Reliability modelling of uninterruptible power supply using probability tree method

The unreliability of public power lines have led to the need of uninterruptible power supply (UPS). Utility power failures will cause unacceptably high risk to the profitability, existence and growth of the vital aspect of business that depends heavily on uninterrupted power supply. For this reason it is important to develop a method to estimate the reliability of such system, to ensure that it will perform satisfactorily when needed. This paper describes and discusses an approach to predict the reliability parameters of the UPS system using the probability tree method. Important UPS reliability parameters such as failure rates (lambda), mean time between failures (MTBF), and reliability (R), can be obtained from this method. These quantitative reliability parameters can play an essential role in selection and application of the UPS. The method was applied to different topologies of UPS systems and comparisons were made between the results obtained form probability tree method and the reliability block diagram (RBD) method

Comparison of the Mechanical Properties of Four-layer Epoxy Composite Reinforced with Natural Jute Fibers and Symmetrical E-glass Synthetic Fibers

Research that produces environmentally friendly products continues to be developing. Research related to the natural fiber jute material and epoxy matrix has done. Epoxy composite jute empowered do with the preparation of symmetry with four layers of fiber volume fraction of 27.89% and composite epoxy e-glass Fiber empowered four balance with 28.86% fiber volume fraction. Mechanical testing is done via Drag test to determine the tensile strength and stretch. From the analysis, it\u27s finding that the tensile strength of the symmetry jute fiber reinforced epoxy tensile strength was 48,378 MPa, and the strain was 11,998%. Meanwhile, the tensile strength and pressure in empowered epoxy e-glass fiber symmetry of four layers, each for 95.516 MPa and 7.7032%. Characterization has also been carried out through SEM testing. The results show that e-glass fiber fractures can still be seen as regular and tend to be straight and flat rods compared to symmetrical fiber-reinforced jute composite epoxy composites whose fibers are irregular. So that shows that the strength of the epoxy composite reinforced e-glass fiber is very large compared to the strength of the four-layer jute fiber-reinforced epoxy composite symmetry

PENGARUH PEMBERIAN TEPUNG DAUN KATUK (SAUROPUS ANDROGYNUS L. MERR)TERHADAP PENINGKATAN DIAMETER SKROTUM PADA KAMBING JANTAN LOKAL

Penelitian ini bertujuan untuk menguji pengaruh pemberian tepung daun katuk terhadap ukuran diameter skrotum testis kambing kacang jantan lokal. Penelitian ini menggunakan 9 ekor kambing kacang jantan lokal dengan umur + 1,5 tahun. Hewan-hewan tersebut dibagi atas 3 kelompok (3 ekor per kelompok) dan diaklimatisasi selama 2 minggu. Kelompok Kontrol (P0), diberikan air distilasi. Kelompok perlakuan (P1), diberikan tepung daun katuk dengan dosis 7,44 gr/ekor/hari, dan (P2) diberikan tepung daun katuk dengan dosis 14,88 gr/ekor/hari. Semua perlakuan diberikan sebanyak 2 kali sehari (pukul 07.30 pagi dan pukul 16.30 sore) selama 35 hari berturut-turut. Selain itu, setiap hari semua kambing diberikan pakan daun kuda-kuda dan rumput serta air minum secara ad libitum. Sesudah perlakuan semua kambing diukur diameter skrotum menggunakan jangka ukur. Data dianalisis dengan menggunakan ANOVA. Hasil penelitian memperlihatkan bahwa tidak terdapat perbedaan yang nyata dari diameter skrotum (P>0.05) antara ketiga kelompok perlakuan. Dengan demikian dapat disimpulkan bahwa pemberian tepung daun katuk tidak memberi pengaruh pada peningkatan diameter skrotum dari testis kambing kacang lokal

PENGARUH KUALITAS TIDUR TERHADAP DAYA TAHAN JANTUNG PARU PADA MAHASISWA PENDIDIKAN DOKTER FAKULTAS KEDOKTERAN UNIVERSITAS SYIAH KUALA

