bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Knowledge and Perspective toward Dental Radiography among Dental Practitioners of Sindh Province Pakistan
Authors: Samejo Imran , Kumar Bharat , Musharraf Hira , Ahmed Jamshed , Memon Lubna , Bhatti Rukhsana
Published: July 2021

BACKGROUND Radiography is one of the important tools that dentists use to diagnose dental diseases in the oral cavity. Exposure of radiation is associated with hazardous effects on oral tissues. Doctors must have enough knowledge regarding the consequences of radiation exposure. The purpose of this study was to assess knowledge and perspective of dental practitioners towards dental radiography. METHODS This descriptive cross-sectional study was conducted in the month of November and December 2020, among dental practitioners who worked in the state of Sindh. All the participants were given the questionnaire survey link through social media including Facebook, WhatsApp, and Email and 24 closed ended questions were asked regarding dental radiography. A total of 247 dental practitioners responded and participated in the study. RESULTS Our study showed that only 3.60 % of general practitioners (GP) reported that they did not have radiographic unit. The participant’s knowledge regarding the technical details of equipment was limited. Majority of dental practitioners preferred long cone, more than 50 % specialist recommended F-speed of film. 34.53 % of general dentists and 37.73 % of specialists responded that they have digital radiography. More than 50 % of dental practitioners didn’t have license for x-ray equipment. Majority of them utilized paralleling technique for periapical x-ray. 63.40 % of GP and only 11.32 % of specialist held x-ray film with the fingers when taking x-ray. 30.41 % of GP and 24.52 % of specialist took the radiographs themselves, whereas 35.05 % had x-ray done by technician. Only 1.54 % of GP and 3.775 % of specialists gave the radiographic packing materials to specialized company in order to discard the waste materials. Only 6.70 % of GP and 11.32 % of specialists had the walls of the x-ray room covered with lead. CONCLUSIONS This study concluded that dental practitioners have little knowledge regarding dental radiography. KEY WORDS Knowledge, Perspective, Dental Practitioners, Dental Radiology
Histopathological Spectrum of Malignant Lesions in a Tertiary Care Hospital in Vizianagaram, India
Authors: Venkatiah Narayan Kanchana Priyadarshini , Polavarapu Srilakshmi
Published: July 2021

BACKGROUND Cancer is the second most common cause of deaths after cardiovascular disorders in the world. In India lakhs of people die due to cancer every year. Many of them do not have access to health care system and those who have access to health care system often reach for help in advanced stage. Incidence of cancer varies from country to country and within the country from region to region. It depends on the environment, lifestyle, and diet. The present research was undertaken to study the incidence of histopathological spectrum of malignant lesions in the local region of northern part of Andhra Pradesh. METHODS The present study is a retrospective study of 42 malignant cases from 159 neoplastic biopsies received over a period of 12 months from January 2019 to December 2019. RESULTS Among 42 malignant cases, 27 were females and 15 were males with a male to female ratio of 1:1.8. the most common age group of presentation with malignancies was 61 - 70 years. Youngest patient was 22 years. Cancer of the cervix was the commonest cancer in females in this region of Andhra Pradesh. Among men it was lung cancer. CONCLUSIONS In the present study, it was observed that the most common malignancy was lung cancer followed by cervical cancer. Squamous cell carcinoma was the most common histopathological type among them. As cancer incidence is more after 50 years this group should be targeted for health education and screening so that early diagnosis and timely treatment can be given. This reduces cancer mortality. KEY WORDS Spectrum of Malignancies, Squamous Cell Carcinoma
Salting Out: A Simple and Reliable Method to Distinguish Between Common Fluid Preservatives and Estimate Alcohol Concentration
Authors: Finkelde Irene , Newsome G. Asher
Published: July 2021

This paper details the salting-out method, which uses the salts potassium carbonate and sodium chloride to distinguish between the three most commonly used fluid preservatives: ethanol, isopropanol, and formalin.

A summary of other methods to identify fluid preservative type and a review of the salting-out method published by Mayfield (2013, Distinguishing between ethanol and isopropanol in natural history collection fluid storage, Society for the Preservation of Natural History Collections, https://spnhc.org/wp-content/uploads/2018/11/Mayfieldfinalwithtablechanges.pdf) are provided. A new salting-out method is presented, which requires a small fluid sample (2–4 ml). It is simple, quick, and relatively inexpensive to implement, making it a viable method to distinguish between common fluid preservatives. The materials and equipment for the salting-out test cost just over $100 US, and tests take approximately 3 minutes per container.

Results of testing on known concentrations and combinations of ethanol, isopropanol, and formalin (a solution of formaldehyde in water) and on samples of fluid preservatives from specimen containers in the Smithsonian National Museum of Natural History and Bernice Pauahi Bishop Museum collections are presented. The results of salting-out tests have been verified by direct analysis in real time mass spectrometry (DART-MS) (Cody et al., 2005, Versatile new ion source for the analysis of materials in open air under ambient conditions, Analytical Chemistry 77(8):2297–302), which confirmed the results of salting-out tests but also highlighted some limitations, particularly when combinations of fluid preservative are encountered.
PEM Fuel Cell Hydrogen Support Using PV-Electrolyzer Generation System
Authors: Bahri Hamza , Harrag Abdelghani
Published: July 2021

In consequence of increasing global energy consumption, the environmental problems such as pollution and the drain of conventional energy resources such as coal, gas and liquefied petrol. To tame this by implementing seeming technology of renewable energy, hydrogen is one of the promising alternative fuels for the future because it has the capability of storing energy of high quality. Therefore, the hydrogen has been visualized to become the cornerstone of future energy systems. It is produced from water electrolysis under electrochemical interaction. Water electrolyzer converts electricity into chemical energy which produces hydrogen and oxygen; this can be achieved by passing DC electric current between two electrodes separated by electrolyte. The direct electric current is delivered by source renewable energy, photovoltaic or wind system. In this paper the different parts of indirect coupling PV with alkaline electrolyzer for hydrogen production have been studied and investigated using Matlab Simulink environment. The developed models allow us the analysis of current-voltage characteristics for both systems PV and Electrolyzer, respectively, as well as the principal parameters affecting the performance of the alkaline electrolyzer.
Chemically Treated Activated Carbon for Supercapacitor Electrode Derived from Starch of Solanum Tuberosum
Authors: Kandasamy Senthil Kumar , Subramanian Balambigai , Krishnamoorthy Hemalatha , Arumugam Chandrasekaran , V Suganthi , M Yuvasri , D Shreelogesh
Published: July 2021

