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Optimization Aging Parameters of Mg Silica Aerogel Using Box-Behnken Approach
No full textThe main objective of the present study was to investigate the application of Box- Behnken design which is a type of optimization design of response surface methodology (RSM) to predict and optimize some aging condition of magnesium silica aerogel (MSA) for improving surface properties such as surface area, pore volume, and pore size. Brunauer- Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) techniques, tap density method and helium pycnometer were used to characterize aerogels. The operating conditions were optimized as a function of the molar ratio of Mg:Si (0.35, 0.50, and 0.65), aging time (24 h, 60 h, and 96 h) and aging temperature (50 degrees C, 70 degrees C, and 90 degrees C). Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for all three properties. Optimized aging factors for synthesis MSA with high BET surface area, high BJH pore volume and average Bill pore size were found to be 0.5 Mg:Si molar ratio, 79.62 degrees C, and 61.51 h, respectively. Under these conditions, magnesium silica aerogels have great properties: 734 m(2).g(-1) BET surface area, 0.41 cm(3).g(-1) BJH pore volume and 4.91 nm BJH pore size, 0.12 g.cm(-3) density and 95 % porosity. A Box-Behnken Method is a useful tool for the optimization of parameters of nanoporous magnesium silica aerogel production
Partial wave analysis of psi(3686) -> K+ K- eta
No full textUsing a sample of (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector, we perform the first partial wave analysis of psi(3686) -> K+K- eta. In addition to the well established states, phi(1020), phi(1680), and K-3(*)(1780), contributions from X(1750), rho(2150), rho(3)(2250), and K-2* (1980) are also observed. The X(1750) state is determined to be a 1(--) resonance. The simultaneous observation of the phi(1680) and X(1750) indicates that the X(1750), with previous observations in photoproduction, is distinct from the phi(1680). The masses, widths, branching fractions of psi(3686) -> K+K- eta, and the intermediate resonances are also measured
A Novel Cancellation Protection Service in Online Reservation System
No full textWeb-based systems are frequently used by the customers as well as travel agencies for online flight reservation and booking. In general, customers prefer to plan their trips as early as possible to take advantage of affordable booking opportunities as the price of flight tickets increases over time. However, changing the flight plan may lead to high penalties for the customers which may turn their profits into a loss in promotion tickets. Motivated by this, in this research work, quality of experience (QoE)-based approach is proposed to support user satisfaction in the aforementioned scenario. A cancellation protection service (CPS) is developed to provide assurance for early booking while establishing a balance between user satisfaction and the profit of the service provider (SP). Furthermore, three different CPS functions, namely Fixed CPS, QoE-based CPS, and Flexible CPS are modeled. In our proposed QoE-based CPS method, Analytic Hierarchy Process (AHP) is adopted to assign appropriate weights to different criteria. The proposed CPS approach can enable the customers to have a refund under certain terms if they decide to cancel their tickets. The proposed method is analyzed with real-world data from an airline reservation system which shows the customer transactions in a 6 months-period. The results indicate the effects of the fixed CPS, flexible CPS, and QoE-based CPS methods in the SP's profit points of view. Last but not least, the proposed QoE-based CPS method provides a balance between both the SP profit and user satisfaction
Displacement Analysis of a Piezoelectric Based Multi-layered Micropump Diaphragm
No full textThis paper presents the diaphragm displacement analysis of multi-layered circular piezoelectric actuator (MCPA) using analytical, numerical and experimental methods. The piezoelectric zirconate titanate (PZT) actuator model examined in this study consists of a structure with 3 different diameters and 7 layers. The multi-layered and multi-covered actuator model was composed of three main layers in different radii and thickness with silicon, brass and the PZT and four additional layers with silver and bonding. When creating an analytical model, the effects of all layers were taken into account on the static deflection performance of the actuator. The classical laminated plate theory based on Kirchhoff thin plate theory was used in the analytic modelling studies of the actuator. The mathematical model, which is the solution of the static displacement equation of the non-homogenous for the MCPA of the micropump, depends on the applied voltage and pressure load together with the material and physical properties. The