32,308 results on '"Mühendislik"'
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2. Milli Eğitim Şûralarında STEM Alanlarına Yönelik Alınan Kararların Değerlendirilmesi.
- Author
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ACAR, Fatih and OĞUZ HAÇAT, Sibel
- Abstract
Copyright of INES Journal: The Journal of International Education Science / Uluslararası Eğitim Bilimleri Dergisi is the property of INES Journal: The Journal of International Education Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
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3. Türkiye'de FeTeMM Eğitim Çalışmalarının Meta Sentezi.
- Author
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KANBEROĞLU, Derviş
- Abstract
Copyright of INES Journal: The Journal of International Education Science / Uluslararası Eğitim Bilimleri Dergisi is the property of INES Journal: The Journal of International Education Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
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4. Selâhaddîn-i Eyyûbî’nin Mühendisi: Bahâeddin Karakuş.
- Author
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KARAKUŞ, Nadir
- Abstract
The Saladin period was a period when the Crusades continued at full speed, the Franks suffered a great defeat at the Battle of Hattin in 1187, and Jerusalem was again in the hands of the Muslims after eighty-eight years. The Third Crusade, which started after this success, left Saladin in a very difficult situation and continued with the defence of Acre and then the great wars. In these achievements of Saladin, a Turk named Baha al-Din Karakush, who is mentioned in the pages of history as his engineer, made a strong impression with his activities. Karakush, who played an active role in the process of ending the Shiite Fatimid rule since 1169, was one of the people who paved the way for Saladin to be the only man in Egypt after 1171. After that, Karakush, who came to the fore with his engineer personality, protected the area between Cairo and Fustat with walls, and became the biggest supporter of Saladin against the Crusader attacks. He used the stones of small ehrams for these activities and built Kal'at al-Jabal, the centers and palaces of the Ayyubids in Cairo. Karakush, which supplies water here, also showed itself with the arched bridges, pools, fountains and stables where horses were tied. Besides religious buildings such as the Kaytan Mosque, he built social spaces such as ribats. Karakush demonstrated another engineering experience during the long siege of Acre. Bahâeddin, who strengthened the walls of the city, which was taken back from the Crusaders, achieved important successes both as a commander and an engineer with the siege of this place by the Crusaders. Karakush, who protected the city with ditches, also took measures to prevent the Crusaders from approaching the walls. Karakush, who attacked the Crusaders with his catapults, also opposed the Frank attacks. In addition to arrow and catapult shots, the Crusaders were overwhelmed with naphtha shots, which is a burning material. Karakush, who enabled naphtha to be a more burning war material with new mixtures in this regard, became one of the symbolic names of Acre defence. This great engineer, who even attracted the attention of the chronicler Ambroise, who was in the court of King Richard of England, became one of the most important symbols of the Third Crusade. Despite this, western sources talked about him very little and mostly devoted to military activities during the siege. We think that knowing such a name and his activities will add a different meaning to our work and will open the door to the technical dimension of the struggles during the Crusades. A work about Karakush, which was written after his death, led to the spread of a parable in the Islamic world. A contemporary of Baha al-Din Karakush, who was jealous of his successful activities in Egypt and the works he left, found his rulings confusing and unjustly denounced him. Originally a Coptic convert, İbn Memmati wrongly accused Karakush of and showed that he was jealous of Karakush in his work titled (al-Fashush fî Ahkami Karakush: The Weaknesses in the Rulings of Karakush). Whatever the case, the works of Saladin's engineer and his active struggle against the Crusader attacks made him immortal and caused his name to be engraved in the memories. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. ESKİŞEHİR OSMANGAZİ ÜNİVERSİTESİ ELEKTRİK ELEKTRONİK MÜHENDİSLİĞİ BÖLÜMÜ.
- Author
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PARLAKTUNA, Osman and ERKAYA, Hasan Hüseyin
- Abstract
Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
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6. Türkiye'de Makine Mühendisliği Eğitimi Veren Üniversitelerin Mevcut Durumunun Araştırılması.
- Author
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Karaçor, Berkay
- Abstract
Copyright of Journal of University Research / Üniversite Araştırmaları Dergisi is the property of Journal of University Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
7. Sınıf Dışı Bütünleşik Mühendislik Tasarım ve Girişimcilik Etkinliklerinin Öğrenci Ürünlerine Etkisi.
- Author
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YÜKSEL TEMİZ, Feyza and YAMAN, Süleyman
- Subjects
DISTRIBUTION (Probability theory) ,STUDENT development ,MIDDLE schools ,INDEPENDENT variables ,EXPERIMENTAL design - Abstract
Copyright of Gazi University Journal of Gazi Educational Faculty (GUJGEF) is the property of Gazi University Journal of Gazi Educational Faculty (GUJGEF) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
8. İnşaat Mühendisliği Eğitiminde Mühendislik Etiği Uygulamaları ve Etkileri.
- Author
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Öztürk, Zahide Bayer, Tavşancı, Özgen, and İster, Şule Nur
- Abstract
Copyright of International Journal of Engineering Research & Development (IJERAD) is the property of International Journal of Engineering Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
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9. TÜRKİYE'DE GIDA MÜHENDİSLİĞİ EĞİTİMİ.
- Author
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BUZRUL, Sencer
- Subjects
MALE employees ,WOMEN employees ,ENGINEERING education ,UNIVERSITY faculty ,RESEARCH assistants - Abstract
Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
10. Theologians with Engineering Degrees: A New Theology School Model Integrating Religion and Science.
- Author
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OKTAR, Süleyman
- Subjects
ISLAMIC civilization ,MUSLIMS ,DOGMATISM ,TOLERATION ,THEOLOGY - Abstract
Copyright of Talim: Journal of Education in Muslim Societies & Communities is the property of Talim: Journal of Education in Muslim Societies & Communities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
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11. Oyun Teorisinin Tıp Etiğine Uyarlanışına Dair Metodolojik Bir Çalışma: Antibiyotik Pazarı ve Televizyon Diyetisyenleri.
- Author
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TEMEL, M. Kemal
- Abstract
Copyright of Turkiye Klinikleri Journal of Medical Ethics-Law & History / Türkiye klinikleri tıp Etiği, Hukuku ve Tarihi Dergisi is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
12. Dynamic multi-objective evolutionary algorithms in noisy environments
- Author
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Shaaban Sahmoud, Haluk Rahmi Topcuoglu, and Sahmoud S., TOPCUOĞLU H. R.
- Subjects
Social Sciences and Humanities ,Information Systems and Management ,Social Sciences (SOC) ,Sosyal Bilimler ve Beşeri Bilimler ,Yazılım ,Mühendislik ,COMPUTER SCIENCE, THEORY & METHODS ,ENGINEERING ,Biyoenformatik ,BİLGİSAYAR BİLİMİ, TEORİ VE YÖNTEM ,Information Systems, Communication and Control Engineering ,Sociology ,Yapay Zeka ,COMPUTER SCIENCE, SOFTWARE ENGINEERING ,Bilgisayar Bilimi Uygulamaları ,Veritabanı ve Veri Yapıları ,Computer Sciences ,Uncertainty ,bioinformatics ,BİLGİ BİLİMİ VE KÜTÜPHANE BİLİMİ ,Computer Science Applications ,Dynamic multi-objective optimization problems ,OTOMASYON & KONTROL SİSTEMLERİ ,Physical Sciences ,Engineering and Technology ,Sosyal Bilimler (SOC) ,Bilgisayar Bilimi ,Change detection ,Teorik Bilgisayar Bilimi ,Bilgi Sistemleri, Haberleşme ve Kontrol Mühendisliği ,Control and System Engineering ,BİLGİSAYAR BİLİMİ, YAZILIM MÜHENDİSLİĞİ ,COMPUTER SCIENCE, ARTIFICIAL INTELLIGENCE ,SOCIAL SCIENCES, GENERAL ,AUTOMATION & CONTROL SYSTEMS ,algorithms ,Bilgi Sistemleri ve Yönetimi ,Theoretical Computer Science ,BİLGİSAYAR BİLİMİ, YAPAY ZEKA ,Database and Data Structures ,Artificial Intelligence ,Library Sciences ,INFORMATION SCIENCE & LIBRARY SCIENCE ,Sosyal ve Beşeri Bilimler ,Bilgisayar Bilimleri ,Social Sciences & Humanities ,Engineering, Computing & Technology (ENG) ,Sosyoloji ,Noise detection ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Sosyal Bilimler Genel ,COMPUTER SCIENCE ,Fizik Bilimleri ,Control and Systems Engineering ,Mühendislik ve Teknoloji ,Kütüphanecilik ,Algoritmalar ,Kontrol ve Sistem Mühendisliği ,Software ,Noisy optimization problems - Abstract
Real-world multi-objective optimization problems encounter different types of uncertainty that may affect the quality of solutions. One common type is the stochastic noise that contaminates the objective functions. Another type of uncertainty is the different forms of dynamism including changes in the objective functions. Although related work in the literature targets only a single type, in this paper, we study Dynamic Multi-objective Optimization problems (DMOPs) contaminated with stochastic noises by dealing with the two types of uncertainty simultaneously. In such problems, handling uncertainty becomes a critical issue since the evolutionary process should be able to distinguish between changes that come from noise and real environmental changes that resulted from different forms of dynamism. To study both noisy and dynamic environments, we propose a flexible mechanism to incorporate noise into the DMOPs. Two novel techniques called Multi-Sensor Detection Mechanism (MSD) and Welford-Based Detection Mechanism (WBD) are proposed to differentiate between real change points and noise points. The proposed techniques are incorporated into a set of Dynamic Multi-objective Evolutionary Algorithms (DMOEAs) to analyze their impact. Our empirical study reveals the effectiveness of the proposed techniques for isolating noise from real dynamic changes and diminishing the noise effect on performance.
