Simulation of brittle damage for fracture process of endodontically treated tooth

The mechanics of brittle damage in porcelain of an endodontically treated maxilla incisor tooth was simulated using finite element method (FEM). For this purpose a very complex composite structure of endodontically treated tooth is simulated under transverse loading. Three dimensional (3D) model of human maxilla incisor tooth root was developed based on Computed Tomography (CT) scan images. Crown, core cement, resin core, dental post, post cement and dentin were created using SolidWorks software, and then the model was imported into ABAQUS-6.9EF software for nonlinear behavior analysis. This study utilizes finite element method to simulate onset and propagation of crack in ceramic layer (porcelain) by the cause of both tension and compression loading related to complexity of the geometry of tooth implant. The simulation has been done using brittle damaged model available in ABAQUS/Explicit in quasi-static load condition. The load-displacement response of whole structure is measured from the top of porcelain by controlling displacement on a rigid rod. Crack initiated at the top of porcelain bellow the location of the rod caused by tension damage at equivalent load of 590 N. Damage in porcelain accounts for up to 63% reduction of whole structure stiffness from the undamaged state. The failure process in porcelain layer can be described by an exponential rate of fracture energy dissipation. This study demonstrated that the proposed finite element model and analysis procedure can be use to predict the nonlinear behavior of tooth implant

A noninvasive molecular approach: exploiting species-locus-specific PCR primers in defeating numts and DNA cross-contamination of cercopithecidae

The lack of a standardized, noninvasive molecular approach to studying genetic aspects of primates has made it hard for primatologists to decode the evolutionary history of these species. Researchers must optimize their own techniques to fully exploit the available samples. Lack of species-locus-specific primers also contributes to difficulties in using noninvasive genetic samples. Thus, the objectives of this study were to develop a standardized technique to collecting samples noninvasively, propose newly designed species-locus-specific primers, and optimize conditions for polymerase chain reaction (PCR) for Macaca fascicularis, M. nemestrina, Trachypithecus cristatus, and T. obscurus. Nine new species-locus-specific primers for three different loci of mitochondrial DNA, namely D-loop, cytochrome oxidase subunit I (COI), and cytochrome b, were successfully designed. These primers proved to be efficient in amplifying larger datasets (up to ~1,000 bp) of the targeted species in the optimized PCR conditions. The species-locus-specific primers are able to anneal to host DNA alone in highly contaminated feces of highlighted species. They can also offer alternatives measures in avoiding contamination related to nuclear insertion of mitochondrial pseudogenes (numts)

Dichromacy: Color Vision Impairment and Consanguinity in Heterogenous Population of Pakistan

Background and Objectives: Dichromacy, an X-linked recessive disorder is identified worldwide, more in males than females. In European Caucasians, its incidence is 8% in males and 0.5% in females. In India, it is 8.73% in males and 1.69% in females, and in Iran, it is 8.18% in males and 0.43% in females. Population based epidemiological data about dichromacy in different ethnic groups in Pakistan is not available. The aim of this study was to find out the population prevalence of inherited red-green dichromacy in a heterogenous population of the district of Chiniot, Punjab, Pakistan, and to determine the impact of consanguinity and ethnicity. Methods: In this cross-sectional study, boys and girls of the higher secondary schools were examined in the three tehsils of district Chiniot. Pseudoisochromatic Ishihara Test has been employed for detection of dichromacy in the study population. The sample size was calculated statistically as 260, which was expanded to 705 and divided by population density of the three tehsils. Results: Screening of 359 males and 346 females revealed 19 (5.29%) dichromat males and only 2 (0.58%) females. The study population belonged to 23 castes / isonym groups. The consanguinity found in the district of Chiniot is 84.82% and in the dichromat families, it is 85.71%, of which 52.37% are first cousin. Interpretation & Conclusion: The study has shown that the incidence of dichromacy could be reduced through genetic counselin

Analisis Kelayakan Finansial USAha Perikanan Payang Jabur (Boat Seine) Di Pelabuhan Perikanan Pantai Asemdoyong Kabupaten Pemalang

