Anti-plane shear waves in an elastic strip rigidly attached to an elastic half-space

We consider the anti-plane shear waves in a domain consisting of an infinite layer with a thin coating lying on an elastic half-space. The elastic properties of the coating, layer, and half-space are assumed to be different. On the free upper surface we assume the compatibility condition within the Gurtin–Murdoch surface elasticity, whereas at the plane interface we consider perfect contact. For this problem there exist two possible regimes related to waves exponentially decaying in the half-space. The first one, called transversely exponential–transversely exponential (TE–TE) regime, is related to waves described by exponential in transverse direction functions; the second, transversely harmonic–transversely exponential (TH–TE) regime, corresponds to waves in the upper layer which have the harmonic behaviour in the transverse direction. Detailed analysis of the derived dispersion equations for both regimes is provided. In particular, the effects of surface stresses, the layer thickness as well as of the ratio of shear moduli of the upper layer and half-space on the dispersion curves is analysed

Phase Diagrams and Crossover in Spatially Anisotropic d=3 Ising, XY Magnetic and Percolation Systems: Exact Renormalization-Group Solutions of Hierarchical Models

Hierarchical lattices that constitute spatially anisotropic systems are introduced. These lattices provide exact solutions for hierarchical models and, simultaneously, approximate solutions for uniaxially or fully anisotropic d=3 physical models. The global phase diagrams, with d=2 and d=1 to d=3 crossovers, are obtained for Ising, XY magnetic models and percolation systems, including crossovers from algebraic order to true long-range order.Comment: 7 pages, 12 figures. Corrected typos, added publication informatio

Evaluating Current Logistics Facilities with Analytical Hyepapchy Process (AHP) and Geographical Information Systems (GIS)

Abstract. Logistics facilities which have important position within logistics supply chain are established in order for the demanded goods to be supplied on time, with the minimum cost and in the shortest duration. Given the cost and time factors, the location of such facilities should be selected very carefully and effectively. Especially, a quick settlement in logistics manner is experienced depending on transportation network, work force, proximity to market and raw materials of the times following the industrialization period after establishing the Republic. Nowadays, with the development of transportation and the communication systems as well as technology transportation costs decreased and the facilities and possibilities transport from one place to another increased. For this reason, like the private sector the public institutions and organizations began to shrink, shut down or merge their facilities. This situation was brought to reconsider the existing facilities. The purpose of this study is to evaluate and analyze current six logistics facilities with Analytical Hierarchy Process (AHP) and Geographical Information Systems (GIS). Analyses results will contribute the decision of revising logistics facilities for which are planned to be restructured. Moreover, suggestions are presented for proper ones to continue operating, for improper ones to get closed or transferred to another place.Keywords. Analytic Hierarchy Process, (AHP), Geographic Information Systems, (GIS), Facility Site Selection.JEL. J61, L86, Q55

Kassel Projesi Cebir Testinde Bir Grup Türk Öğrencinin Genel Başarısı ve Öğrenme Güçlükleri

Ülkemizde örenci baarılarına yönelik uluslararası karılatırmalı çalımalar, öretim programlarını, öretmen yetkinliklerini deerledirmeye yönelik incelemeler, neredeyse yok denecek kadar, azdır. Bu çalımada, uluslararası örenci baarısını belirlemeye yönelik Kassel Projesi Cebir Testi (KaPAT) 1997-98 öretim yılının son haftasında Ankara’nın sosyo-ekonomik gelimilik bakımından orta-alt gelir grubunun yerletii bir bölgedeki ilköretim okulunda sekizinci sınıfta uygulandı; örenci baarılarıyla ilgili derlenen veriler analiz edildi ve yorumlandı. Türkiye’de pilot çalıma olarak tasarlanan uygulamanın yapıldıı okullarda bir grup örencinin KaPAT’ deki genel baarı puan ortalamasının, bazı Avrupa ülkelerle karılatırıldıında, yüzdelerinin daha yüksek; Dou Avrupa ve uzak dou ülkelerinden ise daha düük olduu görülmektedir. Aynı okulda kız ve erkek örencilerin baarı puanları arasında belirgin bir fark olmadıı; bireysel bazda ise örencilerin baarı düzeyinin çok farklı olduu anlaılmaktadır. Bununla birlikte, örencilerin KaPAT soruları içinde ilem aırlıklı soruların yer aldıı EM soru kümesinde baarı oranlarının daha yüksek olduu, “eitlikler ve problemler” diye adlandırılan EP1 ve EP2 soru kümelerinde ise baarı düzeylerinin azaldıı, örencilerin çok sayıda ve deiik türlerde yanlı yaptıkları belirlenmitir. Gözlemlenen bu durum, örencilerin Cebir konularını örenmede bir takım örenme güçlüklerinin olduununun belirgin iaretleri olup özellikle eitlik ve deiken kavramlarında birtakım kavram yanılgılarının olabileceini akla getirmekte; ayrıca, tanıya yönelik uygun ölçme araçları gelitirilerek derinlemesine inceleme yapılmasını gerektirmektedi

