Jerome J. Hoffman、Charles M. Leir1991-01-01Polymer International
Abstract Tetramethylammonium 3‐aminopropyl dimethylsilanolate, readily prepared from bis(3‐aminopropyl) tetramethyldisiloxane and tetramethyl‐ammonium hydroxide pentahydrate, has been found to serve as a highly effective catalyst for the ring opening polymerization of cyclic siloxanes with an end blocker such as bis(3…
Marine Biology and Environmental ChemistrySilicone and Siloxane ChemistryAntimicrobial agents and applications
Masayuki Kuzuya、Shin‐ichi Kondo1991-01-01Chemical and Pharmaceutical Bulletin
The alkaline hydrolysis of several powdered methacryloyl polymeric prodrugs (1P-3P) prepared by mechanochemical polymerization, each of which contains acetaminophen (1), 7-theophyllineacetic acid (2) and 5-fluorouracil (3) as a pendant drug group has been examined in a heterogeneous system on its comparison with that…
Advanced Polymer Synthesis and CharacterizationSynthesis and properties of polymersThermal and Kinetic Analysis
A. J. Romero、C. T. Rhodes1991-01-01Drug Development and Industrial Pharmacy
In an effort to formulate the pharmacologically active ibuprofen isomer ((+)-S-ibuprofen) into a solid oral dosage form, preformulation studies were performed on both the racemate and this stereoisomer of ibuprofen. Results of the respective physical pharmacy profiles were compared to predict the pharmaceutical behavi…
Drug Solubulity and Delivery SystemsCrystallography and molecular interactionsCrystallization and Solubility Studies
C.A. Nucci、S. Pirani、M. Rinaldi1991-01-01IEEE Transactions on Electrical Insulation
Experiments performed on the end-edge contacts of polypropylene capacitors to determine whether the thermal effect is the main cause of their degradation are described. Current pulses with different wave-shapes but with the same value of the Joule integral were applied to the contacts, and the degradation levels were…
Advanced Sensor and Energy Harvesting MaterialsHigh voltage insulation and dielectric phenomenaElectrostatic Discharge in Electronics
Stelios P. Skaribas、Philip J. Pomonis、Antonios T. Sdoukos1991-01-01Journal of Materials Chemistry
A new method has been developed for the low-temperature synthesis of perovskite solids LaMO3 where M = Ni, Co, Mn, using binuclear complexes of the ligand N,N′-bis(3-carboxysalicylidene)ethylenediamine (H4fsaen). The thermal decomposition of such complexes was studied using a thermobalance. The solids that formed afte…
Advancements in Solid Oxide Fuel CellsInorganic Chemistry and MaterialsThermal Expansion and Ionic Conductivity
Krystyna Cieśla、Ewa Gwardys、Tadeusz Z̊öltowski1991-01-01Starch - Stärke
Abstract Indices of relative crystallinity of starch samples after gamma irradiation in dry form or in potatoes have been determined by differential and integral methods and compared with those calculated for corresponding reference samples. In the case of dry samples, the diminution of relative crystallinity was obse…
Metal Extraction and BioleachingCrystallization and Solubility StudiesX-ray Diffraction in Crystallography
Joseph A. Castellano1991-01-01Liquid Crystals Today
(1991). LIQUID CRYSTAL DISPLAY APPLICATIONS: Past, Present & Future. Liquid Crystals Today: Vol. 1, No. 1, pp. 4-6.
Crystallization and Solubility Studiesnanoparticles nucleation surface interactions
Mark Minick、Kristen Fotta、Arshad Khan1991-01-01Biopolymers
Abstract The starch–iodine blue complex formation does not involve negatively charged iodine species like I , I , or I ; rather, neutral iodine units are involved. The heat of reaction is determined to be about −110 kJ for every mole of I‐I unit in the amylose helix, which suggests that the dissociation of I 2 (bindin…
Surfactants and Colloidal SystemsClay minerals and soil interactionsInorganic Fluorides and Related Compounds
Miroslav Svoboda、Bohdan Schneider、J. Štokr1991-01-01Collection of Czechoslovak Chemical Communications
Infrared spectra were measured of condensates generated by heating polyamide-6, polyamide-12, polyamide-11, polyamide-8 and polyamide-6,6 in inert atmosphere at 300, 350, 400, 500, and 600°C for various time. The products of thermal degradation were characterized by infrared spectroscopy. It was found that the thermal…
Polymer crystallization and propertiesThermal and Kinetic AnalysisMaterial Properties and Applications
KiRyong Ha、Skye McClain、Steven L. Suib 等 4 位作者1991-01-01The Journal of Adhesion
Fluoropolymers may be treated with sodium naphthalenide (Na/Naphth) in tetrahydrofuran (THF) so as to increase their ability to form adhesive bonds with other polymers or metals. We describe here a quantitative analysis of the chemical modification which results from such a treatment, using a range of derivatizations…
Polymer Nanocomposites and PropertiesSynthesis and properties of polymersPolymer Nanocomposite Synthesis and Irradiation
P. Porta、Roberto Dragone、G. Fierro 等 6 位作者1991-01-01Journal of Materials Chemistry