Because of the increasing demands in energy, growth in alternate energy sources is inevitable. By activation followed by carbonization of starch of solanum tuberosum makes a porous carbon network as electrode material for supercapacitor. To achieve an improvement in specific capacitance, activating the starch of solanum tuberosum using chemicals such as hydrochloric acid, phosphoric acid and sulphuric acid were done. The structural and electrochemical performance of activated carbon derived from the starch of solanum tuberosum is evaluated using FTIR, XRD, CV, GCD and EIS. The improved performance of chemically treated starch of solanum tuberosum in energy storage mechanism is ascribed to fast ionic diffusion of the electrolyte into and out of the pores. From the CV analysis, the higher specific capacitance (94 F.g-1) is obtained for sulphuric acid treated activated carbon derived from the starch of solanum tuberosum with good capacity retention ratio. From GCD analysis, 78.3, 56.7, 82.7 and 74.9 Fg-1 of specific capacitance is obtained for POC, POCH, POCP and POCS, respectively. When compared to all the prepared samples, POC exhibited small equivalent series resistance and POCS exhibited small charge transfer resistance.
Effect of Silicon Carbide on the Mechanical and Thermal Properties of Snake Grass/Sisal Fiber Reinforced Hybrid Epoxy Composites
Authors: Vijayakumar M , Kumaresan K , Gopal R , Vetrivel S D , Vijayan V
Published: July 2021

In this study, an attempt was made to develop and characterize Snake Grass Fiber (SGF)/Silicon Carbide (SiC)/epoxy and Snake Grass Fiber/Sisal Fiber (SF)/Silicon Carbide/epoxy hybrid composites using a compression moulding technique. Mechanical characteristics of the produced hybrid composites such as tensile, flexural, and hardness tests were analyzed. Also experiments have been carried out to predict the thermal stability of the fabricated composite samples. The interface between fiber and matrix was examined by using Scanning Electron Microscopy (SEM). Among SGF/SiC/epoxy and SGF/SF/SiC/epoxy composites, it has been observed that hybrid composite SGF/SF/SiC/epoxy exhibits the higher hardness of 82 Shore-D, tensile strength of 51 MPa and flexural strength of 73 MPa. In contrast to the mechanical properties, the percentage of water absorption was lower in the SGF/SiC/epoxy hybrid composite. It is proven from the results that the SGF/SF/SiC/epoxy hybrid composites will enhance the strength of the composites. This composite material is also a potential candidate for the hardware of energy devices including electrochemical energy along with Fuel Cell systems.
Can COIL be effective in using diversity to contribute to equality? Experiences of iKudu, a European-South African consortium operating via a decolonised approach to project delivery
Authors: DeWinter Alun , Klamer Reinout
Published: July 2021

The iKudu project is a north-south collaboration between five universities in South Africa and five in Europe. As an EU-funded project, the overall aim is to capacity build around internationalisation at home through Collaborative Online International Learning (COIL). Originally presented at IVEC2020, this paper explores how iKudu navigates and utilises concepts of equality, equity through decolonisation, and Africanisation. Drawing from experiences of the first year of operation, this paper presents how the iKudu project was designed with equality in mind in order to ensure that as many students can engage in internationalisation activities, but notes how the realities of decolonisation introduce challenging contradictions for the consortium to navigate, particularly around the use of the English language in a global context. This paper also presents some of the underlying working philosophies from the perspective of the iKudu leadership to show just how COIL can be effective in contributing to equality within internationalisation of Higher Education (HE).
Virtual exchange facilitated by interactive, digital, cultural artefacts: communities, languages, and activities app (ENACT)
Authors: Dodds Colin B. , Whelan Alison , Kharrufa Ahmed , Satar Müge
Published: July 2021

This chapter is based on a workshop at IVEC 2020 which presented a model of Virtual Exchange (VE) facilitated by interactive, digital, and cultural artefacts created using a progressive web app developed by the EU-funded ENACT project team. The model offers an innovative approach to online intercultural exchange through the opportunity to create, share, appropriate, and re-create cultural artefacts. Drawing on Thorne’s (2016) concept of cultural artefacts, the app is designed to enable artefacts as catalysts for intercultural exchange while “artifacts and humans together create particular morphologies of action” (p. 189). The ENACT project aims to develop Open Educational Resources (OER) that will foster intergenerational and intercultural understanding within and between communities; promote opportunities for intergenerational, intercultural interaction; and offer a real-world, immersive learning experience that brings culture to life. The web app is built on the well-established H5P.org interactive media engine tailored for the creation of, and engagement with interactive digital media for task-based exchange of cultural activities promoting linguistic, digital, and intercultural communication skills development. This chapter outlines how the ENACT app can be implemented in VE at higher education to facilitate deeper, immersive, virtual intercultural exchange experiences that go beyond talking about culture and that offer hands-on cultural experiences based on learning by doing to ensure equitable experiences to all students.
Expectations towards the Morality of Robots: An Overview of Empirical Studies
Authors: Wasielewska Aleksandra
Published: July 2021

