidic additives (silicotungstic acid -- STA, carboxymethylcellulose -- Na-CMC, polymethacrylic acid -- PMA, polyacrylic acid -- PAA) on the molecular mobility of film composition based on polyvinyl alcohol (PVA) in the temperature range 20 - 200 degree(s)C has been evaluated. It has been concluded that interpolymer complexes are formed due to hydrogen bonding of the PVA and polyacidic additive molecules, which results in the change of the PVA stereoregularity. The formation of the complexes depends on the type and concentration of the polyacidic additive, the process of (alpha) -relaxation and, in a certain concentration range of the additive, increases the molecular mobility of the kinetic segments surrounding the complex. The influence of short-term UV-irradiation on the structure and properties of such materials has been investigated. A possibility of the reversible change of molecular mobility and stereoregularity of the examined compositions as a result of short-term UV-irradiation has been established. Introduction of polyacids into the PVA structure gives rise to the electrosensitivity, i.e., the ability to change structure under the action of an electric field. In this case the distinguishing feature is the relation between the molecular mobility and electrosensitivity in the range of parameters where the (alpha) - relaxation occurs.

Nondestructive indication of fatigue damage and residual lifetime in ferromagnetic construction materials

Czech Academy of Sciences Publication Activity Database

Tomáš, Ivan; Kovářík, O.; Vértesy, G.; Kadlecová, Jana

2014-01-01

Roč. 25, č. 6 (2014), "065601-1"-"065601-10" ISSN 0957-0233. [International Symposium on Measurement Technology and Intelligent Instruments /11./ (ISMTII). Aachen, 01.07.2013-03.07.2013] R&D Projects: GA ČR(CZ) GAP108/12/1872 Institutional support: RVO:68378271 Keywords : fatigue * residual lifetime * magnetic nondestructive evaluation * ferromagnetic construction materials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.433, year: 2014

Structural and Material Instability

DEFF Research Database (Denmark)

Cifuentes, Gustavo Cifuentes

This work is a small contribution to the general problem of structural and material instability. In this work, the main subject is the analysis of cracking and failure of structural elements made from quasi-brittle materials like concrete. The analysis is made using the finite element method. Three...

The Motion Planning of Overhead Crane Based on Suppressing Payload Residual Swing

Directory of Open Access Journals (Sweden)

Liu Hua-sen

2016-01-01

Full Text Available Since the overhead crane system is subject to under actuation system due to that overhead crane and payload are connected by flexibility wire rope. The payload generates residual swing when the overhead crane is accelerating/ decelerating the motions. This may cause trouble for the payload precise positioning and motion planning. Hence, an optimization input shaping control method is presented to reduce the under actuated overhead crane’s payload swing caused via the inertia force. The dynamic model of the overhead crane is proposed according to the physics structure of the crane. The input shaper based on the motion planning of the crane is used as the feed forward input to suppress payload residual swing. Simulation and experiment results indicate that the ZV input shaper and ZVD input shaper can reduce the payload swing of the overhead crane.

Mechanical and materials engineering of modern structure and component design

CERN Document Server

Altenbach, Holm

2015-01-01

This book presents the latest findings on mechanical and materials engineering as applied to the design of modern engineering materials and components. The contributions cover the classical fields of mechanical, civil and materials engineering, as well as bioengineering and advanced materials processing and optimization. The materials and structures discussed can be categorized into modern steels, aluminium and titanium alloys, polymers/composite materials, biological and natural materials, material hybrids and modern nano-based materials. Analytical modelling, numerical simulation, state-of-the-art design tools and advanced experimental techniques are applied to characterize the materials’ performance and to design and optimize structures in different fields of engineering applications.

Advanced technique for ultra-thin residue inspection with sub-10nm thickness using high-energy back-scattered electrons

Science.gov (United States)

Han, Jin-Hee

2018-03-01

Recently the aspect ratio of capacitor and via hole of memory semiconductor device has been dramatically increasing in order to store more information in a limited area. A small amount of remained residues after etch process on the bottom of the high aspect ratio structure can make a critical failure in device operation. Back-scattered electrons (BSE) are mainly used for inspecting the defect located at the bottom of the high aspect ratio structure or analyzing the overlay of the multi-layer structure because these electrons have a high linearity with the direction of emission and a high kinetic energy above 50eV. However, there is a limitation on that it cannot detect ultra-thin residue material having a thickness of several nanometers because the surface sensitivity is extremely low. We studied the characteristics of BSE spectra using Monte Carlo simulations for several cases which the high aspect ratio structures have extreme microscopic residues. Based on the assumption that most of the electrons emitted without energy loss are localized on the surface, we selected the detection energy window which has a range of 20eV below the maximum energy of the BSE. This window section is named as the high-energy BSE region. As a result of comparing the detection sensitivity of the conventional and the high-energy BSE detection mode, we found that the detection sensitivity for the residuals which have 2nm thickness is improved by more than 10 times in the high-energy BSE mode. This BSE technology is a new inspection method that can greatly be improved the inspection sensitivity for the ultra-thin residual material presented in the high aspect ratio structure, and its application will be expanded.

Increased component safety through improved methods for residual stress analysis. Subprojects. Consideration of the elastic-plastic material properties (Phase 2). Final report

International Nuclear Information System (INIS)

Mirbach, David von

2015-01-01

Residual stresses in mechanical components can result in both detrimental but also beneficial effects on the strength and lifetime of the components. The most detailed knowledge of the residual stress state is of advantage or a pre-requisite for the assessment of the component performance. Two commonly used methods for determination of residual stresses are the hole drilling method and the ring core method which can be regarded to the mechanical methods. In the context of reactor safety research of the German Federal Ministry of Economic and Energy (BMWi) two fundamental and interacting weak points of the hole drilling method as well as of the ring core method, respectively, in order to determine residual stresses are going to be investigated. As a consequence reliability of the methods will be improved in this joint research project. On the one hand there are effects of geometrical boundary conditions of the components and on the other hand there is the influence of plasticity due to notch effects both affecting the released strain field after removing material and after all the calculated residual stresses. The first issue mentioned above is under the responsibility of the Institute of Materials Engineering (Kassel University) and the last one is investigated by materials testing institute university Stuttgart. As a consequence of a successful project the knowledge base will be considerably improved resulting in benefits for various engineering fields. Especially the quantitative consideration of real residual stress states for optimized component designs will be possible and after all the consequences of residual stresses on safety of components which are used in nuclear facilities can be evaluated. In this second experimental research chapter (phase 2) the findings of the first numerical and theoretical research chapter (phase 1) where proofed. The developed differential calculation method with the method of adaptive calibration functions were compared with the

Residual stress analysis of a multi-layer thin film structure by destructive (curvature) and non-destructive (x-ray) methods

International Nuclear Information System (INIS)

Chen, P.C.; Oshida, Y.

1989-01-01

Multi-layer thin film which has structure of Cu/Cr/K/Cr/Cu prepared by sputtering process was analyzed for interfacial stresses for as-deposited conditions. This structure was also annealed at 150 degrees C, and 350 degrees C for around 15 min. in a vacuum and cooled slowly down for stress analyses. Equations for residual stress estimations for homogeneous material system using layer removal technique (stress relief) is now applied for inhomogeneous system (multi-layer structure). The results are compared with the data obtained from x-ray diffraction technique by using sin 2 Ψ - 2 θ method, for Cu layer. From the present analyses, the data obtained using layer removal seem to be qualitatively consistent with but not quantitatively in agreement with x-ray method

Recent developments of discrete material optimization of laminated composite structures

DEFF Research Database (Denmark)

Lund, Erik; Sørensen, Rene

2015-01-01

This work will give a quick summary of recent developments of the Discrete Material Optimization approach for structural optimization of laminated composite structures. This approach can be seen as a multi-material topology optimization approach for selecting the best ply material and number...... of plies in a laminated composite structure. The conceptual combinatorial design problem is relaxed to a continuous problem such that well-established gradient based optimization techniques can be applied, and the optimization problem is solved on basis of interpolation schemes with penalization...

Structure - materials - production

DEFF Research Database (Denmark)

Gammelgaard Nielsen, Anders; Gammel, Peder; Busch, Jens

2002-01-01

For the last six years th Aarhus School of Architecture has introduced the first year students (there are about 200 students admitted each year) to structure, materials, design and production through a five week course in collaboration with a group of local companies.......For the last six years th Aarhus School of Architecture has introduced the first year students (there are about 200 students admitted each year) to structure, materials, design and production through a five week course in collaboration with a group of local companies....

A strategy for accommodating residual stresses in the assessment of repair weldments based upon measurement of near surface stresses

International Nuclear Information System (INIS)

Mcdonald, E.J.; Hallam, K.R.; Flewitt, P.E.J.

2005-01-01

On many occasions repairs are undertaken to ferritic steel weldments on plant either during construction or to remove service induced defects. These repaired weldments are subsequently put into service with or without a post-weld heat treatment. In either case, but particularly for the latter, there is a need to accommodate the associated residual stresses in structural integrity assessments such as those based upon the R6 failure avoidance procedure. Although in some circumstances the residual macro-stresses developed within weldments of components and structures can be calculated this is not so readily achieved in the case of residual stresses introduced by repair welds. There is a range of physical and mechanical techniques available to undertake the measurement of macro-residual stresses. Of these X-ray diffraction has the advantage that it is essentially non-destructive and offers the potential for evaluating stresses, which exist in the near surface layer. Although for many structural integrity assessments both the magnitude and distribution of residual stresses have to be accommodated it is not practical to make destructive measurements on weld repaired components and structures to establish the through section distribution of stresses. An approach is to derive a description of the appropriate macro-stresses by a combination of measurement and calculation on trial ferritic steel repair weldments. Surface measurements on the plant can then be made to establish the relationship between the repaired component or structure and the trial weld and thereby improve confidence in predicted stresses and their distribution from the near-surface measured values. Hence X-ray diffraction measurements at the near-surface of the plant weldment can be used to underwrite the quality of the repair by confirming the magnitude and distribution of residual stresses used for the integrity assessment to demonstrate continued safe operation

Evaluation of creep residual life for modified 9Cr-1Mo steel based on Omega method

International Nuclear Information System (INIS)

Nonaka, Isamu; Torihata, Shoji; Kihara, Shigemitu; Umaki, Hideo; Maruyama, Kouichi.

