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An integrated model for evaluating the risk factors of crypto-currencies under fuzzy environment
No full textWhile blockchain technology and cryptocurrencies offer numerous advantages and innovations, it is essential to be aware that their implementation processes are fraught with a myriad of risk factors. A study in which risks in cryptocurrencies are evaluated using quantitative data is an important need for investors and academics. As far as it is known from the literature, although blockchain technology is frequently used in different fields, there is no study examining the risks in cryptocurrencies with fuzzy set theory. Unlike the common return and security focused studies in the literature, a comprehensive risk factor determination has been made by evaluating a total of 21 criteria that directly and indirectly affect this virtual currency. Within the study, investors have been provided with insights into the alternatives relevant to the risks under determined through the utilization of an alternative set of considerable magnitude, uncommonly encountered in the existing literature. Considering the complexity and uncertainty of the problem, an Analytic Hierarchy Process and Technique for Order of Preference by Similarity to Ideal Solution method integrated with Spherical fuzzy sets have been used. The most preferred cryptocurrencies have been evaluated according to a set of criteria ranging from their financial structures to their environmental impacts. Ethereum, which stands out with its blockchain structure, has been the best choice. Tether, designed to provide a stable price point, and Dogecoin, designed as a payment system, appeared to be the worst ones
A two-stage stochastic model for an industrial symbiosis network under uncertain demand
No full textIndustrial Symbiosis (IS) networks are structures built by volunteer companies with the aim of exchanging unused or residual resources, benefiting all participating companies. The profitability of these volunteer companies is critical as it affects the sustainability of these networks. Fluctuations in a participating company's production level can potentially disrupt its network by altering the quantity and availability of wastes and by-products. In light of these considerations, we analyse the impact of fluctuations in demand for final products of the companies on company profitability, and waste and by-product usage. For this purpose, we formulated a two-stage stochastic programming model and solved it using the Sample Average Approximation (SAA) method. We tested our model on a theoretical IS network comprising companies in the forest products industry. The results demonstrate that companies in the network keep exchanging by-products and remain profitable despite uncertainties in demand. Consequently, we conclude that the established network exhibits resilience to demand fluctuations, which is an important aspect of its sustainability.Scientific and Technological Research Council of Turkey (TUBITAK) [120M223]We are grateful for the comments provided by the reviewers and editors. In addition, research in this study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK) under grant number 120M223
Euphemisms Related to "Death" in Sehi Bey's Treatise Titled Heşt-Bihişt
No full textÖlüm, her canlının başına gelecek mutlak ve kaçınılmaz bir sondur. Geçmişten bugüne ölüm korkusuyla mücadele eden insan; bu durumu aşmak, yarattığı etkiyi azaltmak için çeşitli yollara başvurmuştur. İnsan kelimelerle düşünen, bu hazine aracılığıyla konuşan bir varlık olmasından dolayı ölümün verdiği acı, keder, korku ve üzüntü dile de yansımaktadır. Ölmek eylemi ve bu kelimenin türevlerinin acı veren yanının etkisini azaltmak amacıyla söz konusu kavram(lar)la ilgili örtmeceler sıklıkla kullanılmaktadır. Bu yolla bahsi geçen durum, dolaylı biçimde anlatılarak insan üzerindeki olumsuz etkisi azaltılmaktadır. Türkçenin zengin bir dil olması, ölüm örtmecelerinde de kendini göstermektedir. Şairlerin ve yazarların hayatının anlatıldığı bir tür olan tezkirelerde ölümle ilgili ifadeler geçmektedir. Çalışmanın temel amacı, Anadolu sahasının ilk tezkiresi olan Sehî Bey’in Heşt-Bihişt adlı eserinde ölüm ile ilgili örtmecelerin ortaya konulup açıklanmasıdır. Eserin tüm ölüm ifadeleri bulunarak bunlardan yalnızca örtmece amacıyla kullanılanlar seçilip fişleme yöntemi kullanılmıştır. Sonuçta dönemin dil özellikleri, toplumun dinî inanışı, kültürel etkenler, gelenek, görenek ve âdetlerinin getirdiği