- Published
- 2023
13. The Approximate Solution of Singularly Perturbed Burger-Huxley Equation with RDTM
- Author
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ARSLAN, Derya
- Subjects
Fen ,Engineering ,Multidisciplinary ,Singularly Perturbed Burger-Huxley Partial Differential Equation,Approximate Solution,Boundary Layer ,Science ,Mühendislik ,General Engineering - Abstract
In this research, the numerical integral method procedure on uniform mesh is used to solve the singularly perturbed problem which has integral boundary value. This method also includes the trapezoid method, the finite difference method, and the Thomas algorithm. The problem is converted to finite difference problem by using finite difference approximations and trapezoid method. Finally, the convergence of the presented method is analyzed through sample application. Thus, the correctness and sufficiency of the method are shown.
- Published
- 2023
14. Fuzzy inverse logic: part-2. validation and evaluation of the method.
- Author
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ÖZTEKİN, Ertekin
- Subjects
- *
FUZZY logic , *EVALUATION methodology , *ENGINEERING design , *FUZZY sets , *CIVIL engineering , *CIVIL engineers - Abstract
In the first part of this study, which consists of two parts, the introduction of the fuzzy inverse logic method, its foundations, computation and process flow and details were given. In this second part, the method was applied on a very simple mathematical problem and on a simple civil engineering design problem in order to investigate and evaluate the validity of the method easily. Fuzzy inverse logic computations have been carried out on these two simple problems for different dimension, sensitivity and acceptable error values. By comparing the obtained results with the desired outputs and mathematical results, the effective computation ability of the method was tried to be revealed. As a result, it is understood that the method developed in this study has many promising aspects in terms of theoretical computations and practical applications and can be used effectively in many scientific fields. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
15. Mühendislik fakültesi öğrencilerinin elektronik atık farkındalıkları
- Author
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Pınar ÖZDEMİR DENİZ, Çiğdem YILMAZ AYDIN, and Emine Didem EVCİ KİRAZ
- Subjects
electronic waste ,recycling ,waste management ,engineering ,student ,elektronik atık ,geri dönüşüm ,atık idaresi ,mühendislik ,öğrenci ,Medicine (General) ,R5-920 - Abstract
Amaç: Günümüzde teknolojik gelişmelerle beraber kullanılan elektronik cihazların sayıca artması ve ömürlerinin hızlı dolması elektronik atık (e-atık) kavramının çevre sağlığı konularının içinde yer almasını sağlamıştır. Çevre sorunlarının oluşmasında ve çözüm üretimi konularında kişilerin çevre duyarlılığı ve çevre eğitimi arasında doğrudan bir ilişki olduğu görülmektedir. Araştırmada çalışma alanı teknoloji olan mühendislik fakültesi öğrencilerinde e-atık ve çevre sorunlarına yönelik farkındalık düzeylerinin değerlendirilmesi amaçlanmıştır. Gereç ve Yöntem: Bu çalışma kesitsel bir çalışma olup; Adnan Menderes Üniversitesi Mühendislik Fakültesi 2016-2017 döneminde eğitim gören Gıda, İnşaat, Elektrik-Elektronik, Makine ve Bilgisayar Mühendisliği bölümleri 1.ve son sınıf öğrencileri ile yapılmıştır. Bulgular: Öğrencilerin çevre sorunlarına yönelik farkındalık ile e-atık düzenlemeleri farkındalık durumları arasında bölümler arası ve sınıflar arası istatistiksel olarak anlamlı bir fark gözlenmemiştir. Ancak her iki farkındalık durumu arasında korelasyon olduğu görülmüştür. Sonuç: Katılımcıların e-atık geri dönüşümü ve mevzuatları açısından bilgi düzeylerinin düşük olduğu tespit edilmiştir. Bu nedenle tüketicilerin konu ile ilgili farkındalıklarının arttırılması sağlanmalıdır. Üreticiler ve belediyeler, geri dönüşüm konusunda daha aktif çalışmalı,e-atığın azaltılması ve uygun şekilde yönetilmesi için daha sıkı düzenlemeler yapılmalıdır.
- Published
- 2019
- Full Text
- View/download PDF
16. Kahramanmaraş İli Hasancıklı Mahallesi ve Yakın Civarının Yerleşime Uygunluk Değerlendirmesi.
- Author
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Kaya, Metin and Özbek, Ahmet
- Subjects
NATURAL disasters ,URBANIZATION - Abstract
Copyright of Abstract of the Geological Congress of Turkey / Türkiye Jeoloji Kurultayı Bildiri Özleri is the property of TMMOB JEOLOJI MUHENDISLERI ODASI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
17. Design and walking analysis of proposed four-legged glass cleaning robot
- Author
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Nihat Cabuk
- Subjects
Engineering ,Serial manipulator ,Legged-robot ,Glass cleaning ,Design ,Kinematic analysis ,Mühendislik ,General Medicine - Abstract
In this study, a legged and wheeled robot model was proposed for cleaning the glass of greenhouses. The robot has four wheels and four legs, each with three degrees of freedom (DOF). The design, kinematic analysis and simulation of the robot was carried out. Glass greenhouses are created by placing glass sheets on T-shaped iron bars arranged in parallel at certain intervals. The robot performs the glass cleaning task by performing two different movements on greenhouse roof. As a first movement, the robot moves like a train moving on the rail on iron bars with wheels, cleaning the glass as it travels. After cleaning the glasses placed between two iron bars along a column, as second movement, the robot passes the next column using legs. These two movements continue until the entire roof of the greenhouse is cleaned. Kinematic analysis of this robot, which is designed with mechanical properties that can make these movements, has been made. Walking simulation of the robot was carried out according to the kinematic analysis. The simulation results showed that this proposed robot can be used to clean glass on the greenhouse roof.
- Published
- 2023
18. An alternative method for the particle size distribution: Image processing
- Author
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Mert AYDIN and T. Fikret KURNAZ
- Subjects
Image processing ,Particle distribution ,Particle size ,Sieve analysis ,Engineering ,Mühendislik ,General Medicine - Abstract
Granular soils are used in different areas of civil engineering due to their easy accessibility and low cost as a material. The sieve analysis method, which has been conducted in rock physics measurements for many years, has been practicing determining the particle size distributions for those materials. In this study, a method based on image analysis technique has been developed as an alternative to traditional sieve analysis method for determining the particle size distribution in granular soils. This technique based on image processing to determine particle distributions via the experimental setup that consist of a camera, tripod, light box and mechanical shaking apparatus. In order to assess the reliability of this technique, each sample was subjected to traditional sieve analysis and the results of both analysis methods were compared. In conclusion, it was observed that the results obtained with the image processing technique had a minimum 95.22% closeness with the sieve analysis experiment data.
- Published
- 2023
19. A comparative assessment for efficient oleuropein extraction from olive leaf (Olea europaea L. folium)
- Author
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Yaşar Kemal RECEPOĞLU, Gülin GÜMÜŞBULUT, and Aslı YÜKSEL ÖZŞEN
- Subjects
Extraction ,Phenolic compound ,Oleuropein ,Olive leaf ,Soxhlet ,Engineering ,Mühendislik ,General Medicine - Abstract
Since oleuropein has long been known in the health sector and is abundant directly in our country as the fourth largest olive producer, oleuropein, the predominant phenolic ingredient in olive leaves, was recovered in this study using Soxhlet extraction. The effects of different solvent types (acetonitrile, ethanol, methanol, and water), extraction period (4 cycles, 4 h, and 8 h), particle size (250-500 µm and 900-2000 µm), and pretreatment of olive leaves on the yield of oleuropein were examined to determine the maximum yield. A greater oleuropein yield was obtained when the particle size of olive leaves utilized for extraction was lowered. Furthermore, aqueous solvents revealed a higher yield of oleuropein than pure solvents and prolonging the extraction duration resulted in a significant increase in the amount of oleuropein extracted. On the other hand, pretreatment of olive leaves resulted in a reduction in oleuropein output. As a result, with 36% extraction efficiency in terms of olive leaf conversion, the highest oleuropein extraction yield was obtained as 13.35 mg g-1 dry leaf for 8 h of extraction time using olive leaves with a particle size of 250-500 µm and an 80% methanol solution as solvent.
- Published
- 2023
20. Facile production of CsPbBr3 perovskite single-crystals in a hydrobromic solution
- Author
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Murat ÖZEN, Cansu AKYEL, and Songül AKBULUT ÖZEN
- Subjects
Engineering ,CsPbBr3 ,Perovskite ,Single-Crystal ,Wet Chemical Synthesis ,Mühendislik ,General Medicine - Abstract
In this study, synthesis of CsPbBr3 perovskite single-crystals in a hydrobromic solution was investigated. Single-crystal growth experiments were conducted at the solution-nucleation border at a constant temperature or controlled cooling conditions. Working at the solution-nucleation border poses some practical difficulties such as fast precipitation. Often researchers opt to oversaturate the solution and use the supernatant after filtration. However, for conditions where the A to B ratio in the precursor solution for the formation of ABX3 is not 1, oversaturation is a waste of resources. In this work, precursor solutions were prepared for a particular working temperature and either held at a constant temperature or were gradually cooled to a predetermined temperature. The constant temperature method resulted in large and clear crystals as it reached saturation more slowly. Crystals prepared at high temperatures appeared to be more transparent with clear facets. Crystals prepared at low temperatures appeared to be opaque with multiple nuclei growth on a single-crystal. Seeding of the saturated solution resulted in larger single-crystals. The procedure adapted in this work made possible the production of clear CsPbBr3 perovskite single-crystals in a hydrobromic acid solution with sizes of up to 5 mm in only 10 days.
