Energy Technology Data Exchange (ETDEWEB)

Evaluates displacement of a railway bridge element of the Walbrzych-Klodzko railway line. The bridge, consisting of three truss sections supported by two pillars made of reinforced concrete, was influenced by longwall mining. Longwalls were perpendicular to the bridge axis. Three coal seams situated in the bridge safety pillar were 550 cm thick. Ground subsidence after seam extraction was 400 cm. Ground subsidence did not cause truss section deformation, nor did it cause additional stresses in truss bridge construction. 2 refs.

Energy Technology Data Exchange (ETDEWEB)

Research and development underway since 1982 has led to the development of a method of reinforcing wood and wood composite structural products (WWC) using high-strength fiber-reinforced plastic. This method allows the use of less wood fiber and lower grade wood fiber for a given load capacity. The first WWC in which reinforcement has been marketed is glulam beams. Marketed under the trade name FiRP{trademark} Reinforced glulam, the product has gained code approval and is now being used in the construction of buildings and bridges in the United States, Japan and other countries. The high-strength fiber-reinforced plastic (FiRP{trademark} Reinforced panel (RP)) has specific characteristics that are required to provide for proper use in WWC`s. This paper discusses these characteristics and the testing requirements to develop code approved allowable design values for carbon, aramid and fiberglass RP`s for such uses. Specific issues such as ...

UK PubMed Central (United Kingdom)

The sequence information available for homeodomains reveals that salt bridges connecting pairs 19/30, 31/42, and 17/52 are frequent, whereas aliphatic residues at these sites are rare and mainly restricted...Full Text Available

International Nuclear Information System (INIS)

Short communication.

Science.gov (United States)

This study presents a semi-active vibration control of a scaled two-span bridge structure. Magneto-rheological fluid dampers are utilized as the semi-active energy absorbing devices, and a bridge vibration control system is developed. Closed-loop control system based on fuzzy logic is used to suppress the bridge deck motion under random excitation. It is demonstrated that this fuzzy logic control system can significantly reduce the relative deck displacement using about 60% less power compared to passive on state, while the absolute deck acceleration remains practically unchanged.

Energy Technology Data Exchange (ETDEWEB)

The structural change of the (100-x)(0.6Li[sub 2]S[center dot]0.4SiS[sub 2])centre dotxLi[sub 3]PO[sub 4] oxysulfide glassesduring crystallization was analyzed by means of solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The unique tetrahedral units of SiO[sub n]S[sub 4-n] (n=1,2,3) and PO[sub n]S[sub 4-n] (n=1,2,3) present in the glass samples vanished and the SiS[sub 4], PS[sub 4], SiO[sub 4] units increased with proceeding of the crystallization process. Nonbridging sulfur and oxygen atoms decreased while bridging oxygens and S[sup 2-] increased with proceeding of the crystallization process. Large structural difference between the glass and the corresponding crystallized sample explained the high stability against crystallization found in the oxysulfide glass with the composition of X=5. (author)

British Library Electronic Table of Contents (United Kingdom)

This paper presents a dynamic displacement influence line method for moving load identification on bridge. The finite element model of Poyang Lake continuous truss bridge-train systems is established and the dispersed modal shapes are acquired by modal analysis. Multi-axle moving train loads are identified with simulated annealing genetic algorithm by minimizing the errors between the measured displacements and the reconstructed displacements from the identified moving loads. In the identification process, the dynamic displacement influence line technique is used to calculate the time history displacement responses of the bridge to avoid solving equations of motion of the bridge repetitively. Several important parameters of the bridge-train system are discussed to investigate their effects...

Energy Technology Data Exchange (ETDEWEB)

Ice jamming, known to cause high water levels at even moderate river flows, is described as both the main and least understood source of ice-related bridge damages. This paper describes a joint study by the New Brunswick Department of Transportation, the Department of the Environment, local governments, and the National Water Research Institute, designed to address problems associated with the interaction of ice jams and bridges. The study consists of collecting information at each of four sites in New Brunswick including: historical data on ice jam locations, causes, and water levels; channel bathymetry, width and slope within each study centred at the respective bridge; and documentation of ice conditions throughout the ice season, including measurement of ice cover thickness, observation of breakup mechanisms, times, causes, characteristics and possible impacts of ice jam release. Data analysis will include determination ...

British Library Electronic Table of Contents (United Kingdom)

We describe a class of organic molecular magnets based on zwitterionic molecules (betaine derivatives) possessing donor, p bridge, and acceptor groups. Using extensive electronic structure calculations we show the electronic ground-state in these systems is magnetic. In addition, we show that the large energy differences computed for the various magnetic states indicate a high Neel temperature. The quantum mechanical nature of the magnetic properties originates from the conjugated p bridge (only p electrons) in cooperation with the molecular donor-acceptor character. The exchange interactions between electron spin are strong, local, and independent on the length of the p bridge.

Science.gov (United States)

... Information behavior in dynamic group work contexts: interwoven situational awareness, dense social networks and contested collaboration in ...

International Nuclear Information System (INIS)

An 'electron-bridge' mechanism of nuclear reaction in an atom or ion by ultra-intense laser fields is presented. A preliminary estimate of the intensity dependence of the rate of disintegration reaction of deuteron nucleus in deuterium atom is made for 800 nm laser fields. For intensities below 5x1021 W/cm2, the rate of disintegration by the 'electron-bridge' mechanism is found to be small, but it rises sharply and becomes large already for ?1022 W/cm2.

Science.gov (United States)

In the present work, a new kind of myoglobin (Mb)/Au nanoparticles composite film was fabricated on pyrolytic graphite (PG) electrodes. Oppositely charged chitosan (CS) and silica (SiO(2)) nanoparticles were alternately adsorbed on the PG surface by the electrostatic interaction between them, forming {CS/SiO(2)}(5) layer-by-layer films. Mb and HAuCl(4) in solution were then simultaneously loaded into {CS/SiO(2)}(5) films. The loaded Au(III) in the films were electrochemically reduced into Au nanoparticles, forming nanocomposite films, designated as {CS/SiO(2)}(5)-Mb-Au. Various techniques such as cyclic voltammetry (CV), square wave voltammetry (SWV), quartz crystal microbalance (QCM), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis were used to characterize the films. Compared with {CS/SiO(2)}(5)-Mb films without Au nanoparticles inside, the {CS/SiO(2)}(5)-Mb-Au films exhibited much ...

International Nuclear Information System (INIS)

In this study, the corrosion behavior of commercially pure titanium (c.p. Ti), Ti-6Al-4V and five new experimental Ti-Cr alloys was evaluated through open-circuit potential (OCP) and potentiodynamic polarization measurement in an artificial saliva containing fluoride. Electron spectroscopy for chemical analysis (ESCA) was used to characterize the composition of the passive films on the alloy after potentiodynamic polarization measurement. It was found that in standard artificial saliva the OCP increases with higher Cr content in Ti-Cr alloys. In 0.5% NaF artificial saliva, the OCP decreases with decreasing Cr in Ti-Cr alloys, and all but Ti-5Cr remain consistently higher than those of c.p Ti and Ti-6Al-4V. Linear polarization results show that artificial saliva and artificial saliva containing 0.5% NaF result in different corrosion behavior in Ti-Cr alloys, c.p.Ti and Ti-6Al-4V. The Ti-Cr alloys had greater resistance to corrosion in the fluoride-containing ...

Science.gov (United States)

With appropriate circuit resistance and inductance and sufficient stored energy, discharging a charged human body or component through an exploding bridgewire (EBW) detonator may cause the detonator to function or may damage the detonator. We have studied the effects of electrostatic discharge (ESD) on a number of exploding bridgewire detonators which were subjected to discharges which passed directly through the bridgewires (pin-to-pin), as well as discharges which passed from the bridge to the metal case of the detonator (pin-to-case). We have performed calculations to determine the values of inductance and resistance for which burst and melt may occur for given ESD sources, using a phenomenological model of bridgewire burst in a computer code called FIRESET. Bridge melt was computed using the same computer code, but using experimental values of bridge resistivity and specific heat up to melt. 13 refs., 5 figs.

Science.gov (United States)

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pat...

UK PubMed Central (United Kingdom)

Alkyl halides react rapidly with purines and pyrimidines in the presence of fluoride ion. Alkylation of thymidine leads to novel dimeric nucleoside derivatives bridged through N3. Alkylation of thymidine...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In this paper, bond cleavage reactions are discussed in relation to the softening and solubilization of coal. Were used 9,10-dihydroanthracene (DHA) and 9,10-dihydrophenanthrene (DHP) as models of hydrogen donating compounds in coal, and bibenzyl, 1,2-diethane, benzylphenylether, and 1,5-dibenzylnaphthalene were used as models of bridge structure compounds. They were compared mutually, as to reactivity of coal against DHA and DHP. For the homolytic cleavage of bridges, DHA with excellent radical supplement performance provided excellent hydrogen donating performance. While, for the ipso-position cleavage of bridges, it was found that DHP can act as an effective hydrogen donor. For the reaction between coal and hydrogenated aromatic compounds, cleavage of relatively weak bonds, such as ether linkage and dimethylene linkage, occurred at about 380{degree}C, and hydrogen from DHA or DHP was consumed. On the other hand, the ...

Energy Technology Data Exchange (ETDEWEB)

The fibre reinforcement of ceramic materials is used above all to improve the toughness and tolerance of damage, compared to unreinforced monolithic ceramics. This improvement is made possibly by the bridging effect of the cracks by the fibres in crack propagation in the matrix. In this work, the crack bridging effect of the fibres is included in a bridge stress equation, in which a clear relationship between bridge stress and crack opening is determined. The most important step for deriving the bridge stress law was determining the probability of failure of a fibre for a given axial stress curve. One relied on the micromechanical analysis of Hutchinson and Jensen here, by which the boundary conditions in multi-fibre materials can be included and realistic assumptions can be made for the load transfer mechanisms in the fibre/matrix boundary surface. (orig./MM) [Deutsch] Die ...

International Science & Technology Center (ISTC)

Metal Matrix Composites on the Basis of Nano-Materials

International Science & Technology Center (ISTC)

Development of the Method of Electrodepositing Nanostructured Composite Coatings with Improved Engineering Properties

Science.gov (United States)

A patient with a totally edentulous maxilla and a seVere Class III intermaxillary relationship in the anterior region was treated by implants. In the mandible, there were 10 teeth between the second premolars. The inclination and width of the maxillary anterior residual bone were measured on cephalometric X-ray film obtained before treatment. The results of cephalometric analysis did not support clockwise rotation of the mandible or lingual angling of the maxillary anterior teeth by use of prosthesis to improve the Class III relationship. Ten implants were simultaneously placed in the maxilla. Then, a maxillary temporary full bridge was seated after reduction of the crown lengths of the mandibular anterior teeth. An apically positioned flap operation was performed to eliminate periodontal pockets and to obtain clinically suitable crown lengths of the mandibular anterior teeth. A noncemented, screw-retained maxillary full bridge and a ...

