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A thermohydrodynamic performance analysis of a fluid film bearing considering with geometrical parameters
No full textBearing performance characteristics such as stiffness, and load capacity, are related to the lubrication fluid circulating through the gap. In the fluid film bearings, the characteristic of the lubrication film also depends on the journal geometry and the viscosity. This study aimed to research the bearing geometry influences on the thermohydrodynamic performance of a circular journal bearing. The temperature distribution is modeled using a 3-dimensional energy equation. The velocity components are obtained on the pressure distribution governed by Dowson's equation. Moreover, the heat transfer between the journal and oil is modeled with Fourier heat conduction equation, and the viscosity equation is derived for SAE10W30 commercial oil as a function of the temperature. An algorithm based on the finite difference method is developed, and a serial simulation is performed for different geometrical parameters such as bearing clearance, and bearing length-to-diameter ratio (L/D). When the radial clearance decreases from 150 i.tm to 100 i.tm, the maximum pressure grows up by 53%, and the maximum temperature decreases by 21%. On the other hand, when the L/D ratio rises from 0.8 to 1, the maximum pressure grows up by 22%, but the temperature distribution does not significantly change. The load capacity, and the stiffness are higher for low radial clearance. The load capacity, and the stiffness increase when the L/D ratio grows up
Drying of dairy products
No full textMilk is a special raw material in the food industry, with its unique components, these components' valuable properties, ease of fractionation, and susceptibility to change. All these features create important opportunities and grounds for the drying of dairy products. Today, a wide variety of dried dairy products are available in the market, and studies continue to improve their quality and variety. Moreover, researchers have carried out studies to preserve the valuable dairy ingredients during drying and deliver them in their active form to the organs, where they will present their prospective impact. As the drying of dairy products is a comprehensive topic, in this chapter, dried dairy products are summarized, and the recent efforts to overcome the challenges in their production are discussed within the scope of some highlighted issues. © 2023 Elsevier Inc. All rights reserved
Green Synthesis and Characterization of Fe2O3 Nanoparticles
No full textThe aim of this study is to produce iron III oxide (Fe2O3) nanoparticles due to their wide application area. The ethanolic extract of curcuma was used in the synthesis method due to number of advantages. These benefits include being inexpensive, widely accessible, simple to extract, and less prone to contamination. The produced particles were analyzed via scanning electron microscope (SEM), energy dispersive analysis (EDX), and transmission electron microscope (TEM). Furthermore, the zeta potential of Fe2O3 particles was determined, ultraviolet–visible spectroscopy (UV) analysis and fourier transform infrared spectroscopy (FTIR) analysis were done. According to the results obtained, granular nanoparticles with particle sizes ranging from 30 to 80 nm were synthesized and it was determined that they were sufficiently stable
Effects of milk types used in Antep cheese production on some cheese organoleptic quality parameters and brine composition during 5-month ripening
No full textAntep cheese is a local Turkish cheese characterized by scalding during production and ripened in brine. In this study, Antep cheeses were produced using mixtures of different milk types (cow, sheep, and goat milk) and ripened for 5 months. The composition, proteolytic ripening extension index (REI), free fatty acid (FFA) content, and volatile compounds of the cheeses and the variation of the brines were analyzed for the 5-month ripening period. Low proteolytic activity in cheese during ripening caused the cheeses to have low REI values (3.92%-7.57%), although it was observed that some parts of the water-soluble nitrogen fractions diffused into