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 general approach to mixed effects modeling of residual variances in generalized linear mixed models

We propose a general Bayesian approach to heteroskedastic error modeling for generalized linear mixed models (GLMM) in which linked functions of conditional means and residual variances are specified as separate linear combinations of fixed and random effects. We focus on the linear mixed model (LMM) analysis of birth weight (BW) and the cumulative probit mixed model (CPMM) analysis of calving ease (CE). The deviance information criterion (DIC) was demonstrated to be useful in correctly choosing between homoskedastic and heteroskedastic error GLMM for both traits when data was generated according to a mixed model specification for both location parameters and residual variances. Heteroskedastic error LMM and CPMM were fitted, respectively, to BW and CE data on 8847 Italian Piemontese first parity dams in which residual variances were modeled as functions of fixed calf sex and random herd effects. The posterior mean residual variance for male calves was over 40% greater than that for female calves for both traits. Also, the posterior means of the standard deviation of the herd-specific variance ratios (relative to a unitary baseline) were estimated to be 0.60 ± 0.09 for BW and 0.74 ± 0.14 for CE. For both traits, the heteroskedastic error LMM and CPMM were chosen over their homoskedastic error counterparts based on DIC values

In vitro mass propagation of Typhonium flagelliforme as affected by plant growth regulators

Tubers were used as explants in in vitro mass propagation of Rodent Tuber (Typhonium flagelliforme). The explants were obtained from sterile plantlets and placed in shoot induction medium containing basal salts of Murashige and Skoog (MS) and various concentrations of 6-benzylaminopurine (BAP) and -naphthaleneacetic acid (NAA). Treatment containing 5 mg/l (w/v) of BAP with 1 mg/l (w/v) of NAA produced the highest number of shoots per explant (29.17) after 12 weeks of culture and also the highest mean fresh weight of shoots formed in treatment containing 5 mg/l (w/v) of BAP with 1 mg/l (w/v) of NAA. For ex vitro establishment, well- rooted plantlets were transferred in potting medium containing peatmoss, perlite and vermiculite (3:1:1)

Analysis of preliminary phytochemical screening of Typhonium flagelliforme

Typhonium flagelliforme (Araceae) is a medicinal herb which is endowed with curative properties against a variety of illness including injuries, oedema, coughs, pulmonary ailments, bleeding and cancer. In order to assess its phytochemical components, an experiment was conducted on one to six month old ex vitro and in vitro extracts of T. flagelliforme. The active (ex vitro and in vitro) extracts of T. flagelliforme were screened for phytochemicals components such as alkaloids, flavonlids, terpenoids and steroids. Alkaloids and flavonoids are the main phytochemical constituents of T. flagelliformewhich are found to be in the highest amount in two and four month old of ex vitro plants. High amounts of main phytochemical constituents were observed during the flowering process which started in two month old plant and finished at the end of the three month old plant

Survey and surveillance development in settings with low human immunodeficiency virus prevalence

In most countries, during the early phases of a human immunodeficiency virus epidemic, independently initiated surveys of perceived high-risk groups tend to precede the development of formal surveillance systems. Unfortunately, in low-prevalence settings, small sample sizes produce unreliable estimates of prevalence and trends, with an inevitable tendency towards positive results. In our study, we present sample size calculations and typical samples used in actual surveys, with Pakistan as our example. More useful data on risk behaviour and potential for spread can be derived from the study of commoner sexually transmitted diseases and associated risk behaviours, including assessments of knowledge, attitudes, beliefs and practices

Analisis Peranan Pemerintah Daerah dalam Peningkatan Prestasi Olahraga di Kabupaten Maros

: This study aimed to describe and analyze the implementation of sports coaching in improving performance in sports in Maros and the factors that affect achievement results showed that the increase of sports achievements in the district\u27s local government is managed and diuapayakan by the Department of Youth, Sport and the Arts supported by KONI district. Department of youth sports and arts carry out its role in the form of coaching by organizing sports events as well as the provision of facilities and infrastructure and to fostering more physically given the responsibility to the KONI. Cooperation between the two sides can not be denied there is a lack of communication smoothly and resulted in the existing work program. Improved sports performance is influenced by several factors, namely: Factors that are supporting the coach a consistent, quality athletes qualified, assistance from the private sector, and implementation of sporting events. While inhibiting factor is the limited facilities and infrastructure, regeneration of athletes who are restricted, limited funds, and fraud match. Sports in Maros

Perancangan Dan Implementasi Pengaturan Kecepatan Motor Tiga Fasa Pada Mesin Sentrifugal Dengan Menggunakan Metode Linear Quadratic Tracking (LQT)

Motor induksi 3 fasa banyak digunakan di industri, salah satunya pada industri pabrik gula. Di industri pabrik gula motor industri 3 fasa digunakan pada mesin sentrifugal. Mesin ini digunakan untuk proses pemisahan cairan massacuite dan strup hingga didapat kristal gula. Pada proses tersebut terjadi Perubahan beban oleh karena itu, pada siklus kecepatannya mengalami proses Charging, Spinning dan Discharging. Namun, Pengaturan kecepatan motor induksi yang ada masih dilakukan secara manual yaitu dengan merubah posisi puli atau ukuran poros dari mesin sentrifugal. Pengaturan dengan metode ini mengakibatkan kecepatan motor akan sulit dikendalikan sesuai dengan yang diharapkan. Pengaturan kecepatan yang tidak tepat juga dapat mengakibatkan hasil produksi gula yang kurang maksimal. Oleh karena itu, dibutuhkan metode kontrol untuk mengoptimalkan kecepatan motor saat mengalami proses charging, spinning dan discharging yang sesuai dengan setpoint yang diberikan. Metode kontrol yang digunakan adalah metode Linear Quadratic Tracking (LQT). Kontroler LQT diimplementasikan pada PLC Mitsubishi Q-series dan dengan HMI GT designer. Dari hasil simulasi didapat pembobot Q= 100 dan R=1. Selanjutnya pembobot Q dan R ini digunakan untuk mendapatkan nilai dari sinyal kontrol. Algoritma sinyal control yang diperoler selanjutnya diubah dalam bahasa pemograman ladder diagram untuk dapat diimplementasikan dengan PLC. Dari hasil implementasi yang dilakukan, didapatkan bahwa kontroler LQT yang digunakan dapat memperbaiki %error hingga 15,8% dari steady state. Selain itu dalam Tugas Akhir ini kontroler LQT juga mampu memperbaiki spesifikasi respon agar menjadi lebih baik. Sehingga Tugas Akhir ini dapat membantu meningkatkan efisiensi mesin sentrifugal