British Library Electronic Table of Contents (United Kingdom)

Background: Mechanisms underlying the association between myocardial bridge (MB)-stenting and in-stent restenosis (ISR) are still unclear. Objective: To assess the impact of MB on ISR using intravascular ultrasound (IVUS). Methods: In the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, 100 left anterior descending artery (LAD) culprit lesions (79 treated with paclitaxel-eluting stents [PES] and 21 treated with bare metal stents) were imaged with serial IVUS immediately postprocedure and at 13 months. Results: At baseline the LAD stent extended into the MB segment beyond the culprit lesion in seven patients (MB-stent group). In the remaining 93 patients the LAD stent was implanted only in the culprit lesion without extending into t...

CERN Document Server

For a genus-1 1-bridge knot in the 3-sphere, that is, a (1,1)-knot, a middle tunnel is a tunnel that is not an upper or lower tunnel for some (1,1)-position. Most torus knots have a middle tunnel, and non-torus-knot examples were obtained by Goda, Hayashi, and Ishihara. In a previous paper, we generalized their construction and calculated the slope invariants for the resulting examples. We give an interated version of the construction that produces many more examples, and calculate their slope invariants. If one starts with the trivial knot, the iterated construction produces the 2-bridge knots, giving a new calculation of the slope invariants of their tunnels. Together with other information, the examples suggest a general classification conjecture for all tunnels of all tunnel number 1 knots.

CERN Document Server

We consider the exact path sampling of the squared Bessel process and some other continuous-time Markov processes, such as the CIR model, constant elasticity of variance diffusion model, and hypergeometric diffusions, which can all be obtained from a squared Bessel process by using a change of variable, time and scale transformation, and/or change of measure. All these diffusions are broadly used in mathematical finance for modelling asset prices, market indices, and interest rates. We show how the probability distributions of a squared Bessel bridge and a squared Bessel process with or without absorption at zero are reduced to randomized gamma distributions. Moreover, for absorbing stochastic processes, we develop a new bridge sampling technique based on conditioning on the first hitting time at zero. Such an approach allows us to simplify simulation schemes. New methods are illustrated with pricing path-dependent options.

British Library Electronic Table of Contents (United Kingdom)

Density functional theory calculations were performed to study the effects of different substituents and bridge groups on the heats of formation (HOFs), thermal stability, and detonation properties for a series of diiminotetrazole derivatives. The isodesmic reaction method was employed to calculate the HOFs of the derivatives using total energies obtained from electronic structure calculations. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the diiminotetrazole derivatives. The detonation velocities and pressures were evaluated by using the semiempirical Kamlet-Jacobs equations, based on the theoretical densities and HOFs. These results provide basic information for the molecular design of novel high-energy density...

British Library Electronic Table of Contents (United Kingdom)

Uragogin and blepharodin were isolated from Crossopetalum uragoga and Maytenus magellanica, respectively. They represent the first examples of a triterpene-neolignan ester and a heptacyclic arylpropanoid-nor-triterpenephenol, hetero-Diels-Alder adducts built with dioxane bridges. Their proposed biosynthetic route is discussed.

Energy Technology Data Exchange (ETDEWEB)

Main results are summarised for a project carried out with the aim of increasing the knowledge of relations between handling characeristics and properties such as moisture content, particle size and shape etc. Handling characteristics that were studied: angle of repose, friction between fuel and different surfaces, the fuel`s tendency to bridge across openings, and its freezing characteristics. Some forty solid biomass fuels were studied, mainly wood fuels, with particle sized from 1 to 200 mm. New methods were developed for measurement of bridging across openings and freezing characeristics. The angle of repose varied between 25 and 55 deg. The particle shape had a significant influence, a high ratio of length/thickness gave a high angle of repose. When the fuel moisture content was increased the angle of repose first increased, then decreased, and finally increased again. The particle size had no influence. The friction depended more on the ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a Honshu-Shikoku linking transmission cable building plan and its technical features. The Chugoku District and the Shikoku District are supplied with power currently by the Chugoku-Shikoku trunk line of 220,000 volts. To cope with the anticipated power shortage, a plan was established to install power cables for 500,000 volts on the Honshu-Shikoku connecting bridge. The plan calls far an installation length of 127.4 km and a transmission capacity of 1.2 million kW per line. The cable installation on the Seto Bridge was completed already, the construction is now in the peak period for building steel towers on the land sections, and laying overhead cables and underground cables. Commencement of the operation is scheduled 1994 on one liner, and 2000 on two lines. The technical features include the Japan's first large-capacity, long-distance underground transmission cable installation, and the installation of the ...

International Nuclear Information System (INIS)

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally occurring cyclopeptide alkaloid, ceanothine B, bind monovalent (Li"+) and divalent (Ca"2"+, Mg"2"+) cations. 4 figures, 1 table.

Energy Technology Data Exchange (ETDEWEB)

Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

Energy Technology Data Exchange (ETDEWEB)

Design-for-reliability concepts can be applied to the products of the construction industry, which includes buildings, bridges, transportation systems, dams, and other structures. The application of a systems approach to designing in reliability emphasizes the importance of incorporating uncertainty in the analyses, the benefits of optimization analyses, and the importance of integrating reliability, safety, and security. 4 refs., 3 figs.

International Nuclear Information System (INIS)

Short note.

Science.gov (United States)

Not Available

Science.gov (United States)

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KoreaScience (Korea)

Full Text Available

International Science & Technology Center (ISTC)

Thermodynamic Stable Metal Compositions for Improvement of an Operational Safety of Constructional Materials under Conditions of Multifactor Loadings of an Aggressive Environment

Science.gov (United States)

... Accession Number : ADD345858. Title : Nondestructive Testing of Polymeric Composite Sandwich Panels Via the Thermographic Halo,. ...

Energy Technology Data Exchange (ETDEWEB)

A fuel composition comprising a liquid hydrocarbon fuel and a detergent amount of the product of reaction between a polyamine and a stearic acid is described.

Science.gov (United States)

... Title : DARPA Program Composition for Embedded Systems (PCES) Program Capstone Demonstration Video (Postprint) (CD-ROM). ...

Science.gov (United States)

... The ultimate compressive strength (UCS) for the HMU/BSG composite is essentially equivalent to the tensile strength exhibited by this system. ...

Science.gov (United States)

... Accession Number : ADD808679. Title : Advanced Composites for Aerospace Require Waterjet Technology. Descriptive Note : Journal article. ...

British Library Electronic Table of Contents (United Kingdom)

The effect of particle/matrix interface debonding on composites consisting of elastic particles and viscoelastic matrix is studied. The interface debonding is represented by a nonlinear cohesive law for the high explosive PBX 9501. The Mori-Tanaka method gives the constitutive relation of the composite in terms of the properties of elastic particles, viscoelastic matrix, and nonlinear cohesive law for interfaces. For the example of a composite with spherical particles subject to hydrostatic tension, simple analytical expressions of the composite stress-strain relation are obtained. The strain rate and temperature have strong effects on the composite behavior. High strain rate and low temperature give high strength of the composite. However, the rate and temperature effects decrease as the ...

International Nuclear Information System (INIS)

Glasses in the system (95-x) [0.25 Na2O-0.75 B2O3]-x P2O5-5 Fe2O3 (0?x?15 mol%), have been prepared by the melt quenching technique. Elastic properties and FT-IR spectroscopic studies have been employed to study the role of P2O5 on the structure of the glass system. Elastic properties Poisson's ratio, micro-hardness and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz (both longitudinal and shear) at room temperature. The results showed that the density and the molar volume increase as both sound velocities and the determined glass transition temperatures decrease with increasing the contents of P2O5. Infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of P2O5 content as a second network former. These results are interpreted in terms of the replacement of the diborate units with B-O-B bridges by phosphate units with ...

Energy Technology Data Exchange (ETDEWEB)

A dipole magnet based on the common coil design, using prereacted Nb{sub 3}Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R&D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting of a 165 mm long section of the magnet straight section was assembled and tested. This paper ...

Energy Technology Data Exchange (ETDEWEB)

This article presents an experimental study on the gasification of leather residues from a tannery by using a throated 10 kW{sub e} downdraft gasifier. The gasification process is conducted over a range of feed rates in the gasifier for the operating temperatures of 1,000 deg C and 1,100 deg C, slightly below atmospheric pressure. In this study, the experimental setup and procedure are also explained in detail. Moreover, the fuel characteristics, components in the produced gas, and side products from the gasification system were measured during the experiments and discussed. It was concluded that the briquetted leather residues were successfully gasified in a downdraft gasifier. However, the large briquette sizes of the leather residues occasionally formed bridging in the throat zone of the gasifier. Therefore the downdraft gasifier should be operated using smaller size briquettes to prevent the bridging in the throat zone in order to ...

Science.gov (United States)

The interaction of the globular protein lysozyme with silica nanoparticles of diameter 20 nm was studied in a pH range between the isoelectric points (IEPs) of silica and the protein (pH 3-11). The adsorption affinity and capacity of lysozyme on the silica particles is increasing progressively with pH, and the adsorbed protein induces bridging aggregation of the silica particles. Structural properties of the aggregates were studied as a function of pH at a fixed protein-to-silica concentration ratio which corresponds to a surface concentration of protein well below a complete monolayer in the complete-binding regime at pH > 6. Sedimentation studies indicate the presence of compact aggregates at pH 4-6 and a loose flocculated network at pH 7-9, followed by a sharp decrease of aggregate size near the IEP of lysozyme. The structure of the bridged silica aggregates was studied by cryo-transmission electron microscopy (cryo-TEM) and small-angle ...

Energy Technology Data Exchange (ETDEWEB)

In this note it is suggested that binuclear platinum(II) complexes with a solely inorganic bridging pyrophosphito ligand also possess many of the complementary advantages of inorganic and organic dyes. They are evaluated for their potential use as a luminescent solar concentrator material. The disadvantages include: the high cost of platinum; the absorption spectra in solution shows a weaker absorption at 452 nm which may cause reabsorption of emitted light; the positions of the absorption and emission maxima are not at the optimal wavelengths for absorption of sunlight and emission to a solar cell. In spite of these drawbacks the author believes the platinum complexes merit consideration for fabrication of solar concentrator devices.

Energy Technology Data Exchange (ETDEWEB)

The defects localization in power cables follows several steps: identification, pre-localization and precise localization. Pre-localization methods, other than echo-metry, are presented first: bridge methods, particular case of low voltage networks, future perspectives. Then, the precise localization methods are described: magneto-acoustic method, audible frequencies method. The particular case of underwater and high-voltage cables is considered too (oil and gas leaks detection). (J.S.)