the brine, causing a lower REI. As a result of lipolysis during ripening, total FFA (TFFA) concentrations in all cheeses were increased, whereas the highest increases were detected in the concentrations of short-chain FFAs. The highest FFA concentrations were determined in cheese produced using goat milk, and the volatile FFA ratio in TFFA exceeded 10% in the third month of ripening. Although it was observed that the milk types used in the production had significant effects on the change of volatile compounds of the produced cheeses and their brines, the impact of the ripening time was more important. Practical ApplicationThis study investigated Antep cheese made with different milk types. Volatile compounds and soluble nitrogen fractions were transferred to the brine by diffusion during ripening. The volatile profile of the cheese varied with milk type, but ripening time was the primary factor influencing volatile compounds. This suggests that the targeted organoleptic properties of the cheese are determined by ripening time and conditions. Additionally, changes in the brine's composition during the ripening process provide insight into how to manage the brine as waste.Scientific Research Project Fund of Adana Alparslan Tuuml;rkes Science and Technology University [18332012]ACKNOWLEDGMENTS This study is a part of the M.Sc. thesis Quality characteristics of Antep cheese manufactured using different milk types and their variation with ripening and is supported by the Scientific Research Project Fund of Adana Alparslan Turkes Science and Technology University under the project number 18332012
Altcoin piyasalarında fiyat balonu oluşumu
No full textLisansüstü Eğitim Enstitüsü, İşletme Ana Bilim Dalı, Finans Bilim DalıBu çalışmanın amacı 2018-2021 yılı dönemleri yüksek piyasa değeri gösteren Dogecoin (DOGE), Crypto.com (CRO), Binance Coin (BNB) ve Polygon (MATIC) gibi altcoin para birimlerinde ekonomik balonların varlığını araştırmaktır. Altcoinlerde finansal balonların varlığını tespit etmek için Supremum Augmented Dickey-Fuller (SADF) sağ kuyruklu birim kök testi kullanıldı. Çalışma sonucunda özellikle 2020Ç4 ve 2021Ç4'te incelenen altcoin fiyatlarında balon oluşumu tespit edildi. Ekonomik balonun tespit edildiği dönemler değerlendirildiğinde balonların haber kaynaklı manipülasyonlara ve Covid-19 korkusuna dayandığı sonucuna varıldı. Çalışma, pandemi sonrası dönemde altcoin piyasalarında balonların varlığına yeni bir ışık tutuyor.The purpose of this study is to investigate the existence of economic bubbles in altcoin currencies such as Dogecoin (DOGE), Crypto.com (CRO), Binance Coin (BNB), and Polygon (MATIC), which showed high market capitalization during the periods 2018-2021. The existence of bubbles in these altcoins are examined by utilizing the Supremum Augmented Dickey-Fuller (SADF) right-tailed unit root test. As a result of this study, a bubble formation was detected in the altcoin prices, which was carefully examined, especially in 2020Q4, and 2021Q4. When the periods in which the economic bubble was detected were evaluated, it was concluded that the bubbles were based on news-related manipulations and Covid-19 fear. This study sheds new light on the existence of bubbles in the altcoin markets in the post-pandemic period
3D-Printed Antenna Design Using Graphene Filament and Copper Tape for High-Tech Air Components
No full textAdditive manufacturing (AM) technologies can produce lighter parts; reduce manual assembly processes; reduce the number of production steps; shorten the production cycle; significantly reduce material consumption; enable the production of prostheses, implants, and artificial organs; and produce end-user products since it is used in many sectors for many reasons; it has also started to be used widely, especially in the field of aerospace. In this study, polylactic acid (PLA) was preferred for the antenna substrate because it is environmentally friendly, easy to recycle, provides convenience in production design with a three-dimensional (3D) printer, and is less expensive compared to other available materials. Copper (Cu) tape and graphene filament were employed for the antenna patch component due to their benefits. The comprehensive comparative analysis