electric-solid coupling of the piezoelectric actuator and the silicon diaphragm layer under the effect of applied voltage load, and the silicon-fluid coupling under the uniform fluid pressure were simulated by numerical modelling with finite elements. In addition, the maximum displacements of the MCPA with silicon exposed to uniform flow pressure and electric voltage load were measured at different frequencies experimentally. It was observed that the results obtained from the analytical model, finite element analysis and experimental studies were sufficiently compatible with each other. Using the verified analytical model, the effects of layer thicknesses, layer diameters and adhesive layer on actuator static displacement performance are discussed
Measurements of Absolute Branching Fractions of Fourteen Exclusive Hadronic D Decays to eta
No full textUsing 2.93 fb(-1) of e(+)e(-) collision data taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we report the first measurements of the absolute branching fractions of 14 hadronic D0(+) decays to exclusive final states with an e.g., D-0 -> K-pi(+)eta, K-S(0)pi(0)eta, K+K-eta, (KSKS0)-K-0 eta, K-pi(+)pi(0)eta, K-S(0)pi(+)pi(-)eta, K-S(0)pi(0)pi(0)eta, and pi(+)pi(-)pi(0)eta; D+ -> K-S(0)pi(+)eta, (KSK+)-K-0 eta, K-pi(+)pi(+)eta, K-S(0)pi(+)pi(0)eta, pi(+)pi(+)pi(-)eta, and pi(+)pi(0)pi(0)eta. Among these decays, the D-0 -> K-pi(+)eta and D+ -> K-S(0)pi(+)eta decays have the largest branching fractions, which are B(D-0 -> K-pi(+)eta) = (1.853 +/- 0.025(stat) +/- 0.031(syst))% and B(D+ -> K-S(0)pi(+)eta) = (1.309 +/- 0.037(star)+/- 0.031(syst))%, respectively. The charge-parity asymmetries for the six decays with highest event yields are determined, and no statistically significant charge-parity violation is found
FTSH: a framework for transition from square image processing to hexagonal image processing
No full textThis paper proposes a novel framework for transition from the ordinary square-pixel-based image processing (SIP) domain to the hexagonal-pixel-based (HIP) domain (FTSH). The conventional image acquisition and processing are based on square pixels. However, HIP can provide promising advantages in many respects, such as degrading the curse of data size and accordingly reducing the processing time. HIP did not achieve satisfactory attraction because all software, including libraries, methods and structures, as well as mathematical operations and methodologies developed to date, are aimed at SIP. In this study, we propose a framework containing the corresponding HIP equivalents of some basic SIP methods and operations. In addition, the results of these basic operations in both SIP and HIP areas are presented comparatively. Since there is no common and standardized framework or library for HIP, this study can be used by other researchers who wish to enter the HIP. Simulation results support the competitive performance of HIP, and this promising performance can be carried far beyond when properly handled and focused
Sağlık Çalışanlarında Teknostres : Bir Özel Hastane Örneği
Get PDFStres, günümüzde hemen her sektörde olduğu gibi sağlık sektöründe de karşı karşıya kalınan bir
sorundur. Bilgi ve iletişim teknolojilerindeki dönüşüm ile, sağlık çalışanları da örgütsel, çevresel ve
kişisel nedenlerle stres yaratan unsurlarından etkilenmektedir. Bu stres kaynaklarından bir tanesi
de teknolojiden kaynaklanan teknostres kavramıdır. Teknostres, bireylerin yeni teknolojilere
adaptasyon sürecinde yaşadıkları stres olarak tanımlanabilir. Bu araştırmanın amacı; özel bir
hastanede görev yapan 159 sağlık çalışanının teknostres düzeylerinin belirlenmesidir. Bu kapsamda
sağlık çalışanlarının sosyo-demografik özelliklerinin teknostres ve teknostres’in alt boyutları olan
tekno aşırı-yüklenme, tekno-işgal, tekno-karmaşıklık, tekno-güvensizlik ve tekno-belirsizlik
üzerindeki etkisi incelenmiştir. Araştırmada; erkek sağlık çalışanlarının kadınlara göre daha fazla
teknostrese maruz kaldıkları, kurumda çalışma süreleri ile meslekte çalışma sürelerinin teknostres
düzeylerini etkilemediği ve genç çalışanların ise yaşlı çalışanlara kıyasla daha fazla teknostres
yaşadıkları tespit edilmiştir. Sonuçların hastane yöneticileri, insan kaynakları birimleri ve bilgi ve
