Finite element or Galerkin type semidiscrete schemes

A finite element of Galerkin type semidiscrete method is proposed for numerical solution of a linear hyperbolic partial differential equation. The question of stability is reduced to the stability of a system of ordinary differential equations for which Dahlquist theory applied. Results of separating the part of numerical solution which causes the spurious oscillation near shock-like response of semidiscrete scheme to a step function initial condition are presented. In general all methods produce such oscillatory overshoots on either side of shocks. This overshoot pathology, which displays a behavior similar to Gibb's phenomena of Fourier series, is explained on the basis of dispersion of separated Fourier components which relies on linearized theory to be satisfactory. Expository results represented

A System Dynamics Approach for Technology Improvement Policy Analysis: The Case for Turkey

Technology has been one of the most important factors of the economic and social growth and globally scaled competitiveness, although not respected as a separate factor by traditional economists until recently. It is now widely accepted that technology improvement plays a very major role on national growth. Technology has a number of interactive and conflicting variables and parameters, which are not allowing an analysis with quantitative tools only. Complex dynamic analysis seems to be a proper tool to handle this sophistication. A system dynamics model constructed for policy analysis in Turkey with respect to technology improvement and comparison of various technology improvement policies. Under the scope of this paper; the elements effecting technology improvement are identified and analyzed by qualitative/quantitative methods, the key relations among these elements are identified, the influence model and the system model are drawn and some scenario analysis are performed for the comparison of possible technology improvement policies.System Dynamics, Economic Growth, Technological Capability, Technology Improvement, Technology Policies

New Phases of Germanene

Germanene, a graphene like single layer structure of Ge, has been shown to be stable and recently grown on Pt and Au substrates. We show that a Ge adatom adsorbed to germanene pushes down the host Ge atom underneath and forms a dumbbell structure. This exothermic process occurs spontaneously. The attractive dumbbell-dumbbell interaction favors high coverage of dumbbells. This letter heralds stable new phases of germanene, which are constructed from periodically repeating coverage of dumbbell structures and display diversity of electronic and magnetic properties.Comment: Published in JPCL http://pubs.acs.org/doi/abs/10.1021/jz500977

The celebrated Ottoman painter:Şeker Ahmet Paşa:Bir doğa ressamı

Taha Toros Arşivi, Dosya No: 480-Şeker Ahmet Paşaİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Türk musikisini ayağa kaldıran adam

Taha Toros Arşivi, Dosya Adı: Müzisyenlerİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

The never-ending Quest for the Elites:New Approaches to the Study of Cemeteries and Social Organization

The Early Bronze Age (EBA) in Anatolia (3100/3000-2000 BCE.)[1] is considered a period of great transition when urban societies developed and when extramural cemeteries started to emerge. Western Anatolian sites like Troy and Külloba have yielded monumental walls, or architecturally distinct quarters. However none of these sites have yielded extramural cemeteries. Extramural cemeteries of the EBA are only associated with small-scale sites such as Karataş (southwest Anatolia) and Demircihöyük (northwest Anatolia) which have been referred to as “chiefdoms”. Labeling these non-urban sites as chiefdoms inevitably led to the quest of finding the chief in these cemeteries. As a result, certain burial types, and burials with grave goods of higher quantity and better quality have been used as evidence for wealth and status, hence the presence of ruling elites. In this paper I suggest different ways of making use of the archaeological data from cemeteries to understand the social organization without falling into the same social evolutionary pitfalls.[1] In this presentation when I refer to Anatolia, I will be referring to the central and western parts of the peninsula, not to eastern Anatolia which in the Early Bronze Age is culturally and economically closer to Northern Mesopotamia

Structural lubricity under ambient conditions.

Despite its fundamental importance, physical mechanisms that govern friction are poorly understood. While a state of ultra-low friction, termed structural lubricity, is expected for any clean, atomically flat interface consisting of two different materials with incommensurate structures, some associated predictions could only be quantitatively confirmed under ultra-high vacuum (UHV) conditions so far. Here, we report structurally lubric sliding under ambient conditions at mesoscopic (∼4,000-130,000 nm(2)) interfaces formed by gold islands on graphite. Ab initio calculations reveal that the gold-graphite interface is expected to remain largely free from contaminant molecules, leading to structurally lubric sliding. The experiments reported here demonstrate the potential for practical lubrication schemes for micro- and nano-electromechanical systems, which would mainly rely on an atomic-scale structural mismatch between the slider and substrate components, via the utilization of material systems featuring clean, atomically flat interfaces under ambient conditions

Short-time Suzuki reactions of arly halides catalyzed by palladium-loaded NaY zeolite under aerobic conditions

Thesis (Master)--İzmir Institute of Technology, Chemistry, İzmir, 2006Includes bibliographical references (leaves: 71-81)Text in English; Abstract: Turkish and Englishxii, 131 leavesThe palladium-catalyzed Suzuki cross-coupling reaction is a powerful methods used in the synthesis of biaryl compounds.In this study, the Suzuki reactions of aryl bromides and chlorides with arylboronic acid were carried out over a Pd(NH3)42+-loaded NaY type zeolite. On the basis of our results, the Pd(NH3)42+-loaded NaY zeolite was found to be highly active for the Suzuki reactions of wide range of aryl bromides and electron poor aryl chlorides at low Pd concentrations (0.1-0.001mol %Pd), in air and at short times (5-45 minutes). The presence of relatively large amount of zeolite (1-4 g) was crucial for the success of the reactions with aryl chlorides. It was determined that there was a synergistic effect of the water- zeolite pair on the reaction rate.It was found that reactions were catalyzed dissolved palladium species. However,the palladium was largely recovered and only traces of palladium remained within the solution at the end of reaction (<0.8 ppm)