Gestão da informação em bibliotecas universitárias: as práticas do Sistema de Bibliotecas da Universidade Federal de Goiás (Sibi/UFG

Directory of Open Access Journals (Sweden)

Luciana Alves Ferreira

2013-01-01

Full Text Available Esta pesquisa descritiva e exploratória objetivou verificar se as atuais práticas de gestão da informação do Sistema de Bibliotecas da Universidade Federal de Goiás (Sibi/UFG atendem às necessidades de informação dos usuários da área de saúde, dos cursos de graduação e pós-graduação (Stricto sensu em Biomedicina e Enfermagem. Para tanto, utilizou-se o modelo de gerenciamento da informação proposto por Choo e realizou-se um estudo de usuário em relação ao uso da Biblioteca Virtual em Saúde da BIREME. Concluiu-se que a gestão da informação no Sibi/UFG é relativamente capaz de atender às necessidades de informação dos usuários dos cursos de Biomedicina e Enfermagem.

Remote MINOS Shift Station at IF-UFG

International Nuclear Information System (INIS)

Tognini, Stefano Castro; Gomes, Ricardo Avelino

2011-01-01

Full text: MINOS is a very well known neutrino experiment mainly designed to study neutrino oscillations and measure the parameters that rule the phenomena. The experiment uses an intense neutrino beam provided by the NuMI (Neutrinos at the Main Injector) beamline at Fermilab and two similar magnetized detectors - the Near Detector located at Fermilab, 1 km downstream the target and 94 m underground; and the Far Detector located in the Soudan Mine in northern Minnesota, 734 km downstream the Near Detector and 713 m underground. The MINOS control room is consisted of four main systems used to monitor the beam, the detectors and the data acquisition process: the Beam Monitoring System - a set of tools used to monitor the status of the NuMI beam, such as its intensity, its alignment with the target and beamline and if the beam data acquisition is working properly; the Online Monitoring System (OM) - responsible for monitoring the electronics of both detectors, which determines the quality of the data; the Detector Control System (DCS) - which monitors the detectors information, such as the high voltage systems, state of the rack protection system, the magnet control, chiller monitor, coil current, humidity and environmental temperatures; and the Data Acquisition System (DAQ) - used to control the runs/subruns and monitor the recording process. The experiment is taking data with the Far Detector since 2003 and with the Near Detector since 2005. The Physics Institute of the Federal University of Goias (IF-UFG) is joining the MINOS Collaboration since June 2009 and this work describes the configuration of our Remote MINOS Shift Station. In order to accomplish the shift tasks with minimum expenditure of time and money efforts, MINOS decided to authorize remote shifts on January 2011. Apart of being able to realize remote shifts, the main goals of our shift station are to allow the training of new users, in particular graduate students; to allow our real-time monitoring of

Possible Gems and Ultra-Fine Grained Polyphase Units in Comet Wild 2.

Science.gov (United States)

Gainsforth, Z.; Butterworth, A. L.; Jilly-Rehak, C. E.; Westphal, A. J.; Brownlee, D. E.; Joswiak, D.; Ogliore, R. C.; Zolensky, M. E.; Bechtel, H. A.; Ebel, D. S.;

Gestão da informação em bibliotecas universitárias: as práticas do Sistema de Bibliotecas da Universidade Federal de Goiás (Sibi/UFG

Directory of Open Access Journals (Sweden)

Luciana Alves Ferreira

2013-04-01

Full Text Available http://dx.doi.org/10.5007/1518-2924.2013v18n36p181   Esta pesquisa descritiva e exploratória objetivou verificar se as atuais práticas de gestão da informação do Sistema de Bibliotecas da Universidade Federal de Goiás (Sibi/UFG atendem às necessidades de informação dos usuários da área de saúde, dos cursos de graduação e pós-graduação (Stricto sensu em Biomedicina e Enfermagem. Para tanto, utilizou-se o modelo de gerenciamento da informação proposto por Choo e realizou-se um estudo de usuário em relação ao uso da Biblioteca Virtual em Saúde da BIREME. Concluiu-se que a gestão da informação no Sibi/UFG é relativamente capaz de atender às necessidades de informação dos usuários dos cursos de Biomedicina e Enfermagem.

Preparation of plant-specific NDA reference material

International Nuclear Information System (INIS)

Abedin-Zadeh, R.; Beetle, T.; Kuhn, E.; Terrey, D.; Turel, S.; Busca, G.; Guardini, S.

1983-01-01

The importance of having suitable and well characterized non-destructive assay (NDA) reference materials for the verification activities of the safeguards control authorities is stressed. The Euratom Inspectorate and the IAEA have initiated an extensive programme for the procurement and preparation of Joint Euratom/IAEA safeguards NDA reference materials with the active participation of the Ispra Establishment of the Euratom Joint Research Centre. The different type and nature of materials, condition of measurements, and plant characteristics and provisions had to be taken into account for plant-specific NDA reference materials. The preparation of each reference material was planned case by case and specific criteria such as limitations in different facilities, measurement capabilities, conditions, product availability and population variability are being ascertained. A procurement scheme was prepared describing step-by-step procedures detailing responsibilities, measurement conditions, destructive analysis schemes, desired characteristics and methods of data evaluation. This paper describes the principles and procedures carried out for the preparation of a reference MOX pin, low enriched uranium reference rods, low enriched uranium reference drums, reference MTR assemblies, and THTR reference pebbles. The scheme for each characterization technique is presented. (author)

A Paradigm for EST Materials Preparation.

Science.gov (United States)

Carreon, Edwina S.; Balarbar, Corazon V.

In many countries, suitable English for special purposes (ESP) textbooks and materials are difficult to find. ESP teachers and program coordinators often must develop their own materials, but preparing such materials requires training. One model that has served as a guide to numerous ESP materials projects is the Hutchinson and Waters' model. This…

Mechanical behavior and strengthening mechanisms in ultrafine grain precipitation-strengthened aluminum alloy

International Nuclear Information System (INIS)

Ma, Kaka; Wen, Haiming; Hu, Tao; Topping, Troy D.; Isheim, Dieter; Seidman, David N.; Lavernia, Enrique J.; Schoenung, Julie M.

2014-01-01

To provide insight into the relationships between precipitation phenomena, grain size and mechanical behavior in a complex precipitation-strengthened alloy system, Al 7075 alloy, a commonly used aluminum alloy, was selected as a model system in the present study. Ultrafine-grained (UFG) bulk materials were fabricated through cryomilling, degassing, hot isostatic pressing and extrusion, followed by a subsequent heat treatment. The mechanical behavior and microstructure of the materials were analyzed and compared directly to the coarse-grained (CG) counterpart. Three-dimensional atom-probe tomography was utilized to investigate the intermetallic precipitates and oxide dispersoids formed in the as-extruded UFG material. UFG 7075 exhibits higher strength than the CG 7075 alloy for each equivalent condition. After a T6 temper, the yield strength (YS) and ultimate tensile strength (UTS) of UFG 7075 achieved 734 and 774 MPa, respectively, which are ∼120 MPa higher than those of the CG equivalent. The strength of as-extruded UFG 7075 (YS: 583 MPa, UTS: 631 MPa) is even higher than that of commercial 7075-T6. More importantly, the strengthening mechanisms in each material were established quantitatively for the first time for this complex precipitation-strengthened system, accounting for grain-boundary, dislocation, solid-solution, precipitation and oxide dispersoid strengthening contributions. Grain-boundary strengthening was the predominant mechanism in as-extruded UFG 7075, contributing a strength increment estimated to be 242 MPa, whereas Orowan precipitation strengthening was predominant in the as-extruded CG 7075 (∼102 MPa) and in the T6-tempered materials, and was estimated to contribute 472 and 414 MPa for CG-T6 and UFG-T6, respectively

Preparation of porous materials for radionuclides capture

International Nuclear Information System (INIS)

Bajzikova, Anna; Smrcek, Stanislav; Kozempel, Jan; Vlk, Martin; Barta, Jan

2015-01-01

Porous materials showing promise for radionuclide capture from water at contaminated sites were prepared. Nanoporous materials (size of pores 1-100 nm) and some polymers are well suited to this purpose owing their affinity for selected radionuclides. Nanoporous metal oxides and silica gel with styrene-divinylbenzene-TODGA-modified surface were prepared, characterized and tested for radionuclide ( 227 Ac, 227 Th, 223 Ra) capture efficiency. (orig.)

Microstructure and mechanical behavior of neutron irradiated ultrafine grained ferritic steel

Energy Technology Data Exchange (ETDEWEB)

Alsabbagh, Ahmad, E-mail: ahalsabb@ncsu.edu [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Sarkar, Apu [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Miller, Brandon [ATR National Scientific User Facility, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Burns, Jatuporn [Center for Advanced Energy Studies, Idaho Falls, ID 83401 (United States); Squires, Leah; Porter, Douglas; Cole, James I. [ATR National Scientific User Facility, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Murty, K.L. [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

2014-10-06

Neutron irradiation effects on ultra-fine grain (UFG) low carbon steel prepared by equal channel angular pressing (ECAP) have been examined. Counterpart samples with conventional grain (CG) sizes have been irradiated alongside with the UFG ones for comparison. Samples were irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 1.37 dpa. Atom probe tomography revealed manganese and silicon-enriched clusters in both UFG and CG steel after neutron irradiation. Mechanical properties were characterized using microhardness and tensile tests, and irradiation of UFG carbon steel revealed minute radiation effects in contrast to the distinct radiation hardening and reduction of ductility in its CG counterpart. After irradiation, micro hardness indicated increases of around 9% for UFG versus 62% for CG steel. Similarly, tensile strength revealed increases of 8% and 94% respectively for UFG and CG steels while corresponding decreases in ductility were 56% versus 82%. X-ray quantitative analysis showed that dislocation density in CG increased after irradiation while no significant change was observed in UFG steel, revealing better radiation tolerance. Quantitative correlations between experimental results and modeling were demonstrated based on irradiation induced precipitate strengthening and dislocation forest hardening mechanisms.

Preparation of fish material for interlaboratory study on PFCs

NARCIS (Netherlands)

Korytar, P.; Kwadijk, C.J.A.F.; Lohman, M.; Barneveld, van E.

2007-01-01

The Institute for Environmental Studies, Vrije Universiteit (IVM) has requested Wageningen IMARES for the preparation of fish material for use in interDlaboratory performance study on analysis of perfluorinated compounds (PFCs). It was requested that the material should be prepared from fillet of

Preparation of pure TiO2 sorption material

International Nuclear Information System (INIS)

Špendlíková, Irena; Raindl, Jakub; Němec, Mojmír

2013-01-01

Among the natural or anthropogenic radionuclides of very low concentrations nowadays measured in environmental samples, the radionuclide of 236 U has been recently included. In these ultra-trace analyses, the purity of sorption materials is very important and the traditional preparation procedures have to be optimized to minimize possible contamination. In the case of the determination of natural concentration of 236 U ( 236 U/ 238 U ∼ 10 -10 - 10 -14 ), the sample treatment procedure has to be modified in order to eliminate possible contamination from anthropogenic 236 U that may result even in more than ten thousand times higher 236 U/ 238 U ratios. Many inorganic and organic materials have been proposed for the extraction of uranium. However, only several of them are suitable for the uranium sorption from the solutions of low uranium concentration, but relatively high salt content, such as fresh water, sea water etc. At the same time they have to meet other limiting parameters such as fast kinetics, chemical stability, and low costs. Among the inorganic sorption materials, titanium dioxide has been studied for years with promising results. Titanium dioxides can be prepared via the hydrolysis of titanium compounds, either inorganic salts or organic derivatives, but their properties strongly depend on the preparation conditions. In classical procedures, titanium dioxides are prepared from commercial inorganic salts, such as sulphates or chlorides, or even from industrial intermediates of the titanium white production. Typically, the resulting titanium dioxides are contaminated with uranium already from the origin. Assuming that most organic compounds do not contain uranium and that it is possible to find 'uranium free' water, titanium dioxide free of uranium contamination could be prepared by the hydrolysis of organic titanium derivatives. The aim of this study was to find a suitable way of pure titanium dioxide preparation and to optimize the preparation

New materials for sample preparation techniques in bioanalysis.

Science.gov (United States)

Nazario, Carlos Eduardo Domingues; Fumes, Bruno Henrique; da Silva, Meire Ribeiro; Lanças, Fernando Mauro

2017-02-01

The analysis of biological samples is a complex and difficult task owing to two basic and complementary issues: the high complexity of most biological matrices and the need to determine minute quantities of active substances and contaminants in such complex sample. To succeed in this endeavor samples are usually subject to three steps of a comprehensive analytical methodological approach: sample preparation, analytes isolation (usually utilizing a chromatographic technique) and qualitative/quantitative analysis (usually with the aid of mass spectrometric tools). Owing to the complex nature of bio-samples, and the very low concentration of the target analytes to be determined, selective sample preparation techniques is mandatory in order to overcome the difficulties imposed by these two constraints. During the last decade new chemical synthesis approaches has been developed and optimized, such as sol-gel and molecularly imprinting technologies, allowing the preparation of novel materials for sample preparation including graphene and derivatives, magnetic materials, ionic liquids, molecularly imprinted polymers, and much more. In this contribution we will review these novel techniques and materials, as well as their application to the bioanalysis niche. Copyright © 2016 Elsevier B.V. All rights reserved.

New preparation of fish material for interlaboratory study on PFCs

NARCIS (Netherlands)

Korytar, P.; Lohman, M.; Kwadijk, C.J.A.F.; Barneveld, van E.

2007-01-01

The Institute for Environmental Studies, Vrije Universiteit (IVM) has requested Wageningen IMARES to prepare a new fish material for use in the interlaboratory performance study on analysis of perfluorinated compounds (PFCs) due to the low amount of contaminants in the previously prepared material.

Preparation of working calibration and test materials: uranyl nitrate solution

International Nuclear Information System (INIS)

Yamamura, S.S.; Spraktes, F.W.; Baldwin, J.M.; Hand, R.L.; Lash, R.P.

1977-05-01

Reliable working calibration and test materials (WCTMs) are essential to a meaningful analytical measurements quality assurance program. This report describes recommended methods for the preparation of uranyl nitrate solution WCTMs for testing analytical methods, for calibrating methods, and for testing personnel. Uranyl nitrate solution WCTMs can be synthesized from characterized starting materials or prepared from typical plant materials by thorough characterization with reference to primary or secondary reference calibration and test materials (PRCTMs or SRCTMs). Recommended starting materials are described along with detailed procedures for (a) preparing several widely-used types of uranyl nitrate solution WCTMs, (b) packaging the WCTMs, (c) analyzing the WCTMs to establish the reference values or to confirm the synthesis, and (d) statistically evaluating the analytical data to assign reference values and to assess the accuracy of the WCTMs

Optimasi Proses Multi-Pass Equal Channel Angular Pressing Dengan Simulasi Komputer

OpenAIRE

Choiron, Moch. Agus; Anam, Khairul; Prasetyo, Totok Tri

2014-01-01

UFG (Ultra-fine grained) material is a material with a grain size between 10 nm to 1000 nm were developed to improve the quality of the material microstructure byreducing the grain size. Equal Channel Angular Pressing (ECAP) is a method to produce the UFG material by utilizing the shear stress on the material. Shear stress distribution in the material as it passes through the channel intersection is important to investigate so that it can be known the die design that can produce a uniform sh...

Preparation and characterization of the fish reference material

International Nuclear Information System (INIS)

Ulrich, Joao Cristiano

2011-01-01

The certified reference materials (CRMs) play an important role in obtaining measurement results traceable to the International System of Units, through an unbroken chain of comparisons. Thus, the demand for new certified reference materials (CRMs) increases every day in all areas of knowledge. The availability of reference materials, mainly in Brazil is still incipient, given that the demand far exceeds the available variety of these materials. The amount of certified reference materials available in the country is insufficient to meet the need of the scientific community and demands for development of new methodologies. Among the many areas in need of reference materials, we highlight the importance for the food trade balance for these products within the country. The certification of food products, intended both for export and for domestic consumption, requires analysis methods that provide precise and accurate results to ensure product quality. This paper describes the preparation and certification of a reference material in the fish matrix in mercury and methylmercury. The study brings together since the stage of material selection, preparation, development of homogeneity and stability studies and characterization. The certification was performed by means of measurements using two analytical techniques, flow injection analysis - cold vapor atomic absorption spectrometry (FIA-CV-AAS) and isotope dilution applied to mass spectrometry (IDMS), which is a primary method. In this work the standards of the ISO 30 (ABNT 30-34) and ISO Guide 35 was used as the basis for the preparation and characterization of the material. For the calculation of uncertainties was used the GUM and Eurachem guide. As a result, was produced and certified a lot of material in relation to the concentration of mercury (Hg = 0.271 ± 0.057 mg g -1 ) and methylmercury (MeHg = 0.245 ± 0.038 mg g -1 ), and informational values of lead and arsenic. (author)

Preparation of ceramic materials for surface characterization

International Nuclear Information System (INIS)

Zipperian, D.C.

1989-01-01

This paper discusses how microstructural preparation permits a microscopic analysis of a material's internal structure, which is related to the physical properties of the material. Today, numerous microstructural quantitative and qualitative measurements are commonly utilized. Several of these include phase determination, phase hardness, phase distribution, grain size and shape, and porosity and size distribution. The most widely used surface characterization techniques are optical microscopy, electron microscopy, and x-ray microscopy. Optical microscopy includes both transmitted-and reflected-light techniques and requires a surface preparation prior to analysis. Transmitted-light microscopy samples require thinning and polishing of both sides of the sample, whereas reflected light techniques require polishing of only one side of the sample

Preparation and evaluation of reference materials for accountancy analysis. (1) Preparation and evaluation method

International Nuclear Information System (INIS)

Takamatsu, Mai; Kacchi, Tomokazu; Murakami, Toshiki; Ai, Hironobu; Sumi, Mika; Abe, Katsuo; Kageyama, Tomio; Nakazawa, Hiroaki

2009-01-01

Isotope dilution mass spectrometry method used for the accountancy analysis at nuclear fuel facilities requires the standard materials called LSD (Large Size Dried) spike. Generally, LSD spikes are prepared from certified reference materials (CRMs) which supplied from foreign laboratories. However, the difficulty of Pu CRM importation is increasing. It is important for safeguards to attain and continue high reliable accountancy analysis and stable securing of LSD spike is essential. Therefore, in order to conserve CRMs, several types of LSD spike were prepared under collaboration work between JAEA and JNFL, such as the amount of nuclear material in one LSD spike is decreased and others. Practical test with actual samples were performed at JNFL Rokkasho reprocessing plant, and those results were compared with the results obtained by using LSD spike which supplied from foreign laboratory. Preparation and verification analysis of LSD spikes and evaluation of uncertainty based on ISO-GUM will be presented. (author)

Preparation of reference material for the measurement of natural radioactivity

International Nuclear Information System (INIS)

Ben Tekaya, Malik

2010-01-01

The objective of this work is to prepare reference material for the calibration of gamma spectrometry, alpha and XRF .Many procedures of chemical preparation and radiological analysis of a reference material from Triple Superphosphate were tested. Several techniques and methods of measurement were used. In addition to a description and validation of these procedures, a study of repeatability was conducted which resulted in a positive characterization of this material.

High strength and utilizable ductility of bulk ultrafine-grained Cu-Al alloys

Science.gov (United States)

An, X. H.; Han, W. Z.; Huang, C. X.; Zhang, P.; Yang, G.; Wu, S. D.; Zhang, Z. F.

2008-05-01

Lack of plasticity is the main drawback for nearly all ultrafine-grained (UFG) materials, which restricts their practical applications. Bulk UFG Cu-Al alloys have been fabricated by using equal channel angular pressing technique. Its ductility was improved to exceed the criteria for structural utility while maintaining a high strength by designing the microstructure via alloying. Factors resulting in the simultaneously enhanced strength and ductility of UFG Cu-Al alloys are the formation of deformation twins and their extensive intersections facilitating accumulation of dislocations.

Investigating the Mechanical Behavior and Deformation Mechanisms of Ultrafinegrained Metal Films Using Ex-situ and In-situ TEM Techniques

Science.gov (United States)

Izadi, Ehsan

Nanocrystalline (NC) and Ultrafine-grained (UFG) metal films exhibit a wide range of enhanced mechanical properties compared to their coarse-grained counterparts. These properties, such as very high strength, primarily arise from the change in the underlying deformation mechanisms. Experimental and simulation studies have shown that because of the small grain size, conventional dislocation plasticity is curtailed in these materials and grain boundary mediated mechanisms become more important. Although the deformation behavior and the underlying mechanisms in these materials have been investigated in depth, relatively little attention has been focused on the inhomogeneous nature of their microstructure (particularly originating from the texture of the film) and its influence on their macroscopic response. Furthermore, the rate dependency of mechanical response in NC/UFG metal films with different textures has not been systematically investigated. The objectives of this dissertation are two-fold. The first objective is to carry out a systematic investigation of the mechanical behavior of NC/UFG thin films with different textures under different loading rates. This includes a novel approach to study the effect of texture-induced plastic anisotropy on mechanical behavior of the films. Efforts are made to correlate the behavior of UFG metal films and the underlying deformation mechanisms. The second objective is to understand the deformation mechanisms of UFG aluminum films using in-situ transmission electron microscopy (TEM) experiments with Automated Crystal Orientation Mapping. This technique enables us to investigate grain rotations in UFG Al films and to monitor the microstructural changes in these films during deformation, thereby revealing detailed information about the deformation mechanisms prevalent in UFG metal films.

Preparation and certification of rice flour reference materials for trace elements analysis

International Nuclear Information System (INIS)

Cho, Kyung Haeng; Park, Chang Joon; Woo, Jin Choon; Suh, Jung Ki; Han, Myung Sub; Lee, Jong Hae

1998-01-01

Rice flour reference materials were prepared from the unpolished rice grown in korea and certified for elemental composition. The reference materials consist of two samples containing normal and high level. The reference material at elevated level was prepared by spiking to the normal rice flour six toxic elements of As, Cd, Cu, Cr, Hg, Pb with 1.0μg/g on a dry weight basis. Homogeneity of the prepared materials was evaluated through the determination of Ca, Cu, Fe, Mn, Zn by instrumental neutron activation analysis (INAA) and atomic absorption spectrometry (AAS). Small variance of elemental composition among inter-bottled samples assured homogeneity of the prepared materials. The materials were decomposed by high pres-sure digestion and microwave digestion method. INAA, AAS, inductively coupled plasma-atomic absorption spectrometry (ICP-AES), ICP-mass spectrometry (MS) and vapour generation techniques were employed to analyze the reference materials. From this independent analytical results, the certified or reference values are determined for As, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, P, Pb, Se, Zn

Preparation and multi-properties determination of radium-containing rocklike material

Science.gov (United States)

Hong, Changshou; Li, Xiangyang; Zhao, Guoyan; Jiang, Fuliang; Li, Ming; Zhang, Shuai; Wang, Hong; Liu, Kaixuan

2018-02-01

The radium-containing rocklike material were fabricated using distilled water, ordinary Portland cement and additives mixed aggregates and admixtures according to certain proportion. The physico-mechanical properties as well as radioactive properties of the prepared rocklike material were measured. Moreover, the properties of typical granite sample were also investigated. It is found on one hand, similarities exist in physical and mechanical properties between the rocklike material and the granite sample, this confirms the validity of the proposed method; on the other hand, the rocklike material generally performs more remarkable radioactive properties compared with the granite sample, while radon diffusive properties in both materials are essentially matching. This study will provide a novel way to prepare reliable radium-containing samples for radon study of underground uranium mine.

Gentamicin-Eluting Titanium Dioxide Nanotubes Grown on the Ultrafine-Grained Titanium.

Science.gov (United States)

Nemati, Sima Hashemi; Hadjizadeh, Afra

2017-08-01

Titanium (Ti)-based materials is the most appropriate choices for the applications as orthopedic and dental implants. In this regard, ultrafine-grained (UFG) titanium with an enhanced mechanical properties and surface energy has attracted more attention. Titanium dioxide (TiO 2 ) nanotubes grown on the titanium could enhance bone bonding, cellular response and are good reservoirs for loading drugs and antibacterial agents. This article investigates gentamicin loading into and release from the TiO 2 nanotubes, grown on the UFG compared to coarse-grained (CG) titanium substrate surfaces. Equal Channel Angular Pressing (ECAP) was employed to produce the UFG structure titanium. TiO 2 nanotubes were grown by the anodizing technique on both UFG and CG titanium substrate surfaces. Scanning electron microscopy (SEM) imaging confirmed TiO 2 nanotube growth on the surface. The UV-vis spectroscopy analysis results show that the amount of gentamicin load-release in the anodized UFG titanium sample is higher than that of CG one which can be explained in terms of thicker TiO 2 nanotube arrays layer formed on UFG sample. Moreover, the anodized UFG titanium samples released the drug in a longer time than CG (1 day for the UFG titanium vs. 3 h for the CG one). Regarding wettability analysis, anodized UFG titanium sample showed more enhanced hydrophilicity than CG counterpart. Therefore, the significantly smaller grain size of pure titanium provided by the ECAP technique coupled with appropriate subsequent anodization treatment not only offers a good combination of biocompatibility and adequate mechanical properties but also it provides a delayed release condition for gentamicin.

Inorganic-organic hybrid polymer for preparation of affiliating material using electron beam irradiation

International Nuclear Information System (INIS)

Chung, Jaeseung; Kim, Seongeun; Kim, Byounggak; Lee, Jongchan; Park, Jihyun; Lee, Byeongcheol

2011-01-01

Recently, silver nano materials have gained a lot of attentions in a variety of applications due to the unique biological, optical, and electrical properties. Especially, the antifouling property of these material is considered to be an important character for biomedical field, marine coatings industry, biosensor, and drug delivery. In this study, we design and synthesize the inorganic-organic hybrid polymer for preparation of affiliating materials. Silver nano materials having antifouling property with different shapes are prepared by control the electron beam irradiation conditions. Inorganic-organic hybrid polymer was synthesized and characterized. → Morphology and size controlled nano materials are prepared using electron beam irradiation. → Silver nano materials having various shapes can be used for antifouling material

Preparation and characterization of a new carbonaceous material for electrochemical systems

Directory of Open Access Journals (Sweden)

ZI JI LIN

2010-02-01

Full Text Available A new carbonaceous material was successfully prepared by the py-rolysis of scrap tire rubber at 600 °C under a nitrogen atmosphere. The physical characteristics of the prepared carbonaceous material were studied by scanning electron microscopy (SEM, X-ray powder diffraction (XRD and X-ray photoelectron spectroscopy (XPS. It was proved that the carbonaceous material had a disordered structure and spherical morphology with an average particle size about 100 nm. The prepared carbonaceous material was also used as electrodes in electrochemical systems to examine its electrochemical performances. It was demonstrated that it delivered a lithium insertion capacity of 658 mA h g-1 during the first cycle with a coulombic efficiency of 68 %. Cyclic voltammograms test results showed that a redox reaction occurred during the cycles. The chemical diffusion coefficient based on the impedance diagram was about 10-10 cm2 s-1. The pyrolytic carbonaceous material derived from scrap tire rubber is therefore considered to be a potential anode material in lithium secondary batteries or capacitors. Furthermore, it is advantageous for environmental protection.

Molten salt processes in special materials preparation

International Nuclear Information System (INIS)

Krishnamurthy, N.; Suri, A.K.

2013-01-01

As a class, molten salts are the largest collection of non aqueous inorganic solvents. On account of their stability at high temperature and compatibility to a number of process requirements, molten salts are considered indispensable to realize many of the numerous benefits of high temperature technology. They play a crucial role and form the basis for numerous elegant processes for the preparation of metals and materials. Molten salt are considered versatile heat transfer media and have led to the evolution of many interesting reactor concepts in fission and possibly in fusion. They also have been the basis of thinking for few novel processes for power generation. While focusing principally on the actual utilization of molten salts for a variety of materials preparation efforts in BARC, this lecture also covers a few of the other areas of technological applications together with the scientific basis for considering the molten salts in such situations. (author)

Preparation and evaluation of reference materials for accountancy analysis. (2) Evaluation results

International Nuclear Information System (INIS)

Sumi, Mika; Abe, Katsuo; Kageyama, Tomio; Nakazawa, Hiroaki; Takamatsu, Mai; Kacchi, Tomokazu; Murakami, Toshiki; Ai, Hironobu

2009-01-01

Destructive analysis for accountancy at nuclear fuel facilities should attain international target values for measurement uncertainties in safeguarding nuclear materials (ITVs). Since measurement uncertainties of isotope dilution mass spectrometry depend on uncertainties of spikes (standard materials) used, utilizing highly reliable standard material is essential. The LSD spikes prepared under collaboration work with JAEA and JNFL has different Pu/U ratio and smaller nuclear material in a spike compared with the LSD spikes used a safeguard laboratories, and the value of Pu which separated and purified from MOX and used as raw material for one of the LSD spike prepared at JAEA were measured at JAEA. Uncertainties of the prepared LSD spikes and the measurement results of actual samples with these LSD spikes were evaluated based on ISO-GUM and compared with ITVs. (author)

Preparation of sewage treatment material PVFM

Directory of Open Access Journals (Sweden)

Wenling YANG

2018-04-01

Full Text Available In order to study the optimal operating condition of the sewage treatment material PVFM(polyvinyl formal, the mechanical blowing method and the chemical foaming method are adopted. Single-factor experiments and orthogonal experiments are conducted to study the factors including the amount of raw materials, reaction time and reaction temperature influencing the preparation of the material PVFM. The material is characterized by SEM. The properties of the material are explored through the contrastive experiments of sewage treatment. The results show that when PVA mass concentration is 9% (50 mL, cellulose content is 0.4 g, sulfuric acid content is 6 mL, formaldehyde content is 6 mL, SDS content is 0.4 g, carbonate calcium content is 0.8 g, reaction temperature is 30 ℃, the dripping time of sulfuric acid is 9 minutes, the dripping time of formaldehyde is 4 minutes, and the curing time is 8 hours, the material has good physical and chemical property, and the results of the contrastive experiments of sewage treatment show that PVFM has good removal effects on both COD and NH4+-N in simulated sewage. The sewage treatment material PVFM with good properties can be obtained by the mechanical blowing method and the chemical foaming method.

Modification of the Surface Topography and Composition of Ultrafine and Coarse Grained Titanium by Chemical Etching.

Science.gov (United States)

Nazarov, Denis V; Zemtsova, Elena G; Solokhin, Alexandr Yu; Valiev, Ruslan Z; Smirnov, Vladimir M

2017-01-13

In this study, we present the detailed investigation of the influence of the etching medium (acidic or basic Piranha solutions) and the etching time on the morphology and surface relief of ultrafine grained (UFG) and coarse grained (CG) titanium. The surface relief and morphology have been studied by means of scanning electron microscopy (SEM), atomic force microscopy (AFM), and the spectral ellipsometry. The composition of the samples has been determined by X-ray fluorescence analysis (XRF) and X-ray Photoelectron Spectroscopy (XPS). Significant difference in the etching behavior of UFG and CG titanium has been found. UFG titanium exhibits higher etching activity independently of the etching medium. Formed structures possess higher homogeneity. The variation of the etching medium and time leads to micro-, nano-, or hierarchical micro/nanostructures on the surface. Significant difference has been found between surface composition for UFG titanium etched in basic and acidic Piranha solution. Based on the experimental data, the possible reasons and mechanisms are considered for the formation of nano- and microstructures. The prospects of etched UFG titanium as the material for implants are discussed.

Porphyrinosilica and metalloporphyrinosilica: hybrid organic-inorganic materials prepared by sol-gel processing

Directory of Open Access Journals (Sweden)

YASSUKO IAMAMOTO

2000-03-01

Full Text Available New materials porphyrinosilica and metalloporphyrinosilica template have been obtained by a sol-gel processing where functionalyzed porphyrins and metalloporphyrins "building blocks" were assembled into a three-dimensional silicate network. The optimized conditions for preparation of these materials are revised. The monomer precursors porphyrinopropylsilyl and metalloporphyrinopropylsilyl preparation reactions and subsequent one pot sol-gel processing with tetraethoxysilane are discussed. In the case of metalloporphyrins the nitrogen base coordinates to the central metal and acts as a template in the molecular imprinting technique. UV-visible absorption spectroscopy, thermogravimetric analysis, electron paramagnetic resonance, nuclear magnetic spectra, infrared spectra, luminescence spectra, surface area and electron spectroscopy imaging of the materials are used to characterize the prepared materials. The catalytic activities of these metalloporphyrinosilica- template are compared.

Porphyrinosilica and metalloporphyrinosilica: hybrid organic-inorganic materials prepared by sol-gel processing

Science.gov (United States)

Iamamoto; Sacco; Biazzotto; Ciuffi; Serra

2000-01-01

New materials porphyrinosilica and metalloporphyrinosilica template have been obtained by a sol-gel processing where functionalyzed porphyrins and metalloporphyrins "building blocks" were assembled into a three-dimensional silicate network. The optimized conditions for preparation of these materials are revised. The monomer precursors porphyrinopropylsilyl and metalloporphyrinopropylsilyl preparation reactions and subsequent one pot sol-gel processing with tetraethoxysilane are discussed. In the case of metalloporphyrins the nitrogen base coordinates to the central metal and acts as a template in the molecular imprinting technique. UV-visible absorption spectroscopy, thermogravimetric analysis, electron paramagnetic resonance, nuclear magnetic spectra, infrared spectra, luminescence spectra, surface area and electron spectroscopy imaging of the materials are used to characterize the prepared materials. The catalytic activities of these metalloporphyrinosilica-template are compared.

Preparation of thin layer materials with macroporous microstructure for SOFC applications

International Nuclear Information System (INIS)

Marrero-Lopez, D.; Ruiz-Morales, J.C.; Pena-Martinez, J.; Canales-Vazquez, J.; Nunez, P.

2008-01-01

A facile and versatile method using polymethyl methacrylate (PMMA) microspheres as pore formers has been developed to prepare thin layer oxide materials with controlled macroporous microstructure. Several mixed oxides with fluorite and perovskite-type structures, i.e. doped zirconia, ceria, ferrites, manganites, and NiO-YSZ composites have been prepared and characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption and mercury porosimetry. The synthesised materials are nanocrystalline and present a homogeneous pore distribution and relatively high specific surface area, which makes them interesting for SOFC and catalysis applications in the intermediate temperature range. - Graphical abstract: Thin films materials of mixed oxides with potential application in SOFC devices have been prepared with macroporous microstructure using PMMA microspheres as pore formers. Display Omitted

The opinions of primary school teachers’ candidates towards material preparation and usage

Directory of Open Access Journals (Sweden)

Zeynep Genc

2017-04-01

Full Text Available Abstract Instruction materials help students to acquire more memorable information. Instruction materials have an important effect on providing more permanent and simple way of learning in every step of education. Instruction materials are the most frequently used by primary school teachers. Primary school teachers should support their lectures with instruction materials in order to provide permanent learning. The Teaching Technologies and Material Designing (TTMD course which is one of the compulsory courses that students must take aims to acquire students the information and skills related with the preparation and use of materials. Evaluation of TTMD course is important in terms of the effectiveness of the course which provides the opportunity of motivating the students to learn by attracting their attention, keeping their attentions alive, making abstract concepts more concrete, facilitating the acquisition of knowledge in an organized way in the process of learning and teaching. In this context, it was aimed to determine the opinions of students in the department of primary school teaching about preparation and use of materials through teaching practice which is done within TTMD course in this study. This study is a descriptive study based on qualitative data. The sample of this research included 37 students from the department of primary school teaching who took TTMD course in the second semester in 2014-2015 academic year at Ataturk Education Faculty of Near East University or students who took this course in previous academic years. The data of this research were collected with structured interview form. According to the results, it was revealed that primary school teachers’ candidates attach importance to prepare and use materials based on their answers about the use and preparation of materials in instruction. When the opinions of primary school teachers candidates about the criteria that they give value in preparing and using

Graphene Emerges as a Versatile Template for Materials Preparation.

Science.gov (United States)

Li, Zhengjie; Wu, Sida; Lv, Wei; Shao, Jiao-Jing; Kang, Feiyu; Yang, Quan-Hong

2016-05-01

Graphene and its derivatives are emerging as a class of novel but versatile templates for the controlled preparation and functionalization of materials. In this paper a conceptual review on graphene-based templates is given, highlighting their versatile roles in materials preparation. Graphene is capable of acting as a low-dimensional hard template, where its two-dimensional morphology directs the formation of novel nanostructures. Graphene oxide and other functionalized graphenes are amphiphilic and may be seen as soft templates for formatting the growth or inducing the controlled assembly of nanostructures. In addition, nanospaces in restacked graphene can be used for confining the growth of sheet-like nanostructures, and assemblies of interlinked graphenes can behave either as skeletons for the formation of composite materials or as sacrificial templates for novel materials with a controlled network structure. In summary, flexible graphene and its derivatives together with an increasing number of assembled structures show great potentials as templates for materials production. Many challenges remain, for example precise structural control of such novel templates and the removal of the non-functional remaining templates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Risks associated with nuclear material recovery and waste preparation

Energy Technology Data Exchange (ETDEWEB)

Fullwood, R R; Erdmann, R C

1983-01-01

An analysis of the risk associated with nuclear material recovery and waste preparation is presented. The steps involve: reprocessing of spent fuel to recycle fissionable material, refabrication of the recovered material for use as reactor fuel, and the transportation links connecting these plants with the power plants and waste repositories. The risks considered are radiological and non-radiological, accident and routine effects on the public and workers during plant construction, operation and decommissioning.

Preparation of oxide materials from metal alkoxides

International Nuclear Information System (INIS)

Turevskaya, E.P.; Turova, N.Ya.; Yanovskaya, M.I.

2000-01-01

The results of studies on the sol-gel technologies on the basis of alkoxides are presented. The synthesis and properties of titanates zirconates, niobates, tantalates, vanadates and solid solutions on the basis of Mo, W and Bi oxides, iron oxides and high-temperature superconductors are presented. The most important aspects, determining the choice of optimal conditions for preparation of oxides of concrete compositions with required properties are pointed out. Accomplishment of the whole chain of studies made it possible to synthesize a broad range of metal alkoxides and study their properties and also carry out large-scale studies on preparation of various oxides and materials on the basis thereof, using the source base of the sol-gel method [ru

Process for preparing coating materials

International Nuclear Information System (INIS)

Ryoke, Hideyasu; Kobayashi, Juichi; Kobayashi, Kei.

1972-01-01

A coating material curable with ionizing radiations or ultraviolet radiation can be prepared by reacting a compound (A) having one OH group and at least one α,β-ethylenic or allyl group with a polyisocyanate. (A) is a diester of a dicarboxylic acid. One of the ester groups may have a terminal α,β-ethylenic or allyl group and the other contains one OH and one α,β-ethylenic or allyl group. (A) is reacted with a polyisocyanate to yield an urethane. The latter may be diluted with a vinyl monomer. When exposed to a radiation, the coating material cures to give a film excellent in adhesion, impact strength and resistances to pollution, water and solvents. Dose of the ionizing radiation (α-, β-, γ-rays, electron beams) is 0.2-20 Mrad. In one example, 116 parts of 2-hydroxyethyl acrylate was reacted with 148 parts of phthalic anhydride and 142 parts of glycidyl methacrylate to give (A). (A) was reacted with 87 parts of tolylenediisocyanate. A metallic panel was coated with the coating material and cured with electron beams (5 Mrad). Pencil hardness was H, and gel fraction measured in acetone was above 97%. The coating was excellent in resistances to solvent and chemicals, impact strength and adhesion. (Kaichi, S.)

Preparation of the Jaws Damaged Parts from Composite Biopolymers Materials

Directory of Open Access Journals (Sweden)

Riyam A. Al-husseini

2017-10-01

Full Text Available Composite materials composing of fusing two materials or more are disaccorded in mechanical and physical characteristics, The studied the effect of changing in the reinforcement percentage by Hydroxyapatite Prepared nano world via the size of the nanoscale powder manufacturing manner chemical precipitation and microwave powders were two types their preparations have been from natural sources: the first type of eggshells and the other from the bones of fish in mechanical Properties which include the tensile strength, elastic modulus, elongation, hardness and tear for composite material consisting of Silicone rubber (SIR reinforced by (µ-n-HA, after strengthening silicone rubber Protect proportions (5,10,15,20 wt% of Article achieved results that increase the additive lead to increased hardness while tougher and modulus of elasticity decreases with added as shown in the diagrams.

Modification of the Surface Topography and Composition of Ultrafine and Coarse Grained Titanium by Chemical Etching

Directory of Open Access Journals (Sweden)

Denis V. Nazarov

2017-01-01

Full Text Available In this study, we present the detailed investigation of the influence of the etching medium (acidic or basic Piranha solutions and the etching time on the morphology and surface relief of ultrafine grained (UFG and coarse grained (CG titanium. The surface relief and morphology have been studied by means of scanning electron microscopy (SEM, atomic force microscopy (AFM, and the spectral ellipsometry. The composition of the samples has been determined by X-ray fluorescence analysis (XRF and X-ray Photoelectron Spectroscopy (XPS. Significant difference in the etching behavior of UFG and CG titanium has been found. UFG titanium exhibits higher etching activity independently of the etching medium. Formed structures possess higher homogeneity. The variation of the etching medium and time leads to micro-, nano-, or hierarchical micro/nanostructures on the surface. Significant difference has been found between surface composition for UFG titanium etched in basic and acidic Piranha solution. Based on the experimental data, the possible reasons and mechanisms are considered for the formation of nano- and microstructures. The prospects of etched UFG titanium as the material for implants are discussed.

Preparation and development of new Pu spike isotopic reference materials at IRMM

Energy Technology Data Exchange (ETDEWEB)

Jakopic, Rozle; Bauwens, Jeroen; Richter, Stephan; Sturm, Monika; Verbruggen, Andre; Wellum, Roger; Eykens, Roger; Kehoe, Frances; Kuehn, Heinz; Aregbe, Yetunde [Institute for Reference Materials and Measurements (IRMM) Joint Research Centre, European Commission, Geel, (Belgium)

2011-12-15

Reliable isotope measurements of nuclear material and the availability of reference materials with small uncertainties in the certified values are of great importance for safeguarding of nuclear materials. They provide the basis for a credible measurement system in the verification of states declarations of their nuclear activities. Worldwide needs for continued and improved Isotopic Reference Materials (IRM) are the main reason for developments of new nuclear reference materials at IRMM. Measurement capabilities of laboratories have evolved considerably over the years, along with progress in modern analytical techniques. Some plutonium reference materials, however, have been on the market for decades and they need to be re-certified to smaller uncertainties. Moreover, new reference materials with appropriately small uncertainties in the certified values need to be made available enabling measurement laboratories to reduce their combined measurement uncertainties. Such high quality plutonium isotopic reference materials are essential for laboratories striving to meet the International Target Values for Measurement Uncertainties in Safeguarding Nuclear Materials (ITVs). The preparation and the certification of such materials are demanding and challenging tasks that require state-of-theart measurement procedures and equipment. The Institute for Reference Materials and Measurements (IRMM) has repeatedly demonstrated its capabilities in plutonium analysis and represents one of the few institutes that supplies plutonium IRMs worldwide. An inter-calibration campaign has been set up at IRMM inter-linking selected plutonium spike IRMs. In the scope of this compatibility study, new reference materials have been prepared for Isotope Dilution Mass Spectrometry (IDMS) in nuclear fuel cycle measurements. A new series of large-sized dried (LSD) spikes, IRMM- 1027n, has been prepared and certified for plutonium and uranium amount content and isotopic composition. These mixed

The effect of grain size on dynamic tensile extrusion behaviour

Directory of Open Access Journals (Sweden)

Park Leeju

2015-01-01

Full Text Available Dynamic tensile extrusion (DTE tests were conducted on coarse grained and ultrafine grained (UFG OFHC Cu, Interstitial free (IF Steel, and pure Ta. Equal channel angular pressing (ECAP of 16passes with Bc for Cu, IF Steel and 4 passes for Ta was employed to fabricated UFG materials. DTE tests were carried out by launching the sphere samples (Dia. 7.62 mm to the conical extrusion die at a speed of ∼500 m/sec. The fragmentation behavior of the soft-recovered fragments were examined and compared with each other. The DTE fragmentation behavior of CG and UFG was numerically simulated by the LS-DYNA FEM code.

Present status and future plans of the study for preparation of Pu reference materials

International Nuclear Information System (INIS)

Sumi, Mika; Kageyama, Tomio; Suzuki, Toru

2007-01-01

All accountancy analysis at the Plutonium Fuel Development Center of JAEA is performed by isotope dilution mass spectrometry with well-characterized standard materials. Though Pu reference materials has been supplied from foreign country, importing those Pu materials is gradually becoming more difficult and may be almost impossible to import them in future. Thus, in order to establish the capability and expertise for the preparation of Pu reference materials, JAEA has started collaborative work with NBL who has high skills for preparing and supplying nuclear reference materials for long periods. One of the targets of this collaboration is preparation of standard material for IDMS (LSD spike). MOX powder which has been stored in JAEA was dissolved and Purified to obtain Pu solution. A small portion of the Purified solution was transported to NBL for analysis. LSD spike will be prepared from this Pu solution and then validation analysis and performance test including stability test will be performed with NBL and JAEA. This report presents status and future plans for the collaboration work. (author)

Preparation of silica-based hybrid materials by gamma irradiation

International Nuclear Information System (INIS)

Gomes, S.R.; Margaca, F.M.A.; Miranda Salvado, I.M.; Ferreira, L.M.; Falcao, A.N.

2006-01-01

Gamma-ray irradiation is well known to promote the crosslinking of polymer chains. The method is now used by the authors to prepare hybrid materials from a mixture of polymer and metallic alkoxides of silicium and zirconium that are usually obtained via the sol-gel process. Macroscopically homogeneous and transparent hybrid materials have been obtained by γ-irradiation of polydimethylsiloxane (PDMS), tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr). The influence of several parameters has been studied. The dose rate was found to have no significant impact in the prepared material. The polymer molecular weight was also observed not to play any special role. It was found that all irradiated samples consist of a polymer gel matrix. In the case where both alkoxides are present there are inorganic oxide regions linked to the PDMS network. However when one of the alkoxides is absent there is no formation of inorganic oxide regions linked to the polymer matrix, there being only a few individual derived molecules of the other alkoxide linked to the polymer

Abordagens metodológicas do ensino do esporte de Educação Física da Faculdade de Educação Física/UFG

Directory of Open Access Journals (Sweden)

2006-11-01

Full Text Available Este texto trata das abordagens metodológicas do ensino do esporte no curso de Educação Física da FEF/UFG, desde a criação do curso até os momentos atuais. Aponta ainda as dificuldades e os acertos na adequação pedagógica do esporte, como componente da cultura corporal, que deveria ser considerada como conteúdo da educação física escolar pelos estudantes, principalmente na prática escolar. PALAVRAS-CHAVE: Abordagens metodológicas, cultura corporal, educação física. This paper is about the methodological approaches to sports teaching at School of Physical Education from its beginning to nowadays. Failure and success are pointed out in sports pedagogical adequacy as a component of corporal culture. It should be considered as a content of school physical education by the students, as far as school practice is considered. KEY WORDS: Methodological approaches, corporal culture, physical education.

[Biomimetic nanohydroxyapatite/gelatin composite material preparation and in vitro study].

Science.gov (United States)

Li, Siriguleng; Hu, Xiaowen

2014-09-01

To prepare nHA/gelatin porous scaffold and to evaluate its physical and chemical properties and biocompatibility. We used nano-powders of HA and gelatin to prepare 3D porous composite scaffold by freeze-drying technique, and used scanning electron microscope, fourier transform infrared spectroscopy and universal testing machine to characterize the composite material. Osteoblasts were primarily cultured, and the third-passage osteoblasts were co-cultured with the composite material. The cell adhesion and morphology were examined under scanning electron microscope. The cell viability analysis was performed by MTT assay, and the alkaline phosphatase activity was measured with alkaline phosphatase kit. Scanning electron microscope showed that the scaffold possessed a 3-dimensional interconnected homogenous porous structure with pore sizes ranging from 150 to 400 μm. Fourier transform infrared spectroscopy showed that the composite material had a strong chemical bond between the inorganic phase and organic phase. The scaffold presented the compressive strength of (3.28 ± 0.51) MPa and porosities of (80.6 ± 4.1)%. Composite materials showed features of had good biocompatibility. Mouse osteoblasts were well adhered and spread on the materials. The grade of the cell toxicity ranged from I to II. On the 5th and 7th day the proliferative rate of osteoblasts on scaffolds in the composite materials was significantly higher than that in the control group. The activity of alkaline phosphatase was obviously higher than that in the control group on Day 1 and 3. Nano-hydroxyapatite and gelatin in certain proportions and under certain conditions can be prepared into a composite biomimetic porous scaffolds with high porosity and three-dimensional structure using freeze-drying method. The scaffold shows good biocompatibility with mouse osteoblasts and may be a novel scaffolds for bone tissue engineering.

Preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage

International Nuclear Information System (INIS)

Konuklu, Yeliz; Ersoy, Orkun

2016-01-01

Highlights: • Sepiolite-based phase change material nanocomposites were prepared. • An easy direct impregnation process was used. • This paper is one of the first study about sepiolite-based phase change material nanocomposites. • Influence of PCM type on thermal properties of nanocomposites was reported. - Abstract: This paper is one of the first study about the preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage applications. Sepiolite is an important natural fibrous raw material. Nanoscale fibrous tubular structure of sepiolite becomes important in nanocomposite preparation. In this study, sepiolite/paraffin and sepiolite/decanoic acid nanocomposites were manufactured by the direct impregnation method. By the preparation of nanocomposites, PCM move in tubular channels of sepiolite, phase changing occurs in these tubes and surface area increases like as in microencapsulation. The structure and properties of nanocomposites PCMs (CPCM) have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The SEM results prove the successful preparation of phase change material/sepiolite nanocomposites and point out that the fibers of sepiolite is modified with phase change materials in the nanocomposite. The phase change enthalpies of melting and freezing were about 62.08 J/g and −62.05 J/g for sepiolite/paraffin nanocomposites and 35.69 J/g and −34.55 J/g for sepiolite/decanoic acid nanocomposites, respectively. The results show that PCM/sepiolite nanocomposites were prepared successfully and their properties are very suitable for thermal energy storage applications.

Preparation, characterization and optical properties of Lanthanum-(nanometer MCM-41) composite materials

International Nuclear Information System (INIS)

Zhai, Q. Z.; Wang, P.

2008-01-01

Nanometer MCM-41 molecular sieve was prepared under a base condition by using cetyltrimethylammonium bromide as template and tetraethyl orthosilicate as silica source by means of hydrothermal method. Lanthanum(III) was incorporated into the nanometer MCM-41 by a liquid phase grafting method. The prepared nano composite materials were characterized by means of powder X-ray diffraction, spectrophotometric analysis, Fourier transform infrared spectroscopy, low temperature nitrogen adsorption-desorption technique, solid diffuse reflectance absorption spectra and luminescence. The powder X-ray diffraction studies show that the nanometer MCM-41 molecular sieve is successfully prepared. The highly ordered meso porous two-dimensional hexagonal channel structure and framework of the support MCM-41 is retained intact in the prepared composite material La-(nanometer MCM-41). The spectrophotometric analysis indicates that lanthanum exists in the prepared nano composite materials. The Fourier transform infrared spectra indicate that the framework of the MCM-41 molecular sieve still remains in the prepared nano composite materials and some framework vibration peaks show blue shifts relative to those of the MCM-41 molecular sieve. The low temperature nitrogen adsorption-desorption indicates that the guest locales in the channel of the molecular sieve. Compared with bulk lanthanum oxide, the guest in the channel of the molecular sieve has smaller particle size and shows a significant blue shift of optical absorption band in solid diffuse reflectance absorption spectra. The observed blue shift in the solid state diffuse reflectance absorption spectra of the lanthanum-(nanometer MCM-41) sample show the obvious stereoscopic confinement effect of the channel of the host on the guest, which further indicates the successful encapsulation of the guest in the host. The La-(nanometer MCM-41) sample shows luminescence

Design, preparation, and application of ordered porous polymer materials

International Nuclear Information System (INIS)

Liu, Qingquan; Tang, Zhe; Ou, Baoli; Liu, Lihua; Zhou, Zhihua; Shen, Shaohua; Duan, Yinxiang

2014-01-01

Ordered porous polymer (OPP) materials have extensively application prospects in the field of separation and purification, biomembrane, solid supports for sensors catalysts, scaffolds for tissue engineering, photonic band gap materials owing to ordered pore arrays, uniform and tunable pore size, high specific surface area, great adsorption capacity, and light weight. The present paper reviewed the preparation techniques of OPP materials like breath figures, hard template, and soft template. Finally, the applications of OPP materials in the field of separation, sensors, and biomedicine are introduced, respectively. - Highlights: • Breath figures involve polymer casting under moist ambience. • Hard template employs monodisperse colloidal spheres as a template. • Soft template utilizes the etched block in copolymers as template

The preparation of four biological reference materials for QUASIMEME

NARCIS (Netherlands)

Leeuwen, van S.P.J.; Pieters, H.; Boer, de J.

2004-01-01

Four biological materials have been prepared for use in QUASIMEME interlaboratory studies including a shrimp sample for metal analysis (QM01-1) and two mussel (QO01-3 and QO02-2) and one mackerel sample (QO02-1) for organic contaminant analysis.

Preparation and characterization of hybrid materials based on polypyrrole and silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Nguyen Duc Nghia; Ngo Trinh Tung [Institute of Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi (Viet Nam)], E-mail: ducnghia264@fpt.vn

2009-09-01

Hybrid material is one of the most promising materials classed in the 21st century because of its unique properties and its advanced applications. In this work, hybrid materials based on polypyrrole (Ppy) and silver nanoparicles were prepared and characterized. The preparation of the hybrid material was performed by the chemical polymerization method. The structure, electrical and thermal properties of Ppy/Ag hybrid materials were characterized by XRD, SEM, and TGA and the conventional four probe method. The results showed that the Ag particles of 4-8 nm were agglomerated during the in-situ polymerization of PPy and formed some clusters with the diameter of 25 -150 nm. By the addition of Ag particles, the electrical conductivity of Ppy increased with increasing Ag concentration. The thermal stability of Ppy was significantly improved by modification with Ag particles.

Preparation and characterization of hybrid materials based on polypyrrole and silver nanoparticles

International Nuclear Information System (INIS)

Nguyen Duc Nghia; Ngo Trinh Tung

2009-01-01

Hybrid material is one of the most promising materials classed in the 21st century because of its unique properties and its advanced applications. In this work, hybrid materials based on polypyrrole (Ppy) and silver nanoparicles were prepared and characterized. The preparation of the hybrid material was performed by the chemical polymerization method. The structure, electrical and thermal properties of Ppy/Ag hybrid materials were characterized by XRD, SEM, and TGA and the conventional four probe method. The results showed that the Ag particles of 4-8 nm were agglomerated during the in-situ polymerization of PPy and formed some clusters with the diameter of 25 -150 nm. By the addition of Ag particles, the electrical conductivity of Ppy increased with increasing Ag concentration. The thermal stability of Ppy was significantly improved by modification with Ag particles.

Severe Plastic Deformation of Commercial Pure Titanium (CP-Ti) for Biomedical Applications: A Brief Review

Science.gov (United States)

Mahmoodian, Reza; Annuar, N. Syahira M.; Faraji, Ghader; Bahar, Nadia Dayana; Razak, Bushroa Abd; Sparham, Mahdi

2017-11-01

This paper reviews severe plastic deformation (SPD) techniques for producing ultrafine-grained (UFG) and nanostructured commercial pure titanium (CP-Ti) for biomedical applications as the best alternative to titanium alloys. SPD processes, effective parameters, and advantages of nanostructured CP-Ti over coarse-grained (CG) material and Ti alloys are briefly reviewed. It is reported that nanostructured CP-Ti processed via SPD exhibits higher mechanical strength comparable to Ti alloys but better biological response and superior biocompatibility. Also, different surface modification techniques offer different results on UFG and CG CP-Ti, leading to nanoscale surface topography in UFG samples. Overall, it is reported that nanostructured CP-Ti processed by SPD could be considered to be the best candidate for biomedical implants.

Preparation and characterization of novel anion phase change heat storage materials.