- Published
- 2023
21. A Study on Torque Ripple Improvement Compared to a Modified Rotor and Stator Poles SRMs with Classical SRMs Using Dynamic and FFT Analysis
- Author
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Hüseyin Çalik, Yusuf Özoğlu, S. Hakan Undil, Ümit Kemallettin Terzi, and Çalik H., ÖZOĞLU Y., Undil S. H., TERZİ Ü. K.
- Subjects
Tarım Alet ve Makineleri ,Tarımsal Bilimler ,Sinyal İşleme ,Farm Machinery ,Mühendislik ,Enerji Mühendisliği ve Güç Teknolojisi ,ENGINEERING ,Energy Engineering and Power Technology ,Makine Mühendisliği ,ENGINEERING, MECHANICAL ,Ziraat ,Biyoyakıt Teknolojisi ,Information Systems, Communication and Control Engineering ,ENERGY & FUELS ,Tarım Makineleri ,MÜHENDİSLİK, MEKANİK ,Electrical and Electronic Engineering ,Engineering, Computing & Technology (ENG) ,Agricultural Tools and Machines ,ENGINEERING, ELECTRICAL & ELECTRONIC ,switched reluctance motor ,Agricultural Sciences ,Elektrik ve Elektronik Mühendisliği ,Mechanical Engineering ,ENERJİ VE YAKITLAR ,Tarımda Enerji ,Agriculture ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Energy in Agriculture ,Fizik Bilimleri ,FFT analysis ,Signal Processing ,Physical Sciences ,Engineering and Technology ,torque ripple reduction ,MÜHENDİSLİK, ELEKTRİK VE ELEKTRONİK ,Mühendislik ve Teknoloji ,Biofuels Technology ,Bilgi Sistemleri, Haberleşme ve Kontrol Mühendisliği - Abstract
SRMs have high torque ripples. Modifying the stator and rotor shape of SRMs is one of their methods to remove torque ripples. In this study, new rotor and stator geometries have been proposed for SRM. Performance characteristics are obtained and dynamic analyses are carried out for both novel and classical 6/4 SRMs. FFT analyses of the torque characteristics are also performed for the both SRMs. The changes in performance and the FFT results of torque characteristics are determined for both the current-controlled and uncontrolled operations in both SRMs. 23.60% and 15.20% improvements in torque ripples are achieved for the uncontrolled and current-controlled operations in SRMs respectively. When the FFT analyses are applied to the torque characteristics, the THD values are obtained as 21.19% and 8.31% in the uncontrolled and controlled motor current operations respectively. A 122 W three-phase 6/4 SRM simulation based on the MATLAB–SIMULINK environment is performed to validate the improvement of the torque ripple of the proposed model.
- Published
- 2023
22. Otomatik Gerilim Regülatörü İçin Hibrit Bir Denetleyici Tasarımı
- Author
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Kenan Unal, Selim Öncü, Güngör Bal, and Nihat Öztürk
- Subjects
Engineering ,Mühendislik ,Synchronous Generator ,Automatic Voltage Regulator ,Fuzzy Logic Controller ,Artificial Bee Colony Algorithm ,Multi-Criteria Decision Making ,TOPSIS ,Senkron Generatör ,Otomatik Gerilim Regülatörü ,Bulanık Mantık Denetleyici ,Yapay Arı Kolonisi Algoritması ,Çok Kriterli Karar Verme - Abstract
Senkron generatörler elektrik enerjisinin üretiminde temel makina olma görevini sürdürmektedir. Senkron generatörlerin çıkış gerilimi ve frekansı uyartım akımı ve devir sayısı değiştirilerek kolayca ayarlanabilmektedir. Genellikle senkron generatörler şebekeye bağlı olarak çalıştıkları için çıkış gerilimi ve frekansının sabit olması gerekmektedir. Gerilimin ayarlanması için kullanılan Otomatik Gerilim Regülatörlerinde çeşitli denetleyici sistemler kullanılmaktadır. Bu çalışmada MATLAB/Simulink programında bulanık mantık tabanlı anahtarlamalı bir hibrit denetleyici yapısı önerilmiştir. Önerilen hibrit denetleyici, Yapay Arı Kolonisi Algoritması kullanılarak optimize edilen PID denetleyiciyle ve Ziegler-Nichols yöntemine dayalı farklı denetleyicilerden elde edilen sonuçlarla karşılaştırılmıştır. Karşılaştırma kriterleri maksimum aşım miktarı, yükselme zamanı ve oturma zamanı olarak belirlenmiştir. Karşılaştırmanın sonuçları da çok kriterli karar verme tekniklerinden biri olan TOPSIS metodu ile analiz edilerek değerlendirilmiş ve sunulmuştur., Synchronous generators are still the main machines in the production of electrical energy. Changing the excitation current and the rotation speed easily adjust their output voltage and frequency. Since synchronous generators are operated with the grid, the output voltage and frequency must be fixed. Various control systems are used in Automatic Voltage Regulators for adjusting the voltage. In this study, a hybrid controller structure proposed and it operates in MATLAB / Simulink program. The simulation results of the proposed AVR is compared with PID adjusted by Artificial Bee Colonies algorithm and Ziegler-Nichols based different controllers. The comparison was made on maximum overshoot, rise and settling time. According to the comparison made, it was seen that the proposed hybrid controller has better response than the other controllers in terms of maximum overshoot, rise and settling time.
- Published
- 2023
23. Design and Fatigue Life Analysis of Air Suspension Z Type Leaf Springs Used in Heavy Commercial Vehicle
- Author
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Dilşad Akgümüş Gök and Aysun Baltaci
- Subjects
Z tipi yaprak yay ,Parabolik yaprak yay ,süspansiyon sistemleri ,sonlu elemanlar ,Engineering ,Leaf spring ,business.industry ,Commercial vehicle ,Mühendislik ,Air suspension ,Environmental science ,Structural engineering ,business ,Z type leaf springs ,Parabolic leaf springs ,Suspension systems ,Finite elements - Abstract
Otomotiv sektöründe özellikle ağır ticari araçlarda araçların ön ve arka akslarında süspansiyon elemanı olarak yaprak yaylar kullanılmaktadır. Her türlü yol koşulunda ve yük altında çalışan yaprak yaylar, tekerlekten ve yerden şasiye iletilen yüklerin sönümlenmesini sağlar. Bu sayede araçta güvenlik ve çalışma konforu sağlar. Yeni nesil araçlarda mekanik süspansiyon sistemleri yerini havalı süspansiyon sistemlerine bırakmıştır. Havalı süspansiyon sistemlerinde; Özellikle ağır ticari araçlarda kullanılan Z tipi parabolik yaprak yaylar, hava körükleri ile geri esneme sağlayan yaprak yay türüdür. Bu çalışmada, Z tipi parabolik yaprak yay tasarımı ve bu yayın sonlu elemanlar analiz yöntemi ile hazırlanan model üzerinden form ve gerilme analizleri yapılmıştır. Sonlu elemanlar analizi kullanılarak bu yaprak yayın yüksek gerilim bölgeleri belirlenmiş ve uygun tasarım seçilmiştir. Son olarak N-Code programında ve fiziksel testler ile bu yaprak yaya ait yorulma ömrü elde edilmiştir., Leaf springs are used as suspension elements in the front and rear axles of vehicles in the automotive industry, especially in heavy commercial vehicles. Leaf springs working all road conditions and under load, it provides damping of the loads transmitted from the wheel and from the ground to the chassis. In this way, it ensures the safety and working comfort in the vehicle. Mechanical suspension systems have been replaced by air suspension systems in new generation vehicles. In air suspension systems; Z type parabolic leaf springs, especially used in heavy commercial vehicles, is a type of leaf spring that provides spring back with air bellows. In this study; Z type parabolic leaf spring design and finite element model of this leaf spring were prepared and form and stress analyzes were performed on the model. By using finite element analysis, high-tension regions of this leaf spring were determined and the appropriate design was selected. Finally, the fatigue life of this spring was obtained in the N-Code program and physical test.
- Published
- 2023
24. Design of Reverse Logistics Network for Waste Tire Incineration in Cement Factories
- Author
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Müjde Erol Genevois and Merva Dinç
- Subjects
Cement ,Engineering ,Waste management ,Reverse logistics ,waste tire incineration ,cement factories ,MILP ,Mühendislik ,Environmental science ,Incineration - Abstract
This study focuses on recovery options for end-of-life tires (ELTs). One of the most proper recovery options for ELTs is incineration of them in cement plants. There are 49 integrated cement factories which have Environmental Permit and License Certificate in Turkey as the final processing plant. Besides benefits of recovering ELTs to environment, cost aspect of process is crucial. In this study, logistic network design of waste tires sent from collection points to these factories to minimize the costs involved is planned. There are three echelons of supply chain as waste tires collection point, contractor firms and cement factories. Model for this network considers transshipment plan of waste tires between the echelons of supply chain and routes used to gather them. Model that deal with this system are expressed as mixed integer linear programming (MILP) problem. As a case study, model verified with data’s for Ankara
- Published
- 2023
25. Döngüsel Kompresörlerde Teknolojik Gelişmeler
- Author
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Duygu GÜRKAN, Melih OKUR, and İhsan KORKUT
- Subjects
Refrigeration ,rotary compressors ,review ,Engineering ,Soğutma ,döngüsel kompresörler ,derleme ,Mühendislik - Abstract
Enerjinin verimli bir şekilde kullanılması, su ve gıda sorunlarından sonra çözümlenmesi gereken en önemli konulardan birisidir. 2020 yılında Türkiye’de yaklaşık 290 milyar kilowatt saat elektrik tüketimi gerçekleşmiştir. Endüstride elektrik tüketiminin yaklaşık olarak %10’u sıkıştırılmış havanın üretimi için kullanılmaktadır. Bu sebeple sıkıştırılmış hava eldesinde kullanılan kompresörlerin performansının arttırılması endüstri ve ülkemiz açısından büyük önem taşımaktadır. Bu çalışmada, son zamanlarda buzdolabı ve klimalarda yaygın olarak kullanılan döngüsel kompresörlerin verimini arttırmaya yönelik çalışmalar konu başlıkları altında derlenmiş ve incelenmiştir. Ayrıca döngüsel kompresörlerin avantaj, dezavantaj ve teknolojik olarak gelişimleri de değerlendirilmiş olup, literatüre katkı sağlanması amaçlanmıştır., The efficient use of energy is one of the most important issues to be solved after water and food problems. In 2020, approximately 290 billion kilowatt-hours of electricity was consumed in Turkey. About 10% of the electricity consumption in industry is used for the production of compressed air. Therefore, increasing the performance of compressors used in the production of compressed air is of great importance for the industry and our country. In this study, studies aimed at increasing the efficiency of rotary compressors, which are widely used in refrigerators and air conditioners, have been compiled and examined under the titles. In addition, advantages, disadvantages and technological developments of rotary compressors were evaluated and it was aimed to contribute to the literature.