birikimle beraber esas alınan tezkirede Sehî Bey’in şairlerin ölümü için yirmi farklı ölüm örtmecesini kullandığı tespit edilmiştir. Heşt-Bihişt’te tezkire yazarının tercih ettiği bu örtük anlatımlarla ölümün hem birey hem toplum üzerindeki sarsıcı, yıkıcı ve yakıcı etkisinin azaltılması hedeflenmiştir.Death is an absolute and inevitable end that will happen to every living thing. People who struggle with the fear of death from past to present; It has resorted to various ways to overcome this situation and reduce its impact. Since man is a being who thinks in words and speaks through this treasure tool, the pain, grief, fear and sadness of death are also reflected in language. Euphemisms related to the concept(s) in question are often used in order to reduce the impact of the painful aspect of the verb - die and its derivatives. In this way, the negative impact on people is reduced by explaining the situation indirectly. The fact that Turkish is a rich language is also manifested in death euphemisms. Expressions about death are mentioned in the theses, which are a genre in which the lives of poets and writers are told. The main purpose of our study is to put forward and explain the euphemisms of the source about death by focusing on Sehi Bey's Heşt Bihişt, which is the first thesis of the Anatolian field. All the death expressions of the work were found, and only those used for euphemism were selected and the plugging method was used. As a result of these studies, it has been determined that Sehi Bey used twenty different death euphemisms for the death of poets in the tezkire, which is based on the linguistic characteristics of the period, the religious belief of the society, cultural factors, traditions, customs and customs. With these indirect, implicit expressions preferred by the author of the tezkire in Hesht Bihisht, it is aimed to reduce and eliminate the shocking, destructive and burning effect of death on both the individual and the society
Neuroprotective role of n-acetylcysteine (NAC): countering doxorubicin neurotoxicity via TH, Nurr1, and iNOS expression
No full textChemotherapy is an effective treatment for cancer, but it can cause cognitive disorders broadly referred to as “chemobrain.” One of the most commonly used chemotherapeutics, doxorubicin (DOX), has been associated with the potential for brain damage and cognitive dysfunction. N-acetylcysteine (NAC) has been identified as a potential brain protector with antiapoptotic, antioxidant, and anti-inflammatory effects. The objective of this study was to investigate the potential protective effect of NAC against DOX-induced brain damage. Female Wistar albino rats were randomly assigned to one of three groups: control, DOX, or NAC prophylaxis. Brain samples were collected for histopathological and immunohistochemical analyses, with a particular focus on regions that are crucial for cognition and memory. The DOX group exhibited significant histopathological changes, including neuronal shrinkage, degeneration, and necrosis in the striatum, hippocampal region, and cerebral cortex. Immunohistochemical analysis revealed the presence of neuroinflammation and neurodegeneration, with an increase in inducible nitric oxide synthetase (iNOS) immunopositivity. Administration of NAC effectively reduced iNOS immunopositivity, neuronal damage, degeneration, and necrosis in the prophylaxis group. Among the brain regions examined, the prophylaxis group demonstrated the most effective protection in the hippocampal region. Therefore, NAC has the potential to protect against or alleviate DOX-induced cognitive impairments
Simulation and Implementation of an Induction Heating System for Heating Brittle Thin Metal Sheets by Various Excitation Current Frequencies
No full textİndüksiyonla ısıtma işlemi birçok farklı değişkenle ilişkili olduğundan dolayı doğrusal olmayan bir problemdir. Bu problemin matematiksel analizi oldukça zordur ve basitleştirilmesi gerekmektedir. Çoğu durumda, parametrelerin mekansal geometriye dayalı olarak hesaplanması da önem taşımaktadır. Bu çalışma indüksiyonla ısıtma probleminin bir simülasyon modelini ele almaktadır. Arşimet spiral bobininin çeşitli akımları ve frekansları altında kırılgan metal levhaların indüksiyonla ısıtma özellikleri, karmaşık yapılara bir çözüm olan COMSOL Multiphysics'in sonlu elemanlar yöntemi kullanılarak simüle edilmiştir. Kısmi etkileri ayırt etmek için bobin modeli, gerçek bobinin geometrisine çok yakın olacak şekilde ayarlanmıştır. Simülasyon süreci iki aşamadan