Science.gov (United States)

Hong, Wei; Lil, Qingshan; Sun, Jing; Di, Youbo; Zhao, Zhou; Yu, Wei'an; Qu, Yuan; Jiao, TiFeng; Wang, Guowei; Xing, Guangzhong

2013-10-01

In this paper, polyurethane phase change material was successfully prepared with TDI with BDO for hard segments and PEG for soft segments. Moreover, based on this the solid-solid phase change material, A-PCM1030 which can release anions was prepared with the successful addition of anion additives A1030 for the first time. Then the test of the above material was conducted utilizing FT-IR, DSC, TEM, WAXD and Air Ion Detector. The Results indicated that the polyurethane phase change material possesses excellent thermal stability since there was no appearance of liquid leakage and phase separation after 50 times warming-cooling thermal cycles. It also presented reversibility on absorbing and releasing heat. In addition, adding a little A1030 can increase the thermal stability and reduce phase transition temperatures, as well as reduce the undercooling of the polyurethane phase change material. In addition, the anion test results suggested that the supreme amount of anion released by A-PCM1030 could reach 2510 anions/cm3 under dynamic conditions, which is beneficial for human health.

Preparation and characterization of the fish reference material; Preparacao e caracterizacao de um material de referencia de peixe

Energy Technology Data Exchange (ETDEWEB)

Ulrich, Joao Cristiano

2011-07-01

The certified reference materials (CRMs) play an important role in obtaining measurement results traceable to the International System of Units, through an unbroken chain of comparisons. Thus, the demand for new certified reference materials (CRMs) increases every day in all areas of knowledge. The availability of reference materials, mainly in Brazil is still incipient, given that the demand far exceeds the available variety of these materials. The amount of certified reference materials available in the country is insufficient to meet the need of the scientific community and demands for development of new methodologies. Among the many areas in need of reference materials, we highlight the importance for the food trade balance for these products within the country. The certification of food products, intended both for export and for domestic consumption, requires analysis methods that provide precise and accurate results to ensure product quality. This paper describes the preparation and certification of a reference material in the fish matrix in mercury and methylmercury. The study brings together since the stage of material selection, preparation, development of homogeneity and stability studies and characterization. The certification was performed by means of measurements using two analytical techniques, flow injection analysis - cold vapor atomic absorption spectrometry (FIA-CV-AAS) and isotope dilution applied to mass spectrometry (IDMS), which is a primary method. In this work the standards of the ISO 30 (ABNT 30-34) and ISO Guide 35 was used as the basis for the preparation and characterization of the material. For the calculation of uncertainties was used the GUM and Eurachem guide. As a result, was produced and certified a lot of material in relation to the concentration of mercury (Hg = 0.271 {+-} 0.057 mg g{sup -1}) and methylmercury (MeHg = 0.245 {+-} 0.038 mg g{sup -1}), and informational values of lead and arsenic. (author)

Preparation and analysis of a marble reference material

International Nuclear Information System (INIS)

Carmo Freitas, M.; Moens, L.; Seabra e Barros, J.

1988-01-01

A 7 kg stone of a Carrara marble was reduced to grains smaller than 100 μm, mixed and homogenized in order to prepare a marble reference material. The homogeneity was tested for 16 elements by instrumental neutron activation analysis (INAA). Through a one-way analysis of variance based on several analyses of each of 15 bottles and within the same bottle, it was concluded that the inter-bottle heterogeneity is not greater than the intra-bottle heterogeneity. Results on the concentration of major and trace elements in the marble reference material, obtained by different laboratories and different techniques, are given. The limestone certified reference material KALKSTEIN KH was used to evaluate measurement accuracy, to intercalibrate laboratories, and to provide compatibility of measurement data. (author) 10 refs.; 12 tabs

Radiation sterilization of some cosmetic raw materials and preparations

International Nuclear Information System (INIS)

Achmatowicz-Szmajke, T.; Bryl-Sandelewska, T.; Galazka, M.

1979-01-01

The problem of microbiological purity of cosmetic preparations is discussed. Some results obtained on the influence of ionizing radiation on organoleptic and physicochemical properties of some cosmetic raw materials and final products are reported. The samples of raw materials and the final products were irradiated with a 10 MeV electron beam from an LAE 13/9 linear accelerator located in INR. The doses delivered to the materials were 0.5 - 2.3 Mrad (5-23 kGy). Immediately after irradiation, organoleptic estimations were made and over the next few days physicochemical investigations were performed. Non-irradiated samples were investigated together with irradiated ones. (T.I.)

Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

KAUST Repository

Bai, Yaocai

2012-01-01

Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different

Radiation processing technology for preparation of fine shaped biomedical materials

Energy Technology Data Exchange (ETDEWEB)

Kumakura, M.; Yoshida, M.; Asano, M. (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment); Yamanaka, H. (Gunma Univ., Maebashi (Japan). School of Medicine)

1992-06-01

Radiation processing technology for the preparation of fine shaped biomedical materials was studied from the aspect of a development of the technology and its application. Electron beam irradiation technology was applied to the preparation of fine shaped biomedical materials such as thin polymer films in diagnosis, in which enzyme and antibody were used as a bioactive substance. Electron beam cast-polymerization and electron beam repeat surface-polymerization, that are surface irradiation techniques of homogeneous hydrophilic monomer solution containing enzymes made it possible to form the immobilized antibody films. In this technique, the films with various thicknesses (50-500 [mu]m) were obtained by regulating the electron beam energy. The thin polymer films immobilizing anti-[alpha]-fetoprotein were evaluated from the aspect of immunoagents for diagnosis of liver cancer. (Author).

Specifiers Properties Information Exchange (SPie): Minimum Building Information Model (BIM) Object Definitions

Science.gov (United States)

2013-03-01

polypropylene - upholsetered Armrest Type UFGS 2.2 n/a Common - Tablet - Cupholder UFGS Section and Date UFGS MAY 2012 12 93 00 SITE...Pipe Hangers, Inserts, Supports UFGS 2.8 n/a ferrous – non-ferrous in MRI suites Valves UFGS 2.9 n/a butterfly – gate – swing check – ball – plug

Materials to prepare hospice families for dying in the home.

Science.gov (United States)

Kehl, Karen A; Kirchhoff, Karin T; Finster, Mark P; Cleary, James F

2008-09-01

Many changes occur in the final hours of life. Family members of those dying at home need to be prepared for these changes, both to understand what is happening and to provide care. The objectives of this study were to describe (1) the written materials used by hospices to prepare families for dying in the home setting and (2) the content of such materials. Questionnaires were sent to 400 randomly selected hospices, of which 170 responded (45.3%) sending their written materials. The most frequently used publications were Gone from My Sight (n = 118 or 69.4%), Final Gifts (n = 44 or 25.9%) and Caregiving (n = 14 or 8.2%). Half (56.5%) of the hospices used other publications and a majority (n = 87 or 51.2%) used multiple publications. Materials were given to the families by nurses (78.2%) or social workers (67.6%). More than 90% of the hospices had materials that addressed the following signs of impending death: decreased fluid intake, decreased food intake, breathing pattern changes, cold extremities, mottling, increased sleeping, changes at the moment of death, audible secretions, urinary output changes, disorientation, incontinence, overall decline and restlessness. Seven signs were addressed less than 30% of the time; pain (28.2%), dyspnea (19.4%), bed-bound state (18.2%), skin changes (18.2%), vital sign changes (17.1%), surge of energy (11.8%) and mandibular breathing (5.9%). Hospice staff should know the content of the materials offered by their agency so they can verbally address the gaps between the written materials and family needs.

Preparation of resveratrol-loaded nanoporous silica materials with different structures

International Nuclear Information System (INIS)

Popova, Margarita; Szegedi, Agnes; Mavrodinova, Vesselina; Novak Tušar, Natasa; Mihály, Judith; Klébert, Szilvia; Benbassat, Niko; Yoncheva, Krassimira

2014-01-01

Solid, nanoporous silica-based spherical mesoporous MCM-41 and KIL-2 with interparticle mesoporosity as well as nanosized zeolite BEA materials differing in morphology and pore size distribution, were used as carriers for the preparation of resveratrol-loaded delivery systems. Two preparation methods have been applied: (i) loading by mixing of resveratrol and mesoporous carrier in solid state and (ii) deposition in ethanol solution. The parent and the resveratrol loaded carriers were characterized by XRD, TEM, N2 physisorption, thermal analysis, and FT-IR spectroscopy. The influence of the support structure on the adsorption capacity and the release kinetics of this poorly soluble compound were investigated. Our results indicated that the chosen nanoporous silica supports are suitable for stabilization of trans-resveratrol and reveal controlled release and ability to protect the supported compound against degradation regardless of loading method. The solid-state dry mixing appears very effective for preparation of drug formulations composed of poorly soluble compound. - Graphical abstract: trans-Resveratrol was stabilized in the pores of BEA zeolite, MCM-41and KIL2 mesoporous silicas. - Highlights: • BEA, KIL-2 and MCM-41 materials were used as carriers for resveratrol loading. • Resveratrol encapsulation in ethanol solution and solid state procedure were applied. • The solid-state preparation appears very effective for stabilization of trans-resveratrol

Preparation of resveratrol-loaded nanoporous silica materials with different structures

Energy Technology Data Exchange (ETDEWEB)

Popova, Margarita, E-mail: mpopova@orgchem.bas.bg [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Szegedi, Agnes [Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2. (Hungary); Mavrodinova, Vesselina [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Novak Tušar, Natasa [National Institute of Chemistry, Ljubljana (Slovenia); Mihály, Judith; Klébert, Szilvia [Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2. (Hungary); Benbassat, Niko; Yoncheva, Krassimira [Faculty of Pharmacy, 2 Dunav Str., 1000 Sofia (Bulgaria)

2014-11-15

Solid, nanoporous silica-based spherical mesoporous MCM-41 and KIL-2 with interparticle mesoporosity as well as nanosized zeolite BEA materials differing in morphology and pore size distribution, were used as carriers for the preparation of resveratrol-loaded delivery systems. Two preparation methods have been applied: (i) loading by mixing of resveratrol and mesoporous carrier in solid state and (ii) deposition in ethanol solution. The parent and the resveratrol loaded carriers were characterized by XRD, TEM, N2 physisorption, thermal analysis, and FT-IR spectroscopy. The influence of the support structure on the adsorption capacity and the release kinetics of this poorly soluble compound were investigated. Our results indicated that the chosen nanoporous silica supports are suitable for stabilization of trans-resveratrol and reveal controlled release and ability to protect the supported compound against degradation regardless of loading method. The solid-state dry mixing appears very effective for preparation of drug formulations composed of poorly soluble compound. - Graphical abstract: trans-Resveratrol was stabilized in the pores of BEA zeolite, MCM-41and KIL2 mesoporous silicas. - Highlights: • BEA, KIL-2 and MCM-41 materials were used as carriers for resveratrol loading. • Resveratrol encapsulation in ethanol solution and solid state procedure were applied. • The solid-state preparation appears very effective for stabilization of trans-resveratrol.

Preparation and characterization of hybrid materials from natural chrysotile

International Nuclear Information System (INIS)

Giraldelli, M.G.; Silva, M.L.C.P.

2010-01-01

Special attention has been given to the development of new materials from natural chrysotile. This fiber has about 40% silicon oxide in its structure with an outer layer of brucite (MgOH 2 ). With the aim of obtaining a material with a more uniform structure, acid leaching was performed to remove the outer layer of brucite, resulting in a silicon oxide hydrate. This material was used as support for the deposition of Nb 2 O 5 .nH 2 O. The Nb 2 O 5 .nH 2 O was prepared by conventional precipitation using as starting material niobium metallic. In this study, we performed the synthesis and characterization of the material SiO 2 .nH 2 O / Nb 2 O 5 .nH 2 O 1:1. Both chrysotile as niobium are widely available national resources, which confirms the economic viability of resource use. The materials studied were characterized by XRD, SEM and TG/DTG. (author)

Study of PDMS conformation in PDMS-based hybrid materials prepared by gamma irradiation

International Nuclear Information System (INIS)

Lancastre, J.J.H.; Fernandes, N.; Margaça, F.M.A.; Miranda Salvado, I.M.; Ferreira, L.M.; Falcão, A.N.; Casimiro, M.H.

2012-01-01

Polydimethylsiloxane-silicate based hybrid materials have recognized properties (high flexibility, low elastic modulus or high mechanical strength) for which there are a large number of applications in development, such as for the bioapplications field. The hybrids addressed in the present study were prepared by gamma irradiation of a mixture of polydimethylsiloxane (PDMS) with tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr) without addition of any solvent or other product. The materials are homogeneous, transparent, monolithic and flexible. The structure dependence on the PrZr content is addressed. A combination of X-ray diffraction (XRD) and Infrared Spectroscopy (IR) was used. The results reveal that the polymer in the hybrids prepared with PrZr, in a content≤5 wt%, shows a structure similar to that in the irradiated pure polymer sample. In these samples the presence of ordered polymer regions is clearly found. For samples prepared with higher content of Zr almost no ordered polymer regions are observed. The addition of PrZr plays an important role on polymer conformation in these hybrid materials. - Highlights: ► PDMS-based hybrid materials were prepared by γ-irradiation. ► FTIR, ATR/FT-IR and XRD techniques were used to characterize the materials. ► Changes in FTIR bands reflect growth of crosslinking network. ► Above certain Zr concentration regions of Zr-silicate oxide are formed. ► Zr content determines conformation of the polymer chain network.

"Smart" Materials Based on Cellulose: A Review of the Preparations, Properties, and Applications.

Science.gov (United States)

Qiu, Xiaoyun; Hu, Shuwen

2013-02-28

Cellulose is the most abundant biomass material in nature, and possesses some promising properties, such as mechanical robustness, hydrophilicity, biocompatibility, and biodegradability. Thus, cellulose has been widely applied in many fields. "Smart" materials based on cellulose have great advantages-especially their intelligent behaviors in reaction to environmental stimuli-and they can be applied to many circumstances, especially as biomaterials. This review aims to present the developments of "smart" materials based on cellulose in the last decade, including the preparations, properties, and applications of these materials. The preparations of "smart" materials based on cellulose by chemical modifications and physical incorporating/blending were reviewed. The responsiveness to pH, temperature, light, electricity, magnetic fields, and mechanical forces, etc. of these "smart" materials in their different forms such as copolymers, nanoparticles, gels, and membranes were also reviewed, and the applications as drug delivery systems, hydrogels, electronic active papers, sensors, shape memory materials and smart membranes, etc. were also described in this review.

Method of preparing an electrode material of lithium-aluminum alloy

Science.gov (United States)

Settle, Jack L.; Myles, Kevin M.; Battles, James E.

1976-01-01

A solid compact having a uniform alloy composition of lithium and aluminum is prepared as a negative electrode for an electrochemical cell. Lithium losses during preparation are minimized by dissolving aluminum within a lithium-rich melt at temperatures near the liquidus temperatures. The desired alloy composition is then solidified and fragmented. The fragments are homogenized to a uniform composition by annealing at a temperature near the solidus temperature. After comminuting to fine particles, the alloy material can be blended with powdered electrolyte and pressed into a solid compact having the desired electrode shape. In the preparation of some electrodes, an electrically conductive metal mesh is embedded into the compact as a current collector.

Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

Directory of Open Access Journals (Sweden)

Lars Borchardt

2011-09-01

Full Text Available For the first time we present the synthesis of CeO2/Si(OC core–shell particles prepared by the miniemulsion technique. The Si(OC core was obtained by means of a polycarbosilane precursor (SMP10, which was subsequently functionalized with ceria and pyrolyzed to the ceramic. The size of these particles could easily be adjusted by varying the surfactants and the surfactant concentration, or by the addition of comonomers. Hence particle sizes ranged from 100 to 1000 nm, tunable by the preparation conditions. All materials were characterized by photon cross correlation spectroscopy, scanning electron microscopy and elemental mapping investigations. Furthermore, first catalytic tests were carried out by temperature programmed oxidation (TPO of methane, and the activity of this material in lowering the onset temperature of methane combustion by 262 K was documented.

Microstructural evolution by heating at 1673-2373 K in ultra-fine grained W-(0.25-1.5)%TiC consolidates

International Nuclear Information System (INIS)

Hidaka, M.; Sakamoto, T.; Kobayashi, S.; Nakai, K.; Kurishita, H.; Arakawa, H.

2007-01-01

Full text of publication follows: Ultra-fine grained (UFG) W-TiC consolidates with nearly full densification are expected to be very promising for their use as divertors and structural materials exposed to irradiation environments because they exhibit good resistance to irradiations with fast neutrons, helium-ions and hydrogen-ions. In view of exposure to high heat loading on divertors, it is necessary to examine microstructural evolution due to high temperature heating in UFG W-TiC consolidates, which is closely related to recrystallization embrittlement. The objective of this study is to clarify how the microstructures in UFG W-TiC consolidates change with annealing at 1673-2373 K, with emphasis on the effects of TiC additions and nano-sized Ar bubbles retained in UFG W-TiC consolidates fabricated by mechanical alloying (MA) in an Ar atmosphere. UFG W-(0.25, 0.5, 0.8, 1.1, 1.5)%TiC (in wt%) consolidates were fabricated by powder metallurgical methods utilizing MA with 3MPDA (three mutually perpendicular directions agitation) bail mill in an atmosphere of purified H 2 (MA-H 2 ) or Ar (MA-Ar), followed by hot isostatic pressing (HIP) at 1623 K. Thin foils for transmission electron microscopy (TEM) observations were prepared from each of the as-HIPed consolidates and subjected to annealing in vacuum at temperatures from 1673 to 2373 K for 3.6 ks by radio-frequency induction heating. TEM examinations and EDX analyses were made using a JEM-2000FX and JEM-4000FX operating at 200 and 400 kV, respectively. It is shown that the as-HIPed specimens exhibit equiaxed grain sizes of 40 to 200 nm which decrease with increasing TiC addition, but the grain size tends to saturate around 1 wt% TiC addition. The nano-sized Ar bubbles in W-TiC with MA-Ar are observed in approximately half of the grains and provide a significant grain refinement effect: The grain size in W-TiC with MA-Ar is approximately half of that with MA-H 2 . Such Ar bubbles are retained even after heating at

Thermoplastic starch materials prepared from rice starch

International Nuclear Information System (INIS)

Pontes, Barbara R.B.; Curvelo, Antonio A.S.

2009-01-01

Rice starch is a source still little studied for the preparation of thermoplastic materials. However, its characteristics, such as the presence of proteins, fats and fibers may turn into thermoplastics with a better performance. The present study intends the evaluation of the viability of making starch thermoplastic from rice starch and glycerol as plasticizer. The results of X-ray diffraction and scanning electronic microscopy demonstrate the thermoplastic acquisition. The increase of plasticizer content brings on more hydrophilic thermoplastics with less resistance to tension and elongation at break. (author)

On tension-compression asymmetry in ultrafine-grained and nanocrystalline metals

KAUST Repository

Gurses, Ercan

2010-12-01

We present a physically motivated computational study explaining the tension/compression (T/C) asymmetry phenomenon in nanocrystalline (nc) and ultrafine-grained (ufg) face centered cubic (fcc) metals utilizing a variational constitutive model where the nc-metal is modeled as a two-phase material consisting of a grain interior phase and a grain boundary affected zone (GBAZ). We show that the existence of voids and their growth in GBAZ renders the material pressure sensitivity due to porous plasticity and that the utilized model provides a physically sound mechanism to capture the experimentally observed T/C asymmetry in nc- and ufg-metals. © 2010 Elsevier B.V. All rights reserved.

Investigation of fatigue crack growth rate of Al 5484 ultrafine grained alloy after ECAP process

Energy Technology Data Exchange (ETDEWEB)

Brynk, Tomasz; Rasinski, Marcin; Pakiela, Zbigniew; Kurzydlowski, Krzysztof J. [Faculty of Materials Science and Engineering, Warsaw University of Technology (Poland); Olejnik, Lech [Faculty of Production Engineering, Warsaw University of Technology (Poland)

2010-05-15

During the last decade equal-channel angular pressing (ECAP) has emerged as a widely used fabrication route of ultrafine-grained (UFG) metals and alloys. Enhanced mechanical properties of UFG materials produced by severe plastic deformation, with a grain size smaller than 1 {mu}m, have been reported in a large number of publications. However, the higher strength does not imply higher resistance to fatigue both high- and low-cyclic. In fact, due to reduced plasticity, higher fatigue crack propagation rates are reported for UFG materials, particularly in low-amplitude range. The aim of this work was to investigate fatigue crack propagation in samples of Al 5483 alloy subjected to ECAP treatment. Because of small dimensions of the coupons processed by ECAP, non-standard, mini-samples were used in a crack propagation tests. Two test procedures were used to estimate stress intensity factor (K). The first was based on optical measurements of crack length from images recorded during the test. The second method was based on digital image correlation (DIC), which was used to determine K value directly from displacement field near the crack tip. Comparison of these two methods is made and the relationship between the intensity of ECAP process (measured in terms of the number of ECAP passes) and fatigue crack propagation rates proposed. In addition to fatigue resistance, the results of tensile tests carried out with mini-samples are presented. Applicability of such samples in the investigations of the mechanical properties of UFG materials is discussed. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Current status of ultra-fine grained W-TiC development for use in irradiation environments

Energy Technology Data Exchange (ETDEWEB)

Kurishita, H [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai-machi, Ibaraki-ken 311-1313 (Japan); Kobayashi, S [Department of Materials Science and Biotechnology, Ehime University, Matsuyama-shi 790-8577 (Japan); Nakai, K [Department of Materials Science and Biotechnology, Ehime University, Matsuyama-shi 790-8577 (Japan); Arakawa, H [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai-machi, Ibaraki-ken 311-1313 (Japan); Matsuo, S [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai-machi, Ibaraki-ken 311-1313 (Japan); Takida, T [ALMT. Corp., 2 Iwase-koshi-machi, Toyama 931-8371 (Japan); Takebe, K [ALMT. Corp., 2 Iwase-koshi-machi, Toyama 931-8371 (Japan); Kawai, M [Institute of Material Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba-shi, Ibaraki-ken 305-0801 (Japan)

2007-03-15

Ultra-fine grained (UFG) W-TiC with a high purity matrix of low dislocation density is expected to exhibit improve resistance to irradiation with neutrons and helium ions and the room temperature mechanical properties. Aiming at such UFG W-TiC with the desired microstructure, powders of W with 0.25-0.8 wt% TiC additions were subjected to mechanical alloying (MA) and hot isostatic pressing (HIP), where purified H{sub 2} and Ar were used as the MA atmosphere. Microstructural observations and room- and high-temperature mechanical tests were performed for UFG W-TiC before and after neutron irradiation to a fluence of 2x10{sup 24} n m{sup -2} at 873 K. It is shown that the MA atmosphere significantly affects grain refinement, room-temperature strength and high-temperature tensile plasticity of UFG W-TiC. W-0.5TiC with H{sub 2} in MA (W-0.5TiC-H{sub 2}) shows a larger strain rate sensitivity of flow stress, m, of 0.5{approx}0.6 at temperatures from 1673 to 1973 K, which is a feature of superplastic materials. Whereas W-0.5TiC-Ar shows a smaller m value of approximately 0.2. No radiation hardening is recognized in UFG W-0.5TiC-H{sub 2} and W-0.5TiC-Ar.

Current status of ultra-fine grained W-TiC development for use in irradiation environments

International Nuclear Information System (INIS)

Kurishita, H; Kobayashi, S; Nakai, K; Arakawa, H; Matsuo, S; Takida, T; Takebe, K; Kawai, M

2007-01-01

Ultra-fine grained (UFG) W-TiC with a high purity matrix of low dislocation density is expected to exhibit improve resistance to irradiation with neutrons and helium ions and the room temperature mechanical properties. Aiming at such UFG W-TiC with the desired microstructure, powders of W with 0.25-0.8 wt% TiC additions were subjected to mechanical alloying (MA) and hot isostatic pressing (HIP), where purified H 2 and Ar were used as the MA atmosphere. Microstructural observations and room- and high-temperature mechanical tests were performed for UFG W-TiC before and after neutron irradiation to a fluence of 2x10 24 n m -2 at 873 K. It is shown that the MA atmosphere significantly affects grain refinement, room-temperature strength and high-temperature tensile plasticity of UFG W-TiC. W-0.5TiC with H 2 in MA (W-0.5TiC-H 2 ) shows a larger strain rate sensitivity of flow stress, m, of 0.5∼0.6 at temperatures from 1673 to 1973 K, which is a feature of superplastic materials. Whereas W-0.5TiC-Ar shows a smaller m value of approximately 0.2. No radiation hardening is recognized in UFG W-0.5TiC-H 2 and W-0.5TiC-Ar

Preparation and certification of Sargasso seaweed reference material

Energy Technology Data Exchange (ETDEWEB)

Okamoto, Kensaku

1988-01-01

Sargasso seaweed reference material was prepared from Sargassum felvellum obtained from an unpolluted area in Japan. The sargasso samples were washed, freeze-dried, pulverized, sieved to pass a 80-mesh screen and finally homogenized. Collaborative studies on the elemental analysis of the sargasso reference material were performed using various analytical techniques. Certified values are provided for Ag, As, Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Na, Pb, Rb, Sr, V and Zn, based on results of determinations by at least three independent analytical techniques. Reference values are reported for Al, Br, Cl, Cr, Cs, Hg, I, P, S, Sb, Sc, Se, Ti and U. The sargasso certified reference material contains high levels of alkali metals, alkaline earth metals, I, Br, As and U, while the concentration of trace elements may be considered to be at the lower end of the range of reported values for marine brown algae. The sargasso sample will be of practical use in marine and environmental sciences as a certified reference material having an elemental composition close to background levels.

Planning and Preparing for Emergency Response to Transport Accidents Involving Radioactive Material. Safety Guide

International Nuclear Information System (INIS)

2009-01-01

This Safety Guide provides guidance on various aspects of emergency planning and preparedness for dealing effectively and safely with transport accidents involving radioactive material, including the assignment of responsibilities. It reflects the requirements specified in Safety Standards Series No. TS-R-1, Regulations for the Safe Transport of Radioactive Material, and those of Safety Series No. 115, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. Contents: 1. Introduction; 2. Framework for planning and preparing for response to accidents in the transport of radioactive material; 3. Responsibilities for planning and preparing for response to accidents in the transport of radioactive material; 4. Planning for response to accidents in the transport of radioactive material; 5. Preparing for response to accidents in the transport of radioactive material; Appendix I: Features of the transport regulations influencing emergency response to transport accidents; Appendix II: Preliminary emergency response reference matrix; Appendix III: Guide to suitable instrumentation; Appendix IV: Overview of emergency management for a transport accident involving radioactive material; Appendix V: Examples of response to transport accidents; Appendix VI: Example equipment kit for a radiation protection team; Annex I: Example of guidance on emergency response to carriers; Annex II: Emergency response guide.

Preparation of nanocrystalline iron-carbon materials as fillers for polymers

International Nuclear Information System (INIS)

Narkiewicz, U; Pelech, I; Roslaniec, Z; Kwiatkowska, M; Arabczyk, W

2007-01-01

This paper presents a method of preparing nanocrystalline iron-carbon materials which can be applied as fillers for polymers. Nanocrystalline iron samples were carburized either under ethylene/hydrogen mixture or under pure ethylene. Three kinds of samples were prepared: cementite/carbon (Fe 3 C/C), iron/cementite (Fe/Fe 3 C) and iron/carbon (Fe/C) ones. After carburization the samples were characterized using XRD and SEM methods. The obtained samples of iron-carbon nanoparticles were applied as fillers to polymer nanocomposites prepared in a polycondensation reaction (in situ) in a poly(ether-ester) matrix. The nanofillers were dispersed in monomers (diols) using a sonificator and a high-speed rotary stirrer. The obtained nanocomposites were characterized as regards their structure (SEM method) and mechanical behaviour

Thermoelectric properties and nanostructures of materials prepared from rice husk ash

Energy Technology Data Exchange (ETDEWEB)

Pukird, S.; Tipparach, U.; Kasian, P. [Ubon Ratchathani Univ., Ubon Ratchathani (Thailand). Dept. of Physics; Limsuwan, P. [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Dept. of Physics

2009-07-01

Thailand produces large amounts of agricultural residues such as rice husk and coconut shells. Rice husk is considered to be a potential source for solar grade silicon. Studies have shown that reasonably pure polycrystalline silicon can be prepared from rice husk white ash by a metallothermic reduction process. This paper reported on a study that investigated the thermoelectric properties of ceramic material prepared by mixing silica from rice husk ash and carbon obtained from coconut shell charcoal. The thermoelectric properties of the materials were examined along with their microstructures. The materials were made from burning rice husk ash and coconut shell at different temperatures and then doped with metal oxides. Pellets were heated at temperature of 700 degrees C for 1-3 hours. The voltage on both sides of the pellets was observed. The electromotive force was found when different temperatures were applied on both sides of the pellet specimens. The Seebeck coefficient was then calculated. The results showed that these materials can be used as thermoelectric devices. Scanning electron microscope (SEM) and energy dispersive X-rays (EDX) were used to investigate the source of materials and the products on the substrates. The images of SEM and EDX showed nanostructures of materials such as nanowires, nanorods and nanoparticles of the products and sources. 22 refs., 2 tabs., 9 figs.

Effect of initial microstructure on the microstructural evolution and mechanical properties of Ti during cold rolling

International Nuclear Information System (INIS)

Stolyarov, V.V.; Zhu, Y.T.; Raab, G.I.; Zharikov, A.I.; Valiev, R.Z.

2004-01-01

Ultrafine-grained (UFG) Ti rods were produced via cold rolling UFG and coarse-grained (CG) Ti stocks. The initial UFG stock was produced via equal channel angular pressing. It was found that the initial UFG structure had beneficial influence on the mechanical properties of the cold-rolled Ti rods. Compared with Ti rods with initial CG microstructure, the Ti rods with the initial UFG microstructure have both higher strength and higher ductility after being cold rolled to varying strains. Transmission electron microscopy revealed that the Ti rods with the initial UFG microstructure had finer, more homogeneous microstructures after cold rolling. This study demonstrates the merit of UFG Ti processed by ECAP for further shaping and forming into structural components with superior mechanical properties

Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

2011-10-17

Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

Influence of grain structure on the deformation mechanism in martensitic shear reversion-induced Fe-16Cr-10Ni model austenitic alloy with low interstitial content: Coarse-grained versus nano-grained/ultrafine-grained structure

Energy Technology Data Exchange (ETDEWEB)

Challa, V.S.A. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials Engineering, and Biomedical Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Misra, R.D.K., E-mail: dmisra2@utep.edu [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials Engineering, and Biomedical Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Somani, M.C. [Center for Advanced Steels Research, The University of Oulu, P.O. Box 4200, 90014 Oulu (Finland); Wang, Z.D. [State Key Laboratory for Rolling and Automation, Northeastern University, 3-11 Wenhua Road, Shenyang 110819 (China)

2016-04-20

Nanograined/ultrafine-grained (NG/UFG) materials characterized by high strength-high ductility combination are excellent vehicles to obtain an unambiguous understanding of deformation mechanisms vis-à-vis their coarse-grained counterparts. In this context, the innovative concept of phase reversion-induced NG/UFG structure enabled achieving high strength besides comparable ductility, for instance, in metastable austenitic stainless steels. In the phase reversion process, severe deformation of austenite at room temperature (typically ~60–80%) transforms face-centered cubic austenite (γ) to body centered cubic martensite (α′). Upon annealing, martensite reverts to austenite leading to extensive grain refinement. The objective of the present study to fundamentally understand the deformation mechanisms in NG/UFG structure in relation to that of the coarse-grained (CG) structure was accomplished by combining depth-sensing nanoscale experiments on an Fe-16Cr-10Ni model austenitic alloy conducted at different strain rates, followed by the study of structural evolution in the deformed zone using transmission electron microscopy (TEM). In the high strength NG/UFG steel (YS~585 MPa), stacking faults and nanotwins contributed to the enhanced ductility (El~35%), while in the case of low strength (YS~260 MPa) coarse-grained (CG) counterpart, ductility was also high (El~40%), but chiefly due to strain-induced martensite, which points to a clear case of grain size effect (and the corresponding level of strength). The distinct change in the deformation mechanism from stacking faults and twinning-induced plasticity (TWIP) in the NG structure to transformation-induced plasticity (TRIP) in the CG structure is elucidated in terms of austenite stability-strain energy relationship. The insights on the relationship between grain structure (and strength) and deformation mechanisms are envisaged to be important in providing a new direction for the futuristic design of high strength

Method for selecting raw materials to preparing ceramic masses: application to raw material for red ceramic

International Nuclear Information System (INIS)

Moreno, Maria Margarita Torres; Rocha, Rogers Raphael da; Zanard, Antenor

2012-01-01

We studied the raw materials used in a factory building blocks, located in Cesario Lange city (SP). It extracts raw materials from various sources in the region to make the dough. The mixtures were prepared from dry milled powders based on data related to the plasticity of the raw materials. It was obtained with the apparatus Vicat-cone in order to obtain similar levels of water absorption of the samples burned at 900 deg C for all compositions. To quantify the proportion of each clay was used the Lever Rule. In this firing temperature, where sintering is mainly by diffusion from a solid state, different compositions of the same set of four raw materials resulted in similar values. (author)

Advanced Research Projects Agency on Materials Preparation and Characterization Research

Science.gov (United States)

Briefly summarized is research concerned with such topics as: Preparation of silica glass from amorphous silica; Glass structure by Raman ...ferroelectrics; Silver iodide crystals; Vapor phase growth; Refractory optical host materials; Hydroxyapatite ; Calcite; Characterization of single crystals with a double crystal spectrometer; Characterization of residual strain.

Particle size studies in the preparation of AQCS reference materials

International Nuclear Information System (INIS)

Fajgelj, A.; Zeisler, R.; Benesch, T.; Dekner, R.

1994-01-01

Particle size determination is one of the important steps in the characterization of physical properties of each particulate material. However, particle size distribution effects also a chemical composition of the material in terms of homogeneity and representativeness of the sample, as well as allows or not a possible sub-sampling of the material. All this is of great importance in the preparation of reference materials for which the chemical composition and physical properties have to be extremely well characterized. In the present paper we intend to present same efforts which have been done by Analytical Quality Control Services (AQCS) of the International Atomic Energy Agency (IAEA) in the field of particle size determination in the production of reference materials. The Malvern product MasterSizer X, based on laser light scattering is used for this purpose and the technique is also shortly discussed. (author)

Preparation and certification of a uranium isotope certified reference material JAERI-U5

International Nuclear Information System (INIS)

Tamura, Shuzo; Hashitani, Hiroshi

1982-06-01

The Committee on Analytical Chemistry of Nuclear Fuels and Reactor Materials, JAERI had planned to prepare a new reference material, JAERI-U5 for uranium isotopic measurement since 1978. The reference material is composed of 6 samples of different enrichment in the range of 0.2 to 4.5 wt. percents of 235 U. The preparation includes dissolution of raw materials, blending of solutions, precipitation of ammonium diuranate, drying and ignition to U 3 O 8 . A mass-spectrometric collaborative analysis was carried out by well-trained two laboratories in this country, JAERI and PNC. The certified values were decided from the result of the collaborative work. As the measurements were based on NBS SRM's, JAERI-U5 should be called tertiary standard. The materials are packed in bottles of low-potassium-content glass for a possible use in non-destructive gamma-rays spectrometry. The reference material has been distributing from JAERI with a price of yen 140,000 per set (6 samples of 2 g of each) since 1979. (author)

Preparation and properties of thin films treatise on materials science and technology

CERN Document Server

Tu, K N

1982-01-01

Treatise on Materials Science and Technology, Volume 24: Preparation and Properties of Thin Films covers the progress made in the preparation of thin films and the corresponding study of their properties. The book discusses the preparation and property correlations in thin film; the variation of microstructure of thin films; and the molecular beam epitaxy of superlattices in thin film. The text also describes the epitaxial growth of silicon structures (thermal-, laser-, and electron-beam-induced); the characterization of grain boundaries in bicrystalline thin films; and the mechanical properti

“Smart” Materials Based on Cellulose: A Review of the Preparations, Properties, and Applications

Science.gov (United States)

Qiu, Xiaoyun; Hu, Shuwen

2013-01-01

Cellulose is the most abundant biomass material in nature, and possesses some promising properties, such as mechanical robustness, hydrophilicity, biocompatibility, and biodegradability. Thus, cellulose has been widely applied in many fields. “Smart” materials based on cellulose have great advantages—especially their intelligent behaviors in reaction to environmental stimuli—and they can be applied to many circumstances, especially as biomaterials. This review aims to present the developments of “smart” materials based on cellulose in the last decade, including the preparations, properties, and applications of these materials. The preparations of “smart” materials based on cellulose by chemical modifications and physical incorporating/blending were reviewed. The responsiveness to pH, temperature, light, electricity, magnetic fields, and mechanical forces, etc. of these “smart” materials in their different forms such as copolymers, nanoparticles, gels, and membranes were also reviewed, and the applications as drug delivery systems, hydrogels, electronic active papers, sensors, shape memory materials and smart membranes, etc. were also described in this review. PMID:28809338

“Smart” Materials Based on Cellulose: A Review of the Preparations, Properties, and Applications

Directory of Open Access Journals (Sweden)

Shuwen Hu

2013-02-01

Full Text Available Cellulose is the most abundant biomass material in nature, and possesses some promising properties, such as mechanical robustness, hydrophilicity, biocompatibility, and biodegradability. Thus, cellulose has been widely applied in many fields. “Smart” materials based on cellulose have great advantages—especially their intelligent behaviors in reaction to environmental stimuli—and they can be applied to many circumstances, especially as biomaterials. This review aims to present the developments of “smart” materials based on cellulose in the last decade, including the preparations, properties, and applications of these materials. The preparations of “smart” materials based on cellulose by chemical modifications and physical incorporating/blending were reviewed. The responsiveness to pH, temperature, light, electricity, magnetic fields, and mechanical forces, etc. of these “smart” materials in their different forms such as copolymers, nanoparticles, gels, and membranes were also reviewed, and the applications as drug delivery systems, hydrogels, electronic active papers, sensors, shape memory materials and smart membranes, etc. were also described in this review.

Preparation of in-house graphite reference material for boron

International Nuclear Information System (INIS)

Kumar, Sanjukta A.; Venkatesh, K.; Swain, Kallola K.; Manisha, V.; Kamble, Granthali S.; Pandey, Shailaja P.; Remya Devi, P.S.; Ghosh, M.; Verma, R.

2016-05-01

Graphite is extensively used in nuclear technology. Boron concentration in graphite is one of the important parameters that decide its acceptability for nuclear applications. Reliable analytical methods are essential for the determination of boron in graphite at concentration about 5 mg kg -1 . Reference materials are used for validation of existing analytical methods and developing new methodologies. In view of the importance of determination of boron in graphite and unavailability of graphite reference material, an In-house graphite reference material was prepared in Analytical Chemistry Division. Graphite source material was procured, processed to obtain powder of ≤ 75 μm (200 mesh) and bottled. Procedures were developed for the determination of boron in graphite using inductively coupled plasma optical emission spectrometry (ICPOES) and inductively coupled plasma mass spectrometry (ICPMS) techniques. Homogeneity testing was carried out on the bottled units and boron content along with the combined and expanded uncertainties were established. The assigned boron concentration in the In-house graphite reference material is (7.3±0.46) mg kg -1 . (author)

Materials Preparation Center

Data.gov (United States)

Federal Laboratory Consortium — MPC is recognized throughout the worldwide research community for its unique capabilities in purification, preparation, and characterization of: rare earth metals,...

Mechanical behavior and dynamic failure of high-strength ultrafine grained tungsten under uniaxial compression

International Nuclear Information System (INIS)

Wei, Q.; Jiao, T.; Ramesh, K.T.; Ma, E.; Kecskes, L.J.; Magness, L.; Dowding, R.; Kazykhanov, V.U.; Valiev, R.Z.

2006-01-01

We have systematically investigated the quasi-static and dynamic mechanical behavior (especially dynamic failure) of ultra-fine grained (UFG) tungsten (W) under uniaxial compression. The starting material is of commercial purity and large grain size. We utilized severe plastic deformation to achieve the ultrafine microstructure characterized by grains and subgrains with sizes of ∼500 nm, as identified by transmission electron microscopy. Results of quasi-static compression show that the UFG W behaves in an elastic-nearly perfect plastic manner (i.e., vanishing strain hardening), with its flow stress approaching 2 GPa, close to twice that of conventional coarse grain W. Post-mortem examinations of the quasi-statically loaded samples show no evidence of cracking, in sharp contrast to the behavior of conventional W (where axial cracking is usually observed). Under uniaxial dynamic compression (strain rate ∼10 3 s -1 ), the true stress-true strain curves of the UFG W exhibit significant flow softening, and the peak stress is ∼3 GPa. Furthermore, the strain rate sensitivity of the UFG W is reduced to half the value of the conventional W. Both in situ high-speed photography and post-mortem examinations reveal shear localization and as a consequence, cracking of the UFG W under dynamic uniaxial compression. These observations are consistent with recent observations on other body-centered cubic metals with nanocrystalline or ultrafine microstructures. The experimental results are discussed using existing models for adiabatic shear localization in metals

Basic considerations for the preparation of performance testing materials as related to performance evaluation acceptance criteria

International Nuclear Information System (INIS)

McCurdy, D.E.; Morton, J.S.

2001-01-01

The preparation of performance testing (PT) materials for environmental and radiobioassay applications involves the use of natural matrix materials containing the analyte of interest, the addition (spiking) of the analyte to a desired matrix (followed by blending for certain matrices) or a combination of the two. The distribution of the sample analyte concentration in a batch of PT samples will reflect the degree of heterogeneity of the analyte in the PT material and/or the reproducibility of the sample preparation process. Commercial and government implemented radioanalytical performance evaluation programs have a variety of acceptable performance criteria. The performance criteria should take into consideration many parameters related to the preparation of the PT materials including the within and between sample analyte heterogeneity, the accuracy of the quantification of an analyte in the PT material and to what 'known' value will a laboratory's result be compared. How sample preparation parameters affect the successful participation in performance evaluation (PE) programs having an acceptance criteria established as a percent difference from a 'known' value or in PE programs using other acceptance criteria, such as the guidance provided in ANSI N42.22 and N13.30 is discussed. (author)

Preparation of SnO2/C biomorphic materials by biotemplating from ...

Indian Academy of Sciences (India)

the micro-fine structure of the natural biological materials, but also is endowed ... nated with Sn(OH)4 sol using ultrasonic technique. The ... The mechanism of preparation has been .... tracheid structure of ramie fibres, and the orientation of the.

Composite Materials with Magnetically Aligned Carbon Nanoparticles and Methods of Preparation

Science.gov (United States)

Hong, Haiping (Inventor); Peterson, G.P. (Bud) (Inventor); Salem, David R. (Inventor)

2018-01-01

The present invention relates to magnetically aligned carbon nanoparticle composites and methods of preparing the same. The composites comprise carbon nanoparticles, host material, magnetically sensitive nanoparticles and surfactant. The composites may have enhanced mechanical, thermal, and/or electrical properties.

[Preparation of sodium alginate-nanohydroxyapatite composite material for bone repair and its biocompatibility].

Science.gov (United States)

Wang, Yanmei; He, Jiacai; Li, Quanli; Shen, Jijia

2014-02-01

To prepare sodium alginate-nanohydroxyapatite composite material and to explore its feasibility as a bone repair material. Sodium alginate-nanohydroxyapatite composite material was prepared using chemical cross-linking and freeze-drying technology. The composite was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and its porosity was measured by liquid displacement method. The fifth passage of bone marrow stromal stem cells (BMSCs) were incubated on the composite material and then growth was observed by inverted microscope and SEM. BMSCs were cultured with liquid extracts of the material, methyl thiazolyl tetrazolium (MTT) assay was used to calculate the relative growth rate (RGR) on 1, 3, 5 d and to evaluate the cytotoxicity. Fresh dog blood was added into the liquid extracts to conduct hemolysis test, the spectrophotometer was used to determine the optical density (OD) and to calculate the hemolysis rate. Sodium alginate-nanohydroxyapatite composite material displayed porosity, the porous pore rate was (88.6 +/- 4.5)%. BMSCs showed full stretching and vigorous growth under inverted microscope and SEM. BMSCs cultured with liquid extracts of the material had good activities. The toxicity of composite material was graded as 1. Hemolysis test results showed that the hemolysis rate of the composite material was 1.28%, thus meeting the requirement of medical biomaterials. The composite material fabricated in this study has high porosity and good biocompatibility.

Preparation of steel slag porous sound-absorbing material using coal powder as pore former.

Science.gov (United States)

Sun, Peng; Guo, Zhancheng

2015-10-01

The aim of the study was to prepare a porous sound-absorbing material using steel slag and fly ash as the main raw material, with coal powder and sodium silicate used as a pore former and binder respectively. The influence of the experimental conditions such as the ratio of fly ash, sintering temperature, sintering time, and porosity regulation on the performance of the porous sound-absorbing material was investigated. The results showed that the specimens prepared by this method had high sound absorption performance and good mechanical properties, and the noise reduction coefficient and compressive strength could reach 0.50 and 6.5MPa, respectively. The compressive strength increased when the dosage of fly ash and sintering temperature were raised. The noise reduction coefficient decreased with increasing ratio of fly ash and reducing pore former, and first increased and then decreased with the increase of sintering temperature and time. The optimum preparation conditions for the porous sound-absorbing material were a proportion of fly ash of 50% (wt.%), percentage of coal powder of 30% (wt.%), sintering temperature of 1130°C, and sintering time of 6.0hr, which were determined by analyzing the properties of the sound-absorbing material. Copyright © 2015. Published by Elsevier B.V.

Preparation and thermal conductivity enhancement of composite phase change materials for electronic thermal management

International Nuclear Information System (INIS)

Wu, Weixiong; Zhang, Guoqing; Ke, Xiufang; Yang, Xiaoqing; Wang, Ziyuan; Liu, Chenzhen

2015-01-01

Highlights: • A kind of composite phase change material board (PCMB) is prepared and tested. • PCMB presents a large thermal storage capacity and enhanced thermal conductivity. • PCMB displays much better cooling effect in comparison to natural air cooling. • PCMB presents different cooling characteristics in comparison to ribbed radiator. - Abstract: A kind of phase change material board (PCMB) was prepared for use in the thermal management of electronics, with paraffin and expanded graphite as the phase change material and matrix, respectively. The as-prepared PCMB presented a large thermal storage capacity of 141.74 J/g and enhanced thermal conductivity of 7.654 W/(m K). As a result, PCMB displayed much better cooling effect in comparison to natural air cooling, i.e., much lower heating rate and better uniformity of temperature distribution. On the other hand, compared with ribbed radiator technology, PCMB also presented different cooling characteristics, demonstrating that they were suitable for different practical application

Preparation of standard hair material and development of analytical methodology

International Nuclear Information System (INIS)

Gangadharan, S.; Ganapathi Iyer, S.; Ali, M.M.; Thantry, S.S.; Verma, R.; Arunachalam, J.; Walvekar, A.P.

1992-01-01

In 1976 Indian Researchers suggested the possible use of hair as an indicator of environmental exposure and established through a study of country wide student population and general population of the metropolitan city of Bombay that human scalp hair could indeed be an effective first level monitor in a scheme of multilevel monitoring of environmental exposure to inorganic pollutants. It was in this context and in view of the ready availability of large quantities of scalp hair subjected to minimum treatment by chemicals that they proposed to participate in the preparation of a standard material of hair. It was also recognized that measurements of trace element concentrations at very low levels require cross-validation by different analytical techniques, even within the same laboratory. The programme of work that has been carried out since the first meeting of the CRP had been aimed at these two objectives. These objectives include the preparation of standard material of hair and the development of analytical methodologies for determination of elements and species of interest. 1 refs., 3 tabs

Hexamethyldisilazane Removal with Mesoporous Materials Prepared from Calcium Fluoride Sludge.

Science.gov (United States)

Kao, Ching-Yang; Lin, Min-Fa; Nguyen, Nhat-Thien; Tsai, Hsiao-Hsin; Chang, Luh-Maan; Chen, Po-Han; Chang, Chang-Tang

2018-05-01

A large amount of calcium fluoride sludge is generated by the semiconductor industry every year. It also requires a high amount of fuel consumption using rotor concentrators and thermal oxidizers to treat VOCs. The mesoporous adsorbent prepared by calcium fluoride sludge was used for VOCs treatment. The semiconductor industry employs HMDS to promote the adhesion of photo-resistant material to oxide(s) due to the formation of silicon dioxide, which blocks porous adsorbents. The adsorption of HMDS (Hexamethyldisiloxane) was tested with mesoporous silica materials synthesized from calcium fluoride (CF-MCM). The resulting samples were characterized by XRD, XRF, FTIR, N2-adsorption-desorption techniques. The prepared samples possessed high specific surface area, large pore volume and large pore diameter. The crystal patterns of CF-MCM were similar with Mobil composite matter (MCM-41) from TEM image. The adsorption capacity of HMDS with CF-MCM was 40 and 80 mg g-1, respectively, under 100 and 500 ppm HMDS. The effects of operation parameters, such as contact time and mixture concentration, on the performance of CF-MCM were also discussed in this study.

Novel polymeric nanocomposites and porous materials prepared using organogels

International Nuclear Information System (INIS)

Lai, Wei-Chi; Tseng, Shen-Chen

2009-01-01

We propose a new method for preparing polymeric nanocomposites and porous materials using self-assembled templates formed by 1,3:2,4-dibenzylidene sorbitol (DBS) organogels. DBS is capable of self-assembling into a 3D nanofibrillar network at relatively low concentrations in some organic solvents to produce organogels. In this study, we induced the formation of such physical cross-linked networks in styrene. Subsequently, we polymerized the styrene in the presence of chemical cross-linkers, divinyl benzene (DVB), with different amounts of DBS using thermal-initiated polymerization. The resulting materials were transparent, homogeneous polystyrene (PS) nanocomposites with both physical and chemical cross-links. The porous polymeric materials were obtained by solvent extraction of the DBS nanofibrils from the PS. Brunauer-Emmett-Teller (BET) measurements show that the amounts of DBS and DVB influenced the specific surface area after the removal of the DBS fibrils.

Novel polymeric nanocomposites and porous materials prepared using organogels

Energy Technology Data Exchange (ETDEWEB)

Lai, Wei-Chi; Tseng, Shen-Chen, E-mail: wclai@mail.tku.edu.t [Department of Chemical and Materials Engineering, Tamkang University, 151 Ying-chuan Road, Tamsui, Taipei 25137, Taiwan (China)

2009-11-25

We propose a new method for preparing polymeric nanocomposites and porous materials using self-assembled templates formed by 1,3:2,4-dibenzylidene sorbitol (DBS) organogels. DBS is capable of self-assembling into a 3D nanofibrillar network at relatively low concentrations in some organic solvents to produce organogels. In this study, we induced the formation of such physical cross-linked networks in styrene. Subsequently, we polymerized the styrene in the presence of chemical cross-linkers, divinyl benzene (DVB), with different amounts of DBS using thermal-initiated polymerization. The resulting materials were transparent, homogeneous polystyrene (PS) nanocomposites with both physical and chemical cross-links. The porous polymeric materials were obtained by solvent extraction of the DBS nanofibrils from the PS. Brunauer-Emmett-Teller (BET) measurements show that the amounts of DBS and DVB influenced the specific surface area after the removal of the DBS fibrils.

Preparation and characterization of multifunctional magnetic mesoporous calcium silicate materials

International Nuclear Information System (INIS)

Zhang, Jianhua; Tao, Cuilian; Zhu, Yufang; Zhu, Min; Li, Jie; Hanagata, Nobutaka

2013-01-01

We have prepared multifunctional magnetic mesoporous Fe–CaSiO 3 materials using triblock copolymer (P123) as a structure-directing agent. The effects of Fe substitution on the mesoporous structure, in vitro bioactivity, magnetic heating ability and drug delivery property of mesoporous CaSiO 3 materials were investigated. Mesoporous Fe–CaSiO 3 materials had similar mesoporous channels (5–6 nm) with different Fe substitution. When 5 and 10% Fe were substituted for Ca in mesoporous CaSiO 3 materials, mesoporous Fe–CaSiO 3 materials still showed good apatite-formation ability and had no cytotoxic effect on osteoblast-like MC3T3-E1 cells evaluated by the elution cell culture assay. On the other hand, mesoporous Fe–CaSiO 3 materials could generate heat to raise the temperature of the surrounding environment in an alternating magnetic field due to their superparamagnetic property. When we use gentamicin (GS) as a model drug, mesoporous Fe–CaSiO 3 materials release GS in a sustained manner. Therefore, magnetic mesoporous Fe–CaSiO 3 materials would be a promising multifunctional platform with bone regeneration, local drug delivery and magnetic hyperthermia. (paper)

Sampling, storage and sample preparation procedures for X ray fluorescence analysis of environmental materials

International Nuclear Information System (INIS)

1997-06-01

X ray fluorescence (XRF) method is one of the most commonly used nuclear analytical technique because of its multielement and non-destructive character, speed, economy and ease of operation. From the point of view of quality assurance practices, sampling and sample preparation procedures are the most crucial steps in all analytical techniques, (including X ray fluorescence) applied for the analysis of heterogeneous materials. This technical document covers recent modes of the X ray fluorescence method and recent developments in sample preparation techniques for the analysis of environmental materials. Refs, figs, tabs

Development of Methods of Preparing Materials for Teaching Machines: Professional Paper 29-68.

Science.gov (United States)

Skinner, B. F.; Zook, Lola M., Ed.

In the preparation of 12-inch disc teaching machine materials for elementary college courses, a preliminary analysis of subject matter and required skills precedes sequential framing. The programer must assess the beginning level of student competence and frame questions to supply new material until the proper response stands alone. Statements for…

Reutilization of discarded biomass for preparing functional polymer materials.

Science.gov (United States)

Wang, Jianfeng; Qian, Wenzhen; He, Yufeng; Xiong, Yubing; Song, Pengfei; Wang, Rong-Min

2017-07-01

Biomass is abundant and recyclable on the earth, which has been assigned numerous roles to human beings. However, over the past decades, accompanying with the rapid expansion of man-made materials, such as alloy, plastic, synthetic rubber and fiber, a great number of natural materials had been neglected and abandoned, such as straw, which cause a waste of resource and environmental pollution. In this review, based on introducing sources of discarded biomass, the main composition and polymer chains in discarded biomass materials, the traditional treatment and novel approach for reutilization of discarded biomass were summarized. The discarded biomass mainly come from plant wastes generated in the process of agriculture and forestry production and manufacturing processes, animal wastes generated in the process of animal husbandry and fishery production as well as the residual wastes produced in the process of food processing and rural living garbage. Compared with the traditional treatment including burning, landfill, feeding and fertilizer, the novel approach for reutilization of discarded biomass principally allotted to energy, ecology and polymer materials. The prepared functional materials covered in composite materials, biopolymer based adsorbent and flocculant, carrier materials, energy materials, smart polymer materials for medical and other intelligent polymer materials, which can effectively serve the environmental management and human life, such as wastewater treatment, catalyst, new energy, tissue engineering, drug controlled release, and coating. To sum up, the renewable and biodegradable discarded biomass resources play a vital role in the sustainable development of human society, as well as will be put more emphases in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Superior radiation-resistant nanoengineered austenitic 304L stainless steel for applications in extreme radiation environments.

Science.gov (United States)

Sun, C; Zheng, S; Wei, C C; Wu, Y; Shao, L; Yang, Y; Hartwig, K T; Maloy, S A; Zinkle, S J; Allen, T R; Wang, H; Zhang, X

2015-01-15

Nuclear energy provides more than 10% of electrical power internationally, and the increasing engagement of nuclear energy is essential to meet the rapid worldwide increase in energy demand. A paramount challenge in the development of advanced nuclear reactors is the discovery of advanced structural materials that can endure extreme environments, such as severe neutron irradiation damage at high temperatures. It has been known for decades that high dose radiation can introduce significant void swelling accompanied by precipitation in austenitic stainless steel (SS). Here we report, however, that through nanoengineering, ultra-fine grained (UFG) 304 L SS with an average grain size of ~100 nm, can withstand Fe ion irradiation at 500 °C to 80 displacements-per-atom (dpa) with moderate grain coarsening. Compared to coarse grained (CG) counterparts, swelling resistance of UFG SS is improved by nearly an order of magnitude and swelling rate is reduced by a factor of 5. M(23)C(6) precipitates, abundant in irradiated CG SS, are largely absent in UFG SS. This study provides a nanoengineering approach to design and discover radiation tolerant metallic materials for applications in extreme radiation environments.

Manufacture of high-strength composite materials from prepregs prepared by radiation processing

International Nuclear Information System (INIS)

Laricheva, V.P.; Korotkij, A.F.