- Published
- 2023
26. Numerical Analysis of NACA 6409 and Eppler 423 Airfoils
- Author
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Seyhun Durmuş and Aytekin Ulutaş
- Subjects
Airfoil ,Engineering ,NACA ,business.industry ,Numerical analysis ,γ-Reθ SST Turbulence Model ,NACA 6409 ,Epler 423 ,RANS ,CFD ,Mühendislik ,Structural engineering ,Reynolds-averaged Navier–Stokes equations ,business ,γ-Reθ SST Türbülans Modeli ,HAD ,Mathematics - Abstract
Bu çalışma, düşük Reynolds sayılarında yüksek taşıma sağlayan yaygın olarak kullanılan iki kanat profilini, ticari kod ANSYS Fluent 19 ile çeşitli türbülans modelleri kullanarak sayısal olarak incelemeyi amaçlamaktadır. Eppler 423 kanat profilini sayısal olarak analiz etmektir. Eppler 423 kanat profili, yüksek taşıma kabiliyeti nedeniyle rüzgâr türbini kanatlarında, çapraz akış fanlarında, planörlerin ana kanatlarında, sportif uçuşlar ve yarışmalar için tasarlanmış radyo kontrollü uçaklarda yaygın kullanılan bir profildir. NACA 6409 kanat profili, serbest uçuş model uçaklarda kullanılır. Literatür taramasında k-ω SST, k-kl-ω ve 𝛾-𝑅𝑒𝜃 geçiş modellerinin sürükleme poler bölgesinin Cl-Cd tahminlerinde, geçiş bölgesi akış rejiminde ve laminer ayrılma noktasında iyi bir tahmin yeteneğine sahip olduğu görülmüştür. Çalışmada RANS modellere ek olarak laminer model de incelenmiştir. Sayısal çözümlerin doğruluğunu ve hassasiyetini sağlamak için kafes duyarlılık çalışması ve yakın duvar modeli kullanılmıştır. Akış yönü vektörü ayrışması tekniği, sadece tek bir ağ kullanarak tüm hücum açılarını simüle etme avantajını sağlamak için kullanılmıştır. Taşıma katsayısı eğrileri ve kutup şemaları, -4 derece hücum açısından başlanarak stol hücum açısına kadar oluşturulmuştur. Deneysel veriler, XFoil analiz verileri ve nümerik analiz verileri en iyi süzülme oranı- (Cl/Cd)maks ve minimum çöküş- (Cl1.5/Cd)maks kriterleri açısından değerlendirilmiştir. Beklendiği gibi, yüksek hücum açısında, üst yüzeydeki geçiş rampası ileri doğru hareket eder ve üst yüzeydeki basınç gradyanı negatif hale gelmiştir. Sonuçlar, ince ağın diğer ağ boyutlarına göre daha iyi sonuçlar verdiği; γ-Reθ SST modelinin diğer türbülans modellerine göre geçiş olayını modellemede daha başarılı olduğunu göstermiştir., The present study aims to numerically examine two commonly used airfoils that provide high lift at low Reynolds numbers, using various turbulence models with the commercial code ANSYS Fluent 19. Eppler 423 airfoil is widely used in wind turbine blades, wings of gliders and R/C airplanes designed for sport flying and competitions thanks to high lift capability. NACA 6409 airfoil is seen in free-flight model planes. In literature review, it has been found that k-ω SST, k-kl-ω and 𝛾-𝑅𝑒𝜃 transition models have a good prediction in Cl-Cd estimation of drag bucket region, transition flow regime, and laminar separation point. In addition to RANS models, laminar model was also investigated. In order to ensure the accuracy and precision of numerical investigations; the grid sensitivity study and near wall model were used. The method of decomposition of flow direction vector procedure has been used to provide the advantage of simulating all angle of attacks using only a single mesh. The lift coefficient curves and polar diagrams were formed from the angle of attack of -4 degree up to the stall. Experimental data, XFoil analysis data and numerical analysis data were evaluated in terms of best glide ratio-(Cl/Cd)max and minimum sink-(Cl1.5/Cd)max criteria. As expected, at high angle of attack, the transition ramp on the upper surface moves forward and the pressure gradient became more adverse. The results showed that fine mesh gives better results than other mesh sizes and transitional γ-Reθ SST model was successful in modelling the transition event than other turbulence models.
- Published
- 2023
27. Development of AZO TCOs with ALD for HEMT and HJSC Solar Cell Applications
- Author
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Deniz Tugrul, Huseyin Altug Cakmak, Ekmel Ozbay, and Bilge Imer
- Subjects
Atomic layer deposition (ALD) ,aluminum doped zinc oxide (AZO) ,transparent conductive oxide (TCO) ,non-alloyed ohmic contacts ,GaN HEMT contact ,Atomik katman kaplama (ALD) ,alüminyum katkılı çinko oksit (AZO) ,transparan iletken oksitler (TCO) ,alaşımlanmamış omik kontaklar ,GaN HEMT contak ,Engineering ,Materials science ,business.industry ,law ,Solar cell ,Mühendislik ,Optoelectronics ,High-electron-mobility transistor ,business ,law.invention - Abstract
Transparan İletken Oksit (TCO) ince filmler günümüzde güneş pilleri, LED’ler, lazerler gibi optoelektronik cihazlarda sıklıkla kullanılmaktadır. Bu kontakların kullanımı cihazların verimliliğini doğrudam etkilemektedir. Bu çalışmanın amacı heteroeklemli güneş hücrelerinin (HJSCs) (n+) a-Si:H yüzünde ve yüksek elektron hareketliliği olan tranzistörlerde (HEMT) kullanmak üzere atomik katman kaplama (ALD) tekniği kullanarak alüminyum katkılı çinko oksit (AZO) üretmek ve optimize etmektir. Bu çalışmada büyütme sıcaklığı ve alüminyum katkılama oranının ALD’de büyütülmüş AZO’nun yapısal, elektriksel ve optik özelliklerine etkisi çalışılmıştır.Sonuçlar göstermiştir ki filmler görünür bölgede %80-90 arasında ışık geçirgenliğine, düşük elektriksel rezistansa (2.04x10-3 ohm.cm) ve 5.25 cm2/V.s değerinde mobiliteye sahiptir., Transparent Conductive Oxide (TCO) films are widely used in optoelectronic devices, such as solar cells, LEDs, and Lasers. Utilization of these contacts directly affects the device efficiencies. Purpose of this study is to produce and optimize properties of Aluminum doped Zinc Oxide (AZO) using a vapor phase technique, Atomic Layer Deposition (ALD) for (n+) a-Si:H surface of silicon Heterojunction Solar Cells (HJSCs) and High Electron Mobility Transistor (HEMT) applications. This study is focused on the effect of the deposition temperature and aluminum atomic concentration on structural, electrical and optical properties of ALD grown AZO ohmic contact films. The results show that as-deposited films have 80-90% transmittance in the visible spectra, low resistance (2.04x10-3 ohm.cm) and mobility value of 5.25 cm2/V.s.
- Published
- 2023
28. CBR testleri ile yollar için fiber türlerinin araştırılması
- Author
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Elif ÇİÇEK and Volkan BUYUKAKIN
- Subjects
Engineering ,pavement ,fibers ,cost benefit ,CBR ,bearing capacity ratio ,lifler ,maliyet avantajı ,taşıma kapasitesi oranı ,Mühendislik - Abstract
In this study, California Bearing Ratio (CBR) tests in a laboratory were performed to observe the behaviour of granular layer fills reinforced with discrete fibers. Six different fiber types were used in granular road layer by using different methods. Firstly, fibers were added in the road as a layer, then they mixed with soil particles, and as a third method they mixed with soil by laying a geotextile in the road layer, in other words it was used as combine reinforced model. And as the last method only a geotextile was laid and used in the pavement soil. By using these methods, the influence of different type of reinforcements on CBR and bearing capacity ratio values were investigated. Additionally, effects on the pavement layer thickness were calculated and for the best configuration of fiber reinforced sample a cost analysis was conducted. As a result of the study, CBR test values for each fiber type used in the study have different values, and for small penetration levels some test results show no improvement for bearing capacity ratio of the road. It was noticed that when increasing the penetration level, the bearing capacity ratios have larger values. Thus, cost and layer thickness numbers were various for different reinforced road layer models. Therefore, in the real life road projects before using fiber types, cost and performance analysis should be made to determine the more effective one., Bilindiği gibi, lifler yol üstyapısının tasarımı için iyileştirme malzemelerinden biri olabilir. Ancak farklı tiplerin California Rulman Oranı (CBR) ve kaplama kalınlığı üzerindeki etkileri henüz bilinmemektedir. Bu nedenle, bu çalışmada granüler kaplama tabakasında farklı yöntemlerle altı farklı lif türü kullanılmıştır. Kompozit donatılı modeller için öncelikle kaplama tabakasına lifler katman olarak eklenmiş, daha sonra toprakla karıştırılmış ve son olarak toprakla karıştırılmış ve katman olarak geotekstil eklenmiştir. Bu üç yöntem kullanılarak farklı tipteki donatıların CBR ve taşıma gücü oranı değerlerine etkisi araştırılmıştır. Ek olarak, kaplama tabakası kalınlığı üzerindeki etkiler hesaplanmış ve lif takviyeli numunenin en iyi konfigürasyonu için bir maliyet analizi yapılmıştır. Çalışma sonucunda, farklı liflerin farklı davranışlar gösterebildiği ve küçük penetrasyon seviyeleri için bazılarının CBR değerlerini iyileştiremediği ve artan penetrasyon taşıma kapasite oranları artırıldığı gözlenmiştir. Bu nedenle gerçek projeler için lif donatı kullanmadan önce maliyet ve performans analizi yapılması gerekliliği belirlenmiştir.