1997-01-01

In order to study the accuracy of creep residual life prediction by the Omega method which is based on creep deformation, a series of creep tests on modified 9Cr-1Mo steel were conducted at 500degC, 550degC and 600degC, and the Omega method was applied to the residual life estimation. The main results obtained are as follows: (1) There was a obvious linear portion, which corresponded to the tertiary creep, in the relationship between logarithm of strain and strain. So it was easy to define the Omega value as a gradient of linear portion. (2) It was proved that the Omega value depended on stress and temperature in such a way as it was the larger, the lower the stress and the lower the temperature. (3) By using the Omega value and strain rate which were determined experimentally, the residual life could be predicted within a factor of 1.5 at the stage of 50% and 80% of actual life. It was confirmed that the accuracy of this method was higher than that of the former method based on rupture time. (4) To apply this method to the residual life evaluation of operating plant materials, the Omega value has to be determined in the lower stress condition. So it is important to develop the extrapolation method of the Omega value based on the laboratory acceleration test to the longer service life. (author)

Manufacturing inspection of electrical steels using Magnetic Barkhausen Noise: residual stress detection

Energy Technology Data Exchange (ETDEWEB)

Samimi, A.A., E-mail: 9aa8@queensu.ca [Queen' s Univ., Applied Magnetics Group, Kingston, Ontario (Canada); Krause, T.W. [Royal Military College of Canada, NDE Lab., Kingston, Ontario (Canada); Clapham, L. [Queen' s Univ., Applied Magnetics Group, Kingston, Ontario (Canada); Gallaugher, M.; Ding, Y.; Chromik, R. [McGill Univ., Dept. of Mining and Materials Engineering, Montreal, Quebec (Canada)

2016-09-15

Non-oriented Electrical Steel (NOES) is the magnetic core lamination material used for flux transfer in rotary machines. The presence of residual stress associated with material processing may be detrimental to magnetic domain structure refinement and as a result, magnetic performance of NOES. Therefore, manufacturing inspection of NOES that identifies the presence of residual stress could contribute to the production of more energy efficient cores. However, standard materials evaluation is limited to destructive and off-line techniques. The present work employed Magnetic Barkhausen Noise (MBN) for nondestructive identification of local residual stress associated with stages in material processing. Analysis of MBN from single strips of NOES demonstrated clear response to applied tensile stress, mechanical shearing, the presence of an insulating coating and punching. The results establish the potential of MBN as a nondestructive testing technology for quality control of electrical steels at various stages of manufacture. (author)

Rigid Residue Scan Simulations Systematically Reveal Residue Entropic Roles in Protein Allostery.

Directory of Open Access Journals (Sweden)

Robert Kalescky

2016-04-01

Full Text Available Intra-protein information is transmitted over distances via allosteric processes. This ubiquitous protein process allows for protein function changes due to ligand binding events. Understanding protein allostery is essential to understanding protein functions. In this study, allostery in the second PDZ domain (PDZ2 in the human PTP1E protein is examined as model system to advance a recently developed rigid residue scan method combining with configurational entropy calculation and principal component analysis. The contributions from individual residues to whole-protein dynamics and allostery were systematically assessed via rigid body simulations of both unbound and ligand-bound states of the protein. The entropic contributions of individual residues to whole-protein dynamics were evaluated based on covariance-based correlation analysis of all simulations. The changes of overall protein entropy when individual residues being held rigid support that the rigidity/flexibility equilibrium in protein structure is governed by the La Châtelier's principle of chemical equilibrium. Key residues of PDZ2 allostery were identified with good agreement with NMR studies of the same protein bound to the same peptide. On the other hand, the change of entropic contribution from each residue upon perturbation revealed intrinsic differences among all the residues. The quasi-harmonic and principal component analyses of simulations without rigid residue perturbation showed a coherent allosteric mode from unbound and bound states, respectively. The projection of simulations with rigid residue perturbation onto coherent allosteric modes demonstrated the intrinsic shifting of ensemble distributions supporting the population-shift theory of protein allostery. Overall, the study presented here provides a robust and systematic approach to estimate the contribution of individual residue internal motion to overall protein dynamics and allostery.

Structural insights into cellulolytic and chitinolytic enzymes revealing crucial residues of insect β-N-acetyl-D-hexosaminidase.

Directory of Open Access Journals (Sweden)

Tian Liu

Full Text Available The chemical similarity of cellulose and chitin supports the idea that their corresponding hydrolytic enzymes would bind β-1,4-linked glucose residues in a similar manner. A structural and mutational analysis was performed for the plant cellulolytic enzyme BGlu1 from Oryza sativa and the insect chitinolytic enzyme OfHex1 from Ostrinia furnacalis. Although BGlu1 shows little amino-acid sequence or topological similarity with OfHex1, three residues (Trp(490, Glu(328, Val(327 in OfHex1, and Trp(358, Tyr(131 and Ile(179 in BGlu1 were identified as being conserved in the +1 sugar binding site. OfHex1 Glu(328 together with Trp(490 was confirmed to be necessary for substrate binding. The mutant E328A exhibited a 8-fold increment in K(m for (GlcNAc(2 and a 42-fold increment in K(i for TMG-chitotriomycin. A crystal structure of E328A in complex with TMG-chitotriomycin was resolved at 2.5 Å, revealing the obvious conformational changes of the catalytic residues (Glu(368 and Asp(367 and the absence of the hydrogen bond between E328A and the C3-OH of the +1 sugar. V327G exhibited the same activity as the wild-type, but acquired the ability to efficiently hydrolyse β-1,2-linked GlcNAc in contrast to the wild-type. Thus, Glu(328 and Val(327 were identified as important for substrate-binding and as glycosidic-bond determinants. A structure-based sequence alignment confirmed the spatial conservation of these three residues in most plant cellulolytic, insect and bacterial chitinolytic enzymes.

Structural model for the first wall W-based material in ITER project

Institute of Scientific and Technical Information of China (English)

Dehua Xu; Xinkui He; Shuiquan Deng; Yong Zhao

2014-01-01

The preparation, characterization, and test of the first wall materials designed to be used in the fusion reactor have remained challenging problems in the material science. This work uses the first-principles method as implemented in the CASTEP package to study the influ-ences of the doped titanium carbide on the structural sta-bility of the W–TiC material. The calculated total energy and enthalpy have been used as criteria to judge the structural models built with consideration of symmetry. Our simulation indicates that the doped TiC tends to form its own domain up to the investigated nano-scale, which implies a possible phase separation. This result reveals the intrinsic reason for the composite nature of the W–TiC material and provides an explanation for the experimen-tally observed phase separation at the nano-scale. Our approach also sheds a light on explaining the enhancing effects of doped components on the durability, reliability, corrosion resistance, etc., in many special steels.

A structural informatics approach to mine kinase knowledge bases.

Science.gov (United States)

Brooijmans, Natasja; Mobilio, Dominick; Walker, Gary; Nilakantan, Ramaswamy; Denny, Rajiah A; Feyfant, Eric; Diller, David; Bikker, Jack; Humblet, Christine

2010-03-01

In this paper, we describe a combination of structural informatics approaches developed to mine data extracted from existing structure knowledge bases (Protein Data Bank and the GVK database) with a focus on kinase ATP-binding site data. In contrast to existing systems that retrieve and analyze protein structures, our techniques are centered on a database of ligand-bound geometries in relation to residues lining the binding site and transparent access to ligand-based SAR data. We illustrate the systems in the context of the Abelson kinase and related inhibitor structures. 2009 Elsevier Ltd. All rights reserved.

Precious-metal-base advanced materials

International Nuclear Information System (INIS)

Nowicki, T.; Carbonnaux, C.

1993-01-01

Precious metals constitute also the base of several advanced materials used in the industry in hundreds of metric tons. Platinum alloys have been used as structural materials for equipments in the glass industry. The essential reason for this is the excellent resistance of platinum alloys to oxidation and electrolytical corrosion in molten glasses at temperatures as high as 1200-1500 C. The major drawback is a weak creep resistance. The unique way for significant improvement of platinum base materials creep resistance is a strengthening by an oxide dispersion (ODS). In the case of CLAL's patented ''Plativer'' materials, 0.05 wt% of Y 2 O 3 is incorporated within the alloy matrix by the flame spraying process. Further improvement of platinum base materials is related, in the authors opinion, to the development of precious metals base intermetallics. Another interesting applications of precious metals are silver base electrical contacts. They are in fact silver matrix composites containing varying amounts of well-dispersed particles of constituents such as CdO, SnO 2 , Ni, WC or C. In the case of such materials, particular properties are required and tested : resistance to arc erosion, resistance to welding and contact resistance. Many other technically fascinating precious metals base materials exist: brazing alloys for assembling metals, superconductors and ceramics; dental materials including magnetic biocompatible alloys; silver composites for superconductor wire jackets. The observation of current evolution indicates very clearly that precious metals cannot be replaced by common metals because of their unique characteristics due to their atomic level properties

Semiconductor wire array structures, and solar cells and photodetectors based on such structures

Science.gov (United States)

Kelzenberg, Michael D.; Atwater, Harry A.; Briggs, Ryan M.; Boettcher, Shannon W.; Lewis, Nathan S.; Petykiewicz, Jan A.

2014-08-19

A structure comprising an array of semiconductor structures, an infill material between the semiconductor materials, and one or more light-trapping elements is described. Photoconverters and photoelectrochemical devices based on such structure also described.

Three-residue turns in alpha/beta-peptides and their application in the design of tertiary structures.

Science.gov (United States)

Sharma, Gangavaram V M; Nagendar, Pendem; Ramakrishna, Kallaganti V S; Chandramouli, Nagula; Choudhary, Madavi; Kunwar, Ajit C

2008-06-02

A new three-residue turn was serendipitously discovered in alpha/beta hybrid peptides derived from alternating C-linked carbo-beta-amino acids (beta-Caa) and L-Ala residues. The three-residue beta-alpha-beta turn at the C termini, nucleated by a helix at the N termini, resulted in helix-turn (HT) supersecondary structures in these peptides. The turn in the HT motif is stabilized by two H bonds-CO(i-2)-NH(i), with a seven-membered pseudoring (gamma turn) in the backward direction, and NH(i-2)-CO(i), with a 13-membered pseudoring in the forward direction (i being the last residue)--at the C termini. The study was extended to generalize the new three-residue turn (beta-alpha-beta) by using different alpha- and beta-amino acids. Furthermore, the HT motifs were efficiently converted, by an extension with helical oligomers at the C termini, into peptides with novel helix-turn-helix (HTH) tertiary structures. However, this resulted in the destabilization of the beta-alpha-beta turn with the concomitant nucleation of another three-residue turn, alpha-beta-beta, which is stabilized by 11- and 15-membered bifurcated H bonds. Extensive NMR spectroscopic studies were carried out to delineate the secondary and tertiary structures in these peptides, which are further supported by molecular dynamics (MD) investigations.

Residual Stress Analysis Based on Acoustic and Optical Methods

Directory of Open Access Journals (Sweden)

Sanichiro Yoshida

2016-02-01

Full Text Available Co-application of acoustoelasticity and optical interferometry to residual stress analysis is discussed. The underlying idea is to combine the advantages of both methods. Acoustoelasticity is capable of evaluating a residual stress absolutely but it is a single point measurement. Optical interferometry is able to measure deformation yielding two-dimensional, full-field data, but it is not suitable for absolute evaluation of residual stresses. By theoretically relating the deformation data to residual stresses, and calibrating it with absolute residual stress evaluated at a reference point, it is possible to measure residual stresses quantitatively, nondestructively and two-dimensionally. The feasibility of the idea has been tested with a butt-jointed dissimilar plate specimen. A steel plate 18.5 mm wide, 50 mm long and 3.37 mm thick is braze-jointed to a cemented carbide plate of the same dimension along the 18.5 mm-side. Acoustoelasticity evaluates the elastic modulus at reference points via acoustic velocity measurement. A tensile load is applied to the specimen at a constant pulling rate in a stress range substantially lower than the yield stress. Optical interferometry measures the resulting acceleration field. Based on the theory of harmonic oscillation, the acceleration field is correlated to compressive and tensile residual stresses qualitatively. The acoustic and optical results show reasonable agreement in the compressive and tensile residual stresses, indicating the feasibility of the idea.