2008-01-01

Scientific principles of the manufacture of high-strength heat-resistant polymer composite materials with the successive ionizing-radiation and heat treatment (via the step of long-lived prepregs) were developed. Methods for the selection of components for the preparation of long-lived prepregs, as well as for the determination of the optimal curing conditions, were proposed. The mechanical properties of the materials were studied [ru

Preparation and hygrothermal properties of composite phase change humidity control materials

International Nuclear Information System (INIS)

Chen, Zhi; Qin, Menghao

2016-01-01

Highlights: • A new kind of phase change humidity control material (PCHCM) was prepared. • The PCHCM can moderate both the indoor temperature and humidity. • The silicon dioxide shell can improve the thermal properties of the composite. • The PCM microcapsules can improve the moisture buffer ability of the composite. • The CPCM/vesuvianite composite has a better hygrothermal performance than pure hygroscopic material. - Abstract: A novel phase change humidity control material (PCHCM) was prepared by using PCM microcapsules and different hygroscopic porous materials. The PCHCM composite can regulate the indoor hygrothermal environment by absorbing or releasing both heat and moisture. The PCM microcapsules were synthesized with methyl triethoxysilane by the sol–gel method. The vesuvianite, sepiolite and zeolite were used as hygroscopic materials. The scanning electron microscopy (SEM) was used to measure the morphology profiles of the microcapsules and PCHCM. The differential scanning calorimetry (DSC) and the thermal gravimetric analysis (TGA) were used to determine the thermal properties and thermal stability. Both the moisture transfer coefficient and moisture buffer value (MBV) of different PCHCMs were measured by the improved cup method. The DSC results showed that the SiO 2 shell can reduce the super-cooling degree of PCM. The super-cooling degrees of microcapsules and PCHCM are lower than that of the pure PCM. The onset temperature of thermal degradation of the microcapsules and PCHCMs is higher than that of pure PCM. Both the moisture transfer coefficient and MBV of PCHCMs are higher than that of the pure hygroscopic materials. The results indicated the PCHCMs have better thermal properties and moisture buffer ability.

Preparation of resveratrol-loaded nanoporous silica materials with different structures

Science.gov (United States)

Popova, Margarita; Szegedi, Agnes; Mavrodinova, Vesselina; Novak Tušar, Natasa; Mihály, Judith; Klébert, Szilvia; Benbassat, Niko; Yoncheva, Krassimira

2014-11-01

Solid, nanoporous silica-based spherical mesoporous MCM-41 and KIL-2 with interparticle mesoporosity as well as nanosized zeolite BEA materials differing in morphology and pore size distribution, were used as carriers for the preparation of resveratrol-loaded delivery systems. Two preparation methods have been applied: (i) loading by mixing of resveratrol and mesoporous carrier in solid state and (ii) deposition in ethanol solution. The parent and the resveratrol loaded carriers were characterized by XRD, TEM, N2 physisorption, thermal analysis, and FT-IR spectroscopy. The influence of the support structure on the adsorption capacity and the release kinetics of this poorly soluble compound were investigated. Our results indicated that the chosen nanoporous silica supports are suitable for stabilization of trans-resveratrol and reveal controlled release and ability to protect the supported compound against degradation regardless of loading method. The solid-state dry mixing appears very effective for preparation of drug formulations composed of poorly soluble compound.

Preparation and certification of trace mercury in water standard reference materials

International Nuclear Information System (INIS)

Moody, J.R.; Paulsen, P.J.; Rains, T.C.; Rook, H.L.

1976-01-01

The study of mercury in natural water supplies requires a Standard Reference Material (SRM) with a certified concentration at the 1 ng/g level. NBS SRM's have been prepared with nominal mercury concentrations of 1.5 μg/g and 1.2 ng/g. Confirmation of these values was obtained by neutron activation, atomic absorption, and isotope dilution-spark source mass spectrometry (IDSSMS). Nitric acid and trace amounts of gold were added to achieve a stable mercury concentration. The precautions observed for cleaning the glass and Teflon containers, preparation of mercury solutions, and the packaging of the SRM's are given. As an example of the care needed in the analysis of mercury at these levels, specific details are presented for the chemistry required to prepare samples for the spark source mass spectrometer

Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

International Nuclear Information System (INIS)

Xi Peng; Gu Xiaohua; Cheng Bowen; Wang Yufei

2009-01-01

Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, 1 H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.

Effect of ageing on tensile behavior of ultrafine grained Al 6061 alloy

Energy Technology Data Exchange (ETDEWEB)

Rao, P. Nageswara [Department of Metallurgical and Materials Engineering & Centre of Nanotechnology, IIT Roorkee, Roorkee 247667 (India); Singh, Dharmendra [Department of Mechanical Engineering, Government Engineering College, Bikaner 304001 (India); Brokmeier, Heinz-Günter [Helmholtz Zentrum Geesthacht, Max Planck Straße 1, Geb 33, D-21502 Geesthacht (Germany); Jayaganthan, R., E-mail: rjayafmt@iitr.ernet.in [Department of Metallurgical and Materials Engineering & Centre of Nanotechnology, IIT Roorkee, Roorkee 247667 (India)

2015-08-12

In the present investigation, the ageing behavior of ultrafine grained (UFG) Al 6061 alloy, processed through multi-directional forging (MDF) at cryogenic temperature was investigated. The evolution of microstructure was investigated through transmission electron microscopy and electron back scattered diffraction technique. The results indicate that homogeneous microstructure with an ultrafine grain morphology (average size 250 nm) was achieved through cryogenic forging of the alloy subjected to prior solutionising treatment. Tensile testing at room temperature revealed that MDFed material after ageing led to significant improvement in work hardening and its tensile ductility. Strengthening of the matrix through various mechanisms has been quantified with the existing models to estimate the yield strength of the as forged and peak aged material. The precipitation hardening response in UFG material is found to be 35% lower than that of the coarse grained material as observed in the present work.

Hierarchy concepts: classification and preparation strategies for zeolite containing materials with hierarchical porosity.

Science.gov (United States)

Schwieger, Wilhelm; Machoke, Albert Gonche; Weissenberger, Tobias; Inayat, Amer; Selvam, Thangaraj; Klumpp, Michael; Inayat, Alexandra

2016-06-13

'Hierarchy' is a property which can be attributed to a manifold of different immaterial systems, such as ideas, items and organisations or material ones like biological systems within living organisms or artificial, man-made constructions. The property 'hierarchy' is mainly characterised by a certain ordering of individual elements relative to each other, often in combination with a certain degree of branching. Especially mass-flow related systems in the natural environment feature special hierarchically branched patterns. This review is a survey into the world of hierarchical systems with special focus on hierarchically porous zeolite materials. A classification of hierarchical porosity is proposed based on the flow distribution pattern within the respective pore systems. In addition, this review might serve as a toolbox providing several synthetic and post-synthetic strategies to prepare zeolitic or zeolite containing material with tailored hierarchical porosity. Very often, such strategies with their underlying principles were developed for improving the performance of the final materials in different technical applications like adsorptive or catalytic processes. In the present review, besides on the hierarchically porous all-zeolite material, special focus is laid on the preparation of zeolitic composite materials with hierarchical porosity capable to face the demands of industrial application.

Property change of advanced tungsten alloys due to neutron irradiation

International Nuclear Information System (INIS)

Fukuda, Makoto; Hasegawa, Akira; Tanno, Takashi; Nogami, Shuhei; Kurishita, Hiroaki

2013-01-01

This study investigates the effect of neutron irradiation on the functional properties of pure tungsten (W) and advanced tungsten alloys (e.g., lanthanum (La)-doped W, potassium (K)-doped W, and ultra-fine-grained (UFG) W–TiC alloys) tested in the Japan Materials Testing Reactor (JMTR) or experimental fast reactor Joyo. The irradiation temperature and damage were in the range 804–1073 K and 0.15–0.47 dpa, respectively. TEM images of all samples after 0.42 dpa irradiation at 1023 K showed voids, black dots, and dislocation loops, indicating that similar damage structures were formed in pure W, La-doped W, K-doped W, and UFG W–0.5 wt% TiC. The electrical resistivity of all specimens increased following neutron irradiation. Nearly identical electrical resistivity and irradiation hardening were observed in pure W, La-doped W, and K-doped W. The electrical resistivity of UFG W–TiC was higher than that of other specimens before and after irradiation, which may be attributed to its ultra-fine-grain structure, as well as the presence of impurities introduced during the alloying process. Compared to the other specimens, the UFG W–TiC was more resistant to irradiation hardening

Digital Materials Related to Food Science and　Cooking Methods for Preparing Eggs

OpenAIRE

沼田, 貴美子; 渡邉, 美奈; ヌマタ, キミコ; ワタナベ, ミナ; Numata, Kimiko; Watanabe, Mina

2009-01-01

We studied methods that were effective for teaching cooking to elementary school pupils using home economics materials. The subject was "Iritamago (scrambled eggs)". We researched the relationship between cookery science and experimental methods of making Iritamago. The various differences in condition and texture of Iritamago were compared among the different cooking utensils, conditions, and preparations of eggs. We created digital materials related to cookery science and the cooking method...

Biomolecular hybrid material and process for preparing same and uses for same

Science.gov (United States)

Kim, Jungbae [Richland, WA

2010-11-23

Disclosed is a composition and method for fabricating novel hybrid materials comprised of, e.g., carbon nanotubes (CNTs) and crosslinked enzyme clusters (CECs). In one method, enzyme-CNT hybrids are prepared by precipitation of enzymes which are subsequently crosslinked, yielding crosslinked enzyme clusters (CECs) on the surface of the CNTs. The CEC-enzyme-CNT hybrids exhibit high activity per unit area or mass as well as improved enzyme stability and longevity over hybrid materials known in the art. The CECs in the disclosed materials permit multilayer biocatalytic coatings to be applied to surfaces providing hybrid materials suitable for use in, e.g., biocatalytic applications and devices as described herein.

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

Directory of Open Access Journals (Sweden)

Sang-Mi Yun

2012-02-01

Full Text Available Objectives The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10. Each experimental group was restored with Caviton (GC, Spacer (Vericom, IRM (Dentsply-Caulk, or Fuji II(GC. Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM. Results There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Sample preparation of energy materials for X-ray nanotomography with micromanipulation.

Science.gov (United States)

Chen-Wiegart, Yu-chen Karen; Camino, Fernando E; Wang, Jun

2014-06-06

X-ray nanotomography presents an unprecedented opportunity to study energy storage/conversion materials at nanometer scales in three dimensions, with both elemental and chemical sensitivity. A critical step in obtaining high-quality X-ray nanotomography data is reliable sample preparation to ensure that the entire sample fits within the field of view of the X-ray microscope. Although focused-ion-beam lift-out has previously been used for large sample (few to tens of microns) preparation, a difficult undercut and lift-out procedure results in a time-consuming sample preparation process. Herein, we propose a much simpler and direct sample preparation method to resolve the issues that block the view of the sample base after milling and during the lift-out process. This method is applied on a solid-oxide fuel cell and a lithium-ion battery electrode, before numerous critical 3D morphological parameters are extracted, which are highly relevant to their electrochemical performance. A broad application of this method for microstructure study with X-ray nanotomography is discussed and presented. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of a Carbon Doped Tissue-Mimicking Material with High Dielectric Properties for Microwave Imaging Application

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Siang-Wen Lan

2016-07-01

Full Text Available In this paper, the oil-in-gelatin based tissue-mimicking materials (TMMs doped with carbon based materials including carbon nanotube, graphene ink or lignin were prepared. The volume percent for gelatin based mixtures and oil based mixtures were both around 50%, and the doping amounts were 2 wt %, 4 wt %, and 6 wt %. The effect of doping material and amount on the microwave dielectric properties including dielectric constant and conductivity were investigated over an ultra-wide frequency range from 2 GHz to 20 GHz. The coaxial open-ended reflection technology was used to evaluate the microwave dielectric properties. Six measured values in different locations of each sample were averaged and the standard deviations of all the measured dielectric properties, including dielectric constant and conductivity, were less than one, indicating a good uniformity of the prepared samples. Without doping, the dielectric constant was equal to 23 ± 2 approximately. Results showed with doping of carbon based materials that the dielectric constant and conductivity both increased about 5% to 20%, and the increment was dependent on the doping amount. By proper selection of doping amount of the carbon based materials, the prepared material could map the required dielectric properties of special tissues. The proposed materials were suitable for the phantom used in the microwave medical imaging system.

Research on risk assessment for maritime transport of radioactive materials. Preparation of maritime accident data for risk assessment

International Nuclear Information System (INIS)

Odano, Naoteru; Sawada, Ken-ichi; Mochiduki, Hiromitsu; Hirao, Yoshihiro; Asami, Mitsufumi

2010-01-01

Maritime transport of radioactive materials has been playing an important role in the nuclear fuel cycle in Japan. Due to recent increase of transported radioactive materials and diversification of transport packages with enlargement of nuclear research, development and utilization, safety securement for maritime transport of radioactive materials is one of important issues in the nuclear fuel cycle. Based squarely on the current circumstances, this paper summarizes discussion on importance of utilization of results of risk assessment for maritime transport of radioactive materials. A plan for development of comprehensive methodology to assess risks in maritime transport of radioactive materials is also described. Preparations of database of maritime accident to be necessary for risk assessment are also summarized. The prepared data could be utilized for future quantitative risk assessment, such as the event trees and fault trees analyses, for maritime transport of radioactive materials. The frequency of severe accident that the package might be damaged is also estimated using prepared data. (author)

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

International Nuclear Information System (INIS)

Sun, Zhiming; Zhang, Yuzhong; Zheng, Shuilin; Park, Yuri; Frost, Ray L.

2013-01-01

Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value

Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

Energy Technology Data Exchange (ETDEWEB)

Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

2013-04-20

Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

Preparation of cathode materials for Li-ion cells by acid dissolution

International Nuclear Information System (INIS)

Oh, Si Hyoung; Jeong, Woon Tae; Cho, Won Il; Cho, Byung Won; Woo, Kyoungja

2005-01-01

New synthesis route called acid dissolution method, preparing the high-performance cathode materials for the lithium-ion cells, was successfully developed. In this method, insoluble starting materials such as metal carbonates or metal hydroxides are dissolved in strong organic acidic solution which contains a chelating agent. And then, the solvent of the solution containing starting materials is eliminated to obtain the xerogel of the initial solution whose chemical form is expressed as Li[MA 3 ], where M is a transition metal atom and A is the anion of the organic acid. The xerogel is then calcined at the high temperature to obtain polycrystalline cathode materials. In this work, the applicability of this method was demonstrated synthesizing a polycrystalline single-phase LiCoO 2 using lithium carbonate, cobalt hydroxide as the insoluble starting materials and the acrylic acid as a chelating agent. The synthesized powders calcined at 800 deg. C showed a good electrochemical performance in the half-cell test

Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

Science.gov (United States)

Linsheng, Li; Guoxiang, Lin; Lihui, Li

2016-08-12

In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.

Automated SEM and TEM sample preparation applied to copper/low k materials

Science.gov (United States)

Reyes, R.; Shaapur, F.; Griffiths, D.; Diebold, A. C.; Foran, B.; Raz, E.

2001-01-01

We describe the use of automated microcleaving for preparation of both SEM and TEM samples as done by SELA's new MC500 and TEMstation tools. The MC500 is an automated microcleaving tool that is capable of producing cleaves with 0.25 μm accuracy resulting in SEM-ready samples. The TEMstation is capable of taking a sample output from the MC500 (or from SELA's earlier MC200 tool) and producing a FIB ready slice of 25±5 μm, mounted on a TEM-washer and ready for FIB thinning to electron transparency for TEM analysis. The materials selected for the tool set evaluation mainly included the Cu/TaN/HOSP low-k system. The paper is divided into three sections, experimental approach, SEM preparation and analysis of HOSP low-k, and TEM preparation and analysis of Cu/TaN/HOSP low-k samples. For the samples discussed, data is presented to show the quality of preparation provided by these new automated tools.

Sol-gel Process in Preparation of Organic-inorganic Hybrid Materials

Directory of Open Access Journals (Sweden)

Macan, J

2008-07-01

Full Text Available Organic-inorganic hybrid materials are a sort of nanostructured material in which the organic and inorganic phases are mixed at molecular level. The inorganic phase in hybrid materials is formed by the sol-gel process, which consists of reactions of hydrolysis and condensation of metal (usually silicon alkoxides. Flexibility of sol-gel process enables creation of hybrid materials with varying organic and inorganic phases in different ratios, and consequently fine-tuning of their properties. In order to obtain true hybrid materials, contact between the phases should be at molecular level, so phase separation between thermodynamically incompatible organic and inorganic phases has to be prevented. Phase interaction can be improved by formation of hydrogen or covalent bonds between them during preparation of hybrid materials. Covalent bond can be introduced by organically modified silicon alkoxides containing a reactive organic group (substituent capable of reacting with the organic phase. In order to obtain hybrid materials with desired structures, a detailed knowledge of hydrolysis and condensation mechanism is necessary. The choice of catalyst, whether acid or base, has the most significant influence on the structure of the inorganic phase. Other important parameters are alkoxide concentration, water: alkoxide ratio, type of alkoxide groups, solvent used, temperature, purity of chemicals used, etc. Hydrolysis and condensation of organically modified silicon alkoxides are additionally influenced by nature and size of the organic supstituent.

Reassessment of the Upper Fremont Glacier ice-core chronologies by synchronizing of ice-core-water isotopes to a nearby tree-ring chronology

Science.gov (United States)

Chellman, Nathan J.; McConnell, Joseph R.; Arienzo, Monica; Pederson, Gregory T.; Aarons, Sarah; Csank, Adam

2017-01-01

The Upper Fremont Glacier (UFG), Wyoming, is one of the few continental glaciers in the contiguous United States known to preserve environmental and climate records spanning recent centuries. A pair of ice cores taken from UFG have been studied extensively to document changes in climate and industrial pollution (most notably, mid-19th century increases in mercury pollution). Fundamental to these studies is the chronology used to map ice-core depth to age. Here, we present a revised chronology for the UFG ice cores based on new measurements and using a novel dating approach of synchronizing continuous water isotope measurements to a nearby tree-ring chronology. While consistent with the few unambiguous age controls underpinning the previous UFG chronologies, the new interpretation suggests a very different time scale for the UFG cores with changes of up to 80 years. Mercury increases previously associated with the mid-19th century Gold Rush now coincide with early-20th century industrial emissions, aligning the UFG record with other North American mercury records from ice and lake sediment cores. Additionally, new UFG records of industrial pollutants parallel changes documented in ice cores from southern Greenland, further validating the new UFG chronologies while documenting the extent of late 19th and early 20th century pollution in remote North America.

Grain size engineering of bcc refractory metals: Top-down and bottom-up-Application to tungsten

International Nuclear Information System (INIS)

Kecskes, L.J.; Cho, K.C.; Dowding, R.J.; Schuster, B.E.; Valiev, R.Z.; Wei, Q.

2007-01-01

We have used two general methodologies for the production of ultrafine grained (UFG) and nanocrystalline (NC) tungsten (W) metal samples: top-down and bottom-up. In the first, Equal channel angular extrusion (ECAE), coupled with warm rolling has been used to fabricate UFG W, and high pressure torsion (HPT) was used to fabricate NC W. We demonstrate an abrupt shift in the deformation mechanism, particularly under dynamic compressive loading, in UFG and NC W. This novel deformation mechanism, a dramatic transition from a uniform deformation mode to that of localized shearing, is shared by other UFG and NC body-centerd cubic (BCC) metals. We have also conducted a series of bottom-up experiments to consolidate powdered UFG W precursors into solid bodies. The bottom-up approach relies on rapid, high-temperature consolidation, specifically designed for UFG and NC W powders. The mechanical property results from the top-down UFG and NC W were used as minimum property benchmarks to guide and design the experimental protocols and parameters for use in the bottom-up procedures. Preliminary results, showing rapid grain growth during the consolidation cycle, did not achieve full density in the W samples. Further development of high-purity W nanopowders and appropriate grain-growth inhibitors (e.g., Zener pinning) will be required to successfully produce bulk-sized UFG and NC W samples

Preparation and Characterisation of LiFePO4/CNT Material for Li-Ion Batteries

Directory of Open Access Journals (Sweden)

Rushanah Mohamed

2011-01-01

Full Text Available Li-ion battery cathode materials were synthesised via a mechanical activation and thermal treatment process and systematically studied. LiFePO4/CNT composite cathode materials were successfully prepared from LiFePO4 material. The synthesis technique involved growth of carbon nanotubes onto the LiFePO4 using a novel spray pyrolysis-modified CVD technique. The technique yielded LiFePO4/CNT composite cathode material displaying good electrochemical activity. The composite cathode exhibited excellent electrochemical performances with 163 mAh/g discharge capacity with 94% cycle efficiency at a 0.1 C discharge rate in the first cycle, with a capacity fade of approximately 10% after 30 cycles. The results indicate that carbon nanotube addition can enable LiFePO4 to display a higher discharge capacity at a fast rate with high efficiency. The research is of potential interest for the application of carbon nanotubes as a new conducting additive in cathode preparation and for the development of high-power Li-ion batteries for hybrid electric vehicles.

Optimization of Sample Preparation processes of Bone Material for Raman Spectroscopy.

Science.gov (United States)

Chikhani, Madelen; Wuhrer, Richard; Green, Hayley

2018-03-30

Raman spectroscopy has recently been investigated for use in the calculation of postmortem interval from skeletal material. The fluorescence generated by samples, which affects the interpretation of Raman data, is a major limitation. This study compares the effectiveness of two sample preparation techniques, chemical bleaching and scraping, in the reduction of fluorescence from bone samples during testing with Raman spectroscopy. Visual assessment of Raman spectra obtained at 1064 nm excitation following the preparation protocols indicates an overall reduction in fluorescence. Results demonstrate that scraping is more effective at resolving fluorescence than chemical bleaching. The scraping of skeletonized remains prior to Raman analysis is a less destructive method and allows for the preservation of a bone sample in a state closest to its original form, which is beneficial in forensic investigations. It is recommended that bone scraping supersedes chemical bleaching as the preferred method for sample preparation prior to Raman spectroscopy. © 2018 American Academy of Forensic Sciences.

DoD Fuel Facilities Criteria

Science.gov (United States)

2015-04-27

Pantograph Feb-2010 UFGS 33 58 00 Leak Detection for Fueling Systems Apr-2008 UFGS 33 52 43.13 Aviation Fuel Piping Feb-2010 UFGS 33 59 00 Tightness of... Pipeline Pressure Testing Guidelines  Specifications  Questions 2 7/12/2017 3 7/12/2017 DoD Fuels Facilities Documents  Unified...UFGS)  Most in the 33 nn nn series  Associated with Standard Designs  Available on WBDG site  Coating Systems 4 7/12/2017 Pipeline

Preparation of a new gamma irradiated PVC-Olive oil cake plastic composite material

International Nuclear Information System (INIS)

Messaud, F.A.; Almsmary, Y.A.; Elwerfalli, S.M.; Benayad, S.M.; Haraga, S.O.; Benfaid, N.A.; Kabar, Y.M.

2003-01-01

This paper dealt with the investigation on preparing new plastic composite material, utilizing polyvinyl chloride polymer (a commercial product in abu-kammash chemical complex) and olive oil cake (a waste of many olive oil production factories), followed by gamma irradiation (26.3 Kg ry) o induce crosslinking of the polymer. The new material possess good, electrical and mechanical properties as compared to plastic products of (PVC plastic pipe factory), and which could be used as new construction anti corrosive material, such as special roofing and partitioning or household goods

Preparation and structural characterization of the thermoluminescent material CaSO4: Dy

International Nuclear Information System (INIS)

Sanchez R, A.; Azorin, J.; Gonzalez M, P.R.; Rivera, T.

2005-01-01

The grade of crystallinity of a material is important so that the one is presented the thermoluminescence phenomenon; for what is necessary to study those structural characteristic of a TL material and to correlate them with its TL response when being irradiated with ionizing radiation. The calcium sulfate activated with Dysprosium (CaSO 4 : Dy) it is a material that has demonstrated its efficiency in the dosimetry of the ionizing radiation for the thermoluminescence method. In this work the structural characterization of this prepared material for the recrystallization method by means of the evaporation of the solvent and their relationship with their TL response is presented. The results showed that the best material to be used in thermoluminescent dosimetry presents a crystalline structure in orthorhombic phase and a particle size in the interval of 80 μm to 200 μm. (Author)

Preparation process and properties of LiCoO2/PANI/dodecylbenzenesulfonate composite electrode materials

International Nuclear Information System (INIS)

Ferchichi, Karima; Hbaieb, Souhaira; Amdouni, Noureddine; Kalfat, Rafik; Chevalier, Yves

2013-01-01

Composite materials that combine the lithium exchanging material LiCoO 2 and the conductive polymer poly(aniline) (PANI) have been investigated regarding their possible application to electrode materials of lithium batteries. Such composite materials have been prepared by means of polymerization of aniline in acidic suspensions of LiCoO 2 particles. PANI was synthesized by oxidative polymerization of aniline by ammonium persulfate in the presence of sodium dodecylbenzenesulfonate (SDBS) as a micellar template and dopant. The composite material consisted in LiCoO 2 particles dispersed in a continuous matrix of PANI. The ribbon-like morphology of the powdered material was distinctly different of the morphologies of the parent materials. The conductive material had conductivity close to that of PANI because the LiCoO 2 content of the composite material was low. The presence of the poorly conductive inorganic phase caused a significant loss of conductivity, showing that LiCoO 2 blocked electronic transfers between PANI crystallites. Ammonium persulfate caused the loss of lithium from LiCoO 2 when it was used at high concentration in the polymerization recipe. In this case a new phase made of Co 3 O 4 formed by chemical decomposition of Li x CoO 2 . Thin films prepared from stable suspensions of composite materials in water show comparable electrical performance to that measured for bulk materials. - Highlights: • LiCoO 2 was incorporated in a conductive polymer matrix made of PANI. • The hybrid material retained the high conductive properties of PANI. • Loss of lithium by persulfate oxidation caused conversion of LiCoO 2 into Co 3 O 4

Preparation and certification of arsenate [As(V)] reference material, NMIJ CRM 7912-a.

Science.gov (United States)

Narukawa, Tomohiro; Kuroiwa, Takayoshi; Narushima, Izumi; Jimbo, Yasujiro; Suzuki, Toshihiro; Chiba, Koichi

2010-05-01

Arsenate [As(V)] solution reference material, National Metrology Institute of Japan (NMIJ) certified reference material (CRM) 7912-a, for speciation of arsenic species was developed and certified by NMIJ, the National Institute of Advanced Industrial Science and Technology. High-purity As(2)O(3) reagent powder was dissolved in 0.8 M HNO(3) solution and As(III) was oxidized to As(V) with HNO(3) to prepare 100 mg kg(-1) of As(V) candidate CRM solution. The solution was bottled in 400 bottles (50 mL each). The concentration of As(V) was determined by four independent analytical techniques-inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectrometry, graphite furnace atomic absorption spectrometry, and liquid chromatography inductively coupled plasma mass spectrometry-according to As(V) calibration solutions, which were prepared from the arsenic standard of the Japan Calibration Service system and whose species was guaranteed to be As(V) by NMIJ. The uncertainties of all the measurements and preparation procedures were evaluated. The certified value of As(V) in the CRM is (99.53 +/- 1.67) mg kg(-1) (k = 2).

Initial Study on Thin Film Preparation of Carbon Nanodots Composites as Luminescence Material

Science.gov (United States)

Iskandar, F.; Aimon, A. H.; Akmaluddin, A. R.; Nuryadin, B. W.; Abdullah, M.

2016-08-01

Nowadays, the developments of phosphors materials require elements without noble metals and simple production process. Carbon nanodots (C-dots) are one of phosphor materials with wide range of emission band, and high biocompatibility. In this research thin film carbon nanodots composite have been prepared by spin coating method. Prior deposition, powder carbon nanodots were synthesized from a mixture of commercial urea as the nitrogen sources and citric acid as a carbon source by using hydrothermal and microwave-assisted heating method. The prepared powder was dispersed in transparent epoxy resin and then coated on glass substrate. The photoluminescence result for sample with 0.035 g citric acid exhibited an intense, single, homogeneous and broad spectrum with yellowish emission upon excitation at 365 nm. The Fourier Transform Infrared Spectroscopy (FTIR) result showed the existences of C=C, C-H, C=O, N-H and O-H functional groups which confirmed the quality of the sample. Further, based on UV-Vis measurement, the prepared thin film was highly transparent (transmittance 90%) with estimated film thickness around 764 nm. This result may open an opportunity for optoelectronic devices.

Initial Study on Thin Film Preparation of Carbon Nanodots Composites as Luminescence Material

International Nuclear Information System (INIS)

Iskandar, F; Aimon, A H; Akmaluddin, A R; Abdullah, M; Nuryadin, B W

2016-01-01

Nowadays, the developments of phosphors materials require elements without noble metals and simple production process. Carbon nanodots (C-dots) are one of phosphor materials with wide range of emission band, and high biocompatibility. In this research thin film carbon nanodots composite have been prepared by spin coating method. Prior deposition, powder carbon nanodots were synthesized from a mixture of commercial urea as the nitrogen sources and citric acid as a carbon source by using hydrothermal and microwave-assisted heating method. The prepared powder was dispersed in transparent epoxy resin and then coated on glass substrate. The photoluminescence result for sample with 0.035 g citric acid exhibited an intense, single, homogeneous and broad spectrum with yellowish emission upon excitation at 365 nm. The Fourier Transform Infrared Spectroscopy (FTIR) result showed the existences of C=C, C-H, C=O, N-H and O-H functional groups which confirmed the quality of the sample. Further, based on UV-Vis measurement, the prepared thin film was highly transparent (transmittance 90%) with estimated film thickness around 764 nm. This result may open an opportunity for optoelectronic devices. (paper)

MICROCT AND PREPARATION OF ß-TCP GRANULAR MATERIAL BY THE POLYURETHANE FOAM METHOD

Directory of Open Access Journals (Sweden)

Robert Filmon

2011-05-01

Full Text Available Commercial ß-tricalcium phosphate (ß-TCP is commercialy available in granules manufactured by sintering of powders. We have evaluated the different steps of the manufacturing process of ß-TCP ceramics granules prepared from blocks obtained with the polyurethane foam technology. Three types of slurry were prepared with 10, 15 and 25 g of ß-TCP per gram of polyurethane foam. Analysis was done by scanning electron microscopy, EDX, Raman spectroscopy and microcomputed tomography combined with image analysis. A special algorithm was used to identify the internal microporosity (created by the calcination of the foam from the internal macroporosity due to the spatial repartition of the material. The low ß-TCP dosages readily infiltrated the foam and the slurry was deposited along the polymer rods. On the contrary, the highest concentration produced inhomogeneous infiltrated blocks and foam cavities appeared completely filled in some areas. 2D microcomputed sections and reconstructed 3D models evidenced this phenomenon and the frequency distribution of the thickness and separation of material trabeculae confirmed the heterogeneity of the distribution. When crushed, blocks prepared with the 25 g slurry provided the largest and irregular granulates.

Porous Chromatographic Materials as Substrates for Preparing Synthetic Nuclear Explosion Debris Particles

International Nuclear Information System (INIS)

Harvey, Scott D.; Liezers, Martin; Antolick, Kathryn C.; Garcia, Ben J.; Sweet, Lucas E.; Carman, April J.; Eiden, Gregory C.

2013-01-01

In this study, we investigated several porous chromatographic materials as synthetic substrates for preparing surrogate nuclear explosion debris particles. The resulting synthetic debris materials are of interest for use in developing analytical methods. Eighteen metals, including some of forensic interest, were loaded onto materials by immersing them in metal solutions (556 mg/L of each metal) to fill the pores, applying gentle heat (110°C) to drive off water, and then treating them at high temperatures (up to 800°C) in air to form less soluble metal species. High-boiling-point metals were uniformly loaded on spherical controlled-pore glass to emulate early fallout, whereas low-boiling-point metals were loaded on core-shell silica to represent coated particles formed later in the nuclear fallout-formation process. Analytical studies were applied to characterize solubility, material balance, and formation of recalcitrant species. Dissolution experiments indicated loading was 1.5 to 3 times higher than expected from the pore volume alone, a result attributed to surface coating. Analysis of load solutions before and after filling the material pores revealed that most metals were passively loaded; that is, solutions filled the pores without active metal discrimination. However, niobium and tin concentrations were lower in solutions after pore filling, and were found in elevated concentrations in the final products, indicating some metals were selectively loaded. High-temperature treatments caused reduced solubility of several metal species, and loss of some metals (rhenium and tellurium) because volatile species were formed. Sample preparation reproducibility was high (the inter-batch relative standard deviation was 7.8%, and the intra-batch relative standard deviation was 0.84%) indicating that this material is suitable for use as a working standard for analytical methods development. We anticipate future standardized radionuclide-loaded materials will find use in

Evaluation and additional recommendations for preparing a whole blood control material

Directory of Open Access Journals (Sweden)

Nilda E. Fink

1998-04-01

Full Text Available OBJECTIVE: The assessment of an easy to prepare and low cost control material for Hematology, available for manual and automated methods. MATERIAL AND METHOD: Aliquots of stabilized whole blood were prepared by partial fixation with aldehydes; the stability at different temperatures (4. 20 and 37 °C during periods of up to 8-9 weeks and aliquot variability with both methods were controlled. RESULTS: Aliquot variability with automated methods at day 1, expressed as CV% (coefficient of variation was: white blood cells (WBC 2.7, red blood cells (RBC 0.7, hemoglobin (Hb 0.6, hematocrit (Hct 0.7, mean cell volume (MCV 0.3, mean cell hemoglobin (MCH 0.6, mean cell hemoglobin concentration (MCHC 0.7, and platelets (PLT 4.6. The CV (coefficient of variation percentages obtained with manual methods in one of the batches were: WBC 23, Hct 2.8, Hb 4.5, MCHC 5.9, PLT 41. Samples stored at 4ºC and 20ºC showed good stability, only a very low initial hemolysis being observed, whereas those stored at 37ºC deteriobed a rapidly (metahemoglobin formation, aggregation of WBC and platelets, as well as alteration of erythrocyte indexes. CONCLUSIONS: It was confirmed that, as long as there is no exposure to high temperatures during distribution, this material is stable, allowing assessment, both esternal and internal, for control purposes, with acceptable reproductivity, both for manual and auttomatic methods.

Porous Materials from Thermally Activated Kaolinite: Preparation, Characterization and Application

Directory of Open Access Journals (Sweden)

Jun Luo

2017-06-01

Full Text Available In the present study, porous alumina/silica materials were prepared by selective leaching of silicon/aluminum constituents from thermal-activated kaolinite in inorganic acid or alkali liquor. The correlations between the characteristics of the prepared porous materials and the dissolution properties of activated kaolinite were also investigated. The results show that the specific surface area (SSA of porous alumina/silica increases with silica/alumina dissolution, but without marked change of the BJH pore size. Furthermore, change in pore volume is more dependent on activation temperature. The porous alumina and silica obtained from alkali leaching of kaolinite activated at 1150 °C for 15 min and acid leaching of kaolinite activated at 850 °C for 15 min are mesoporous, with SSAs, BJH pore sizes and pore volumes of 55.8 m2/g and 280.3 m2/g, 6.06 nm and 3.06 nm, 0.1455 mL/g and 0.1945 mL/g, respectively. According to the adsorption tests, porous alumina has superior adsorption capacities for Cu2+, Pb2+ and Cd2+ compared with porous silica and activated carbon. The maximum capacities of porous alumina for Cu2+, Pb2+ and Cd2+ are 134 mg/g, 183 mg/g and 195 mg/g, respectively, at 30 °C.

Preparation and properties of antimony thin film anode materials

Institute of Scientific and Technical Information of China (English)

SU Shufa; CAO Gaoshao; ZHAO Xinbing

2004-01-01

Metallic antimony thin films were deposited by magnetron sputtering and electrodeposition. Electrochemical properties of the thin film as anode materials for lithium-ion batteries were investigated and compared with those of antimony powder. It was found that both magnetron sputtering and electrodeposition are easily controllable processes to deposit antimony films with fiat charge/discharge potential plateaus. The electrochemical performances of antimony thin films, especially those prepared with magnetron sputtering, are better than those of antimony powder. The reversible capacities of the magnetron sputtered antimony thin film are above 400 mA h g-1 in the first 15 cycles.

Selective Preparation of trans-Carveol over Ceria Supported Mesoporous Materials MCM-41 and SBA-15

Directory of Open Access Journals (Sweden)

Nariman F. Salakhutdinov

2013-05-01

Full Text Available Ce-modified mesoporous silica materials MCM-41 and SBA-15, namely 32 wt % Ce–Si–MCM-41, 16 wt % Ce–H–MCM-41 and 20 wt % Ce–Si–SBA-15, were prepared, characterized and studied in the selective preparation of trans-carveol by α-pinene oxide isomerization. The characterizations of these catalysts were performed using scanning electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption and FTIR pyridine adsorption. Selective preparation of trans-carveol was carried out in the liquid phase in a batch reactor. The activity and the selectivity of catalyst were observed to be influenced by their acidity, basicity and morphology of the mesoporous materials. The formation of trans-carveol is moreover strongly influenced by the basicity of the used solvent and in order to achieve high yields of this desired alcohol it is necessary to use polar basic solvent.

Porous chromatographic materials as substrates for preparing synthetic nuclear explosion debris particles

International Nuclear Information System (INIS)

Harvey, S.D.; Carman, A.J.; Martin Liezers; Antolick, K.C.; Garcia, B.J.; Eiden, G.C.; Sweet, L.E.

2013-01-01

Several porous chromatographic materials were investigated as synthetic substrates for preparing surrogate nuclear explosion debris particles. Eighteen metals, including some of forensic interest, were loaded onto materials by immersing them in metal solutions (556 mg/L of each metal) to fill the pores, applying gentle heat (110 deg C) to drive off water, and then treating them at high temperatures (up to 800 deg C) in air to form less soluble metal species. High-boiling-point metals were uniformly loaded on spherical controlled-pore glass to emulate early fallout, whereas low-boiling-point metals were loaded on core-shell silica to represent coated particles formed later in the nuclear fallout-formation process. Analytical studies characterized material balance and the formation of recalcitrant species. Metal loading was 1.5-3 times higher than expected from the pore volume alone, a result attributed to surface coating. Most metals were passively loaded; that is, solutions filled the pores without active metal discrimination. However, niobium and tin concentrations were lower in solutions after pore filling, and were found in elevated concentrations in the final products, indicating selective loading. High-temperature treatments caused reduced solubility of several metals, and the loss of some volatile species (rhenium and tellurium). Sample preparation reproducibility was high (the inter- and intra-batch relative standard deviations were 7.8 and 0.84 %, respectively) indicating suitability for use as a working standard for analytical methods development. We anticipate future standardized radionuclide-loaded materials will find use in radioanalytical methods development and/or serve as a starting material for the synthesis of more complex nuclear explosion debris forms (e.g., Trinitite). (author)

Preparation and characterization of macrocapsules containing microencapsulated PCMs (phase change materials) for thermal energy storage

International Nuclear Information System (INIS)

Han, Pengju; Lu, Lixin; Qiu, Xiaolin; Tang, Yali; Wang, Jun

2015-01-01

This paper was aimed to prepare, characterize and determine the comprehensive evaluation of promising composite macrocapsules containing microencapsulated PCMs (phase change materials) with calcium alginate gels as the matrix material. Macrocapsules containing microcapsules were fabricated by piercing-solidifying incuber method. Two kinds of microcapsules with n-tetradecane as core material, UF (urea-formaldehyde) and PMMA (poly(methyl methacrylate)) respectively as shell materials were prepared initially. For application concerns, thermal durability and mechanical property of macrocapsules were investigated by TGA (thermal gravimetric analysis) and Texture Analyser for the first time, respectively. The results showed excellent thermal stability and the compressive resistance of macrocapsules was sufficient for common application. The morphology and chemical structure of the prepared microcapsules and macrocapsules were characterized by SEM (scanning electron microscopy) and FT-IR (fourier transform infrared) spectroscopy method. Phase change behaviors and thermal durability of microcapsules and macrocapsules were investigated by DSC (differential scanning calorimetry). In order to improve latent heat of composite microcapsules, the core-shell weight ratio of tetradecane/UF shell microcapsules was chosen as 5.5:1 which obtained the phase change enthalpy of 194.1 J g −1 determined by DSC. In conclusion, these properties make it a feasible composite in applications of textile, building and cold-chain transportation. - Highlights: • We improved the phase change enthalpy with a higher core-shell ratio. • Urea-formaldehyde was firstly used as a shell material in the composite. • Mechanical and thermal durability property of the macrocapsules was firstly investigated in our work.

Effect of preparation methods of LiNi1-xCoxO2 cathode materials on their chemical structure and electrode performance

International Nuclear Information System (INIS)

Cho, J.; Kim, G.; Lim, H.S.

1999-01-01

The authors have studied effects of different starting materials on preparation of LiNi 1-x Co x O 2 cathode material for a Li-ion cell where x = 0.1, 0.2, and 0.3, and the electrochemical properties of resulting compounds from two different preparation methods. A preparation method (method B) which uses spherical powder of Ni 1-x Co x (OH) 2 as one of the starting material produced a much superior cathode material than the other method (method A) which uses Ni(OH) 2 and Co(OH) 2 . Method A produced compounds with relatively high degrees of cation mixing which reduces electrochemical utilization (discharge capacity), increases irreversible capacity, and reduces stability on cycling of the cathode material. Method B, in contrast, produced cathode material with a much reduced degree of cation-mixing, thus improving the electrochemical properties. The spherical particle of material prepared by method B has the additional advantage of improved packing density of the electrode with improved volumetric energy density. The ratio of c/a was increased and the electrochemical stability on cycling of the material was improved as the content of Co (value of x) is increased

Prepare of microanalysis reference material for nuclear analysis of Chinese ancient ceramic

International Nuclear Information System (INIS)

Feng Songlin; Xu Qing; Feng Xiangqian; Fan Dongyu; Lei Yong; Cheng Lin

2005-01-01

Some analytic technique can play important role for identifying the provenance and age of ceramic ware. However, it is usually not allowed to destructive analyze for a valuable intact porcelain ware. These analysis methods such as X-ray Fluorescence (XRF), Proton Induced X-ray Emission (PIXE), and Synchrotron Radiation X-ray Fluorescence (SRXRF) are suitable for nondestructive analysis of ancient ceramic wares. In order to compare the analytic data obtained by different measuring method and identify the provenance and age accurately, the effective way is to calibrate elemental concentration in body and glaze of ceramic ware. Microanalysis reference material (MRM) of ancient ceramic has to be prepared for achieving quantitative analysis. A solid powder 99% in size of 500 mesh for microanalysis reference material (MRM) has being prepared in institute of high energy physics. The minimum analytic masses of 1 mg were determined by Neutron Activation Analysis (NAA) for these elements (Sc, Cr, Co, Rb: Cs, La, Ce, Nd, Sm, Tb, Yb, Lu; Hf, Ta, Th, U), and by SRXRF for elements (K, Ca, Ti, Mn, Fe, Zn; Rb, Sr).

Sample preparation techniques of biological material for isotope analysis

International Nuclear Information System (INIS)

Axmann, H.; Sebastianelli, A.; Arrillaga, J.L.

1990-01-01

Sample preparation is an essential step in all isotope-aided experiments but often it is not given enough attention. The methods of sample preparation are very important to obtain reliable and precise analytical data and for further interpretation of results. The size of a sample required for chemical analysis is usually very small (10mg-1500mg). On the other hand the amount of harvested plant material from plots in a field experiment is often bulky (several kilograms) and the entire sample is too large for processing. In addition, while approaching maturity many crops show not only differences in physical consistency but also a non-uniformity in 15 N content among plant parts, requiring a plant fractionation or separation into parts (vegetative and reproductive) e.g. shoots and spikes, in case of small grain cereals, shoots and pods in case of grain legumes and tops and roots or beets (including crown) in case of sugar beet, etc. In any case the ultimate goal of these procedures is to obtain representative subsample harvested from greenhouse or field experiments for chemical analysis. Before harvesting an isotopic-aided experiment the method of sampling has to be selected. It should be based on the type of information required in relation to the objectives of the research and the availability of resources (staff, sample preparation equipment, analytical facilities, chemicals and supplies, etc.). 10 refs, 3 figs, 3 tabs

Ultrafine grained steels processed by equal channel angular pressing

International Nuclear Information System (INIS)

Shin, Dong Hyuk; Park, Kyung-Tae

2005-01-01

Recent development of ultrafine grained (UFG) low carbon steels by using equal channel angular pressing (ECAP) and their room temperature tensile properties are reviewed, focusing on the strategies overcoming their inherent mechanical drawbacks. In addition to ferrite grain refinement, when proper post heat treatments are imposed, carbon atom dissolution from pearlitic cementite during ECAP can be utilized for microstructural modification such as uniform distribution of nano-sized cementite particles or microalloying element carbides inside UFG ferrite grains and fabrication of UFG ferrite/martensite dual phase steel. The utilization of nano-sized particles is effective on improving thermal stability of UFG low carbon ferrite/pearlite steel but less effective on improving its tensile properties. By contrast, UFG ferrite/martensite dual phase steel exhibits an excellent combination of ultrahigh strength, large uniform elongation and extensive strain hardenability

Sampling and sample preparation methods for the analysis of trace elements in biological material

International Nuclear Information System (INIS)

Sansoni, B.; Iyengar, V.

1978-05-01

The authors attempt to give a most systamtic possible treatment of the sample taking and sample preparation of biological material (particularly in human medicine) for trace analysis (e.g. neutron activation analysis, atomic absorption spectrometry). Contamination and loss problems are discussed as well as the manifold problems of the different consistency of solid and liquid biological materials, as well as the stabilization of the sample material. The process of dry and wet ashing is particularly dealt with, where new methods are also described. (RB) [de

Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

KAUST Repository

Bai, Yaocai

2012-06-01

Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different pH conditions. The pH values were found to have great influence on the reduction of graphene oxides. Acidic and neutral media yielded reduced graphene oxides with more oxygen-functional groups, lower specific surface areas but broader pore size distributions than those in basic medium. Variations induced by the pH changes resulted in great differences in the supercapacitor performance. The graphene produced in the basic solution presented mainly electric double layer behavior with specific capacitance of 185 F/g, while the other two showed additional pseudocapacitance behavior with specific capacitance of 225 F/g (acidic) and 230 F/g (neutral), all at a constant current density of 1A/g. The other one is that different reduced graphene oxides were prepared via solution based hydrazine reduction, low temperature thermal reduction, and hydrothermal reduction. The as- prepared samples were then investigated by UV-vis spectroscopy, X-ray diffraction, Raman spectroscopy, and Scanning electron microscope. The supercapacitor performances were also studied and the hydrothermally reduced graphene oxide exhibited the highest specific capacitance.

Preparation of standard hair material and development of analytical methodology

International Nuclear Information System (INIS)

Gangadharan, S.; Walvekar, A.P.; Ali, M.M.; Thantry, S.S.; Verma, R.; Devi, R.

1995-01-01

The concept of the use of human scalp hair as a first level indicator of exposure to inorganic pollutants has been established by us earlier. Efforts towards the preparation of a hair reference material are described. The analytical approaches for the determination of total mercury by cold vapour AAS and INAA and of methylmercury by extraction combined with gas chromatography coupled to an ECD are summarized with results on some of the samples analyzed, including the stability of values over a period of time of storage. (author)

Significant Corrosion Resistance in an Ultrafine-Grained Al6063 Alloy with a Bimodal Grain-Size Distribution through a Self-Anodic Protection Mechanism

Directory of Open Access Journals (Sweden)

Mahdieh Shakoori Oskooie

2016-12-01

Full Text Available The bimodal microstructures of Al6063 consisting of 15, 30, and 45 vol. % coarse-grained (CG bands within the ultrafine-grained (UFG matrix were synthesized via blending of high-energy mechanically milled powders with unmilled powders followed by hot powder extrusion. The corrosion behavior of the bimodal specimens was assessed by means of polarization, steady-state cyclic polarization and impedance tests, whereas their microstructural features and corrosion products were examined using optical microscopy (OM, scanning transmission electron microscopy (STEM, field emission scanning electron microscopy (FE-SEM, electron backscattered diffraction (EBSD, energy dispersive spectroscopy (EDS, and X-ray diffraction (XRD techniques. The bimodal Al6063 containing 15 vol. % CG phase exhibits the highest corrosion resistance among the bimodal microstructures and even superior electrochemical behavior compared with the plain UFG and CG materials in the 3.5% NaCl solution. The enhanced corrosion resistance is attributed to the optimum cathode to anode surface area ratio that gives rise to the formation of an effective galvanic couple between CG areas and the UFG matrix. The operational galvanic coupling leads to the domination of a “self-anodic protection system” on bimodal microstructure and consequently forms a uniform thick protective passive layer over it. In contrast, the 45 vol. % CG bimodal specimen shows the least corrosion resistance due to the catastrophic galvanic corrosion in UFG regions. The observed results for UFG Al6063 suggest that metallurgical tailoring of the grain structure in terms of bimodal microstructures leads to simultaneous enhancement in the electrochemical behavior and mechanical properties of passivable alloys that are usually inversely correlated. The mechanism of self-anodic protection for passivable metals with bimodal microstructures is discussed here for the first time.

Preparation of a Sulfonated Carbonaceous Material from Lignosulfonate and Its Usefulness as an Esterification Catalyst

Directory of Open Access Journals (Sweden)

Duckhee Lee

2013-07-01

Full Text Available Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%–29% after it was exposed to hot water (95 °C for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications.

Nanocasting of Periodic Mesoporous Materials as an Effective Strategy to Prepare Mixed Phases of Titania

Directory of Open Access Journals (Sweden)

Luther Mahoney

2015-12-01

Full Text Available Mesoporous titanium dioxide materials were prepared using a nanocasting technique involving silica SBA-15 as the hard-template. At an optimal loading of titanium precursor, the hexagonal periodic array of pores in SBA-15 was retained. The phases of titanium dioxide could be easily varied by the number of impregnation cycles and the nature of titanium alkoxide employed. Low number of impregnation cycles produced mixed phases of anatase and TiO2(B. The mesoporous TiO2 materials were tested for solar hydrogen production, and the material consisting of 98% anatase and 2% TiO2(B exhibited the highest yield of hydrogen from the photocatalytic splitting of water. The periodicity of the pores was an important factor that influenced the photocatalytic activity. This study indicates that mixed phases of titania containing ordered array of pores can be prepared by using the nanocasting strategy.

Preparation, characterization and certification of uranium isotope reference materials

International Nuclear Information System (INIS)

Oliveira Junior, Olivio Pereira de

2006-01-01

This work describes the preparation, characterization and certification of a set of uranium isotope reference materials ranging from 0.5 to 20.0 % of 235 U in mass. The most important concepts of metrology in chemical measurements were applied so that the certified quantities in these materials could be directly traceable to the International System of Units (SI). As a consequence of this approach, these materials can be used in the instruments calibration, estimation of measurement uncertainty, method validation, assessment of performance of analysts, quality control routines and interlaboratory comparison programmes. The most advanced methods and techniques in mass spectrometry, that is, gas source mass spectrometry (GSMS), thermal ionisation mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICPMS) were investigated to identify which are the dominant components in the uncertainty and to quantify its contribution to the final value of the measurement uncertainty of the isotopic ratio. The results obtained were then compared to verify which are the methods and techniques associated to the lowest measurement uncertainty values. The isotope amount ratio n( 235 U)/n( 238 U) was certified in the materials produced to expanded uncertainties ranging from 0.02 to 0.10 % and the ratios n( 234 U)/n( 238 U) and n( 236 U)/n( 238 U), to uncertainties ranging from 0.03 to 2.20 %. These values fully comply to the requirements of the isotopic characterization of nuclear fuel as well as the analysis of environmental samples for nuclear safeguards. (author)

Preparation and thermal properties characterization of carbonate salt/carbon nanomaterial composite phase change material

International Nuclear Information System (INIS)

Tao, Y.B.; Lin, C.H.; He, Y.L.

2015-01-01

Highlights: • Nanocomposite phase change materials were prepared and characterized. • Larger specific surface area is more efficient to enhance specific heat. • Columnar structure is more efficient to enhance thermal conductivity. • Thermal conductivity enhancement is the key. • Single walled carbon nanotube is the optimal nanomaterial additive. - Abstract: To enhance the performance of high temperature salt phase change material, four kinds of carbon nanomaterials with different microstructures were mixed into binary carbonate eutectic salts to prepare carbonate salt/nanomaterial composite phase change material. The microstructures of the nanomaterial and composite phase change material were characterized by scanning electron microscope. The thermal properties such as melting point, melting enthalpy, specific heat, thermal conductivity and total thermal energy storage capacity were characterized. The results show that the nanomaterial microstructure has great effects on composite phase change material thermal properties. The sheet structure Graphene is the best additive to enhance specific heat, which could be enhanced up to 18.57%. The single walled carbon nanotube with columnar structure is the best additive to enhance thermal conductivity, which could be enhanced up to 56.98%. Melting point increases but melting enthalpy decreases with nanomaterial specific surface area increase. Although the additives decrease the melting enthalpy of composite phase change material, they also enhance the specific heat. As a combined result, the additives have little effects on thermal energy storage capacity. So, for phase change material performance enhancement, more emphasis should be placed on thermal conductivity enhancement and single walled carbon nanotube is the optimal nanomaterial additive

Improvements in or relating to method of preparing porous material/synthetic polymer composites

International Nuclear Information System (INIS)

Hills, P.R.; McGahan, D.J.

1976-01-01

A method for preparing a composite material is described comprising polymerising a monoethylenically unsaturated monomer of a mixture of copolymerisable monoethylenically unsaturated monomers in a porous material, excluding a porous natural cellulosic fibre material, the polymerisable liquid being admixed in the porous material with a saturated aliphatic hydrocarbon or a halogen derivative thereof. It is preferable that the polymerisable liquid and the hydrocarbon or halogen derivative are present in the porous material. Impregnation may be carried out by a vacuum technique or by simple immersion. The monomers that may be used are listed, but a mixture of styrene and acrylonitrile is preferred in the proportions 60 : 40 by volume. Polymerisation may be effected by irradiation, preferably with 60 Co γ-radiation. Suitable porous materials include concrete, stone, and fibreboard. If concrete is used the composite material may be used for pressure pipes and other articles normally made of steel. Examples of the application of the process are given. (U.K.)

Preparation and Characterization of Carbon Nano tube-based Electrochromic Material

International Nuclear Information System (INIS)

Muhammad Shahazmi Mohd Zambri; Norani Muti Mohamed; Kait, C.F.

2011-01-01

Electrochromic materials that can change their optical properties reversibly for an applied potential due to electrochemical oxidation and reduction have been used in various applications of electrochromic windows or smart glass. Conducting polymer like poly aniline (PANI) is one of the most promising electrochromic materials because of its ease of synthesis and environmental stability. However, the electrochemically deposited poly aniline exhibit substantial resistivity which is attributed to the lack of conducting pathways at the nano scale associated with random deposition morphology. This paper describes the study in developing electrochromic material that will exhibit higher conductivity by using carbon nano tubes (CNTs) as the filler. Preparation of electrochromic material on ITO and FTO glass substrate was done by electrochemical process using mixture of CNTs and PANI in H 2 SO 4 at several loading of CNTs, voltage applied and duration of the process. PANI and PANI/ CNTs films produced were then characterized using SEM and Hall Effect measurement. From the study, highly conductive PANI/ CNTs film can be obtained by using optimum condition of the process parameters. PANI film deposited on FTO glass substrate was also found to be of good quality with conductivity two orders of magnitude higher than the film deposited on ITO glass substrate. (author)

Method of preparation of carbon materials for use as electrodes in rechargeable batteries

Science.gov (United States)

Doddapaneni, Narayan; Wang, James C. F.; Crocker, Robert W.; Ingersoll, David; Firsich, David W.

1999-01-01

A method of producing carbon materials for use as electrodes in rechargeable batteries. Electrodes prepared from these carbon materials exhibit intercalation efficiencies of .apprxeq.80% for lithium, low irreversible loss of lithium, long cycle life, are capable of sustaining a high rates of discharge and are cheap and easy to manufacture. The method comprises a novel two-step stabilization process in which polymeric precursor materials are stabilized by first heating in an inert atmosphere and subsequently heating in air. During the stabilization process, the polymeric precursor material can be agitated to reduce particle fusion and promote mass transfer of oxygen and water vapor. The stabilized, polymeric precursor materials can then be converted to a synthetic carbon, suitable for fabricating electrodes for use in rechargeable batteries, by heating to a high temperature in a flowing inert atmosphere.

