Fungsi Minyak Isolasi Pada Tranformator Yang Berkapasitas Besar

Sekarang seperti kita ketahui, pada era globalisasi kebutuhan akan Tenaga Listrik cenderung sudah merupakan hal yang sangat vital, atau sangat dibutuhkan. Maka keberadaan Gardu Induk pada instalansi listrik PLN khususnya, dan Perusahaan-Perusahaan yangmembutuhkan tenaga listrik pada umumnya, sangat mutlakdiperlukan. Hal ini juga dilakukan pada fungsi minyak trafo. Tujuan penelitian adalah mengetahui cara pemeliharaan minyak isolasi yang baik dan benar untuk dipakai pada transformator yang berkapasitas besar. Hasil Penelitian menunjukkan bahwa Minyak Isolasi adalah merupakan pendingin dari pada belitan yang ada pada trafo dan sekaligus merupakan isolasi antara yang bertegangan dengan body trafo. Pemeliharaan Minyak Isolasi terutama pada trafo nomor 4 di Gardu Induk Kebasen, perlu dilengkapi dengan alat – alat pengamanan agar Minyak Transformator bisa selamat / aman dari gangguan – gangguan yang timbul. Dan Pemeliharaan minyak isolasi perlu persiapan pemikiran urutan kerja, alat–alat bantu, dan pengecekan–pengecekan seperti minyak minyak transformator, tegangan input-output, frekuensi

Rancang Bangun Aktuator Pada Prototype Sistem Peringatan Dini Pengendalian Banjir Dengan Menggunakan Electronic Data Process

Dimasa sekarang, perkembangan dunia teknologi semakin cepat, namun kecanggihan tersebut tidak dapat dilawan oleh kekutan alam. Banjir yang merupakan masalah klasik bagi setiap kota yang ada didunia merupakan bencana yang sering sekali terjadi, yang diakibatkan dari beberapa aspek contohnya adalah humam error. Kecanggihan teknologi dimasa sekarang yang bertumpu pada bidng elektronika dan instrumentasi dpat dijadikan modal awal dalam pengembangan teknologi pengendalian pintu air yang berbasis pada Electronic data process..Metodologi penelitian yang digunakan dalam pembuatan teknologi ini adalah dengan pengumpulan data dari obyek dan menggunakan landasan literatur dengan mempelajari teori – teori dari buku – buku, majalah, internet, maupun tulisan – tulisan yang dapat membantu menyelesaikan masalah dengan menguji kebenaran dari hasil penelitian.Sebagai hasil dari penelitian ini adalah sebuah tekologi pengendalian pintu air yang dapat bekerja menutup dan membuka pintu air berdasarkan tinggi rendahnya permukaan air sungai dalam waktu tertentu secara otomatis. Yang berbasis pada pemrosesan data elektronik atau electronic data process (EDP) dengan aktuator sebagai peran utama dalam mengangkat dan menutup pintu air, dengan terlebih dahulu melalui beberapa proses dari komponen-komponen yang lain sebagai pemicu dalam menggerakan aktuator itu sendiiri

Study of implosion in an attractive Bose-Einstein condensate

By solving the Gross-Pitaevskii equation analytically and numerically, we reexamine the implosion phenomena that occur beyond the critical value of the number of atoms of an attractive Bose-Einstein condensate (BEC) with cigar-shape trapping geometry. We theoretically calculate the critical number of atoms in the condensate by using Ritz's variational optimization technique and investigate the stability and collapse dynamics of the attractive BEC by numerically solving the time dependent Gross-Pitavskii equation

Effectiveness of Newer Tip Design of Laser in Removing the Smear Layer at the Apical Third of Curved Root Canals: An Ex Vivo study

