743 research outputs found
Texture, microhardness and corrosion resistance of 316L stainless steel
The texture, microhardness, and corrosion resistance of cold worked 316L steel were evaluated. The X-ray diffraction analysis in particular permitted to disclose and identify the main textures variations in the structure of the investigated steel after its deformation within the range 10 - 80%. The corrosion resistance was studied using Tafel polarization tests. It was shown that the increase in deformation degree drastically decreases the relative intensity of {111} planes. Besides, with high degree of cold deformation microhardness increases while corrosion resistance deteriorates. This article has been retracted. Link to the retractio
Bakhtiari, Leskinen and Torma Reply
This is a Reply to: Comment on "Spectral Signatures of the
Fulde-Ferrell-Larkin-Ovchinnikov Order Parameter in One-Dimensional Optical
Lattices" R. A. Molina J. Dukelksy, and P. Schmitteckert, Phys. Rev. Lett. 102,
168901 (2009)Comment: 1 page, published versio
Numerical Modelling of Wave-Induced Current and Wave Transformation in Presence of Submerged Breakwaters
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Pomeranchuk effect and spin-gradient cooling of Bose-Bose mixtures in an optical lattice
We theoretically investigate finite-temperature thermodynamics and
demagnetization cooling of two-component Bose-Bose mixtures in a cubic optical
lattice, by using bosonic dynamical mean field theory (BDMFT). We calculate the
finite-temperature phase diagram, and remarkably find that the system can be
heated from the superfluid into the Mott insulator at low temperature,
analogous to the Pomeranchuk effect in 3He. This provides a promising many-body
cooling technique. We examine the entropy distribution in the trapped system
and discuss its dependence on temperature and an applied magnetic field
gradient. Our numerical simulations quantitatively validate the spin-gradient
demagnetization cooling scheme proposed in recent experiments.Comment: 9 pages, 8 figure
The effect of zinc bath temperature on the morphology, texture and corrosion behaviour of industrially produced hot-dip galvanized coatings
The purpose of this work is to identify the influence of zinc bath temperature on the morphology, texture and corrosion behavior of hot-dip galvanized coatings. Hot-dip galvanized samples were prepared at temperature in the range of 450-480 °C in steps of 10 °C, which is the conventional galvanizing temperature range in the galvanizing industries. The morphology of coatings was examined with optical microscopy and scanning electron microscopy (SEM). The composition of the coating layers was determined using energy dispersive spectroscopy (EDS) analysis. The texture of the coatings was evaluated using X-ray diffraction. Corrosion behavior was performed using salt spray cabinet test and Tafel extrapolation test. From the experimental results, it was found that increasing the zinc bath temperature affects the morphology of the galvanized coatings provoking the appearance of cracks in the coating structure. These cracks prevent formation of a compact structure. In addition, it was concluded that (00.2) basal plane texture component was weakened by increasing the zinc bath temperature and, conversely, appearance of (10.1) prism component, (20.1) high angle pyramidal component and low angle component prevailed. Besides, coatings with strong (00.2) texture component and weaker (20.1) components have better corrosion resistance than the coatings with weak (00.2) and strong (20.1) texture components. Furthermore, corrosion resistance of the galvanized coatings was decreased by increasing the zinc bath temperature. http://dx.doi.org/10.5937/metmateng1401041
Improved pitting corrosion resistance of S.S 316L by Pulsed Current Gas Tungsten Arc Welding
In this study, S.S 316L was welded using Direct Current Gas Tungsten Arc Welding (DGTAW) and Pulsed Current Gas Tungsten Arc Welding (PGTAW) methods. Optical observations, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) were employed to study the effect of continuous and pulse currents on microstructure and phase transformation in weld metal (WM). In addition pits morphology were evaluated by SEM. The corrosion behaviour was analyzed using cyclic polarizaton tests and Mott-schottky measurements. The pulse current resulted in finer grain and more ferrite in WM. This can be due to the decrease in heat input and higher cooling rate encouraged by pulse current. Cyclic potentiodynamic polarization tests showed that the WM of sample produced by pulse current show higher corrosion and pitting resistances than that in sample produced by continuous current. The reason is attributed to lower segregation of solute elements such as chromium and molybdenum into the delta-ferrite and also finer grain size produced in WM due to lower heat input and higher cooling rate. Both of these factors increase the stability of passive layer formed. The results showed that the corrosion behaviour of WM in both conditions (pulse and continuous current) is higher than the base metal (BM). This fact is attributed to the presence of ferrite bands formed in BM due to the segregation of alloy elements. The Mott-schottky plots confirmed that the passive layer formed on welded samples was an n-type semiconductor. The results showed that the samples showed less pitting resistance contained more oxygen vacancies in their passive film structure. It is also concluded that the breakdown of passive layer and pitting formation obey point defect model (PDM). Keywords: S.S 316L, Pulsed Current Gas Tungsten Arc Welding (PGTAW), lacy ferrite, vermicular ferrite, Pitting corrosion, Mott- Schottky