The use of sesame oil in sea bream feeds and its effects on growth and body chemical composition

As fish oil availability declines worldwide and its price rises, there is a growing need to engage in scientific investigations into alternative oil sources for incorporation into fish feeds. This study aimed to determine the effects of dietary sesame oil on the growth performance, feed utilization, and nutritional composition of sea bream (*Sparus aurata*). Twenty-five individual fish (initial mean weight: 32.38±0.27 g) were placed in each tank in triplicate. Four experimental fish meal-based (iso-proteic 49% and iso-lipidic 20%) diets were formulated; the control (C) group contains 100% of fish oil (FO) and varying amounts (20, 40, 60%) of sesame oil (SO). During the 75-day experiment, the fish were fed 3 times a day, and the mean ambient temperature and dissolved oxygen values were measured as 22.5±0.5°C and 6.8±0.3 mg/L, respectively. At the beginning of the experiment, 20 fish were sampled to determine their nutrient composition and somatic indexes. In the end, 4 fish were collected for the same procedures and 4 for each tank's muscle and liver fatty acid compositions. At the end of the study, the S60 group exhibited the lowest final weight (FW) and feed utilization parameters. On the other hand, there were no statistical differences between FO, SO20, and SO40 in terms of FW. In addition, the SO40 group had the best feed conversion ratio (FCR) among the groups (P\<0.05). The whole-body lipid compositions of the groups were different. The highest lipid level was found in SO40 with 15.83±0.36%. Muscle and liver fatty acid composition was significantly affected by the fatty acid profile of experimental feeds. While total ω-6 fatty acids were higher in the SO groups than in group C, total ω-3 fatty acids were higher in the C group compared to the SO groups (P\<0.05). The ω-3/ω-6 ratios in the SO20 and SO40 groups showed similarity, while the highest ratio was observed in the control group (P\<0.05). As a result, according to data obtained from our study, it is predicted that 40% SO could be added to sea bream feed instead of FO in terms of growth performance, feed utilization, and nutritional composition

d=3 Anisotropic and d=2 tJ Models: Phase Diagrams, Thermodynamic Properties, and Chemical Potential Shift

The anisotropic d=3 tJ model is studied by renormalization-group theory, yielding the evolution of the system as interplane coupling is varied from the isotropic three-dimensional to quasi-two-dimensional regimes. Finite-temperature phase diagrams, chemical potential shifts, and in-plane and interplane kinetic energies and antiferromagnetic correlations are calculated for the entire range of electron densities. We find that the novel tau phase, seen in earlier studies of the isotropic d=3 tJ model, and potentially corresponding to the superconducting phase in high-T_c materials, persists even for strong anisotropy. While the tau phase appears at low temperatures at 30-35% hole doping away from =1, at smaller hole dopings we see a complex lamellar structure of antiferromagnetic and disordered regions, with a suppressed chemical potential shift, a possible marker of incommensurate ordering in the form of microscopic stripes. An investigation of the renormalization-group flows for the isotropic two-dimensional tJ model also shows a pre-signature of the tau phase, which appears with finite transition temperatures upon addition of the smallest interplane coupling.Comment: 13 pages, 7 figures; replaced with published versio

Effects of vitamin A and E on arginase activity, ornithine and urea levels in brain tissues of rats on long-term alcohol administration

