International Journal of New Findings in Engineering, Science and Technology
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Öğe Investigation of an exact solution of a mixed boundary value problem using the residue method(Istanbul Gedik University, 2024) Sinsoysal, Bahaddin; Rasulov, Mahir A.In this study, a finite differences method is proposed for solving a mixed problem, which represents phenomena in hydrodynamics. To evaluate the approximate solution of the problem, its analytical solution is also constructed by the residue method developed by M.L. Rasulov, which is applied to find the solution of the partial differential equations containing time-dependent derivatives at boundary conditions. The formula for expansion of an arbitrary function in a series of residues of the solution of the corresponding spectral problem is used to show that the solution of the mixed boundary-value problem can be represented by the given residue formula. The use of the residual method gives an exact solution for the mixed boundary value problem, represented as a rapidly decreasing series. The derived formula makes it possible to formally establish both the existence and the uniqueness of the solution. Moreover, the derived formula provides a framework for evaluation, allowing a comparative analysis between the exact solution and the numerical approach.Öğe Monte Carlo simulation of distance dependent quantum entanglement in mixed XXZ Heisenberg spin-1/2 chains(Istanbul Gedik University, 2024) Duru, İzzet Paruğ; Aktaş, ŞahinThe quantum entanglement of mixed XXZ Heisenberg spin-1/2 chain is examined. We quantify localizable entanglement (LE) in terms of upper/lower bounds through Quantum Monte Carlo simulations. Loop algorithm is chosen to numerically calculate thermodynamic quantities including spin-spin correlations. The exchange coupling, Zeeman energy, and dipolar interaction are literally taken into account. Findings summarize that the strength of dipole-dipole interaction (D) and external magnetic field (Bz) are notable in entanglement formation driving creation and extinction of entanglement. The creation and extinction of entanglement depend on D and Bz. Furthermore, strong fields at the critical temperatures lead a non-monotonic/monotonic behavior introducing revival phenomena. Nevertheless, strong D provides the distance-dependent stability of LE values, preserving unity.Öğe The characterization of electrospun PANI/PEO nanofibers at different electrospinning conditions at room temperature(Istanbul Gedik University, 2024) Konuk Ege, Gözde; Akay Sefer, Özge; Yüce, HüseyinNanofiber structures have wide usage area thanks to their excellent properties from sensor technologies, biomedical systems to tissue engineering, drug delivery systems. Electrospinning method is a versatile method that can produce very fine nanofibers with a simple production mechanism. On the other hand, it is important to optimize the fabrication parameters in order to obtain the appropriate nanofiber structure. In this study, PANI/PEO (Polyaniline/Polyethylene oxide) electrospun nanofibers are fabricated under ambient conditions and the effects of solution viscosity and collector rotation speed on fiber structure are discussed. Electrospun PANI/PEO nanofibers structures are investigated by scanning electron microscope (SEM). According to the SEM results, it is seen that the high viscosity nanofibers have straight and rigid structures. However, the low viscosity nanofiber structures break down at each collector speed, but the fiber orientations increase as the collector rotation speed increases. It is estimated that this study will be guide for future work on PANI.Öğe In-plant logistics issues and methodologies analysis: case study(Istanbul Gedik University, 2024) Ateş, OzanInplant logistics, unlike other dimensions of logistics, has not been adequately analyzed in the literature and practices. Internal logistics, which can be defined as material transportation movements that occur in a closed area by nature, has a high impact on cost, quality and customer satisfaction in the relevant field. Lean logistics is the logistics dimension of lean production. Since logistics activities, like production activities, are ongoing activities, the improvements to be made will have a great impact. In this study, the solutions offered by a logistics company with problems related to internal logistics and the solutions offered by the author from a lean logistics perspective are included comparatively at the end of the study.