- Published
- 2023
29. Decoding Polymer Architecture Effect on Ion Clustering, Chain Dynamics, and Ionic Conductivity in Polymer Electrolytes
- Author
-
Recep Bakar, Saeid Darvishi, Umut Aydemir, Ugur Yahsi, Cumali Tav, Yusuf Ziya Menceloglu, Erkan Senses, and Bakar R., Darvishi S., Aydemir U., YAHŞİ U., TAV C., Menceloglu Y. Z., Senses E.
- Subjects
Tarımsal Bilimler ,Sinyal İşleme ,Temel Bilimler (SCI) ,Mühendislik ,Enerji Mühendisliği ve Güç Teknolojisi ,ENGINEERING ,homopolymer electrolytes ,ion pairing and clustering ,Physical Chemistry ,MATERIALS SCIENCE ,Kimya ,Ziraat ,Information Systems, Communication and Control Engineering ,Kimya Mühendisliği (çeşitli) ,CHEMISTRY ,ENERGY & FUELS ,Kimya Mühendisliği ve Teknolojisi ,Materials Chemistry ,Electrochemistry ,ELEKTROKİMYA ,Chemical Engineering (miscellaneous) ,MÜHENDİSLİK, KİMYASAL ,ENGINEERING, ELECTRICAL & ELECTRONIC ,Malzeme Kimyası ,Agricultural Sciences ,Elektrik ve Elektronik Mühendisliği ,Temel Bilimler ,ENERJİ VE YAKITLAR ,Tarımda Enerji ,Fizikokimya ,Agriculture ,phase diagram ,Energy in Agriculture ,Natural Sciences (SCI) ,Physical Sciences ,free volume ,ionic conductivity ,Engineering and Technology ,Biofuels Technology ,Bilgi Sistemleri, Haberleşme ve Kontrol Mühendisliği ,Natural Sciences ,Farm Machinery ,Energy Engineering and Power Technology ,MATERIALS SCIENCE, MULTIDISCIPLINARY ,Chemical Engineering and Technology ,Biyoyakıt Teknolojisi ,polymer architecture ,Tarım Makineleri ,poly(ethylene oxide) ,Electrical and Electronic Engineering ,MALZEME BİLİMİ, ÇOKDİSİPLİNLİ ,Engineering, Computing & Technology (ENG) ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Elektrokimya ,Fizik Bilimleri ,Signal Processing ,viscosity ,MÜHENDİSLİK, ELEKTRİK VE ELEKTRONİK ,Mühendislik ve Teknoloji ,Malzeme Bilimi ,ENGINEERING, CHEMICAL - Abstract
Poly(ethylene oxide) (PEO)-based polymer electrolytes are a promising class of materials for use in lithium-ion batteries due to their high ionic conductivity and flexibility. In this study, the effects of polymer architecture including linear, star, and hyperbranched and salt (lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI)) concentration on the glass transition (Tg), microstructure, phase diagram, free volume, and bulk viscosity, all of which play a significant role in determining the ionic conductivity of the electrolyte, have been systematically studied for PEO-based polymer electrolytes. The branching of PEO widens the liquid phase toward lower salt concentrations, suggesting decreased crystallization and improved ion coordination. At high salt loadings, ion clustering is common for all electrolytes, yet the cluster size and distribution appear to be strongly architecture-dependent. Also, the ionic conductivity is maximized at a salt concentration of [Li/EO ≈ 0.085] for all architectures, and the highly branched polymers displayed as much as three times higher ionic conductivity (with respect to the linear analogue) for the same total molar mass. The architecture-dependent ionic conductivity is attributed to the enhanced free volume measured by positron annihilation lifetime spectroscopy. Interestingly, despite the strong architecture dependence of ionic conductivity, the salt addition in the highly branched architectures results in accelerated yet similar monomeric friction coefficients for these polymers, offering significant potential toward decoupling of conductivity from segmental dynamics of polymer electrolytes, leading to outstanding battery performance.
- Published
- 2023
30. Gas Turbine Performance Monitoring and Operation Challenges: A Review
- Author
-
Samar TAHA, Firas ISMAİL, and Sivadass THİRUCHELVAM
- Subjects
Engineering ,Multidisciplinary ,Mühendislik ,General Engineering ,Fault ,Gas Turbine ,Machine learning ,Swirl ,Sensor - Abstract
Gas turbines efficiently produce high amounts of electrical power hence they have been widely deployed as dependable power generators. It has been detected that the performance of gas turbines is a function of plenty of operational parameters and environmental variables. The impacts of those variables on the said performance can be mitigated using powerful monitoring techniques. Thus, extra maintenance costs, component defect costs, and manpower costs can be illuminated. This paper has enlisted the factors impacting gas turbine efficiency. It has also reviewed multiple monitoring solutions for the said impacting factors, It has been concluded that all types of sensors have ignored errors in their work, which may exacerbate the problems of malfunctions in gas turbines due to the critical environment in which they operate (heat, fumes, etc.); however, the machine learning-based monitoring systems excel in addressing such problems. The most cost-effective and accurate monitoring task can be achieved by using machine learning and deep learning tools.
- Published
- 2023
31. A novel cycle counting perspective for energy management of grid integrated battery energy storage systems
- Author
-
Kubra Nur Akpinar, Burcu Gundogdu, Okan Ozgonenel, and Akpinar K. N., Gundogdu B., Ozgonenel O.
- Subjects
Cycle counting ,Tarımsal Bilimler ,Genel Enerji ,Farm Machinery ,Mühendislik ,ENGINEERING ,SOC management ,Ziraat ,Biyoyakıt Teknolojisi ,ENERGY & FUELS ,Tarım Makineleri ,Battery aging ,Engineering, Computing & Technology (ENG) ,BESS ,Agricultural Sciences ,ENERJİ VE YAKITLAR ,Energy management ,Tarımda Enerji ,Agriculture ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Energy in Agriculture ,General Energy ,Fizik Bilimleri ,Physical Sciences ,Engineering and Technology ,Frequency ancillary service ,Mühendislik ve Teknoloji ,Biofuels Technology - Abstract
© 2022 The Author(s)Battery energy storage systems (BESS) are essential for flexible and reliable grid performance as the number of renewable energy sources in grids rises. The operational life of the batteries in BESS should be taken into account for maximum cost savings, despite the fact that they are beneficial for economical grid operation. In this context, this paper present a new battery cycle counting perspective for energy management of grid-connected BESS. For this purpose battery\"s one full charge–discharge cycle characteristic is compared with the operating battery charge–discharge cycle every time step. This comparison was explained mathematically and graphically in detail. The results are compared with the rain flow counting method which is the most popular cycle counting algorithm. Consequently, this cycle counting approach successfully counts the battery charge/discharge cycles and it has shown that has an advantage for BESSs due to being specifically developed just for batteries.
- Published
- 2023
32. Low-Cost Alpha Cabin Like Test Box Proposal for the Development of New Acoustic Sound Insulation Materials
- Author
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Hatice Mehtap BULUKLU, Filiz BAL KOÇYİĞİT, and Ercan KÖSE
- Subjects
Acoustic ,Alpha cabin ,Sound insulation ,Acoustic materials ,Low cost ,Engineering ,Multidisciplinary ,Mühendislik ,General Engineering - Abstract
Experimental criteria for sound insulation material recommendation and design have an important share in indoor acoustic control. Among these criteria, laboratories with devices such as impedance tubes, alpha cabins and reverberation rooms used to measure and analyze parameters such as sound transmission loss and sound absorption coefficient have been investigated. In literature, it has been observed that there are studies on acoustic materials and the tests applied to these materials, but the application is more limited. According to research data, an Alpha Cabin model system design that can be used to develop new types of acoustic sound materials has been proposed. In addition to the fact that a large number of experimental measurements can be performed at lower costs using the designed Alpha Cabin model system, many tests can be performed easily for different material designs in a very short time. To perform these tests, the Alpha Cabin system has been designed based on noise and sound insulation. For example, floating flooring, ribbed connection, and so on. Afterward, different insulation materials were used for insulation purposes and standards were achieved. The Alpha Cabin test system, which was designed and developed, overlaps the experimental and theoretical data for 500, 2000, and 4000 Hz when compared with the values of 29.1 dB for 500 Hz, 38.6 dB for 2000 Hz, and 49 dB for 4000 Hz measured in the Acoustic Facade Panel Test Room, and it has been observed that it can be used in the development of new sound insulation materials.