Energy Technology Data Exchange (ETDEWEB)

17 papers are presented. Topics covered include: the POG system - a new concept in the use of ANFO; demolition of a motorway bridge; presplit and smooth blasting; VIBReX - a predictive code for assessing the effect of blast design on ground vibration; ground vibrations from blasting; digital seismographs; human response to blasting and the effects on planning conditions; landform construction by restoration blasting; use of small diameter explosives; efficient priming; safety management in the explosives industry; and the law on packaging of explosives. Two papers have been abstracted separately.

International Nuclear Information System (INIS)

The effect of variations of the fundamental constants on the thermonuclear rate of the triple alpha reaction, "4He(#alpha##alpha#, #gamma#)"1"2C, that bridges the gap between "4He and "1"2C is investigated. We have followed the evolution of 15 and 60 M#centre dot# zero metallicity stellar models, up to the end of core helium burning. They are assumed to be representative of the first (Population III) stars. The calculated oxygen carbon abundances resulting from helium burning can then be used to constrain the variation of the fundamental constants.

Energy Technology Data Exchange (ETDEWEB)

Consol R&D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-field: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

International Nuclear Information System (INIS)

This handbook breaks down the complex field of nuclear reactor calculations into major steps. Each step presents a detailed analysis of the problems to be solved, the parameters involved, and the elaborate computer programs developed to perform the calculations. This book bridges the gap between nuclear reactor theory and the implementation of that theory, including the problems to be encountered and the level of confidence that should be given to the methods described. Volume III: Control Rods and Burnable Absorber Calculations. Perturbation Theory for Nuclear Reactor Analysis. Thermal Reactors Calculations. Fast Reactor Calculations. Seed-Blanket Reactors. Index.

British Library Electronic Table of Contents (United Kingdom)

A tobermorite/hydroxyapatite composite was prepared by hydrothermal treatment using diatomaceous earth, ?-tricalcium phosphate and slaked lime starting materials. The XRD patterns of the composite confirmed that tobermorite and hydroxyapatite were formed after the hydrothermal process. The bending strength of the composite reached a level higher than 9?MPa after the hydrothermal process. The development of the bending strength was due to the formation of tobermorite and hydroxyapatite during the hydrothermal process. The composite had a high specific surface area due to these newly formed crystals.

Science.gov (United States)

A process is provided for conducting organic compound conversion over a catalyst composition comprising a supported crystalline zeolite having a high initial silica-to-alumina mole ratio, said supported zeolite being prepared by compositing said crystalline zeolite with alumina, reacting the composite with a particular hydrogen fluoride solution in a specified way, drying the hydrogen fluoride reacted composite, treating the dried composite by hydrolysis, ammonolysis and/or by contact with an ammonium salt solution, and calcining the resulting material.

Energy Technology Data Exchange (ETDEWEB)

Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite. (author).

Science.gov (United States)

Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite.

Science.gov (United States)

This study investigated weathering effects on polyvinyl chloride (PVC) based wood plastic composites (WPC), with a focus on the color and structure that is attributed to the material composition. It is directed towards quantifying the main chemical modifi...

Energy Technology Data Exchange (ETDEWEB)

This report presents a brief description of the fabrication and advantages of a composite, carbon-metal fiber material which does not require lubrication.

CERN Document Server

Preparation of covalently modified organic-inorganic composite nanoparticles and their interfacial electron transfer researches

International Nuclear Information System (INIS)

... Commission, Rio de Janeiro Rio de Janeiro, RJ (Brazil) 26-27 Nov 1998 1

UK PubMed Central (United Kingdom)

This article addresses the need for new data on indirect effects of natural and anthropogenic aerosol particles on atmospheric ice clouds. Simultaneous measurements of the concentration and composition...Full Text Available

UK PubMed Central (United Kingdom)

Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth...Full Text Available

Science.gov (United States)

structures made out of composite laminates and/or composite sandwich panels. A Spectral Finite Element Method (SFEM) [19, 20] is used for evaluating the ...

CERN Document Server

Composition of the Scientific Policy Committee Appointment of Two New Members by the Chairman of the Committee (J. Specht, A. Wroblewski)

Science.gov (United States)

A Composite Architecture for Network Security at JPL. Robert B. Mead, Tom G. Dearmond, and Joseph S. Sherif. JPL, California Institute of Technology ...

Energy Technology Data Exchange (ETDEWEB)

The high temperature abrasive wear resistant of the composites with different Al{sub 2}O{sub 3} volume fractions, particle coating and size were investigated and the failure action of composites under different conditions at high temperature was analyzed. The results showed that the high temperature abrasive wear resistant of composite with Ni coating and wide size and 39% volume fraction of particle is the best among all composites examined. (orig.)

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Characteristics of advanced composites are investigated. The fibers considered are Kevlar and carbon. The greatest advantage of composites over metals is emphasized, and lies in their permitting designers to obtain properties in exactly the locations desired. Kevlar replaced S-glass on the Trident 2 missile, saving 800 lbs. and adding 800 miles to its range. Military aircraft builders find that advanced carbon composites more often than not win out over Kevlar.

KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

... BUCKLING ANALYSIS OF METAL MATRIX COMPOSITE SANDWICH PANELS UNDER DIFFERENT THERMAL ENVIRONMENTS , Technical Memorandum ...

International Nuclear Information System (INIS)

The thermal properties of five types of radiation-induced wood-polymer composites based on a tropical hardwood, rubberwood (Hevea braziliensis), was studied by oxygen index measurement, differential thermal analysis (DTA) and thermogravimetry (TG). The DTA and TG curves of composites were different from those of rubberwood, which can be attributed to the presence of the incorporated polymers. Of the five composites, the one impregnated with bis(2-chloroethyl)vinyl phosphonate reduced the initial temperature of decomposition, increased the peak temperatures of exothermic reactions, and increased the char yield. Comparison with physical blends of rubberwood and the corresponding polymer provided some evidence of chemical interaction of wood and polymer in some of the composites. (author).

Environmental Research Database

ObjectivesThe primary aim is to enable China to address its energy and infrastructure issues in a sustainable manner, without hindering economic progress, with the UK benefiting from an enhanced uptake of its technology, knowledge and expertise through enhanced business opportunities and strengthened collaboration with key Chinese Institutions. ~%~~%~Objectives~%~1) To build capacity and capability in technology transfer and knowledge exploitation in Chinese and UK business and industry through practical, [continued...]DescriptionThe Chinese 11th Five-Year Plan considers Sustainable Energy Supply and Sustainable Built Environment as crucial for achieving sustainable development. Recognising the potential benefits, the UK government has actively encouraged international collaborations with China. Two Engineering Schools at Queen's University Belfast (QUB), with internationally recognised research excellence in the Built Environment and in Electric Power & Control, ...

Energy Technology Data Exchange (ETDEWEB)

Development of a strategy for forecasting river ice breakup and jamming on the Saint John River in New Brunswick was described. Methods used to identify ice jam-prone areas by simple temperature-based methods to fairly complex computer models using site specific data, were summarized. Recent technological advances in developing forecasts, including the NWRI probe for remotely measuring ice jam thickness, the RIVJAM model for determining stages upstream of an ice jam, and computational procedures for estimating the thrust exerted by ice jams against bridges, were also reviewed. Criteria and recommendations for river ice breakup and ice jamming for the Saint John River were provided. (Abstract only).

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A geological and geotechnical framework was provided in order to facilitate understanding of the damage to structures resulting from soil conditions during the earthquake of January 17, 1995 at Hyogo-ken Nanbu (Kobe), Japan. Special attention was paid to the large scale failures of the quay walls in the port of Kobe, resulting from liquefaction. The performance of structures in improved and unimproved ground were compared. It was observed that locations with some previous site improvements through densification behaved satisfactorily, despite unanticipated high levels of ground motion. Soil-structure interaction problems, such as pile foundations, bridge piers, lifelines, and an underground subway station were also described. Reference was made to the significance of these failures for the seismic design in the Fraser Delta in British Columbia in view of the area`s proneness to liquefaction during a major earthquake. 31 refs., 5 tabs., 45 figs.

International Nuclear Information System (INIS)

The noncrystalline compounds MoS_3, WS_3 and MoSe_3 were studied by X-ray diffraction. From the diffuse intensities radial distribution functions were computed and interpreted in terms of pair distribution functions. The substances are built up by microcrystallites which contain three metal atoms and are bridged statistically to each another. The shortest metal chalcogen distances d(MoS) approximately d(WS) = 2.40 +- 0.05 A and d(MoSe) = 2.50 +- 0.05 A are significantly longer than in MS- or MSe compounds with a d"0 configuration of the metal respectively and metal-metal distances within the microcrystallites are less than 3 A. (author).

Energy Technology Data Exchange (ETDEWEB)

Exploding bridgewire detonators with fine PETN powder were fabricated by the almost same method as the assembling process of ordinary electric detonators and the relationship between the detonating condition (bridge current waveform) in the single detonator initiation and the transmission time was studied. In addition, its jitter was also examined by simultaneous initiation of the detonators connected in series. It was revealed that the transmission time varied almost linearly against the inverse number of the rate of current rise and this variation was mainly due to the time needed for the bridgewire explosion. The jitter of the transmission time was within 0.1 microsecond. Although the cause of the jitter could not be determined, it was considered feasible to reduce the time jitter further by minimizing dimentional tolerances of fixing plugs and improving the loading process of PETN powder. 11 refs., 6 figs.

Energy Technology Data Exchange (ETDEWEB)

The confluence of technology development and market readiness is opening up major business opportunities for photovoltaic (PV) systems throughout the developing world. The National Renewable Energy Laboratory (NREL) and Sandia National Laboratories in Abuquerque (Sandia), working on behalf of the U.S. Department of Energy, have launched pilot projects in several countries throughout the world over the past 3 years. The focus of these pilot projects has been the development of in-country institutional capabilities necessary to deliver the promise of PV electricity to the rural populations. In addition to country-specific activities, NREL is conducting several technology, information, and partnership projects focused on further accelerating the education, training, business, and technology developments necessary to bridge the gap between promise and reality. This paper summarizes these efforts.

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: The Nuclear Power Plants (NPPs) are always designed for the highest level of safety against postulated accidents which may be initiated due to internal or external causes. One of the external/internal causes, which may lead to accident in the reactor and its associated systems, is fire in certain vital areas of the plant. Conventionally, the fire containment approach and/or the fire confinement approach is used in designing the fire protection systems of NPPs. Indian NPPs (PHWRs) follow the combined approach to ensure plant safety and all newly designed plants are required to comply with the provisions of Atomic Energy Regulatory Board (AERB) fire safety Guide. In respect of older plants, the reassessment of adequacy of fire safety provisions in the light of current advances has becomes essential so as to decide upon the steps for retrofitting. Keeping this in mind the deterministic fire hazard analysis was carried out for the Madras Atomic Power ...