The main objective of this paper is to discuss people’s expectations towards social robots’ moral attitudes. Conclusions are based on the results of three selected empirical studies which used stories of robots (and humans) acting in hypothetical scenarios to assess the moral acceptance of their attitudes. The analysis indicates both the differences and similarities in expectations towards the robot and human attitudes. Decisions to remove someone’s autonomy are less acceptable from robots than from humans. In certain circumstances, the protection of a human’s life is considered more morally right than the protection of the robot’s being. Robots are also more strongly expected to make utilitarian choices than human agents. However, there are situations in which people make consequentialist moral judgements when evaluating both the human and the robot decisions. Both robots and humans receive a similar overall amount of blame. Furthermore, it can be concluded that robots should protect their existence and obey people, but in some situations, they should be able to hurt a human being. Differences in results can be partially explained by the character of experimental tasks. The present findings might be of considerable use in implementing morality into robots and also in the legal evaluation of their behaviours and attitudes.
Making Human Traits Visible, Objectively and Validly, through Experimentally Designed Questionnaires
Authors: Lind Georg
Published: July 2021

Researchers who need valid and objective data for evaluating their theories or the efficacy of educational methods and programs have to choose between two equally undesirable alternatives: either they can use “objective” methods which have a questionable validity, or they can turn to “subjective” assessment methods with better validity. In other words, while subjective approaches to the study of human traits may be, or really are, valid, they lack objectivity, that is, they may be biased toward the researcher’s theory. On the other hand, objective approaches to the study of psychological traits often lack psychological underpinning but are solely designed to fit a certain statistical model. Thus, we cannot know what these instruments really measure. Here I present a new approach to the study of human traits, which claims to be objective as well as psychologically valid, namely the concept Experimental Questionnaire (EQ). An EQ lets us make traits visible without relying on dubious statistical assumptions. Thus, it makes it possible for the researcher to test the psychological theory underlying its designs. The EQ methodology is not only an idea, but it has been applied for constructing the Moral Competence Test (MCT) and for testing the assumptions about the nature of moral competence which were used to design it. So far, all the studies have clearly confirmed their validity. This makes the MCT suitable for testing hypotheses regarding the relevance and teachability of moral competence, and, therefore, also for evaluating the efficacy and efficiency of educational methods of fostering this competence. Experimentally designed questionnaires can also be used in other fields of educational and psychological research in which testable theories about the nature of its objects have been developed.
Giving Moral Competence High Priority in Medical Education. New MCT-based Research Findings from the Polish Context
Authors: Nowak Ewa , Barciszewska Anna-Maria , Lind Georg , Hemmerling Kay , Taradi Sunčana Kukolja
Published: July 2021

Nowadays, healthcare and medical education is qualified by test scores and competitiveness. This article considers its quality in terms of improving the moral competence of future healthcare providers. Objectives. Examining the relevance of moral competence in medico-clinical decision-making despite the paradigm shift and discussing the up-to-date findings on healthcare students (Polish sample). Design and method. N=115 participants were surveyed with a standard Moral Competence Test to examine how their moral competence development was affected by the learning environment and further important factors. Results. The sample allowed the identification of a regress in moral competence during students’ pre-clinical curriculum, and progress during their clinical curriculum. A gender-related bias, a segmentation effect, and a pronunciation effect were noticed. Explanations. Scholarly literature usually reports a linear decrease of medical students’ C-scores resulting from, e.g., competitive trends in education. We identified such trends in terms of gender-specific competitive tactics. Religious and ethical affiliations were discussed to explain the unexpected gender bias and the related segmentation and pronunciation effects. The findings can be regarded as predictive for similar developments in educational institutions regardless of cultural contexts as the sample examined in this article represents medical education in a country facing a transition from a non-competitive to competitive tertiary education model, and between presecular and monocultural to secular and pluralist social ethics.
TÜRK SİGORTACILIK SEKTÖRÜNDE ETKİNLİK VE BELİRLEYENLERİ: VERİ ZARFLAMA ANALİZİ VE PARÇALI REGRESYON MODELİ BULGULARI
Authors: EKİNCİ Ramazan
Published: July 2021

Bu çalışmanın amacı, Türk sigortacılık sektörünün hayat dışı branşında faaliyet gösteren sigorta şirketlerinin 2010-2019 dönemine ait verileri ile etkinliklerini ölçmek ve etkinliğin belirleyenlerini ortaya koymaktır. Çalışmada sigorta şirketlerinin etkinliği önce radyal temelli yaklaşımla – geleneksel Veri Zarflama Analizi (VZA) – daha sonra radyal olmayan yaklaşımla – Aylak Temelli Veri Zarflama Analizi – incelenmiştir. Ulaşılan tahmin sonuçlarına göre ölçeğe göre sabit getiri varsayımı altında ortalama etkinlik düzeyinin %71.45; ölçeğe göre değişen getiri varsayımı altında %80.15 olduğu bulgusuna ulaşılmıştır. Aylak temelli yaklaşım kullanılarak elde edilen tahmin sonuçlarına göre, ölçeğe göre sabit getiri varsayımı altında ortalama etkinlik düzeyi %60.00; değişen getiri varsayımına altında %70.73 olarak tahmin edilmiştir. Etkinliğe etki eden çevresel faktörlerden firma büyüklüğü, likidite düzeyi, özsermaye karlılığı, hasar prim oranı, yoğunlaşma oranı ve ekonomik büyüme gibi değişkenler etkinliği pozitif yönde etkilerken, özsermaye rasyosu ve enflasyon (IR) değişkenleri negatif yönde etkilemektedir.
KAMU ÇALIŞANLARININ FİNANSAL OKURYAZARLIK DÜZEYLERİNİN ÖLÇÜLMESİ: ISPARTA İLİ ÖRNEĞİ
Authors: GÜLTEKİN Gürkan , ÇARIKÇI Oğuzhan
Published: July 2021

