Osmaniye Korkut Ata University Academic Repository
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Borlanmış AISI H11 Takım Çeliğinin Kaplama Özellikleri ve Korozyon Oranının Makine Öğrenmesi Temelli Modellenmesi
No full textYüksek sertlik, aşınma ve korozyon direncinde önemli ölçüde artışlar sağlaması nedeniyle borlama işlemi kullanılan en yaygın termokimyasal kaplama işlemlerinden birisidir. Bu çalışmada sıcak iş takım çeliklerinden AISI H11 malzemenin kutu borlama tekniğiyle borlanmasında işlem sıcaklığı ve süresinin kaplama kalınlığı, yüzey pürüzlülüğü, sertliği ve korozyon oranına etkisi makine öğrenmesi yöntemleriyle modellenmiş ve incelenmiştir. Çalışma kapsamında çoklu doğrusal, K en yakın komşu, destek vektör makinesi, karar ağacı, rastgele orman ve ekstrem eğim arttırma regresyon algoritmaları ile modeller oluşturulmuş ve bu modellerin performansları R2, ortalama mutlak hata ve ortalama kare hatası kriterleri kullanılarak kıyaslanmıştır. Kaplama tabakası kalınlık ve sertlikleri işlem sıcaklığı ve süresi ile artmaktadır. Diğer yandan bu özellikleri üzerinde borlama sıcaklığı süreye göre daha etkilidir. Regresyon modeli sonuçları incelendiğinde kaplama parametrelerinin kaplama kalınlığına ve pürüzlülüğe olan etkilerinin birleşerek korozyon oranı üzerinde kümülatif bir etkiye dönüştüğü görülmüştür. Çalışma sonucunda AISI H11 çeliğinin borlanmasında korozyon direnci için optimum parametre değerlerinin 1000 °C ve 2,2 saat olduğu sonucuna varılmıştır
The impact of geopolitical risks on clean energy mineral prices: Does the Russia-Ukrainian war matter?
No full textThe transition to a low-carbon economy requires a steady and secure supply of minerals, which are susceptible to international tensions. In particular, the coronavirus pandemic in 2019 and the Russia-Ukraine conflict in 2022 are two novel shocks affecting the clean energy market. Measuring the impact of increasing geopolitical risks due to these shocks on the clean energy sector is critical to the future of sustainable development. In this framework, this study uses wavelet coherence analysis and time-varying parameter VAR methods to examine the impact of geopolitical risks on the prices of aluminum, copper, lead, zinc, cobalt, and nickel from January 1992 to August 2022. The results show that mineral prices decreased during the COVID-19 period and increased after the Russia-Ukraine conflict. The results also indicate that global geopolitical risk has a moderating effect on the prices of copper, aluminum, cobalt, and zinc, while geopolitical risk associated with Russia increases the prices of all minerals except cobalt. These results imply that the problems in Russia destabilize the prices of mineral commodities used in the renewable energy market, while the global geopolitical risks do not pose serious problems. Therefore, the Russian-Ukrainian conflict should be resolved in order to use clean energy minerals more effectively
Dr. Sait Bilal Golem (1899-1955): Veterinarian and pioneer researcher of public health in Albania and Turkey
No full textSait Bilal Golem is an Albanian veterinarian who graduated from the Military Veterinary School in 1920. Golem started his doctorate in microbiology at Alfort Veterinary School. In this process, he worked as an assistant to the world-renowned French microbiologist Dr Gaston Ramon at the Pasteur Institute. After his doctorate, he returned to Albania and established the Veterinary Affairs Organization and made significant contributions to its structuring in international standards. Dr Golem returned to Turkiye in 1926 and started working at the Central Institute of Hygiene. Dr Golem, together with physicians and veterinarians at this institute, diagnosed brucellosis in animals and humans with serological methods for the first time in Turkiye. Moreover, he isolated Newcastle virus from embryonated eggs for the first time and prepared Komarov type attenuated dry vaccine against this virus for the first time in Turkiye. He conducted the first research on the diagnosis of Q fever and prepared the first intradermal BCG vaccine in Turkiye. Through his studies for both public and animal health in Turkiye, he has contributed to the One Health concept with an understanding that transcends time
Development of Comparative Forecasting Models of Daily Prices of Aggressive Pension Mutual Funds by Univariate Time Series Methods
