Parallel tracks as quasi-steady states for the magnetic boundary layers in neutron-star low-mass X-ray binaries

The neutron stars in low-mass X-ray binaries (LMXBs) are usually thought to be weakly magnetized objects accreting matter from their low-mass companions in the form of a disk. Albeit weak as compared to those in young neutron-star systems, the neutron-star magnetospheres in LMXBs can play an important role in determining the correlations between spectral and temporal properties. Parallel tracks appearing in the plane of kilohertz (kHz) quasi-periodic oscillation (QPO) frequency versus X-ray flux can be used as a tool to study the magnetosphere-disk interaction in neutron-star LMXBs. For dynamically important weak fields, the formation of a non-Keplerian magnetic boundary layer at the innermost disk truncated near the surface of the neutron star is highly likely. Such a boundary region may harbor oscillatory modes of frequencies in the kHz range. We generate parallel tracks using the boundary region model of kHz QPOs. We also present the direct application of our model to the reproduction of the observed parallel tracks of individual sources such as 4U 1608--52, 4U 1636--53, and Aql X-1. We reveal how the radial width of the boundary layer must vary in the long-term flux evolution of each source to regenerate the parallel tracks. The run of the radial width looks similar for different sources and can be fitted by a generic model function describing the average steady behavior of the boundary region in the long term. The parallel tracks then correspond to the possible quasi-steady states the source can occupy around the average trend.Comment: 16 pages, 15 figures, accepted for publication in Ap

The Relationship of Burr Height and Blanking Force with Clearance in the Blanking Process of AA5754 Aluminium Alloy

The effect of clearance and sheet thickness in the AA5754 sheet material blanking process on the burr formation and blanking force was examined experimentally. Measurements of the burr height and blanking force were performed in a modular die with six different clearance values (8 %, 10 %, 12 %, 14 %, 16 % and 18 %) by applying the blanking process to the AA5754 sheet metal of 1 mm and 2 mm in thickness. The influence rate of parameters affecting the burr height, the blanking force, and the mathematical relationship between them were identified by using the analysis of variance (ANOVA) and the regression analysis. Thus, it was determined that the burr formation increased with increased clearance and that the blanking force was not affected in the same proportion. In addition, it was found that the sheet thickness and clearance affected the burr formation at rates of 23.24 % and 76.15 %, respectively; on the other hand, the sheet thickness and clearance affected the blanking force at rates of 99.72 % and 0.24 %, respectively

Kompozit Yama İle Tamir Edilmiş İnce Levhalarda Yorulma Çatlak İlerlemesi Üzerinde Yapıştırma Parametrelerinin Etkisi

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada kompozit yama kullanılarak yapıştırıcı ile bir yüzü tamir edilmiş çatlak içeren ince Alüminyum levhaların yorulma davranışı sayısal olarak incelenmiştir. Kompozit yama olarak cam/epoksiden üretilmiş farklı kalınlık ve fiber takviye açılarında yamalar kullanılmış olup, merkezinde yükleme doğrultusuna göre farklı açılarda konumlanmış çatlağa sahip levha ise 2024-T3 Alüminyum alaşımıdır. Yorulma yükü etkisi altında levhada çatlak ucu gerilme şiddet faktörleri, çatlak ilerleme doğrultusu ve levha ömrü sayısal olarak hesaplanmıştır. Çözümde sonlu elemanlar paket programı ANSYS,12.1 kullanılmıştır ve tamir edilmiş levha üç boyutlu olarak modellenmiştir. Gerilme şiddet faktörü; Yer değiştirme Extrapolasyon (YE) metodu ile hesaplanmıştır. Kompozit yama özelliklerinin, çatlak doğrultularının ve yapıştırıcı kalınlıklarının değişiminin çatlak ilerlemesi ve ömür üzerindeki etkisi araştırılmıştır. Elde edilen sonuçlar grafikler halinde sunulmuştur. Anahtar Kelimeler: Kompozit yama, yorulma, çatlak ilerlemesi, sonlu elemanlar metodu, gerilme şiddet faktörü.In this study, fatigue behavior of single-side repaired aluminum plates is investigated, numerically. Composite patch obtained from glass/epoxy laminate which are manufactured for different thickness and fiber orientation angles are used. Aluminum Alloy plates having centered crack whose axes are selected at different angles according to the load direction is 2023-T3. Crack tip stress intensity factor, crack growth direction and plate life are solved under fatigue load condition. In the numerical solution, ANSYS, 12.1 finite element package program is used and the repaired plate is modeled as the three dimensional. Stress intensity factor is calculated by using Displacement Extrapolation (DE) method. Effect of variation of composite patch properties, crack directions and adhesive thickness on crack growth and life is examined. Obtained results are presented in the form of graphs. Keywords: Composite patch, stress intensity factor, finite element analysis, adhesive, pin joint

The determinants of foreign direct investment outflows from the European Union countries.