Son yıllarda meydana gelen global krizler, nüfus artışları, yapay zekanın getirdiği yeniliklerle azalacak olan işgücü etkisi, bireylerin ve toplumların istek ve ihtiyaçlarındaki sürekli değişmeler ve küreselleşme neticesinde artan tüketim çılgınlığı bireyleri, aileleri, toplumları ve ülkeleri tasarruf konusunda daha duyarlı olmaya ve finansal okuryazarlık konusunda donanımlı olmaya muhtaç etmektedir. Bu çalışmada kamu çalışanlarının kamu personel sınıflarına göre sınıflandırılarak finansal okuryazarlık düzeylerinin ölçülmesi amaçlanmıştır. Bu sebeple Isparta ilinde çalışan genel idare hizmetleri, teknik hizmetler, sağlık hizmetleri ve yardımcı sağlık hizmetleri, eğitim öğretim hizmetleri, avukatlık hizmetleri, emniyet hizmetleri, din hizmetleri ve yardımcı hizmetler sınıflarındaki 450 çalışana anket uygulanmıştır. Finansal okuryazarlık seviyelerinin ölçülmesi için farklı kaynaklardan alınan ölçekler kullanılmıştır. Yapılan analizler sonucunda kamu personel sınıflarının operasyonel işlem, ekonomi yorum kabiliyeti, riskten korunma ve sözleşme metni bilinirliği faktörlerine ilişkin anlamlı farklılıkların olduğu saptanmıştır.
KREDİ RİSK PRİMİ, DÖVİZ KURLARI VE BAZI EMTİALARIN BİST100 PERFORMANSINA ETKİSİ
Authors: TUFANER Mustafa Batuhan
Published: July 2021

Borsalar, yerli ve yabancı yatırımcıların tasarruflarını değerlendirdiği finansal piyasalardır. Özellikle, yatırım ihtiyacı yüksek olan gelişmekte olan ülkelerde kredi genişlemesi için bir likidite kaynağı olarak görülmektedir. Finansal kırılganlık seviyesi yüksek olan bu ülkelerin borsaları hem ulusal hem de uluslararası arenada meydana gelen ekonomik, sosyal ve politik gelişmelerden etkilenebilmektedir. Bunların en başında ise CDS risk primleri gelmektedir. Bu bağlamda çalışmanın amacı, BİST100 endeksi ile CDS risk primi, dolar kuru, ons altın fiyatı ve brent petrol fiyatı arasındaki ilişkiyi incelemektir. Araştırmada, 2015w50-2020w2 dönemi haftalık veriler kullanılarak analiz edilmiştir. İlk olarak, serilerin durağanlığını sınamak amacıyla ADF ve PP birim kök testleri yapılmıştır. Ardından, değişkenler arasındaki uzun dönem ilişkisinin tespit edilmesi amacıyla, Johansen eşbütünleşme testi uygulanmıştır. Daha sonra, modelde yer alan değişkenler arasında nedensellik ilişkisinin mevcut olup olmadığının tespit edilmesi için VAR temelli Granger nedensellik testi gerçekleştirilmiştir. İz ve Maksimum Özdeğer testi sonuçlarına bakıldığında, değişkenler arasında bir eşbütünleşme ilişkisi olmadığı sonucuna varılmıştır. Granger nedensellik testi sonuçlarına bakıldığında, CDS’den BİST100’e ve USD’den BİST100’e tek taraflı bir nedensellik ilişkisi olduğu anlaşılmıştır.
BELEDİYE TAŞINMAZLARININ DEĞERLENDİRİLMESİNDE YEREL YÖNETİM BANKACILIĞININ ROLÜ VE BELEDİYELERİN YAKLAŞIMI
Authors: YEĞİNER Pınar , TANRIVERMİŞ Yeşim
Published: July 2021

Kamu arazileri ve bu arazilerin değerlendirilmesi içinde bulunduğumuz yüzyılda ülkemizin ekonomik gelişme süreci için oldukça önemli bir hale gelmiştir. Bu sebeple araziler etkin ve verimli kullanılması gereken bir kaynak olarak görülmelidir. Ancak, yerel yönetimlerin kaynak ihtiyaçlarını hızlı bir şekilde karşılamak istemesi kamu arazilerinin yeterli analizler yapılmadan kullanılmasına neden olmaktadır. Yerel yönetim bankası olan İLBANK A.Ş.’nin içinde bulunduğu yeniden yapılandırma sürecinde edindiği görevler arasında Banka için kaynak yaratıp elde edilen gelir ile yerel yönetimlerin finansman arayışlarına destek olmak yer almaktadır. Yerel yönetimler kendi gelirlerini arttırmak ve hizmetlerini tamamlamak amacıyla kaynak arayışında bulunurken birçok kurum/kuruluş da kaynak geliştirme çalışmalarını kendi bünyesinde gerçekleştirmektedir. Farklı kurumların aynı işi kendi bünyesinde yapmaya çalışması nedeniyle kaynak geliştirme süreci bir bütün halinde ilerleyememekte, yeterli kaynak bulunamamakta, yeterli teknik birikimi olmayan kurumlar da işin içerisine girmekte ve tüm bunlar, sürecin başarısız bir şekilde tamamlanmasına sebep olmaktadır. Bu çalışmada, farklı kurumlar ve birimler altında yapılan işlemlerin tek bir sistem vasıtasıyla daha hızlı ve verimli bir süreçle gerçekleştirilmesinin mümkün olup olmayacağı araştırılmakta, belediyelerin bu konuda görüşleri alınarak katılımcı bir yaklaşımla yeni yöntemlerin geliştirilmesi amaçlanmaktadır. Önceki çalışmalardan farklı olarak bu araştırmada; yerel yönetimlere uzun vadeli kaynak sağlama veya kaynak geliştirme çalışmalarının İLBANK A.Ş. ile belediye iş birliğinde yapılması ve başarı olanakları irdelenmiştir. Sürecin kurumlar arası bütünleşmiş bir sistemle yürütülmesi, düzgün ve sürdürülebilir işleyiş açısından zorunlu olmaktadır. Böylece yerel yönetimlerin hizmetlerini daha kaliteli ve hızlı bir şekilde gerçekleştirmeleri ve kamu arazilerinin değerlendirilmesi işlemlerini daha etkili bir yaklaşımla yürütebilmeleri mümkün görülmektedir.
TÜRKİYE’DE KENTSEL DÖNÜŞÜMÜN FİNANSMANINDA YENİLİKÇİ VE ALTERNATİF FİNANSMAN MODELLERİNİN KULLANILMA POTANSİYELİNİN BELİRLENMESİNE YÖNELİK ARAŞTIRMA
Authors: TANINMIŞ YÜCEMEMİŞ Başak , KURT Timuçin
Published: July 2021

