Homology and symmetry breaking in Rayleigh-Benard convection: Experiments and simulations

Algebraic topology (homology) is used to analyze the weakly turbulent state of spiral defect chaos in both laboratory experiments and numerical simulations of Rayleigh-Benard convection.The analysis reveals topological asymmetries that arise when non-Boussinesq effects are present.Comment: 21 pages with 6 figure

KONFEKSİYON SEKTÖRÜNDE MÜŞTERİ SADAKATİNE ETKİ EDEN FAKTÖRLER

Bu çalışma, konfeksiyon sektöründe müşteri sadakatini etkileyen faktörleri, kişisel bazda demografik ve davranışsal farklılıklarla ilgili bu faktörler üzerinde müşteri görüşlerini ve sektörle ilgili müşteri sadakati algılamasını ortaya koymayı amaçlamaktadır. Bu amaçla, farklı yaş, gelir, meslek, medeni durum, eğitim düzeyi ve cinsiyete mensup 400 kişiyle yüz yüze anket yapılmıştır. Anket sonuçları spearman korelasyon, kruskal-wallis ve mann whitney-u testleri ile analiz edilmiştir.ABSTRACT This study aims to study the parameters effecting customer loyalty in ready-made clothes sector, to determine customer?s view in these parameters regarding demographics and behaviroal differences in individual base, and to identify the factors effecting customer?s loyalty in the sector. For this purpose, a face to face questionnaire including 400 test subject and different age, income, occupation, marital status,education level and sex grups is being applied. The questionnaire results are being analyzed by spearman coorelation test, kruskal-wallis test and mann whitney-u test.Keywords: Customers loyalty, demographical and bahoviorial variable

Metastable quasicrystal-induced nucleation in a bulk glass-forming liquid

This study presents a unique Mg-based alloy composition in the Mg-Zn-Yb system which exhibits bulk metallic glass, metastable icosahedral quasicrystals (iQCs), and crystalline approximant phases in the as-cast condition. Microscopy revealed a smooth gradual transition from glass to QC. We also report the complete melting of a metastable eutectic phase mixture (including a QC phase), generated via suppression of the metastable-to-stable phase transition at high heating rates using fast differential scanning calorimetry (FDSC). The melting temperature and enthalpy of fusion of this phase mixture could be measured directly, which unambiguously proves its metastability in any temperature range. The kinetic pathway from liquid state to stable solid state (an approximant phase) minimizes the free-energy barrier for nucleation through an intermediate state (metastable QC phase) because of its low solid- liquid interfacial energy. At high undercooling of the liquid, where diffusion is limited, another approximant phase with near-liquid composition forms just above the glass-transition temperature. These experimental results shed light on the competition between metastable and stable crystals, and on glass formation via system frustration associated with the presence of several free-energy minima

Thermodynamic Aspects of Homogeneous Nucleation Enhanced by Icosahedral Short Range Order in Liquid Fcc-Type Alloys

We have recently shown that minute solute element additions to liquid metallic alloys can strongly influence the nucleation of the fcc phase and act as a grain refinement method. Electron back-scattered diffraction observations revealed a concomitant increase in the percentage of nearest neighbor (nn) grains that are in a twin relationship. Furthermore, multiple-twinned (MT) nn grain configurations with a fivefold symmetry around a common direction have been identified, an occurrence that can be explained when the symmetry of the icosahedron is accounted for. It was then conjectured that a new nucleation mechanism occurs in two steps: first, the formation of small icosahedral quasicrystals in the melt, followed by heteroepitaxy of the fcc phase on facets of these quasicrystals. In the present contribution, based on thermodynamics arguments, it is proposed that the first step occurs by spinodal decomposition of the liquid, in a manner similar to Guinier-Preston zones formation in solid state precipitation, while the second step is a transformation of these quasicrystal precursors into MT-fcc nanocrystals once the driving force for this transformation is sufficient to overcome the fcc-liquid interfacial energy and the elastic strains associated with MT-fcc nanoparticles. This explanation sets up guidelines for finding solute elements and composition ranges that favor this grain refinement mechanism

Quasicrystal-Enhanced Nucleation During the Solidification of fcc Metallic Alloys: A Tentative Thermodynamic Approach