oluşmaktadır. İlk durum, frekans alanı analizinde uyarma akımı frekansının kademeli olarak arttırılmasıyla ısıtma işleminin değerlendirilmesi ile elde edilirken, ikinci durum, frekans geçici durumunda sabit frekanslı bir akımın uygulanması ve ısıtma işleminin modelde değerlendirilmesi ile elde edilir. Dolayısıyla simülasyon modeli her iki durumda da iş parçası malzemesinin doğrusal olmayan elektromanyetik ve termal özellikleri hakkında temel bilgileri sağlar. Simülasyon modeli sonuçlarını doğrulamak için bir laboratuvar modeli geliştirilip ve deneysel sıcaklık ölçümleri simülasyon sonuçlarıyla karşılaştırılmıştır.The induction heating process is a highly nonlinear problem due to its connection with various factors. The complex nature of this issue presents a notable difficulty for mathematical analysis and requires a simplification. Additionally, deriving parameters from spatial geometry can be a challenging undertaking in most instances. This paper deals with a simulation model of the induction heating problemThe finite element method within COMSOL Multiphysics is utilized to simulate the induction heating characteristics of fragile metal sheets subjected to different currents and frequencies from an Archimedean spiral coil. This serves as an effective solution for intricate constructions. To distinguish between partial influences, the coil model is modified to closely mirror the actual coil's geometry. The simulation process includes two phases. The former situation is attained by evaluating heating process by gradually increasing the excitation current frequency in frequency domain analysis and the latter scenario is achieved by implementing constant frequency current in a frequency transient condition and assessing the heating procedure within the model. Therefore, in both instances, the simulation model offers crucial insights into the nonlinear electromagnetic and thermal properties of the the workpiece material. To confirm the results of the simulation model, a laboratory prototype is constructed, and comparison between experimental temperature measurements and simulation results is conducted
The effect of union commitment on job engagement and organizational commitment
No full textSosyal Bilimler Enstitüsü, İşletme Ana Bilim DalıEldeki çalışmada sendikaların değeri, örgütsel bağlılık ve iş tatmini kavramlarına odaklanan bir yazıdan bahsedilmektedir. Sendikaların hem işçilerin haklarını savunan bir örgüt hem de işverenlerin bir örgütü olduğu vurgulanmaktadır. İş doyumu kavramı Hawthorne araştırmalarından başlayarak önem kazanmış ve Maslow - ihtiyaçlar hiyerarşisi ve Herzberg- Çift Faktör Teorisi gibi teorilerle açıklanmıştır. Tezde iş memnuniyeti, örgütsel bağlılık ve katılımcıların iş doyum düzeyi arasındaki ilişkiyi ele almaktadır. Yönetsel özerklik ve örgütsel adalet gibi faktörlerin iş doyumu üzerindeki etkileri de vurgulanmaktadır. Örgütsel bağlılık ise örgütün amaçlarına katılma isteği olarak tanımlanmış ve davranışsal ve tutumsal bağlılık ile devam bağlılığı olarak üç aşamada incelenmiştir. Tezin son bölümünde ise 400 kişi ile yapılan bir anketin amacı ve veri analizi hakkında bilgiler yer almaktadır. Araştırmanın amacı, katılımcıların sendikaya bağlılık, iş memnuniyeti ve örgütsel bağlılık düzeylerini belirlemektir. Bu amaçla bir takım sorulara cevap aranmıştır.In this study, an article focusing on the importance of unions and the concepts of job satisfaction and organizational commitment is mentioned. It is emphasized that unions are both an organization that defends the rights of workers and an organization of employers. The concept of job satisfaction gained importance starting with Hawthorne research and was explained by theories such as Maslow's hierarchy of needs and Herzberg's Double Factor Theory. The thesis deals with the relationship between job satisfaction, organizational commitment and teachers' job satisfaction level. The effects of factors such as managerial autonomy and organizational justice on job satisfaction are also emphasized. Organizational commitment, on the other hand, was defined as the willingness to participate in the goals of the organization and examined in three dimensions: attitudinal commitment, behavioral commitment and continuance commitment. In the last part of the thesis, there is information about the purpose and data analysis of a survey with 400 people. The aim of the research is to determine the union commitment, job satisfaction and organizational commitment levels of the participants. For this purpose, answers were sought to a number of questions