Operations planning for agricultural harvesters using ant colony optimization
An approach based on ant colony optimization for the generation for optimal field coverage plans for the harvesting operations using the optimal track sequence principle B-patterns was presented. The case where the harvester unloads to a stationary facility located out of the field area, or in the field boundary, was examined. In this operation type there are capacity constraints to the load that a primary unit, or a harvester in this specific case, can carry and consequently, it is not able to complete the task of harvesting a field area and therefore it has to leave the field area, to unload, and return to continue the task one or more times. Results from comparing the optimal plans with conventional plans generated by operators show reductions in the in-field nonworking distance in the range of 19.3-42.1% while the savings in the total non-working distance were in the range of 18-43.8%. These savings provide a high potential for the implementation of the ant colony optimization approach for the case of harvesting operations that are not supported by transport carts for the out-of-the-field removal of the crops, a practice case that is normally followed in developing countries, due to lack of resources
Spectral signatures of the Fulde-Ferrell-Larkin-Ovchinnikov order parameter in one-dimensional optical lattices
We address an imbalanced two-component atomic Fermi gas restricted by a
one-dimensional (1D) optical lattice and an external harmonic potential, within
the mean-field Bogoliubov-de Gennes (BdG) formalism. We show that
characteristic features of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state
are visible in the RF-spectra and in the momentum resolved photoemission
spectra of the gas. Specially, Andreev states or mid-gap states can be clearly
resolved, which gives a direct experimentally observable signature of the
oscillating order parameter.Comment: published versio
Application of rapid environmental impacts assessment matrix and Iranian matrix in environmental impact assessment of solid waste landfill of Shahrekord
زمینه و هدف: یکی از مهمترین معضلات محیط زیستی تولید بیش از اندازه مواد زائد جامد شهری و مدیریت این مواد است. ارزیابی اثرات محیط زیستی (Environmental Impact Assessment= EIA) به عنوان راهکاری جهت به حداقل رساندن اثرات منفی دارای اهمیت است. هدف از این مطالعه استفاده از فرآیند EIA برای به حداقل رساندن اثرات محیط زیستی محل دفن زباله های شهرکرد و ارائه گزینه مناسب برای مدیران و برنامه ریزان این شهر بود. روش بررسی: در این مطالعه توصیفی-تحلیلی ارزیابی اثرات محیط زیستی محل دفن پسماند جامد شهرکرد در سال 1391 با دو روش ماتریس ارزیابی سریع اثرات محیط زیستی (Rapid Impact Assessment Matrix= RIAM) و ماتریس ایرانی (ماتریس اصلاح شده لئوپولد) مبتنی بر بازدیدهای میدانی و جمع آوری اطلاعات از منابع متعدد انجام شد. مقایسه چهار گزینه موجود شامل ادامه دفن به شیوه کنونی، ارتقاء کیفیت دفن، احداث محل دفن بهداشتی جدید و احداث کارخانه کمپوست و بازیافت انجام شد. یافته ها: ادامه روند کنونی دفن دارای امتیاز در RIAM، 1443- و در ماتریس ایرانی 9/3- بود. امتیاز گزینه کمپوست بازیافت در RIAM، 816- و در ماتریس ایرانی 1 برآورد شد. همچنین در نتایج دو روش برای اولویت گذاری ارتقاء کیفیت دفن و احداث محل دفن بهداشتی اختلاف مشاهده شد. نتیجه گیری: بر اساس هر دو روش، ادامه دفن به شیوه کنونی از لحاظ بهداشتی غیر قابل قبول و ادامه روند کنونی همراه با آسیب های محیط زیستی شدید است. کارخانه کمپوست-بازیافت با توجه به پتانسیل پسماندهای تولیدی در این شهر در اولویت گزینه های موجود قرار دارد
Texture, microhardness and corrosion resistance of 316L stainless steel
The texture, microhardness, and corrosion resistance of cold worked 316L steel were evaluated. The X-ray diffraction analysis in particular permitted to disclose and identify the main textures variations in the structure of the investigated steel after its deformation within the range 10 - 80%. The corrosion resistance was studied using Tafel polarization tests. It was shown that the increase in deformation degree drastically decreases the relative intensity of {111} planes. Besides, with high degree of cold deformation microhardness increases while corrosion resistance deteriorates. This article has been retracted. Link to the retractio
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