Showing papers by "Istanbul Technical University published in 1993"
TL;DR: In this paper, the authors describe the orogenic evolution of the southeast Anatolian Orogenic belt based mostly on new geologic data collected from its constituent tectonic units in the course of new mapping programs of the past decade.
Abstract: This paper describes the orogenic evolution of the southeast Anatolian orogenic belt based mostly on new geologic data collected from its constituent tectonic units in the course of new mapping programs of the past decade. The southeast Anatolian orogenic segment of the Alpides may be divided into three approximately east-west-trending zones. From south to north, they are the Arabian Platform, followed by a zone of imbrication, and then a zone of nappes. The Arabian Platform includes a mostly marine, sedimentary succession deposited from early Cambrian to middle Miocene time. The zone of imbrication is a narrow belt sandwiched between the Arabian Platform and the zone of nappes. It consists of imbricated thrust slices emplaced onto a Late Cretaceous to early Miocene sequence. The zone of nappes is the highest tectonic unit, consisting of two stacks of nappes simply designated the lower and upper nappes. The lower nappe is represented by the slices of a polyphase metamorpbic ophiolitic assemblage and the Maden Group. The upper nappe rests on the lower nappe and is represented by the Bitlis and Poturge metamorphic massifs. Southeastern Anatolia underwent two major episodes of Alpide deformation. The first occurred during the Late Cretaceous period, when ophiolite was emplaced on the Arabian Platform. This event was not the consequence of a continental collision. The ophiolite obduction onto the Arabian Platform was followed by a regionwide extension and a new marine transgression over the platform immediately after the ophiolite obduction. The second episode of deformation occurred during middle Eocene-Miocene time in two distinct stages as a result of the progressive elimination and complete closure of the ocean(s) which led to the collision between the zone of nappes located to the north (being a part of Eurasia) and the Arabian plate. The Maden marginal basin formed north of the subduction zone that eliminated the ocean between Eurasia and Arabia, along the southern margin of the Taurus belt, and abutted the Arabian Plate much later, during the final collision. The second episode of deformation formed the present orogenic segment leading to the amalgamation of different tectonic units. These amalgamated nappes collided with the Arabian plate and welded onto it at the latest stage of the orogenic evolution during the Miocene epoch.
465 citations
TL;DR: The results on the global asymptotic stability are useful for the design of a generalized CNN such that the orbit of each state converges to a globally asymPTotically stable equilibrium point which depends only on the input and not on the initial state.
Abstract: A rather general class of neural networks, called generalized cellular neural networks (CNNs), is introduced. the new model covers most of the known neural network architectures, including cellular neural networks, Hopfield networks and multilayer perceptrons. Several sets of conditions ensuring the input-output stability and global asymptotic stability of generalized CNNs have been obtained. the conditions for the stability of individual cells are checked in the frequency domain, while the stability of the overall network is analysed in terms of the stability of individual cells and the connectivity characteristics. the results on the global asymptotic stability are useful for the design of a generalized CNN such that the orbit of each state converges to a globally asymptotically stable equilibrium point which depends only on the input and not on the initial state. Such a network defines an algebraic map from the space of external inputs to the space of steady state values of the outputs and hence can accomplish cognitive and computational tasks.
84 citations
TL;DR: In this paper, a laboratory-scale hybrid upflow anaerobic sludge blanket reactor (HUASBR) was used to treat dairy effluents from a large integrated industry with a maximum production capacity of 500 tons of milk per day.
61 citations
TL;DR: In this article, the dispersive refractive index and extinction coefficient of CdS thin films were evaluated from spectrophotometric transmittance characteristic in the visible region, and the authors found that the refractive indices depend on the deposition rate with values between 2.48 and 2.60.
48 citations
TL;DR: In this paper, oxine and alkyl oxine were used as modifiers in scheelite flotation and their adsorption mechanism was investigated, which showed that oxine increases the negative zeta potential of scheelites to a less negative value whereas calcite was not changed with this reagent and became more negative upon treatment with quebracho.
47 citations
TL;DR: In this paper, the potential of conventional methods to remove COD and micropollutants has not been fully explored and the extent of COD removal by conventional methods is investigated.
46 citations
TL;DR: In this paper, two strong wastes, citric acid plant effluent and cheese whey, were tested for their inert COD content and a newly developed procedure was used for the assessment of the soluble and particulate residual COD.
44 citations
TL;DR: In this paper, an optimization model of the activated sludge wastewater treatment systems was presented, which is relatively complex, containing a series of unit processes, each designed to achieve a specific goal.
39 citations
39 citations
TL;DR: In this article, two main types of CuxO film exhibiting different optical properties are characterized optically and morphologically: reddish gray and colorless films, and the results determined for the optical constants are in aggreement with the results found in the literature.
37 citations
TL;DR: In this paper, the authors used long period P and SH waveforms and first motion polarities of P waves to determine the source parameters of the Cubukdag (in the eastern section of the Buyuk Menderes graben) earthquake of 1986 October 11.