Maternal Blood Group Is a Possible Predictor for Developing Congenital Heart Disease in Turkish Children with Down's Syndrome
No full textWe aimed to evaluate the clinical characteristics and the risk factors for the anomalies of Down's syndrome (DS) patients and reviewed the relation of blood groups of the patients and the mothers with these anomalies. Pediatric patients who were diagnosed with trisomy 21 between 2010 and 2022 were enrolled in this study. The medical records of the DS patients and their parents were retrospectively reviewed. A total of 48 patients applied to our clinic. 24 (50%) patients were diagnosed with congenital heart disease. 21 (43.75%) patients had hypothyroidism. The distribution of individual congenital heart defects (CHDs) was as follows: ventricular septal defect in eight (33.3%) patients, one of which also had patent ductus arteriosus (PDA); atrioventricular septal defects in seven (29.1%) patients; atrial septal defects in four (16.6%) patients, one of which also had patent ducus arteriosus; and PDA in five (20.8%) patients. One (4.2%) patient had tetralogy of Fallot. The incidence of CHD in patients with maternal blood group A was significantly higher than those without CHD, with a prevalence of 63.6 and 21.1%, respectively ( p = 0.020). Binary logistic regression analysis showed that maternal blood group A was a risk factor for CHDs (odds ratio = 6.563; 95% confidence interval: 1.259-34.204; p = 0.025). Although we found that the rate of advanced father age was high in hypothyroidism type, the regression analysis showed that it was not a risk factor. We found that maternal blood group A increased the likelihood of being born with CHDs in DS
Clinical and Treatment Evaluation of Anaphylaxis in Children Aged 0-2 Years: Multicenter Study
No full textBackgroundDiagnosing anaphylaxis in children within the first 2 years of life can be difficult due to the often confusing and nonspecific signs and symptoms.ObjectiveThis study focuses on the phenotype of anaphylaxis in children within the first 2 years of life and aims to increase awareness of anaphylaxis in this age group.MethodsThe study included children between 0 and 2 years who were diagnosed as having anaphylaxis by pediatric allergists in 11 tertiary hospitals.ResultsA total of 402 anaphylaxis episodes experienced by 360 patients (68.7% males) were included in the study. Food was the most common causative agent (n = 374, 93%), with the most common foods being cow's milk (n = 179, 44.6%). Drugs were the second most common trigger (n = 15, 3.7%). The most common clinical findings were cutaneous (95%) and respiratory (72%); nonspecific symptoms such as weakness (n = 63, 15.6%) and hoarseness (n = 14, 3.4%) were also reported. There was a biphasic course in 3 infants (0.8%). Only 3 of the 41 parents who had an adrenaline autoinjector used it during anaphylaxis.ConclusionInfants experience anaphylaxis most often when they are at home with their mothers, and the most common triggers are foods, particularly cow's milk and egg. Greater awareness of anaphylaxis symptoms and autoinjector use among mothers can facilitate management.ImpactInfant anaphylaxis cases may present with different symptoms compared to classic presentations, potentially leading to diagnostic oversight.The study elucidates the clinical course of anaphylaxis in children under 2 years of age.It details the treatment strategies employed in managing these cases.Anaphylaxis triggers were identified over several years.Cases from 11 regions of Turkey were included, representing a population reflective of national data.The study highlights the distinctiveness of anaphylaxis cases in children within the first 2 years of life
An investigation of prospective mathematics teachers' perceptual processes of geometric reasoning