Convergence of a residual based artificial viscosity finite element method

KAUST Repository

Nazarov, Murtazo

2013-02-01

We present a residual based artificial viscosity finite element method to solve conservation laws. The Galerkin approximation is stabilized by only residual based artificial viscosity, without any least-squares, SUPG, or streamline diffusion terms. We prove convergence of the method, applied to a scalar conservation law in two space dimensions, toward an unique entropy solution for implicit time stepping schemes. © 2012 Elsevier B.V. All rights reserved.

Proceedings of the 7. biennial residue-to-revenue residual wood conference 2007

International Nuclear Information System (INIS)

Raulin, J.

2007-01-01

This conference provided information on the highest and best use of residual wood, which is quickly becoming a valuable commodity. Issues concerning forest residues, sawmill wastes, agricultural residues and urban organic materials were discussed along with trends in Canadian surplus mill waste production. The evolving nature and technologies of the biomass business were highlighted with particular focus on how to generate energy and save money through the use of residual wood. Residual wood energy projects and developments in Canada, North America and Europe were outlined along with biomass development in relation to forest fires and insect disturbances. Cogeneration technologies using wood wastes for thermal heat, steam and electricity were also presented, along with transportation fuel technologies for the production of ethanol. It was noted that with the rising cost of energy, the forest industry is seeking energy solutions based on the use of residual wood. The range of economically practical residual wood solutions continues to grow as energy prices increase. The conference was attended by more than 200 delegates from the forest industry, suppliers and government representatives, to discuss policies and procedures currently in place. Industry investment is being stimulated by the potential for biofuels and biochemicals, as well as the co-operation between the forest and energy sectors. The conference featured 23 presentations, of which 12 have been catalogued separately for inclusion in this database. refs., tabs., figs

Functional validation of Ca2+-binding residues from the crystal structure of the BK ion channel.

Science.gov (United States)

Kshatri, Aravind S; Gonzalez-Hernandez, Alberto J; Giraldez, Teresa

2018-04-01

BK channels are dually regulated by voltage and Ca 2+ , providing a cellular mechanism to couple electrical and chemical signalling. Intracellular Ca 2+ concentration is sensed by a large cytoplasmic region in the channel known as "gating ring", which is formed by four tandems of regulator of conductance for K + (RCK1 and RCK2) domains. The recent crystal structure of the full-length BK channel from Aplysia californica has provided new information about the residues involved in Ca 2+ coordination at the high-affinity binding sites located in the RCK1 and RCK2 domains, as well as their cooperativity. Some of these residues have not been previously studied in the human BK channel. In this work we have investigated, through site directed mutagenesis and electrophysiology, the effects of these residues on channel activation by voltage and Ca 2+ . Our results demonstrate that the side chains of two non-conserved residues proposed to coordinate Ca 2+ in the A. californica structure (G523 and E591) have no apparent functional role in the human BK Ca 2+ sensing mechanism. Consistent with the crystal structure, our data indicate that in the human channel the conserved residue R514 participates in Ca 2+ coordination in the RCK1 binding site. Additionally, this study provides functional evidence indicating that R514 also interacts with residues E902 and Y904 connected to the Ca 2+ binding site in RCK2. Interestingly, it has been proposed that this interaction may constitute a structural correlate underlying the cooperative interactions between the two high-affinity Ca 2+ binding sites regulating the Ca 2+ dependent gating of the BK channel. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting DNA-binding proteins and binding residues by complex structure prediction and application to human proteome.

Directory of Open Access Journals (Sweden)

Huiying Zhao

Full Text Available As more and more protein sequences are uncovered from increasingly inexpensive sequencing techniques, an urgent task is to find their functions. This work presents a highly reliable computational technique for predicting DNA-binding function at the level of protein-DNA complex structures, rather than low-resolution two-state prediction of DNA-binding as most existing techniques do. The method first predicts protein-DNA complex structure by utilizing the template-based structure prediction technique HHblits, followed by binding affinity prediction based on a knowledge-based energy function (Distance-scaled finite ideal-gas reference state for protein-DNA interactions. A leave-one-out cross validation of the method based on 179 DNA-binding and 3797 non-binding protein domains achieves a Matthews correlation coefficient (MCC of 0.77 with high precision (94% and high sensitivity (65%. We further found 51% sensitivity for 82 newly determined structures of DNA-binding proteins and 56% sensitivity for the human proteome. In addition, the method provides a reasonably accurate prediction of DNA-binding residues in proteins based on predicted DNA-binding complex structures. Its application to human proteome leads to more than 300 novel DNA-binding proteins; some of these predicted structures were validated by known structures of homologous proteins in APO forms. The method [SPOT-Seq (DNA] is available as an on-line server at http://sparks-lab.org.

Balance of natural radionuclides in the brown coal based power generation and harmlessness of the residues and side product utilization

International Nuclear Information System (INIS)

Schulz, Hartmut; Kunze, Christian; Hummrich, Holger

2017-01-01

During brown coal combustion a partial enrichment of natural radionuclides occurs in different residues. Residues and side product from brown coal based power generation are used in different ways, for example filter ashes and gypsum from flue gas desulfurization facilities are used in the construction materials fabrication and slags for road construction. Detailed measurement and accounting of radionuclides in the mass throughputs in coal combustion power plants have shown that the utilized gypsum and filter ashes are harmless in radiologic aspects.

Residual stress effects in LMFBR fracture assessment procedures

International Nuclear Information System (INIS)

Hooton, D.G.

1984-01-01

Two post-yield fracture mechanics methods, which have been developed into fully detailed failure assessment procedures for ferritic structures, have been reviewed from the point of view of the manner in which as-welded residual stress effects are incorporated, and comparisons then made with finite element and theoretical models of centre-cracked plates containing residual/thermal stresses in the form of crack-driving force curves. Applying the procedures to austenitic structures, comparisons are made in terms of failure assessment curves and it is recommended that the preferred method for the prediction of critical crack sizes in LMFBR austenitic structures containing as-welded residual stresses is the CEGB-R6 procedure based on a flow stress defined at 3% strain in the parent plate. When the prediction of failure loads in such structures is required, it is suggested that the CEGB-R6 procedure be used with residual/thermal stresses factored to give a maximum total stress of flow stress magnitude

Proceedings of a specialist meeting on regulatory approaches for the control of environmental residues containing naturally occurring radioactive material. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

Naturally occurring radionuclides are present in most material. The most common naturally occurring radionuclides in material are those of the uranium and thorium series and potassium-40. This material is commonly referred to as Naturally Occurring Radioactive Material (NORM). In some material the levels of naturally occurring radionuclides are significantly higher, to the extent that regulatory control may be required for radiation protection purposes. Regulation of NORM presents a range of new challenges for both regulators and operators. Unlike more traditional industries dealing with radionuclides, NORM industries have generally not had any radiological oversight and, for example, are not equipped for radiological monitoring. Some consumer goods containing NORM, which have not traditionally been considered as a radiological problem (such as some fertilizers), may require regulation and this may have social and economic consequences. The transport and disposal of NORM are also a concern, particularly due to the large volumes, which may need to be considered. For the majority of NORM, disposal has been by conventional means in the same way as for non-hazardous waste with no specific attention to radiological aspects. In some cases, there may be a need for intervention into existing NORM disposal sites. The International Commission on Radiological Protection (ICRP) published ICRP No. 82, Protection of the Public in Situations of Prolonged Radiation Exposure in 2000. This document provides guidance on managing residues, such as those arising from NORM industries, with potential impact on the public. However, with NORM residual waste there may be three different situations: residual waste created as the result of a past practice, residual waste created by an ongoing practice and waste which will arise from future activities. Regulation of NORM may therefore be consistent with consideration of a practice, an intervention or a combination of both. Different regulatory

Proceedings of a specialist meeting on regulatory approaches for the control of environmental residues containing naturally occurring radioactive material. Working material

International Nuclear Information System (INIS)

2005-01-01

Naturally occurring radionuclides are present in most material. The most common naturally occurring radionuclides in material are those of the uranium and thorium series and potassium-40. This material is commonly referred to as Naturally Occurring Radioactive Material (NORM). In some material the levels of naturally occurring radionuclides are significantly higher, to the extent that regulatory control may be required for radiation protection purposes. Regulation of NORM presents a range of new challenges for both regulators and operators. Unlike more traditional industries dealing with radionuclides, NORM industries have generally not had any radiological oversight and, for example, are not equipped for radiological monitoring. Some consumer goods containing NORM, which have not traditionally been considered as a radiological problem (such as some fertilizers), may require regulation and this may have social and economic consequences. The transport and disposal of NORM are also a concern, particularly due to the large volumes, which may need to be considered. For the majority of NORM, disposal has been by conventional means in the same way as for non-hazardous waste with no specific attention to radiological aspects. In some cases, there may be a need for intervention into existing NORM disposal sites. The International Commission on Radiological Protection (ICRP) published ICRP No. 82, Protection of the Public in Situations of Prolonged Radiation Exposure in 2000. This document provides guidance on managing residues, such as those arising from NORM industries, with potential impact on the public. However, with NORM residual waste there may be three different situations: residual waste created as the result of a past practice, residual waste created by an ongoing practice and waste which will arise from future activities. Regulation of NORM may therefore be consistent with consideration of a practice, an intervention or a combination of both. Different regulatory

Identification of residue pairing in interacting β-strands from a predicted residue contact map.

Science.gov (United States)

Mao, Wenzhi; Wang, Tong; Zhang, Wenxuan; Gong, Haipeng

2018-04-19

Despite the rapid progress of protein residue contact prediction, predicted residue contact maps frequently contain many errors. However, information of residue pairing in β strands could be extracted from a noisy contact map, due to the presence of characteristic contact patterns in β-β interactions. This information may benefit the tertiary structure prediction of mainly β proteins. In this work, we propose a novel ridge-detection-based β-β contact predictor to identify residue pairing in β strands from any predicted residue contact map. Our algorithm RDb 2 C adopts ridge detection, a well-developed technique in computer image processing, to capture consecutive residue contacts, and then utilizes a novel multi-stage random forest framework to integrate the ridge information and additional features for prediction. Starting from the predicted contact map of CCMpred, RDb 2 C remarkably outperforms all state-of-the-art methods on two conventional test sets of β proteins (BetaSheet916 and BetaSheet1452), and achieves F1-scores of ~ 62% and ~ 76% at the residue level and strand level, respectively. Taking the prediction of the more advanced RaptorX-Contact as input, RDb 2 C achieves impressively higher performance, with F1-scores reaching ~ 76% and ~ 86% at the residue level and strand level, respectively. In a test of structural modeling using the top 1 L predicted contacts as constraints, for 61 mainly β proteins, the average TM-score achieves 0.442 when using the raw RaptorX-Contact prediction, but increases to 0.506 when using the improved prediction by RDb 2 C. Our method can significantly improve the prediction of β-β contacts from any predicted residue contact maps. Prediction results of our algorithm could be directly applied to effectively facilitate the practical structure prediction of mainly β proteins. All source data and codes are available at http://166.111.152.91/Downloads.html or the GitHub address of https://github.com/wzmao/RDb2C .

Composite materials for aircraft structures

National Research Council Canada - National Science Library

Baker, A. A; Dutton, Stuart; Kelly, Donald

2004-01-01

... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...