No full textThe primary goal of the individual pension system is to enhance retirees' living standards by generating supplementary income through the investment of their savings during retirement. This involves guiding individuals to invest their savings in pension mutual funds. This research aims to develop comparative forecasting models using Autoregressive Integrated Moving Average (ARIMA) and Exponential Smoothing techniques for the daily prices of pension mutual funds categorized as aggressive risk. The study utilizes data from 2020 to 2023 pertaining to a pension mutual fund provided by a Turkish pension company. The dataset is split into a training set (75%) and a validation set (25%). Mean Absolute Percentage Error (MAPE) is employed to gauge the error measurement values of the training and validation sets of the developed forecasting models. The findings reveal that for the validation sets, ARIMA model performs best for the İş Bank participation index funds, whereas Exponential Smoothing forecasting models yield the lowest MAPE values for equity, group equity, and secondary equity funds. This research can serve as a decision-making tool for the effective management of high-yield pension mutual funds and aid pension companies in enhancing the appeal of their product offerings to customers.Not Applicabl
Exact Transient Heat Conduction of Functionally Graded Thick Structures
No full textClosed form solution of the transient thermal analysis in functionally graded cylindrical and spherical bodies under different thermal loads are presented. It is assumed that the material properties change according to the different inhomogeneity parameters according to the power-law in the radial direction. In the partial differential equation obtained under these conditions, the time dependence is eluted with the Laplace transform and transformed into Bessel differential equation in Laplacian space. This equation, which is solved with Bessel functions in Laplacian space, is transformed into physical space with the modified inverse Durbin method. Behaviors of cylindrical and spherical bodies under constant, convective and time-dependent boundary conditions are investigated. Besides, it is aimed to obtain benchmark solutions for these structures to the literature
A comparative investigation of eco-friendly fly ash-based geopolymer mortar produced by using electrical and heat curing: Mechanical properties, energy consumption and cost
No full textThis study investigates the eco-friendly fly ash-based geopolymer mortar (GM) production using electrical curing (EC) and heat curing. Within the scope of the study, GM produced using the EC method was compared with GM produced using the heat curing (HC) method in terms of mechanical properties, energy consumption, and cost. The study consists of a preliminary experiment to determine the parameters to be used, mortar experiments using the limited parameters defined in preliminary experiments, and an energy consumption and cost analysis. In the preliminary experiments, different mix designs produced according to different MS modulus and Na 2 O concentrations were studied to decide an applicable range for temperatures of HC and an applicable range for voltages of EC. In the second stage, EC and HC were compared according to temperature changes in GMs, current changes in GMs, and compressive strength (CS). As a final stage, an energy consumption and cost analysis were performed to compare two curing methods according to the updated dollar-based unit prices for electricity per kWh for industrial uses in various countries in February 2024. Results showed that the MS modulus should be at least 1.2 and the Na 2 O concentration should be 10 % on average to obtain a workable mortar. The compressive strength of all mortars with any MS modulus increased up to 100 degrees C and then decreased HC applied samples. Stress values of 20, 25, 30, and 35 volts are applicable and the highest compressive strength values could be obtained with 25 volts, and 6 h of application is sufficient at 25 volts EC. MS module is a key parameter in current and temperature change. In EC application, 30 volts is the threshold value, and when an electrical voltage above 30 volts is applied, the mortar 's internal temperature suddenly reaches the peak value and the desired compressive strength results cannot be achieved. According to the cost analysis, it is seen that the HC electricity cost is 6.78 times more than the EC cost. A comprehensive efficiency calculation is strongly recommended for future studies. It has also been concluded that geopolymers could gain strength at much lower voltage values, so they have the potential to consume less electrical energy in comparison to conventional concrete.Adana Alparslan Turkes, Science and Technology University Scientific Research Projects Coordination Department [21103011]This article has been supported by the Adana Alparslan Turkes, Science and Technology University Scientific Research Projects Coordination Department under 21103011 Project No