No full textFen Bilimleri Enstitüsü, İlköğretim Matematik Öğretmenliği Ana Bilim DalıBu çalışmanın amacı ilköğretim matematik öğretmeni adaylarının geometrik muhakeme süreçlerini ve geometrik muhakemenin algısal süreçlerini incelemektir. Araştırma 2022-2023 eğitim yılında Orta Anadolu'da bir devlet üniversitesinde birinci ve dördüncü sınıfta öğrenim gören toplamda 62 gönüllü ilköğretim matematik öğretmen adayı ile yapılmıştır. Verilerin toplanması, analizi ve yorumlanmasında nitel araştırma yöntemleri arasında yer alan durum çalışması yöntemi tercih edilmiştir. Araştırmanın verileri, Duval'in bilişsel modelinin ilkelerinden hareketle dokuz sorudan oluşan "Geometrik Muhakeme Süreçleri ve Geometrik Muhakemenin Algısal Süreçleri Soru Seti" ve "yarı yapılandırılmış görüşmeler" ile elde edilmiştir. Yarı yapılandırılmış görüşmeler 9 gönüllü öğretmen adayı ile yapılmıştır. Araştırma kapsamında elde edilen veriler, hem frekans analiz hem de betimsel analiz yaklaşımı ile analiz edilmiştir. Elde edilen bulgular sonucunda görsel algı ve sözel algı sorularında verilen yanıtlar doğrultusunda öğretmen adaylarının çoğunluğunun geometrik şekli doğru isimlendirip, sözel algı muhakeme sürecine sahip olduğu görülmüştür. Sıralı algı sorularında öğretmen adaylarının çoğunluğu geometrik şekli araç kullanmadan şeklin kuruluşunu tarif ederek çizmişler ve bu sonuç onların sıralı algıyı kullandıklarını göstermektedir. Son olarak işlevsel algı sorularında öğretmen adaylarının çoğunluğu geometrik şekli alt parçacıklara ayırarak işlevsel algıyı kullandıkları tespit edilmiştir. Diğer taraftan, soru setindeki tüm sorulara her iki sınıf seviyesinde öğrenim gören öğretmen adaylarının çoğunluğunun matematiksel kavramlar kullanarak tasvir ettikleri için teorik muhakeme becerisine sahip olduğu sonucuna ulaşılmıştır.The aim of this study is to examine the geometric reasoning processes of prospective elementary mathematics teachers and the figure apprehension processes. The research was conducted with a total of 62 volunteer prospective elementary mathematics teachers who were continuing their education as a 1st and 4th grader at a state university in Central Anatolia in the 2022-2023 academic year. The case study method, which is among qualitative research, was preferred to collect, analyz and interpret data. The data of the research were obtained through "Geometric Reasoning Processes and Figure Apprehension Processes of Geometric Reasoning Question Set" consisting of nine questions based on the principles of Duval's cognitive model. Alsosemi-structured interviews were conducted with 9 volunteer prospective teachers. The data obtained within the scope of the research was analyzed with both frequency analysis and descriptive analysis approaches. As a result of the findings, it was seen that the majority of prospective teachers named the geometric shape correctly and had a discursive apprehension reasoning process, in line with the answers given to the perceptual apprehension and discursive apprehension questions. In the sequential perception questions, the majority of prospective teachers drew the geometric shape by describing the construction of the shape without using tools, which shows that they used sequential perception. Finally, it was determined that in operative perception questions, the majority of prospective teachers used operative perception by dividing the geometric shape into sub-particles. On the other hand, it was concluded that the majority of prospective teachers studying at both grade levels had theoretical discursive process because they described all questions in the question set using mathematical concepts
Developments in the RCCI engines powered by several alternative fuel types: An overview
No full textThe perspective on internal combustion engines (ICEs) has changed because of the step-by-step decrease in oil reserves, environmental concerns, and many other reasons. However, the use of these engines will continue in the coming years. The development of ICEs has accelerated in recent years. As a result, studies on systems that can improve performance and reduce pollution in engines are carried out by many researchers. The basis of the studies carried out in this context is the change in the combustion mode. In other words, the emergence of different combustion modes is given importance by researchers. Among these, many studies have been made on the implementation of the reactivity-controlled compression ignition (RCCI) combustion mode. RCCI engine uses two different fuels. These fuels are low-reactivity (alcohol, gasoline, etc.) and high-reactivity (diesel, biodiesel, etc.) fuels. In addition, the fact that different alternative fuel types can be employed in these engines has made them popular all over the world. This review presents the results of the effects of parameters such as fuel ratio, different injection strategies, exhaust gas recirculation (EGR) rate, compression ratio, and piston geometry on the performance, emissions, and combustion behavior of RCCI engines using both conventional and alternative fuels. This study has been compiled to provide an overview of the current status of the RCCI concept and to offer benefits to researchers