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The analysis of relationship between intention to leave, job satisfaction, organizational commitment, leadership and job stress: A hospital exampleİşten ayrılma niyeti, iş tatmini, örgütsel bağlılık, liderlik ve iş stresi arasındaki ilişkilerin analizi: Bir hastane örneği

Technologic improvements, rising competition conditions, importance of ‘knowledge’, diffusion of continuous innovation principles are effected human resources politics of organizations. The aims of this study are to analyze the relationship between intention to leave, transformational leadership, job satisfaction, job stress and organizational commitment; to determine effects of transformational leaderships, job satisfaction and job stress on intention to leave and effects of transformational leadership, job stress and organizational commitment on job satisfaction. In this cross-sectional study, survey method was used for measurement technique. A survey was conducted among 208 permanent  hospital staff who worked in public hospital in Kahramanmaraş. In this study, personal information form, intention to leave scale, transformational leadership scale, job satisfaction scale, job stress scale and organizational commitment scale were used. Correlation and regression analyze were calculated. In this study, it was determined that intention to leave was at low level, on the other hand transformational leadership and job satisfaction were at moderate level and job stress and organizational commitment were at partly above average. According to Pearson Corelation Analyze, (a) intention to leave is negatively correlated with  job satisfaction and positively correlated with job stress; (b) there was negative relationship between job satisfaction and job stress; positive relationship between transformational leadership and organizational commitment. According to Multiple Linear Regression Analyze, it was determined that transformational leadership, job satisfaction and job stress explained 18% of total variance in intention to leave. Job satisfaction provided negatively and job stress provided positively contribution to model. According to other Multiple Linear Regression Analyze, it was shown that transformational leadership, job stress and organizational commitment explained 23% of total variance in job satisfaction. Organizational commitment provided positively and job stress provided negatively contribution to model. ÖzetTeknolojik ilerlemeler, artan rekabet koşulları,  sürekli yenilik prensiplerinin yaygınlaşması, örgütlerde insan kaynağı ile ilgili politikaları etkilemeye başlamıştır. Çalışmanın amacı; işten ayrılma niyeti, dönüşümcü liderlik, iş tatmini, iş stresi ve örgütsel bağlılık değişkenleri arasındaki ilişkileri analiz etmek; dönüşümcü liderlik, iş tatmini ve iş stresinin işten ayrılma niyeti üzerine etkisini; dönüşümcü liderlik, iş stresi ve örgütsel bağlılığın iş tatmini üzerine etkisini incelemektir. Kesitsel bir saha araştırması olan bu çalışmada ölçüm tekniği olarak anket yöntemi kullanılmıştır. Araştırma Kahramanmaraş’ta bulunan bir kamu hastanesinde görev yapan 208 kadrolu hastane çalışanı ile yapılmıştır. Çalışmada katılımcıların kişisel özelliklerini ortaya koyan soruların yanında işten ayrılma niyeti ölçeği, dönüşümcü liderlik ölçeği, iş tatmini ölçeği, iş stresi ölçeği ve örgütsel bağlılık ölçeği kullanılmıştır. Çalışmada korelasyon ve regresyon analizleri yapılmıştır. Çalışmada, işten ayrılma niyetinin düşük düzeyde çıktığı, dönüşümcü liderlik ve iş tatminin orta düzeyde, iş stresi ve örgütsel bağlılığın kısmen de olsa ortalamanın üzerinde çıktığı belirlenmiştir. Yapılan Pearson Korelasyon Analizine göre (a) işten ayrılma niyeti ile iş tatmini negatif, iş stresi pozitif yönde ilişki gösterirken; (b) iş tatmini ile iş stresi arasında negatif, dönüşümcü liderlik ve örgütsel bağlılık arasında pozitif ilişki gözlenmiştir. Yapılan Çoklu Doğrusal Regresyon Analizine göre dönüşümcü liderlik, iş tatmini ve iş stresinin işten ayrılma niyetindeki toplam varyansın %18’ini açıkladığı belirlenmiştir. Modele iş tatmini negatif yönde, iş stresi ise pozitif yönde anlamlı katkı sağlamaktadırlar. Diğer Çoklu Doğrusal Regresyon Analizine göre ise dönüşümcü liderlik, iş stresi ve örgütsel bağlılığın iş tatminindeki toplam varyansın %23’ünü açıkladığı saptanmıştır. Modele örgütsel bağlılık pozitif, iş stresi ise negatif yönde anlamlı katkı sağlamaktadırlar.