Energy Technology Data Exchange (ETDEWEB)

The conference proceedings contains 30 papers of which five are abstracted separately. The subjects covered include fatigue crack growth in aircraft materials, fractographic measurements, fatigue cracks in nylon 66 blends, cyclic inelastic deformation aspects, prestressing, tensile cracks in creeping solids, creep-crack-growth in 304 stainless steel, high-temperature fatigue, parallel impact loading, numerical fracture dynamic code, J-resistance curves, specimen geometry effects, reactor piping systems, temperature dependence of fracture toughness, small-scale yielding, compact specimens, power hardening materials, semi-empirical fracture analyses, pipeline girth welds, wrought steels, and A36 bridge steels.

Energy Technology Data Exchange (ETDEWEB)

The invention concerns a device for the energy-saving heating of fuel in the supply pipe to an internal combustion engine to regain energy from the fuel itself, particularly but not exclusively for a Diesel engine. A part of the quantity of heat added to the fuel between the tank and the injection nozzles is given up by excess fuel not to the tank, but to the fuel lifted upstream of the injection pump. The device is characterised by the fact that it has a heat exchanger, which absorbs heat from the fuel at the level of the injection pump or upstream of it, and takes this to the fuel above the injection pump. The heat exchanger is preferably mounted upstream of a filter and close to it. A bridging pipe, which may be integrated in the heat exchanger, permits the heat exchanger to be short-circuited depending on the fuel temperature.

Energy Technology Data Exchange (ETDEWEB)

The availability of dimeric Pt(I) complexes with bridging bis(diphenylphosphino)methane ligands, (L--L')/sup n+/, presents an opportunity to study the physical properties and reactivity of metal-metal bonds as a function of the ligand trans to it with a minimum of competing variables. Several interesting trends of Pt-P coupling constants with the Pt-L and Pt-Pt bond lengths in Pt(I) dimers, (L--L')/sup n+/, and structurally related Pt(II) complexes are reported here. The data indicate that the Pt-P coupling constants continue to be sensitive indicators of not only the structure and stereochemistry of platinum phosphine complexes but also the electronic and steric influences of the ligand in such complexes, 23 references, 1 figure, 4 tables.

British Library Electronic Table of Contents (United Kingdom)

Uridine phosphorylase (UPP) catalyzes the reversible conversion of uridine to uracil and ribose-1-phosphate and plays an important pharmacological role in activating fluoropyrimidine nucleoside chemotherapeutic agents such as 5-fluorouracil and capecitabine. Most vertebrate animals, including humans, possess two homologs of this enzyme (UPP1 & UPP2), of which UPP1 has been more thoroughly studied and is better characterized. Here, we report two crystallographic structures of human UPP2 (hUPP2) in distinctly active and inactive conformations. These structures reveal that a conditional intramolecular disulfide bridge can form within the protein that dislocates a critical phosphate-coordinating arginine residue (R100) away from the active site, disabling the enzyme. In vitro activity measurem...

International Nuclear Information System (INIS)

There is growing interest in the use of natural fibres as the reinforcements for polymer composites in the automotive industry and as matrix for composites in building products application to replace synthetic fibres. In this respect the aim of this study is to develop an environmental friendly composites for furniture industry based on EFB fibres and sago starch. In this preliminary study, a basic composition and processing of EFB fibres-sago starch composites were established and the properties of the composites were determined. EFB fibre content was varied between 50-80% by weight. The amount of sago starch in liquid form was also varied and final weight percentage of sago starch added into the EFB fibres was adjusted accordingly. The mixtures of EFB fibres and sago starch were blended using Haake Rheomixer. The preliminary results indicate that the impact ...

Energy Technology Data Exchange (ETDEWEB)

To study the effect of CuO on the electrochemical properties of MgNi alloy, the MgNi-xCuO (x = 3, 5 and 10 wt%) composites were prepared by ball-milling method. The X-ray diffraction (XRD) analysis showed that the structures of the composites were amorphous. The cycle stability of the composites was improved compared to pure MgNi alloy due to the enhancement of the anti-corrosion property in the alkaline electrolyte, and the composite with 5 wt% CuO ball-milled for 15 h exhibited the best performance. Electrochemical impedance spectroscopy (EIS) and potential-step measurements indicated that the electrochemical kinetics of the composites was improved.

Energy Technology Data Exchange (ETDEWEB)

Glasses in the system (95-x) [0.25 Na{sub 2}O-0.75 B{sub 2}O{sub 3}]-x P{sub 2}O{sub 5}-5 Fe{sub 2}O{sub 3} (0<=x<=15 mol%), have been prepared by the melt quenching technique. Elastic properties and FT-IR spectroscopic studies have been employed to study the role of P{sub 2}O{sub 5} on the structure of the glass system. Elastic properties Poisson's ratio, micro-hardness and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz (both longitudinal and shear) at room temperature. The results showed that the density and the molar volume increase as both sound velocities and the determined glass transition temperatures decrease with increasing the contents of P{sub 2}O{sub 5}. Infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of P{sub 2}O{sub 5} content as a second network former. These results are interpreted in terms of the replacement of ...

Energy Technology Data Exchange (ETDEWEB)

The Northeast Gateway Energy Bridge Deepwater Port project was commissioned in 2005 and is based on a proprietary energy bridge shipboard regasification technology. The offshore liquefied natural gas (LNG) facility will be located in federal waters 13 miles southeast of Gloucester and was designed to cope with the extreme weather of the Massachusetts Bay. A dual-buoy system will be capable of ensuring continuous delivery of natural gas. Throughput capacity will range from 400 to over 800 MMcf/d. Vessels used at the port have capacities of 138,000 m{sup 3} and 150,900 m{sup 3} with peak sendout rates of 600 MMcf/d. The vessels have the capacity to rapidly increase and decrease their delivery rates. During periods of peak demand, 2 vessels can be simultaneously accommodated at the port, which has been designed to accommodate larger vessels to maximize future throughput. This presentation presented details of the port's design phases and ...

International Nuclear Information System (INIS)

Ab initio total energy calculations within the framework of density functional theory have been performed for atomic hydrogen and oxygen chemisorption on the (0001) surface of double hexagonal packed (dhcp) americium using a full-potential all-electron linearized augmented plane wave plus local orbitals method. Chemisorption energies were optimized with respect to the distance of the adatom from the relaxed surface for three adsorption sites, namely top, bridge, and hollow hcp sites, the ad-layer structure corresponding to the coverage of a 0.25 monolayer in all cases. Chemisorption energies were computed at the scalar-relativistic level (no spin-orbit coupling NSOC) and at the fully relativistic level (with spin-orbit coupling SOC). The two-fold bridge adsorption site was found to be the most stable site for O at both the NSOC and SOC theoretical levels with chemisorption energies of 8.204 eV and 8.368 eV respectively, while the three-fold ...

UK PubMed Central (United Kingdom)

The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol) thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene...Full Text Available

International Nuclear Information System (INIS)

Superconducting Cu-rich composites containing the A-15 compounds V_3Si or V_3Ga were made by the ''Tsuei'' process (melting into ingots followed by cold working and heat treatment). Superconducting transition temperatures of the composites were measured. X-ray diffraction analyses were performed. Microstructures were studied using both the optical metallograph and the scanning electron microscope. For some composites containing V_3Ga, the critical current densities as functions of transverse magnetic field up to 60 kG, and as functions of temperature from 4.2 to 12"0K were measured. It was found that the Tsuei process does not work for the composites containing V_3Si, but works satisfactorily for V_3Ga; reasons are discussed. Relations between measured properties and various metallurgical factors such as alloy compositions, cross-section reduction ratios, and heat treatment are ...

UK PubMed Central (United Kingdom)

In this study, we report the physico-chemical and biological properties of a novel biodegradable composite scaffold made of nano-hydroxyapatite and natural derived polymers of chitosan and carboxymethyl...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The present invention relates to a method of acidizing a subterranean formation or well bore employing an acidic solution containing a corrosion inhibitor composition comprising an inhibiting effective amount of an acetylenic alcohol, a quaternary ammonium compound, an aromatic hydrocarbon and an antimony compound.

UK PubMed Central (United Kingdom)

Improving the anti-demineralizing/remineralizing and mechanical properties of amorphous calcium phosphate (ACP) composites has been the focus of our recent research. In this study, an ethoxylated...Full Text Available

UK PubMed Central (United Kingdom)

This study compared the effectiveness of collaborative group composition and instructional method on reasoning gains and achievement in college biology. Based on initial student reasoning ability (i.e.,...Full Text Available

Science.gov (United States)

A summary of research conducted during the first year is presented. The research objectives were sought by conducting two tasks: (1) investigation of probabilistic design techniques for reliability-based design of composite sandwich panels, and (2) examin...

UK PubMed Central (United Kingdom)

In this study we determined the composition and biogeochemistry of novel, brightly colored, white and orange microbial mats at the surface of a brine seep at the outer rim of the Chefren mud volcano....Full Text Available

UK PubMed Central (United Kingdom)

The objectives of this study were to quantify the effect of 16 ppm of dietary monensin on milk production and composition of dairy cows, and to investigate factors having a potential impact on this...Full Text Available

International Nuclear Information System (INIS)

... thermal power plants thermal reactors water cooled reactors WATER

CERN Document Server

We provide an algebraic study of the local composite operators A_\\mu A_\

Science.gov (United States)

Surface crystallization and surface-to-bulk ratio in high-level waste glasses.

KoreaScience (Korea)

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International Nuclear Information System (INIS)

This is a preliminary study on the sound absorption properties of two tropical hardwoods, Light Red Meranti and Ramin, and their wood-polymer composites. Sound absorption is measured using a standing wave apparatus. The samples are of one thickness (7 mm) and cut longitudinally. Wood-polymer composites are made by impregnating the samples with methyl methacrylate which is polymerized in situ through #gamma#-irradiation. Both woods and their composites are better sound absorbers at higher sound frequencies. With partial impregnation, the absorption coefficients are improved upon particularly in the region between 1-3 kHz. (author).

International Science & Technology Center (ISTC)

Development of SHS-technologies for SiC, Si3N4 and Ceramic Composites on Their Basis from Rocks

Science.gov (United States)

... interactive surfaces and interfaces, and 3) the more complex a ... carbonate or calcium phosphate with a thin interface ... diameter) for nerve prosthesis. ...

Science.gov (United States)

Moisture ingression was studied in several composite sandwich panels.No observable ingression was

Science.gov (United States)

... The task consisted of determination of the most economical composition of the charge of the cupola furnace of the foundry. 21s was no simple task. ...