Preparation of a porous Sn@C nanocomposite as a high-performance anode material for lithium-ion batteries

Science.gov (United States)

Zhang, Yanjun; Jiang, Li; Wang, Chunru

2015-07-01

A porous Sn@C nanocomposite was prepared via a facile hydrothermal method combined with a simple post-calcination process, using stannous octoate as the Sn source and glucose as the C source. The as-prepared Sn@C nanocomposite exhibited excellent electrochemical behavior with a high reversible capacity, long cycle life and good rate capability when used as an anode material for lithium ion batteries.A porous Sn@C nanocomposite was prepared via a facile hydrothermal method combined with a simple post-calcination process, using stannous octoate as the Sn source and glucose as the C source. The as-prepared Sn@C nanocomposite exhibited excellent electrochemical behavior with a high reversible capacity, long cycle life and good rate capability when used as an anode material for lithium ion batteries. Electronic supplementary information (ESI) available: Detailed experimental procedure and additional characterization, including a Raman spectrum, TGA curve, N2 adsorption-desorption isotherm, TEM images and SEM images. See DOI: 10.1039/c5nr03093e

Preparation and Characterization of Biomass-Derived Advanced Carbon Materials for Lithium-Ion Battery Applications

Science.gov (United States)

Hardiansyah, Andri; Chaldun, Elsy Rahimi; Nuryadin, Bebeh Wahid; Fikriyyah, Anti Khoerul; Subhan, Achmad; Ghozali, Muhammad; Purwasasmita, Bambang Sunendar

2018-07-01

In this study, carbon-based advanced materials for lithium-ion battery applications were prepared by using soybean waste-based biomass material, through a straightforward process of heat treatment followed by chemical modification processes. Various types of carbon-based advanced materials were developed. Physicochemical characteristics and electrochemical performance of the resultant materials were characterized systematically. Scanning electron microscopy observation revealed that the activated carbon and graphene exhibits wrinkles structures and porous morphology. Electrochemical impedance spectroscopy (EIS) revealed that both activated carbon and graphene-based material exhibited a good conductivity. For instance, the graphene-based material exhibited equivalent series resistance value of 25.9 Ω as measured by EIS. The graphene-based material also exhibited good reversibility and cyclic performance. Eventually, it would be anticipated that the utilization of soybean waste-based biomass material, which is conforming to the principles of green materials, could revolutionize the development of advanced material for high-performance energy storage applications, especially for lithium-ion batteries application.

Preparation of sintered foam materials by alkali-activated coal fly ash.

Science.gov (United States)

Zhao, Yelong; Ye, Junwei; Lu, Xiaobin; Liu, Mangang; Lin, Yuan; Gong, Weitao; Ning, Guiling

2010-02-15

Coal fly ash from coal fired power stations is a potential raw material for the production of ceramic tiles, bricks and blocks. Previous works have demonstrated that coal fly ash consists mainly of glassy spheres that are relatively resistant to reaction. An objective of this research was to investigate the effect of alkali on the preparation process of the foam material. Moreover, the influence of foam dosage on the water absorption, apparent density and compressive strength was evaluated. The experimental results showed that homogenous microstructures of interconnected pores could be obtained by adding 13 wt.% foaming agent at 1050 degrees C, leading to foams presenting water absorption, apparent density and compressive strength values of about 126.5%, 0.414 g/cm(3), 6.76 MPa, respectively.

The preparation and analysis of minerals for use as reference material

International Nuclear Information System (INIS)

Stoch, H.

1976-01-01

This report covers the progress made in the collection of the material for reference samples, and the five interlaboratory analytical programmes (ferrochromium slags, fluorspar, 'mixed' NIMROC samples, rare earths, and ferromanganese slags). The description of the internal analytical programme has been subdivided into eight main categories, and a comprehensive list of evaluated results covering a wide range of materials is included. Additional results for thorium, rare earths, tin, tantalum, and niobium for the appropriate reference samples are included in updated tables. The main purpose in the preparation of these samples is to provide control samples for analytical work at the National Institute for Metallurgy. Where there is a special need, limited quantities of the samples can be made available to other laboratories

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

Science.gov (United States)

Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

Unified Facilities Criteria (UFC) Design Guide. Army Reserve Facilities

Science.gov (United States)

2010-02-01

horticulturally appropriate to the site specific location in which they are planted. Consideration should be given to adjacent structures and improvements...impact FPI Federal Prison Industries FPM Feet per minute GFCI Government-furnished/contractor-installed or Ground-Fault Circuit Interrupter GFGI...Uniform Federal Accessibility Standards UFGs Unified Facility Guide Specifications UFGs Rst UFGS - Reserve Support Team UnICoR Federal Prison Industry

Nitrogen-doped hierarchical porous carbon materials prepared from meta-aminophenol formaldehyde resin for supercapacitor with high rate performance

International Nuclear Information System (INIS)

Zhou, Jin; Zhang, Zhongshen; Xing, Wei; Yu, Jing; Han, Guoxing; Si, Weijiang; Zhuo, Shuping

2015-01-01

Graphical abstract: N-doped hierarchical porous carbons with high rate capacitive performance are prepared by a combination method of nano-SiO 2 template/KOH activation. - Highlights: • A mass produced nano-SiO 2 is used to prepared hierarchical porous carbon. • N-doped hierarchical porous carbon materials are easily prepared. • The NHPCs materials exhibit a very high capacitance of up to 260.5 F g −1 . • The NHPC-800 sample shows very high rate capability. • Hierarchical porosity and N-doping synergistically enhances the whole capacitance. - Abstract: In this work, nitrogen-doped hierarchical porous carbon materials (NHPCs) are prepared by a two-step method combined of a hard template process and KOH-activation treatment. Low cost and large-scale commercial nano-SiO 2 are used as a hard template. The hierarchical porosity, structure and nitrogen-doped surface chemical properties are proved by a varies of means, such as scanning electron microscopy, transition electron microscopy, N 2 sorption, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. When the prepared NHPCs materials are used as the electrode materials for supercapacitors in KOH electrolyte, they exhibit very high specific capacitance, good power capability and excellent cyclic stability. NHPC-800 carbon shows a high capacitance of 114.0 F g −1 at the current density of 40 A g −1 , responding to a high energy and power densities of 4.0 Wh kg −1 and 10 000 W kg −1 , and a very short drain time of 1.4 s. The excellent capacitive performance may be due to the synergistic effect of the hierarchical porosity, high effective surface area and heteroatom doping, resulting in both electrochemical double layer and Faradaic capacitance contributions

Preparation process and properties of LiCoO{sub 2}/PANI/dodecylbenzenesulfonate composite electrode materials

Energy Technology Data Exchange (ETDEWEB)

Ferchichi, Karima, E-mail: ferchichikarima1@gmail.com [UR Physico-Chimie des Matériaux Solides, Faculté des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Hbaieb, Souhaira, E-mail: souhaira.bouchaira@gmail.com [UR Physico-Chimie des Matériaux Solides, Faculté des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Amdouni, Noureddine, E-mail: nouredin.amdouni@fst.rnu.tn [UR Physico-Chimie des Matériaux Solides, Faculté des Sciences de Tunis, Manar II, 2092 Tunis (Tunisia); Kalfat, Rafik, E-mail: rafik.kalfat@gmail.com [Institut National de Recherche et d' Analyse Physico-Chimique, 2020 Sidi Thabet (Tunisia); Chevalier, Yves, E-mail: chevalier@lagep.univ-lyon1.fr [Laboratoire d' Automatique et de Génie des Procédés (LAGEP), CNRS UMR 5007, Université Claude Bernard Lyon 1, 69622 Villeurbanne (France)

2013-10-01

Composite materials that combine the lithium exchanging material LiCoO{sub 2} and the conductive polymer poly(aniline) (PANI) have been investigated regarding their possible application to electrode materials of lithium batteries. Such composite materials have been prepared by means of polymerization of aniline in acidic suspensions of LiCoO{sub 2} particles. PANI was synthesized by oxidative polymerization of aniline by ammonium persulfate in the presence of sodium dodecylbenzenesulfonate (SDBS) as a micellar template and dopant. The composite material consisted in LiCoO{sub 2} particles dispersed in a continuous matrix of PANI. The ribbon-like morphology of the powdered material was distinctly different of the morphologies of the parent materials. The conductive material had conductivity close to that of PANI because the LiCoO{sub 2} content of the composite material was low. The presence of the poorly conductive inorganic phase caused a significant loss of conductivity, showing that LiCoO{sub 2} blocked electronic transfers between PANI crystallites. Ammonium persulfate caused the loss of lithium from LiCoO{sub 2} when it was used at high concentration in the polymerization recipe. In this case a new phase made of Co{sub 3}O{sub 4} formed by chemical decomposition of Li{sub x}CoO{sub 2}. Thin films prepared from stable suspensions of composite materials in water show comparable electrical performance to that measured for bulk materials. - Highlights: • LiCoO{sub 2} was incorporated in a conductive polymer matrix made of PANI. • The hybrid material retained the high conductive properties of PANI. • Loss of lithium by persulfate oxidation caused conversion of LiCoO{sub 2} into Co{sub 3}O{sub 4}.

Characterization of a wollastonite glass-ceramic material prepared using sugar cane bagasse ash (SCBA) as one of the raw materials

Energy Technology Data Exchange (ETDEWEB)

Teixeira, Silvio R., E-mail: rainho@fct.unesp.br [Universidade Estadual Paulista — UNESP, Faculdade de Ciências e Tecnologia — FCT, 19060-900 Presidente Prudente — SP (Brazil); Souza, Agda E. [Universidade Estadual Paulista — UNESP, Faculdade de Ciências e Tecnologia — FCT, 19060-900 Presidente Prudente — SP (Brazil); Carvalho, Claudio L.; Reynoso, Victor C.S. [Universidade Estadual Paulista — UNESP, Faculdade de Engenharia de Ilha Solteira — FEIS, 15385-000 Ilha Solteira – SP (Brazil); Romero, Maximina; Rincón, Jesús Ma. [Instituto de Ciencias de la Construccion Eduardo Torroja — IETCC, CSIC, 28033 Madrid (Spain)

2014-12-15

Glass-ceramic material prepared with sugar cane bagasse ash as one of the raw materials was characterized to determine some important properties for its application as a coating material. X-ray diffraction patterns showed that wollastonite-2M (CaSiO{sub 3}) was the major glass-ceramic phase. The Rietveld method was used to quantify the crystalline (60 wt.%) and vitreous (40 wt.%) phases in the glass-ceramic. The microstructure (determined by scanning electron microscopy) of this material had a marble appearance, showing a microporous network of elongated crystals with some areas with dendritic, feather-like ordering. Microhardness data gave a mean hardness value of 564.4 HV (Vickers-hardness), and light microscopy disclosed a greenish brown colored material with a vitreous luster. - Highlights: • We studied the properties of a glass-ceramic material obtained from sugarcane ash. • This material has the appearance and hardness of natural stones. • A refining method gave information about its amorphous and crystalline phases. • This material has potential to be used as coating plates for buildings.

Characterization of a wollastonite glass-ceramic material prepared using sugar cane bagasse ash (SCBA) as one of the raw materials

International Nuclear Information System (INIS)

Teixeira, Silvio R.; Souza, Agda E.; Carvalho, Claudio L.; Reynoso, Victor C.S.; Romero, Maximina; Rincón, Jesús Ma.

2014-01-01

Glass-ceramic material prepared with sugar cane bagasse ash as one of the raw materials was characterized to determine some important properties for its application as a coating material. X-ray diffraction patterns showed that wollastonite-2M (CaSiO 3 ) was the major glass-ceramic phase. The Rietveld method was used to quantify the crystalline (60 wt.%) and vitreous (40 wt.%) phases in the glass-ceramic. The microstructure (determined by scanning electron microscopy) of this material had a marble appearance, showing a microporous network of elongated crystals with some areas with dendritic, feather-like ordering. Microhardness data gave a mean hardness value of 564.4 HV (Vickers-hardness), and light microscopy disclosed a greenish brown colored material with a vitreous luster. - Highlights: • We studied the properties of a glass-ceramic material obtained from sugarcane ash. • This material has the appearance and hardness of natural stones. • A refining method gave information about its amorphous and crystalline phases. • This material has potential to be used as coating plates for buildings

The preparation and certification of a South African phosphate concentrate for use as a reference material

International Nuclear Information System (INIS)

Hansen, R.G.

1985-01-01

This report describes the preparation, analysis, and certification of South African Reference Material (SARM) 32. The material is a phosphate concentrate from the Phalaborwa deposit, and was supplied by the Phosphate Development Corporation Ltd (Foskor). Eighteen laboratories in eight countries used a variety of analytical techniques to provide the analytical results

A survey of collection development for United States Medical Licensing Examination (USMLE) and National Board Dental Examination (NBDE) preparation material.

Science.gov (United States)

Hendrix, Dean; Hasman, Linda

2008-07-01

The research sought to ascertain medical and dental libraries' collection development policies, evaluation methods, purchase decisions, and issues that relate to print and electronic United States Medical Licensing Examination (USMLE) and National Board Dental Examination (NBDE) preparation materials. The investigators surveyed librarians supporting American Association of Medical Colleges (AAMC)-accredited medical schools (n = 58/125) on the USMLE and librarians supporting American Dental Association (ADA)-accredited dental schools (n = 23/56) on the NBDE. The investigators analyzed the data by cross-tabulating and filtering the results using EFM Continuum web survey software. Investigators also surveyed print and electronic USMLE and NBDE preparation materials from 2004-2007 to determine the number of publications and existence of reviews. A majority of responding AAMC libraries (62%, n = 58) provide at least 1 electronic or online USMLE preparation resource and buy an average of 11.6 print USMLE titles annually. Due to a paucity of NBDE print and electronic resources, ADA libraries bought significantly fewer print resources, and only 1 subscribed to an electronic resource. The most often reported evaluation methods for both populations were feedback from medical or dental students, feedback from medical or dental faculty, and online trials. Some AAMC (10%, n = 58) and ADA libraries (39%, n = 23) libraries reported that no evaluation of these materials occured at their libraries. From 2004-2007, publishers produced 45 USMLE preparation resources (total n = 546) to every 1 NBDE preparation resource (total n = 12). Users' needs, institutional missions and goals, financial status, and official collection policies most often underlie decisions to collect or not collect examination preparation materials. Evaluating the quality of examination preparation materials can be problematic due to lack of published reviews, lack of usability testing by libraries, and

Preparation of thermo-sensitive slow releasing material and its application in low tar tobacco

Directory of Open Access Journals (Sweden)

Tian Zhong

2017-04-01

Full Text Available To solve some sensory defects such as fragrance deficiency,strong dry sense,poor satisfaction in the development of ultra-low tar tobacco products,we prepared a new thermo sensitive slow releasing composite material with tobacco aroma.The characterization results showed that the as-prepared thermosensitive particles have better aroma enhancing and slow releasing effects.Also,the aroma components of the tip stick containing thermosensitive particles were detected and its sensory quality was evaluated.The results showed that composite tip stick could enhance the aroma and improve the sensory quality of the cigarettes.

Preparation and characterization of nanostructured MWCNT-TiO2 composite materials for photocatalytic water treatment applications

International Nuclear Information System (INIS)

Wang Wendong; Serp, Philippe; Kalck, Philippe; Silva, Claudia Gomes; Faria, Joaquim Luis

2008-01-01

Nanoscale composite materials containing multi-walled carbon nanotubes (MWCNT) and titania were prepared by using a modified sol-gel method. The composites were comprehensively characterized by thermogravimetric analysis, nitrogen adsorption-desorption isotherm, powder X-ray diffraction, scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectroscopy. The analysis revealed the presence of titania crystallites of about 7.5 nm aggregated together with MWCNT in particles of 15-20 nm of diameter. The photoactivity of the prepared materials, under UV or visible irradiation, was tested using the conversion of phenol from model aqueous solutions as probe reaction. A synergy effect on the photocatalytic activities observed for the composite catalysts was discussed in terms of a strong interphase interaction between carbon and TiO 2 phases by comparing the different roles of MWCNT in the composite materials

Preparation and Performance of Poly(butyl fumarate-Based Material for Potential Application in LED Encapsulation

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Liang Wang

2017-02-01

Full Text Available A UV-curable poly(butyl fumarate (PBF/poly(propylene fumarate-diacrylate (PPF-DA hybrid material with good performance for LED encapsulation is introduced in the paper. They have been prepared by radical polymerization using PBF and PPF-DA macromers with a UV curing system. PBF and PPF-DA were characterized by Fourier-transform infrared (FT-IR and H-nuclear magnetic resonance (1H NMR. The thermal behavior, optical and mechanical properties of the material were examined by thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, ultraviolet-visible spectroscopy (UV–vis, and a material testing system mechanical testing machine, respectively. The results indicated that the hybrid material has a suitable refractive index (n = 1.537 and high transmittance (99.64% in visible range before/after thermal aging. With the increasing of the double bond ratio from 0.5 to 2, the water absorption ratios of the prepared encapsulation material were 1.22%, 1.87% and 2.88%, respectively. The mechanical property experiments showed that bonding strength was in the range of 1.86–3.40 MPa, tensile-shear strength ranged from 0.84 MPa to 1.57 MPa, and compression strength was in the range of 5.10–27.65 MPa. The cured PBF/PPF-DA hybrid material can be used as a light-emitting diode (LED encapsulant, owing to its suitable refractive index, high transparency, excellent thermal stability, lower water absorption, and good mechanical properties.

Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

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Wenning Shen

Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

Constitutive modeling of strain rate effects in nanocrystalline and ultrafine grained polycrystals

KAUST Repository

Gurses, Ercan

2011-05-01

We present a variational two-phase constitutive model capable of capturing the enhanced rate sensitivity in nanocrystalline (nc) and ultrafine-grained (ufg) fcc metals. The nc/ufg-material consists of a grain interior phase and a grain boundary affected zone (GBAZ). The behavior of the GBAZ is described by a rate-dependent isotropic porous plasticity model, whereas a rate-independent crystal-plasticity model which accounts for the transition from partial dislocation to full dislocation mediated plasticity is employed for the grain interior. The scale bridging from a single grain to a polycrystal is done by a Taylor-type homogenization. It is shown that the enhanced rate sensitivity caused by the grain size refinement is successfully captured by the proposed model. © 2011 Elsevier Ltd. All rights reserved.

Constitutive modeling of strain rate effects in nanocrystalline and ultrafine grained polycrystals

KAUST Repository

Gurses, Ercan; El Sayed, Tamer S.

2011-01-01

We present a variational two-phase constitutive model capable of capturing the enhanced rate sensitivity in nanocrystalline (nc) and ultrafine-grained (ufg) fcc metals. The nc/ufg-material consists of a grain interior phase and a grain boundary affected zone (GBAZ). The behavior of the GBAZ is described by a rate-dependent isotropic porous plasticity model, whereas a rate-independent crystal-plasticity model which accounts for the transition from partial dislocation to full dislocation mediated plasticity is employed for the grain interior. The scale bridging from a single grain to a polycrystal is done by a Taylor-type homogenization. It is shown that the enhanced rate sensitivity caused by the grain size refinement is successfully captured by the proposed model. © 2011 Elsevier Ltd. All rights reserved.

Effect of sintering conditions on the microstructural and mechanical characteristics of porous magnesium materials prepared by powder metallurgy.

Science.gov (United States)

Čapek, Jaroslav; Vojtěch, Dalibor

2014-02-01

There has recently been an increased demand for porous magnesium materials in many applications, especially in the medical field. Powder metallurgy appears to be a promising approach for the preparation of such materials. Many works have dealt with the preparation of porous magnesium; however, the effect of sintering conditions on material properties has rarely been investigated. In this work, we investigated porous magnesium samples that were prepared by powder metallurgy using ammonium bicarbonate spacer particles. The effects of the purity of the argon atmosphere and sintering time on the microstructure (SEM, EDX and XRD) and mechanical behaviour (universal loading machine and Vickers hardness tester) of porous magnesium were studied. The porosities of the prepared samples ranged from 24 to 29 vol.% depending on the sintering conditions. The purity of atmosphere played a significant role when the sintering time exceeded 6h. Under a gettered argon atmosphere, a prolonged sintering time enhanced diffusion connections between magnesium particles and improved the mechanical properties of the samples, whereas under a technical argon atmosphere, oxidation at the particle surfaces caused deterioration in the mechanical properties of the samples. These results suggest that a refined atmosphere is required to improve the mechanical properties of porous magnesium. © 2013.

Bulk-scaffolded hydrogen storage and releasing materials and methods for preparing and using same

Science.gov (United States)

Autrey, S Thomas [West Richland, WA; Karkamkar, Abhijeet J [Richland, WA; Gutowska, Anna [Richland, WA; Li, Liyu [Richland, WA; Li, Xiaohong S [Richland, WA; Shin, Yongsoon [Richland, WA

2011-06-21

Compositions are disclosed for storing and releasing hydrogen and methods for preparing and using same. These hydrogen storage and releasing materials exhibit fast release rates at low release temperatures without unwanted side reactions, thus preserving desired levels of purity and enabling applications in combustion and fuel cell applications.

Preparation of Al/Si functionally graded materials using ultrasonic separation method

Directory of Open Access Journals (Sweden)

Zhang Zhongtao

2008-08-01

Full Text Available Functionally graded materials (FGM have been widely used in many industries such as aerospace, energy and electronics. In this experimental study of fabricating FGM, an approach was developed to prepare Al/Si FGM using power ultrasonic separation method. Material sample with continuously changing composition and performance/properties was successfully produced. Results showed that the microstructure of the FGM sample transited, from its top to bottom, from the hypereutectic structure with a large quantity of primary Si gradually to the eutectic, and fi nally to the hypoeutectic with numerous primary Al dendrites. The distribution of primary Si and microhardness of the FGM sample also presented graded characteristics, resulting that the wear resistance of the FGM sample decreased from top to bottom. Preliminary discussion was made on the mechanism of the formation of Al/Si FGM.

Dynamic restoration of severely predeformed, ultrafine-grained pure Cu at 373 K observed in situ

Czech Academy of Sciences Publication Activity Database

Král, Petr; Blum, W.; Dvořák, Jiří; Eisenlohr, P.; Petrenec, M.; Sklenička, Václav

2017-01-01

Roč. 134, DEC (2017), s. 329-334 ISSN 1044-5803 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : ECAP * Dynamic grain coarsening * UFG copper * In situ Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 2.714, year: 2016

Fatigue properties of ultra-fine grain Cu–Cr alloy processed by equal-channel angular pressing

International Nuclear Information System (INIS)

Wang, Q.J.; Du, Z.Z.; Luo, L.; Wang, W.

2012-01-01

Highlights: ► The UFG Cu–Cr alloys processed by ECAP possess high strength and sufficient ductility. ► The ECAPed sample with UFG under strain controlled fatigue exhibited cyclic softening and lower fatigue limit compared to the unECAPed one. ► That cyclic softening of UFG Cu–Cr alloy is associated with some dislocation annihilation and the substructure recovery. ► Shear bands, microcracks and final fracture of UFG Cu–Cr fatigue samples occur predominantly along the shear plane corresponding to the last ECAP. - Abstract: A precipitation-hardening copper based alloy (Cu–0.6 wt.% Cr) was selected and the ultra-fine grain (UFG) microstructure was obtained by equal channel angular pressing (ECAP). The alloys tensile behaviors and fatigue properties were investigated experimentally, the results indicated that the Cu–Cr alloy processed by ECAP possessed high strength and sufficient ductility and the 12-passes ECAPed sample with UFG under strain controlled fatigue exhibited cyclic softening and lower fatigue limit compared to the unECAPed one. Moreover, the shear bands on the surface of cycled samples were also studied by scanning electron microscopy, the results showed that the oriented distribution of defects along the shear plane in the last ECAP processing was one of the major mechanisms of SBs formation.

The application of prepared porous carbon materials: Effect of different components on the heavy metal adsorption.

Science.gov (United States)

Song, Min; Wei, Yuexing; Yu, Lei; Tang, Xinhong

2016-06-01

In this study, five typical municipal solid waste (MSW) components (tyres, cardboard, polyvinyl chloride (PVC), acrylic textile, toilet paper) were used as raw materials to prepare four kinds of MSW-based carbon materials (paperboard-based carbon materials (AC1); the tyres and paperboard-based carbon materials (AC2); the tyres, paperboard and PVC-based carbon materials (AC3); the tyres, paperboard, toilet paper, PVC and acrylic textile-based carbon materials (AC4)) by the KOH activation method. The characteristic results illustrate that the prepared carbon adsorbents exhibited a large pore volume, high surface area and sufficient oxygen functional groups. Furthermore, the application of AC1, AC2, AC3, AC4 on different heavy metal (Cu(2+), Zn(2+), Pb(2+), Cr(3+)) removals was explored to investigate their adsorption properties. The effects of reaction time, pH, temperature and adsorbent dosage on the adsorption capability of heavy metals were investigated. Comparisons of heavy metal adsorption on carbon of different components were carried out. Among the four samples, AC1 exhibits the highest adsorption capacity for Cu(2+); the highest adsorption capacities of Pb(2+) and Zn(2+) are obtained for AC2; that of Cr(3+) are obtained for AC4. In addition, the carbon materials exhibit better adsorption capability of Cu(2+) and Pb(2+) than the other two kind of metal ions (Zn(2+) and Cr(3+)). © The Author(s) 2016.

Preparation of thermoluminescent materials

International Nuclear Information System (INIS)

1976-01-01

Thermoluminescent materials have been found to be suitable for measuring long term exposures to low level ionizing radiation. Oxyhalides of lanthanum, gadolinium and yttrium, including the oxychlorides and oxybromides are activated with terbium and have been found to be most efficient oxygendominated phosphors having thermoradiant efficiencies with excitation by low level ionizing radiation. Thermoluminescence response increases when the previous materials have hafnium and zirconium additives

Development of resistance welding process. 4. Preparation of pressuring enclosed creep test specimen of 7A material

International Nuclear Information System (INIS)

Endo, Hideo; Seki, Masayuki; Ishibashi, Fujio; Hirako, Kazuhito; Tsukada, Tatsuya

2001-02-01

Mechanical strength in the position welded by resistance welding system was examined in 1999. The test specimens were destroyed in the welding position in a shorter time than expected in the creep test. Therefore, test specimens were prepared to evaluate the cause of destruction. Inner-pressure enclosed creep test specimens were prepared by resistance welding method. Cladding material with low deviation of thickness and high re-crystallization rate was used. Heat treatment after resistance welding was performed to remove the influence of residual stress and the precipitation of carbides. (1) Before preparation of specimens, the welding condition was fixed. Three test specimens were prepared. Two specimens without heat treatment were transported to MMS in Oarai Engineering Center on Aug. 4, 2000. One specimen with heat treatment was transported to MMS after evaluating the residual stress to get optimum heat treatment condition. (2) Specimens were prepared with welding end plugs to both ends of ferritic ODS cladding. Enclosing sides were welded with highly strong Ferritic/Martensitic steel end plugs. The other sides were welded with ferritic ODS end plugs. (3) Some kinds of electrical wave data were obtained during performing welding. Welding position was evaluated with supersonic detector after performing welding. (4) Mechanical strength of welding position in high temperature 800degC was confirmed to be equal to or larger than that of cladding material. The highly qualified specimens in the present were successfully prepared. (author)

Preparation and Characterization of Lignin-based Membrane Material

Directory of Open Access Journals (Sweden)

Shuai Wang

2015-07-01

Full Text Available Lignin-based membrane material was prepared from lignosulfonate extracted from sulfite pulping. The effects of formaldehyde, polyvinyl alcohol (PVA, urea, borax, glutaraldehyde (GD, and dimethyl phthalate (DMP on tensile strength and water absorption were investigated. The experimental results showed that the optimum conditions were as follows: a reaction temperature of 85 °C, 22.22 wt.% lignosulfonate, 1.59 wt.% borax, 22.22 wt.% urea, 31.75 wt.% formaldehyde, 22.22 wt.% PVA, 32.32 wt.% GD (to PVA glue, and 32.32 wt.% DMP (to PVA glue. Under these conditions, the tensile strength reached 2.2 ×104 Pa and the water absorption was 35.2%. The products were characterized by Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. The results showed that the product components were compatible in this system, and the introduction of cross-linking agents may have resulted in a decrease in pore size.

Quality assessment of organic coffee beans for the preparation of a candidate reference material

International Nuclear Information System (INIS)

Tagliaferro, F.S.; Nadai Fernandes de, E.A.; Bacchi, M.A.

2006-01-01

A random sampling was carried out in the coffee beans collected for the preparation of the organic green coffee reference material in view of assessing the homogeneity and the presence of soil as impurity. Fifteen samples were taken for the between-sample homogeneity evaluation. One of the samples was selected and 10 test portions withdrawn for the within-sample homogeneity evaluation. Br, Ca, Co, Cs, Fe, K, Na, Rb, Sc and Zn were determined by instrumental neutron activation analysis (INAA). The F-test demonstrated that the material is homogeneous for Ca, Co, Cs, K and Sc, but not homogeneous for Br, Fe, Na, Rb and Zn. Results of terrigenous elements suggested negligible soil contamination in the raw material. (author)

Reliability of Scores Obtained from Self-, Peer-, and Teacher-Assessments on Teaching Materials Prepared by Teacher Candidates

Science.gov (United States)

Nalbantoglu Yilmaz, Funda

2017-01-01

This study aims to determine the reliability of scores obtained from self-, peer-, and teacher-assessments in terms of teaching materials prepared by teacher candidates. The study group of this research constitutes 56 teacher candidates. In the scope of research, teacher candidates were asked to develop teaching material related to their study.…

Influence of interface preparation on minority carrier lifetime for low bandgap tandem solar cell materials

Energy Technology Data Exchange (ETDEWEB)

Szabo, Nadine; Sagol, B. Erol; Seidel, Ulf; Schwarzburg, Klaus; Hannappel, Thomas [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

2010-07-01

III-V semiconductor compounds grown by MOVPE are implemented in todays state-of-the-art third generation multi-junction solar cells. The current record multi junction solar cell grown on germanium, having Ge, Ga(In)As and GaInP as subcells, reached a record efficiency of 41.6%. The efficiency of these multi junction solar cells could be significantly increased, if its low bandgap Ge subcell would be replaced by a more efficient tandem. For this purpose the low bandgap materials InGaAs and InGaAsP are suitable. The bandgap composition of these materials allows a better yield of the solar spectrum. Based on InGaAs/InGaAsP absorber materials we have developed a low bandgap tandem solar cell with optimized bandgaps. Results of time resolved photoluminescence (TRPL) for the IR-bandgap compounds InGaAsP (1.03 eV)/InGaAs (0.73 eV) are presented. The lifetime of minority carriers is one of the most important properties of solar cell absorber materials. We show on the example of the low band gap tandem cell how the choice of the materials, the quality of the bulk, the optimization of the band gap energies and the preparation of the critical interfaces are essential to build a high efficiency solar cell. The quality of the bulk and the preparation of the critical interfaces are essential for the growth of the double heterostructure (DHS).

Preparation of reference material for organochlorine pesticides in a herbal matrix.

Science.gov (United States)

Wong, Yiu Chung; Wong, Siu Kay; Kam, Tat Ting

2008-12-01

The development of reference material for four organochlorine pesticides, namely hexachlorobenzene and three isomers of hexachlorocyclohexane (alpha-hexachlorocyclohexane, beta-hexachlorocyclohexane and gamma-hexachlorocyclohexane), in a ginseng root sample is presented. Raw materials (Panax ginseng) were purchased from a local market and confirmed to contain certain levels of incurred organochlorine pesticide residues by a validated gas chromatography-mass selective detection method. A total of more than 300 bottles each containing 25 g of samples were prepared after the materials had been freeze-dried, milled and thoroughly mixed. The homogeneity and stability of samples from randomly selected bottles were verified and the reference values were characterized using a highly precise isotope dilution gas chromatography-mass spectrometry (ID-GCMS) method that was recently developed by our laboratory. The purity of standard organochlorine chemicals was determined against certified reference materials to establish the accuracy of the ID-GCMS analysis. The concentrations (+/- expanded uncertainty) of hexachlorobenzene, alpha-hexachlorocyclohexane, beta-hexachlorocyclohexane and gamma-hexachlorocyclohexane in the reference material were 0.198 +/- 0.015, 0.450 +/- 0.022, 0.213 +/- 0.011 and 0.370 +/- 0.032 mg kg(-1), respectively. A portion (70 bottles) of the samples was also used in a proficiency testing (PT) scheme for assessing the testing capabilities of field laboratories. The consensus mean values of the PT obtained from the 70 participants were on the same order but deviated by -2.7 to -14.1% from those of the assigned reference values. Because of the wide spread of participants' data (relative standard deviation ranging from 44 to 56%), the PT results were not included in the calculation of the assigned values of the reference materials. The materials served as suitable reference materials to ascertain the quality control and validation processes for the

Preparation, characterization, and thermal properties of starch microencapsulated fatty acids as phase change materials thermal energy storage applications

Science.gov (United States)

Stable starch-oil composites can be prepared from renewable resources by excess steam jet-cooking aqueous slurries of starch and vegetable oils or other hydrophobic materials. Fatty acids such as stearic acid are promising phase change materials (PCMs) for latent heat thermal energy storage applica...

Micro-deformation behavior in micro-compression with high-purity aluminum processed by ECAP

Directory of Open Access Journals (Sweden)

Xu Jie

2015-01-01

Full Text Available Ultrafine-grained (UFG materials have a potential for applications in micro-forming since grain size appears to be the dominant factor which determines the limiting size of the geometrical features. In this research, high-purity Al was processed by equal-channel angular pressing (ECAP at room temperature through 1–8 passes. Analysis shows that processing by ECAP produces a UFG structure with a grain size of ~1.3 μm and with microhardness and microstructural homogeneity. Micro-compression testing was carried out with different specimen dimensions using the annealed sample and after ECAP processing through 1–8 passes. The results show the flow stress increases significantly after ECAP processing by comparison with the annealed material. The flow stress generally reaches a maximum value after 2 passes which is consistent with the results of microhardness. The flow stress decreases with decreasing specimen diameter from 4 mm to 1 mm which demonstrates that size effects also exist in the ultrafine-grained materials. However, the deformation mechanism in ultrafine-grained pure Al changes from strain strengthening to softening by dynamic recovery by comparison with the annealed material.

An attempt to prepare and characterize a soil reference material for Cr(VI) and Cr(III)

International Nuclear Information System (INIS)

Solano, G.; Katz, S.A.; Holzbecher, J.; Chatt, A.

1994-01-01

Reference materials for the speciation and quantification of chromium in contaminated soils were prepared by impregnating diatomaceous earth with BaCrO 4 and Cr 2 O 3 . The chromium concentrations of these materials were confirmed to be 200 mg/kg both by atomic absorption spectrometry and by instrumental neutron activation analysis, but monthly assays over two calendar quarters of the reference material impregnated with BaCrO 4 revealed the hexavalent chromium was not stable in this matrix. (author) 6 refs,; 2 tabs

Preparation and characterization of a Perna perna (Linnaeus, 1758) mussel reference material

International Nuclear Information System (INIS)

Moreira, Edson Goncalves

2010-01-01

The use of certified reference materials in chemical analysis is an important requirement in quality assurance systems, as it allows the validation of analytical methods and the realization of the metrological traceability of results. Then, it is possible to obtain valid and comparable results not only in space, but also in time. In this study, all the steps for the preparation of a national mussel reference material were attained, from the collection of the bulk material to processing steps such as freeze-drying, grinding, bottling and sterilization. Internationally accepted principles were applied for the homogeneity and stability assessment of the material, using instrumental neutron activation analysis and atomic absorption spectrometry as analytical techniques. By means of a collaborative program with participation of Brazilian and foreign laboratories, the chemical characterization of the material was performed. Element content in the mass percentage to mg kg -1 range was determined for 47 elements and some radionuclides, naturally present in the material. With the application of suitable statistical treatment to the data, it was considered that the content of 11 of those elements may be certified: As, Ca, Cl, Co, K, Mg, Mn, Na, Se, Th and Zn. This study may be considered an important step in the national metrological development, as it shows that the production and characterization of biological reference materials, mussel in particular, is feasible in Brazil, as a tool for quality assurance of environmental and nutritional studies performed in the country. (author)

Preparation of PtRu/Carbon hybrid materials by hydrothermal carbonization: A study of the Pt:Ru atomic ratio

International Nuclear Information System (INIS)

Tusi, Marcelo Marques; Brandalise, Michele; Correa, Olandir Vercino; Oliveira Neto, Almir; Linardi, Marcelo; Spinace, Estevam Vitorio; Villalba, Juan Carlo

2009-01-01

PtRu/Carbon materials with different Pt:Ru atomic ratios (30:70, 50:50, 60:40, 80:20 and 90:10) and 5 wt% of nominal metal load were prepared by hydrothermal carbonization using H 2 PtCl 6.6 H 2 O and RuCl 3. xH 2 O as metals sources and catalysts of the carbonization process and starch as carbon source and reducing agent. The obtained materials were treated at 900 deg C under argon and characterized by EDX, XRD and cyclic voltammetry. The electro-oxidation of methanol was studied by cyclic voltammetry and chronoamperometry using thin porous coating technique. The PtRu/Carbon materials showed Pt:Ru atomic ratios obtained by EDX similar to the nominal ones. XRD analysis showed that Pt face-cubic centered (FCC) and Ru hexagonal close-packed (HCP) phases coexist in the obtained materials. The average crystallite sizes of the Pt (FCC) phase were in the range of 8-12 nm. The material prepared with Pt:Ru atomic ratio of 50:50 showed the best performance for methanol electro-oxidation. (author)

Process of preparing ethanol by continuous fermentation of polysaccharide-containing materials

Energy Technology Data Exchange (ETDEWEB)

Ehnstroem, L.K.J.

1981-04-16

The invention concerns a process of preparing ethanol by continuous fermentation of polysaccharide - containing raw materials. Fermentation, hereby, occurs in one or several fermentors while dividing one stream of the fermentation liquid into a yeast-concentrate stream and a yeast-free stream and, if neccessary, a sludge stream. The yeast-concentrate stream is re-fed into the fermentor and at least part of the yeast-free stream is directed into a simple evaporator corresponding to one or several distilling stages where it is separated partially in an ethanol-enriched initial vapour stream supplying a facility to produce the desired ethanol quality, and partially in a liquid initial bottom stream re-fed at least in part into the fermentor. The characteristic feature of this new process is that a raw-material stream is fed into a closed circuit containing the fermentor and the evaporator, and that, in the evaporator, the raw-material stream is hydrolysed to a fermentable state. This hydrolysis is carried out most favourably by enzymes - preferably a gluco-amylase - at a temperature ranging from 35/sup 0/C to 75/sup 0/C.

Polymer dispersed liquid crystals. Pt.1 Concept, Preparation and Materials

International Nuclear Information System (INIS)

Hakemi, H. A.; Santangelo, M.

1998-01-01

It is more than a decade since Polymer Dispersed Liquid Crystal (PDLC) film technology became the subject of a world-wide scientific and industrial research and development for commercial applications as large-area reflective displays and electrooptical windows, for privacy, security and light transmission control. In view of current interest and intensive fundamental and industrial research on PDLC, the authors attempt to provide a review of the state-of-art of this technology, from concept to its industrial production, in a series of articles. In the present introductory part, the authors discuss the basic concept, the principle of operation, the materials and the preparation techniques of a PDLC device by phase separation method [it

Preparation of glass-forming materials from granulated blast furnace slag

Science.gov (United States)

Alonso, M.; Sáinz, E.; Lopez, F. A.

1996-10-01

Glass precursor materials, to be used for the vitrification of hazardous wastes, have been prepared from blast furnace slag powder through a sol-gel route. The slag is initially reacted with a mixture of alcohol (ethanol or methanol) and mineral acid (HNO3 or H2SO4) to give a sol principally consisting of Si, Ca, Al, and Mg alkoxides. Gelation is carried out with variable amounts of either ammonia or water. The gelation rate can be made as fast as desired by adding excess hydrolizing agent or else by distilling the excess alcohol out of the alkoxide solution. The resulting gel is first dried at low temperature and ground. The powder thus obtained is then heat treated at several temperatures. The intermediate and final materials are characterized by thermal analysis, infrared (IR) spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and chemical analysis. From the results, the operating conditions yielding a variety of glass precursors differing in their composition are established. The method, in comparison with direct vitrification of slag, presents a number of advantages: (1) the glass precursor obtained devitrifies at higher temperatures; (2) it enables the adjustment, to a certain extent, of the chemical composition of the glass precursor; and (3) it permits recovering marketable materials at different stages of the process.

Interplay between grain structure and protein adsorption on functional response of osteoblasts: ultrafine-grained versus coarse-grained substrates.

Science.gov (United States)

Misra, R D K; Nune, C; Pesacreta, T C; Somani, M C; Karjalainen, L P

2013-01-01

The rapid adsorption of proteins is the starting and primary biological response that occurs when a biomedical device is implanted in the physiological system. The biological response, however, depends on the surface characteristics of the device. Considering the significant interest in nano-/ultrafine surfaces and nanostructured coatings, we describe here, the interplay between grain structure and protein adsorption (bovine serum albumin: BSA) on osteoblasts functions by comparing nanograined/ultrafine-grained (NG/UFG) and coarse-grained (CG: grain size in the micrometer range) substrates by investigating cell-substrate interactions. The protein adsorption on NG/UFG surface was beneficial in favorably modulating biological functions including cell attachment, proliferation, and viability, whereas the effect was less pronounced on protein adsorbed CG surface. Additionally, immunofluorescence studies demonstrated stronger vinculin signals associated with actin stress fibers in the outer regions of the cells and cellular extensions on protein adsorbed NG/UFG surface. The functional response followed the sequence: NG/UFG(BSA) > NG/UFG > CG(BSA) > CG. The differences in the cellular response on bare and protein adsorbed NG/UFG and CG surfaces are attributed to cumulative contribution of grain structure and degree of hydrophilicity. The study underscores the potential advantages of protein adsorption on artificial biomedical devices to enhance the bioactivity and regulate biological functions. Copyright © 2012 Wiley Periodicals, Inc.

Preparation and property study of MnO2/CNPs as electrode materials of electrochemical supercapacitors

Directory of Open Access Journals (Sweden)

JIANG Chao

2016-12-01

Full Text Available MnO2 nanorods deposited on carbon nanospheres (MnO2/CNPs as electrode materials of electrochemical supercapacitors have been synthesized via a hydrothermal synthesis.The micro morphologies and phases of the as-prepared MnO2/CNPs were characterized by field emission scanning electro microscopy(FESEM and X-ray diffraction(XRD.The electrochemical properties of nanomaterials were tested by cyclic voltammetry and galvanostatic charge-discharge.At a current density of 0.1 A/g using 1 mol/L Na2SO4 as electrolyte,the as-prepared MnO2/CNPs exhibit excellent specific capacitance of 305.6 F/g,far larger than carbon nanospheres (49.3 F/g.At a current density of 5 A/g,the specific capacitance of MnO2/CNPs is 235 F/g,which is 76.9% of the specific capacitance under 1 A/g current density.These results demonstrated that MnO2/CNPs may show potential application for electrode materials in electrochemical supercapacitors.

Efficiency of organic acid preparations for the elimination of naturally occurring Salmonella in feed material.

Science.gov (United States)

Axmann, Sonja; Kolar, Veronika; Adler, Andreas; Strnad, Irmengard

2017-11-01

Salmonella can enter animal stocks via feedstuffs, thus posing not only an infection risk for animals, but also threatening to contaminate food of animal origin and finally humans. Salmonella contamination in feedstuffs is still a recurring and serious issue in animal production (especially for the poultry sector), and is regularly detected upon self-monitoring by feed companies (self-checks) and official inspections authorities. Operators within the feed chain in certain cases need to use hygienic condition enhancers, such as organic acids, to improve the quality of feed for animal nutrition, providing additional guarantees for the protection of animal and public health. The present study investigated the efficiencies of five organic acid preparations. The acid products were added to three different feed materials contaminated with Salmonella (contamination occurred by recontamination in the course of the production process) at seven different inclusion rates (1-7%) and analysed after 1, 2, and 7 days' exposure time using culture method (tenfold analysis). A reliable standard was established for defining a successful decontamination under the prevailing test conditions: 10 Salmonella-negative results out of 10 tested samples (0/10: i.e. 0 positive samples and 10 negative samples). The results demonstrated that the tested preparations showed significant differences with regard to the reduction in Salmonella contamination. At an inclusion rate of 7% of the feed materials, two out of five acid preparations showed an insufficient, very small, decontamination effect, whereas two others had a relatively large partial effect. Reliable decontamination was demonstrated only for one acid preparation, however, subject to the use of the highest acid concentration.

Characterization of Lone Pine, California, tremolite asbestos and preparation of research material

Science.gov (United States)

Harper, Martin; Van Gosen, Bradley S.; Crankshaw, Owen S; Doorn, Stacy S; Ennis, J. Todd; Harrison, Sara E

2014-01-01

Well-characterized amphibole asbestos mineral samples are required for use as analytical standards and in future research projects. Currently, the National Institute for Standards and Technology Standard Reference Material samples of asbestos are listed as ‘Discontinued’. The National Institute for Occupational Safety and Health (NIOSH) has a goal under the Asbestos Roadmap of locating and characterizing research materials for future use. Where an initial characterization analysis determines that a collected material is appropriate for use as a research material in terms of composition and asbestiform habit, sufficient amounts of the material will be collected to make it publicly available. An abandoned mine near Lone Pine, California, contains a vein of tremolite asbestos, which was the probable source of a reference material that has been available for the past 17 years from the Health and Safety Laboratory (HSL) in the UK. Newly collected fibrous vein material from this mine was analyzed at Research Triangle Institute (RTI International) with some additional analysis by the US Geological Survey’s Denver Microbeam Laboratory. The analysis at RTI International included: (i) polarized light microscopy (PLM) with a determination of principal optical properties; (ii) X-ray diffraction; (iii) transmission electron microscopy, including energy dispersive X-ray spectroscopy and selected-area electron diffraction; and (iv) spindle stage analysis using PLM to determine whether individual fibers and bundles of the samples were polycrystalline or single-crystal cleavage fragments. The overall findings of the study indicated that the material is tremolite asbestos with characteristics substantially similar to the earlier distributed HSL reference material. A larger quantity of material was prepared by sorting, acid-washing and mixing for sub-division into vials of ~10g each. These vials have been transferred from NIOSH to RTI International, from where they can be

Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

KAUST Repository

Pahovnik, David

2015-09-01

Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization mechanisms using conventional (various amines) as well as some recently developed initiators (hexamethyldisilazane, N-heterocyclic persistent carbenes, etc.) is presented, and their benefits and drawbacks for preparation of polypeptides with well-defined chain lengths and chain-end functionality are discussed. Recent examples from literature are used to illustrate different possibilities for synthesis of pure polypeptide materials with different molecular architectures bearing various functional groups, which are introduced either by modification of amino acids, before they are transformed into corresponding Ncarboxyanhydrides, or by post-polymerization modifications using protective groups and/or orthogonal functional groups. Different approaches for preparation of polypeptide-based hybrid materials are discussed as well using examples from recent literature. Syntheses of simple block copolymers or copolymers with more complex molecular architectures (graft and star copolymers) as well as modifications of nanoparticles and other surfaces with polypeptides are described.

Influence of Specimen Preparation and Test Methods on the Flexural Strength Results of Monolithic Zirconia Materials.

Science.gov (United States)

Schatz, Christine; Strickstrock, Monika; Roos, Malgorzata; Edelhoff, Daniel; Eichberger, Marlis; Zylla, Isabella-Maria; Stawarczyk, Bogna

2016-03-09

The aim of this work was to evaluate the influence of specimen preparation and test method on the flexural strength results of monolithic zirconia. Different monolithic zirconia materials (Ceramill Zolid (Amann Girrbach, Koblach, Austria), Zenostar ZrTranslucent (Wieland Dental, Pforzheim, Germany), and DD Bio zx² (Dental Direkt, Spenge, Germany)) were tested with three different methods: 3-point, 4-point, and biaxial flexural strength. Additionally, different specimen preparation methods were applied: either dry polishing before sintering or wet polishing after sintering. Each subgroup included 40 specimens. The surface roughness was assessed using scanning electron microscopy (SEM) and a profilometer whereas monoclinic phase transformation was investigated with X-ray diffraction. The data were analyzed using a three-way Analysis of Variance (ANOVA) with respect to the three factors: zirconia, specimen preparation, and test method. One-way ANOVA was conducted for the test method and zirconia factors within the combination of two other factors. A 2-parameter Weibull distribution assumption was applied to analyze the reliability under different testing conditions. In general, values measured using the 4-point test method presented the lowest flexural strength values. The flexural strength findings can be grouped in the following order: 4-point strength values than prepared before sintering. The Weibull moduli ranged from 5.1 to 16.5. Specimens polished before sintering showed higher surface roughness values than specimens polished after sintering. In contrast, no strong impact of the polishing procedures on the monoclinic surface layer was observed. No impact of zirconia material on flexural strength was found. The test method and the preparation method significantly influenced the flexural strength values.

Preparation of mesohollow and microporous carbon nanofiber and its application in cathode material for lithium–sulfur batteries

International Nuclear Information System (INIS)

Wu, Yuanhe; Gao, Mingxia; Li, Xiang; Liu, Yongfeng; Pan, Hongge

2014-01-01

Highlights: • Mesohollow and microporous carbon fibers were prepared via electrospinning and carbonization. • Sulfur (S) incorporated into the porous fibers by thermal heating in 60 wt.%, forming composite. • S fills fully in the micropores and partially in the mesohollows of the carbon fibers. • The composite shows high capacity and capacity retention as cathode material for Li–S batteries. • Mesohollow and microporous structure is effective in improving the property of S cathode. - Abstract: Mesohollow and microporous carbon nanofibers (MhMpCFs) were prepared by a coaxial electrospinning with polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) as outer and inner spinning solutions followed by a carbonization. The carbon fibers were thermal treated with sublimed sulfur to form S/MhMpCFs composite, which was used as cathode material for lithium–sulfur batteries. Electrochemical study shows that the S/MhMpCFs cathode material provides a maximum capacity of 815 mA h/g after several cycles of activation, and the capacity retains 715 mA h/g after 70 cycles, corresponding to a retention of 88%. The electrochemical property of the S/MhMpCFs composite is much superior than the S-incorporated solid carbon fibers prepared from electrospinning of single PAN. The mechanism of the enhanced electrochemical property of the S/MhMpCFs composite is discussed

Preparation of cathode materials for solid oxide solid fuel (SOFC) using gelatin

International Nuclear Information System (INIS)

Silva, R.M.; Aquino, F. de M.; Macedo, D.A. de; Sa, A.M.; Galvao, G.O.

2016-01-01

Fuel cells are electrochemical devices that convert chemical energy into electrical energy. These devices are basically divided into interconnectors, electrolyte, anode, and cathode. Recently, studies of improvements in microstructural and morphological properties of calcium cobaltate (Ca_3Co_4O_9, C349) has been made regarding its potential use as SOFC cathode for intermediate temperature. Gelatin has proven to be effective as a polymerizing agent in the synthesis of nanocrystalline materials. This work reports the synthesis and characterization of the C349 cathode using commercial gelatin. The structural properties of the material were determined by X-ray diffraction (XRD). Morphological characterization was performed by scanning electron microscopy (SEM). The results showed the formation of the crystalline phase at 900 °C, indicating the effectiveness of the gelatin in the preparation of cathodes for SOFC. (author)

Effect of type of cavity preparation (bur,Er:YAG laser and restorative materials on prevention of caries lesion

Directory of Open Access Journals (Sweden)

Masumeh Hasani Tabatabaei

2017-03-01

Full Text Available Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence. Materials and Methods: In this experimental study, eighty human teeth were collected and stored in normal saline. The teeth were soft-tissue debrided and cleaned with water/pumice slurry and rubber cups in a low-speed handpiece. Speciments were randomly divided in two main groups. Cavities were prepared with diamond burs or Er:YAG laser (10 Hz, 300 mJ, 3W. Each group was divided into 4 sub-groups, and restored with a glass-ionomer cement (Fuji IX, resin modified glass-ionomer (Fuji II LC, total etch bonding + composite resin or self-etch bonding + composite resin. The specimens were submitted to pH cycling. Speciments were then sectioned, polished and Vickers microhardness measurements were performed on each specimen. Differences among the medians were analyzed using two way ANOVA test at a 95% confidence level and Tukey test. Results: Statistical analysis showed significant difference in the type of substrate (enamel, dentin in both main groups (P<0.0001 but no differences in the caries lesion development between the cavities restored with the same material and prepared with diamond burs or Er:YAG laser. Conclusion: The Er:YAG laser used for cavity preparation and different types of restorative materials used did not show the ability to guarantee significantly more acid-resistance tooth structure against demineralization.

Synthesis of inorganic materials in a supercritical carbon dioxide medium. Application to ceramic cross-flow filtration membranes preparation

International Nuclear Information System (INIS)

Papet, Sebastien

2000-01-01

Membrane separations, using cross-flow mineral ceramic membranes, allows fractionation of aqueous solutions due to the molecular sieve effect and electrostatic charges. To obtain a high selectivity, preparation of new selective ceramic membranes is necessary. We propose in this document two different routes to prepare such cross-flow tubular mineral membranes. In the first exposed method, a ceramic material is used, titanium dioxide, synthesized in supercritical carbon dioxide by the hydrolysis of an organometallic precursor of the oxide. The influence of operating parameters is similar to what is observed during a liquid-phase synthesis (sol-gel process), and leads us to control the size and texture of the prepared particles. This material is then used to prepare mineral membrane with a compressed layer process. The particles are mixed with organic components to form a liquid suspension. A layer is then deposited on the internal surface of a tubular porous support by slip-casting. The layer is then dried and compressed on the support before sintering. The obtained membranes arc in the ultrafiltration range. A second process has been developed in this work. It consists on the hydrolysis, in a supercritical CO 2 medium, of a precursor of titanium dioxide infiltrated into the support. The obtained material is then both deposited on the support but also infiltrated into the porosity. This new method leads to obtain ultrafiltration membranes that retain molecules which molecular weight is round 4000 g.mol -1 . Furthermore, we studied mass transfer mechanisms in cross-flow filtration of aqueous solutions. An electrostatic model, based on generalized Nernst-Planck equation that takes into account electrostatic interactions between solutes and the ceramic material, lead us to obtain a good correlation between experimental results and the numerical simulation. (author) [fr

A novel material Li{sub 2}NiFe{sub 2}O{sub 4}: Preparation and performance as anode of lithium ion battery

Energy Technology Data Exchange (ETDEWEB)

Ding, Keqiang, E-mail: dkeqiang@263.net [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, Hebei, 050024 (China); Zhao, Jing [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, Hebei, 050024 (China); Zhou, Jinming, E-mail: zhoujm@iccas.ac.cn [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, Hebei, 050024 (China); Zhao, Yongbo; Chen, Yuying; Liu, Likun [College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, Hebei, 050024 (China); Wang, Li [Institute of Nuclear & New Energy Technology, Beijing Key Lab of Fine Ceramics, Tsinghua University, Beijing, 100084 (China); He, Xiangming, E-mail: hexm@tsinghua.edu.cn [Institute of Nuclear & New Energy Technology, Beijing Key Lab of Fine Ceramics, Tsinghua University, Beijing, 100084 (China); Guo, Zhanhu, E-mail: zguo10@utk.edu [Integrated Composites Laboratory (ICL), Chemical and Biomolecular Engineering Department, University of Tennessee Knoxville, Knoxville, NT, 37996 (United States)

2016-07-01

For the first time, the preparation and characterization of a novel anode material Li{sub 2}NiFe{sub 2}O{sub 4} are reported in this work. The preparation of Li{sub 2}NiFe{sub 2}O{sub 4} is conducted under the air conditions by using a subsection calcination method. The influence of annealing periods on the properties of the resultant materials is thoroughly explored. The characteristics of the materials are mainly examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS). The results of the XRD patterns effectively demonstrate the formation of crystalline Li{sub 2}NiFe{sub 2}O{sub 4}, and the SEM images indicate that particles with octahedron crystal morphology are prepared and the 9 h-annealed sample has the smallest particle size among all the prepared samples. The results of electrochemical measurements reveal that 9 h-calcined sample delivers a high specific capacity of 203 mAh g{sup −1} after 20 cycles at a current density of 100 mA g{sup −1}. The successful preparation of Li{sub 2}NiFe{sub 2}O{sub 4} is believed to be able to trigger the research work concerning the novel group of Li{sub 2}MFe{sub 2}O{sub 4} materials. - Highlights: • A novel anode material Li{sub 2}NiFe{sub 2}O{sub 4} was prepared under the air conditions. • Li{sub 2}NiFe{sub 2}O{sub 4} showed well-defined octahedron crystal morphology. • 9 h-annealed Li{sub 2}NiFe{sub 2}O{sub 4} delivered a capacity of 203 mAh g{sup −1}.

