Showing papers by "Istanbul Technical University published in 1990"
TL;DR: In this article, it was shown that a large number of basaltic shield and fissure eruptions of transitional tholeiitic - alkaline composition were derived from the Arabia- Eurasia collision zone.
681 citations
85 citations
Book•
01 Jan 1990TL;DR: In this article, the textural terms foliation, granoblastic polygonal texture, acicular texture, decussate texture plastic deformation and mylonitization time relations between deformation reaction textures textures textures of polymetamorphism.
Abstract: Part 1 Settings of metamorphism: contact metamorphism intermediate regional and dynamic metamorphism regional metamorphism with weak deformation cataclastic metamorphism hydrothermal metasomatism impact metamorphism medium pressure type - prehnite pumpellytite facies, greenschist facies chlorite zone, biotite zone, garnet zone, amphibolite facies staurolite zone, kyanite zone, sillimanite zone high temperature metamorphism of pelites - amphbolite facies sillimanite K-feldspar zone, granulite facies low pressure metamorphism of pelites - hornblende hornfels facies, pyroxene hornfels facies, sanidinite facies high pressure metamorphism of pelites - blueschist facies, eclogite facies, granulite facies metamorphism of tuffs, greywackes and cherts marbles and calc-silicates metamorphism of basic and intermediate igneous rocks - medium pressure, high pressure metamorphosed ultrabasic rocks metamorphosed acid rocks. Part 2 Textures: simple textural terms - foliation, granoblastic polygonal texture, acicular texture, decussate texture plastic deformation and mylonitization time relations between deformation and metamorphism reaction textures textures of polymetamorphism.
52 citations
TL;DR: In this article, mixedmode crack initiation and propagation starting from the aggregatematrix interface in concrete under uniaxial compression was investigated using fracture mechanics approach, finite element mode.
Abstract: Mixedmode crack initiation and propagation starting from the aggregatematrix interface in concrete under uniaxial compression was investigated using fracture mechanics approach, finite element mode...
34 citations
TL;DR: In this paper, a mechanistic investigation was carried out in alkaline medium to interpret the electrocatalytic properties of palladium for the oxidation of ethylene glycol, and the kinetic parameters, estimated from electrochemical data, suggest a one electron step to be rate determining.
31 citations
TL;DR: Azo-benzoin initiators are useful for the synthesis of polymers with photoactive end groups as discussed by the authors, and they exhibit initiator properties similar to that of common azo initiators.
Abstract: Azo-benzoin initiators are useful for the synthesis of polymers with photoactive end groups. The kinetics of the bulk polymerization of styrene initiated by 4,4′-azobis(4-cyanopentanoyl)bis(α-methylolbenzoin methyl ether) (ABME) was investigated. On the basis of kinetic parameters, it was found that azo-benzoin initiators exhibit initiator properties similar to that of common azo initiators. A relatively high chain transfer constant of the initiator (C1) may be attributed to the presence of α-methylolbenzoin methyl ether groups in the structure.
Azo-Benzoin-Initiatoren sind fur die Herstellung von Polymeren mit photosensitiven Endgruppen geeignet. Diese Arbeit beschreibt die kinetischen Parameter der radikalischen Substanzpolymerisation von Styrol mit 4-4′-Azobis-(4-cyanopentanoyl)-bis-(α-methylolbenzoin-methylether) (ABME). Die Initiatoreigenschaften von ABME ahneln denen gebrauchlicher Azoinitiatoren; die relativ zu diesen hohere Kettenubertragungskonstante von ABME konnte durch die Methoxygruppen im Molekul bedingt sein.
24 citations
TL;DR: In this article, a structural modification is proposed to account for this effect, by incorporating mechanisms responsible for the generation of soluble microbial products, considered residual for the particular operating conditions of the activated sludge systems.
24 citations
TL;DR: In this article, the effect of Ce(IV) concentration, temperature, time, and monomer concentration on the yield and molecular weight of polyacrylonitrile was studied.
Abstract: The polymerization of acrylonitrile in the presence of Ce(IV) salts and ketonic resin such as methyl ethyl ketone/formaldehyde and cyclohexanone/formaldehyde resin was investigated. Block copolymer of ketonic resin–polyacrylonitrile was produced. The effect of Ce(IV) concentration, temperature, time, and monomer concentration on the yield and molecular weight was studied. Maximum yield was obtained at 50°C and ceric ammonium nitrate concentration of 0.033 mol/L.
24 citations
TL;DR: In this article, a static solution is obtained and contact radius is determined, and this is used as an initial configuration of the forced vibrations, which are assumed to be due to the time dependency of the load.