Öğe Mechatronics system design and implementation of a pneumatic hand rehabilitation device(Istanbul Gedik University, 2024) Gülnergiz, Emre TuğberkThis study presents the development of a mechatronic device for an additively manufactured Pneumatic Artificial Muscle (PAM) rehabilitation orthosis. Within this scope, the system's electro-pneumatic, mechanical, control, and software designs have been designed and implemented. The device, intended to directly interact with both patients and therapists within the bio-mechatronic process, is equipped with an intuitive graphical user interface (GUI). Utilizing a FlexSensor to measure hand flexion/extension angles, the device employs a solenoid valve, along with a trigger relay, for the inflation and deflation of the orthosis. During the electronic design phase, challenges such as interference and latency were mitigated through the implementation of isolations in the design. Employing a PD (Proportion-Derivative) control loop on the ATmega328 microcontroller, control parameters were determined empirically. By excluding a compressor pump inside the device, a lightweight, portable, and cost-effective system was accomplished. While potential enhancements discussed in the conclusion will be considered in future studies, the current prototype effectively fulfills the project objectives.Öğe Dynamic simulation of the performance of a solar assisted heat pump in different climates(Istanbul Gedik University, 2024) Alipour, Bahareh; Karami, Maryam; Heidarnejad, ParisaOne method to reduce energy consumption in buildings is using solar assisted heat pumps, in which the combination of heat pump and solar collector is used to improve the thermal performance. In this paper, TRNSYS and EES software are used to simulate the performance of an indirect expansion solar assisted heat pump. Dynamic simulation of the system is performed by changing parameters such as mass flow rate of collector working fluid and the collector area in five climates including Hot/Dry, Cold/Dry, Moderate/Humid, Hot/semi-Humid, and Hot/Humid. The results show that, in January, the Cold/Dry climate had the lowest free energy ratio (FER) because of high space heating load. In this month, Hot/semi-Humid climate has the highest FER, because of the higher solar radiation and no need to space heating. The annual FER in Hot/Dry zone is 71% which is higher than that other zones. The lowest FER related to Moderate/Humid climate due to high humidity and cloudiness.Öğe Biological insights into energy storage technologies(Istanbul Gedik University, 2024) Kırmızıtaş, Fatma Ceren; Günder, Burhan Baran; Köse, AliIn the face of increasing energy demands and environmental concerns, the search for sustainable and efficient energy storage technologies has intensified. This review presents a holistic survey of innovative solutions by examining biological approaches. The study proceeds through three thematic sections: Biological Fuel Cells and Battery Systems, Photosynthesis and Solar Energy Storage, and Energy Generation at the Cellular Level. The first section, Biological Fuel Cells and Battery Systems describes the integration of biological processes into energy storage mechanisms. The use of biological systems and their contribution to the development of environmentally friendly and high performance energy storage technologies are discussed. In the 2nd section, Photosynthesis and Solar Energy Storage are very prominent in sustainability and energy efficiency issues in terms of both energy production and energy source food production while reducing carbon dioxide with photosynthesis-based energy storage methods. Energy production at the cellular level is discussed in the last section, Adenosine triphosphate (ATP), which is necessary for the cell to perform processes such as growth, reproduction and response to environmental stimuli, is characterized as the primary fuel. ATP production is carried out by mitochondria in animal cells and chloroplast in plant cells. Energy storage at the cellular level is carried out by molecules such as glycogen and lipids in animal cells and starch in plant cells. Considering all three issues, it has been observed that biological-based energy storage methods have numerous advantages in terms of sustainability and energy efficiency. In application areas where engineering approaches are at the forefront, it is thought that it may be possible to design more sustainable and highly energy efficient energy production systems by gaining new perspectives with biology-based simulation studies.Öğe Developing soil liquefaction analysis program created on visual basic analysis in MS excel based on the 2018 Turkish seismic code(Istanbul Gedik University, 2024) Özcan, Mahmut; Nazilli, Hasan Bozkurt; Tolon, MertThe rapid increase in the world's population, the desire to revise old structures or to need new structures, and the decrease in usable areas in some big cities lead engineers to examine ground conditions more. Due to Turkey's location and geological structure, earthquake occurrences are quite high. The loss of life and property, which has increased with the earthquakes that have occurred in our country in recent years, has been examined and it has been seen that this situation is related to the ground factor rather than the superstructure design inadequacies. In this sense, the main goal of investors is to optimize the profit to be obtained by providing the aesthetics of the superstructure, comfort, and interior quality in building projects such as residences and offices. For this reason, geotechnical design is becoming a discipline that needs to be solved most economically. Starting the investment without paying due attention to the seismicity of the ground in the investment budgets, when