Factors Affecting the Adoption of Mobile Shopping Applications in the Context of Extended Technology Acceptance Model

DergiPark: 617630trakyasobedMobile shopping applications offered in the context of mobile shopping activities are used intensively by consumers. In this respect, determining the factors that affect consumers’ decision to use these applications will enable businesses to develop these applications in line with the needs of consumers’. Accordingly, in this study, it is aimed to examine the factors affecting the adoption of mobile shopping applications by consumers. Within the scope of the study, an extended Technology Acceptance Model (TAM) is obtained by adding perceived enjoyment, innovativeness, trust and satisfaction variables to the Technology Acceptance Model and the resulting model is evaluated. Data were collected by using convenience sampling method and conducting face to face surveys method. The data obtained were analyzed by using exploratory factor analysis, reliability analysis, confirmatory factor analysis and structural equation modeling. As a result of the research, it was found that satisfaction variable is positively affected by perceived usefulness, innovativeness and trust variables; in addition, perceived usefulness, satisfaction, innovativeness and trust variables positively influences the behavioral intention variable.Mobil pazarlama faaliyetleri kapsamında sunulan mobil alışveriş uygulamaları, tüketiciler tarafından yoğun olarak kullanılmaktadır. Bu bakımdan, tüketicilerin mobil alışveriş uygulamalarını kullanma kararı vermelerini etkileyen faktörlerin belirlenmesi, işletmelerin söz konusu uygulamaları tüketicilerin ihtiyaçlarına uygun olarak geliştirebilmelerine imkan sağlayacaktır. Bu doğrultuda, bu çalışmada, tüketicilerin mobil alışveriş uygulamalarını benimsemelerini etkileyen faktörlerin incelenmesi amaçlanmaktadır. Çalışma kapsamında, Teknoloji Kabul Modeli (TKM)’ne algılanan eğlence, yenilikçilik, güven ve tatmin değişkenleri eklenerek genişletilmiş bir Teknoloji Kabul Modeli elde edilmekte ve oluşan model değerlendirilmektedir. Çalışmada, kolayda örnekleme ve yüz yüze anket yöntemleri ile veri toplanmıştır. Elde edilen veriler; keşfedici faktör analizi, güvenilirlik analizi, doğrulayıcı faktör analizi ve yapısal eşitlik modellemesi kullanılarak analiz edilmiştir. Araştırma sonucunda, tatmin değişkeninin algılanan fayda, yenilikçilik ve güven değişkenleri tarafından pozitif şekilde etkilendiği; ayrıca algılanan fayda, tatmin, yenilikçilik ve güven değişkenlerinin davranışsal niyet değişkenini pozitif olarak etkilediği tespit edilmiştir

Probability of twin boundary formation associated with the nucleation of equiaxed grains on icosahedral quasicrystal templates

Recently, we have shown that minute Cr additions (typically 0.1 wt%) to Al-Zn alloys solidified in a uniform temperature field lead to the formation of fine equiaxed fcc Al grains [1]. Furthermore, these grains exhibit an unexpectedly large number of twin, or near-twin, relationships with their nearest neighbors and some of them even show a 5-fold symmetry multi-twin relationship with a common direction. Similar observations have been made for yellow gold alloys (Au-12.5wt%Cu-12.5wt%Ag) inoculated with very small amounts of Ir (5-200 ppm) [2]. These results become fully consistent when one considers that the primary fcc phase forms on facets of icosahedral quasicrystals (iQC's), either by heteroepitaxy solidification or by peritectic transformation, with the following relationship: (fcc) parallel to 3-fold symmetry iQC axes, (fcc) perpendicular to 2-fold symmetry iQC axes. The present study contributes to a better understanding of the frequency of twin boundary formation by the nucleation of fcc phase from an iQC template. A simple stereological model for the formation of equiaxed grains on such iQC templates has been derived. It is based on a 3D Voronoi tessellation of randomly distributed and oriented iQC template centers. Each iQC nucleation template site is the origin of 20 fcc grains with the heteroepitaxy relationships mentioned above on the 20 facets of the iQC. Therefore, the neighboring grains having a common iQC nucleation site contributes to the twin boundary frequency, while those coming from different iQC sites have random grain boundary orientations. The twin boundary frequency of the grains nucleated from iQC templates seen in 2D metallographic sections is compared with that measured in EBSD reconstructed grain structures