Bu çalışma, “20 yıl içerisinde ülke genelinde 6,5 milyon konutun dönüşümünün sağlanması” olarak ifade edilen ulusal Kentsel Dönüşüm Politikamızın ekonomik belirsizlik ve kriz koşullarında aksamadan ve etkin bir şekilde uygulama boyutuna taşınabilmesi için yenilikçi ve alternatif finansman modellerinden yararlanma potansiyelini ortaya koymak amacıyla hazırlanmıştır. Bu bağlamda, ülkemizde kentsel dönüşümde gelinen aşama ve bu süreçte doğrudan ya da dolaylı olarak yer alan paydaşların kentsel dönüşümün finansmanında yenilikçi ve alternatif modellerin kullanılma potansiyeline dair görüş ve önerilerine odaklanılmıştır. Bunun için, geliştirilen metodolojik kurgu dâhilinde ülke genelinde mülakat ve anket çalışmaları yapılmıştır.
Elde edilen bulgulara göre, kentsel dönüşüm uygulaması gerçekleştiren kurumların %62’si finansman temininde zorlukla karşılaşırken, %56’sının son beş yılda başlattığı kentsel dönüşüm projelerinin en az birisi gerekli finansman temin edilemediği için kesintiye uğramıştır. Önümüzdeki dönemde Covid-19 salgınının da etkisiyle bu sorunun daha da artacağı yönünde genel bir görüş birliği söz konusudur. Bu veriler, her dört kurumdan sadece birinin “kentsel dönüşüm uygulamalarının finansmanında kullanılma potansiyeli olan yenilikçi ve alternatif finansman modelleri” hakkında bilgi sahibi olduğu sonucu ile birlikte değerlendirildiğinde; bu modellerin kullanılabilmesi için uygulayıcı aktörler nezdinde farkındalığın ve yetkinliğin arttırılması gerekmektedir.
FİNANSAL SİSTEMİN MEKÂNSAL ÖRGÜTLENMESİ: 19. YÜZYILDA LONDRA’NIN FİNANS MERKEZİ OLMASI
Authors: GÜNEŞ Cihan , AKYÜZ Mert
Published: July 2021

Finansal gelişmişlik ve ekonomik büyüme arasında pozitif korelasyon olduğunu gösteren çok sayıda çalışma vardır. Finans merkezleri de daha büyük ölçekli işlem hacmiyle finansal işlemlerin ve kurumların kümelendiği işlem maliyetlerini azaltan bir mekânsal örgütlenme şeklinde ortaya çıkmıştır. Bu çerçevede Avrupa’nın Büyük Ayrışma sürecini yaşadığı 19. yüzyılda finans merkezlerinin ilk modern örneklerinden biri olan Londra örneğini açıklamak finansal sistemin mekânsal örgütlenmesini anlayabilmek açısından önem arz etmektedir. Bu bağlamda bu çalışmanın amacı; 19. yüzyılda Londra’nın finans merkezi olabilmesine imkân tanıyan faktörleri ve bu örgütlenmenin etkilerini inceleyebilmektir. Birincil ve ikincil önemdeki faktörlerin tümünün İngiltere’de gerçekleşmesi ve Londra’nın kurumsal ve ekonomik açıdan avantajlı pozisyonu sayesinde finans merkezi olduğu sonucuna ulaşılmıştır.
BORSA İSTANBUL MALİ ENDEKSİ İLE MAKROEKONOMİK DEĞİŞKENLERİN ARDL SINIR TESTİ İLE ANALİZİ
Authors: KARACA Süleyman Serdar , KOYUNCU Tuğba , ÇEVİK Mustafa
Published: July 2021

Mali endekste işlem gören pay senetlerine yapılan yatırımların tutarı ve süresi mevcut konjonktürden ve politik etkenlerden olduğu kadar faiz, enflasyon ve döviz kuru gibi diğer makroekonomik faktörlerden de etkilenmektedir. Bu bağlamda, çalışmada BİST Mali Endeksi (XUMAL) ile dolar kuru, faiz oranı, enflasyon oranı, altın fiyatları, kapasite kullanım oranı ve sanayi üretim endeksi arasındaki ilişkiler araştırılmıştır. Ocak 2007 – Ocak 2019 dönemine ait aylık verilerden oluşan 140 gözlemden oluşan veri seti ile yapılan ARDL sınır testi sonucunda değişkenler arasında uzun dönemli ilişkilerin varlığı belirlenmiştir. Çalışma sonucunda faiz oranlarındaki ve sanayi üretim endeksindeki artışların kısa ve uzun dönemde mali endeksi olumlu yönde etkilediği ve döviz kurundaki artışın Mali Endeksi olumsuz etkilediği bulgusuna ulaşılmıştır. Hata düzeltme modeli (VECM - vector error correction model) sonuçlarına göre ise sanayi üretim endeksi ile Mali Endeksi arasında çift yönlü bir ilişki tespit edilmiştir.
PİYASA VOLATİLİTESİNİN KONUT KREDİ HACMİNE ETKİSİ: TÜRK BANKACILIK SEKTÖRÜNE İLİŞKİN BİR UYGULAMA
Authors: KOÇ İlker , BUMİN Mete , DEMİR Yaşam
Published: July 2021

Türkiye konut finansmanı piyasasının en önemli kaynağı olan konut kredileri son yıllarda büyük gelişim

göstermiştir. Konut kredilerinin gelişimini etkileyen en önemli değişken ise konut kredisi maliyeti olan kredi

faiz oranlarıdır. Diğer taraftan, faiz oranı düzeyinden bağımsız olarak konut kredisi hacmi ile faiz oranı volatilitesi

arasında bir ilişkinin varlığı söz konusudur. Bu çalışmada, Türk bankacılık sektöründe kullandırılan konut

kredisi hacmi ile faiz oranı volatilitesi arasındaki ilişkinin ekonometrik yöntemlerle analiz edilmesi hedeflenmiştir.