The purpose of this ex vivo study was to investigate the effectiveness of newer tip design of Er,Cr:YSGG laser in removing the smear layer at the apical third of curved root canals. A total of 81 freshly extracted single rooted intact human mandibular premolars teeth with 15-30º canal curvature were selected for the study and were decoronated at the level of cemento enamel junction. The roots were divided in to three main groups with 27 samples each. GROUP I - Irrigants not activated by laser (non lased group). GROUP II - Irrigants activated by Er,Cr:YSGG laser with plain tip and GROUP III-Irrigants activated by Er,Cr:YSGG laser with conical tip and each group were further divided in to three sub groups of 9 samples each with EDTA, CHX, NaOCl respectively. In all the three groups, Canals were prepared with rotary nickel-titanium (Ni-Ti) instruments to a working length 1 mm short of the apex to size F3 by using Protaper instruments. In Group I the canal was irrigated with 17% EDTA, 2% Chlorhexidine and 3% NaOCl without laser irradiation, where as in Group II and Group III the canal was irrigated with 17% EDTA, 2% Chlorhexidine and 3% NaOCl respectively with Plain and conical fiber tips was placed 5mm from the apex in the root canal and the appropriate irrigant solution was then activated for 20 second. The teeth were then grooved longitudinally with a diamond disc on their buccal and lingual surfaces and were split into two halves with a chisel and mallet. The split half of the tooth in which apex was most visible used for SEM evaluation at 1000 X magnification and smear layer scoring was done using Torabinejad’s scoring system. The result of the present study were subjected to statistical analysis to interpret the smear layer removal in each group and also between the groups. ONE-WAY ANOVA followed by POST HOC TUKEY HSD test was used for statistical analysis in the present study. CONCLUSION: Within the limitations of this ex vivo study it can be concluded that: 1. Er,Cr:YSGG laser with conical fiber tip performed better removal of smear layer in the apical third of the curved root canal system. 2. Conical fiber tip performed better than plain fiber tip for removing smear layer in the apical third of the curved root canal system. 3. Among the irrigants used EDTA showed better effectiveness in smear layer removal followed by CHX and NaOCl in the apical third of the curved root canal system. This suggests that to ensure complete removal of smear layer from the root canal system it may be prudent to activate EDTA with conical tip design of Er,Cr:YSGG laser during irrigation protocol in the curved root canals

THE SPATIAL PATTERN OF URBANIZATION AND SMALL CITIES DEVELOPMENT IN CENTRAL JAVA: A CASE STUDY OF SEMARANG-YOGYAKARTA-SURAKARTA REGION

The special form of urbanization in Indonesia has led to a variety of themes on the urban development studies in Indonesia. Since 1990s, there has been an emphasis on the development of mega-urban regions, particularly those surrounding Jakarta as the biggest and the prime city in Indonesia. This research is aimed at elaborating the previous knowledge on the urbanization pattern in Indonesia, and Java in particular. More specifically, this study examines urban development trend in Central Java. The analysis of urbanization in this study can be classified into two categories, i.e. analysis of the urbanization level and analysis of the urbanization growth. These two analyses are combined by applying some GIS methods in order to understand the pattern of urbanization in the region. It is found that the urbanization process in Central Java has transformed the predominantly rural regions in the 1980s into the urban ones. The rapid growth of urban population forms some observable pattern that may be different to the national pattern. There are common spatial patterns, such as the importance of the coastal region and the essential role of the larger urban centers in the urbanization. In this regards, the emergence of the smaller centers has also contributed to the process, especially in bridging a more balanced development between major urban centers and their respective rural hinterland

Analisis Finansial Penggunaan Benih Kentang G4 Bersertifikat dalam Meningkatkan Pendapatan Usahatani Petani Kentang

