1,720,977 research outputs found
Energy and exergy analysis of Sivas TÜRASAŞ heat center hot water boilers
No full textBu tez çalışmasında Sivas' ta bulunan TÜRASAŞ Sivas Bölge Müdürlüğü Isı Merkezindeki saatte 5.000.000 kapasitesine sahip kalorifer kazanının, enerji ve ekserji analizi yapılmış ve kazanın her bir bölümünün ekserji kaybı hesaplanmıştır. Bunların neticesinde ekserji verimleri (ikinci yasa verimleri) bulunarak sonuçlar grafik halinde verilmiştir. Yapılan analiz sonucunda kazanda ısıl verim %84.97, ekserji verimi %15.63 olarak hesaplanmıştır.In this thesis study, energy and exergy analysis of the 5,000,000 capacity central heating boiler in TÜRASAŞ Sivas Regional Directorate Heat Center located in Sivas was performed and exergy loss of each section of the boiler was calculated. As a result of these, exergy efficiencies (second law efficiencies) were found and the results were given in a graphical form. As a result of the analysis, the thermal efficiency of the boiler was calculated as 84.97%, exergy efficiency as 15.63%
Experimental investigation on the usability of ground source heat pump based on Sivas conditions
No full textFen Bilimleri Enstitüsü, Makine Mühendisliği Ana Bilim DalıSunulan çalışmada, Sivas ilinde toprak kaynaklı ısı pompasının kullanılabilirliği araştırılmıştır. Yatay tip toprak kaynaklı ısı pompası deney sistemi Sivas Cumhuriyet Üniversitesi yerleşkesinde bulunan enerji evine kurulmuştur. Toprak altı ısı değiştiricisi, toplam boru boyu 370 m ve 4 hat şeklinde oluşturulmuş ve 2,5 m toprak derinliğine yerleştirilmiştir. Topraktan su - antifriz karışımı dolaştırılarak ısı çekilmiştir. 2016 yılının Aralık ayında gerçekleştirilen deneyler sırasında iç ortam sıcaklığı, dış ortam sıcaklığı, su-antifriz karışımının buharlaştırıcıya giriş çıkış sıcaklığı, soğutucu akışkanın ısı pompası elemanlarına giriş çıkış sıcaklıkları, ısıtma suyunun radyatörlere gidiş ve dönüş sıcaklıkları ve farklı derinliklerde toprak sıcaklıkları ölçülmüştür. Ayrıca kompresör giriş ve çıkış basınçları, su-antifriz karışımının ve ısıtma suyunun debisi ve güç tüketimleri ölçülmüştür. Sistemde yapılan analizlere göre her bir sistem elemanının ekserji kaybı ekserji verimi, ekserji kaybı oranı ve termodinamik mükemmellik derecesi incelenmiştir. Isı pompasının ve Sistemin ekserji verimi sırasıyla %34 -% 30 ve %29-%26 arasında elde edilmiştir.In this study, the exergy of a ground source heat pump in the province of Sivas was investigated. Horizontal type ground source heat pump test system is installed in the energy house located in Sivas Cumhuriyet University campus. The subterranean heat exchanger was constructed in total length of 370 m and 4 lines and placed at 2.5 m depth of soil. A mixture of water and antifreeze is circulated through the soil and the heat is with drawn. During the experiments carried out in December 2016, the ambient temperature, the outdoor temperature, the inlet / outlet temperature of the mixture of water and antifreeze, the inlet and outlet temperatures of the refrigerant to the heat pump elements, the heating and returning temperatures of the heating water to the radiators and the soil temperatures at different depths were measured. In addition, compressor inlet and outlet pressures, water-antifreeze mixture and heating water flow and power consumption are measured. According to analyzes made in the system, exergy loss, exergy efficiency, exergy loss ratio of each system element and thermodynamic perfect degree has been examined. Exergy efficiency of the heat pump and the system were obtained between 34% and 30% and between 29% and 26%, respectively
EXPERIMENTAL INVESTIGATİON OF DYNAMIC FRICTION COEFFICIENT OF AISI 1040 AND AISI 4140 STEELS
No full textÇeşitli mühendislik uygulamalarında yaygın olarak kullanılan AISI 1040 ve AISI 4140 çeliklerinin sürtünme davranışlarının detaylı bir şekilde incelenmesi, makinelerin performansını artırmak ve dayanıklılıklarını optimize etmek açısından önemlidir. Bu çalışmada, kayma sürtünmesi ve çelik malzemelerin dinamik sürtünme katsayılarını etkileyen faktörlerin literatür taraması yapılarak, AISI1040 ve AISI4140 çelikleri üzerinde gerçekleştirilen deneysel çalışmaların sonuçları değerlendirilmiştir. Çeşitli deney koşullarında elde edilen verilere dayanarak, temas yükü, kayma hızı, kayma süresi ve yüzey pürüzlülüğü gibi faktörlerin çeliklerin sürtünme katsayıları üzerindeki etkileri detaylı bir şekilde incelenmiştir.A detailed study of the frictional behaviour of AISI 1040 and AISI 4140 steels, which are widely used in various engineering applications, is important for improving the performance of machines and optimising their durability. In this study, the factors affecting sliding friction and dynamic friction coefficients of steel materials are reviewed in the literature and the results of experimental studies on AISI 1040 and AISI 4140 steels are evaluated. Based on the data obtained under various experimental conditions, the effects of factors such as contact load, sliding speed, sliding time and surface roughness on the friction coefficients of steels are analysed in detail
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