Fresh evidence of the impact of economic complexity, health expenditure, natural resources, plastic consumption, and renewable energy in air pollution deaths in the USA? An empirical approach
No full textMost plastic waste generated from plastic consumption cannot be recycled and is destroyed by burning. As a result of burning plastics, microplastics spread into the atmosphere, increasing air pollution. Respiratory diseases and chronic health problems are caused by air pollution. Approximately 7 million people die each year due to pollution -related ailments. Therefore, it is crucial to provide empirical evidence rather than approximate estimates of the role of plastic consumption in air pollution -related deaths. Also, understanding the causes of air pollution -related deaths and demonstrating the policies' effectiveness will provide valuable insights for policymakers, the international community, and researchers. This study investigates the effects of plastic consumption, health expenditures, natural resources, economic complexity, and renewable energy on air pollution deaths in the USA from 1995 to 2019 using the novel Fourier Augmented ARDL method. The findings show that plastic consumption, health expenditures, natural resources, and economic complexity increase air pollution deaths, while renewable energy decreases it. Such findings imply that plastic consumption is an essential determinant of air pollution -related mortality, that health policy must be reconsidered, that efficient use of resources is important and that sophisticated economic structures do not always produce the desired results. Overall, policymakers should review health policies to reduce deaths from air pollution and take measures to support green growth using renewable energy and economic complexity tools
Optimization of Product Costs in the Food and Beverage Business: A Target Costing Approach
No full textPurpose – The study aims to evaluate the feasibility of implementing the target costing method in a local food and beverage business, aiming to optimize product costs and boost product demand through cost reduction and pricing products below market prices. Design/methodology/approach – Interviews were conducted with business owners to develop standard recipe cards for the four products, and a comparison was made between current costs and target costs. Analysis of standard recipe cards for these products was performed to calculate material cost ratios, unit contributions, and contribution rates. The target costing method was implemented by adjusting the quantities of components and exploring supplier alternatives to reduce costs and increase target cost indices. Findings – The findings revealed that the target costing approach led to varying degrees of cost reduction and improved contribution margins for the four products. However, the desired enhancements in target cost indices were not fully achieved, highlighting the need for further assessment of supply, pricing, and material sourcing. Discussion – The study highlights the potential of target costing in optimizing costs and stimulating demand in the food and beverage industry. It also suggested that additional research and adjustments might be necessary to fully realize the benefits of the target costing method in specific cases. Furthermore, comparing costs across multiple businesses or considering franchise establishments in future studies could offer more insights into the effectiveness of target costing in different scenarios
Determining solutions to increase the energy efficiency level of an existing building through building energy analysis
No full textOsmaniye Korkut Ata Üniversitesi Mühendislik Fakültesi binası için enerji perfomansı analizi ve güneş panelleri ile binanın enerji giderlerinin iyileşmesine yönelik çalışma. Bu çalışmada Fakülte binası DesignBuilder yazılımı aracılığı ile 3 boyutlu modellenmiş ve bu model üzerinden enerji performansı incelenmiştir. Enerji performans değerlerine göre ve binanın koşullarına uygun güneş panelleri eklenmiş ve bu panellerin enerji üretimi hesaplanmıştır.Energy performance analysis for the Osmaniye Korkut Ata University Faculty of Engineering building and a study on improving the energy costs of the building with solar panels. In this study, the Faculty building was modeled in 3D using DesignBuilder software and its energy performance was examined through this model. Solar panels were added according to their energy performance values and suitable for the conditions of the building, and the energy production of these panels was calculated
