Experimental determination of cooling performance on heat sinks with cone-jet electrospray mode

This study was funded by Ataturk University Coordination Unit of Scientific Research Projects under grant no FBA-2018-6965.In this study, electrospray cooling characteristics for smooth surface heat sink and finned surface heat sink were investigated. An experimental study was carried out using ethanol for 7 different heat fluxes in the cone-jet mode, in which a stable and continuous droplet diameter is produced. In the experiments, 7 kV voltage, 20 mm nozzle-to-substrate distance, a stainless steel nozzle with 0.61 mm inner diameter (d(i)) and 0.45-0.60 ml/min flow rates were used. Due to that the two flow rate values are very close to each other, no difference in the formation of electrospray was observed, but since the amount of fluid sent to the heat sink is higher, at 0.60 ml/min flow rate, 15-44% better a cooling was achieved under different heat fluxes compared to 0.45 ml/min flow rate. In addition, finned heat sink applied for the first time in electrospray cooling provided approximately 1.3-1.6 times better cooling than smooth surface heat sink. The effect of electrospray dripping on cooling in a finned heat sink is expressed by enhancement ratio (ER). Additionally, the change in fin enhancement ratio (FER), which denotes the enhancement of cooling in finned heat sink in comparison to that in finless heat sink, was scrutinized at different surface temperatures. As a result, as a distinction from the studies on improving heat transfer with electrospray cooling, it was suggested that finned surface heat sinks, which were not used before, can be used as an effective parameter to further enhance the heat transfer

İşçi sağlığı ve güvenliği yönetim sistemleri incelenmesi ve veri analizi incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışmada, Türkiye'de İnşaat sektörü iş kazası riskleri değerlendirilmiştir. Toplam Kalite Yönetimi ile İşçi Sağlığı ve Güvenliği sistemi arasındaki ilişki 25 adet inşaat firmasının şantiyelerde somut verileri baz alınarak araştırılmış, şantiyelere ilişkin İSG kayıtları derlenerek bir veri tabanı oluşturulmuştur. Firmalarda İşçi Sağlığı ve Güvenliği programlarını daha çabuk, aktif oluşturmak ve risklerin asgari düzeye indirilebilmesi için her şeyden önce işçilerin de katılımının sağlanması önemli bir faktör olarak karşımıza çıkacaktır. Ülkemizde, teknik personelin karıştığı iş kazaları ve söz konusu kazalar sonucu meydana gelen ölüm ve yaralanma olayları oldukça fazladır.Yapılan analizler sonucu firmaların sağlık ve güvenlik sorumluklarını aktif olarak yerine getirebilmeleri için etkili bir yönetim sistemine ihtiyaç vardır. Ayrıca ISO 9001, ISO 14001 ve OHSAS 18001 İş Sağlığı ve Güvenliği Yönetim Sistemi incelenmiş ve bu gereksinimlerin İnşaat Sektörünün mihenk taşı olduğu saptanmıştır.In this study, we evaluated the risks of occupational accidents the construction sector in Turkey. Total Quality Management and Occupational Health and Safety system, the relationship between the construction company 25 pieces of concrete on construction sites, based on information researched, OHS records compiled a database of jobsites. Occupational Health and Safety programs more quickly than companies, active form and, above all, to be downloaded to minimize risks to workers participation will be seen as an important factor. In our country, the technical staff that work accidents and accidents involving death or personal injury as a result of events occurring is quite high.As a result of the analyzes of companies active in the health and safety responsibilities of an effective management system is needed to fulfill. In addition, ISO 9001, ISO 14001 and OHSAS 18001 Occupational Health and Safety Management System requirements are examined and found to be the touch stone of construction sector

Shooting Control Application from a Quadruped Robot with a Weapon System via Sliding mode Control Method

With the developing technological process, it is expected that the usage of robots will increase in defense systems as in every field. One of the main objectives of the robotic studies for the defense industry is to capture the targeted success under all kinds of disruptive effects with robotic systems and to present this technology to the service of the army. A weapon system with a single degree of freedom was placed on a quadruped robot. System’s dynamic behavior, which has 12 degrees of freedom and planar movements, is modeled mathematically. Simulations of the shots made to the fixed targets were carried out during the walking of the quadruped robot. The gun barrel stabilization was realized to achieve accurate shots under disruptive effects. The sliding-mode control method was used to perform the barrel stabilisation. In this study, it is shown that a quadruped robot with a weapon system can perform successful shots against fixed targets. MATLAB is used for simulations and the results are shown with figures, graphics, and tables

The effect of intradermal administration of inactive platelet-rich plasma on flap viability in rats