iletişim teknolojileri uzmanlarına uygulama süreçlerinde yardımcı olacağı düşünülmektedir.Stress is a problem faced in the health sector as in almost every sector today. With the transformation in information and communication technologies, healthcare professionals are also affected by factors that create stress for organizational, environmental and personal reasons. One of these stress sources is the concept of technostress caused by technology. Technostress can be defined as the stress that individuals experience during the adaptation process to new technologies. The purpose of this research is the determination of technostress levels of 159 healthcare workers working in a private hospital. In this context, the effects of socio-demographic characteristics of healthcare workers on techno-overload, techno-occupation, techno-complexity, techno-insecurity and techno-uncertainty, which are sub-dimensions of technostress, have been examined. In the study; it has been determined that male healthcare workers are exposed to techno-stress more than women, their working hours and working hours in the institution do not affect their techno-stress levels, and younger employees experience more techno-stress than older employees. The results are thought to help hospital managers, human resources units and information and communication technology specialists in their implementation processes
Discussing Future Role of Social Media on Construction and Project Management through Evaluation of Students Attitudes
No full textIt is an undeniable fact that information technologies have changed the classical business habits and brought different effects on various businesses in the last decade. Despite the slow progress of technological adaptation in construction industry, it seems that interest of youngsters, who will continue their professions in construction management field in the future; in using communication tools such as internet and social media will accelerate this period. Therefore, it is not difficult to predict that the construction sector entrepreneurs, who use information networks and social media platforms efficiently, will be able to reach their customers and targets more easily in the future and the companies which cannot integrate will be inevitably unsuccessful. The aim of this study is to discuss the role of social media on the construction and project management field through evaluating students’ attitudes. With the results obtained in this study, a perspective on the attitudes of the new generation stakeholders who will work in the sector was obtained. By looking at these attitudes, innovative steps can be taken for the sector. Especially in the sector, which has a traditional perspective, the way of doing business can evolve in different ways and the integration of the new generation into the sector can be achieve
Changing Balancing Behaviors in Turkish Foreign Policy During AKP Period (2002-2019)
No full textStates' foreign policies and their strategies to attain them are not fixed. When international and domestic dynamics change, policies and strategies may change. Although systemic factors play role in this process, government and regime changes come into prominence as principal factors. During the 17-year period of AKP which came to power in 2002, there have been significant changes in the goals and the means of foreign policy. Balancing and balancing behaviors are among important foreign policy implementing means of middle powers like Turkey. In this article, as change process of foreign policy in Turkey is examined, changing balancing behaviors and strategies are emphasized. In this context, states' balancing behaviors are discussed with a literature review in the first part. In the second part, the question of how a new government restructures a state's foreign policy is analyzed. In the final part, Turkey's changing balancing behaviors with regard to the foreign policy restructuring are studied by focusing on the period of 2002-2019
DEĞİŞİM YÖNETİMİ İLE ÜCRET VE ÖDÜLLENDİRME SİSTEMİ ARASINDAKİ İLİŞKİ: SİVİL HAVACILIK SEKTÖRÜNDE FAALİYET GÖSTEREN YER HİZMETLERİ İŞLETMELERİNDE BİR ARAŞTIRMA
No full textBu çalışmanın amacı, sivil havacılık sektöründe faaliyet gösteren yer hizmetleri
işletmelerinde değişim yönetimi süreci ile ücret ve ödüllendirme sistemi arasındaki ilişkiyi ve ücret
ve ödüllendirme sisteminin değişim yönetimi süreçlerine etkisini tespit etmektir. Değişim süreçleri
yönetilmesi gereken bir süreçtir ve çok farklı unsurlar tarafından olumlu ya da olumsuz olarak
etkilenmektedir. Bu unsurlardan bir tanesinin ücret ve ödüllendirme sistemi olduğu
düşünülmektedir. Bu nedenle araştırmada, bağımlı değişken olarak değişim yönetimi süreçleri ve
bağımsız değişken olarak ücret ve ödüllendirme sistemi belirlenmiştir. Çalışmamızda, sürekli
değişim ve gelişim içerisinde olan sivil havacılık sektörü ele alınmıştır. Bu bağlamda, Türkiye’deki
Sivil Havacılık Genel Müdürlüğü’nün, Havaalanları Yer Hizmetleri Yönetmeliği (SHY-22)
hükümlerine uygun olarak yetkilendirdiği ve ruhsatlandırdığı 37 adet yer hizmetleri işletmesinde
çalışan orta ve üst düzey yöneticileri araştırma kapsamına alınmıştır. Söz konusu 37 işletmenin 16
adedinden geri dönüş alınabilmiş ve araştırmaya, 16 işletmenin 171 üst ve orta kademe
yöneticilerden alınan cevaplar dâhil edilmiştir. Araştırmanın sonucunda ise; değişim yönetimi ile
ücret ve ödüllendirme sistemi arasında güçlü bir ilişki olduğu; ücret ve ödüllendirme sisteminin,
değişim yönetimi süreçlerine anlamlı bir etkisinin olduğu tespit edilmiştir