the risk of liquefaction in the ground may come to the fore, it is possible to avoid unaccounted ground improvement methods, so new buildings with the risk of soil liquefaction are added to the unsafe old building stock. With the 2018 Seismic Code in Turkey, liquefaction on the ground and different problems that occur in the ground have been examined in more detail. Within the scope of the study, it was focused on getting faster results with faster and on-site determinations of the liquefaction situation on the ground, thanks to the Visual Basic application program prepared in Excel. In this sense, with the program prepared as the aim of the study, it is aimed to enable the construction of the soil liquefaction analysis to be made quickly and with less cost and to start the construction with a realistic budget and structural models. The program continuously increases its sensitivity and accuracy with additional inputs. This allows geotechnical engineers to achieve faster and earlier results Earthquake; Soil Liquefaction; TBDY; 2018 Turkish Seismic Code RegulationÖğe Dielectric and optical properties of Eux(Bi1-x)Sr2CaCu2O6.5 (x=0.3 and 1) samples(Istanbul Gedik University, 2024) Canci Matur, Utku; Aslan Çataltepe, Özden; Tabanlı, SevcanEu-based copper oxide layered ceramics have some interesting dielectric properties depending on its stoichiometric ratios and elements used in ceramics. In this study, optical properties of EuSr2CaCu2O6.5 and Eu0.3Bi0.7Sr2CaCu2O6.5 samples and dielectric property of EuSr2CaCu2O6.5 sample were investigated for the first time. Negative real permittivity for EuSr2CaCu2O6+x sample was observed at temperature with 373 K and higher temperatures and below than the cross over frequency with 14 Hz. Moreover, it is determined that Eu3+ concentration in the material affects the relative emission intensity.Öğe Using artificial ıntelligence algorithms to detect hate speech in social media posts(Istanbul Gedik University, 2024) Yerden, Aytaç Uğur; Turgut, KadirDetecting hate speech on social media is of great importance to prevent negative impacts on people and communities and to remove such content. However, detecting hate speech is a complex and challenging process due to linguistic and cultural diversity. Therefore, it is important to develop powerful and effective machine learning algorithms. Since detecting such content using traditional methods can be time-consuming and costly, it is stated that artificial intelligence-based machine learning algorithms have great potential in this regard. The aim of this study is to evaluate the performance of artificial intelligence-based machine learning algorithms used in detecting posts containing hate speech on social media. The study focuses on the problem of detecting and managing hate speech on social media platforms. In this study, we will compare the performances of different algorithms and determine the most suitable methods. Additionally, the effects of the dataset and feature extraction methods on algorithm performance will be analyzed. Algorithms are often based on natural language processing techniques and try to detect hate speech by learning features in texts. The performance of these algorithms can vary depending on factors such as language, culture, the attributes they use, and the training dataset, so a comprehensive analysis is required. In the research, the performance of the algorithms used in detecting hate speech was compared with the dataset and feature extraction methods. In this process, the algorithms' linguistic and cross-cultural effectiveness, feature selection and representation, false positive and false negative rates, and overall accuracy will be analyzed.Öğe Exploring organizational perspectives on sustainable development: a comparative study of companies in Dubai and Istanbul(Istanbul Gedik University, 2023) Bambouk, Basheer; Gümüş, Tuğbay Burçin; Ulutagay, GözdeThis research presents the findings of a study on the perceptions of sustainable development among companies in Dubai and Istanbul. It starts by providing an overview of the definitions, objectives, benefits, and requirements of sustainability, also highlighting some examples of best practices in this area. Then presents the results of a questionnaire survey that has been conducted to gather the views of companies on sustainable development and compare them. The main point of this research is to acknowledge the perspectives of companies in Dubai and Istanbul on sustainable development. This study aims to identify the sustainable development challenges that companies are currently facing and may face in the future, from an organizational perspective. It also aims to examine how companies can address these challenges in a way that benefits both their own operations and the larger society by contributing to sustainable development. The focus of the research is on understanding how companies can address these challenges from within their own organizational structures and practices. The survey results reveal similarities and differences in sustainability practices between Istanbul and Dubai. Istanbul-based companies prioritize