Energy Technology Data Exchange (ETDEWEB)

A heat storage compostion comprises sodium sulfate decahydrate as main component, a supercooling inhibitor, and a solid-liquid separation inhibitor. The composition is characterized in that hydraulic calcium sulfate and/or calcium sulfate dihydrate is contained as the solid-liquid separation inhibitor in an amount of 2-15 wt% base on the whole weight of the composition, whereby the solid-liquid separation, i.e. the sedimentation of the anhydrous sodium sulfate during the phase transition, is effectively prevented and the long-term stability is improved. The long-term stabilty of the composition can be more improved by addition of a silcia series of thickener.

KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The Cu- and Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of a mixture of gas-atomized metallic glass powders and ductile brass powders. The brass powders added for the enhancement of plasticity are well distributed in the matrix after consolidation. The matrix of the composite materials remains as a fully amorphous phase after consolidation process. With increasing the brass content, the level of plasticity strain increased, although the level of strength decreased. The successful consolidation of metallic glass matrix composite with high density was attributed to viscous flow in the supercooled liquid state during spark plasma sintering.

Energy Technology Data Exchange (ETDEWEB)

A variety of engineering and experimental applications require primary support structures which are self-centering. High mechanical strength, low-density, carbon fiber/epoxy matrix composite springs are used in unique planar, cylindrical, conical, and spherical configurations to self-center components. The sinusoidal and triangular-shaped composite springs are readily manufactured and assembled into component hardware. Design considerations, flexural strength properties, load bearing and centering data plus procedures for the manufacture of composite springs are presented.

Science.gov (United States)

A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, ...

Science.gov (United States)

A flutter-motion equation is presently derived for a 2D composite sandwich panel considering the total lateral displacement of the plate as the sum of the displacement due to bending of the plate, and that which is due to shear deformation at the core. The effects of core thickness and stacking sequence of the faces on the flutter boundary of the plate are discussed; it is shown that the sandwich panel greatly improves the flutter boundary over that of a composite laminate panel, provided it has sufficient core thickness.

Energy Technology Data Exchange (ETDEWEB)

A new method for the determination of the cmc using a dialysis technique which allows monometric species to diffuse through but no micelles has been applied for determining the mixed micelle composition. The method is based on determining the amount of surfactant that diffuses through at two different times which allows for the calculation of the cmc by use of the appropriate equation. This method requires the preparation of only one concentration of solution and lends itself particularly well to the determination of the composition of mixed micelles. (orig.)

International Nuclear Information System (INIS)

The structure and properties of composite powder coatings on the base of titanium carbide are studied. It is shown the electron-beam welding deposition of powders on the base of nickel and titanium carbide allows to produce of high-quality wear-resistant coatings which superior in density and hardness compared with sputtered ones. Changes of hardening phase volume percentage as well as composition of metal matrix make possible to control coatings hardness

Energy Technology Data Exchange (ETDEWEB)

The gas composition of recent thermal waters is in perfect conformity with their geologic-tectonic positions. The composition of gas-liquid inclusions in the basic-hyperbasic xenoliths of basaltoid lavas depends on the depth from which xenoliths are supplied. (The depth is determined by using the methods of geological thermobarometers). By comparing available data the conclusion was drawn that the gas compositions of thermal waters reflect the depth of generation of deep fluid which heats them and depends on the penetration depth of the fluid-conducting fissure zones.

British Library Electronic Table of Contents (United Kingdom)

The integration of the environmental problem in the design of industrial products leads us to incorporate vegetal fibres and recycled polymers into composite materials. The aim of this work is to study the behaviour and the environmental interest of a recycled PP/hemp fibre after several injection cycles. The mechanical and rheological behaviour of recycled PP/hemp composite was first studied by using tensile, dynamical mechanic analysis and rheological measurements. Then, to better understand the influence of the recycling, a morphology study was carried out on composites by using optical and electron microscopy. Finally, we investigated the environmental advantages of our composite thanks to a simplified environmental assessment. Our results highlighted the environmental interest of usin...

British Library Electronic Table of Contents (United Kingdom)

The age hardening behavior of Al-4.5%Cu alloy composite reinforced with zircon sand particulates and produced by stir casting route has been investigated in different quenching media viz, water, oil, and salt brine solution (7wt%). Optical microscopy of the as cast alloy composite indicates that the matrix of the composite has the cellular structure. Copper rich CuAl2 precipitates have been found near particle matrix interface. The results of ageing demonstrate that the microhardness of age hardenable Al-Cu based alloy composites depend on the quenching medium in which they are heat treated. Salt brine quenching is faster as compared to water and oil, even if higher strength is obtained but cannot be used for complex shapes and thin sections where oil quenching is the alternative due to mi...

International Nuclear Information System (INIS)

This study is an attempt to measure the quantities of elements in a composite by irradiating that composite with #gamma#-rays of various energies and detecting the transmitted radiation through the composite. A previous knowledge of the number of the elements and their attenuation coefficients is required. The quantities are calculated by solving the matrix of a linear system of equations. A computer program was developed to select the best combinations of the available energies. Five criteria were established to determine these energy combinations: (i) the determinant of the attenuation coefficient matrix; (ii) the condition number, (iii) the number of times the solution of the matrix leads to acceptable results; (iv) the indicator, (a new concept); (v) the standard deviations of the results. The intended application of this technique in medicine is to measure the bone mineral content of the skeleton. An examination of the ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Poly(butylene terephthalate) (PBT) composites containing multiwalled carbon nanotubes (MWCNTs) were prepared using a melt-blending process and used to examine the effects on the composite structure and properties of replacing PBT with acrylic acid-grafted PBT (PBT-g-AA). PBT-g-AA and multihydroxyl-functionalized MWCNTs (MWCNTs-OH) were used to improve the compatibility and dispersibility of the MWCNTs within the PBT matrix. The composites were characterized morphologically using transmission electron microscopy, and chemically using Fourier transform infrared, solid-state 13C NMR and UV-visible absorption spectroscopy. The antibacterial and electrical conductivity properties of the composites were also evaluated. MWCNTs or MWCNTs-OH enhanced the antibacterial activity and electric...

Energy Technology Data Exchange (ETDEWEB)

The effect of the coated composite surface of particles on the mechanical properties of the powder bed was investigated. Polyethylene-silica surface composite powder was prepared at several coating ratios with Hybridizer. Various tests on mechanical properties of the powder bed were carried out with the prepared powder, and the following results were obtained: The ultimate tensile strength depends only on the cohesive force between particles, and the contact probability model of composite particles led to good agreement between the experimental and calculated values. The coefficient of internal friction and cohesive shear strength were influenced due to the interlocking effect of the surface roughness of composite particles. The effects of coating particles became small with dynamic properties like angle of repose. It is possible to control the mechanical properties in a step wise fashion by changing ...

British Library Electronic Table of Contents (United Kingdom)

To improve the friction and wear behavior of carbon fabric reinforced polymer composites (CFRP), nano-SiO2 was deposited on the fabric surface. The friction and wear behavior of the resulting composites were investigated on a model ring-on-block test rig. Experimental results revealed that fiber surface treatment contributed to largely improve the tribological properties of the CFRP composites. Scanning electron microscope (SEM) investigation showed that the worn surface of the surface modified CFRP composite was smoother under given load and sliding rate. Field emission scanning electron microscopy (FESEM), FTIR and X-ray photoelectron spectroscopy (XPS) studies of the carbon fiber surface showed that nanostructured Sio2 thin film can be obtained by SiO2 sols deposition, which improved th...

International Nuclear Information System (INIS)

Composite materials of synthetics (based on monomers, oligomers and thermoplastics) and of natural polymers (wood and other fibrous cellulosics) prepared by radiation processing, offer valuable structural materials with enhanced coupling forces between the components. The applied polymer chemistry of such composites shows several common features with that of radiation grafting, e.g. the polymerization rate of oligomer-monomer mixtures in wood remains in most cases proportional to the square-root of the initiating dose-rate, just as in the simultaneous grafting, demonstrating that the chain termination kinetics remain regularly bimolecular in the corresponding dose-rate ranges. In the processing experiences of such composites, low dose requirement, easy process-control, and good technical feasibility have been found for composites of wood with oligomer-monomer mixtures, for coconut fibres with ...

International Nuclear Information System (INIS)

Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g"-"1 and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell which protected the ...

International Nuclear Information System (INIS)

The composite of doped lanthanum gallate (La_0_._9Sr_0_._1Ga_0_._8Mg_0_._2O_2_._8_5, LSGM) and doped ceria (Ce_0_._8Sm_0_._2O_1_._9, CSO) was investigated as an electrolyte for solid oxide fuel cell (SOFC). The LSGM-CSO composite was examined by X-ray diffraction (XRD) and impedance spectroscopy. It was found that the sintered LSGM-CSO composite contains mainly fluorite CeO_2 phase and a minority impurity phase, Sm_3Ga_5O_1_2. The LSGM-CSO composite electrolyte shows a small grain boundary response in the impedance spectroscopy as compared to LSGM and CSO pellets. The composite electrolyte exhibits the highest conductivity in the temperature range of 250-600 "oC, compared to LSGM and CSO. The LSGM-CSO composite can be expected to be an attractive intermediate temperature electrolyte material for solid oxide fuel cells.

Energy Technology Data Exchange (ETDEWEB)

MmMg{sub 12}-Ni amorphous or nanocrystalline composites (Mm: Ce-rich mischmetal) were prepared through the ball-milling method, and their electrochemical hydrogen storage performance was investigated and compared with that of ball-milled CeMg{sub 12}-Ni composites. It was found that the ball-milled MmMg{sub 12}-Ni composites had larger initial discharge capacities and better high rate dischargeability. Analysis of electrochemical impedance spectra (EIS) shows that the reaction resistance and hydrogen diffusion resistance of the ball-milled MmMg{sub 12}-Ni composites are lower as a result of the decrease in Ce content, and thus can contribute to the larger discharge capacity and better high rate dischargeability. Additionally, the cycle performance of the ball-milled MmMg{sub 12}-Ni composites is better than those of the ball-milled CeMg{sub 12}-Ni composites. ...

Science.gov (United States)

Automatic weapons such as machine guns and submachine guns are found in the German-speaking region only in special army and police units and appear accordingly rarely in homicides, suicides and accidents. In the following, the findings in two cases of death with the use of machine and submachine guns are presented. The first case was a fatal accident during shooting on a training area (current machine gun of the German army, calibre 7.62 x 51 mm), the second case was a killing during a physical conflict (submachine gun MP 40 from World War II, calibre 9 x 19 mm). In the case with the machine gun autopsy disclosed typical entry holes corresponding to the calibre, but unusually large exit wounds with tissue bridges in the wound ground, measuring 4 x 2.5 cm in diameter. By contrast, the second case (submachine gun) showed "normal" entry and exit wounds. The differences are mainly caused by deviating ballistic data of the ammunition used. They are discussed against the ...