This paper employs a panel econometric model, and takes the horizontal and vertical FDI approach into account in the same empirical specification to scrutinize the determinants of FDI outflows from the selected EU countries at the industry level. We show that both cost related factors and potential demand are important and they mostly significantly affect FDI outflows from these selected EU countries.Foreign Direct Investment; Environmental Sensitivity; European Union Countries.

KUŞAK VE YOL İNİSİYATİFİNİN KODLARI: BİR MEDYA İÇERİK ANALİZİ

The aim of this study is to examine the reflections of China's One Belt One Road Project in US press from the date when the project was announced to 2019 through content analysis technique. For this purpose, the news in The New York Times which is the oldest and leading newspaper in the field of economy in USA and has audiences who have liberal and at the left of the center political values, has been analyzed. Some of the codes and categories extracted have become prominent for all those years. These are; Maritime Silk Road, Pakistan, China and Kazakhstan codes under OBOR Member Countries category; Facilities Connectivity, Financial Integration, Policy Coordination and Industrial Cooperation codes under OBOR Project Priorities category and Italy and America codes under Other Countries category.Bu çalışmanın amacı, Çin'in Tek Kuşak Tek Yol Projesi'nin projesini, duyurulduğu tarihten 2019 yılına kadar içerik analizi tekniği ile yansımalarını incelemektir. Bu amaç doğrultusunda ABD’de ekonomi alanında en eski ve önde gelen bununla birlikte liberal ve merkez siyasi değerlerin solunda okuyucuları bulunan The New York Times'daki haberler analiz edilmiştir. Tüm yılları kapsayan analizde bazı kategori ve kodların ön plana çıktığı görülmektedir. Bunlar: Deniz İpek Yolu, OBOR Üye Ülkeler kategorisi altında Pakistan, Çin ve Kazakistan kodları, OBOR Proje Öncelikleri kategorisi altında Altyapı Entegrasyonu, Finansal Entegrasyon, Politik İlişkiler ve Sektörel İşbirliği kodları ve Diğer Ülkeler kategorisi altındaki İtalya ve Amerika kodlarıdır

How Precise Is Dental Volumetric Tomography in the Prediction of Bone Density?

Objectives. The aim of this study was to review the bone density assessment techniques and evaluate the macroscopic structure of bone specimens scored by Hounsfield Units (HUs) and decide if they are always in congruence. Methods. The mandible of a formalin-fixed human cadaver was scanned by dental volumetric tomography (DVT) for planning of the specimen positions and fabrication of a surgical guide and a surgical stent was fabricated afterwards. Bone cylinders of 3.5 mm diameter and 5 mm length, were excised from the mandible using the surgical stent with a slow speed trephine drill. After removal of the cylinders two more scans were performed and the images of the first scan were used for the determination of the HU values. The removed bone cylinder was inspected macroscopically as well by micro-CT scan. Results. The highest HU values were recorded in the interforaminal region, especially in the midline (408–742). Posterior regions showed lower HU values, especially the first molar regions (22–61 for the right; 14–66 for the left first molar regions). Conclusion. Within the limitations of this pilot study, it can be concluded that HU values alone could be a misleading diagnostic tool for the determination of bone density

Yapay Sinir Ağları ile Web İçeriklerini Sınıflandırma

Recent developments and widespread usage of the Internet have made business and processes to be completed faster and easily in electronic media. The increasing size of the stored, transferred and processed data brings many problems that affect access to information on the Web. Because of users’ need get to access to the information in electronic environment quickly, correctly and appropriately, different methods of classification and categorization of data are strictly needed. Millions of search engines should be supported with new approaches every day in order for users to get access to relevant information quickly. In this study, Multilayered Perceptrons (MLP) artificial neural network model is used to classify the web sites according to the specified subjects. A software is developed to select the feature vector, to train the neural network and finally to categorize the web sites correctly. It is considered that this intelligent approach will provide more accurate and secure platform to the Internet users for classifying web contents precisely