Bu amaçla, “Üç Aşamalı En Küçük Kareler” (ÜAEEK) yöntemi ile tahmin edilen eşanlı denklem modeli

esas alınmıştır. Bu çalışma ile Türk bankacılık sektöründeki konut kredilerinin piyasa faiz oranı volatilitesi ile

ilişkisi incelenerek bu alanda literatürdeki eksikliğin giderilmesine katkı sağlanması hedeflenmektedir. Modelde

yer alan ve genel olarak durağan olmayan konut kredisi, gelir, enflasyon ve faiz oranı volatilitesi zaman serilerinin

ÜAEEK yöntemi tahmini için uzun dönemli eşbütünleşme yaklaşımından faydalanmıştır. Analiz sonucunda,

piyasa volatilitesinin konut kredisi hacmi üzerinde önemli bir etkisi olduğu bulgusuna ulaşılmıştır. Ayrıca,

bu durumun faiz oranlarının genel olarak negatif eğilimli olduğu dönemlerde tasarruf sahiplerinin daha

yüksek getirili araçlara yönelmesinden kaynaklanmış olabileceği değerlendirilmiştir.
AN OVERVIEW OF VOLUNTARY PRIVATE PENSION FUNDS IN TURKEY
Authors: KAYHAN Fatih , TOGAN EĞRİCAN Aslı
Published: July 2021

We provide an overview of the voluntary pension fund market in Turkey by starting with recent developments in the global pension markets and then focusing on the pension fund reform in Turkey and the following developments since 2003. Findings from the literature indicate that the reforms on the introduction of voluntary pension funds in Turkey have positive implications for the overall national savings rates and capital market development. Voluntary pension funds create extra income for beneficiaries after their retirement. However, redesigning the system in a simplified structure is necessary in order to increase participation, inclusion and also to ensure persistency.
The B-topology onS∗-doubly quasicontinuous posets
Authors: Sun Tao , Li Qingguo , Zou Zhiwei
Published: July 2021

The notions ofos{o}_{s}-convergence andS∗{S}^{\ast }-doubly quasicontinuous posets are introduced, which can be viewed as common generalizations of Birkhoff’s order-convergence andS∗{S}^{\ast }-doubly continuous posets, respectively. We first consider the relationship betweenos{o}_{s}-convergence and B-topology and show that the topology induced byos{o}_{s}-convergence according to the standard topological approach is the B-topology precisely. Then, the topological characterization for theS∗{S}^{\ast }-doubly quasicontinuity is presented. It is proved that a poset isS∗{S}^{\ast }-doubly quasicontinuous iff the poset equipped with the B-topology is locally hyperclosed iff the lattice of all B-open subsets of the poset is hypercontinuous. Finally, the order theoretical condition for theos{o}_{s}-convergence being topological is given and the complete regularity of B-topology onS∗{S}^{\ast }-doubly quasicontinuous posets is explored.
Analysis of the Corrosion Behavior of Vapor-Deposited CrN-Coated Zirconium under Normal Operation and Accident Scenarios
Authors: Dever Caitlin , Daub Kevin , Nordin Heidi M.
Published: July 2021

Chromium nitride (CrN) coatings are considered as possible protective barrier materials for Zircaloys. CrN-coated zirconium alloys were exposed to primary water (300°C) and steam environments to evaluate their resistance to corrosion under normal reactor operating conditions and under accident conditions. A number of surface analytical techniques, including scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, secondary ion mass spectrometry, and transmission electron microscopy were used to evaluate the effectiveness of the coatings. To examine the effects of irradiation, coated samples were exposed in-flux and out-of-flux at the Halden reactor at temperatures of 280°C and 325°C. The CrN coatings have been shown to be a barrier to corrosion and deuterium ingress under aqueous corrosion conditions and to act as a temporary barrier to corrosion under steam conditions.
Experimental Simulation of the Behavior of E110 Claddings under Accident Conditions Using Electrically Heated Bundles
Authors: Hózer Zoltán , Nagy Imre , Farkas Róbert , Vér Nóra , Horváth Márta , Novotny Tamás , Perez-Feró Erzsébet , Király Márton , Kis Zoltán , Maróti Boglárka , Szentmiklósi László , Holecz Péter , Auguszt György , Gémes György
Published: July 2021

The integral behavior of zirconium cladding materials was tested under design basis and beyond design basis accident conditions in the CODEX (COre Degradation EXperiment) facility. The test series included five experiments and covered the typical loss-of-coolant accident conditions for normal reactor operation, shutdown conditions, and wet storage in the spent fuel pool. The electrically heated experimental bundles were composed of seven rods with a hexagonal arrangement. Traditional and sponge-based E110 claddings were used in the same bundle in order to carry out parallel testing of the two materials. The fuel rods were filled with alumina pellets and were pressurized with inert gas. Detailed posttest examination of the experimental bundles was carried out in order to collect information on the degradation process and on the final state of the rods. Four-point bending-type mechanical tests were carried out with the cladding tubes. Prompt gamma-ray neutron activation imaging driven by neutron radiography and hot extraction methods was applied to characterize the axial hydrogen profile. The eddy current technique and laser profilometry were used to investigate the deformation of ballooned rods. The microstructure of the claddings was examined by metallography. The experiments provided new information on ballooning, burst, high-temperature steam oxidation, and load-bearing capability during water quench of oxidized E110 claddings. The observed differences between traditional and sponge-based E110 alloys were in good agreement with the results from small-scale separate effect tests regarding burst and oxide layer formation.
Zirconium-Applied Anisotropic Cluster Dynamics for Irradiation-Induced Defect Modeling in Presence of Hydrogen
Authors: Brimbal Daniel , Chaari Nermine , Barberis Pierre , Bourlier Florent
Published: July 2021