customer-focused sustainability, while Dubai-based companies excel in sustainable operations. Istanbul ranked first in ethics and safety, while Dubai focused more on environmental impact. Both cities prioritize a safe work environment, but Istanbul focuses on employee engagement, while Dubai prioritizes energy efficiency and ethical sourcing. Common barriers include a lack of awareness, difficulty finding sustainable suppliers, and regulatory restrictions. Dubai companies perceive the higher implementation of sustainable strategies and measurable results. Regular evaluation, sharing of best practices, and alignment of sustainability priorities can drive improvements. Companies need to consider their unique context and challenges to effectively integrate sustainability into their business strategies, and overcome barriers. Collaboration, education, and stakeholder engagement are crucial for fostering a more sustainable future in both Istanbul and Dubai.Öğe Determining the appropriate transportation option with the decision tree(Istanbul Gedik University, 2023) Ateş, OzanDue to the fact that the population density in Turkey is concentrated in the Marmara region, many businesses are positioning their facilities in this region. For this reason, logistics companies, also called 3PL, serving these businesses are located in the same region. Logistics companies determine various transportation strategies according to the shipment volumes of the customers they serve. The main objectives of these strategies are based on cost minimization, productivity increase and improvement of customer service levels. In this publication, a decision tree was used to determine the transportation strategy of a customer of the logistics company whose case study was conducted. The costs of alternative options, including the current transportation option, were calculated and the transportation option with the lowest cost was preferred. In the study, real data was used and a case study was carried out in a logistics company serving in our country. The reason why the decision tree method is preferred is that it is easy to implement and can answer many basic logistics problems.Öğe Improving the thermal comfort of the structures by applying the sustainable engineering requirements(Istanbul Gedik University, 2023) Ali, Basheer Majeed; Ghasemlounia, RedvanModern thermal comfort theories recommend that a restricted temperature difference be evenly maintained throughout all architectural styles, regions, and people. This strategy treats structure inhabitants for heating purposes, resulting in thermal comfort criteria that necessitate power climate management measures. This frequently results in a high need for air conditioning. Initial investigation and new Technology, HVAC (Heating, Ventilation, and Climate Control) advanced facilities are contesting conventional assumptions of thermal comfort criteria on the basis that they ignore main social and environmental comfort elements. In this paper the researcher took the effect of the modification in the design on the thermal comfort by several engineering solutions for reducing the total main radiant temperature (TMRT(, Potential air temperature (PAT), and the developing of the relative humidity (RH) with the wind speed (WS) Which are playing a significant role on improving the urban heat island (UHI) The research mainly aims to analyze the effect of urban green spaces on the urban heat island as a common strategy for improving the thermal comfort.Öğe Design of a cold storage with R507A refrigerant for the preservation of twenty-five tons of apples in the Ankara province(Istanbul Gedik University, 2023) Fenni, Berker Özün; Köse, Ali; Heidarnejad, ParisaIn the absence of proper humidity and temperature conditions, undried fresh foods will experience physiological and biological deterioration, resulting in mass loss and the development of mold. Thanks to this rationale, humanity has endeavored to keep food products from deteriorating. This can be observed through the use of cold rooms constructed by the Ancient Romans using clay and the cooling chambers known as "Yakhch?l" developed by the Persians. The advancement of refrigeration technology has persisted since the era of ancient civilizations. The advent of refrigeration cycles has significantly streamlined the implementation of containment technology. The presence of these systems in residential settings can be attributed to the development of the vapor compression refrigeration cycle and the compact nature of this technology, which enables convenient freezing or cooling of products for storage purposes. Vapor compression refrigeration cycles are still widely employed in various applications, such as office and automotive air conditioning systems, refrigerators, and industrial cold rooms. This study aims to develop an industrial cold room design tailored explicitly for storing and transporting apples, a perishable agricultural commodity. The primary objective is to ensure that the apples are maintained in optimal humidity and temperature conditions, thereby preventing any degradation, even when handling large quantities in Ankara.