- Published
- 2023
33. The Effects of Diflubenzuron on Acetylcholinesterase (EC 3.1.1.7) Activity and Liver Ultrastructure in Wistar Rats
- Author
-
Nursel GÜL, Nuri YİĞİT, Fulya SAYGILI YİĞİT, Eda YAZICI ÖZÇELİK, and Hakan ESKİZENGİN
- Subjects
Diflubenzuron ,Rat ,Liver ultrastructure ,Acetylcholinesterase enzymatic activity ,Engineering ,Multidisciplinary ,Mühendislik ,General Engineering - Abstract
Diflubenzuron is a commonly used larvicide/biocidal substance. The present study aimed to reveal the effects of diflubenzuron on Acetylcholinesterase (AChE) enzymatic activity and liver histopathology of a mammalian species (rats). The animals fed with various doses of diflubenzuron and the liver tissues of rats were taken on the 10th, 20th, 25th, 45th days and sixth month. AChE activity of liver was measured by spectrophotometer. Tissues were embedded in Araldite 502 (Sigma), took ultrathin sections, and examined under a 100 CX II Transmission Electron Microscope. AChE activity in the chronic dose of diflubenzuron group was like that in the control group. The enzymatic activity in the subacute dose was found to be significantly different from the control group. After subacute dose exposure was terminated, the AChE activity was still lower on the 45th day compared with the control group. Chronic and subacute doses caused adverse effects to liver tissues, such as numerous mitochondria, abnormally structured nuclei in the hepatocytes and many lipid droplets in the sinusoids of the liver ultrastructure. After the subacute dose was terminated, liver damage was still observed on the 20th and 25th days, but the liver tissue was partly regenerated on the 45th day. Cellular damage might recover after 45 days, but AChE activity probably takes more time to reach a normal level.
- Published
- 2023
34. A Comparison Study of Higher Education Graduates of Germany and Turkey
- Author
-
Erol YÜCEL and Serpil EROL
- Subjects
Engineering ,Multidisciplinary ,Higher education ,Graduates ,Education level ,Field of education ,Mühendislik ,General Engineering - Abstract
This research focused on higher education graduates in Germany and Turkey on all fields of education, especially engineering programs in terms of all education levels and gender. The study has provided situational awareness in general on all fields of education, levels of education and gender, but on the “Engineering, manufacturing and construction” field in detail. In the research, many important findings are identified. Turkey’s ED7 (Master’s or equivalent level) and ED8 (Doctoral or equivalent level) graduate numbers and ratios are significantly lower than Germany when compared to the ED6 level. The research also revealed us that the graduation ratios of ED6 (Bachelor’s or equivalent level) and ED7 among female engineers in Germany are close to each other, indicating that female engineers in Germany are more likely to hold a master's degree after undergraduate education. Among these findings, the most important finding is; while the gender ratio of higher education graduates in Germany at all education levels is almost equal between male and female students, this ratio has started to increase in favor of female graduates in Turkey. This situation developed differently among graduates of engineering programs. While engineering graduates in Germany had a fixed ratio of approximately 80.5% male and 19.5% female graduates between 2014 and 2019. In Turkey, this ratio is improving in favor of female graduates from 32.8% in 2014 to 34.9% in 2019. In this research, it is concluded that the higher education intelligence needs to be top priority for higher education officials.
- Published
- 2023
35. Least Square Support Vector Machines Laguerre Hammerstein Model Identification and Non-linear Model Predictive Controller Design for pH Neutralization Process
- Author
-
Akshaykumar NAREGALKAR and Subbulekshmi D
- Subjects
Engineering ,Multidisciplinary ,Mühendislik ,General Engineering ,Hammerstein model ,Non-linear System ,Identification & Control ,Laguerre filter ,LSSVMpH neutralization - Abstract
The ability to describe the nonlinear process dynamics is an essential feature of the Hammerstein model that paved more research and application studies in system identification and control. Using the Hammerstein model, this study shows an alternative approach to identify and control the highly nonlinear pH neutralization process. This Hammerstein model called Laguerre Least Square Support Vector Machines (LLSSVM) models the static nonlinearity with LSSVM and the linear part with Laguerre filter. The identified LLSSVM Hammerstein model performance evaluation with Mean Squared Error (MSE) and Variance Accounted For (VAF) is better than the Linear Laguerre model. We apply the identified LLSSVM Hammerstein model to implement a Nonlinear Model Predictive Controller (NMPC) to control the pH neutralization process. Then evaluated NMPC performance in terms of Integral Squared Error (ISE), Integral Absolute Error (IAE), and Total Variation (TV) and Control Effort (CE) parameters to verify its effectiveness in set-point tracking and disturbance rejection problems. The comparison of the NMPC with the Linear Laguerre Model-based Predictive Controller (LMPC) shows better performance of the NMPC than the LMPC. Results show that the LLSSVM Hammerstein model replicates the pH neutralization process well than the Linear Laguerre model. Also, the identified LLSSVM Hammerstein model provides an efficient NMPC than the LMPC for the pH neutralization process.
- Published
- 2023
36. Numerical Analysis of Hydraulic and Thermal Performance of Al2O3-Water Nanofluid in a Zigzag Channel with Central Winglets
- Author
-
Selma AKÇAY
- Subjects
Engineering ,Multidisciplinary ,Mühendislik ,General Engineering ,Zigzag channel ,Central winglet ,Nanofluid ,Heat transfer ,Friction factor - Abstract
This study numerically examined the impacts of central winglets and Al2O3-water nanofluid on the thermo-hydraulic performance in a zigzag channel. The analyzes based on Computational Fluid Dynamic (CFD) using the SIMPLE algorithm are actualized for nanofluid flow in Reynolds numbers (Re) varying between 200 and 1200. The volume fraction of nanoparticle (φ) is changed from 1% to 5 %. The upper and lower zigzag surfaces are kept at Tw = 350 K constant temperature. The results are given in terms of thermal improvement (η), dimensionless friction factor (Γ), and thermo-hydraulic performance (THP). In addition, the work is compared with the zigzag channel without winglet for the base fluid. The temperature and velocity distributions are obtained for the zigzag channel with and without winglet at different Reynolds numbers. The results show that the nanofluid and winglets contribute considerably to the enhancement of heat transfer, but the friction factor slightly increases. The heat transfer improves with increasing inlet velocity and particle volume fraction. The highest thermo-hydraulic performance is obtained as approximately 2.12 for Re = 400 and φ = 0.05.
- Published
- 2023
37. State-Of-The-Art On Reversible Multiplier Architectures and Its Comparison for Future Quantum Computing
- Author
-
Hemalatha K N and Sangeetha B G
- Subjects
Engineering ,Multidisciplinary ,Reversible logic ,Array multiplier ,Booth multiplier ,Vedic multiplier ,Quantum cost ,Mühendislik ,General Engineering - Abstract
Multiplication is the key crucial operation in realizing digital signal processing (DSP) functions. It is accomplished by using diverse multiplier architectures. Multiplication operation is furthermost basic and normally used action in the central processing unit (CPU). The multiplication operation is the most fundamental and commonly performed activity in the central processing unit (CPU). An efficient multiplier design should have a high speed, small area, and a low power consumption. Compact, efficient multipliers with minimal power dissipation are needed. The proposed paper provides a thorough inspection of multipliers such as the Array multiplier, Booth multiplier, column bypass multiplier, Baugh-Wooley multiplier, and Vedic multiplier based on their operational activities and working, as well as their benefits and limits. A comparison of these multipliers' performance parameters such as speed, area, power consumption, quantum cost, garbage generation and circuit complexity.
- Published
- 2023
38. On Quaternions with Higher Order Jacobsthal Numbers Components
- Author
-
Engin ÖZKAN and Mine UYSAL
- Subjects
Engineering ,Multidisciplinary ,Exponential generating functions ,Higher order Jacobsthal numbers ,Higher order Jacobsthal quaternions ,Binet formula ,Mühendislik ,General Engineering - Abstract
In this study, we present higher order Jacobsthal numbers. Then we define higher order Jacobsthal quaternions by using higher order Jacobsthal numbers. We give the concept of the norm and conjugate for these quaternions. We express and prove some propositions related to these quaternions. Also, we find the recurrence relation, the Binet formula and the generating function for these quaternions. Finally, we calculate Cassini, Catalan, Vajda and d’Ocagne identities for higher order Jacobsthal quaternions.
- Published
- 2023
39. Analysis of the Structural, Electronic and Magnetic Properties of Pd2FeTl
- Author
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Ziya MERDAN and Fadime Irmak BALMUMCU
- Subjects
Engineering ,Multidisciplinary ,Mühendislik ,General Engineering ,Electronic structure ,DFT ,GGA-PBE ,Magnetic property ,Pd2FeTl - Abstract
The electronic, magnetic and structural properties of Pd2FeTl compound were investigated in this study. The Vienna Simulation Package program was used to perform calculations, based on DFT and Generalized Gradient Approximation. The lattice parameter of 6.360A0 and its magnetic moment value of 3.063μB/f.u. are calculated. The values for the magnetic moment and lattice parameter were found to be in conformity with those in the literature. As electronic properties and band structures were calculated, also the density of state curves compatible with the band structures were drawn. There is no band gap between the energy bands in terms of Pd2FeTl compound and according to the calculations, this compound has a metallic structure.