Fast Detection of Material Deformation through Structural Dissimilarity

Energy Technology Data Exchange (ETDEWEB)

Ushizima, Daniela; Perciano, Talita; Parkinson, Dilworth

2015-10-29

Designing materials that are resistant to extreme temperatures and brittleness relies on assessing structural dynamics of samples. Algorithms are critically important to characterize material deformation under stress conditions. Here, we report on our design of coarse-grain parallel algorithms for image quality assessment based on structural information and on crack detection of gigabyte-scale experimental datasets. We show how key steps can be decomposed into distinct processing flows, one based on structural similarity (SSIM) quality measure, and another on spectral content. These algorithms act upon image blocks that fit into memory, and can execute independently. We discuss the scientific relevance of the problem, key developments, and decomposition of complementary tasks into separate executions. We show how to apply SSIM to detect material degradation, and illustrate how this metric can be allied to spectral analysis for structure probing, while using tiled multi-resolution pyramids stored in HDF5 chunked multi-dimensional arrays. Results show that the proposed experimental data representation supports an average compression rate of 10X, and data compression scales linearly with the data size. We also illustrate how to correlate SSIM to crack formation, and how to use our numerical schemes to enable fast detection of deformation from 3D datasets evolving in time.

Role of iron and aluminum coagulant metal residuals and lead release from drinking water pipe materials.

Science.gov (United States)

Knowles, Alisha D; Nguyen, Caroline K; Edwards, Marc A; Stoddart, Amina; McIlwain, Brad; Gagnon, Graham A

2015-01-01

Bench-scale experiments investigated the role of iron and aluminum residuals in lead release in a low alkalinity and high (> 0.5) chloride-to-sulfate mass ratio (CSMR) in water. Lead leaching was examined for two lead-bearing plumbing materials, including harvested lead pipe and new lead: tin solder, after exposure to water with simulated aluminum sulfate, polyaluminum chloride and ferric sulfate coagulation treatments with 1-25-μM levels of iron or aluminum residuals in the water. The release of lead from systems with harvested lead pipe was highly correlated with levels of residual aluminum or iron present in samples (R(2) = 0.66-0.88), consistent with sorption of lead onto the aluminum and iron hydroxides during stagnation. The results indicate that aluminum and iron coagulant residuals, at levels complying with recommended guidelines, can sometimes play a significant role in lead mobilization from premise plumbing.

Process solutions for reducing PR residue over non-planar wafer

Science.gov (United States)

Lin, C. H.; Huang, C. H.; Yang, Elvis; Yang, T. H.; Chen, K. C.; Lu, Chih-Yuan

2011-03-01

SAS (Self-Aligned Source) process has been widely adopted on manufacturing NOR Flash devices. To form the SAS structure, the compromise between small space patterning and sufficiently removing photo resist residue in topographical substrate has been a critical challenge as the device scaling down. In this study, photo simulation, layout optimization, resist processing and tri-layer materials were evaluated to form defect-free and highly extendible SAS structure for NOR Flash devices. Photo simulation suggested more coherent light source allowed the incident light to reach the trench bottom that facilitates the removal of photo resist. Mask bias also benefited the process latitude extension for residue-free SAS printing. In the photo resist processing, both lowering the SB (Soft Bake) and raising PEB (Post-Exposure Bake) temperature of photo resist were helpful to broaden the process window but the final pattern profile was not good enough. Thermal flow for pos-exposure pattern shrinkage achieved small CD (Critical Dimension) patterning with residue-free, however the materials loading effect is another issue to be addressed at memory array boundary. Tri-layer scheme demonstrated good results in terms of free from residue, better substrate reflectivity control, enabling smaller space printing to loosen overlay specification and minimizing the poly gate clipping defect. It was finally proposed to combine with etch effort to from the SAS structure. Besides it is also promising to extend to even smaller technology nodes.

Diverse effects of distance cutoff and residue interval on the performance of distance-dependent atom-pair potential in protein structure prediction.

Science.gov (United States)

Yao, Yuangen; Gui, Rong; Liu, Quan; Yi, Ming; Deng, Haiyou

2017-12-08

As one of the most successful knowledge-based energy functions, the distance-dependent atom-pair potential is widely used in all aspects of protein structure prediction, including conformational search, model refinement, and model assessment. During the last two decades, great efforts have been made to improve the reference state of the potential, while other factors that also strongly affect the performance of the potential have been relatively less investigated. Based on different distance cutoffs (from 5 to 22 Å) and residue intervals (from 0 to 15) as well as six different reference states, we constructed a series of distance-dependent atom-pair potentials and tested them on several groups of structural decoy sets collected from diverse sources. A comprehensive investigation has been performed to clarify the effects of distance cutoff and residue interval on the potential's performance. Our results provide a new perspective as well as a practical guidance for optimizing distance-dependent statistical potentials. The optimal distance cutoff and residue interval are highly related with the reference state that the potential is based on, the measurements of the potential's performance, and the decoy sets that the potential is applied to. The performance of distance-dependent statistical potential can be significantly improved when the best statistical parameters for the specific application environment are adopted.

Site-Mutation of Hydrophobic Core Residues Synchronically Poise Super Interleukin 2 for Signaling: Identifying Distant Structural Effects through Affordable Computations

Directory of Open Access Journals (Sweden)

Longcan Mei

2018-03-01

Full Text Available A superkine variant of interleukin-2 with six site mutations away from the binding interface developed from the yeast display technique has been previously characterized as undergoing a distal structure alteration which is responsible for its super-potency and provides an elegant case study with which to get insight about how to utilize allosteric effect to achieve desirable protein functions. By examining the dynamic network and the allosteric pathways related to those mutated residues using various computational approaches, we found that nanosecond time scale all-atom molecular dynamics simulations can identify the dynamic network as efficient as an ensemble algorithm. The differentiated pathways for the six core residues form a dynamic network that outlines the area of structure alteration. The results offer potentials of using affordable computing power to predict allosteric structure of mutants in knowledge-based mutagenesis.

Multi-Material Design Optimization of Composite Structures

DEFF Research Database (Denmark)

Hvejsel, Christian Frier

properties. The modeling encompasses discrete orientationing of orthotropic materials, selection between different distinct materials as well as removal of material representing holes in the structure within a unified parametrization. The direct generalization of two-phase topology optimization to any number...... of a relaxation-based search heuristic that accelerates a Generalized Benders' Decomposition technique for global optimization and enables the solution of medium-scale problems to global optimality. Improvements in the ability to solve larger problems to global optimality are found and potentially further...... improvements may be obtained with this technique in combination with cheaper heuristics....

Material Properties Analysis of Structural Members in Pumpkin Balloons

Science.gov (United States)

Sterling, W. J.

2003-01-01

The efficient design, service-life qualification, and reliability predictions for lightweight aerospace structures require careful mechanical properties analysis of candidate structural materials. The demand for high-quality laboratory data is particularly acute when the candidate material or the structural design has little history. The pumpkin-shaped super-pressure balloon presents both challenges. Its design utilizes load members (tendons) extending from apex to base around the gas envelope to achieve a lightweight structure. The candidate tendon material is highly weight-efficient braided HM cord. Previous mechanical properties studies of Zylon have focused on fiber and yarn, and industrial use of the material in tensile applications is limited. For high-performance polymers, a carefully plamed and executed properties analysis scheme is required to ensure the data are relevant to the desired application. Because no directly-applicable testing standard was available, a protocol was developed based on guidelines fiom professional and industry organizations. Due to the liquid-crystalline nature of the polymer, the cord is very stiff, creeps very little, and does not yield. Therefore, the key material property for this application is the breaking strength. The pretension load and gauge length were found to have negligible effect on the measured breaking strength over the ranges investigated. Strain rate was found to have no effect on breaking strength, within the range of rates suggested by the standards organizations. However, at the lower rate more similar to ULDB operations, the strength was reduced. The breaking strength increased when the experiment temperature was decreased from ambient to 183K which is the lowest temperature ULDB is expected to experience. The measured strength under all test conditions was well below that resulting from direct scale-up of fiber strength based on the manufacturers data. This expected result is due to the effects of the

Prediction of retained residual stresses in laboratory fracture mechanics specimens extracted from welded components

International Nuclear Information System (INIS)

Hurlston, R.G.; Sherry, A.H.; James, P.; Sharples, J.K.

2015-01-01

The measurement of weld material fracture toughness properties is important for the structural integrity assessment of engineering components. However, welds can contain high levels of residual stress and these can be retained in fracture mechanics specimens, particularly when machined from non-stress relieved welds. Retained residual stresses can make the measurement of valid fracture toughness properties difficult. This paper describes the results of analytical work undertaken to investigate factors that can influence the magnitude and distribution of residual stresses retained in fracture mechanics specimen blanks extracted from as-welded ferritic and austenitic stainless steel plates. The results indicate that significant levels of residual stress can be retained in specimen blanks prior to notching, and that the magnitude and distribution of stress is dependent upon material properties, specimen geometry and size, and extraction location through the thickness of the weld. Finite element modelling is shown to provide a useful approach for estimating the level and distributions of retained residual stresses. A new stress partitioning approach has been developed to estimate retained stress levels and results compare favourably with FE analysis and available experimental data. The approach can help guide the selection of specimen geometry and machining strategies to minimise the level of residual stresses retained in fracture mechanics specimen blanks extracted from non stress-relieved welds and thus improve the measurement of weld fracture toughness properties. - Highlights: • A simplified method for generating realistic weld residual stresses has been developed. • It has been shown that significant levels of residual stress can be retained within laboratory fracture mechanics specimens. • The level and distribution is dependant upon material, specimen type, specimen size and extraction location. • A method has been developed to allow estimates of the

Residual stress measurements in thick structural weldments by means of neutron diffraction

International Nuclear Information System (INIS)

Ohms, C.; Youtsos, A.G.; Idsert, P. v.d.; Timke, T.

2000-01-01

Welding residual stresses in large structural components are a major concern with respect to their performance and lifetime. In large structures reasonable thermal stress relief treatment is usually impossible due to the component size. On the other hand, prediction of welding stresses by numerical modelling has not yet proven to be generally reliable, while the experimental determination of such stresses remains a demanding task. At the high flux reactor (HFR), Petten, a new residual stress diffractometer has been installed recently capable of handling of components up to 1000 kg - the large component neutron diffraction facility (LCNDF). It has facilitated residual stress measurements in two large welded components, of which results are presented here. The first component represents a bi-metallic weld in form of a pipe of 25 mm wall thickness. Three dimensional measurements of residual stress are discussed in detail. The second specimen is a 66 mm wall thickness austenitic steel nuclear piping weld. Results on relief of strain within the weld through post weld heat treatment (PWHT) are presented. Additionally results obtained earlier at former CRNL (CAN) on a section of a thick nuclear piping weld are presented in order to illustrate the variation in the reference lattice parameter trough the weld and the heat affected zone (HAZ). These results clearly show the necessity to determine the reference parameters for each location in all measurement directions by means of measurements in small coupons free of macro-stresses. (orig.)

Structural and Electronic Features of Sb-Based Electrode Materials: 121Sb Moessbauer Spectrometry

International Nuclear Information System (INIS)

Ionica, C. M.; Aldon, L.; Lippens, P. E.; Morato, F.; Olivier-Fourcade, J.; Jumas, J.-C.

2004-01-01

Lithium insertion mechanisms in two antimony based compounds: CoSb 3 and CoSb have been studied by means of 121 Sb Moessbauer spectrometry. Structural and electronic modifications induced by insertion of lithium have been characterised for different depths of discharge. In all cases the insertion mechanisms can be described from several steps. In the first step antimony is partially dispersed in the metallic matrix with amorphisation of the electrode material and in a second step we can observe the alloy forming (Li 3 Sb). However this amorphous alloy remains in interaction with the matrix allowing then a good reversibility.