In situ study of thermally activated flow and dynamic restoration of ultrafine-grained pure Cu at 373 K

Czech Academy of Sciences Publication Activity Database

Blum, W.; Král, Petr; Dvořák, Jiří; Petrenec, M.; Eisenlohr, P.; Sklenička, Václav

2017-01-01

Roč. 32, č. 24 (2017), s. 4514-4521 ISSN 0884-2914 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : Cu * dynamic grain coarsening * dynamic recovery * ECAP * in situ * stress relaxation * UFG Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 1.673, year: 2016

New problems in solid-state chemistry solved by high pressure conditions: an exciting perspective for preparing new materials

OpenAIRE

Demazeau , Gérard

1988-01-01

International audience; The high-pressure technique is an efficient tool in solid-state chemistry for preparing new materials of low stability or metastable character. During the last 20 years, this technique has been used and developed especially in three principal areas : synthesis of new materials, either for a better basic approach of scientific problems or for industrial applications studies of structural transformations in situ evolution of some physical properties of materials under pr...

Solvent properties of hydrazine in the preparation of metal chalcogenide bulk materials and films.

Science.gov (United States)

Yuan, Min; Mitzi, David B

2009-08-21

A combination of unique solvent properties of hydrazine enables the direct dissolution of a range of metal chalcogenides at ambient temperature, rendering this an extraordinarily simple and soft synthetic approach to prepare new metal chalcogenide-based materials. The extended metal chalcogenide parent framework is broken up during this process, and the resulting metal chalcogenide building units are re-organized into network structures (from 0D to 3D) based upon their interactions with the hydrazine/hydrazinium moieties. This Perspective will review recent crystal and materials chemistry developments within this family of compounds and will briefly discuss the utility of this approach in metal chalcogenide thin-film deposition.

Development of Ultra-Fine-Grained Structure in AISI 321 Austenitic Stainless Steel

Science.gov (United States)

Tiamiyu, A. A.; Szpunar, J. A.; Odeshi, A. G.; Oguocha, I.; Eskandari, M.

2017-12-01

Ultra-fine-grained (UFG) structure was developed in AISI 321 austenitic stainless steel (ASS) using cryogenic rolling followed by annealing treatments at 923 K, 973 K, 1023 K, and 1073 K (650 °C, 700 °C, 750 °C, and 800 °C) for different lengths of time. The α'-martensite to γ-austenite reversion behavior and the associated texture development were analyzed in the cryo-rolled specimens after annealing. The activation energy, Q, required for the reversion of α'-martensite to γ-austenite in the steel was estimated to be 80 kJ mol-1. TiC precipitates and unreversed triple junction α'-martensite played major roles in the development of UFG structure through the Zener pinning of grain boundaries. The optimum annealing temperature and time for the development of UFG structure in the cryo-rolled AISI 321 steel are (a) 923 K (650 °C) for approximately 28800 seconds and (b) 1023 K (750 °C) for 600 seconds, with average grain sizes of 0.22 and 0.31 µm, respectively. Annealing at 1023 K (750 °C) is considered a better alternative since the volume fraction of precipitated carbides in specimens annealed at 1023 K (750 °C) are less than those annealed at 923 K (650 °C). More so, the energy consumption during prolonged annealing time to achieve an UFG structure at 923 K (650 °C) is higher due to low phase reversion rate. The hardness of the UFG specimens is 195 pct greater than that of the as-received steel. The higher volume fraction of TiC precipitates in the UFG structure may be an additional source of hardening. Micro and macrotexture analysis indicated {110}〈uvw〉 as the major texture component of the austenite grains in the UFG structure. Its intensity is stronger in the specimen annealed at low temperatures.

Methodological developments and materials in salt-rock preparation for irradiation experiments

International Nuclear Information System (INIS)

Garcia Celma, A.; Van Wees, H.; Miralles, L.

1991-01-01

For the first time synthetic salt-rock samples have been produced. Production and preparation of those samples and of other types of rock-salt for experiments and observation require many special handlings. We applied technical knowledge already developed by the HPT Laboratory of the Geology Department of the Rijksuniversiteit Utrecht (high pressure techniques, salt-rock preparation), and by the workshops of the ECN, Petten, and FDO, Amsterdam (mechanical precision). Procedures have been applied and/or modified to solve specific problems. Many of them were never reported before. Moreover, new techniques have been developed. Rock-salt samples have been machined, sawn, ground, glued, etc., with a maximum of precision, a minimum of damage and in dry conditions (without water). Etching, peeling and thin section production has been carried out on irradiated and unirradiated samples. Valves, end pieces, jackets, etc. have been tested and/or produced. These handlings were directed to produce samples for the HAW experiment. Their development required not only knowledge, but also a lot of trial, failures and time. To avoid repetition of this effort, the procedures, materials, instruments and their characteristics are described in detail in this report

Innovative plant protection means prepared natural raw materials

Directory of Open Access Journals (Sweden)

Omar Lomtadze

2018-03-01

Full Text Available Were developed new compositions preparation against pests and diseases of plant: Insekto-acaricide “Antipest”, Fungicide “Antifungal”, a drug against of overwintering pests “Proinsekt” and nutritious preparation “Si-humate”.The effectiveness of trial oil-emulsion preparation “Proinsect” was assessed by the spread of pests - San Jose scale (Diaspidiotus perniciosus and mountain ash bentwing (Leucoptera scitella Costa on treated trees. According to field testing, the efficiency of preparation “Proinsect” exceeds the effectiveness of one of the best imported oily preparation “Sipcomol”, which was selected as a reference.Joint content in composition of synthetic pyretroids with turpentine oil, supposedly synergism takes place (turpentines cause prolonged action of synthetic pyrethroid. In working solutions, obtained from turpentine oil containing composition concentration of pyretroid is low, but it is enough during the whole period of pest development cycle. According to the comparative field testing of “Antipest” and imported preparations, against for fruits pests their efficiency is at almost one level, despite the low content (by 30–40% of pyrethroid (cypermethrin in “Antipest”.The developed phosphate preparation “Antifungal” is a little bit less effective compared to Bordeaux mixture. If well take into account significant decrease of intensity of disease spread and development after the action of phosphate preparation, also very low toxicity zinc hydro- and dihydrophosphates compared to the blue vitriol (Copper(II sulfate, the developed fungicide preparation can be successfully used instead of traditional Bordeaux mixture and in particular against the peach leaf curl.According to the results of field trials, effect, of developed silicon containing humic nutrient composition -“Si-humate” on experimental 2-year-old seedlings apples and peach is on the average 15–17% better than the control ones in

Preparation and characterization of form-stable paraffin/polyurethane composites as phase change materials for thermal energy storage

International Nuclear Information System (INIS)

Chen, Keping; Yu, Xuejiang; Tian, Chunrong; Wang, Jianhua

2014-01-01

Highlights: • Paraffin/polyurethane composite as form-stable phase change material was prepared by bulk polymerization. • Paraffin/polyurethane composite possesses typical character of dual phase transition. • Total latent heat of n-eicosane/PUPCM is as high as 141.2 J/g. • Maximum encapsulation ratio for n-octadecane/PUPCM composites is 25% w/w. - Abstract: Polyurethane phase change material (PUPCM) has been demonstrated to be effective solid–solid phase change material for thermal energy storage. However, the high cost and complex process on preparation of PUPCMs with high enthalpy and broad phase transition temperature range can prohibit industrial-scale applications. In this work, a series of novel form-stable paraffin/PUPCMs composites (n-octadecane/PUPCM, n-eicosane/PUPCM and paraffin wax/PUPCM) with high enthalpy and broad phase transition temperature range (20–65 °C) were directly synthesized via bulk polymerization. The composites were prepared at different mass fractions of n-octadecane (10, 20, 25, 30% w/w). The results indicated that the maximum encapsulation ratio for n-octadecane/PUPCM10000 composites was around 25% w/w. The chemical structure and crystalline properties of these composites were characterized by Fourier transform infrared spectroscopy (FT-IR), polarizing optical microscopy (POM), wide-angle X-ray diffraction (WAXD). Thermal properties and thermal reliability of the composites were determined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). From DSC analysis, the composites showed a typical dual phase change temperature. The enthalpy for the composite with 25% w/w n-eicosane was as high as 141.2 J/g. TGA analysis indicated that the composites degraded at considerably high temperatures. The process of preparation of PUPCMs and their composites was very simple, inexpensive, environmental friendly and easy to process into desired shapes, which could find the promising applications in solar

Preparation and use of polymeric materials containing hydrophobic anions and plasticizers for separation of cesium and strontium

International Nuclear Information System (INIS)

Abney, K.D.; Kinkead, S.A.; Mason, C.F.V.; Rais, J.

1997-01-01

Preparation and use is described for polymeric materials containing hydrophobic anions and plasticizers for extraction of cesium and strontium. The use of polymeric materials containing plasticizers which are solvents for hydrophobic anions such as derivatives of cobalt dicarbollide or tetraphenylborate which are capable of extracting cesium and strontium ions from aqueous solutions in contact with the polymeric materials, is described. The polymeric material may also include a synergistic agent for a given ion like polyethylene glycol or a crown ether, for removal of radioactive isotopes of cesium and strontium from solutions of diverse composition and, in particular, for solutions containing large excess of sodium nitrate

Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

Science.gov (United States)

Dang, Xugang; Chen, Hui; Shan, Zhihua

2017-07-01

One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

Optimization of substrate preparation for oyster mushroom (Pleurotus ostreatus) cultivation by studying different raw materials and substrate preparation conditions (composting: phases I and II).

Science.gov (United States)

Vieira, Fabrício Rocha; de Andrade, Meire Cristina Nogueira

2016-11-01

In recent years, oyster mushroom (Pleurotus ostreatus) has become one of the most cultivated mushrooms in the world, mainly in Brazil. Among many factors involved in a mushroom production, substrate preparation is the most critical step, which can be influenced by composting management techniques. Looking forward to optimizing the substrate preparation process, were tested different composting conditions (7 and 14 days of composting with or without conditioning), potential raw materials (decumbens grass, brizantha grass and sugarcane straw) and nitrogen supplementation (with or without wheat bran) on oyster mushroom yield and biological efficiency (BE). The substrate composted for 7 days with conditioning showed higher yield and biological efficiency of mushroom (24.04 and 100.54 %, respectively). Substrates without conditioning (7 and 14 days of composting) showed smaller mushroom yield and biological efficiency. Among the raw materials tested, brizantha grass showed higher mushroom yield followed by decumbens grass, sugarcane straw and wheat straw (28.5, 24.32, 23.5 and 19.27 %, respectively). Brizantha grass also showed higher biological efficiency followed by sugarcane straw, decumbens grass and wheat straw (123.95, 103.70, 96.90 and 86.44 %, respectively). Supplementation with wheat bran improved yield and biological efficiency in all substrate formulations tested; thus, oyster mushroom yield and biological efficiency were influenced by substrate formulation (raw materials), supplementation and composting conditions.

CYCLIC PLASTIC BEHAVIOUR OF UFG COPPER UNDER CONTROLLED STRESS AND STRAIN LOADING

Directory of Open Access Journals (Sweden)

Lucie Navrátilová

2012-01-01

Full Text Available The influence of stress- and strain-controlled loading on microstructure and cyclic plastic behaviour of ultrafine-grained copper prepared by equal channel angular pressing was examined. The stability of microstructure is a characteristic feature for stress-controlled test whereas grain coarsening and development of bimodal structure was observed after plastic strain-controlled tests. An attempt to explain the observed behaviour was made.

An Approach to Preparing Ni-P with Different Phases for Use as Supercapacitor Electrode Materials.

Science.gov (United States)

Wang, Dan; Kong, Ling-Bin; Liu, Mao-Cheng; Luo, Yong-Chun; Kang, Long

2015-12-01

Herein, we describe a simple two-step approach to prepare nickel phosphide with different phases, such as Ni2 P and Ni5 P4 , to explain the influence of material microstructure and electrical conductivity on electrochemical performance. In this approach, we first prepared a Ni-P precursor through a ball milling process, then controlled the synthesis of either Ni2 P or Ni5 P4 by the annealing method. The as-prepared Ni2 P and Ni5 P4 are investigated as supercapacitor electrode materials for potential energy storage applications. The Ni2 P exhibits a high specific capacitance of 843.25 F g(-1) , whereas the specific capacitance of Ni5 P4 is 801.5 F g(-1) . Ni2 P possesses better cycle stability and rate capability than Ni5 P4 . In addition, the Fe2 O3 //Ni2 P supercapacitor displays a high energy density of 35.5 Wh kg(-1) at a power density of 400 W kg(-1) and long cycle stability with a specific capacitance retention rate of 96 % after 1000 cycles, whereas the Fe2 O3 //Ni5 P4 supercapacitor exhibits a high energy density of 29.8 Wh kg(-1) at a power density of 400 W kg(-1) and a specific capacitance retention rate of 86 % after 1000 cycles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and performance of novel polyvinylpyrrolidone/polyethylene glycol phase change materials composite fibers by centrifugal spinning

Science.gov (United States)

Zhang, Xiaoguang; Qiao, Jiaxin; Zhao, Hang; Huang, Zhaohui; Liu, Yangai; Fang, Minghao; Wu, Xiaowen; Min, Xin

2018-01-01

Currently, phase change materials (PCMs) composite fibers are typically prepared by electrospinning. However, electrospinning exhibits safety concerns and a low production rate, which limit its practical applications as a cost-effective fiber fabrication approach. Therefore, a novel, and simple centrifugal spinning technology is employed to extrude fibers from composite solutions using a high-speed rotary and perforated spinneret. The composite fibers based on polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) were prepared by centrifugal spinning. The SEM of PVP/PEG composite fibers indicated that the fibrous morphology is well preserved. The DSC and TGA indicated that PVP/PEG composite fibers exhibit good thermal properties.

Specimen preparation for nano-scale investigation of cementitious repair material.

Science.gov (United States)

Azarsa, Pejman; Gupta, Rishi

2018-04-01

Cementitious Repair Materials (CRMs) in the construction industry have been used for many decades now and has become a very important part of activities in cement world. The performance of some of these CRMs when applied to retrofitting concrete structural elements is also well documented. However, the characterization of some of the CRMs at the micro- and nano level is not fully documented. The first step to studying materials at the microscopic level is to be able to fabricate proper specimens for microscopy. In this study, a special and newly developed class of CRM was selected and fabricated by Focused Ion Beam (FIB) using well-known "Lift-out" technique. The prepared specimen was later examined using various analytical techniques such as energy dispersive x-ray analysis using one of the highest and most stable Scanning Transmission Electron Holography Microscopy (STEHM) around the world. This process enabled understanding of the composition, morphology, and spatial distribution of various phases of the CRM. It was observed that the microstructure consisted of a very fine, compact, and homogenous amorphous structure. X-ray analysis indicated that there was considerable deviation between the Si/Ca ratios for the hydrated product. Copyright © 2018 Elsevier Ltd. All rights reserved.

"Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

Science.gov (United States)

Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

2016-07-01

The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials.

Polish reference material: corn flour (INCT-CF-3)for inorganic trace analysis - preparation and certification

International Nuclear Information System (INIS)

Polkowska-Motrenko, H.; Dybczynski, R.; Chajduk, E.; Danko, B.; Kulisa, K.; Samczynski, Z.; Sypula, M.; Szopa, Z.

2006-01-01

Preparation, examination and certification of the new matrix reference material of biological origin: Corn Flour (INCT-CF-3) is described. The material was prepared from corn grown in Poland according to Polish standard PN-A-74205:1997. The material was sieved through the 250 mm nylon sieves and stored in a polyethylene (PE) bag. Approximately 50 kg of sieved corn flour was collected. Examination by optical microscopy revealed that Martin's diameter of over 98% of particles was below 25 mm. The whole lot of corn flour was then homogenized by mixing for 20 hours in a 110 dm 3 PE drum rotated in three directions. Preliminary homogeneity testing by X-ray fluorescence (XRF) method and final checking of homogeneity by neutron activation analysis (NAA) after distribution of the material into containers revealed, that it is sufficiently homogeneous at least for a sample size ≥ 100 mg. In order to assure the long-term stability, all containers with INCT-CF-3 were sterilized by electron beam radiation. Long-term stability was checked by analyzing concentrations of selected elements in the material stored in the air-conditioned room at 20 o C. Short-term stability was examined by the determination of concentrations of the selected elements in the bottle stored in the CO 2 incubator at 37 o C. The material was certified on the basis of a worldwide interlaboratory comparison, in which 92 laboratories from 19 countries participated providing 962 laboratory averages (4228 individual determinations) for 57 elements. A method of data evaluation leading to assignment of certified values was the same as that used previously in the Laboratory of the Department of Analytical Chemistry, Institute of Nuclear Chemistry and Technology. The result for Mo was obtained by definitive methods developed in the Laboratory and used to support the certification process. Analytical uncertainties and stability uncertainties were quantified to arrive at combined uncertainties of the certified

Nanostructured Carbon Materials as Supports in the Preparation of Direct Methanol Fuel Cell Electrocatalysts

Directory of Open Access Journals (Sweden)

María Jesús Lázaro

2013-08-01

Full Text Available Different advanced nanostructured carbon materials, such as carbon nanocoils, carbon nanofibers, graphitized ordered mesoporous carbons and carbon xerogels, presenting interesting features such as high electrical conductivity and extensively developed porous structure were synthesized and used as supports in the preparation of electrocatalysts for direct methanol fuel cells (DMFCs. The main advantage of these supports is that their physical properties and surface chemistry can be tailored to adapt the carbonaceous material to the catalytic requirements. Moreover, all of them present a highly mesoporous structure, diminishing diffusion problems, and both graphitic character and surface area can be conveniently modified. In the present work, the influence of the particular features of each material on the catalytic activity and stability was analyzed. Results have been compared with those obtained for commercial catalysts supported on Vulcan XC-72R, Pt/C and PtRu/C (ETEK. Both a highly ordered graphitic and mesopore-enriched structure of these advanced nanostructured materials resulted in an improved electrochemical performance in comparison to the commercial catalysts assayed, both towards CO and alcohol oxidation.

Preparation and characterization of stearic acid/expanded graphite composites as thermal energy storage materials

International Nuclear Information System (INIS)

Fang, Guiyin; Li, Hui; Chen, Zhi; Liu, Xu

2010-01-01

Stearic acid/expanded graphite composites with different mass ratios were prepared by absorbing liquid stearic acid into the expanded graphite. In the composite materials, the stearic acid was used as the phase change material for thermal energy storage, and the expanded graphite acted as the supporting material. Fourier transformation infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermal diffusivity measurement were used to determine the chemical structure, crystalline phase, microstructure and thermal diffusivity of the composites, respectively. The thermal properties and thermal stability were investigated by differential scanning calorimetry and thermogravimetric analysis. The thermal analysis results indicated that the materials exhibited the same phase transition characteristics as the stearic acid and their latent heats were approximately the same as the values calculated based on the weight fraction of the stearic acid in the composites. The microstructural analysis results showed that the stearic acid was well absorbed in the porous network of the expanded graphite, and there was no leakage of the stearic acid from the composites even when it was in the molten state.

Preparation of Neo-Literate Materials for Rural Development. Final Report of a Regional Workshop on the Preparation of Literacy Follow-Up Materials in Asia and the Pacific (6th, Kuching, Sarawak, Malaysia, September 21-30, 1988).

Science.gov (United States)

Asian Cultural Centre for UNESCO, Tokyo (Japan).

The proceedings of the sixth regional workshop consist of a description of the project and the workshop; a description of the field survey, preparation, and field testing of materials by the group; five papers presented at the workshop; and notes on planned follow-up activities in the participating countries. The workshop culminated a project on…

Use of radiation technology in preparing materials for bioengineering and medical science

International Nuclear Information System (INIS)

Hoffman, A.S.

1982-01-01

There is a wide variety of materials which are foreign to the body and which are used in contact with body fluids. These materials are called biomaterials. They include polymers (fibres, rubbers, moulded plastics, emulsions, coatings, fluids, etc.), metals, ceramics, carbons, reconstituted or specially treated natural tissues, and composites of various combinations of such material classes. By far the most diverse use of biomaterials exists within the polymer class: in these organic materials, ionizing radiation has a unique ability to initiate free radical and ionic reactions without the need to add catalysts or to heat. Thus, new polymers or new forms of polymers may be synthesized or existing polymers may be chemically modified by a relatively simple, additive-free processing step at room temperature - sometimes with potential for simultaneous sterilization. Other advantages may be obtained by cooling to the glassy state before irradiation. There are three basic radiation processes which are utilized for preparing new or modified biomaterials. These are: (1) graft co-polymerization of monomers and polymers; (2) radiation polymerization, as pure monomer(s), in solution, as an emulsion, or in the solid state (e.g., below Tsub(G)); and (3) radiation crosslinking, in a solution or swollen state, or in the solid state. Simultaneous or subsequent chemical or biochemical processing steps can yield novel biomaterials having specific biological activity. Immobilization of enzymes, antibodies, drugs, cells etc., on or within the radiation-processed material, can yield novel biomaterials with great potential in the clinic or clinical laboratory. All these processes and products are reviewed. (author)

agradecimento aos consultores ad hoc

Directory of Open Access Journals (Sweden)

REA Editor

2012-02-01

Full Text Available Agradecemos aos professores Nildo Viana (UFG e Flavio Sofiati (UFG, organizadores do DOSSIÊ JUVENTUDE & SOCIEDADE, e aos Consultores Ad hoc pela leitura e apreciação crítica dos artigos submetidos e publicados nesta edição.

Preparation of shaped bodies

International Nuclear Information System (INIS)

Sutcliffe, P.W.; Isaacs, J.W.; Lyon, C.E.

1979-01-01

A method for the preparation of a shaped body includes pressing a powder to give a 'green' shaped body, the powder having been made by comminuting a material prepared by means of a gelation process, the material prior to comminuting being of a selected physical configuration (e.g. spherical). Thus, a material prepared by means of a gelation process can be transported and handled in an environmentally desirable, substantially dust-free form (e.g. spherical particles) and then comminuted to produce a powder for pressing into e.g. a shaped nuclear fuel body (e.g. pellets of (70%U/30%Pu)O 2 ), which can be sintered. (author)

Chitosan-cellulose composite materials: Preparation, Characterization and application for removal of microcystin

Energy Technology Data Exchange (ETDEWEB)

Tran, Chieu D., E-mail: chieu.tran@marquette.edu [Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States); Duri, Simon [Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States); Delneri, Ambra; Franko, Mladen [Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, 5001 Nova Gorica (Slovenia)

2013-05-15

Highlights: •A novel and recyclable synthetic method using an ionic liquid, a Green Solvent. •Ecocomposite materials were synthesized from cellulose (CEL) and chitosan (CS). •Adding CEL into CS substantially increases tensile strength of the composite. •The composite is much better adsorbent for cyanotoxins than other materials. •The composite can be reused because adsorbed microcystin can be desorbed. -- Abstract: We developed a simple and one-step method to prepare biocompatible composites from cellulose (CEL) and chitosan (CS). [BMIm{sup +}Cl{sup −}], an ionic liquid (IL), was used as a green solvent to dissolve and prepare the [CEL + CS] composites. Since majority (>88%) of IL used was recovered for reuse by distilling the aqueous washings of [CEL + CS], the method is recyclable. XRD, FTIR, NIR, {sup 13}C CP-MAS-NMR and SEM were used to monitor the dissolution and to characterize the composites. The composite was found to have combined advantages of their components: superior mechanical strength (from CEL) and excellent adsorption capability for microcystin-LR, a deadly toxin produced by cyanobacteria (from CS). Specifically, the mechanical strength of the composites increased with CEL loading; e.g., up to 5× increase in tensile strength was achieved by adding 80% of CEL into CS. Kinetic results of adsorption confirm that unique properties of CS remain intact in the composite, i.e., it is not only a very good adsorbent for microcystin but also is better than all other available adsorbents. For example, it can adsorb 4× times more microcystin than the best reported adsorbent. Importantly, the microcystin adsorbed can be quantitatively desorbed to enable the composite to be reused with similar adsorption efficiency.

Chitosan-cellulose composite materials: Preparation, Characterization and application for removal of microcystin

International Nuclear Information System (INIS)

Tran, Chieu D.; Duri, Simon; Delneri, Ambra; Franko, Mladen

2013-01-01

Highlights: •A novel and recyclable synthetic method using an ionic liquid, a Green Solvent. •Ecocomposite materials were synthesized from cellulose (CEL) and chitosan (CS). •Adding CEL into CS substantially increases tensile strength of the composite. •The composite is much better adsorbent for cyanotoxins than other materials. •The composite can be reused because adsorbed microcystin can be desorbed. -- Abstract: We developed a simple and one-step method to prepare biocompatible composites from cellulose (CEL) and chitosan (CS). [BMIm + Cl − ], an ionic liquid (IL), was used as a green solvent to dissolve and prepare the [CEL + CS] composites. Since majority (>88%) of IL used was recovered for reuse by distilling the aqueous washings of [CEL + CS], the method is recyclable. XRD, FTIR, NIR, 13 C CP-MAS-NMR and SEM were used to monitor the dissolution and to characterize the composites. The composite was found to have combined advantages of their components: superior mechanical strength (from CEL) and excellent adsorption capability for microcystin-LR, a deadly toxin produced by cyanobacteria (from CS). Specifically, the mechanical strength of the composites increased with CEL loading; e.g., up to 5× increase in tensile strength was achieved by adding 80% of CEL into CS. Kinetic results of adsorption confirm that unique properties of CS remain intact in the composite, i.e., it is not only a very good adsorbent for microcystin but also is better than all other available adsorbents. For example, it can adsorb 4× times more microcystin than the best reported adsorbent. Importantly, the microcystin adsorbed can be quantitatively desorbed to enable the composite to be reused with similar adsorption efficiency

Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

KAUST Repository

Pahovnik, David; Hadjichristidis, Nikolaos

2015-01-01

Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization

Preparation and structural characterization of the thermoluminescent material CaSO{sub 4}: Dy; Preparacion y caracterizacion estructural del material termoluminiscente CaSO{sub 4}: Dy

Energy Technology Data Exchange (ETDEWEB)

Sanchez R, A.; Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Gonzalez M, P.R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Rivera, T. [CICATA-IPN, Legaria 694, 11500 Mexico D.F. (Mexico)

2005-07-01

The grade of crystallinity of a material is important so that the one is presented the thermoluminescence phenomenon; for what is necessary to study those structural characteristic of a TL material and to correlate them with its TL response when being irradiated with ionizing radiation. The calcium sulfate activated with Dysprosium (CaSO{sub 4}: Dy) it is a material that has demonstrated its efficiency in the dosimetry of the ionizing radiation for the thermoluminescence method. In this work the structural characterization of this prepared material for the recrystallization method by means of the evaporation of the solvent and their relationship with their TL response is presented. The results showed that the best material to be used in thermoluminescent dosimetry presents a crystalline structure in orthorhombic phase and a particle size in the interval of 80 {mu}m to 200 {mu}m. (Author)

Chemical preparation of biological materials for accurate chromium determination by isotope dilution mass spectrometry

International Nuclear Information System (INIS)

Dunstan, L.P.; Garner, E.L.

1977-01-01

The current interest in trace elements in biological materials has created a need for accurate methods of analysis. The source of discrepancies and variations in chromium concentration determinations is often traceable to inadequate methods of sample preparation. Any method of Cr analysis that requires acid digestion of a biological matrix must take into consideration the existence or formation of a volatile Cr component. In addition, because Cr is often present at concentrations less than 1 μg/g, the analytical blank becomes a potential source of error. Chemical procedures have been developed for the digestion of the biological matrix and the separation of Cr without either large analytical blanks or significant losses by volatilization. These procedures have been used for the analysis of NBS Standard Reference Material (SRM) 1569 Brewers Yeast; SRM 1577 Bovine Liver; SRM 1570 Spinach and other biological materials including human hair and nails. At this time, samples containing 1 μg of Cr can be determined with an estimated accuracy of 2 percent

Review of New Technology for Preparing Crystalline Silicon Solar Cell Materials by Metallurgical Method

Science.gov (United States)

Li, Man; Dai, Yongnian; Ma, Wenhui; Yang, Bin; Chu, Qingmei

2017-11-01

The goals of greatly reducing the photovoltaic power cost and making it less than that of thermal power to realize photovoltaic power grid parity without state subsidies are focused on in this paper. The research status, key technologies and development of the new technology for preparing crystalline silicon solar cell materials by metallurgical method at home and abroad are reviewed. The important effects of impurities and defects in crystalline silicon on its properties are analysed. The importance of new technology on reducing production costs and improving its quality to increase the cell conversion efficiency are emphasized. The previous research results show that the raw materials of crystalline silicon are extremely abundant. The product of crystalline silicon can meet the quality requirements of solar cell materials: Si ≥ 6 N, P 1 Ω cm, minority carrier life > 25 μs cell conversion efficiency of about 19.3%, the product costs energy consumption energy consumption, low carbon and sustainable development are prospected.

A new way for preparing superconducting materials: the electrochemical oxidation of La2CuO4

International Nuclear Information System (INIS)

Wattiaux, A.; Park, J.C.; Grenier, J.C.; Pouchard, M.

1990-01-01

The electrochemical oxidation in alkaline medium is described as a new way for preparing superconducting oxides at room temperature. The application of this method to La 2 CuO 4 gave rise to a metallic material with a superconducting behaviour below 39 K and whose physical and chemical features appear as quite promising [fr

Morphological Study Of Border Area Of Pulp-Capping Materials And Er:YAG Laser Prepared Hard Dental Surface

Directory of Open Access Journals (Sweden)

Stefanova Vessela P.

2015-03-01

Full Text Available Introduction: Vital pulp therapy involves biologically based therapeutic activities aimed at restoring health and preserving the vitality of cariously or traumatically damaged pulp. Adaptation of pulp-capping materials to the prepared tooth surface may be the key to the success of biological tooth treatment.

Enhanced in vitro biocompatibility of ultrafine-grained titanium with hierarchical porous surface

International Nuclear Information System (INIS)

Zheng, C.Y.; Nie, F.L.; Zheng, Y.F.; Cheng, Y.; Wei, S.C.; Valiev, R.Z.

2011-01-01

Bulk ultrafine-grained Ti (UFG Ti) was successfully fabricated by equal-channel angular pressing (ECAP) technique in the present study, and to further improve its surface biocompatibility, surface modification techniques including sandblasting, acid etching and alkali treatment were employed to produce a hierarchical porous surface. The effect of the above surface treatments on the surface roughness, wettability, electrochemical corrosion behavior, apatite forming ability and cellular behavior of UFG Ti were systematically investigated with the coarse-grained Ti as control. Results show that UFG-Ti with surface modification had no pitting corrosion and presented low corrosion rate in simulated body fluids (SBF). The hierarchical porous surface yielded by surface modification enhanced the ability of UFG Ti to form a complete apatite layer when soaked in SBF and promoted osteoblast-like cells attachment and proliferation in vitro, which promises to have a significant impact on increasing bone-bonding ability and reducing healing time when implanted due to faster tissue integration.

Preparation of Cementitious Material Using Smelting Slag and Tailings and the Solidification and Leaching of Pb2+

Directory of Open Access Journals (Sweden)

Dan Zhang

2015-01-01

Full Text Available The composite cementitious materials were prepared with lead-zinc tailings, lead-zinc smelting slag, and cement clinker. The effect of material ratio on the mechanical properties, the phase analysis, and microstructures were investigated. The effect of the pH and stripping time on the leaching amount of lead ion was discussed. The results show that the additive amount of the tailings should be minimized for the cementitious materials meeting the strength requirements, controlled within 10%. The leaching amount of cementitious materials remains low in a larger range of pH, which can effectively reduce the leaching of heavy metal lead. The leaching kinetics of lead ions in the three kinds of samples could be better described by the pseudo-second-model.

Preparation and Gas Adsorption of Porous Materials from Molecular Precursors

DEFF Research Database (Denmark)

Hu, Xinming

with bimodal porosity are produced via cyclotrimerization of two aromatic tetranitriles and in situ carbonization in molten ZnCl2. The carbonization occurs by decomposition of triazine rings, which results in complete loss of nitrogen and formation of substantial mesopores. The resulting materials possess...... surface areas above 1200 m2 g−1 and exhibit exceptionally high H2 uptake (up to 2.34 wt% at 77 K and 1 bar) but low CO2 uptake capacity. In Chapter 4, a nitrogen-rich porous carbon is prepared via cyclotrimerization of a perfluorinated aromatic nitrile and in situ carbonization in molten ZnCl2......), and H2 (2.0 wt%, 77 K and 1.0 bar). Chapters 5, 6, and 7 deal with the construction of triazatriangulenium (TATA)-based ionic porous frameworks. A variety of polycondensation reactions have been applied, but only FeCl3-promoted oxidative polymerization of thiophene-/carbazolefunctionalized TATAs...

Preparation and properties of highly conductive palmitic acid/graphene oxide composites as thermal energy storage materials

International Nuclear Information System (INIS)

Mehrali, Mohammad; Latibari, Sara Tahan; Mehrali, Mehdi; Indra Mahlia, Teuku Meurah; Cornelis Metselaar, Hendrik Simon

2013-01-01

PA/GO (palmitic acid/graphene oxide) as PCMs (phase change materials) prepared by vacuum impregnation method, have high thermal conductivity. The GO (graphene oxide) composite was used as supporting material to improve thermal conductivity and shape stabilization of composite PCM (phase change material). SEM (Scanning electronic microscope), FT-IR (Fourier transformation infrared spectroscope) and XRD (X-ray diffractometer) were applied to determine microstructure, chemical structure and crystalloid phase of palmitic acid/GO composites, respectively. DSC (Differential scanning calorimeter) test was done to investigate thermal properties which include melting and solidifying temperatures and latent heat. FT-IR analysis represented that the composite instruction of porous palmitic acid and GO were physical. The temperatures of melting, freezing and latent heats of the composite measured through DSC analysis were 60.45, 60.05 °C, 101.23 and 101.49 kJ/kg, respectively. Thermal cycling test showed that the form-stable composite PCM has good thermal reliability and chemical stability. Thermal conductivity of the composite PCM was improved by more than three times from 0.21 to 1.02. As a result, due to their acceptable thermal properties, good thermal reliability, chemical stability and great thermal conductivities, we can consider the prepared form-stable composites as highly conductive PCMs for thermal energy storage applications. - Highlights: • Novel composite PCM with high thermal conductivity and latent heat storage. • New thermal cycling test for thermal reliability of composite PCMs. • Increasing thermal conductivity of composite PCM with graphene oxide. • Increasing thermal stability of phase change material by adding graphene oxide

Ligand combination strategy for the preparation of novel low-dimensional and open-framework metal cluster materials

Science.gov (United States)

Anokhina, Ekaterina V.

Low-dimensional and open-framework materials containing transition metals have a wide range of applications in redox catalysis, solid-state batteries, and electronic and magnetic devices. This dissertation reports on research carried out with the goal to develop a strategy for the preparation of low-dimensional and open-framework materials using octahedral metal clusters as building blocks. Our approach takes its roots from crystal engineering principles where the desired framework topologies are achieved through building block design. The key idea of this work is to induce directional bonding preferences in the cluster units using a combination of ligands with a large difference in charge density. This investigation led to the preparation and characterization of a new family of niobium oxychloride cluster compounds with original structure types exhibiting 1ow-dimensional or open-framework character. Most of these materials have framework topologies unprecedented in compounds containing octahedral clusters. Comparative analysis of their structural features indicates that the novel cluster connectivity patterns in these systems are the result of complex interplay between the effects of anisotropic ligand arrangement in the cluster unit and optimization of ligand-counterion electrostatic interactions. The important role played by these factors sets niobium oxychloride systems apart from cluster compounds with one ligand type or statistical ligand distribution where the main structure-determining factor is the total number of ligands. These results provide a blueprint for expanding the ligand combination strategy to other transition metal cluster systems and for the future rational design of cluster-based materials.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation

Directory of Open Access Journals (Sweden)

Niranjan Joshi

2013-01-01

Objective: The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. Materials and Methods: For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. Results: The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. Conclusion: The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Preparation of functional composite materials based on chemically derived graphene using solution process

International Nuclear Information System (INIS)

Kim, M; Hyun, W J; Mun, S C; Park, O O

2015-01-01

Chemically derived graphenes were assembled into functional composite materials using solution process from stable solvent dispersion. We have developed foldable electronic circuits on paper substrates using vacuum filtration of graphene nanoplates dispersion and a selective transfer process without need for special equipment. The electronic circuits on paper substrates revealed only a small change in conductance under various folding angles and maintained an electronic path after repetitive folding and unfolding. We also prepared flexible. binder-free graphene paper-like materials by addition of graphene oxide as a film stabilizer. This graphene papers showed outstanding electrical conductivity up to 26,000 S/m and high charge capacity as an anode in lithium-ion battery without any post-treatments. For last case, multi-functional thin film structures of graphene nanoplates were fabricated by using layer-by-layer assembly technique, showing optical transparency, electrical conductivity and enhanced gas barrier property. (paper)

Preparation of biological samples for transmission X-ray microanalysis: a review of alternative procedures to the use of sectioned material

International Nuclear Information System (INIS)

Sigee, D.C.

1988-01-01

Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular. The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case of cell homogenates and biological fluids, the technique has been used mainly with microdroplets of animal material. The use of X-ray microanalysis with purified biochemicals is considered in relation to both particulate and non-particulate samples. In the latter category, the application of this technique for analysis of thin films of metalloprotein is particularly emphasised. It is concluded that wider use could be made of the range of preparative techniques available - both within a particular investigation, and in diverse fields of study. Transmission X-ray microanalysis has implications for environmental, physiological and molecular biology as well as cell biology

Effect of type of cavity preparation (bur,Er:YAG laser) and restorative materials on prevention of caries lesion

OpenAIRE

Masumeh Hasani Tabatabaei; Sakineh Arami; Fatemeh Khajavi; Zohreh Moradi

2017-01-01

Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence. Materials and Methods: In this experimental study, eighty...

Study on the preparation of the SiCp/Al-20Si-3Cu functionally graded material using spray deposition

International Nuclear Information System (INIS)

Su, B.; Yan, H.G.; Chen, G.; Shi, J.L.; Chen, J.H.; Zeng, P.L.

2010-01-01

Research highlights: → The SiCp/Al-20Si-3Cu functionally gradient material (FGM) was successfully prepared via the spray deposition technique. → The SiCp/Al-20Si-3Cu functionally gradient material (FGM) was successfully prepared via the spray deposition technique. → In the experimental setup, the novel devices play an important role in adjusting the output of SiCp to prepare the FGM. → The experiment results reveal that the SiCp weight fraction of the as-deposited preform from the top to the bottom ranges almost continuously from 0% to 30%. → The fraction of SiC particles has no obvious influence on the phase constitutions of the SiCp/Al-20Si-3Cu FGM. - Abstract: The SiCp/Al-20Si-3Cu functionally gradient material (FGMs) was successfully prepared via the spray deposition technique accompanied with an automatic control system. The results reveal that the SiCp weight fraction of the as-deposited preform from the top to the bottom ranges almost continuously from 0% to 30%. The part with the higher SiCp weight fraction exhibits a relatively smaller density than that with the lower SiCp weight fraction. However, the microhardness and the porosity increase with the increasing SiCp weight fraction in the as-deposited preform. The X-ray diffraction results exhibit that the secondary phases in the regions with the different amount of SiC particles are the same such as Al 2 Cu and AlCuMg. The spray deposition technology is promising to produce a wide range of other FGMs.

Basic Studies on Sponge Cake Making as a Teaching Material of Food Preparation

OpenAIRE

Shiratsuti, Hiroko; Ikawa, Yoshiko

1994-01-01

The purpose of this study is to investigate about the basic condition for sponge cake making usable as a teaching material of food preparation. The results were as follows : 1. Egg foams were stable under high concentration of sucrose and low temperature. The cake with 34% sucrose showed a good appearance. 2. Substituting starch for wheat flour was effective to keep low viscosity of batters. 3. The data for the baking process indicated the importance of the first and second stages in baking, ...

Preparation and Properties of Paraffin/TiO2/Active-carbon Composite Phase Change Materials

Directory of Open Access Journals (Sweden)

HAO Yong-gan

2016-11-01

Full Text Available A novel composite phase change materials (PCMs of paraffin/TiO2/active-carbon was prepared by a microemulsion method, where paraffin acted as a PCM and titanium dioxide (TiO2 as matrix material, and a small amount of active carbon was added to improve the thermal conductivity. The compositions, morphology and thermal properties of the paraffin/TiO2/active-carbon composite PCMs were characterized by XRD, SEM, TGA and DSC respectively. The shape stability during phase change process of this composite was also tested. The results show that paraffin is well encapsulated by TiO2 matrix, and thus exhibiting excellent shape-stabilized phase change feature. Besides, this composite PCM also presents superhydrophobic property. Therefore, these multifunctional features will endow PCMs with important application potential in energy efficient buildings.

Development, preparation, and characterization of high-performance superconducting materials for space applications. Progress Report

International Nuclear Information System (INIS)

Thorpe, A.N.; Barkatt, A.

1991-12-01

The preparation of high-temperature superconducting ceramics in bulk form is a major challenge in materials science. The current status of both partial melting and melt quenching techniques, with or without an intermediate powder processing stage, is described in detail, and the problems associated with each of the methods are discussed. Results of studies performed on melt-processed materials are reported and discussed. The discussion places emphasis on magnetization and on other physical properties associated with it, such as critical current density, levitation force, and flux creep. The nature of structural features which give rise to flux pinning, including both small and large defects, is discussed with reference to theoretical considerations. The rates of flux creep and the factors involved in attempting to retard the decay of the magnetization are surveyed

Preparation of Silver Nano-Particles and Use as a Material for Water Sterilization

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Tran Hong Con

2011-01-01

Full Text Available High dispersed nanodimensional silver metal (nanosilver solution of concentration ranging from 40 to 400 mg/L was prepared from silver nitrate in water media with and without dispersing reagent. The reduction process was initiated by ammonium hydroxide and glucose was used as a reductive reagent. The nanosilver solution was characterized by color changing from light-yellow to yellow, brown, red-brown, brown-green, dark-green, blue, dark-blue and those were depending on silver concentration and dimension of silver metal particles. The nanosilver solution was possibly used as a direct sterilizing reagent or coating on calcinated laterite grains to create sterilizing material in bacterial removing filter. Direct sterilization ability of nanosilver solution and nanosilver coated material was investigated. The results showed that with 10 ppb nanosilver in supplied water, all bacteria will be removed within 25–30 min. 10 mm thick layer of silica gel or 20 mm of calcinated laterite coated nanosilver could remove all bacteria in water flowed though with maximum flow rate of 100 L.m2/min. Moreover, sterilizing material was nontoxic and applicable for drinking water production.

Pressure-jump induced rapid solidification of melt: a method of preparing amorphous materials

Science.gov (United States)

Liu, Xiuru; Jia, Ru; Zhang, Doudou; Yuan, Chaosheng; Shao, Chunguang; Hong, Shiming

2018-04-01

By using a self-designed pressure-jump apparatus, we investigated the melt solidification behavior in rapid compression process for several kinds of materials, such as elementary sulfur, polymer polyether-ether-ketone (PEEK) and poly-ethylene-terephthalate, alloy La68Al10Cu20Co2 and Nd60Cu20Ni10Al10. Experimental results clearly show that their melts could be solidified to be amorphous states through the rapid compression process. Bulk amorphous PEEK with 24 mm in diameter and 12 mm in height was prepared, which exceeds the size obtained by melt quenching method. The bulk amorphous sulfur thus obtained exhibited extraordinarily high thermal stability, and an abnormal exothermic transition to liquid sulfur was observed at around 396 K for the first time. Furthermore, it is suggested that the glass transition pressure and critical compression rate exist to form the amorphous phase. This approach of rapid compression is very attractive not only because it is a new technique of make bulk amorphous materials, but also because novel properties are expected in the amorphous materials solidified by the pressure-jump within milliseconds or microseconds.

Composite phase change materials prepared by encapsuling paraffin in PVC macrocapsules

International Nuclear Information System (INIS)

Chen, Yingbo; Zhang, Shifeng; Zhang, Qi; Chen, Yusheng; Zhang, Yufeng

2014-01-01

Highlights: • PVC macrocapsules coated with SiO 2 were synthesized. • Paraffin was encapsuled in the capsules. • The composite PCM has high heat capacity. • The composite PCM has no surpercooling. - Abstract: A novel phase change material capsules with SiO 2 in their surface was prepared by absorbing paraffin into PVC hollow capsules and by the polycondensation reaction of TEOS in different conditions. X-ray photoelectron spectroscopy (XPS) analysis and scanning electronic microscope (SEM) were used to determine chemical composition and microstructure of the composite capsules, respectively. Enthalpy capacity and thermal stability of the composite capsules are systematically characterized by using differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA) and thermocycling tests. The composite has high heat capacity with good stability and absence of supercooling phenomena

Efficient preparation of highly hydrogenated graphene and its application as a high-performance anode material for lithium ion batteries

Science.gov (United States)

Chen, Wufeng; Zhu, Zhiye; Li, Sirong; Chen, Chunhua; Yan, Lifeng

2012-03-01

A novel method has been developed to prepare hydrogenated graphene (HG) via a direct synchronized reduction and hydrogenation of graphene oxide (GO) in an aqueous suspension under 60Co gamma ray irradiation at room temperature. GO can be reduced by the aqueous electrons (eaq-) while the hydrogenation takes place due to the hydrogen radicals formed in situ under irradiation. The maximum hydrogen content of the as-prepared highly hydrogenated graphene (HHG) is found to be 5.27 wt% with H/C = 0.76. The yield of the target product is on the gram scale. The as-prepared HHG also shows high performance as an anode material for lithium ion batteries.

Strain localization and fatigue crack initiation in ultrafine-grained copper in high- and giga-cycle region

Czech Academy of Sciences Publication Activity Database

Kunz, Ludvík; Lukáš, Petr; Navrátilová, L.

2014-01-01

Roč. 58, JAN (2014), s. 202-208 ISSN 0142-1123 R&D Projects: GA ČR GAP108/10/2001; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Fatigue crack initiation * Strain localization * Stability of ultrafine-grained structure * UFG Cu Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.275, year: 2014

Polish reference material: soya bean flour (INCT-SBF-4) for inorganic trace analysis - preparation and certification

International Nuclear Information System (INIS)

Polkowska-Motrenko, H.; Dybczynski, R.; Chajduk, E.; Danko, B.; Kulisa, K.; Samczynski, Z.; Sypula, M.; Szopa, Z.

2006-01-01

Preparation, examination and certification of the new matrix reference material of biological origin: Soya Bean Flour (INCT-SBF-4) is described. The material was prepared from soya bean grown in India, not genetically modified. After milling, the material was sieved through the 150 mm nylon sieves and stored in a polyethylene (PE) bag. Approximately 50 kg of sieved soya bean flour was collected. Examination by optical microscopy revealed that Martin's diameter of over 90% of particles was below 50 mm. The whole lot of soya bean flour was then homogenized by mixing for 20 hours in a 110 dm 3 PE drum rotated in three directions. Preliminary homogeneity testing by X-ray fluorescence (XRF) method and final checking of homogeneity by neutron activation analysis (NAA) after distribution of the material into containers revealed, that it is sufficiently homogeneous at least for a sample size ≥ 100 mg. In order to assure the long-term stability, all containers with INCT-SBF-4 were sterilized by electron beam radiation. Long-term stability was checked by analyzing concentrations of selected elements in the material stored in the air-conditioned room at 20 o C. Short-term stability was examined by the determination of concentrations of the selected elements in the bottle stored in the CO 2 incubator at 37 o C. The material was certified on the basis of a worldwide interlaboratory comparison, in which 92 laboratories from 19 countries participated providing 1107 laboratory averages (4873 individual determinations) for 58 elements. A method of data evaluation leading to assignment of certified values was the same as that used previously in the Laboratory of the Department of Analytical Chemistry, Institute of Nuclear Chemistry and Technology. The results for a few elements were obtained by definitive methods developed in the Laboratory and used to support the certification process. Analytical uncertainties and stability uncertainties were quantified to arrive at combined

Nanocrystalline ceramic materials

Science.gov (United States)

Siegel, Richard W.; Nieman, G. William; Weertman, Julia R.

1994-01-01

A method for preparing a treated nanocrystalline metallic material. The method of preparation includes providing a starting nanocrystalline metallic material with a grain size less than about 35 nm, compacting the starting nanocrystalline metallic material in an inert atmosphere and annealing the compacted metallic material at a temperature less than about one-half the melting point of the metallic material.

Time-lapse cinematography in living Drosophila tissues: preparation of material.

Science.gov (United States)

Davis, Ilan; Parton, Richard M

2006-11-01

The fruit fly, Drosophila melanogaster, has been an extraordinarily successful model organism for studying the genetic basis of development and evolution. It is arguably the best-understood complex multicellular model system, owing its success to many factors. Recent developments in imaging techniques, in particular sophisticated fluorescence microscopy methods and equipment, now allow cellular events to be studied at high resolution in living material. This ability has enabled the study of features that tend to be lost or damaged by fixation, such as transient or dynamic events. Although many of the techniques of live cell imaging in Drosophila are shared with the greater community of cell biologists working on other model systems, studying living fly tissues presents unique difficulties in keeping the cells alive, introducing fluorescent probes, and imaging through thick hazy cytoplasm. This protocol outlines the preparation of major tissue types amenable to study by time-lapse cinematography and different methods for keeping them alive.

Preparation and performance optimization of TPBISi green-light organic luminescent material devices

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Zheng Huajing

2017-01-01

Full Text Available The Study analyzed and tested the absorption spectrum, photoluminescence spectrum, and device’s electroluminescence spectrum of a new silole material. The device with Silol as an emitting layer, emitted green-light whose structure is ITO/NPB/2,2,3,3-tetraphenyl-4,4-bisthienylsilole(TPBTSi/Alq3/Mg: A by improvement of preparation technology and optimization of thin film. It reaches the maximum luminescence of 11290.2 cd/m2, the maximum luminous efficiency of 0.84 lm/W, luminescence spectrum of 516 nm, chromaticity diagram CIE coordinate of(0.275, 0.4568 when voltage is 15V. All of the above is the green characteristic spectrum of TPBTSi.

Studies on preparation and adaptive thermal control performance of novel PTC (positive temperature coefficient) materials with controllable Curie temperatures

International Nuclear Information System (INIS)

Cheng, Wen-long; Yuan, Shuai; Song, Jia-liang

2014-01-01

PTC (positive temperature coefficient) material is a kind of thermo-sensitive material. In this study, a series of novel PTC materials adapted to thermal control of electron devices are prepared. By adding different low-melting-point blend matrixes into GP (graphite powder)/LDPE (low density polyethylene) composite, the Curie temperatures are adjusted to 9 °C, 25 °C, 34 °C and 41 °C, and the resistance–temperature coefficients are enhanced to 1.57/°C–2.15/°C. These PTC materials remain solid in the temperature region of PTC effect, which makes it possible to be used as heating element to achieve adaptive temperature control. In addition, the adaptive thermal control performances of this kind of materials are investigated both experimentally and theoretically. The result shows that the adaptive effect becomes more significant while the resistance–temperature coefficient increases. A critical heating power defined as the initial heating power which makes the equilibrium temperature reach terminal temperature is presented. The adaptive temperature control will be effective only if the initial power is below this value. The critical heating power is determined by the Curie temperature and resistance–temperature coefficient of PTC materials, and a higher Curie temperature or resistance–temperature coefficient will lead to a larger critical heating power. - Highlights: • A series of novel PTC (positive temperature coefficient) materials were prepared. • The Curie point of PTC material can be adjusted by choosing different blend matrixes. • The resistance–temperature coefficient of PTC materials is enhanced to 2.15/°C. • The material has good adaptive temperature control ability with no auxiliary method. • A mathematical model is established to analyze the performance and applicability

A simple preparation of calibration curve standards of 134Cs and 137Cs by serial dilution of a standard reference material

International Nuclear Information System (INIS)

Labrecque, J.J.; Rosales, P.A.

1990-01-01

Two sets of calibration standards for 134 Cs and 137 Cs were prepared by small serial dilution of a natural matrix standard reference material, IAEA-154 whey powder. The first set was intended to screen imported milk powders which were suspected to be contaminated with 134 Cs and 137 Cs. Their concentration ranged from 40 to 400 Bq/kg. The other set of calibration standards was prepared to measure the environmental levels of 137 Cs in commercial Venezuelan milk powders. Their concentration ranged from 3 to 10 Bq/kg of 137 Cs. The accuracy of these calibration curves was checked by IAEA-152 and A-14 milk powders. Their measured values were in good agreement with their certified values. Finally, it is shown that these preparation techniques using serial dilution of a standard reference material were simple, rapid, precise, accurate and cost-effective. (author) 5 refs.; 5 figs.; 3 tabs

Metallographic preparation of Zr-2.5Nb pressure tube material for examination of inclusions

International Nuclear Information System (INIS)

Lockley, A.J.

1994-11-01

The traditional final polish of Zr-2.5Nb alloy comprises an attack polish that contains a 0.05 μm alumina or fly-ash slurry with dilute hydrofluoric acid. This polish preferentially etches the material adjacent to the inclusions and distorts or removes the inclusions. A final polish has been developed that uses a caustic alumina slurry to produce a chemical-mechanical polish that keeps the inclusions intact. This preparation is reproducible, suitable for automation, and retains smaller inclusions. (author). 2 refs., 5 figs

Computer Assisted Educational Material Preparation for Fourth Grade Primary School Students' English Language Class in Teaching Numbers

Science.gov (United States)

Yüzen, Abdulkadir; Karamete, Aysen

2016-01-01

In this study, using ADDIE instructional design model, it is aimed to prepare English language educational material for 4th grade primary students to teach them numbers. At the same time, ARCS model of motivation's attention, relevance and satisfaction phases are also taken into consideration. This study also comprises of Design Based Research…

Easy and industrially applicable impregnation process for preparation of diatomite-based phase change material nanocomposites for thermal energy storage

International Nuclear Information System (INIS)

Konuklu, Yeliz; Ersoy, Orkun; Gokce, Ozgur

2015-01-01

The high porosity, high oil and water absorption capacity and low density of diatomite make it ideal for industrial applications. The porous structure of diatomite protects phase change materials (PCMs) from environmental factors as a supporting matrix and phase changes occur in nanopores of diatomite. Previous research on diatomite/PCMs composites aimed optimal composite preparation but many methods were feasible only in laboratory scale. In large scale industrial fabrication, easy, continuous and steady state methods are need to be performed. The main purpose of this study was to prepare leakage-free, thermally stable nanocomposite PCMs (nanoCPCMs) by an easy, continuous and steady state method for high temperature thermal energy storage applications. A series of nanoCPCMs with different paraffin:diatomite mass ratios were prepared. The properties of nanoCPCMs have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The leak (exudation) test was performed on prepared composites at higher temperatures (95 °C) in comparison with literature. As the optimum composite for thermal energy storage applications, thermal reliability of nanoCPCM was evaluated after 400 cycles of melting and freezing. NanoCPCM melted at 36.55 °C with latent heat of 53.1 J/g. - Highlights: • Diatomite-based phase change material nanocomposites were prepared. • An easy and industrially applicable impregnation process was developed. • Influence of diatomite: PCM mass ratio on thermal properties reported.

Sample preparation

International Nuclear Information System (INIS)

Anon.

1992-01-01

Sample preparation prior to HPLC analysis is certainly one of the most important steps to consider in trace or ultratrace analysis. For many years scientists have tried to simplify the sample preparation process. It is rarely possible to inject a neat liquid sample or a sample where preparation may not be any more complex than dissolution of the sample in a given solvent. The last process alone can remove insoluble materials, which is especially helpful with the samples in complex matrices if other interactions do not affect extraction. Here, it is very likely a large number of components will not dissolve and are, therefore, eliminated by a simple filtration process. In most cases, the process of sample preparation is not as simple as dissolution of the component interest. At times, enrichment is necessary, that is, the component of interest is present in very large volume or mass of material. It needs to be concentrated in some manner so a small volume of the concentrated or enriched sample can be injected into HPLC. 88 refs

Organ culture storage of pre-prepared corneal donor material for Descemet's membrane endothelial keratoplasty.