Under irradiation, zirconium (Zr) alloys experience free growth, following a three-step kinetic: a transitioning phase with fast growth, followed by a stabilization phase, and finally an acceleration phase (fluence 6 to 10 × 1021 n/cm2). While the initial growth kinetics are related to the  dislocation loops, the acceleration phase is driven by the nucleation and growth of  dislocation loops. Corrosion of zirconium alloys in a pressurized water reactor environment leads to an increase in their hydrogen content, with hydrogen being a subproduct of the oxidation reaction. Experiments have evidenced that increasing hydrogen content in zirconium alloys leads to higher  loop linear density. Atomistic modeling also shows that increasing the hydrogen concentration lowers the stacking fault energy of the  loops and thus stabilizes them. Using cluster dynamics calculations, this study attempts to simulate the microstructural evolution observed in zirconium alloys under irradiation, based on the diffusional anisotropy difference model, which is well adapted for zirconium. The hydrogen effect is included in this model by means of its influence on the stacking fault energy of  loops. After neutron irradiation in the research reactor, the microstructure of prehydrided Zr alloy samples has been characterized. A correlation between the hydrogen content in the samples and the nucleation and growth of  dislocation loops is highlighted. The modeling results are then compared to the experimental observations and a good agreement is obtained.
Full-Scale Fracture Toughness Behavior of Zr-2.5Nb Pressure Tubes with High Hydrogen Concentrations and Different Hydride Morphologies
Authors: Cui Jun , Shek Gordon K.
Published: July 2021

Fracture toughness is required for fracture initiation and leak-before-break evaluation of Zr-2.5Nb pressure tubes in Canadian Deuterium Uranium, or CANDU, reactors. The effects of high hydrogen concentration ([H]) and associated hydride morphology on fracture toughness need to be better characterized to support continued operation and reactor life extension. This paper summarizes results from 16 rising pressure burst tests performed on Zr-2.5Nb pressure tubes. Test variables include: material variability, hydrogen concentration, hydride orientation, and test temperature. Hydride orientation was characterized by the hydride continuity coefficient (HCC). The tests were performed over a range of temperatures to characterize the fracture toughness behavior in the lower-shelf, transition, and upper-shelf fracture regimes. Test results indicate that, under essentially the same hydride reorientation conditions, there was large variation in hydride reorientation between the two tubes tested. At room temperature, the fracture toughness of the hydrided specimens was significantly lower than that of the specimens containing as-fabricated [H]. Increasing [H] from 60 ppm to 100 ppm led to more reoriented hydrides and a further reduction in fracture toughness, and increasing from 100 ppm to 130 ppm did not lead to a further increase in reoriented hydrides or a reduction in fracture toughness. Hydrided specimens with relatively low HCC exhibited a gradual transition behavior from lower shelf to upper shelf. Hydrided specimens with high HCC exhibited a relatively steep transition behavior. Increasing HCC led to a reduction in fracture toughness in the lower-shelf regime and an increase in transition temperature from lower shelf to upper shelf. Examinations of hydride morphologies and fracture surfaces suggested that the crack growth behavior was dominated by hydride fracture in the lower-shelf regime and mainly governed by matrix failure in the upper-shelf regime. A combination of both fracture mechanisms occurred in the transition region. All test specimens with different [H] and hydride morphologies approached the upper-shelf toughness at 150°C.
Characterization of Hydrides and the α-Zr Matrix in Zirconium Alloys: Effects of Stresses, Microstructure, and Neutron Irradiation on Hydride Texture, Terminal Solid Solubility, and Dislocation Structure
Authors: Vizcaino Pablo , Flores Alejandra V. , Vicente Alvarez Miguel A. , Santisteban Javier R. , Domizzi Gladys , Tolley Alfredo , Condó Adriana , Almer Jonathan D.
Published: July 2021

Synchrotron X-ray diffraction, transmission electron microscopy, and high-resolution transmission electron microscopy experiments were performed on samples from Zr-2.5Nb alloy pressure tubes and Zircaloy-4 fuel channels materials in order to define hydride precipitation temperatures, hydride texture, the matrix hydride orientation relationship, and dislocation densities. For Zr-2.5Nb, studies included in situ constant stress tests performed on dog-bone specimens cycled between room temperature and 400°C, where hydrides were completely dissolved and reprecipiated. For Zircaloy-4, analysis included ex-service Zircaloy-4 irradiated to ~ 1022 neutrons/cm2. Careful interpretation and analysis of azimuthal variations around the Debye-Scherrer rings allowed a clear description of both texture and dislocation densities of δ-hydride precipitates. The main findings are: (1) In Zr-2.5Nb pressure tubes, the terminal solid solubility for hydride dissolution and the terminal solid solubility for precipitation (TSSP) temperatures depend on the orientation of the parent α-Zr grain. Hydrides both precipitate and dissolve at slightly lower temperatures (~ 5°C and ~ 15°C, respectively) in grains having their c-axis parallel to the tube hoop direction than those with their c-axis ~ 20° off from the hoop direction. (2) Application of a stress along the tube hoop direction during precipitation increases TSSP temperatures and favors hydride precipitation on grains with c-axes stretched by the load. For grains with the c-axis parallel to the applied load, TSSP temperatures increase at a rate of (0.08 ± 0.02)°C/MPa, nearly two orders of magnitude higher than previous estimates. (3) Precipitates of δ-hydride are heavily dislocated, yet display large variations (1.6 to 10 × 1014 m−2) depending on the microstructure and hydrogen content of the parent material.
Fundamental Understanding of Nb Effect on Corrosion Mechanisms of Irradiated Zr-Nb Alloys
Authors: Yu Zefeng , Moorehead Michael , Borrel Léo , Hu Jing , Bachhav Mukesh , Couet Adrien
Published: July 2021