Copper–cobalt oxysalts of various Cu : Co atomic ratios (100 : 0. 92 : 8, 85 : 15, 77 : 23, 67 : 33, 15 : 85, 0 : 100) have been prepared by coprecipitation, at constant pH, from solutions of copper and cobalt nitrates added to a solution of NaHCO3; the structure and chemical nature of the Cu—Co oxysalts have been inv…
ZnO doping and propertiesCatalytic Processes in Materials ScienceCopper-based nanomaterials and applications
Takashi Kubo、Mayumi Uno1991-01-01OpenAlex
The a-c impedance measurements were made for oxide films formed in high temperature steam on Zry-2 with varying precipitate distributions. TEM and EDX analyses were also carried out on precipitates in oxide films. The electrical resistivity of oxide films tends to increase with an increase in nodular corrosion resista…
Corrosion Behavior and InhibitionHigh-Temperature Coating BehaviorsNuclear Materials and Properties
Ken Beazley1991-01-01The Paper Conservator
Summary The paper is divided into two parts. In Part 1, after a brief historical introduction the advantages and disadvantages of using mineral fillers in the manufacture of paper are summarised. Details of the origin, methods of production and basic physical properties of kaolin, natural calcium carbonate, precipitat…
Polymer Nanocomposites and PropertiesClay minerals and soil interactionsIron oxide chemistry and applications
T. L. Aselage、David Emin1991-01-01AIP conference proceedings
Recent experiments support a previously proposed model of the location of carbon within the boron carbide structure as a function of carbon concentration. The main features of the model are the presence of carbon within icosahedral units over the entire single phase region, and the progressive replacement of CBC chain…
Advanced ceramic materials synthesisThermal properties of materialsBoron and Carbon Nanomaterials Research
K.S. Annakutty、K. Kishore1991-01-01Die Makromolekulare Chemie
Abstract Pyrolysis gas chromatographic studies were carried out on two polyphosphate esters of bisphenol A Systematic name: 2,2′‐isopropylidendiphenol. . The gaseous pyrolysis products were found to be mainly phenols and a few phosphate compounds. The identification of phosphorus compounds in the gas phase proves a ga…
Flame retardant materials and propertiesSynthesis and properties of polymersThermal and Kinetic Analysis
Hideo Nakajima、M. Koiwa1991-01-01Bulletin of the Japan Institute of Metals
Recent studies of self-diffusion and impurity diffusion in α- and β-titanium are reviewed. The transition metal elements and phosphorus exhibit fast diffusion in α-Ti, which are three to five orders of magnitude faster than the self-diffusion. The mechanism of the fast diffusion is discussed on the basis of the severa…
High Temperature Alloys and CreepIntermetallics and Advanced Alloy PropertiesTitanium Alloys Microstructure and Properties
Riccardo Basso、S. Carbonin、A. Delia Giusta1991-01-01Zeitschrift für Kristallographie
Crystal structure refinement was carried out on a defect spinel with composition Mg 0.388 Al 2.408 O 4 synthesized at 2050°C Combining information from site occupancies and bond distances for tetrahedral and octahedral sites, the following cation and vacancy distribution were obtained: (Al 0.653 Mg 0.347 )(Al 1.755 Mg…
Glass properties and applicationsMicrowave Dielectric Ceramics SynthesisNuclear materials and radiation effects
António Checa1991-01-01Lethaia
Checa, A. 1991 01 15: Sectorial expansion and shell morphogenesis in molluses. Lethaia. Vol. 24, pp. 97–114. Oslo. ISSN 0024–1164. Any coiled shell can be described as a series of independent helicospirals that join homologous points along the shell surface. The cross-section is therefore seen as a set of points. obta…
Paleontology and Stratigraphy of FossilsMarine Bivalve and Aquaculture StudiesCalcium Carbonate Crystallization and Inhibition
E. Guglielminotti、F. Boccuzzi1991-01-01Journal of the Chemical Society Faraday Transactions
The adsorption and the surface reactions of ammonia and nitric oxide on differently pretreated Ru/TiO2 samples have been investigated by means of FTIR spectroscopy. On all the samples, both oxidized and reduced, the ammonia is adsorbed at room temperature in an undissociated form on different Ti4+ surface ions, (at co…
Catalytic Processes in Materials ScienceCatalysis and Oxidation ReactionsAmmonia Synthesis and Nitrogen Reduction
Michael C. Pirrung、Christopher P. Holmes、Daniel Horowitz 等 4 位作者1991-01-01Journal of the American Chemical Society
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism and stereochemistry of .alpha.,.beta.-dihydroxyacid dehydrataseMichael C. Pirrung, Christopher P. Holmes, Daniel M. Horowitz, and David S. NunnCite this: J. Am. Chem. Soc. 1991, 113, 3, 1020–1025Publication Date (Print):January 1, 1991Publication History Published…
Enzyme Structure and FunctionMicrobial metabolism and enzyme functionBiochemical Acid Research Studies