Abstract: SUMMARY
Long period P and SH waveforms and first motion polarities of P waves were used to determine the source parameters of the Cubukdag (in the eastern section of the Buyuk Menderes graben) earthquake of 1986 October 11, the waveforms used in this event include the WWSSN, and the digitally recorded seismograms of the DWWSSN, SRO and ASRO networks. the minimum misfit solution obtained by the inversion of teleseismic body waveforms are better constrained that those of the previously published Harvard Centroid-Moment Tensor solution, and are in good agreement with field observations and the local geometry of the graben.
TL;DR: In this article, the floatability of a typical boron mineral, colemanite, was investigated in a microflotation cell by using anionic and cationic surfactants as collectors and tannic acid as a depressant.
Abstract: The development of reagent strategies for the flotation of boron minerals requires an understanding of flotation chemistry of reagent/mineral interactions. The floatability of a typical boron mineral, colemanite, was investigated in a microflotation cell by using anionic and cationic surfactants as collectors and tannic acid as a depressant. The results obtained with zeta potential measurements together with flotation tests reveal that colemanite is floatable with both anionic and cationic surfactants at its natural pH of 9.3. While the floatability of colemanite with anionic surfactants decreases with increasing pH, that with a cationic surfactant exhibits a maximum at pH 10.2, indicating the major role of electrostatic interactions in the system.
TL;DR: In this paper, the authors showed that the previously suggested seismic gap along the North Anatolian fault, east of Erzincan, still remains unruptured, and that the aftershock distribution concentrated at an area of the intersection between the intersection of the North and the Ovacik faults.
Abstract: The 13 March 1992 Erzincan earthquake, M=6.8, occurred in the eastern half of the Erzincan basin. The largest aftershock took place near Pulumur on 15 March 1992. No clear surface breaks were observed, although teleseismic studies suggested that it was a strike-slip earthquake striking parallel to the North Anatolian fault, with a focus of approximately 10±2 km depth, 30 km rupture length, 95 cm of slip, and a 1.16×1026 dyn.cm seismic moment. The aftershock distribution concentrated at an area of the intersection between the North Anatolian fault and the Ovacik fault. These results indicate that the previously suggested seismic gap along the North Anatolian fault, east of Erzincan, still remains unruptured.
TL;DR: Steady state fluorescence was used to examine the interdiffusion of polymer molecules during annealing of a latex film at and above the glass transition temperature as mentioned in this paper, which was found to have 34 kcal mol−1 activation energy.
TL;DR: The Lyapunov matrix equation is considered, where the solution is a nonnegative definite matrix, i.e. a matrix admitting decomposition in square root factors, and an algorithm for findings the square root factor without preliminary finding the solution itself is given.
DOI•
24 Jun 1993TL;DR: In this paper, the authors investigated the spectral evolution of breaking and nearly breaking waves propagating over a submerged trapezoidal bar and found that wave breaking itself does not play crucial role in the evolution of the spectral shape, but contributes simply by extracting energy roughly in proportion to the local spectral density.
Abstract: Spectral evolution of breaking and nearly breaking waves propagating over a submerged trapezoidal bar has been investigated in laboratory experiments. It is found that wave breaking itself does not play a crucial role in the evolution of the spectral shape, but contributes simply by extracting energy roughly in proportion to the local spectral density. For nonbreaking waves, a Boussinesq model with improved dispersion characteristics is found to simulate the wave evolution very well. On the basis of these findings, it is suggested to combine a semi-empirical model for the overall energy dissipation with a nondissipative Boussinesq model so as to obtain a model for simulation of spectral evolution of breaking waves.
TL;DR: In this article, the relationship between ash composition and ash fusion characteristic temperatures for some Turkish lignites was investigated, and the results suggest that the chemical composition has a significant effect on the ash fusion temperatures.
Abstract: The purpose of this paper was to investigate the relationship between ash composition and ash fusion characteristic temperatures for some Turkish lignites. The lignite samples used are from different areas in Turkey. Regression analysis was used to relate the ash composition to the ash fusion behaviour. The results suggest that the chemical composition has a significant effect on the ash fusion temperatures. To consider Fe2O3 as an acidic ash constituent makes the realtionships between the selected ash composition parameters and ash fusion temperatures clearer.
TL;DR: In this paper, fixed-bed pyrolysis and hydropyrolytic experiments at different temperatures and pressures have been conducted on a sample of Euphorbia Rigida extracted with n-hexane and methanol to remove low molecular mass terpenoids and saccharides to elucidate the extent of oil formation from the remaining predominantly cellulosic structure.
TL;DR: In this paper, the mean differences in moisture, ash, volatile matter and fixed carbon contents between the TGA and ASTM methods are 0.38, 0.68, 1.53% and 1.47%, respectively.
TL;DR: In this article, in situ-modified cyclohexanone-formaldehyde and acetophenoneformaldehyde resins with compounds such as diphenols, melamine, and p-toluene sulfonamide were studied.
Abstract: Preparation of in situ-modified cyclohexanone-formaldehyde and acetophenone-formaldehyde resins with compounds such as diphenols, melamine, and p-toluene sulfonamide were studied. Modification of acetophenone-formaldehyde resins with hydroxylamine, semicarbazide, phenylhydrazine, phthalic anhydride, and acetic anhydride was also studied. Melting points, solubilities in organic solvents, and FTIR and NMR spectra of modified resins were determined. © 1993 John Wiley & Sons, Inc.