Science.gov (United States)

Bhogal, Maninder; Matter, Karl; Balda, Maria S; Allan, Bruce D

2016-11-01

To evaluate the effect of media composition and storage method on pre-prepared Descemet's membrane endothelial keratoplasty (DMEK) grafts. 50 corneas were used. Endothelial wound healing and proliferation in different media were assessed using a standard injury model. DMEK grafts were stored using three methods: peeling with free scroll storage; partial peeling with storage on the stroma and fluid bubble separation with storage on the stroma. Endothelial cell (EC) phenotype and the extent of endothelial overgrowth were examined. Global cell viability was assessed for storage methods that maintained a normal cell phenotype. 1 mm wounds healed within 4 days. Enhanced media did not increase EC proliferation but may have increased EC migration into the wounded area. Grafts that had been trephined showed evidence of EC overgrowth, whereas preservation of a physical barrier in the bubble group prevented this. In grafts stored in enhanced media or reapposed to the stroma after trephination, endothelial migration occurred sooner and cells underwent endothelial-mesenchymal transformation. Ongoing cell loss, with new patterns of cell death, was observed after returning grafts to storage. Grafts stored as free scrolls retained more viable ECs than grafts prepared with the fluid bubble method (74.2± 3% vs 60.3±6%, p=0.04 (n=8). Free scroll storage is superior to liquid bubble and partial peeling techniques. Free scrolls only showed overgrowth of ECs after 4 days in organ culture, indicating a viable time window for the clinical use of pre-prepared DMEK donor material using this method. Methods for tissue preparation and storage media developed for whole corneas should not be used in pre-prepared DMEK grafts without prior evaluation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Study on preparation and thermal property of binary fatty acid and the binary fatty acids/diatomite composite phase change materials

International Nuclear Information System (INIS)

Li, Min; Kao, Hongtao; Wu, Zhishen; Tan, Jinmiao

2011-01-01

This study prepared a series of binary phase change materials by mixing decanoic acid, dodecanoic acid, hexadecanoic acid and octadecanoic acid each other. The phase-transition temperature of binary fatty acid and its corresponding mixing proportion are calculated with phase diagram thermodynamic method. The results are verified by the experimental result of the heat absorption curve and the Differential Scanning Calorimetry (DSC) analysis curve. The results show that the calculation method of phase diagram thermodynamic calculation can be taken as a basis for mixing proportion of binary fatty acid phase change materials. In addition, the decanoic-dodecanoic acid/diatomite composite phase change material (PCM) are prepared and its microstructure, thermal property and thermal reliability are characterized. The result shows that the decanoic-dodecanoic acid is uniformly adsorbed into diatomite and the form-stable PCM are formed. The phase-transition temperature and the latent heat of the decanoic-dodecanoic acid/diatomite composite PCMs is 16.74 o C and 66.8114 J/g, respectively.

Selective Preparation of Furfural from Xylose over Sulfonic Acid Functionalized Mesoporous Sba-15 Materials

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Panpan Li

2011-04-01

Full Text Available Sulfonic acid functionalized mesoporous SBA-15 materials were prepared using the co-condensation and grafting methods, respectively, and their catalytic performance in the dehydration of xylose to furfural was examined. SBA-15-SO3H(C prepared by the co-condensation method showed 92–95% xylose conversion and 74% furfural selectivity, and 68–70% furfural yield under the given reaction conditions. The deactivation and regeneration of the SBA-15-SO3H(C catalyst for the dehydration of xylose was also investigated. The results indicate that the used and regeneration catalysts retained the SBA-15 mesoporous structure, and the S content of SBA-15-SO3H(C almost did not change. The deactivation of the catalysts is proposed to be associated with the accumulation of byproducts, which is caused by the loss reaction of furfural. After regeneration by H2O2, the catalytic activity of the catalyst almost recovered.

Sol-gel preparation of uranium oxide spheres

International Nuclear Information System (INIS)

Dolezal, J.; Urbanek, V.

1978-01-01

Information is presented on problems of preparing nuclear fuel by the sol-gel method. Basic data on different process types are given. A more detailed description of the method of preparation of spherical particles of uranium oxide gel developed and used at the Nuclear Research Institute at Rez is given. Advantages and disadvantages of sol-gel materials are discussed in comparison with fuel materials prepared by classical precipitation methods. The feasibility of the sol-gel methods for preparing other materials is shortly mentioned and their application outlined. (author)

Readability of Hospice Materials to Prepare Families for Caregiving at the Time of Death

Science.gov (United States)

Kehl, Karen A.; McCarty, Kayla N.

2012-01-01

Many health care materials are not written at levels that can be understood by most lay people. In this descriptive study, we examined the readability of documents used by hospices to prepare families for caregiving at the time of death. We used two common formulae to examine the documents. The mean Flesch-Kincaid grade level was 8.95 (SD 1.80). The mean Simple Measure of Gobbledygook grade level was 11.06 (SD 1.36). When we used the Colors Label Ease for Adult Readers instrument, it became evident that medical terminology was the primary reason for the high grade levels. Most documents (78%) included medical terms that were directly (46.2%) or indirectly (25.6%) explained in the text. Modification of hospice materials could improve families’ comprehension of information important for optimal end-of-life care. PMID:22492500

Cytotoxicity of Light-Cured Dental Materials according to Different Sample Preparation Methods

Directory of Open Access Journals (Sweden)

Myung-Jin Lee

2017-03-01

Full Text Available Dental light-cured resins can undergo different degrees of polymerization when applied in vivo. When polymerization is incomplete, toxic monomers may be released into the oral cavity. The present study assessed the cytotoxicity of different materials, using sample preparation methods that mirror clinical conditions. Composite and bonding resins were used and divided into four groups according to sample preparation method: uncured; directly cured samples, which were cured after being placed on solidified agar; post-cured samples were polymerized before being placed on agar; and “removed unreacted layer” samples had their oxygen-inhibition layer removed after polymerization. Cytotoxicity was evaluated using an agar diffusion test, MTT assay, and confocal microscopy. Uncured samples were the most cytotoxic, while removed unreacted layer samples were the least cytotoxic (p < 0.05. In the MTT assay, cell viability increased significantly in every group as the concentration of the extracts decreased (p < 0.05. Extracts from post-cured and removed unreacted layer samples of bonding resin were less toxic than post-cured and removed unreacted layer samples of composite resin. Removal of the oxygen-inhibition layer resulted in the lowest cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility.

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

Science.gov (United States)

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

2014-05-21

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

Formic acid as additive for the preparation of high-performance FePO4 materials by spray drying method

CSIR Research Space (South Africa)

Yanga, F

2017-12-01

Full Text Available International, vol. 43(18): 16652-16658 Formic acid as additive for the preparation of high-performance FePO4 materials by spray drying method Yanga F Zhang H Shao Y Song H Liao S Ren J ABSTRACT: High-performance ferric phosphate (FePO4...

Preparation and certification of the Polish reference material 'Oriental Tobacco Leaves' (CTA-OTL-1) for inorganic trace analysis

International Nuclear Information System (INIS)

Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z.

1996-01-01

A new Polish certified reference material 'Oriental Tobacco Leaves' (CTA-OTL-1) for inorganic trace analysis was prepared. Fresh tobacco leaves of variety 'Oriental' were dried, ground and sieved. All precautions were taken to avoid contamination of material with metals. The next step was homogenization. Preliminary homogeneity checking consisted in determining of Ca, Fe and K content by X-ray fluorescence. Final homogeneity testing was performed by neutron activation analysis determining Co, Cr, Fe and Rb. To assure long-term stability, the whole lot of material was sterilized by electron beam radiation. Certification of the candidate reference material was done on the basis of world-wide interlaboratory comparisons exercise in which 61 laboratories, using various analytical methods participated. (author). 30 refs, 12 tabs, 21 figs

Preparation and certification of the Polish reference material `Oriental Tobacco Leaves` (CTA-OTL-1) for inorganic trace analysis

Energy Technology Data Exchange (ETDEWEB)

Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

1996-12-31

A new Polish certified reference material `Oriental Tobacco Leaves` (CTA-OTL-1) for inorganic trace analysis was prepared. Fresh tobacco leaves of variety `Oriental` were dried, ground and sieved. All precautions were taken to avoid contamination of material with metals. The next step was homogenization. Preliminary homogeneity checking consisted in determining of Ca, Fe and K content by X-ray fluorescence. Final homogeneity testing was performed by neutron activation analysis determining Co, Cr, Fe and Rb. To assure long-term stability, the whole lot of material was sterilized by electron beam radiation. Certification of the candidate reference material was done on the basis of world-wide interlaboratory comparisons exercise in which 61 laboratories, using various analytical methods participated. (author). 30 refs, 12 tabs, 21 figs.

Specimen preparation of irradiated materials for examination in the atom probe field ion microscope

International Nuclear Information System (INIS)

Russell, K.F.; Miller, M.K.

1994-01-01

The atom probe field ion microscope (APFIM) requires specimens in the form of ultrasharp needles. Basic protective measures used to reduce exposure druing specimen preparation are discussed. The low-level radioactive specimen blanks may be made using a two-stage electropolishing process using a thin layer of electrolyte floating on a denser inert liquid; this produces a necked region and eventually two specimens from each single blank. The amount of material handled may also be reduced using a micropolishing technique to repolish blunt or fractured specimens. Control of contamination and possible spills is discussed

Silica scintillating materials prepared by sol-gel methods

International Nuclear Information System (INIS)

Werst, D.W.; Sauer, M.C. Jr.; Cromack, K.R.; Lin, Y.; Tartakovsky, E.A.; Trifunac, A.D.

1993-01-01

Silica was investigated as a rad-hard alternative to organic polymer hosts for organic scintillators. Silica sol-gels were prepared by hydrolysis of tetramethoxysilane in alcohol solutions. organic dyes were incorporated into the gels by dissolving in methanol at the sol stage of gel formation. The silica sol-gel matrix is very rad-hard. The radiation stability of silica scintillators prepared by this method is dye-limited. Transient radioluminescence was measured following excitation with 30 ps pulses of 20 MeV electrons

The influence of Saccharomyces cerevisiae enzyme ratio on preparation virgin coconut oil for candidate in-house reference materials

Science.gov (United States)

Rohyami, Yuli; Anjani, Rafika Debby; Purwanti, Napthalina Putri

2017-03-01

Virgin coconut oil is an excellent product which has result of oil processing business opportunities in the international market. Standardization of virgin coconut oil necessary to satisfy the requirements industry needs. This research is expected as procedure preparation of reference materials. Preparation of virgin coconut oil by Sacharomycescerevisiaeenzyme. Based on the results of this study concluded that the ratio of Saccharomyces cerevisiae can affect the yield of virgin coconut oil produced. The preparation of virgin coconut oil enzymatically using a variety of mass ratio of 0.001 to 0.006% is obtained yield average of 12.40%. The optimum separation of virgin coconut oil on the use of enzymes with a mass ratio of 0.002%. The average water content at a ratio of 0.002% is 0.04 % with a value of uncertainty is 0.005%. The average iodine number in virgin coconut oil produced is 2.4403 ± 0,1974 grams of iodine per 100 grams of oil and optimum iodine number is obtained from the manufacturing process virgin coconut oil with a ratio of 0.006% Saccharomyces cerevisiae. Sacharomycescerevisiae with a ratio of 0.002% results virgin coconut oil with acid number 0.3068 ± 0.1098%. The peroxide value of virgin coconut oil between 0.0108 ± 0.009 to 0.0114 ± 0015milli-equivalent per kilograms. Organoleptic test results and test chemical parameters can be used as the test data that can be developed in prototype preparation of candidate in-house reference material in the testing standards of quality virgin coconut oil.

Direct investigation of (sub-) surface preparation artifacts in GaAs based materials by FIB sectioning

Energy Technology Data Exchange (ETDEWEB)

Belz, Jürgen; Beyer, Andreas; Torunski, Torsten; Stolz, Wolfgang; Volz, Kerstin

2016-04-15

The introduction of preparation artifacts is almost inevitable when producing samples for (scanning) transmission electron microscopy ((S)TEM). These artifacts can be divided in extrinsic artifacts like damage processes and intrinsic artifacts caused by the deviations from the volume strain state in thin elastically strained material systems. The reduction and estimation of those effects is of great importance for the quantitative analysis of (S)TEM images. Thus, optimized ion beam preparation conditions are investigated for high quality samples. Therefore, the surface topology is investigated directly with atomic force microscopy (AFM) on the actual TEM samples. Additionally, the sectioning of those samples by a focused ion beam (FIB) is used to investigate the damage depth profile directly in the TEM. The AFM measurements show good quantitative agreement of sample height modulation due to strain relaxation to finite elements simulations. Strong indications of (sub-) surface damage by ion beams are observed. Their influence on high angle annular dark field (HAADF) imaging is estimated with focus on thickness determination by absolute intensity methods. Data consolidation of AFM and TEM measurements reveals a 3.5 nm surface amorphization, negligible surface roughness on the scale of angstroms and a sub-surface damage profile in the range of up to 8.0 nm in crystalline gallium arsenide (GaAs) and GaAs-based ternary alloys. A correction scheme for thickness evaluation of absolute HAADF intensities is proposed and applied for GaAs based materials. - Highlights: • The damage by Ar-ion milling during TEM sample preparation is investigated directly. • After FIB sectioning damage and deep disorder of c-GaAs is seen in cross-section. • The influence of such disorder on conventional ADF measurements is estimated. • A correction for HAADF measurements is proposed with focus on thickness estimations.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation.

Science.gov (United States)

Joshi, Niranjan; Shetty, Sridhar N; Prasad, Krishna D

2013-01-01

The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

A new strategy to simultaneous increase in the strength and ductility of AA2024 alloy via accumulative roll bonding (ARB)

Energy Technology Data Exchange (ETDEWEB)

Naseri, M.; Reihanian, M. [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz (Iran, Islamic Republic of); Borhani, E., E-mail: e.borhani@semnan.ac.ir [Department of Nano Technology, Nano Materials Group, Semnan University, Semnan (Iran, Islamic Republic of)

2016-02-22

Nano/ultrafine grained (NG/UFG) AA2024 alloy produced by accumulative roll bonding (ARB) showed high strength (420 MPa) and very limited elongation (about 1.3%). A new strategy via ARB was developed to improve elongation (about 10%) of AA2024 alloy with a relatively high strength (365 MPa). The present strategy produced a bimodal structure consisting of coarse and ultrafine elongated grains in comparison to the UFG alloy. Electron backscattered diffraction (EBSD) revealed that after 4 ARB cycles, the fraction of high angle grain boundaries and mean misorientation angle of the boundaries in the bimodal grain structure were 61% and 27.34°, respectively, in comparison to that of annealed (54% and 24.96°) and UFG (79% and 34.27°) alloy. The crystallographic texture results indicated that, unlike the annealed AA2024 alloy, the intensity of Brass {011}<211> and S {123}<634> components remarkably increased in the UFG and bimodal alloy. Scanning electron microscopy (SEM) observations demonstrated that failure mode in bimodal alloy was ductile fracture with a combination of deep and shallow dimples.

Release of axonally transported material from an in vitro amphibian sciatic nerve preparation

International Nuclear Information System (INIS)

Snyder, R.E.

1988-01-01

The rapid axonal transport of a pulse of [35S]methionine-labelled material was used to study the release of transported material from amphibian nerve maintained in vitro. Following creation of a moving pulse of activity in a dorsal root ganglion-sciatic nerve preparation, the ganglion was removed and the nerve placed in a three-compartment tray, the section of nerve in the middle compartment containing no truncated branches (unbranched section). All three compartments were filled with a saline solution that in some studies contained nonradioactive methionine (1.0 mmol/L). Analysis of studies in which nonradioactive methionine was absent revealed that labelled material appeared in the bathing solution of the end compartments that contained truncated branches, but not in the solution of the middle (unbranched) compartment. The quantity of label released in the branched compartments was approximately 6% of that remaining in the corresponding section of nerve following an 18-20 h incubation period. However, when nonradioactive methionine was present, all compartments showed an additional activity in the bathing solution of approximately 10% of that remaining in the nerve. In another study in which a position-sensitive detector of ionizing radiation was used to monitor progress of the pulse, it was found that activity did not enter the bathing solution of a compartment prior to the pulse of activity. It is concluded that in the absence of methionine from the bathing solution, axonally transported material is released only from regions of nerve that contain severed axons; however, the presence of methionine allows transported material to be released from nerve containing intact axons. Ultrafiltration studies and thin-layer chromatography revealed the majority of material released to be of low-molecular weight (less than 30,000 daltons) and not free [35S]methionine

QUECHUA LANGUAGE MATERIALS PROJECT, GUIDE TO THE MATERIALS.

Science.gov (United States)

SOLA, DONALD F.

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

Study on preparation of montmorillonite-based composite phase change materials and their applications in thermal storage building materials

International Nuclear Information System (INIS)

Fang Xiaoming; Zhang Zhengguo; Chen Zhonghua

2008-01-01

Three composite phase change materials (PCMs) were prepared by blending butyl stearate, dodecanol and RT20 with an organically modified montmorillonite (MMT), respectively. After the three composite PCMs were characterized by DSC, it was indicated that the RT20/MMT composite PCM was a good candidate for building applications due to its large latent heat, suitable phase change temperature and good performance stability. Compared with RT20, the RT20/MMT composite PCM exhibited higher heat transfer efficiency and had good compatibility with gypsum due to the combination with MMT. The composite gypsum boards containing RT20/MMT composite PCM had the function of reducing building energy consumption by reducing the indoor temperature variation, and the function was enhanced with the increase in the mass ratio of the RT20/MMT composite PCM

Preparing technicians for engineering materials technology

Science.gov (United States)

Jacobs, James A.; Metzloff, Carlton H.

1990-01-01

A long held principle is that for every engineer and scientist there is a need for ten technicians to maximize the efficiency of the technology team for meeting needs of industry and government. Developing an adequate supply of technicians to meet the requirements of the materials related industry will be a challenge and difficult to accomplish. A variety of agencies feel the need and wish to support development of engineering materials technology programs. In a joint effort among Battelle Laboratories, the Department of Energy (DOE) and Northwest College and University Association for Science (NORCUS), the development of an engineering materials technology program for vocational programs and community colleges for the Pacific Northwest Region was recently completed. This effort has implications for a national model. The model Associate of Applied Science degree in Engineering Materials Technology shown provides a general structure. It purposely has course titles which need delimiting while also including a core of courses necessary to develop cognitive, affective and psychomotor skills with the underlining principles of math, science and technology so students have job entry skills, and so that students can learn about and adapt to evolving technology.

Carbon nanotubes for gas detection: materials preparation and device assembly

International Nuclear Information System (INIS)

Terranova, M L; Lucci, M; Orlanducci, S; Tamburri, E; Sessa, V; Reale, A; Carlo, A Di

2007-01-01

An efficient sensing device for NH 3 and NO x detection has been realized using ordered arrays of single-walled C nanotubes deposited onto an interdigitated electrode platform operating at room temperature. The sensing material has been prepared using several chemical-physical techniques for purification and positioning of the nanotubes inside the electrode gaps. In particular, both DC and AC fields have been applied in order to move and to align the nanostructures by electrophoresis and dielectrophoresis processes. We investigated the effects of different voltages applied to a gate contact on the back side of the substrate on the performances of the device and found that for different gas species (NH 3 , NO x ) a constant gate bias increases the sensitivity for gas detection. Moreover, in this paper we demonstrate that a pulsed bias applied to the gate contact facilitates the gas interaction with the nanotubes, either reducing the absorption times or accelerating the desorption times, thus providing a fast acceleration and a dramatic improvement of the time dependent behaviour of the device

Preparation of an In-House Reference Material Containing Fumonisins in Thai Rice and Matrix Extension of the Analytical Method for Japanese Rice

Science.gov (United States)

Awaludin, Norhafniza; Nagata, Reiko; Kawasaki, Tomomi; Kushiro, Masayo

2009-01-01

Mycotoxin contamination in rice is less reported, compared to that in wheat or maize, however, some Fusarium fungi occasionally infect rice in the paddy field. Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which often ruins maize. Rice adherent fungus Gibberella fujikuroi is taxonomically near to F. verticillioides, and there are sporadic reports of fumonisin contamination in rice from Asia, Europe and the United States. Therefore, there exists the potential risk of fumonisin contamination in rice as well as the need for the validated analytical method for fumonisins in rice. Although both natural and spiked reference materials are available for some Fusarium mycotoxins in matrices of wheat and maize, there are no reference materials for Fusarium mycotoxins in rice. In this study, we have developed a method for the preparation of a reference material containing fumonisins in Thai rice. A ShakeMaster grinding machine was used for the preparation of a mixed material of blank Thai rice and F. verticillioides-infected Thai rice. The homogeneity of the mixed material was confirmed by one-way analysis of variance, which led this material to serve as an in-house reference material. Using this reference material, several procedures to extract fumonisins from Thai rice were compared. Accordingly, we proved the applicability of an effective extraction procedure for the determination of fumonisins in Japanese rice. PMID:22069540

Preparation, characterization and thermal properties of binary nitrate salts/expanded graphite as composite phase change material

Energy Technology Data Exchange (ETDEWEB)

Xiao, Junbing [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Huang, Jin, E-mail: huangjiner@126.com [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Zhu, Panpan; Wang, Changhong [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Li, Xinxi [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing (China)

2014-07-01

Highlights: • The expanded graphite enhanced thermal conductivity coefficient greatly. • The aqueous solution method adopting ultrasonic was utilized to disperse EG. • The combination of composite was physical without chemical reaction. • The reduction on total latent heat was slight after the adding EG. - Abstract: The binary nitrate salts/expanded graphite (EG) composite phase change material (PCM) were prepared via adding different mass rate of EG to binary nitrate salts consisting of NaNO{sub 3} and KNO{sub 3} (6:4) by aqueous solution method adopting ultrasonic. The morphology and chemical composition of EG and the composite PCM were characterized and investigated by X-ray diffraction (XRD), scan electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), respectively. Laser thermal conductivity instrument and differential scanning calorimeter (DSC) were employed to measure thermo physical properties. Drawing the conclusion from investigation, that EG had enhanced thermal conductivity coefficient which largely increased to 4.884 W/(m K) and reduced total latent heat by mostly 11.0%. The morphology and phase structure results indicated that EG were well dispersed into and physically combined with molten salts. In general, the prepared composite PCM could be a suitable phase change material for thermal energy storage.

Preparation, characterization and thermal properties of binary nitrate salts/expanded graphite as composite phase change material

International Nuclear Information System (INIS)

Xiao, Junbing; Huang, Jin; Zhu, Panpan; Wang, Changhong; Li, Xinxi

2014-01-01

Highlights: • The expanded graphite enhanced thermal conductivity coefficient greatly. • The aqueous solution method adopting ultrasonic was utilized to disperse EG. • The combination of composite was physical without chemical reaction. • The reduction on total latent heat was slight after the adding EG. - Abstract: The binary nitrate salts/expanded graphite (EG) composite phase change material (PCM) were prepared via adding different mass rate of EG to binary nitrate salts consisting of NaNO 3 and KNO 3 (6:4) by aqueous solution method adopting ultrasonic. The morphology and chemical composition of EG and the composite PCM were characterized and investigated by X-ray diffraction (XRD), scan electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM), respectively. Laser thermal conductivity instrument and differential scanning calorimeter (DSC) were employed to measure thermo physical properties. Drawing the conclusion from investigation, that EG had enhanced thermal conductivity coefficient which largely increased to 4.884 W/(m K) and reduced total latent heat by mostly 11.0%. The morphology and phase structure results indicated that EG were well dispersed into and physically combined with molten salts. In general, the prepared composite PCM could be a suitable phase change material for thermal energy storage

Nano-sized Li4Ti5O12 anode material with excellent performance prepared by solid state reaction: The effect of precursor size and morphology

International Nuclear Information System (INIS)

Li, Xiangru; Hu, Hao; Huang, Sheng; Yu, Gaige; Gao, Lin; Liu, Haowen; Yu, Ying

2013-01-01

Graphical abstract: - Highlights: • Nano-sized Li 4 Ti 5 O 12 has been prepared through solid state reaction by using axiolitic TiO 2 as precursor. • The prepared nano-sized Li 4 Ti 5 O 12 anode material shows excellent electrochemical performance. • The utilization of precursor with special morphology and size is one of the useful ways to prepare more active electrode materials. - Abstract: Spinel nano-sized Li 4 Ti 5 O 12 anode material of secondary lithium-ion battery has been successfully prepared by solid state reaction using axiolitic TiO 2 assembled by 10–20 nm nanoparticles and Li 2 CO 3 as precursors. The synthesis condition, grain size effect and corresponding electrochemical performance of the special Li 4 Ti 5 O 12 have been studied in comparison with those of the normal Li 4 Ti 5 O 12 originated from commercial TiO 2 . We also propose the mechanism that using the nano-scaled TiO 2 with special structure and unexcess Li 2 CO 3 as precursors can synthesize pure phase nano-sized Li 4 Ti 5 O 12 at 800 °C through solid state reaction. The prepared nano-sized Li 4 Ti 5 O 12 anode material for Li-ion batteries shows excellent capacity performance with rate capacity of 174.2, 164.0, 157.4, 146.4 and 129.6 mA h g −1 at 0.5, 1, 2, 5 and 10 C, respectively, and capacity retention of 95.1% after 100 cycles at 1 C. In addition, the specific capacity fade for the cell with the different Li 4 Ti 5 O 12 active materials resulted from the increase of internal resistance after 100 cycles is compared

Isotope research materials

International Nuclear Information System (INIS)

Anon.

1977-01-01

Preparation of research isotope materials is described. Topics covered include: separation of tritium from aqueous effluents by bipolar electrolysis; stable isotope targets and research materials; radioisotope targets and research materials; preparation of an 241 Am metallurgical specimen; reactor dosimeters; ceramic and cermet development; fission-fragment-generating targets of 235 UO 2 ; and wire dosimeters for Westinghouse--Bettis

Preparation and Thermal Properties of Eutectic Hydrate Salt Phase Change Thermal Energy Storage Material

OpenAIRE

Liang, Lin; Chen, Xi

2018-01-01

In this study, a new cold storage phase change material eutectic hydrate salt (K2HPO4·3H2O–NaH2PO4·2H2O–Na2S2O3·5H2O) was prepared, modified, and tested. The modification was performed by adding a nucleating agent and thickener. The physical properties such as viscosity, surface tension, cold storage characteristics, supercooling, and the stability during freeze-thaw cycles were studied. Results show that the use of nucleating agents, such as sodium tetraborate, sodium fluoride, and nanoparti...

Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

Science.gov (United States)

Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

2013-12-01

Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Preparation of candidate reference materials for the determination of phosphorus containing flame retardants in styrene-based polymers.

Science.gov (United States)

Roth, Thomas; Urpi Bertran, Raquel; Latza, Andreas; Andörfer-Lang, Katrin; Hügelschäffer, Claudia; Pöhlein, Manfred; Puchta, Ralph; Placht, Christian; Maid, Harald; Bauer, Walter; van Eldik, Rudi

2015-04-01

Candidate reference materials (RM) for the analysis of phosphorus-based flame retardants in styrene-based polymers were prepared using a self-made mini-extruder. Due to legal requirements of the current restriction for the use of certain hazardous substances in electrical and electronic equipment, focus now is placed on phosphorus-based flame retardants instead of the brominated kind. Newly developed analytical methods for the first-mentioned substances also require RMs similar to industrial samples for validation and verification purposes. Hence, the prepared candidate RMs contained resorcinol-bis-(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), triphenyl phosphate and triphenyl phosphine oxide as phosphorus-based flame retardants. Blends of polycarbonate and acrylonitrile-co-butadiene-co-styrene as well as blends of high-impact polystyrene and polyphenylene oxide were chosen as carrier polymers. Homogeneity and thermal stability of the candidate RMs were investigated. Results showed that the candidate RMs were comparable to the available industrial materials. Measurements by ICP/OES, FTIR and NMR confirmed the expected concentrations of the flame retardants and proved that analyte loss and degradation, respectively, was below the uncertainty of measurement during the extrusion process. Thus, the candidate RMs were found to be suitable for laboratory use.

Preparation and Photocatalytic Property of TiO2/Diatomite-Based Porous Ceramics Composite Materials

Directory of Open Access Journals (Sweden)

Shuilin Zheng

2012-01-01

Full Text Available The diatomite-based porous ceramics was made by low-temperature sintering. Then the nano-TiO2/diatomite-based porous ceramics composite materials were prepared by hydrolysis deposition method with titanium tetrachloride as the precursor of TiO2 and diatomite-based porous as the supporting body of the nano-TiO2. The structure and microscopic appearance of nano-TiO2/diatomite-based porous ceramics composite materials was characterized by XRD and SEM. The photocatalytic property of the composite was investigated by the degradation of malachite green. Results showed that, after calcination at 550°C, TiO2 thin film loaded on the diatomite-based porous ceramics is anatase TiO2 and average grain size of TiO2 is about 10 nm. The degradation ratio of the composite for 5 mg/L malachite green solution reached 86.2% after irradiation for 6 h under ultraviolet.

Preparation of an estuarine sediment quality control material for the determination of trace metals

Directory of Open Access Journals (Sweden)

Hatje Vanessa

2006-01-01

Full Text Available Quality Control Materials (QCM have being used routinely in daily laboratory work as a tool to fill the gap between need and availability of Certified Reference Materials (CRM. The QCM are a low-cost alternative to CRMs, and they are in high demand, especially, for the implementation of quality control systems in laboratories of several areas. This paper describes the preparation of a QCM for the determination of trace metals in estuarine sediments and the results of an interlaboratory exercise. Homogeneity and stability studies were performed and analysis of variance was carried out with the results. No statistical significant differences were observed in the concentrations of Co, Cr, Cu, Mn, Pb and Zn between- or within bottle results. Neither the storage nor temperature affected the results. Therefore, the QCM produced is considered homogeneous and stable and can be used for statistical control charts, evaluation of reproducibility and interlaboratory exercises.

Microstructural development under interrupted hot deformation and the mechanical properties of a cast Mg–Gd–Y–Zr alloy

Energy Technology Data Exchange (ETDEWEB)

Xiao, Zhenyu [Educational Key Laboratory of Nonferrous Metal Materials Science and Engineering, School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yang, Xuyue [Educational Key Laboratory of Nonferrous Metal Materials Science and Engineering, School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Institute for Materials Microstructure, Central South University, Changsha 410083 (China); Yang, Yi; Zhang, Zhirou; Zhang, Duxiu; Li, Yi [Educational Key Laboratory of Nonferrous Metal Materials Science and Engineering, School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Sakai, Taku [UEC Tokyo (The University of Electro-Communications), Chofu, Tokyo 182-8585 (Japan)

2016-01-15

Microstructural development under interrupted hot deformation of a cast Mg–Gd–Y–Zr alloy was investigated by optical microscopy (OM) and electron backscattering diffraction (EBSD) technology and the resultant mechanical properties were detected through tensile tests at room temperature. Ultrafine grains (UFGs) were remarkably developed under the condition of interrupted hot forging, resulting in an improvement of ambient mechanical properties. The basal texture was weakened by an effective increase of the volume fraction of UFGs under interrupted hot forging. These resulted in an improvement of tensile ductility with little or no drop in strength, i.e. the volume fraction of UFGs was raised from 30% to 70%, leading to an increase of the ambient tensile elongation from 15% to 23%.

Solvothermal preparation of ZnO nanorods as anode material for improved cycle life Zn/AgO batteries.

Directory of Open Access Journals (Sweden)

Shafiq Ullah

Full Text Available Nano materials with high surface area increase the kinetics and extent of the redox reactions, thus resulting in high power and energy densities. In this study high surface area zinc oxide nanorods have been synthesized by surfactant free ethylene glycol assisted solvothermal method. The nanorods thus prepared have diameters in the submicron range (300 ~ 500 nm with high aspect ratio. They have uniform geometry and well aligned direction. These nanorods are characterized by XRD, SEM, Specific Surface Area Analysis, solubility in alkaline medium, EDX analysis and galvanostatic charge/discharge studies in Zn/AgO batteries. The prepared zinc oxide nanorods have low solubility in alkaline medium with higher structural stability, which imparts the improved cycle life stability to Zn/AgO cells.

Preparation of n-type Bi{sub 2}Te{sub 3} thermoelectric materials by non-contact dispenser printing combined with selective laser melting

Energy Technology Data Exchange (ETDEWEB)

Wu, Keping; Yan, Yonggao; Zhang, Jian; Mao, Yu; Xie, Hongyao; Zhang, Qingjie; Tang, Xinfeng [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei (China); Yang, Jihui [Department of Materials Science and Engineering, University of Washington, Seattle, WA (United States); Uher, Ctirad [Department of Physics, University of Michigan, Ann Arbor, MI (United States)

2017-06-15

The manufacturing cost has been a bottle neck for broader applications of thermoelectric (TE) modules. We have developed a rapid, facile, and low cost method that combines non-contact dispenser printing with selective laser melting (SLM) and we demonstrate it on n-type Bi{sub 2}Te{sub 3}-based materials. Using this approach, single phase n-type Bi{sub 2}Te{sub 2.7}Se{sub 0.3} thin layers with the Seebeck coefficient of -152 μV K{sup -1} at 300 K have been prepared. Assembling such thin layers on top of each other, the performance of thus prepared bulk sample is comparable to Bi{sub 2}Te{sub 3}-based materials fabricated by the conventional techniques. Dispenser printing combined with SLM is a promising manufacturing process for TE materials. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Preparation and thermal energy storage properties of paraffin/expanded graphite composite phase change material

International Nuclear Information System (INIS)

Zhang, Zhengguo; Zhang, Ni; Peng, Jing; Fang, Xiaoming; Gao, Xuenong; Fang, Yutang

2012-01-01

Highlights: ► EG was obtained by microwave irradiation to prepare the paraffin/EG composite PCM. ► Composite PCM was characterized by XRD to investigate the chemical compatibility. ► Temperature profiles of the composite PCM were obtained during thermal energy storage. -- Abstract: The paraffin/expanded graphite (EG) composite phase change material (PCM) was prepared by absorbing liquid paraffin into EG, in which paraffin was chosen as the PCM. EG was produced by microwave irradiation performed at room temperature. It was found that the EG prepared at 800 W irradiation power for 10 s exhibited the maximum sorption capacity of 92 wt% for paraffin. Scanning electron microscopy images showed that paraffin was uniformly dispersed in the pores of EG. Differential scanning calorimeter analysis indicated that the melting temperature of the composite PCM was close to that of paraffin, and its latent heat was equivalent to the calculated value based on the mass fraction of paraffin in the composite. X-ray diffraction analysis showed that the composite PCM was just a combination of paraffin with EG, and no new substance was produced. Thermal energy storage performance of the composite PCM was tested in a latent thermal energy storage (LTES) system. Transients of axial and radial temperature profiles were obtained in the LTES for the composite PCM and paraffin. The thermal energy storage charging duration for the composite PCM was reduced obviously compared to paraffin.

Preparation and enhanced electrochemical properties of nano-sulfur/poly(pyrrole-co-aniline) cathode material for lithium/sulfur batteries

International Nuclear Information System (INIS)

Qiu Linlin; Zhang Shichao; Zhang Lan; Sun, Mingming; Wang Weikun

2010-01-01

Poly(pyrrole-co-aniline) (PPyA) copolymer nanofibers were prepared by chemical oxidation method with cetyltrimethyl ammonium chloride (CTAC) as template, and the nano-sulfur/poly(pyrrole-co-aniline) (S/PPyA) composite material in lithium batteries was achieved via co-heating the mixture of PPyA and sublimed sulfur at 160 deg. C for 24 h. The component and structure of the materials were characterized by FTIR, Raman, XRD, and SEM. PPyA with nanofiber network structure was employed as a conductive matrix, adsorbing agent and firm reaction chamber for the sulfur cathode materials. The nano-dispersed composite exhibited a specific capacity up to 1285 mAh g -1 in the initial cycle and remained 866 mAh g -1 after 40 cycles.

Hydrophilic nanoporous materials

DEFF Research Database (Denmark)

2010-01-01

The present application discloses a method for preparing and rendering hydrophilic a nanoporous material of a polymer matrix which has a porosity of 0.1-90 percent (v/v), such that the ratio between the final water absorption (percent (w/w)) and the porosity (percent (v/v)) is at least 0.05, the ......The present application discloses a method for preparing and rendering hydrophilic a nanoporous material of a polymer matrix which has a porosity of 0.1-90 percent (v/v), such that the ratio between the final water absorption (percent (w/w)) and the porosity (percent (v/v)) is at least 0.......05, the method comprising the steps of: (a) preparing a precursor material comprising at least one polymeric component and having a first phase and a second phase; (b) removal of at least a part of the first phase of the precursor material prepared in step (a) so as to leave behind a nanoporous material...... of the polymer matrix; (c) irradiating at least a part of said nanoporous material with light of a wave length of in the range of 250-400 nm (or 200-700 nm) in the presence of oxygen and/or ozone. Corresponding hydrophilic nanoporous materials are also disclosed. L...

High temperature tensile properties and their application to toughness enhancement in ultra-fine grained W-(0-1.5)wt% TiC

Energy Technology Data Exchange (ETDEWEB)

Kurishita, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan)], E-mail: kurishi@imr.tohoku.ac.jp; Matsuo, S.; Arakawa, H.; Narui, M.; Yamazaki, M. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Sakamoto, T.; Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime University, Matsuyama, Ehime 790-8577 (Japan); Takida, T.; Takebe, K. [A.L.M.T. Corp., 2 Iwase-koshi-machi, Toyama, Toyama 931-8543 (Japan); Kawai, M. [Institute of Material Structure Science, KEK, Tsukuba, Ibaraki 305-0801 (Japan); Yoshida, N. [Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

2009-04-30

Ultra-fine grained (UFG) W-TiC consolidates are very promising for use as divertors in fusion reactors, however, the assurance of room-temperature ductility of UFG W-TiC remains unsettled. The assurance requires a sufficient degree of plastic working for the consolidates and thus overcoming of poor plastic workability in UFG W-TiC by applying superplasticity. Therefore, the magnitudes of elongation to fracture and flow stress which are important measures for plastic working were examined for UFG W-(0-1.5)%TiC (in wt%) at 1673-1973 K where superplasticity occurs without appreciable grain growth. It is shown that the elongation and flow stress are strongly dependent on TiC addition and atmosphere (Ar, H{sub 2}) during mechanical alloying (MA). As the TiC addition increases, the elongation significantly increases without appreciable increase in the flow stress level. W-TiC fabricated with MA in H{sub 2} exhibits larger elongation and larger strain rate sensitivity of flow stress than W-TiC with MA in Ar. These results were applied to perform plastic working and the room-temperature bend test results for plastic worked W-1.0%TiC are shown.

Preparation of calibration materials for microanalysis of Ti minerals by direct fusion of synthetic and natural materials: experience with LA-ICP-MS analysis of some important minor and trace elements in ilmenite and rutile.

Science.gov (United States)

Odegård, M; Mansfeld, J; Dundas, S H

2001-08-01

Calibration materials for microanalysis of Ti minerals have been prepared by direct fusion of synthetic and natural materials by resistance heating in high-purity graphite electrodes. Synthetic materials were FeTiO3 and TiO2 reagents doped with minor and trace elements; CRMs for ilmenite, rutile, and a Ti-rich magnetite were used as natural materials. Problems occurred during fusion of Fe2O3-rich materials, because at atmospheric pressure Fe2O3 decomposes into Fe3O4 and O2 at 1462 degrees C. An alternative fusion technique under pressure was tested, but the resulting materials were characterized by extensive segregation and development of separate phases. Fe2O3-rich materials were therefore fused below this temperature, resulting in a form of sintering, without conversion of the materials into amorphous glasses. The fused materials were studied by optical microscopy and EPMA, and tested as calibration materials by inductively coupled plasma mass spectrometry, equipped with laser ablation for sample introduction (LA-ICP-MS). It was demonstrated that calibration curves based on materials of rutile composition, within normal analytical uncertainty, generally coincide with calibration curves based on materials of ilmenite composition. It is, therefore, concluded that LA-ICP-MS analysis of Ti minerals can with advantage be based exclusively on calibration materials prepared for rutile, thereby avoiding the special fusion problems related to oxide mixtures of ilmenite composition. It is documented that sintered materials were in good overall agreement with homogeneous glass materials, an observation that indicates that in other situations also sintered mineral concentrates might be a useful alternative for instrument calibration, e.g. as alternative to pressed powders.

Preparation of DNA from cytological material: effects of fixation, staining, and mounting medium on DNA yield and quality.

Science.gov (United States)

Dejmek, Annika; Zendehrokh, Nooreldin; Tomaszewska, Malgorzata; Edsjö, Anders

2013-07-01

Personalized oncology requires molecular analysis of tumor cells. Several studies have demonstrated that cytological material is suitable for DNA analysis, but to the authors' knowledge there are no systematic studies comparing how the yield and quality of extracted DNA is affected by the various techniques used for the preparation of cytological material. DNA yield and quality were compared using cultured human lung cancer cells subjected to different preparation techniques used in routine cytology, including fixation, mounting medium, and staining. The results were compared with the outcome of epidermal growth factor receptor (EGFR) genotyping of 66 clinical cytological samples using the same DNA preparation protocol. All tested protocol combinations resulted in fragment lengths of at least 388 base pairs. The mounting agent EcoMount resulted in higher yields than traditional xylene-based medium. Spray and ethanol fixation resulted in both a higher yield and better DNA quality than air drying. In liquid-based cytology (LBC) methods, CytoLyt solution resulted in a 5-fold higher yield than CytoRich Red. Papanicolaou staining provided twice the yield of hematoxylin and eosin staining in both liquid-based preparations. Genotyping outcome and quality control values from the clinical EGFR genotyping demonstrated a sufficient amount and amplifiability of DNA in both spray-fixed and air-dried cytological samples. Reliable clinical genotyping can be performed using all tested methods. However, in the cell line experiments, spray- or ethanol-fixed, Papanicolaou-stained slides provided the best results in terms of yield and fragment length. In LBC, the DNA recovery efficiency of the preserving medium may differ considerably, which should be taken into consideration when introducing LBC. Cancer (Cancer Cytopathol) 2013;121:344-353. © 2013 American Cancer Society. © 2013 American Cancer Society.

Analyte-triggered luminescence of Eu{sup 3+} ions encapsulated in Nafion membranes -preparation of hybrid materials from in membrane chemical reactions-

Energy Technology Data Exchange (ETDEWEB)

Aguilar-Sánchez, Rocío, E-mail: raguilar@ifuap.buap.mx [Depto. Química Analítica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570 (Mexico); Zelocualtecatl-Montiel, Iván [Depto. Química Analítica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570 (Mexico); Gálvez-Vázquez, María de Jesús [Depto. Química Analítica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570 (Mexico); Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado postal J-48, Puebla 72570 (Mexico); Silva-González, Rutilo [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado postal J-48, Puebla 72570 (Mexico)

2017-04-15

The possibility to perform chemical reactions inside polymer materials opens a unique opportunity to control and prepare materials for diverse solid-state applications. Based on the affinity of Eu{sup 3+} ions for oxygen functionalities, in this work we report the luminescence enhancement of Eu{sup 3+} ions inserted in Nafion membranes (Naf/Eu{sup 3+}) by in-situ complexing to oxalate. The formation of a europium-oxalate type complex enhances Eu{sup 3+} luminescence emission, which could be exploited for the construction of devices for oxalate sensing and the fabrication of highly luminescent materials. Possible analytical applications of Naf/Eu{sup 3+} membranes were evaluated by fluorescence spectroscopy through the linear response with concentration. The complex formation was followed by infrared spectroscopy and SEM-EDS analysis. - Highlights: • Luminescence enhancement by complexation of Eu{sup 3+} ions to oxalate inside Nafion. • Performance of chemical reactions inside Nafion/polymer membranes. • An easy and novel method to prepare luminescent solid devices. • Possibility to develop luminescent sensors by analyte-triggered optical response.

Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

OpenAIRE

Musa Ahmad; T.W. Tan

2017-01-01

An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to ...

The Polymerization of MMA and ST to Prepare Material with Gradient Refractive Index in Electric Field

Directory of Open Access Journals (Sweden)

Yao Huang

2015-01-01

Full Text Available Light scattering material with gradient refractive index was prepared under the electrical field by taking methyl methacrylate (MMA monomer as the matrix with the addition of a little preheated styrene (ST and peroxidation benzoin formyl (BPO. The material obtained under electrical field presented different transmittance and molecular weight at different parts of the cylindrical sample along the axis of the direction of electric field which led to the layering phenomenon and gradient refractive index. The disparity of molecular weight between different layers can be as much as 230 thousand. There were several peaks in the figure of GPC test of the sample under electric field. This proved that there were polymers with different molecular weights in the sample. Therefore, it can be concluded that electrical field has a significant effect on polymerization.

Division of Materials Science (DMS) meeting presentation

Energy Technology Data Exchange (ETDEWEB)

Cline, C.F.; Weber, M.J.

1982-11-08

Materials preparation techniques are listed. Materials preparation capabilities are discussed for making BeF/sub 2/ glasses and other materials. Materials characterization techniques are listed. (DLC)

High Strength-High Ductility Combination Ultrafine-Grained Dual-Phase Steels Through Introduction of High Degree of Strain at Room Temperature Followed by Ultrarapid Heating During Continuous Annealing of a Nb-Microalloyed Steel

Science.gov (United States)

Deng, Yonggang; Di, Hongshuang; Hu, Meiyuan; Zhang, Jiecen; Misra, R. D. K.

2017-07-01

Ultrafine-grained dual-phase (UFG-DP) steel consisting of ferrite (1.2 μm) and martensite (1 μm) was uniquely processed via combination of hot rolling, cold rolling and continuous annealing of a low-carbon Nb-microalloyed steel. Room temperature tensile properties were evaluated and fracture mechanisms studied and compared to the coarse-grained (CG) counterpart. In contrast to the CG-DP steel, UFG-DP had 12.7% higher ultimate tensile strength and 10.7% greater uniform elongation. This is partly attributed to the increase in the initial strain-hardening rate, decrease in nanohardness ratio of martensite and ferrite. Moreover, a decreasing number of ferrite grains with {001} orientation increased the cleavage fracture stress and increased the crack initiation threshold stress with consequent improvement in ductility UFG-DP steel.

Kinetic, volumetric and structural effects induced by liquid Ga penetration into ultrafine grained Al

International Nuclear Information System (INIS)

Naderi, Mehrnoosh; Peterlechner, Martin; Schafler, Erhard; Divinski, Sergiy V.; Wilde, Gerhard

2015-01-01

Kinetic, volumetric and structural effects induced by penetration of liquid Ga in ultrafine grained (UFG) Al produced by severe plastic deformation using high-pressure torsion were studied by isothermal dilatometric measurements, electron microscopy, atomic force microscopy and X-ray diffraction. Severe plastic deformation changed the distribution of impurities and their segregation was revealed by transmission electron microscopy. Two-stage length changes of UFG Al were observed which are explained by counteracting effects of expansion due to grain boundary segregation of Ga and contraction due to precipitation and recrystallization. After applying Ga, the kinetics of the liquid Ga penetration in UFG Al is studied in-situ in the electron microscope by the “first appearance” method and the time scales are in agreement with those inducing the volumetric changes

Preparation and characterisation of mixed silicon oxycarbide materials; Preparacion y caracterizacion de materiales de oxicarburo de silicio mixtos

Energy Technology Data Exchange (ETDEWEB)

Tellez, L.; Tamayo, A.; Mazo, M. A.; Rubio, F.; Rubio, J.

2010-07-01

In this work different mixed Silicon oxicarbide materials have been prepared. Si, Si-Ti, Si-Zr and Si-Al oxicarbide materials have been obtained from pyrolisis at 1000 degree centigrade and 1300 degree centigrade of the respective preceramic materials. After pyrolisis X, D and T units of the oxycarbide structure have been observed in such materials. They show the presence of Si-C and Si-O bonds in a given material. The characterization has been carried out by means of FT-IR, Raman NMR {sup 2}9Si, NMR {sup 1}3C and XRD. The formation of Si-Ti, Si-Zr and Si-Al bonds has been estimated in accordance with the decrease of the Si-O-Si wave number observed in the FT-IR spectra. Si and Si-Ti oxycarbide materials do not lead to crystallisation after pyrolisis at highest temperatures, however for Si-Zr and Si-Al oxycarbide materials different crystalline phases have been observed. All pyrolised materials present free and carbidic carbon. After pyrolisis at 1300 degree centigrade the free carbon reacts with Si-O bonds to form SiC{sub 4} groups which must be assigned to nucleus of the {beta}-SiC crystals. (Author)

Preparation of polymeric materials by radiation for different industrial waste treatment

International Nuclear Information System (INIS)

Maziad, N.A.M.

1997-01-01

Preparation of synthetic membranes using radiation induced graft copolymerization of styrene ( Sty ), acrylic acid ( A Ac ) and styrene/acrylic acid (Sty/A Ac) onto low density polyethylene ( LDPE ), polypropylene ( PP ) and polyvinyl chloride ( PVC ) films are carried out . The effect of preparation conditions on the grafting yield and on the homogeneity of grafting is thoroughly investigated. Characterization and some physical properties such as mechanical, electrical conductivity and thermal behaviour of the prepared grafted membranes are studied. Thus, the possibility of their practicable use are determined. In addition, possible applications of such prepared membranes in the separation of heavy metals such as Fe 3+, Cd 2+ and Pb 2+ from waste water are investigated. It is found that, the prepared grafted membranes have a good affinity towards the adsorption or chelation with F 3+ and Pb 2+ either in a mixture containing other metals or if they exist alone in the feed solution . It is recommended that such prepared grafted membranes could be useful in separation of Pb 2+ ions from a mixture of other metal ions

Preparation and thermal properties of Glauber’s salt-based phase-change materials for Qinghai-Tibet Plateau solar greenhouses

Science.gov (United States)

Jiang, Zipeng; Tie, Shengnian

2017-07-01

This paper reports the preparation and characterization of eutectic Glauber’s salt-based composite, phase-change materials (G-PCMs). PCMs were prepared using industrial-grade sodium sulfate decahydrate (Na2SO4 ṡ 10H2O) as the basic material. Other salts were added to obtain the eutectic Glauber’s salt-based PCMs with phase-change temperatures of 25∘C, 15∘C and 10∘C. The modification of the G-PCMs was designed using the same experimental method to select the efficient nucleating, thickening and thermal conductive agents. The results show that borax can be an effective nucleating agent, sodium carboxymethyl cellulose is an excellent thickener and carbon powder is a good thermal conductive agent. The phase-change temperature, latent heat and thermal conductivity of the three different PCMs are 23.9∘C, 15.4∘C and 9.5∘C; 179.6, 129 and 116.2 J/g; and 1.02, 1.10 and 1.23 W/(m K), respectively. These PCMs possess suitable phase-change temperature, high latent heat and good thermal conductivity, and can be used in Qinghai-Tibet Plateau agricultural solar greenhouses.

A practical method for target preparation of powdered materials

International Nuclear Information System (INIS)

Sugai, Isao.

1977-01-01

This is the sixth report on the practical method of target preparation for use in nuclear physics experiments following the previous one (INS-TL-131, 1976). We have made various targets by developing the centrifugal precipitation method, which is particularly effective in the cases; (a) metal with high melting point and low vapor pressure, (b) oxides which are difficult to prepare by the usual vacuum evaporation technique and (c) some enriched isotopes which are very minute in quantity (less than - 10 mg) and low in recovery ratio. The samples were once suspended in liquid paraffin by ultrasonic wave vibrator, and then centrifugally precipitated on a thin backing foil such as Mylar or aluminum set and the bottom of the centrifugal tube. Uniformity of target made in this way was checked by an 24 Am-α ray thickness gauge. Contaminations smudged in the preparing process were checked by irradiating the targets with the proton beam from the FM Cyclotron at I.N.S. (auth.)

Definition and preparation of glassy matrices by innovating processes to confine radioactive wastes and industrial toxic materials

International Nuclear Information System (INIS)

Moncouyoux, J.P.

1995-01-01

The confinement by vitrification of high-level radioactive wastes is studied in the CEA for fifteen years. These studies have lead to the preparation of glassy matrices by innovating processes. These processes can be applied to non-radioactive toxic materials treatment too. In this work are more particularly described the glassy matrix long-dated behaviour and the different vitrification processes used (by direct induction in cold crucible, by transferred arc plasma). (O.L.). 1 tab

Preparation and Thermal Properties of Eutectic Hydrate Salt Phase Change Thermal Energy Storage Material

Directory of Open Access Journals (Sweden)

Lin Liang

2018-01-01

Full Text Available In this study, a new cold storage phase change material eutectic hydrate salt (K2HPO4·3H2O–NaH2PO4·2H2O–Na2S2O3·5H2O was prepared, modified, and tested. The modification was performed by adding a nucleating agent and thickener. The physical properties such as viscosity, surface tension, cold storage characteristics, supercooling, and the stability during freeze-thaw cycles were studied. Results show that the use of nucleating agents, such as sodium tetraborate, sodium fluoride, and nanoparticles, are effective. The solidification temperature and latent heat of these materials which was added with 0, 3, and 5 wt% thickeners were −11.9, −10.6, and −14.8°C and 127.2, 118.6, 82.56 J/g, respectively. Adding a nucleating agent can effectively improve the nucleation rate and nucleation stability. Furthermore, increasing viscosity has a positive impact on the solidification rate, supercooling, and the stability during freeze-thaw cycles.

Preparation and properties of the fast-curing γ-ray-shielding materials based on polyurethane

Energy Technology Data Exchange (ETDEWEB)

Ni, Minxuan; Tang, Xiao Bin; Chai, Hao; Zhang, Yun; Chen, Tuo; Chen, Da [Dept. of Nuclear Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing (China)

2016-12-15

In this study, fast-curing shielding materials were prepared with a two-component polyurethane matrix and a filler material of PbO through a one-step, laboratory-scale method. With an increase in the filler content, viscosity increased. However, the two components showed a small difference. Curing time decreased as the filler content increased. The minimum tack-free time of 27 s was obtained at a filler content of 70 wt%. Tensile strength and compressive strength initially increased and then decreased as the filler content increased. Even when the filler content reached 60 wt%, mechanical properties were still greater than those of the matrix. Cohesional strength decreased as the filler content increased. However, cohesional strength was still greater than 100 kPa at a filler content of 60 wt%. The γ-ray-shielding properties increased with the increase in the filler content, and composite thickness could be increased to improve the shielding performance when the energy of γ-rays was high. When the filler content was 60 wt%, the composite showed excellent comprehensive properties.

Preparation, characterization, and thermal properties of microencapsulated phase change material for thermal energy storage

Energy Technology Data Exchange (ETDEWEB)

Alkan, Cemil; Sari, Ahmet; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey); Uzun, Orhan [Department of Physics, Gaziosmanpasa University, 60240 Tokat (Turkey)

2009-01-15

This study is focused on the preparation, characterization, and determination of thermal properties of microencapsulated docosane with polymethylmethacrylate (PMMA) as phase change material for thermal energy storage. Microencapsulation of docosane has been carried out by emulsion polymerization. The microencapsulated phase change material (MEPCM) was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Thermal properties and thermal stability of MEPCM were measured by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). DSC analysis indicated that the docosane in the microcapsules melts at 41.0 C and crystallizes at 40.6 C. It has latent heats of 54.6 and -48.7 J/g for melting and crystallization, respectively. TGA showed that the MEPCM degraded in three distinguishable steps and had good chemical stability. Accelerated thermal cycling tests also indicated that the MEPCM had good thermal reliability. Based on all these results, it can be concluded that the microencapsulated docosane as MEPCMs have good potential for thermal energy storage purposes such as solar space heating applications. (author)

The preparation and electrochemical performances of LiFePO4-multiwalled nanotubes composite cathode materials for lithium ion batteries

International Nuclear Information System (INIS)

Feng Yan

2010-01-01

LiFePO 4 -MWCNTs (multi-walled carbon nanotubes) composite cathode materials were prepared by mixing LiFePO 4 and MWCNTs in ethanol followed by heat-treatment at 500 deg. C for 5 h. The structural, morphology and electrochemical performances of LiFePO 4 -MWCNTs composite materials were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), galvanostatic charge-discharge cycle tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicated that MWCNTs adding improved the electronic conductivity, the discharge capacity, cycle stability and lithium ion diffusion kinetics of LiFePO 4 , but MWCNTs adding did not charge the orthorhombic olivine-type structure of LiFePO 4 . In all these prepared LiFePO 4 with x wt.% MWCNTs (x = 4, 7, 10) composites, 7 wt.% MWCNTs adding composite cathode shows the best electrochemical performance, which gets an initial discharge capacity of 152.7 mAh g -1 at 0.18 C discharge rates with capacity retention ratio of 97.77% after 100 cycles.