Although zirconium-niobium (Zr-Nb) alloys are commonly used over Zircaloys as fuel claddings in light-water reactors, the fundamental understanding of Nb effects on oxidation and hydrogen pickup mechanisms, especially under irradiation, is still lacking. This study aims at filling this knowledge gap by coupling state-of-the-art experimental and modeling approaches on a set of Zr-xNb (x = 0.5/1.0) model alloys, with different heat treatments and irradiation dose levels to understand the effect of Nb redistribution on corrosion kinetics. To investigate the effect of irradiation on Nb distribution in a Zr-Nb metal substrate, Zr-Nb alloys have been irradiated by 2-MeV protons up to 1 dpa (flat region, about 1.3 × 1019 ions/cm2) at 350°C at the University of Wisconsin Ion Beam Laboratory. Nb redistribution after irradiation has been characterized by scanning transmission electron microscopy and atom probe tomography with a focus on radiation-induced platelets and solute concentrations. Results from atom probe tomography show that indeed solute concentration in solid solution decreases with irradiation dose, which may explain the enhanced corrosion resistance of irradiated Zr-Nb alloys via space-charge effects in the oxide. To understand the correlation between oxide space charge and corrosion kinetics, X-ray absorption near-edge spectroscopy was performed to measure the Nb oxidation states as a function of exposure time and oxide depth in two different annealed Zr-1.0Nb samples, corroded in high-temperature water up to 240 days. X-ray absorption near-edge spectroscopy results show that Zr-1.0Nb with lower, sub-parabolic, corrosion kinetics contains less Nb concentration in solid solution. Lastly, the observed corrosion kinetics are rationalized based on the coupled current charge compensation model in terms of Nb redistribution and its compensation effect on oxide space charges. The effect of irradiation on corrosion kinetics of Zr-Nb alloys is discussed in the light of experimental and modeling results.
Toward a Mechanistic Understanding of Pellet Cladding Interaction Using Advanced 3D Characterization and Atomistic Simulation
Authors: Frankel Philipp , Garner Alistair , Plowman Adam , Hanlon Sean M. , Gillen Conor , Phillion Andrew , Race Christopher P. , Donoghue Jack , Anghel Clara , Ambard Antoine , Daymond Mark R.
Published: July 2021

Iodine-induced stress corrosion cracking (I-SCC) has long been proposed as a primary cause of pellet cladding interaction failures in light water reactors. The I-SCC process has been studied in great detail but its precise mechanism and the influence of local microstructure remains uncertain. In this study, a large-scale investigation was undertaken of a sample produced by a novel rig for I-SCC using analytical three-dimensional characterization and then it was related to atomistic simulations describing the orientation dependence of iodine segregation and its influence on various types of boundaries. In situ monitoring capability enabled an I-SCC crack to be arrested in a compact tension specimen machined from Zircaloy-4 plate before failure, and serial sectioning by a plasma-focused ion beam allowed detailed characterization of an entire cracked region consisting of nearly 1,000 grains. By relating the crack path to the local microstructure three-dimensionally, new insights could be gained about the crack propagation during I-SCC. The crack was observed to be primarily transgranular in nature, progressing along basal planes; but away from the crack tip, a significant proportion of intergranular cracking was also observed. By careful analysis, this study was able to relate the nature of the crack progression directly to the individual grain orientations and their level of deformation. Particular grain orientations were observed to be resistant to I-SCC attack and resulted in crack deflection. The formation of twins in the vicinity of the crack was also observed and the role of twins discussed. Complementary density functional theory modeling examined the effects of iodine impurities at different positions within the microstructure. Simulations suggested that transgranular basal cleavage was energetically accessible and might be preferable to cleavage on prismatic planes, even if this would result in significant deviation of the crack path. These results are discussed with respect to the experimental observations.
Toward an Improved Understanding of the Mechanisms Involved in the Increased Hydrogen Uptake and Corrosion at High Burnups in Zirconium Based Claddings
Authors: Abolhassani Sousan , Baris Adrienn , Grabherr Robin , Hawes Jonathan , Colldeweih Aaron , Vanta Radovan , Restani Renato , Hermann Armin , Bertsch Johannes , Chollet Melanie , Kuri Goutam , Martin Matthias , Portier Stephane , Wiese Holger , Schweikert Herbert , Bart Gerhard , Ammon Katja , Ledergerber Guido , Limbäck Magnus
Published: July 2021

In reactor environment, under irradiation, the corrosion and hydrogen uptake do not follow the rules valid for autoclave conditions. After sufficient study, it has been demonstrated that these two phenomena are different in reactor and not only the rate of corrosion but also that of hydrogen uptake change. In many alloys, they increase at high burnups. The causes of this change in behavior with irradiation are still debated. Although most aspects of this topic are examined, the full picture is not yet portrayed. In the frame of a project running at PSI, different alloys irradiated in two types of reactors are analyzed to correlate the characterization to the change of behavior. The metal-oxide microstructure has been examined by analytical techniques such as electron probe microanalysis, three-dimensional focused ion beam and transmission electron microscopy. The mechanical properties of the oxide in the vicinity of the metal-oxide interface as well as its semiconducting properties are explored at a microscopic level. In order to see the evolution of the aforementioned properties, a high-burnup sample is compared with the low-burnup material of the same cladding. The evolution of the aforementioned properties is considered to determine the different factors at the origin of the modified hydrogen pickup fraction at high burnup. Other alloys are then examined searching for similar behaviors. From these measurements, it can be concluded that not a single mechanism is involved in the process of oxidation and hydrogen uptake. In particular, as the residence time increases, different modifications and their mechanisms run in parallel. It is demonstrated that the “multilayer” formed from metal and oxide, responsible for the protection of the cladding against the ingress of different species, becomes more porous and less conducting in the oxide, but also its mechanical strength is modified. These progressive changes lead to different schemes for corrosion and hydrogen uptake.