ABSTRAKKualitas tidur telah diketahui dapat memberikan dampak pada kondisi kesehatan. Salah satu dampak yang diberikan dari kualitas tidur jika kualitas tidur itu buruk adalah meningkatnya sitokin pro-inflamasi dan terganggunya kontrol vagal organ jantung sehingga daya tahan jantung paru dapat menurun. Penelitian ini bertujuan untuk melihat adanya pengaruh kualitas tidur terhadap daya tahan jantung paru pada mahasiswa Pendidikan Dokter Fakultas Kedokteran Universitas Syiah Kuala. Jenis penelitian ini adalah analitik observasional dengan rancangan cross-sectional. Data penelitian ini diperoleh dari 80 responden yang telah memenuhi kriteria inklusi dengan teknik sampling stratified random sampling. Hasil dari penelitian ini menunjukkan dari 80 responden, 49 responden (61.2%) memiliki kualitas tidur buruk, sedangkan 62 responden (77.5%) memiliki daya tahan jantung paru sedang. Berdasarkan hasil analisis uji Mann Whitney, didapatkan p value=0,004 (

Optimization of hot press forging parameters in direct recycling of aluminium chip (AA 6061)

This study introduces a new approach of direct recycling using the hot press forging process that eliminates the two intermediate processes of cold-compact and pre-heating. This method leads to low energy consumption without intervening the metallurgical processes. In this study, the optimum of machined chips from high speed milling is recycled by hot press forging. The mechanical properties and surface integrity of the different chips were investigated. The performance of recycled aluminium AA 6061 chips in the mechanical and physical properties were compared with the original aluminium billet. Response surface methodology (RSM) was used to develop mathematical model of the effects on pre-compaction cycle, holding time and suitable pressure significant to the process. It is hoped that, utilization of primary metal could be fully utilized by direct recycling technique (hot press forging) introduced in this study and at the same time developing a sustainable manufacturing process technology for future needs

Mengelola Potensi Destruktif Olahraga ke Arah Pengembangan Kebijakan Olahraga yang Komprehensif

Olahraga umumnya mencerminkan nilai-nilai apa yang menjadi rujukan masyarakat. Olahraga dapat menjadi wahana untuk membina dan sekaligus membentuk watak kepribadian. Di sisi lain, olahraga dapat pula menyebarkan nilai-nilai pertentangan atau konflik dan bahkan bisa mempersubur masalah sosial seperti: diskriminasi, ketidakjujuran, korupsi dan praktek suap, pemukulan wasit, perkelahian antarpemain atau antarsupporter, bahkan antarkeduanya, serta berbagai bentuk konflik lainnya. Karena itu, tulisan ini bertujuan untuk menguraikan akar permasalahan perilaku potensi destruktif olahraga tersebut yang dapat mengancam integrasi sosial bahkan integrasi bangsa. Tulisan ini juga mengajukan tawaran suatu pola pengembangan olahraga yang dapat meminimalisir potensi destruktif tersebut melalui suatu kebijakan keolahragaan yang komprehensif

Didactical Reduction of Teaching Materials of Spermatophytes to Make Easier on Information Processing and to Reduce Mental Effort of Senior High School Student

This research aims to facilitate students in processing teaching material information and reducing student mental effort in Spermatophytes learning. This study using posttest only control group design. The subject for this study is the tenth class of MIA at one of Ciamis Senior High School which consist of 34 control-class students and 37 experiment-class students. Teaching in control-class use regular biology textbook from their school, then for teaching in experiment-class use flowchart as result of didactical reduction process. Information processing of the student is measured by task complexity worksheet and student mental effort is measured by questionnaire subjective rating scale (Likert scale). Student learning outcomes are measured on aspects of reasoning using pencil test. The data were analyzed statistically with mean test and correlation test. Research outcome showing that studentsinformation processing at experiment-class is higher and have significant difference than control-class. The high value of information processing and low value mental effort students in the experimental-class was significantly correlated with higher learning outcomes. This outcome show that didactical reduction can facilitate students for processing teaching material and reduce students mental effort so the teaching outcomes become better