Amaç: Sıçanlarda uzun süreli alkol kullanımının beyin arjinaz enzim aktivitesi ve ornitin üzerine etkisi ile C ve E vitaminlerinin bu parametreler üzerindeki etkisi araştırıldı. Çalışma Planı: Çalışmada 4-6 aylık, 75 erkek Wistar Albino cinsi sıçan kullanıldı. On beşerlik gruplar halinde beş çalışma grubu oluşturuldu. Birinci gruba alkole eşit kaloride glukoz oral yoldan verilirken, 2. gruba alkol, 3. gruba alkole ek olarak C vitamini, 4. gruba alkole ek olarak E vitamini, 5. gruba alkole ek olarak C ve E vitaminleri 20 hafta süreyle verildi. Yirminci hafta sonunda sıçanlar sakrifiye edildi. Beyin dokusu örneklerinde arjinaz enzim aktivitesi, ornitin ve üre düzeyleri ölçüldü. Bulgular: Beyin dokusu arjinaz aktivitesi, ornitin ve üre düzeyleri tedavi alan gruplarda alkol grubuna oranla anlamlı olarak yüksek bulundu. Sonuç: Kronik alkol kullanımında arttığı bilinen nitrik oksit sentazın (NOS), L-arjinin havuzunun tükenmesine yol açarak arjinaz enzim aktivitesinde azalmaya neden olabileceği, antioksidan vitaminler olarak C ve E vitaminlerinin kullanımının, oksidatif stresi azaltıp arjinaz/NOS yolağını arjinaz lehine çevirebileceği ve olumsuz etkileri bilinen nitrik oksit üretiminin azalmasının söz konusu olabileceği düşünülmektedir. Aynı anda üretimi artan poliaminler bu olumlu etkiyi daha da artırabilecektir. Dolayısı ile kronik alkol kullanımının zararlı etkilerini azaltmada C ve E vitaminlerinden yararlanılabilir.Objectives: The effect of long-term alcohol administration on brain arginase enzyme activity, ornithine and urea levels and the changes induced by administration of vitamins C and E were investigated. Study Design: Seventy-five male Wistar Albino rats between 4-6 months of age were used. Five study groups, each consisting of 15 rats were formed. The first group received oral glucose with a calorie value equivalent to alcohol. The second group received alcohol, the third, fourth and fifth groups received vitamins C, E and C+E, respectively, in addition to alcohol, for 20 weeks. All animals were sacrificed by the end of 20 weeks and arginase activity, ornithine and urea levels were measured in brain tissue samples. Results: In the treatment groups, arginase activities, ornithine and urea levels were significantly higher than the alcohol group (group 2). Conclusion: These results suggest that the nitric oxide synthase (NOS) enzyme which isshown to have increased in chronic alcohol intake, may cause a decrease in arginase enzyme activity via depleting the L-arginine pool. Antioxidant replacement therapy may increase the arginase enzyme activity and therefore lead to a decrease in nitric oxide production which has been shown to have some negative effects. On the other hand, simultaneously increased polyamine production may potentiate the beneficial effects of these vitamins.Thus, vitamins C and E may prove to be effective in reducing the deleterious effects of chronic alcohol consumption

Site selection of the Colombian antarctic research station based on fuzzy-topsis algorithm

By 2025 the Republic of Colombia aims to be an advisory member of the Antarctic Treaty System (ATS) and the installation of a scientific station is necessary to upscale the scientific capabilities. The aim of this paper is showing the results of the implementation of a Fuzzy TOPSIS algorithm for site selection of the Colombian Antarctic Scientific Station. A three-phase methodology was AQ1 proposed, and the obtained results allowed to identify the optimum location for the station, considering key success factors and regulatory constraints

Viscous compressible hydrodynamics at planes, spheres and cylinders with finite surface slip

We consider the linearized time-dependent Navier-Stokes equation including finite compressibility and viscosity. We first constitute the Green's function, from which we derive the flow profiles and response functions for a plane, a sphere and a cylinder for arbitrary surface slip length. For high driving frequency the flow pattern is dominated by the diffusion of vorticity and compression, for low frequency compression propagates in the form of sound waves which are exponentially damped at a screening length larger than the sound wave length. The crossover between the diffusive and propagative compression regimes occurs at the fluid's intrinsic frequency $\omega$ ∼ c 2 $\rho_{0}^{}$/$\eta$ , with c the speed of sound, $\rho_{0}^{}$ the fluid density and $\eta$ the viscosity. In the propagative regime the hydrodynamic response function of spheres and cylinders exhibits a high-frequency resonance when the particle size is of the order of the sound wave length. A distinct low-frequency resonance occurs at the boundary between the propagative and diffusive regimes. Those resonant features should be detectable experimentally by tracking the diffusion of particles, as well as by measuring the fluctuation spectrum or the response spectrum of trapped particles. Since the response function depends sensitively on the slip length, in principle the slip length can be deduced from an experimentally measured response function