Materials Literature
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PURPOSE: To compare the contrast effects of gadodiamide injection at 0.3 and at 1.5 T, at different concentrations in phantoms, and to correlate the results to clinical doses used for examining brain lesions. MATERIAL AND METHODS: Gel phantoms with T1 and T2 corresponding to brain gray matter were doped with different…
An investigation has been carried out on the effect of plastic strains on the magnetic properties of grain-oriented and nonoriented 3% by weight SiFe alloys. A drastic degradation of these properties with increasing deformations is observed for magnetic field amplitudes ranging between 0 and 2000 A/m. Empirical relati…
An automated apparatus to determine the steady-state and transient water vapor permeation behavior of fabrics and semipermeable laminates is described. Typical test results for representative types of fabrics and semipermeable membrane laminates are shown, as well as correlations between this test and two other water…
Polymeric drug-delivery systems are attractive as a means of effectively controlling drug concentration and for targeting specific regions in the body. Until recently, most polymers investigated for drug-delivery applications were either linear (nonbranched) or crosslinked (highly branched) in nature. Current advances…
Many types of materials are used in manufacturing industry today. Some of the more important ones are metals, alloys, and plastics. Different kinds of metals and alloys are used for different purposes and the diagram in Fig 6.1 shows some metals and alloys that are in common use.
Thc SPS (Spark Plasma Sintering) proccss is a new matcrials symttjesos proccssing technology recentlydcvclopcd by Sumitomo Coal Mining Co., Ltd., Japan. This paper describes the principles and fcaturcsof the SPS process, inluding the basic configuration of the Sumitom's SPS systcm, as well as the SPSproccss applicatio…
The viscosities of the four series of mixed alkali glass melts such as 25(Na2O+K2O)⋅75SiO2, 25(Na2O+K2O)⋅5Al2O3⋅70SiO2, 25(Na2O+K2O)⋅7.5Al2O3⋅67.5SiO2 and 25(Na2O+K2O)⋅10Al2O3⋅65SiO2 as well as their Tg were measured to elucidate a relation between property behaviors and mixed alkali effect models. The base mixed alka…
The chain scission rate constant and the initiator decomposition efficiency are very important kinetic parameters in the chemically initiated degradation of polypropylene. These two kinetic parameters have been estimated using both deterministic and stochastic modelling procedures. To relate the chain scission rate co…
The effect of particle size and the addition of Ir on the relative sulfur sensitivity of Pt-based catalysts has been studied. Cyclopentane hydrogenolysis, a structure-sensitive reaction, was employed as a test reaction and thiophene as the poisoning molecule. Fresh and sintered monometallic Pt/Al 2 O 3 and bimetallic…
The crystal structure of monoclinic phase [ P 2 1 / c Z = 4] has been refined by the Rietveld analysis of X‐ray powder diffraction data to study the size and charge effects of dopant M n + on the unit‐cell parameters of monoclinic ZrO 2 −2 mol% MO n /2 solid solutions ( n = 4 for M = Ce; n = 3 for M = La, Nd, Sm, Y, E…
The electrochemical reduction of pyrazine (pz) on a silver electrode from a 1.0 M KBr solution has been investigated by surface enhanced Raman scattering (SERS). New bands from products of reduced pyrazine were observed at potentials more negative than -900 mV (vs. SCE). The main product is believed to be the 1,4-dihy…
A design model of sewage sludge incineration plants has been developed to examine the possibilities for energy recovery. It was evident that, without sludge drying, there was a high fuel (methane) consumptions (149-192 Nm 3 /t sludge cake at 25% concentrations), but considerable amount of electric energy is obtainable…
EXAFS and XANES spectra have been recorded at the copper K-absorption edge on hydrotalcite samples, which contain 10 mol% copper, in order to determine the local environment of the copper ions. The vanishingly small magnitude of the pre-edge peak in the XANES region of the spectra indicates a centrosymmetric coordinat…
A quasi‐planar dithiadiazafulvalene (DTDAF) with high electrondonating properties is reported. The chemical synthesis of a phenyl‐ N,N′ ‐bridged DTDAF (the Figure shows an ORTEP drawing of the DTDAF ⊕⊙ cation radical) is described together with the preparation of a charge‐transfer set by an situ trapping and investiga…
The crystal structure of the nickel(II) complex of 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (H 2 doda) has been determined. The ligand binds in a cis-octahedral fashion through the four nitrogen atoms and two carboxylate groups and dimerizes via an apparently symmetrical hydrogen bond from the non-bonding oxyg…
We recently designed and produced a family of new swelling-type materials that are potentially capable of self-fixation in bone. These materials are designed to absorb body fluids and swell by small amounts, which will allow the implants made from these materials to achieve self-fixation by an expansion-fit mechanism.…
FTIR spectroscopy of CO adsorbed at liquid-nitrogen temperature on zeolite K-L revealed two main IR absorption bands at 2161 and at 2150 cm -1 , respectively. These bands were assigned to the C–O-stretching mode of carbon monoxide interacting, through the carbon atom, with K + ions present in the main channel of the z…
SummaryIn order to reduce corrosion rates, zinc plated parts are usually chromated. Recently Chromates have caused increasingly environmental concern, for both allergic effects among workers touching chromated parts and toxic effects on fish, plants and bacteria.A molybdate based alternative has been developed to repl…
Our investigation is focused on the understanding of high-field phenomena in polymers. In highly insulating materials such as polyethylene, space charge has a strong influence on both the short and long term breakdown strengths. The aim of this report is to demonstrate and discuss the importance of the dynamics of vol…
A series of ruthenium–copper bimetallic catalysts on silica were prepared by the co-impregnation method. The amount of ruthenium was maintained constant at 1 wt.%. Copper loadings varied from 0.01 to 0.1 wt.%. Catalysts were characterized using surface area measurements (BET), CO adsorption followed by temperature-pro…