Structural characterization of amorphous materials applied to low-k organosilicate materials

Energy Technology Data Exchange (ETDEWEB)

Raymunt, Alexandra Cooper, E-mail: amc442@cornell.edu; Clancy, Paulette

2014-07-01

We present a methodology to create computational atomistic-level models of porous amorphous materials, in particular, an organosilicate structure for ultra-low dielectric constant (ULK) materials known as “SiCOH.” The method combines the ability to satisfy geometric and chemical constraints with subsequent molecular dynamics (MD) techniques as a way to capture the complexities of the porous and amorphous nature of these materials. The motivation for studying ULK materials arises from a desire to understand the origin of the material's weak mechanical properties. The first step towards understanding how these materials might behave under processing conditions that are intended to improve their mechanical properties is to develop a suitable computational model of the material and hence is the focus of this paper. We define the atomic-scale topology of ULK materials that have been produced by chemical vapor deposition-like experimental techniques. Specifically, we have developed a method of defining the initial atom configurations and interactions, as well as a method to rearrange these starting configurations into relaxed structures. The main advantage of our described approach is the ability of our structure generation method to maintain a random distribution of relevant structural motifs throughout the structure, without relying on large unit cells and periodic boundaries to approximate the behavior of this complex material. The minimization of the different models was accomplished using replica exchange molecular dynamics (REMD). Following the generation of the ‘equilibrium’ configurations that result from REMD for a ULK material of a pre-specified composition, we demonstrate that its structural properties, including bonding topology, porosity and pore size distribution are similar to experimentally used ULK materials. - Highlights: • Method for creating a model of a low dielectric constant organosilicate material • Method of defining porosity in

Synthesis/literature review for determining structural layer coefficients (SLC) of bases.

Science.gov (United States)

2014-12-01

FDOTs current method of determining a base material structural layer coefficient (SLC) is detailed in the : Materials Manual, Chapter 2.1, Structural Layer Coefficients for Flexible Pavement Base Materials. : Currently, any new base material not a...

AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 34th and AIAA/ASME Adaptive Structures Forum, La Jolla, CA, Apr. 19-22, 1993, Technical Papers. Pts. 1-6

Science.gov (United States)

Topics addressed include the prediction of helicopter component loads using neural networks, spacecraft on-orbit coupled loads analysis, hypersonic flutter of a curved shallow panel with aerodynamic heating, thermal-acoustic fatigue of ceramic matrix composite materials, transition elements based on transfinite interpolation, damage progression in stiffened composite panels, a direct treatment of min-max dynamic response optimization problems, and sources of helicopter rotor hub inplane shears. Also discussed are dynamics of a layered elastic system, confidence bounds on structural reliability, mixed triangular space-time finite elements, advanced transparency development for USAF aircraft, a low-velocity impact on a graphite/PEEK, an automated mode-tracking strategy, transonic flutter suppression by a passive flap, a nonlinear response of composite panels to random excitation, an optimal placement of elastic supports on a simply supported plate, a probabilistic assessment of composite structures, a model for mode I failure of laminated composites, a residual flexibility approach to multibody dynamics,and multilayer piezoelectric actuators.

Converting biowaste corncob residue into high value added porous carbon for supercapacitor electrodes.

Science.gov (United States)

Qu, Wen-Hui; Xu, Yuan-Yuan; Lu, An-Hui; Zhang, Xiang-Qian; Li, Wen-Cui

2015-08-01

In this report, corncob residue, the main by-product in the furfural industry, is used as a precursor to prepare porous carbon by a simple and direct thermal treatment: one-step activation without pre-carbonization. As a consequence, the corncob residue derived porous carbon achieves a high surface area of 1210 m(2) g(-1) after ash-removal. The carbon material has the advantages of low cost and low environmental impact, with a superior electrochemical performance compared to those polymer-based synthetic carbons as electrode material for a supercapacitor. The carbon electrode exhibits a high capacitance of 314 F g(-1) in 6M KOH electrolyte. The corresponding sample also shows a superb cycling stability. Almost no capacitance decay was observed after 100,000 cycles. The excellent electrochemical performance is due to the combination of a high specific surface area with a fraction of mesopores and highly stable structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modelling of residual stresses in valves Norem hard-facing alloys: a material characterization issue

International Nuclear Information System (INIS)

Mathieu, J.P.; Arnoldi, F.; Gauthier, E.; Beaurin, G.

2011-01-01

Replacement of cobalt-based hard-facing alloys (Stellite) is of high interest within the topic of reduction of human radiation exposure during field-work. Iron-based hard-facing alloys, such as Norem, are considered as good replacement candidates. Their wear characteristics are known to be quite equivalent to Stellite but are counter-balanced by lack of feedback in the field, especially about their resistance/toughness to brutal thermal shocks (60 C - 280 C for primary water). Norem alloys show a solid-solution strengthened austenitic dendrites matrix with a continuous network of eutectic and non-eutectic carbides at the grain boundaries. Toughness evaluation also requires information about residual stresses due to the welding (deposition) process: this work aims at furnishing tools for this purpose. First part of the work involved a microstructural study in order to compare the as-received material to other Norem samples previously observed in EDF's works and literature. A characterization of the different phase evolutions after heating and fast cooling of Norem is then made, in order to characterize whether metallurgical aspects have to be considered in the mechanical part during welding modelling: it appears that no strong solid-solid phase transformation may occur in welding situation. Tensile characterization is then performed on bulk PTAW (Plasma Transferred Arc Welding) specimens. A simplified welding simulation is eventually conducted on different axis-symmetric geometry and on real valve geometry in order to define a representative sample that will be used for further investigation on residual stresses. (authors)

Prospects of joining multi-material structures

Science.gov (United States)

Sankaranarayanan, R.; Hynes, N. Rajesh Jesudoss

2018-05-01

Spring up trends and necessities make the pipelines for the brand new Technologies. The same way, Multimaterial structures emerging as fruitful alternatives for the conventional structures in the manufacturing sector. Especially manufacturing of transport vehicles is placing a perfect platform for these new structures. Bonding or joining technology plays a crucial role in the field of manufacturing for sustainability. These latest structures are purely depending on such joining technologies so that multi-material structuring can be possible practically. The real challenge lies on joining dissimilar materials of different properties and nature. Escalation of thermoplastic usage in large structural components also faces similar ambiguity for joining multi-material structures. Adhesive bonding, mechanical fastening and are the answering technologies for multi-material structures. This current paper analysis the prospects of these bonding technologies to meet the challenges of tomorrow.

Improved structural integrity through advances in reliable residual stress measurement: the impact of ENGIN-X

Science.gov (United States)

Edwards, L.; Santisteban, J. R.

The determination of accurate reliable residual stresses is critical to many fields of structural integrity. Neutron stress measurement is a non-destructive technique that uniquely provides insights into stress fields deep within engineering components and structures. As such, it has become an increasingly important tool within engineering, leading to improved manufacturing processes to reduce stress and distortion as well as to the definition of more precise lifing procedures. This paper describes the likely impact of the next generation of dedicated engineering stress diffractometers currently being constructed and the utility of the technique using examples of residual stresses both beneficial and detrimental to structural integrity.

Residual Stress Developed During the Cure of Thermosetting Polymers: Optimizing Cure Schedule to Minimize Stress.

Energy Technology Data Exchange (ETDEWEB)

Kropka, Jamie Michael; Stavig, Mark E.; Jaramillo, Rex

2016-06-01

When thermosetting polymers are used to bond or encapsulate electrical, mechanical or optical assemblies, residual stress, which often affects the performance and/or reliability of these devices, develops within the structure. The Thin-Disk-on-Cylinder structural response test is demonstrated as a powerful tool to design epoxy encapsulant cure schedules to reduce residual stress, even when all the details of the material evolution during cure are not explicitly known. The test's ability to (1) distinguish between cohesive and adhesive failure modes and (2) demonstrate methodologies to eliminate failure and reduce residual stress, make choices of cure schedules that optimize stress in the encapsulant unambiguous. For the 828/DEA/GMB material in the Thin-Disk-on-Cylinder geometry, the stress associated with cure is significant and outweighs that associated with cool down from the final cure temperature to room temperature (for measured lid strain, Scure I > I I e+h erma * II) * The difference between the final cure temperature and 1 1 -- the temperature at which the material gels, Tf-T ge i, was demonstrated to be a primary factor in determining the residual stress associated with cure. Increasing T f -T ge i leads to a reduction in cure stress that is described as being associated with balancing some of the 828/DEA/GMB cure shrinkage with thermal expansion. The ability to tune residual stress associated with cure by controlling T f -T ge i would be anticipated to translate to other thermosetting encapsulation materials, but the times and temperatures appropriate for a given material may vary widely.

Extracting dimer structures from simulations of organic-based materials using QM/MM methods

Energy Technology Data Exchange (ETDEWEB)

Pérez-Jiménez, A.J., E-mail: aj.perez@ua.es; Sancho-García, J.C., E-mail: jc.sancho@ua.es

2015-09-28

Highlights: • DFT geometries of isolated dimers in organic crystals differ from experimental ones. • This can be corrected using QM/MM geometry optimizations. • The QM = B3LYP–D3(ZD)/cc-pVDZ and MM = GAFF combination works reasonably well. - Abstract: The functionality of weakly bound organic materials, either in Nanoelectronics or in Materials Science, is known to be strongly affected by their morphology. Theoretical predictions of the underlying structure–property relationships are frequently based on calculations performed on isolated dimers, but the optimized structure of the latter may significantly differ from experimental data even when dispersion-corrected methods are used for it. Here, we address this problem on two organic crystals, namely coronene and 5,6,11,12-tetrachlorotetracene, concluding that it is caused by the absence of the surrounding monomers present in the crystal, and that it can be efficiently cured when the dimer is embedded into a general Quantum Mechanics/Molecular Mechanics (QM/MM) geometry optimization scheme. We also investigate how the size of the MM region affects the results. These findings may be helpful for the simulation of the morphology of active materials in crystalline or glassy samples.

Effect of solvent on the structure of a protein (H3.1) with a coarse-grained model with knowledge-based interactions

Science.gov (United States)

Pandey, Ras; Farmer, Barry

2013-03-01

Quality of solvent plays a critical role in modulating the structure of a protein along with the temperature. Using a coarse-grained Monte Carlo simulation based on three knowledge-based contact potentials (MJ, BT, BFKV) we examine the structure and dynamics of a histone (H3.1). The empty lattice sites constitute the effective solvent medium in which the protein is embedded. Residue-solvent characteristic interaction is based on the hydropathy index while the residue-residue interaction is used from the knowledge-based contact matrices derived from ensembles of protein structures in the protein data bank. Large scale simulations are performed to analyze the structure of protein for a range of residue-solvent interaction strength, a measure of the solvent quality with each potential. Unlike the monotonic thermal response, the radius of gyration of the protein exhibits non-monotonic dependence of the solvent strength. Quantitative comparison of the structure and dynamics emerging from three knowledge-based potentials will be presented in this talk. This work is supported by Air Force Research Laboratory.

Residual stresses around Vickers indents

International Nuclear Information System (INIS)

Pajares, A.; Guiberteau, F.; Steinbrech, R.W.