Alat tangkap Payang Jabur di Pelabuhan Perikanan Pantai Asemdoyong dari tahun ke tahun mengalami perkembangan. Dengan demikian, perlu diketahui seberapa jauh kegiatan perikanan Payang Jabur masih dapat berjalan dan layak untuk diusahakan. Tujuan penelitian ini adalah untuk mengetahui cara pengoperasian Payang Jabur, menganalisis besarnya biaya, keuntungan dan tingkat kelayakan finansial dari USAha perikanan Payang Jabur. Metode yang digunakan dalam penelitian ini adalah metode deskriptif yang bersifat survei. Metode pengambilan sampel yang digunakan adalah metode sensus. Metode pengumpulan datanya berupa metode observasi, wawancara, studi pustaka, dan dokumentasi. Dalam penelitian ini populasi berjumlah 35 pemilik kapal (juragan) maka diambil semua untuk responden. Hasil analisis finansial diketahui bahwa investasi yang diperlukan dalam USAha perikanan payang jabur di Asemdoyong rata-rata sebesar Rp. 37.242.857,- penerimaan rata-rata Rp. 155.158.494,- per tahun dengan biaya total rata-rata sebesar Rp. 121.675.211,- per tahun. Dengan demikian rata-rata keuntungan yang didapat dalam satu tahun sebesar Rp. 33.483.283,-. Analisis kelayakan diketahui rata-rata nilai NPV sebesar Rp. 134.856.778,- nilai B/C Ratio adalah 1,28; nilai IRR sebesar 76 % dan PP 1,11 tahun. Analisis tersebut memiliki nilai NPV positif, B/C Ratio > 1 dan IRR > discount rate. Hal ini menunjukkan USAha perikanan payang jabur di Pelabuhan Perikanan Pantai Asemdoyong memiliki peluang yang baik dan layak untuk dikembangkan

Simulasi Numerik Peningkatan Perpindahan Panas Menggunakan Concave Delta Winglet Vortex Generators di dalam Penukar Kalor Jenis Fin-and-tube

Penelitian ini bertujuan untuk mengetahui efek dari penggunaan vortex generator terhadap karakteristik termal penukar kalor jenis plain fin and tube menggunakan simulasi numerik. Concave delta winglet pairs (CDWPs) digunakan sebagai vortex generator. Karakteristik termal diperoleh dengan membandingkan fin yang menggunakan CDWPs dengan yang tanpa menggunakan vortex generator serta membandingkan penggunaan perbedaan jumlah pasangan vortex generator. Aliran udara di dalam saluran fin diasumsikan sebagai fluida incompressible dan laminar yang mana bilangan Reynolds berada pada rentang 280 sampai dengan 960. Dari hasil simulasi diperoleh bahwa koefisien perpindahan panas konveksi untuk fin yang menggunakan 1, 3, dan 7 CDWPs berturut-turut meningkat berkisar antara 7,4-23,9%, 18,6-60,6%, dan 41-100% dibandingkan fin tanpa vortex generator (baseline). Nilai hCDWPs/hDWPs dari fin yang menggunakan 1, 3, dan 7 VGs berturut-turut berkisar antara 1,06-1,1; 1,1-1,4; dan 1,2-1,4

Mangrove (Rhizophoro Apiculata) Fannins As A Potential Corrosion Inhibitor For Aluminium In Acidic Medium.

Utilisation of a green corrosion inhibitor formulated from natural, biodegradable and nontoxic organic compounds in industries has been extensively explored by a*great number of researchers. Investigation of tannins extracted from Mangrove Rhizophoro Apiculata sp. as a corrosion inhibitor for aluminum alloy has been carried out in acidic medium

Analisis Diskriminan Sebagai Alat Manajemen Risiko Pembiayaan Pada Lembaga Keuangan Mikro Syariah, KBMT Wihdatul Ummah

Sebagai lembaga keuangan mikro syariah, yang kegiatannya melakukan pembiayaan, tidak dapat dipisahkan dari pembiayaan risiko. Risiko pembiayaan dinilai oleh rasio Non Performing Financing (NPF). Trend NPF di Koperasi Baitul Maal wa Tamwil (BMT)-Wihdatul Ummah cenderung menurun, namun menunjukkan perbaikan dalam peramalan 3 tahun berikutnya. Diperlukan evaluasi dalam menilai kelayakan debitur untuk risiko pembiayaan yang dapat dikendalikan. Mengevaluasi kelayakan debitur memperoleh faktor-faktor yang mempengaruhi sistem penilaian tingkat risiko pembiayaan melalui analisis diskriminan. Faktor-faktor ini adalah pendekatan variabel karakter dan persyaratan dari BMT