Purpose: To evaluate the effect of inactive form of platelet rich plasma (PRP) on the flap viability. Methods: Thirty six rats were used. Rats were divided into six groups then 9x3 cm random pattern skin flaps were elevated from dorsum of all rats. For precluding vascularization from the base, a silicone layer was placed under the flap in groups 2(only flap+silicone), 4(saline+silicone) and 6(PRP+silicone). In groups 1(only flap), 2(only flap+silicone) nothing was done except flap surgery. In groups 3(saline) and 4(saline+silicone), saline was applied intradermally, in groups 5(PRP) and 6(PRP+silicone), inactive form of PRP which obtained from different 16 rats was applied intradermally, into certain points of flaps immediately after surgery. After 7 days flap necrosis ratio was measured in all groups. Results: Mean necrosis rate in group 5(PRP) (16.05%) was statistically significantly lower than group 1(only flap) (31,93%) and group 3(saline) (30,43%) (p < 0.001). Mean necrosis rate in group 6(PRP+silicone) (36.37%) was statistically significantly lower than group 2(only flap+silicone) (47.93%) and group 4(saline+silicone) (45.65%) (p < 0.001). Conclusion: Intradermal inactive platelet rich plasma administration decreases flap necrosis so for skin application

GÖVDE BORULU ISI DEĞİŞTİRİCİ İÇİN ISI TRANSFER KATSAYISININ TEORİK VE DENEYSEL İNCELENMESİ

Bu çalışmanın amacı, soğutucu akışkan olarak R404A’nın kullanıldığı kompresörlü soğutma sisteminde gövde borulu ısı değiştiricinin akış halinde kaynama esnasındaki toplam ısı transfer katsayısının değişiminin sistem parametrelerine göre incelenmesidir. Bu amaç doğrultusunda deneysel bir sistem kurulmuş ve evaporatör basıncı ve sıcaklığının, soğutucu akışkan debisinin ve soğutma suyu debisinin toplam ısı transfer katsayısı üzerindeki etkisi incelenmiştir. Deney çalışması, evaporatör basıncın 2.73 - 5.76 bar ve soğutucu akışkan kütle akısının 64.64 - 152.68 kg/m2s olduğu aralıklarda yapılmıştır. Kullanılan gövde - borulu ısı değiştirici 60 cm boyunda ve bir geçişte iç çapı 8 mm ve dış çapı 10 mm olan 9 adet bakır borudan oluşmaktadır. Yapılan deneylerden elde edilen sonuçlar kullanılarak kaynama esnasındaki toplam ısı transfer katsayısı hesaplanmıştır. Deney sonuçları hesaplandıktan sonra literatürde önerilmiş üç farklı bağıntı kullanılarak kaynama esnasındaki ısı transfer katsayısı tekrar elde edilmiştir. Elde edilen değer ile deney sonuçları karşılaştırılmıştır

Innovative systems for earthquake resistant masonry enclosures in RC buildings

The Commission of the European Communities has recently funded a research project for the benefit of Associations of Small and Medium Enterprises (SME-AGs), aimed at developing innovative systems for masonry enclosures. More in general, the project deals with external partition systems for reinforced concrete framed buildings, such as infill walls and envelopes, and with internal partitions. The project involves sixteen partners from seven European countries, among which there are seven universities and research centres, five industrial associations, and four small and medium enterprises. In the present contribution, an overview of the main objectives and steps of the project is given. A general summary of the various construction systems that are being developed and designed is given. The future developments in terms of experimental programs, numerical analyses, and final expected outcomes of the project are described

Bacteremia due to Acinetobacter ursingii in infants: Reports of two cases

Acinetobacter ursingii is an aerobic, gram-negative, opportunistic microorganism which is rarely isolated among Acinetobacter species. We present two immunocompetent infants who developed bacteremia due to A.ursingii. The first patient is a two -month- old boy who had been hospitalized in pediatric surgery unit for suspected tracheo-esophageal fistula because of recurrent aspiration pneumonia unresponsive to antibiotic therapy. The second patient is a fourteen -month- old boy with prolonged vomiting and diarrhea. A. ursingii was isolated from their blood cultures. They were successfully treated with ampicillin-sulbactam. Although A.ursingii has recently been isolated from a clinical specimen; reports of infection with A.ursingii in children are rare. A.ursingii should be kept in mind as an opportunistic microorganism in children.Pan African Medical Journal 2016; 2

Detailed Investigation of Glass Balustrade in Kashirskaya Shopping Mall Project

Glass balustrade construction, envisaged for architectural considerations, was utilised in Kashirskaya shopping center in Moscow, Russia. Modifications were required in the manufacturer's design, to be further verified by full scale tests, on the most used largest sized panels. 3-D finite element computer model of glass balustrades and connection members were formed and ultimate capacity and service limit calculations were made according to the related regulations. Results were compared with the experiments carried out on full-scale glass balustrades tested at METU Structural Mechanics Laboratory