1995-01-01

The residual stresses generated by Vickers indentation in brittle materials and their changes due to annealing and surface removal were studied in 4 mol% yttria partially stabilized zirconia (4Y-PSZ). Three experimental methods to gain information about the residual stress field were applied: (i) crack profile measurements based on serial sectioning, (ii) controlled crack propagation in post indentation bending tests and (iii) double indentation tests with smaller secondary indents located around a larger primary impression. Three zones of different residual stress behavior are deduced from the experiments. Beneath the impression a crack free spherical zone of high hydrostatic stresses exists. This core zone is followed by a transition regime where indentation cracks develop but still experience hydrostatic stresses. Finally, in an outward third zone, the crack contour is entirely governed by the tensile residual stress intensity (elastically deformed region). Annealing and surface removal reduce this crack driving stress intensity. The specific changes of the residual stresses due to the post indentation treatments are described and discussed in detail for the three zones

Quadratic residues and non-residues selected topics

CERN Document Server

Wright, Steve

2016-01-01

This book offers an account of the classical theory of quadratic residues and non-residues with the goal of using that theory as a lens through which to view the development of some of the fundamental methods employed in modern elementary, algebraic, and analytic number theory. The first three chapters present some basic facts and the history of quadratic residues and non-residues and discuss various proofs of the Law of Quadratic Reciprosity in depth, with an emphasis on the six proofs that Gauss published. The remaining seven chapters explore some interesting applications of the Law of Quadratic Reciprocity, prove some results concerning the distribution and arithmetic structure of quadratic residues and non-residues, provide a detailed proof of Dirichlet’s Class-Number Formula, and discuss the question of whether quadratic residues are randomly distributed. The text is a valuable resource for graduate and advanced undergraduate students as well as for mathematicians interested in number theory.

Structural analysis of CuO / CeO2-based catalytic materials intended for PROX reaction: Part I

International Nuclear Information System (INIS)

Neiva, L.S.; Simoes, A.N.; Bispo, A.; Ribeiro, M.A.; Gama, L.

2011-01-01

This work relates the synthesis process of CuO/CeO 2 catalytic materials by a combustion reaction method as well as it introduces a structural analysis of the developed material, this structural analysis had as main focus to evaluate the influence of the doping substance (CuO) when being incorporated in the hostess matrix structure that is CeO 2 . The CuO/CeO catalytic materials developed in this work are destined to preferential oxidation of CO reaction (PROX). The developed materials were characterized by XRD, SEM and textural complete analysis by the BET method. According to the results, the CuO incorporation changed crystallinity of the structure of the catalytic materials. On the other hand, the morphologic and textural characteristics did not showed significant differences regarding the presence of the doping substance (CuO) in the structure of the developed materials. The porosity of the structures of the developed catalytic materials belongs to the type macroporous. (author)

Direct methods and residue type specific isotope labeling in NMR structure determination and model-driven sequential assignment

International Nuclear Information System (INIS)

Schedlbauer, Andreas; Auer, Renate; Ledolter, Karin; Tollinger, Martin; Kloiber, Karin; Lichtenecker, Roman; Ruedisser, Simon; Hommel, Ulrich; Schmid, Walther; Konrat, Robert; Kontaxis, Georg

2008-01-01

Direct methods in NMR based structure determination start from an unassigned ensemble of unconnected gaseous hydrogen atoms. Under favorable conditions they can produce low resolution structures of proteins. Usually a prohibitively large number of NOEs is required, to solve a protein structure ab-initio, but even with a much smaller set of distance restraints low resolution models can be obtained which resemble a protein fold. One problem is that at such low resolution and in the absence of a force field it is impossible to distinguish the correct protein fold from its mirror image. In a hybrid approach these ambiguous models have the potential to aid in the process of sequential backbone chemical shift assignment when 13 C β and 13 C' shifts are not available for sensitivity reasons. Regardless of the overall fold they enhance the information content of the NOE spectra. These, combined with residue specific labeling and minimal triple-resonance data using 13 C α connectivity can provide almost complete sequential assignment. Strategies for residue type specific labeling with customized isotope labeling patterns are of great advantage in this context. Furthermore, this approach is to some extent error-tolerant with respect to data incompleteness, limited precision of the peak picking, and structural errors caused by misassignment of NOEs

Testing of residual monomer content reduction possibility on acrilic resins quality

Directory of Open Access Journals (Sweden)

Kostić Milena

2011-01-01

Full Text Available Poly (methyl methacrylate (PMMA is material widely used in dentistry. Despite the various methods used to initiate the polymerization of acrylic resins, the conversion of monomer to polymer is not complete thus leaving some unreacted methyl methacrylate (MMA, known as residual monomer (RM, in denture structure. RM in dental acrylic resins has deleterious effects on their mechanical properties and their biocompatibility. The objective of the work was to test the residual monomer reduction possibility by applying the appropriate postpolymerization treatment as well as to determine the effects of this reduction on pressure yields stress and surface structure characteristics of the acrylic resins. Postpolymerization treatments and water storage induced reduction of RM amount in cold-polymerized acrylic resins improved their mechanical properties and the homogenized surface structure. After the polymerization of heat-polymerized acrylic resins the post-polymerization treatments for improving the quality of this material type are not necessary.

Protein-RNA interface residue prediction using machine learning: an assessment of the state of the art.

Science.gov (United States)

Walia, Rasna R; Caragea, Cornelia; Lewis, Benjamin A; Towfic, Fadi; Terribilini, Michael; El-Manzalawy, Yasser; Dobbs, Drena; Honavar, Vasant

2012-05-10

RNA molecules play diverse functional and structural roles in cells. They function as messengers for transferring genetic information from DNA to proteins, as the primary genetic material in many viruses, as catalysts (ribozymes) important for protein synthesis and RNA processing, and as essential and ubiquitous regulators of gene expression in living organisms. Many of these functions depend on precisely orchestrated interactions between RNA molecules and specific proteins in cells. Understanding the molecular mechanisms by which proteins recognize and bind RNA is essential for comprehending the functional implications of these interactions, but the recognition 'code' that mediates interactions between proteins and RNA is not yet understood. Success in deciphering this code would dramatically impact the development of new therapeutic strategies for intervening in devastating diseases such as AIDS and cancer. Because of the high cost of experimental determination of protein-RNA interfaces, there is an increasing reliance on statistical machine learning methods for training predictors of RNA-binding residues in proteins. However, because of differences in the choice of datasets, performance measures, and data representations used, it has been difficult to obtain an accurate assessment of the current state of the art in protein-RNA interface prediction. We provide a review of published approaches for predicting RNA-binding residues in proteins and a systematic comparison and critical assessment of protein-RNA interface residue predictors trained using these approaches on three carefully curated non-redundant datasets. We directly compare two widely used machine learning algorithms (Naïve Bayes (NB) and Support Vector Machine (SVM)) using three different data representations in which features are encoded using either sequence- or structure-based windows. Our results show that (i) Sequence-based classifiers that use a position-specific scoring matrix (PSSM)-based

Biphasic DC measurement approach for enhanced measurement stability and multi-channel sampling of self-sensing multi-functional structural materials doped with carbon-based additives

Science.gov (United States)

Downey, Austin; D'Alessandro, Antonella; Ubertini, Filippo; Laflamme, Simon; Geiger, Randall

2017-06-01

Investigation of multi-functional carbon-based self-sensing structural materials for structural health monitoring applications is a topic of growing interest. These materials are self-sensing in the sense that they can provide measurable electrical outputs corresponding to physical changes such as strain or induced damage. Nevertheless, the development of an appropriate measurement technique for such materials is yet to be achieved, as many results in the literature suggest that these materials exhibit a drift in their output when measured with direct current (DC) methods. In most of the cases, the electrical output is a resistance and the reported drift is an increase in resistance from the time the measurement starts due to material polarization. Alternating current methods seem more appropriate at eliminating the time drift. However, published results show they are not immune to drift. Moreover, the use of multiple impedance measurement devices (LCR meters) does not allow for the simultaneous multi-channel sampling of multi-sectioned self-sensing materials due to signal crosstalk. The capability to simultaneously monitor multiple sections of self-sensing structural materials is needed to deploy these multi-functional materials for structural health monitoring. Here, a biphasic DC measurement approach with a periodic measure/discharge cycle in the form of a square wave sensing current is used to provide consistent, stable resistance measurements for self-sensing structural materials. DC measurements are made during the measurement region of the square wave while material depolarization is obtained during the discharge region of the periodic signal. The proposed technique is experimentally shown to remove the signal drift in a carbon-based self-sensing cementitious material while providing simultaneous multi-channel measurements of a multi-sectioned self-sensing material. The application of the proposed electrical measurement technique appears promising for real

Exergo-economic analysis of biogas production from residual and waste materials for use in energy conversion plants; Exergooekonomische Analyse der Biogaserzeugung aus Rest- und Abfallstoffen fuer den Einsatz in Energieumwandlungsanlagen

Energy Technology Data Exchange (ETDEWEB)

Nagel, Janet [Beuth Hochschule fuer Technik Berlin (Germany)

2015-07-01

Biogenic residual and waste materials are subject to fundamentally different conditions than other renewable resources. Also the purposes for their use in conversion plants are different. Whereas the use of renewable energies in energy conversions plants serves to produce power and heat, biogenic residual and waste materials are primarily focused to be disposed. Considering the sustainable philosophy ''cradle to cradle'' an additional use for these input materials is gaining interest. Energy and exergy balances show that plant and process concepts have a great influence on the energetic conversion. Especially by looking at an exergy-analysis an overall assessment is made based on the working part of the product like power or heat. If economic factors are added, local, regional, and supra-regional influences can be observed and a comprehensive overview of the optimal energetic and economic use of the input materials can be given. A decision which concept of converting biogenic residual and waste materials is to be preferred cannot be made yet. Furthermore, additional ecologic/energetic, economic, and social factors should be taken into account. These factors could be included into the exergoeconomic analysis using a scoring system with economic values.

Ceramic materials on perovskite-type structure for electronic applications

International Nuclear Information System (INIS)

Surowiak, Z.

2003-01-01

Ceramic materials exhibiting the perovskite-type structure constitute among others, resource base for many fields of widely understood electronics (i.e., piezoelectronics, accustoelectronics, optoelectronics, computer science, tele- and radioelectronics etc.). Most often they are used for fabrication of different type sensors (detectors), transducers, ferroelectric memories, limiters of the electronic current intensity, etc., and hence they are numbered among so-called intelligent materials. Prototype structure of this group of materials is the structure of the mineral called perovskite (CaTiO 3 ). By means of right choice of the chemical composition of ABO 3 and deforming the regular perovskite structure (m3m) more than 5000 different chemical compounds and solid solutions exhibiting the perovskite-type structure have been fabricated. The concept of perovskite functional ceramics among often things ferroelectric ceramics, pyroelectric ceramics, piezoelectric ceramics, electrostrictive ceramics, posistor ceramics, superconductive ceramics and ferromagnetic ceramics. New possibilities of application of the perovskite-type ceramics are opened by nanotechnology. (author)

EPR-based material modelling of soils

Science.gov (United States)

Faramarzi, Asaad; Alani, Amir M.