Abstract: At first the static solution is obtained and contact radius is determined. Later, this is used as an initial configuration of the forced vibrations. The forced vibrations are assumed to be due to the time dependency of the load. The solution is carried out by Galerkin's method and by using modal functions of the completely free plate. Numerical results are illustrated in figures for stepwise change of the loading
24 citations
TL;DR: In this paper, the results of a pilot-plant study on the Anaerobic Fluidized-Bed Reactor (AFBR) treatment of brewery wastes were reported, showing that a COD removal efficiency of greater than 75% was achieved at an organic loading rate (OLR) of 8.9 kg COD/m3 of expended bed/day for 82 days from start-up.
22 citations
TL;DR: In this paper, a new lumped parameter mathematical model for geothermal reservoirs in the presence of carbon dioxide is presented, which can be used to better understand the behavior of hot water systems that contain CO 2 and to forecast future performance.
TL;DR: In this article, temperature profiles have been used to detect the form of segregation patterns in two fluidized-bed combustors (0.11 m and 0.2 m i.d.).
TL;DR: In this paper, block copolymers containing segments of poly(ethylene oxide) and polystyrene were synthesized, and the resulting polymeric peroxycarbamates were used as free radical initiators for vinyl polymerization.
Abstract: Block copolymers containing segments of poly(ethylene oxide) and polystyrene were synthesized. Dihydroxyl-terminated polyethers (PEG-4000 and PEG-20,000) were reacted with an aliphatic diisocyanate (3-isocyanatomethyl-3,5,5-trimethyl-cyclohexyl-isocyanate) and with an aliphatic hydroperoxide (t-butyl hydroperoxide). The resulting polymeric peroxycarbamates were used as free radical initiators for vinyl polymerization. Formation of block copolymers was illustrated by several characterization methods such as chemical and UV analysis, infrared spectroscopy, and DSC thermograms. Mechanical characterization of the copolymers was made on the basis of the stress—strain curves obtained from a mechanical testing instrument (Tensilon).
TL;DR: In this article, the authors investigated the treatment alternatives for high-strength acid waters from an edible oil refinery and determined an appropriate treatment system for high strength acid waters using a full-scale Dissolved Air Flotation (DAF) plant.
01 Jan 1990
TL;DR: In this article, it was shown that if by some chance discrimination in a particular field of social contact is increased or decreased, the psychological force behind it that is prejudice tends to change so as to support actual behaviour.
Abstract: Disparity, in its specific meaning, can be defined as inequality, difference, or incongruity. Meanwhile, as Myrdal (1972, p. 17) pointed out, ’…experience shows that if by some chance discrimination in a particular field of social contact is increased or decreased the psychological force behind it that is prejudice tends to change so as to support actual behaviour. This too fits into the general pattern of circular causation.’ In this sense, there are certain periods when opposing forces balance one another. However, when the whole system moves after a shock by a push or a pull, then the changes in the forces work in the same direction because the variables are interlocked in circular causation.
TL;DR: In this paper, the authors analyzed the experience of three Turkish truck manufacturing firms under import substitution and export-oriented industrialization strategies and identified some of the factors which influence their technological efforts.
TL;DR: In this article, a polyamides containing crown ether moieties and various amounts of N Nunits in the main chain were prepared by solution polycondensatio between cis-diamino dibenzo-18-crown-6 (DADC) and adipoyl chloride (AC) with the addition of 4,4′-azobis(4-cyanopentanyl chloride) (ACPC).
Abstract: Macroazonitriles containing crown ether moieties and various amounts of N Nunits in the main chain were prepared by solution polycondensatio between cis-diamino dibenzo-18-crown-6 (DADC) and adipoyl chloride (AC) or terephtaloyl chloride (TPC) with the addition of 4,4′-azobis(4-cyanopentanyl chloride) (ACPC). Decomposition of the azo linkage present in the polyamides, obtained by using TPC, were studied by DSC. The rate constants and activation energies for the decomposition were determined and a small effect of terephtaloyl group on the rate was observed. The kinetics of the polymerization of styrene by the poly(azoamide), obtained from ACPC and DADC were investigated in DMSO.
TL;DR: In this article, the major and trace element contents of ten phosphorite nodules from representative exposures along the 400-mile long outcrop belt from the northern Quachita to central Missouri were determined.
TL;DR: In this paper, the authors used graphite furnace atomic absorption spectrometers to determine lead and chromium by graphite-furnace atomization of the elements in graphite furnaces.