Sufi aesthetics and semiotics: reflections of Mevlana's Philosophy in the art of Mutluhan Taş
No full textjourney and quest for closeness to God. This understanding has profoundly influenced many artists throughout history who view art as a means of attaining truth. The symbolic language of Mevlana Jalaluddin Rumi, along with concepts such as love and "wahdat al-wujud" (the unity of being), has been pivotal in transforming Sufism into an aesthetic form. This study explores the impact of Mevlana’s philosophy on modern art and its reflections in the works of artist Mutluhan Taş, thereby uncovering the place of Sufi aesthetics in contemporary art. Adopting a semiotic approach, the study seeks to analyze the meanings of symbolic expressions in art associated with Sufism. This article endeavors to illustrate the influence of Mevlana's Sufi philosophy on Mutluhan Taş's artworks and to reveal the role of Sufi thought in modern art. The research employs a qualitative methodology structured within the framework of semiotic analysis. Based on the theoretical foundations of Mevlevi and Sufi thought, it examines the symbols used in artistic works and their spiritual messages. Selected works by Mutluhan Taş, particularly those featuring Sufi symbols and metaphysical dimensions, such as "Fana Fillah" and "Post Sema-i," are analyzed in detail for their visual representation of Sufi philosophy. The artworks are examined through semiotic analysis, evaluating the Sufi meanings of the symbols and their effects on the viewer and exploring how Sufi aesthetics integrate with contemporary art practices. In Mutluhan Taş's works, Mevlana's philosophy, combined with fundamental Sufi themes such as love, unity, and existence, imbues a metaphysical dimension. The symbols in these works stand out as metaphors reflecting an individual's inner journey and effort to reach divine truth. This study sheds light on the relationship between Sufi aesthetics and contemporary art, contributing to understanding how modern artists interpret Sufi philosophy. It is suggested that future research could examine the reflections of Sufi aesthetics in other artistic disciplines.Sufism is a profound philosophical and spiritual approach centered on an individual's inner journey and quest for closeness to God. This understanding has profoundly influenced many artists throughout history who view art as a means of attaining truth. The symbolic language of Mevlana Jalaluddin Rumi, along with concepts such as love and "wahdat al-wujud" (the unity of being), has been pivotal in transforming Sufism into an aesthetic form. This study explores the impact of Mevlana’s philosophy on modern art and its reflections in the works of artist Mutluhan Taş, thereby uncovering the place of Sufi aesthetics in contemporary art. Adopting a semiotic approach, the study seeks to analyze the meanings of symbolic expressions in art associated with Sufism. This article endeavors to illustrate the influence of Mevlana's Sufi philosophy on Mutluhan Taş's artworks and to reveal the role of Sufi thought in modern art. The research employs a qualitative methodology structured within the framework of semiotic analysis. Based on the theoretical foundations of Mevlevi and Sufi thought, it examines the symbols used in artistic works and their spiritual messages. Selected works by Mutluhan Taş, particularly those featuring Sufi symbols and metaphysical dimensions, such as "Fana Fillah" and "Post Sema-i," are analyzed in detail for their visual representation of Sufi philosophy. The artworks are examined through semiotic analysis, evaluating the Sufi meanings of the symbols and their effects on the viewer and exploring how Sufi aesthetics integrate with contemporary art practices. In Mutluhan Taş's works, Mevlana's philosophy, combined with fundamental Sufi themes such as love, unity, and existence, imbues a metaphysical dimension. The symbols in these works stand out as metaphors reflecting an individual's inner journey and effort to reach divine truth. This study sheds light on the relationship between Sufi aesthetics and contemporary art, contributing to understanding how modern artists interpret Sufi philosophy. It is suggested that future research could examine the reflections of Sufi aesthetics in other artistic disciplines