ABSTRAK. Permasalahan utama usahatani kentang ialah produktivitas rerata yang masih rendah, yaitu sekitar16,94 t/ha. Penggunaan benih G4 bersertifikat diharapkan dapat meningkatkan produksi dan pendapatan para petanikentang. Penelitian mengenai analisis finansial penggunaan benih G4 bersertifikat dalam meningkatkan pendapatanusahatani kentang di Indonesia telah dilakukan di Kecamatan Pangalengan, Bandung, Jawa Barat dan KecamatanBatur, Banjarnegara, Jawa Tengah, dari bulan Januari-Desember 2008. Tujuan penelitian ialah menganalisis secarafinansial penggunaan benih kentang G4 bersertifikat dalam hal biaya, produksi, penerimaan, dan keuntungan bersihusahatani dibanding dengan penggunaan benih kentang tidak bersertifikat. Penelitian dilaksanakan dengan metodesurvei. Data primer diperoleh melalui wawancara berstruktur dengan petani, sedangkan data sekunder dikumpulkan dariinstansi terkait. Analisis data kualitatif dilakukan secara deskriptif, sedangkan analisis biaya dan pendapatan dilakukandengan metode analisis finansial statik serta uji t untuk membandingkan dua perlakuan. Hasil analisis biaya usahatanikentang menunjukkan bahwa di Pangalengan rerata biaya produksi kentang dengan benih G4 bersertifikat mencapaiRp37.042.970,00, dan benih tidak bersertifikat Rp29.305.108,00 per ha/musim. Di Batur, rerata biaya produksikentang dengan benih G4 bersertifikat mencapai Rp23.718.196,00 dan benih tidak bersertifikat Rp22.589.475,00 perha/musim. Di Pangalengan, rerata produksi kentang yang dihasilkan dengan benih G4 bersertifikat mencapai 26.364kg, dan benih tidak bersertifikat mencapai 22.001 kg per ha/musim. Di Batur, rerata produksi kentang dengan benihG4 bersertifikat dan benih tidak bersertifikat masing-masing mencapai 16.976 kg dan 14.031 kg per ha/musim. Hasilanalisis masukan dan keluaran menunjukkan bahwa, di Pangalengan usahatani kentang yang menggunakan benihG4 bersertifikat dan benih tidak bersertifikat mendapatkan penerimaan serta keuntungan bersih masing-masingRp70.417.354,00 dan Rp53.529.785,00 serta Rp33.374.384,00 dan Rp24.224.677,00 per ha/musim, sedangkan di Baturmendapatkan penerimaan Rp67.130.010,00 dan Rp51.338.645,00 serta keuntungan bersih sebesar Rp43.411.814,00dan Rp28.749.170,00 per ha/musim. Hasil perhitungan uji t menunjukkan bahwa, di Pangalengan penggunaan benihkentang G4 bersertifikat memperlihatkan adanya perbedaan nyata dalam biaya dan penerimaan, sedangkan di Batur,memperlihatkan adanya perbedaan nyata dalam penerimaan dan keuntungan bersih usahatani dibanding dengan yangmenggunakan benih tidak bersertifikat.ABSTRACT. Ridwan, H.K., Nurmalinda, Sabari, and Y. Hilman. 2010. Financial Analysis of Potato FarmingSystem Using G4 Certified Seed to Improve Potato Farmer’s Income. The main problem on potato farmingsystem was low productivity (16.94 t/ha). The use of certified seeds (generation four/G4) was expected to improveproductivity and potato farmers income. The research was conducted at Pangalengan District, Bandung, West JavaProvince and Batur District, Banjarnegara, Central Java, from January to December 2008. The objectives of thisresearch was to analyze financially the used of certified seed (G4) in term of production cost, productivity, revenue,and profit of potato farming in comparation with the used of uncertified seed. The study was conducted by usingsurvey method. Primary data were obtained through interviewing farmers and secondary data were collected fromthe related institutions. Qualitative data were analyzed descriptively, while the cost and income analysis weredone by static method, and t test. The results indicated that the production cost in Pangalengan reached as much asRp37,042,970.00/ha (using certified seeds) and Rp29,305,108.00/ha (using uncertified seeds). Similar result wasobtained in Batur, the production cost was Rp23,718,196.00/ha (using certified seeds) and Rp22,589,475.00/ha (usinguncertified seeds). In Pangalengan, potato productivity reached 26,364 kg/ha (using certified seeds) and 22,001 kg/ha (using uncertified seeds), while in Batur, the productivity was about 16,976 kg/ha (using certified seeds) and14,031 kg/ha (using uncertified seeds). The result of input and output analyses showed that in Pangalengan, potatofarming provide revenue and profit about Rp.70,417,354.00 and Rp.33,374,384.00/ha/season respectively (usingcertified seeds), while uncertified seeds gave revenue and profit Rp.53,529,785.00/ha and Rp.24,224,677.00/ha/season, respectively. Whereas in Batur, the use of certified seeds provide revenue and profit Rp.67,130,010.00 andRp.43,411,818.00/ha/season respectively, while uncertified seeds provide Rp.51,338,645.00 and Rp.28,749,170.00/ha/season respectively. The results of t-test showed that in Pangalengan, the use of certified seeds was significantlydifferent in term of production cost and revenue, while in Batur, there were a significant different on the revenue andbenefit between the use of certified and uncertified seeds

Harmonics Minimization Of A Three Phase Cascaded H-Bridge Multilevel Inverter

For more than two decades, multilevel inverter technology has drawn tremendous interest among researchers from industry and academia in recent years due to its superior performance. In this regards,the main objectives of this this thesis are to study, modeling, design and develop a prototype of a three-phase cascaded H-Bridge Multilevel inverter (CHB-MLI) based on Newton-Raphson technique that aims to analyze the performance of the inverter output for harmonic minimization. The source codes programming based on Newton-Raphson method was developed, and then stored into the Digital Signal Processing (DSP) TMS320F2812. The proposed controller based on Newton Raphson was applied to CHB-MLI. The optimization of this system had managed to minimize the harmonic contents of the inverter output. Besides, the experimental results of the developed prototype are discussed. In addition, the performance of the proposed system was compared between simulation and experimental results for both Optimization and Non-optimization techniques. The Optimization of this system had been capable in reducing the harmonic contents of the inverter output. Thus, optimization and Non-optimization of the CHB-MLI system had been successfully demonstrated in this study. Finally the development of a three phase CHB-MLI based on DSP, its controller and power electronic devices would be a challenging future research in minimize the content of harmonic of the inverter output