- Published
- 2023
40. IoT Based Humidity and Temperature Control System for Smart Warehouse
- Author
-
Bipin Kumar RAİ
- Subjects
Engineering ,Multidisciplinary ,Mühendislik ,General Engineering ,Warehouse ,NodeMCU ,DHT-11 ,Machine Learning ,Internet of Things (IoT) - Abstract
In daily life, vitamins fruits and vegetables play a very important role in human life. The farmer produces grains or vegetables in huge quantities. Due to lack of storage problem farmer suffers. It is necessary to store all these things in a special warehouse. Thus, improper storage of grains or fruits is essential to meet the increasing demands. Storage time and fruit quality are greatly influenced by storage environmental factors. Therefore, it is important for the fruit storage environment to perform multi-parameter monitoring and analyze the collected parameters and then regulate and control. The quality of grains and other perishable goods kept in a warehouse usually deteriorates due to lack of monitoring and proper maintenance of their required suitable conditions in such a large area. The proposed methodology deals with the storage of grains, fruits, etc., and to identify their temperature and humidity patterns so that they will not be degraded. Establishing the environment in relation to the nature of the crop so as to determine an optimum threshold with an appropriate pattern of monitoring and change. The main goal of this research article is to provide solutions to prevent rotting of grains and fruits in the storage area.
- Published
- 2023
41. Review on Optimization Techniques for AGV’s Optimization in Flexible Manufacturing System
- Author
-
Manoj GUPTA
- Subjects
Engineering ,Multidisciplinary ,Mühendislik ,General Engineering ,AGV ,FMS ,Genetic Algorithm ,Heuristic approach - Abstract
Production systems have been growing exponentially in size in recent decades. One of the problems in the manufacturing system is that a need of effective and efficient materials transportation between the workstations. Auto-mated guided vehicles (AGV’s) can provide a satisfactory solution to this issue. Because of this, AGV’s is a one of the most important material handling tool used in flexible manufacturing system (FMS). The designing, scheduling and routing of the AGV’s are the key issues for the reason that performance of AVG’s in flexible manufacturing system depends on these parameters. The failure of AGVs may significantly impact the operation and efficiency of the entire system, and it is a critical issue. In this paper the aims to answer How the reliability of individual AGVs in the system assessed? , and How AGVs affects the performance of the whole FMS system?. It was also discussed that optimizing techniques to improve the performance of AGV in FMS. This paper discussed the details studies of approaches and optimization techniques used for optimizing AGV’s in FMS including design and their control.
- Published
- 2023
42. Effects of ethyl proxitol (1-ethoxy-2-propanol) additive on combustion and emission characteristics of biodiesel blends
- Author
-
Mahmut Beyaz, Selman Aydın, Ramazan Şener, Cenk Sayin, and Beyaz M., Aydın S., Şener R., SAYIN C.
- Subjects
Tarımsal Bilimler ,Atık Yönetimi ve Bertarafı ,ENGINEERING, ENVIRONMENTAL ,Farm Machinery ,Mühendislik ,ENGINEERING ,biodiesel ,Ziraat ,Biyoyakıt Teknolojisi ,ENERGY & FUELS ,emission ,Ethyl proxitol ,Tarım Makineleri ,Engineering, Computing & Technology (ENG) ,Waste Management and Disposal ,Yenilenebilir Enerji, Sürdürülebilirlik ve Çevre ,Agricultural Sciences ,Renewable Energy, Sustainability and the Environment ,ENERJİ VE YAKITLAR ,Tarımda Enerji ,Agriculture ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Energy in Agriculture ,Fizik Bilimleri ,Physical Sciences ,Engineering and Technology ,MÜHENDİSLİK, ÇEVRE ,Mühendislik ve Teknoloji ,Biofuels Technology ,cold filter plugging point ,combustion - Abstract
The cold filter plugging point (CFPP) value of biodiesel fuel blends need to be improved because of it has been reported that utilizing high concentrations of biodiesel blends in cold climates can cause major issues. Therefore, the main objective of the study is to improve CFPP value of biodiesel blends using ethyl proxitol additive. It is also to examine combustion and emission of the blends behavior. Biodiesel blends were prepared as; 5% ethyl proxitol-10% biodiesel-85% ultra-low sulfur diesel (ULSD) named as E5B10 and 5% ethyl proxitol-20% biodiesel-75% ULSD named as E5B20 fuel. These fuel blends were compared with ULSD fuel in a compression ignition engine at a constant engine speed of 1500 rev/min and four different loads (idle, 1, 2, and 3 bar BMEP) of eddy current dynamometer. The addition of ethyl proxitol led to a decrease in in-cylinder pressure and temperature due to an about 1˚ later SOC and 2˚ earlier EOC compared to ULSD. The pressure rise rate was slightly higher compared to ULSD at both low and high loads, with a difference of about 1 bar per degree. As a result, these blends with improved CFPP value can be used in cold climates.
- Published
- 2023
43. Stable hemiaminals from axially chiral pyridine compounds
- Author
-
Senel Teke Tuncel, Ilke Demir, Safiye Sağ Erdem, Ilknur Dogan, and Tuncel S. T., Demir I., ERDEM S., Dogan I.
- Subjects
Temel Bilimler (SCI) ,Mühendislik ,ENGINEERING ,stable hemiami ,Sağlık Bilimleri ,Biochemistry ,Physical Chemistry ,Organik Kimya ,Kimya ,Analytical Chemistry ,CHEMISTRY ,Biyokimya ,BİYOKİMYA VE MOLEKÜLER BİYOLOJİ ,Drug Discovery ,Kimya Mühendisliği ve Teknolojisi ,FARMAKOLOJİ VE ECZACILIK ,MÜHENDİSLİK, KİMYASAL ,PHARMACOLOGY & PHARMACY ,Spectroscopy ,PHARMACOLOGY & TOXICOLOGY ,İlaç Keşfi ,intramolecular hydrogen bonding ,Temel Bilimler ,Basic Pharmaceutics Sciences ,Spektroskopi ,Fizikokimya ,Life Sciences ,CHEMISTRY, ORGANIC ,Kataliz ,KİMYA, ANALİTİK ,MOLECULAR BIOLOGY & GENETICS ,Farmakoloji ve Toksikoloji ,Natural Sciences (SCI) ,Physical Sciences ,pyridine compounds ,Engineering and Technology ,Natural Sciences ,BIOCHEMISTRY & MOLECULAR BIOLOGY ,Sitogenetik ,2-iminothiazolidin-4-ol ,axially chiral hemiaminal ,Farmakoloji ,Life Sciences (LIFE) ,Molecular Biology and Genetics ,Chemical Engineering and Technology ,Catalysis ,CHEMISTRY, ANALYTICAL ,SPEKTROSKOPİ ,KİMYA, ORGANİK ,Yaşam Bilimleri ,Health Sciences ,Biyoinorganik Kimya ,Cytogenetic ,Engineering, Computing & Technology (ENG) ,Eczacılık ,Bioinorganic Chemistry ,Moleküler Biyoloji ve Genetik ,stable hemiaminal ,Pharmacology ,Organic Chemistry ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Pharmacology and Therapeutics ,Temel Eczacılık Bilimleri ,Fizik Bilimleri ,Yaşam Bilimleri (LIFE) ,Analitik Kimya ,Mühendislik ve Teknoloji ,ENGINEERING, CHEMICAL - Abstract
© 2023 Wiley Periodicals LLC.In this study, we have synthesized a series of 3-(pyridin-2-yl)-2-(pyridin-2-ylimino)thiazolidin-4-ol derivatives regioselectively from 2-iminothiazolidin-4-ones using LiAlH4 at room temperature. Due to the presence of the restricted rotation around the N3-Caryl single bond, the formation of M/P isomers was observed. The OH group of the hemiaminal was found to orient itself on the same side with pyridyl nitrogen during this restricted rotation to form an intramolecular hydrogen bond, which was demonstrated by the computational DFT study. This orientation presumably inhibited the occurrence of dehydration and stabilized the molecule.
- Published
- 2023
44. Effect of Bumper Thickness with Collision Simulation of Passenger Vehicles
- Author
-
Ferhat Özcan, Aydin Gullu, Sezgin Ersoy, and Özcan F., Gullu A., Ersoy S.
- Subjects
Mechanical Engineering ,Mühendislik ,Computational Mechanics ,ENGINEERING ,Mühendislik, Bilişim ve Teknoloji (ENG) ,METALLURGY & METALLURGICAL ENGINEERING ,Makine Mühendisliği ,Metallurgical and Materials Engineering ,MATERIALS SCIENCE ,Hesaplamalı Mekanik ,ENGINEERING, MECHANICAL ,Makina Mühendisliği ,Metalurji ve Malzeme Mühendisliği ,Fizik Bilimleri ,Physical Sciences ,Automotive Engineering ,Engineering and Technology ,MÜHENDİSLİK, MEKANİK ,Mühendislik ve Teknoloji ,METALURJİ VE METALURJİ MÜHENDİSLİĞİ ,Otomotiv Mühendisliği ,Engineering, Computing & Technology (ENG) ,Malzeme Bilimi - Abstract
The finite element method is the most common method used to solve engineering and mathematical model problems. Related solution areas include structural analysis, heat transfer, mass transport and electromagnetic potential. FEM is a specific numerical method used to solve partial differential equations in two or three space variables. To solve a problem, FEM breaks up a large system into smaller, simpler parts called finite elements. First, a three-dimensional model of the system to be analyzed is produced. While defining the model, the materials and connection types found in the model are also deter-mined. Afterwards, the model is divided into small parts and analyzed under specified conditions. A crash test will be conducted in this study. For this, the conditions of the vehicle parts will be examined by hitting a wall under the conditions of which the model design of the vehicle is determined. Crash tests were carried out for two different bumper thicknesses on the same vehicle and the test results were examined. The vehicle speed is modeled as 20 m/s in the simulation carried out from the moment of impact until 0.14 seconds later. The effect of buffer thickness on axial displacements at impact and energy changes are presented.