2013-04-01

In the past few decades, as a result of the rapid developments in computational software and hardware, alternative computer aided pattern recognition approaches have been introduced to modelling many engineering problems, including constitutive modelling of materials. The main idea behind pattern recognition systems is that they learn adaptively from experience and extract various discriminants, each appropriate for its purpose. In this work an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR). EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial tests are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well-known conventional material models and it is shown that EPR-based models can provide a better prediction for the behaviour of soils. The main benefits of using EPR-based material models are that it provides a unified approach to constitutive modelling of all materials (i.e., all aspects of material behaviour can be implemented within a unified environment of an EPR model); it does not require any arbitrary choice of constitutive (mathematical) models. In EPR-based material models there are no material parameters to be identified. As the model is trained directly from experimental data therefore, EPR-based material models are the shortest route from experimental research (data) to numerical modelling. Another advantage of EPR-based constitutive model is that as more experimental data become available, the quality of the EPR prediction can be improved by learning from the additional data, and therefore, the EPR model can become more effective and robust. The developed EPR-based material models can be incorporated in finite element (FE) analysis.

Residual stress in the first wall coating materials of TiC and TiN for fusion reactor

International Nuclear Information System (INIS)

Qiu Shaoyu

1997-01-01

Residual stresses measurement in the first wall coating of a fusion reactor of TiC and TiN films by X-ray diffraction 'sin 2 ψ methods' were described. The authors have studied on the effect of conditions of specimen preparation (such as coating method, substrate materials, film thickness and deposition temperature) on the residual stress of TiC and TiN films coated onto Mo, 316LSS and Pocographite by chemical vapor deposition (CVD) and physical vapor deposition (PVD) method. All films prepared in this study were found to have a compressive stresses and the CVD method gave lower residual stress than PVD method. TiC film coated on Mo substrate at 1100 degree C by CVD method showed that residual stress as the film thickness was raised from 14 μm to 60 μm, on the other hand, residual stress by PVD method exhibited a high compressive stresses, this kind of stress was principally the intrinsic stress, and a marked decrease in the residual with raising the deposition temperature (200 degree C∼650 degree C) was demonstrated. Origins of the residual stress were discussed by correlation with differences between thermal expansion coefficients, and also with fabrication methods

Inference of Functionally-Relevant N-acetyltransferase Residues Based on Statistical Correlations.

Directory of Open Access Journals (Sweden)

Andrew F Neuwald

2016-12-01

Full Text Available Over evolutionary time, members of a superfamily of homologous proteins sharing a common structural core diverge into subgroups filling various functional niches. At the sequence level, such divergence appears as correlations that arise from residue patterns distinct to each subgroup. Such a superfamily may be viewed as a population of sequences corresponding to a complex, high-dimensional probability distribution. Here we model this distribution as hierarchical interrelated hidden Markov models (hiHMMs, which describe these sequence correlations implicitly. By characterizing such correlations one may hope to obtain information regarding functionally-relevant properties that have thus far evaded detection. To do so, we infer a hiHMM distribution from sequence data using Bayes' theorem and Markov chain Monte Carlo (MCMC sampling, which is widely recognized as the most effective approach for characterizing a complex, high dimensional distribution. Other routines then map correlated residue patterns to available structures with a view to hypothesis generation. When applied to N-acetyltransferases, this reveals sequence and structural features indicative of functionally important, yet generally unknown biochemical properties. Even for sets of proteins for which nothing is known beyond unannotated sequences and structures, this can lead to helpful insights. We describe, for example, a putative coenzyme-A-induced-fit substrate binding mechanism mediated by arginine residue switching between salt bridge and π-π stacking interactions. A suite of programs implementing this approach is available (psed.igs.umaryland.edu.

Inference of Functionally-Relevant N-acetyltransferase Residues Based on Statistical Correlations.

Science.gov (United States)

Neuwald, Andrew F; Altschul, Stephen F

2016-12-01

Over evolutionary time, members of a superfamily of homologous proteins sharing a common structural core diverge into subgroups filling various functional niches. At the sequence level, such divergence appears as correlations that arise from residue patterns distinct to each subgroup. Such a superfamily may be viewed as a population of sequences corresponding to a complex, high-dimensional probability distribution. Here we model this distribution as hierarchical interrelated hidden Markov models (hiHMMs), which describe these sequence correlations implicitly. By characterizing such correlations one may hope to obtain information regarding functionally-relevant properties that have thus far evaded detection. To do so, we infer a hiHMM distribution from sequence data using Bayes' theorem and Markov chain Monte Carlo (MCMC) sampling, which is widely recognized as the most effective approach for characterizing a complex, high dimensional distribution. Other routines then map correlated residue patterns to available structures with a view to hypothesis generation. When applied to N-acetyltransferases, this reveals sequence and structural features indicative of functionally important, yet generally unknown biochemical properties. Even for sets of proteins for which nothing is known beyond unannotated sequences and structures, this can lead to helpful insights. We describe, for example, a putative coenzyme-A-induced-fit substrate binding mechanism mediated by arginine residue switching between salt bridge and π-π stacking interactions. A suite of programs implementing this approach is available (psed.igs.umaryland.edu).

Silicon based light-emitting materials and devices

International Nuclear Information System (INIS)

Chen Weide

1999-01-01

Silicon based light-emitting materials and devices are the key to optoelectronic integration. Recently, there has been significant progress in materials engineering methods. The author reviews the latest developments in this area including erbium doped silicon, porous silicon, nanocrystalline silicon and Si/SiO 2 superlattice structures. The incorporation of these different materials into devices is described and future device prospects are assessed

Radiation Effects on Spacecraft Structural Materials

International Nuclear Information System (INIS)

Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

2002-01-01

Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

Molybdenum silicide based materials and their properties

International Nuclear Information System (INIS)

Yao, Z.; Stiglich, J.; Sudarshan, T.S.

1999-01-01

Molybdenum disilicide (MoSi 2 ) is a promising candidate material for high temperature structural applications. It is a high melting point (2030 C) material with excellent oxidation resistance and a moderate density (6.24 g/cm 3 ). However, low toughness at low temperatures and high creep rates at elevated temperatures have hindered its commercialization in structural applications. Much effort has been invested in MoSi 2 composites as alternatives to pure molybdenum disilicide for oxidizing and aggressive environments. Molybdenum disilicide-based heating elements have been used extensively in high-temperature furnaces. The low electrical resistance of silicides in combination with high thermal stability, electron-migration resistance, and excellent diffusion-barrier characteristics is important for microelectronic applications. Projected applications of MoSi 2 -based materials include turbine airfoils, combustion chamber components in oxidizing environments, missile nozzles, molten metal lances, industrial gas burners, diesel engine glow plugs, and materials for glass processing. On this paper, synthesis, fabrication, and properties of the monolithic and composite molybdenum silicides are reviewed

Study on the Leak Rate Estimation of SG Tubes and Residual Stress Estimation based on Plastic Deformation

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Jin; Chang, Yoon Suk; Lee, Dock Jin; Lee, Tae Rin; Choi, Shin Beom; Jeong, Jae Uk; Yeum, Seung Won [Sungkyunkwan University, Seoul (Korea, Republic of)

2009-02-15

In this research project, a leak rate estimation model was developed for steam generator tubes with through wall cracks. The modelling was based on the leak data from 23 tube specimens. Also, the procedure of finite element analysis was developed for residual stress calculation of dissimilar metal weld in a bottom mounted instrumentation. The effect of geometric variables related with the residual stress in penetration weld part was investigated by using the developed analysis procedure. The key subjects dealt in this research are: 1. Development of leak rate estimation model for steam generator tubes with through wall cracks 2. Development of the program which can perform the structure and leakage integrity evaluation for steam generator tubes 3. Development of analysis procedure for bottom mounted instrumentation weld residual stress 4. Analysis on the effects of geometric variables on weld residual stress It is anticipated that the technologies developed in this study are applicable for integrity estimation of steam generator tubes and weld part in NPP.

Development of the structural materials information center

International Nuclear Information System (INIS)

Oland, C.B.; Naus, D.J.

1990-01-01

The U.S. Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where data and information on the time variation of concrete and other structural material properties under the influence of pertinent environmental stressors and aging factors are being collected and assembled into a database. This database will be used to assist in the prediction of potential long-term deterioration of critical structural components in nuclear power plants and to establish limits on hostile environmental exposure for these structures and materials. Two complementary database formats have been developed. The Structural Materials Handbook is an expandable, hard copy handbook that contains complete sets of data and information for selected portland cement concrete, metallic reinforcement, prestressing tendon, and structural steel materials. The Structural Materials Electronic Database is accessible by an IBM-compatible personal computer and provides an efficient means for searching the various database files to locate materials with similar properties. The database formats have been developed to accommodate data and information on the time-variation of concrete and other structural material properties. To date, the database includes information on concrete, reinforcement, prestressing, and structural steel materials

Characterization of Structure and Damage in Materials in Four Dimensions

Energy Technology Data Exchange (ETDEWEB)

Robertson, I. M. [Univ. of Illinois, Urbana, IL (United States); Schuh, C. A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vetrano, J. S. [U.S. Department of Energy, Washington, DC (United States); Browning, N. D. [Univ. of California, Davis, CA (United States); Field, D. P. [Washington State Univ., Pullman, WA (United States); Jensen, D. J. [Technical Univ. of Denmark, Roskilde (Denmark); Miller, M. K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baker, I. [Darmouth College, Hanover, NH (United States); Dunand, D. C. [Northwestern Univ., Evanston, IL (United States); Dunin-Borkowski, R. [Technical Univ. of Denmark, Lyngby (Denmark); Kabius, B. [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, T. [Cameca Instruments Corp., Madison, WI (United States); Lozano-Perez, S. [Univ. of Oxford (United Kingdom); Misra, A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rohrer, G. S. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Rollett, A. D. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Taheri, M. [Drexel Univ., Philadelphia, PA (United States); Thompson, G. B. [Univ. of Alabama, Tuscaloosa, AL (United States); Uchic, M. [Air Force Research Lab. (AFRL), Wright-Patterson AFB, OH (United States); Wang, X. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Was, G. [Univ. of Michigan, Ann Arbor, MI (United States)

2010-09-30

The materials characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when materials scientists can quantify material structure across orders of magnitude in length and time scales (i.e., in four dimensions) completely. This paper presents a viewpoint on the materials characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future development. Electron microscopy; atom-probe tomography; X-ray, neutron and electron tomography; serial sectioning tomography; and diffraction-based analysis methods are reviewed, and opportunities for their future development are highlighted. Particular attention is paid to studies that have pioneered the synergetic use of multiple techniques to provide complementary views of a single structure or process; several of these studies represent the state-of-the-art in characterization, and suggest a trajectory for the continued development of the field. Based on this review, a set of grand challenges for characterization science is identified, including suggestions for instrumentation advances, scientific problems in microstructure analysis, and complex structure evolution problems involving materials damage. The future of microstructural characterization is proposed to be one not only where individual techniques are pushed to their limits, but where the community devises strategies of technique synergy to address complex multiscale problems in materials science and engineering.

Characteristics of cassava starch fermentation wastewater based on structural degradation of starch granules

Directory of Open Access Journals (Sweden)

Juliane Mascarenhas Pereira

2016-01-01

Full Text Available ABSTRACT: Sour cassava starch is a naturally modified starch produced by fermentation and sun drying, achieving the property of expansion upon baking. Sour cassava starch' bakery products can be prepared without the addition of yeast and it is gluten free. The fermentation process associated with this product has been well studied, but the wastewater, with high acidity and richness in other organic compounds derived from starch degradation, requires further investigation. In this study, the structure of solids present in this residue was studied, seeking to future applications for new materials. The solids of the wastewater were spray dried with maltodextrin (MD with dextrose equivalent (DE of 5 and 15 and the structure of the powder was evaluated by scanning electron microscopy. A regular structure with a network arrangement was observed for the dried material with MD of 5 DE, in contrast to the original and fermented starches structure, which suggests a regular organization of this new material, to be studied in future applications.