between a full-wave model and a 3D-printed prototype of the antenna via the CST Microwave Studio program was demonstrated here. The surface characterization was achieved with scanning electron microscope and energy dispersive X-ray (SEM-EDX) and X-ray diffractometer (XRD) analysis. The homogeneous Cu and oxidized graphene (GO) were detected. The weight percent of carbon (C) and oxygen (O) on the graphene surface was 59.82% and 40.18%, respectively. The Cu (111), Cu (200), and Cu (220) peaks were determined on the Cu tape. The GO (011) peak was seen in the XRD spectra of the graphene sheet. The simulation and measurement comparisons are quite satisfactory. The antennas, produced using a conventional 3D printer, will be beneficial for various applications in aeronautics and astronautics.Adana Alparslan Tuerkes~Science and Technology University Scientific Research Projects Coordination Unit [19119001]We are deeply thankful to TUBITAK ATAM (the Scientific and Technological Research Institution of Turkey Antenna Test and Research Laboratory) for the analysis. This work has been supported by Adana Alparslan Tuerkes Science and Technology University Scientific Research Projects Coordination Unit under grant number 19119001
Muhasebe tarihi dergilerinde yayınlanan çalışmalar üzerine karşılaştırmalı bir inceleme
No full textLisansüstü Eğitim Enstitüsü, İşletme (İngilizce) Ana Bilim DalıMuhasebe tarihi en önemli kaynaklarından olan muhasebe tarihi dergileri 1970'lerin başından itibaren yayınlanmaya başlamıştır. O tarihten başlayarak günümüze kadar toplam yedi muhasebe tarihi dergisi yayın hayatına başlamış ve devam etmektedir. Bu dergilerden ilk üçü muhasebe tarihi yayıncılığı bakımından öncü olarak kabul edilmektedir. Yayına hayatına 2011 yılında başlayan son dergi ise, Türkiye'de yayınlanmakta olan muhasebe tarihi dergisidir. Bu suretle, çalışmanın amacı,1970'lere kadar dayanan muhasebe tarihi alanında öncü üç muhasebe tarihi dergisi ve Türkiye'de yayınlanmakta olan muhasebe tarihi dergisinde yayınlanan makalelerin bibliyometrik analizini gerçekleştirmektir. Bu amaçla seçilen dört dergide, 1974-2021 yılları arasında yayınlanmış 2.968 başlıkta yer alan eserler içinde yüzde 53'lük paya sahip olan 1.562 makale tespit edilmiştir. Söz konusu makaleler; tür, konu yazarlık bağlamı (sayı, ortaklık ve tekrar etme), anahtar kelimeler, makalelerde incelenen coğrafya ve zaman dilimi bakımından ayrıntılı olarak MAXQDA nitel araştırma programı aracılığıyla içerik analizi yapılarak incelenmiştir. İncelenen dergilerden elde edilen bulgular; dört muhasebe dergisinde de yüzde ellinin üzerinde arşiv araştırması makalelerin bulunduğunu; makalelerde ele alınan konuların çoğunlukla teknik muhasebe uygulamaları üzerine yoğunlaştığı ancak muhasebe ile ilgili olmayan, özel alan olarak sınıflandırılan, konuların bazı temel muhasebe konularından dahi fazla yer tuttuğu görülmüştür. Toplam 3.708 yazar ismine ulaşılmış olup, toplam yazarların ancak yüzde 17'si kadındır. Ortak yazarlık ve tekrar eden yazarlıkta da oranların; tek yazarlık ve sadece bir kez muhasebe tarihi çalışması yapanlara oranla düşük olduğu tespit edilmiştir. İncelenen makalelerde toplam 4.635 anahtar kelime tespit edilmiş olup, "muhasebe tarihi" yerine sadece "muhasebe" kelimesinin daha sık anahtar kelime olarak kullanıldığı görülmüştür. Makalelerde geçen lokasyonlar bakımından bulgular incelenen üç yabancı dergide ABD, İngiltere, İtalya, Fransa; ulusal dergide ise, Osmanlı, Rusya ve Türkiye üzerinde yoğunlaşmıştır. Makalelerin yaklaşık üçte biri herhangi bir zaman dilimini işaret etmezken, tüm dergilerde 19. ve 20. yüzyılları inceleyen çalışmalar yoğunluktadır. Araştırma sonuçları, muhasebe tarihi alanında yayınlanan dört dergi kapsamında; makalelerin arşiv araştırması ağırlıklı olduğu ancak artık muhasebe tarihi araştırmalarının teknik muhasebe uygulamalarından ayrılarak muhasebe tarihi ile ilişkili konulara yoğunlaşması gerektiğine dikkat çekmektedir. Ayrıca yazarların muhasebe tarihi birikimlerini ortak yazarlarla paylaşarak bu alanda çalışmalarını artırmaları ve kadın yazar katılımının artırılmasıyla alanda çeşitliliğin artacağı değerlendirilmektedir. Bilimsel araştırmalarda görünürlüğün artması için seçilen anahtar kelimelerin muhasebe tarihi ile