- Published
- 2023
45. A Framework for Mitigating Excessive Transportation in the Context of Manufacturing Localization
- Author
-
Enes Eryarsoy, Hakki Nalcioglu, Huseyin Selcuk Kilic, Ahmet Selcuk Yalcin, Selim Zaim, Dursun Delen, and Eryarsoy E., Nalcioglu H., KILIÇ H. S., Yalcin A., Zaim S., Delen D.
- Subjects
inshoring ,AHP ,Temel Bilimler (SCI) ,Mühendislik ,ENGINEERING ,Transportation ,localization ,MATHEMATICS ,Information Systems, Communication and Control Engineering ,Yapay Zeka ,Sustainable development ,Matematik ,Hesaplamalı Teori ve Matematik ,Computer Sciences ,Temel Bilimler ,Applied Mathematics ,Outsourcing ,MATHEMATICS, APPLIED ,OTOMASYON & KONTROL SİSTEMLERİ ,Computational Theory and Mathematics ,Natural Sciences (SCI) ,Physical Sciences ,Engineering and Technology ,Bilgisayar Bilimi ,fuzzy logic ,Bilgi Sistemleri, Haberleşme ve Kontrol Mühendisliği ,Control and System Engineering ,Natural Sciences ,COMPUTER SCIENCE, ARTIFICIAL INTELLIGENCE ,AUTOMATION & CONTROL SYSTEMS ,algorithms ,BİLGİSAYAR BİLİMİ, YAPAY ZEKA ,Artificial Intelligence ,reshoring ,Uygulamalı matematik ,Bilgisayar Bilimleri ,Engineering, Computing & Technology (ENG) ,offshoring ,Location awareness ,Mühendislik, Bilişim ve Teknoloji (ENG) ,COMPUTER SCIENCE ,MATEMATİK, UYGULAMALI ,Costs ,Manufacturing ,Fizik Bilimleri ,Control and Systems Engineering ,Mühendislik ve Teknoloji ,Algoritmalar ,Companies ,Kontrol ve Sistem Mühendisliği - Abstract
IEEEWhile the zeitgeist of today prescribes localization as a key to eliminate the excessive transportation for manufacturing firms, firm-level practical and workable guidelines that go beyond maxims are scant. Laden with analytical methods, this paper offers a phronetic, customizable framework based on Lean Six Sigma (LSS). The framework mimics Define-Measure-Analyze-Improve-Control (DMAIC) process. The early phases of the framework, ex-ante, prescribe the use of a variety tools and techniques from Lean Six sigma (LSS) and employ fuzzy analytic hierarchy process (FAHP) to extract the vital few root-causes that may impede localization. The latter phases suggest the use of design of experiments (DOE) to evaluate the root-causes, ex-post. The paper outlines a clear and established procedure and demonstrates each analytical phase using evidence from a two-year real-world application in steel industry.
- Published
- 2023
46. SINIF ÖĞRETMENLERİNİN FEN BİLİMLERİ DERSİ ÖĞRETİM PROGRAMINA EKLENEN FEN, MÜHENDİSLİK VE GİRİŞİMCİLİK UYGULAMALARINA YÖNELİK GÖRÜŞLERİNİN İNCELENMESİ.
- Author
-
ÖZKAN, Reis and AKÇAY, Nilüfer OKUR
- Abstract
Copyright of Journal of National Education / Millî Eğitim Dergisi is the property of Milli Egitim Bakanligi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
- Full Text
- View/download PDF
47. Ab-initio Calculations of the Half-metallic Ferromagnetic New Variant Perovskites Li2CrO6 and Li2CuO6
- Author
-
Özdemir, Evren Görkem
- Subjects
Engineering ,Multidisciplinary ,GGA ,WIEN2k ,Half-metallicity ,Ab-initio ,Perovskite ,Mühendislik ,General Engineering - Abstract
The half-metallic calculations of new variant perovskites Li2CrO6 and Li2CuO6 were carried out by using WIEN2k computational code. First, the ferromagnetic (FM) and non-magnetic (NM) phases were compared, and FM phases were obtained energetically more stable. The equilibrium lattice constants were obtained as 7.63 Å and 7.66 Å for Li2CrO6 and Li2CuO6, respectively. Second, the electronic calculations were performed, and the semiconduction properties were seen in spin-up states while spin-down states showed metallic nature. The band gaps were obtained as 1.806 eV and 1.177 eV for Li2CrO6 and Li2CuO6, respectively. Since variant perovskites Li2CrO6 and Li2CuO6 showed 100% spin polarizations, these were obtained as true half-metallic ferromagnetic materials. Then the total magnetic moments were obtained as 4.00 μB/f.u., 5.00 μB/f.u. When both the electronic and magnetic properties of the compounds are examined, the variant perovskites Li2CrO6 and Li2CuO6 are suitable materials for spintronics applications.
- Published
- 2024
48. Internal stakeholders’ voices for overcoming the challenges presented by studying engineering through the medium of English in Oman.
- Author
-
Holi Ali, Holi Ibrahim
- Subjects
ENGINEERING teachers ,LANGUAGE teachers ,CRITICAL thinking ,LANGUAGE ability ,ORAL communication ,ENGINEERING students - Abstract
Copyright of Journal of Language & Linguistics Studies is the property of Journal of Language & Linguistics Studies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
- Full Text
- View/download PDF
49. Investigation of simultaneous effects of noise barriers on near-road noise and air pollutants
- Author
-
KESKİN, SIDDIK SİNAN and Tezel-Oguz M. N., Marasli M., Sari D., Ozkurt N., KESKİN S. S.
- Subjects
Environmental Engineering ,Atık Yönetimi ve Bertarafı ,Kirlilik ,ENGINEERING, ENVIRONMENTAL ,Mühendislik ,ENGINEERING ,Mühendislik, Bilişim ve Teknoloji (ENG) ,Combined exposure ,Pollution ,Road-traffic noise ,Near-road air pollution ,Noise barrier ,Çevre Mühendisliği ,Fizik Bilimleri ,Physical Sciences ,Engineering and Technology ,Environmental Chemistry ,MÜHENDİSLİK, ÇEVRE ,Mühendislik ve Teknoloji ,Engineering, Computing & Technology (ENG) ,Çevre Kimyası ,Waste Management and Disposal - Abstract
Noise barriers are one of the common solutions to control road traffic noise. Many studies have also shown that noise barriers cause reductions in near-road air pollutant concentrations. In this study, the simultaneous effects of a specific noise barrier application on near-road noise and air pollution at a specific location were investigated. In this context, air pollution, noise, and meteorological parameters were measured simultaneously at two points, road and receptor sides of a 50 m long, 4 m high glass fiber reinforced concrete noise barrier on a highway section. Results indicated that the noise barrier has an average 23 % reduction effect on the NOx concentration in addition to the noise level reduction at the receptor side. Besides, bi-weekly average passive sampler measurement results for BTEX pollutants indicate lower values at the receptor side of the barrier compared to the free field measurement results. In addition to real-time and passive sampler measurements, NOx and noise dispersions were modeled using RLINE and SoundPLAN 8.2 software, respectively. Comparisons of the measurement results with the model results indicated strong correlations. Model-calculated NOx and noise values under the free field conditions are highly compatible with a correlation coefficient (r) of 0.78. Although the noise barrier has a reduction effect on both parameters, it has been observed that their dispersion mechanisms are different. This study showed that noise barriers considerably affect the dispersion of road-sourced air pollutants at the receptor side. Further studies are needed to optimize noise barrier designs with different physical and material properties and application scenarios considering noise and air pollutants together.
- Published
- 2023
50. An energy-aware combinatorial auction-based virtual machine scheduling model and heuristics for green cloud computing
- Author
-
ÖZER, ALİ HAYDAR and Öner E., ÖZER A. H.
- Subjects
General Computer Science ,Sinyal İşleme ,Mühendislik ,ENGINEERING ,Information Systems, Communication and Control Engineering ,Cloud computing ,Bilgisayar Bilimleri ,Electrical and Electronic Engineering ,Engineering, Computing & Technology (ENG) ,Genel Bilgisayar Bilimi ,ENGINEERING, ELECTRICAL & ELECTRONIC ,Resource scheduling ,Virtual machine placement ,Computer Sciences ,Elektrik ve Elektronik Mühendisliği ,Mühendislik, Bilişim ve Teknoloji (ENG) ,COMPUTER SCIENCE ,Energy-aware ,Combinatorial auctions ,Fizik Bilimleri ,Genetic algorithm ,Signal Processing ,Physical Sciences ,Engineering and Technology ,Bilgisayar Bilimi ,MÜHENDİSLİK, ELEKTRİK VE ELEKTRONİK ,Mühendislik ve Teknoloji ,Bilgi Sistemleri, Haberleşme ve Kontrol Mühendisliği - Abstract
Considering the increasing demand for cloud computing, and the financial and environmental impact of the increasing energy consumption trend of data centers, improving energy efficiency is vital for cloud service providers. In this study, an energy-aware virtual machine scheduling model is proposed which is based on the multi-unit nondiscriminatory combinatorial auction. The model includes a powerful bidding language that allows users to declare their complicated virtual machine requests using logical AND and OR relations along with the time constraints. The study also presents the formal definition of the model and the associated optimization problem for determining the optimum schedule and energy-efficient placement of VMs on physical servers. The optimization problem is formulated using integer linear programming and several heuristic solution methods including the Genetic Algorithm are proposed for this problem. The performances of the model and the proposed heuristics are assessed on a comprehensive test suite. The proposed model is estimated to provide approximately a 37% improvement in revenues, and the solution methods are estimated to provide high-quality solutions within only 5% of the optimum which enable the model to be deployed in large-scale clouds.
- Published
- 2023
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