Mechanical properties of permeable materials with an organized structure on the base of continuous metal fibers

International Nuclear Information System (INIS)

Karpinos, D.M.; Rutkovskij, A.E.; Zorin, V.A.; Ivanchuk, A.A.

1979-01-01

The mechanical properties were studied for permeable fibrous materials with an organized structure on the base of continuous metal fibers (from Kh18N9T steel) subjected to preliminary reprocessing volumetric net half-finished products. The effect of geometrical parameters of the net half-finished products and of their orientation in packing are shown to affect the mechanical properties within a wide range of porosities

Use of fly ash, phosphogypsum and red mud as a liner material for the disposal of hazardous zinc leach residue waste.

Science.gov (United States)

Coruh, Semra; Ergun, Osman Nuri

2010-01-15

Increasing amounts of residues and waste materials coming from industrial activities in different processes have become an increasingly urgent problem for the future. The release of large quantities of heavy metals into the environment has resulted in a number of environmental problems. The present study investigated the safe disposal of the zinc leach residue waste using industrial residues such as fly ash, phosphogypsum and red mud. In the study, leachability of heavy metals from the zinc leach residue has been evaluated by mine water leaching procedure (MWLP) and toxicity characteristic leaching procedure (TCLP). Zinc removal from leachate was studied using fly ash, phosphogypsum and red mud. The adsorption capacities and adsorption efficiencies were determined. The adsorption rate data was analyzed according to the pseudo-second-order kinetic, Elovich kinetic and intra-particle diffusion kinetic models. The pseudo-second-order kinetic was the best fit kinetic model for the experimental data. The results show that addition of fly ash, phosphogypsum and red mud to the zinc leach residue drastically reduces the heavy metal content in the leachate and could be used as liner materials.

Residual stress analysis in thick uranium films

International Nuclear Information System (INIS)

Hodge, A.M.; Foreman, R.J.; Gallegos, G.F.

2005-01-01

Residual stress analysis was performed on thick, 1-25 μm, depleted uranium (DU) films deposited on an Al substrate by magnetron sputtering. Two distinct characterization techniques were used to measure substrate curvature before and after deposition. Stress evaluation was performed using the Benabdi/Roche equation, which is based on beam theory of a bi-layer material. The residual stress evolution was studied as a function of coating thickness and applied negative bias voltage (0, -200, -300 V). The stresses developed were always compressive; however, increasing the coating thickness and applying a bias voltage presented a trend towards more tensile stresses and thus an overall reduction of residual stresses

Effect of pretreatment on biomass residue structure and the application of pyrolysed and composted biomass residues in soilless culture.

Directory of Open Access Journals (Sweden)

Linna Suo

Full Text Available The changes in the structural characteristics of biomass residues during pyrolysis and composting were investigated. The biomass residues particles were prepared by pyrolysing at temperatures ranging from 350 to 400. For soilless production of the ornamental plant Anthurium andraeanum, pure sphagnum peat moss (P has traditionally been used as the growing medium. This use of P must be reduced, however, because P is an expensive and nonrenewable resource. The current study investigated the use of biomass residues as substitutes for P in A. andraeanum production. Plants were grown for 15 months in 10 soilless media that contained different proportions of pyrolysed corn cobs (PC, composted corn cobs (C, pyrolysed garden wastes (PG, and P. Although the media altered the plant nutrient content, A. andraeanum growth, development, and yield were similar with media consisting of 50% P+50% PC, 50% P+35% PC+15% PG, and 100% P. This finding indicates that, when pyrolysed, organic wastes, which are otherwise an environmental problem, can be used to reduce the requirement for peat in the soilless culture of A. andraeanum.

Superamphiphobic overhang structured coating on a biobased material

Energy Technology Data Exchange (ETDEWEB)

Tuominen, Mikko, E-mail: mikko.tuominen@sp.se [SP Technical Research Institute of Sweden—Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm (Sweden); Teisala, Hannu [Tampere University of Technology, Paper Converting and Packaging Technology, Department of Materials Science, P.O. Box 589, FI-33101 Tampere (Finland); Haapanen, Janne; Mäkelä, Jyrki M. [Tampere University of Technology, Aerosol Physics Laboratory, Department of Physics, P.O. Box 692, FI-33101 Tampere (Finland); Honkanen, Mari; Vippola, Minnamari [Tampere University of Technology, Material Characterization, Department of Materials Science, P.O. Box 589, FI-33101 Tampere (Finland); Bardage, Stig [SP Technical Research Institute of Sweden, Sustainable Built Environment, Biobased Materials and Products, Box 5609, SE-114 86 Stockholm (Sweden); Wålinder, Magnus E.P. [KTH Royal Institute of Technology, Department of Civil and Architectural Engineering, Building Materials, SE-100 44 Stockholm (Sweden); Swerin, Agne [SP Technical Research Institute of Sweden—Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm (Sweden); KTH Royal Institute of Technology, Department of Chemistry, Surface and Corrosion Science, SE-100 44 Stockholm (Sweden)

2016-12-15

Highlights: • A superamphiphobic coating on a wood shows extreme liquid repellence against water, ethylene glycol, diiodomethane and olive oil. • The coated wood sample can have the required geometrical homogeneity to establish superamphiphobic properties. • To our knowledge, this is the first time superamphiphobicity based on overhang structures has been shown for a renewable bio-based material.A superamphiphobic coating on a wood shows extreme liquid repellence with static contact angles (CA) greater than 150° and roll-off angles less than 10° against water, ethylene glycol, diiodomethane and olive oil. - Abstract: A superamphiphobic coating on a biobased material shows extreme liquid repellency with static contact angles (CA) greater than 150° and roll-off angles less than 10° against water, ethylene glycol, diiodomethane and olive oil, and a CA for hexadecane greater than 130°. The coating consisting of titania nanoparticles deposited by liquid flame spray (LFS) and hydrophobized using plasma-polymerized perfluorohexane was applied to a birch hardwood. Scanning electron microscopy (SEM) imaging after sample preparation by UV laser ablation of coated areas revealed that capped structures were formed and this, together with the geometrically homogeneous wood structure, fulfilled the criteria for overhang structures to occur. The coating showed high hydrophobic durability by still being non-wetted after 500 000 water drop impacts, and this is discussed in relation to geometrical factors and wetting forces. The coating was semi-transparent with no significant coloration. A self-cleaning effect was demonstrated with both water and oil droplets. A self-cleanable, durable and highly transparent superamphiphobic coating based on a capped overhang structure has a great potential for commercial feasibility in a variety of applications, here exemplified for a biobased material.

Radiation-beam technologies of structural materials treatment

International Nuclear Information System (INIS)

Kalin, B.A.

2001-01-01

Considered in the paper are the most advanced and prospective radiation-beam technologies (RBT) for treatment of structural materials, as applied to modifying the structural-phase state in the surface layers of half-finished products and articles with the purpose to improve their service properties. Ion-beam, plasma, and ion-plasma, as well as the technologies based on the use of concentrated fluxes of energy, generated by laser radiation, high-power pulsed electron and ion beams, and high-temperature pulsed plasma fluxes are analysed. As applied to improvement of the corrosion and erosion resistance, breaking strength, friction and wear resistance, and crack resistance, the directions of the choice and the use of RBT have been considered for changes of the surface layer state by applying covers and films, and by a change of the surface topography (relief), surface structure and defects, and the element composition and phase state of materials [ru

A review of residual stress analysis using thermoelastic techniques

Energy Technology Data Exchange (ETDEWEB)

Robinson, A F; Dulieu-Barton, J M; Quinn, S [University of Southampton, School of Engineering Sciences, Highfield, Southampton, SO17 1BJ (United Kingdom); Burguete, R L [Airbus UK Ltd., New Filton House, Filton, Bristol, BS99 7AR (United Kingdom)

2009-08-01

Thermoelastic Stress Analysis (TSA) is a full-field technique for experimental stress analysis that is based on infra-red thermography. The technique has proved to be extremely effective for studying elastic stress fields and is now well established. It is based on the measurement of the temperature change that occurs as a result of a stress change. As residual stress is essentially a mean stress it is accepted that the linear form of the TSA relationship cannot be used to evaluate residual stresses. However, there are situations where this linear relationship is not valid or departures in material properties due to manufacturing procedures have enabled evaluations of residual stresses. The purpose of this paper is to review the current status of using a TSA based approach for the evaluation of residual stresses and to provide some examples of where promising results have been obtained.

A review of residual stress analysis using thermoelastic techniques

International Nuclear Information System (INIS)

Robinson, A F; Dulieu-Barton, J M; Quinn, S; Burguete, R L

2009-01-01

Thermoelastic Stress Analysis (TSA) is a full-field technique for experimental stress analysis that is based on infra-red thermography. The technique has proved to be extremely effective for studying elastic stress fields and is now well established. It is based on the measurement of the temperature change that occurs as a result of a stress change. As residual stress is essentially a mean stress it is accepted that the linear form of the TSA relationship cannot be used to evaluate residual stresses. However, there are situations where this linear relationship is not valid or departures in material properties due to manufacturing procedures have enabled evaluations of residual stresses. The purpose of this paper is to review the current status of using a TSA based approach for the evaluation of residual stresses and to provide some examples of where promising results have been obtained.

Food Access, Food Subsidy, and Residue-Based Bioenergy ...

International Development Research Centre (IDRC) Digital Library (Canada)

Food Access, Food Subsidy, and Residue-Based Bioenergy Production in ... The goal is to show how the Indian government can improve access to food ... IDRC has signed a Memorandum of Understanding (MoU) with the Government of ...

Systems and strippable coatings for decontaminating structures that include porous material

Science.gov (United States)

Fox, Robert V [Idaho Falls, ID; Avci, Recep [Bozeman, MT; Groenewold, Gary S [Idaho Falls, ID

2011-12-06

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

Overview of fast reactor structural materials programme in India

International Nuclear Information System (INIS)

Rodriguez, P.; Paranjpe, S.R.; Chetal, S.C.; Mannan, S.L.; Ray, S.K.; Seetharaman, V.; Srinivasan, G.

The fast reactor structural materials activities in India comprise of the programme on the materials for the Fast Breeder Test Reactor (FBTR), the construction of which is nearing completion, and the programme on the candidate materials for the Prototype Fast Breeder Reactor (PFBR) which is now in the design stage. For the materials in use in FBTR, the main thrust has been towards detailed evaluation and documentation of long term (creep) properties of type 316 stainless steel base material in air. For the PFBR the philosophy has been to identify the candidate materials and to evolve a wider scope for the testing and evaluation programmes. The major structural component is identified as variants of type 304 stainless steel and the programmes undertaken include study of low cycle fatigue properties and environmental effects on creep and stress rupture properties. Evaluations of aging embrittlement of type 316 stainless steel base material and weldments are also in progress. The paper lists the testing programmes identified for adoption in the near future. These include creep-fatigue damage studies and fracture mechanics studies on weldments for type 304 stainless steel and testing programme on 2.25 Cr-1 Mo and 9 Cr-1 Mo steels, the identified candidate materials for steam generators. The development efforts also include a comprehensive programme on inelastic analysis procedure. (author)

Geophysical exploration of historical mine dumps for the estimation of valuable residuals