ilintili olmasına özen gösterilmesi; dar ülke örneklem ve kısıtlı zaman dilimlerinin dışına çıkılması konularında muhasebe tarihi araştırmacılarının daha fazla eğilim göstermesi gerektiği hususları değerlendirilmiştir.Accounting history journals, which are among the most important sources of accounting history, have been published since the early 1970s. Starting from that date, a total of seven accounting history journals have started their publication life and continue. The first three of these journals are considered to be pioneers in accounting history publishing. The last journal, which started its publication life in 2011, is the journal of accounting history published in Turkey. In this way, the aim of the study is to perform the bibliometric analysis of the articles published in the three leading accounting history journals in the field of accounting history dating back to the 1970s and the accounting history journal published in Turkey. For this purpose, 1,562 articles, which have a 53 percent share among the works in 2,968 titles, published between 1974-2021 in the four journals selected for this purpose, were identified. The articles in question; genre, subject authorship context (number, partnership and repetition), keywords, geography and time period examined in the articles were examined in detail by content analysis through the MAXQDA qualitative research program. Findings from the reviewed journals; that there are more than fifty percent archival research articles in all four accounting journals; It has been observed that the topics covered in the articles mostly focus on technical accounting practices, but the topics that are not related to accounting, classified as special fields, take up more space than even some basic accounting topics. A total of 3,708 author names were reached, and only 17 percent of the total authors are women. The rates of co-authorship and repeat authorship; It has been determined that it is lower than those who have done a single authorship and accounting history study only once. A total of 4,635 keywords were identified in the articles examined, and it was seen that only the word "accounting" was used more frequently as a keyword instead of "accounting date". In three foreign journals, the findings of which were examined in terms of the locations mentioned in the articles, USA, England, Italy, France; in the national journal, it focused on the Ottoman Empire, Russia and Turkey. While about a third of the articles do not indicate any time period, studies examining the 19th and 20th centuries are concentrated in all journals. The results of the research, within the scope of four journals published in the field of accounting history; It draws attention to the fact that the articles are mainly on archival research, but now accounting history studies should be separated from technical accounting applications and focus on accounting history-related issues. In addition, it is considered that the diversity in the field will increase with the increase of the authors' work in this field by sharing their accounting history knowledge with co-authors and increasing the participation of women writers. In order to increase visibility in scientific research, care should be taken to ensure that the selected keywords are related to the accounting history; It has been evaluated that accounting history researchers should show more tendency in terms of narrow country sample and going beyond limited time periods
Analysing Vehicle Routing in Urban Pest Control Using a Cluster-First Route-Second Approach
No full text11th International Conference on Information Technology, ICIT 2023 -- 9 August 2023 through 10 August 2023 -- Amman -- 192131Insects are generally characterized as organisms that have negative impacts on both human health and the environment in areas where human habitation exists. These pests typically inhabit and reproduce in locations that contain waste, such as garbage sites, abandoned places, and septic tanks. House flies, for instance, can significantly affect the daily lives of individuals and even prompt widespread epidemics by transmitting diseases to humans. To mitigate the proliferation of pests and minimize their environmental damage, pest