Preparation of Epoxidized Palm Olein as Renewable Material by Using Peroxy Acids

International Nuclear Information System (INIS)

Darfizzi Derawi; Jumat Salimon; Waled Abdo Ahmed

2014-01-01

Epoxidized palm olein (EPO o ) was prepared through generated in situ of performic acid (HCOOOH), and peracetic acid (CH 3 COOOH) as epoxidation agent with the presence of sulphuric acid (H 2 SO 4 ) 3 % v/ wt as catalyst. Formic acid (HCOOH) or acetic acid (CH 3 COOH) as oxygen carrier and hydrogen peroxide (H 2 O 2 ) as oxygen donor in the reaction system. Highly conversion (95.5 %) of oxirane ring was obtained by using performic acid as epoxidation agent at 150 minutes of reaction time. The reaction yield was 90 % by weight. EPO o has showed good physicochemical properties as renewable material for industrial applications. Carbon ( 13 C-NMR) and proton ( 1 H-NMR) spectra showed the present of epoxy profile at 54 ppm and 2.9 ppm. Epoxy group was detected on 844 cm -1 by fourier transformation infra-red (FTIR) spectra. (author)

Preparation and properties of lauric acid/silicon dioxide composites as form-stable phase change materials for thermal energy storage

International Nuclear Information System (INIS)

Fang Guiyin; Li Hui; Liu Xu

2010-01-01

Form-stable lauric acid (LA)/silicon dioxide (SiO 2 ) composite phase change materials were prepared using sol-gel methods. The LA was used as the phase change material for thermal energy storage, with the SiO 2 acting as the supporting material. The structural analysis of these form-stable LA/SiO 2 composite phase change materials was carried out using Fourier transformation infrared spectroscope (FT-IR). The microstructure of the form-stable composite phase change materials was observed by a scanning electronic microscope (SEM). The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the LA was well dispersed in the porous network of SiO 2 . The DSC results indicated that the melting latent heat of the form-stable composite phase change material is 117.21 kJ kg -1 when the mass percentage of the LA in the SiO 2 is 64.8%. The results of the TGA showed that these materials have good thermal stability. The form-stable composite phase change materials can be used for thermal energy storage in waste heat recovery and solar heating systems.

The preparation and performance of calcium carbide-derived carbon/polyaniline composite electrode material for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Zheng, Liping; Wang, Xianyou; Li, Na; An, Hongfang; Chen, Huajie [School of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications of Minister of Education, Xiangtan University, Hunan 411105 (China); Wang, Ying; Guo, Jia [School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Hubei 430073 (China)

2010-03-15

Calcium carbide (CaC{sub 2})-derived carbon (CCDC)/polyaniline (PANI) composite materials are prepared by in situ chemical oxidation polymerization of an aniline solution containing well-dispersed CCDC. The structure and morphology of CCDC/PANI composite are characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM) and N{sub 2} sorption isotherms. It has been found that PANI was uniformly deposited on the surface and the inner pores of CCDC. The supercapacitive behaviors of the CCDC/PANI composite materials are investigated with cyclic voltammetry (CV), galvanostatic charge/discharge and cycle life measurements. The results show that the CCDC/PANI composite electrodes have higher specific capacitances than the as grown CCDC electrodes and higher stability than the conducting polymers. The capacitance of CCDC/PANI composite electrode is as high as 713.4 F g{sup -1} measured by cyclic voltammetry at 1 mV s{sup -1}. Besides, the capacitance retention of coin supercapacitor remained 80.1% after 1000 cycles. (author)

Uniform β-Co(OH)2 disc-like nanostructures prepared by low-temperature electrochemical rout as an electrode material for supercapacitors

Science.gov (United States)

Aghazadeh, Mustafa; Shiri, Hamid Mohammad; Barmi, Abbas-Ali Malek

2013-05-01

Uniform nanostructures of cobalt hydroxide were successfully prepared by a low-temperature electrochemical method via galvanostatically deposition from a 0.005 M Co(NO3)3 bath at 10 °C. The XRD and FT-IR analyses showed that the prepared sample has a single crystalline hexagonal phase of the brucite-like Co(OH)2. Morphological characterization by SEM and TEM revealed that the prepared β-Co(OH)2 was composed of uniform compact disc-like nanostructures with diameters of 40-50 nm. The electrochemical performance of the prepared β-Co(OH)2 was evaluated using cyclic voltammetry and charge-discharge tests. A maximum specific capacitance of 736.5 F g-1 was obtained in aqueous 1 M KOH with the potential range of -0.2-0.5 V (vs. Ag/AgCl) at the scan rate of 10 mV s-1, suggesting the potential application of the prepared nanostructures as an electrode material in electrochemical supercapacitors. The results of this work showed that the low-temperature cathodic electrodeposition method can be recognized as a new and facile route for the synthesis of cobalt hydroxide nanodiscs as a promising candidate for the electrochemical supercapacitors.

Effect of Hydrogen Peroxide Content on the Preparation of Peroxotitanate Materials for the Treatment of Radioactive Wastewater

Directory of Open Access Journals (Sweden)

Wein-Duo Yang

2016-01-01

Full Text Available The modification of peroxotitanate using hydrogen peroxide significantly improved the ion-exchange capacity of titanate materials as sorbents for metal ions contained in a radioactive waste simulant solution. The effects of hydrogen peroxide content (hydrogen peroxide/titanium isopropoxide molar ratios, hereafter expressed as H/T on the properties of as-prepared titanate synthesized at 130°C and at pH of 6-7, followed by freeze-drying, were investigated. The peroxotitanate materials thus obtained were characterized by XRD, BET, SEM, TEM, EDX, ICP, and Raman spectroscopy. At an H/T ratio of 2, peroxotitanate predominantly exhibited an amorphous structure, with a clearly observed tubular or fibrous structure. Furthermore, peroxotitanate modified at an H/T ratio of 2 exhibited the best ion-exchange capacity of 191 mg g−1 for metal ions contained in a radioactive waste simulant solution. Hence, these peroxotitanate materials are suitable for removing metal ions from wastewater, especially lanthanide ions (Ln3+ and Sr2+.

Preparation and thermal properties of short carbon fibers/erythritol phase change materials

International Nuclear Information System (INIS)

Zhang, Qiang; Luo, Zhiling; Guo, Qilin; Wu, Gaohui

2017-01-01

Highlights: • Short carbon fiber (SCF)/erythritol phase change composites (PCCs) are prepared and tested. • The PCCs possess large heat capacity and high thermal conductivity. • The size of SCFs can affect thermal conductivities of SCF/erythritol PCCs. • The size of SCFs has negligible effects on melting points and enthalpies. • The SCF/erythritol PCCs show good temperature-regulated property. - Abstract: The thermal properties of the short carbon fibers (SCFs) filled erythritol phase change composites (PCCs) were investigated experimentally. The samples were prepared with different mass loadings of two kinds of SCFs, 1%, 2%, 4%, 7% and 10%. The melting points and phase change enthalpies were measured by differential scanning calorimeter (DSC). The effects of SCFs on the melting points are relatively small but the enthalpies were reduced with the loadings of SCFs. The greatest loss of enthalpies is 11.3% for composites filled with 10% SCFs. The thermal conductivities increased with the loadings of SCFs but not linearly. The highest thermal conductivity is 3.92 W/(m⋅K) for the composites with 10% longer SCFs, which was enhanced by 407.8% compared to pure erythritol (0.77 W/(m⋅K)). Composites filled with longer SCFs possess higher thermal conductivity and the mechanisms were discussed. A simple setup was made to test the temperature-regulated property of these materials. These include pure erythritol and phase change composites with different loading of SCFs. The PCCs have shown good application potential and the longer SCFs can lead to the better performance of PCCs.

Highly conductive cathode materials for Li-ion batteries prepared by thermal nanocrystallization of selected oxide glasses

Energy Technology Data Exchange (ETDEWEB)

Pietrzak, T.K.; Wasiucionek, M.; Michalski, P.P.; Kaleta, A.; Garbarczyk, J.E., E-mail: garbar@if.pw.edu.pl

2016-11-15

Glassy analogs of two important cathode materials for Li-ion cells: V{sub 2}O{sub 5} and phosphoolivine LiFePO{sub 4} were heat-treated in order to prepare nanocrystallized materials with high electronic conductivity of up to 7 × 10{sup −2} S cm{sup −1} and ca 7 × 10{sup −3} S cm{sup −1} at 25 °C, respectively. There is a clear correlation between the crystallization phenomena and the increase in the electrical conductivity for both groups of glasses. Electrochemical tests of heat-treated glasses of the V{sub 2}O{sub 5}–P{sub 2}O{sub 5} system, used as cathodes in lithium cells confirm their good gravimetric capacity and reversibility. Heat-treatment of glasses of the Li{sub 2}O–FeO–V{sub 2}O{sub 5}–P{sub 2}O{sub 5} system also leads to a high increase in the conductivity and to formation of nanocrystalline grains in the glassy matrix, evidenced by HR-TEM images. The temperature dependence of the conductivity of these materials follows the Arrhenius formula. The presented results indicate that the overall increase in conductivity in nanocrystallized materials is due to good charge transport properties of their interfacial regions.

Preparation and certification of Re-Os dating reference materials: Molybdenites HLP and JDC

Science.gov (United States)

Du, A.; Wu, S.; Sun, D.; Wang, Shaoming; Qu, W.; Markey, R.; Stain, H.; Morgan, J.; Malinovskiy, D.

2004-01-01

Two Re-Os dating reference material molybdenites were prepared. Molybdenite JDC and molybdenite HLP are from a carbonate vein-type molybdenum-(lead)- uranium deposit in the Jinduicheng-Huanglongpu area of Shaanxi province, China. The samples proved to be homogeneous, based on the coefficient of variation of analytical results and an analysis of variance test. The sampling weight was 0.1 g for JDC and 0.025 g for HLP. An isotope dilution method was used for the determination of Re and Os. Sample decomposition and preconcentration of Re and Os prior to measurement were accomplished using a variety of methods: acid digestion, alkali fusion, ion exchange and solvent extraction. Negative thermal ionisation mass spectrometry and inductively coupled plasma-mass spectrometry were used for the determination of Re and 187Os concentration and isotope ratios. The certified values include the contents of Re and Os and the model ages. For HLP, the Re content was 283.8 ?? 6.2 ??g g-1, 187Os was 659 ?? 14 ng g-1 and the Re-Os model age was 221.4 ?? 5.6 Ma. For JDC, the Re content was 17.39 ?? 0.32 ng g-1, 187Os was 25.46 ?? 0.60 ng g-1 and the Re-Os model age was 139.6 ?? 3.8 Ma. Uncertainties for both certified reference materials are stated at the 95% level of confidence. Three laboratories (from three countries: P.R. China, USA, Sweden) joined in the certification programme. These certified reference materials are primarily useful for Re-Os dating of molybdenite, sulfides, black shale, etc.

Nanograined Ti–Nb microalloy steel achieved by Accumulative Roll Bonding (ARB) process

International Nuclear Information System (INIS)

Tohidi, A.A.; Ketabchi, M.; Hasannia, A.

2013-01-01

Over the last decade, nanocrystalline and ultra-fine grained (UFG) materials with grain size less than 1 μm have aroused considerable interest due to their superior mechanical properties compared to conventionally grained materials. In this work Ti–Nb microalloy steel was processed by the severe plastic deformation (SPD) technique called Accumulative Roll Bonding (ARB) in order to produce an ultra-fine grained microstructure and improve the mechanical properties. After initial preparation to achieve good sheet bonding, 8 cycles of ARB at 550 °C were successfully performed. Observation of optical microstructure, scanning electron microscopy (SEM) micrographs, and X-Ray Diffraction (XRD) peak broadening analysis were used for the characterization of grain structure of the ARB processed sample. The mechanical attributes after rolling and cooling were examined. It was calculated that metal's yield and tensile strength increased by 334% and 215% respectively, while the ductility dropped from as-received value of 34% to 2.9%. Microhardness of the material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of the ARB process. At the 8th pass, the hardness values increased by 230%. The rolling process was stopped at 8th cycle when cracking of the edge became pronounced

Preparation of molecularly imprinted polymers simazine as material potentiometric sensor

Directory of Open Access Journals (Sweden)

Bow Yohandri

2017-01-01

Full Text Available Molecular imprinting technology is a promising technique for creating recognition elements for selected compounds and has been successfully applied for synthesis of environmental pollutants such as simazine. Simazine is a pesticide ingredient that is commonly used in agriculture, which has devastating effects on the environment if used excessively. Molecularly imprinted polymer (MIP provides cavities to form a particular space generated by removing the template when the polymer has formed. In this study, MIP using simazine as template had been made by the cooling-heating method and used as a material potentiometric sensor for detecting simazine. A template (simazine was incorporated into a pre-polymerization solution that contains a methacrylic acid as functional monomer, an ethylene glycol dimethacrylate as cross linker, and benzoyl peroxide as initiator. Characterization was performed by scanning electron microscope (SEM and fourier transforms infra-red (FTIR. The FTIR spectra of the MIP showed that the peaks of amine group decrease significantly, indicating that the simazine concentration decreases drastically. Characterization by SEM images showing the broadest pore size distribution with the highest number of pores in the MIP prepared under the heating time of 150 min. The MIPs therefore could be applied as a simazine sensor.

40 CFR 761.323 - Sample preparation.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sample preparation. 761.323 Section... Remediation Waste Samples § 761.323 Sample preparation. (a) The comparison study requires analysis of a... concentrations by dilution. Any excess material resulting from the preparation of these samples, which is not...

Preparation and certification of the Polish reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis

International Nuclear Information System (INIS)

Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z.

1997-01-01

A new Polish certified reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis has been prepared. Certification of the candidate reference material was based on the world-wide interlaboratory comparison in which 60 laboratories from 18 countries, participated using various analytical methods and techniques. Data evaluation performed by means of the new multifunctional software package -SSQC. Recommended values were assigned for 33 and 'information' values for 10 elements, respectively. The validity of 'certified' values was confirmed for several elements using 'very accurate' methods developed in this Laboratory. (author)

Hierarchical porous carbon materials prepared using nano-ZnO as a template and activation agent for ultrahigh power supercapacitors.

Science.gov (United States)

Wang, Haoran; Yu, Shukai; Xu, Bin

2016-09-20

Hierarchical porous carbon materials with high surface areas and a localized graphitic structure were simply prepared from sucrose using nano-ZnO as a hard template, activation agent and graphitization catalyst simultaneously, which exhibit an outstanding high-rate performance and can endure an ultrafast scan rate of 20 V s -1 and ultrahigh current density of 1000 A g -1 .

Appropriate materials and preparation techniques for polycrystalline-thin-film thermophotovoltaic cells

Science.gov (United States)

Dhere, Neelkanth G.

1997-03-01

Polycrystalline-thin-film thermophotovoltaic (TPV) cells have excellent potential for reducing the cost of TPV generators so as to address the hitherto inaccessible and highly competitive markets such as self-powered gas-fired residential warm air furnaces and energy-efficient electric cars, etc. Recent progress in polycrystalline-thin-film solar cells have made it possible to satisfy the diffusion length and intrinsic junction rectification criteria for TPV cells operating at high fluences. Continuous ranges of direct bandgaps of the ternary and pseudoternary compounds such as Hg1-xCdxTe, Pb1-xCdxTe, Hg1-xZnxTe, and Pb1-xZnxS cover the region of interest of 0.50-0.75 eV for efficient TPV conversion. Other ternary and pseudoternary compounds which show direct bandgaps in most of or all of the 0.50-0.75 eV range are Pb1-xZnxTe, Sn1-xCd2xTe2, Pb1-xCdxSe, Pb1-xZnxSe, and Pb1-xCdxS. Hg1-xCdxTe (with x~0.21) has been studied extensively for infrared detectors. PbTe and Pb1-xSnxTe have also been studied for infrared detectors. Not much work has been carried out on Hg1-xZnxTe thin films. Hg1-xCdxTe and Pb1-xCdxTe alloys cover a wide range of cut-off wavelengths from the far infrared to the near visible. Acceptors and donors are introduced in these materials by excess non-metal (Te) and excess metal (Hg and Pb) respectively. Extrinsic acceptor impurities are Cu, Au, and As while and In and Al are donor impurities. Hg1-xCdxTe thin films have been deposited by isothermal vapor-phase epitaxy (VPE), liquid phase epitaxy (LPE), hot-wall metalorganic chemical vapor deposition (MOCVD), electrodeposition, sputtering, molecular beam epitaxy (MBE), laser-assisted evaporation, and vacuum evaporation with or without hot-wall enclosure. The challenge in the preparation of Hg1-xCdxTe is to provide excess mercury incidence rate, to optimize the deposition parameters for enhanced mercury incorporation, and to achieve the requisite stoichiometry, grain size, and doping. MBE and MOCVD

Preparation, characterization, and thermal properties of the microencapsulation of a hydrated salt as phase change energy storage materials

International Nuclear Information System (INIS)

Huang, Jin; Wang, Tingyu; Zhu, Panpan; Xiao, Junbin

2013-01-01

Highlights: ► Phase change point and fusion heat of samples are about 51 °Cand 150 J/g respectively. ► DSC results indicated the core material is not Na 2 HPO 4 ·12H 2 O but Na 2 HPO 4 ·7H 2 O. ► Encapsulation takes a significant role in reducing subcooling degree. - Abstract: Microcapsules loaded by disodium hydrogen phosphate heptahydrate (Na 2 HPO 4 ·7H 2 O) were prepared by means of the suspension copolymerization-solvent volatile method, with modified polymethylmethacrylate (PMMA) as coating polymer under the conditions of various organic solvents. The formation of the microencapsulated phase change materials (MEPCMs)-PMMA/Na 2 HPO 4 ·7H 2 O was investigated and analyzed. The morphology of the resultant materials was characterized by using scanning electron microscope (SEM) and phase contrast microscope. Its final composition was confirmed by the Fourier transformation infrared (FT-IR). Thermo gravimetric analyzer (TGA) and differential scanning calorimetry (DSC) were adopted to reveal its thermal stability and thermal properties. Results indicated that the materials owned improved subcooling degree and good thermal properties, enabling the materials to be one promising phase change materials for thermal energy storage

Preparation, characterization, and thermal properties of the microencapsulation of a hydrated salt as phase change energy storage materials

Energy Technology Data Exchange (ETDEWEB)

Huang, Jin, E-mail: huangjiner@126.com [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Wang, Tingyu; Zhu, Panpan; Xiao, Junbin [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China)

2013-04-10

Highlights: ► Phase change point and fusion heat of samples are about 51 °Cand 150 J/g respectively. ► DSC results indicated the core material is not Na{sub 2}HPO{sub 4}·12H{sub 2}O but Na{sub 2}HPO{sub 4}·7H{sub 2}O. ► Encapsulation takes a significant role in reducing subcooling degree. - Abstract: Microcapsules loaded by disodium hydrogen phosphate heptahydrate (Na{sub 2}HPO{sub 4}·7H{sub 2}O) were prepared by means of the suspension copolymerization-solvent volatile method, with modified polymethylmethacrylate (PMMA) as coating polymer under the conditions of various organic solvents. The formation of the microencapsulated phase change materials (MEPCMs)-PMMA/Na{sub 2}HPO{sub 4}·7H{sub 2}O was investigated and analyzed. The morphology of the resultant materials was characterized by using scanning electron microscope (SEM) and phase contrast microscope. Its final composition was confirmed by the Fourier transformation infrared (FT-IR). Thermo gravimetric analyzer (TGA) and differential scanning calorimetry (DSC) were adopted to reveal its thermal stability and thermal properties. Results indicated that the materials owned improved subcooling degree and good thermal properties, enabling the materials to be one promising phase change materials for thermal energy storage.

Hierarchically mesoporous silica materials prepared from the uniaxially stretched polypropylene membrane and surfactant templates

International Nuclear Information System (INIS)

Wang Xiaocong; Ma Jin; Liu Jin; Zhou Chen; Zhao, Yan; Yi Shouzhi; Yang Zhenzhong

2006-01-01

Hierarchically mesoporous silica materials with a bimodal distribution were template-prepared from uniaxially stretched polypropylene membrane in the presence of a surfactant via a sol-gel process. Their regularity and morphologies were characterized by transmission electron microscopy (TEM), x-ray diffraction and Brunauer-Emmett-Teller (BET) surface area analysis. The larger channel pores formed by removing the microfibrils of uniaxially stretched polypropylene membrane have a broad pore size distribution, and their size is around 13 nm. In contrast, the smaller mesopores formed by surfactant templates have a narrow distribution; their size is about 3.9 nm. The size of the smaller pores could be tuned from 2 to 6 nm by selecting different surfactants and by changing the concentration of reactants

Preparation of high-purity cerium nitrate

International Nuclear Information System (INIS)

Avila, Daniela Moraes; Silva Queiroz, Carlos Alberto da; Santos Mucillo, Eliana Navarro dos

1995-01-01

The preparation of high-purity cerium nitrate has been carried out Cerium oxide has been prepared by fractioned precipitation and ionic exchange techniques, using a concentrate with approximately 85% of cerium oxide from NUCLEMON as raw material. Five sequential ion-exchange columns with a retention capacity of 170 g each have been used. The ethylenediamine-tetraacetic acid (EDTA) was used as eluent. The cerium content has been determined by gravimetry and iodometry techniques. The resulting cerium oxide has a purity > 99%. This material was transformed in cerium nitrate to be used as precursor for the preparation of Zirconia-ceria ceramics by the coprecipitation technique. (author)

Room temperature deformation mechanisms in ultrafine-grained materials processed by hot isostatic pressing

International Nuclear Information System (INIS)

Cao, W.Q.; Dirras, G.F.; Benyoucef, M.; Bacroix, B.

2007-01-01

Ultrafine-grained (uf-g) and microcrystalline-grained (mc-g) irons have been fabricated by hot isostatic pressing of nanopowders. The mechanical properties have been characterized by compressive tests at room temperature and the resulting microstructures and textures have been determined by combining electron back scatter diffraction and transmission electron microscopy. A transition of the deformation mode, from work hardening to work softening occurs for grain sizes below ∼1 μm, reflecting a transition of the deformation mode from homogeneous to localized deformation into shear bands (SBs). The homogeneous deformation is found to be lattice dislocation-based while the deformation within SBs involves lattice dislocations as well as boundary-related mechanisms, possibly grain boundary sliding accommodated by boundary opening

Preparation and properties of palmitic-stearic acid eutectic mixture/expanded graphite composite as phase change material for energy storage

International Nuclear Information System (INIS)

Zhang, Nan; Yuan, Yanping; Du, Yanxia; Cao, Xiaoling; Yuan, Yaguang

2014-01-01

A novel composite PCM (phase change material) with PA-SA (palmitic-stearic acid) eutectic mixture as PCM and EG (expanded graphite) as supporting material was prepared. The optimum absorption ratio of PA-SA/EG (Palmitic-stearic acid/expanded graphite) composite PCM was determined as PA-SA:EG = 13:1 (by mass). Scanning electron microscope and Fourier transformation infrared spectroscopy results show that PA-SA was uniformly distributed in the porous network structure of EG due to the physical action. Thermal property and thermal stability of the PA-SA/EG composite PCM were characterized by DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis). DSC results indicated that the melting and freezing temperatures and latent heats of PA-SA/EG were measured as 53.89 °C and 54.37 °C, and 166.27 J/g and 166.13 J/g. TGA test results revealed that PA-SA/EG had a good thermal stability in working temperature range. Thermal cycling test results showed PA-SA/EG had a good thermal reliability after 720 thermal cycles. Thermal conductivity of the composite PCM was measured as 2.51 W/m K, much higher than that of PA-SA. The thermal energy storage and release rates of PA-SA/EG were also increased due to the high thermal conductivity of EG. In conclusion, the prepared PA-SA/EG composite PCM can be acted as a potential material for thermal energy storage due to the acceptable thermal properties, good thermal reliability and stability, high thermal conductivity. - Highlights: • PA-SA/EG (Palmitic-stearic acid/expanded graphite) composite PCM was prepared. • Optimum absorption ratio of PA-SA in EG was obtained as 13:1 (by mass). • Thermal conductivity and performance of PA-SA/EG have been significate improved. • PA-SA/EG has a good thermal reliability and thermal stability

Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

Directory of Open Access Journals (Sweden)

Musa Ahmad

2017-11-01

Full Text Available An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to any pH changes and could be used to determine the end-point of the acid-base titration.

Preparation and characterization of hybrid materials from natural chrysotile; Preparacao e caracterizacao de materiais hibridos a partir da crisotila natural

Energy Technology Data Exchange (ETDEWEB)

Giraldelli, M.G.; Silva, M.L.C.P., E-mail: marciogiraldelli@hotmail.co [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia

2010-07-01

Special attention has been given to the development of new materials from natural chrysotile. This fiber has about 40% silicon oxide in its structure with an outer layer of brucite (MgOH{sub 2}). With the aim of obtaining a material with a more uniform structure, acid leaching was performed to remove the outer layer of brucite, resulting in a silicon oxide hydrate. This material was used as support for the deposition of Nb{sub 2}O{sub 5}.nH{sub 2}O. The Nb{sub 2}O{sub 5}.nH{sub 2}O was prepared by conventional precipitation using as starting material niobium metallic. In this study, we performed the synthesis and characterization of the material SiO{sub 2}.nH{sub 2}O / Nb{sub 2}O{sub 5}.nH{sub 2}O 1:1. Both chrysotile as niobium are widely available national resources, which confirms the economic viability of resource use. The materials studied were characterized by XRD, SEM and TG/DTG. (author)

Preparation and properties of poly(vinyl alcohol)-g-octadecanol copolymers based solid–solid phase change materials

International Nuclear Information System (INIS)

Shi Haifeng; Li Jianhua; Jin Yanmei; Yin Yiping; Zhang Xingxiang

2011-01-01

Highlights: ► In this paper, our objective is just focused on the preparation and characterization of such SSPCMs aiming at providing one suitable material for improving the thermal stability and preventing the liquid leakage from the matrix. Here, the SSPCMs can be fabricated by grafting to method between poly(vinyl alcohol) and octadecanol, which the grafting ratio can be controlled by adjusting the feeding components. ► The thermal properties, crystalline structure and morphology were detailed studies by WAXD, FT-IR, TGA and DSC, proving that the PVA-g-octadecanol process the better thermal storage ability and thermal stability. Compared with pure octadecanol, the heat fusion of PVA-g-octadecanol decreased due to the mobility confinement and the lower rearrangements of C18 alkyl side chains. ► This result is for the first time reported, and is a meaningful result for the investigation of the solid–solid phase change materials, and the preparation process provides one template-directed approach to obtain the high-performance materials with the better heat storage and thermal stability. - Abstract: The heat storage and phase transition behavior of a series of poly(vinyl alcohol)-g-octadecanol copolymers (PVA-g-C18OH) with apparent grafting ratios ranging from 283 to 503%, synthesized through “grafting to” method, has been investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM). PVA-g-C18OH copolymers exhibit the better thermal stability against C18OH, and the thermal energy storage ability (ΔH m ) is of dependence on the apparent grafting ratios. Compared with C18OH, the lower thermal storage efficiency possible is attributed to the less CH 2 groups entered into the crystalline domains and the frustrated mobility of the grafted C18 alkyl side chains between PVA backbones. The results show that

Preparation and certification of the Polish reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis

Energy Technology Data Exchange (ETDEWEB)

Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z.

1997-12-31

A new Polish certified reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis has been prepared. Certification of the candidate reference material was based on the world-wide interlaboratory comparison in which 60 laboratories from 18 countries, participated using various analytical methods and techniques. Data evaluation performed by means of the new multifunctional software package -SSQC. Recommended values were assigned for 33 and `information` values for 10 elements, respectively. The validity of `certified` values was confirmed for several elements using `very accurate` methods developed in this Laboratory. (author). 47 refs, 28 figs, 12 tabs.

Recent advances in applications of nanomaterials for sample preparation.

Science.gov (United States)

Xu, Linnan; Qi, Xiaoyue; Li, Xianjiang; Bai, Yu; Liu, Huwei

2016-01-01

Sample preparation is a key step for qualitative and quantitative analysis of trace analytes in complicated matrix. Along with the rapid development of nanotechnology in material science, numerous nanomaterials have been developed with particularly useful applications in analytical chemistry. Benefitting from their high specific areas, increased surface activities, and unprecedented physical/chemical properties, the potentials of nanomaterials for rapid and efficient sample preparation have been exploited extensively. In this review, recent progress of novel nanomaterials applied in sample preparation has been summarized and discussed. Both nanoparticles and nanoporous materials are evaluated for their unusual performance in sample preparation. Various compositions and functionalizations extended the applications of nanomaterials in sample preparations, and distinct size and shape selectivity was generated from the diversified pore structures of nanoporous materials. Such great variety make nanomaterials a kind of versatile tools in sample preparation for almost all categories of analytes. Copyright © 2015 Elsevier B.V. All rights reserved.

Preparation, characterization and use of a reference material to proficiency testing for determination of metals in fish tissue in natura

International Nuclear Information System (INIS)

Santana, Luciana Vieira de

2013-01-01

The proficiency tests are widely used to evaluate the analytical capacity of laboratories and also as part of the accreditation process. For this reason, are important tools for the control of the quality of the analytical results obtained in the laboratories that work directly with seafood companies. In Brazil there are no providers of proficiency testing for metals potentially toxic in fish tissues. In this work will be described all steps used for the production of reference materials to be used in a proficiency testing pilot study for As, Cd, Pb and Hg in fish tissue following the recommendations of the ISO Guide 35. He preparation scheme consisted in selecting the individuals, cleaning, grinding, homogenization and fortification with As, Cd and Pb in two concentration levels. The preparation resulted in 164 sachets of 10 g each. In order to evaluate the effect of gamma irradiation in the samples conservation 52 sachets were irradiated with 60 Co (10.00 ± 1.05 kGy) in a gamma cell. This material with others non irradiated 52 sachets were used for the homogeneity and stability studies. The remaining 60 were used for the proficiency testing. The results demonstrated that both materials were homogeneous and presented good stability (during a period of 45 days). However, the irradiated material present better integrity, concerning biological degradation, when stored in ambient temperature. For this reason they were used to the proficiency testing pilot program. Ten laboratories participated in the proficiency testing pilot study and the results were evaluated using the following tests: z-score, confidence ellipse and En numbers. This work demonstrates the capability of the laboratory to produce reference materials as well as to organize and conduct proficiency testing. (author)

PREPARATION OF ULTRA-LOW VOLUME WEIGHT AUTOCLAVED AERATED CONCRETE

Directory of Open Access Journals (Sweden)

Ondrej Koutny

2016-12-01

Full Text Available Autoclaved aerated concrete is a modern construction material that gains its popularity especially due to its thermal insulation performance resulting from low volume weight and porous structure with sufficient mechanical strength. Nowadays, there are attempts to use this material for thermal insulation purposes and to replace current systems, which have many disadvantages, mainly concerning durability. The key for improvement of thermal insulation properties is therefore obtaining a material based on autoclaved aerated concrete with extremely low volume weight (below 200 kg/m ³ ensuring good thermal isolation properties, but with sufficient mechanical properties to allow easy manipulation. This material can be prepared by foaming very fine powder materials such as silica fume or very finely ground sand. This paper deals with the possibilities of preparation and summarizes the basic requirements for successful preparation of such a material.

Restricted access magnetic materials prepared by dual surface modification for selective extraction of therapeutic drugs from biological fluids

Energy Technology Data Exchange (ETDEWEB)

Wang Yu; Wang Yuxia; Chen Lei [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China); Wan Qianhong, E-mail: qhwan@tju.edu.cn [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China)

2012-02-15

Magnetic porous particles with dual functionality have been prepared by a two-step procedure and evaluated as novel restricted access materials for extraction of therapeutic agents from biological fluids. The magnetic silica particles served as scaffolds were first modified with diol groups, which were then converted to octadecyl esters through reaction with stearoyl chloride. In the second step, the octadecyl esters on the exterior surface were hydrolyzed by the action of lipase to yield magnetic particles with hydrophobic reversed-phase ligands on the inner surface and biocompatible diol groups on the outer surface. The restricted access behavior of the resulting materials was confirmed by differential binding of small molecules such as methotrexate (MTX), leucovorin (LV) and folic acid (FA) relative to bovine serum albumin. While MTX, LV and FA were all bound to the magnetic particles with high affinity, the adsorption of the protein was markedly reduced due to size exclusion effect. The utility of the magnetic particles for sample preparation was tested in solid-phase extraction of MTX, LV and FA from spiked human serum and the effects of the SPE conditions on the recovery of the analytes were systematically studied. Moreover, the magnetic particle-based sample preparation procedure coupled with reversed-phase liquid chromatography analysis was validated in terms of specificity, linearity and reproducibility. The method was shown to be free from interference of endogenous compounds and linear over the concentration range of 0.5-10 {mu}g/mL for the three drugs studied. The limits of detection for the three drugs in serum were in the range of 0.160-0.302 {mu}g/mL. Reproducibility expressed as the RSD of the recovery for ten replicated extractions at three different concentrations was found to be less than 8.93%. With a unique combination of surface functionality with magnetic cores, the restricted access magnetic particles may be adapted in automated and high

Preparation and Characterization of Enzyme Compartments in UV-Cured Polyurethane-Based Materials and Their Application in Enzymatic Reactions

Directory of Open Access Journals (Sweden)

Diana Uhrich

2017-11-01

Full Text Available The preparation and characterization of UV-cured polyurethane-based materials for the mild inclusion immobilization of enzymes was investigated. Full curing of the polymer precursor/enzyme solution mixture was realized by a short irradiation with UV-light at ambient temperatures. The included aqueous enzyme solution remains highly dispersed in the polymer material with an even size distribution throughout the polymer material. The presented concept provides stable enzyme compartments which were applied for an alcohol dehydrogenase-catalyzed reduction reaction in organic solvents. Cofactor regeneration was achieved by a substrate-coupled approach via 2-propanol or an enzyme-coupled approach by a glucose dehydrogenase. This reaction concept can also be used for a simultaneous application of contrary biocatalytic reaction conditions within an enzymatic cascade reaction. Independent polymer-based reaction compartments were provided for two incompatible enzymatic reaction systems (alcohol dehydrogenase and hydroxynitrile lyase, while the relevant reactants diffuse between the applied compartments.

Preparation of iron-deposited graphite surface for application as cathode material during electrochemical vat-dyeing process

International Nuclear Information System (INIS)

Anbu Kulandainathan, M.; Kiruthika, K.; Christopher, G.; Babu, K. Firoz; Muthukumaran, A.; Noel, M.

2008-01-01

Iron-deposited graphite surfaces were prepared, characterized and employed as cathode materials for electrochemical vat-dyeing process containing very low concentration of sodium dithionite. The electrodeposition, in presence of ammonium thiocyanate and gelatin or animal glue as binding additives, were found to give finer iron deposits for improved electrochemical dyeing application. The electrodeposits were characterized using scanning electron microscopy, electron-dispersive X-ray spectroscopy and X-ray diffraction methods, before and after electrochemical dyeing process. The electrochemical activity of the iron-deposited graphite electrodes always stored in water seems to depend on the surface-bound Fe 3+ /Fe 2+ redox species. Vat dyes like C.I. Vat Violet 1, C.I. Vat Green 1 and C.I. Vat Blue 4 could be efficiently dyed employing these above electrode materials. The colour intensity and washing fastness of the dyed fabrics were found to be equal with conventionally dyed fabrics. The electrodes could also be reused for the dyeing process

Cathode material for lithium ion accumulators prepared by screen printing for Smart Textile applications

Science.gov (United States)

Syrový, T.; Kazda, T.; Syrová, L.; Vondrák, J.; Kubáč, L.; Sedlaříková, M.

2016-03-01

The presented study is focused on the development of LiFePO4 based cathode for thin and flexible screen printed secondary lithium based accumulators. An ink formulation was developed for the screen printing technique, which enabled mass production of accumulator's cathode for Smart Label and Smart Textile applications. The screen printed cathode was compared with an electrode prepared by the bar coating technique using an ink formulation based on the standard approach of ink composition. Obtained LiFePO4 cathode layers were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and galvanostatic charge/discharge measurements at different loads. The discharge capacity, capacity retention and stability at a high C rate of the LiFePO4 cathode were improved when Super P and PVDF were replaced by conductive polymers PEDOT:PSS. The achieved capacity during cycling at various C rates was approximately the same at the beginning and at the end, and it was about 151 mAh/g for cycling under 1C. The obtained results of this novelty electrode layer exceed the parameters of several electrode layers based on LiFePO4 published in literature in terms of capacity, cycling stability and overcomes them in terms of simplicity/industrial process ability of cathode layer fabrication and electrode material preparation.

Synthesis and characterization of nanostructured iron compounds prepared from the decomposition of iron pentacarbonyl dispersed into carbon materials with varying porosities

International Nuclear Information System (INIS)

Schettino, Miguel A. Jr.; Cunha, Alfredo G.; Nunes, Evaristo; Passamani, Edson C.; Freitas, Jair C. C.; Emmerich, Francisco G.; Morigaki, Milton K.

2016-01-01

This work describes the production and characterization of carbon-iron nanocomposites obtained from the decomposition of iron pentacarbonyl (Fe(CO) 5 ) mixed with different carbon materials: a high surface area activated carbon (AC), powdered graphite (G), milled graphite (MG), and carbon black (CB). The nanocomposites were prepared either under argon or in ambient atmosphere, with a fixed ratio of Fe(CO) 5 (4.0 mL) to carbon precursor (2.0 g). The images of scanning electron microscopy and the analysis of textural properties indicated the presence of nanostructured Fe compounds homogeneously dispersed into the different classes of pores of the carbon matrices. The elemental Fe content was always larger for samples prepared in ambient atmosphere, reaching values in the range of 20–32 wt%. On the other hand, samples prepared under argon showed reduced Fe content, with values in the range 5–10 wt% for samples prepared from precursors with low surface area (G, MG, and CB) and a much higher value (~19 wt%) for samples prepared from the precursor of high surface area (AC). Mössbauer spectroscopy and X-ray diffractometry showed that the nanoparticles were mostly composed of iron oxides in the case of the samples prepared in oxygen-rich ambient atmosphere and also for the AC-derived nanocomposite prepared under argon, which is consistent with the large oxygen content of this precursor. For the other precursors, with reduced or no oxygen content, metallic iron and iron carbides were found to be the dominant phases in samples prepared under oxygen-free atmosphere. The samples prepared in ambient atmosphere and the AC-derived sample prepared under argon exhibited superparamagnetic behavior at room temperature, as revealed by temperature-dependent magnetization curves and Mössbauer spectroscopy.

Amorphous and nanocrystalline materials preparation, properties, and applications

CERN Document Server

Inoue, A

2001-01-01

Amorphous and nanocrystalline materials are a class of their own. Their properties are quite different to those of the corresponding crystalline materials. This book gives systematic insight into their physical properties, structure, behaviour, and design for special advanced applications.

Microstructure, texture evolution, mechanical properties and corrosion behavior of ECAP processed ZK60 magnesium alloy for biodegradable applications.

Science.gov (United States)

Mostaed, Ehsan; Hashempour, Mazdak; Fabrizi, Alberto; Dellasega, David; Bestetti, Massimiliano; Bonollo, Franco; Vedani, Maurizio

2014-09-01

Ultra-fine grained ZK60 Mg alloy was obtained by multi-pass equal-channel angular pressing at different temperatures of 250°C, 200°C and 150°C. Microstructural observations showed a significant grain refinement after ECAP, leading to an equiaxed and ultrafine grain (UFG) structure with average size of 600nm. The original extrusion fiber texture with planes oriented parallel to extrusion direction was gradually undermined during ECAP process and eventually it was substituted by a newly stronger texture component with considerably higher intensity, coinciding with ECAP shear plane. A combination of texture modification and grain refinement in UFG samples led to a marked reduction in mechanical asymmetric behavior compared to the as-received alloy, as well as adequate mechanical properties with about 100% improvement in elongation to failure while keeping relatively high tensile strength. Open circuit potential, potentiodynamic and weight loss measurements in a phosphate buffer solution electrolyte revealed an improved corrosion resistance of UFG alloy compared to the extruded one, stemming from a shift of corrosion regime from localized pitting in the as-received sample to a more uniform corrosion mode with reduced localized attack in ECAP processed alloy. Compression tests on immersed samples showed that the rate of loss of mechanical integrity in the UFG sample was lower than that in the as-received sample. Copyright © 2014 Elsevier Ltd. All rights reserved.

Innovative methods for inorganic sample preparation

Energy Technology Data Exchange (ETDEWEB)

Essling, A.M.; Huff, E.A.; Graczyk, D.G.

1992-04-01

Procedures and guidelines are given for the dissolution of a variety of selected materials using fusion, microwave, and Parr bomb techniques. These materials include germanium glass, corium-concrete mixtures, and zeolites. Emphasis is placed on sample-preparation approaches that produce a single master solution suitable for complete multielement characterization of the sample. In addition, data are presented on the soil microwave digestion method approved by the Environmental Protection Agency (EPA). Advantages and disadvantages of each sample-preparation technique are summarized.

Innovative methods for inorganic sample preparation

International Nuclear Information System (INIS)

Essling, A.M.; Huff, E.A.; Graczyk, D.G.

1992-04-01

Procedures and guidelines are given for the dissolution of a variety of selected materials using fusion, microwave, and Parr bomb techniques. These materials include germanium glass, corium-concrete mixtures, and zeolites. Emphasis is placed on sample-preparation approaches that produce a single master solution suitable for complete multielement characterization of the sample. In addition, data are presented on the soil microwave digestion method approved by the Environmental Protection Agency (EPA). Advantages and disadvantages of each sample-preparation technique are summarized

Preparation and certification of certified reference materials JAERI-Z21, Z22 and Z23 for analysis of zirconium and its alloys

International Nuclear Information System (INIS)

Takashima, Kyoichiro

1991-03-01

The Sub-Committee on Chemical Analysis of Nuclear Materials was organized in April 1987, under the Committee on Analytical Chemistry of Nuclear Fuels and Reactor Materials, JAERI, for renewal of certified reference materials of zirconium base alloys and zirconium metal. Collaborative analysis was carried out among ten participating laboratories for the certification of the JAERI CRMs Z21 to Z23. As a results of the collaborative works, the certified values for sixteen elements (Sn, Fe, Ni, Cr, Hf, Al, Si, Co, Cu, Ti, Mn, Pb, U, Cd, B and W) in the CRMs were given. In this report, preparation of raw materials, homogeneity test, chemical analysis for certification by collaborative works during April 1987 to March 1990 are described. (author)

Preparation of eugenol-based polyurethane

Science.gov (United States)

Li, Yupeng; Luo, Fang; Cheng, Chuanjie

2018-03-01

The regenerative eugenol was used as the starting material to prepare diol species by two steps, with a total yield of 28%. Furthermore, the prepared diol reacts with 1,6-hexadiisocyanate(HDI) to afford the corresponding polyurethane (PU). The structure of intermediates and PU are characterized by 1H-NMR or IR.

Biomimetic hydrogel materials

Science.gov (United States)

Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

2000-01-01

Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

Preparation of Pt Nanocatalyst on Carbon Materials via a Reduction Reaction of a Pt Precursor in a Drying Process.

Science.gov (United States)

Lee, Jae-Young; Lee, Woo-Kum; Rim, Hyung-Ryul; Joung, Gyu-Bum; Weidner, John W; Lee, Hong-Ki

2016-06-01

Platinum (Pt) nanocatalyst for a proton-exchange membrane fuel cell (PEMFC) was prepared on a carbon black particle or a graphite particle coated with a nafion polymer via a reduction of platinum(II) bis(acetylacetonate) denoted as Pt(acac)2 as a Pt precursor in a drying process. Sublimed Pt(acac)2 adsorbed on the nafion-coated carbon materials was reduced to Pt nanoparticles in a glass reactor at 180 degrees C of N2 atmosphere. The morphology of Pt nanoparticles on carbon materials was observed by scanning electron microscopy (SEM) and the distribution of Pt nanoparticles was done by transmission electron microscopy (TEM). The particle size was estimated by analyzing the TEM image using an image analyzer. It was found that nano-sized Pt particles were deposited on the surface of carbon materials, and the number density and the average particle size increased with increasing reduction time.

Non-aqueous metathesis as a general approach to prepare nanodispersed materials: Case study of scheelites

International Nuclear Information System (INIS)

Afanasiev, Pavel

2015-01-01

A general approach to the preparation of inorganic nanoparticles is proposed, using metathesis of precursor salts in non-aqueous liquids. Nanoparticles of scheelites AMO 4 (A=Ba, Sr, Ca; M=Mo, W), were obtained with a quantitative yield. Precipitations in formamide, N-methylformamide, propylene carbonate, DMSO and polyols often provide narrow particle size distributions. Advantageous morphology was explained by strong ionic association in non-aqueous solvents, leading to slow nucleation and negligible Ostwald ripening. Mean particle size below 10 nm and high specific surface areas were obtained for several Ca(Sr)Mo(W)O 4 materials, making them promising for applications as adsorbents or catalysts. Zeta-potential of scheelites in aqueous suspensions showed negative values in a wide range of pH. Systematic study of optical properties demonstrated variation of optical gap in the sequences W>Mo and Ba>Sr>Ca. The observed trends were reproduced by DFT calculations. No quantum confinement effect was observed for small particles, though the surface states induce low-energy features in the optical spectra. - Graphical abstract: Scheelites AMO 4 (A=Ca, Sr, Ba; M=Mo, W) were prepared in various non-aqueous liquids with high specific surface areas and narrow size distributions. The optical gap of scheelites changes in the series Caprepared in various non-aqueous liquids. • Narrow size distributions explained by ionic association in non-aqueous media. • Nanoparticles of less than 10 nm size and highest ever specific surface areas were obtained. • Optical gap of scheelites changes in the series Ca

Preparation and characterization of electronically conducting polypyrrole-montmorillonite nanocomposite and its potential application as a cathode material for oxygen reduction

International Nuclear Information System (INIS)

Rajapakse, R.M.G.; Murakami, Kenji; Bandara, H.M.N.; Rajapakse, R.M.M.Y.; Velauthamurti, K.; Wijeratne, S.

2010-01-01

Simple wet chemical processes were deployed to prepare low-cost conducting nanocomposites based on natural clays with 2:1 layered structures such as sodium montmorillonite (MMT). Ce(IV) modified MMT was used for the spontaneous polymerization of pyrrole within clay interlayers. The resulted clay-conducting polypyrrole nanocomposites containing the reduced form of the oxidising agent, have been extensively characterized by X-ray diffraction (XRD) technique for interlayer spacing variations and by Fourier transform infra red (FT-IR) spectroscopy to study the interactions between the clay and polymer functional groups. DC polarization technique with both blocking and non-blocking electrodes was used to distinguish between the ionic and electronic transport numbers and to recognize the type of mobile ionic species. AC impedance analysis further resolved the electrical conduction of these materials. Bulk conductivity analysis implied that the polypyrrole (PPY) formed within Ce(IV) modified MMT posses dominant electronic conductivity. The low-cost, light-weight and stable polymer-clay nanocomposite prepared by Ce(IV) intercalated MMT, [Ce(III)-PPY-MMT], seems to be a promising cathode material for oxygen reduction and hence may find applications in fuel cell industries.

Contributions in the Preparation and Processing of Composite Material Type Silumin 3 - Reinforced Matrix with S235JR Steel Mesh

Directory of Open Access Journals (Sweden)

Remus Belu-Nica

2015-07-01

Full Text Available In the paper are presented concrete data on developing technological batches of metal composite material (MCM type Silumin 3-reinforced matrix with steel mesh S235JR, with the indicating of the parameter and of the distinct stages of work. The samples from prepared batches were cut along and across by water jet abrasive process and were subjected to a destructive testing program and microstructural examination, obtaining results in concordance with the desired quality. The abrasive material used for cut was GMA granite with the average mesh of 80, the particle size ranging between 150-300 µm, density 2300 kg/m3 and melting point 1240°C.

Preparation of conducting solid mixtures

International Nuclear Information System (INIS)

Spokas, J.J.

1978-01-01

The application of conducting plastic mixtures to the fundamental problem of radiation dosimetry is briefly reviewed. A particular approach to achieving formulations with the necessary characteristics is described. A number of successful mixtures are defined for a number of different specific dosimetry situations. To obtain high quality stable materials requires intense blending and working of the materials at elevated temperatures. One machine that succeeds in this task is the Shonka plastics mixer-extruder. The Shonka mixer is described in complete detail. The procedures used in preparing representative formulations with this device are presented. A number of properties of successful conducting mixtures so prepared are summarized. The conditions required for molding such material are given. Several special welding methods for specific application with these formulations have been devised and are described

The promising application of graphene oxide as coating materials in orthopedic implants: preparation, characterization and cell behavior

International Nuclear Information System (INIS)

Zhao, Changhong; Lu, Xiuzhen; Liu, Johan; Zanden, Carl

2015-01-01

To investigate the potential application of graphene oxide (GO) in bone repair, this study is focused on the preparation, characterization and cell behavior of graphene oxide coatings on quartz substrata. GO coatings were prepared on the substrata using a modified dip-coating procedure. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy results demonstrated that the as-prepared coatings in this study were homogeneous and had an average thickness of ∼67 nm. The rapid formation of a hydroxyapatite (HA) layer in the simulated body fluid (SBF) on GO coated substrata at day 14, as proved by SEM and x-ray diffraction (XRD), strongly indicated the bioactivity of coated substrata. In addition, MC3T3-E1 cells were cultured on the coated substrata to evaluate cellular activities. Compared with the non-coated substrata and tissue culture plates, no significant difference was observed on the coated substrata in terms of cytotoxicity, viability, proliferation and apoptosis. However, interestingly, higher levels of alkaline phosphatase (ALP) activity and osteocalcin (OC) secretion were observed on the coated substrata, indicating that GO coatings enhanced cell differentiation compared with non-coated substrata and tissue culture plates. This study suggests that GO coatings had excellent biocompatibility and more importantly promoted MC3T3-E1 cell differentiation and might be a good candidate as a coating material for orthopedic implants. (paper)

Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles.

Science.gov (United States)

Yang, Haibin; Memon, Shazim Ali; Bao, Xiaohua; Cui, Hongzhi; Li, Dongxu

2017-04-07

Energy piles-A fairly new renewable energy concept-Use a ground heat exchanger (GHE) in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs) to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM) were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications.

Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles

Science.gov (United States)

Yang, Haibin; Memon, Shazim Ali; Bao, Xiaohua; Cui, Hongzhi; Li, Dongxu

2017-01-01

Energy piles—A fairly new renewable energy concept—Use a ground heat exchanger (GHE) in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs) to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM) were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications. PMID:28772752

Preparation of CMC-modified melamine resin spherical nano-phase change energy storage materials.

Science.gov (United States)

Hu, Xiaofeng; Huang, Zhanhua; Zhang, Yanhua

2014-01-30

A novel carboxymethyl cellulose (CMC)-modified melamine-formaldehyde (MF) phase change capsule with excellent encapsulation was prepared by in situ polymerization. Effects of CMC on the properties of the capsules were studied by Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). The results showed that the CMC-modified capsules had an average diameter of about 50nm and good uniformity. The phase change enthalpy of the capsules was increased and the cracking ratio decreased by incorporating a suitable amount of CMC. The optimum phase change enthalpy of the nanocapsules was 83.46J/g, and their paraffin content was 63.1%. The heat resistance of the capsule shells decreased after CMC modification. In addition, the nanocapsule cracking ratio of the nanocapsules was 11.0%, which is highly attractive for their application as nano phase change materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preparation and Mechanical Properties of Fiber Reinforced PLA for 3D Printing Materials

Science.gov (United States)

Li, Xionghao; Ni, Zhongjin; Bai, Shuyang; Lou, Baiyang

2018-03-01

The cellulose prepared by means of TEMPO oxidation method and glass fibre was blended with PLA respectively, and were spun into enhanced PLA wires. This study evaluates the wire rods that is from extruder is suitable for FDM printing by various physical characterization tests to determine their feasibility as a 3D printing filament materials. The cellulose and glass fibre is blended with PLA and spun into the reinforced PLA filament respectively, which is applied to FDM printing technology. The results showed that the intensity of strike resistant of the reinforced PLA filament made from cellulose and PLA is 34% to 60% higher than the PLA filament, meanwhile the tensile strength is 43% to 52% higher than the pure one. The other enhanced PLA filament is 13% to 35% higher than the PLA filament in intensity of strike resistant, and the tensile strength is 54% to 61% higher than the pure one.

Uniform hollow Fe3O4 spheres prepared by template-free solvothermal method as anode material for lithium-ion batteries

International Nuclear Information System (INIS)

Zhang Jingjing; Yao Yu; Huang Tao; Yu Aishui

2012-01-01

Graphical abstract: Unique hollow Fe 3 O 4 spheres assembled by Fe 3 O 4 nanoparticles prepared by a simple template-free solvothermal reaction are tested as anode material for lithium-ion batteries. The results show that the material delivers reversible specific capacities of 870 mA h g −1 even after 50 cycles at 100 mA g −1 and 836 mA h g −1 at 500 mA g −1 . The excellent electrochemical performance can be attributed to their hollow nanostructure and excellent structural stability. Highlights: ► Uniform hollow Fe 3 O 4 spheres were prepared by a template-free solvothermal method. ► The hollow Fe 3 O 4 spheres have the capacity of 870 mA h g −1 at 50th cycle. ► The specific capacity can be well maintained at a large current density. ► The hollow Fe 3 O 4 spheres exhibit enhanced rate capability. ► Electrochemical performance of hollow Fe 3 O 4 spheres is better than Fe 3 O 4 powders. - Abstract: Unique hollow Fe 3 O 4 spheres are prepared by a simple template-free solvothermal reaction. In the reaction, ethylene glycol (EG) and polyvinylpyrrolidone (PVP) serve as the reducing agent and surface stabilizer, respectively. NH 4 Ac plays the role of the structure-directing agent, which combines with the Ostwald ripening process, resulting in the favored formation of hollow structures. The morphologies and structures are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The hollow Fe 3 O 4 spheres exhibit excellent cycling and rate performance as anode material for lithium-ion batteries, delivering reversible specific capacities of 870 mA h g −1 even after 50 cycles at 100 mA g −1 and 836 mA h g −1 at 500 mA g −1 . The excellent electrochemical performance can be attributed to their hollow nanostructure and excellent structural stability.

Fatigue crack propagation in UFG Ti grade 4 processed by severe plastic deformation

Czech Academy of Sciences Publication Activity Database

Fintová, Stanislava; Arzaghi, M.; Kuběna, Ivo; Kunz, Ludvík; Sarrazin-Baudoux, C.

2017-01-01

Roč. 98, MAY (2017), s. 187-194 ISSN 0142-1123 R&D Projects: GA MŠk(CZ) LQ1601; GA MŠk LM2015069 Institutional support: RVO:68081723 Keywords : Titanium * Fatigue * Crack growth * Crack closure * Equal channel angular processing Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 2.899, year: 2016 http://www.sciencedirect.com/science/article/pii/S014211231730035X

{sup 90}Y microspheres prepared by sol-gel method, promising medical material for radioembolization of liver malignancies

Energy Technology Data Exchange (ETDEWEB)

Łada, Wiesława, E-mail: w.lada@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Iller, Edward [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Wawszczak, Danuta [Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Dorodna 16 (Poland); Konior, Marcin, E-mail: marcin.konior@polatom.pl [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland); Dziel, Tomasz [National Centre for Nuclear Research, Radioisotope Centre POLATOM, 05-400 Otwock, Andrzej Sołtan 7 (Poland)

2016-10-01

A new technology for the production of radiopharmaceutical {sup 90}Y microspheres in the form of spherical yttrium oxide grains obtained by sol-gel method has been described. The authors present and discuss the results of investigations performed in the development of new production technology of yttrium microspheres and determination of their physic-chemical properties. The final product has the structure of spherical yttrium oxide grains with a diameter 25–100 μm, is stable and free from contaminants. Irradiation of 20 mg samples of grains with diameter of 20–50 μm in the thermal neutron flux of 1.7 × 10{sup 14} cm{sup −2} s{sup −1} at the core of MARIA research nuclear reactor allowed to obtain microspheres labelled with the {sup 90}Y isotope on the way of the nuclear reaction {sup 89}Y(n, γ){sup 90}Y. Specific activity of irradiated microspheres has been determined by application of absolute triple to double coincidence ratio method (TDCR) and has been evaluated at 190 MBq/mg Y. {sup 90}Y microspheres prepared by the proposed technique can be regarded as a promising medical material for radioembolization of liver malignancies. - Highlights: • Sol-gel methods for preparation of spherical yttrium trioxide grains have been proposed. • Determination condition for irradiation {sup 89}Y{sub 2}O{sub 3} grains in nuclear reactor • Evaluation of specific activity of {sup 90}Y microspheres • Estimation of {sup 90}Y microspheres as promising medical material for radioembolization.

