Dikdörtgen kesitli bir kanaldaki kararsız ısı transferinin sayısal 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.Elektronik devrelerdeki ısı üreten elemanlarla benzeşim kurmak üzere, dikdörtgen kesitli bir kanal girişindeki ısının sinüsoidal olarak değiştirildiği kabul edilmiş ve daimi olmayan rejimde laminer ile türbülanslı akış için ısı taşınımı sayısal ve üç boyutlu olarak incelenmiştir.İlk çalışmalar pürüzsüz (bloksuz) kanal geometrisi için yapılmış ve daha sonraki aşamada ise, elektronik devre elemanlarını temsilen yerleştirilen bloklar ile zorlanmış ısı taşınımı sayısal olarak incelenmiştir. Çalışmalarda Reynolds sayısı, laminer akış için 1120 ? 2225 ve türbülanslı akış içinse 11240 - 22284 aralığında alınmış, ısı giriş frekansı da 0.02 Hz'den 0.24 Hz'e kadar değiştirilmiştir.Termal giriş bölgesindeki daimi olmayan ısı transferi, sayısal akışkanlar dinamiği (CFD) kodu olan Star-CCM+ ile çözülmüş ve kanalın uzun ekseni boyunca sıcaklık değişimleri ve genliği, Reynolds sayısı ve giriş frekansına bağlı olarak elde edilmiştir.Elde edilen sayısal sonuçlarla, deneysel ve sayısal sonuçlar karşılaştırılmış ve küçük hata değerleri elde edilmiştir.In order to simulate heat producing elements on electronic circuits, heat input at the inlet of a rectangular duct is supposed to vary sinusoidally and three dimensional transient forced convection for laminar and turbulent flows are investigated numerically.Initial studies were conducted for smooth rectangular duct (without arrays of block-like electronic components) and further implementations were focused on numerical investigation of forced convection heat transfer with blocks. Reynolds numbers in the range of 1120 ? 2225 for laminar flow and 11240 - 22284 for turbulent flow were selected. Inlet frequencies (ß) varied between 0.02 Hz and 0.24 Hz.Transient heat transfer in the thermal entrance region was solved by computational fluid dynamics (CFD) code called Star-CCM+ and temperature amplitudes were obtained through centerline of the duct.Numerical results were compared with experimental results. Acceptable derivations were obtained with small differentiations

Partisipasi Masyarakat Dalam Pelestarian Mangrove Di Desa Bumbulan Kecamatan Paguat

Penelitian bertujuan untuk mengetahui bagaimana partisipasi  masyarakat dalam  pelestarian mangrove di Desa Bumbulan Kecamatan Paguat. Jenis Penelitian ini menggunakan penelitian kualitatif deskriptif, dan teknik pengumpulan data menggunakan observasi, wawancara  dan dokumentasi. Temuan dilapangan menunjukan  bahwa partisipasi masyarakat dalam pelestarian mangrove di Desa Bumbulan dikatakan baik yaitu berupa partisipasi dalam pengambilan keputusan, partisipasi dalam pelaksanaan, partisipasi dalam pengambilan manfaat, dan partisipasi dalam evaluasi. Berdasarkan hasil penelitian menunjukan bahwa yang paling dominan terhadap partisipasi masyarakat dalam pelestarian mangrove yaitu partisipasidalam pengambilan manfaat karenadengan adanya pelestarian mangrove masyarakat bisa membuat bagian dari tanaman  mangrove sebagai hasil yang bisa bermanfaat bagi masyarakat

The response of a high voltage transformer with various geometries of core joint design

The core losses in a three phase transformer can be significantly reduced by improving the core joint geometry. The researchers were applied numerous types of T-joint designs in order to reach the optimum design that can be used in three phase transformer to reduction the losses. Two types of T-joint design are presented in this paper; T-joint with 90° butt-lap design and T-joint with 45° mitered design. A 3-phase distribution transformer was simulated in 3D using Ansys Maxwell software. The core loss for a three-leg three phase transformer rated 1000 KVA and the flux density distribution are investigated. The simulation results show the core losses were increased up to 3% and the flux density was increased to reach more than 22% flux density become higher when using T-joint with 90° butt-lap design as compared with T-joint with 45° mitered design

Analisis Kemampuan Literasi Sains Ditinjau dari Aspek Kompetensi Sains Siswa pada Materi Global Warming

Penelitian ini bertujuan: (1) Untuk menganalisis kemampuan literasi sains ditinjau dari aspek kompetensi sains siswa kelas VIII SMP Negeri 1 Gorontalo pada materi global warming. (2) Untuk menganalisis kemampuan literasi sains ditinjau dari aspek kompetensi sains siswa kelas VIII SMP Negeri 2 Gorontalo pada materi global warming. Teknik pengumpulan data menggunakan tes pilihan ganda berjumlah 12 nomor soal. Hasil penelitian menunjukkan bahwa: (1) Sebagian besar kemampuan literasi sains siswa kelas VIII SMP Negeri 1 Gorontalo secara keseluruhan pada aspek kompetensi berada pada kategori rendah, dengan persentase siswa sebesar 91,16%. Adapun persentase kemampuan literasi sains aspek kompetensi siswa kelas VIII SMP Negeri 1 Gorontalo pada indikator menjelaskan fenomena secara ilmiah sebesar 34,35% tergolong rendah, indikator mengevaluasi dan merancang inquiri ilmiah sebesar 42% tergolong rendah dan indkator menafsirkan data & bukti secara ilmiah sebesar 28,23% tergolong rendah. (2) Sebagian besar kemampuan literasi sains siswa kelas VIII SMP Negeri 2 Gorontalo secara keseluruhan pada aspek kompetensi berada pada kategori rendah, dengan persentase siswa sebesar 95,68%. Adapun persentase kemampuan literasi sains aspek kompetensi siswa kelas VIII SMP Negeri 2 Gorontalo pada indikator menjelaskan fenomena secara ilmiah sebesar 33,95% tergolong rendah, indikator mengevaluasi dan merancang inquiri ilmiah sebesar 30,25% tergolong rendah dan indkator menafsirkan data & bukti secara ilmiah sebesar 30,71% tergolong rendah