control is a crucial responsibility that falls under the jurisdiction of municipalities in Turkey. Municipalities commonly utilize chemical-based methods that are non-hazardous to humans and the environment while concurrently efficacious in exterminating pests or thwarting their reproduction. These chemicals are typically prepared by experts and then applied to the areas in which the pests reside. However, the primary issue that municipalities encounter is the vast expanse of land that needs to be managed, coupled with limited resources in terms of both human labor and equipment, alongside the dispersal of pests' living and breeding locations throughout a broad territory. To address this problem, this study employed the coordinates of previously identified insect nests. These nests were divided into clusters based on predetermined criteria using the k-means method within the municipality borders. Then, utilizing Google or-tools, the distance to be covered by the vehicle for each cluster was calculated. Finally, comparisons were made between the obtained results, and various recommendations were proposed. © 2023 IEEE.Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, TÜBİTAK, (5220069
YENİDEN İŞLEVLENDİRMEDE YAPININ FİZİKSEL ÇEVRE DENETİMİ PERFORMANSININ KULLANICI ÜZERİNDEN DEĞERLENDİRİLMESİ
No full textYeniden işlevlendirilen yapılarda fiziksel çevre denetimi performansını, kullanıcı odaklı mimari tasarım süreçlerinde ve sürecin geri bildirim aşamalarında önem teşkil eden “kullanıcı” üzerinden değerlendirmek, çalışmanın amacını oluşturmaktadır. Değerlendirme sürecinde kullanılmak üzere bir ölçek geliştirilmiştir. Ölçek; ısıtma, soğutma, havalandırma, aydınlatma, akustik, güvenlik ve nem olmak üzere yedi ölçütten oluşmaktadır. Her ölçütün içerdiği değerlendirme önermeleri ile kullanıcılardan veri elde edilmesi sağlanmıştır. Çalışmada, Adana’nın Seyhan ilçesinde yer alan ve yeniden işlevlendirilmiş olan Hamamlı Konak yapısı ele alınmış ve yapının kullanıcıları çalışmanın örneklemi olarak belirlenmiştir. Fiziksel çevre denetimi performansı, kullanıcıları üzerinden incelenen Hamamlı Konak’ın özellikle ısıtma ölçütünde yetersiz kaldığı; akustik, aydınlatma, havalandırma ve güvenlik ölçütlerinde ortalama değerler aldığı; nem ve soğutma ölçütlerinde ise performansının daha yüksek olduğu sonucuna varılmıştır. Çalışmada elde edilen bulgular ve sonuçlar dahilinde yapının fiziksel çevre denetimi performansını arttırmaya yönelik iyileştirmelerin yapılması, kullanıcıların yapıyı kullanma sürecindeki konfor koşullarının artması ve memnuniyet düzeylerinin yükselmesinin sağlanması açısından önemli bulunmuştur
Early Epileptic Seizure Prediction Using EEG Signals with Machine Learning
No full text9th World Congress on Electrical Engineering and Computer Systems and Sciences, EECSS 2023 -- 3 August 2023 through 5 August 2023 -- London -- 305029Epilepsy is a chronic disease that dates back to ancient times and affects people only during seizures. Since the onset of seizures is unknown, it heavily poor affects the living standards of patients. If seizure onset can be predicted in sufficient advance, seizures can be prevented with drugs to be used or an opportunity can be provided for patients who cannot be stopped with drugs to move to a safe zone. For this purpose, to predict an epileptic seizure, before a certain period of time happens, frequency-based feature extraction is applied with the use of recorded EEG data. Bases of the study rely on creating time for patients to reach necessary medications approximately ahead 30-60 minutes before having an epileptic seizure. In this respect, an open-access dataset with 24 pediatric patients’ EEG recordings was used and frequency-based feature extraction was performed using wavelet transformation. Afterward, classification performances of the features are compared for a k-nearest neighbor (k-NN), random forest algorithm (RF), support vector machine (SVM), and J48 which are extensively used machine learning techniques. In accordance with the classification results, the average highest accuracy was acquired as 99.87% with the SVM classifier. © 2023, Avestia Publishing. All rights reserved.Adana Alparslan Türkeş Bilim ve Teknoloji Üniversitesi, ATÜ, (22303005