Mechanical and Electrical Properties of Sulfur-Containing Polymeric Materials Prepared via Inverse Vulcanization

Directory of Open Access Journals (Sweden)

Sergej Diez

2017-02-01

Full Text Available Recently, new methods have been developed for the utilization of elemental sulfur as a feedstock for novel polymeric materials. One promising method is the inverse vulcanization, which is used to prepare polymeric structures derived from sulfur and divinyl comonomers. However, the mechanical and electrical properties of the products are virtually unexplored. Hence, in the present study, we synthesized a 200 g scale of amorphous, hydrophobic as well as translucent, hyperbranched polymeric sulfur networks that provide a high thermal resistance (>220 °C. The polymeric material properties of these sulfur copolymers can be controlled significantly by varying the monomers as well as the feed content. The investigated comonomers are divinylbenzene (DVB and 1,3-diisopropenylbenzene (DIB. Plastomers with low elastic content and high shape retention containing 12.5%–30% DVB as well as low viscose waxy plastomers with a high flow behavior containing a high DVB content of 30%–35% were obtained. Copolymers with 15%–30% DIB act, on the one hand, as thermoplastics and, on the other hand, as vitreous thermosets with a DIB of 30%–35%. Results of the thermogravimetric analysis (TGA, the dynamic scanning calorimetry (DSC and mechanical characterization, such as stress–strain experiments and dynamic mechanical thermal analysis, are discussed with the outcome that they support the assumption of a polymeric cross-linked network structure in the form of hyper-branched polymers.

Coated electroactive materials

Science.gov (United States)

Amine, Khalil; Abouimrane, Ali

2016-08-30

A process includes suspending an electroactive material in a solvent, suspending or dissolving a carbon precursor in the solvent; and depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material. Compositions include a graphene-coated electroactive material prepared from a solution phase mixture or suspension of an electroactive material and graphene, graphene oxide, or a mixture thereof.

Materials and material testing

International Nuclear Information System (INIS)

Joergens, H.

1978-01-01

A review based on 105 literature quotations is given on the latest state of development in the steel sector and in the field of non-ferrous metals and plastics. The works quoted also include, preparation, working, welding including simulation methods, improvement of weldability, material mechanics (explanation of defects mechanisms by means of fracture mechanics), defect causes (corrosion, erosion, hydrogen influence), mechanical-technological and non-destructive material testing. Examples from the field of reactor building are also given within there topics. (IHOE) [de

Effect of severe plastic deformation on microstructure and mechanical properties of magnesium and aluminium alloys in wide range of strain rates

Science.gov (United States)

Skripnyak, Vladimir; Skripnyak, Evgeniya; Skripnyak, Vladimir; Vaganova, Irina; Skripnyak, Nataliya

2013-06-01

Results of researches testify that a grain size have a strong influence on the mechanical behavior of metals and alloys. Ultrafine grained HCP and FCC metal alloys present higher values of the spall strength than a corresponding coarse grained counterparts. In the present study we investigate the effect of grain size distribution on the flow stress and strength under dynamic compression and tension of aluminium and magnesium alloys. Microstructure and grain size distribution in alloys were varied by carrying out severe plastic deformation during the multiple-pass equal channel angular pressing, cyclic constrained groove pressing, and surface mechanical attrition treatment. Tests were performed using a VHS-Instron servo-hydraulic machine. Ultra high speed camera Phantom V710 was used for photo registration of deformation and fracture of specimens in range of strain rates from 0,01 to 1000 1/s. In dynamic regime UFG alloys exhibit a stronger decrease in ductility compared to the coarse grained material. The plastic flow of UFG alloys with a bimodal grain size distribution was highly localized. Shear bands and shear crack nucleation and growth were recorded using high speed photography.

Restricted access magnetic materials prepared by dual surface modification for selective extraction of therapeutic drugs from biological fluids

International Nuclear Information System (INIS)

Wang Yu; Wang Yuxia; Chen Lei; Wan Qianhong

2012-01-01

Magnetic porous particles with dual functionality have been prepared by a two-step procedure and evaluated as novel restricted access materials for extraction of therapeutic agents from biological fluids. The magnetic silica particles served as scaffolds were first modified with diol groups, which were then converted to octadecyl esters through reaction with stearoyl chloride. In the second step, the octadecyl esters on the exterior surface were hydrolyzed by the action of lipase to yield magnetic particles with hydrophobic reversed-phase ligands on the inner surface and biocompatible diol groups on the outer surface. The restricted access behavior of the resulting materials was confirmed by differential binding of small molecules such as methotrexate (MTX), leucovorin (LV) and folic acid (FA) relative to bovine serum albumin. While MTX, LV and FA were all bound to the magnetic particles with high affinity, the adsorption of the protein was markedly reduced due to size exclusion effect. The utility of the magnetic particles for sample preparation was tested in solid-phase extraction of MTX, LV and FA from spiked human serum and the effects of the SPE conditions on the recovery of the analytes were systematically studied. Moreover, the magnetic particle-based sample preparation procedure coupled with reversed-phase liquid chromatography analysis was validated in terms of specificity, linearity and reproducibility. The method was shown to be free from interference of endogenous compounds and linear over the concentration range of 0.5-10 μg/mL for the three drugs studied. The limits of detection for the three drugs in serum were in the range of 0.160-0.302 μg/mL. Reproducibility expressed as the RSD of the recovery for ten replicated extractions at three different concentrations was found to be less than 8.93%. With a unique combination of surface functionality with magnetic cores, the restricted access magnetic particles may be adapted in automated and high

Preparation of Cr{sub 2}O{sub 3} nanoparticles for superthermites by the detonation of an explosive nanocomposite material

Energy Technology Data Exchange (ETDEWEB)

Comet, Marc, E-mail: marc.comet@isl.eu; Pichot, Vincent; Siegert, Benny; Fousson, Eric [NS3E, UMR 3208 ISL/CNRS, French-German Research Institute of Saint-Louis (ISL) (France); Mory, Julien; Moitrier, Florence [French-German Research Institute of Saint-Louis (ISL) (France); Spitzer, Denis [NS3E, UMR 3208 ISL/CNRS, French-German Research Institute of Saint-Louis (ISL) (France)

2011-05-15

This article reports on the preparation of chromium(III) oxide nanoparticles by detonation. For this purpose, a high explosive-hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-has been solidified from a solution infiltrated into the macro- and mesoporosity of Cr{sub 2}O{sub 3} powder obtained by the combustion of ammonium dichromate. The resulting Cr{sub 2}O{sub 3}/RDX nanocomposite material was embedded in a cylindrical charge of pure explosive and detonated in order to fragment the metallic oxide into nanoparticles. The resulting soot contains Cr{sub 2}O{sub 3} nanoparticles, nanodiamonds, amorphous carbon species and inorganic particles resulting from the erosion by the blast of the detonation tank wall. The purification process consists in (i) removing the carbonaceous species by an oxidative treatment at 500 Degree-Sign C and (ii) dissolving the mineral particles by a chemical treatment with hydrofluoric acid. Contrary to what could be expected, the Cr{sub 2}O{sub 3} particles formed during the detonation are twice larger than those of initial Cr{sub 2}O{sub 3}. The detonation causes the fragmentation of the porous oxide and the melting of resulting particles. Nanometric droplets of molten Cr{sub 2}O{sub 3} are ejected and quenched by the water in which the charge is fired. Despite their larger size, the Cr{sub 2}O{sub 3} nanoparticles prepared by detonation were found to be less aggregated than those of the initial oxide used as precursor. Finally, the Cr{sub 2}O{sub 3} synthesized by detonation was used to prepare a superthermite with aluminium nanoparticles. This material possesses a lower sensitivity and a more regular combustion compared to the one made of initial Cr{sub 2}O{sub 3}.

Preparation of Carbon-Encapsulated ZnO Tetrahedron as an Anode Material for Ultralong Cycle Life Performance Lithium-ion Batteries

International Nuclear Information System (INIS)

Ren, Zhimin; Wang, Zhiyu; Chen, Chao; Wang, Jia; Fu, Xinxin; Fan, Chenyao; Qian, Guodong

2014-01-01

Highlights: • A novel architecture of 3D carbon framework to encapsulate ZnO nanocrystals was prepared. • The ZnO@C exhibits ultralong cycle life and high specific capacity when was used as anode. • The in situ carbonization leads to a strong connection between the carbon and ZnO. - ABSTRACT: In this paper we report a novel architecture of three-dimension (3D) carbon framework to encapsulate tetrahedron ZnO nanocrystals that serves as an anode material for lithium-ion batteries (LIBs). The ZnO@C composites are prepared via a simple internal-reflux method combined with subsequent calcination in argon. The amorphous carbon is formed on the surface of the ZnO crystals by in situ carbonization of the surfactant, which leads to a strong connection between the carbon framework and the active materials and guarantees faster charge transfer on the electrode. The ZnO crystal calcined at 500°C (ZnO@C-5) possesses regular tetrahedron shape with a side length of 150-200 nm and all of them are uniformly anchored among the network of amorphous carbon. The developed ZnO@C structures not only improve the electronic conductivity of the electrode, but they also offer a larger volume expansion of ZnO during cycling. As a result, the ZnO@C-5 demonstrates a higher reversible capacity, ultralong cycle life and better rate capability than that of the ZnO@C-7 and pure ZnO crystals. After 300 cycles, the ZnO@C-5 demonstrates a high capacity of 518 mAhg −1 at a current density of 110.7 mAg −1 . Moreover, this simple approach prepared the 3D composites architecture could shed light on the design and synthesis of other transition metal oxides for energy storage

Synthesis and characterization of Sr- and Mg-doped Lanthanum gallate electrolyte materials prepared via the Pechini method

International Nuclear Information System (INIS)

Shi Min; Xu Yudong; Liu Anping; Liu Ning; Wang Can; Majewski, P.; Aldinger, F.

2009-01-01

The powders of Sr- and Mg-doped lanthanum gallate (La 0.85 Sr 0.15 Ga 0.80 Mg 0.2 O 2.825 ; LSGM) were synthesized by the Pechini method. The XRD pattern indicates that the main phase (LaGaO 3 ) exists in the uncalcined powders. The LSGM materials are composed of the main phase without secondary phases when calcined at 1400 deg. C. The LSGM materials contain fewer amounts of secondary phases than those prepared by the sol-gel method and solid-state reaction method at the same calcination temperature. TEM image of the powders indicate that the average grain size is about 80 nm. The conductivity increases with the testing temperature increasing. The curve of ln(σT) vs 1/T exists two straight lines intersecting at T* (T* is about 602 deg. C). It indicates that activation energy of oxygen-vacancy motion at lower temperatures is greater than that at higher temperatures

Synthesis and characterization of Sr- and Mg-doped Lanthanum gallate electrolyte materials prepared via the Pechini method

Energy Technology Data Exchange (ETDEWEB)

Shi Min [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China)], E-mail: shimin@mail.hf.ah.cn; Xu Yudong; Liu Anping; Liu Ning; Wang Can [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Majewski, P.; Aldinger, F. [Max-Planck-Institut fur Metallforschung, Pulvermetallurgisches Laboratorium, Heisenbergstr. 5, D-70569 Stuttgart (Germany)

2009-03-15

The powders of Sr- and Mg-doped lanthanum gallate (La{sub 0.85}Sr{sub 0.15}Ga{sub 0.80}Mg{sub 0.2}O{sub 2.825}; LSGM) were synthesized by the Pechini method. The XRD pattern indicates that the main phase (LaGaO{sub 3}) exists in the uncalcined powders. The LSGM materials are composed of the main phase without secondary phases when calcined at 1400 deg. C. The LSGM materials contain fewer amounts of secondary phases than those prepared by the sol-gel method and solid-state reaction method at the same calcination temperature. TEM image of the powders indicate that the average grain size is about 80 nm. The conductivity increases with the testing temperature increasing. The curve of ln({sigma}T) vs 1/T exists two straight lines intersecting at T* (T* is about 602 deg. C). It indicates that activation energy of oxygen-vacancy motion at lower temperatures is greater than that at higher temperatures.

Enseignement Bilingue: Problemes Souleves par la Preparation d'un Materiel Pedagogique pour des Franco-Ontariens (Bilingual Education: Problems Raised by the Preparation of Teaching Materials for Franco-Ontarians). Working Papers on Bilingualism, No. 1.

Science.gov (United States)

Cooke, David; Lamerand, Raymond

This paper reports on a program developed to prepare teaching materials for the instruction of French to adolescents who have French as a native language but no longer speak French at home. A principal goal is to create situations that will inspire students to communicate in French, and to avoid purely academic exercises. Since students tend to…

Modern permanent magnetic materials - preparation and properties

International Nuclear Information System (INIS)

Rodewald, W.

1989-01-01

First of all, the basic properties of the classical (steel, AlNiCo) permanent magnetic materials and the modern rare-earth (RE) permanent magnetic materials are compared. Since the properties of RE permanent magnets depend on the particular production process, the fundamentals of the main industrial processes (powder metallurgy, rapid-solidification technique) are described and the typical properties are explained. Furthermore the production processes in development such as mechanical alloying, melt spinning technique and extrusion upsetting are briefly outlined. For applying the permanent magnets, they have to be completely magnetized. The magnetization behaviour of the various RE permanent magnets is discussed by means of the internal demagnetization curve. Finally the various influences on the temperature stability of RE permanent magnets are compiled. (orig./MM) [de

Effect of ionizing radiation on the properties of prepared plastic/starch blends and their applications as biodegradable materials

International Nuclear Information System (INIS)

Khalil, S.A.

2010-01-01

Blends based on different ratios of plasticised starch (PLST), low density poly-ethyleen (LDPE) were prepared by mixing in extrouder. The LDPE/PLST/POMA (poly-olefin maleic anhydride) and LDPE/PLST/TMPTA (tri-methylol propane tri-acrylate) were exposed to different doses of electron beam. The effect of mixing and E-Beam irradiation on the thermal, mechanical, water absorption, and structure morphology properties were investigated. The results showed that the addition of compatibilizers and E-Beam irradiation improve all the physical properties, which provides suitable material based on natural polymer for biodegradable plastic.

In-situ preparation of functionalized molecular sieve material and a methodology to remove template

Science.gov (United States)

Yadav, Rekha; Ahmed, Maqsood; Singh, Arvind Kumar; Sakthivel, Ayyamperumal

2016-03-01

A series of diaminosilane-functionalized silicoaluminophosphate molecular sieve (SAPO-37) was prepared by in-situ synthesis, and a novel method was developed for the selective removal of structure directing agent (SDA)/template from the functionalized SAPO-37.The complete removal of the SDA was evident according to FT-IR, TGA, 13C MAS-NMR and elemental analysis. The developed method was found to be efficient for removal of template from microporous molecular sieve viz., SAPO-37 and can be applied for other microporous molecular sieves such as SAPO-5, SAPO-40, etc. The powder XRD pattern of the template-removed samples showed a highly crystalline SAPO-37 phase. Argentometric titration revealed that more than 90% of diamine functionality exposed on the surface was accessible for catalytic applications. The resultant materials showed promising activity for ring opening of epoxide with aniline to yield β-amino-alcohol.

In-situ preparation of functionalized molecular sieve material and a methodology to remove template.

Science.gov (United States)

Yadav, Rekha; Ahmed, Maqsood; Singh, Arvind Kumar; Sakthivel, Ayyamperumal

2016-03-10

A series of diaminosilane-functionalized silicoaluminophosphate molecular sieve (SAPO-37) was prepared by in-situ synthesis, and a novel method was developed for the selective removal of structure directing agent (SDA)/template from the functionalized SAPO-37.The complete removal of the SDA was evident according to FT-IR, TGA, (13)C MAS-NMR and elemental analysis. The developed method was found to be efficient for removal of template from microporous molecular sieve viz., SAPO-37 and can be applied for other microporous molecular sieves such as SAPO-5, SAPO-40, etc. The powder XRD pattern of the template-removed samples showed a highly crystalline SAPO-37 phase. Argentometric titration revealed that more than 90% of diamine functionality exposed on the surface was accessible for catalytic applications. The resultant materials showed promising activity for ring opening of epoxide with aniline to yield β-amino-alcohol.

Preparation and characterization of trihydroxamic acid functionalized carbon materials for the removal of Cu(II) ions from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Godino-Salido, M. Luz, E-mail: mlgodino@ujaen.es [Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén (Spain); Santiago-Medina, Antonio; López-Garzón, Rafael; Gutiérrez-Valero, María D.; Arranz-Mascarós, Paloma; López de la Torre, M. Dolores [Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén (Spain); Domingo-García, María; López-Garzón, F. Javier [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071, Granada (Spain)

2016-11-30

Highlights: • Hybrid materials made by irreversible adsorption of a deferoxamine derivative on ACs. • The surface trihydroxamate groups are the active functions of the hybrid materials. • Great adsorption capacity for Cu(II) of novel trihydroxamic acid functionalized ACs. • Desorption of Cu(II) from the loaded hybrid materials regenerates the parent hybrids. - Abstract: The main objective of this study is to prepare and characterize two functionalizated carbon materials with enhanced adsorptive properties for Cu(II). Thus, two novel hybrid materials have been prepared by a non-covalent functionalization method based on the adsorption of a pyrimidine-desferrioxamine-B conjugate compound (H{sub 4}L) on two activated carbons, ACs (labelled Merck and F). The adsorption of H{sub 4}L on the ACs is pH-dependent and highly irreversible. This is due to strong π-π interactions between the arene centers of the ACs and the pyrimidine moiety of H{sub 4}L. The textural characterization of the AC/H{sub 4}L hybrids shows large decreases of their surface areas. Thus the values of Merck and F are 1031 and 1426 m{sup 2}/g respectively, while these of Merck/H{sub 4}L and F/H{sub 4}L hybrids are 200 and 322 m{sup 2}/g. An important decrease in the micropore volumes is also found, due to the blockage of narrow porosity produced by the adsorption of H{sub 4}L molecules. The ACs/H{sub 4}L hybrids show larger adsorption capacities for Cu(II) (0.105(4) and 0.13(2) mmol/g, at pH 2.0, and 0.20(3) and 0.242(9) mmol/g, at pH 5.5, for Merck/H{sub 4}L and F/H{sub 4}L, respectively) than those of the ACs (0.024(6) and 0.096(9) mmol/g, at pH 2.0, and 0.10(2) and 0.177(8) mmol/g, at pH 5.5, for Merck and F respectively), which is explained on the basis of the complexing ability of the trihydroxamic acid functions. The desorption of Cu(II) from the ACs/H{sub 4}L/Cu(II) materials in acid solution allows the regeneration of most active sites (78.5% in the case of Merck/H{sub 4}L/Cu(II) and 83

Restricted access magnetic materials prepared by dual surface modification for selective extraction of therapeutic drugs from biological fluids

Science.gov (United States)

Wang, Yu; Wang, Yuxia; Chen, Lei; Wan, Qian-Hong

2012-02-01

Magnetic porous particles with dual functionality have been prepared by a two-step procedure and evaluated as novel restricted access materials for extraction of therapeutic agents from biological fluids. The magnetic silica particles served as scaffolds were first modified with diol groups, which were then converted to octadecyl esters through reaction with stearoyl chloride. In the second step, the octadecyl esters on the exterior surface were hydrolyzed by the action of lipase to yield magnetic particles with hydrophobic reversed-phase ligands on the inner surface and biocompatible diol groups on the outer surface. The restricted access behavior of the resulting materials was confirmed by differential binding of small molecules such as methotrexate (MTX), leucovorin (LV) and folic acid (FA) relative to bovine serum albumin. While MTX, LV and FA were all bound to the magnetic particles with high affinity, the adsorption of the protein was markedly reduced due to size exclusion effect. The utility of the magnetic particles for sample preparation was tested in solid-phase extraction of MTX, LV and FA from spiked human serum and the effects of the SPE conditions on the recovery of the analytes were systematically studied. Moreover, the magnetic particle-based sample preparation procedure coupled with reversed-phase liquid chromatography analysis was validated in terms of specificity, linearity and reproducibility. The method was shown to be free from interference of endogenous compounds and linear over the concentration range of 0.5-10 μg/mL for the three drugs studied. The limits of detection for the three drugs in serum were in the range of 0.160-0.302 μg/mL. Reproducibility expressed as the RSD of the recovery for ten replicated extractions at three different concentrations was found to be less than 8.93%. With a unique combination of surface functionality with magnetic cores, the restricted access magnetic particles may be adapted in automated and high

Carbon-Nickel oxide nanocomposites: Preparation and charecterisation

CSIR Research Space (South Africa)

Tile, N

2011-07-01

Full Text Available Nanocomposite materials have wide range of applications in solar energy conversion. In this work, C-NiO nanocomposite coatings are prepared using sol-gel synthesis and deposited on aluminium substrates using a spin coater. The coatings are prepared...

10th International School of Materials Science and Technology : Intercalation in Layered Materials "Ettore Majorana"

CERN Document Server

1986-01-01

This volume is prepared from lecture notes for the course "Intercalation in Layered Materials" which was held at the Ettore Majorana Centre for Scientific Culture at Erice, Sicily in July, 1986, as part of the International School of Materials Science and Tech­ nology. The course itself consisted of formal tutorial lectures, workshops, and informal discussions. Lecture notes were prepared for the formal lectures, and short summaries of many of the workshop presentations were prepared. This volume is based on these lecture notes and research summaries. The material is addressed to advanced graduate students and postdoctoral researchers and assumes a background in basic solid state physics. The goals of this volume on Intercalation in Layered Materials include an introduc­ tion to the field for potential new participants, an in-depth and broad exposure for stu­ dents and young investigators already working in the field, a basis for cross-fertilization between workers on various layered host materials...

IAEA biological reference materials

International Nuclear Information System (INIS)

Parr, R.M.; Schelenz, R.; Ballestra, S.

1988-01-01

The Analytical Quality Control Services programme of the IAEA encompasses a wide variety of intercomparisons and reference materials. This paper reviews only those aspects of the subject having to do with biological reference materials. The 1988 programme foresees 13 new intercomparison exercises, one for major, minor and trace elements, five for radionuclides, and seven for stable isotopes. Twenty-two natural matrix biological reference materials are available: twelve for major, minor and trace elements, six for radionuclides, and four for chlorinated hydrocarbons. Seven new intercomparisons and reference materials are in preparation or under active consideration. Guidelines on the correct use of reference materials are being prepared for publication in 1989 in consultation with other major international producers and users of biological reference materials. The IAEA database on available reference materials is being updated and expanded in scope, and a new publication is planned for 1989. (orig.)

Preparation of bovine muscle, bovine liver and pig kidney reference materials and the certification of the contents of nine elements of toxicological and nutritional interest

International Nuclear Information System (INIS)

Wagstaffe, P.J.; Muntau, H.

1987-01-01

The preparation of 3 meat reference materials (bovine muscle, bovine liver and pig kidney) and the steps taken to confirm their homogeneity and stability are described. Details are presented of a preliminary intercomparison and of the final collaborative exercise which led to the certification of the contents of 9 elements of toxicological and nutritional importance. Indicative values are given for the contents of a further 9 elements in these materials. (orig.)

Collagen immobilized PVA hydrogel-hydroxyapatite composites prepared by kneading methods as a material for peripheral cuff of artificial cornea

International Nuclear Information System (INIS)

Kobayashi, Hisatoshi; Kato, Masabumi; Taguchi, Tetsushi; Ikoma, Toshiyuki; Miyashita, Hideyuki; Shimmura, Shigeto; Tsubota, Kazuo; Tanaka, Junzo

2004-01-01

In order to achieve the firm fixation of the artificial cornea to host tissues, composites of collagen-immobilized poly(vinyl alcohol) hydrogel with hydroxyapatite were synthesized by a hydroxyapatite particles kneading method. The preparation method, characterization, and the results of corneal cell adhesion and proliferation on the composite material were studied. PVA-COL-HAp composites were successfully synthesized. A micro-porous structure of the PVA-COL-HAp could be introduced by hydrochloric acid treatment and the porosity could be controlled by the pH of the hydrochloric acid solution, the treatment time, and the crystallinity of the HAp particles. Chick embryonic keratocyto-like cells were well attached and proliferated on the PVA-COL-HAp composites. This material showed potential for keratoprosthesis application. Further study such as a long-term animal study is now required

Preparation of nanoencapsulated phase change material as latent functionally thermal fluid

Energy Technology Data Exchange (ETDEWEB)

Fang Yutang; Kuang Shengyan; Gao Xuenong; Zhang Zhengguo, E-mail: ppytfang@scut.edu.c [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

2009-02-07

Nanoencapsulated phase change material with polystyrene as the shell and n-octadecane as the core was synthesized using the ultrasonic technique and miniemulsion in situ polymerization. The influences of polymerization factors, including initiator, chain transfer agent (CTA), surfactant, n-octadecane/styrene ratio and hydrophilic co-monomer, on the morphology and thermophysical properties of nanocapsules were systematically investigated. The optimized polymerization conditions were 0.5 wt% of initiator (2,2-azobisisobutyronitrile), 0.4 wt% of CTA (n-dodecyl mercaptan), 2% of composite surfactants which were composed of sodium dodecyl sulfate and poly-(ethylene glycol) monooctylphenyl ether by 1 : 1 in weight ratio, 1 wt% of hydrophilic co-monomer butyl acrylate or 3 wt% of methyl methacrylate and 1 : 1 n-octadecane to styrene in weight ratio. Under these conditions, the z-average size of prepared nanocapsules was 124 nm and the phase change enthalpy was 124.4 kJ kg{sup -1}. The heat capacity was as high as 11.61 kJ kg{sup -1} K{sup -1} at the latex concentration of 20.6 wt%. Thermal stability and viscosity testing show that this fluid had excellent resistance to thermal shock (after 100 cycles, no liquid Oct was observed during heating) and low viscosity (only 3.61 mPa s at the latex concentration of 20.6 wt%), which seems to be promising as a latent functionally thermal fluid.

Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al–Cu alloys with minor Sc addition

International Nuclear Information System (INIS)

Jiang, L.; Li, J.K.; Liu, G.; Wang, R.H.; Chen, B.A.; Zhang, J.Y.; Sun, J.; Yang, M.X.; Yang, G.; Yang, J.; Cao, X.Z.

2015-01-01

Heat-treatable Al alloys containing Al–2.5 wt% Cu (Al–Cu) and Al–2.5 wt% Cu–0.3 wt% Sc (Al–Cu–Sc) with different grain length scales, i.e., average grain size >10 μm ( defined coarse grained, CG), 1–2 μm (fine grained, FG), and <1 μm (ultrafine grained, UFG), were prepared by equal-channel angular pressing (ECAP). The length scale and Sc microalloying effects and their interplay on the precipitation behavior and mechanical properties of the Al–Cu alloys were systematically investigated. In the Al–Cu alloys, intergranular θ-Al 2 Cu precipitation gradually dominated by sacrificing the intragranular θ′-Al 2 Cu precipitation with reducing the length scale. Especially in the UFG regime, only intergranular θ-Al 2 Cu particles were precipitated and intragranular θ′-Al 2 Cu precipitation was completely disappeared. This led to a remarkable reduction in yield strength and ductility due to insufficient dislocation storage capacity. The minor Sc addition resulted in a microalloying effect in the Al–Cu alloy, which, however, is strongly dependent on the length scale. The smaller is the grain size, the more active is the microalloying effect that promotes the intragranular precipitation while reduces the intergranular precipitation. Correspondingly, compared with their Sc-free counterparts, the yield strength of post-aged CG, FG, and UFG Al–Cu alloys with Sc addition increased by ~36 MPa, ~56 MPa, and ~150 MPa, simultaneously in tensile elongation by ~20%, ~30%, and 280%, respectively. The grain size-induced evolutions in vacancy concentration/distribution and number density of vacancy-solute/solute–solute clusters and their influences on precipitation nucleation and kinetics have been comprehensively considered to rationalize the length scale-dependent Sc microalloying mechanisms using positron annihilation lifetime spectrum and three dimension atom probe. The increase in ductility was analyzed in the light of Sc microalloying effect and the

Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al–Cu alloys with minor Sc addition

Energy Technology Data Exchange (ETDEWEB)

Jiang, L.; Li, J.K. [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Liu, G., E-mail: lgsammer@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, R.H. [School of Materials Science and Engineering, Xi' an University of Technology, Xi' an 710048 (China); Chen, B.A.; Zhang, J.Y. [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Sun, J., E-mail: junsun@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Yang, M.X.; Yang, G. [Central Iron and Steel Research Institute, Beijing 100081 (China); Yang, J.; Cao, X.Z. [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2015-06-18

Heat-treatable Al alloys containing Al–2.5 wt% Cu (Al–Cu) and Al–2.5 wt% Cu–0.3 wt% Sc (Al–Cu–Sc) with different grain length scales, i.e., average grain size >10 μm ( defined coarse grained, CG), 1–2 μm (fine grained, FG), and <1 μm (ultrafine grained, UFG), were prepared by equal-channel angular pressing (ECAP). The length scale and Sc microalloying effects and their interplay on the precipitation behavior and mechanical properties of the Al–Cu alloys were systematically investigated. In the Al–Cu alloys, intergranular θ-Al{sub 2}Cu precipitation gradually dominated by sacrificing the intragranular θ′-Al{sub 2}Cu precipitation with reducing the length scale. Especially in the UFG regime, only intergranular θ-Al{sub 2}Cu particles were precipitated and intragranular θ′-Al{sub 2}Cu precipitation was completely disappeared. This led to a remarkable reduction in yield strength and ductility due to insufficient dislocation storage capacity. The minor Sc addition resulted in a microalloying effect in the Al–Cu alloy, which, however, is strongly dependent on the length scale. The smaller is the grain size, the more active is the microalloying effect that promotes the intragranular precipitation while reduces the intergranular precipitation. Correspondingly, compared with their Sc-free counterparts, the yield strength of post-aged CG, FG, and UFG Al–Cu alloys with Sc addition increased by ~36 MPa, ~56 MPa, and ~150 MPa, simultaneously in tensile elongation by ~20%, ~30%, and 280%, respectively. The grain size-induced evolutions in vacancy concentration/distribution and number density of vacancy-solute/solute–solute clusters and their influences on precipitation nucleation and kinetics have been comprehensively considered to rationalize the length scale-dependent Sc microalloying mechanisms using positron annihilation lifetime spectrum and three dimension atom probe. The increase in ductility was analyzed in the light of Sc microalloying

Sample Preparation of Nano-sized Inorganic Materials for Scanning Electron Microscopy or Transmission Electron Microscopy: Scientific Operating Procedure SOP-P-2

Science.gov (United States)

2015-07-01

process. • aggregate, n—in nanotechnology from IUPAC (http://goldbook.iupac.org/A00184.html), certain materials used as catalysts or supports consist...aqueous extractant was found to provide stable suspensions of secondary titanium dioxide particles for a variety of analytic techniques. Further...Abu-daabes, A. Alassali, and J. Y. S. Lin. 2013. Ordered mesoporous silica prepared by quiescent interfacial growth method–Effects of reaction

Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles

Directory of Open Access Journals (Sweden)

Haibin Yang

2017-04-01

Full Text Available Energy piles—A fairly new renewable energy concept—Use a ground heat exchanger (GHE in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications.

Preparation of inorganic crystalline compounds induced by ionizing, UV and laser radiation

International Nuclear Information System (INIS)

Cuba, V.; Pavelkova, T.; Barta, J.; Indrei, J.; Gbur, T.; Pospisil, M.; Mucka, V.; Docekalova, Z.; Zavadilova, A.; Vlk, M.

2011-01-01

Complete text of publication follows. Radiation methods represent powerful tool for synthesis of various inorganic materials. Study of solid particles formation from solutions in the field of UV or ionizing radiation is one of the very promising and long term pursued trends in photochemistry and radiation chemistry. The motivation may be various, either preparation of new materials or removal of hazardous contaminants (e.g. heavy metals) from wastewater. This work deals with preparation of some metal oxides, synthetic garnets and spinel structures via irradiation of aqueous solutions containing precursors, i.e. soluble metal salts, radical scavengers and/or macromolecular stabilizers. Namely, results on radiation induced preparation of nickel, zinc, yttrium and aluminium oxides are summarized, as well as zinc peroxide, yttrium / lutetium - aluminium garnets and cobalt(II) aluminate. 60 Co irradiator, linear electron accelerator, medium pressure UV lamp and solid state laser were used as the sources of radiation. Aside from preparation, various physico-chemical and structural properties of compounds prepared were also studied. All used modifications of radiation method are rather convenient and simple, and yield (nano)powder materials with interesting characteristics. Prepared materials generally have high chemical purity, high specific surface area and narrow distribution of particles size (ranging in tens of nm). Generally, all types of irradiation result in materials with comparable properties and structural characteristics; but in the case of synthetic garnets and spinels, preparation using UV-radiation seems to be the most convenient for their preparation. Among compounds discussed, only zinc oxide and zinc peroxide were prepared directly via irradiation. For preparation of other crystalline compounds, additional heat treatment (at low temperature) of amorphous solid phase formed under irradiation was necessary.

Uranium reference materials

International Nuclear Information System (INIS)

Donivan, S.; Chessmore, R.

1987-07-01

The Technical Measurements Center has prepared uranium mill tailings reference materials for use by remedial action contractors and cognizant federal and state agencies. Four materials were prepared with varying concentrations of radionuclides, using three tailings materials and a river-bottom soil diluent. All materials were ground, dried, and blended thoroughly to ensure homogeneity. The analyses on which the recommended values for nuclides in the reference materials are based were performed, using independent methods, by the UNC Geotech (UNC) Chemistry Laboratory, Grand Junction, Colorado, and by C.W. Sill (Sill), Idaho National Engineering Laboratory, Idaho Falls, Idaho. Several statistical tests were performed on the analytical data to characterize the reference materials. Results of these tests reveal that the four reference materials are homogeneous and that no large systematic bias exists between the analytical methods used by Sill and those used by TMC. The average values for radionuclides of the two data sets, representing an unbiased estimate, were used as the recommended values for concentrations of nuclides in the reference materials. The recommended concentrations of radionuclides in the four reference materials are provided. Use of these reference materials will aid in providing uniform standardization among measurements made by remedial action contractors. 11 refs., 9 tabs

About preparation and properties of UC based fuel materials

International Nuclear Information System (INIS)

Vooght, D. de; Timmermans, W.; Batist, R. de.

1978-07-01

The sintering behaviour and the effect of a numer of production parameters on the properties of sintered UC materials have been studied. Materials investigated include slightly hyperstoichiometric UC(UCsub(1+x)), oxygen containing UC[U(CO)] and UC containing both oxygen and nitrogen [U(CON)]. The materials have been characterized in terms of grain size distribution for the pre-sintering powder, of porosity distribution for the powdered material and for the green and sintered pellets and of the density of the green and sintered pellets. Carbothermic reaction temperature, milling time, and to some extent sintering temperature have been varied. The report discusses the possible correlations between several parameters such as milling time, powder fineness, density, grain size of the sintered product, composition (O,N content), etc. (author)

Guide to nondestructive assay standards: Preparation criteria, availability, and practical considerations

International Nuclear Information System (INIS)

Stewart, J.E.; Hsue, S.T.; Sampson, T.E.

1997-01-01

For certification and measurement control, nondestructive assay (NDA) instruments and methods used for verification measurement of special nuclear materials (SNMs) require calibrations based on certified reference materials (CRMs), or working reference materials (WRMs), traceable to the national system of measurements, and adequately characteristic of the unknowns. The Department of Energy Office of Safeguards and Security is sponsoring production of a comprehensive guide to preparation of NDA standards. The scope of the report includes preparation criteria, current availability of CRMs and WRMs, practical considerations for preparation and characterization, and an extensive bibliography. In preparing the report, based primarily on experience at Los Alamos, we have found that standards preparation is highly dependent on the particular NDA method being applied. We therefore include sections that contain information specific to commonly used neutron and gamma-ray NDA techniques. 16 refs., 4 figs., 2 tabs

PREPARATION, CHARACTERISATION AND APPLICATION OF ...

African Journals Online (AJOL)

Polyamine-silica hybrids were prepared by a one-pot sol-gel method via a neutral amine templating route. At low loadings (ca. 1 mmol organic group per g of silica) the resultant materials displayed properties typical of M41S-type materials, namely, high surface area (typically 600 m2 g-1) and controlled porosity with an ...

Physical Properties Investigation of Reduced Graphene Oxide Thin Films Prepared by Material Inkjet Printing

Directory of Open Access Journals (Sweden)

Veronika Schmiedova

2017-01-01

Full Text Available The article is focused on the study of the optical properties of inkjet-printed graphene oxide (GO layers by spectroscopic ellipsometry. Due to its unique optical and electrical properties, GO can be used as, for example, a transparent and flexible electrode material in organic and printed electronics. Spectroscopic ellipsometry was used to characterize the optical response of the GO layer and its reduced form (rGO, obtainable, for example, by reduction of prepared layers by either annealing, UV radiation, or chemical reduction in the visible range. The thicknesses of the layers were determined by a mechanical profilometer and used as an input parameter for optical modeling. Ellipsometric spectra were analyzed according to the dispersion model and the influence of the reduction of GO on optical constants is discussed. Thus, detailed analysis of the ellipsometric data provides a unique tool for qualitative and also quantitative description of the optical properties of GO thin films for electronic applications.

Polymeric materials from renewable resources

Energy Technology Data Exchange (ETDEWEB)

Frollini, Elisabete; Rodrigues, Bruno V. M.; Silva, Cristina G. da; Castro, Daniele O.; Ramires, Elaine C.; Oliveira, Fernando de; Santos, Rachel P. O. [Macromolecular Materials and Lignocellulosic Fibers Group, Center for Research on Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, São Paulo (Brazil)

2016-05-18

The goals of our studies have been the use of renewable raw materials in the preparation of polymeric materials with diversified properties. In this context, lignosulfonate, which is produced in large scale around the world, but not widely used in the production of polymeric materials, was used to replace phenol and polyols in the preparation of phenolic- (Ligno-PH) and polyurethane-type (Ligno-PU) polymers, respectively. These polymers were used to prepare composites reinforced with sisal lignocellulosic fibers. The use of lignosulfonate in the formulation of both types of polymers was beneficial, because in general composites with improved properties, specially impact strength, were obtained. Composites were also prepared from the so called “biopolyethylene” (HDPE), curaua lignocellulosic fiber, and castor oil (CO). All composites HDBPE/CO/Fiber exhibited higher impact strength, when compared to those of the corresponding HDBPE/Fiber. These results, combined with others (eg SEM images of the fractured surfaces) indicated that, in addition to acting as a plasticizer, this oil may have acted as a compatibilizer of the hydrophilic fiber with the hydrophobic polymer. The set of results indicated that (i) mats with nano (diameter ≤ 100nm) and/or ultrafine (submicron scale) fibers were produced, (ii) hybrid fibers were produced (bio-based mats composites), (iii) cellulosic pulp (CP) and/or lignin (Lig) can be combined with PET matrices to control properties such as stiffness and hydrophilicity of the respective mats. Materials with diversified properties were prepared from high content of renewable raw materials, thus fulfilling the proposed targets.

Polymeric materials from renewable resources

Science.gov (United States)

Frollini, Elisabete; Rodrigues, Bruno V. M.; da Silva, Cristina G.; Castro, Daniele O.; Ramires, Elaine C.; de Oliveira, Fernando; Santos, Rachel P. O.

2016-05-01

The goals of our studies have been the use of renewable raw materials in the preparation of polymeric materials with diversified properties. In this context, lignosulfonate, which is produced in large scale around the world, but not widely used in the production of polymeric materials, was used to replace phenol and polyols in the preparation of phenolic- (Ligno-PH) and polyurethane-type (Ligno-PU) polymers, respectively. These polymers were used to prepare composites reinforced with sisal lignocellulosic fibers. The use of lignosulfonate in the formulation of both types of polymers was beneficial, because in general composites with improved properties, specially impact strength, were obtained. Composites were also prepared from the so called "biopolyethylene" (HDPE), curaua lignocellulosic fiber, and castor oil (CO). All composites HDBPE/CO/Fiber exhibited higher impact strength, when compared to those of the corresponding HDBPE/Fiber. These results, combined with others (eg SEM images of the fractured surfaces) indicated that, in addition to acting as a plasticizer, this oil may have acted as a compatibilizer of the hydrophilic fiber with the hydrophobic polymer. The set of results indicated that (i) mats with nano (diameter ≤ 100nm) and/or ultrafine (submicron scale) fibers were produced, (ii) hybrid fibers were produced (bio-based mats composites), (iii) cellulosic pulp (CP) and/or lignin (Lig) can be combined with PET matrices to control properties such as stiffness and hydrophilicity of the respective mats. Materials with diversified properties were prepared from high content of renewable raw materials, thus fulfilling the proposed targets.

Chitosan-nanosilica hybrid materials: Preparation and properties

International Nuclear Information System (INIS)

Podust, T.V.; Kulik, T.V.; Palyanytsya, B.B.; Gun’ko, V.M.; Tóth, A.; Mikhalovska, L.; Menyhárd, A.; László, K.

2014-01-01

Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO 2 , TiO 2 /SiO 2 and Al 2 O 3 /SiO 2 ). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S BET of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface

Chitosan-nanosilica hybrid materials: Preparation and properties

Energy Technology Data Exchange (ETDEWEB)

Podust, T.V., E-mail: tania_list@yahoo.com [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Kulik, T.V., E-mail: tanyakulyk@i.ua [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Palyanytsya, B.B.; Gun’ko, V.M. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Tóth, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Mikhalovska, L. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Menyhárd, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Institute of Materials Science and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (Hungary); László, K. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

2014-11-30

Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO{sub 2}, TiO{sub 2}/SiO{sub 2} and Al{sub 2}O{sub 3}/SiO{sub 2}). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S{sub BET} of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface.

A behavior of O/M ratio and its effect for Material Accounting in feed preparation process of MOX fabrication line

International Nuclear Information System (INIS)

Kuba, Meiji; Kashimura, Motoaki; Suzuki, Toru; Yamaguchi, Toshihiro; Deguchi, Morimoto; Otani, Tetsuo

1997-01-01

An evaluation test to investigate the behavior of the Oxygen to Metal ratio (O/M ratio) drift and its effect to material accounting in Feed preparation process was carried out in operational MOX fuel fabrication process, Plutonium Fuel Production Facility (PFPF) of Power Reactor and Nuclear Fuel Development Corporation (PNC). The test results clearly show the transition of O/M ratio along the Feed preparation process flow and it was increased gradually according to the progress of process steps. It leveled off after Feed lot blending operation and then it remained stable around 2.25. Analytical result of plutonium concentration after the correction with the changes of moisture concentration on the same sample as O/M ratio analysis has strong correlation with O/M ratio result as the theory. Therefore, it was confirmed that the plutonium concentration of the MOX should be corrected on the basis of the changes in O/M ratio and moisture concentration. Sample taking after blending operation was carried out at Cross Blending process step. An analysis of variance for plutonium concentration using two-way layout, whose factors are feed blending batch (factor A) and container (factor B), is carried out. Since no significant difference was observed in factor A nor B, the test concludes that a sample taken after blending operation can be considered as representative for the whole material blended by cross blending operation. Now the software of 'Material Accounting System' is being modified to improved one, that is, the plutonium concentration after the intermediate storage and after treatment in a process glove box is corrected with the change of O/M ratio and moisture concentration. (J.P.N.)

Design and preparation of novel polyarylene ether materials based on Diels-Alder reaction as the crosslinker for electrooptical modulators

Science.gov (United States)

Gao, Wu; Hou, Wenjun; Zhen, Zhen; Liu, Xinhou; Liu, Jialei; Fedorchuk, A. A.; Czaja, P.

2016-07-01

Novel crosslinkable organic linear electro-optical (EO) material based on polyarylene ether as the main chain host polymer was designed and prepared. The host polymer with rigid aromatic has demonstrated a good compatibility with the guest chromophore. Long side chain with anthracene ensured the crosslinkable reaction and appropriate glass transition temperature of the host polymer (55 °C). The EO r33 tensor coefficient for this novel EO material has been magnitude of 66 pm/V at 1310 nm and the excellent long term stability at 85 °C. These parameters permit to consider their application in fabrication of organic electro optical devices. The semi-empirical and DFT quantum chemical simulations were performed for 4 principal chromophores to clarify a role of cross-linker in the enhancement of the ground state dipole moments and effective hyperpolarizabilities.

Preparing paraffin wax, etc

Energy Technology Data Exchange (ETDEWEB)

1935-12-27

A process is described for preparing paraffin wax by separation from substances containing bitumen, consisting of treating the raw material at an elevated temperature under such moderate conditions and by means of such organic solvents that the bitumen present in the raw material or formed in the process dissolves as well as the asphaltic and phenolic substances and the humic acids which may be said to be neither extracts nor decomposed materials, and then submitting the products and extracts to a treatment with hydrogen gas, which is effected below 300/sup 0/C, and passing the material over fixed hydrogenation catalysts above 300/sup 0/C by means of hydrogenation catalysts finely dispersed in carbonaceous materials all avoiding decomposition with the formation of volatile products.

Preparation and characterization of flame retardant n-hexadecane/silicon dioxide composites as thermal energy storage materials.

Science.gov (United States)

Fang, Guiyin; Li, Hui; Chen, Zhi; Liu, Xu

2010-09-15

Flame retardant n-hexadecane/silicon dioxide (SiO(2)) composites as thermal energy storage materials were prepared using sol-gel methods. In the composites, n-hexadecane was used as the phase change material for thermal energy storage, and SiO(2) acted as the supporting material that is fire resistant. In order to further improve flame retardant property of the composites, the expanded graphite (EG) was added in the composites. Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD) and scanning electronic microscope (SEM) were used to determine chemical structure, crystalloid phase and microstructure of flame retardant n-hexadecane/SiO(2) composites, respectively. The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the n-hexadecane was well dispersed in the porous network of the SiO(2). The DSC results indicated that the melting and solidifying latent heats of the composites are 147.58 and 145.10 kJ/kg when the mass percentage of the n-hexadecane in the composites is 73.3%. The TGA results showed that the loading of the EG increased the charred residue amount of the composites at 700 degrees C, contributing to the improved thermal stability of the composites. It was observed from SEM photographs that the homogeneous and compact charred residue structure after combustion improved the flammability of the composites. Copyright 2010 Elsevier B.V. All rights reserved.

Preparation of fine powdered composite for latent heat storage

Energy Technology Data Exchange (ETDEWEB)

Fořt, Jan, E-mail: jan.fort.1@fsv.cvut.cz; Trník, Anton, E-mail: anton.trnik@fsv.cvut.cz; Pavlíková, Milena, E-mail: milena.pavlikova@fsv.cvut.cz; Pavlík, Zbyšek, E-mail: pavlikz@fsv.cvut.cz [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic); Pomaleski, Marina, E-mail: marina-pomaleski@fsv.cvut.cz [Faculty of Civil Engineering, Architecture and Urbanism, University of Campinas, R. Saturnino de Brito 224, 13083-889 Campinas – SP (Brazil)

2016-07-07

Application of latent heat storage building envelope systems using phase-change materials represents an attractive method of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. This study deals with a preparation of a new type of powdered phase change composite material for thermal energy storage. The idea of a composite is based upon the impregnation of a natural silicate material by a reasonably priced commercially produced pure phase change material and forming the homogenous composite powdered structure. For the preparation of the composite, vacuum impregnation method is used. The particle size distribution accessed by the laser diffraction apparatus proves that incorporation of the organic phase change material into the structure of inorganic siliceous pozzolana does not lead to the clustering of the particles. The compatibility of the prepared composite is characterized by the Fourier transformation infrared analysis (FTIR). Performed DSC analysis shows potential of the developed composite for thermal energy storage that can be easily incorporated into the cement-based matrix of building materials. Based on the obtained results, application of the developed phase change composite can be considered with a great promise.

Preparation of new nano magnetic material Fe3O4@g-C3N4 and good adsorption performance on uranium ion

Science.gov (United States)

Long, Wei; Liu, Huijun; Yan, Xueming; Fu, Li

2018-03-01

A new nano magnetic material Fe3O4@g-C3N4 was prepared by deposition reduction method, which performed good adsorption performance to uranium ion. Characterization results showed that the g-C3N4 particles were wrapped around the nano magnetic Fe3O4 particles, and the textural properties of this material was improved, so the adsorption performance to uranium ion was good. Adsorption experiments of this material demonstrated that the optimum pH value was 10, the optimum mass of adsorbent was 6.5 mg and the optimum adsorption time was 150 min in the initial concentration of 140 mg/L uranium ion solution system, and the maximum adsorption capacity was up to 352.1 mg/g and the maximum adsorption rate was more than 90%.

Guide to nondestructive assay standards: Preparation criteria, availability, and practical considerations

International Nuclear Information System (INIS)

Hsue, S.T.; Stewart, J.E.; Sampson, T.E.; Butler, G.W.; Rudy, C.R.; Rinard, P.M.

1997-10-01

For certification and measurement control, nondestructive assay (NDA) instruments and methods used for verification measurements of special nuclear materials (SNMs) require calibrations based on certified reference materials (CRMs), or working reference materials (WRMs), traceable to the national system of measurements, and adequately characteristic of the unknowns. The Department of Energy Office of Safeguards and Security is sponsoring production of a comprehensive guide to preparation of NDA standards. The scope of the report includes preparation criteria, current availability of CRMs and WRMs, practical considerations for preparation and characterization, and an extensive bibliography. In preparing the report, based primarily on experience at Los Alamos, they have found that standards preparation is highly dependent on the particular NDA method being applied. They therefore include sections that contain information specific to commonly used neutron and gamma-ray NDA techniques. They also present approaches that are alternatives to, or minimize requirements for physical standards

Electrically conductive composite material

Science.gov (United States)

Clough, Roger L.; Sylwester, Alan P.

1989-01-01

An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistant pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like.

Autohydrolysis processing as an alternative to enhance cellulose solubility and preparation of its regenerated bio-based materials

Energy Technology Data Exchange (ETDEWEB)

Gan, Sinyee, E-mail: gansinyee@hotmail.com; Zakaria, Sarani, E-mail: szakaria@ukm.edu.my; Chen, Ruey Shan; Chia, Chin Hua; Padzil, Farah Nadia Mohammad; Moosavi, Seyedehmaryam

2017-05-01

Kenaf core pulp has been successfully autohydrolysed using an autoclave heated in oil bath at various reaction temperature at 100, 120 and 140 °C. Membranes, hydrogels and aerogels were then prepared from autohydrolysed kenaf in urea/alkaline medium by casting on the glass plate, by using epichlorohydrin (ECH) as cross-linker via stirring and freeze-drying method, respectively. The autohydrolysis process reduced the molecular weight of cellulose and enhanced cellulose solubility and viscosity. Structure and properties of the regenerated products were measured with Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Ultraviolet–visible (UV–Vis) spectrophotometer and swelling testing. As the autohydrolysis temperature increased, the porosity of cellulose membranes (as seen from the morphology) increased. The autohydrolysis process improved the swelling porperties and transparency of regenerated cellulose hydrogels. This finding is expected to be useful in reducing molecular weight of cellulose in order to produce regenerated bio-based cellulose materials. - Highlights: • Autohydrolysis temperature is negatively correlated to cellulose molecular weight. • Cellulose solubility and viscosity are improved after cellulose pretreatment. • Autohydrolysis improved the properties of regenerated cellulose materials.

Preparation of Nano-sized Bismuth-Doped Fe3O4 as an Excellent Magnetic Material for Supercapacitor Electrodes

Science.gov (United States)

Aghazadeh, Mustafa; Karimzadeh, Isa; Ganjali, Mohammad Reza

2018-03-01

Nano-sized Bi3+-doped iron oxide (n-Bi-IO) particles were prepared through a one-pot electrochemical procedure, and the product was evaluated using x-ray diffraction, field-emission scanning electron microscopy and energy-dispersive x-ray spectroscopy. Based on the analyses, the average size of the n-Bi-IO was determined to be 10 nm. Galvanostatic charge-discharge (GCD) evaluations revealed that the specific capacitance of the material reached 235 F g-1 at a discharge condition of 0.2 A g-1. n-Bi-IO had a 94.2% capacity retention after 2000 GCD cycles. Further vibrating sample magnetometery analyses showed that the product has enhanced superparamagnetic qualities (i.e. M r = 0.15 emu g-1 and H Ci = 2.71 G) in comparison to iron oxide nanoparticles (i.e. M r = 0.95 emu g-1 and H Ci = 14.62 G). Given the results, the product is considered to be a promising material for developing high performance supercapacitor electrodes.

Preparation and Study of Electromagnetic Interference Shielding Materials Comprised of Ni-Co Coated on Web-Like Biocarbon Nanofibers via Electroless Deposition

Directory of Open Access Journals (Sweden)

Xiaohu Huang

2015-01-01

Full Text Available Electromagnetic interference (EMI shielding materials made of Ni-Co coated on web-like biocarbon nanofibers were successfully prepared by electroless plating. Biocarbon nanofibers (CF with a novel web-like structure comprised of entangled and interconnected carbon nanoribbons were obtained using bacterial cellulose pyrolyzed at 1200°C. Paraffin wax matrix composites filled with different loadings (10, 20, and 30 wt%, resp. of CF and Ni-Co coated CF (NCCF were prepared. The electrical conductivities and electromagnetic parameters of the composites were investigated by the four-probe method and vector network analysis. From these results, the EMI shielding efficiencies (SE of NCCF composites were shown to be significantly higher than that of CF at the same mass fraction. The paraffin wax composites containing 30 wt% NCCF showed the highest EMI SE of 41.2 dB (99.99% attenuation, which are attributed to the higher electrical conductivity and permittivity of the NCCF composites than the CF composites. Additionally, EMI SE increased with an increase in CF and NCCF loading and the absorption was determined to be the primary factor governing EMI shielding. This study conclusively reveals that NCCF composites have potential applications as EMI shielding materials.

Preparation and characterization of a new hybrid material formed by reaction of cobalt (II) nitroprusside and octa(aminopropyl)silsesquioxane

International Nuclear Information System (INIS)

Magossi, Mariana de Souza; Carmo, Devaney Ribeiro do

2016-01-01

Full text: The term silsesquioxane etymologically refers to the nanostructured compounds that has structures that feature the empirical formula (RSiO 1,5 ) n , where R is a hydrogen atom or an organic group. Each silicon atom is connected on an average of 1.5 oxygen atoms and a group R (hydrocarbon, or an organic group) [1]. In this work, a new hybrid material (ACCoN) based on octa(aminopropyl)silsesquioxane (AC) and cobalt (II) nitroprusside have been prepared following a new synthesis route. Within this context, the objective of this work was to prepare and characterize this new material for electro analytical purposes. The ACCoN was characterized by several techniques such as: spectroscopy in the region of infrared (FTIR), Energy-Dispersive X-ray spectroscopy (EDS), Scanning Electron microscopy (SEM) and X-Ray Diffraction (XRD). The FTIR spectra showed absorption bands in 1106 cm -1 refer to the stretching vibration ν s (Si-O-Si) characteristics of the structure of silsesquioxane. An important vibration can be observed which is related to the stretching vibrations of the type νN-O which occurs near 1945 cm -1 , characteristic of the sodium nitroprusside, where in the ACCoN the νN-O is shifted for more high frequency (about 117 cm -1 ) relative to sodium nitroprusside. Additionally a drastic reduction of stretching vibrations intensity νC≡N was observed in the ACCoN. This fact is an indicative of the formation of the intervalence complex, where the CN- and metal centers are bound. Through SEM and EDS spectroscopies was observed clusters of cubic particles with an average size of 325 nm. The ACCoN presents the elements Si, O, N, Co and Fe in its structure. Therefore through the aforementioned spectroscopic analysis, we conclude that the preparation of ACCoN was successfully conducted. [1] Cordes, D. B.; Lickiss, P. D.; Rataboul, F. Chemical Reviews, vol. 110, p. 2081-2173 (2010). (author)

Preparation and characterization of a new hybrid material formed by reaction of cobalt (II) nitroprusside and octa(aminopropyl)silsesquioxane