M9 Anaçlı Elma Bahçelerinde Organik Yetiştiriciliğin Uygulanabilirliği

M9 anacı üzerine aşılı Williams Pride, Jonafree, Rajka ve Golden Delicious elma çeşitlerinde organik tarım uygulamaları ile konvansiyonel tarım uygulaması fenolojik özellikler, verim, kalite, hastalık ve zararlılar, hasat sonrası muhafaza, pazarlama imkanları ve maliyet bakımından karşılaştırılmıştır. Bu çalışma ile Eğirdir (Isparta) koşulları ve benzer bölgelerde organik elma yetiştiriciliğinin uygulanabilirliği araştırılmıştır. Veriler değerlendirildiğinde kümülatif verim bakımından en yüksek değer konvansiyonel yetiştiricilikte Rajka çeşidinden elde edilirken en düşük değer organik yetiştiricilikteki 3. uygulamadaki Jonafree çeşidinden elde edilmiştir. Pazarlanabilir meyve oranı bakımından hem konvansiyonel hem de organik yetiştiricilikte en yüksek değerler Rajka çeşidinden elde edilmiştir. Yapılan ekonomik analizde, 1 kg elma maliyeti organik yetiştiricilikte daha yüksek olmasına rağmen, 2008 yılı elma satış fiyatlarına göre organik elma yetiştiriciliğinin daha karlı olduğu görülmektedir

Analysis on magnetic flux density and core loss for hexagonal and butt-lap core joint transformers

This paper presents the results of new hexagonal configuration at the T-joint of three-phase transformer core. The proposed model is compared with previous T-joint design, Butt-lap, which is widely used at present by many transformer manufacturers. The magnetic flux density distribution and core loss of a transformer rated 1000kVA are analyzed for the two types of T-joint design. The 3D simulation are carried out by using the ANSYS-Maxwell software. The results show that the magnetic flux density of the hexagonal shape T-joint is well distributed compared to that in the Butt-lap T-joint design. The core loss for the proposed model (hexagon) T-joint indicates a reduction of more than 11 % compared to the Butt-lap T-joint design

New optimization technique to design the core of three-phase transformer

Reduction losses in three-phase transformers have drawn the attention of researchers, in the recent years. In this study, an intelligent algorithm employing particle swarm optimization (PSO) has been used to get the optimum T-joint design of a core in a three-phase transformer. This technique was employed to design a new geometry of a joint to obtain the minimum loss in a three-phase transformer. In achieving this target, a 3D finite element method had been used to simulate the proposed transformer model. Power losses in the core and winding losses had been considered as the heat sources, and the results were validated based on the test data obtained from transformer factory. The results presented that the total losses have been decreased up to 10% compared to the corresponding values from common designs. Moreover, the core losses have been reduced in the range of 11% compared to similar parameters in the conventional design

In vitro evaluation of antiviral properties of edible bird nest extract against feline infectious peritonitis virus

An in vitro study was carried out to evaluate the antiviral properties of edible bird nest extract (BNE) against feline infectious peritonitis virus (FIPV). Cytotoxicity assay was conducted towards BNE test material in Crandell Feline Kidney (CrFK) cells using MTT assay to determine the 50% cytotoxic concentration (CC50)values. For antiviral test, three treatments were used to determine the antiviral inhibition effect by BNE extract. Co-treatment [(V+E) +C] was done by mixing the virus(V) and extract(E) together before inoculating into cells(C). Pre-treatment [(E+C) +V], involved treatment of extract before inoculation of the cells with virus. Post-treatment [(V+C) +E] was done by inoculating the virus first into the cells before inoculation of extract. Ten-fold dilutions of BNE were used to determine the CC50 until 8th doubling dilutions. The FIPV dose was fixed for 100TCID50. Cytotoxicity assay showed that all concentrations could be used for antiviral assay except for the stock solution. The results also showed that the extract was non-toxic to the cells. For antiviral assay, all treatments showed inhibitory effects on virus multiplication in the cells where pre-treatment showed the highest effect compared to the other two treatments. However, the finding was not statistically significant from the control treatment groups (P<0.05)

Anti N-Methyl-D-Aspartate Receptor encephalitis with ovarian teratoma: a dilemma in diagnosis

We report a rare case of altered mental status in a young patient with immature ovarian teratoma. A 22-year-old woman presented with seizures, hallucination, amnesia and orofacial dyskinesia. Examination and investigation revealed an ovarian massand asalphing-oophorectomy was performed. The histopathological examination result showed an immature teratoma grade 2 with thepresence of immature primitive glial tissue. Her CSF N-Methyl-D-Aspartic acid receptor (Anti-NMDAR) antibodytest was positive. N-Methyl-D-Aspartic acid receptor antibody associated limbic encephalitis is an autoimmune antibody-mediated neuropsychiatric disorder. Resection of the tumour and immunotherapy resulted in full recovery