CERN Document Server

We outline to the community the value of a Magellanic Clouds Survey that consists of three components: I) a complete-area, high resolution, multi-band UV-near-IR broadband survey; II) a narrowband survey in 7 key nebular filters to cover a statistically significant sample of representative HII regions and a large-area, contiguous survey of the diffuse, warm ISM; and III) a comprehensive FUV spectroscopic survey of 1300 early-type stars. The science areas enabled by such a dataset are as follows: A) assessment of massive star feedback in both HII regions and the diffuse, warm ISM; B) completion of a comprehensive study of the 30 Doradus giant extragalactic HII region (GEHR); C) development and quantitative parameterization of stellar clustering properties; D) extensive FUV studies of early-type stellar atmospheres and their energy distributions; and E) similarly extensive FUV absorption-line studies of molecular cloud structure and ISM extinction properties. These data will also allow a ...

CERN Document Server

This thesis is divided up into five chapters as outlined below. Chapter 1 gives the background to the techniques used in this thesis including X-ray structure determination and ab initio methods. An overview of some recent studies using ab initio methods to study transition metal complexes is also given. Chapter 2 investigates structural trans influence in a number of transition metal and p-block complexes. The database and ab initio studies showed that the classical trans influence model based on Pt(II) chemistry does not always hold. For some systems (eg. d sup 1 sup 0 s sup 0 for Sb sup V and Sn sup I sup V) the cis influence is of similar magnitude to the trans influence. For other systems (d sup 0), the trans influence is not as powerful as usually assumed. Chapter 3 is an investigation into the bridging chloride unit. A database study was performed on three systems (M-CI-M', M-CI...H and M-CI...Li/Na/K). Reaction pathway analysis was carried out for the ...

International Nuclear Information System (INIS)

The Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI-2 Reactor Building during February and March 1982 and was designed to investigate the effectiveness of various surface decontamination techniques. The polar crane, D-rings, missile shields, refueling canal, fueling bridge, major equipment, floors and some walls were flushed with low pressure water. Water lances were directed manually and applied water at temperatures between ambient and 60"0C at a flow rate of about 95 liters per minute. In addition, floor surfaces on the 305-ft elevation and floor surfaces and major equipment on the 347-ft elevation were sprayed with high pressure water (floors in the Reactor Building are designated by their elevations above sea level). The water pressure in this case varied between 13.8 and 41.4 mPa and water temperature was at a maximum 60"0C. Certain surfaces were also decontaminated using either strippable coatings or a mechanical ...

CERN Document Server

Abstract The aim of this project was to develop an OPC server to communicate over an RS232 serial line. This communication media is commonly used with commercial instruments. The development was made for a High Voltage power supply in the context of the Alice [1] experiment. In addition, the structured modular concept will allow changing the transmission media or power supply type with little effort. The high voltage power supply should be accessible remotely through a network. OPC[2] is an acronym for OLE[3] for Process Control. OPC is based on the DCOM [3] communication protocol, which allows communication with any computer running a Windows based OS. This standard is widely used in industry to access device data through Windows applications. The concept is based on the client-server architecture. The hardware and the software architecture are described. Subsequently details of the implemented programs are given with emphasis on the possibility to replace parts of the software ...

International Nuclear Information System (INIS)

New oxomolybdenum(V) complexes MoOClL (where LH_2 = Schiff base) derived from ethanolamine and salicylaldehyde, 5-chlorosalicylaldehyde, 5-bromosalicylaldehyde, 5-nitrosalicylaldehyde, 3-ethoxysalicylaldehyde and 2-hydroxy-1-naphthaldehyde have been synthesized and characterised by elemental analyses, conductance, molecular weight, i.r. and electronic spectra and magnetic measurements. The Schiff bases behave as dibasic tridentate ONO donor ligands. The complexes are non-electrolytes and dimers. The complexes exhibit subnormal magnetic moments and are involved in antiferromagnetic exchange with S = 0 ground state. The complexes exhibit electronic spectral bands at ca. 13000 and ca. 17000 cm"-"1 due to the transitions dsub(xy)->dsub(xz,yz) ("2B_2->"2E) and dsub(xy)->dsub(x2-y2) ("2B_2->"2B_1), respectively. The #nu#(Mo=O) frequency of the complexes is observed in the 900-970 cm"-"1 region. On the basis of the magnetic susceptibility, i.r. and molecular weight data a ...

Energy Technology Data Exchange (ETDEWEB)

This report describes the results of EPRI Program S404-28, titled Experimental Modeling of Eddy Current Response'', conducted by the Westinghouse Science and Technology Center (STC). The Westinghouse STC demonstrates that its mercury modeling technique provides an unique bridge between steam generator eddy current field inspection conditions and predictions obtained using recently developed analytical models. The mercury modeling technique was used systematically to explore factors which contribute to primary water stress corrosion cracking (PWSCC) sizing inaccuracy, including probe design, coil excitation frequency, crack length, and crack morphology. Two new proposed techniques for inverting crack lengths from eddy current data are compared with the technique commonly used in field data analysis for PWSCC. The performance of uniform field eddy current probes is compared with the performance of pancake coil probe designs, and an assessment of the ...

Energy Technology Data Exchange (ETDEWEB)

A considerable amount of chemical knowledge of marine sediments has been acquired in recent years but has not yet been utilized by paleomagnetists. On the other hand, geochemists are often unaware of the usefulness of numerous magnetic techniques. In this review we try to bridge this gap, and in particular, we outline many of the chemical and magnetic principles that should allow paleomagnetists to better identify and undertand chemical changes that affect the magnetic properties of marine sediments. The chemical principles include those for distinguishing the four major sources of sediments (continental, biological, authigenic/hydrogenous, volcanic/hydrothermal) from one another by determining elemental abundance distributions, as well as for investigating the stabilities of mineral phases relative to changes in pE and pH. The magnetic principles include the effects of authigenesis and diagenesis on magnetic properties, particularly on the direction and intensity ...

Energy Technology Data Exchange (ETDEWEB)

A micro-mechanistic understanding of bone fracture that encompasses how cracks interact with the underlying microstructure and defines their local failure mode is lacking, despite extensive research on the response of bone to a variety of factors like aging, loading, and/or disease. Micro-mechanical models for fracture incorporating such local failure criteria have been widely developed for metallic and ceramic materials systems; however, few such deliberations have been undertaken for the fracture of bone. In fact, although the fracture event in mineralized tissues such as bone is commonly believed to be locally strain controlled, until recently there has been little experimental evidence to support this widely held belief. In the present study, a series of in vitro experiments involving a double-notch bend test geometry are performed in order to shed further light on the nature of the local cracking events that precede catastrophic fracture in bone and to define their relationship to ...

Energy Technology Data Exchange (ETDEWEB)

In this report the effects of harmonics in marine power systems is discussed and a comparison is given between the most typical converter types, including pulse width modulated drives, load commutated inverters and cycloconverters. The effect of harmonic distortion on the power system equipment and loads is first briefly discussed. Special attention is given to the circumstances in the low voltage distribution system, where general load equipment is connected. In addition to the total harmonic distortion the effect of voltage deviation to the supply quality is also considered. The origin of harmonics in the load currents of the three converter types is then considered. The differences between the converters are outlined, and the most typical spectra are presented. The possible means for reducing the harmonic distortion are also studied. The solutions considered are the increasing of the short circuit level, the use of harmonic filters and the increasing of the pulse number. In the case ...

International Nuclear Information System (INIS)

Cu"2"+ ions are alternatively bridged by end-on and asymmetrical end-to-end (EE) azido groups in copper (II)-azido compound [#left brace#Cu(L)(N_3)_2#right brace#_n] (L=benzylamine). The electronic structure of its ferromagnetic ground state has been calculated using the self-consistent full-potential linearized augmented plane wave method based on the density functional theory. The spin populations have been found to be strongly positive on the Cu"2"+ ions, weakly positive on the terminal nitrogen atoms of the azido groups as well as on the nitrogen atoms of the benzylamine, and feeble on the central nitrogen atoms of the azido groups. Based on the spin distribution obtained from calculation, the ferromagnetic coupling through the azido groups has been analyzed as resulting from a spin delocalization from the Cu"2"+ ions toward the azido groups. But the result also indicates that the spin polarization effect may also take part in the magnetic coupling through the ...

Energy Technology Data Exchange (ETDEWEB)

Two major modes of CO adsorption on SiO{sub 2}-supported Pd reflect different extents of back-donation, which is, at least in part, controlled by the local electron density at the adsorption site. The fraction of CO in the bridging mode (B) increases and that of the linear mode (L) decreases, with increasing size of the Pd particles, indicating high electron density at Pd atoms in terraces of close-packed crystal faces, in agreement with Smoluchowski's classical model. For samples reduced at 300{degree}C our data points and those of other authors are located on a common curve of B/L vs metal dispersion. Extensive reduction at 600{degree}C results in significantly lower B/L values, attributed to the incipient formation of a palladium silicide. Oxidation followed by reduction at 300{degree}C destroys the silicide, and the B/L value returns to the original curve.

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Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, are responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. Because cortical bone exhibits rising crack-growth resistance with crack extension, unlike most previous studies the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the ex vivo crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; the initiation toughness decreases some 40% over six decades from 40 to 100 years, while the growth toughness is effectively eliminated over the ...

British Library Electronic Table of Contents (United Kingdom)

The 1H NMR, electronic absorption, and luminescence spectra, as well as voltammograms of the reduction and oxidation of the complexes [Pd(C?N)(N?N)]ClO4 and [Pd(C?N)(?-OOCCH3)]2 [where (C?N)? is deprotonated 2-phenyl-4,5-dihydro-1,3-oxazole, and N?N is ethylenediamine or 2,2?-bipyridine (bpy)] were compared. Magnetic nonequivalence of protons in the dihydrooxazole ring and upfield shift of the corresponding signals were observed as a result of anisotropic effect of the ring current in palladated phenyl substituents in the [Pd(C?N)(?-OOCCH3)]2 complex having a C 2 symmetry. One-electron reduction wave of [Pd(C?N)bpy]+ was assigned to ligand-centered electron transfer to the ?* orbital of 2,2?-bipyridine, and two oxidation waves of [Pd(C?N)(?-OOCCH3)]2 were attributed to successive one-elect...

Energy Technology Data Exchange (ETDEWEB)

As lithium battery technology sets out to bridge the gap between portable electronics and the electrical automotive industry, cathode materials still stand as the bottleneck regarding performances. In the realm of highly attractive polyanion-type structures as high-voltage cathode materials, the sulfate group (SO{sub 4}){sup 2-} possesses an acknowledged superiority over other contenders in terms of open circuit voltage arising from the inductive effect of strong covalent S-O bonds. In parallel, novel lithium insertion mechanisms are providing alternatives to traditional intercalation, enabling reversible multi-electron processes securing high capacities. Combining both of these advantageous features, we report here the successful electrochemical reactivity of copper sulfate pentahydrate (CuSO{sub 4}.5H{sub 2}O) with respect to lithium insertion via a two-electron displacement reaction entailing the extrusion of metallic copper at a dual voltage of 3.2 V and 2.7 V ...