TL;DR: The cationic polymerization of typical monomers, such as cyclohexene oxide and 1,4-butanedioldiglycidyl ether or of vinyl ethers such as n-butylvinyl ether, is induced by UV irradiation of monomer formulations containing a substituted vinyl bromide as light absorbing agent and an appropriate nonabsorbing onium salt as mentioned in this paper.
Abstract: The cationic polymerization of typical monomers, e.g. of oxiranes such as cyclohexene oxide and 1,4-butanedioldiglycidyl ether or of vinyl ethers such as n-butylvinyl ether, is induced by UV irradiation of monomer formulations containing a substituted vinyl bromide as light absorbing agent and an appropriate non-absorbing onium salt. Experiments performed with 1,2,2-triphenyl vinyl bromide or 1,2,2-tri(4-methoxyphenyl) vinyl bromide and N-ethoxy-2-methyl-pyridinium or triphenyl sulfonium hexafluorophosphate are described in the paper.
TL;DR: In this article, it was shown that the polynomial matrix factorization relative to the imaginary axis may be reduced to the successive solution of Lyapunov equations, i.e. the factorization is reduced to a sequence of generalized LyAPunov equation, not to the solution of generalized Riccati equation.
TL;DR: In this article, the effluent of a laboratory-scale SBR contained significant amounts of non-biodegradable COD and the performance of SBR with respect to its nitrogen removal potential from piggery wastewaters was evaluated.
TL;DR: In this article, the role of different process parameters on the reaction rate was investigated in the enzymatic hydrolysis of used frying oil catalyzed by native lipase of Nigelk sativa seed.
Abstract: The enzymatic hydrolysis of used frying oil catalyzed by native lipase ofNigelk sativa seed was investigated under different conditions to elucidate the role of different process parameters on the reaction rate Data fitted the first-order rate equation
01 Jan 1993
TL;DR: The understanding of the design knowledge, a part of design research, requires investigation into designing activity, so the information known by the designers is considered, how and when it is used while solving such a design problem.
Abstract: At present we are questioning design methods from a different point of view. We are working with computers and trying to decode the methods of the professional practice into computers to be used by the professional practitioners in their turn. These approaches lead us to the investigation of the design knowledge of designers. The understanding of the design knowledge, a part of design research, requires investigation into designing activity. Design research obligates us to apply different approaches and the methods of different disciplines. But in the elicitation of the design knowledge we have to consider the information known by the designers, how that information is gained, how that information is processed, how and when it is used while solving such a design problem. Several disciplines are used in the design process, according to their relevance to the problem area. When we look at a multi-disciplinary area such as designing, we must clarify the disciplines or sciences involved, and their relation to design must be studied.
TL;DR: In this paper, DTA ignition temperatures and DTG maximum peak temperatures were correlated with the CaO, MgO, Na 2 O and K 2 O contents of twenty-one Turkish lignites.
TL;DR: In this paper, the tailings produced from the calcination of Bigadic colemanite ore are upgraded by means of a gravity concentration method, and the combined results of calcination and tabling resulted in a final concentrate containing 51.88% B2O3 with an 84.41% recovery rate.
DOI•
24 Jun 1993
TL;DR: In this paper, data collected from measurements performed in waves propagating over a trapezoidal bar on a horizontal bottom are used to test a fully nonlinear numerical model, including both regular and random waves.
Abstract: Data collected from measurements performed in waves propagating over a trapezoidal bar on a horizontal bottom are used to test a fully nonlinear numerical model. The experiments include both regular and random waves. Wave form evolutions in the shoaling region, the near resonant wave-wave interactions over the bar, and finally the decomposition behind the bar are well predicted. The results provide assurance for the reliability of the numerical model.
TL;DR: In this article, a transient fluorescence technique was used to study small molecule (1-naphthylmethyl privalate) diffusion into poly (methyl methacrylate) (PMMA) particles sterically stabilized by polyisobutylene (PIB) was studied.
Abstract: Small molecule (1-naphthylmethyl privalate) (NMP) diffusion into poly (methyl methacrylate) (PMMA) particles sterically stabilized by polyisobutylene (PIB) were studied by the transient fluorescence technique. Mean lifetimes of NMP increased as it diffused into the interphase region indicating that diffusion is accompained by quenching of excited NMP molecules by PIB phase. A delayed Fickian diffusion model is fitted to experimental data and a diffusion coefficient is measured around 10−19 cm2/s at room temperature. PIB density distribution in the interphase domain is found to be Gaussian. A supporting experiment is performed in Anthracene labelled PMMA particles using the direct-energy transfer method. Reversed Gaussian distribution is detected for the PMMA density in the interphase domain. © 1993 John Wiley & Sons, Inc.
TL;DR: Modelling and economic analysis of the conversion from an existing job shop system to a cellular manufacturing system are performed in order to justify the cellular Manufacturing system.