The role of work life balance in the effect of boundaryless career and protean career attitudes on subjective career success

In conjunction with the rise of new career approaches such as boundaryless career and protean career in today's working life, the subjective aspect of career success has begun to be emphasized in boundaryless career and protean career approaches, unlike the traditional career approach that emphasizes the objective aspect of career success. In this direction, the effect of boundaryless career and protean career attitudes on subjective career success was examined in this study. In addition, whether the work-life balance has a moderator role on this effect has been examined. Research data were collected from 400 white-collar employees who work in private sector enterprises in Istanbul and have at least five years of work experience. To test the hypotheses; hierarchical regression analysis was performed using the SPSS program. As a result of the study, the moderator role of work-life balance on the effect of boundaryless career attitude and protean career attitude on subjective career success has been determined

The analysis of the effects of social support, job alienation and job stress on labour performanceSosyal destek, işe yabancılaşma ve iş stresinin işgören performansı üzerindeki etkisinin incelenmesi

The efficiency, quality and productivity of health services depends on ‘labour’ Labour’s job performance can be affected by personal characteristics, work condition, attitudes of workers and managers. The first aim of this study is, to determine whether there is a relationship between labour performance, job alienation, job stress, social support (friend/parents/partner) and various personal characteristics such as gender, marital status, age, education status, lenght of working, income; the second aim is to determine whether job alienation, job stress, social support and various personal characteristices are affected labour’s performance. This study is a cross-sectional study. The study population was 583 voluntary hospital staffs at Adıyaman Public Hospital Association’s hospital which have  inpatient services. In this study, we used personal information form, Labour Performance Scale, Multi dimension social support scale, Job stress scale, Job alienation scale. Descriptive statistics, t-tests in independence group, Pearson Correlation analyse and Multiple Linear Regression Analyse have used for data analyzing. According to results of study, there was a significant differences between gender and labour performance; there was a negative significant relationship between labour performance, job alienation and friend support; there was a positive significant relationship between labour performance, partner support, parent support and length of working in institution. On the other hand job alienation affected labour performance negatively; partner support and parent support affected labour performance positively. ÖzetSağlık hizmetlerinin etkililiği, verimliliği ve kalitelisi “insan gücü”ne bağlıdır. İnsan gücünün iş performansı da kişisel özelliklerden, çalışma koşullarından, yöneticilerin ve çalışanların tutum ve davranışlardan etkilenebilmektedir. Yapılan bu çalışmanın birinci amacı, işgören performansı ile işe yabancılaşma, iş stresi, özel insan desteği, arkadaş desteği, aile desteği ve bazı kişisel özellikler arasında ilişki olup olmadığını belirlemek; ikinci amacı ise işe yabancılaşma, iş stresi, özel insan desteği, arkadaş desteği, aile desteği ve bazı kişisel özelliklerin işgören performansını etkileyip etkilemediğini belirlemektir. Çalışma kesitsel tipte bir alan çalışmasıdır. Adıyaman Kamu Hastaneleri Birliği’ne bağlı hastanelerde görev yapan ve çalışmaya gönüllü olarak katılan 583 kişi araştırma grubunu oluşturmaktadır. Araştırmada kişisel bilgi formu, işgören performans ölçeği, çok boyutlu sosyal destek ölçeği, işe yabancılaşma ölçeği ve iş stres ölçeği kullanılmıştır. Çalışmada, tanımlayıcı istatistikler, Bağımsız grup t testi, Pearson Korelasyon Analizi ve Çoklu Doğrusal Regresyon Analizi kullanılmıştır. Araştırma sonuçlarına göre; cinsiyet ile işgören performansı arasında anlamlı bir fark olduğu, işgören performansı ile işe yabancılaşma ve arkadaş desteği arasında negatif anlamlı ilişki olduğu; işgören performansı ile özel insan, aile desteği ve kurumda çalışma süresi arasında pozitif anlamlı ilişki olduğu belirlenmiştir. Ayrıca işgören performansını işe yabancılaşmanın negatif yönde; özel insan ve aile desteğinin ise pozitif yönde etkilediği saptanmıştır