Energy Technology Data Exchange (ETDEWEB)

The computer aided coal structure construction system is proposed, and a computational construction example is presented. The coal structure construction engine of this system fabricates molecular structure by connecting fragments sequentially inputted through a user interface. The best structure candidate is determined using construction knowledge and partial energy evaluation every addition of one fragment, and this process is subsequently repeated. The structure evaluation engine analyzes the 3-D conformation candidate by molecular dynamics, and evaluates the conformation by determining the energy value of an optimum structure. As an example, this system was applied to construction of coal molecular structure based on the actual data of partial structure composed of 26 structures from 2l kinds of aromatic cluster structures, 27 bonds from 2 kinds of bridged bonds, and 16 groups from 2 kinds of terminal substitutional groups. As a result, this system could ...

Science.gov (United States)

Besides the multifunctionality, another equally important aspect of nanoparticles is their engineerability to control the geometrical and chemical properties during fabrication. In this work, we exploited this aspect to define asymmetric surface chemistry of an iron oxide nanosphere by controlling the topology of ligand expression on its surface resulting in a particle with two faces, one displaying only amines and the other only thiols. Specifically, amine-functionalized iron oxide nanospheres were attached on a solid support via a crosslinker containing a disulfide bridge. Liberation of the nanosphere using thiolytic cleavage created thiols on the portion of the particle's surface that interacted with the solid support. Employing a solid-phase strategy and a step-by-step addition of particles, the two unique faces on the same nanosphere served as fittings to assemble them into linear nano-chains. Assembly of chains with various lengths and aspect ratios was ...

Energy Technology Data Exchange (ETDEWEB)

Magnetic coupling between two or more metal centers is an important facet of d- and f-block transition metal chemistry due to its implications in chemical bonding. With respect to actinide metals, magnetic coupling between polymetallic actinide centers is less well-known. Of the few documented examples, only one bimetallic uranium(V) complex, [(MeC{sub 5}H{sub 4}){sub 2}U]{sub 2}[{mu}-1,4-N{sub 2}C{sub 6}H{sub 4}] (1), has unequivocally demonstrated antiferromagnetic coupling. This complex employs a {pi}-conjugated 1,4-phenylenedimide ligand system which bridges the two f{sup 1}-metal centers and enables antiferromagentic coupling between unpaired f-e1ectrons residing in a {pi}-symmetry orbital. In this communication, we report the synthesis of a dimeric bis(imido) uranium(V) iodide complex and demonstrate with magnetic susceptibility measurements and density functional theory (DFT) calculations that the f{sup 1}-uranium centers display antiferromagnetic coupling ...

Energy Technology Data Exchange (ETDEWEB)

This project was conducted to evaluate novel approaches for removing radioactive strontium (Sr) and cesium (Cs) from the tank wastes. The bulk of the Sr removal research conducted as part of this project investigated adsorption of Sr onto a novel adsorbent known as iron-oxide-coated sand. The second major focus of the work was on the removal of cesium. Since the chemistries of strontium and cesium have little commonality, different materials (namely, cesium scavengers known as hexacyanoferrates, HCFs) were employed in these tests. This study bridged several scientific areas and yielded valuable knowledge for implementing new technological processes. The applicability of the results extends beyond the highly specialized application niches investigated experimentally to other issues of potential interest for EMSP programs (e.g., separation of chromium from a variety of wastes using IOCS, separation of Cs from neutral and acidic wastes with EC-controlled HCFs).

Energy Technology Data Exchange (ETDEWEB)

A technique for delivering genes carried by recombinant retroviruses into specific cell types could have numerous applications in oncology, developmental biology, and gene therapy. As a first step toward this remote goal the authors designed a procedure allowing in vitro cell targeting by retroviruses. Biotinylated antibodies against the viral envelope protein on one side, and against specific cell membrane markers on the other side, were bridged by streptavidin and used to link the virus to the host. The method was successfully used to infect human cells with ecotropic murine retroviruses by means of major histocompatibility complex class I and class II antigens and appears easily adaptable to other cell, membrane markers. Moreover, the sequential protocol they design, although allowing infection of human cells, requires less stringent safety constraints than would handling of amphotropic virus stocks.

DEFF Research Database (Denmark)

This paper presents a new grid connected inverter for fuel cells. It consists of a two stage power conversion topology. Since the fuel cell operates with a low voltage in a wide voltage range (25 V-45 V) this volt- age must be transformed to around 350-400 V in order to invert this dc power into ac power to the grid. The proposed converter consists of an isolated dc-dc converter cascaded with a single phase H-bridge inverter. The dc-dc converter is a current-fed push-pull converter. A new dedicated voltage mode startup procedure has been developed in order to limit the inrush current during startup. The inverter is controlled as a power factor controller with resistor emulation.Experimental results of converter efficiency, grid performance and fuel cell response are shown for a 1 kW prototype. The proposed converter exhibits a high efficiency in a wide power range (higher than 92%) and the inverter operates with a near unity power factor and a low current THD.

International Nuclear Information System (INIS)

Six uranyl coordination compounds, UO_2(OH)(PYCA) (1), UO_2(PYCA)_2(H_2O).2H_2O (2), UO_2(PIC)_2 (3), UO_2(H_2O)_2(NIC)_2 (4), UO_2(OH)(HINIC)(INIC) (5), and UO_2(PYTAC)_2(H_2O)_2 (6) were grown as single crystals via hydrothermal synthesis (PYCA - pyrazine-2-carboxylate, PIC - picolinate, NIC - nicotinate, INIC - iso-nicotinate, and PYTAC - 2-(pyridin-4-yl)thiazole-5-carboxylate) to study their optical properties. All six compounds have been identified via single crystal X-ray diffraction and fully characterized via powder X-ray diffraction, infrared spectroscopy, UV-Vis spectroscopy, and fluorescence spectroscopy. Three of the complexes, 1, 3, and 6, represent new structures, and their synthesis and structural characterization is detailed within. The structures of 2, 4, and 5 have previously been reported in the literature. Coordination polymer 1 crystallizes in the orthorhombic space group Pca21 (a = 13.5476(5) Angstroms, b = 6.6047(2) Angstroms, c = 8.3458(3) Angstroms), and forms ...

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the role of amorphous SiO{sub 2} particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO{sub 2} particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO{sub 2} was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO{sub 2} particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of {gamma}-phase and amorphous nano-SiO{sub 2} particles, and under alloying temperature (1000 deg. C) condition, the nano-SiO{sub 2} particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of ...

International Nuclear Information System (INIS)

For several decades, ceramic matrix composite have been attracted attention in advanced structural and tribological applications. Advanced structural ceramics are presently used in diverse tribological applications such as tips for ballpoint pens, precision instrument bearings and cutting tools inserts. Design and selection of ceramics for these applications require reliable data on the effects of temperature, load and environment on the tribological behavior of these ceramics. In the present work, #alpha#-sialon matrix composites reinforced with different amounts of #beta#-sialon fibers were produced with the aim of improving their toughness to increase the industrial applications. The wear properties of #alpha#-sialon matrix composites were evaluated by carried out wear tests using a pin-on-disk tribometer under dry conditions. The #alpha#-sialon matrix composites were manufactured by slip casting and ...

International Nuclear Information System (INIS)

General estimates and references are made in connection with the role of technological physics in obtaining materials with specific features. The first part of the paper presents the modification of weak wood essences as well as technological processes at bench-scale and semi industrial scale of wood-plastic composites, under various irradiation conditions. Two technological installations for the fabrication of wood-plastic composites on both scales with technical and practical specifications of their performances are presented. Experimental data for different wood-plastic composite systems using some local wood essences in combination with several polymer and copolymer systems are given. Impregnation and polymerization levels are mentioned for every specific system. The radiation dose rate and integrated dose are given for every experimental polymerization system. The features of the wood-plastic ...

International Nuclear Information System (INIS)

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been ...

International Nuclear Information System (INIS)

Researches on oil palm empty fruit bunch (EFB) fibers and thermoplastic composites have been carried out by many workers in the last decade. The main focus was to enhance the properties of the resultant composites in view of the incompatibility of the two components. Thus, efforts have been made to enhance their properties by using coupling agents, treating the fibers and modifying the matrices. In this study, the effects of electron beam (EB) irradiation and some reactive additives (RAs) on the mechanical properties of EFB-PP (polypropylene) composites were evaluated. Different modes of irradiation were investigated. Mono, di and tri functional of monomers of RAs were used. irradiating PP alone, compared to irradiating the EFB fibers or irradiating both components, gave optimum properties for EFB-PP composites. Further, improvements of the properties of the composites were achieved ...

Energy Technology Data Exchange (ETDEWEB)

For the development of high ionic conductive solid electrolyte, LiTi2(PO4)3 (LTP), one of the promising inorganic solid electrolyte, was synthesized to investigate an effect of additional lithium salt on the ion conductivity. Lithium salt added LTP composite electrolyte sintered at 900{degree}C exhibited highest conductivity, which was two order magnitude higher than pure LTP. Effects of lithium salt addition are as follows. Conductivity of the composite electrolyte provided larger sintering temperature dependence than the pure LTP. From X-ray diffraction analysis, structures and compositions were resemble between two composite electrolytes. Byproducts except LTP provided rather low conductivity. It was suggested that melted constitution in the composite can affect the sintering improvement by the additional lithium salt at temperatures over 800 {degree}C. From the observation of ...

Energy Technology Data Exchange (ETDEWEB)

The fuel composition heterogeneity effect on reactor performance parameters was assessed by refueling simulations for three DUPIC fuel options of fuel composition heterogeneity control: the fissile content adjustment, the reactivity control by slightly enriched and depleted uranium, and the reactivity control by natural uranium. For each DUPIC fuel option, the simulations were performed using 30 heterogeneous fuel types which were determined by the agglomerative hierarchical clustering method. The heterogeneity effect was considered during the refueling simulation by randomly selecting fuel types for the refueling operation. The refueling simulations of the heterogeneous core have shown that the key performance parameters such as the maximum channel power (MCP), maximum bundle power (MBP), and channel power peaking factor (CPPF) are close to those of the core that has single fuel type. For the three DUPIC fuel options, the uncertainties of MCP, ...

International Nuclear Information System (INIS)

The composition of sputter-deposited HgS films was determined by electron microprobe analysis. From the relative x-ray intensity as a function of film thickness, the depth of the ionizations that produce SK sub(#alpha#) and HgM sub(#alpha#) was found to be approximately 0.65 #mu#m at an accelerating voltage of 15 kV. This value agreed well with a value calculated from Castaings' empirical law after absorption correction. The determination of film composition was limited to sufficiently thicker films than this critical value, usually 1 - 2 #mu#m thick. The relation between the conposition of bulk standard determined by chemical analysis and the x-ray intensity ratio was used for the correction of film composition. The results showed that the crystal structure of HgS films was independent of the composition, i.e., the growth of metastable #betta#-HgS films was not caused by the nonstoichiometry, and that ...