Abstract: Potassium chloride, calcium chloride, sodium chloride and magnesium chloride cause many different types of interference in the determination of lead and chromium by graphite furnace atomic absorption spectrometry. Simultaneous volatilization of the analyte and the interferent from different, but close, points in the tube are very helpful in the explanation of interference mechanisms. The kind of interference that affects the sensitivity of the determination depends on the thermal behavior of the matrix before and during atomization of the elements. If chloride vapor is formed by decomposition of the matrix before or during atomization of the analyte elements, the formation of a metal chloride in the gas phase may be responsible for decreasing in the sensitivity. If, on the other hand, the matrix is present as a solid or liquid while the elements atomize, the occlusion of the analyte in the bulk of the matrix and the loss by a carrier-type mechanism or a slower transfer of heat to the analyte delaying the atomization cause some changes in the sensitivity. Expulsion of analyte vapors by expanding matrix gases was not effective due to the low heating-rate of the system used
TL;DR: The rapid development of the Turkish construction industry in overseas markets provides a contrast to the internationalization of other countries' construction industries as discussed by the authors, by focusing initially on low-technology projects in difficult locations and exploiting its mobile low-cost labour force, the Turkish industry has rapidly gained in experience and sophistication, thereby enriching its domestic construction industry.
Abstract: The rapid development of the Turkish construction industry in overseas markets provides a contrast to the internationalization of other countries' construction industries. By focusing initially on low-technology projects in difficult locations and exploiting its mobile low-cost labour force, the Turkish industry has rapidly gained in experience and sophistication, thereby enriching its domestic construction industry. The internationalization of the Turkish industry has required the development of new institutions and attitudes within Turkey and the rapid development of financial systems.
TL;DR: In this paper, the static and dynamic stability of variable thickness annular plates subject to periodic in-plane forces is studied using a sector finite element model with the wave propagation technique of cyclic symmetry, and the instability regions are determined for a wide range of excitation frequencies with different boundary conditions by using Bolotin's method with the effect of static forces taken into account.
TL;DR: The kinetics of the polymerization of styrene initiated by 4,4′-azobis(4-cyanopentanoyl chloride) (ACPC) was investigated in bulk and in benzene solution at 60°C as mentioned in this paper.
TL;DR: In this paper, the work of A.K.N.S. which is based on the sl(2, R) valued soliton connection is extended to obtain new integrable coupled nonlinear partial differential equations.
Abstract: The work of A.K.N.S. which is based on the sl(2, R) valued soliton connection is extended to obtain new integrable coupled nonlinear partial differential equations. This is achieved by assuming the soliton connection having values in a simple Lie, Kac-Moody, Lie superalgebras. Extensions of some of the integrable nonlinear partial differential equations are given explicitly. In particular the coupled NLS equations on various homogeneous spaces and the coupled modified KdV integro-differential equations are obtained on symmetric spaces.
TL;DR: In this paper, the effect of martensite content on the high cycle fatigue performance of commercial grade SAE 5115 carburizing steel has been investigated and possible correlations between the quasi-static and fatigue properties have been sought.
Abstract: The work reported here results from a study on the effect of martensite content on the high cycle fatigue performance in which possible correlations between the quasi-static and fatigue properties have been sought. Commercial grade SAE 5115 carburizing steel was used in this study
TL;DR: In this article, a large number of textile plants in Turkey have been studied and evaluated in terms of characteristics and treatability of wastewaters involved as related to relevant production parameters, exhibiting significant differences for each plant.
TL;DR: In this paper, the spatial and temporal limits of agglomeration are determined by the extent of segregation in a fluidized bed of lignite ash and sand, where the ash may behave as flotsam or jetsam according to its particle size.
01 Jan 1990
TL;DR: In this article, a continuous approach is adopted in order to find the total variation of a general performance criterion, which may find important physical applications in simultaneous shape optimization and control of large space structures in time by applied thermal and/or mechanical loads.
Abstract: A continuous approach is adopted in order to find the total variation of a general performance criterion. The present analysis may find important physical applications in the simultaneous shape optimization and control of large space structures in time by applied thermal and/or mechanical loads. The adjoint variable method and the material derivative concept are used to find the sensitivity expressions
TL;DR: In this paper, a comprehensive wastewater pollution abatement program implemented at a plant producing pharmaceutical products by fermentation is described, where a fraction of cooling discharges was mixed with process wastes in the planning and design of the treatment flow scheme to lower the BOD concentration below 2000 mgl −1, and to provide an equalization and buffering capacity for hydraulic and toxic shocks.