International Nuclear Information System (INIS)

Wood plastic composite (WPC) has been prepared with a low grade wood simul (Salmalia malabarica) of Bangladesh under Co-60 gamma irradiation using MMA as the bulk monomer combined with methanol as the swelling solvent at different urea concentrations. Effect of a second solute such as NVP, TPGDA and TMPTA in the impregnating solution is evaluated. NVP appears to be the best co-additive/second solute among all the additives used to yield the composite with the highest polymer loading (PL) and tensile strength (TS) at 0.5% urea concentration. (author).

Science.gov (United States)

The results of studies on: (1) development of suitable glass compositions for solidification and vitrification of high level radioactive wastes, and (2) the characteristics of these compositions, namely, leaching, mechanical properties, thermal conductivity, viscosity and homogeneity evaluation are reported. Inactive simulated purex waste was used for compositions reported herein. The data generated on leaching and other product characteristics of the selected vitrified waste products was used to evaluate the performance of corresponding experimental units and techniques with respect to their reproducibility and reliability.

Energy Technology Data Exchange (ETDEWEB)

The resistance of six tropical hardwoods to fungal degradation by two wild-type strains of Phanerochaete chrysosporium Burdsall was investigated using vermiculite burial and wood-block weight loss techniques. Radiation-induced wood-polymer composites (WPC), based on two hardwoods Ramin and Rubberwood with methyl methacrylate, were prepared, and samples were also exposed to the wood-rotting fungus. A significant improvement in resistance to fungal decay was observed in the WPC. Scanning-electron micrographs of the two woods and their composites after fungal degradation are presented and discussed.

Energy Technology Data Exchange (ETDEWEB)

A plane stress constitutive relation is developed for laminate composites undergoing matrix cracking and therefore displaying significant nonlinear stress-strain behavior. The constitutive relation is similar in some respects to a phenomenological theory of plasticity in that it is fit to data from uniaxial tests. The constitutive equations are specialized to brittle matrix composites (especially CMCs) in the form of cross-piles and quasi-isotropic laminates. Several problems involving stress redistribution at holes and notches due to nonlinear stress-strain behavior are investigated with the aid of the constitutive law.

Energy Technology Data Exchange (ETDEWEB)

The repeated use and limited lifetime of a composite tiring vessel compel a need to survey techniques for monitoring the structural integrity of the vessel in order to determine when it should be retired. Various nondestructive techniques were researched and evaluated based on their applicability to the vessel. The methods were visual inspection, liquid penetrant testing, magnetic particle testing, surface mounted strain gauges, thermal inspection, acoustic emission, ultrasonic testing, radiography, eddy current testing, and embedded fiber optic sensors. It was determined that embedded fiber optic sensor is the most promising technique due to their ability to be embedded within layers of composites and their immunity to electromagnetic interference.

International Nuclear Information System (INIS)

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

Energy Technology Data Exchange (ETDEWEB)

A gelcasting composition has improved drying behavior, machinability and shelf life in the dried and unfired state. The composition includes an inorganic powder, solvent, monomer system soluble in the solvent, an initiator system for polymerizing the monomer system, and a plasticizer soluble in the solvent. Dispersants and other processing aides to control slurry properties can be added. The plasticizer imparts an ability to dry thick section parts, to store samples in the dried state without cracking under conditions of varying relative humidity, and to machine dry gelcast parts without cracking or chipping. A method of making gelcast parts is also disclosed.

Science.gov (United States)

We proposed and numerically investigated the influence of spatial symmetry on the terahertz frequency region response of composite planar metamaterials based on deformed split ring resonators. Compared with the original simple structures, the composite metamaterials with different spatial symmetries exhibited exotic electromagnetic properties. The electromagnetic response of a specific configuration with C4 symmetry was identical to the structure with simple lattice. Especially, for configurations with broken symmetry, very sharp Drude-like resonances with high quality factor were observed. The electric field and current distribution associated the resonances were analyzed for deep understanding of the underlying physical properties.

British Library Electronic Table of Contents (United Kingdom)

The concentrates of scattered organic matter???kerogen-like polymer, which is insoluble in acids and organic solvents???were isolated from rock samples taken at different depths from various stratigraphic units at the productive deposits of the Orenburg oil-gas condensate field using chemical methods. The chemical composition of the kerogen-like polymer and the concentrations of trace elements in it were studied. The regularities of evolutionary changes in the composition of the organic matter and the concentrations of trace elements in it in the order of the kerogen-like polymer and the following its consecutive derivatives were established: asphaltenes, ethanol-benzene tars, benzene tars, oils, and paraffins

International Nuclear Information System (INIS)

The aim of this paper was to describe ability to intercalation of laboratory prepared carbon composites and their constituents. In work the following materials were tested; pinch-based fibres of P-120 and K-1100 manufacturer's designations, carbon matrix and resulting composites. To prepare a matrix of composites, phenol-formaldehyde resin (Z) and pinch-based precursor (PAK) were used. After initial carbonization, the carbon matrix was heated to 2150 "oC i to improve ability to the future intercalation. Three kinds of composites (P/Z, K/Z and K/PAK), with two directional reinforcement (2D), were prepared. All carbon samples were intercalated with copper chloride(II). To study the structure of all materials, before and after intercalation, X-ray diffraction method was used. It enabled to measure microstructure parameters (L_c and L_a), interplanar distance (d_0_0_2) thickness of an intercalation layer ...

Energy Technology Data Exchange (ETDEWEB)

This work contains 27 chapters which cover recent advances in fracture mechanics applied to cement-based composites: concrete, reinforced concrete, and fiber reinforced concrete. The book, based on a NATO Advanced Study Institute, is a comprehensive survey of treating nonlinearity associated with crack growth in brittle materials such as cement composites, rocks and ice. The book is divided into 8 major themes: advances in nonlinear fracture mechanics; fracture processes; numerical modelling of fracture; experimental methods of determining fracture parameters; damage and continuum modelling; strain-rate and dynamic effects of crack propagation; stress-corrosion, time and temperature effects on fracture; and implications for concrete structures.

International Nuclear Information System (INIS)

Both microstructural graded and homogenous single-phase #alpha#-Sialon is obtained from Si_3N_4 powder for a broad range of compositions of practical interest. Elongated grains of #alpha#-Sialon could be developed in the monophase material by controlled mechanism of nucleation and growth. Tailoring of microstructure was realized through slow transformation reaction from Si_3N_4 to #alpha#-Sialon at lower temperature than sintering temperature when the composition is near the #alpha#-Sialon phase boundary. The mechanical properties are strongly correlated with the microstructure and are enhanced greatly in the optimized Sialon composition. (author)

Science.gov (United States)

... The constancy of the X-ray intensity ratio for each element in Table 8 as the X-ray tube settings were changed shows the excellent compensating ...

International Nuclear Information System (INIS)

The variation of surface composition and sintering of the binary Pd_7Ag_3 nanoparticles prepared by chemical reduction were studied. The composition of the as-prepared Pd_7Ag_3 nanoparticles across the diameter is inhomogeneous due to different reduction potentials of Pd and Ag. Upon heating, Ag will migrate to the surface because of its lower surface energy. Surface modification results in variation of surface composition during the sintering process. Stearic acid acts as a grain growth inhibitor. The migration of Ag to the surface is suppressed and the sintering is retarded. Modification by polyethylene glycol leads to more migration of Ag atoms from the core to the surface. This makes the nanoparticles easier to sinter.

International Nuclear Information System (INIS)

A highly sensitive and stable tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)_3 "2"+) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy)_3 "2"+ immobilized in the ECL sensor by adsorption of Ru(bpy)_3 "2"+ onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-titania-Nafion showed improved ECL sensitivity for tripropylamine (TPA) compared to the ECL sensors based on ...

UK PubMed Central (United Kingdom)

The biophysical properties of membrane phospholipids are controlled by the composition of their constituent fatty acids and are tightly regulated in Escherichia...Full Text Available

UK PubMed Central (United Kingdom)

The lipid composition of skin is important to a variety of functions served by this organ. Therefore, skin expresses multiple enzymes that synthesize and metabolize lipids. An important class of lipid...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The thermal stability of wood polymer composites made with extractive-free wood from four different wood species was studied. Hot water (HW) extractives, ethanol/cyclohexane (E/C) extractives and both types of extractives were eliminated from A. cyclops, E. grandis, P. radiata and Q. alba. Composites of LLDPE and 10 wt% of wood were prepared, using poly vinyl alcohol-co-ethylene (EVOH) as a compatibilizer. The thermal degradation behavior of the composites was characterized with thermogravimetric analysis (TGA). The obtained results showed that in all cases, the degradation temperatures shifted to higher values after removal of the extractives. The removal of E/C extractives was less effective in its improvement of the thermal stability than the removal of HW extractives. The largest improvement on the thermal stability of WPCs was achieved when both types of extractives (E/C and HW) were removed.

British Library Electronic Table of Contents (United Kingdom)

In this study acrylonitrile-butadiene-styrene (ABS) terpolymer was reinforced with HNO3-treated short carbon fibers (HCFs). The effects of HCF concentration on the tensile properties of the composites were examined. Increasing the HCF concentration in the ABS matrix from 10 wt% to 30 wt% resulted in improved tensile strength and tensile modulus. To obtain a strong interaction at the interface, polyamide-6 (PA6) at varying concentrations was introduced into the ABS/10 wt% HCF composite. The incorporation and increasing amount of PA6 in the composites increased tensile properties of the ABS/PA6/HCF systems due to the improved adhesion at the interface, which was confirmed by the ratio of tensile strength as an adhesion parameter. These results were also supported by scanning electron microgr...

Science.gov (United States)

curves are also directly translatable to metal-matrix composites. ..... 4~f4'4 ..... result of learning curve. The most important reduction in cost as a ...

British Library Electronic Table of Contents (United Kingdom)

Coordination of CoCl2 solutions to the silica polyamine composite, WP-1, made with the branched polymer polyethylenimine (PEI) shows irreversible binding resulting from surface oxidation of the Co2+-Co3+. This is not the case for the silica polyamine composite BP-1 made with the linear polymer polyallylamine where reversible binding and no oxidation is observed. These observations suggested that oxidation of the cobalt was related to the greater coordination number available with the branched polyamine relative to the linear polyamine. A study of the kinetics of cobalt binding to WP-1 indicated initial loading of Co2+ at relatively low coordination number followed by desorption of Co2+ leading to oxidation and irreversible binding. Exclusion of oxygen from the composite-cobalt solution mix...